KR101713377B1 - Method for polymerizing paste PVC and forming material - Google Patents

Abstract

The present invention relates to a paste PVC polymerization method and a foamed molded article, and it is an object of the present invention to overcome the disadvantages of handling the defoaming agent due to the high viscosity of the conventional defoaming agent and the problem of remaining without evaporation during drying of the paste PVC latex, It is possible to shorten the polymerization time by effectively removing the foam in the reflux condenser and preventing deterioration of the heat-releasing performance while maintaining the physical properties of the paste PVC, and at the same time, It is possible to stably produce a paste PVC resin applicable to the production of foamed molded articles such as artificial leather, topsheet, wallpaper, floor coverings, gloves, carpets and the like.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a paste PVC polymerizing method,

The present invention relates to a paste PVC polymerization method and a foamed molded article, and more particularly, to a method of polymerizing a foamed PVC product by polymerizing a specific liquid compound into a polymerization reactor at a specific point in time during polymerization and polymerizing to effectively remove bubbles in the reflux condenser, A paste PVC polymerization method for preventing performance degradation, and a foamed molded article comprising the paste PVC obtained by this method.

Vinyl chloride resin (hereinafter referred to as PVC) is divided into straight PVC and paste PVC according to the association structure determined in the manufacturing method. Straight PVC is prepared by suspension polymerization method with particle size of about 100 ~ 200㎛ and paste PVC is prepared by fine suspension polymerization, emulsion polymerization, or seed emulsion polymerization with powder particles of about 0.1 ~ 2㎛ size. Further, the straight resin is processed by the calender method, and the paste resin is processed by the casting method.

The paste vinyl chloride resin is prepared by adding a vinyl chloride monomer alone or a mixture of a vinyl chloride monomer and a monomer copolymerizable therewith (these are collectively referred to as a vinyl chloride monomer) in an aqueous medium with an emulsifier and an oil-soluble polymerization initiator, Suspension polymerization is carried out. If necessary, auxiliary dispersants such as higher alcohols and higher fatty acids may be used.

In general, 80 to 98% by weight of the vinyl chloride monomer used in the paste vinyl chloride resin polymerization is converted into a paste vinyl chloride resin, and the remaining unreacted monomer is removed to obtain a latex having a solid content of 50% by weight. The paste vinyl chloride resin is obtained by spray drying the latex from a spray dryer.

High temperature steam of 200 캜 is required to evaporate about 50% by weight of water in the latex during the drying process. The paste PVC is one of general-purpose resins widely used for everyday household goods such as architectural materials, wallpaper, artificial leather, woven fabrics, sheets and films, and industrial applications.

The vinyl chloride monomer is emulsified or emulsion-polymerized by adding an emulsifier or a water-soluble initiator in an aqueous medium by another polymerization method. In seed emulsion polymerization, seeds of two different average particle sizes are injected at the beginning of polymerization and vinyl chloride monomers are grown while reacting with the seed to produce final latex particles.

During the paste PVC polymerization reaction, many bubbles are generated. When the bubbles are excessively generated and the level of the inside of the reactor is completely filled up, the feed line of the polymerization reactor and the reflux condenser line are clogged.

At this time, when the foam flows into the reflux condenser and is filled, the cooling opportunity of the vinyl chloride monomer is reduced, and the heat-removing performance is lowered. In addition, the PVC particles contained in the foam adhere to the wall of the reflux condenser tube to form scale, and it takes much time and effort to remove it.

In order to solve such a problem, the defoaming agent is added to remove the foam, but the paste PVC remains unremoved upon drying, which adversely affects the physical properties of the paste PVC, so that the input is very limited . The defoaming agent is usually a mineral oil type or silicone, which usually has a viscosity of 1,000 to 3,000 cp (at 20 ° C). In addition, since it is an oil component, it is not soluble in water. Therefore, in order to dilute it, a dispersing system should be added. However, its use is limited because it affects the final PVC particle shape. Therefore, it is difficult to inject the polymer during the polymerization through the line, so that it is difficult to accurately mix the desired amount of the polymer.

In fact, in the early and middle stages of polymerization, the production of foam in the reactor is suppressed by the continuous introduction of vinyl chloride monomer, but at the end of the polymerization in which the introduction of the vinyl chloride monomer is completed, measures for foam removal are still required because PVC conversion is 70 to 75% At this point, the heat generated by the Trommsforf effect is rapidly increased, and the temperature of the reactor is also rapidly increased.

As a result, there is a possibility that the pressure in the reactor will exceed the allowable pressure due to an increase in the pressure in the reactor.

Therefore, it is an object of the present invention to overcome the cost disadvantages of handling defoaming agents of the prior art defoaming agents and the problems that remain unevaporated during drying of the paste PVC latex, and at certain times during the polymerization a specific liquid compound is introduced into the polymerization reactor, To thereby effectively prevent foaming in the reflux condenser and to prevent deterioration of heat-separating performance while maintaining the physical properties of the paste PVC, and to provide a foamed molded article comprising the paste PVC obtained by the method.

In order to solve the above-mentioned problems, the present invention relates to a process for producing a vinyl chloride polymer composition, which comprises, during paste PVC polymerization, a vinyl chloride monomer having a viscosity of 10 to 50 cP (at 20 캜) And a liquid phase compound in an amount of not less than 1 part by weight.

The present invention also provides a foamed molded article comprising the paste PVC obtained by the above-mentioned method.

The paste PVC polymerization method and the paste PVC of the present invention overcome the problem of costly handling due to the high viscosity of the conventional defoaming agent and the problem of remaining without evaporation during drying of the paste PVC latex, And it is effective to effectively remove bubbles in the reflux condenser while maintaining the physical properties of the paste PVC so as to prevent deterioration of the heat-insulating performance. Thus, not only the polymerization time can be shortened, but also the artificial leather , Flooring materials, flooring materials, gloves, carpets, and the like.

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

In the present invention, in the paste PVC polymerization, 0.0005 parts by weight or more of a liquid compound in a total amount based on 100 parts by weight of a vinyl chloride monomer having a viscosity of 10-50 cP or less (at 20 ° C) at the time of completion of the introduction of the vinyl chloride monomer .

For reference, in the present invention, the term " completion time of vinyl chloride monomer loading " means that the input flow rate is automatically controlled by the intensity of the reaction based on the reactor heat- Can be systemized.

The liquid compound may be introduced through a reflux condenser provided in a paste PVC polymerization reactor. In particular, the liquid compound may be filled in the reflux condenser to fill the void, thereby reducing the chance of cooling the vinyl chloride monomer and deteriorating the heat- It is more preferable to divide and input at specific intervals.

As the liquid compound, for example, aliphatic alcohols having a viscosity of 10 to 50 cP or less (at 20 ° C) and having 8 to 10 carbon atoms may be most suitable for the present application. When the number of carbon atoms is more than 10, it is insoluble in water. Conversely, when the number of carbon atoms is less than 8, the function of removing bubbles is lost.

Even when the liquid compound is used without dilution, the effect of the liquid compound as a defoaming agent is not impaired. However, since the amount of the liquid compound used is very small, it is preferable to dilute the liquid compound with water in consideration of ease of introduction.

Although the dilution ratio is not specified, the dilution ratio is high, and the higher the proportion of water in the latex resin is, the more the amount of water to be removed in the drying step is increased and the drying cost burden is increased. If the amount of water is too much, , The polymerization reaction may be delayed. For example, the dilution ratio may be 1: 10-1: 50 by weight.

The total amount of the liquid compound (before dilution) may be 0.0005 parts by weight or more, or 0.0005 to 0.005 parts by weight based on 100 parts by weight of the vinyl chloride monomer, and the remaining amount after the drying step Can be prevented from adversely affecting the physical properties of the soap paste PVC resin, particularly the foaming properties.

The above-described split injection may be, for example, 3 to 4 times of injection at 20 to 30 minute intervals.

The unreacted compound in the liquid compound has the advantage that it evaporates along with water vapor during paste PVC drying (for example, spray drying), and does not adversely affect the physical properties of the paste PVC.

The paste PVC polymerization is, for example, one in which 0.001 to 0.01 part by weight of a polymerization initiator and 0.5 to 2.0 parts by weight of an anionic surfactant are added to a polymerization reactor based on 100 parts by weight of a vinyl chloride monomer and subjected to fine suspension polymerization, emulsion polymerization or seed emulsion polymerization .

In the seed emulsion polymerization, seeds different in two kinds of average particle diameters are injected at the beginning of polymerization, and the vinyl chloride monomer grows while reacting with the seed to prepare final latex particles. The seed has an average particle diameter of about 0.4 to 1.5 占 퐉, the second seed is prepared by emulsion polymerization and has an average particle diameter of about 0.1 to 0.4 占 퐉. Also in this case, an auxiliary dispersing agent such as a higher alcohol or a higher fatty acid may be used, if necessary.

In the seed emulsion polymerization, it may be necessary to homogenize the first seed using a rotor-stator type homogenizer pump.

In addition, the micro suspension polymerization method is advantageous in that the heat of polymerization can be easily removed, and the polymer can be obtained in a size of about 0.1 to 2 μm, which is a convenient size for use.

In the micro suspension polymerization method, deionized water, a vinyl chloride monomer (or a mixture of two comonomers), a surfactant, an auxiliary surfactant, and a polymerization initiator are mixed with stirring, and then the high-pressure homogenizer is operated to transfer the reactants to the reactor The reaction is allowed to proceed to the reaction temperature. After completion of the reaction, spray drying is performed to obtain a powdery paste-like vinyl chloride resin.

During the micro suspension polymerization, it may be necessary to operate a high-pressure homogenizer to produce homogeneous monomer droplets. That is, a high-pressure homogenizer is used before the polymerization of the paste vinyl chloride resin by the fine suspension polymerization. The high-pressure homogenizer can adjust the droplet size of the vinyl chloride monomer through mechanical operation of a mixture of vinyl chloride monomer, polymerization initiator, surfactant, deionized water, etc. before the polymerization reaction.

For example, a monomer capable of copolymerizing with vinyl chloride or vinyl chloride, a polymerization initiator, and a surfactant are mixed with strong stirring, and the mixture is passed through the high-pressure homogenizer to form a small droplet of 0.05 to 1.5 탆 into the reactor. To 65 占 폚 to give a paste vinyl chloride resin.

The type and shape of the reactor, stirrer, baffle, etc. used in the present invention are not particularly limited, and an apparatus used for the fine suspension polymerization or emulsion polymerization of a conventional vinyl chloride monomer can be used.

Examples of the anionic surfactant 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, alkyldisulfonic acid diphenyl oxides And ammonium salts of alkyldisulfonic acid diphenyl oxides can be used, but they are usually selected according to the application of the product.

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 amount of the polymerization initiator used varies depending on the polymerization temperature, the reaction time, the kind of the polymerization initiator, and the like. For example, an oil-soluble initiator and a water-soluble initiator can be used. Specifically, the oil-soluble initiator is selected from the group consisting of dipentyl peroxide, di-3,3,5-trimethylhexanoyl peroxide, dira lauroyl peroxide, diisopropyl peroxy dicarbonate, di- 2-ethylhexyl peroxydicarbonate, azobisisobutyronitrile, azobis-2-methylbutyronitrile, or azobis-2,4-dimethylvaleronitrile, and the water-soluble initiator may be potassium persulfide, Ammonium sulphide or hydrogen peroxide.

The polymerization initiator is preferably contained in an amount of 0.001 to 2.0 parts by weight based on 100 parts by weight of the total amount of the vinyl chloride monomer. When the content of the polymerization initiator is less than 0.001 part by weight, the polymerization reactivity is deteriorated. There is a problem that it is difficult to heat the polymerization reaction heat.

As another example, the polymerization time can be shortened by controlling the initial reactivity using 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 an isothermal reaction method while controlling the initial reactivity using such an oxidation-reduction initiator, the reaction stability is improved and the foam properties are improved and the reaction time is shortened.

When the oxidation-reduction initiator system is used, the initiator decomposition is activated by continuously adding it during the reaction, and when all of the initiator is added all at once, side effects of suppressing radical formation are generated.

According to the above method, not only the polymerization time can be shortened, but also the maximum reached temperature at the end of the reaction can be reduced. If necessary, the spray-dried paste may be classified or pulverized.

In order to prepare the plastisol using the powder paste of the present invention, a conventionally used method for preparing the vinyl chloride resin plastisol can be used. That is, the vinyl chloride powder paste may contain additives such as plasticizers such as heat stabilizers, fillers, foaming agents, foaming accelerators, surfactants, viscosity reducing agents, adhesion imparting agents, Other resins or the like may be blended as required, and the mixture may be sufficiently shaken to homogeneity using a planetary mixer, a kneader, a roller, or the like to prepare a plastisol.

The plasticizer to be used in the preparation of the plastisol is not particularly limited and includes, for example, dibasic phthalate, diisobutyl phthalate, diheptyl phthalate, di- (2-ethylhexyl) phthalate, diphthalic acid- Phthalic acid derivatives such as benzyl phthalate, naphthalate, diisodecyl phthalate, diundecyl phthalate, dicyclohexyl phthalate, butyl benzyl phthalate and diphenyl phthalate, isophthalic acid derivatives, adipic acid derivatives, sebacic acid derivatives, Derivatives, pyromellitic acid derivatives; Itaconic acid derivatives, oleic acid derivatives; Phosphoric acid derivatives, glycol derivatives, glycerin derivatives, adipic acid-based polyester, sebacic acid-based polyester, and the like. These plasticizers may be used singly or in combination of two or more. The blending amount of the plasticizer can be appropriately adjusted by those skilled in the art according to the application.

The powder paste of the present invention may be prepared by mixing a vinyl chloride resin for mixing having an average particle diameter of 10 to 60 占 퐉, which is known as a mixed resin, a diluted resin, etc., for the purpose of improving the hardness and glossiness of the molded article.

The method of obtaining the foam from the plastisol of the present invention may be carried out by a method commonly used in this field and is not described here.

The paste PVC obtained by the above-mentioned method can also maintain the expansion ratio when applied to foam molding. For reference, it is applicable to the manufacture of artificial leather, carvings, wallpaper, floor coverings, gloves and carpets.

Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples are illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

Example 1

Paste PVC latex was prepared by emulsion polymerization using two kinds of seed particles of different sizes.

Specifically, the first seed is prepared by adding a vinyl chloride monomer, an emulsifier, and an oil-soluble initiator, homogenizing the mixture using a rotor-stator type homogenizer pump, and polymerizing the mixture. The first seed has an average particle diameter of about 0.66 μm, 2 Seed is emulsion polymerization (the emulsifier used is sodium laurylsulfate (SLS), the total amount of which is 2.5 w / w in 100 w / w of vinyl chloride monomer, 0.1 wt. 0.9 part by weight was continuously added thereto for 4 hours, and after completion of polymerization, 1.5 weight parts were added). The average particle diameter was about 0.19 탆.

The first seed (large) and the second seed (small) were charged in a 500 L high-pressure reactor equipped with a reflux condenser at a weight ratio of 1: 0.5 and an oxidation-reduction initiator was used for polymerization activation. The concentration of ascorbic acid was 0.44% (concentration) at the beginning of the polymerization in the aqueous solution state of 4% (concentration), and the concentration of ascorbic acid was 0.44% (concentration) In aqueous solution

After the completion of the temperature raising (at the point of time when the polymerization temperature reached 57.5 ° C), the reactor was supplied with a flow rate of 0.8 kg / hr into the reactor for 45 minutes. Thereafter, the reaction mode designed by the program was designed so that the calorific value does not exceed the reactor heat- And the flow rate of the aqueous solution was automatically adjusted.

While the polymerization was progressing at 57.5 ° C, vinyl chloride monomer (100 kg was added in advance of polymerization at the initial stage of polymerization and then 115 Kg was continuously supplied for 3 hours and 30 minutes from the completion of the temperature increase) Through the line connected to the reflux condenser tube at the point of time when the continuous supply is completed (at the time when the amount set by the prescription is completed under a system in which the input flow rate is automatically controlled by the intensity of the reaction based on the heat- 99 g of water was added to 11 g (corresponding to 0.0005 part by weight based on 100 parts by weight of vinyl chloride monomer) of a mixed alcohol of n-octyl alcohol having a concentration of 100% as an alcohol and having a viscosity of 10 to 50 cP and a decyl alcohol (mixing ratio 1: And 110 g of aliphatic alcohol-water mixture diluted in a weight ratio of 1:10 were added in three portions at intervals of 20 minutes and emulsion polymerization was carried out.

The polymerization time after completion of the polymerization (the time required for the reactor pressure to reach 3.5 kG from the time of the introduction of the oxidation-reduction initiator) and the maximum temperature reached at the end of the reaction from the point after the polymerization conversion rate of 70% were recorded. The obtained latex was spray-dried to obtain a vinyl chloride type powdery phase.

Example 2

Except that the total amount of mixed alcohol of n-octyl alcohol and decyl alcohol (mixing ratio 1: 1) was increased to 110 g (0.005 parts by weight based on 100 parts by weight of vinyl chloride monomer) in the above Example 1 and additionally added without dilution with water Was prepared in the same manner as in Example 1 to prepare a vinyl chloride type powdered latex.

Example 3

In Example 1, 11g (0.0005 parts by weight of 100 parts by weight of vinyl chloride monomer) of a mixed alcohol of n-octyl alcohol and decyl alcohol (mixing ratio 1: 1) was mixed with 539g of water and diluted to a weight ratio of 1:50, A vinyl chloride type powdery phase was prepared from latex polymerized in the same manner as in Example 1 except that the aliphatic alcohol and water mixture was added in portions.

Comparative Example 1

At the time when the introduction of the vinyl chloride monomer is completed in the first embodiment (at the time when the amount of the amount set by the prescription is completed under the system in which the input flow rate is automatically controlled by the intensity of the reaction based on the reactor heat- A total of 11 g of a mixed alcohol of n-octyl alcohol and decyl alcohol (mixing ratio: 1: 1) as an alcohol (0.0005 parts by weight based on 100 parts by weight of vinyl chloride monomer) was mixed with 99 g of water and diluted at a ratio of 1:10, thereby obtaining a total of 110 g of aliphatic alcohol- A vinyl chloride powder phase was prepared from the latex polymerized in the same manner as in Example 1, except that the water mixture was added all at once.

Comparative Example 2

A vinyl chloride powder phase was prepared from latex polymerized in the same manner as in Example 1, except that a mixed alcohol of n-octyl alcohol and decyl alcohol (mixing ratio: 1: 1) was used as an aliphatic alcohol in Example 1 Respectively.

Comparative Example 3

At the time when the introduction of the vinyl chloride monomer is completed in the first embodiment (at the time when the amount of the amount set by the prescription is completed under the system in which the input flow rate is automatically controlled by the intensity of the reaction based on the reactor heat- Same as Example 1 except that 0.0005 part by weight of FoamStar A10 (Cognis corporation product) as a defoaming agent instead of a mixed alcohol of n-octyl alcohol and decyl alcohol (mixing ratio 1: 1) was added as an alcohol based on 100 parts by weight of vinyl chloride monomer Vinyl chloride powder phase was prepared from the polymerized latex.

Comparative Example 4

Except that the total amount of mixed alcohol of n-octyl alcohol and decyl alcohol (mixing ratio 1: 1) was increased to 1,100 g (0.05 parts by weight based on 100 parts by weight of vinyl chloride monomer) in Example 1, , A vinyl chloride type powdery phase was prepared from the latex polymerized in the same manner as in Example 1.

Comparative Example 5

In Example 1, 5,489 g of water was mixed with 11 g (0.0005 part by weight based on 100 parts by weight of vinyl chloride monomer) of a mixed alcohol of n-octyl alcohol and decyl alcohol (mixing ratio 1: 1) to dilute the mixture at a weight ratio of 1: g of an aliphatic alcohol-water mixture was added in portions to prepare a vinyl chloride type powdery phase with the latex polymerized in the same manner as in Example 1.

The physical properties of the above Examples 1 to 3 and Comparative Examples 1 to 5 are summarized in the following Table 1, and at the same time, the plastisol was produced according to the following method, and the expansion ratio was measured. Together.

< Plastisol  Manufacturing>

To 100 parts by weight of powdery paste PVC, 70 parts by weight of dioctyl phthalate, 30 parts by weight of calcium carbonate, 3 parts by weight of a foaming agent and 3 parts by weight of a stabilizer were added as a plasticizer, stirred at 500 rpm for 10 minutes and then stirred at 800 rpm for 10 minutes, The sol was prepared and then vacuum degassed.

Foam magnification: The plastisol obtained on the coated paper was coated at 150 캜 for 45 seconds, heated at 210 캜 for 100 seconds, expanded, and the expansion ratio was calculated at a thickness ratio before and after foaming.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Dilution concentration of liquid compound 1:10 X 1:50 1:10 X 1:10 X 1: 500 The amount of the liquid compound (PPM) 500 5,000 500 500 X 500 50,000 500 Polymerization time (minutes) 278 277 282 287 299 280 275 295 Maximum end temperature of reaction (℃) 74.43 73.67 72.89 81.3 83.32 76.27 70.2 68.54 Expansion ratio 3.94 3.90 3.94 3.94 3.96 3.72 3.68 3.93

In Table 1, in Examples 1 to 3 polymerized according to the present invention, foaming in the reactor was continuously suppressed even after completion of the introduction of the vinyl chloride monomer continuously supplied at the end of the reaction, The polymerization time was shortened and the maximum temperature reached at the end of the reaction was greatly reduced. At the same time, the physical properties of the expansion ratio were not lowered.

Particularly, as shown in Comparative Example 1, since the foaming suppression effect was less than 30 minutes when the liquid compound was added all at once, it was required to perform the batch addition.

Further, as shown in Examples 1 and 2, 500 PPM of the liquid compound is sufficient, and the effect as a defoaming agent is similar when the polymerization time is shortened and the maximum temperature reached the end of the reaction.

On the other hand, as shown in Comparative Example 4, when the excess amount of the liquid compound was added, some liquid compounds remained after the drying process, resulting in lowered foaming properties.

Also, as can be seen from the comparison of Examples 1 and 3 and Comparative Example 5, if the dilution ratio of the liquid compound is too high, the polymerization is delayed at the end of the reaction by cooling, which results in lowering the dilution ratio as much as possible .

Claims (14)

0.0005 to 0.005 part by weight of a total of 8 to 10 carbon atoms of aliphatic alcohol having a viscosity of 10 to 50 cP (at 20 캜) based on 100 parts by weight of a vinyl chloride monomer is added at the time of completing the PVC polymerization during paste PVC polymerization &Lt; / RTI &gt;
The method according to claim 1,
Wherein the aliphatic alcohol is introduced through a reflux condenser provided in a paste PVC polymerization reactor.
delete delete The method according to claim 1,
Wherein the aliphatic alcohol is diluted with water at a weight ratio of 1:10 to 1:50.
The method according to claim 1,
Wherein said step of introducing is carried out three to four times at intervals of 20 to 30 minutes.
The method according to claim 1,
Wherein the unreacted compound in the aliphatic alcohol is removed by evaporation during the drying process of the paste PVC.
The method according to claim 1,
Wherein the paste PVC polymerization is carried out in the presence of 0.001 to 0.01 part by weight of a polymerization initiator and 0.5 to 2.0 parts by weight of an anionic surfactant based on 100 parts by weight of a vinyl chloride monomer, Polymerization method.
9. The method of claim 8,
Examples of the anionic surfactant 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, alkyldisulfonic acid diphenyl oxides An alkali metal salt and an ammonium salt of an alkyldisulfonic acid diphenyl oxide.
9. The method of claim 8,
The vinyl chloride monomer is a mixture of a vinyl chloride monomer alone or a monomer copolymerizable with a vinyl chloride monomer, and the monomer copolymerizable with the vinyl chloride monomer is a vinyl ester, an aromatic vinyl compound, an acrylic acid, a monoolefin, and a vinylidene halide Selected from the group consisting of polypropylene and polypropylene.
9. The method of claim 8,
The polymerization initiator may be selected from the group consisting of dipentyl peroxide, di-3,3,5-trimethylhexanoyl peroxide, dilauryl peroxide, diisopropyl peroxy dicarbonate, di-2-butyl peroxy dicarbonate, Characterized by being at least one selected from the group consisting of azobisisobutyronitrile, azobis-2-methylbutyronitrile, azobis-2,4-dimethylvaleronitrile, potassium persulfate, ammonium persulfate and hydrogen peroxide By weight.
9. The method of claim 8,
Wherein the micro suspension polymerization or the seed emulsion polymerization comprises a homogenization treatment step.
A foamed molded article comprising the paste PVC obtained by the method of claim 1.
14. The method of claim 13,
Wherein the foamed molded article is selected from artificial leather, topsheet, wallpaper, floor coverings, gloves, and carpets.