Vinyl chloride-based resin composition

Abstract

The present invention relates to a vinyl chloride-based resin composition, which exhibits excellent cold resistance and permanent compression set properties by comprising an elastomer and a vinyl chloride-based polymer having a high degree of polymerization and a high polydispersity index.

Description

Vinyl chloride-based resin composition

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0159248 filed November 11, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] Technology field

[0004] The present invention relates to a vinyl chloride resin composition that is particularly suitable for use as a chassis gasket or door belt, as it comprises a vinyl chloride-based polymer with a high degree of polymerization and an elastomer, thereby having excellent processability and cold resistance, and a molded article formed therefrom.

[0005] Polyvinyl chloride resin has been widely used for general purposes in various applications such as wires, fabrics, flooring, tarpaulins, and hoses due to its advantages of being relatively inexpensive, having excellent mechanical strength, weather resistance, insulation, and oil resistance, and being easy to process when used with auxiliary materials such as plasticizers and heat stabilizers.

[0006] However, the aforementioned polyvinyl chloride resin has limitations in that it lacks permanent compression set and cold resistance even when mixed with other processing auxiliary materials. Consequently, when used in window gaskets or automotive door belts, problems arise such as reduced durability and increased wind noise as the winter season passes.

[0007] Therefore, research is needed on new vinyl chloride-based resin compositions that can solve the problems of such existing polyvinyl chloride resins.

[0008] The present invention aims to provide a novel vinyl chloride resin composition capable of exhibiting excellent cold resistance and permanent compression set by using a vinyl chloride-based polymer with a high degree of polymerization in combination with an elastomer.

[0009] To solve the above-mentioned problem, the present invention provides a vinyl chloride-based resin composition.

[0010] Specifically, (1) the present invention provides a vinyl chloride resin composition comprising a vinyl chloride polymer and an elastomer having a degree of polymerization of 3700 or more and 5000 or less and a polydispersity index of 3.5 or more, and having a permanent compression set of 35% or more and 50% or less at 70°C.

[0011] (2) The present invention provides a vinyl chloride resin composition according to (1), wherein the polydispersity index of the vinyl chloride polymer is 3.7 or higher and 4.1 or lower.

[0012] (3) The present invention provides a vinyl chloride resin composition according to (1) or (2), wherein the vinyl chloride polymer has a low molecular weight content of 28% or more and 32% or less, with a molecular weight of 100,000 g / mol or less.

[0013] (4) The present invention provides a vinyl chloride resin composition in which, in any one of (1) to (3), the vinyl chloride polymer has a cold plasticizer absorption (CPA) of 40 phr or more and 60 phr or less.

[0014] (5) The present invention provides a vinyl chloride resin composition characterized in that, in any one of (1) to (4), the vinyl chloride polymer has a peak in the region between 19.40 and 19.60 minutes of retention time in the graph obtained from the pyrolysis-gas chromatography analysis result.

[0015] (6) The present invention provides a vinyl chloride resin composition in which, in any one of (1) to (5), the elastomer is one or more selected from the group consisting of natural rubber, styrene-butadiene rubber, chloroprene rubber, acrylic rubber, butyl rubber, fluororubber, silicone rubber, urethane rubber and nitrile-butadiene rubber.

[0016] (7) The present invention provides a vinyl chloride resin composition in which, in any one of (1) to (6), the elastomer is partially cross-linked.

[0017] (8) The present invention provides a vinyl chloride resin composition in which, in any one of (1) to (7), the elastomer has a gel content of 60 weight% or more.

[0018] (9) The present invention provides a vinyl chloride resin composition in any one of (1) to (8), wherein the elastomer is a partially cross-linked nitrile-butadiene rubber.

[0019] (10) The present invention provides a vinyl chloride resin composition in which, in any one of (1) to (9), the elastomer is included in an amount of 40 parts by weight or more and 100 parts by weight or less per 100 parts by weight of the vinyl chloride polymer.

[0020] (11) The present invention provides a vinyl chloride resin composition in which, in any one of (1) to (10), the resin composition further comprises a plasticizer, wherein the plasticizer is included in an amount of 50 parts by weight or more and 130 parts by weight or less per 100 parts by weight of the vinyl chloride polymer.

[0021] (12) The present invention provides a vinyl chloride resin composition in which, in any one of (1) to (11), the resin composition further comprises a stabilizer, wherein the stabilizer is included in an amount of 1 part by weight or more and 15 parts by weight or less per 100 parts by weight of the vinyl chloride polymer.

[0022] (13) The present invention provides a vinyl chloride resin composition in which, in any one of (1) to (12), the resin composition further comprises an inorganic filler, and the inorganic filler is included in an amount of 10 parts by weight or more and 50 parts by weight or less per 100 parts by weight of the vinyl chloride polymer.

[0023] (14) The present invention provides a vinyl chloride resin composition in which, in any one of (1) to (13), the resin composition further comprises a lubricant, wherein the lubricant is included in an amount of 0.05 parts by weight or more and 1 part by weight or less per 100 parts by weight of the vinyl chloride polymer.

[0024] (15) The present invention provides a vinyl chloride resin composition in which, in any one of (1) to (14), the resin composition further comprises a processing aid, wherein the processing aid is included in an amount of 0.1 parts by weight or more and 5 parts by weight or less per 100 parts by weight of the vinyl chloride polymer.

[0025] The vinyl chloride resin of the present invention incorporates a vinyl chloride polymer with a high degree of polymerization and a high polydispersity index together with an elastomer, thereby improving the relatively poor cold resistance and permanent compression set of the vinyl chloride polymer itself, while maintaining the excellent plasticizer absorption rate, mechanical properties, and weather resistance derived from the high degree of polymerization vinyl chloride polymer. Accordingly, the vinyl chloride resin of the present invention may be particularly suitable for use in applications such as window and door gaskets or automobile door belts.

[0026] The present invention will be described in more detail below.

[0027] 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.

[0028] 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.

[0029]

[0030] Vinyl chloride-based resin composition

[0031] The present invention provides a vinyl chloride resin composition comprising a vinyl chloride polymer and an elastomer having a degree of polymerization of 3,700 or more and 5,000 or less and a polydispersity index of 3.5 or more, and having a permanent compression set of 35% or more and 50% or less at 70°C.

[0032]

[0033] Below, the vinyl chloride-based resin composition of the present invention will be described in more detail.

[0034]

[0035] vinyl chloride-based polymer

[0036] The vinyl chloride polymer included in the vinyl chloride resin composition of the present invention is characterized by a high degree of polymerization and a high polydispersity index.

[0037] More specifically, the vinyl chloride-based polymer may have a degree of polymerization of 3,700 or more and 5,000 or less, and a polydispersity index of 3.5 or more.

[0038]

[0039] Existing vinyl chloride-based polymer products known to possess a high degree of polymerization have limitations in that, even with a high degree of polymerization, their polydispersity index is low, resulting in insufficient mechanical properties and insufficiently fast melting speeds. In this invention, a vinyl chloride-based polymer is used that possesses both a high degree of polymerization and a high polydispersity index, thereby enabling the simultaneous realization of the advantages of a high degree of polymerization, namely heat resistance, and the advantages of a high polydispersity index, namely excellent melting characteristics.

[0040]

[0041] More specifically, the degree of polymerization of the vinyl chloride-based polymer included in the resin composition of the present invention may be 3,700 or more, 3,800 or more, 3,900 or more, 4,000 or more, or 4,050 or more, and 5,000 or less, 4,900 or less, 4,800 or less, 4,700 or less, 4,600 or less, 4,500 or less, 4,400 or less, 4,300 or less, or 4,200 or less. It is not easy to significantly increase the degree of polymerization of the vinyl chloride-based polymer itself beyond the range described above, and the vinyl chloride-based polymer included in the resin composition of the present invention can have excellent heat resistance properties by having a degree of polymerization within the range described above. Meanwhile, the degree of polymerization can be measured using the viscosity of the vinyl chloride-based polymer. More specifically, 0.5 g of the vinyl chloride-based polymer is mixed with 100 mL of cyclohexanone and heated at 110°C for 2 hours to completely dissolve it. After cooling the flask containing the solution by placing it in a water bath at 30°C, 10 mL of the measurement solution is introduced into a viscometer, and the viscosity can be measured by measuring the time based on passing the reference scale line (ASTM-D1243). The degree of polymerization can be calculated by converting the measured viscosity using a conversion table for the measured viscosity, K-Value, and degree of polymerization (refer to PVC Technology literature).

[0042]

[0043] The number average molecular weight of the vinyl chloride-based polymer included in the resin composition of the present invention may be 100,000 g / mol or more and 150,000 g / mol or less, preferably 100,000 g / mol or more, 105,000 g / mol or more, 110,000 g / mol or more, 115,000 g / mol or more, or 120,000 g / mol or more, and may be 150,000 g / mol or less, 145,000 g / mol or less, 140,000 g / mol or less, 135,000 g / mol or less, or 130,000 g / mol or less. In addition, the weight average molecular weight of the vinyl chloride-based polymer included in the resin composition of the present invention may be 430,000 g / mol or more and 515,000 g / mol or less, preferably 430,000 g / mol or more, 440,000 g / mol or more, 445,000 g / mol or more, 450,000 g / mol or more, 455,000 g / mol or more, or 460,000 g / mol or more, and may be 515,000 g / mol or less, 510,000 g / mol or less, 505,000 g / mol or less, 500,000 g / mol or less, 495,000 g / mol or less, or 490,000 g / mol or less. The number average molecular weight and weight average molecular weight can be measured using conventional methods, for example, by using a GPC (gel permeation chromatography) facility. More specifically, 0.02 g of the obtained vinyl chloride-based polymer is dissolved in 20 mL of THF, foreign substances are removed using a 0.45 μm filter, and the sample is fed into a gel permeation chromatography (GPC) facility (Waters 2414 RID, column: PLgel mini-mixed B x 2) to measure and analyze under conditions of a flow rate of 0.3 mL / min and a column temperature of 40°C.

[0044]

[0045] The polydispersity index (PDI) of the vinyl chloride-based polymer included in the resin composition of the present invention may be 3.5 or higher, preferably 3.5 or higher, 3.6 or higher, 3.7 or higher, 3.8 or higher, or 3.85 or higher, and may be 4.1 or lower, 4.0 or lower, or 3.95 or lower. 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 included in the resin composition of 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.

[0046]

[0047] In the vinyl chloride-based polymer included in the resin composition of the present invention, the content of low molecular weight, having a molecular weight of 100,000 g / mol or less, included in the vinyl chloride-based polymer may be 28% by weight or more and 32% by weight or less, and preferably 28% by weight or more, 28.5% by weight or more, 29% by weight or more, 29.5% by weight or more, or 30% by weight or more, and 32% by weight or less, 31.5% by weight or less, or 31% by weight or less. As previously explained, the above 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 included in the resin composition 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 a region with a molecular weight of 100,000 g / mol or less to the total area of ​​the molecular weight graph obtained through GPC (gel penetration chromatography) analysis of the vinyl chloride-based polymer.

[0048]

[0049] In addition, the vinyl chloride-based polymer included in the resin composition of 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 the GPC 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 included in the resin composition of the present invention may exhibit such characteristics because the content of low molecular weight is maintained at a relatively high level. Meanwhile, the GPC analysis may be performed by dissolving 0.02g of the vinyl chloride-based polymer in 20mL of THF, filtering out impurities with a 0.45㎛ filter, and then performing the analysis under conditions of a flow rate of 0.3mL / min and a column temperature of 40℃. The molecular weight graph obtained through the GPC analysis may have the horizontal axis as the logarithm of the molecular weight (log(M)) and the vertical axis as the value obtained by differentiating the fraction w with the log(M) value (dw / dlog(M)).

[0050]

[0051] The vinyl chloride-based polymer included in the resin composition of 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 result of a specimen obtained by compounding the vinyl chloride-based polymer is 60 seconds or less. Preferably, the time between the two points may be 55 seconds or less, 50 seconds or less, or 45 seconds or less.

[0052] In addition, the vinyl chloride-based polymer included in the resin composition of 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.

[0053] 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.

[0054]

[0055] 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.

[0056]

[0057] The vinyl chloride-based polymer included in the resin composition of 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 / cm³3 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.

[0058]

[0059] In addition, the vinyl chloride-based polymer included in the resin composition of 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 CPA of 90 phr or less, 80 phr or less, 70 phr or less, or 60 phr or less. The above plasticizer absorption rate is determined by introducing a vinyl chloride-based polymer resin, cotton, and a plasticizer into a specified glass tube, centrifuging, and measuring the content of the plasticizer absorbed within the resin. The measurement may be 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 can be calculated using the following formula.

[0060] Plasticizer absorption rate = {(m3-m2) / (m2-m1)} x 100

[0061] m1 = Combined weight of glass tube and cotton

[0062] m2 = Combined weight of glass tubes, resin, and cotton

[0063] m3 = Combined weight of glass tube, resin, and cotton after plasticizer absorption

[0064]

[0065] The vinyl chloride-based polymer included in the resin composition of the present invention is characterized by having a peak in the region between 19.40 and 19.60 minutes of retention time in the graph obtained from the pyrolysis-gas chromatography analysis results. The said peak may indicate that the isophthalate-based chain extender used in the polymerization process of the vinyl chloride-based polymer is appropriately distributed within the polymer chain, and in particular, the vinyl chloride-based polymer included in the resin composition of the present invention may exhibit a peak in the region between 19.4 and 19.6 minutes of retention time, preferably in the region between 19.45 and 19.5 minutes. The said peak may be derived from an isophthalate-based compound, and more specifically, may be derived from diallyl isophthalate.

[0066] Meanwhile, the above-mentioned pyrolysis-gas chromatography analysis (Py-GC / MSD) involves heat-treating a vinyl chloride-based polymer at a constant temperature to remove impurities, then pyrolyzing the polymer at a higher temperature to form a mixture of compounds with relatively small molecular weights, and subsequently performing gas chromatographic analysis on such a mixture.

[0067] The heat treatment may be performed at 250 to 350°C, and more specifically, it may be performed by starting at a temperature of 250 to 300°C, heating at a constant heating rate until the temperature reaches 300 to 350°C, and then maintaining the temperature for a certain period of time from the point at which the temperature is reached. Even more specifically, the heat treatment may be performed by starting at a temperature of 280°C, heating at a rate of 20°C / min, reaching 320°C, and then maintaining the temperature at 320°C for 2 minutes. In this case, the total heat treatment time may be 4 minutes.

[0068] After the above heat treatment, the thermal decomposition may be performed at a temperature sufficient for the polymer chains within the polymer to decompose, more specifically at a temperature of 500°C or higher and 700°C or lower, more specifically at a temperature of 550°C to 650°C, and particularly preferably at 590°C.

[0069] The gas chromatography analysis performed after the above heat treatment and pyrolysis may be performed under the following conditions.

[0070] Injector temperature: 300℃ (isothermal)

[0071] Carrier gas: Helium gas (Flow rate: 1.4 mL / min)

[0072] Column: HP-5MS capillary(30m x 250㎛ x 0.25㎛)

[0073] Oven: 40℃ / 3 min, 10℃ / min, hold at 320℃ for 15 minutes

[0074] Detector: MSD(scan mode)

[0075]

[0076] In addition, the vinyl chloride-based polymer included in the resin composition of 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 included in the resin composition 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.

[0077]

[0078] The vinyl chloride-based polymer included in the resin composition of the present invention may be in powder form.

[0079]

[0080] elastomer

[0081] The vinyl chloride-based resin composition of the present invention may include an elastomer together with the vinyl chloride-based polymer described above. The elastomer can improve the relatively inferior permanent compression set and cold resistance of the high-polymerization-degree vinyl chloride-based polymer.

[0082]

[0083] More specifically, the elastomer may be one or more selected from the group consisting of natural rubber, styrene-butadiene rubber, chloroprene rubber, acrylic rubber, butyl rubber, fluororubber, silicone rubber, urethane rubber, and nitrile-butadiene rubber, and preferably may be nitrile-butadiene rubber.

[0084] In addition, the above elastomer may be partially crosslinked. More specifically, the above elastomer may be partially crosslinked and have a gel content of 60% by weight or more, preferably 65% ​​by weight or more and 80% by weight or less. Generally, elastomers have a high degree of crosslinking through sulfur crosslinking and possess thermosetting properties; however, the elastomer used in the present invention is partially crosslinked, which has excellent compatibility with vinyl chloride-based polymers and has the advantage of enabling the reuse of the vinyl chloride-based resin composition thereafter. Furthermore, by using such a partially crosslinked elastomer, the vinyl chloride-based resin composition of the present invention may not contain incidental additives such as sulfur, crosslinking agents, or crosslinking accelerators, and has the advantage of being usable without a subsequent crosslinking process. Furthermore, when using nitrile-butadiene rubber partially crosslinked with the above elastomer, the physical properties of the vinyl chloride resin composition can be improved by supplementing the cold resistance and permanent compression set of the vinyl chloride polymer.

[0085] The above elastomer may be included in an amount of 40 parts by weight or more and 100 parts by weight or less relative to 100 parts by weight of the vinyl chloride-based polymer, and preferably may be included in an amount of 40 parts by weight or more, 50 parts by weight or more, 60 parts by weight or more, or 65 parts by weight or more, and 100 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less, or 75 parts by weight or less. If the content of the above elastomer is not appropriate, the balance of physical properties of the resin composition may be reduced.

[0086]

[0087] The vinyl chloride-based resin composition of the present invention may have a permanent compression set of 35% or more and 50% or less at 70°C by including the elastomer. The permanent compression set can be measured using a button-type test specimen (a straight mold with a thickness of 12.70 ± 0.13 mm and a diameter of about 29.0 mm) prepared according to the KS M 6518 and ASTM D396 test methods, and the vinyl chloride-based resin composition of the present invention may have excellent durability by having a permanent compression set within the above range.

[0088]

[0089] Meanwhile, the vinyl chloride-based resin composition provided by the present invention may further include a plasticizer. As the 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.

[0090] The above plasticizer may be included in an amount of 50 parts by weight or more and 130 parts by weight or less per 100 parts by weight of the vinyl chloride-based polymer, preferably in an amount of 50 parts by weight or more, 60 parts by weight or more, or 70 parts by weight or more, and may be included in an amount of 130 parts by weight or less, 120 parts by weight or less, or 110 parts by weight or less.

[0091]

[0092] In addition, the vinyl chloride-based resin composition provided by the present invention may further include a stabilizer. The stabilizer may be a conventional stabilizer used in conjunction with a vinyl chloride-based polymer, and specifically, may include Ca-Zn-based compounds; Ba-Zn-based compounds; mercaptide-based compounds; organic tin-based compounds such as maleic acid-based compounds or carboxylic acid-based compounds; metallic soap-based compounds such as Mg-stearate, Ca-stearate, Pb-stearate, Cd-stearate, or Ba-stearate; phenol-based compounds; phosphate ester-based compounds; or phosphite ester-based compounds; and one or more of the fillers listed above may be selected and used according to the application. Preferably, a Ca-Zn-based compound may be used in the present invention.

[0093] The above stabilizer may be included in an amount of 1 part by weight or more and 15 parts by weight or less per 100 parts by weight of the vinyl chloride-based polymer, preferably in an amount of 1 part by weight or more, 3 parts by weight or more, or 5 parts by weight or more, and in an amount of 15 parts by weight or less, 13 parts by weight or less, or 10 parts by weight or less.

[0094]

[0095] In addition, the vinyl chloride-based resin composition provided by the present invention may further include an inorganic filler. The inorganic filler may be a conventional inorganic filler used together with a vinyl chloride-based polymer, and specifically, calcium carbonate, clay, talc, or diatomaceous earth may be used.

[0096] The above inorganic filler may be included in an amount of 10 parts by weight or more and 50 parts by weight or less per 100 parts by weight of the vinyl chloride-based polymer, preferably in an amount of 10 parts by weight or more, 15 parts by weight or more, or 20 parts by weight or more, and may be included in an amount of 50 parts by weight or less, 45 parts by weight or less, or 40 parts by weight or less.

[0097]

[0098] In addition, the vinyl chloride-based resin composition provided by the present invention may further include a lubricant. Conventional commercial lubricants may be used as the lubricant.

[0099] The above lubricant may be included in an amount of 0.05 parts by weight or more and 1 part by weight or less per 100 parts by weight of the vinyl chloride-based polymer, preferably in an amount of 0.1 parts by weight or more, 0.15 parts by weight or more, or 0.2 parts by weight or more, and may be included in an amount of 1 part by weight or less, 0.8 parts by weight or less, 0.6 parts by weight or less, or 0.5 parts by weight or less.

[0100]

[0101] In addition, the vinyl chloride-based resin composition provided by the present invention may further include a processing aid. Conventional commercial processing aids may be used as the processing aid.

[0102] The above processing aid may be included in an amount of 0.1 parts by weight or more and 5 parts by weight or less per 100 parts by weight of the vinyl chloride-based polymer, preferably in an amount of 0.1 parts by weight or more, 0.5 parts by weight or more, or 1 part by weight or more, and may be included in an amount of 5 parts by weight or less, 3 parts by weight or less, or 2 parts by weight or less.

[0103]

[0104] 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.

[0105]

[0106] Preparation Example

[0107] Internal volume of 1m² equipped with reflux condenser and stirrer 3 450 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.

[0108] 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.

[0109]

[0110] Examples and Comparative Examples

[0111] Vinyl chloride resin compositions were prepared with the compositions listed in Tables 1 and 2 below. The numbers listed in each cell of the table represent the relative weight parts of each component. Meanwhile, the vinyl chloride polymers used in the comparative example, LS100 (degree of polymerization: 990, weight average molecular weight: 141997 g / mol, number average molecular weight: 64764 g / mol, polydispersity index: 2.19, plasticizer absorption rate: 24 wt%) and LS130S (degree of polymerization: 1280, weight average molecular weight: 191876 g / mol, number average molecular weight: 71409 g / mol, polydispersity index: 2.69, plasticizer absorption rate: 28.5 wt%), are vinyl chloride polymer products from LG Chem.

[0112] Type Example 1 Example 2 Example 3 Example 4 Example 5 Vinyl Chloride Polymer Preparation Example 100100100100100 Elastomer Partially Cross-linked NBR(P35)4070100--Partially Cross-linked NBR(P83)---40100 Stabilizer RUP-144S77777 Plasticizer TOTM100100100100100 Inorganic Filler CaCO3(OMYA 1T)3030303030 Lubricant AC6290.30.30.30.30.3 Processing Aid PA93222222

[0113] Type Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Vinyl chloride-based polymer LS100 100-100-100-LS130S-100-100-100 Elastomer Partially cross-linked NBR(P35)----100100 Partially cross-linked NBR(P83)------Stabilizer RUP-144S777777 Plasticizer TOTM7070 1001007070 Inorganic filler CaCO3(OMYA 1T)303030303030 Lubricant AC6290.30.30.30.30.30.30.3 Processing aid PA932222222

[0114] * TOTM: Tri(2-ethylhexyl) trimellitate

[0115]

[0116] Meanwhile, the gel content of the partially cross-linked NBR was measured by the toluene extraction method. 1 g of partially cross-linked NBR was placed in a 250 mL beaker, 100 g of toluene was added, and after being stored in a dark room for 12 hours, the insoluble matter was filtered through a sieve. The insoluble matter was then dried at 85°C for 4 hours to obtain solid matter, and the gel content was calculated by dividing the weight of the solid matter by the initial weight of NBR and multiplying by 100%. The gel content of both types of partially cross-linked NBR used, P35 and P83, was confirmed to be 65 wt%.

[0117]

[0118] Experimental Example 1. Measurement of the degree of polymerization and molecular weight of vinyl chloride-based polymers

[0119] The degree of polymerization and molecular weight of the vinyl chloride-based polymer prepared in the above preparation example were measured, and the results are summarized in Table 3 below.

[0120] Meanwhile, the degree of polymerization and molecular weight were measured using the following method.

[0121] 1) Degree of polymerization:

[0122] 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).

[0123] 2) Molecular weight and low molecular weight content:

[0124] 0.02 g of the obtained vinyl chloride-based polymer was dissolved in 20 mL of THF, and impurities were removed using a 0.45 µm filter. Subsequently, the sample was introduced into a gel permeation chromatography (GPC) system (Waters 2414 RID, column: PLgel mini-mixed B x 2) and measured and analyzed under conditions of a flow rate of 0.3 mL / min and a column temperature of 40°C.

[0125] 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.

[0126]

[0127] Preparation Example Degree of Polymerization 4,100 Number Average Molecular Weight (g / mol) 125,949 Weight Average Molecular Weight (g / mol) 485,170 Polydispersity Index 3.85 Low Molecular Weight Content (weight%) 28.9

[0128] Through the results of Table 3 above, it was confirmed that the vinyl chloride-based polymer used in the resin composition of the present invention has a high degree of polymerization and, at the same time, a high polydispersity index.

[0129]

[0130] Experimental Example 2. Measurement of physical properties of the prepared vinyl chloride-based resin composition

[0131] The following physical properties were measured for the vinyl chloride-based resin compositions prepared in the above examples and comparative examples, and the results are summarized in Table 4.

[0132] 1) Hardness (Shore A): Measured in accordance with KS M 6518 and ASTM D2240. More specifically, a ZwickRoell hardness tester was used, and the hardness was measured using the Shore A type for samples with a thickness of 12 mm or more. The prepared sample was placed on the sample measuring plate, tipped down, and the hardness value was checked after 10 seconds. The average value was calculated after measuring at five points.

[0133] 2) Specific gravity (g / cm³) 3The weight of the specimen manufactured in accordance with KS M 6518 was measured, and the weight was calculated by dividing the said weight by the volume of the specimen.

[0134] 3) Permanent compression set (C-set, @70℃, %): Measured using a button-type test specimen (thickness 12.70±0.13mm, diameter approximately 29.0mm) manufactured according to KS M 6518 and ASTM D396 test methods.

[0135] 4) Tensile strength (MPa) and elongation (%): Dumbbell-shaped specimen No. 3 was prepared in accordance with KS M 6518 and ISO 37 test methods, and measured using a tensile testing machine (Instron, 3345). The average value of the values ​​measured using five samples was recorded.

[0136] 5) Cold resistance (°C): Measured according to KS M 6676 and ASTM D2137.

[0137]

[0138] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Hardness 60 60 60 60 70 70 Poor Blending Poor Blending 70 70 Specific Gravity 1.1 3 1.1 2 1.1 1.1 3 1.1 1.2 3 1.2 3 1.2 3 C-set 4 5 4 0 3 5 4 8 4 2 6 0 5 8 5 8 5 6 Tensile Strength 10.4 1 1.1 1 1.2 1 0.4 1 1.1 9 8 10 9 Elongation 3 4 9 3 5 0 3 5 1 3 4 9 3 5 1 2 8 0 3 0 3 0 3 10 Cold Resistance -50 -52 or less -52 or less -50 -52 or less -38 -40 -38 -40

[0139] Through the results of Table 4 above, it can be seen that the vinyl chloride resin composition of the present invention achieves superior effects compared to cases where a vinyl chloride polymer with a relatively low degree of polymerization is used or where no elastomer is used.

Claims

1. A vinyl chloride-based polymer having a degree of polymerization of 3,700 or more and 5,000 or less, and a polydispersity index of 3.5 or more; and Includes elastomer; A vinyl chloride resin composition having a permanent compression set of 35% or more and 50% or less at 70℃.

2. In Paragraph 1, A vinyl chloride resin composition having a polydispersity index of 3.7 or higher and 4.1 or lower of the above vinyl chloride-based polymer.

3. In Paragraph 1, The above vinyl chloride-based polymer is a vinyl chloride resin composition having a low molecular weight content of 28% by weight or more and 32% by weight or less, with a molecular weight of 100,000 g / mol or less.

4. In Paragraph 1, The above vinyl chloride-based polymer is a vinyl chloride-based resin composition having a cold plasticizer absorption (CPA) of 40 phr or more and 60 phr or less.

5. In Paragraph 1, A vinyl chloride resin composition characterized in that the above vinyl chloride polymer has a peak in the region between 19.40 and 19.60 minutes of retention time in the graph obtained from pyrolysis-gas chromatography analysis.

6. In Paragraph 1, The above elastomer is a vinyl chloride-based resin composition comprising one or more selected from the group consisting of natural rubber, styrene-butadiene rubber, chloroprene rubber, acrylic rubber, butyl rubber, fluororubber, silicone rubber, urethane rubber, and nitrile-butadiene rubber.

7. In Paragraph 1, The above elastomer is a vinyl chloride-based resin composition that is partially cross-linked.

8. In Paragraph 1, The above elastomer is a vinyl chloride-based resin composition having a gel content of 60 weight% or more.

9. In Paragraph 1, The above elastomer is a vinyl chloride-based resin composition that is partially cross-linked nitrile-butadiene rubber.

10. In Paragraph 1, A vinyl chloride resin composition in which the above elastomer is included in an amount of 40 parts by weight or more and 100 parts by weight or less per 100 parts by weight of a vinyl chloride polymer.

11. In Paragraph 1, The above resin composition further includes a plasticizer, and A vinyl chloride resin composition in which the above plasticizer is included in an amount of 50 parts by weight or more and 130 parts by weight or less per 100 parts by weight of a vinyl chloride polymer.

12. In Paragraph 1, The above resin composition further includes a stabilizer, and A vinyl chloride resin composition comprising at least 1 part by weight and no more than 15 parts by weight per 100 parts by weight of the vinyl chloride polymer.

13. In Paragraph 1, The above resin composition further comprises an inorganic filler, and A vinyl chloride resin composition in which the above-mentioned inorganic filler is included in an amount of 10 parts by weight or more and 50 parts by weight or less per 100 parts by weight of a vinyl chloride polymer.

14. In Paragraph 1, The above resin composition further includes a lubricant, and A vinyl chloride resin composition in which the above lubricant is included in an amount of 0.05 parts by weight or more and 1 part by weight or less per 100 parts by weight of a vinyl chloride polymer.

15. In Paragraph 1, The above resin composition further includes a processing aid, and A vinyl chloride resin composition comprising the above processing aid in an amount of 0.1 parts by weight or more and 5 parts by weight or less per 100 parts by weight of a vinyl chloride polymer.