Olefin polymer and method for producing the same

Abstract

The present invention relates to an olefin-based polymer, and more particularly to an olefin-based polymer which is excellent in processability and mechanical strength at the same time, and a method for producing the same.

Description

[Technical Field]

[0001] The present invention relates to an olefin-based polymer, and more particularly to an olefin-based polymer that is excellent in processability and exhibits excellent mechanical strength while having a low density, and a method for producing the same. [Background technology]

[0002] Metallocene catalysts, one of the catalysts used to polymerize olefins, are compounds in which ligands such as cyclopentadienyl, indenyl, or cycloheptadienyl are coordinated to a transition metal or a transition metal halide, and have a sandwich structure as their basic structure.

[0003] Ziegler-Natta catalysts, another catalyst used to polymerize olefins, have metal components that act as active sites dispersed on an inert solid surface, resulting in non-uniform active site properties.Metallocene catalysts, on the other hand, are single-site catalysts, as they are compounds with a uniform structure, and all active sites have the same polymerization properties.Polymers polymerized with such metallocene catalysts have narrow molecular weight distributions and uniform comonomer distributions, resulting in higher copolymerization activity than Ziegler-Natta catalysts.

[0004] Linear low-density polyethylene (LLDPE) is produced by copolymerizing ethylene and alpha-olefins at low pressure using a polymerization catalyst. It has a narrow molecular weight distribution, short chain branches (SCB) of a certain length, and generally no long chain branches (LCB). In addition to the properties of regular polyethylene, films made from LLDPE have high breaking strength and elongation, as well as excellent tear strength and impact strength. As a result, they are widely used in stretch films and overlap films, where conventional LLDPE and HLDPE are difficult to use.

[0005] Meanwhile, there have been attempts to polymerize olefin polymers using a single metallocene catalyst, but the olefin polymers polymerized in the past have had problems such as poor processability and mechanical strength.

[0006] Therefore, the current situation is that there is an urgent need to develop olefin-based polymers that can ensure excellent processability and mechanical strength while having low density. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been devised to overcome the above-mentioned problems, and an object of the present invention is to provide an olefin polymer which has excellent processability and exhibits excellent mechanical strength while having a low density, and a method for producing the same. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention provides a method for producing an olefin-based polymer, which includes a step of polymerizing an olefin-based monomer in the presence of a catalyst at a predetermined ethylene partial pressure to produce an olefin-based polymer, and which satisfies the following condition (1):

[0009]

number

[0010] In this case, in the condition (1), Pc2 is the ethylene partial pressure (bar), and MFR is the olefin polymer

number

[0011] According to one embodiment of the present invention, the olefin-based polymer may have a melt flow index of 0.5 to 1.5 g / 10 min measured at 190°C under a load of 2.16 kg according to ASTM D1238, or may have a melt flow index of 20 to 30 g / 10 min measured at 190°C under a load of 21.6 kg.

[0012] The ethylene partial pressure may be 9.5 to 16.5 bar.

[0013] The catalyst may also include a hybrid catalyst containing a first compound and a second compound that are different from each other and are represented by Chemical Formula 1 below.

[0014] [ka]

[0015] In the above-mentioned Chemical Formula 1, M1 may be titanium (Ti), zirconium (Zr) or hafnium (Hf); X1 is a halogen, a substituted or unsubstituted C1-C5 alkyl group, a substituted or unsubstituted C2-C5 alkenyl group, a substituted or unsubstituted C1-C5 alkynyl group, a substituted or unsubstituted C1-C5 alkoxy group, a substituted or unsubstituted C6-C 20 aryloxy groups, substituted or unsubstituted C6-C 20or a substituted or unsubstituted C2-C 20 may be a heteroaryl group of the formula: R 1 and R 2 are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C5 alkyl group, a substituted or unsubstituted C2 to C5 alkenyl group, a substituted or unsubstituted C1 to C5 alkynyl group, a substituted or unsubstituted C1 to C5 alkoxy group, a substituted or unsubstituted C6 to C 20 aryloxy groups, substituted or unsubstituted C6-C 20 or a substituted or unsubstituted C2-C 20 may be a heteroaryl group of the formula: a and b may each independently be an integer of 1 to 5.

[0016] The catalyst may further include a promoter compound containing at least one of a compound represented by the following formula 2, a compound represented by the following formula 3, and a compound represented by the following formula 4.

[0017] [ka]

[0018] [ka]

[0019] [ka]

[0020] In the above formula 2, R 3 is a halogen atom or halogen-substituted or unsubstituted C1-C 20 and n may be an integer of 2 or greater, In the formula 3, M2 may be aluminum (Al) or boron (B), and R 4 , R 5 and R 6are each independently a halogen atom, a halogen-substituted or unsubstituted C1-C 20 or halogen-substituted or unsubstituted C1-C 20 may be an alkoxy group of the formula In the formula (4), L may be a neutral or cationic Lewis base, [LH] + and [L] + may be a Bronsted acid, Z may be a Group 13 element, and each A is independently a substituted or unsubstituted C-C 20 an aryl group or a substituted or unsubstituted C1-C 20 It may also be an alkyl group of the formula:

[0021] The catalyst may further include a support that can support at least one of the hybrid catalyst and the promoter compound, and that includes at least one of silica, alumina, and magnesia.

[0022] The present invention also provides an olefin-based polymer that satisfies the following condition (1):

[0023]

number

[0024] In this case, in the condition (1), Pc2 is the ethylene partial pressure (bar), and MFR is the olefin polymer

number

[0025] According to one embodiment of the present invention, the olefin-based polymer may have a melt flow index of 0.5 to 1.5 g / 10 min measured at 190°C under a load of 2.16 kg according to ASTM D1238, or may have a melt flow index of 20 to 30 g / 10 min measured at 190°C under a load of 21.6 kg.

[0026] The olefin-based polymer can further satisfy the following condition (2).

[0027]

number

[0028] In this case, the drop impact strength in the condition (2) indicates a drop impact strength measured in accordance with ASTM D1709.

[0029] The ethylene partial pressure may be 9.5 to 16.5 bar.

[0030] The olefin polymer has a density of 0.915 to 0.935 kg / m 3 The drop impact strength may be 520 g or more. [Effects of the Invention]

[0031] The olefin polymer and the method for producing the same according to the present invention are excellent in processability and can simultaneously exhibit the effect of excellent mechanical strength while having a low density. DETAILED DESCRIPTION OF THE INVENTION

[0032] DETAILED DESCRIPTION OF THE INVENTION The present invention may be embodied in various different forms and is not limited to the embodiments set forth herein.

[0033] As described above, conventional olefin polymers and their manufacturing methods using a metallocene single catalyst have the problem of poor processability and mechanical strength.

[0034] Therefore, in order to solve the above-mentioned problems, the present invention provides a method for producing an olefin-based polymer, which includes a step of polymerizing an olefin-based monomer at a predetermined ethylene partial pressure in the presence of a catalyst to produce an olefin-based polymer, and seeks to solve the above-mentioned problems.

[0035] As a result, the present invention can exhibit excellent processability and excellent mechanical strength while simultaneously exhibiting low density.

[0036] On the other hand, the process for producing an olefin polymer according to the present invention satisfies the following condition (1).

[0037] Condition (1) is:

number

number

[0038] In this case, in the condition (1), Pc2 is the ethylene partial pressure (bar), and MFR is the olefin polymer

number

[0039] If, in the above condition (1),

number

number

[0040] Meanwhile, the step of polymerizing an olefin-based monomer in the presence of a catalyst at a predetermined ethylene partial pressure to produce an olefin-based polymer may include the steps of preparing a catalyst and producing an olefin-based polymer at a predetermined ethylene partial pressure.

[0041] First, the step of preparing the catalyst will be described.

[0042] According to one embodiment of the present invention, the catalyst may include a hybrid catalyst, preferably a hybrid catalyst including a first compound and a second compound different from each other and represented by the following Chemical Formula 1:

[0043] [ka]

[0044] In the above-mentioned Chemical Formula 1, M1 is titanium (Ti), zirconium (Zr) or hafnium (Hf); X1 is a halogen, a substituted or unsubstituted C1-C5 alkyl group, a substituted or unsubstituted C2-C5 alkenyl group, a substituted or unsubstituted C1-C5 alkynyl group, a substituted or unsubstituted C1-C5 alkoxy group, a substituted or unsubstituted C6-C 20 aryloxy groups, substituted or unsubstituted C6-C 20 or a substituted or unsubstituted C2-C 20 is a heteroaryl group of the formula R 1 and R 2 are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C5 alkyl group, a substituted or unsubstituted C2 to C5 alkenyl group, a substituted or unsubstituted C1 to C5 alkynyl group, a substituted or unsubstituted C1 to C5 alkoxy group, a substituted or unsubstituted C6 to C 20 aryloxy groups, substituted or unsubstituted C6-C 20 or a substituted or unsubstituted C2-C 20 is a heteroaryl group of the formula a and b each independently represent an integer of 1 to 5;

[0045] Preferably, in the above formula 1, M1 may be zirconium (Zr) or hafnium (Hf); X1 may be a halogen, a substituted or unsubstituted C1-C5 alkyl group, a substituted or unsubstituted C2-C5 alkenyl group, a substituted or unsubstituted C1-C5 alkynyl group, or a substituted or unsubstituted C1-C5 alkoxy group; R 1 and R 2 may each independently be hydrogen, a substituted or unsubstituted C1 to C5 alkyl group, a substituted or unsubstituted C2 to C5 alkenyl group, a substituted or unsubstituted C1 to C5 alkynyl group, or a substituted or unsubstituted C1 to C5 alkoxy group.

[0046] On the other hand, the first compound may preferably be a compound represented by the following formula 1-1, and the second compound may preferably be a compound represented by the following formula 1-2.

[0047] [ka]

[0048] [ka]

[0049] It may be advantageous to achieve the object of the present invention by including the hybrid catalyst while satisfying the above-mentioned condition (1), it may be even more advantageous to achieve the object of the present invention by including the first compound and the second compound while satisfying the above-mentioned condition (1), and it may be even more advantageous to achieve the object of the present invention by including the first compound represented by Chemical Formula 1-1 and the second compound represented by Compound 1-2 while satisfying the above-mentioned condition (1).

[0050] On the other hand, when the catalyst is a hybrid catalyst containing the first compound and the second compound, the hybrid catalyst may contain the first compound and the second compound in a weight ratio of 1:0.1 to 0.8, preferably 1:0.12 to 0.7. When the weight ratio of the first compound and the second compound satisfies the above range, it can be more advantageous to achieve the object of the present invention.

[0051] According to one embodiment of the present invention, the catalyst may further include a promoter compound, and preferably, the promoter compound may include at least one of a compound represented by the following formula 2, a compound represented by the following formula 3, and a compound represented by the following formula 4:

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] In the above formula 2, R 3 is a halogen atom or halogen-substituted or unsubstituted C1-C 20 where n is an integer of 2 or greater, In the formula 3, M2 is aluminum (Al) or boron (B), and R 4 , R 5 and R 6 are each independently a halogen atom, a halogen-substituted or unsubstituted C1-C 20 or halogen-substituted or unsubstituted C1-C 20 is an alkoxy group of the formula In the formula 4, L is a neutral or cationic Lewis base, [LH] + and [L]+ is a Bronsted acid, Z is a Group 13 element, and A is each independently a substituted or unsubstituted C6-C 20 an aryl group or a substituted or unsubstituted C1-C 20 is an alkyl group.

[0056] On the other hand, more preferably, the co-catalyst compound may include an aluminoxane, and even more preferably, the aluminoxane may be methyl aluminoxane (MAO), which may be more advantageous in achieving the object of the present invention.

[0057] According to an embodiment of the present invention, the catalyst may further include a support for supporting at least one of the hybrid catalyst and the co-catalyst compound, preferably the hybrid catalyst and the co-catalyst compound.

[0058] The carrier may be any known carrier without limitation as long as it can support the above-mentioned hybrid catalyst and promoter compound. Preferably, the carrier contains one or more of silica, alumina, and magneia, more preferably silica, which may be more advantageous in achieving the object of the present invention.

[0059] As described above, when the catalyst includes the support, the hybrid catalyst, and the co-catalyst compound supported on the support, preparing the catalyst may include mixing the hybrid catalyst and the co-catalyst compound to form a mixed catalyst; mixing the mixed catalyst, a support, and a solvent to support the hybrid catalyst and the co-catalyst compound on the support; and drying the support supporting the hybrid catalyst and the co-catalyst compound.

[0060] The mixed catalyst may be formed by mixing the hybrid catalyst and a cocatalyst compound, and the cocatalyst compound may be mixed in a cocatalyst solution at a concentration of 5 to 15%. The hybrid catalyst and the cocatalyst compound may be mixed by mixing the hybrid catalyst and the cocatalyst solution at a weight ratio of 1:130 to 180, preferably 1:140 to 170. Meeting the weight ratio of the hybrid catalyst to the cocatalyst solution may be more advantageous in achieving the object of the present invention. In this case, the solvent of the cocatalyst solution may be the same as or different from the solvent used in the supporting step described below, but is not limited thereto.

[0061] In addition, the supporting step may involve mixing the mixed catalyst (including the solvent of the cocatalyst solution) and the support in a weight ratio of 1:0.1 to 0.35, preferably 1:0.12 to 0.32, and mixing the solvent in an amount of 150 to 350 parts by weight, preferably 200 to 300 parts by weight, per 100 parts by weight of the support. Meeting the ranges for the weight ratio of the mixed catalyst to the support and the solvent content can be more advantageous in achieving the objectives of the present invention. In this case, the solvent may be any solvent commonly used in the art, and may preferably include, but is not limited to, toluene.

[0062] On the other hand, the loading step may be carried out at a temperature of 55 to 85° C. for 1 to 3 hours, preferably at a temperature of 60 to 80° C. for 1.5 to 2.5 hours, but is not limited thereto.

[0063] The step of drying the support carrying the hybrid catalyst and the promoter compound may be performed at a temperature of 45 to 75°C for 8 to 14 hours, preferably at a temperature of 50 to 70°C for 9 to 13 hours under vacuum conditions, but is not limited thereto.

[0064] Next, the step of producing an olefin polymer at a predetermined ethylene partial pressure will be described.

[0065] The step of producing the olefin polymer is carried out by polymerizing an olefin monomer at a predetermined ethylene partial pressure, and the ethylene partial pressure may be 9.5 to 16.5 bar, preferably 9.8 to 16.2 bar, so as to satisfy the condition (1). If the ethylene partial pressure is less than 9.5 bar, the mechanical strength may decrease, and if the ethylene partial pressure exceeds 16.5 bar, the processability may decrease, or even if the processability is good, the mechanical strength may decrease and / or the density may increase.

[0066] The olefin monomer is selected from the group consisting of C2 to C 20 α-olefins, C1 to C 20 Diolefins, C3 to C 20 Cycloolefins and C3-C 20 The cyclodiolefin may be at least one selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, and 1-hexadecene.

[0067] On the other hand, in order to satisfy the condition (1), the olefin polymer produced by the above-mentioned production method may have a melt flow index of 0.5 to 1.5 g / 10 min measured at 190°C under a load of 2.16 kg according to ASTM D1238, or may have a melt flow index of 20 to 30 g / 10 min measured at 190°C under a load of 21.6 kg according to ASTM D1238, and preferably have a melt flow index of 0.6 to 1.4 g / 10 min measured at 190°C under a load of 2.16 kg, or may have a melt flow index of 20.5 to 29 g / 10 min measured at 190°C under a load of 21.6 kg according to ASTM D1238. By satisfying the ranges of the melt flow index measured at 190°C under a load of 2.16 kg and the melt flow index measured at 190°C under a load of 21.6 kg according to ASTM D1238, the olefin polymer can exhibit low density while simultaneously exhibiting excellent processability and mechanical strength.

[0068] The method for producing an olefin-based polymer according to the present invention has been described above, but this is merely an example and may include additional processes and conditions.

[0069] The present invention also provides an olefin-based polymer that satisfies the following condition (1):

[0070] Condition (1) is:

number

number

[0071] In this case, in the condition (1), Pc2 is the ethylene partial pressure (bar), and MFR is the olefin polymer

number

[0072] The explanation of the condition (1) and its related factors such as ethylene partial pressure and melt flow index is omitted here because it is the same as that in the above-mentioned method for producing an olefin polymer.

[0073] On the other hand, the olefin-based polymer according to the present invention can further satisfy the following condition (2).

[0074] Condition (2) is:

number

number

[0075] In this case, the drop impact strength in the condition (2) indicates a drop impact strength measured in accordance with ASTM D1709.

[0076] If, in the above condition (2),

number

number

[0077] On the other hand, the density of the olefin polymer according to the present invention is 0.915 to 0.935 kg / m 2 Preferably, the density of the olefin polymer is 0.916 to 0.933 kg / m 2If the density of the olefin polymer is 0.915 kg / m 2 If it is less than 0.935 kg / m, the mechanical properties of the olefin polymer may be poor, and the density may be less than 0.935 kg / m. 2 If it exceeds this value, the processability may be poor.

[0078] The olefin polymer according to the present invention may have a drop impact strength of 520 g or more, preferably 540 g or more, thereby achieving excellent strength despite a low density. [Example]

[0079] The present invention will be described in more detail below through examples. However, the following examples should not be construed as limiting the scope of the present invention, but should be construed as being for the purpose of aiding in the understanding of the present invention.

[0080] <Preparation example: Preparation of hybrid catalyst> The first compound represented by the following formula 1-1 and the second compound represented by the following formula 1-2 were purchased from MCN Material Technologies (Shanghai), and a hybrid catalyst was prepared without any further purification process. At this time, 8.1 kg of the first compound represented by the following formula 1-1 and 3.4 kg of the compound represented by the following formula 1-2 were prepared.

[0081] [ka]

[0082] [ka]

[0083] Example: Catalyst Production The entire amount of the hybrid catalyst prepared in the above Preparation Example and 1800 kg of a co-catalyst solution containing 10% concentration of methylaluminoxane as a co-catalyst compound, containing toluene as a solvent, were stirred at 25° C. for 1 hour to prepare a mixed catalyst.

[0084] Next, the prepared mixed catalyst and 400 kg of silica (XPO-2402) as a carrier were added, and 1000 L of toluene was further added as a solvent. After stirring at 70°C for 2 hours, the mixture was washed with 100 L of toluene three times and then dried under vacuum at 60°C for 12 hours to obtain 560 kg of catalyst.

[0085] <Production Examples 1 to 4 and Comparative Production Examples 1 and 2: Production of Olefin Polymers> Ethylene / 1-hexene polymerization was carried out using a continuous gas-phase polymerization reactor with a fluidized bed. The amounts of hydrogen and 1-hexene added and the ethylene partial pressure were adjusted as shown in Tables 1 and 2 below to produce the olefin polymers shown in Tables 1 and 2.

[0086] <Comparative Production Examples 3 and 4> A linear low-density polyethylene polymer (M1810HN, Hanwha Solutions) sold by Hanwha Solutions was manufactured, and each olefin polymer was manufactured by making the changes shown in Table 2 below.

[0087] <Experimental Example> The olefin polymers produced in the above Production Examples and Comparative Production Examples were evaluated for the following physical properties, and the results are shown in Tables 1 and 2.

[0088] 1.Melt flow index measurement The melt flow index (I) of each of the olefin polymers produced in the Production Examples and Comparative Production Examples was measured at 190°C under a load of 21.6 kg (weight: 21.6 kg) in accordance with ASTM D1238. 21.6 ) was measured at 190°C with a load of 2.16 kg (weight of 2.16 kg), and the melt flow index (I 2.16 ) and then measure I 21.6 / I 2.16 The melt flow ratio (MFR, processability) was measured by calculating the formula:

[0089] 2. Density Measurement The density of each of the olefin polymers produced in the Production Examples and Comparative Production Examples was measured in accordance with ASTM D1505.

[0090] 3. Drop impact strength measurement The drop impact strength of each of the olefin polymers produced in the Production Examples and Comparative Production Examples was measured in accordance with ASTM D1709.

[0091] [Table 1]

[0092] [Table 2]

[0093] As can be seen from Tables 1 and 2, Preparation Examples 1 to 4, which satisfy all of the production conditions and physical properties (ethylene partial pressure, melt flow index ratio, etc.) of the olefin polymer of the present invention, simultaneously exhibit significantly superior processability and mechanical properties compared to Comparative Preparation Examples 1 to 4, which do not satisfy any of the conditions.

[0094] On the other hand, Comparative Production Example 2 had not bad strength and mechanical strength, but this was due to its significantly higher density. It was excellent in processability, and it is clear that this does not meet the objective of the present invention, which is to achieve low density and high strength.

[0095] Although one embodiment of the present invention has been described above, the concept of the present invention is not limited to the embodiment presented in this specification, and a person skilled in the art who understands the concept of the present invention can easily propose other embodiments by adding, changing, deleting, or adding components within the scope of the same concept, which would also be considered to fall within the scope of the concept of the present invention.

Claims

1. The method includes the step of polymerizing an olefinic monomer in the presence of a catalyst at a predetermined ethylene partial pressure to produce an olefinic polymer, A method for producing an olefin polymer, which satisfies the following condition (1): [Equation 1] In this case, in the condition (1), Pc ２ is the ethylene partial pressure (bar), and MFR is the olefin polymer [Equation 2] Represents.

2. The olefin-based polymer may have a melt flow index of 0.5 to 1.5 g / 10 min measured at 190° C. under a load of 2.16 kg according to ASTM D1238, or a melt flow index of 20 to 30 g / 10 min measured at 190° C. under a load of 21.6 kg according to ASTM D1238.

3. The method for producing an olefin polymer according to claim 1, wherein the ethylene partial pressure is 9.5 to 16.5 bar.

4. The method for producing an olefin polymer according to claim 1, wherein the catalyst comprises a hybrid catalyst comprising a first compound and a second compound, each of which is different from each other and is represented by the following Chemical Formula 1: 【Chemistry 1】 In the above Chemical Formula 1, M １ is titanium (Ti), zirconium (Zr) or hafnium (Hf), X １ is a halogen, substituted or unsubstituted C １ ~C ５ alkyl groups of the formula ２ ~C ５ an alkenyl group of the formula １ ~C ５ an alkynyl group of the formula １ ~C ５ an alkoxy group of the formula ６ ~C ２０ an aryloxy group of the formula ６ ~C ２０ or a substituted or unsubstituted C ２ ~C ２０ is a heteroaryl group of the formula R １ and R ２ are each independently hydrogen, deuterium, substituted or unsubstituted C １ ~C ５ alkyl groups of the formula ２ ~C ５ an alkenyl group of the formula １ ~C ５ an alkynyl group of the formula １ ~C ５ an alkoxy group of the formula ６ ~C ２０ an aryloxy group of the formula ６ ~C ２０ or a substituted or unsubstituted C ２ ~C ２０ is a heteroaryl group of the formula a and b each independently represent an integer of 1 to 5;

5. The catalyst further contains a co-catalyst compound containing one or more of a compound represented by the following formula 2, a compound represented by the following formula 3, and a compound represented by the following formula 4. The method for producing an olefin polymer according to claim 4. 【Chemistry 2】 【Transformation 3】 【Chemistry 4】 In the above formula 2, R ３ is a halogen atom or a halogen-substituted or unsubstituted C １ ~C ２０ wherein n is an integer of 2 or greater; In the above formula 3, M ２ is aluminum (Al) or boron (B), and R ４ , R ５ and R ６ are each independently a halogen atom, a halogen-substituted or unsubstituted C １ ~C ２０ or a hydrocarbon group of the formula: １ ~C ２０ is an alkoxy group of the formula In the formula 4, L is a neutral or cationic Lewis base, [L-H] ＋ and [L] ＋ is a Bronsted acid, Z is a Group 13 element, and A is each independently a substituted or unsubstituted C ６ ~C ２０ an aryl group or a substituted or unsubstituted C １ ~C ２０ is an alkyl group.

6. The method for producing an olefin polymer according to claim 5, wherein the catalyst further comprises a support capable of supporting any one or more of the hybrid catalyst and the co-catalyst compound, and the support comprises any one or more of silica, alumina, and magnesia.

7. An olefin-based polymer that satisfies the following condition (1): [Equation 3] In this case, in the condition (1), Pc ２ is the ethylene partial pressure (bar), and MFR is the melt flow rate of the olefin polymer. [Equation 4] Represents.

8. The olefin-based polymer according to claim 7, wherein the olefin-based polymer has a melt flow index of 0.5 to 1.5 g / 10 min measured at 190°C under a load of 2.16 kg according to ASTM D1238, and a melt flow index of 20 to 30 g / 10 min measured at 190°C under a load of 21.6 kg.

9. The olefin-based polymer according to claim 7 , further satisfying the following condition (2): [Equation 5] In this case, under the condition (2), Pc ２ is the ethylene partial pressure (bar), and the drop impact strength indicates the drop impact strength measured in accordance with ASTM D1709.

10. The olefin-based polymer according to any one of claims 7 to 9, wherein the ethylene partial pressure is 9.5 to 16.5 bar.

11. The olefin polymer has a density of 0.915 to 0.935 kg / m ３ The olefin-based polymer according to claim 7, which has a drop impact strength of 520 g or more.

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