阅读说明：本技术 用于制备氯乙烯基聚合物的组合物和使用其制备氯乙烯基聚合物的方法 (Composition for preparing vinyl chloride-based polymer and method for preparing vinyl chloride-based polymer using same ) 是由 全亮俊 李贤珉 河玄圭 金健地 李光珍 朱镇爀 朴宰贤 于 2019-10-30 设计创作，主要内容包括：本发明涉及一种用于制备氯乙烯基聚合物的组合物和使用该组合物制备氯乙烯基聚合物的方法,其中,本发明可以提供一种用于制备氯乙烯基聚合物的组合物和使用该组合物制备氯乙烯基聚合物的方法,其中,由于所述用于制备氯乙烯基聚合物的组合物包含由碳酸盐类金属盐组成的pH调节剂和过渡金属催化剂,但是对过渡金属催化剂的量进行控制,并且对还原剂进行控制使得包含痕量的还原剂或不包含还原剂,因此,生产率优异,同时包含制备的氯乙烯基聚合物的增塑溶胶的发泡和粘度性能保持在优异水平。(The present invention relates to a composition for preparing a vinyl chloride-based polymer and a method for preparing a vinyl chloride-based polymer using the same, wherein the present invention can provide a composition for preparing a vinyl chloride-based polymer and a method for preparing a vinyl chloride-based polymer using the same, in which productivity is excellent while foaming and viscosity properties of a plastisol including a prepared vinyl chloride-based polymer are maintained at an excellent level since the composition for preparing a vinyl chloride-based polymer includes a pH adjusting agent consisting of a carbonate-based metal salt and a transition metal catalyst, but the amount of the transition metal catalyst is controlled, and the reducing agent is controlled so as to include a trace amount of the reducing agent or not.)

1. A composition for preparing a vinyl chloride-based polymer, the composition comprising:

a vinyl chloride-based monomer;

a transition metal catalyst, a pH adjusting agent consisting of a carbonate-based metal salt, and a reducing agent in an amount of 0ppm to 150ppm based on the weight of the vinyl chloride-based monomer,

wherein the transition metal catalyst is contained in an amount of 0.01 to 3.0ppm based on the weight of the vinyl chloride-based monomer.

2. The composition for preparing a vinyl chloride-based polymer according to claim 1, wherein the carbonate-based metal salt comprises a metal salt selected from sodium carbonate (Na)₂CO₃) Sodium bicarbonate (NaHCO)₃) Magnesium carbonate (MgCO)₃) Calcium carbonate (CaCO)₃) And potassium carbonate (K)₂CO₃) At least one of (1).

3. The composition for the production of a vinyl chloride-based polymer according to claim 1, wherein the composition for the production of a vinyl chloride-based polymer does not contain a reducing agent.

4. The composition for the production of a vinyl chloride-based polymer according to claim 1, wherein the composition for the production of a vinyl chloride-based polymer does not contain an oxidizing agent.

5. The composition for preparing a vinyl chloride-based polymer according to claim 1, wherein the transition metal catalyst is contained in an amount of 0.01 to 1.2ppm based on the weight of the vinyl chloride-based monomer.

6. The composition for preparing a vinyl chloride-based polymer according to claim 1, wherein the content of the pH-adjusting agent is 50ppm to 1,200ppm based on the weight of the vinyl chloride-based monomer.

7. The composition for preparing a vinyl chloride-based polymer according to claim 1, wherein the transition metal catalyst comprises one or more elements selected from copper sulfate (CuSO)₄) And ferrous sulfate (FeSO)₄) At least one of (1).

8. A method for producing a vinyl chloride-based polymer, comprising the steps of:

step 1, adding 0.01 to 3.0ppm of a transition metal catalyst, a pH adjusting agent consisting of a carbonate-based metal salt, and 0 to 150ppm of a reducing agent based on the weight of a vinyl chloride-based monomer to a polymerization reactor; and

and 2, adding a vinyl chloride-based monomer into the polymerization reactor to carry out polymerization.

9. The method of claim 8, further comprising vacuuming the polymerization reactor prior to step 2.

10. The method of claim 8, wherein the polymerization reactor comprises one or more emulsifiers and a polymerization initiator.

11. The production method according to claim 8, wherein the polymerization is performed by any one method selected from pure emulsion polymerization, seeded emulsion polymerization, and microsuspension polymerization.

Technical Field

Cross Reference to Related Applications

This application claims the benefit of korean patent application No. 10-2018-.

Technical Field

The present invention relates to a composition for preparing a vinyl chloride-based polymer, which can improve foaming properties and viscosity properties as well as productivity of the prepared polymer; and a method for producing a vinyl chloride-based polymer using the composition.

Background

The vinyl chloride-based polymer is a polymer containing 50% or more of a repeating unit derived from Vinyl Chloride Monomer (VCM), and among them, has various applications because of its cheapness, easy control of hardness, and suitability for most processing apparatuses. In addition, since a vinyl chloride-based polymer can provide molded articles having excellent physical and chemical properties such as mechanical strength, weather resistance and chemical resistance, the vinyl chloride-based polymer is being widely used in many fields.

The vinyl chloride-based resin is a general-purpose resin most widely used throughout the world as a living and industrial material, and among them, typically, a linear vinyl chloride-based resin is prepared as powder particles having a size of about 100 to 200 μm by a suspension polymerization method, and a pasty vinyl chloride-based resin is prepared as powder particles having a size of about 0.1 to 2 μm by an emulsion polymerization method.

As for the paste-type vinyl chloride-based resin, a latex obtained by emulsion polymerization is usually dried by a spray drying method to form final resin particles, and the particles are dispersed in a solvent or a plasticizer, and used in products such as flooring materials, wallpaper, tarpaulin, raincoat, glove, automobile undercoating, and carpet tile by methods such as coating (reverse roll coating, blade coating, screen coating, spray coating), gravure printing and screen printing, spin casting, and shell mold casting and dipping.

As described above, since the paste-type vinyl chloride-based resin is a general-purpose plastic widely used in various fields, studies have been made to improve the productivity of the paste-type vinyl chloride-based resin. For example, an oxidation-reduction polymerization (redox polymerization) method has been proposed as one of the methods capable of improving productivity in the production of a vinyl chloride-grade resin in paste form. The redox polymerization can effectively shorten the reaction time by oxidizing and/or reducing metal ions and metals using a mediator, thereby improving productivity, and, in the case where the redox polymerization is particularly used for an emulsion polymerization method in which heat generation is concentrated at the end of the reaction, can obtain a more uniform heat distribution by activating the initial reaction.

However, in the conventional redox polymerization, the amount of metal ions formed from the transition metal catalyst must be large enough to sufficiently increase reactivity, and an oxidizing agent and/or a reducing agent must be added to regenerate the metal ions, but in the case where an oxidizing agent and/or a reducing agent is added in a predetermined amount or more, foaming properties and viscosity properties of the produced vinyl chloride-based resin may deteriorate.

Therefore, there is a need for a composition and a polymerization method for producing a vinyl chloride-based polymer, which can improve reactivity while maintaining foaming properties and viscosity properties of the produced vinyl chloride-based resin at excellent levels.

[ Prior art documents ]

[ patent document ]

(patent document 1) Korean patent application laid-open No.10-2016-

Disclosure of Invention

Technical problem

The present invention is directed to providing a composition for preparing a vinyl chloride-based polymer and a method for preparing a vinyl chloride-based polymer using the same, wherein, since the composition for preparing a vinyl chloride-based polymer includes a transition metal catalyst and a pH adjusting agent, but a carbonate-based metal salt is used as a pH adjusting agent, the amount of the transition metal catalyst can be reduced, polymerization productivity can be improved by including a trace amount of a reducing agent that has been essentially included in the past, or even without including a reducing agent, and foaming properties and viscosity properties of a plastisol including the prepared vinyl chloride-based polymer can be improved to an excellent level.

Technical scheme

According to an aspect of the present invention, there is provided a composition for preparing a vinyl chloride-based polymer, the composition comprising a vinyl chloride-based monomer, a transition metal catalyst, a pH adjusting agent consisting of a carbonate-based metal salt, and a reducing agent in an amount of 0ppm to 150ppm based on the weight of the vinyl chloride-based monomer, wherein the transition metal catalyst is contained in an amount of 0.01ppm to 3.0ppm based on the weight of the vinyl chloride-based monomer.

According to another aspect of the present invention, there is provided a method for preparing a vinyl chloride-based polymer, comprising the steps of: charging a polymerization reactor with 0.01 to 3.0ppm of a transition metal catalyst, a pH adjusting agent consisting of a carbonate-based metal salt, and 0 to 150ppm of a reducing agent, based on the weight of a vinyl chloride-based monomer (step 1); and carrying out polymerization by adding a vinyl chloride-based monomer to the polymerization reactor (step 2).

Advantageous effects

In the present invention, since a carbonate-based metal salt is used as a pH adjuster in an oxidation-reduction polymerization (redox polymerization) system for preparing a vinyl chloride-based polymer, the amount of a transition metal catalyst contained in a composition for preparing a polymer may be significantly reduced, and a reducing agent, which must be contained in a conventional redox polymerization system, may not be contained, or a trace amount of a reducing agent may be contained, whereby productivity may be improved by improving polymerization reactivity while ensuring excellent levels of foaming properties and viscosity properties of a plastisol including the prepared vinyl chloride-based polymer.

Detailed Description

Hereinafter, the present invention will be described in more detail so that the present invention can be more clearly understood.

It should be understood that the words or terms used in the specification and claims should not be construed as meaning defined in commonly used dictionaries. It should also be understood that these words or terms should be interpreted as having meanings consistent with their meanings in the background of the related art and the technical idea of the present invention based on the principle that the inventor can appropriately define the meanings of the words or terms to best explain the present invention.

Definition of terms

The term "polymer" used in the present specification means a high molecular compound prepared by polymerizing monomers, whether they are of the same or different kinds. Thus, the generic term "polymer" refers to a polymer prepared from only one type of monomer, where it includes the commonly used term homopolymer and the term interpolymer as defined below.

The expression "vinyl chloride-based polymer" used in the present specification inclusively denotes a compound formed by polymerizing a vinyl chloride-based monomer, wherein it may refer to a polymer chain derived from the vinyl chloride-based monomer.

The term "plastisol" used in the present specification means a mixture in which a resin and a plasticizer are mixed so that the mixture can be formed, cast or processed into a form of a continuous film by heating, and, for example, may mean a paste form in which a vinyl chloride-based polymer and a plasticizer are mixed.

The term "composition" as used in this specification includes mixtures comprising the respective constituents as well as reaction and decomposition products formed from the respective constituents.

In the present specification, the average particle diameter (D)₅₀) Can be defined as a particle diameter corresponding to 50% of the cumulative number of particles in the particle diameter distribution curve of the particles. For example, average particle diameter (D)₅₀) Laser diffraction methods may be used for measurement. Laser diffraction methods can typically measure particle sizes ranging from the submicron level to several millimeters, and can yield highly reproducible and high resolution results.

1. Composition for producing vinyl chloride-based polymer

An embodiment of the present invention provides a composition for preparing a vinyl chloride-based polymer, comprising a vinyl chloride-based monomer, a transition metal catalyst, a pH adjusting agent consisting of a carbonate-based metal salt, and a reducing agent in an amount of 0ppm to 150ppm based on the weight of the vinyl chloride-based monomer, wherein the transition metal catalyst is contained in an amount of 0.01ppm to 3.0ppm based on the weight of the vinyl chloride-based monomer.

Generally, the composition for preparing a polymer comprises a vinyl chloride-based monomer, a transition metal catalyst, a pH adjusting agent, and an oxidizing agent and/or a reducing agent that can be used in an oxidation-reduction polymerization (redox polymerization) system for preparing a vinyl chloride-based polymer. In this case, since a strongly basic substance such as sodium hydroxide, which is mainly used as a pH adjuster, has a very high pH and is free from carbonate ions, when an excessive amount of the strongly basic substance is added for optimizing pH adjustment, it may be difficult to form a vinyl chloride-based polymer for plastisol processing due to an agglomeration phenomenon, there is a risk of excessive foaming when foam formulation is performed by plastisol processing, and a large amount of volatile organic compounds may be generated. In addition, in the case where a small amount of a strong basic substance is added to stabilize the prepared polymer latex and maintain viscosity and foaming property, it does not contribute to improvement of reactivity, and thus, productivity may be lowered. Further, in the case of using a substance free from carbonate ions as a pH adjustor, since the substance cannot oxidize and/or reduce metal ions formed from transition metals, it is necessary to substantially contain an oxidizing agent and/or a reducing agent to maintain the redox polymerization system.

In this case, the oxidizing agent and/or the reducing agent mainly used for the vinyl chloride-based polymerization process may be a weak acid substance, and if an excessive amount of the weak acid substance is added to sufficiently oxidize or reduce the metal ions, the polymerization is performed under acidic conditions due to a decrease in pH during the polymerization, and thus, the decomposition reaction of the initiator having higher reactivity under low pH conditions may be excessive, thereby causing a problem of runaway of the polymerization reaction and a problem of an increase in the amount of volatile organic compounds of the produced polymer. In the case of producing a polymer under acidic conditions, there arises a problem that the heat resistance of the polymer itself is remarkably deteriorated as the number of defective sites in the produced polymer increases.

In addition, in the case of using an acidic substance such as potassium phosphate as a pH adjuster, since the pH in the polymerization reaction is further lowered, the polymerization is also carried out under acidic conditions, and the same problems as those occurring when an oxidizing agent and/or a reducing agent are added as described above occur.

Therefore, it is desirable to use a carbonate metal salt as a pH adjuster in order to achieve all effects of improvement in viscosity and foaming properties of the produced polymer and plastisol and improvement in polymerization productivity.

Since the carbonate-based metal salt pH adjuster contains carbonate ions, an acidic reducing agent, which must be contained in a conventional composition for preparing a vinyl chloride-based polymer, may not be contained, or a trace amount of an acidic reducing agent may be contained, and since a reduction reaction with metal ions of a transition metal catalyst is smooth, the amount of the transition metal catalyst may be significantly reduced, and thus, deterioration of physical properties, such as increase in viscosity and deterioration of foam color, which may occur due to the inclusion of a large amount of the transition metal catalyst may be prevented. In addition, CO due to carbonate ions generated by reduction reaction of metal ions₃ ^-The radical may decompose the polymerization initiator to further increase the activity of the polymerization initiator and may function to supply electrons to the structural defects of the prepared vinyl chloride-based polymer, and thus, has an effect of improving the structural defects of the polymer, whereby the reactivity of the plastisol and the viscosity and foaming properties may be simultaneously improved.

The composition for preparing a vinyl chloride-based polymer according to an embodiment of the present invention may contain no reducing agent, or may contain less than 150ppm of a reducing agent based on the weight of the vinyl chloride-based monomer, and may preferably contain no reducing agent. In the case where the content of the reducing agent is more than 150ppm in the present invention, since both the carbonate-based metal salt as the pH adjuster and the excessive reducing agent contribute to the reduction reaction, it is difficult to control the polymerization process due to rapid increase of the reaction temperature and the reaction pressure caused by high polymerization reactivity, and therefore, there are problems in that a polymer having desired physical properties cannot be obtained, and in that foam color of plastisol may be deteriorated due to the residual reducing agent component in the prepared polymer.

In addition, the composition for preparing a vinyl chloride-based polymer according to an embodiment of the present invention can sufficiently improve reactivity by using a carbonate-based metal salt even if it does not contain an oxidizing agent as an auxiliary raw material for improving reactivity, and, in the case of containing an oxidizing agent, it is desirable not to contain an oxidizing agent capable of oxidizing metal ions as well as a reducing agent in order to stabilize the polymerization reaction and prevent the viscosity and foam properties of plastisol from deteriorating, since the same problems described in the reducing agent may occur.

The content of the transition metal catalyst according to an embodiment of the present invention may be 0.01 to 3.0ppm, preferably 0.01 to 1.2ppm, and more preferably 0.01 to 0.5ppm, based on the weight of the vinyl chloride-based monomer. The transition metal catalyst is a substance capable of improving reactivity by promoting the activity of an initiator, wherein when the amount of the transition metal catalyst is large, reactivity can be improved even with a relatively small amount of the initiator, but in the case where the transition metal catalyst is excessively contained in an amount of more than 3.0ppm, since it is difficult to control reactivity at the initial stage of polymerization, the number of initially formed polymer particles may greatly increase, and thus, the viscosity of the prepared polymer and plastisol may significantly increase due to the transition metal catalyst component remaining in the polymer, and the foam color of the polymer and plastisol may deteriorate.

In addition, since the pH adjustor consisting of the carbonate-based metal salt is used in the present invention, the present invention has an effect of improving the reactivity to an excellent level even with a small amount of the transition metal catalyst.

According to an embodiment of the present invention, the carbonate-based metal salt is not particularly limited as long as it contains carbonate ion (CO)₃ ^2-) That is, however, in terms of improving reactivity, the carbonate-based metal salt may preferably include one selected from sodium carbonate (Na)₂CO₃) Sodium bicarbonate (NaHCO)₃) Magnesium carbonate (MgCO)₃) Calcium carbonate (CaCO)₃) And potassium carbonate (K)₂CO₃) And may more preferably comprise sodium carbonate, sodium bicarbonate, potassium carbonate, or mixtures thereof.

According to an embodiment of the present invention, the content of the carbonate-based metal salt may be 50ppm to 1,200ppm, preferably 100ppm to 1,000ppm, more preferably 150ppm to 1,000ppm, based on the total weight of the vinyl chloride-based monomer. In the case where the amount of the carbonate-based metal salt is within the above range, since an optimal pH can be obtained during polymerization and a reduction reaction with the transition metal catalyst can be made at an appropriate level, viscosity properties and foam color of the prepared polymer and plastisol can be improved to excellent levels while achieving an effect of improving polymerization productivity.

The transition metal catalyst according to an embodiment of the present invention is not limited as long as it is a transition metal compound used for preparing a vinyl chloride-based polymer, and may specifically include copper sulfate, iron sulfate, or a mixture thereof. The copper sulfate may include copper (I) sulfate (Cu)₂SO₄) Copper (II) sulfate (CuSO)₄) Or mixtures thereof, the iron sulfate may Include Iron (II) sulfate (FeSO)₄) Iron (III) sulfate (Fe)₂(SO₄)₃) Or mixtures thereof.

The vinyl chloride-based polymer prepared by using the composition for preparing a vinyl chloride-based polymer according to an embodiment of the present invention may be not only a polymer composed solely of a vinyl chloride-based monomer but also a copolymer of a vinyl chloride-based monomer as a main component and a vinyl-based monomer copolymerizable with the vinyl chloride-based monomer. When the vinyl chloride-based polymer is a copolymer of a vinyl chloride monomer and a vinyl-based monomer, the content of vinyl chloride in the copolymer may be 50% or more.

Thus, the vinyl chloride-based monomer that may be used according to embodiments of the present invention may be a vinyl chloride monomer; or may be a mixture of vinyl chloride and a vinyl-based monomer copolymerizable with vinyl chloride. The vinyl-based monomer is not particularly limited, but may include: olefin compounds such as ethylene, propylene and butane; vinyl esters such as vinyl acetate, vinyl propionate, and vinyl stearate; unsaturated nitriles such as acrylonitrile; vinyl alkyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl octyl ether and vinyl lauryl ether; halogenated vinylidene groups such as vinylidene chloride; unsaturated fatty acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, and itaconic anhydride, and anhydrides of these fatty acids; unsaturated fatty acid esters such as methyl acrylate, ethyl acrylate, monomethyl maleate, dimethyl maleate and butyl benzyl maleate; and a crosslinkable monomer such as diallyl phthalate, and either one of them or a mixture of two or more of them may be used.

2. Process for producing vinyl chloride-based polymer

The present invention provides a method for producing a vinyl chloride-based polymer, the method comprising a step of polymerizing a vinyl chloride-based monomer by using the above-mentioned composition for producing a vinyl chloride-based polymer.

Specifically, the method for preparing a vinyl chloride-based polymer according to an embodiment of the present invention may include the steps of: charging a polymerization reactor with 0.01 to 3.0ppm of a transition metal catalyst, a pH adjusting agent consisting of a carbonate-based metal salt, and 0 to 150ppm of a reducing agent, based on the weight of a vinyl chloride-based monomer (step 1); and carrying out polymerization by adding a vinyl chloride-based monomer to the polymerization reactor (step 2).

In addition, according to an embodiment of the present invention, the present invention may further include a step of subjecting the polymerization reactor to vacuum treatment before the step 2).

In this case, the polymerization reactor may be a polymerization reactor filled with one or more emulsifiers and a polymerization initiator, and herein, the expression "… -filled polymerization reactor" means that additives such as a polymerization initiator and one or more emulsifiers have been introduced into the polymerization reactor before adding the vinyl chloride-based monomer, that is, it means that the polymerization reactor is a polymerization reactor including one or more emulsifiers and a polymerization initiator.

In addition, according to an embodiment of the present invention, auxiliary raw materials such as a solvent (polymerization water) and a chain transfer agent may be added in addition to the one or more emulsifiers and the polymerization initiator, and the type of substance added as an auxiliary raw material, the polymerization temperature, the type of the polymerization initiator, or the type of the emulsifier may be appropriately selected according to the type of emulsion polymerization described below.

The preparation method of the vinyl chloride-based polymer according to the present invention may be carried out by a polymerization method commonly used in the art, and the polymerization may be carried out, specifically, by pure emulsion polymerization, seeded emulsion polymerization, or microsuspension polymerization.

Hereinafter, the seeded emulsion polymerization, the micro-suspension polymerization and the pure emulsion polymerization will be described, respectively.

Seed emulsion polymerization

In case the polymerization is a seeded emulsion polymerization, the polymerization may comprise the following steps: preparing a vinyl chloride-based polymer seed (step i); and adding the above-mentioned composition for producing a vinyl chloride-based polymer to the polymerization seed and carrying out polymerization (step ii).

That is, according to the present invention, the seeded emulsion polymerization is characterized in that a carbonate-based metal salt is included in the polymerized composition for preparing a polymer of step ii.

Step i

Step i is a step of preparing a vinyl chloride-based polymerization seed in order to increase the binding force of the vinyl chloride-based monomer, provide a bimodal effect to the finally prepared vinyl chloride-based polymer, or realize polymer particles having a monomodal molecular weight distribution larger than that of pure emulsion polymerization.

The polymerization seed is not particularly limited, but may include one type of seed (first seed or second seed) according to the purpose, and may be a seed mixture in which the first seed and the second seed having different average particle diameters are mixed, and in the case of preparing the seed mixture, the seed mixture may be a mixture in which the first seed and the second seed are mixed in an appropriate weight ratio, for example, a mixture in which the first seed and the second seed are mixed in a weight ratio of 1:1 to 3: 1.

Hereinafter, the first seed will be described in detail.

The first seed may be prepared by adding 100 parts by weight of a vinyl chloride-based monomer and 0.1 to 15 parts by weight of a first emulsifier to a reactor filled with a polymerization initiator, homogenizing, and then performing emulsion polymerization at a temperature of 30 to 70 ℃.

The reactor filled with the polymerization initiator may mean a reactor containing a mixed solution containing the polymerization initiator, and the mixed solution may further contain polymerization water, a separate emulsifier, a reaction inhibitor, and a dispersant in addition to the polymerization initiator, but the present invention is not limited thereto.

It is desirable that the polymerization initiator is used in an amount of 0.01 to 2 parts by weight based on 100 parts by weight of the vinyl chloride-based monomer, and the average particle diameter of the finally formed first seed may be adjusted according to the amount of the polymerization initiator used. For example, as the amount of the polymerization initiator used increases, the average particle diameter of the finally formed first seed may decrease.

Average particle diameter (D) of first seed particles₅₀) May be 0.5 μm to 1.0 μm.

The polymerization initiator is not particularly limited, but at least one of a water-soluble initiator and an oil-soluble initiator may be used, and, for example, the polymerization initiator may include at least one oil-soluble polymerization initiator selected from the group consisting of peroxycarbonates, peroxyesters, and azo-based compounds. Specifically, the oil-soluble polymerization initiator may include at least one selected from the group consisting of Lauryl Peroxide (LPO), di-2-ethylhexyl peroxydicarbonate (OPP), diisopropyl peroxydicarbonate, tert-butyl peroxypivalate, tert-butyl peroxyneodecanoate, and 2, 2-azobisisobutyronitrile, and, for example, may include Lauryl Peroxide (LPO), di-2-ethylhexyl peroxydicarbonate (OPP), or a mixture thereof.

The first emulsifier may include at least one selected from the group consisting of sodium lauryl sulfate, lauryl benzene sulfonic acid, alpha-olefin sulfonate, sodium dodecylbenzene sulfonate, sodium lauryl ethoxylated sulfate, sodium stearyl sulfate, sodium lauryl ether sulfate, and linear alkyl benzene sulfonate. Further, the separate emulsifier may be the same as the first emulsifier, or may be included in the first emulsifier.

The reaction inhibitor is not particularly limited, but, for example, para-quinone, hydroquinone, butylated hydroxytoluene, monomethyl ether hydroquinone, 4-butylcatechol, diphenylamine, triisopropanolamine and triethanolamine may be used.

In addition, the dispersant is not particularly limited, but, for example, higher alcohols such as lauryl alcohol, myristyl alcohol, and stearyl alcohol, or higher fatty acids such as lauric acid, myristic acid, palmitic acid, and stearic acid may be used.

The homogenization is not particularly limited, but may be performed by homogenizing at a temperature of 20 ℃ or less, particularly at a temperature of 5 ℃ to 15 ℃ for 1 hour to 3 hours using a homogenizer. In this case, the homogenizer is not particularly limited, but a conventional homogenizer known in the art may be used, for example, a rotor-stator type homogenizer may be used, and the total pressure of the homogenizer during homogenization may be in the range of 1,000psi to 2,000 psi. Further, homogenization may be performed by distributing the polymerization mixture to the front end and the rear end of the homogenizer, as needed.

The emulsion polymerization for preparing the first seed may be performed at a temperature of 30 to 70 ℃ as described above, and specifically, the emulsion polymerization may be initiated by raising the temperature from the homogenization temperature by 40 to 50 ℃, and may be performed by performing the polymerization for 5 to 15 hours.

In addition, as described above, the polymerization seed may include a second seed having an average particle diameter different from that of the first seed, and a seed mixture in which the first seed and the second seed are appropriately mixed may be used according to need.

Hereinafter, the second seed will be described in detail.

A second seed according to an embodiment of the present invention may be prepared by: adding 100 parts by weight of a vinyl chloride-based monomer to a reactor filled with a first emulsifier, and initiating polymerization at a temperature of 30 to 70 ℃; and continuously adding a second emulsifier during the polymerization, and performing emulsion polymerization for 4 to 10 hours.

The reactor filled with the first emulsifier means a reactor containing an emulsion containing the first emulsifier, and the emulsion may contain polymerization water and a polymerization initiator in addition to the first emulsifier.

The first emulsifier may be used in an amount of 0.01 parts by weight to 1 part by weight based on 100 parts by weight of the vinyl chloride-based monomer, and the average particle diameter of the finally formed second seed may be adjusted according to the amount of the first emulsifier. For example, as the amount of the first emulsifier used increases, the average particle size of the finally formed second seed increases.

Average particle diameter (D) of the second seed particles₅₀) May be 0.05 μm to 0.5 μm.

The polymerization initiator may be a water-soluble polymerization initiator, and may specifically include at least one selected from the group consisting of potassium persulfate, ammonium persulfate, and hydrogen peroxide.

The second emulsifier is continuously added to the reactor during the emulsion polymerization, and may be used in an amount of 0.01 to 6 parts by weight, based on 100 parts by weight of the vinyl chloride-based monomer.

The specific type of the first emulsifier is the same as described above, the second emulsifier may be the same as or may be included in the first emulsifier described above, and the first emulsifier and the second emulsifier used in the present invention may refer to different types of substances, or may refer to only the order of addition. Thus, the first emulsifier and the second emulsifier may be the same substance or may be different substances from each other.

Step ii

Step ii is a step of obtaining a vinyl chloride-based polymer by adding the above-described composition for preparing a vinyl chloride-based polymer, which includes a carbonate-based metal salt according to an embodiment of the present invention, to the vinyl chloride-based polymerization seed prepared in step i to perform polymerization.

The polymerization in step ii is not limited, but may be performed by adding a transition metal catalyst, a pH adjusting agent consisting of a carbonate-based metal salt, a reducing agent, and a vinyl chloride-based monomer to a polymerization reactor in which the first seed, the second seed or the seed mixture and polymerization water are mixed and reacting. Further, the first emulsifier may be continuously added before and/or during the polymerization of the composition for preparing a vinyl chloride-based polymer, and the reaction may be carried out by further adding additives such as a polymerization initiator, a chain transfer agent, and an electrolyte during the polymerization.

Alternatively, the polymerization reactor may be subjected to a vacuum treatment prior to the addition of the vinyl chloride-based monomer during the polymerization.

Since the composition for preparing a vinyl chloride-based polymer according to an embodiment of the present invention is used in the seeded emulsion polymerization, the same effects as described above, for example, an increase in productivity and improvement in viscosity properties and foam color of the polymer and plastisol can be achieved, and the detailed description about the addition amounts and types of the carbonate-based metal salt, the transition metal catalyst, and the reducing agent is the same as described above.

Specifically, a transition metal catalyst, a pH adjusting agent consisting of a carbonate-based metal salt, and optionally a reducing agent are added to a polymerization reactor containing 70 to 200 parts by weight of polymerized water and 0.1 to 20 parts by weight of a first seed, a second seed, or a seed mixture containing the first seed and the second seed, based on 100 parts by weight of a vinyl chloride-based monomer, 100 parts by weight of the vinyl chloride-based monomer is added after the polymerization reactor is vacuum-treated, and polymerization can be initiated at a temperature ranging from 30 to 70 ℃. In this case, the amounts of the transition metal catalyst, the pH adjustor consisting of the carbonate-based metal salt and the reducing agent are the same as those in the above-described composition for preparing the vinyl chloride-based polymer. Further, 0.2 to 2.5 parts by weight of the first emulsifier may be continuously added during the reaction or before the vacuum treatment of the reactor based on 100 parts by weight of the vinyl chloride-based monomer, and the reaction may be carried out by further adding additives, for example, 0.1 to 1.5 parts by weight of the polymerization initiator, 0.5 to 2.0 parts by weight of the electrolyte, and 0.1 to 1.0 parts by weight of the chain transfer agent, based on 100 parts by weight of the vinyl chloride-based monomer, as necessary. Further, a dispersant may be included in the polymerization, but the present invention is not limited thereto, and preferably, a dispersant may not be included.

The polymerization initiator is classified into oil-soluble polymerization initiators and water-soluble polymerization initiators, and an appropriate polymerization initiator may be used according to the application and need. The water-soluble polymerization initiator may include at least one selected from the group consisting of potassium persulfate, ammonium persulfate, and hydrogen peroxide, and the oil-soluble polymerization initiator may include at least one selected from the group consisting of peroxycarbonate, peroxyester, and azo-type compound, specific examples of which are the same as those described above.

The chain transfer agent is not particularly limited, but, for example, n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan and t-dodecyl mercaptan may be included.

The electrolyte is not particularly limited, but, for example, may include at least one selected from the group consisting of potassium chloride, sodium chloride, potassium bicarbonate, sodium carbonate, potassium bisulfite, sodium bisulfite, potassium pyrophosphate, tetrasodium pyrophosphate, tripotassium phosphate, trisodium phosphate, dipotassium phosphate, and disodium phosphate.

In addition, the polymerization may include a homogenization process, the homogenization may be performed by the above-described method, and in addition, additives, such as a reaction inhibitor, may be the same as those described above.

Microsuspension polymerization

In the case where the polymerization is microsuspension polymerization, the polymerization may include a step of polymerizing the vinyl chloride-based monomer by adding the composition for preparing a vinyl chloride-based polymer according to an embodiment of the present invention to a polymerization reactor filled with one or more emulsifiers, one or more co-emulsifiers, and polymerization water.

Specifically, the polymerization may be a step of performing microsuspension polymerization at a temperature of 30 ℃ to 70 ℃ after adding a transition metal catalyst, a pH adjusting agent consisting of a carbonate-based metal salt, a reducing agent, and a vinyl chloride-based monomer to a polymerization reactor filled with one or more emulsifiers, one or more co-emulsifiers, and polymerization water.

Alternatively, the polymerization reactor may be subjected to a vacuum treatment prior to the addition of the vinyl chloride-based monomer in the polymerization.

In addition, the time for adding the polymerization initiator in the polymerization is not limited, but, for example, the polymerization initiator may be added before the addition of the vinyl chloride-based monomer, for example, before the vacuum treatment of the polymerization reactor, or the polymerization initiator may be added together with the addition of the vinyl chloride-based monomer.

Similarly, since the above-mentioned composition for producing a vinyl chloride-based polymer is also used in microsuspension polymerization, the same effects as described above, for example, an increase in productivity of the polymer and plastisol and an improvement in viscosity property and foam color, can be achieved, and the detailed description about the addition amounts and types of the carbonate-based metal salt, the transition metal catalyst, and the reducing agent is the same as described above.

The polymerization reactor filled with one or more emulsifiers, one or more co-emulsifiers, and polymerization water means a polymerization reactor containing a mixed solution of one or more emulsifiers, one or more co-emulsifiers, and polymerization water, and the mixed solution may further contain additives, for example, a reaction inhibitor, 0.5 to 2.0 parts by weight of an electrolyte, and 0.1 to 2.0 parts by weight of a chain transfer agent, in addition to the emulsifiers, the co-emulsifiers, and the polymerization water, as needed, but the present invention is not limited thereto. The additives may be the same as those described above. The dispersing agent may be included in the microsuspension polymerization, but the present invention is not limited thereto, and the specific type of the dispersing agent may be the same as those described above.

The emulsifier in the micro suspension polymerization may be added in an amount of 0.1 parts by weight to 5 parts by weight, for example, 0.1 parts by weight to 2.0 parts by weight, based on 100 parts by weight of the vinyl chloride-based monomer, and the type of the emulsifier may be the same as the above-mentioned first emulsifier, or may be included in the first emulsifier.

The co-emulsifier may be added in an amount of 0.1 to 6.0 parts by weight, for example, 0.1 to 3.0 parts by weight, based on 100 parts by weight of the vinyl chloride-based monomer, and the co-emulsifier may include an alcohol compound having 12 to 20 carbon atoms.

The polymerization initiator may be an oil-soluble polymerization initiator, and may be added in an amount of 0.01 parts by weight to 2 parts by weight, based on 100 parts by weight of the vinyl chloride-based monomer, and the specific type of the oil-soluble polymerization initiator may be the same as described above.

In addition, since the particle size in the micro suspension polymerization can be adjusted by the homogenization process, it is desirable to include the homogenization process, and in particular, the homogenization process may be performed in the same manner as described above.

Pure emulsion polymerization

In the case where the polymerization is emulsion polymerization, the polymerization may include a step of polymerizing the vinyl chloride-based monomer by adding the composition for preparing a vinyl chloride-based polymer according to an embodiment of the present invention to a polymerization reactor filled with one or more first emulsifiers and a polymerization initiator.

Specifically, the polymerization may include a step of adding a transition metal catalyst, a pH adjuster composed of a carbonate-based metal salt, a reducing agent, and a vinyl chloride-based monomer to a polymerization reactor including one or more first emulsifiers and a polymerization initiator to perform polymerization, and in this case, the polymerization is performed by performing polymerization at a temperature of 30 ℃ to 70 ℃. In addition, the second emulsifier may be additionally added separately from the first emulsifier during the polymerization, and may be continuously added during the polymerization.

Alternatively, the polymerization reactor may be subjected to a vacuum treatment prior to the addition of the vinyl chloride-based monomer in the polymerization.

Since the above-mentioned composition for preparing a vinyl chloride-based polymer is also used in pure emulsion polymerization, the same effects as described above, for example, the productivity improvement of the polymer and plastisol and the viscosity property and foam color improvement, can be achieved, and the detailed description about the addition amounts and types of the carbonate-based metal salt, the transition metal catalyst and the reducing agent is the same as that described above.

The reactor filled with the first emulsifier and the polymerization initiator means a reactor containing a mixture containing the first emulsifier and the polymerization initiator, and the mixture may further contain additives such as polymerization water, a dispersant, a reaction inhibitor, a chain transfer agent, and an electrolyte, in addition to the first emulsifier and the polymerization initiator.

The first emulsifier may be used in an amount of 0.005 parts by weight to 0.5 parts by weight, based on 100 parts by weight of the vinyl chloride-based monomer, and the type of the first emulsifier is the same as described above.

The polymerization initiator may be a water-soluble polymerization initiator, and may be used in an amount of 0.01 parts by weight to 2.0 parts by weight, based on 100 parts by weight of the vinyl chloride-based monomer, and the water-soluble polymerization initiator may include at least one selected from the group consisting of potassium persulfate, ammonium persulfate, and hydrogen peroxide.

In addition, the second emulsifier is continuously added to the reactor during polymerization, and may be used in an amount of 0.01 to 6 parts by weight, based on 100 parts by weight of the vinyl chloride-based monomer. The second emulsifier may be the same as or may be included in the first emulsifier described above, and the first emulsifier and the second emulsifier used in the present invention may refer to different types of substances or may refer to only the order of addition. Thus, the first emulsifier and the second emulsifier may be the same substance or may be different substances from each other.

In addition, as described above, the polymerization reactor may further contain 70 to 200 parts by weight of polymerization water based on 100 parts by weight of the vinyl chloride-based monomer contained in the composition for preparing a vinyl chloride-based polymer, and furthermore, the reaction may be carried out by further adding additives, for example, 0.5 to 2.0 parts by weight of the electrolyte, 0.1 to 2.0 parts by weight of the chain transfer agent and the reaction inhibitor, based on 100 parts by weight of the vinyl chloride-based monomer contained in the composition for preparing a vinyl chloride-based polymer, as necessary. Here, specific types of the electrolyte, the chain transfer agent, and the reaction inhibitor are the same as those described above.

In addition, in the preparation method according to an embodiment of the present invention, the polymerization may be performed at a pH of 7 to 12, for example, a pH of 9 to 10, and the pH may be obtained according to the use of a pH adjuster containing a carbonate-based metal salt. Therefore, in the case where the polymerization is carried out under an alkaline condition, a stable polymerization reaction can be carried out as described above.

The polymerization carried out according to one embodiment of the present invention may be carried out at a pressure of 3.0kgf/cm in the reactor²To 5.0kgf/cm²Is terminated when it is within the range of (1).

In addition, according to the present invention, a step of drying the prepared vinyl chloride-based polymer may be further included, wherein the drying is not particularly limited in this case but may be performed by a method well known in the art, and the drying may be performed specifically according to a spray drying method. Dehydration and washing steps may also be included prior to drying.

3. Vinyl chloride-based polymer and plastisol

The present invention provides a vinyl chloride-based polymer prepared by the above-described preparation method and a plastisol including a plasticizer.

The vinyl chloride-based polymer according to the present invention is prepared by the above-mentioned preparation method, wherein, since it is a vinyl chloride-based polymer that generates a very small amount of volatile organic compounds, the performance of the polymer can be equal to or superior to that of the conventional vinyl chloride-based polymer.

The vinyl chloride-based polymer according to the present invention may be, for example, a paste-like vinyl chloride-based polymer.

The plastisol according to an embodiment of the present invention may further include 40 to 180 parts by weight, 80 to 160 parts by weight, or 100 to 140 parts by weight of a plasticizer based on 100 parts by weight of the vinyl chloride-based polymer, and may further include additives such as a dispersion diluent, a heat stabilizer, a viscosity modifier, and a foaming agent, as needed.

The expression "plasticizer" in the present invention may refer to an organic additive substance which serves to improve the high-temperature moldability of a thermoplastic resin by being added to the resin to enhance the thermoplasticity.

As the plasticizer and the additive, those known in the art may be used.

Since the plastisol according to the embodiment of the present invention has excellent viscosity characteristics by including the vinyl chloride-based polymer prepared by the above-described preparation method, the plastisol may have excellent processability as well as excellent other properties and foaming properties.

Examples

Hereinafter, the present invention will be described in more detail according to specific embodiments. However, the following examples are provided only to illustrate the present invention, and the scope of the present invention is not limited thereto.

Example 1

100 parts by weight of polymerization water, 0.07 part by weight of an initiator (potassium persulfate), 0.025 part by weight of an emulsifier (sodium lauryl sulfate), 800ppm (based on the weight of vinyl chloride monomer) of sodium carbonate and 0.1ppm (based on the weight of vinyl chloride monomer) of copper sulfate (CuSO)₄) Adding into the mixture with an internal volume of 1m³And a reactor equipped with a stirrer, and the reactor was evacuated while being stirred. 100 parts by weight of vinyl chloride monomer was added to the reactor in a vacuum state, and then the temperature of the reactor was increased to 50 ℃ to initiate polymerization. In this case, after the initiation of polymerization, 1.0 part by weight of an emulsifier (sodium lauryl sulfate) was further continuously added. When the pressure of the reactor reached 3.5kgf/cm²The reaction was terminated at once, and the prepared polymer latex was recovered and then spray-dried to prepare a vinyl chloride polymer.

Example 2

A vinyl chloride polymer was prepared in the same manner as in example 1, except that 0.02ppm of copper sulfate was added based on the weight of vinyl chloride monomer in example 1.

Example 3

Except that in example 1,200ppm of sodium carbonate (Na) was added based on the weight of vinyl chloride monomer₂CO₃) Except that, a vinyl chloride polymer was prepared in the same manner as in example 1.

Example 4

Except that in example 1 sodium bicarbonate (NaHCO) was added₃) A vinyl chloride polymer was prepared in the same manner as in example 1, except that sodium carbonate was replaced.

Example 5

Except that potassium carbonate (K) was added in example 1₂CO₃) A vinyl chloride polymer was prepared in the same manner as in example 1, except that sodium carbonate was replaced.

Example 6

A vinyl chloride polymer was prepared in the same manner as in example 1, except that 100ppm (based on the weight of vinyl chloride monomer) of ascorbic acid was added as a reducing agent when the initial auxiliary raw material was added in example 1.

Example 7

A vinyl chloride polymer was prepared in the same manner as in example 1, except that 1.0ppm of copper sulfate was added based on the weight of vinyl chloride monomer in example 1.

Example 8

1) Seed particle preparation

73kg of polymerization water, 1.21kg of Lauryl Peroxide (LPO) and 0.9g of paraquinone were charged in a 200L high pressure reactor, and the reactor was evacuated to-730 mmHg. 66kg of vinyl chloride monomer and 7.8kg of sodium dodecylbenzenesulfonate were added to the reactor under vacuum, and mixed for 15 minutes with stirring. The internal temperature of the reactor was reduced to 20 ℃ or less, and homogenization was performed using a rotor-stator type homogenizer for 2 hours. After completion of homogenization, polymerization was carried out while setting the internal temperature of the reactor to 42 ℃. After 558 minutes, when the pressure of the reactor reached 3.5kgf/cm²In this case, the reaction was terminated, and unreacted vinyl chloride monomer was recovered and removed to obtain seed particles having an average particle diameter of 0.9. mu.m.

2) Preparation of vinyl chloride polymers

A vinyl chloride polymer was prepared in the same manner as in example 1, except that 0.5 parts by weight of seed particles (average particle diameter: 0.9 μm) were added when the initial auxiliary raw material was added in example 1.

Example 9

A vinyl chloride polymer was prepared in the same manner as in example 1, except that 0.05 parts by weight of an oil-soluble initiator (di- (2-ethylhexyl) peroxydicarbonate) was added instead of the water-soluble initiator (potassium persulfate) in example 1, 1.0 parts by weight of a co-emulsifier (cetostearyl alcohol) was added when the initial auxiliary raw materials were added, and after vinyl chloride monomer was added under vacuum, a homogenizer was operated to perform a homogenization process by distributing a total pressure of 1600psi at the front end and the rear end in a ratio of 50:50, respectively.

Comparative example 1

A vinyl chloride polymer was prepared in the same manner as in example 1, except that sodium hydroxide was added instead of sodium carbonate in example 1.

Comparative example 2

A vinyl chloride polymer was prepared in the same manner as in example 3, except that sodium hydroxide was added instead of sodium carbonate in example 3.

Comparative example 3

A vinyl chloride polymer was prepared in the same manner as in example 1, except that 5ppm of copper sulfate was added based on the weight of vinyl chloride monomer in example 1.

Comparative example 4

A vinyl chloride polymer was prepared in the same manner as in example 3, except that 100ppm of sodium carbonate and 100ppm of sodium hydroxide were added instead of 200ppm of sodium carbonate in example 3.

Comparative example 5

A vinyl chloride polymer was prepared in the same manner as in example 1, except that 200ppm of ascorbic acid was added as a reducing agent based on the weight of vinyl chloride monomer when the initial auxiliary raw materials were added in example 1.

Comparative example 6

A vinyl chloride polymer was prepared in the same manner as in example 3, except that 200ppm of ascorbic acid was added as a reducing agent based on the weight of vinyl chloride monomer when the initial auxiliary raw materials were added in example 3.

Comparative example 7

A vinyl chloride polymer was prepared in the same manner as in example 1, except that sodium carbonate was not added and 200ppm of ascorbic acid was added as a reducing agent based on the weight of vinyl chloride monomer when the initial auxiliary raw material was added in example 1.

Comparative example 8

A vinyl chloride polymer was prepared in the same manner as in example 1, except that sodium carbonate was not added when the initial auxiliary raw material was added, 200ppm of ascorbic acid was added as a reducing agent, based on the weight of vinyl chloride monomer, and 5ppm of copper sulfate was added in example 1.

Experimental example 1

1) Evaluation of reactivity

The degree of improvement in reactivity of the polymerization reaction with respect to the control group was evaluated based on the following indexes by checking reactivity during the production of vinyl chloride polymers in examples and comparative examples, and the results thereof are shown in table 1 below. In this case, as for the polymerization reaction of the control group, the polymerization reaction in the pure emulsion polymerization was performed under the same conditions as in example 1 without adding a transition metal catalyst and a pH adjuster (without using a redox polymerization system).

Very good: very good reactivity

O: good reactivity

And (delta): similar level of polymerization or delayed reaction to control

X: forced termination of the reaction due to runaway reaction or agglomeration

Here, the runaway reaction means a reaction state in which the polymerization reaction is excessively promoted so that the reaction is not controlled, and therefore, the heat release pattern is not uniform, and the amount of generated heat greatly increases, so that the amount of heat discharged is insufficient with respect to the amount of generated heat, thereby abnormally increasing the pressure and temperature in the polymerization process.

2) Volatile weight loss

Volatile weight loss was measured using a spray tester (Horizon-FTS, Thermo Fischer Scientific Inc.) according to DIN 75-201B. After setting the atomization tester (Horizon-FTS, Thermo Fischer Scientific Inc.) to 100 ℃, the weight of the empty foil was measured and recorded. Thereafter, 10g of each of the vinyl chloride polymer samples prepared in examples and comparative examples was weighed in an empty beaker and placed in a cylinder, and a sealing process of covering the top end of the cylinder with an aluminum foil was performed. Thereafter, the cylinder was heated at 100 ℃ for 16 hours, the foil was taken out, the weight of the foil was measured after 4 hours, and the value obtained by subtracting the measured weight of the heat-treated sample from the weight of the initial sample was expressed as a volatile weight loss, and the results thereof are shown in table 1 below. Higher volatile weight loss indicates a greater amount of volatile organic compounds in the polymer produced.

Experimental example 2: physical Properties of plastisol

1) Viscosity of the oil

After 100g of each of the vinyl chloride polymers prepared in examples and comparative examples and 66.7g of diisononyl phthalate (DINP) were mixed at 800rpm for 10 minutes using an EUROSTAR IKA-WERKE mixer to prepare each plastisol, the viscosity was measured using a rheometer (AR2000EX Peltier Plate, TA Instruments) having a parallel Plate jig of 40mm and a gap of 500 μm, and the results thereof are listed in Table 1 below.

2) Foaming Property (foam color)

100g of each of the vinyl chloride polymers prepared in examples and comparative examples, 80g of bis (2-propylheptyl) phthalate (DPHP), 3g of Ba/Zn stabilizer, and 3g of acrylonitrile-based foaming agent were mixed at 800rpm using an EUROSTAR IKA-WERKE mixer for 10 minutes to prepare each plastisol, the prepared plastisols were coated on release paper and coated with a 0.5mm bar, and then a pre-gelled sheet was prepared at 150 ℃ for 45 seconds using a Mathis oven and gelled at 200 ℃ for 90 seconds to prepare a foamed sheet. The whiteness index of the prepared foam sheet was measured according to ASTM E313-73 using a spectrophotometer (CM-700d) and is shown in Table 1 below. The higher the measured white index, the better the thermal stability, and good thermal stability indicates good foaming properties, such as foam color quality.

[ Table 1]

As shown in table 1, for examples 1 to 9 using a carbonate metalloid salt as a pH adjuster according to an embodiment of the present invention and applying a redox polymerization system, and the amounts of a transition metal catalyst and a reducing agent are controlled, it can be confirmed that since reactivity is improved while viscosity and foaming property of plastisol are significantly improved as compared to comparative examples 1 to 8 which are out of the scope of the present invention, productivity is improved, and it can be confirmed that volatile weight loss of polymer is also significantly low.

Specifically, for comparative example 1, which was the same conditions as in example 1, example 4 and example 5 except that a carbonate-based metal salt was not included as a pH adjuster, normal polymer latex could not be obtained because agglomeration of latex occurred during polymerization, and for comparative example 2, which was a pH adjuster in a reduced amount as compared with comparative example 1 to prevent agglomeration of latex, it was confirmed that no reaction improvement effect was exhibited because the reaction was delayed even under the same conditions as in example 3.

In addition, in comparative example 3 in which a carbonate metal salt was used as a pH adjuster, but a transition metal catalyst was excessively added in an amount of more than 3.0ppm, since a runaway reaction occurred, it was confirmed that the reaction was forcibly terminated without any other choice, and the viscosity and foaming properties of the prepared polymer plastisols were also deteriorated as compared to examples 1 to 9. In comparative example 4 in which a carbonate-based metal salt was used as a pH adjuster, but sodium hydroxide was used together instead of the carbonate-based metal salt, it was confirmed that the reaction improvement effect was not obtained and the volatile weight loss was hardly reduced, unlike comparative example 3 in which only a carbonate-based metal salt was used under the same conditions.

In addition, it was confirmed that the viscosity and foaming property of the plastisol were deteriorated or no effect of improving the reactivity was obtained for comparative examples 5 to 8 to which an excessive amount of the reducing agent was added, and particularly, it was confirmed that the amount of the volatile organic compound was high in each polymer because the volatile weight loss was high for comparative examples 7 and 8 which did not contain the carbonate-based metal salt.

Therefore, since the amounts of the transition metal catalyst and the reducing agent were controlled while using the pH adjuster composed of the carbonate-based metal salt, it was confirmed that the reactivity could be improved while improving the viscosity and foaming performance of the plastisol.