KR101702176B1 - Method for preparing polyvinyl chloride polymer, emulsion polymerization composition of vinyl chloride, and paste polyvinyl chloride polymer - Google Patents

Abstract

The present invention relates to a process for producing a vinyl chloride polymer, an emulsion polymerization composition of vinyl chloride and a vinyl chloride polymer, and, in accordance with the present invention, there is provided a process for producing a foamed vinyl chloride polymer by emulsion polymerization of vinyl chloride in a polymerization reactor equipped with a reflux condenser, An emulsion polymerization composition of vinyl chloride, a process for producing a vinyl chloride polymer, and a process for producing the vinyl chloride polymer, which can efficiently suppress the generation of the volatile components, thereby improving the efficiency of the reflux condenser and shortening the polymerization time, There is an effect of providing a paste vinyl chloride polymer produced therefrom.

Description

TECHNICAL FIELD The present invention relates to a method for producing a vinyl chloride polymer, an emulsion polymerization composition of vinyl chloride, and a paste vinyl chloride polymer. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinyl chloride

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a vinyl chloride polymer, an emulsion polymerization composition of vinyl chloride and a vinyl chloride polymer, and more particularly, To an emulsion polymerization composition of vinyl chloride, a process for producing a vinyl chloride polymer, and a paste vinyl chloride polymer obtained therefrom, which can improve the efficiency and shorten the polymerization time, reduce the scale generation amount and lower the production cost.

As the polymerization method used in the production of the paste vinyl chloride polymer, fine suspension polymerization and seed emulsion polymerization are mainly used. In order to carry out the polymerization, a large amount of bubbles are generated when the emulsifier is dropped from the top and rotated by a stirrer in the course of collectively or continuously introducing vinyl chloride monomer (VCM), polymerization water, initiator and emulsifier into a polymerization reactor equipped with a reflux condenser and a stirrer .

In addition to the bubbles generated at the time of input of the raw material, when the foam produced by the action of the vinyl chloride monomer, the vinyl chloride polymer, the polymerization water, the emulsifier, the initiator or the activator is added during the polymerization reaction, Is higher.

Particularly, as the polymerization reaction progresses due to the difference in specific gravity between the vinyl chloride monomer and the vinyl chloride polymer, the volume of the liquid phase in the polymerization reactor gradually decreases, but the height of the foam level due to foam generation becomes rather high.

When bubbles are excessively generated and the height of the foam level inside the polymerization reactor reaches the uppermost part of the polymerization reactor, the polymerization reactor raw material introduction line, the reflux condenser line, And the scale is formed, and such a scale falls back into the polymerization reactor again, resulting in an increase in the number of protrusions of the obtained vinyl chloride polymer. In the above, the projections are particles which are small and hard like sand grains and do not easily loosen by the plasticizer.

In this case, the foaming agent may be removed by injecting a defoaming agent into the polymerization reactor. However, excessive use of the defoaming agent may adversely affect the physical properties of the obtained vinyl chloride polymer. Therefore, the amount of the vinyl chloride polymer to be added is limited, Thereby increasing the manufacturing cost.

If the bubbles flow into the reflux condenser excessively, the effective heat transfer area is reduced, thereby deteriorating the heat-releasing performance. In addition, some small vinyl chloride polymer particles together with the foam accumulate scale on the inner wall of the reflux condenser, and it takes much time and effort to remove it, and at least during the scaling removal operation, the polymerization reactor should be stopped The productivity of the vinyl chloride polymer can be lowered.

Therefore, in the polymerization of the vinyl chloride monomer in the polymerization reactor equipped with the reflux condenser, it is possible to efficiently produce a paste vinyl chloride polymer which can stably produce a high-quality paste vinyl chloride polymer while allowing efficient heat- It is required to develop an emulsion polymerization composition of vinyl and a manufacturing process using the same.

It is an object of the present invention to improve the efficiency of the reflux condenser by effectively suppressing the generation of foam during the emulsion polymerization reaction of vinyl chloride in a polymerization reactor equipped with a reflux condenser to facilitate heat removal and shorten the polymerization time, And a vinyl chloride polymer prepared from the emulsion polymerization composition of vinyl chloride, and a process for producing a vinyl chloride polymer using the same.

In order to achieve the above object, the present invention provides a method for producing a vinyl chloride polymer,

Polymerizing a vinyl chloride monomer in a polymerization reactor equipped with a reflux condenser, wherein the emulsifier-free pre-polymerization step; And an emulsifier-containing polymerization step.

Further, in the emulsion polymerization composition of vinyl chloride of the present invention,

A polymerization composition of a vinyl chloride monomer used in the above-mentioned method is characterized by containing a post polymerization emulsifier.

Further, the paste vinyl chloride polymer of the present invention is characterized in that it is produced by the above-described method for producing a vinyl chloride polymer.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to effectively suppress the generation of foam during the emulsion polymerization reaction of vinyl chloride, improve the efficiency of the reflux condenser, improve the heat removal, shorten the polymerization time, reduce the scale generation amount, There is provided an emulsion polymerization composition of vinyl chloride, a process for producing a vinyl chloride polymer, and a vinyl chloride polymer produced therefrom.

FIGS. 1 to 3 are graphs showing changes in the heat release amount of the reflux condenser according to the polymerization temperature patterns of Examples 1 to 5 and Comparative Examples 1 to 3 of the present invention.

Hereinafter, the present invention will be described in more detail.

A method for producing a vinyl chloride polymer according to the present invention comprises polymerizing a vinyl chloride monomer in a polymerization reactor equipped with a reflux condenser, And an emulsifier-containing polymerization step.

For reference, unless otherwise specified, the terms "emulsifier-free pre-polymerization step" and "emulsion polymerization-containing polymerization step" used in the present invention are carried out without adding an emulsifier in the emulsion polymerization of the vinyl chloride monomer A post-polymerization step in which an emulsifier is added, and a post-polymerization step in which polymerization is carried out, respectively.

The post polymerization time point may be, for example, 20% or more, or 24 to 36%, of the polymerization conversion rate in the emulsifier pre-polymerization step.

As a specific example, the polymerization step after containing the emulsifier may be carried out at a point between the polymerization conversion point of the emulsifier pre-polymerization step and the point at which the polymerization conversion rate is 20% or more and the polymerization end point or less, It is within a range that the heat-releasing performance of the reflux condenser provided in the polymerization reactor can be maintained without affecting the polymerization rate of the monomers.

As another example, the polymerization step after containing the emulsifier may be carried out by introducing the post polymerization emulsifier at a polymerization conversion rate of 90% or less from the point of polymerization conversion of 25-36%, and performing the polymerization.

As another example, the emulsifier charged into the polymerization conversion ratio may be continuously added at a rate of 0.1 to 0.5 parts by weight / hour, or 0.15 to 0.27 parts by weight / hour based on 100 parts by weight of the total amount of the vinyl chloride monomer Can be input.

As used herein, the term "rate of weight / hour of administration" unless otherwise specified, refers to the weight of the emulsifying agent administered per hour at the point of administration as described above, and the weight per gram of vinyl chloride Based on 100 parts by weight of the total of monomers. For example, "1 part by weight / hour" means that the amount corresponding to 1 part by weight based on 100 parts by weight of the total amount of vinyl chloride monomer used for producing the paste vinyl chloride polymer is introduced into the polymerization reactor over 1 hour .

For example, the emulsifier pre-polymerization may be performed by introducing a predetermined amount of a vinyl chloride monomer, a vinyl chloride seed and water into a polymerization reactor and initiating polymerization.

The predetermined vinyl chloride monomer may be 30 to 100% by weight, or 45 to 60% by weight, based on 100% by weight of the total amount of the vinyl chloride monomer used in the polymerization, and the residual vinyl chloride monomer may have a specific vinyl chloride monomer content 70 to 0% by weight, or 40 to 55% by weight.

The remaining vinyl chloride monomer may be added to the polymerization reactor continuously with 70 to 0% by weight of the remaining vinyl chloride monomer, except for the predetermined vinyl chloride monomer, and the remaining vinyl chloride monomer may be added at a point where the conversion rate of the emulsifier pre- After the emulsifier is contained, it can be continuously introduced to the point below the end of the polymerization.

In the present invention, the pre-polymerization and post-polymerization can be carried out under isothermal or non-isothermal conditions. For example, at 30 to 80 ° C.

The emulsion polymerization is terminated when the reaction pressure is reduced to about 4 kg / cm ² , and the total reaction time is about 3 to 7 hours, which can be shortened by about 1 hour compared to the conventional reaction time.

According to the production method of the present invention, it is possible to provide a paste vinyl chloride resin that can shorten the time required for polymerization and lower the end-of-polymerization temperature while also reducing the scale generation amount and reducing the manufacturing cost.

Specifically, the time (min) required for the polymerization may be shorter by 25 to 60 minutes than the time (min) required for the polymerization, which is measured by continuously feeding the emulsifier through the entire polymerization and the post polymerization. That is, according to the present invention, by minimizing foam generation by optimizing the emulsifier content in the polymerization reaction during polymerization, the heat-removing function, which is the original function of the reflux condenser, is effectively maintained, and as a result, the time required for polymerization can also be shortened.

The terminal temperature (占 폚) of the polymerization may be 5 to 10 占 폚 lower than the terminal temperature (占 폚) of the polymerization measured by continuously feeding the emulsifier throughout the entire polymerization and the post polymerization. That is, according to the present invention, by optimizing the emulsifier content in the polymerization reaction during polymerization to minimize foaming, the heat-retaining function, which is the original function of the reflux condenser, is effectively maintained, and as a result, the terminal temperature of the polymerization can also be reduced.

The maximum calorific value measured in the reflux condenser may be 150 Kcal or more, for example.

Unless otherwise specified, the term "calorific value" refers to a value measured using a calorimeter such as an inverse equation, a conduction diagram, a potential difference equation, an ultrasonic type or an optical type, taking into account factors such as flow rate and temperature in a polymerization reactor And can be calculated by measuring the temperature of the water at the inlet and outlet of the condenser and the flow rate of the water and substituting it into the formula Q = cmt (see FIGS. 1 to 3).

For reference, the capacity of the polymerization reactor used in the polymerization in the present invention is not particularly limited and is applicable to a large reactor. And a generally used stirring device may be used. Specifically, the wing type may be a paddle type, a pitched paddle type, a turbine type, a bluemagine type, a pfaudler type, And a baffle can be a cylindrical type, a D type, a loop type, a finger type, or the like.

As the reflux condenser, a well-known reflux condenser may be used which is connected to the main body of the polymerization reactor by one or more conduits and has a structure in which the vapor and the condensate move therein. For example, the reflux condenser may be a coil type, a spiral type, And tube type.

The paste vinyl chloride polymer slurry prepared by the method of the present invention can be dried to remove moisture using a fluidized bed dryer under the usual reaction conditions to obtain a final paste of vinyl chloride polymer. .

The emulsion polymerization composition of vinyl chloride used in the vinyl chloride polymer production method may be variously provided. For example, it may be a polymer composition containing a post polymerization emulsifier.

For reference, the term " post polymerization emulsifier " unless otherwise specified means that the polymerization without addition of an emulsifier in the emulsion polymerization of the vinyl chloride monomer is carried out in a polymerization Quot; refers to the emulsifier used in the post-polymerizations.

In the present invention, the post-polymerization emulsifier can be substituted for the defoaming agent effect only by adjusting the injection timing during emulsion polymerization. The post polymerization time can be, for example, 20% or more, or 24 to 36% have.

Examples of the post polymerization emulsifier include nonionic emulsifiers and anionic emulsifiers. Specific examples thereof include linear fatty acids having 6 to 20 carbon atoms, branched fatty acids having 6 to 20 carbon atoms, alkylsulfonic acids, alkylarylsulfonic acids, Sulfosuccinic acid esters, alkyl sulfates, alkali metal salts of alkyldisulfonic acid diphenyl oxides, and ammonium salts of alkyldisulfonic acid diphenyl oxides.

The amount of the post polymerization emulsifier may be, for example, 0.01 to 0.7 parts by weight, or 0.3 to 0.6 parts by weight, based on 100 parts by weight of the vinyl chloride monomer.

For reference, the content range falls within the range of 0.13 to 0.15 parts by weight reduced relative to the continuous introduction of the emulsifier during the pre-polymerization and post-polymerization described above, and therefore, the resultant emulsion unreacted in the resulting latex can be minimized.

The vinyl chloride monomer is a mixture of a vinyl chloride monomer alone or a monomer capable of copolymerizing with a vinyl chloride monomer. Examples of the monomer copolymerizable with the vinyl chloride monomer include vinyl esters, aromatic vinyl compounds, acrylic acid monoolefins, Halide . ≪ / RTI >

The emulsion polymerization composition according to the present invention may contain, for example, 0.01 to 20 parts by weight of a vinyl chloride chloride, 30 to 150 parts by weight of water, 0.1 to 15 parts by weight of a vinyl chloride seed, 40 to 130 parts by weight.

As a specific example, the vinyl chloride chloride may include an initiator. The initiator may be, for example, 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate, cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, cumyl Butyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, lauryl peroxide, peroxyneoheptanoate, t-amyl peroxyneodecanoate, t-butyl peroxyneodecanoate, have.

If necessary, the initial reactivity can be controlled by using a water-soluble initiator or an oxidation-reduction initiator system. Specific examples of the oxidation-reduction initiator include copper sulfate and ascorbic acid. When the vinyl chloride resin is prepared by the isothermal reaction method while controlling the initial reactivity by using such an oxidation-reduction initiator, the reaction stability is improved and the latex properties are improved, so that the reaction time can be shortened and the productivity can be improved.

In the present invention, the initiator is used in an amount of 0.02 to 0.2 parts by weight, or 0.04 to 0.2 parts by weight per 100 parts by weight of the total monomers for vinyl chloride chloride, 0.12 parts by weight.

For reference, in the present invention, the initiator contained in the vinyl chloride seed serves as a polymerization initiator during the emulsion polymerization, so that the initiator may not be included separately.

The vinyl chloride seed thus obtained may be one having an average particle diameter of 100 to 1500 nm.

As the vinyl chloride seed, a large diameter seed alone or a mixture of a small diameter seed and a large diameter seed may be used.

The amount of the charged seed may be 0.5 to 3 on the basis of the seed weight ratio of the small-diameter seeds.

As another example, the small-particle-diameter seed may be prepared by emulsion polymerization and have an average particle size within a range of 100 to 400 nm, and the large-diameter seed may be prepared by adding a vinyl chloride monomer, an emulsifier, Homogenizer pump and then polymerized. The average particle diameter may be in the range of 400 to 1000 nm.

The emulsion polymerization composition of the vinyl chloride can be used in the form of a pigment or a pigment in the form of a pigment, a lubricant, a UV stabilizer, a heat stabilizer, a light stabilizer, a reinforcing agent, a filler, a flame retardant, a foaming agent, a low gloss agent, an antistatic agent, And may further comprise at least one selected additive. The additive can be used, for example, within a range not adversely affecting physical properties of the emulsion polymerization composition of the vinyl chloride of the present invention.

The paste vinyl chloride resin obtained by the above-mentioned method can reduce the residual monomer content.

Further, when applied to foam molding, whiteness and expansion ratio can be maintained, so that it can be applied to the production of artificial leather, flooring, wallpaper, floor coverings, gloves, and carpets.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

[Example]

Device Manufacturing Example

As a device used in this experiment, a calorimeter was installed at the top of a 500-liter high-pressure polymerization reactor equipped with a shell and tubular reflux condenser. The length from the top of the polymerization reactor to the lowermost end of the calorimeter was 11% of the height of the polymerization reactor (in this experiment, the distance from the top of the polymerization reactor to the bottom of the thermal calorimeter was 130 mm) The length entering the reactor was set at 110 mm (9% of the height of the polymerization reactor). At this time, the laser calorimeter was used for the laser calorimetry.

An emulsifier supply pipe is provided in the upper portion of the polymerization reactor so that an emulsifier can be introduced separately from the line for charging the vinyl chloride monomer. The emulsifier supply pipe is provided with a flow rate control valve for controlling the charging rate of the emulsifier supplied through the emulsifier supply pipe into the polymerization reactor.

Example 1

Paste PVC latex was prepared by emulsion polymerization using seed particles.

Specifically, the seeds were charged into a polymerization reactor, and 50 parts by weight of a vinyl chloride monomer in a total of 66 parts by weight of water (based on 100 parts by weight of vinyl chloride monomer) and 100 parts by weight of total vinyl chloride monomer were added thereto.

The polymerization temperature was raised to 58 캜 and polymerization was started. During the polymerization (pre-polymerization step), the remaining 50 parts by weight of vinyl chloride monomer was continuously fed into the reactor over 3 hours and 30 minutes.

When the conversion rate of the polymerization reached 36% in the pre-polymerization step, the introduction of sodium dodecylbenzenesulfonate as a post emulsifier into the reactor was initiated to give a total of 0.5 part by weight (total of 100 parts by weight of vinyl chloride monomer ) Was continuously supplied at the time when the reactor pressure reached 4.0 kg / cm < ² > until the reaction was terminated (post polymerization stage).

The resultant vinyl chloride latex was spray-dried to obtain a powdery-phase vinyl chloride resin having an average particle size of 100 to 1000 nm.

Example 2

The same procedure as in Example 1 was carried out except that the post emulsifier charged in the post polymerization step was continuously introduced at a polymerization conversion rate of 26% and the total charge amount was 0.6 part by weight in Example 1, Respectively.

Example 3

In Example 1, a post emulsifier having a temperature elevation temperature of 54 占 폚 in the prepolymerization step was introduced at a polymerization conversion rate of 27% and continuously introduced, and the total amount of the emulsifier was 0.58 parts by weight The same process as in Example 1 was performed.

Example 4

The same procedure as in Example 3 was carried out except that the post emulsifier charged in the post polymerization step was continuously introduced at a polymerization conversion rate of 33% and the total charge amount was 0.49 part by weight in Example 3 Respectively.

Example 5

In Example 1, a post emulsifier which was not subjected to non-isothermal polymerization at a temperature elevating temperature of 56.5 DEG C and a temperature of 51.5 DEG C after 1 hour from the initiation of polymerization and then charged into a post polymerization stage was charged at a polymerization conversion rate of 24% And the same procedure as in Example 1 was carried out except that the total charge amount was 0.57 parts by weight.

Comparative Example 1

In Example 1, a post emulsifier to be added to the post-polymerization step was continuously charged from the start of the prepolymerization step (polymerization conversion rate: 0%) to the end of the polymerization, and the amount of the emulsifier was changed to 0.75 parts by weight, Was carried out.

Comparative Example 2

In Example 3, the post emulsifier charged in the post-polymerization step was continuously charged from the initiation of the prepolymerization stage (polymerization conversion rate: 0%) to the end of the polymerization, and the amount of the charged emulsion was changed to 0.73 parts by weight, Was carried out.

Comparative Example 3

In Example 5, the post emulsifier charged in the post polymerization step was continuously charged from the start of the prepolymerization step (polymerization conversion rate: 0%) to the end of the polymerization, and the charge amount of the emulsion was changed to 0.71 parts by weight, Was carried out.

Comparative Example 4

The same procedure as in Example 2 was carried out except that the post emulsifier charged in the post-polymerization step was continuously introduced at a polymerization conversion rate of 15% and continuously charged in the same manner as in Example 2, except that the total charge amount was 0.675 parts by weight. Respectively.

Comparative Example 5

The same procedure as in Example 5 was carried out except that the post emulsifier charged in the post polymerization step was continuously introduced at a polymerization conversion rate of 14% and continuously charged, and the total charge amount was 0.64 parts by weight. Respectively.

For the powder phase polyvinyl chloride resin obtained in Examples 1-5 and Comparative Examples 1-5, the polymerization temperature, the conversion rate at the start of the feeding of the post emulsifier and the total input amount, the time required for polymerization, the amount of scale generation, And the temperature of the terminal period were measured and the results are summarized in Table 1 below.

<Test items>

* Polymerization time (min): The time required for reactor pressure to reach 4kG was measured from the pre-polymerization stage to the post-polymerization stage.

Scale Generation (g): The amount of foreign matters and macromolecules to be filtered by passing the latex through a mesh in the blowdown process of latex after polymerization was measured.

* End of polymerization temperature (占 폚): The maximum temperature reached at the end of the reaction from the point after the polymerization conversion rate of 50% was recorded.

division Example Comparative Example One 2 3 4 5 One 2 3 4 5 Polymerization temperature (캜) 58 58 54 54 56.5->
51.5 58 54 56.5->
51.5 58 56.5->
51.5 Conversion rate (%) at the start of input of post-emulsifier 36 26 27 33 24 Immediately after heating Immediately after heating Immediately after heating 15 14 The total amount of the post emulsifier (parts by weight) 0.5 0.6 0.58 0.49 0.57 0.75 0.73 0.71 0.675 0.64 Feeding speed (parts by weight / hour) 0.33 0.24 0.19 0.20 0.16 0.21 0.16 0.16 0.22 0.16 Polymerization time (min) 224 247 268 282 306 270 315 350 265 345 Scale generation (g) 570 560 200 110 1800 1070 340 2240 620 2280 End of polymerization temperature (캜) 70 68 66 66 65 75 74 75 70.19 71.15

As a result of the emulsion polymerization of vinyl chloride under the isothermal condition of 58 ° C through Table 1 and FIG. 1, as a result of the emulsion polymerization of vinyl chloride, the emulsion polymerization was carried out in the same manner as in Example 1 And 2, the total amount of the emulsifier added to Comparative Example 1 in which the same type of emulsifier was continuously added from the beginning to the end of polymerization was reduced, the polymerization time was shortened, the amount of scale generation was remarkably reduced, and the temperature at the end of polymerization was also lowered I could. These results show that it is possible to solve the bubble excess which occurs during the polymerization without using the defoaming agent.

As a result of the emulsion polymerization of vinyl chloride under an isothermal condition at 54 ° C. through Table 1 and FIG. 2, the emulsion polymerization was carried out in the same manner as in Example 3 wherein the emulsion polymerization pre-polymerization step and the post- And 4, the total amount of the emulsifier to be added to Comparative Example 2 in which the same type of emulsifier was continuously added from the beginning to the end of polymerization was reduced, the polymerization time was shortened, the amount of scale generation was remarkably reduced, I could confirm.

Further, as a result of the emulsion polymerization of vinyl chloride under non-isothermal conditions in which the polymerization was started at 56.5 ° C. and the polymerization temperature was controlled at 51.5 ° C. through Table 1 and FIG. 3, In the case of Example 5 in which post-polymerization was carried out using a post emulsifier, the total amount of emulsifier added to Comparative Example 3 in which the same type of emulsifier was continuously added from the start to the end of polymerization, the polymerization time was shortened, And the temperature at the end of polymerization was also lowered.

Meanwhile, in Table 1, when the post emulsifier was added at a conversion rate of 26%, the amount of emulsifier added to Comparative Example 4, which started to be added at a conversion rate of 15% , The polymerization time was shortened, and the temperature at the end of polymerization was also lowered. In addition, the total amount of the emulsifier added to Comparative Example 5 in which the addition was started at the conversion rate of 24% and the addition of the emulsifier was started at the conversion rate of 14%, the polymerization time was shortened and the amount of scale generation was remarkably decreased. The temperature was also lowered.

From this, it was found that it is appropriate to start the injection at the point of time when the conversion rate is 20% or more or 24% or more when the post emulsifier is added.

Also, although the residual monomer content was not measured, it was predicted that the residual monomer content was low due to the increased monomer content since the total heat amount was increased.

Claims (13)

Polymerizing a vinyl chloride monomer in a polymerization reactor equipped with a reflux condenser, wherein the emulsifier-free pre-polymerization step; And the polymerization step after the emulsifier is contained, wherein the polymerization step after the emulsifier-containing polymerization step is carried out at a polymerization conversion rate of 26 to 36% in the emulsifier pre-polymerization step and at a polymerization conversion rate of 90% 45 to 60% by weight of vinyl chloride monomer and 100 to 60% by weight of vinyl chloride monomer and water are added to a polymerization reactor to initiate polymerization, and 40 to 55% by weight of total vinyl chloride monomer is emulsion- The conversion rate was 0% or more, the emulsion polymerization was carried out continuously until the end of post polymerization,
The polymerization reactor equipped with the reflux condenser is a polymerization reactor having a shell-and-tube type reflux condenser, and an emulsifier supply pipe is provided in the upper part of the polymerization reactor so that an emulsifier can be introduced separately from the line for charging the vinyl chloride monomer, Wherein the supply pipe is provided with a flow rate control valve for controlling an injection rate of the emulsifier. delete The method according to claim 1,
Wherein the emulsifier is continuously added at an application rate of 0.1 part by weight to 0.5 part by weight / hour based on 100 parts by weight of the vinyl chloride monomer. delete delete delete delete delete delete delete delete delete delete

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