KR101683333B1 - Method for preparing vinyl chloride based resin - Google Patents

Abstract

The present invention relates to a process for producing a high-quality vinyl chloride resin having excellent thermal stability. According to the present invention, there is provided a process for producing a vinyl chloride resin by suspension polymerization of a vinyl chloride monomer in the presence of a polymerization initiator, Can provide a suspension polymerization method of a vinyl chloride resin capable of enhancing thermal stability and securing processability by initially introducing a salt as a hydrogen ion index controlling agent together with a cellulose dispersant.

Description

[0001] The present invention relates to a method for preparing a vinyl chloride resin,

More particularly, the present invention relates to a method for producing a vinyl chloride resin by suspension polymerization of a vinyl chloride monomer, wherein a salt having a basicity in water is reacted with a hydrogen ion The present invention also provides a suspension polymerization method of a vinyl chloride resin which can be initially injected together with a cellulose dispersant as an index controlling agent to enhance thermal stability and ensure processability.

BACKGROUND OF THE INVENTION [0002] Vinyl chloride resins are used in a wide variety of fields such as pipes, films, window frames, wire covers, wrap films, sheets and the like because of their low cost and excellent quality balance.

Thermal stability is one of the most important qualities of vinyl chloride resin. When processed, it is a property directly related to the color of vinyl chloride resin. The vinyl chloride resin having poor heat stability has an initial coloring property close to yellow, and is discolored to brown or black in a short time during long-term thermal processing. The coloring and discoloration of the vinyl chloride system is caused by the dehydrochlorination reaction and the oxidation reaction occurring during or after the polymerization.

In order to improve the thermal stability of the vinyl chloride resin, it is necessary to prevent the dehydrochlorination reaction and the oxidation reaction. As a measure to prevent the oxidation reaction, various heat stabilizers may be added to the vinyl chloride resin after the reaction. The heat stabilizer acts as a reducing agent instead of a vinyl chloride resin. Since the heat stabilizer can act as a reaction inhibitor at the same time, it is usually added to the reactor after completion of the reaction or mixed with the vinyl chloride resin before processing and then processed together. The method used to prevent the dehydrochlorination reaction is to dissolve a basic salt in water such as sulfuric acid and ammonia in a reactor before or after polymerization, or to dissolve it in a vinyl chloride monomer storage tank.

The dehydrogenation reaction produces a continuous double bond in the chain of the vinyl chloride resin itself, which not only affects the initial coloration but also has a high reactivity, resulting in a faster oxidation reaction during processing. The dehydrogenation reaction is a reaction for generating an acid and an acid generated at the same time serves as a catalyst and is further accelerated. Therefore, when a salt having basicity is used, the dehydrogenation reaction can be delayed.

Since the dehydrogenation reaction occurs even during the polymerization, it is preferable to use a basic salt before the polymerization to prevent this. However, the vinyl acetate-vinyl alcohol copolymer mainly used as a dispersant in the suspension polymerization of a vinyl chloride resin is not suitable for use with a basic salt because the protective colloid property and the surfactant property are greatly deteriorated in a base environment. Therefore, in the present invention, a basic dispersion is initially used in place of the vinyl acetate-vinyl alcohol copolymer and a basic salt is initially added thereto. Previously, there were many examples in which a vinyl chloride resin was polymerized using a cellulose-based dispersant instead of a vinyl acetate-vinyl alcohol copolymer.

For example, in US Pat. No. 3,945,958, Shinetsu discloses a vinyl chloride-based resin having high workability and uniform physical properties by using two types of cellulose dispersants having a viscosity of up to 100 cps and 400 cps at 20 ° C in a 2% To obtain a resin.

In U.S. Patent No. 4,612,345, Dow Corporation obtained a vinyl chloride resin having a high porosity by using a cellulose dispersant having a methoxy group content of about 50,000 and a propyl hydroxy group content of 15 to 35%.

In addition, there are many examples in which a vinyl chloride resin is polymerized by using a cellulose-based dispersant, but there has been no case in which thermal stability has been examined. In all cases, by controlling the degree of substitution of viscosity, methoxy group and propyl hydroxy group, It was regulated. The processability of the vinyl chloride resin depends on the surface and internal shape, porosity and size of the vinyl chloride resin, all of which are dependent variables of the surfactant activity and the protective colloid property of the dispersant.

Since there is a difference in the limit of the surfactant activity that the cellulose dispersant and the vinyl acetate-vinyl alcohol copolymer dispersant have, there are cases where only the cellulose dispersant is used in some special vinyl chloride resins. However, Processability can also be achieved through the combination of various vinyl acetate-vinyl alcohol copolymers with different degrees of hydration and degree of polymerization as well as cellulose dispersants. Considering that the unit price of the cellulose dispersant is much higher than the unit price of the acetate alcohol copolymer, the use of the cellulose dispersant may deteriorate in terms of processability in terms of economy.

Therefore, when the vinyl acetate-vinyl alcohol copolymer and the basic salt are initially used at the same time, there is a need for a solution to overcome the problem that the diameter of the vinyl chloride resin becomes excessively large and a large scale is generated.

In order to overcome the above problem, the present invention provides high thermal stability and equivalent processability when a basic salt is initially used and a formulation containing a cellulose-based dispersant instead of a vinyl acetate-vinyl alcohol copolymer as an active ingredient is used can do.

That is, an object of the present invention is to provide a method for producing a vinyl chloride resin by suspension polymerization of a vinyl chloride monomer, wherein a cellulose dispersant and a basic salt are used as a hydrogen ion index modifier at the beginning of the polymerization to increase the thermal stability of the vinyl chloride resin have.

According to the present invention, a vinyl chloride resin by suspension polymerization is produced,

Wherein the suspension polymerization is carried out by adding polymerized water, a cellulose dispersant and a hydrogen ion index controlling basic salt at 70 to 100 ° C at the initial stage of the polymerization.

As described above, it is possible to provide a suspension polymerization method of a high-quality vinyl chloride resin capable of enhancing thermal stability and securing processability.

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

That is, in the present invention, a vinyl chloride resin is produced by suspension polymerization, and the suspension polymerization is performed by charging polymerization water, a cellulose dispersant and a hydrogen ion index controlling basic salt at 70 to 100 ° C at the beginning of polymerization .

The polymerization reaction can be carried out at 70 to 100 ° C in a reactor, and then the polymerization reaction can be started immediately, thereby maximizing the economical effect.

The cellulose dispersant may be one or more selected from among cellulose having a methoxy group content of 15 to 40% by weight, a hydroxyl group content of 3 to 20% by weight, and a viscosity of 2% aqueous solution measured at 20 ° C of 10 to 20,000 cps.

The cellulose-based dispersant may be in the range of 0.03 to 5 parts by weight based on 100 parts by weight of the vinyl chloride monomer used in the suspension polymerization.

As a specific example, the cellulose dispersant may comprise from 29 to 40 weight percent, from 29 to 35 weight percent, or from 29 to 31 weight percent methoxy groups, from 10 to 20 weight percent, from 10 to 15 weight percent, or from 10 to 13 weight percent, A second dispersant having a viscosity of 2% aqueous solution of 10 to 40 cps, 10 to 30 cps, or 10 to 20 cps measured at 20 캜; and a second dispersant having a methoxy group content of 15 to 29 wt%, 20 to 29 wt% Or less than 20% by weight and less than 25% by weight, a propylhydroxyl group of 3% by weight or more and less than 10% by weight, 5% by weight or more and less than 10% by weight, or 7% A first dispersant having a viscosity of 2% aqueous solution of 40 cps or more and 20,000 cps or less and 60 to 10,000 cps or 80 to 1,000 cps in a weight ratio of 1: 0.2 to 4, or 1: 0.5 to 2 .

The cellulose dispersant may include a vinyl acetate-vinyl alcohol copolymer resin having a degree of hydration of 40 to 98%. For example, one of the second dispersant or the first dispersant may be a vinyl acetate having a degree of hydration of 40 to 98% Acetate-vinyl alcohol copolymer resin.

As used herein, the term "hydrogen ion index controlling basic salt " used in the present invention refers to salts used as bases in water and used for controlling hydrogen ion index unless otherwise specified.

The basic hydrogen ion index controlling basic salt may be at least one selected from sodium hydrogencarbonate and sodium hydrogen sulfide. The hydrogen ion index controlling basic salt may be, for example, sodium hydrogencarbonate.

The hydrogen ion index controlling basic salt may be used in an amount of 0.001 to 1 part by weight, or 0.01 to 0.08 part by weight, based on 100 parts by weight of the vinyl chloride monomer used in the suspension polymerization. If the lower limit is below the lower limit, the neutralization effect is lowered and the thermal stability is lowered. When the upper limit is exceeded, the hydrogen ion index of the polymerization water becomes excessively high.

For example, the suspension polymerization may be performed by preparing a polymerization water at 70 to 100 캜 in a reactor, and then polymerizing it by introducing a polymerization initiator.

As another example, the suspension polymerization may be such that the high-temperature polymerized water is mixed with a protective colloid assistant containing a vinyl chloride monomer and a cellulose dispersant as an active ingredient, and a polymerization initiator is added to the mixed solution to be polymerized. As another example, the suspension polymerization can be carried out batchwise.

Wherein the protective colloid preparation comprises a cellulose dispersant as an active ingredient, Furthermore It may further comprise an unsaturated organic acid. The unsaturated organic acid may be, for example, acrylic acid, methacrylic acid, itaconic acid, and the like.

The cellulose dispersant may be of the above-mentioned kind, and may include a vinyl acetate-vinyl alcohol copolymer resin having a degree of hydration of 40 to 98% as required.

As a specific example, the suspension polymerization may be carried out in the presence of a polymerization initiator in an amount of from 120 to 150 parts by weight, a polymerization initiator in an amount of from 0.02 to 0.2 part by weight, and a protective colloid preparation containing the cellulose dispersant as an active ingredient, in an amount of 0.03 By weight to 5 parts by weight.

The vinyl chloride-based resin used in the present invention is not limited to a resin prepared by using a vinyl chloride monomer alone but also by a mixture of a vinyl chloride monomer and a vinyl monomer copolymerizable therewith (the content of the vinyl chloride monomer in the resin composition is 50 wt% %).

The protective colloid adjuvant containing the cellulose dispersant may be included in an amount of 0.03 to 5 parts by weight, or 0.05 to 2.5 parts by weight based on 100 parts by weight of the vinyl chloride monomer. Scale generation can be prevented by the formation of coarse particles in the above range.

Examples of the polymerization initiator usable in the present invention include diacyl peroxides such as dicumyl peroxide, dipentyl peroxide, di-3,5,5-trimethylhexanoyl peroxide and diaryl peroxide, diisopropyl Peroxydicarbonates such as peroxydicarbonate, di-sec-butylperoxydicarbonate and di-2-ethylhexyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, t Peroxyesters such as amyl peroxyneodecanoate, cumyl peroxyneodecanoate, cumyl peroxyneoheptanoate, and 1,1,3,3-tetramethylbutyl peroxyneodecanoate, azobis -2,4-dimethylvaleronitrile, and sulfates such as potassium persulfate and ammonium persulfate, and they may be used alone or in combination of two or more thereof. The amount to be used is determined by factors such as the manufacturing process, productivity, quality, etc. Generally, the amount of the vinyl chloride monomer may be 0.02 to 0.2 parts by weight, or 0.04 to 0.12 parts by weight based on 100 parts by weight of the vinyl chloride monomer. Below the lower limit, the reaction time is delayed and the productivity is lowered. If the upper limit is exceeded, the resin may remain in the final resin product to lower the initial coloring property of the resin.

Examples of the antioxidant that can be used in the present invention prior to stopping the reaction include the kinds used in the production of the vinyl chloride resin such as triethylene glycol-bis-3- (3-t-butyl- Hydroxyphenyl) propionate, hydroquinone, p-methoxyphenol, t-butylhydroxyanisole, n-octadecyl-3- (4-hydroxy-3,5-di- ) Propionate, 2,5-di-t-butylhydroquinone, 4,4-butylidenebis (3-methyl-6-t-butylphenol), t- (6-t-butyl-m-cresol), phenol compounds such as tocopherol, amine compounds such as N, N-diphenylphenylenediamine and 4,4-bis (dimethylbenzyl) diphenylamine, Mercaptans, and 1,2-diphenyl-2-thiol, which may be used alone or in combination of two or more.

The reactor used in the present invention may be a stirring apparatus used for suspension polymerization of a vinyl chloride resin. For example, the stirring blade type may be a paddle type, a pitched paddle type, a bloomers gin, A pfaudler type turbine type propeller type or an agitator combined with two or more types of agitating blades may be used, and a plate type, a cylindrical type, a D type, a loop type or a finger type Can be used as a baffle.

The vinyl chloride resin slurry may be dried under a normal reaction condition with a fluidized bed dryer to produce a final vinyl chloride resin.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example  One

320 kg of deionized water at 80 ° C was charged into a 1 m ³ internal volume reactor having a reflux condenser and 160 g of a cellulose dispersant having a methoxy group content of 23% and a propylhydroxyl group content of 6.5% and having a viscosity of 100 cps at 20 ° C at 20 ° C 180 g of a cellulose dispersant having a methoxy group of 29% and a hydroxyl group of propyl group of 10% at 20 ° C and a 2% aqueous solution viscosity of 15 cps, and 50 g of sodium hydrogencarbonate were charged in a reactor and 300 kg of a vinyl chloride monomer Then, 170 g of t-butyl peroxyneodecanonate was added to initiate the reaction.

The polymerization reaction while maintaining the reaction temperature during the entire course by 64 ℃ allowed to proceed the reaction, and then as an antioxidant to the time when the pressure reaches 8.0 kg / cm ² of the polymerization reactor (the time of the polymerization conversion rate is equivalent to approximately 85%) (3-t-butyl-4-hydroxy-5-methylphenyl) propionate was obtained in the same manner as in Example 1, except that 5 g of triethyleneglycol-bis- (2,2,6,6-tetramethylpiperidin- 36 g was added and unreacted monomers were recovered and the resin slurry was recovered in a polymerization reactor. The slurry thus obtained was dried in a fluidized bed drier by a conventional method to obtain a vinyl chloride resin.

Example  2

In Example 1, a cellulose dispersant having a methoxy group content of 23% and a hydroxy propyl group content of 6.5% and having a viscosity of 100 cps at 20 DEG C and a 2% aqueous solution was replaced with 28.5% of a methoxy group and 6% % Aqueous solution viscosity of 50 cps was put into the flask. The polymerization was carried out under the same conditions as in Example 1 and evaluated.

Example  3

In Example 1, the cellulose dispersant in which the methoxy group was replaced by 29% and the hydroxypropyl group was replaced by 10%, and the cellulose dispersant having a viscosity of 15 cps at 20 ° C and 2% aqueous solution was replaced with 29% of methoxy group and 11.5% % Aqueous solution viscosity was 45 cps, and the polymerization was carried out under the same conditions as in Example 1 and evaluated.

Example  4

In the same manner as in Example 1, except that a cellulose dispersant having a methoxy group content of 29% and a hydroxyl group content group of 10% substituted therein and having a viscosity of 15 cps at 20 ° C and 2% aqueous solution was replaced with 180 g of a 49% vinyl acetate- , Polymerization was carried out under the same conditions as in Example 1 and evaluated.

Example  5

Polymerization was carried out under the same conditions as in Example 1 except that 30 g of sodium hydrogencarbonate was added at the beginning of the polymerization in Example 1, and the evaluation was carried out.

Example  6

In Example 1, and the polymerization temperature was maintained at 57 ℃ and the polymerization is carried out under the same conditions as in Example 1 except for changing the time to inject an anti-oxidant to 7.0 kg / cm ² and evaluated.

Comparative Example  One

320 kg of deionized water at 80 ° C was charged into a 1 m ³ internal volume reactor having a reflux condenser and 160 g of a cellulose dispersant having a methoxy group content of 23% and a propylhydroxyl group content of 6.5% and having a viscosity of 100 cps at 20 ° C at 20 ° C , 180 g of a cellulose dispersant having a methoxy group of 29% and a hydroxyl group of propyl group of 10% substituted therein and having a viscosity of 15 cps at 20 ° C and 2% aqueous solution were added in a batch, 300 kg of a vinyl chloride monomer was added thereto, 170 g of decanoate was added to initiate the reaction.

The polymerization reaction while maintaining the reaction temperature during the entire course by 64 ℃ allowed to proceed the reaction, and then as an antioxidant to the time when the pressure reaches 8.0 kg / cm ² of the polymerization reactor (the time of the polymerization conversion rate is equivalent to approximately 85%) (3-t-butyl-4-hydroxy-5-methylphenyl) propionate was obtained in the same manner as in Example 1, except that 5 g of triethyleneglycol-bis- (2,2,6,6-tetramethylpiperidin- 36 g of sodium hydrogen carbonate and 50 g of sodium hydrogencarbonate were added, unreacted monomers were recovered, and the resin slurry was recovered in a polymerization reactor. The slurry thus obtained was dried in a fluidized bed drier by a conventional method to obtain a vinyl chloride resin.

Comparative Example  2

In Comparative Example 1, 160 g of a 80% vinyl acetate-vinyl alcohol copolymer having a degree of hydration of 80% instead of a cellulose dispersant having a methoxy group content of 23% and a hydroxyl group content of 6.5% and having a viscosity of 2% Polymerization was carried out under the same conditions as in Comparative Example 1 and evaluated, except that sodium hydrogen was initially added.

Comparative Example  3

In Comparative Example 1, 160 g of an 80% vinyl acetate-vinyl alcohol copolymer having a degree of hydration of 80% instead of a cellulose dispersant having a methoxy group content of 23% and a hydroxyl group content of 6.5% and a viscosity at 20 ° C of 2% A cellulose acylate-vinyl alcohol copolymer was added in an amount of 180 g instead of a cellulose dispersant having a period of 29% and a propylhydroxyl group of 10% substituted therein and having a viscosity of 15 cps at 20 DEG C and 2% , Polymerization was carried out under the same conditions as in Comparative Example 1 and evaluated.

Comparative Example  4

In Comparative Example 1, polymerization was carried out under the same conditions as in Comparative Example 1, except that sodium hydrogen carbonate was added in an amount of 10 g initially, not after polymerization.

Comparative Example  5

In Comparative Example 1, polymerization was carried out under the same conditions as in Comparative Example 1, except that sodium hydrogen carbonate was not added before and after polymerization.

Comparative Example  6

In Comparative Example 1, and the polymerization temperature was maintained at 57 ℃ and the polymerization is carried out under the same conditions as in Comparative Example 1 except for changing the time to inject an anti-oxidant to 7.0 kg / cm ² and evaluated.

Comparative Example  7

In Comparative Example 1, the polymerization was carried out under the same conditions as in Comparative Example 1 except that the deionized water was replaced with 25 ° C deionized water instead of 80 ° C deionized water.

The physical properties of the vinyl chloride resin prepared in Examples 1-6 and 1-7 and the polymerization conversion during the polymerization were measured by the following methods, and the results are shown in Table 1 below.

≪ Measurement of physical properties &

* Measurement of polymerization degree: Measured by ASTM D1 243-79.

* Apparent Specific Gravity: Measured according to ASTM D1 895-89.

* Plasticizer absorption rate: The amount of DOP absorbed by the sample in accordance with ASTM D3367-95 is expressed in weight% with respect to the sample before absorption.

* Particle distribution measurement : The weight percentages of the samples having passed through the sieve of # 60 and # 200 were measured according to the particle distribution measurement method of ASTM D1 705, and measured.

* Fish eye (fish - eye) can: by using a vinyl chloride resin 100 parts by weight DOP 45 parts by weight of stearic acid, barium, 0.1 part by weight of tin based stabilizer, 0.2 parts by weight of 6-inch roll of carbon black 0.1 parts by weight of 140 ℃ The mixture was blended for 5 minutes, and then a sheet having a thickness of 0.3 mm was prepared. The sheet was expressed by the number of white transparent particles in 400 cm ² of the sheet.

Evaluation of thermal stability: 100 parts by weight of the obtained vinyl chloride resin, 2 parts by weight of TiO ₂ , 0.7 parts by weight of lead stearate, 1 part by weight of acrylic processing aid and 0.3 part by weight of a foaming agent were mixed and kneaded for 5 minutes using a 6 inch roll at 190 ° C Then, a sheet having a thickness of 0.3 mm was prepared, and whiteness was measured by L, a, and b methods.

Metrics unit Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Degree of polymerization 800 800 800 800 800 1030 Particle size ㎛ 140 131 152 163 138 132 Apparent specific gravity g / cc 0.511 0.492 0.525 0.508 0.508 0.477 Plasticizer absorption rate % 20.3 22.4 19.1 23.0 20.1 26.0 Particle Size Distribution # 60 % 100 100 100 100 100 100 Particle Size Distribution # 200 % 2.0 3.1 0.8 0.4 2.2 3.6 Fishie Eye Ea 6 4 9 4 6 7 Whiteness 68.4 68.2 68.7 68.5 67.5 76.1 Metrics unit Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Degree of polymerization 800 800 800 800 800 1030 810 Particle size ㎛ 139 189 Oversize 141 140 133 135 Apparent specific gravity g / cc 0.514 0.512 0.512 0.513 0.478 0.501 Plasticizer absorption rate % 20.1 20.0 20.4 20.3 25.4 20.5 Particle Size Distribution # 60 % 100 100 100 100 100 100 Particle Size Distribution # 200 % 2.2 0.2 2.2 2.5 3.2 2.5 Fishie Eye Ea 7 200 8 6 8 6 Whiteness 65.3 68.1 65.9 64.3 73.1 65.9

As shown in Table 1, in Examples 1 to 6 in which polymerization was started using high-temperature polymerization water and sodium hydrogen carbonate having basicity in water was added at the initial stage of polymerization, the whiteness improvement was observed as a whole. This is because hydroxide ions in water neutralize the hydrochloric acid generated by the dehydrochlorination reaction.

On the other hand, in Comparative Example 1 and Comparative Example 6 in which sodium hydrogen carbonate was added after polymerization, the whiteness quality was poor as compared with the example in which sodium bicarbonate was initially added to the polymerization. In Comparative Example 5 in which sodium hydrogencarbonate was not added, the whiteness quality was further deteriorated.

Even when sodium hydrogencarbonate was added, the whiteness quality of Comparative Example 4, which was small in amount, was insignificant.

Further, in Comparative Examples 2 and 3 in which sodium hydrogen carbonate was added at the initial stage of the polymerization and the vinyl acetate-vinyl alcohol copolymer not used as a cellulose dispersant was added, the grain size of the vinyl chloride resin was greatly increased to decrease the workability, And the evaluation itself was impossible. It is inferred that the hydroxide ion generated by the salt acts as a catalyst to hydrate the vinyl acetate-vinyl alcohol copolymer.

On the other hand, in Comparative Example 7 in which high temperature polymerized water was not used in combination, the plasticizer absorption rate and the degree of polymerization were increased as compared with Example 1. This is because the polymerization at a low temperature is prolonged due to the high- For reference, in Comparative Example 7, the total reaction time was prolonged by 30 minutes or more compared with other 64 ° C polymerization, and productivity was lowered.

Claims (12)

A vinyl chloride resin is produced by suspension polymerization,
The suspension polymerization is carried out by adding polymerization water, a cellulose dispersant and a hydrogen ion index controlling basic salt at 70 to 100 ° C at the initial stage of the polymerization, wherein the cellulose dispersant contains 29 to 40% by weight of a methoxy group, 10 to 20% , A dispersant having a viscosity of 2% aqueous solution of 10 to 40 cps measured at 20 캜, a propylene copolymer having a methoxy group content of not less than 15% by weight and less than 29% by weight, a propyl group group of not less than 3% by weight and less than 10% % Aqueous solution viscosity of not less than 40 cps and not more than 20,000 cps in a weight ratio of 1: 0.89 to 4, wherein the hydrogen ion index controlling basic salt is prepared by mixing at least one selected from sodium hydrogencarbonate and sodium hydrogen sulfide with 100 parts by weight of a vinyl chloride monomer Is in the range of 0.01 to 0.08 part by weight based on the weight of the vinyl chloride resin. delete The method according to claim 1,
Wherein the cellulose dispersant is in the range of 0.03 to 5 parts by weight based on 100 parts by weight of the vinyl chloride monomer used in the suspension polymerization. delete The method according to claim 1,
Wherein the cellulose dispersant comprises a vinyl acetate-vinyl alcohol copolymer resin having a degree of hydration of 40 to 98%. delete delete The method according to claim 1,
Wherein the suspension polymerization is carried out by polymerizing water in a reactor at 70 to 100 占 폚 and then polymerizing by the introduction of a polymerization initiator. The method according to claim 1,
Wherein the suspension polymerization is carried out by mixing the polymerization water with a protective colloid assistant comprising a vinyl chloride monomer and a cellulose dispersant as an effective component, and introducing a polymerization initiator into the mixed solution to polymerize the vinyl chloride resin. delete 10. The method of claim 9,
Wherein the protective colloid assistant comprising the cellulose dispersant as an active ingredient comprises a vinyl acetate-vinyl alcohol copolymer resin having a degree of hydration of 40 to 98%. The method according to claim 1,
The suspension polymerization is carried out in an amount of 120 to 150 parts by weight of polymerization water, 0.02 to 0.2 part by weight of a polymerization initiator, and 0.03 to 5 parts by weight of a protective colloid preparation containing a cellulose dispersant as an active ingredient, based on 100 parts by weight of the vinyl chloride monomer Wherein the vinyl chloride resin is a polyvinyl chloride resin.