Recycled epdm rubber composition and molded article prepared therefrom

Abstract

One embodiment of the present specification provides a recycled EPDM rubber composition comprising waste EPDM rubber and a polyolefin elastomer.

Description

Technology Field

[0001] This specification relates to a recycled EPDM rubber composition and a molded article made therefrom. Background Technology

[0002] Recently, as global warming and environmental pollution issues have become increasingly serious, interest in the treatment of industrial waste has been growing, and interest in the recycling of petrochemical products is rising worldwide. However, due to their cross-linked structure, rubber materials are relatively difficult to recycle compared to general plastics, so they are primarily disposed of through methods such as incineration or landfilling.

[0003] EPDM (Ethylene Propylene Diene Monomer), also known as ethylene propylene rubber, is a high-performance synthetic rubber obtained by copolymerizing ethylene, propylene, and a diene that functions as a crosslinking site. EPDM rubber has excellent heat resistance, ozone resistance, and chemical resistance, and is used in various fields such as automotive body seals, tire tubes, hoses, washing machine gaskets, electrical wires, and construction materials.

[0004] Meanwhile, used EPDM rubber products or EPDM rubber scrap generated during the rubber production process were conventionally classified as byproduct waste and treated as difficult to recycle due to the large amount of additives used in the vulcanization process. Consequently, waste EPDM rubber was primarily disposed of by incineration, but this method posed problems by causing water and air pollution.

[0005] Consequently, although there have been attempts to recycle waste EPDM rubber, recycled EPDM rubber produced using waste EPDM exhibited inferior mechanical properties compared to conventional EPDM rubber. Furthermore, while a desulfurization process is required for recycling waste EPDM rubber, recycled EPDM rubber produced through this process presented a problem where odors were generated due to severed sulfur bonds.

[0006] Therefore, there is a need to develop a recycled EPDM rubber composition that contains waste EPDM rubber, possesses excellent mechanical properties, and can solve the odor problem. The problem to be solved

[0007] The details described in this specification are intended to solve the problems of the aforementioned prior art, and one objective of this specification is to provide a recycled EPDM rubber composition that includes waste EPDM rubber, has excellent mechanical properties, and solves the odor problem.

[0008] Another objective of this specification is to provide a rubber molded article that is environmentally friendly by using waste EPDM rubber and exhibits excellent mechanical properties and low odor characteristics through upcycling. means of solving the problem

[0009] According to one aspect, a recycled EPDM rubber composition comprising waste EPDM rubber and a polyolefin elastomer is provided.

[0010] In one embodiment, the polyolefin elastomer may be a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.

[0011] In one embodiment, the melt flow index of the polyolefin elastomer (@190 ℃ / 2.16 kg, ASTM D1238) may be 0.1 to 20.0 g / 10 min.

[0012] In one embodiment, the Mooney viscosity (ML1+4, @121 ℃, ASTM D1646) of the polyolefin elastomer may be 10 to 30 MU.

[0013] In one embodiment, the tensile strength at break (500 mm / min, ASTM D638) of the polyolefin elastomer is 50 to 250 kgf / cm 2 It could be.

[0014] In one embodiment, the elongation at break of the polyolefin elastomer (500 mm / min, ASTM D638) may be 500 to 900%.

[0015] In one embodiment, the content of the polyolefin elastomer may be 5 to 35 parts by weight per 100 parts by weight of the waste EPDM rubber.

[0016] In one embodiment, the recycled EPDM rubber composition may further include a deodorizing agent.

[0017] In one embodiment, the deodorizing agent may be one selected from the group consisting of diatomite, alumina, sodium oxide, and a combination of two or more of these.

[0018] In one embodiment, the content of the deodorizer may be 1 to 20 parts by weight per 100 parts by weight of the waste EPDM rubber.

[0019] According to another aspect, a molded article manufactured from the above recycled EPDM rubber composition is provided. Effects of the invention

[0020] A recycled EPDM rubber composition according to one aspect of the present specification includes waste EPDM rubber and has excellent mechanical properties, while also being able to solve the odor problem associated with the use of waste EPDM rubber.

[0021] In addition, a molded article according to another aspect of this specification is environmentally friendly by using waste EPDM rubber and can exhibit excellent mechanical properties and low odor characteristics through upcycling.

[0022] The effects of one aspect of this specification are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configurations described in the detailed description or claims of this specification. Specific details for implementing the invention

[0023] Hereinafter, one aspect of this specification will be described based on specific examples. However, the details described in this specification may be implemented in various different forms and are therefore not limited to the embodiments described herein.

[0024] Throughout the specification, when it is stated that a part is "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0025] When a range of numerical values ​​is described in this specification, unless a specific range is otherwise described, the value has the precision of significant figures provided according to the standard rules in chemistry for significant figures. For example, 10 includes a range of 5.0 to 14.9, and the number 10.0 includes a range of 9.50 to 10.49.

[0026] Recycled EPDM rubber composition

[0027] A recycled EPDM rubber composition according to one aspect of the present specification comprises waste EPDM rubber and a polyolefin elastomer.

[0028] The above recycled EPDM rubber composition is eco-friendly as it uses waste EPDM (Ethylene Propylene Diene Monomer) rubber, and by including a polyolefin elastomer, it exhibits excellent mechanical properties such as high tensile strength and elongation, making it applicable to the manufacture of upcycling products.

[0029] The above waste EPDM rubber may be waste EPDM rubber powder produced by crushing or grinding used EPDM rubber products or EPDM rubber scraps generated in the rubber production process.

[0030] The above waste EPDM rubber may be desulfurized waste EPDM rubber powder.

[0031] The content of the waste EPDM rubber may be 65% by weight or more based on the total weight of the recycled EPDM rubber composition. For example, it may be 65% by weight or more, 66% by weight or more, 67% by weight or more, 68% by weight or more, 69% by weight or more, 70% by weight or more, 71% by weight or more, 72% by weight or more, 73% by weight or more, 74% by weight or more, 75% by weight or more, 80% by weight or more, 85% by weight or more, or 90% by weight or more. If the content of waste EPDM rubber is less than the above range, the specific gravity of the molded product may decrease, and the eco-friendliness may be reduced as the proportion of recycled material decreases. Meanwhile, since a higher content of waste EPDM rubber is advantageous for eco-friendliness, there is no specific upper limit, but it may be limited to about 95% by weight in consideration of the content of the polyolefin elastomer described later.

[0032] The above polyolefin elastomer may be a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. For example, the above polyolefin elastomer may be a copolymer of ethylene and an α-olefin having 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 carbon atoms, or a range between two of these values. Preferably, it may be a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, but is not limited thereto.

[0033] The melt flow index (MI; Melt Index) (@190 ℃ / 2.16 kg, ASTM D1238) of the above polyolefin elastomer may be 0.1 to 20.0 g / 10 min. For example, 0.1 g / 10min, 0.2 g / 10min, 0.3 g / 10min, 0.4 g / 10min, 0.5 g / 10min, 0.6 g / 10min, 0.7 g / 10min, 0.8 g / 10min, 0.9 g / 10min, 1.0 g / 10min, 1.1 g / 10min, 1.2 g / 10min, 1.3 g / 10min, 1.4 g / 10min, 1.5 g / 10min, 2.0 g / 10min, 2.5 g / 10min, 3.0 g / 10min, 3.5 g / 10min, 4.0 g / 10min, 4.5 g / 10min, 5.0 g / 10min, 6.0 g / 10min, 7.0 g / 10min, It may be 8.0 g / 10min, 9.0 g / 10min, 10.0 g / 10min, 11.0 g / 10min, 12.0 g / 10min, 13.0 g / 10min, 14.0 g / 10min, 15.0 g / 10min, 16.0 g / 10min, 17.0 g / 10min, 18.0 g / 10min, 19.0 g / 10min, 20.0 g / 10min, or a range between two of these values. If the melt flow index of the polyolefin elastomer is below the above range, it may be difficult to measure or compatibility with waste EPDM rubber may be reduced, and if it exceeds the above range, the tensile strength and elongation of the molded article made from the recycled EPDM rubber composition may be reduced.

[0034] The Mooney viscosity (ML1+4, @121 °C, ASTM D1646) of the above polyolefin elastomer may be 10 to 30 MU. For example, it may be 10 MU, 11 MU, 12 MU, 13 MU, 14 MU, 15 MU, 16 MU, 17 MU, 18 MU, 19 MU, 20 MU, 21 MU, 22 MU, 23 MU, 24 MU, 25 MU, 26 MU, 27 MU, 28 MU, 29 MU, 30 MU, or a range between two of these values. If the Mooney viscosity of the polyolefin elastomer is below the above range, the tensile strength and elongation of the molded article made from the recycled EPDM rubber composition may decrease, and if it exceeds the above range, compatibility with waste EPDM rubber may decrease.

[0035] The tensile strength at break of the above polyolefin elastomer (500 mm / min, ASTM D638) is 50–250 kgf / cm 2 It can be. For example, 50 kgf / cm² 2 , 60 kgf / cm 2 , 70 kgf / cm 2 , 80 kgf / cm 2 , 90 kgf / cm 2 , 100 kgf / cm 2 , 110 kgf / cm 2 , 120 kgf / cm 2 , 130 kgf / cm 2 , 140 kgf / cm 2 , 150 kgf / cm 2 , 160 kgf / cm 2 , 170 kgf / cm 2 , 180 kgf / cm 2 , 190 kgf / cm 2 , 200 kgf / cm 2 , 210 kgf / cm 2 , 220 kgf / cm 2 , 230 kgf / cm 2 , 240 kgf / cm 2 , 250 kgf / cm 2Alternatively, it may be a range between two of these values. If the tensile strength at break of the polyolefin elastomer is below the above range, the tensile strength and elongation of the molded article made from the recycled EPDM rubber composition may decrease, and if it exceeds the above range, compatibility with waste EPDM rubber may decrease.

[0036] The elongation at break of the above polyolefin elastomer (500 mm / min, ASTM D638) may be 500 to 900%. For example, it may be 500%, 550%, 600%, 650%, 700%, 750%, 800%, 850%, 900%, or a range between two of these values. If the elongation at break of the polyolefin elastomer falls outside the above range, the tensile strength and elongation of the molded article made from the recycled EPDM rubber composition may decrease.

[0037] The content of the polyolefin elastomer may be 5 to 35 parts by weight per 100 parts by weight of the waste EPDM rubber. For example, it may be 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, or a range between two of these values. If the content of the polyolefin elastomer is less than the above range, the tensile strength and elongation of the molded article made from the recycled EPDM rubber composition may decrease, and if it exceeds the above range, the specific gravity of the molded article may decrease.

[0038] The above recycled EPDM rubber composition may further include a deodorizing agent. If the above recycled EPDM rubber composition further includes a deodorizing agent, the odor of waste EPDM rubber can be improved to manufacture a molded article exhibiting low odor characteristics.

[0039] The above deodorizing agent may be one selected from the group consisting of diatomaceous earth, alumina, sodium oxide, and combinations of two or more of these. When one selected from the group consisting of diatomaceous earth, alumina, sodium oxide, and combinations of two or more of these is used as a deodorizing agent, the molded article may exhibit superior low odor characteristics compared to when bentonite or zeolite, which are known as conventional deodorizing agents, are used.

[0040] The content of the deodorizing agent may be 1 to 20 parts by weight per 100 parts by weight of the waste EPDM rubber. For example, it may be 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, 20 parts by weight, or a range between two of these values. If the content of the deodorizing agent is less than the above range, the odor improvement effect of the recycled EPDM rubber composition may be reduced, and if it exceeds the above range, mechanical properties such as tensile strength and elongation of the molded article made from the recycled EPDM rubber composition may be reduced.

[0041] The above recycled EPDM rubber composition may further include one selected from the group consisting of stearic acid, zinc oxide, PEG 4000, accelerators, crosslinking agents, and combinations of two or more of these, but is not limited thereto, and may further include known components or additives that are typically included in rubber compositions.

[0042] The recycled EPDM rubber composition described above can be manufactured in various ways, and the manufacturing method is not particularly limited. However, as a preferred example, it can be manufactured by the following method.

[0043] <Crushing / Grinding Process>

[0044] First, waste EPDM rubber is prepared and crushed or ground to produce waste EPDM rubber powder. The waste EPDM rubber may be used EPDM rubber products or EPDM rubber scrap generated from the rubber production process. The waste EPDM rubber may be crushed or ground to a size of 5 mm or less, but is not limited thereto.

[0045] Demetallization Treatment

[0046] Next, metal is separated from the waste EPDM rubber powder. The separation of the metal may be performed using a magnet, but is not limited thereto.

[0047] Desulfurization Treatment

[0048] Next, the waste EPDM rubber powder separated from the above metal is desulfurized.

[0049] Step (a) above can be performed by an extrusion type desulfurization machine. Here, the compression type desulfurization machine uses a screw extruder, which is a mechanical heating means, to shear and heat the waste EPDM rubber powder, raising the temperature to a level where sulfur crosslinking bonds can be severed, thereby performing desulfurization treatment.

[0050] As a compression type desulfurizing machine, a single-screw extruder is suitable, but it is preferable to use a multi-screw extruder, such as a two-screw extruder, which can stably perform desulfurization by shear heating.

[0051] The desulfurization treatment of step (a) above may be performed at a temperature of 200 to 500 ℃. For example, it may be performed at 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, 360℃, 370℃, 380℃, 390℃, 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 490℃, 500℃, or at a temperature between two of these temperatures.

[0052] <Manufacture of Recycled EPDM Rubber Composition>

[0053] A recycled EPDM rubber composition is prepared by adding a polyolefin elastomer to the above-mentioned desulfurized EPDM rubber powder. The type, physical properties, and content of the polyolefin elastomer added herein are as described above.

[0054] A deodorizing agent may be further added during the preparation of the above-mentioned recycled EPDM rubber composition. By adding a deodorizing agent in this manner, the odor of waste EPDM rubber can be improved, thereby enabling the production of recycled EPDM rubber exhibiting low-odor characteristics. The type and content of the deodorizing agent added here are as described above.

[0055] When manufacturing the above recycled EPDM rubber composition, an additive consisting of stearic acid, zinc oxide, PEG 4000, an accelerator, a crosslinking agent, and a combination of two or more of these may be further added.

[0056] molded product

[0057] A molded article according to another aspect of the present specification may be manufactured by extruding the aforementioned recycled EPDM rubber composition.

[0058] The above-mentioned molded product may be an upcycled product that is eco-friendly by using waste EPDM rubber and exhibits excellent mechanical properties such as tensile strength and elongation, while also displaying low odor characteristics.

[0059] The tensile strength at break of the above molded product (200 mm / min, KS M6518) is 85~150 kgf / cm 2 It could be. For example, 85 kgf / cm² 2 , 90 kgf / cm 2 , 95 kgf / cm 2 , 100 kgf / cm 2 , 105 kgf / cm 2 , 110 kgf / cm 2 , 115 kgf / cm 2 , 120 kgf / cm 2, 125 kgf / cm 2 , 130 kgf / cm 2 , 135 kgf / cm 2 , 140 kgf / cm 2 , 145 kgf / cm 2 , 150 kgf / cm 2 Or it may be a range between two of these values.

[0060] The elongation at break of the above-mentioned molded product (200 mm / min, KS M6518) may be 200% to 500%. For example, it may be 200%, 250%, 300%, 350%, 400%, 450%, 500%, or a range between two of these values.

[0061] The embodiments of this specification will be described in more detail below. However, the following experimental results represent only representative results among the above embodiments, and the scope and content of this specification should not be interpreted as being narrowed or limited by the embodiments. The respective effects of various embodiments of this specification not explicitly presented below will be described in detail in the relevant sections.

[0062] Examples and Comparative Examples

[0063] Waste EPDM rubber was crushed to a size of 5 mm or less to produce waste EPDM rubber powder. Metals present in the waste EPDM rubber powder were separated using a magnet, and a desulfurization process was performed at a temperature of 360 ℃ using a 165Φ extruder. Subsequently, a rubber composition was prepared by blending according to the compositions shown in Tables 1 and 2 below, and foreign substances were removed using a 20-inch washing roll.

[0064] The components used in the manufacture of the rubber composition are as follows.

[0065] - Waste EPDM Rubber: R-EPDM (Korea TRS Co.)

[0066] -POE 1: Solumer 891 (SK Geocentric, Ethylene-Octene Copolymer, Density: 0.885 g / cm³) 3 (ASTM D792), Melt flow index: 1.0 g / 10 min @190 ℃ / 2.16 kg (ASTM D1238), Mooney viscosity: 21 MU @121℃ (ASTM D1646, ML1+4), Tensile strength at break: 170 kgf / cm² 2 (ASTM D638, 500 mm / min), Elongation at break: 700% (ASTM D638, 500 mm / min), Shore A hardness: 81 (ASTM D2240, 1 sec), Shore D hardness: 29 (ASTM D2240, 1 sec))

[0067] -POE 2: Solumer 881 (SK Geocentric, Ethylene-Octene Copolymer, Density: 0.880 g / cm³) 3 (ASTM D792), Melt flow index: 1.0 g / 10 min @190 ℃ / 2.16 kg (ASTM D1238), Mooney viscosity: 21 MU @121℃ (ASTM D1646, ML1+4), Tensile strength at break: 150 kgf / cm² 2 (ASTM D638, 500 mm / min), Elongation at break: 800% (ASTM D638, 500 mm / min), Shore A hardness: 79 (ASTM D2240, 1 sec), Shore D hardness: 25 (ASTM D2240, 1 sec))

[0068] -POE 3: Engage 8407 (DOW, Ethylene-Octene Copolymer, Density: 0.870 g / cm³) 3 (ASTM D792), Melt flow index: 30 g / 10 min @190 ℃ / 2.16 kg (ASTM D1238), Mooney viscosity: 2 MU @121℃ (ASTM D1646, ML1+4), Tensile strength at break: 33.65 kgf / cm² 2(ASTM D638, 510 mm / min), Elongation at break: 1000% (ASTM D638, 510 mm / min), Shore A hardness: 72 (ASTM D2240, 1 sec), Shore D hardness: 20 (ASTM D2240, 1 sec))

[0069] -s-PB: RB-810 (JSR Company)

[0070] -Phenol Resin: KPA-1350K (Kolon Industries)

[0071] - Peroxide: F40-KEP (ARKEMA)

[0072] Classification (weight part) Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Waste EPDM rubber 100 100 100 100 100 100 100 100 100 POE 1 10 - - 20 30 - - - - POE 2 - 10 - - - - - - - POE 3 - - 10 - - - - - - s-PB - - - - - - 10 - - phenolic resin - - - - - - - 10 - peroxide - - - - - - - - 10 stearic acid 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 zinc oxide 5 5 5 5 5 5 5 5 5 PEG 4000 2 2 2 2 2 2 2 2 2 accelerant 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 crosslinking agent 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2

[0073] Classification (weight part) Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Comparative Example 5 Comparative Example 6 Waste EPDM rubber 100 100 100 100 100 100 100 100 POE 1 10 10 10 10 10 10 10 10 Diatomite 5 - - 10 15 3 - - Alumina - 5 - - - 3 - - Sodium oxide - - 5 - - 3 - - Bentonite - - - - - - 5 - Zeolite - - - - - - - 5 stearic acid 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 zinc oxide 5 5 5 5 5 5 5 5 PEG 4000 2 2 2 2 2 2 2 2 accelerant 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 crosslinking agent 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2

[0074] Experimental Example 1

[0075] The rubber compositions prepared in Examples 1-5 and Comparative Examples 1-4 above were sheet-extruded using a 250Φ extruder, passed through an 80 mesh strainer, and then cut to produce rubber specimens.

[0076] The hardness, tensile strength, elongation, and specific gravity of each rubber specimen were measured using the following methods. The results are shown in Table 3 below.

[0077] - Hardness: Measured using a Shore A hardness tester.

[0078] - Tensile strength and elongation: Measurements were taken by cutting a dumbbell-shaped specimen No. 4 as specified in KS M6518 using a 1.0 mm thick sheet. Tension was maintained at a tensile speed of 200 mm / min until the specimen fractured, and the average value of 5 measurements was used as the tensile strength and elongation values.

[0079] - Specific gravity: Measured according to ASTM D792.

[0080] division Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 hardness 77 6 74 78 78 76 73 83 73 Tensile strength (kg·f / cm²) 2 ) 109 102 88 114 128 80 69 65 80 Growth rate (%) 260 240 220 300 430 130 170 170 170 Specific gravity (g / cm²) 2 ) 1.284 1.282 1.279 1.246 1.211 1.364 1.282 1.295 1.349

[0081] Referring to Table 3 above, it was confirmed that rubber specimens prepared from the rubber compositions of Examples 1 to 5, which incorporated polyolefin elastomer (POE), exhibited superior mechanical properties with higher tensile strength and elongation compared to the rubber compositions of Comparative Examples 1 to 4, which did not incorporate POE. In particular, rubber specimens prepared from the rubber compositions of Examples 1, 2, 4, and 5, which incorporated SK Geocentric’s Solumer 891 (POE 1) or Solumer 881 (POE 2), showed even better mechanical properties than Example 3, which incorporated DOW’s Engage 8407 (POE 3).

[0082] On the other hand, it was confirmed that rubber specimens prepared with the rubber compositions of Comparative Examples 2 to 4, which were formulated with syndiotactic 1,2-polybutadiene (s-PB), phenolic resin, or peroxide, showed a slight increase in elongation compared to Comparative Example 1, but the tensile strength did not increase or actually decreased.

[0083] Experimental Example 2

[0084] The rubber compositions prepared in Examples 6-11 and Comparative Examples 1, 5-6 were sheet-extruded using a 250Φ extruder, passed through an 80 mesh strainer, and then cut to produce rubber specimens.

[0085] The odor grade of each rubber specimen was measured according to the MS 300-34 standard (Odor Testing), which is the odor testing method for automotive interior and exterior materials. The results are shown in Table 4 below. A lower grade indicates improved odor.

[0086] division Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Comparative Example 1 Comparative Example 5 Comparative Example 6 Smell rating 5.5 5.5 5.5 5.5 5.0 5.0 6.0 6.0 6.0

[0087] Referring to Table 4 above, it was confirmed that the rubber specimens prepared with the rubber compositions of Examples 6 to 11, in which one or more of diatomaceous earth, alumina, and sodium oxide were additionally blended into the rubber composition of Example 1, had improved odor compared to the specimens prepared with the rubber composition of Comparative Example 1.

[0088] On the other hand, rubber specimens prepared with the rubber compositions of Comparative Examples 5 and 6, which incorporated bentonite or zeolite, had an odor at a level equivalent to that of Comparative Example 1.

[0089] The foregoing description of this specification is for illustrative purposes only, and those skilled in the art to which one aspect of this specification pertains will understand that other specific forms can be easily modified without altering the technical concept or essential features described in this specification. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0090] The scope of this specification is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of this specification.

Claims

Claim 1 A recycled EPDM rubber composition comprising desulfurized waste EPDM rubber and a polyolefin elastomer having a tensile strength at break (500 mm / min, ASTM D638) of 50 to 250 kgf / cm² and an elongation at break (500 mm / min, ASTM D638) of 500 to 900%. Claim 2 A recycled EPDM rubber composition according to claim 1, wherein the polyolefin elastomer is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. Claim 3 A recycled EPDM rubber composition according to claim 1, wherein the melt flow index of the polyolefin elastomer (@190 ℃ / 2.16 kg, ASTM D1238) is 0.1 to 20.0 g / 10 min. Claim 4 A recycled EPDM rubber composition according to claim 1, wherein the Mooney viscosity (ML1+4, @121 ℃, ASTM D1646) of the polyolefin elastomer is 10 to 30 MU. Claim 5 delete Claim 6 delete Claim 7 A recycled EPDM rubber composition according to claim 1, wherein the content of the polyolefin elastomer is 5 to 35 parts by weight per 100 parts by weight of the waste EPDM rubber. Claim 8 In claim 1, the recycled EPDM rubber composition further comprises a deodorizing agent. Claim 9 In claim 8, the deodorizing agent is one selected from the group consisting of diatomaceous earth, alumina, sodium oxide, and a combination of two or more of these, in a recycled EPDM rubber composition. Claim 10 A recycled EPDM rubber composition according to claim 8, wherein the content of the deodorizing agent is 1 to 20 parts by weight per 100 parts by weight of the waste EPDM rubber. Claim 11 A molded article manufactured from the recycled EPDM rubber composition of claim 1.

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