Vinyl chloride-based polymer, resin composition comprising same and preparation method therefor

Abstract

The present invention relates to a vinyl chloride-based polymer, a resin composition comprising same and a preparation method therefor, the vinyl chloride-based polymer having a degree of polymerization of 2800-5000, and having a peak in a region between 17 minutes and 18 minutes of retention time in a graph obtained as a result of pyrolysis-gas chromatography analysis.

Description

Vinyl chloride-based polymer, resin composition containing the same, and method for manufacturing the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0145691 filed October 23, 2024 and Korean Patent Application No. 10-2025-0133371 filed September 17, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0003] Technology field

[0004] The present invention relates to a novel vinyl chloride polymer capable of realizing excellent physical properties by having a high degree of polymerization and a high polydispersity index and a low content of low molecular weight compared to existing vinyl chloride polymer products, a resin composition containing the same, and a method for manufacturing the same.

[0005] Due to the recent rapid adoption of electric vehicles, the market for charging cables is also expanding rapidly. Materials being considered for use in these charging cables include flame-retardant polyethylene (PE) resin, thermoplastic polyurethane (TPU) resin, or polyvinyl chloride (PVC) resin.

[0006] However, due to the inherent flame retardancy limitations of polyethylene resin, a large amount of flame retardant must be added to improve it; conversely, this excessive addition of flame retardant presents a problem in that it actually degrades the mechanical properties of the resin itself. Furthermore, while thermoplastic polyurethane resin demonstrates a reasonably satisfactory effect in terms of flame retardancy, it suffers from the problem of being inferior in terms of heat resistance.

[0007] Meanwhile, polyvinyl chloride resin is relatively inexpensive and offers excellent mechanical strength, weather resistance, insulation, and oil resistance, as well as a certain level of flame retardancy; however, it suffers from insufficient heat resistance, leading to the problem of the polyvinyl chloride sheath being damaged by the heat generated during rapid charging. Therefore, to apply polyvinyl chloride resin to charging cables, its flame retardancy and heat resistance must be further improved.

[0008] Chlorinated polyvinyl chloride (C-PVC), obtained by further chlorinating polyvinyl chloride resin, has been proposed as a method to improve the flame retardancy and heat resistance of polyvinyl chloride resin. However, since the manufacturing of such chlorinated polyvinyl chloride is difficult and the production process is costly, it fails to capitalize on the advantage of the relatively low price of conventional polyvinyl chloride. Furthermore, the presence of a large number of partially highly chlorinated chains causes hydrogen chloride gas to be generated through the thermal decomposition of these chains during the molding process, leading to the problem of mold surface contamination. Additionally, such mold surface contamination results in carbonization marks on the surface of the final molded product, thereby reducing continuous productivity during the molding process.

[0009] As an alternative to this, improving heat resistance by increasing the degree of polymerization of the polyvinyl chloride resin itself is also a viable option to consider. The degree of polymerization of general polyvinyl chloride resin is around 1,000, and even for polyvinyl chloride resins used for special purposes, the degree of polymerization is only about 1,500. To increase the degree of polymerization, the polymerization temperature must be significantly lowered during the manufacturing process of polyvinyl chloride resin; however, since lowering the polymerization temperature reduces reactivity and lowers productivity, there are limitations to manufacturing polyvinyl chloride resins with a high degree of polymerization. Additionally, while adding large amounts of chain extenders or crosslinking agents to increase the degree of polymerization could be considered, there is a problem that fish-eye may occur because a large amount of gel is formed due to the large amount of crosslinking agents added.

[0010] Therefore, research is needed on vinyl chloride-based polymers with a high degree of polymerization that can maintain the physical properties of the final polyvinyl chloride resin at an excellent level without reducing productivity during the reaction process.

[0011] The present invention aims to provide a vinyl chloride-based polymer having excellent heat resistance due to a high degree of polymerization, excellent mechanical properties and melting rate due to a high polydispersity index and low molecular weight content, a resin composition containing the same, and a method for manufacturing the same.

[0012] To solve the above-mentioned problem, the present invention provides a novel vinyl chloride-based polymer and a method for manufacturing the same.

[0013] Specifically, (1) the present invention provides a vinyl chloride-based polymer characterized by having a degree of polymerization of 2800 or more and 5000 or less, and having a peak in the region between 17 minutes and 18 minutes of retention time in a graph obtained from a pyrolysis-gas chromatography analysis performed under the following conditions:

[0014] [Analysis Conditions]

[0015] 1) Thermal desorption temperature: 200 to 300℃

[0016] 2) GC / MSD conditions

[0017] Injector temperature: 300℃ (isothermal)

[0018] Carrier gas: Helium gas (flow rate: 1.0 mL / min)

[0019] Column: HP-5MS capillary(30m x 250㎛ x 0.25㎛)

[0020] Oven: 50℃ / 5 min, 15℃ / min, hold at 320℃ for 10 minutes

[0021] Detector: MSD(scan mode)

[0022] (2) The present invention provides a vinyl chloride polymer in which the peak of (1) is derived from an isophthalate compound.

[0023] (3) The present invention provides a vinyl chloride-based polymer in which the degree of polymerization in (1) or (2) is 3600 or more and 4500 or less.

[0024] (4) The present invention provides a vinyl chloride-based polymer having a polydispersity index of 3 or more, calculated from the weight average molecular weight and number average molecular weight obtained through gel permeation chromatography (GPC) analysis with polystyrene as a reference material in accordance with US EPA 3640A: 1994, in any one of (1) to (3).

[0025] (5) The present invention provides a vinyl chloride-based polymer having a low molecular weight content of 25% by weight or more and 40% by weight or less, wherein the molecular weight is 100,000 g / mol or less in the molecular weight graph obtained through gel permeation chromatography (GPC) analysis using polystyrene as a reference material in accordance with US EPA 3640A: 1994.

[0026] (6) The present invention provides a vinyl chloride-based polymer having a cross-linked gel content of 3% by weight or less in any one of (1) to (5).

[0027] (7) The present invention provides a resin composition comprising a vinyl chloride-based polymer according to any one of (1) to (6) above.

[0028] (8) The present invention provides a resin composition that further comprises one or more additives selected from the group consisting of plasticizers, stabilizers and fillers, in accordance with (7).

[0029] (9) The present invention provides a method for producing a vinyl chloride polymer comprising the steps of: preparing a chain extension agent by uniformly dispersing an isophthalate-based chain extender, a nonionic emulsifier, and polyvinyl alcohol (S1); introducing polymerization water, an initiator, the chain extension agent, and a vinyl chloride monomer into a polymerization reactor and starting a polymerization reaction (S2); and performing a polymerization reaction at a temperature of 50°C or lower to synthesize a vinyl chloride polymer (S3).

[0030] (10) The present invention provides a method for manufacturing a vinyl chloride polymer in which the isophthalate-based chain extender is diallyl isophthalate, in accordance with (9).

[0031] (11) The present invention provides a method for producing a vinyl chloride-based polymer in which, in (9) or (10) above, the nonionic emulsifier is one or more selected from the group consisting of polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate, sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate, glyceryl monooleate, and glyceryl monostearate.

[0032] (12) The present invention provides a method for producing a vinyl chloride-based polymer in any one of (9) to (11), wherein the sum HLB value of the chain extension aid is 8 or more and 11.5 or less.

[0033] (13) The present invention provides a method for producing a vinyl chloride-based polymer, wherein in any one of (9) to (12), the polymerization reaction is suspension polymerization.

[0034] The vinyl chloride-based polymer produced using the manufacturing method of the present invention has a high degree of polymerization and excellent heat resistance, and at the same time, excellent mechanical properties and melting rate, making it particularly suitable for use as a material in various fields requiring both heat resistance and mechanical properties, such as a material for electric vehicle charging cables.

[0035] Figure 1 shows a graph of Py-GC / MSD analysis results for vinyl chloride-based polymers according to Examples 1 to 3 of the present invention and vinyl chloride-based polymers according to Comparative Examples 3 and 4.

[0036] The present invention will be described in more detail below.

[0037] Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0038] Meanwhile, the term "vinyl chloride polymer" as used in this specification encompasses compounds produced by polymerizing vinyl chloride monomers, that is, vinyl chloride monomers alone or a mixture of vinyl chloride monomers and vinyl monomers copolymerizable with vinyl chloride monomers, and may refer to polymer chains derived from vinyl chloride monomers.

[0039]

[0040] vinyl chloride-based polymer

[0041] The present invention provides a vinyl chloride-based polymer characterized by having a degree of polymerization of 2800 or more and 5000 or less, and having a peak in the region between 17 and 18 minutes of retention time in a graph obtained from pyrolysis-gas chromatography analysis performed under the following conditions:

[0042] [Analysis Conditions]

[0043] 1) Thermal desorption temperature: 200 to 300℃

[0044] 2) GC / MSD conditions

[0045] Injector temperature: 300℃ (isothermal)

[0046] Carrier gas: Helium gas (flow rate: 1.0 mL / min)

[0047] Column: HP-5MS capillary(30m x 250㎛ x 0.25㎛)

[0048] Oven: 50℃ / 5 min, 15℃ / min, hold at 320℃ for 10 minutes

[0049] Detector: MSD(scan mode)

[0050]

[0051] Conventional vinyl chloride polymer products known for having a high degree of polymerization are manufactured using phthalate-based chain extenders. However, when phthalate-based chain extenders are used in this manner, there is a problem in that the phthalate-based chain extenders themselves, which are harmful to the human body, remain in the final product. Furthermore, the vinyl chloride polymers produced therefrom have limitations, such as a low polydispersity index, a high content of low molecular weight polymers, insufficient mechanical properties, and an insufficiently fast melting rate. The present invention provides a vinyl chloride polymer that possesses a high degree of polymerization and can achieve superior performance compared to conventional high-degree-of-polymerization vinyl chloride polymers manufactured using phthalate-based chain extenders, while having low toxicity to the human body by not using phthalate-based chain extenders.

[0052]

[0053] More specifically, the degree of polymerization of the vinyl chloride-based polymer provided by the present invention is 2800 or more, 2900 or more, 3000 or more, 3100 or more, 3200 or more, 3300 or more, 3400 or more, 3500 or more, 3600 or more, 3650 or more, 3700 or more, 3750 or more, 3800 or more, 3850 or more, 3900 or more, 3950 or more, 4000 or more, 4050 or more, or 4100 or more, and is 5000 or less, 4950 or less, 4900 or less, 4850 or less, 4800 or less, 4750 or less, 4700 or less, 4650 or less, 4600 or less, 4550 or less, 4500 or less, 4450 or less, 4400 or less. It may be 4350 or less, 4300 or less, 4250 or less, or 4200 or less. Increasing the degree of polymerization of the vinyl chloride-based polymer itself significantly beyond the range described above may be technically difficult under general manufacturing conditions and may not be desirable in terms of economic feasibility, and the vinyl chloride-based polymer of the present invention can have excellent heat resistance properties by having a degree of polymerization within the range described above.

[0054]

[0055] The vinyl chloride-based polymer provided by the present invention is characterized by having a peak in the region between 17 and 18 minutes of retention time in the graph obtained from the pyrolysis-gas chromatography analysis results under the conditions described above. The said peak may indicate that the isophthalate-based chain extender used in the polymerization process of the vinyl chloride-based polymer of the present invention is appropriately distributed within the polymer chain, and in particular, the vinyl chloride-based polymer provided by the present invention may exhibit a peak in the region between 17 and 18 minutes, 17 and 17.5 minutes, 17.1 and 17.5 minutes, or 17.2 and 17.4 minutes of retention time. The said peak may be derived from an isophthalate-based compound, and more specifically, may be derived from diallyl isophthalate.

[0056]

[0057] Meanwhile, the above-mentioned pyrolysis-gas chromatography analysis (Py-GC / MSD) involves thermally desorbing the vinyl chloride-based polymer at a temperature where the polymer does not decompose to remove residual volatile components within the vinyl chloride-based polymer, and performing gas chromatographic analysis on the removed volatile components.

[0058] Accordingly, the above thermal desorption can be performed at a temperature of 300°C or lower, which is a temperature at which the vinyl chloride-based polymer does not decompose, and more specifically at 200 to 300°C, and more specifically at 230 to 270°C, 240 to 260°C, or 250°C.

[0059] More specifically, the pyrolysis-gas chromatography analysis may be performed under the following conditions.

[0060] 1) Thermal desorption temperature: 200 to 300℃

[0061] 2) GC / MSD conditions

[0062] Injector temperature: 300℃ (isothermal)

[0063] Carrier gas: Helium gas (flow rate: 1.0 mL / min)

[0064] Column: HP-5MS capillary(30m x 250㎛ x 0.25㎛)

[0065] Oven: 50℃ / 5 min, 15℃ / min, hold at 320℃ for 10 minutes

[0066] Detector: MSD(scan mode)

[0067]

[0068] In the vinyl chloride-based polymer provided by the present invention, the number average molecular weight obtained through gel permeation chromatography (GPC) analysis using polystyrene as a reference material pursuant to US EPA 3640A:1994 may be 100,000 g / mol or more and 200,000 g / mol or less, preferably 100,000 g / mol or more, 103,000 g / mol or more, 105,000 g / mol or more, 108,000 g / mol or more, or 110,000 g / mol or more, and 200,000 g / mol or less, 190,000 g / mol or less, 180,000 g / mol or less, 170,000 g / mol or less, 160,000 g / mol or less, 150,000 g / mol or less, or 145,000 g / mol It may be less than or equal to 140,000 g / mol, less than or equal to 135,000 g / mol, or less than or equal to 130,000 g / mol.In addition, the weight average molecular weight of the vinyl chloride-based polymer obtained through the gel permeation chromatography (GPC) analysis may be 400,000 g / mol or more and 700,000 g / mol or less, preferably 410,000 g / mol or more, 415,000 g / mol or more, 420,000 g / mol or more, 425,000 g / mol or more, 430,000 g / mol or more, or 435,000 g / mol or more, while being 700,000 g / mol or less, 690,000 g / mol or less, 680,000 g / mol or less, 670,000 g / mol or less, 660,000 g / mol or less, 650,000 g / mol or less, 640,000 g / mol or less, 630,000 g / mol or less, It may be 620,000 g / mol or less, 610,000 g / mol or less, 600,000 g / mol or less, 590,000 g / mol or less, 580,000 g / mol or less, 570,000 g / mol or less, 560,000 g / mol or less, 550,000 g / mol or less, 540,000 g / mol or less, 530,000 g / mol or less, 520,000 g / mol or less, 510,000 g / mol or less, 500,000 g / mol or less, or 490,000 g / mol or less. The number average molecular weight and weight average molecular weight may be relative molecular weights obtained through gel permeation chromatography (GPC) analysis using polystyrene as a reference material. More specifically, the gel permeation chromatography analysis can be performed in accordance with US EPA 3640A:1994 and can be performed under the following conditions.

[0069] 1) Equipment used: Use GPC Autoprep Model 1002 A or B

[0070] 2) Column Condition: 700mm x 25mm ID glass column, packed with 70g of Bio Beads (S-X3, 200-400 mesh) as packing material (Manufacturer: Bio-Rad Labatories, Richmond, CA, Catalog 152-2750 or equivalent)

[0071] 3) Sample conditions: A sample with a concentration of 5 to 10 mg / mL is prepared by dissolving the obtained vinyl chloride-based polymer in a cyclohexane / methylene chloride mixture (1:1, v / v). Then, the sample is passed through a 0.45 μm filter for microfiltration, and approximately 5 mL of the sample is injected at a rate of 5.0 mL / min, while maintaining the column temperature at room temperature.

[0072] 4) Detection method: Analyzed with a UV detector

[0073]

[0074] In the present invention, the polydispersity index (PDI) calculated from the weight-average molecular weight and number-average molecular weight obtained through the gel permeation chromatography analysis may be 3 or higher, preferably 3.1 or higher, 3.2 or higher, 3.3 or higher, 3.4 or higher, 3.5 or higher, 3.55 or higher, 3.6 or higher, 3.65 or higher, 3.7 or higher, 3.75 or higher, or 3.8 or higher, while being 6 or lower, 5.9 or lower, 5.8 or lower, 5.7 or lower, 5.6 or lower, 5.5 or lower, 5.4 or lower, 5.3 or lower, 5.2 or lower, 5.1 or lower, 5 or lower, 4.9 or lower, 4.8 or lower, 4.7 or lower, 4.6 or lower, 4.5 or lower, 4.4 or lower, 4.3 or lower, 4.2 or lower, 4.1 or lower, 4.0 or lower, or 3.95 or lower. Or it may be 3.9 or less. The polydispersity index is a value calculated by dividing the weight-average molecular weight (Mw) of the polymer by the number-average molecular weight (Mn), and the melting characteristics of the vinyl chloride-based polymer may be superior when the polydispersity index is within the range described above. More specifically, the vinyl chloride-based polymer provided by the present invention may maintain excellent processability by maintaining a high relative proportion of low molecular weight compared to other vinyl chloride-based polymers having a similar degree of polymerization, and accordingly may have a polydispersity index within the range described above.

[0075]

[0076] In the vinyl chloride-based polymer provided by the present invention, the low molecular weight content, in which the molecular weight is 100,000 g / mol or less in the molecular weight graph obtained through gel permeation chromatography analysis, may be 25 wt% or more and 40 wt% or less, preferably 25 wt% or more, 25.5 wt% or more, 26 wt% or more, 26.5 wt% or more, 27 wt% or more, or 27.5 wt% or more, and may be 40 wt% or less, 39 wt% or less, 38 wt% or less, 37 wt% or less, 36 wt% or less, or 35 wt% or less. As previously explained, the low molecular weight content is a high value compared to the low molecular weight content of existing similar high-polymerization-degree vinyl chloride-based polymers, and the vinyl chloride-based polymer of the present invention can have superior processability by having a low molecular weight content within the above-described range. Meanwhile, the low molecular weight content can be calculated as the ratio of the area occupied by the region with a molecular weight of 100,000 g / mol or less to the total area of ​​the molecular weight graph obtained through the gel permeation chromatography analysis. The molecular weight graph may refer to a molecular weight distribution curve with the x-axis as log(M) and the vertical axis as dW / d(logM).

[0077]

[0078] In addition, the vinyl chloride-based polymer provided by the present invention may have an area of ​​the left region based on the molecular weight value where a peak appears in the molecular weight graph obtained through gel permeation chromatography analysis that is 50% or more of the total area of ​​the graph. The left region refers to a region with a relatively low molecular weight, and the vinyl chloride-based polymer of the present invention can exhibit such characteristics because the content of low molecular weight is maintained at a relatively high level.

[0079]

[0080] In addition, the vinyl chloride-based polymer provided by the present invention may have a crosslinked gel content of 3% by weight or less, and preferably 2.5% by weight or less, 2% by weight or less, 1.5% by weight or less, 1% by weight or less, 0.8% by weight or less, 0.5% by weight or less, 0.3% by weight or less, 0.2% by weight or less, or 0.1% by weight or less. The crosslinked gel content may be measured using a Soxhlet extractor, and due to the low crosslinked gel content, the vinyl chloride-based polymer of the present invention may not produce any or almost no unmelted particles during processing. If unmelted particles are produced during processing, this may act as a defect in the product.

[0081]

[0082] The vinyl chloride-based polymer provided by the present invention may be characterized in that the time between the point where the torque reaches a maximum value and the point where the torque reaches a maximum value in the graph obtained from the melting rate analysis of a specimen obtained by compounding the vinyl chloride-based polymer is 60 seconds or less. The time between the two points may preferably be 55 seconds or less, 50 seconds or less, or 45 seconds or less.

[0083] In addition, the vinyl chloride-based polymer provided by the present invention may be characterized in that the time between the point in time when the torque reaches a maximum point and the point in time when the torque recovers to a torque value corresponding to the torque value of the maximum point after said point, as shown in the graph obtained from the melting rate analysis result of a specimen obtained by compounding the vinyl chloride-based polymer, is 30 seconds or less. In addition, the time between said two points in time may preferably be 28 seconds or less, 26 seconds or less, or 24 seconds or less.

[0084] The above compound formulation may be formulated by mixing 80 parts by weight or less of a plasticizer, 10 parts by weight or less of a stabilizer, and 10 to 150 parts by weight of a filler, based on 100 parts by weight of a vinyl chloride-based polymer. More specifically, the above compound formulation may be formulated by mixing 70 parts by weight of triisononyl trimellitate (plasticizer), 6 parts by weight of RUP-166S (stabilizer), and 20 parts by weight of calcium carbonate (filler) with respect to 100 parts by weight of a vinyl chloride-based polymer.

[0085]

[0086] The melting rate analysis of the specimen obtained after the above compound formulation may be performed using a Brabender plastograph with the resin composition, and may be performed while operating the device at a temperature of 135°C and a speed of 70 rpm. The graph obtained from the melting rate analysis may be a graph with time on the horizontal axis and torque value on the vertical axis.

[0087]

[0088] The vinyl chloride-based polymer provided by the present invention has a bulk density of 0.5 g / cm³ 3 It may be less than or equal to, preferably 0.45 g / cm³ 3 Less than or equal to 0.1 g / cm³ 3 Above, 0.2g / cm² 3 Above, 0.3g / cm² 3 Above or 0.4 g / cm³ 3 The above bulk density may be greater than or equal to the above. The above bulk density can be measured according to a conventional method, and can be calculated by filling a container with a certain volume of vinyl chloride polymer, measuring the weight, and dividing the measured weight by the volume of the container.

[0089]

[0090] In addition, the vinyl chloride-based polymer provided by the present invention may have a cold plasticizer absorption (CPA) of 40 phr or more, 43 phr or more, 45 phr or more, 47 phr or more, 49 phr or more, or 50 phr or more, and may have a cold plasticizer absorption of 90 phr or less, 80 phr or less, 70 phr or less, 60 phr or less, 55 phr or less, or 53 phr or less. The above plasticizer absorption rate is measured by introducing a vinyl chloride-based polymer resin and a plasticizer into a specified glass tube, centrifuging, and then measuring the content of the plasticizer absorbed in the resin. It may be measured under conditions of 1.0 g of vinyl chloride-based polymer, 2.0 g of plasticizer, a centrifuge speed of 3,900 rpm, and operation at 20°C for 30 minutes.

[0091]

[0092] The vinyl chloride-based polymer of the present invention may be in powder form and may be mixed with various additive components as described below to be used as a resin composition.

[0093]

[0094] Resin composition

[0095] The present invention provides a resin composition comprising the vinyl chloride-based polymer described above.

[0096]

[0097] More specifically, the resin composition may further include one or more additives selected from the group consisting of plasticizers, stabilizers, and fillers in addition to the vinyl chloride-based polymer.

[0098]

[0099] As the above plasticizer, a conventional commercial plasticizer may be used, and examples include phthalate-based plasticizers, isophthalate-based plasticizers, terephthalate-based plasticizers, trimellitate-based plasticizers, citrate-based plasticizers, hydrogenated phthalate-based plasticizers, hydrogenated isophthalate-based plasticizers, hydrogenated terephthalate-based plasticizers, etc. The above plasticizer may be included in an amount of 80 parts by weight or less, preferably 60 to 80 parts by weight, based on 100 parts by weight of the vinyl chloride-based polymer.

[0100]

[0101] As the above stabilizer, a conventional stabilizer used together with a vinyl chloride-based polymer may be used. Specifically, examples include Ca-Zn compounds; Ba-Zn compounds; mercaptide compounds; organic tin compounds such as maleic acid compounds or carboxylic acid compounds; metallic soap compounds such as Mg-stearate, Ca-stearate, Pb-stearate, Cd-stearate, or Ba-stearate; phenol compounds; phosphate ester compounds; or phosphite ester compounds; and one or more of the fillers listed above may be selected and used according to the application. Preferably, a Ca-Zn compound may be used in the present invention. The above stabilizer may be included in an amount of 10 parts by weight or less, preferably 4 to 8 parts by weight, based on 100 parts by weight of the vinyl chloride-based polymer.

[0102]

[0103] The above filler may be a conventional filler used with a vinyl chloride-based polymer, specifically calcium carbonate, clay, talc, or diatomaceous earth. The above filler may be included in an amount of 10 to 150 parts by weight, preferably 20 to 50 parts by weight, based on 100 parts by weight of the vinyl chloride-based polymer.

[0104]

[0105] As previously examined, the vinyl chloride-based polymer of the present invention exhibits excellent melting characteristics, and accordingly, in a resin composition containing said vinyl chloride-based polymer, the time between the point where the torque reaches a maximum value and the point where the torque reaches a maximum value in the graph obtained from the melting rate analysis result may be 60 seconds or less.

[0106]

[0107] Method for manufacturing vinyl chloride-based polymers

[0108] The present invention provides a method for manufacturing a vinyl chloride-based polymer as described above.

[0109]

[0110] More specifically, the present invention provides a method for manufacturing a vinyl chloride polymer comprising the steps of: preparing a chain extension aid by uniformly dispersing an isophthalate-based chain extender, a nonionic emulsifier, and polyvinyl alcohol (S1); introducing polymerization water, an initiator, the chain extension aid, and a vinyl chloride monomer into a polymerization reactor and initiating a polymerization reaction (S2); and performing a polymerization reaction at a temperature of 50°C or lower to synthesize a vinyl chloride polymer (S3).

[0111]

[0112] The vinyl chloride-based polymer of the present invention can be manufactured by using the chain extension aid and performing the polymerization reaction at a low temperature of 50°C or lower. Below, the method for manufacturing the vinyl chloride-based polymer of the present invention will be described in more detail.

[0113]

[0114] S1 stage

[0115] Prior to carrying out the polymerization reaction, a step of preparing a chain extension aid by uniformly dispersing a chain extender, a nonionic emulsifier, and polyvinyl alcohol may be performed. The chain extender is used in the polymerization reaction to increase the degree of polymerization by extending the polymer chain. However, if the chain extender is directly introduced into the polymerization reactor, the chain extender may not be uniformly dispersed, resulting in the production of a non-uniform vinyl chloride-based polymer. Therefore, in the method for producing a vinyl chloride-based polymer according to the present invention, a chain extension aid prepared by mixing the chain extender with a nonionic emulsifier and polyvinyl alcohol and then uniformly dispersing it is used.

[0116] Meanwhile, the chain extender used in the present invention may be an isophthalate-based chain extender, and more specifically, the isophthalate-based chain extender may be diallyl isophthalate. Unlike phthalate-based chain extenders that have been used frequently in the past, the isophthalate-based chain extender is harmless to the human body and can provide an excellent chain extension effect even at a low concentration.

[0117] The above isophthalate-based chain extender may be added at a concentration of 800 ppm or more and 3000 ppm or less relative to the total amount of vinyl chloride-based monomers added, and preferably at a concentration of 850 ppm or more, 900 ppm or more, 950 ppm or more, 1000 ppm or more, 1050 ppm or more, or 1100 ppm or more, and 2900 ppm or less, 2800 ppm or less, 2700 ppm or less, 2600 ppm or less, 2500 ppm or less, 2400 ppm or less, 2300 ppm or less, 2200 ppm or less, 2100 ppm or less, 2000 ppm or less, 1900 ppm or less, 1800 ppm or less, 1700 ppm or less, 1600 ppm or less, or 1500 ppm or less. Within the aforementioned range, the degree of polymerization of the polymer can be sufficiently increased while minimizing the crosslinked gel content.

[0118] The above nonionic emulsifier has lipophilicity and is intended to disperse the above isophthalate-based chain extender more uniformly. It may be one or more selected from the group consisting of polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate, sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate, glyceryl monooleate, and glyceryl monostearate, and preferably may be sorbitan monolaurate.

[0119] The above nonionic emulsifier may be added at a concentration of 300 ppm or more and 3000 ppm or less relative to the total amount of vinyl chloride monomers added, and preferably at a concentration of 400 ppm or more, 500 ppm or more, 600 ppm or more, 700 ppm or more, 800 ppm or more, 850 ppm or more, or 900 ppm or more, and at a concentration of 2900 ppm or less, 2800 ppm or less, 2700 ppm or less, 2600 ppm or less, 2500 ppm or less, 2400 ppm or less, 2300 ppm or less, 2200 ppm or less, 2100 ppm or less, 2000 ppm or less, 1900 ppm or less, 1800 ppm or less, 1700 ppm or less, 1600 ppm or less, or 1500 ppm or less. If the above conditions are satisfied, the average particle size of the vinyl chloride-based polymer can be maintained at an appropriate level.

[0120] The weight ratio between the above isophthalate-based chain extender and the nonionic emulsifier may be 1:0.01 to 15.00, preferably 1:0.03 to 13.50, more preferably 1:0.50 to 10.00, even more preferably 1:0.60 to 9.00, and most preferably 1:0.07 to 8.00.

[0121] The above polyvinyl alcohol has hydrophilicity and serves to disperse isophthalate-based chain extenders more uniformly. As the above polyvinyl alcohol, various types of polyvinyl alcohols with different degrees of hydration may be mixed and used, and the polyvinyl alcohol may include low-hydration polyvinyl alcohol with a degree of hydration of 30 to 65 mol% and high-hydration polyvinyl alcohol with a degree of hydration of 70 to 95 mol%. When the low-hydration polyvinyl alcohol and high-hydration polyvinyl alcohol are mixed and used, the stability of the final particles can be increased, the basic physical properties of the polymer obtained finally can be easily controlled, and a polymer with excellent meltability can be manufactured. Meanwhile, the above polyvinyl alcohol is in the form of polyvinyl acetate hydrated to substitute a portion of the acetate with alcohol, and the degree of hydration is defined as the degree to which the acetate is substituted with alcohol. The weight ratio between the low-hydration polyvinyl alcohol and the high-hydration polyvinyl alcohol may be 3:7 to 7:3, and preferably 5:5 to 7:3.

[0122] Meanwhile, the above polyvinyl alcohol can be used in an amount of 0.5 parts by weight or less per 100 parts by weight of vinyl chloride monomer, and preferably 0.5 parts by weight or less, 0.4 parts by weight or less, 0.3 parts by weight or less, or 0.2 parts by weight or less, and can be used in an amount of 0.05 parts by weight or more or 0.1 parts by weight or more.

[0123]

[0124] The sum HLB value of the chain extension agent may be 8 or higher and 11.5 or lower, and more preferably 9 to 11.5. The HLB value refers to the hydrophilic-lipophilic balance, and a higher HLB value indicates higher hydrophilicity. The sum HLB value refers to the average value based on the weight of the HLB values ​​of each component, and the sum HLB value of the chain extension agent of the present invention can be calculated from the HLB values ​​of the nonionic emulsifier and polyvinyl alcohol. For example, the sum HLB value of 60 weight% of component A with an HLB of 10 and 40 weight% of component B with an HLB of 5 is 10*0.6+5*0.4=8.

[0125]

[0126] S2 stage

[0127] A polymerization reaction can be initiated in the presence of a chain extension aid prepared through the preceding steps.

[0128] The polymerization reaction of the present invention may be a suspension polymerization, and the suspension polymerization may be carried out in the presence of a polymerization water. The polymerization water may be used as a polymerization solvent, and various types of polymerization water, such as distilled water or deionized water, may be used, and preferably, deionized water may be used. The temperature of the polymerization water may be appropriately selected considering the temperature at which the suspension polymerization is performed, and the amount of the polymerization water may also be appropriately used according to the polymerization conditions, for example, at least 70 parts by weight, specifically 70 to 300 parts by weight, per 100 parts by weight of the vinyl chloride monomer.

[0129]

[0130] The above initiator is not particularly limited as long as it is applied to the suspension polymerization of vinyl chloride monomers, and specifically, the above initiator may be one or more selected from the group consisting of polyacyl peroxide-based initiators, peroxydicarbonate-based initiators, peroxyester-based initiators, sulfate-based initiators and azo-based initiators.

[0131] More specifically, the diacyl peroxide-based initiator may be one or more selected from the group consisting of dicumyl peroxide, dipentyl peroxide, 3,3,5-trimethylhexanoyl peroxide, and dilauryl peroxide. The peroxydicarbonate-based initiator may be one or more selected from the group consisting of diisopropyl peroxydicarbonate, di-sec-butylperoxydicarbonate, and di-2-ethylhexyl peroxide. The peroxyester-based initiator may be t-butylperoxypivalate or t-butylperoxyneodecanoate, or a mixture thereof. The sulfate-based initiator may be potassium persulfate or ammonium persulfate, or a mixture thereof. The azo-based initiator may be azobis-2,4-dimethylvaleronitrile.

[0132] The above initiator may be added in an amount of 0.02 to 0.2 parts by weight per 100 parts by weight of vinyl chloride monomer, and preferably in an amount of 0.04 to 0.12 parts by weight. If the amount of initiator added is too small, the reaction time is delayed and productivity is reduced, and if the amount of initiator added is too large, the initiator may not be completely consumed during the polymerization process and may remain in the vinyl chloride polymer produced at the end, which may reduce the thermal stability of the resin.

[0133]

[0134] S3 stage

[0135] A polymerization reaction can be initiated through the preceding steps, and after the polymerization reaction has proceeded to a certain extent, the reaction can be terminated to obtain a vinyl chloride-based polymer.

[0136] In this step, the temperature condition under which the polymerization reaction is performed may be 50°C or lower, preferably 30°C or higher, 33°C or higher, 35°C or higher, 37°C or higher, 40°C or higher, or 43°C or higher, and may be 50°C or lower, 49°C or lower, 48°C or lower, 47°C or lower, 46°C or lower, or 45°C or lower. As the temperature at which the polymerization reaction proceeds decreases, the degree of polymerization of the obtained vinyl chloride-based polymer increases; however, if the reaction temperature is excessively low, the reaction rate decreases significantly, and the productivity of the vinyl chloride-based polymer manufacturing process decreases significantly. Therefore, under the above-described temperature conditions, it is possible to efficiently produce a high-quality vinyl chloride-based polymer with a high degree of polymerization while minimizing the decrease in productivity.

[0137]

[0138] After performing a polymerization reaction to some extent in this step, the reaction can be terminated by adding a reaction terminator. The reaction terminator can terminate the polymerization reaction by reacting with the remaining unreacted initiator to cause the initiator to lose its function, and may be one or more selected from the group consisting of phenol compounds, amine compounds, nitrile compounds, and sulfur compounds. The above phenol compounds are triethylene glycol-bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate, hydroquinone, p-methoxy phenol, t-butyl-4-hydroxyanisole, n-octadecyl-3-(4-hydroxy-3,5-di-t-butylphenyl)propionate, 2,5-di-t-butyl hydroquinone, and 4,4'-butylidene bis(3-methyl-6-t-butyl It may be one or more selected from the group consisting of phenol (4,4'-butylidene bis(3-methyl-t-butyl phenol), t-butyl catechol, 4,4-thiobis(6-t-butyl-m-cresol)), and tocopherol. The amine compound may be one or more selected from the group consisting of N,N-diphenyl-p-phenylenediamine and 4,4-bis(dimethylbenzyl)diphenyl.The above nitrile compound may be one or more selected from the group consisting of 2-phenyl nitronyl nitroxide, 3-imidazoline nitroxide, and 4-hydroxy-2,2,6,6-tetramethyl piperidine-1-oxyl. The above sulfur compound may be one or more selected from the group consisting of dodecyl mercaptan and 1,2-biphenyl-2-thiol.

[0139]

[0140] In the method for manufacturing a vinyl chloride-based polymer according to the present invention, additives such as antioxidants, bases, crosslinking agents, polymerization regulators, chain transfer agents, antistatic agents, anti-scaling agents, and surfactants may be additionally added. The types and amounts of said additives are not particularly limited and may be used in the usual types and amounts known in the art. The said additives may be added at any point during the polymerization process, and may be added all at once or continuously.

[0141]

[0142] Preferred embodiments are presented below to aid in understanding the present invention. However, the following embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention.

[0143]

[0144] Example 1

[0145] Internal volume of 1m² equipped with reflux condenser and stirrer 3450 kg of deionized water was introduced into a stainless steel polymerization reactor, and a stirrer was operated at 175 rpm. Separately, 150 g of polyvinyl alcohol with a hydration degree of 80 mol%, 200 g of polyvinyl alcohol with a hydration degree of 40 mol%, 270 g of sorbitan monolaurate (a nonionic emulsifier), and 338 g of diallyl isophthalate were mixed separately and uniformly dispersed to obtain a chain extension aid.

[0146] 270 kg of the above chain extension agent and vinyl chloride monomer were introduced into the polymerization reactor, and 44 g of cumyl peroxyneodecanoate and 44 g of peroxydicarbonic acid bisester were introduced as an organic peroxide initiator composition to initiate the polymerization reaction. The reaction was carried out while maintaining the temperature of the polymerization reaction at 45°C, and the pressure of the polymerization reactor was 5.8 kg / cm² 2 At the point when the reaction was reached, 81 g of triethylene glycol-bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate was added as a reaction terminator to terminate the reaction. Afterwards, the unreacted monomer and the generated vinyl chloride polymer slurry were separated and recovered, and the slurry was dried in a fluidized bed dryer to obtain a vinyl chloride polymer.

[0147]

[0148] Example 2

[0149] A vinyl chloride-based polymer was obtained by carrying out the same procedure as in Example 1 above, except that 313 g of sorbitan monolaurate, a nonionic emulsifier, and 357 g of diallyl isophthalate were added, and the temperature of the polymerization reaction was maintained at 43.8°C.

[0150]

[0151] Example 3

[0152] A vinyl chloride-based polymer was obtained by carrying out the same procedure as in Example 1 above, except that 357 g of sorbitan monolaurate and 357 g of diallyl isophthalate, which are nonionic emulsifiers, were added, and the temperature of the polymerization reaction was maintained at 44°C.

[0153]

[0154] Comparative Example 1

[0155] In Example 1 above, a chain extension agent was prepared without using sorbitan monolaurate and diallyl isophthalate during the preparation process of the chain extension agent.

[0156] Afterwards, the polymerization reaction temperature is maintained at 57℃, and the polymerization reactor pressure is 7.6 kg / cm² 2 A vinyl chloride-based polymer was obtained by carrying out the same procedure as in Example 1, except that the reaction was terminated when it was reached.

[0157]

[0158] Comparative Example 2

[0159] In Comparative Example 1 above, the temperature of the polymerization reaction was maintained at 45°C, and the polymerization reactor pressure was 5.8 kg / cm² 2 A vinyl chloride-based polymer was obtained by carrying out the same procedure as in Example 1, except that the reaction was terminated when it was reached.

[0160]

[0161] Comparative Example 3

[0162] A vinyl chloride-based polymer was obtained by carrying out the same procedure as in Example 1 above, except that 135 g of sorbitan monolaurate, a nonionic emulsifier, and 169 g of diallyl isophthalate were added.

[0163]

[0164] Comparative Example 4

[0165] A vinyl chloride-based polymer was obtained by carrying out the same procedure as in Example 1 above, except that 338 g of diallyl phthalate was used instead of diallyl isophthalate.

[0166]

[0167] The manufacturing conditions of the above examples and comparative examples are summarized in Table 1 below. Manufacturing conditions not listed in Table 1 below were applied identically to all examples and comparative examples.

[0168] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Sorbitan monolaurate 270g 313g 357g --135g 270g Diallyl isophthalate 338g 357g 357g --169g -Diallyl phthalate ------338g Polymerization reaction temperature 45℃ 43.8℃ 44℃ 57℃ 45℃ 45℃ 45℃ Reaction termination point pressure 5.8kg / cm² 2 5.8 kg / cm² 2 5.8 kg / cm² 2 7.6 kg / cm² 2 5.8 kg / cm² 2 5.8 kg / cm² 2 5.8 kg / cm² 2

[0169] Experimental Example 1. Py-GC / MSD Analysis of Vinyl Chloride Polymers

[0170] Py-GC / MSD analysis was performed on the vinyl chloride-based polymers of Examples 1 to 3 and Comparative Examples 3 and 4 prepared using a chain extender. 5 to 10 mg of sample was used, and the specific analysis conditions are as follows.

[0171] 1) Thermal desorption temperature (furnace temperature): 250℃

[0172] 2) GC / MSD conditions

[0173] Injector temperature: 300℃ (isothermal)

[0174] Carrier gas: Helium gas (flow rate: 1.0 mL / min)

[0175] Column: HP-5MS capillary(30m x 250㎛ x 0.25㎛)

[0176] Oven: 50℃ / 5 min, 15℃ / min, hold at 320℃ for 10 minutes

[0177] Detector: MSD(scan mode)

[0178] After performing the above Py-GC / MSD analysis, m / z + The graph obtained as a result of extracting and organizing 189 ions is shown in Fig. 1.

[0179] As can be seen from Figure 1, in the case of Examples 1 to 3 using isophthalate-based chain extenders and Comparative Example 3, a peak was observed within the retention time range of 17 to 18 minutes. On the other hand, in the case of Comparative Example 4 using diallyl phthalate as a chain extender, a peak appeared at a faster time of 16.8 minutes, which is expected to be a peak derived from diallyl phthalate.

[0180]

[0181] Experimental Example 2. Measurement of degree of polymerization, molecular weight, and cross-linked gel content of vinyl chloride-based polymer

[0182] The degree of polymerization, molecular weight, and crosslinked gel content of the vinyl chloride-based polymers of the above examples and comparative examples were measured, and the results are summarized in Table 2 below.

[0183] Meanwhile, the degree of polymerization and molecular weight were measured using the following method.

[0184] 1) Degree of polymerization:

[0185] 0.5 g of the obtained vinyl chloride-based polymer was mixed with 100 mL of cyclohexanone and heated at 110°C for 2 hours to completely dissolve it. Afterward, the flask containing the solution was cooled by placing it in a water bath at 30°C, and then 10 mL of the measurement solution was added to a viscometer. The viscosity was measured by measuring the time based on passing the reference scale line (ASTM-D1243), and the degree of polymerization was calculated from the measured viscosity using a conversion table for viscosity, K-Value, and degree of polymerization (refer to PVC Technology literature).

[0186] 2) Molecular weight and low molecular weight content:

[0187] Gel permeation chromatography analysis was performed in accordance with US EPA 3640A: 1994. The specific conditions are as follows.

[0188] (1) Equipment used: GPC Autoprep Model 1002 A or B was used.

[0189] (2) Column conditions: 700 mm x 25 mm ID glass column, packed with 70 g of Bio Beads (S-X3, 200-400 mesh) as packing material (Manufacturer: Bio-Rad Labatories, Richmond, CA, Catalog 152-2750 or equivalent thereof)

[0190] (3) Sample conditions: A vinyl chloride-based polymer obtained was dissolved in a cyclohexane / methylene chloride mixture (1:1, v / v) to prepare a sample with a concentration of 5 to 10 mg / mL. Then, the sample was passed through a 0.45 μm filter for microfiltration, and about 5 mL of the sample was injected at a rate of 5.0 mL / min. The column temperature was maintained at room temperature.

[0191] (4) Detection method: Analyzed using a UV detector.

[0192] The low molecular weight content was calculated from the proportion corresponding to the portion where the value of log(Molecular weight) relative to the total molecular weight in the GPC results was 5 or less.

[0193]

[0194] The low molecular weight content was calculated from the proportion corresponding to the portion where the value of log(Molecular weight) relative to the total molecular weight in the GPC results was 5 or less.

[0195] 3) Cross-linked gel content: After weighing a cylindrical filter (Thimble filter), a vinyl chloride-based polymer was placed inside it and inserted into a Soxhlet extractor. 500 ml of tetrahydrofuran was added to a 1 L flask, all glassware was connected, and stirring, heating, and reflux were started at 95°C (above the boiling point of tetrahydrofuran) while water was flowing through a reflux condenser. After refluxing for 48 hours, the cylindrical filter was removed, dried in an oven, and weighed; the cross-linked gel content was determined by the difference in filter weight.

[0196] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Degree of Polymerization 4,100 4,224 4,117 1,050 1,650 2,650 4,100 Mn (g / mol) 125,949 117,841 114,893 64,764 98,858 123,201 145,496 Mw (g / mol) 485,170 438,987 440,859 141,997 224,983 398,538 494,115 Polydispersity Index 3.85 3.73 3.83 2.19 2.27 3.23 3.39 Low Molecular Weight Content (weight%) 27.6 33.1 34.8 49.5 33.9 25.5 23.4 Cross-linked gel content (weight%) 000000 3.1

[0197] Through the results of Table 2 above, it was confirmed that the vinyl chloride-based polymer of the present invention has a high degree of polymerization and, at the same time, a high polydispersity index, and compared to Comparative Example 4, which is a vinyl chloride-based polymer with the same high degree of polymerization, it has a relatively higher content of low molecular weight and a lower cross-linked gel content. In addition, in the case of Comparative Example 3, which used an isophthalate-based chain extender in the same way as the example but in an insufficient amount, a sufficient polymerization reaction was not carried out, resulting in both the degree of polymerization and the polydispersity index of the vinyl chloride-based polymer being lower than those of the example.

[0198]

[0199] Experimental Example 3. Confirmation of mechanical properties of the prepared vinyl chloride-based polymer

[0200] 100g of the vinyl chloride-based polymer obtained in the above examples and comparative examples was mixed with 70g of triisononyl trimellitate (plasticizer), 6g of RUP-166S (stabilizer), and 20g of calcium carbonate (filler) to form a compound formulation. Subsequently, a 1mm specimen was produced by rolling milling at 190℃ and pressing at 195℃. Tensile strength and elongation were measured on the produced specimens using a UTM at a speed of 20mm / min, and the results are shown in Table 3 below.

[0201] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Tensile strength (kg / cm²) 2 )173176175157168169167 New Rate(%)205207204203214189196

[0202] From the results of Table 3 above, it can be seen that the vinyl chloride-based polymer of the present invention has uniformly superior mechanical properties compared to the vinyl chloride-based polymer of the comparative example.

[0203]

[0204] Experimental Example 3. Confirmation of heat resistance properties of the prepared vinyl chloride-based polymer

[0205] The specimen prepared in Experimental Example 2 above was stored in an oven at 158°C for 168 hours, and the ratio of tensile strength and elongation before and after storage was measured and summarized in Table 4 below.

[0206] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Retention rate of tensile strength (%) 107 109 108 8397 105 107 Retention rate of elongation (%) 66 69 68 404 36 355

[0207] From the results of Table 4 above, it can be seen that the vinyl chloride-based polymer of the present invention maintains its tensile strength and elongation even when exposed to high temperatures for a long period of time, and through this, it can be seen that the vinyl chloride-based polymer of the present invention has excellent heat resistance.

[0208]

[0209] Experimental Example 4. Confirmation of melting characteristics of the prepared vinyl chloride-based polymer

[0210] After formulating the compound under the same conditions as in Experiment 2, the melting rate was analyzed by operating a Brabender plastograph tester at 135°C and 70 rpm, and the melting viscosity was analyzed using a TA DISCOVERY rheometer under conditions of 8 mm plate-to-plate, 1.0 mm gap, 190°C, 1.0% strain, and angular velocity of 0.1 to 100 rad / s. The melting rate was analyzed for Examples 1 to 3 and Comparative Example 4, and the melting viscosity was analyzed for Examples 1 to 3 and Comparative Examples 2 to 4.

[0211] The measured melting rate and viscosity values ​​are summarized in Table 5 below. The melting rate refers to the time required for the torque to stabilize in the melting rate graph, and the melting viscosity refers to the viscosity value at a specific angular velocity.

[0212] Example 1 Example 2 Example 3 Comparative Example 2 Comparative Example 3 Comparative Example 4 Melting rate (s) 48 50 49--80 Melting viscosity (Pa·s @ 190℃) 1 rad / s 58,789 60,125 60,102 24,192 50,247 77,992 10 rad / s 9,705 9,906 9,807 5,514 9,007 12,326 100 rad / s 1,790 1,830 1,820 1,240 1,808 2,214

[0213] As can be seen from the results of Figures 1 and 2 and Table 5 above, the vinyl chloride-based polymer of the present invention can exhibit superior melting characteristics compared to the vinyl chloride-based polymer of Comparative Example 4, which exhibits a similar level of degree of polymerization.

[0214]

[0215] Experimental Example 5. Measurement of Plasticizer Absorption Rate and Bulk Density

[0216] The plasticizer absorption rate and bulk density of the vinyl chloride-based polymers prepared in the above examples and comparative examples were measured. Each characteristic was measured by the following method.

[0217] 1) Plasticizer absorption rate:

[0218] The plasticizer absorption rate was measured by introducing vinyl chloride-based polymer resin, cotton, and a plasticizer into a specified glass tube, centrifuging the sample, and measuring the content of the plasticizer absorbed into the resin. The measurement was performed under conditions of 1.0 g of vinyl chloride polymer, 2.0 g of plasticizer, a centrifuge speed of 3,900 rpm, and operation at 20°C for 30 minutes (partially utilizing the measurement method based on ASTM-D3367). More specifically, the plasticizer absorption rate value was calculated using the following formula.

[0219] Plasticizer absorption rate = {(m3-m2) / (m2-m1)} x 100

[0220] m1 = Combined weight of glass tube and cotton

[0221] m2 = Combined weight of glass tubes, resin, and cotton

[0222] m3 = Combined weight of glass tube, resin, and cotton after plasticizer absorption

[0223] 2) Bulk density

[0224] 100g of vinyl chloride-based polymer was weighed into a 500mL container, and 0.27g of silica gel was added to prevent static electricity and mixed. Afterward, the prepared sample was placed into a bulk density meter of a certain volume, the weight was measured, and the measured weight was divided by the volume to calculate the value.

[0225] The measurement results are shown in Table 6 below.

[0226] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Plasticizer absorption rate (phr) 5 1 5 2 5 1 2 5 3 1 3 3 50 Bulk density (g / cm³) 3 )0.430.430.430.550.520.490.44

[0227] From the results of Table 6 above, it can be seen that the vinyl chloride-based polymer of the present invention exhibits a higher plasticizer absorption rate compared to conventional low-polymerization-degree vinyl chloride-based polymers.

Claims

1. The degree of polymerization is 2800 or higher and 5000 or lower, and A vinyl chloride-based polymer characterized by having a peak in the region between a retention time of 17 to 18 minutes in the graph obtained from the results of pyrolysis-gas chromatography analysis performed under the following conditions: [Analysis Conditions] 1) Thermal desorption temperature: 200 to 300℃ 2) GC / MSD conditions Injector temperature: 300℃ (isothermal) Carrier gas: Helium gas (flow rate: 1.0 mL / min) Column: HP-5MS capillary(30m x 250㎛ x 0.25㎛) Oven: 50℃ / 5 min, 15℃ / min, hold at 320℃ for 10 minutes Detector: MSD(scan mode) 2. In Paragraph 1, The above peak is a vinyl chloride polymer derived from an isophthalate compound.

3. In Paragraph 1, The above vinyl chloride-based polymer has a degree of polymerization of 3600 or more and 4500 or less.

4. In Paragraph 1, A vinyl chloride-based polymer having a polydispersity index of 3 or higher, calculated from the weight-average molecular weight and number-average molecular weight obtained through gel permeation chromatography (GPC) analysis using polystyrene as a reference material in accordance with US EPA 3640A: 1994.

5. In Paragraph 1, A vinyl chloride-based polymer having a low molecular weight content of 25 wt% or more and 40 wt% or less, with a molecular weight of 100,000 g / mol or less, as shown in the molecular weight graph obtained by gel permeation chromatography (GPC) analysis using polystyrene as a reference material pursuant to US EPA 3640A: 1994.

6. In Paragraph 1, Vinyl chloride-based polymer having a cross-linked gel content of 3 weight% or less.

7. A resin composition comprising a vinyl chloride-based polymer according to any one of claims 1 to 6.

8. In Paragraph 7, A resin composition comprising one or more additives selected from the group consisting of plasticizers, stabilizers, and fillers.

9. A step (S1) of preparing a chain extension aid by uniformly dispersing an isophthalate-based chain extender, a nonionic emulsifier, and polyvinyl alcohol; A step (S2) of introducing polymerization water, an initiator, the chain extension aid and a vinyl chloride monomer into a polymerization reactor and initiating a polymerization reaction; and A method for manufacturing a vinyl chloride-based polymer according to claim 1, comprising the step (S3) of synthesizing a vinyl chloride-based polymer by performing a polymerization reaction at a temperature of 50℃ or lower.

10. In Paragraph 9, A method for manufacturing a vinyl chloride-based polymer in which the above-mentioned isophthalate-based chain extender is diallyl isophthalate.

11. In Paragraph 9, A method for manufacturing a vinyl chloride-based polymer in which the above-mentioned nonionic emulsifier is one or more selected from the group consisting of polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate, sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate, glyceryl monooleate, and glyceryl monostearate.

12. In Paragraph 9, A method for manufacturing a vinyl chloride-based polymer in which the sum of the chain extension aids is 8 or more and 11.5 or less.

13. In Paragraph 9, A method for manufacturing a vinyl chloride-based polymer in which the above polymerization reaction is a suspension polymerization.

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