Method for producing vinyl chloride copolymer

Abstract

The present invention relates to a method for producing a vinyl chloride copolymer by copolymerizing a vinyl chloride polymer with a polymerizable monomer, which can produce a highly heat-resistant vinyl chloride copolymer by optimizing the ratio of repeating units in a polyvinyl chloride chain to a reducing agent, a monomer, a catalyst, and a ligand.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0139524 filed on October 26, 2022, and all contents disclosed in the documents of said Korean patent application are incorporated by reference into this specification.

[0002] The present invention relates to a method for producing a highly functional vinyl chloride copolymer by atom transfer radical polymerization (hereinafter abbreviated as ATRP). [Background technology]

[0003] Polyvinyl chloride resin is a representative thermoplastic resin, and is widely used in various product fields due to its flexibility, high abrasion resistance, and ease of coloring. Polyvinyl chloride resin is produced by polymerizing vinyl chloride monomer, but since vinyl chloride monomer has poor reactivity with other types of monomers, it is not often used in the form of a copolymer, and is mainly used in the form of a homopolymer such as polyvinyl chloride.

[0004] Therefore, the most common method for compensating for the poor physical properties of polyvinyl chloride is to blend polyvinyl chloride with other polymers having the required physical properties, but this method not only requires separate equipment for blending, but also causes other problems in that if the compatibility between the blended polymer and polyvinyl chloride is poor, the desired physical properties cannot be achieved or the blending process itself is not easy.

[0005] Copolymerization using atom transfer radical polymerization (ATRP) is being researched as an alternative to such blend processing methods. ATRP is a method of further radically polymerizing polymerizable monomers on polyvinyl chloride in the polymer state, and it is possible to copolymerize polyvinyl chloride with polymerizable monomers such as styrene and methyl methacrylate, and the copolymerization of such monomers can complement the inferior physical properties of the polymer itself. However, even when applying ATRP, the properties of the copolymer produced may vary depending on conditions such as the type and amount of catalyst used, the type and amount of reducing agent used, the type and amount of ligand used, and the polymerization temperature. As a result, in-depth research is needed on a copolymer production method that can produce an optimal vinyl chloride copolymer. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] KR10-2013-0136936A(2013.12.13) [Patent Document 2] KR10-2014-0125134A(2014.10.28) Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve the problems of the prior art as described above, and aims to provide a method for producing a vinyl chloride copolymer using ATRP, which can produce a highly functional, particularly highly heat-resistant, vinyl chloride copolymer by optimizing the ratio of repeating units in a polyvinyl chloride chain to a reducing agent, a monomer, a catalyst, and a ligand. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a method for producing a vinyl chloride copolymer. Specifically, (1) the present invention provides a method for producing a vinyl chloride copolymer, comprising: a step (S1) of adding a reducing agent, a polymerizable monomer, a catalyst, and a ligand to a solution containing polyvinyl chloride; and a step (S2) of heating the solution to carry out a polymerization reaction, wherein the molar ratio of repeating units in a chain of polyvinyl chloride in the solution to the added catalyst is 1000:0.3 to 1000:0.6.

[0009] (2) In the present invention, the catalyst is Cu(0), Fe(0), Cu 2 Te, Cu 2 Se, CuCl 2 , Cu 2 S, Cu 2 O, FeCl 2 , and Na 2 S 2 O 4 The present invention provides a method for producing the vinyl chloride copolymer according to the above (1), wherein the method is one or more selected from the group consisting of:

[0010] (3) The present invention provides the method for producing a vinyl chloride copolymer according to the above (1) or (2), wherein the molar ratio of the repeating units in the polyvinyl chloride chain in the solution to the polymerizable monomer to be added is 1:1 to 1:3.

[0011] (4) In the present invention, there is provided a method for producing a vinyl chloride copolymer according to any one of (1) to (3) above, wherein the polymerizable monomer is one or more selected from the group consisting of C1-12 alkyl (meth)acrylate, styrene, C3-12 cycloalkyl (meth)acrylate, C1-12 sulfoalkyl (meth)acrylate, acrylonitrile, polyoxyethylene (meth)acrylate, poly(ethylene glycol) methyl ether (meth)acrylate, (2-acetoacetoxy)ethyl (meth)acrylate, (meth)acrylamide, N-vinylpyrrolidone, and derivatives thereof.

[0012] (5) The present invention provides the method for producing a vinyl chloride copolymer according to any one of (1) to (4) above, wherein a molar ratio of a repeating unit in a polyvinyl chloride chain in the solution to the ligand added is 1000:0.5 to 1000:1.5.

[0013] (6) The present invention provides a method for producing a vinyl chloride copolymer according to any one of (1) to (5) above, wherein the ligand is one or more selected from the group consisting of 2,2'-bipyridine, triphenylphosphine, alkyl-2,2'-bipyridine, 4,4-dinonyl-2,2'-bipyridine, 4,4-diheptyl-2,2'-bipyridine, tris(2-aminoethyl)amine, tris[2-(dimethylamino)ethyl]amine, tris[(2-pyridyl)methyl]amine, N,N,N',N',N''-pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetraamine, and tetramethylethylenediamine.

[0014] (7) In the present invention, the reducing agent is Sn(EH) 2 and one or more soluble reducing agents selected from the group consisting of ascorbic acid, glucose, and azobisisobutyronitrile.

[0015] (8) The present invention provides a method for producing a vinyl chloride copolymer according to any one of (1) to (7) above, wherein a molar ratio of a repeating unit in a polyvinyl chloride chain in the solution to the reducing agent added is 1000:5 to 1000:20.

[0016] (9) The present invention provides the method for producing a vinyl chloride copolymer according to any one of (1) to (8) above, wherein the reducing agent is a metallic solid reducing agent selected from the group consisting of copper, zinc, magnesium, and iron.

[0017] (10) The present invention provides the method for producing a vinyl chloride copolymer according to any one of (1) to (9) above, wherein a solvent for the solution is one or more selected from the group consisting of cyclohexanone, tetrahydrofuran, methyl ethyl ketone, and dimethylformamide.

[0018] (11) The present invention provides the method for producing a vinyl chloride copolymer according to any one of (1) to (10) above, wherein the step S1 includes a bubbling step for removing oxygen from the solution.

[0019] (12) The present invention provides the method for producing a vinyl chloride copolymer according to any one of (1) to (11) above, wherein the S2 step is carried out at a temperature of 25 to 200° C. for 0.1 to 100 hours.

[0020] (13) The present invention provides the method for producing a vinyl chloride copolymer according to any one of (1) to (12) above, wherein the S2 step is carried out until a polymerization conversion rate reaches 50% or more.

[0021] (14) The present invention provides a method for producing a vinyl chloride copolymer according to any one of the above (1) to (13), further comprising the steps of: cooling and filtering the polymerization reaction product (S3); and drying the filtered vinyl chloride copolymer (S4).

[0022] (15) The present invention provides a vinyl chloride copolymer comprising a unit derived from a vinyl chloride monomer and a unit derived from a polymerizable monomer, the polymerizable monomer being at least one selected from the group consisting of C1-12 alkyl (meth)acrylate, styrene, C3-12 cycloalkyl (meth)acrylate, C1-12 sulfoalkyl (meth)acrylate, acrylonitrile, polyoxyethylene (meth)acrylate, poly(ethylene glycol) methyl ether (meth)acrylate, (2-acetoacetoxy)ethyl (meth)acrylate, (meth)acrylamide, N-vinylpyrrolidone, and derivatives thereof, and having a glass transition temperature (Tg) of 90 to 120°C. Effect of the Invention

[0023] The vinyl chloride copolymer produced by the production method of the present invention has a higher glass transition temperature than conventional vinyl chloride copolymers, and can therefore be widely used in various product fields where high heat resistance is required. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The present invention will now be described in more detail. The terms and words used in this specification and the claims should not be interpreted in a limited manner to their ordinary or dictionary meanings, but should be interpreted in a manner that is consistent with the technical idea of ​​the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best describe their invention.

[0025] Method for producing vinyl chloride copolymer The present invention relates to a method for producing a vinyl chloride copolymer using conventional ATRP, which can achieve high conversion in the polymerization process and excellent thermal stability of the final copolymer by optimizing the amount of catalyst added based on the number of moles of repeating units in the chain of polyvinyl chloride in a solution.

[0026] Specifically, the present invention provides a method for producing a vinyl chloride copolymer, comprising: a step (S1) of adding a reducing agent, a polymerizable monomer, a catalyst, and a ligand to a solution containing polyvinyl chloride; and a step (S2) of heating the solution to carry out a polymerization reaction, wherein the molar ratio of repeating units in a chain of polyvinyl chloride in the solution to the added catalyst is 1000:0.3 to 1000:0.6.

[0027] In the present invention, a vinyl chloride copolymer is formed by further copolymerizing a polymerizable monomer with polyvinyl chloride in the form of a polymer, and thus polyvinyl chloride is used as one reaction raw material. The polyvinyl chloride used in the present invention preferably has a weight average molecular weight of 30,000 to 100,000 g / mol, and more specifically, one having a weight average molecular weight of 50,000 to 85,000 g / mol may be used. When one having a weight average molecular weight within the above-mentioned range is used, polyvinyl chloride is well dispersed in a solvent, and the polymerizable monomer can be copolymerized uniformly.

[0028] On the other hand, the catalysts introduced in the S1 step are Cu(0), Fe(0), Cu 2 Te, Cu 2 Se, CuCl 2 , Cu 2 S, Cu 2 O, FeCl 2 , and Na 2 S 2 O 4 and particularly preferably CuCl 2 The catalysts listed above are catalysts that have the property of being able to effectively donate electrons to polyvinyl chloride, and are catalysts that are used in the polymerization reaction using ATRP.

[0029] The present invention has a main technical feature of optimizing the amount of the catalyst based on the amount of repeating units in the polyvinyl chloride chain to improve the physical properties, especially the heat resistance, of the vinyl chloride copolymer finally produced. More specifically, the amount of catalyst added in the S1 step may be such that the molar ratio of the repeating units in the polyvinyl chloride chain in the solution to the catalyst added is 1000:0.3 to 1000:0.6, preferably 1000:0.4 to 1000:0.6. When the amount of catalyst added is within the above range, a sufficiently high conversion rate can be obtained, and the heat resistance of the vinyl chloride copolymer finally produced can be further improved. Meanwhile, the mole number of the repeating units in the polyvinyl chloride chain can be calculated by dividing the molecular weight of the polyvinyl chloride polymer used by the molecular weight of the repeating units, which may be the degree of polymerization of the polyvinyl chloride used.

[0030] In the method for producing a vinyl chloride copolymer of the present invention, the molar ratio of the repeating unit in the polyvinyl chloride chain in the solution to the polymerizable monomer to be added may be 1:1 to 1:3, preferably 1:1.5 to 1:2.5. If the amount of the polymerizable monomer is less than this, the amount of monomer polymerized is relatively small, and a sufficient degree of conversion cannot be obtained, and if the amount of the polymerizable monomer is more than this, the physical properties of some of the finally produced copolymer may be inferior.

[0031] The polymerizable monomer is a monomer that contains a double bond and can be used as a monomer for radical polymerization, and more specifically, may be one or more selected from the group consisting of C1-12 alkyl (meth)acrylate, styrene, C3-12 cycloalkyl (meth)acrylate, C1-12 sulfoalkyl (meth)acrylate, acrylonitrile, polyoxyethylene (meth)acrylate, poly(ethylene glycol) methyl ether (meth)acrylate, (2-acetoacetoxy)ethyl (meth)acrylate, (meth)acrylamide, N-vinylpyrrolidone, and derivatives thereof. Particularly preferably, the polymerizable monomer may be styrene or methyl methacrylate. When the above-mentioned polymerizable monomer is further copolymerized with polyvinyl chloride, the copolymer finally produced has excellent thermal stability and can maintain the excellent properties of polyvinyl chloride itself.

[0032] In the method for producing a vinyl chloride copolymer of the present invention, the molar ratio of the repeating units in the polyvinyl chloride chain in the solution to the ligand added may be 1000:0.5 to 1000:1.5, particularly preferably 1000:0.6 to 1000:1.2. The ligand is a component capable of bonding to a metal or metal ion in the catalyst through a coordinate bond, and the ligand bonded to the metal component allows the polymerization reaction to be effectively controlled.

[0033] The ligand may be one or more selected from the group consisting of 2,2'-bipyridine, triphenylphosphine, alkyl-2,2'-bipyridine, 4,4-dinonyl-2,2'-bipyridine, 4,4-diheptyl-2,2'-bipyridine, tris(2-aminoethyl)amine, tris[2-(dimethylamino)ethyl]amine, tris[(2-pyridyl)methyl]amine, N,N,N',N',N''-pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetraamine, and tetramethylethylenediamine. The ligands listed above easily form coordinate bonds with the metal component in the catalyst and facilitate the copolymerization reaction.

[0034] In the method for producing a vinyl chloride copolymer of the present invention, the reducing agent is Sn(EH) 2 The reducing agent may be one or more soluble reducing agents selected from the group consisting of ascorbic acid, glucose, and azobisisobutyronitrile, in which case the molar ratio of the repeating units in the chain of polyvinyl chloride in the solution to the reducing agent to be added may be 1000:5 to 1000:20, preferably 1000:6 to 1000:12. When the soluble reducing agents of the above types are used in the above ratios, it is possible to minimize the coupling reaction in which radicals generated during the polymerization reaction are combined with each other to terminate the polymerization reaction, and it is possible to sufficiently increase the activity of the catalyst to be added together.

[0035] On the other hand, in addition to the above-described soluble reducing agent, the reducing agent may be a metallic solid reducing agent selected from the group consisting of copper, zinc, magnesium, and iron. The metallic solid reducing agent may be used in a solid form immersed in the solution, or in a wire-like form to increase the specific surface area. The metallic solid reducing agent has the advantage that it can be repeatedly reused.

[0036] In the method for producing a vinyl chloride copolymer of the present invention, the solvent of the solution may be one or more selected from the group consisting of cyclohexanone, tetrahydrofuran, methyl ethyl ketone, and dimethylformamide. The above-listed solvents have the advantage that they can dissolve the above-mentioned components well and do not interfere with the polymerization reaction.

[0037] Meanwhile, step S1 may include a bubbling step for removing oxygen from the solution. If oxygen is present in the solution, it may induce a side reaction during the copolymerization process, so the solution may be bubbled with nitrogen or an inert gas to minimize the oxygen content.

[0038] The S2 step, which is a polymerization step performed after the S1 step, may be performed at a temperature of 25 to 200°C, preferably 80 to 150°C, for 0.1 to 100 hours, preferably 6 to 48 hours. If the temperature in the polymerization step is too low, sufficient energy required for the polymerization reaction cannot be supplied, and sufficient conversion cannot be obtained. If the temperature in the polymerization step is too high, problems such as side reactions occurring due to the high temperature or the color of the vinyl chloride copolymer itself produced being deteriorated may occur. If the time in the polymerization step is too short, sufficient conversion cannot be obtained, and if it is too long, there is a drawback that a large amount of energy is consumed to maintain the reaction.

[0039] The step S2 in which polymerization is carried out may be carried out until the polymerization conversion rate is 50% or more. When the polymerization reaction is carried out under the above-mentioned conditions, the conversion rate of the finally obtained copolymer may be 50% or more.

[0040] The method for producing a vinyl chloride copolymer of the present invention may further include a step (S3) of cooling and filtering the polymerization reaction product and a step (S4) of drying the filtered vinyl chloride copolymer in addition to the above-mentioned steps S1 and S2. The steps S3 and S4 make it possible to obtain a pure vinyl chloride copolymer free of unreacted monomers, solvents, etc. The cooling and drying temperature conditions in the steps S3 and S4 can be appropriately set by those skilled in the art as necessary.

[0041] Vinyl chloride copolymer The present invention provides a vinyl chloride copolymer produced by the above-mentioned production method. Specifically, the present invention provides a vinyl chloride copolymer comprising a unit derived from a vinyl chloride monomer and a unit derived from a polymerizable monomer, the polymerizable monomer being at least one selected from the group consisting of C1-12 alkyl (meth)acrylate, styrene, C3-12 cycloalkyl (meth)acrylate, C1-12 sulfoalkyl (meth)acrylate, acrylonitrile, polyoxyethylene (meth)acrylate, poly(ethylene glycol) methyl ether (meth)acrylate, (2-acetoacetoxy)ethyl (meth)acrylate, (meth)acrylamide, N-vinylpyrrolidone, and derivatives thereof, and having a glass transition temperature (Tg) of 90 to 120°C.

[0042] The vinyl chloride copolymer provided by the present invention has a form in which a polymerizable monomer is further copolymerized with a vinyl chloride polymer, and has a relatively high glass transition temperature, specifically, a glass transition temperature of 90 to 120°C, by optimizing the amount of catalyst added during the reaction process. The vinyl chloride copolymer of the present invention is particularly suitable for use in fields where conventional PVC has been used, particularly in fields where high heat resistance is required.

[0043] Hereinafter, the present invention will be described in more detail with reference to examples and experimental examples in order to specifically explain the present invention, but the present invention is not limited to these examples and experimental examples. The examples of the present invention may be modified in various different forms, and the scope of the present invention should not be interpreted as being limited to the examples described below. The examples of the present invention are provided to more specifically explain the present invention to those having average knowledge in the art.

[0044] material The polyvinyl chloride used had a weight average molecular weight of 62,500 g / mol, and styrene or methyl methacrylate was used as the polymerizable monomer. The reducing agent was Sn(EH) 2 Alternatively, copper wire is used, and the catalyst is CuCl 2The ligand used was tris[(2-pyridyl)methyl]amine (TPMA), and the solvent used was cyclohexanone.

[0045] Examples and Comparative Examples About 450g of cyclohexanone solvent was added to a 2L flask equipped with a reflux condenser, and then 25g of polyvinyl chloride was added and stirred until it was dissolved and transparent. Then, a reducing agent and a polymerizable monomer were added, and nitrogen bubbling was performed for about 30 minutes. At this time, a 1% by weight stock solution of the catalyst and ligand was also prepared in the same solvent, and nitrogen bubbling was performed. Then, the flask was immersed in an oil bath set at the polymerization temperature, and after 30 minutes, the catalyst and ligand were added. Then, the polymerization reaction was performed for 24 hours. After the polymerization was completed, about 200g of tetrahydrofuran was added, and the reactant was cooled to room temperature, and then the reactant was precipitated using isopropyl alcohol, filtered, and dried in a vacuum drying oven at 30°C for 24 hours to obtain the final product. The types and contents of monomers, catalysts, reducing agents, and ligands used in each of the Examples and Comparative Examples, as well as the polymerization temperatures, are summarized in Table 1 below.

[0046] [Table 1]

[0047] *MMA: Methyl methacrylate *TPMA: Tris[(2-pyridyl)methyl]amine *PVCru: Number of repeating units in the polyvinyl chloride chain *M: number of moles of polymerizable monomer *Cat: number of moles of catalyst *Li: moles of ligand *RA: moles of reducing agent / depth of immersion in solution for metallic reducing agents

[0048] On the other hand, in Example 8 of the above table, recycled PVC was used as the reaction raw material instead of ordinary PVC, and the PVC also had a weight average molecular weight of 62,500 g / mol.

[0049] Experimental example 1. Confirmation of conversion rate Before and after the polymerization, 0.2 g of the polymerization sample was taken and precipitated in 4 g of methanol, and then analyzed by GC to determine [M]. 0 and [M] t The conversion rate was then calculated using the following formula. 0 is the amount of initial monomer, [M] t means the amount of monomer after the polymerization reaction is completed. Conversion rate = ([M] 0 -[M] t ) / [M] 0 ×100% The results are summarized in Table 2 below.

[0050] [Table 2]

[0051] As can be seen from Table 2 above, all of the examples of the present invention achieved a high conversion rate of 50% or more, while the comparative examples showed a low conversion rate of as low as 10%. In particular, Comparative Example 3 used less catalyst than the present invention, and Comparative Example 4 used more catalyst than the present invention, and both Comparative Examples 3 and 4 achieved a low conversion rate compared to the examples of the present invention, which means that a particularly high conversion rate is achieved within the range of the catalyst usage amount limited in the present invention.

[0052] In addition, among the examples, Examples 5 to 8 showed high conversion rates, which was confirmed to be due to the fact that MMA, the monomer used in Examples 5 to 8, showed higher reactivity than styrene. In the case of Comparative Example 5, gelation occurred during the polymerization process, making it difficult to measure the conversion rate itself. Moreover, Examples 6 and 7, in which the copper wire was reused, also showed high conversion rates, confirming that a sufficiently high conversion rate can be obtained even when a metallic reducing agent is reused.

[0053] Experimental Example 2: Confirmation of the glass transition temperature of copolymer The glass transition temperatures of the copolymers prepared in the above examples and comparative examples were confirmed. The glass transition temperatures were confirmed using DSC analysis, and the analysis equipment used was a DSC2500 manufactured by TA Instruments. The results are summarized in Table 3 below.

[0054] [Table 3]

[0055] As can be seen from Table 3, the copolymers produced in the examples of the present invention exhibited high glass transition temperatures of 90°C or more, while the copolymers produced in the comparative examples exhibited relatively low glass transition temperatures. This confirms that the copolymers produced using the production method of the present invention have high heat resistance and are therefore applicable to various product fields that require high heat resistance. Meanwhile, in the case of Comparative Example 5, as the conversion rate could not be measured as mentioned above, gelation occurred during polymerization, so the glass transition temperature could not be measured accurately.

[0056] Experimental example 3. Confirmation of the occurrence of coupling reaction The coupling reaction means that the radicals generated in the radical polymerization process combine with other radicals, making it impossible for the polymerization reaction to proceed further. The occurrence of the coupling reaction means that the copolymerization process does not proceed smoothly, and the occurrence of the coupling reaction can be confirmed by GPC. The occurrence of the coupling reaction was confirmed by GPC for the examples and comparative examples of the present invention, and the results are summarized in Table 4 below. Meanwhile, the GPC analysis was performed using ALLIANCE E2695 product manufactured by Waters.

[0057] [Table 4]

[0058] As can be seen from Table 4 above, in Comparative Examples 4 and 5, where a larger amount of catalyst was used than in the present invention, a coupling reaction occurred, and in particular, in Comparative Example 5, where a larger amount of catalyst was used, the coupling reaction occurred at a very early stage. In Comparative Example 5, the coupling reaction also occurred at an early stage, so polymerization was not carried out sufficiently, and as a result, as seen in the previous Experimental Example 1, gelation occurred and the conversion itself could not be measured. From this, it was confirmed that the amount of catalyst used in the present invention is within a range in which an optimal conversion rate can be achieved without causing a coupling reaction.

Claims

1. A step (S1) of introducing a reducing agent, a polymerizable monomer, a catalyst, and a ligand into a solution containing polyvinyl chloride; A step (S2) of heating the solution to carry out a polymerization reaction; Including, A method for producing a vinyl chloride copolymer, wherein the molar ratio of repeating units in the polyvinyl chloride chain in the solution to the catalyst added is 1000:0.3 to 1000:0.

6.

2. The catalyst is Cu(0), Fe(0), Cu ２ Te, Cu ２ Se, CuCl ２ , Cu ２ S, Cu ２ O, FeCl ２ , and Na ２ S ２ O ４ The method for producing a vinyl chloride copolymer according to claim 1, wherein the copolymer is one or more selected from the group consisting of:

3. 2. The method for producing a vinyl chloride copolymer according to claim 1, wherein a molar ratio of a repeating unit in a polyvinyl chloride chain in the solution to the polymerizable monomer to be added is 1:1 to 1:

3.

4. The method for producing a vinyl chloride copolymer according to claim 1, wherein the polymerizable monomer is one or more selected from the group consisting of C1-12 alkyl (meth)acrylate, styrene, C3-12 cycloalkyl (meth)acrylate, C1-12 sulfoalkyl (meth)acrylate, acrylonitrile, polyoxyethylene (meth)acrylate, poly(ethylene glycol) methyl ether (meth)acrylate, (2-acetoacetoxy)ethyl (meth)acrylate, (meth)acrylamide, N-vinylpyrrolidone, and derivatives thereof.

5. 2. The method for producing a vinyl chloride copolymer according to claim 1, wherein the molar ratio of the repeating units in the polyvinyl chloride chain in the solution to the ligand added is 1000:0.5 to 1000:1.

5.

6. The method for producing a vinyl chloride copolymer according to claim 1, wherein the ligand is one or more selected from the group consisting of 2,2'-bipyridine, triphenylphosphine, alkyl-2,2'-bipyridine, 4,4-dinonyl-2,2'-bipyridine, 4,4-diheptyl-2,2'-bipyridine, tris(2-aminoethyl)amine, tris[2-(dimethylamino)ethyl]amine, tris[(2-pyridyl)methyl]amine, N,N,N',N',N''-pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetraamine, and tetramethylethylenediamine.

7. The reducing agent is Sn(EH). ２ 2. The method for producing a vinyl chloride copolymer according to claim 1, wherein the soluble reducing agent is one or more selected from the group consisting of ascorbic acid, glucose, and azobisisobutyronitrile.

8. 8. The method for producing a vinyl chloride copolymer according to claim 7, wherein the molar ratio of the repeating units in the polyvinyl chloride chain in the solution to the reducing agent added is 1000:5 to 1000:

20.

9. 2. The method for producing a vinyl chloride copolymer according to claim 1, wherein the reducing agent is a metallic solid reducing agent selected from the group consisting of copper, zinc, magnesium, and iron.

10. 2. The method for producing a vinyl chloride copolymer according to claim 1, wherein the solvent of the solution is one or more selected from the group consisting of cyclohexanone, tetrahydrofuran, methyl ethyl ketone, and dimethylformamide.

11. 2. The method for producing a vinyl chloride copolymer according to claim 1, wherein the step S1 includes a bubbling step for removing oxygen from the solution.

12. The method for producing a vinyl chloride copolymer according to claim 1, wherein the step S2 is carried out at a temperature of 25 to 200° C. for 0.1 to 100 hours.

13. The method for producing a vinyl chloride copolymer according to claim 1 , wherein the step S2 is carried out until a polymerization conversion rate reaches 50% or more.

14. Cooling and filtering the polymerization reaction (S3); The method for producing a vinyl chloride copolymer according to claim 1, further comprising the step (S4) of drying the filtered vinyl chloride copolymer.

15. Contains units derived from vinyl chloride monomer and units derived from polymerizable monomers, the polymerizable monomer is at least one selected from the group consisting of C1-12 alkyl (meth)acrylate, styrene, C3-12 cycloalkyl (meth)acrylate, C1-12 sulfoalkyl (meth)acrylate, acrylonitrile, polyoxyethylene (meth)acrylate, poly(ethylene glycol) methyl ether (meth)acrylate, (2-acetoacetoxy)ethyl (meth)acrylate, (meth)acrylamide, N-vinylpyrrolidone, and derivatives thereof; A vinyl chloride copolymer having a glass transition temperature (Tg) of 90 to 120°C.

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