KR102564409B1 - A method for preparing vinyl chloride based polymer - Google Patents

Abstract

In the present invention, when preparing a vinyl chloride polymer, a transition metal catalyst and a carbonate-based metal salt are introduced to carry out a redox polymerization reaction, but the timing and amount of the carbonate-based metal salt are adjusted to reduce defective parts in the vinyl chloride-based polymer, thereby reducing heat The present invention relates to a method for producing a vinyl chloride-based polymer having excellent stability and, therefore, excellent productivity while maintaining the foaming and viscosity properties of a plastisol containing the polymer at excellent levels.

Description

Manufacturing method of vinyl chloride polymer {A METHOD FOR PREPARING VINYL CHLORIDE BASED POLYMER}

The present invention relates to a method for producing a vinyl chloride-based polymer capable of improving productivity and significantly reducing defective parts in the polymer to be produced, thereby improving foam and viscosity properties.

Vinyl chloride-based polymer is a polymer containing 50% by weight or more of repeating units derived from vinyl chloride monomer (VCM), and is inexpensive, has easy hardness control, and is applicable to most processing equipment. is diverse. In addition, it is widely used in various fields because it can provide a molded article excellent in physical and chemical properties, such as mechanical strength, weather resistance, and chemical resistance.

On the other hand, vinyl chloride-based resin is a general-purpose resin most widely used worldwide as a living and industrial material. Typically, straight vinyl chloride-based resin is produced by suspension polymerization with powder particles having a size of about 100 to 200 μm, The paste vinyl chloride-based resin is prepared by emulsion polymerization with powder particles having a size of about 0.1 to 2 μm.

In general, paste vinyl chloride-based resin is dried by spray drying latex obtained by emulsion polymerization to form final resin particles, and the particles are dispersed in a solvent or plasticizer to be coated (reverse roll-coating, knife coating, screen coating, Through processes such as spray coating, gravure and screen printing, rotation casting, shell casting and dipping, flooring, wallpaper, tarpaulin, raincoats, gloves, and automobile underbody It is applied to products such as coatings and carpet tiles.

Since the paste vinyl chloride-based resin is a general-purpose plastic widely used in various fields, studies have been conducted to increase the productivity of the paste vinyl chloride-based resin. For example, a redox polymerization method has been proposed as one of the methods for increasing productivity in preparing a paste vinyl chloride-based resin. Oxidation-reduction polymerization could improve productivity by effectively shortening the reaction time by using metal ions and mediators that oxidize and/or reduce metals. By activating it, the heat of polymerization concentrated at the end can be more evenly distributed.

However, only the adoption of the conventional redox polymerization method could partially improve the concentration of polymerization heat concentrated at the end of polymerization, but could not completely solve it. It is not possible to completely solve the problem of low thermal stability due to occurrence of internal defects.

In addition, in the conventional redox polymerization, the content of metal ions formed from the transition metal catalyst must be sufficiently high in order to sufficiently improve the reactivity, and the input of an oxidizing agent and/or a reducing agent to regenerate the metal ions is necessarily required, but the oxidizing agent and/or Alternatively, when a certain amount or more of the reducing agent is added, foaming and viscosity properties of the vinyl chloride-based resin produced may deteriorate.

Therefore, there is a need for a method for preparing a vinyl chloride polymer capable of reducing defects in the produced vinyl chloride polymer and thus simultaneously improving reactivity while maintaining foaming and viscosity properties at excellent levels.

Republic of Korea Patent Publication No. 10-2016-0058567

The present invention has been made to solve the problems of the prior art, and proceeds with a redox polymerization reaction using a carbonate-based metal salt and a transition metal catalyst when preparing a vinyl chloride-based polymer, while controlling the input time and amount of the carbonate-based metal salt As a result, the content of volatile organic compounds in the vinyl chloride-based polymer produced is reduced, and the defective parts in the polymer are reduced, resulting in excellent thermal stability, thereby maintaining the foaming and viscosity properties of the plastisol containing the polymer at an excellent level and improving productivity. It is intended to provide a method for producing this excellent vinyl chloride polymer.

According to one embodiment of the present invention for solving the above problems, in the presence of at least one emulsifier and a polymerization initiator, by introducing a transition metal catalyst to polymerize a vinyl chloride-based monomer (step 1); and adding a carbonate-based metal salt at a polymerization conversion rate of 5 to 67% (step 2).

The present invention improves productivity by improving reactivity during the production of vinyl chloride polymer by using a transition metal catalyst and carbonate-based metal salt, while controlling the input time and selective amount of carbonate-based metal salt. Volatile organic vinyl chloride polymer prepared by It is possible to significantly reduce the content of the compound and greatly reduce the defect part in the polymer to improve thermal stability, and accordingly, it is possible to secure the viscosity and foam properties of the plastisol containing the vinyl chloride-based polymer at an excellent level. there is.

Hereinafter, the present invention will be described in more detail to aid understanding of the present invention.

The terms or words used in the description and claims of the present invention should not be construed as being limited to ordinary or dictionary meanings, and the inventors use the concept of terms appropriately to describe their invention in the best way. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical spirit of the present invention.

Definition of Terms

As used herein, the term "polymer" refers to a polymeric compound prepared by polymerizing monomers, whether of the same or different types. The generic term polymer thus encompasses the term homopolymer, commonly used to refer to a polymer prepared from only one monomer, and the term interpolymer, as defined below.

The term "vinyl chloride-based polymer" used herein encompasses compounds produced by polymerization of vinyl chloride-based monomers, and may mean a polymer chain derived from vinyl chloride-based monomers.

As used herein, the term "plastisol" refers to a mixture of a resin and a plasticizer so that it can be molded, molded, or processed into a continuous film by heating, for example, a mixture of a vinyl chloride-based polymer and a plasticizer. It may represent a paste form.

As used herein, the term “composition” includes mixtures of materials comprising the composition as well as reaction products and decomposition products formed from the materials of the composition.

In the present specification, the average particle diameter (D ₅₀ ) may be defined as a particle diameter corresponding to 50% of the cumulative number in the particle diameter distribution curve of the particles. The average particle diameter (D ₅₀ ) may be measured using, for example, a laser diffraction method. The laser diffraction method is generally capable of measuring particle diameters of several millimeters in the submicron region, and can obtain results with high reproducibility and high resolution.

As used herein, the term "defective portion" refers to a unit generated by an abnormal reaction, unreacted or side reaction between monomers in addition to the repeating unit present in the main chain of the polymer, and refers to a portion containing other unintended functional groups, The functional group at this time may be referred to as a "defect" and may include an unsaturated bond and/or a saturated chloroalkyl.

The present invention includes the step of polymerizing a vinyl chloride-based monomer by introducing a transition metal catalyst in the presence of at least one emulsifier and a polymerization initiator, wherein in the polymerization step, a carbonate-based metal salt at a polymerization conversion rate of 5 to 67% It provides a method for producing a vinyl chloride-based polymer by adding a.

The method for producing the vinyl chloride-based polymer according to an embodiment of the present invention includes the step of polymerizing the vinyl chloride-based monomer by introducing a transition metal catalyst in the presence of at least one emulsifier and a polymerization initiator, and a polymerization reaction in a reactor. Initiating to form a vinyl chloride-based monomer into a vinyl chloride-based polymer.

Specifically, the polymerization includes the steps of injecting additives including at least one emulsifier and a polymerization initiator into a polymerization reactor (step 1); vacuuming the polymerization reactor (step 2); And it may include a step (step 3) of polymerization by introducing a vinyl chloride-based monomer into the polymerization reactor subjected to vacuum treatment.

In the production method according to an embodiment of the present invention, the transition metal catalyst may be added in an amount of 0.01 to 5.0 ppm, preferably 0.01 to 3.0 ppm, and more preferably 0.01 to 5.0 ppm based on the weight of the vinyl chloride monomer. 2.5 ppm can be injected. When a transition metal catalyst that satisfies the above range is introduced, the effect of improving reactivity is excellent, and the thermal stability of the prepared polymer, the viscosity characteristics of plastisol, and foaming properties can be further improved. In addition, in the present invention, since the activity of the transition metal catalyst can be improved by adding the carbonate-based metal salt during polymerization, a very small amount of the transition metal catalyst can be used compared to the amount of the transition metal catalyst in the conventional redox polymerization system. As such, there is an advantage in that reactivity is greatly improved even when a small amount of a transition metal catalyst is added.

According to an embodiment of the present invention, in addition to the one or more emulsifiers and polymerization initiators, additives such as a solvent (polymerization number) and a molecular weight modifier may be further added. The type of and the type of emulsifier may be appropriately selected depending on the type of emulsion polymerization described below.

The method for preparing the vinyl chloride-based polymer according to the present invention may be performed by a polymerization method commonly used in the art, and specifically, polymerization may be performed by pure emulsion polymerization, seed emulsion polymerization, or microsuspension polymerization. .

Hereinafter, seed emulsion polymerization, microsuspension polymerization, and pure emulsion polymerization will be separately described.

seed emulsion polymerization

When the polymerization is seed emulsion polymerization, the polymerization may include preparing a vinyl chloride-based polymerization seed (step a); and adding a transition metal catalyst and a vinyl chloride-based monomer to the polymerization seed to perform polymerization (step b), wherein a carbonate-based metal salt is added at a polymerization conversion rate of 5 to 67% in the polymerization step. it could be

step a

The step a is to increase the binding force of the vinyl chloride monomer, impart a bimodal effect to the finally produced vinyl chloride polymer, or implement larger particles than pure emulsion polymerization in a polymer having a unimodal molecular weight distribution. To this end, it is a step of preparing a vinyl chloride-based polymerization seed.

The polymerization seed is not particularly limited and may include one type of seed (first seed or second seed) as desired, and may be a seed mixture obtained by mixing the first seed and the second seed having different average particle diameters. In the case of preparing a seed mixture, the first seed and the second seed may be mixed in an appropriate weight ratio, specifically, the first seed and the second seed are mixed in a weight ratio of 1: 1 to 3: 1 it could be

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 monomer and 0.1 part by weight to 15 parts by weight of a first emulsifier to a reactor filled with a polymerization initiator, homogenizing the mixture, and then performing emulsion polymerization at a temperature of 30 ° C to 70 ° C. there is.

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

The polymerization initiator may be preferably used in an amount of 0.01 part by weight to 2 parts by weight based on 100 parts by weight of the vinyl chloride monomer, and the average particle diameter of the finally produced first seed may be adjusted according to the amount of the polymerization initiator. . For example, as the amount of the polymerization initiator increases, the average particle diameter of the finally produced first seed may decrease.

The first seed particle may have an average particle diameter (D50) of 0.5 μm to 1.0 μm.

The polymerization initiator is not particularly limited, and any one or more of a water-soluble initiator and an oil-soluble initiator may be used, and for example, one or more oil-soluble polymerization initiators selected from the group consisting of peroxy carbonates, peroxy esters, and azo-based compounds may be used. . Specifically, the oil-soluble polymerization initiator is lauryl peroxide (LPO), di-2-ethylhexyl peroxycarbonate (OPP), diisopropyl peroxy dicarbonate, t-butyl peroxypivalate, t-butyl peroxy It may be one or more selected from the group consisting of neodecanoate and 2,2-azobisisobutyronitrile, for example, lauryl peroxide (LPO), di-2-ethylhexyl peroxycarbonate (OPP) or mixtures thereof.

The first emulsifier is sodium lauryl sulfate, lauryl benzene sulfonic acid, alpha-olefin sulfonate, sodium dodecyl benzene sulfonate, sodium lauryl ethoxylated sulfate, sodium octadecyl sulfate, sodium lauryl ether sulfate and straight chain It may be at least one selected from the group consisting of alkylbenzene sulfonic acid salts. In addition, the additional emulsifier may be the same as or included in the first emulsifier.

The reaction inhibitor is not particularly limited, but for example, paraquinone, hydroquinone, butylated hydroxy toluene, monomethyl ether hydroquinone, quaternary butyl catechol, diphenyl amine, triisopropanol amine, triethanol amine etc. can be used.

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

The homogenization is not particularly limited, but may be performed by homogenizing for 1 hour to 3 hours using a homogenizer at a temperature of 20 ° C or less, preferably 5 ° C to 15 ° C. At this time, the homogenizer is not particularly limited and a common one 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 the homogenization process may be 1000 psi to 2000 psi. . In addition, if necessary, homogenization may be performed by distributing the polymerization mixture to the front and rear ends of the homogenizer.

Emulsion polymerization for preparing the first seed may be carried out at a temperature of 30 ° C to 70 ° C as described above, and specifically, the emulsion polymerization is started by raising the temperature to 40 ° C to 50 ° C from the homogenization temperature and initiating 5 hours It may be carried out by proceeding emulsion polymerization for 15 hours.

In addition, as described above, the polymerization seed may include a second seed having a different average particle diameter from the first seed, and if necessary, a seed mixture in which the first seed and the second seed are properly mixed may be used. there is.

Hereinafter, the second seed will be described in detail.

The second seed according to an embodiment of the present invention is prepared by adding 100 parts by weight of a vinyl chloride monomer to a reactor filled with a first emulsifier and initiating polymerization at a temperature of 30 ° C to 70 ° C; 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 represents a reactor containing an emulsion containing the first emulsifier, and the emulsion may include polymerization water, a polymerization initiator, and the like in addition to the first emulsifier.

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

The second seed particle may have an average particle diameter (D50) of 0.05 μm to 0.5 μm.

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

The second emulsifier is continuously introduced into the reactor during 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 monomer.

The specific type of the first emulsifier is as described above, the second emulsifier may be the same as or included in the first emulsifier described above, and the first emulsifier and the second emulsifier used in the present invention are of different types. It may mean a substance, or it may mean just the order of input. Accordingly, the first emulsifier and the second emulsifier may be the same material or different materials.

step b

Step b is a step in which a transition metal catalyst and a vinyl chloride monomer are added to the vinyl chloride polymerization seed prepared in step a, and polymerization is initiated to proceed with polymerization in order to obtain a vinyl chloride polymer.

The polymerization of step b is not limited thereto, but may be performed by introducing a transition metal catalyst and a vinyl chloride-based monomer into a polymerization reactor in which the first seed, the second seed or the seed mixture and the polymerization water are mixed and then reacting. In addition, a first emulsifier may be further added to the polymerization reactor, and at this time, the first emulsifier may be continuously added before the vinyl chloride monomer and/or during the polymerization. The reaction may proceed by additionally introducing additives such as a molecular weight regulator and an electrolyte.

In addition, the polymerization reactor may be vacuum treated before introducing the vinyl chloride monomer in the polymerization.

Specifically, the polymerization is performed by adding 70 parts by weight to 200 parts by weight of polymerization water and 0.1 part by weight to 20 parts by weight of a seed mixture including the first seed, the second seed, or the first seed and the second seed, based on 100 parts by weight of the vinyl chloride monomer. A transition metal catalyst is added to a polymerization reactor containing parts by weight, the polymerization reactor is vacuum-treated, 100 parts by weight of a vinyl chloride monomer is added, and polymerization may be initiated at a temperature range of 30°C to 70°C. At this time, the input amount of the transition metal catalyst is the same as described above. In addition, 0.2 to 2.5 parts by weight of the first emulsifier may be continuously added to 100 parts by weight of the vinyl chloride monomer during the reaction or before the vacuum treatment of the reactor, and if necessary, 100 parts by weight of the vinyl chloride monomer 0.1 to 1.5 parts by weight of a polymerization initiator, 0.5 to 2.0 parts by weight of an electrolyte, and 0.1 to 1.0 parts by weight of an additive such as a molecular weight regulator may be additionally added to proceed with the reaction. In addition, a dispersing agent may be included in the polymerization, but is not limited thereto, and preferably may not include a dispersing agent.

The polymerization initiator is divided into an oil-soluble polymerization initiator and a water-soluble polymerization initiator, and an appropriate polymerization initiator may be used depending on the purpose and need. The water-soluble polymerization initiator may be one or more selected from the group consisting of potassium persulfate, ammonium persulfate, and hydrogen peroxide, and the oil-soluble polymerization initiator may be one selected from the group consisting of peroxy carbonates, peroxy esters, and azo-based compounds. It may be more than that, and specific examples are the same as those described above.

The vinyl chloride-based polymer according to an embodiment of the present invention may be not only a polymer composed of a vinyl chloride monomer but also a copolymer of a vinyl chloride monomer and a vinyl-based monomer copolymerizable with the vinyl chloride monomer. In this case, when the vinyl chloride-based polymer is a copolymer of a vinyl chloride monomer and a vinyl-based monomer, 50% or more of vinyl chloride may be contained in the copolymer.

Accordingly, the vinyl chloride-based monomer usable according to an embodiment of the present invention may be a single vinyl chloride material; Alternatively, it may be a mixture of vinyl chloride and a vinyl-based monomer copolymerizable with the vinyl chloride. The vinyl monomer is not particularly limited, but olefin compounds such as ethylene, propylene, and butene, vinyl esters such as vinyl acetate, vinyl propionate, and vinyl stearate, and unsaturated nitriles such as acrylonitrile vinyl alkyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl octyl ether, and vinyl lauryl ether, vinylidene halogens such as vinylidene chloride, acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid , unsaturated fatty acids such as 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 butylbenzyl maleate, cross-linking of diallyl phthalate, etc. and the like, and any one or a mixture of two or more of these may be used.

The molecular weight modifier is not particularly limited, but may be, for example, n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, or the like.

The electrolyte is, for example, potassium chloride, sodium chloride, potassium bicarbonate, sodium carbonate, potassium carbonate, potassium hydrogen sulfite, sodium hydrogen sulfite, tetrapotassium pyrophosphate, tetrasodium pyrophosphate, tripotassium phosphate, trisodium phosphate, dipotassium hydrogen phosphate and disodium hydrogen phosphate. It may be one or more selected from the group consisting of, but the electrolyte is not particularly limited, but for example, potassium chloride, sodium chloride, potassium bicarbonate, sodium carbonate, potassium carbonate, potassium hydrogen sulfite, sodium hydrogen sulfite, tetrapotassium pyrophosphate, tetrasodium pyrophosphate , tripotassium phosphate, trisodium phosphate, dipotassium hydrogen phosphate and disodium hydrogen phosphate may be at least one selected from the group consisting of.

In addition, the polymerization may include a homogenization process, homogenization may be performed through the method described above, and additives such as reaction inhibitors may be as described above.

microsuspension polymerization

When the polymerization is microsuspension polymerization, the polymerization step is performed by introducing a transition metal catalyst and a vinyl chloride-based monomer into a polymerization reactor filled with one or more emulsifiers, one or more auxiliary emulsifiers, and polymerization water, and then homogenizing them, followed by homogenization at 30 ° C. It may be a step of performing microsuspension polymerization at a temperature of 70 ° C., and in the polymerization step, a carbonate-based metal salt may be added at a time when the polymerization conversion rate is 5 to 67%.

In addition, in the polymerization, the inside of the polymerization reactor may be vacuum-treated before introducing the vinyl chloride monomer.

In addition, in the polymerization, the polymerization initiator is not limited at the time of addition, and for example, it may be added before adding the vinyl chloride monomer, specifically before vacuuming the inside of the polymerization reactor, or while adding the vinyl chloride monomer. A polymerization initiator may be added together.

A reactor filled with at least one emulsifier, at least one auxiliary emulsifier, and polymerization water represents a reactor containing a mixed solution containing at least one emulsifier, at least one auxiliary emulsifier, and polymerization water, and the mixed solution is an emulsifier and a auxiliary emulsifier. and additives such as a reaction inhibitor, 0.5 parts by weight to 2.0 parts by weight of an electrolyte, and 0.1 parts by weight to 2.0 parts by weight of a molecular weight modifier, if necessary, in addition to polymerization water, but are not limited thereto. The additives may be those described above. In the microsuspension polymerization, a dispersing agent may be included, but is not limited thereto, and specific types of the dispersing agent are as described above.

In the microsuspension polymerization, the emulsifier may be added in an amount of 0.1 part by weight to 5 parts by weight, preferably 0.1 part by weight to 2.0 parts by weight, based on 100 parts by weight of the vinyl chloride monomer. 1 may be the same as or included as an emulsifier.

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

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

In addition, since the microsuspension polymerization can control the particle size by going through a homogenization process, it is preferable to include a homogenization process, and specifically, the homogenization process can be performed in the same way as the above-mentioned method.

pure emulsion polymerization

When the polymerization is (pure) emulsion polymerization, the polymerization step is to introduce a transition metal catalyst and a vinyl chloride monomer into a polymerization reactor filled with at least one first emulsifier and a polymerization initiator, and react at a temperature of 30 ° C to 70 ° C. It may be a step of performing polymerization, and in the polymerization step, a carbonate-based metal salt may be added at a time when the polymerization conversion rate is 5 to 67%.

In addition, during polymerization, a second emulsifier may be additionally added separately from the first emulsifier, and the second emulsifier may be continuously added during polymerization.

The reactor filled with the first emulsifier and the polymerization initiator represents a reactor containing a mixture including the first emulsifier and the polymerization initiator, that is, the polymerization reactor includes at least one emulsifier and a polymerization initiator. In addition, the mixture may further include additives such as polymerization water, a dispersant, a reaction inhibitor, a molecular weight modifier, 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 to 0.5 parts by weight based on 100 parts by weight of the vinyl chloride monomer, and the type of the first emulsifier is as described above.

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

In addition, the second emulsifier is continuously introduced into the reactor during the polymerization, and may be used in an amount of 0.01 part by weight to 6 parts by weight based on 100 parts by weight of the vinyl chloride monomer. The second emulsifier may be the same as or included in the first emulsifier described above, and the first emulsifier and the second emulsifier used in the present invention may mean materials of different types, and only the order of addition it could mean Accordingly, the first emulsifier and the second emulsifier may be the same material or different materials.

In addition, as described above, the polymerization reactor may further include 70 to 200 parts by weight of polymerization water based on 100 parts by weight of the vinyl chloride monomer, and if necessary, 0.5 to 200 parts by weight based on 100 parts by weight of the vinyl chloride monomer. Additives such as 2.0 parts by weight of an electrolyte, 0.1 to 2.0 parts by weight of a molecular weight modifier, and a reaction inhibitor may be further added to proceed with the reaction. Here, the specific types of electrolyte, molecular weight modifier, reaction inhibitor, etc. are as described above.

In the method for producing the vinyl chloride-based polymer according to an embodiment of the present invention, in the polymerization step, a carbonate-based metal salt may be added at a polymerization conversion rate of 5 to 67%, and a carbonate-based agent acting as a pH adjusting agent By adding a specific amount of metal salt during polymerization, basic conditions suitable for polymerization are formed to prevent reaction runaway and stabilize the polymerization reaction. It is possible to improve structural instability and thermal stability of a polymer having a polymer, thereby reducing the amount of volatile organic compounds generated, and improving the viscosity and foam properties of plastisol.

In general, in a redox polymerization system that can be applied when preparing a vinyl chloride polymer, polymerization is performed by mixing a vinyl chloride monomer, a transition metal catalyst, a pH adjusting agent, an oxidizing agent, and/or a reducing agent. At this time, strong basic substances such as sodium hydroxide, which is mainly used as a pH adjusting agent, has a very high pH and does not contain carbonate ions, so when an excessive amount is added for optimum pH control, the vinyl chloride polymer for plastisol processing is damaged due to aggregation. It may be difficult to form, and problems such as over-foaming may occur when foaming prescription is applied through plastisol processing, and a large amount of volatile organic compounds may occur. In addition, when a small amount of a strong base material is added to stabilize the prepared polymer latex and to maintain viscosity and foam properties, it does not help to improve reactivity, resulting in poor productivity. In addition, when a material without carbonate ions is used as a pH adjusting agent, since metal ions formed from transition metals cannot be oxidized and/or reduced, an oxidizing agent and/or reducing agent must be included in order to sustain the redox polymerization system. there is a problem.

At this time, the oxidizing agent and / or reducing agent mainly used in the vinyl chloride polymerization process may be a substance of a weak acid, and when an excessive amount of the substance of the weak acid is added in an amount sufficient to oxidize or reduce the metal ion, the pH during polymerization Since the polymerization is performed under acidic conditions by lowering the pH, the decomposition reaction of the initiator having greater reactivity is excessive under low pH conditions, causing runaway polymerization and increasing the content of volatile organic compounds in the produced polymer. In addition, when the polymer is produced under acidic conditions, as the number of defect sites in the polymer produced increases, the heat resistance of the polymer itself may be greatly deteriorated.

In addition, when an acidic substance such as potassium phosphate is applied as a pH adjusting agent, the pH in the polymerization reaction is further lowered so that polymerization can be performed under acidic conditions, so the same problem as when an oxidizing agent and/or a reducing agent is added as described above occurs. can happen

Therefore, it is preferable to add a carbonate-based metal salt in the polymerization step in order to realize both the improvement of viscosity and foam properties of the polymer and plastisol to be produced and the effect of increasing polymerization productivity.

Since the carbonate-based metal salt contains carbonate ions, it does not contain or may contain a small amount of an acidic reducing agent that is essentially used in conventional redox polymerization systems, and as the metal ion and reduction reaction of the transition metal catalyst are smoothly performed, It is possible to significantly reduce the content of the transition metal catalyst, thereby preventing deterioration in 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, and also carbonate produced by the reduction reaction of metal ions Since the CO ₃ ^- radical of the ion decomposes the polymerization initiator, it further enhances the activity of the polymerization initiator and can play a role in donating electrons to the structurally defective part of the vinyl chloride-based polymer produced, which is also effective in improving the structural defect of the polymer. It is possible to simultaneously improve reactivity and foam properties and viscosity properties of plastisol.

In other words, according to one embodiment of the present invention, even when a redox polymerization system is applied using a carbonate-based metal salt (pH adjuster) and a transition metal catalyst, productivity is improved without introducing an oxidizing agent and a reducing agent unlike the prior art. There are advantages that can be greatly improved.

In addition, in the production method according to an embodiment of the present invention, polymerization may be performed under conditions of pH 7 to 12, preferably pH 9 to 10, which may be expressed by using a carbonate-based metal salt. When polymerization is performed under basic conditions that satisfy the above pH, a stable polymerization reaction can be achieved as described above.

According to one embodiment of the present invention, the carbonate-based metal salt is not limited as long as it contains carbonate ions (CO ₃ ^2- ), but preferably sodium carbonate (Na ₂ CO ₃ ), sodium hydrogen carbonate (NaHCO ₃ ), magnesium carbonate (MgCO ₃ ), calcium carbonate (CaCO ₃ ) and potassium carbonate (K ₂ CO ₃ ). or mixtures thereof.

In addition, according to one embodiment of the present invention, the carbonate-based metal salt can be added when the polymerization conversion rate is 5 to 67%, preferably 40 to 67%, more preferably 45 to 65% may be invested in. When the carbonate-based metal salt is added at a time when the polymerization conversion rate is less than 5%, the decomposition reaction of the initiator may be inhibited at the initial reaction initiation stage, and reactivity may not be improved. In the case of polymerization, it is difficult to control the reactivity in the early and middle stages of polymerization as the basic pH conditions that can carry out stable polymerization reactions are formed late, and the concentration of polymerization heat cannot be prevented. Since the effect of reducing the occurrence of structural defects cannot be secured, the thermal stability of the prepared polymer may be poor and the volatile organic compound in the polymer cannot be reduced. The foam color may also cause a problem of deterioration.

In addition, the method of adding the carbonate-based metal salt is not limited, and batch input, continuous input or divided input methods may be applied, and even when the batch input method is applied, the desired effect in the present invention can be sufficiently expressed. In terms of improving the structural stability of the produced polymer and the foam properties of the plastisol, a continuous or divided injection method is preferred.

According to one embodiment of the present invention, the carbonate-based metal salt may be added in an amount of 0.03 to 0.30 parts by weight, preferably 0.03 to 0.20 parts by weight, more preferably 0.05 to 0.15 parts by weight, based on 100 parts by weight of the vinyl chloride monomer. can be put in When the carbonate-based metal salt is added in an amount of less than 0.03 parts by weight, it is difficult to reduce the proportion of defective parts in the polymer produced due to the small amount added, and thus, the thermal stability of the polymer may deteriorate, and the amount of the carbonate-based metal salt in excess of 0.30 parts by weight When the basic material is added in an excessive amount and the reaction pH is increased, the decomposition of the polymerization initiator is inhibited and the reactivity is lowered, and furthermore, the effect of reducing structural defects in the polymer is lowered, so the foaming color deteriorates. .

The transition metal catalyst according to an embodiment of the present invention is not limited as long as it is a transition metal compound applied to the production of a vinyl chloride-based polymer, and specifically includes copper sulfate (CuSO ₄ ), iron sulfate (FeSO ₄ ) or a mixture thereof. can do.

The polymerization performed according to an embodiment of the present invention may be terminated when the pressure in the reactor reaches 3.0 to 5.0 kgf/cm ² .

In addition, according to the present invention, a step of drying the prepared vinyl chloride-based polymer may be further included, at which time the drying is not particularly limited and may be performed by a method commonly known in the art, specifically It can be carried out according to the spray drying method. Prior to the drying, dehydration and washing steps may be further included.

The present invention provides a plastisol comprising a vinyl chloride-based polymer and a plasticizer prepared by the above production method.

The vinyl chloride-based polymer according to the present invention is produced by the above manufacturing method, and has a significantly low ratio of structural defects in the polymer and a very small amount of volatile organic compounds. It may be at a level equal to or higher than the comparison.

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

The present invention provides a plastisol comprising a vinyl chloride-based polymer and a plasticizer prepared by the above production method.

The plastisol according to an embodiment of the present invention may further include 40 parts by weight to 180 parts by weight, or 80 parts by weight 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 polymer. And, if necessary, additives such as a dispersion diluent, a heat stabilizer, a viscosity modifier, and a foaming agent may be further included.

In the present invention, "plasticizer" may refer to an organic additive material that serves to improve molding processability at a high temperature by adding to a thermoplastic resin to increase thermoplasticity.

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

The plastisol according to an embodiment of the present invention includes the vinyl chloride-based polymer prepared by the above manufacturing method, and thus has excellent viscosity characteristics, excellent processability, and other performance characteristics and foaming characteristics.

Example

Hereinafter, the present invention will be described in more detail by examples. However, the following examples are intended to illustrate the present invention, and the scope of the present invention is not limited only to these examples.

Example 1

100 parts by weight of polymerized water, 0.07 parts by weight of initiator (Potassium persulfate), 0.025 parts by weight of sodium lauryl sulfate, and 2 ppm of copper sulfate (CuSO ₄ ) based on the weight of vinyl chloride monomer were added to a high-pressure reactor, and a vacuum was applied to the reactor while stirring. walked After adding 100 parts by weight of vinyl chloride monomer to a reactor in a vacuum state, the temperature of the reactor was raised to 56° C. to initiate polymerization. At this time, after the polymerization was initiated, 1.0 parts by weight of sodium lauryl sulfate was continuously added to the reactor during the polymerization time, while 0.05 parts by weight of sodium carbonate (Na ₂ CO ₃ ) was added at a polymerization conversion rate of 10%. When the internal pressure of the reactor reached 3.5 kgf/cm ² , the reaction was terminated, and the prepared polymer latex was recovered and 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 0.08 parts by weight of sodium carbonate (Na ₂ CO ₃ ) was added in Example 1.

Example 3

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that 0.08 parts by weight of sodium carbonate (Na ₂ CO ₃ ) was added at a polymerization conversion rate of 50% in Example 1.

Example 4

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that 0.08 parts by weight of sodium carbonate (Na ₂ CO ₃ ) was added at a polymerization conversion rate of 65% in Example 1.

Example 5

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that 0.05 part by weight of sodium bicarbonate (NaHCO ₃ ) was added at a polymerization conversion rate of 10% instead of sodium carbonate in Example 1.

Example 6

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that 0.15 parts by weight of sodium bicarbonate (NaHCO ₃ ) was added at a polymerization conversion rate of 65% instead of sodium carbonate in Example 1.

Example 7

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that 0.08 parts by weight of potassium carbonate (K ₂ CO ₃ ) was added at a polymerization conversion rate of 65% instead of sodium carbonate in Example 1.

Example 8

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that 0.11 parts by weight of sodium carbonate was added at a polymerization conversion rate of 65% in Example 1.

Example 9

In Example 1, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that 0.03 parts by weight of sodium carbonate was added twice at a polymerization conversion rate of 10% and 0.08 parts by weight at a polymerization conversion rate of 65%. did

Example 10

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that a total of 0.08 parts by weight of sodium carbonate was continuously added for 1 hour from the point at which the polymerization conversion rate was 50% in Example 1.

Example 11

1) Preparation of seed particles

73 kg of polymerized water, 1.21 kg of lauryl peroxide (LPO), and 0.9 g of paraquinone were put into a 200 ℓ high-pressure reactor, and a vacuum was applied at -730 mmHg. 66 kg of vinyl chloride monomer and 7.8 kg of sodium dodecyl benzene sulfonate were added to a reactor under vacuum, and mixed by stirring for 15 minutes. The internal temperature of the reactor was lowered to 20° C. or less and homogenization was performed for 2 hours using a rotor-stator type homogenizer. After homogenization was completed, polymerization was performed by adjusting the internal temperature of the reactor to 42 ° C. After 558 minutes, when the pressure in the reactor reached 3.5 kg/cm ² , the reaction was terminated, and unreacted vinyl chloride monomer was recovered and removed, and the average particle diameter was 0.9 Seed particles of μm were obtained.

2) Production of vinyl chloride polymer

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

Example 12

In Example 1, 0.05 parts by weight of an oil-soluble initiator (di-(2-ethylhexyl) peroxydicarbonate) was added instead of the water-soluble initiator (Potassium persulfate), and 1.0 parts by weight of an auxiliary emulsifier (Cetostearyl Alcohol) was added when the initial additives were added. In addition, vinyl chloride in the same manner as in Example 1, except for the homogenization process in which a total pressure of 1600 psi is distributed to the homogenizer at a ratio of 50:50 to the front and rear ends, respectively, after the addition of vinyl chloride monomer under vacuum conditions. based polymer was prepared.

Example 13

In Example 1, 0.25 parts by weight of sodium carbonate (Na ₂ CO ₃ ) was added at a polymerization conversion rate of 65%, and copper sulfate was added in an amount of 1 ppm based on the weight of vinyl chloride monomer. A vinyl polymer was prepared.

Comparative Example 1

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that sodium carbonate and copper sulfate were not added in Example 1.

Comparative Example 2

A vinyl chloride-based polymer was prepared in the same manner as in Example 1, except that 0.08 parts by weight of sodium hydroxide (NaOH) was added instead of sodium carbonate in Example 1 when the initial auxiliary material was added.

Comparative Example 3

A vinyl chloride-based polymer was prepared in the same manner as in Example 1, except that 0.02 parts by weight of sodium hydroxide (NaOH) was added instead of sodium carbonate in Example 1 when the initial auxiliary material was added.

Comparative Example 4

A vinyl chloride-based polymer was prepared in the same manner as in Example 1, except that 0.08 parts by weight of sodium hydroxide (NaOH) was added at a polymerization conversion rate of 50% instead of sodium carbonate in Example 1.

Comparative Example 5

A vinyl chloride-based polymer was prepared in the same manner as in Example 1, except that 0.08 parts by weight of sodium carbonate was added in Example 1 and copper sulfate was not added.

Comparative Example 6

A vinyl chloride-based polymer was prepared in the same manner as in Example 1, except that 0.08 parts by weight of sodium carbonate was added in the initial auxiliary material in Example 1.

Comparative Example 7

A vinyl chloride-based polymer was prepared in the same manner as in Example 1, except that 0.08 parts by weight of sodium carbonate was added at a polymerization conversion rate of 70% in Example 1.

Comparative Example 8

A vinyl chloride-based polymer was prepared in the same manner as in Example 1, except that 0.08 parts by weight of sodium carbonate was added immediately after the polymerization was completed (when the conversion rate was about 90%).

Comparative Example 9

A vinyl chloride-based polymer was prepared in the same manner as in Example 1, except that 0.35 parts by weight of sodium carbonate was added at a polymerization conversion rate of 50% in Example 1.

Table 1 below is a table showing input conditions of the carbonate-based metal salt (pH adjuster) and the transition metal catalyst (copper sulfate) of the Examples and Comparative Examples.

division Carbonate-based metal salt CuSO ₄ input
(ppm) type input
(parts by weight) Input point
(conversion rate, %) Example 1 Na ₂ CO ₃ 0.05 10 2 Example 2 Na ₂ CO ₃ 0.08 10 2 Example 3 Na ₂ CO ₃ 0.08 50 2 Example 4 Na ₂ CO ₃ 0.08 65 2 Example 5 NaHC0 ₃ 0.05 10 2 Example 6 NaHC0 ₃ 0.15 65 2 Example 7 K ₂ CO ₃ 0.08 65 2 Example 8 Na ₂ CO ₃ 0.11 65 2 Example 9 Na ₂ CO ₃ 0.03+0.08 10+65 2 Example 10 Na ₂ CO ₃ 0.08 50 (1 hour input) 2 Example 11 Na ₂ CO ₃ 0.05 10 2 Example 12 Na ₂ CO ₃ 0.05 10 2 Example 13 Na ₂ CO ₃ 0.25 65 One Comparative Example 1 - - - - Comparative Example 2 NaOH 0.08 0 2 Comparative Example 3 NaOH 0.02 0 2 Comparative Example 4 NaOH 0.08 50 2 Comparative Example 5 Na ₂ CO ₃ 0.08 65 - Comparative Example 6 Na ₂ CO ₃ 0.08 0 2 Comparative Example 7 Na ₂ CO ₃ 0.08 70 2 Comparative Example 8 Na ₂ CO ₃ 0.08 90 2 Comparative Example 9 Na ₂ CO ₃ 0.35 50 2

Experimental Example 1

1) Reactivity evaluation

Reactivity was confirmed during the preparation of the vinyl chloride polymer prepared in the above Examples and Comparative Examples, and the degree of improvement in reactivity was evaluated based on the following indexes compared to the reaction time of Comparative Example 1, and the results are shown in Table 2 below.

◎: Very good reactivity

○: excellent reactivity

△: Similar level or reaction delay to Comparative Example 1

X: Aggregation

2) Degree of defects in the polymer

Using an analyzer Bruker Avance III HD 700Mhz NMR, the vinyl chloride polymer samples prepared in Examples and Comparative Examples were dissolved in tetrahydrofuran solvent (THF-d8), and then the NMR 1H spectrum was measured at room temperature, and the PVC defect The content was scanned more than 1,000 times, calculated based on the integral of the 1H NMR spectrum, and measured in terms of the number of total double bonds per 1,000 vinyl chloride units in the polymer. . The lower the defectivity measurement index value, the smaller the percentage of defective parts in the polymer.

3) Volatilization reduction

It was measured using a fogging tester (Horizon-FTS, Thermo Fisher Scientific Co.) according to DIN 75-201B. After setting the fogging tester (Horizon-FTS, Thermo Fisher Scientific) to 100 ° C, weigh the empty foil and record it. Thereafter, 10 g of each vinyl chloride polymer sample prepared in Examples and Comparative Examples is improved in an empty beaker, put into a cylinder, and a sealing process of covering the top of the cylinder with aluminum foil is performed. After heating at 100 ° C. for 16 hours, the foil was taken out and the weight was measured after 4 hours, and the value obtained by subtracting the weight of the sample measured after the heat treatment from the weight of the first sample was shown as the volatilization loss, and shown in Table 2 below The results were shown. The higher the volatilization loss, the higher the content of volatile organic compounds in the prepared polymer.

Experimental Example 2: Measurement of plastisol physical properties

1) Viscosity

Plastisol was prepared by blending 100 g of the vinyl chloride polymer and 66.7 g of diisononylphthalate (DINP) prepared in the above Examples and Comparative Examples with a EUROSTAR IKA-WERKE mixer at 800 rpm for 10 minutes, and then Rheometer (AR2000EX Viscosity was measured using a peltier plate (TA Instruments Co.) with a measuring fixture of 40 mm paraller plate and a measuring gap of 500 μm, and the results are shown in Table 2 below.

2) Foam properties (foam color)

100 g of the vinyl chloride polymer prepared in Examples and Comparative Examples, 80 g of di(2-propylheptyl)phthalate (DPHP), 3 g of Ba/Zn stabilizer, and 3 g of acrylonitrile-based foaming agent were mixed with a EUROSTAR IKA-WERKE mixer. Plastisol was prepared by blending at 800 rpm for 10 minutes, and the prepared plastisol was applied to a release paper and coated with a 0.5 mm rod, and then pre-gelled by using a Mathis oven at 150 ° C. for 45 seconds. (pregelling sheet) was prepared and gelled at 200 ° C. for 90 seconds to prepare a foam sheet. The white index of the prepared foam sheet was measured according to ASTM E 313-73 using a color difference meter (CM-700d), and is shown in Table 2 below. The higher the measured white index value, the better the thermal stability, and the excellent thermal stability means that the foam properties such as foam color quality are excellent.

division Reactivity metrics Defectity Metrics Volatilization loss (mg) viscosity
(Pas) foam properties Example 1 ○ 1.20 0.35 150 45 Example 2 ○ 1.17 0.25 150 45 Example 3 ◎ 0.99 0.30 150 44 Example 4 ◎ 0.97 0.29 140 43 Example 5 ○ 1.12 0.32 150 42 Example 6 ◎ 0.96 0.36 130 45 Example 7 ◎ 1.06 0.31 150 43 Example 8 ◎ 0.98 0.29 150 43 Example 9 ◎ 0.97 0.27 150 46 Example 10 ◎ 0.97 0.28 150 44 Example 11 ○ 1.19 0.30 130 42 Example 12 ○ 0.98 0.32 150 44 Example 13 ○ 1.08 0.20 130 44 Comparative Example 1 △ 2.35 1.31 170 22 Comparative Example 2 X (agglomeration) not measurable not measurable not measurable not measurable Comparative Example 3 △ 1.34 0.78 110 40 Comparative Example 4 X (agglomeration) not measurable not measurable not measurable not measurable Comparative Example 5 △ 1.89 0.23 140 39 Comparative Example 6 △ 1.20 0.21 140 41 Comparative Example 7 ◎ 1.89 0.98 150 38 Comparative Example 8 ◎ 2.01 1.14 150 36 Comparative Example 9 △ 1.99 0.51 190 37

As shown in Table 2, the transition metal catalyst was added during the initial auxiliary material input, and the carbonate-based metal salt was added during polymerization, but the input amount and input time of the carbonate-based metal salt were controlled. In Examples 1 to 13, the carbonate-based metal salt was not added. It can be confirmed that even if the mixture is added or added, the reactivity improvement effect is excellent compared to Comparative Examples 1 to 9, which deviate from the input amount and timing of the present invention, and at the same time, the physical properties of the polymer and the plastisol are also improved.

Specifically, even though a redox polymerization system was applied, Comparative Examples 2 to 4 in which a carbonate-based metal salt was not included and sodium hydroxide, a strong base material, was added. In the case of adding a relatively small amount to prevent this, it can be seen that the reactivity improvement effect is not seen, the structural instability cannot be improved, and the viscosity and foam properties of the plastisol are lowered. In addition, it can be confirmed that the effect of reducing volatile organic compounds is not seen by not using a carbonate-based metal salt.

In addition, Comparative Example 5 in which the transition metal catalyst was not added under the same conditions as the Example of the present invention showed that the reactivity was not improved and the ratio of structural defects was not reduced, and the carbonate-based metal salt was added too early. Even in the case of Comparative Example 6, it can be seen that the basic condition is formed from the beginning, and the effect of improving the reactivity is relatively invisible compared to the example in which polymerization was actively performed under acidic conditions at the beginning of the reaction.

In addition, Comparative Examples 7 and 8, in which the carbonate-based metal salt was added at the later stage of polymerization, could not reduce the structural defects of the polymer formed in the early and middle stages of polymerization, and did not show the effect of reducing the amount of volatile organic compounds generated. It can be confirmed that the foam properties are also deteriorated.

In addition, Comparative Example 9 in which an excessive amount of carbonate-based metal salt was added has a high ratio of carbonate-based metal salt, so it can be confirmed that it cannot have a reactivity improvement effect compared to Example, structural defects and foam properties are lowered, and viscosity is also slightly increased Thus, it can be confirmed that the viscosity physical properties are lowered.

Claims (10)

In the presence of at least one emulsifier and a polymerization initiator, polymerizing a vinyl chloride-based monomer by introducing a transition metal catalyst; Including,
In the polymerization step, a carbonate-based metal salt is added at a time when the polymerization conversion rate is 5 to 67%,
The carbonate-based metal salt is a method for producing a vinyl chloride-based polymer to add 0.03 to 0.30 parts by weight based on 100 parts by weight of the vinyl chloride-based monomer.
According to claim 1,
The carbonate-based metal salt is one selected from the group consisting of sodium carbonate (Na ₂ CO ₃ ), sodium hydrogen carbonate (NaHCO ₃ ), magnesium carbonate (MgCO ₃ ), calcium carbonate (CaCO ₃ ) and potassium carbonate (K ₂ CO ₃ ). Method for producing a vinyl chloride-based polymer comprising the above.
delete According to claim 1,
The carbonate-based metal salt is a method for producing a vinyl chloride-based polymer that is added at a polymerization conversion rate of 40 to 67%.
According to claim 1,
The method for producing a vinyl chloride-based polymer wherein the carbonate-based metal salt is dividedly introduced at least twice or more.
According to claim 1,
The carbonate-based metal salt is a method for producing a vinyl chloride-based polymer that is continuously introduced.
According to claim 1,
The transition metal catalyst is a method for producing a vinyl chloride-based polymer by adding 0.01 to 5.0 ppm based on the weight of the vinyl chloride-based monomer.
According to claim 1,
The transition metal catalyst is a method for producing a vinyl chloride-based polymer comprising at least one or more of copper sulfate and iron sulfate.
According to claim 1,
A method for producing a vinyl chloride-based polymer in which an oxidizing agent and a reducing agent are not introduced in the polymerization step.
According to claim 1,
The polymerization is a method for producing a vinyl chloride-based polymer that is carried out by any one method selected from the group consisting of pure emulsion polymerization, seed emulsion polymerization, and microsuspension polymerization.