JPH03103408A - Device and method for preparing vinyl chloride resin - Google Patents

Abstract

PURPOSE:To provide the subject resin having good flow characteristics and used for pastes, etc., without the adhesion of scales by subjecting monomers containing vinyl chloride to a microsuspension or emulsion polymerization using a polymerization device equipped with a stirrer and having a specific ratio of effective inner diameter/effective height. CONSTITUTION:Monomers containing vinyl choride are subjected to a microsuspension or emulsion polymerization in the presence of a radial polymerization initiator and a dispersing agent or emulsifying agent in ion-exchanged water at 50 deg.C in a polymerization device to provide the objective resin, the polymerization device being equipped with a stirrer and having an effective height(H)/effective inner diameter(D) of >=4, preferably 5-15, and an outer periphery diameter(d) of the stirrer/effective inner diameter(D) of >=0.6, preferably 0.7-0.9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a polymerization apparatus and method applicable to the production of vinyl chloride resin, particularly vinyl chloride resin for paste.

Vinyl chloride resins, particularly vinyl chloride resins for paste, are produced by micro-suspension polymerization or emulsion polymerization.

The microl% turbidity polymerization method involves mixing vinyl chloride or a monomer mainly composed of vinyl chloride, water, an emulsifier, a polymerization initiator soluble in the monomer, and other polymerization aids in equipment other than the polymerization equipment. After homogenizing under high shear, the mixture is transferred to a polymerization apparatus and polymerized under stirring to produce fine vinyl chloride resin particles with an average resin diameter of about 0.2 to 3 μm.

The droplets dispersed in the homogenization process are relatively stable because they are protected by an emulsifier, but in the latter half of the polymerization, the particles become unstable, and if the stirring during the polymerization is too strong, the droplets become unstable. Coalescence due to collision is promoted, leading to an increase in coarse particles, an increase in the amount of scale adhering to the polymerization equipment walls and stirring blades, and in extreme cases, the latex may aggregate and break.

Furthermore, changes in particle size distribution due to an increase in coarse particles often lead to deterioration of fluid properties such as sol viscosity of the product.

Therefore, in the micro suspension polymerization method, a low-shear type stirring blade is generally used for stirring during polymerization, and the heat transfer coefficient of the polymerization equipment jacket is smaller than that in the suspension polymerization method, which requires vigorous stirring. In order to improve polymerization productivity, the ability to remove polymerization heat has been the rate-limiting factor.

On the other hand, in the emulsion polymerization method, an anionic surfactant and/or a nonionic surfactant is used as an emulsifier, and water-soluble peroxide,
Salting in an aqueous medium using a combination of a water-soluble peroxide and a water-soluble reducing agent or a combination of an oil-soluble peroxide and a water-soluble reducing agent as a polymerization initiator, if necessary in the presence of other polymerization auxiliaries. By polymerizing vinyl monomer, the average particle diameter is 0.1~
By carrying out emulsion polymerization to produce microparticles with a diameter of 0.4 μm and in the presence of vinyl chloride resin prepared in advance as seed particles, the seed particles are enlarged using the seed particles as nuclei.
There is a seeded emulsion polymerization method that produces relatively large particles of 4 to 2 μl.

If the emulsifier is present in excess, fine particles will be generated.
The emulsifier is added in the minimum amount necessary to coat the precipitated polymer, and the particles are extremely unstable during polymerization. Therefore, in the emulsion polymerization method as well, micro! ! ! Similar to the turbid polymerization method, relatively gentle stirring is employed, and improving the ability to remove polymerization heat is important in improving productivity in the polymerization process.

The structure of the polymerization apparatus used for batch polymerization using the micro suspension polymerization method or emulsion polymerization method as described above is such that sufficient mixing in the vertical direction within the polymerization apparatus is taken into consideration.
A tank-type polymerization apparatus with /D (H is the effective height of the polymerization apparatus and D is the effective diameter of the polymerization apparatus) of about 1 to 3 is generally used.

In such a polymerization apparatus, various heat removal methods can be considered to solve the above-mentioned problems regarding heat removal.
For example, there are methods to increase the overall heat transfer coefficient by increasing the heat transfer area, changing the material of the polymerization equipment, devising the structure of the jacket and the shape of the stirring blade, and increasing the temperature difference by using a low-temperature refrigerant. .

Conventional methods for increasing the heat transfer area include a method of passing cooling water through stirring blades and baffles, a method of using a reflux condenser (Japanese Patent Application Laid-open No. 153894/1984), and a method of using an external cooling device. (Unexamined Japanese Patent Publication No. 1975 5-1
5 7 6 0 7) and a method using a polymerization device with a draft tube (Japanese Patent Laid-Open No. 55-62908)
Publication No. 2), etc. have been proposed.

However, in the method using baffles, there are problems such as the coalescence of particles is promoted by stirring near the stirring blades and baffles, resulting in an increase in coarse particles, the structure becomes multi-fiber, and the amount of scale adhesion increases. Regarding the method of using a Reflags condenser, (in the emulsion polymerization method, the Kalimicro suspension polymerization method, which is commonly used, causes scale adhesion due to foaming of the reaction mixture, abnormal pressure increase due to insufficient entrainment of refluxed vinyl chloride monomer, and bulk polymerization. In addition, the method using an external cooling device has problems such as breakage of the latex due to large shear in the circulation pump, increased roughness, and scale buildup in the cooler, so it is difficult to put it into practical use. Various challenges remain.

A polymerization apparatus with a draft tube is a method in which polymerization is carried out while the reaction mixture is slowly circulated through a draft tube under flow conditions with little turbulence, and is effective in suppressing the generation of scale. However, it is impossible to completely eliminate scale adhesion, and it is difficult to remove scale once it has adhered, especially cleaning between the draft tube and the wall of the polymerization equipment and the lower part of the circulation stirring blade, which poses a problem for long-term stable operation. was there.

In addition, the method of increasing the overall heat transfer coefficient has problems such as equipment constraints such as the generation of scale and mixing conditions, as well as an increase in the production cost of the equipment, and the method of increasing the temperature difference has problems such as There was a problem that running costs increased.

[Problems to be Solved by the Invention] Therefore, a vinyl chloride resin, especially for pastes, which solves the above-mentioned problems and has high removal ability, less scale adhesion and generation of coarse particles, and good sol viscosity. It is an object of the present invention to provide a highly productive polymerization apparatus and method suitable for microsuspension polymerization or emulsion polymerization for producing vinyl chloride resin.

[Means for Solving the Problems] The present inventor has diligently studied in detail the relationship between the structure of a polymerization apparatus and polymerization conditions, and the quality characteristics of vinyl chloride resin such as scale adhesion, coarse particle amount and sol viscosity, and heat transfer coefficient. As a result of this study, we have completed the present invention.

The present invention comprises a stirrer, and the effective inner diameter of the polymerization apparatus (
The ratio (H/D) of the effective height (H) to D) is 4 or more,
A polymerization apparatus is provided for use in microsuspension polymerization or emulsion polymerization of monomers containing vinyl chloride, preferably 5 to 15.

The microsuspension polymerization method and emulsion polymerization method in the present invention refer to the polymerization methods described in the prior art section of this specification.

In a particularly preferred embodiment of the present invention, the ratio (d/
D) is 0.6 or more, preferably 0.7 to 0.9.

Further, the present invention provides vinyl chloride by micro-suspension polymerization or emulsion polymerization of vinyl chloride using a polymerization apparatus that satisfies the conditions of the above-mentioned H/D, preferably the above-mentioned d/D in addition to H/D. A method for producing resins, particularly vinyl chloride resins for pastes, is provided.

By applying the apparatus and method of the present invention, the ability to remove heat from the polymerization system is increased, scale adhesion and generation of coarse particles are reduced, and PVC resin for paste with good sol viscosity can be produced in a short time. It became possible to polymerize.

The present invention will be explained in detail below.

The structure of the polymerization apparatus is preferably as simple as possible from the viewpoint of scale attachment and removal.

Therefore, it is preferable that the shape of the polymerization apparatus used in the present invention is such that at least the majority of the portion substantially used for polymerization is a straight cylindrical shape (i.e., tower-shaped). Ratio of effective height (H) to effective inner diameter (D) (
H/D) is 4 or more, preferably 5 to 15.

The effective height is usually used to mean the depth of liquid when liquid is supplied to the polymerization apparatus, but it may also be considered to be the length of the straight body of the polymerization apparatus.

In general, long polymerization apparatuses with a large H/D have insufficient mixing in the vertical direction, so although they may be employed in continuous reactions, they are rarely used in batch reactions.

The reasons for this are: (1) the reaction system becomes non-uniform due to insufficient mixing in the vertical direction; and (2) it is difficult to control the sharpness of the reaction system.

However, in the micro-suspension polymerization of vinyl chloride, a relatively stable latex that has been homogenized and dispersed to a particle size of approximately 1 μm is polymerized while being gently stirred.
The inventor's studies have revealed that even when a polymerization apparatus with /D of 4 or more is used, the particle size distribution does not change in the upper and lower parts of the polymerization apparatus, and there is no problem in terms of quality.

In addition, in the emulsion polymerization method, vinyl chloride is added continuously from the bottom of the polymerization apparatus, and the buoyancy of the vinyl chloride monomer is used to uniformly disperse it above and below the polymerization apparatus, and the initiator and emulsifier are added to the sides of the polymerization apparatus. It has been found that the problem associated with insufficient mixing in the vertical direction can be solved by supplying from a plurality of upper and lower additional ports. Therefore, in any polymerization method, even if H/D is increased, the above reason (2) can be solved.

Next, we will discuss the reason for the above (2). This problem is
When using a long polymerization device with an H/D of 4 or more, the conventional control method causes a temperature distribution in the vertical direction of the polymerization device, resulting in the production of particles with a wide degree of polymerization distribution.

In particular, when the polymerization equipment is enlarged, the heat removal capacity per unit volume decreases, and if the internal temperature of the polymerization equipment rises slightly from the control balance point, the amount of heat removed is insufficient compared to the calorific value, causing the internal temperature to rise. Polymerization proceeds in the so-called unstable region where the temperature rises, so once a temperature distribution occurs and the temperature at the top of the polymerization apparatus rises, the specific gravity of the liquid at the top decreases and the difference in specific gravity of the liquid within the apparatus increases. It becomes increasingly difficult to mix the liquids in the vertical direction within the polymerization apparatus, and there is a risk that a runaway reaction will eventually occur.

To solve this problem, it is possible to divide the jacket of the polymerization apparatus and cool the upper part of the polymerization apparatus more than the lower part, thereby creating mixed flow in the vertical direction due to natural convection and achieving a uniform temperature distribution. It turned out that.

Specifically, it is desirable to detect the temperature inside the polymerization apparatus at at least two points in the vertical direction, to divide the corresponding jacket into at least two or more parts in the vertical direction, and to control the temperature in each independent loop.

When comparing polymerization equipment with the same capacity, the larger the H/D, the larger the heat transfer area per unit volume.
If this is the case, H/D is less than 20, preferably 15, because in industrial-scale polymerization equipment, problems arise in terms of layout, maintenance, and cleaning of the polymerization equipment becomes complicated.
It is as follows.

The stirring blade used in the polymerization apparatus of the present invention is preferably one that generates little scale, mixes the entire polymerization apparatus uniformly, and has good heat transfer.The blade shape that satisfies these conditions is a concave blade, a comb type. Examples include wings, paddle wings, spiral wings, etc., and are not particularly limited.

In a particularly preferred embodiment, the ratio (d/D) between the inner diameter of the polymerization apparatus and the outer diameter of the stirring blade is 0.6 or more, more preferably 0.7 to 0.9.

When d/D is 0.9 or more, the scale increases due to shear between the blades and the walls of the polymerization device, making it impossible to increase the rotational speed;
This is because if the rotation speed is less than 0.6, the scale increases due to shear near the blades and the heat transfer coefficient cannot be increased.

The cross-sectional shape of the blades may be flat, cylindrical, oval, etc., and preferably a type that allows refrigerant to pass through the inside of the blade.

Baffles are often used to improve vertical and radial mixing and increase heat transfer area, but in the polymerization of PVC resin for pastes, localized shear near the baffles can increase scale formation. As a result, the stirring rotational speed cannot be increased, and the heat transfer efficiency may actually decrease. Therefore, it is important to determine the shape of the baffle in relation to the shape of the stirring blade.

The monomer used in the present invention is selected from vinyl chloride or a mixture of vinyl chloride and a copolymerizable monomer (vinyl chloride in the mixture is usually 70% by weight or more). Therefore, in this specification, the term "vinyl chloride resin" means a resin obtained by polymerizing only vinyl chloride monomers or a resin obtained by polymerizing monomers mainly containing vinyl chloride. It is used as a thing. Monomers copolymerizable with vinyl chloride include olefins such as ethylene, brobylene and n-butene, vinyl acetate, vinyl propionate,
Vinyl esters such as vinyl laurate and vinyl stearate, unsaturated acids and their esters such as acrylic acid, methacrylic acid and itaconic acid, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, octyl vinyl ether and lauryl vinyl ether, maleic acid and Examples include fumaric acid and its anhydrides, their esters, aromatic vinyls, unsaturated nitriles, and the like.

Emulsifiers used in the present invention include common anionic surfactants such as alkyl sulfonates, alkylaryl sulfonates, alkyl alcohol sulfate salts, fatty acid salts or dialkyl sulfosuccinates;
In particular, alkali metal salts, nonionic surfactants such as glycerol esters, glycol esters or sorbitan esters of higher fatty acids: higher alcohol condensates,
Examples include higher fatty acid condensates and polypropylene oxide condensates.

Oil-soluble (monomer soluble) polymerization initiators used in the microsuspension polymerization of the present invention include aromatic initiators such as penzoyl peroxide, p-chlorobenzoyl peroxide, and 2,4-dichlorobenzoyl peroxide. aliphatic diasilver oxides having an alkyl group having 5 to 17 carbon atoms, such as group diasilver oxides, cabroyl peroxides, lauroyl peroxides and 3,5,5-trimethylhexanol peroxides;
Azo compounds such as azobisisobutyronitrile and azobisvaleronitrile, peroxyesters of organic acids such as t-butylperoxypiparate, peroxydicarbonates such as diisopropylperoxydicarbonate and dioctylperoxydicarbonate and known oil-soluble polymerization initiators such as acetylcyclohexylsulfonyl peroxide. These may be used alone or in combination of two or more dissolved in these solvents or vinyl chloride monomers.

Examples of water-soluble polymerization initiators used in the emulsion polymerization method of the present invention include peroxides such as hydrogen peroxide, ammonium persulfate, sodium perborate, potassium persulfate, and sodium persulfate. As, t
-butyl hydroperoxide, isopentane hydroperoxide, cumene hydroperoxide, t
Examples include organic hydroperoxides such as butyl isopylbenzene hydroperoxide and diisopropylbenzene hydroperoxide, together with suitable water-soluble reducing agents such as sodium bisulfite, sodium thiosulfite, sodium pyrosulfite, and Rongalite. A combination system can also be used.

Other polymerization aids used in the present invention include:
Higher alcohols such as cetyl alcohol and lauryl alcohol, higher fatty acids or their esters such as lauric acid, palmitic acid and stearic acid, aromatic hydrocarbons, higher aliphatic hydrocarbons, halogenated hydrocarbons such as chlorinated paraffin, polyvinyl alcohol , gelatin, particle size reducing agents (such as sodium sulfate and sodium bicarbonate), chain transfer agents, polymerization inhibitors, and the like. These can be used alone or in combination of two or more.

In addition, for homogenization, known homogenizers or methods such as one- or two-stage high-pressure pumps, colloid mills, centrifugal pumps, homomixers, vibratory stirrers, high-pressure jets up nozzles or orifices, and ultrasonic waves may be used. I can do it.

The polymerization reaction is carried out according to a conventional method, for example, the polymerization temperature is 40 to 75°C, the amount of water for polymerization is in the range of 0.6 to 3 times the weight of the total monomer, and an emulsifier, The amounts of the polymerization initiator and other polymerization aids used may also be the usual amounts. Note that since emulsifiers, polymerization initiators, polymerization aids, etc. remain in the supply line, etc., some of the water used for polymerization may be used to wash and remove these, and this washing water may be introduced into the reactor. .

Furthermore, in order to prevent scale adhesion, it is desirable to apply an anti-scale agent to the wall surface of the polymerization apparatus in advance.

[Effects of the Invention] The effects of the present invention are that the heat removal capacity is greater than that of conventional methods, and stable temperature control is obtained, so the polymerization time is shortened.
Moreover, it is possible to improve productivity in the polymerization of a vinyl chloride resin for paste having good sol viscosity without increasing scale adhesion or coarse particles.

Hereinafter, the present invention will be specifically explained with reference to Examples.

In order to compare the heat removal capacity, different effective volumes of H/D 1.
A 1+' polymerization apparatus was used. In Examples 1 to 6 and Comparative Examples 1 to 4, the minimum jacket temperature was 39 to
40°C, Examples 7 to 9 and Comparative Examples 5 and 6 were emulsion polymerized by determining the amount of polymerization initiator in advance so that the minimum jacket temperature was 33 to 34°C.

Example! 1.2-390 kg of ion-exchanged water in a dispersion tank with a stirrer
Then, 2.0 kg of sodium lauryl sulfate was added to 60 kg of ion-exchanged water in advance. 7 kg and 2.0 kg of cetyl alcohol. 7 kg of emulsifier aqueous solution dissolved at 80°C and cooled to room temperature, and α. α゜-azobisisobutyrovaleronitrile (ABVN) 1 4 4g toluene 0
．． After adding the polymerization initiator dissolved in 5Q and degassing for 10 minutes, 450 kg of vinyl chloride monomer was charged and dispersed and homogenized using a centrifugal pump with a capacity of 10 m'/Hr for 60 minutes while stirring.

Next, this dispersion was coated with a scale preventive agent in advance and degassed. The diameter of the dispersion was 0.65 m, and the height of the straight body part was 3.25 a+.
(H/D = 5), jacket heat transfer area 6.71I
Transferred to a stainless steel polymerization apparatus equipped with paddle blades of 1" and outer diameter of the blades of 5 to 2 cm (d/D=0.8), and heated with nitrogen so that the pressure inside the apparatus was 1 Kg/cm" higher than the pressure inside the apparatus at that time. The pressure was increased at 50°C, and the temperature was raised while stirring to carry out polymerization at 50°C. The stirring rotation speed was 20 r. p. m. Met.

Unreacted vinyl chloride monomer was recovered when the pressure inside the apparatus decreased to 7 Kg/ea+''G.The temperature inside the apparatus was detected at two points, the upper and lower points, and the jacket was divided into two parts, each of which was independently controlled.

The polymerization conversion rate, amount of coarse particles, amount of scale, and sol viscosity of the obtained latex were measured.

The amount of rough ablation was measured as the amount of resin in the latex that passed through a 32 mesh sieve and remained on a 100 mesh sieve (weight percent based on the charged vinyl chloride monomer).
.

The amount of scale was measured as the total amount of scale remaining or attached in the polymerization apparatus and scale collected by a 10-mesh wire gauze provided in the latex discharging line (percentage relative to the charged vinyl chloride monomer).

The sol viscosity was determined by drying the latex at 52°C in a Soubray dryer, adding 65 parts by weight of dioctyl phthalate (DOP) to 100 parts by weight of the resin that was ground in a grinder, and kneading the sol in a grinder at 30°C. This is the viscosity (centivoise) measured with a BM viscometer after being kept in a constant temperature bath for 1 hour.

Examples 2 to 5 In Examples 2, 3, 4, and 5, the amount of ABVN was 135 g, 162 g, 194 g, and
It was set to 207g.

In addition, each stirring blade has an outer diameter of 20.8 cm (d/D
=0.4), 3 1.2cm (d/D=0.6), 41
．． 6cm (d/D=0.8), 46.8cm (d/D
A stainless steel polymerization apparatus with a diameter of 0.52 m, a straight body height of 5.2 a + (H/D = 10), and a jacket heat transfer area of 8.31 was equipped with gate-shaped wings of 0.9). Dispersion homogenization and polymerization were carried out in the same manner as in Example 1 except for this.

The stirring speed was 40 r.m. each. p. m. , 30r.
p. a. , 2 3 r. p. m. , 2 1 r. p. m
．． Met.

Kokankoi i The amount of ABVN is 207g, the diameter is 0.45a + (d / D = 0.8
), straight body height 6.75 m (H/D = 15),
Dispersion homogenization and polymerization were carried out in the same manner as in Example 1, except that a stainless steel polymerization apparatus with a jacket heat transfer area of 9.2 m'' was used.

Comparative Example 1 1 g of ABVN8 as a polymerization initiator, outer diameter of stirring blade 32
diameter 0.8 m (d/D=0.4
), straight body height 2m (H/D=2.5), heat transfer area 5
．． Dispersion homogenization and polymerization were carried out in the same manner as in Example 1 except that a 3 m' stainless steel polymerization apparatus was used. However, the temperature inside the apparatus was controlled at point l.

The stirring rotation speed was 30 r. p. m. Met.

Star 4 Salmon 4 Same as Example 1 except that 13 g of ABVN1 was used as a polymerization initiator and a portal blade with an outer diameter of 64 cm (d/D = 0.8) was attached as a stirring blade to the polymerization apparatus used in Comparative Example 1. Dispersion homogenization and polymerization were performed using the method described in .

The stirring rotation speed is 17 r. p. m. Met.

Comparative Example 3 ABVN 1 2 2 g as a polymerization initiator, Comparative Example 1
A cylindrical baffle 4 with an outer diameter of 6.5 cn+ was installed in the polymerization apparatus used in
Dispersion homogenization and polymerization were carried out in the same manner as in Example 1, except that a book was attached and polymerization was carried out while cooling with a jacket and baffles. The stirring rotation speed was 30 r. p. Met.

Comparative Example 4 The amount of ABVN was 194 g, and polymerization was started in the same manner as in Example 1 using the polymerization apparatus used in Comparative Example 1. The stirring rotation speed was 30 r. p. m. Met.

However, from the second hour after the start of polymerization until before recovery, latex from the polymerization apparatus is extracted and passed through a diaphragm pump to a double-tube heat exchanger (external cooler) with a heat transfer area of 1.5 m. Polymerization was carried out by controlling the polymerization temperature with a jacket while removing 0 0 0 kcal/Hr of heat and returning it to the polymerization apparatus.

Upon inspection of the equipment after polymerization, a large amount of scale was found inside the pump, heat exchanger, and latex piping.

The results of Examples 1 to 6 and Comparative Examples 1 to 4 are shown in Table 1.

Example 7 390 kg of ion-exchanged water was added to the polymerization apparatus used in Example 1.
0.3 μ seed latex 1 kg (as solid content), sodium lauryl sulfate 120 g 1 Rongarit}7 6.
5g - FeSO4.7HtO O. 0 2 2g
was charged and the pressure was reduced using a vacuum pump until the internal pressure reached 25 mmHg, then 22.5 kg of vinyl chloride monomer was initially charged and the temperature was increased to 60 r.p.m. p. m. The temperature was raised while stirring.

Hydrogen peroxide 0.05% when the device temperature reaches 40℃
The aqueous solution is 5.4 (2/Hr for the first 3 hours, 2.772/Hr for the 4th hour, and 54f for the 5th hour.
/Hr, and after the 5th hour, it was added evenly to the liquid so as to be 1.34Q/Hr from three additional ports provided in the vertical direction of the polymerization apparatus according to changes in the liquid level.

At the same time, the remaining 427.5 kg of vinyl chloride monomer was passed through a nozzle with an inner diameter of 4 mm from the bottom of the polymerization apparatus, and the temperature was increased at 40°C while adding vinyl chloride according to the vinyl chloride lLffi addition rate determined from the polymerization conversion curve predicted in advance. Polymerized.

During polymerization, the latex was sampled every hour, and the total amount of vinyl chloride monomer charged was 15% or more than the polymerization conversion rate.
The additional speed has been corrected so that it is less than 20%.

Furthermore, 5% aqueous solution of sodium dodecylbenzene sulfate 4
0.5Q from 2 hours to 8 hours after the start of polymerization 6.7
Addition was made at a constant speed of 512/Hr. At 10.5 hours of polymerization time, the supply of hydrogen peroxide was stopped, and unreacted vinyl chloride monomer was recovered.

Aikan carp 4 Polymerization was carried out in the same manner as in Example 7 using the polymerization vessel used in Example 5.

However, hydrogen peroxide is O. 1% aqueous solution for the first 2 hours.
．． 512/Hr, 2.2512/Hr until the 3rd hour,
1.29Q/Hr until the 4th hour, 1.29Q/Hr after the 4th hour.
Add 5% aqueous solution of sodium dodecylbenzene sulfate at 9Q from 1.5 hours to 6 hours.
/Hr at a constant speed (total amount 40.512).

Eight hours after the start of polymerization, the supply of hydrogen peroxide was stopped, and unreacted vinyl chloride monomer was recovered. Stirring speed is 6 3
r. p. m. Met.

Example 9 Polymerization was carried out in the same manner as in Example 8 using the polymerization apparatus used in Example 6. The stirring rotation speed was 75r. p. l. Met.

Salt butterfly carp i Polymerization was carried out in the same manner as in Example 7 using the polymerization apparatus used in Comparative Example 1.

However, for hydrogen peroxide, use a 0.05% aqueous solution at 1.812/Hr for the first 4 hours and 0.912/Hr until the 7th hour.
r, 5% aqueous solution of sodium dodecylbenzene sulfate was added at 0.5212/Hr until the 9th hour, and 0.4412/Hr after the 9th hour, from the 2nd and 5th hour to the 13th hour after the start of polymerization. Added constant velocity at 3.86Q/Hr (
Total amount 40.512).

The supply of hydrogen peroxide was stopped 18 hours after the start of polymerization, and unreacted vinyl chloride monomer was recovered. Stirring speed is 90
r. p. m. Met.

Salt 4 Koiaki Polymerization was carried out using the same polymerization apparatus as used in Comparative Example 1 and the same polymerization recipe as in Example 8.

However, a glue flux condenser with a heat transfer area of 3 m attached to the top of the polymerization apparatus allows
The amount of heat removed is 10.000 to 15,000
Polymerization was carried out while adjusting the temperature to O kcal/Hr.

Eight hours after the start of polymerization, the supply of hydrogen peroxide was stopped and unreacted vinyl chloride monomer was recovered. Stirring speed is 90 r
．． p. m. Met.

The results of Examples 7 to 9 and Comparative Examples 5 and 6 are shown in Table 2.

Claims (1)

[Claims] 1. It comprises a stirrer, and the ratio (H/D) of the effective height (H) to the effective inner diameter (D) is 4 or more, preferably 5 to 1.
5. A polymerization device used for micro-suspension polymerization or emulsion polymerization of monomers containing vinyl chloride. 2. The ratio (d/D) of the outer peripheral diameter (d) of the stirring blade to the effective inner diameter (D) is 0.6 or more, preferably 0.7 to 0.9.
The polymerization apparatus according to claim 1. 3. A method for producing a vinyl chloride resin by carrying out micro-suspension polymerization or emulsion polymerization of a monomer containing vinyl chloride using the polymerization apparatus according to claim 1 or 2.