Polyethylene and film comprising same

Abstract

The present invention relates to polyethylene that has a significantly improved melt strength at low zero shear viscosity, and a minimized processing load, and thus can produce a polyethylene film having excellent processability and drop impact strength which can be applied to wide-width agricultural films or an all-polyethylene single material (All-PE_Uni) used for shrinkable films.

Description

Polyethylene and films containing the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0087705, filed July 3, 2024, and Korean Patent Application No. 10-2025-0089581, filed July 3, 2025, the entire contents of which are incorporated herein by reference.

[0003]

[0004] The present invention relates to polyethylene capable of producing a film having both excellent processability and drop impact strength applicable to wide-width agricultural films, shrink films, and polyethylene single materials (All-PE_Uni) of MDO films while significantly improving melt strength at low zero shear viscosity.

[0005]

[0006] Linear low density polyethylene (LLDPE) with long chain branches (LCB) is manufactured by copolymerizing ethylene and alpha olefins at low pressure using a polymerization catalyst. It is a resin with a narrow molecular weight distribution, short chain branches (SCB) of a certain length, and long chain branches (LCB).

[0007]

[0008] Linear low density polyethylene (LLDPE) is a resin manufactured by copolymerizing ethylene and alpha-olefin at low pressure using a polymerization catalyst. It has a narrow molecular weight distribution, short-chain branches of a certain length, and no long-chain branches.

[0009]

[0010] Linear low-density polyethylene film has the characteristics of general polyethylene, as well as high breaking strength and elongation, excellent film processability and transparency, and superior tear strength and drop impact strength, so its use is increasing in industrial films such as food packaging and industrial laminated films, heavy-duty films, and stretch wrap films, where conventional low-density polyethylene or high-density polyethylene is difficult to apply.

[0011]

[0012] Linear low-density polyethylene (LPE) is generally known to exhibit increased drop impact strength as density decreases. However, the use of large amounts of comonomers to manufacture LPE can lead to increased fouling during the slurry polymerization process, and the resulting film can become sticky, necessitating increased use of anti-blocking agents. Furthermore, production processes can become unstable, and the resulting polyethylene morphology can deteriorate, resulting in a decrease in bulk density.

[0013]

[0014] Due to recent market trends in sustainability and D4R (Design For Recyclability), the demand for down-gauging (D / G) is increasing, and accordingly, the demand for linear low-density polyethylene with excellent molding processability and drop impact strength is also increasing.

[0015]

[0016] Before COVID-19, D / G focused on reducing the thickness of the polyethylene layer in multilayer films from a cost perspective. However, post-COVID-19, increased concern about environmental issues has led to increased demand for downgauging for recycling purposes and energy consumption to reduce carbon emissions. This increased focus on energy efficiency, including energy consumption, has led to a surge in demand for LCBed mLLDPE, which offers a balanced mix of processability and physical properties.

[0017]

[0018] Furthermore, LLDPE film possesses the characteristics of general polyethylene, along with high breaking strength and elongation, and superior tear strength and impact strength. This has led to its increasing use in stretch films and overlap films, where conventional low-density polyethylene or high-density polyethylene (HDPE) is difficult to apply. However, despite its excellent mechanical properties, LLDPE has poor processability in blown film. Blown film, also known as inflation film, is a film manufactured by blowing air into molten plastic to inflate it.

[0019]

[0020] Factors to consider when processing blown film include bubble stability and processing load, with bubble stability being a particularly important consideration. Bubble stability refers to the ability of the film to maintain its shape without tearing when producing film by injecting air into molten plastic. This is related to melt strength (MS).

[0021]

[0022] Melt strength refers to the strength to maintain a shape that can withstand molding and processing in a softened molten state. The melt strength of low density polyethylene (LDPE) is higher than that of LLDPE. This is because the side chains of LDPE are more intertwined than those of LLDPE, making it more advantageous in withstanding molding and processing. Therefore, a method of blending LDPE to produce a film has been proposed to supplement the melt strength of LLDPE. However, this method causes a problem in that the mechanical properties of existing LLDPE are significantly reduced even when a very small amount of LDPE is added.

[0023]

[0024] In this regard, a method of improving the processability of the film by introducing LCB into LLDPE has been proposed, but although bubble stability issues such as bubble sagging in agricultural wide-width vinyl houses have been resolved, bubble stability problems such as draw resonance, frost line height instability (FLH instability), and bubble breakage have occurred when processing films less than 50 ㎛ due to the recent downgauging issue. In particular, in order to improve this bubble stability problem, a technology to improve the melt strength by introducing LCB into the high molecular weight region of LLDPE has been proposed. However, since a small amount of LCB is introduced, the melt index is lowered, which increases the zero-point conduction viscosity. In addition, despite the introduction of LCB, the processing pressure of the film extruder increases, which causes problems such as increased compressor maintenance and energy consumption.

[0025]

[0026] Accordingly, in response to recent environmental issues such as CO2 reduction and downgauging issues due to cost reduction and recycling, there is a need to develop polyethylene that can significantly improve melt strength while producing a film with excellent processability and drop impact strength applicable to wide-width agricultural films or polyethylene single material (All-PE_Uni) for shrink film applications.

[0027]

[0028] In particular, when manufacturing MDO (Machine Direction Oriented) polyethylene single material (MDO All-PE material) film as a single material for shrink films and food / industrial polymers, the demand for linear low-density polyethylene (LCBed-mLLDPE) with long chain branches (LCB) for high haze characteristics even at low stretch ratios or for property balance is increasing.

[0029]

[0030] The present invention aims to provide a polyethylene capable of producing a film having excellent processability and drop impact strength, which can be applied to wide-width agricultural films, shrink film applications, polymer single materials, and All-PE (Uni) materials, while significantly improving melt strength.

[0031]

[0032] In addition, the present invention seeks to provide a film comprising the polyethylene.

[0033]

[0034] In one embodiment of the present invention, the density measured according to ASTM D 1505 standard is 0.915 g / cm 3 Above 0.940 g / cm 3 Below this, the melting index MI measured under a load of 2.16 kg at a temperature of 190 ℃ according to ASTM D 1238 standard 2.16The melting index (MI) is 0.7 g / 10 min or more and 1.6 g / 10 min or less, and is measured under a load of 21.6 kg and 2.16 kg at a temperature of 190 ℃ according to ASTM D 1238. 21.6 and melting index MI 2.16 The melt flow rate (MFRR, MI) is the ratio of 21.6 / MI 2.16 ) is 25 or more and 35 or less, and when analyzed by ARES (advanced rheometric expansion system) by temperature, polyethylene satisfying the conditions of (a1) and (a2) below is provided:

[0035] (a1) In a graph where the phase angle (δ) is on the x-axis and the activation energy (Ea) according to the change in the phase angle (δ) is on the y-axis, there is no inflection point where the phase angle (δ) shows the maximum value of Ea when it is 45° or more, and the maximum value of Ea in the graph is 20 kJ / mol or more and 60 kJ / mol or less,

[0036] (a2) When the absolute value of the complex shear modulus (|G*|) is 0.01 MPa, the phase angle (δ) is 63° or more and 75° or less.

[0037]

[0038] In addition, in another embodiment of the present invention, a film comprising the polyethylene of the above embodiment is provided.

[0039]

[0040] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention.

[0041]

[0042] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0043]

[0044] In this specification, the terms “comprise,” “include,” or “have” are intended to describe a feature, number, step, component, or combination thereof implemented, but do not exclude the possibility of one or more other features, numbers, steps, components, combinations, or additions thereof.

[0045]

[0046] In addition, the terms "about," "substantially," and the like used throughout this specification are used in a meaning that is at or close to the numerical value when manufacturing and material tolerances inherent to the meanings mentioned are presented, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure in which exact or absolute values ​​are mentioned to aid understanding of the present invention.

[0047]

[0048] Additionally, in the present invention, (co)polymer means both a homopolymer and a copolymer.

[0049]

[0050] Unless otherwise defined herein, “copolymerization” may mean block copolymerization, random copolymerization, graft copolymerization or alternating copolymerization, and “copolymer” may mean block copolymer, random copolymer, graft copolymer or alternating copolymer.

[0051]

[0052] The present invention is susceptible to various modifications and takes various forms. Specific examples are illustrated and described in detail below. However, this does not limit the invention to a specific disclosed form, but rather encompasses all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0053]

[0054] Hereinafter, the present invention will be described in detail.

[0055]

[0056] polyethylene

[0057]

[0058] According to one aspect of the present invention, a density measured according to ASTM D 1505 standard is 0.915 g / cm 3 Above 0.940 g / cm 3 Below is the melting index MI measured under a load of 2.16 kg at a temperature of 190 ℃ according to ASTM D 1238 standard. 2.16 The melting index (MI) is 0.7 g / 10 min or more and 1.6 g / 10 min or less, and is measured under a load of 21.6 kg and 2.16 kg at a temperature of 190 ℃ according to ASTM D 1238. 21.6 and melting index MI 2.16 The melt flow rate (MFRR, MI) is the ratio of 21.6 / MI 2.16 ) is 25 or more and 35 or less, and when analyzed by ARES (advanced rheometric expansion system) by temperature, polyethylene satisfying the conditions of (a1) and (a2) below is provided:

[0059] (a1) In a graph where the phase angle (δ) is on the x-axis and the activation energy (Ea) according to the change in the phase angle (δ) is on the y-axis, there is no inflection point where the phase angle (δ) shows the maximum value of Ea when it is 45° or more, and the maximum value of Ea in the graph is 20 kJ / mol or more and 60 kJ / mol or less,

[0060] (a2) When the absolute value of the complex shear modulus (|G*|) is 0.01 MPa, the phase angle (δ) is 63° or more and 75° or less.

[0061]

[0062] For reference, in this specification, "part by weight" means a relative concept that expresses the weight of a substance as a ratio based on the weight of the remaining substance. For example, in a mixture containing 50 g of substance A, 20 g of substance B, and 30 g of substance C, the amounts of substance B and substance C are 40 parts by weight and 60 parts by weight, respectively, based on 100 parts by weight of substance A.

[0063]

[0064] Meanwhile, "% by weight" refers to an absolute concept that expresses the weight of a certain substance as a percentage of the total weight. In the mixture in the example above, the contents of substance A, substance B, and substance C are 50% by weight, 20% by weight, and 30% by weight, respectively, out of 100% of the total weight of the mixture.

[0065]

[0066] In the present invention, the polyethylene has a density and a melt index (MI) 2.16 ), melt flow index (MI) 21.6 / MI 2.16 ) and temperature-dependent ARES (advanced rheometric expansion system) analysis, the Ea(δ) graph characteristics, Ea maximum value, and the phase angle (δ) value when the absolute value (|G*|) of the complex shear modulus (G*) is 0.01 MPa are all optimized, thereby reducing the processing load during film extrusion and significantly improving the melt strength, and it can be a polymer suitable for food / industrial downgauge as it has both good processability and drop impact strength applicable to All-PE(Uni) material in wide-width agricultural films or shrink films.

[0067]

[0068] Accordingly, the present invention provides a polyethylene that has a multi-modal crystal distribution by introducing LCB into LLDPE by applying a specific metallocene catalyst described below, has a small zero shear viscosity (η0) and significantly improves melt strength, thereby reducing processing load during film extrusion and has excellent processability and drop impact strength applicable to a single polymer material, a single polyethylene material (All-PE_Uni), in wide-width agricultural films, shrink films, food / industrial MDO films, etc., and can be applied to downgauging.

[0069]

[0070] Polyethylene according to one embodiment of the present invention can exhibit density, melt index, and melt flow index characteristics equivalent to linear low density polyethylene (LLDPE) in order to maintain excellent mechanical properties thereof.

[0071]

[0072] Specifically, the polyethylene has a density of 0.915 g / cm as measured according to the American Society for Testing and Materials ASTM D 1505 standard. 3 Above 0.940 g / cm 3 Below. The density of the above polyethylene is 0.915 g / cm 3 If it is less than 0.940 g / cm, it is difficult to ensure stability in the slurry polymerization process. In addition, density and drop impact strength have a trade-off relationship, and the density of polyethylene is 0.940 g / cm 3 If it exceeds, it is difficult to down-gauge during film manufacturing due to the decrease in drop impact strength. More specifically, the density of the polyethylene is 0.915 g / cm 3 or 0.916 g / cm 3 or 0.917 g / cm 3 or 0.918 g / cm 3 Ideally, 0.940 g / cm 3or less, or 0.939 g / cm 3 or less, or 0.938 g / cm 3 Below, 0.937 g / cm 3 or less, or 0.936 g / cm 3 or less, or 0.935 g / cm 3 or less, or 0.934 g / cm 3 or less, or 0.933 g / cm 3 or less, or 0.932 g / cm 3 Below, 0.931 g / cm 3 or less, or 0.930 g / cm 3 or less, or 0.929 g / cm 3 or less, or 0.928 g / cm 3 Below, 0.927 g / cm 3 or less, or 0.926 g / cm 3 or less, or 0.925 g / cm 3 It could be as follows:

[0073]

[0074] In addition, the polyethylene has a melt index (MI) measured at a temperature of 190°C and a load of 2.16 kg according to ASTM D 1238. 2.16 ) is 0.7 g / 10 min or more and 1.6 g / 10 min or less. The melt index (MI) of the polyethylene 2.16 ) is less than 0.7 g / 10 min, the mechanical properties such as toughness are excellent, but there is a concern that the molding processability may deteriorate. In addition, the melt index (MI) of the polyethylene 2.16 ) exceeds 1.6 g / 10 min, the molding processability is excellent, but there is a risk of deterioration in mechanical properties. More specifically, the melt index (MI) 2.16) may be 0.7 g / 10 min or more, or 0.8 g / 10 min or more, or 0.9 g / 10 min or more, or 0.95 g / 10 min or more, or 1.0 g / 10 min or more, but 1.5 g / 10 min or less, or 1.4 g / 10 min or less, or 1.3 g / 10 min or less, or 1.2 g / 10 min or less, or 1.15 g / 10 min or less.

[0075]

[0076] The above polyethylene can have excellent mechanical properties such as high melt strength of linear low density polyethylene (LLDPE) by optimizing the melt flow rate (MFRR) along with density and melt index.

[0077]

[0078] Specifically, the polyethylene has a melt index (MI) measured at a temperature of 190°C under a load of 21.6 kg and 2.16 kg, respectively, according to ASTM D 1238. 21.6 and melting index MI 2.16 The melt flow rate (MFRR, MI) is the ratio of 21.6 / MI 2.16 ) is 25 or more and 35 or less. If the melt flow rate (MFRR) of the polyethylene is narrowly less than 25, the mechanical properties such as toughness are excellent, but there is a concern that the molding processability may deteriorate, and if the melt flow rate (MFRR) exceeds 35, the molding processability is excellent, but there is a concern that the mechanical properties may deteriorate. More specifically, the melt flow rate (MFRR) of the polyethylene may be 25.5 or more, or 26.0 or more, or 26.5 or more, or 27.0 or more, or 27.5 or more, or 28.0 or more, or 28.2 or more, and 34.9 or less, or 34.8 or less, or 34.7 or less, or 34.6 or less, or 34.5 or less, or 34.4 or less, or 34.3 or less, or 34.2 or less.

[0079]

[0080] In addition, the polyethylene has a high load melt index MI measured under a load of 21.6 kg at a temperature of 190°C according to ASTM D 1238. 21.6 The high load melting index MI may be 12.5 g / 10 min or more and 56 g / 10 min or less. More specifically, the high load melting index MI 21.6 is 13 g / 10min or more, or 13.5 g / 10min or more, or 14 g / 10min or more, or 14.5 g / 10min or more, or 15 g / 10min or more, or 15.5 g / 10min or more, or 16 g / 10min or more, or 16.5 g / 10min or more, or 17 g / 10min or more, or 17.5 g / 10min or more, and 55 g / 10min or less, or 54 g / 10min or less, or 53 g / 10min or less, or 52 g / 10min or less, or 51 g / 10min or less, or 50 g / 10min or less, or 49 g / 10min or less, or 48 g / 10min or less, or 47 g / 10min or less, or 46 g / 10min or less, or 45 g / 10min or less, or It may be 44 g / 10min or less, or 43 g / 10min or less, or 42 g / 10min or less, or 41 g / 10min or less, or 40 g / 10min or less.

[0081]

[0082] And, the polyethylene may have a Z-average molecular weight (Mz) of 250,000 g / mol or more or 250,000 g / mol to 480,000 g / mol. The Z-average molecular weight (Mz) of the polyethylene is 250,000 g / mol or more, or 255,000 g / mol or more, or 258,000 g / mol or more, or 260,000 g / mol or more, or 265,000 g / mol or more, or 268,000 g / mol or more, or 270,000 g / mol or more, or 272,000 g / mol or more, or 273,000 g / mol or more, or 274,000 g / mol or more, or 275,000 g / mol or more, or 276,000 g / mol or more, and 475,000 g / mol or less, or 470,000 g / mol or less, or 465,000 g / mol or less, or 460,000 g / mol or less, or It may be 458,000 g / mol or less, or 455,000 g / mol or less, or 452,000 g / mol or less, or 450,000 g / mol or less, or 448,000 g / mol or less, or 445,000 g / mol or less, or 440,000 g / mol or less, or 439,0000 g / mol or less.

[0083]

[0084] Additionally, the polyethylene may have a weight average molecular weight (Mw) of 60,000 g / mol or more and 120,000 g / mol or less. The weight average molecular weight (Mw) of the above polyethylene is 62,000 g / mol or more, or 65,000 g / mol or more, or 68,000 g / mol or more, or 70,000 g / mol or more, or 72,000 g / mol or more, or 75,000 g / mol or more, or 78,000 g / mol or more, or 80,000 g / mol or more, or 82,000 g / mol or more, or 83,500 g / mol or more, or 85,000 g / mol or more, or 86,500 g / mol or more, or 88,000 g / mol or more, or 89,500 g / mol or more, or 90,000 g / mol or more, or 90,500 g / mol or more, or 92,000 g / mol or more, or 93,500 g / mol or more than 95,000 g / mol, or more than 96,500 g / mol, but not more than 118,000 g / mol, or not more than 117,500 g / mol, or not more than 117,000 g / mol, or not more than 116,500 g / mol, or not more than 116,000 g / mol, or not more than 115,500 g / mol, or not more than 115,000 g / mol, or not more than 114,500 g / mol, or not more than 114,000 g / mol, or not more than 113,500 g / mol, or not more than 113,000 g / mol, or not more than 112,500 g / mol, or not more than 112,000 g / mol, or not more than 111,500 g / mol, or not more than 111,200 g / mol.

[0085]

[0086] Additionally, the polyethylene may have a number average molecular weight (Mn) of 18,000 g / mol or more and 40,000 g / mol or less. The number average molecular weight (Mn) of the polyethylene is 18,200 g / mol or more, or 18,500 g / mol or more, or 18,800 g / mol or more, or 19,000 g / mol or more, or 19,200 g / mol or more, or 19,300 g / mol or more, or 19,500 g / mol or more, or 19,800 g / mol or more, or 20,100 g / mol or more, or 20,200 g / mol or more, or 20,300 g / mol or more, or 20,400 g / mol or more, or 20,500 g / mol or more, or 20,600 g / mol or more, or 20,700 g / mol or more, and 39,000 g / mol or less, or 38,000 g / mol or less, or 37,000 g / mol or less, or 36,000 g / mol or less, or 35,000 g / mol or less, or 34,500 g / mol or less, or 34,000 g / mol or less, or 33,500 g / mol or less, or 33,000 g / mol or less, or 32,500 g / mol or less, or 32,000 g / mol or less, or 31,800 g / mol or less.

[0087]

[0088] Additionally, the polyethylene may have a peak molecular weight (Mp) of 38,000 g / mol or more and 96,000 g / mol or less. The number average molecular weight (Mn) of the polyethylene is 39,000 g / mol or more, or 40,000 g / mol or more, or 42,000 g / mol or more, or 44,000 g / mol or more, or 45,000 g / mol or more, or 46,000 g / mol or more, or 48,000 g / mol or more, or 50,000 g / mol or more, or 52,000 g / mol or more, or 53,500 g / mol or more, or 55,000 g / mol or more, or 56,000 g / mol or more, or 57,000 g / mol or more, or 58,000 g / mol or more, or 59,000 g / mol or more, or 60,000 g / mol or more, or 61,000 g / mol or more, or 62,000 g / mol and may be 95,000 g / mol or less, or 92,000 g / mol or less, or 90,000 g / mol or less, or 85,000 g / mol or less, or 80,000 g / mol or less, or 78,000 g / mol or less, or 76,000 g / mol or less, or 75,500 g / mol or less, or 75,000 g / mol or less, or 74,500 g / mol or less, or 74,000 g / mol or less, or 73,800 g / mol or less.

[0089]

[0090] In addition, the molecular weight distribution (Mw / Mn) determined by the ratio (Mw / Mn) of the number average molecular weight (Mn) to the weight average molecular weight (Mw) of the polyethylene may be 3.0 or more and 5.0 or less. If the molecular weight distribution (Mw / Mn) of the polyethylene is narrow, less than 3.0, the mechanical properties such as toughness are excellent, but there is a concern that the molding processability may deteriorate, and if the molecular weight distribution exceeds 5.0, the molding processability is excellent, but there is a concern that the mechanical properties may deteriorate. More specifically, the molecular weight distribution (Mw / Mn) of the polyethylene may be 3.1 or more, or 3.2 or more, or 3.3 or more, or 3.4 or more, or 3.5 or more, and 4.9 or less, or 4.85 or less, or 4.8 or less, or 4.75 or less, or 4.7 or less, or 4.67 or less, or 4.6 or less, or 4.55 or less, or 4.5 or less, or 4.35 or less, or 4.3 or less, or 4.25 or less, or 4.21 or less. The polyethylene according to the present invention can exhibit well-balanced improved molding processability and mechanical properties by satisfying the above-described molecular weight distribution conditions.

[0091]

[0092] In addition, the ratio of the Z-average molecular weight (Mz) to the number-average molecular weight (Mn) of the polyethylene may be 8.0 or more and 22.0 or less. If the molecular weight distribution (Mw / Mn) of the polyethylene is narrow, less than 3.0, the mechanical properties such as toughness are excellent, but there is a concern that the molding processability may deteriorate, and if the molecular weight distribution exceeds 5.0, the molding processability is excellent, but there is a concern that the mechanical properties may deteriorate. More specifically, the molecular weight distribution (Mw / Mn) of the polyethylene may be 8.5 or more, or 8.8 or more, or 9.0 or more, or 9.2 or more, or 9.4 or more, and 21.5 or less, or 21 or less, or 20.5 or less, or 20 or less, or 19.8 or less, or 19.5 or less, or 19.2 or less. The polyethylene according to the present invention can exhibit well-balanced improved molding processability and mechanical properties by satisfying the above-described molecular weight distribution conditions.

[0093]

[0094] In the present invention, the weight average molecular weight (Mw) and number average molecular weight (Mn), etc. are conversion values ​​for standard polystyrene measured using gel permeation chromatography (GPC, gel permeation chromatography, manufactured by Water). That is, the weight average molecular weight (Mw) and number average molecular weight (Mn) are polystyrene conversion molecular weights analyzed by GPC. However, the weight average molecular weight is not limited thereto and may be measured by other methods known in the technical field to which the present invention pertains.

[0095]

[0096] Meanwhile, polyethylene according to one embodiment of the present invention has a density and melt index (MI) as described above. 2.16 ), melt flow rate ratio (MFRR, MI 21.6 / MI 2.16) and at the same time, by optimizing the phase angle (δ) value at 0.01 MPa of the Ea(δ) graph characteristics, Ea maximum value, and the absolute value (|G*|) of the complex shear modulus in the ARES (advanced rheometric expansion system) analysis by temperature, the mechanical properties such as melt strength can be significantly improved without slightly reducing the melt index or greatly increasing the zero shear viscosity, while reducing the processing load of the film extruder, thereby reducing extruder maintenance and energy consumption and having excellent characteristics that are effective for down-gauging.

[0097]

[0098] For example, in the case of the polyethylene, as shown in Fig. 1, when analyzing the advanced rheometric expansion system (ARES) by temperature, there is no inflection point where the phase angle (δ) shows the maximum value of Ea when the phase angle (δ) is 45° or more in a graph where the phase angle (δ) is the x-axis and the activation energy (Ea) according to the change in the phase angle (δ) is the y-axis, and the maximum value of Ea in the graph is 20 kJ / mol or more and 60 kJ / mol or less. More specifically, the Ea maximum value of the Ea(δ) graph may be 21 kJ / mol or more, or 22 kJ / mol or more, or 23 kJ / mol or more, or 24 kJ / mol or more, or 25 kJ / mol or more, or 26 kJ / mol or more, or 28 kJ / mol or more, or 30 kJ / mol or more, or 32 kJ / mol or more, or 33 kJ / mol or more, and 59 kJ / mol or less, or 58 kJ / mol or less, or 57 kJ / mol or less, or 55 kJ / mol or less, or 52 kJ / mol or less, or 50 kJ / mol or less, or 48 kJ / mol or less, or 45 kJ / mol or less, or 42 kJ / mol or less, or 40 kJ / mol or less, or 39 kJ / mol or less, or 38 kJ / mol or less.

[0099]

[0100] Specifically, in the Ea(δ) graph described above, the polyethylene may have a maximum Ea value at a phase angle (δ) of 46° or more, or 47° or more, or 48° or more, or 49° or more, or 50° or more, or 51° or more, or 52° or more, or 53° or more, or 54° or more, or 55° or more, or 56° or more, or 57° or more, or 58° or more, or 59° or more, or 60° or more, or 61° or more, or 62° or more, or 63° or more, and may also have a phase angle (δ) of 80° or less, or 78° or less, or 76° or less, or 75° or less, or 74° or less, or 73° or less, or 72° or less, or 71° or less, or 70° or less, or 69° or less, or 68° or less, or It can appear at 67° or less, or 66° or less, or 65° or less. As a result, the polyethylene can have excellent mechanical properties such as melt strength as linear low density polyethylene (LLDPE) having a long chain branch (LCB).

[0101]

[0102] As described above, the polyethylene according to one embodiment of the present invention does not show an inflection point indicating the maximum value of Ea in a graph of activation energy (Ea) according to a change in phase angle (δ) on the y-axis, and in the graph, the maximum value of Ea is 20 kJ / mol or more and 60 kJ / mol or less, so that the activation energy (Ea) remains constant according to a change in phase angle (δ), and exhibits characteristics of a uniform molecular structure and excellent processability. Such polyethylene has no phase separation or structural inflection point, and is a linear low density polyethylene (LLDPE) with long chain branch (LCB), but has a very uniform molecular structure and a form close to a linear polymer with few branches. In addition, the maximum value of Ea appears when the phase angle (δ) is 45° or more. Due to these characteristics, the polyethylene according to one embodiment of the present invention has high flow resistance even at high temperatures, excellent thermal and mechanical stability, small shear-thinning, low zero shear viscosity (η0), significantly improved melt strength, and exhibits viscoelastic behavior against external stress, so that it can effectively absorb or alleviate vibration or impact.

[0103]

[0104] Specifically, the temperature-dependent advanced rheometric expansion system (ARES) analysis of the polyethylene and the Ea maximum value of the Ea(δ) graph can be calculated by the method disclosed in “Macromolecules 2010, 43, 7341-7350”, and the Ea maximum value can be calculated by the slope of the phase angle for each temperature according to Equation 1 below. As an example, the method for measuring the temperature-dependent advanced rheometric expansion system (ARES) analysis of the polyethylene and the Ea maximum value of the Ea(δ) graph is as described in the test example described below.

[0105] [Formula 1]

[0106]

[0107] In the above equation 1,

[0108] ω(T) is the frequency (in radians / second) at which the phase angle δ has a certain value (e.g. δ=60°) at temperature T,

[0109] ω(T) is the frequency at which the same δ value is obtained at the reference temperature (T),

[0110] Ea is the activation energy (J / mol),

[0111] R is the gas constant (8.314 J / mol K),

[0112] T is the absolute temperature (K),

[0113] exp(-Ea / RT) represents the temperature sensitivity according to activation energy.

[0114]

[0115] As described above, the polyethylene according to one embodiment of the present invention has no inflection point showing the maximum value of Ea when the phase angle (δ) is 45° or more in a graph in which the phase angle (δ) is represented as the x-axis and the activation energy (Ea) according to the change in the phase angle (δ) is represented as the y-axis, and the maximum value of Ea in the graph is between 20 kJ / mol and 60 kJ / mol, and exhibits a characteristic in which no abrupt increase or inflection point is observed for the activation energy (Ea) according to the change in the phase angle (δ). In particular, no separate inflection point appears when the phase angle (δ) is 55° or more. Due to these characteristics, the polyethylene according to one embodiment of the present invention can realize excellent mechanical properties such as small shear-thinning and small zero shear viscosity (η0) under specific rheological conditions, while significantly improving melt strength.

[0116]

[0117] Therefore, the polyethylene of the present invention can provide a film having excellent processability and drop impact strength applicable to a single polymer material.

[0118]

[0119] In addition, when the above polyethylene is analyzed by the advanced rheometric expansion system (ARES) according to temperature, when the absolute value (|G*|) of the complex shear modulus is 0.01 MPa, the phase angle (δ) is 63° to 75°. For example, as shown in Fig. 2, the polyethylene may have a phase angle (δ) of 63° to 75° in a vGP plot graph in which the absolute value (|G*|) of the complex shear modulus is on the x-axis and the phase angle (δ) is on the y-axis when the absolute value (|G*|) of the complex shear modulus is 0.01 MPa. More specifically, the absolute value of G* may be such that the phase angle (δ) at 0.01 MPa is 63.5° or more, or 64° or more, or 64.5° or more, or 65° or more, or 65.5° or more, or 65.8° or more, or 66° or more, and 74.5° or less, or 74° or less, or 73.5° or less, or 73.2° or less, or 73° or less, or 72.8° or less, or 72.5° or less.

[0120]

[0121] As described above, the polyethylene according to one embodiment of the present invention exhibits a phase angle (δ) of 63° to 75° under low frequency or low shear stress conditions with an absolute G* value of 0.01 MPa, so that it exhibits viscoelastic behavior against external stress while significantly improving melt strength with small shear-thinning and small zero shear viscosity (η0), and can effectively absorb or alleviate vibration or impact, and has excellent processability applicable to All-PE(Uni) materials in agricultural films or shrink films.

[0122]

[0123] In addition, when the above polyethylene is analyzed by ARES (advanced rheometric expansion system) at different temperatures, when the absolute value (|G*|) of the complex shear modulus is 0.1 MPa, the phase angle (δ) is 50° or more and 65° or less. More specifically, the absolute value of G* is 0.1 MPa, the phase angle (δ) is 50.5° or more, or 50.8° or more, or 51° or more, or 51.2° or more, or 51.5° or more, or 51.8° or more, or 52° or more, or 52.2° or more, or 52.4° or more, or 52.5° or more, and 64° or less, or 63.5° or less, or 63° or less, or 62.5° or less, or 62° or less, or 61.5° or less, or 61° or less, or 60.5° or less, or 60° or less, or 59.5° or less, or 59° or less, or 58.5° or less, or 58° or less, or 57.5° or less, or 57° or less, or 56.5° or less, or It may be 56° or less, or 55.5° or less, or 55° or less, or 54.5° or less, or 54.1° or less.

[0124]

[0125] Specifically, the phase angle (δ) of the temperature-dependent ARES (advanced rheometric expansion system) analysis and Ea(δ) graph of the polyethylene can be measured using the Van Gurp-Palmen method (refer to M. Van Gurp and J. Palmen, 67 Rheology Bulletin 5 (1998). More specifically, when measuring the phase angle (δ) when the absolute value (|G*|) of the complex shear modulus is 0.01 MPa and 0.1 MPa, the phase angle (δ) is the arctangent of the ratio of the storage modulus (G', MPa) and the loss modulus (G'', MPa), i.e., δ = arctan -1 It is calculated as (G'' / G'), and the absolute value of the complex elastic modulus |G*| is (G' 2 + G'' 2 ) 1 / 2 It is calculated as follows. For example, the method for analyzing the temperature-dependent ARES (advanced rheometric expansion system) of the polyethylene and measuring the phase angle (δ) of the Ea(δ) graph is as described in the test example described below.

[0126]

[0127] As mentioned above, the density and melting index (MI) 2.16 ), melt flow rate ratio (MFRR, MI 21.6 / MI 2.16) and at the same time optimizing the Ea(δ) graph characteristics, Ea maximum value and G* absolute value in the temperature-dependent ARES (advanced rheometric expansion system) analysis, all satisfy the conditions of the phase angle (δ) value at 0.01 MPa, so that the polyethylene according to the present invention can exhibit excellent mechanical properties that significantly improve melt strength while having small shear-thinning and small zero shear viscosity (η0), as well as excellent drop impact strength properties and improved molding processability.

[0128]

[0129] Meanwhile, the polyethylene may satisfy one or more, two or more, or all of the following conditions (b1) to (b3):

[0130] (b1) ER calculated according to the following mathematical formula 1: 1.00 dyn / cm 2 Above 2.5 dyn / cm 2 below,

[0131] (b2) PDR calculated according to the following mathematical formula 2: 3.0 or more and 15 or less,

[0132] (b3) The zero shear viscosity η calculated according to the following mathematical formula 3 0 : 25,000 Pa·s or less,

[0133] [Mathematical Formula 1]

[0134]

[0135] In the above mathematical formula 1,

[0136] C1 is a constant, 1.781x10 -3 And,

[0137] G' is the storage modulus of polyethylene (dyne / cm 2 ) and

[0138] G"ref is the loss modulus of polyethylene, 5000 dyne / cm 2 And,

[0139] [Equation 2]

[0140]

[0141] In the above mathematical expression 2,

[0142] η*1, η*2, and η*3 are the reference complex elastic moduli G, respectively. * ref1 , G * ref2 , and G * ref3 As the complex viscosity in , G * ref1 =1.95x10 4 dyne / cm 2 And, G * ref2 =(G * ref1 G * ref3 ) 1 / 2 , and log10(G * ref3 / G * ref1 )=2 is used as a standard,

[0143] [Equation 3]

[0144]

[0145] In the above mathematical formula 3,

[0146] N is the number of modes, and G i is the elastic modulus (dyne / cm) corresponding to the relaxation time. 2 ), and τ i is the relaxation time (s).

[0147]

[0148] Specifically, the polyethylene has an ER (Polydispersity at the High MW) of 1.00 dyn / cm determined according to the above mathematical formula 1. 2 Above 2.5 dyn / cm 2 Below is the text.

[0149]

[0150] ER, also known as rheological polydispersity, is derived from measurements of the rheological properties (or rheological properties) of polymer melts. The rheological properties of polymer melts are highly dependent on their underlying molecular structure, specifically molecular weight, molecular weight distribution, and long chain branching (LCB). ER quantifies polydispersity at high Mw, independent of molecular weight and molecular weight distribution in polyethylene.

[0151]

[0152] A higher ER value indicates greater polydispersity at high Mw and the presence of molecules with long relaxation times. A lower ER value indicates less polydispersity at high Mw and the presence of molecules with short relaxation times.

[0153]

[0154] More specifically, the polyethylene according to the present invention has an ER of 1.00 dyn / cm 2 ideal, or 1.02 dyn / cm 2 ideal, or 1.04 dyn / cm 2 or 1.05 dyn / cm 2 ideal, or 1.06 dyn / cm 2 or 1.08 dyn / cm 2 or 1.10 dyn / cm 2 or 1.12 dyn / cm 2 ideal, or 1.14 dyn / cm 2 or 1.15 dyn / cm 2 or 1.16 dyn / cm 2 ideal, or 1.17 dyn / cm 2 ideal, or 1.18 dyn / cm 2 ideal, or 1.19 dyn / cm 2 or 1.20 dyn / cm 2 ideal, or 1.21 dyn / cm 2 Above, 2.5 dyn / cm 2 or less, or 2.48 dyn / cm2 or less, or 2.46 dyn / cm 2 or less, or 2.42 dyn / cm 2 Below, 2.40 dyn / cm 2 or less, or 2.38 dyn / cm 2 or less, or 2.36 dyn / cm 2 or less, or 2.34 dyn / cm 2 or less, or 2.32 dyn / cm 2 or less than 2.30 dyn / cm 2 or less, or 2.28 dyn / cm 2 or less, or 2.26 dyn / cm 2 or less, or 2.25 dyn / cm 2 or less, or 2.24 dyn / cm 2 or less, or 2.23 dyn / cm 2 or less, or 2.22 dyn / cm 2 or less, or 2.21 dyn / cm 2 The polyethylene according to the present invention can exhibit excellent molding processability by satisfying the ER conditions within the above-described range.

[0155]

[0156] Meanwhile, ER can be calculated by the method disclosed in “New measures of polydispersity from rheological data on polymer melts”, Journal of Applied Polymer Science, vol. 57, 1605~1626 (1995). The method and conditions for measuring ER in the present invention are as described in the following test examples.

[0157]

[0158] In addition, the polyethylene according to the present invention has an Overall Polydispersity (PDR) of 3.0 or more and 15 or less, determined according to the above mathematical formula 2:

[0159]

[0160] In the above mathematical expression 2, η*1, η*2, and η*3 are the reference complex elastic moduli G, respectively. * ref1 , G * ref2 , and G * ref3 is the complex viscosity in . In the present invention, G * ref1 =1.95x10 4 dyn / cm 2 And, G * ref2 = (G * ref1 G * ref3 ) 1 / 2 , and for linear polymers, log10(G * ref3 / G * ref1 )=2 were used as the standard to obtain η*1, η*2, and η*3.

[0161]

[0162] ER does not reflect contributions from low MW. Therefore, if we are interested in overall polydispersity, i.e. both high and low MW contributions, then the complex modulus (G * ) uses the PDR function.

[0163] PDR represents the overall polydispersity of polyethylene, and in the above mathematical expression 2, represents shear sensitivity, represents the curvature of the viscosity curve. A higher PDR means greater shear sensitivity and polydispersity, resulting in better moldability. A lower PDR means less shear sensitivity and polydispersity, resulting in worse moldability.

[0164]

[0165] More specifically, the polyethylene according to the present invention may have a PDR of 3.0 or more, or 3.2 or more, or 3.4 or more, or 3.6 or more, or 3.8 or more, or 4.0 or more, or 4.2 or more, or 4.4 or more, or 4.6 or more, or 4.8 or more, or 5.0 or more, or 5.2 or more, or 5.4 or more, or 5.6 or more, or 5.8 or more, or 6.0 or more, or 6.2 or more, or 6.4 or more, or 6.5 or more, and 15 or less, or 38.0 or less, or 36.0 or less, or 35.5 or less, or 35.0 or less, or 11.6 or less. The polyethylene according to the present invention may exhibit excellent molding processability by exhibiting a PDR in the above range.

[0166]

[0167] The method and conditions for measuring PDR in the present invention are as described in the following test examples.

[0168]

[0169] In addition, the polyethylene according to the present invention can also have a zero shear viscosity (η0) calculated using relaxation time spectrum analysis.

[0170]

[0171] Specifically, the polyethylene according to the present invention has a zero shear viscosity (η) calculated according to the above mathematical formula 3 from the relaxation time spectrum analysis results. 0) is less than 25,000 Pa·s. More specifically, the polyethylene has a zero shear viscosity of 24,900 Pa·s or less, or 24,800 Pa·s or less, or 24,700 Pa·s or less, or 24,600 Pa·s or less, or 24,500 Pa·s or less, or 24,400 Pa·s or less, or 24,200 Pa·s or less, or 24,000 Pa·s or less, or 23,500 Pa·s or less, or 23,000 Pa·s or less, or 22,500 Pa·s or less, or 22,000 Pa·s or less, or 21,500 Pa·s or less, or 21,000 Pa·s or less, or 20,500 Pa·s or less, or 20,000 Pa·s or less, or 19,500 Pa·s or less, or 19,000 Pa·s or less, The polyethylene may have a zero shear viscosity of 18,500 Pa·s or less, or 18,000 Pa·s or less, or 17,500 Pa·s or less, or 17,000 Pa·s or less, or 16,500 Pa·s or less, or 16,000 Pa·s or less, or 15,500 Pa·s or less, or 15,000 Pa·s or less, or 14,500 Pa·s or less. In addition, the polyethylene may have a zero shear viscosity of 5,000 Pa·s or more, or 6,000 Pa·s or more, or 7,000 Pa·s or more, or 7,500 Pa·s or more, or 8,000 Pa·s or more, or 8,500 Pa·s or more, or 9,000 Pa·s or more, or 9,500 Pa·s or more.

[0172]

[0173] The polyethylene according to the present invention has rheological properties controlled within an optimal range as described above, and thus can exhibit excellent molding processability and drop impact strength properties.

[0174]

[0175] In addition, the polyethylene according to the present invention can satisfy one or more of the following conditions (c1) and (c2), or both:

[0176] (c1) Head pressure: 170 bar or less,

[0177] (c2) The Output Index calculated according to the following mathematical formula 4 is 2.00 g / (min·bar) or more,

[0178] [Equation 4]

[0179]

[0180]

[0181] More specifically, the polyethylene may have a processing pressure of 170 bar or less, or 168 bar or less, or 165 bar or less, or 162 bar or less, or 160 bar or less, or 159 bar or less, or 158 bar or less, and 160 bar or more, or 120 bar or more, or 125 bar or more, or 130 bar or more, or 135 bar or more, or 140 bar or more, or 142 bar or more, or 145 bar or more.

[0182]

[0183] In addition, the polyethylene has an Output Index calculated according to the above mathematical formula 4, more specifically, an Output Index of 2.00 g / (min·bar) or more, or 2.20 g / (min·bar) or more, or 2.40 g / (min·bar) or more, or 2.50 g / (min·bar) or more, or 2.55 g / (min·bar) or more, or 2.60 g / (min·bar) or more, or 2.65 g / (min·bar) or more, or 2.70 g / (min·bar) or more, or 2.75 g / (min·bar) or more, and 3.20 g / (min·bar) or less, or 3.10 g / (min·bar) or less, or 3.00 g / (min·bar) or less, or 2.95 g / (min·bar) or less, or 2.90 g / (min·bar) or less, or 2.85 g / (min·bar) or less, or 2.80 g / (min·bar) or less.

[0184]

[0185] The polyethylene according to the present invention can exhibit excellent molding processability by satisfying the above-mentioned processing pressure and Output Index range conditions:

[0186]

[0187] Meanwhile, the method and conditions for measuring the processing pressure and extrusion amount in the present invention are as described in the following test examples.

[0188]

[0189] The polyethylene according to the present invention can exhibit excellent mechanical properties such as melt strength along with excellent molding processability.

[0190]

[0191] Specifically, the above polyethylene may have a melt strength of 60 mN or more, or from 60 mN to 100 mN. Specifically, the melt strength may be 62 mN or more, or 65 mN or more, or 69 mN or more, or 98 mN or less, or 95 mN or less, or 90 mN or less. However, if the melt strength is too high, exceeding about 100 mN, bubble bursting and drawing resonance may occur during high-speed processing (thin film manufacturing).

[0192]

[0193] Specifically, the melt strength can be measured at 190°C using a capillary rheometer, for example, a Gφttfert Elongational Rheometer (RHOTENS). For example, the melt strength can be measured using a Goettfert Rheotens 71.97 with a Model 3211 Instron capillary rheometer attached. The polyethylene resin film melt is discharged through a capillary die (flat die, 180 degree angle) having a length to diameter (L / D) ratio of 15. After equilibrating the sample at 190°C for 10 minutes, the piston is moved at a speed of 1 inch / minute (2.54 cm / minute). The standard test temperature can be 190°C. The sample can be elongated at 1.2 mm / s. 2 The polyethylene is pulled uniaxially by a set of accelerating nips located 100 mm below the die with an acceleration of . The tension is recorded as a function of the pulling speed of the nip rolls. The melt strength is defined as the plateau force (mN) before the strand breaks. The method for measuring the melt strength of the polyethylene is as described in the test examples described below.

[0194]

[0195] In addition, the polyethylene according to the present invention may have a take-off max velocity of 300 mm / sec or more or 300 mm / sec to 1000 mm / sec. More specifically, the take-off max velocity may be 300 mm / sec or more, or 310 mm / sec or more, or 315 mm / sec or more, or 320 mm / sec or more, or 350 mm / sec or more, or 380 mm / sec or more, or 420 mm / sec or more, or 450 mm / sec or more, or 480 mm / sec or more, or 500 mm / sec or more, or 505 mm / sec or more, or 510 mm / sec or more, or 515 mm / sec or more, or 520 mm / sec or more, and 1000 mm / sec or less, or 950 mm / sec or less, or 900 mm / sec or less, or 850 mm / sec or less, or 800 mm / sec or less, or 750 mm / sec or less, or mm / sec or less, or 700 mm / sec or less, or 680 mm / sec or less, or It may be 670 mm / sec or less, or 660 mm / sec or less, or 650 mm / sec or less, or 640 mm / sec or less, or 630 mm / sec or less, or 620 mm / sec or less, or 610 mm / sec or less, or 600 mm / sec or less, or 590 mm / sec or less, or 585 mm / sec or less, or 580 mm / sec or less, or 575 mm / sec or less.

[0196]

[0197] Specifically, when the take-off max velocity is high, such as 300 mm / sec or more, both stretching stability and mechanical properties of the film are improved during film processing, and when it is less than 300 mm / sec, productivity decreases, processing defects such as wrinkles and stretching are likely to occur, and problems that make it unsuitable for high-speed production may occur. The method for measuring the take-off max velocity is as described in the test examples described below.

[0198]

[0199] In addition, the polyethylene according to the present invention is linear low density polyethylene (LLDPE) having a long chain branch (LCB), and the branching index g'(vis,bulk) for the total absolute molecular weight of the polyethylene calculated according to the following mathematical formula 5 may be 0.81 or less:

[0200] [Equation 5]

[0201]

[0202] In the above mathematical expression 5,

[0203] ηb is the intrinsic viscosity of the polyethylene, i.e., the intrinsic viscosity of the branched polyethylene,

[0204] ηl is the absolute molecular weight (M) equal to that of the polyethylene abs ) as the intrinsic viscosity of linear polyethylene, i.e., the same absolute molecular weight (M ) as the branched polyethylene. abs ) is the intrinsic viscosity of linear polyethylene, and is a value calculated according to the following mathematical formula 6.

[0205] [Equation 6]

[0206] ηl =KM α

[0207] In the above mathematical expression 6,

[0208] M is the absolute molecular weight (M) of the linear polyethylene abs ) and,

[0209] K is 0.000523,

[0210] α is 0.708.

[0211]

[0212] In particular, the polyethylene may have a branching index g'(vis,bulk) of 0.81 or less or 0.4 to 0.81 for the total viscosity average molecular weight of the polyethylene calculated according to the above-described mathematical formula 5. More specifically, the branching index g'(vis,bulk) may be 0.81 or less, or 0.80 or less, or 0.79 or less, or 0.785 or less, or 0.78 or less, or 0.775 or less, or 0.77 or less, or 0.765 or less, or 0.76 or less, or 0.755 or less, or 0.752 or less, or 0.75 or less, or 0.749 or less, or 0.748 or less, and may also be 0.4 or more, or 0.42 or more, or 0.45 or more, or 0.48 or more, or 0.5 or more, or 0.52 or more, or 0.54 or more, or 0.56 or more, or 0.58 or more, or 0.6 or more, or 0.62 or more, or 0.65 or more, or 0.68 or more, or 0.7 or more, or It may be 0.71 or more, or 0.715 or more, or 0.72 or more, or 0.725 or more, or 0.73 or more. Accordingly, the polyethylene has improved melt strength and processing stability, and excellent drop impact strength, making it suitable for various processing processes such as blown film, foaming, and extrusion, and for products requiring durability.

[0213]

[0214] In addition, the polyethylene has a molecular structure in which the molecules in the high molecular weight region are mainly linear and have little long-chain branching, and thus has excellent mechanical strength and crystallinity, and has improved stability in the processing process, making it suitable for applications in which durability and strength are important, such as pipes, films, and blow molding.

[0215]

[0216] In particular, the g'(vis,bulk) value of the polyethylene in this specification indicates the degree of LCB introduced into mLLDPE, and the smaller the value, the greater the LCB content. Zero shear viscosity (η0) refers to the viscosity at very low flow, and is a factor related to the flowability and melt strength of the polymer, and can be measured and calculated using the relaxation time spectrum of ARES. Specifically, the method for measuring g'(vis,bulk) of the polyethylene is as described in the test example described below.

[0217]

[0218] The polyethylene according to the present invention can satisfy one or more, two or more, three or more, or all four of the following conditions (d1) to (d4) based on the total weight of polyethylene during temperature rising elution fractionation analysis of cross-fraction chromatography:

[0219] (d1) Elution temperature (Te) when the content of the eluted polymer is 50 wt% 50 ) is 70.0 ℃ or higher,

[0220] (d2) The content of the polymer fraction eluted at an elution temperature of 80 ℃ or higher is 30.0 to 60.0 wt%,

[0221] (d3) The content of the polymer fraction eluted at a dissolution temperature of 60°C or higher and less than 80°C is 30.0 to 60.0 wt%,

[0222] (d4) The content of a polymer fraction eluted at a dissolution temperature of 30°C or higher and less than 60°C is 10.0 to 30.0 wt%.

[0223]

[0224] The conditions (d1) to (d4) above mean that the polyethylene according to the present invention has a multimodal crystal distribution with different molecular weight distributions. By having this multimodal crystal distribution and controlling the molecular weight distribution according to crystallinity, the polyethylene can exhibit improved rigidity along with excellent molding processability and low processing pressure.

[0225]

[0226] More specifically, the polyethylene according to the present invention has an elution temperature (Te) when the content of the eluted polymer is 50 wt% based on the total weight of polyethylene in the TREF analysis of CFC, i.e., when 50 wt% of the total weight of polyethylene polymer is eluted. 50 ) is 70.0 ℃ or higher. More specifically, the elution temperature (Te) when the content of the polymer to be eluted is 50 wt% based on the total weight of polyethylene 50 ) may be 70.0 ℃ or higher, or 71.0 ℃ or higher, or 71.5 ℃ or higher, or 72.0 ℃ or higher, and 85.0 ℃ or lower, or 84.0 ℃ or lower, or 83.0 ℃ or lower, or 82.0 ℃ or lower, or 81.0 ℃ or lower, or 80.0 ℃ or lower, or 79.0 ℃ or lower, or 78.0 ℃ or lower, or 77 ℃ or lower, or 76.8 ℃ or lower, or 75.0 ℃ or lower.

[0227]

[0228] These characteristics imply a molecular structure in which highly and low-crystallinity portions can be split in a polymer with a multimodal crystal distribution. Accordingly, the polyethylene according to the present invention can exhibit well-balanced improved moldability and rigidity.

[0229]

[0230] In addition, the polyethylene may have a content of a polymer (M1) fraction eluted at an elution temperature of 80° C. or higher in TREF analysis of CFC, based on the total weight of polyethylene, of 30.0 wt% or more, or 30.1 wt% or more, or 30.2 wt% or more, or 30.3 wt% or more, or 30.4 wt% or more, or 30.5 wt% or more, or 30.6 wt% or more, or 30.7 wt% or more, or 30.8 wt% or more, and 60.0 wt% or less, or 55.9 wt% or less, or 55.8 wt% or less, or 55.7 wt% or less, or 55.6 wt% or less.

[0231]

[0232] The M1 fraction content affects the stiffness of films made from polyethylene. Lower M1 fraction content leads to lower stiffness. On the other hand, if the M1 fraction content exceeds 60.0 wt%, the toughness and drop impact strength of the polyethylene may deteriorate. The polyethylene according to the present invention exhibits excellent stiffness by containing the M1 fraction within the aforementioned content range.

[0233]

[0234] In addition, the polyethylene has a content of a polymer (M2) fraction eluting at an elution temperature of 60°C or higher and less than 80°C of 30.0 wt% or more, or 30.5 wt% or more, or 31.0 wt% or more, or 31.5 wt% or more, or 32.0 wt% or more, or 32.5 wt% or more, or 33.0 wt% or more, or 33.2 wt% or more, or 33.4 wt% or more, or 33.5 wt% or more, or 33.6 wt% or more, or 33.7 wt% or more, and 60 wt% or less, or 59.8 wt% or less, or 59.5 wt% or less, or 59.0 wt% or less, or 58.5 wt% or less, or 58.0 wt% or less, or 57.5 wt% or less, or 57.0 wt% or less, or 56.5 wt% or less, Alternatively, it may be 56.0 wt% or less, or 55.5 wt% or less, or 55.2 wt% or less.

[0235]

[0236] The range of the above elution temperature of 60 ℃ or more and less than 80 ℃ is a major section that determines the density and MI of polyethylene. Typically, linear low-density polyethylene (LLDPE) having a density of 0.940 g / cm3 or less has a high crystal distribution in the above elution temperature range. In this regard, the polyethylene according to the present invention can exhibit excellent molding processability by having a low density and including an M2 fraction in the above content range. On the other hand, in the case of polyethylene having a content of the M2 fraction of less than 30.0 wt% and a high content of the M3 fraction, i.e., polyethylene having a large crystal distribution at Te of 80 ℃ or more, exhibits a high density, so that the molding processability is greatly reduced.

[0237]

[0238] In addition, the polyethylene has a content of a polymer (M3) fraction eluting at an elution temperature of 30°C or higher and less than 60°C of 10.0 wt% or more, or 10.3 wt% or more, or 10.5 wt% or more, or 10.8 wt% or more, or 11.0 wt% or more, or 11.2 wt% or more, and 30.0 wt% or less, or 29.0 wt% or less, or 28.0 wt% or less, or 27.0 wt% or less, or 26.0 wt% or less, or 25.0 wt% or less, or 24.0 wt% or less, or 23.0 wt% or less, or 22.0 wt% or less, or 21.0 wt% or less, or 20.0 wt% or less, or 19.0 wt% or less, or 18.5 wt% or less, or 18.0 wt% or less, or 17.5 % by weight or less, or 17.0% by weight or less, or 16.5% by weight or less.

[0239]

[0240] The polymer (M3) eluted in the range of the above-mentioned elution temperature being 30°C or higher and less than 60°C delays secondary crystallization between the die and the frost line during blown film production, and as a result, reduces the size of the crystal lamellae, thereby improving the molding processability. However, if the content of the M3 fraction is less than 10.0 wt%, the low-temperature sealing characteristics and hot-tack characteristics may deteriorate due to the increase in lamellae resulting from the increase in the crystallization rate. On the other hand, if the content of the M3 exceeds 30.0 wt%, the low-crystal content affecting the mechanical strength characteristics relatively increases, and thus the rigidity may deteriorate during film production.

[0241]

[0242] In addition, the polyethylene according to the present invention has a content of a polymer fraction (SF) eluted at an elution temperature of 35°C or lower of 5.0 to 30.0 wt% based on the total weight of polyethylene when subjected to TREF analysis of CFC. More specifically, the content of the SF is 5.0 wt% or more, or 6.0 wt% or more, or 7.0 wt% or more, or 8.0 wt% or more, or 9.0 wt% or more, or 10.0 wt% or more, and 30.0 wt% or less, or 29.0 wt% or less, or 28.0 wt% or less, or 27.0 wt% or less, or 26.0 wt% or less, or 25.5 wt% or less, or 25.0 wt% or less, or 24.0 wt% or less, or 23.0 wt% or less, or 22.0 wt% or less, or 21.0 wt% or less, or 20.0 wt% or less, or 19.0 wt% or less, or 18.0 wt% or less, or 18.0 wt% or less, or 17.0 wt% or less, or 16.0 wt% or less, or 15.0 wt% or less, Or it may be 14.0 wt% or less, or 13.0 wt% or less, or 12.0 wt% or less.

[0243]

[0244] In addition, the total content of the temperature-dependent elution polymer fractions based on the total weight of the polyethylene does not exceed 100 wt%.

[0245]

[0246] Meanwhile, polyethylene exhibiting these properties may be, for example, a copolymer of ethylene and alpha olefin.

[0247] At this time, the alpha-olefin may include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, and mixtures thereof. Among these, the polyethylene may be a copolymer of ethylene and 1-hexene.

[0248]

[0249] If the polyethylene is a copolymer as described above, the above-described properties can be more easily achieved. However, the type of polyethylene is not limited to the above-described types, and any of a variety of polyethylene types known in the technical field to which the present invention pertains can be provided as long as they exhibit the above-described properties.

[0250]

[0251] Method for manufacturing polyethylene

[0252]

[0253] According to another aspect of the present invention, a method for producing the above-described polyethylene is provided.

[0254]

[0255] In particular, polyethylene having the above-described physical properties is manufactured in the presence of a metallocene catalyst.

[0256]

[0257] Specifically, the method for producing the polyethylene comprises a step of polymerizing ethylene in the presence of a hybrid supported metallocene catalyst comprising a first transition metal compound represented by the following chemical formula 1, a second transition metal compound represented by the following chemical formula 2, a cocatalyst, and a carrier:

[0258] [Chemical Formula 1]

[0259]

[0260] In the above chemical formula 1,

[0261] M1 is a group 4 transition metal,

[0262] X 11 and X 12 are each independently, C 1-20 Alkyl, or halogen,

[0263] A1 is carbon, silicon, or germanium,

[0264] R 11 and R 12 are each independently, C 6-20Aryl, C 7-20 Alkylaryl, C 7-20 Arylalkyl, or C 7-20 It is an alkoxyaryl,

[0265] Q 11 and Q 12 One of them is C 2-20 One is alkoxyalkyl, and the other is C 1-20 It is alkyl,

[0266] [Chemical Formula 2]

[0267]

[0268] In the above chemical formula 2,

[0269] M2 is a group 4 transition metal,

[0270] X 21 and X 22 are each independently, C 1-20 Alkyl or halogen,

[0271] R 21 Silver hydrogen, C 1-20 Alkyl, or C 2-20 It is an alkoxyalkyl,

[0272] R 22 Inland R 25 are each independently hydrogen, C 1-20 Alkyl, C 6-20 Aryl, C 7-20 Alkylaryl, or C 7-20 Arylalkyl,

[0273] Q 21 and Q 22 are each independently, C 1-20 Alkyl or C 2-20 It is an alkoxyalkyl,

[0274] Q 21 and Q 22, and R 21 At least one of C 2-20 It is an alkoxyalkyl.

[0275]

[0276] The above manufacturing method is only an example for implementing the polyethylene according to the present invention, and the polyethylene of the present invention is not limited to the above manufacturing method.

[0277]

[0278] According to the above embodiment, a hybrid supported metallocene catalyst having improved copolymerizability and support performance compared to a conventional one can be provided by using a precursor containing a first transition metal compound (A) represented by the above chemical formula 1 and a second transition metal compound (B) represented by the above chemical formula 2 in a specific ratio.

[0279]

[0280] In the transition metal compound included in the hybrid supported metallocene catalyst according to the above embodiment, the substituents of the chemical formulae 1 and 2 are described more specifically as follows.

[0281]

[0282] The halogen can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0283]

[0284] C above 1-20 The alkyl of may be straight-chain, branched-chain or cyclic alkyl. Specifically, the C 1-20 The alkyl may be a straight chain alkyl having 1 to 20 carbon atoms; a straight chain alkyl having 1 to 10 carbon atoms; a straight chain alkyl having 1 to 5 carbon atoms; a branched chain or cyclic alkyl having 3 to 20 carbon atoms; a branched chain or cyclic alkyl having 3 to 15 carbon atoms; or a branched chain or cyclic alkyl having 3 to 10 carbon atoms. More specifically, the alkyl having 1 to 20 carbon atoms may be a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, or a cyclohexyl group.

[0285]

[0286] C 1-20The alkoxy of may be a straight-chain, branched-chain or cyclic alkoxy group. Specifically, the C 1-20 The alkoxy may be a straight chain alkoxy group having 1 to 20 carbon atoms; a straight chain alkoxy group having 1 to 10 carbon atoms; a straight chain alkoxy group having 1 to 5 carbon atoms; a branched chain or cyclic alkoxy group having 3 to 20 carbon atoms; a branched chain or cyclic alkoxy group having 3 to 15 carbon atoms; or a branched chain or cyclic alkoxy group having 3 to 10 carbon atoms. More specifically, the alkoxy group having 1 to 20 carbon atoms may be a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, an iso-butoxy group, a tert-butoxy group, an n-pentoxy group, an iso-pentoxy group, a neo-pentoxy group, or a cyclohexene group.

[0287]

[0288] C 2-20 Alkoxyalkyl of -R y -OR z Alkyl (-R) with a structure containing y ) is one or more hydrogens of alkoxy (-OR z ) may be a substituent substituted with. Specifically, the alkoxyalkyl having 2 to 20 carbon atoms may be a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an iso-propoxymethyl group, an iso-propoxyethyl group, an iso-propoxyhectyl group, a tert-butoxymethyl group, a tert-butoxyethyl group, or a tert-butoxyhexyl group.

[0289] C 6-20 The aryl of may refer to a monocyclic, bicyclic or tricyclic aromatic hydrocarbon. Specifically, the C6 to C20 aryl may be a phenyl group, a naphthyl group or anthracenyl group.

[0290]

[0291] C 7-20 The alkylaryl of may mean a substituent in which one or more hydrogens of the aryl are replaced by alkyl. Specifically, the C 7-20The alkylaryl may be methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl, di-tert-butylphenyl, or cyclohexylphenyl.

[0292]

[0293] C 7-20 Arylalkyl of may mean a substituent in which one or more hydrogens of alkyl are replaced by aryl. Specifically, the C 7-20 The arylalkyl group may be benzyl, phenylpropyl or phenylhexyl.

[0294]

[0295] C 7-20 Alkoxyaryl of -R c -OR d Aryl(-R) with a structure containing c ) is one or more hydrogens of alkoxy (-OR d ) may be a substituent substituted with. Specifically, the alkoxyaryl having 7 to 20 carbon atoms may be a methoxyphenyl group, an ethoxyphenyl group, an iso-propoxyphenyl group, or a tert-butoxyphenyl group.

[0296]

[0297] Also, group 4 transition metals can include titanium, zirconium, and hafnium.

[0298]

[0299] In the present invention, the hybrid supported metallocene catalyst is a hybrid catalyst comprising a first transition metal compound having a high molecular weight and high polymerizability, and a second transition metal compound having a low molecular weight and low polymerizability.

[0300]

[0301] Specifically, the first transition metal compound represented by the above chemical formula 1 contributes to producing a high molecular weight copolymer having a high SCB content, and the second transition metal compound represented by the above chemical formula 2 contributes to producing a low molecular weight copolymer having a low SCB (short chain branch) content.

[0302]

[0303] Accordingly, the hybrid supported metallocene catalyst of the present invention can exhibit high copolymerizability in polyethylene in the high molecular weight range due to the first transition metal compound, while exhibiting low copolymerizability in polyethylene in the low molecular weight range due to the action of the second transition metal compound. As a result, polyethylene produced using the hybrid supported metallocene catalyst can exhibit a high MFRR compared to polyethylene having a similar density due to the introduction of LCB (long chain branch) in the high molecular weight range, and can exhibit excellent processability and high transparency.

[0304]

[0305] In the present invention, in the hybrid supported metallocene catalyst, the first transition metal compound contributes to the production of a high molecular weight copolymer and exhibits a relatively high comonomer incorporation rate compared to the second transition metal compound.

[0306]

[0307] Specifically, in the above chemical formula 1, M1 is a Group 4 transition metal, preferably zirconium (Zr) or titanium (Ti), and more preferably zirconium (Zr).

[0308]

[0309] X 11 and X 12 are each independently, C 1-20 Alkyl, or halogen, preferably halogen, more preferably chloro (Cl).

[0310]

[0311] When Zr is included as the central metal of the first transition metal compound represented by the above chemical formula 1, compared to when other Group 14 elements such as Hf are included, it has more orbitals capable of accepting electrons, so it can easily bind to a monomer with higher affinity, and as a result, it can exhibit a superior catalytic activity improvement effect.

[0312]

[0313] In addition, the compound represented by the above chemical formula 1 is a bridge group of two indene derivative compounds, A1(Q 11 )(Q 12 ) includes a group. In the above chemical formula 1, A1 may be carbon, silicon, or germanium, and preferably silicon.

[0314]

[0315] Q, a substituent of A1 11 and Q 12 One of them is C 2-20 One is alkoxyalkyl, and the other is C 1-20 Alkyl, preferably Q 11 and Q 12 One of them is C 1-4 One is alkyl, and the other is C 2-20 It may be an alkoxyalkyl. In this way, Q, which is a substituent of the above A1 11 and Q 12 Either one of C 2-20 It may contain a tether group of alkoxyalkyl. Q 11 and Q 12 If either of them has a tether group, leaching of the catalyst precursor is prevented during the polymerization reaction, and as a result, fouling caused by the reaction of the leached catalyst precursor and the cocatalyst can be prevented.

[0316]

[0317] In addition, in addition to the leaching prevention effect of the above-mentioned catalyst precursor, compared to the carbon bridge in the conventional metallocene compound, the atomic size is larger and the available angle is increased, so that the monomer can easily approach during the polymerization reaction, thereby exhibiting better catalytic activity. This effect is achieved in the above-mentioned tether Q 11 and Q 12 Either one of -(CH2) n -R a (Above R a is C 1-6 Alkoxy group, more specifically C 1-6 Straight chain alkoxy group or C 3-6 It may be a branched alkoxy group, more specifically a C such as a tert-butoxy group. 3-6 branched alkoxy, and n is an integer from 2 to 10, or from 3 to 9), and further, the remaining one is C 1-4 It can be further increased if it is alkyl. Preferably, Q 11 and Q 12 One of them may be tert-butoxypropyl, tert-butoxybutyl, tert-butoxypentyl, or tert-butoxyhexyl, and the other may be methyl.

[0318]

[0319] Also, in the above chemical formula 1, R 11 and R 12 are each independently, C 6-20 Aryl, C 7-20 Alkylaryl, C 7-20 Arylalkyl, or C 7-20 It is an alkoxyaryl. That is, in the chemical formula 1, the hydrogen at the 4th position of the indene derivative compound is each independently C 6-20 Aryl, C 7-20 Alkylaryl, C 7-20 Arylalkyl, or C 7-20It can be substituted with an alkoxyaryl. As described above, when an indene derivative compound includes a substituent containing an aryl group, it can exhibit better catalytic activity due to the inductive effect that can supply sufficient electrons. Accordingly, the R 11 and R 12 is preferably C 6-20 Aryl, or C 7-20 It may be alkylaryl, more preferably phenyl, naphthyl, methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl, di-tert-butylphenyl.

[0320]

[0321] In addition, the methyl group substituted at position 2 of the indene derivative compound in chemical formula 1 can secure appropriate copolymerizability and molecular weight by the appropriate steric effect of ethylene and comonomer approaching the active site where polymerization proceeds.

[0322]

[0323] Specific examples of the first transition metal compound represented by the above chemical formula 1 include compounds having the following structures, but the present invention is not limited thereto.

[0324]

[0325]

[0326]

[0327]

[0328]

[0329] The first transition metal compound represented by the above chemical formula 1 can be synthesized by applying known reactions, and a more detailed synthesis method can be found in the examples.

[0330]

[0331] Meanwhile, the second transition metal compound represented by Chemical Formula 2 is a cross-linked structure of two cyclopentadiene derivative compounds, allowing for easy control of the electronic and steric environments surrounding the transition metal. As a result, the chemical structure, molecular weight distribution, and mechanical properties of the synthesized polyethylene can be easily controlled.

[0332]

[0333] Specifically, in the above chemical formula 2, M2 is a group 4 transition metal, preferably zirconium (Zr) or titanium (Ti), and more preferably zirconium (Zr).

[0334]

[0335] X 21 and X 22 are each independently, C 1-20 Alkyl, or halogen, preferably halogen, more preferably chloro (Cl).

[0336]

[0337] When Zr is included as the central metal of the second transition metal compound represented by the above chemical formula 2, compared to when other Group 14 elements such as Hf are included, it has more orbitals capable of accepting electrons, so it can easily bind to a monomer with higher affinity, and as a result, it can exhibit a superior catalytic activity improvement effect.

[0338]

[0339] In addition, the compound represented by the above chemical formula 2 is A2(Q) as a bridging group of two cyclopentadiene derivative compounds. 21 )(Q 22 ) includes a group. In the above chemical formula 2, A2 may be carbon, silicon, or germanium, and preferably silicon.

[0340]

[0341] In addition, in the second transition metal compound represented by the above chemical formula 2, R22 Inland R 25 are each independently hydrogen, C 1-20 Alkyl, C 6-20 Aryl, C 7-20 Alkylaryl, or C 7-20 Arylalkyl, and Q 21 and Q 22 are each independently, C 1-20 Alkyl or C 2-20 It is an alkoxyalkyl, and the bridging group is A2(Q 21 )(Q 22 ) as a substituent Q 21 and Q 22 , and R, a substituent of a cyclopentadiene derivative compound 21 At least one of C 2-20 It is an alkoxyalkyl.

[0342]

[0343] In this way, Q 21 and Q 22 , and R 21 At least one of C 2-20 It may contain a tether group of alkoxyalkyl. Q 21 and Q 22 , and R 21 If at least one of the catalyst precursors has a tether group, leaching of the catalyst precursor is prevented during the polymerization reaction, and as a result, fouling caused by the reaction of the leached catalyst precursor and the cocatalyst can be prevented.

[0344]

[0345] In addition, in addition to the leaching prevention effect of the above-mentioned catalyst precursor, compared to the carbon bridge in the conventional metallocene compound, the atomic size is larger and the available angle is increased, so that the monomer can easily approach during the polymerization reaction, thereby exhibiting better catalytic activity. This effect is the Q 21 and Q 22 , and R 21 At least one of -(CH2) n -R b (Above R b is C 1-6 Alkoxy group, more specifically C 1-6 Straight chain alkoxy group or C 3-6 It may be a branched alkoxy group, more specifically a C such as a tert-butoxy group. 3-6 branched alkoxy, and n is an integer from 2 to 10, or from 3 to 9), and further, the remaining one is C 1-4 It can be further increased if it is alkyl. Preferably, Q 21 and Q 22 , and R 21 Any one or more of them may be tert-butoxyethyl, tert-butoxypropyl, tert-butoxybutyl, tert-butoxypentyl, or tert-butoxyhexyl.

[0346]

[0347] In addition, in the second transition metal compound represented by the above chemical formula 2, R 22 Inland R 25 are each independently hydrogen, C 1-20 Alkyl, C 6-20 Aryl, C 7-20 Alkylaryl, or C 7-20 It is arylalkyl. R 22 Inland R 25 are preferably each independently hydrogen, C 1-6 Alkyl, or C 6-10 It can be aryl, and more preferably, hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, phenyl, naphthyl, methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl, di-tert-butylphenyl.

[0348]

[0349] In one implementation example, R22 Inland R 25 Two or more are C 1-6 Alkyl, or C 6-10 may be aryl. In other embodiments, R 22 Inland R 25 are all C 1-6 Alkyl, preferably methyl, or R 22 Inland R 25 More than two C 6-10 It may be aryl, preferably phenyl.

[0350]

[0351] In the above chemical formula 2, one of the cyclopentadiene derivative compounds is R 22 Inland R 25 By substituting with a substituent of the first transition metal compound represented by the above chemical formula 1, it can exhibit superior catalytic activity through the inductive effect that can supply sufficient electrons and the appropriate steric effect, and by appropriately controlling the distribution of the comonomer of the polyethylene produced in combination with the first transition metal compound represented by the above chemical formula 1, it can simultaneously improve dosability and processability. In addition, it exhibits excellent hydrogen reactivity, so that the amount of wax generated during the polymerization reaction can be reduced, and as a result, process stability can be improved.

[0352]

[0353] Specific examples of the second transition metal compound represented by the above chemical formula 2 include compounds having the following structures, but the present invention is not limited thereto.

[0354]

[0355]

[0356]

[0357] .

[0358]

[0359] The second transition metal compound represented by the above chemical formula 2 can be synthesized by applying known reactions, and a more detailed synthesis method can be found in the examples.

[0360]

[0361] Meanwhile, in the present invention, the hybrid supported metallocene catalyst can increase catalytic activity and further improve the properties of the polymer produced by controlling the molar ratio of the first and second transition metal compounds.

[0362]

[0363] For example, in the hybrid supported metallocene catalyst, the first transition metal compound represented by the chemical formula 1 may contribute to forming a high molecular weight, high polymerization linear copolymer, and the second transition metal compound represented by the chemical formula 2 may contribute to forming a low molecular weight, low copolymerization linear copolymer. The hybrid supported metallocene catalyst may exhibit excellent support performance, catalytic activity, and high copolymerization by using the first transition metal compound with high copolymerization and the second transition metal compound with low copolymerization together as a hybrid catalyst. In particular, when producing linear low-density polyethylene in a slurry process under such a hybrid supported metallocene catalyst, process stability is improved, thereby preventing fouling problems that have occurred in the past. In addition, polyethylene manufactured using the above hybrid supported metallocene catalyst exhibits a high MFRR compared to polyethylene having a similar density due to the introduction of LCB (long chain branch) in the high molecular weight region, and can exhibit excellent processability and high transparency.

[0364]

[0365] Specifically, the hybrid supported metallocene catalyst may include the first and second transition metal compounds in a molar ratio of 1:10 to 10:1. When the above-mentioned mixing ratio conditions are satisfied, the activity of the catalyst is excellently maintained, while the high and low copolymerization properties of the polyethylene produced from the hybrid supported catalyst are optimized, thereby further improving transparency and processability. More specifically, the molar ratio of the first and second transition metal compounds may be 1:10 or more, or 1:9 or more, or 1:8 or more, or 1:7 or more, or 1:6 or more, or 1:5 or more, or 1:5 or more, or 1:4 or more, or 1:3 or more, or 1:2 or more, or 1:1 or more, but 10:1 or less, or 9:1 or less, or 8:1 or less, or 7:1 or less, or 6:1 or less, or 5:1 or less, or 4:1 or less, or 3:1 or less, or 2:1 or less.

[0366]

[0367] Additionally, in the present invention, the hybrid supported metallocene catalyst includes a cocatalyst. When the hybrid supported metallocene catalyst includes a cocatalyst, it can exhibit high catalytic activity while improving process stability.

[0368]

[0369] Specifically, the cocatalyst may include at least one compound represented by the following chemical formula 3.

[0370] [Chemical Formula 3]

[0371] -[Al(R 41 )-O]a-

[0372] In the above chemical formula 3,

[0373] R 41 is a halogen; or C substituted or unsubstituted with a halogen 1-20 It is hydrocarbyl;

[0374] a is an integer greater than or equal to 2.

[0375]

[0376] Meanwhile, in the present specification, a hydrocarbyl group is a monovalent functional group in the form of removing a hydrogen atom from a hydrocarbon, and may include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an aralkenyl group, an aralkynyl group, an alkylaryl group, an alkenylaryl group, and an alkynylaryl group. In addition, the hydrocarbyl group having 1 to 20 carbon atoms may be a hydrocarbyl group having 1 to 15 carbon atoms or 1 to 10 carbon atoms. Specifically, the hydrocarbyl group having 1 to 20 carbon atoms is a straight-chain, branched-chain, or cyclic alkyl group such as a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, or a cyclohexyl group; Or it may be an aryl group such as a phenyl group, a naphthyl group, or anthracenyl group.

[0377]

[0378] Examples of compounds represented by the above chemical formula 3 include alkylaluminoxane compounds such as methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, or butylaluminoxane, and any one of these or a mixture of two or more thereof may be used.

[0379]

[0380] Among the above compounds, the cocatalyst may be, more specifically, an alkylaluminoxane cocatalyst such as methylaluminoxane.

[0381]

[0382] The above alkylaluminoxane cocatalyst can further enhance catalytic activity by including a metal element that stabilizes the first and second transition metal compounds and acts as a Lewis acid to form a bond through a Lewis acid-base interaction with a functional group introduced into a bridge group of the first and second transition metal compounds.

[0383]

[0384] In addition, the amount of the cocatalyst used can be appropriately adjusted depending on the properties or effects of the desired catalyst and polyethylene. For example, when silica is used as the carrier described below, the cocatalyst can be supported in an amount of 100 g or more, 1000 g or more, or 2000 g or more, and 6000 g or less, or 5500 g or less, or 5400 g or less, based on the weight of the carrier, for example, 1,000 g of silica.

[0385]

[0386] In addition, in the present invention, the hybrid supported metallocene catalyst may include a carrier. When the hybrid supported metallocene catalyst includes a carrier, the first and second transition metal compounds are used in the form of a supported catalyst supported on the carrier.

[0387]

[0388] As the carrier, a carrier having a highly reactive hydroxyl group, silanol group, or siloxane group on the surface can be used, and for this purpose, a carrier whose surface has been modified by calcination or whose surface has had moisture removed by drying can be used.

[0389]

[0390] For example, silica manufactured by calcining silica gel, silica such as silica dried at high temperature, silica-alumina, and silica-magnesia can be used, and these can typically contain oxide, carbonate, sulfate, and nitrate components such as Na2O, K2CO3, BaSO4, and Mg(NO3)2.

[0391]

[0392] When used in a supported catalyst state, the particle shape and bulk density of the polymer produced are excellent, and it can be suitably used in conventional slurry polymerization, bulk polymerization, and gas phase polymerization processes. In addition, among various supports, the silica support is supported by chemical bonding of the functional group of the transition metal compound, so that almost no catalyst is liberated from the surface of the support during the ethylene polymerization process, and as a result, fouling caused by adhesion of the reactor wall or polymer particles to each other can be minimized when producing polyethylene by slurry or gas phase polymerization.

[0393]

[0394] The above-mentioned carrier may have an average particle diameter (D50) of 20 to 40 μm. When the above-mentioned particle size is present, the transition metal compound can be supported with superior efficiency, and as a result, the catalytic activity can be enhanced. More specifically, the carrier may have an average particle diameter of 20 μm or more, or 25 μm or more, and 40 μm or less, or 30 μm or less.

[0395]

[0396] In addition, when supported on the carrier, the first and second transition metal compounds may be supported in an amount of, for example, 1 mmol or more, 3 mmol or more, 5 mmol or more, 7 mmol or more, or 10 mmol or more, and 100 mmol or less, or 80 mmol or less, or 60 mmol or less, or 50 mmol or less, based on 1,000 g of the silica carrier. When supported in the above amount range, it may exhibit appropriate supported catalytic activity, which may be advantageous in terms of maintaining the activity of the catalyst and economic efficiency.

[0397]

[0398] In the present specification, the hybrid supported metallocene catalyst having the above-described configuration, the catalyst composition having the above-described configuration, can be produced by a production method including a step of supporting a promoter compound on a support, and a step of supporting the first and second transition metal compounds on the support, wherein the supporting order of the promoter and the first and second transition metal compounds can be changed as needed, and the supporting order of the first and second transition metal compounds can also be changed as needed. The first and second transition metal compounds may be supported simultaneously. Considering the effect of the supported catalyst having a structure determined according to the supporting order, among these, supporting the promoter on the support and then sequentially supporting the first and second transition metal compounds can enable the produced supported catalyst to implement high catalytic activity and better process stability in the process of producing polyethylene.

[0399]

[0400] As described above, the hybrid supported metallocene catalyst can exhibit excellent catalytic activity by including first and second transition metal compounds having specific structures. Accordingly, the hybrid supported metallocene catalyst can be suitably used for the polymerization of ethylene monomers and olefin monomers.

[0401]

[0402] Accordingly, the present invention provides a method for producing polyethylene, comprising a step of polymerizing an ethylene monomer and an alpha-olefin monomer while introducing hydrogen in the presence of the hybrid supported metallocene catalyst.

[0403]

[0404] Specific examples of the above alpha-olefin monomers include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, norbornene, norbornadiene, ethylidenenorbornene, phenylnorbornene, vinylnorbornene, dicyclopentadiene, 1,4-butadiene, 1,5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene, 3-chloromethylstyrene, etc., and two or more of these monomers may be mixed and copolymerized. More specifically, the alpha-olefin monomer may be 1-butene, 1-hexene, or 1-octene.

[0405]

[0406] The amount of the alpha-olefin monomer added may be determined depending on the properties of the polyethylene to be manufactured. For example, considering the effects of improving the properties, transparency, and processability of the polyethylene to be implemented in the present invention, the alpha-olefin monomer may be added in an amount of 5 to 20 wt% based on the total weight of the monomers including the ethylene monomer and the alpha-olefin monomer. More specifically, the alpha-olefin monomer may be added in an amount of 5 wt% or more, or 6 wt% or more, or 7 wt% or more, or 8 wt% or more, or 9 wt% or more, or 10 wt% or more, and 20 wt% or less, or 19 wt% or less, or 18 wt% or less, or 17 wt% or less, based on the total weight of the monomers including the ethylene monomer and the alpha-olefin monomer.

[0407]

[0408] The above polymerization reaction is carried out under the condition of hydrogen input.

[0409]

[0410] Specifically, hydrogen may be introduced in an amount of 5 to 500 ppm, more specifically 5 ppm or more, or 10 ppm or more, or 20 ppm or more, or 30 ppm or more, and 500 ppm or less, or 450 ppm or less, or 400 ppm or less, or 350 ppm or less, or 300 ppm or less, or 250 ppm or less, or 200 ppm or less, based on the total weight of monomers including ethylene monomers and alpha-olefin monomers. When introduced in the above range, it may be easier to implement the physical properties of the polyethylene described above. When the polymerization reaction is performed under conditions without introducing hydrogen, the melt index (MI) of the polyethylene produced may be significantly lowered.

[0411]

[0412] The above polymerization reaction can be carried out as a slurry polymerization reaction.

[0413]

[0414] Accordingly, it can be performed using a single continuous slurry polymerization reactor or a loop slurry reactor.

[0415]

[0416] In addition, the hybrid supported catalyst can be dissolved or diluted and injected into an aliphatic hydrocarbon solvent having 4 to 12 carbon atoms, such as isobutane, pentane, hexane, heptane, nonane, decane, and their isomers, an aromatic hydrocarbon solvent such as toluene and benzene, a hydrocarbon solvent substituted with a chlorine atom such as dichloromethane and chlorobenzene, etc. It is preferable to use the solvent used here after removing a small amount of water or air, etc. that act as catalyst poisons, by treating it with a small amount of alkyl aluminum, and it is also possible to use it by further using a cocatalyst.

[0417]

[0418] In addition, the polymerization reaction may be carried out at a temperature of 40°C or higher, or 60°C or higher, or 80°C or higher, and 110°C or lower, or 100°C or lower, or 90°C or lower. In addition, when the pressure conditions are further controlled during the polymerization reaction, the polymerization reaction may be carried out under a pressure of 5 bar or higher, or 10 bar or higher, or 20 bar or higher, and 50 bar or lower, or 45 bar or lower, or 40 bar or lower. When polymerization is carried out under such temperatures and pressures, the desired physical properties of polyethylene can be more easily realized.

[0419]

[0420] Meanwhile, polyethylene as described above can be produced through a method including a step of copolymerizing ethylene and alpha-olefin in the presence of the hybrid supported metallocene catalyst.

[0421]

[0422] The above-described hybrid supported catalyst can exhibit excellent supporting performance, catalytic activity and high copolymerizability, and can produce polyethylene that can produce a film having both excellent processability and drop impact strength applicable to wide-width agricultural films, shrink films, and MDO (Machine Direction Oriented) polyethylene single materials (MDO All-PE(Uni) materials) while significantly improving melt strength and reducing processing load during film extrusion without significantly reducing melt index or increasing zero shear viscosity.

[0423]

[0424] The above method for producing polyethylene can be carried out by a slurry polymerization method using ethylene and alpha-olefin as raw materials in the presence of the above-described hybrid supported catalyst, using a conventional device and contact technology.

[0425]

[0426] The method for producing the above polyethylene may copolymerize ethylene and alpha-olefin using a continuous slurry polymerization reactor, a loop slurry reactor, etc., but is not limited thereto.

[0427]

[0428] Here, the alpha-olefin is as described above, and for example, 1-hexene can be used as the alpha-olefin. Accordingly, in the slurry polymerization, by polymerizing the ethylene and 1-hexene, it is possible to produce a polyethylene film that can significantly improve melt strength and has excellent processability and drop impact strength applicable to wide agricultural films, shrink films, and MDO (Machine Direction Oriented) polyethylene single materials, i.e., MDO All-PE (Uni) materials.

[0429]

[0430] In this way, the polyethylene according to the present invention can be produced by copolymerizing ethylene and alpha-olefin using the supported metallocene catalyst described above.

[0431]

[0432] By the above-described manufacturing method, polyethylene having the above-described physical properties can be manufactured.

[0433]

[0434] polyethylene film

[0435]

[0436] According to another aspect of the present invention, a film comprising the above-described polyethylene is provided.

[0437]

[0438] In particular, polyethylene, possessing the above-described physical properties, exhibits excellent processability during film manufacturing due to its processing load characteristics, and possesses excellent mechanical properties such as melt strength and drop impact strength. Accordingly, it can be usefully applied in various fields requiring excellent processability and drop impact strength. In particular, the polyethylene can be stably formed into a film using a melt-blown process, etc.

[0439]

[0440] The above polyethylene film can be manufactured by a conventional film manufacturing method, except that polyethylene having the properties described above is used.

[0441]

[0442] For example, when processing the polyethylene film, the polyethylene can be manufactured by inflation molding to a predetermined thickness, specifically, 15 micrometers (㎛) to 200 micrometers (㎛), for example, 50 micrometers (㎛), using an extruder. At this time, the extrusion temperature of the extruder is 160 o C to 200 o C, for example, 185 o C may be. Also, the blow up ratio (BUR) may be 3.4 or less, more specifically 1.5 to 3.0.

[0443]

[0444] In addition, the polyethylene film according to the present invention may further include additives well known in the art in addition to the polyethylene described above. Specifically, such additives include solvents, heat stabilizers, antioxidants, UV absorbers, light stabilizers, metal deactivators, fillers, reinforcing agents, plasticizers, lubricants, emulsifiers, pigments, optical bleaching agents, flame retardants, antistatic agents, and foaming agents. The types of the additives are not particularly limited, and general additives known in the art can be used.

[0445]

[0446] The polyethylene film according to one embodiment of the present invention manufactured by the above method can significantly improve melt strength while minimizing processing load without significantly reducing melt index or significantly increasing zero shear viscosity, thereby improving both processability and drop impact strength applicable to All-PE(Uni) material in wide-width agricultural films or shrink films.

[0447]

[0448] In particular, the polyethylene film has a density and melt index (MI) 2.16 ), melt flow index (MI) 21.6 / MI 2.16 ) and temperature-dependent ARES (advanced rheometric expansion system) analysis, the Ea(δ) graph characteristics and the Ea maximum value and G* absolute value are optimized for the phase angle(δ) value at 0.01 MPa, so it is suitable for food / industrial downgauge due to its good processability and drop impact applicable to All-PE(Uni) materials.

[0449]

[0450] Specifically, the polyethylene film can exhibit drop impact strength characteristics.

[0451]

[0452] Specifically, when the film is a single-layer film having a film thickness of 45 to 55 μm, or 48 to 52 μm, more specifically 50 μm, the drop impact strength measured according to ASTM D 1709 [Method A] may be 1000 gf or more, or 1010 gf or more, or 1020 gf or more, or 1030 gf or more, or 1040 gf or more, or 1050 gf or more, or 1060 gf or more, or 1070 gf or more, or 1080 gf or more, or 1090 gf or more, or 1100 gf or more, or 1110 gf or more, or 1115 gf or more, or 1120 gf or more, or 1125 gf or more. In addition, the higher the drop impact strength, the better, so there is no particular upper limit, but for example, it may be 2,000 gf or less, or 1,980 gf or less, or 1,900 gf or less.

[0453]

[0454] For reference, the above drop impact strength may be measured on a film formed into a single-layer film having a thickness of 45 to 55 μm, or 48 to 52 μm, more specifically 50 μm, using a blown film extruder (die diameter 120 mm, die gap 2.0 mm, BUR 2.5, Dual air-ring system), from a composition containing 95 wt% or more, or 96 wt% or more, or 97 wt% or more, or 98 wt% or more, or 99 wt% or more, of the polyethylene of the present invention based on the total composition.

[0455]

[0456] The above polyethylene film has excellent film processability and drop impact strength, and is a product with excellent mechanical properties such as tensile strength and impact strength, and can be effectively used in the manufacture of agricultural films, lamination films, and general industrial polyethylene films. Among these films, heat shrinkable films are applied to industrial packaging, food, beverage, and general product packaging. In particular, the polyethylene film according to the present invention has good bubble stability even during high-speed processing depending on the take-off speed, has a wide processing area, and has excellent MD / TD tear strength balance (Elmendorf tear balance) and drop impact strength, so it can be applied to downgauging, and can obtain excellent effects in recent environmental issues (CO2 reduction) and cost reduction.

[0457]

[0458] The polyethylene according to the present invention has an excellent effect of being able to manufacture a polyethylene film having both excellent processability and drop impact strength applicable to wide-width agricultural films or All-PE(Uni) materials for shrink film applications by minimizing processing load while significantly improving melt strength without significantly reducing the melt index or significantly increasing the zero shear viscosity.

[0459]

[0460] Figure 1 is a graph in which the phase angle (δ) is plotted on the x-axis and the activation energy (Ea) according to the change in the phase angle (δ) is plotted on the y-axis, obtained by performing a Dynamic Frequency Sweep Test using an advanced rheometric expansion system (ARES) at different temperatures for polyethylene of examples and comparative examples.

[0461]

[0462] Figure 2 is a vGP plot graph with the absolute value of the complex shear modulus (|G*|) on the x-axis and the phase angle (δ) on the y-axis, obtained by performing a Dynamic Frequency Sweep Test using an advanced rheometric expansion system (ARES) at different temperatures for polyethylene of examples and comparative examples.

[0463]

[0464] Hereinafter, embodiments of the present invention will be described in more detail in the following examples. However, the following examples are merely illustrative of embodiments of the present invention, and the content of the present invention is not limited by the following examples.

[0465]

[0466] [Example]

[0467] <Preparation of the first metallocene compound>

[0468] Synthesis Example 1-1

[0469] (Cat 1-1)

[0470]

[0471] Preparation of ligand compounds

[0472] 6-Chlorohexan-1-ol (1 equiv.) was dissolved in hexane (1 M), and Amberlyst (10 wt%) was added. Isobutene gas was bubbled at room temperature for 3 hours. 1-(tert-butoxy)-6-chlorohexane was obtained by filtering through Celite and vacuum drying. Mg (1.5 eq) was prepared in another flask, washed with HCl and acetone, and vacuum dried. THF (1 M) was added, and 10% 1-(tert-butoxy)-6-chlorohexane was added. After refluxing and completing activation, the mixture was cooled to 50°C, and the remaining 90% 1-(tert-butoxy)-6-chlorohexane was slowly added. The reaction was maintained overnight. The mixture was filtered through Celite, and 1 equivalent of MeSiCl3 was dissolved in THF (1 M) in a new flask, and Grignard reagent was slowly added at -25°C. The mixture was stirred overnight at room temperature, the solvent was completely dried, and the mixture was filtered after replacing with hexane to obtain (6-(tert-butoxy)hexyl)dichloro(methyl)silane.

[0473]

[0474] 7-(4-(tert-butyl)phenyl)-2-methyl-1H-indene (16.00 mmol) was added to a Schlink flask and dried under reduced pressure for 30 minutes. THF (60 mL) was added and stirred to completely dissolve. After cooling the flask to -25 °C, n-BuLi (2.5 M, 6.4 mL) was slowly added dropwise with stirring. After stirring at 25 °C for 12 hours, CuCN (5 mol%) was added. After stirring for 30 minutes, it was cooled to -25 °C. (6-(tert-butoxy)hexyl)dichloro(methyl)silane (8.00 mmol) was added and stirred at 25 °C for 12 hours. Water was added, stirred for 1 hour, and then extracted. The organic layer was dehydrated with MgSO4, filtered, and dried again to obtain the ligand compound.

[0475]

[0476] Preparation of transition metal compounds

[0477] To the ligand compound obtained above, 21 mL of toluene and 2.1 mL of diethyl ether were added and stirred. After cooling to -25 °C, n-BuLi (2.5 M, 12.8 mL) was slowly added dropwise while stirring. The mixture was stirred at 25 °C for 12 h and cooled to -20 °C, and then ZrCl4·2THF (8.00 mmol) dissolved in toluene (1 M) was added. After stirring at 25 °C for 12 h, the solvent was completely dried. The mixture was dissolved in DCM, filtered, and the filtrate was dried and recrystallized using dichloromethane, pentane, and hexane to obtain a transition metal compound of structural formula Cat 1-1 in a yield of 34% (racemic / meso ratio 30:1).

[0478]

[0479] 1H NMR (500 MHz, CDCl3, 7.26 ppm): 1.20 (9H, s), 1.27 (3H, s), 1.34 (18H, s), 1.20-1.90 (10H, m), 2.25 (3H, s), 2.26 (3H, s), 3.38 (2H, t), 7.00 (2H, s), 7.09-7.13 (2H, m), 7.38 (2H, d), 7.45 (4H, d), 7.58 (4H, d), 7.59 (2H, d), 7.65 (2H, d)

[0480]

[0481] Synthesis Example 1-2

[0482] (Cat 1-2)

[0483]

[0484] Preparation of ligand compounds

[0485] A ligand compound was prepared in the same manner as the preparation of the ligand compound in Synthesis Example 1-1, except that 2-methyl-7-phenyl-1H-indene was used instead of 7-(4-(tert-butyl)phenyl)-2-methyl-1H-indene in Synthesis Example 1-1.

[0486]

[0487] Preparation of transition metal compounds

[0488] Except that the ligand compound of Synthesis Example 1-2 was used instead of the ligand compound of Synthesis Example 1-1, the same method as for preparing the transition metal compound of Synthesis Example 1-1 was used, and the transition metal compound of structural formula Cat 1-2 was obtained in a yield of 35% (ratio of racemic / meso was 30:1).

[0489]

[0490] 1H NMR (500 MHz, C6D6, 7.15 ppm): 1.19(9H, s), 1.32(3H, s), 1.48~1.86(10H, m), 2.25(6H, s), 3.37(2H, t), 6.95(2H, s), 7.13(2H, t), 7.36(2H, d), 7.43(6H, t), 7.62(4H, d), 7.67(2H, d)

[0491]

[0492] Synthesis Example 2-1

[0493] (Cat 2-1)

[0494]

[0495]

[0496] Preparation of ligand compounds

[0497] 6-Chlorohexan-1-ol (1 equiv) was dissolved in hexane (1 M), and Amberlyst (10 wt%) was added. Isobutene gas was bubbled at room temperature for 3 hours. 1-(tert-butoxy)-6-chlorohexane was obtained by filtering through celite and drying in vacuum. 1-(tert-butoxy)-6-chlorohexane (20.0 mmol) was weighed into a flask, and THF (1.0 M) was added. After cooling to -25 °C, sodium cyclopentadiene (1.0 M in THF, 1 eq) was added. After stirring at room temperature for 12 hours, the solvent was completely dried, hexane was replaced, and filtering was performed to obtain 1-(6-(tert-butoxy)hexyl)cyclopenta-1,3-diene.

[0498] Tetramethylcyclopentadiene (10.00 mmol) was added to a Schlenk flask and dried under reduced pressure for 30 minutes. THF (40 mL) was added, cooled to -25 °C, and n-BuLi (2.5 M, 4 mL) was slowly added dropwise with stirring. The mixture was stirred at 25 °C for 12 hours and then cooled to -25 °C. Me2SiCl2 (dichlorodimethylsilane, 10.00 mmol) was added and stirred at 25 °C for 12 hours. In another flask, previously synthesized 1-(6-(tert-butoxy)hexyl)cyclopenta-1,3-diene (10.00 mmol) and THF (40 mL) were added, cooled to -25 °C, and n-BuLi (2.5 M, 4 mL) was slowly added dropwise with stirring. The mixture was then stirred at 25 °C for 12 hours. After cooling the previously synthesized Chlorodimethyl(2,3,4,5-tetramethylcyclopenta-2,4-dien-1-yl)silane flask to -25 ℃, Lithium 1-(6-(tert-butoxy)hexyl)cyclopenta-1,3-diene was slowly added dropwise. After stirring at 25 ℃ for 12 hours, water was added, stirring for 1 hour, and extraction was performed. The organic layer was dehydrated with MgSO4, filtered again, and dried to obtain the ligand compound.

[0499]

[0500] Preparation of transition metal compounds

[0501] 25 mL of diethyl ether was added to the ligand compound obtained above and stirred. After cooling to -25 °C, n-BuLi (2.5 M, 8 mL) was slowly added dropwise while stirring. The mixture was stirred at 25 °C for 12 h and cooled to -20 °C, and then ZrCl4·2THF (10.00 mmol) dissolved in toluene (1 M) was added. After stirring at 25 °C for 12 h, the solvent was completely dried. DCM was added, filtered, the filtrate was dried, and recrystallized using hexane to obtain a transition metal compound of structural formula Cat 2-1 in a yield of 25%.

[0502]

[0503] 1 H NMR (500 MHz, C6D6, 7.15 ppm): 0.37(3H, s), 0.39(3H, s), 1.12(9H, s), 1.32-1.40(4H, m), 1.53-1.60(4H, m), 1.66(3H, s), 1.73(3H, s), 2.01(3H, s), 2.03(3H, s), 2.79-2.85(2H, m), 3.23(2H, t), 5.16(1H, t), 5.43(1H, t), 6.73(1H, t)

[0504]

[0505] Synthesis Example 2-2

[0506] (Cat 2-2)

[0507]

[0508]

[0509] Preparation of ligand compounds

[0510] A ligand compound was prepared in the same manner as the preparation of the ligand compound of Synthesis Example 2-1, except that 2-bromoethan-1-ol was used instead of 6-chlorohexan-1-ol in Synthesis Example 2-1.

[0511]

[0512] Preparation of transition metal compounds

[0513] Except that the ligand compound of Synthesis Example 2-2 was used instead of the ligand compound of Synthesis Example 2-1, the preparation was carried out in the same manner as the preparation of the transition metal compound of Synthesis Example 2-1, and a transition metal compound of structural formula Cat 2-2 was obtained in a yield of 60%.

[0514]

[0515] 1 H NMR (500 MHz, C6D6, 7.15 ppm): 0.38(3H, s), 0.40(3H, s), 1.13(9H, s), 1.61(3H, s), 1.69(3H, s), 2.03(3H, s), 2.05(3H, s), 2.58-2.65(2H, m), 3.25(2H, t), 5.15(1H, t), 5.43(1H, t), 6.72(1H, t)

[0516]

[0517] <Preparation of Hybrid Supported Metallocene Catalysts>

[0518] Manufacturing Example 1

[0519] 2.0 kg of toluene and 1000 g of silica (Grace Davison, SP2410) were charged into a 20L SUS high-pressure reactor, and stirred while raising the temperature of the reactor to 40°C. 5.4 kg of methylaluminoxane (10 wt% in toluene, manufactured by Albemarle) was charged into the reactor, and the temperature was raised to 70°C, followed by stirring at about 200 rpm for about 12 hours. Thereafter, the temperature of the reactor was lowered to 40°C, and stirring was stopped. The reaction product was allowed to stand for about 10 minutes and then decantated. 2.0 kg of toluene was then added to the reaction product, stirred for about 10 minutes, stopped, allowed to stand for about 30 minutes, and then decantated.

[0520]

[0521] 2.0 kg of toluene was charged into the reactor, and then the first transition metal compound of structural formula Cat 1-1 (40.0 mmol) prepared in Synthesis Example 1-1, the second transition metal compound of structural formula Cat 2-1 (20.0 mmol) prepared in Synthesis Example 2-1, and 1000 mL of toluene were charged. The temperature of the reactor was raised to 85°C, and stirring was performed for about 90 minutes.

[0522]

[0523] Afterwards, the temperature of the reactor was lowered to room temperature, stirring was stopped, the reaction product was allowed to stand for about 30 minutes, and the reaction product was decantated. Next, 3 kg of hexane was added to the reactor, and the hexane slurry solution was transferred to a 20 L filter dryer, the solution was filtered, and dried under reduced pressure at 50 °C for about 4 hours to obtain about 1.5 kg of a hybrid supported metallocene catalyst.

[0524]

[0525] Manufacturing Example 2

[0526] 2.0 kg of toluene and 1000 g of silica (Grace Davison, SP2410) were charged into a 20L SUS high-pressure reactor, and stirred while raising the temperature of the reactor to 40°C. 5.4 kg of methylaluminoxane (10 wt% in toluene, manufactured by Albemarle) was charged into the reactor, and the temperature was raised to 70°C, followed by stirring at about 200 rpm for about 12 hours. Thereafter, the temperature of the reactor was lowered to 40°C, and stirring was stopped. The reaction product was allowed to stand for about 10 minutes and then decantated. 2.0 kg of toluene was then added to the reaction product, stirred for about 10 minutes, stopped, allowed to stand for about 30 minutes, and then decantated.

[0527]

[0528] 2.0 kg of toluene was charged into the reactor, and then the first transition metal compound of structural formula Cat 1-1 (70.0 mmol) prepared in Synthesis Example 1-1, the second transition metal compound of structural formula Cat 2-1 (20.0 mmol) prepared in Synthesis Example 2-1, and 1000 mL of toluene were charged. The temperature of the reactor was raised to 85°C, and stirring was performed for about 90 minutes.

[0529]

[0530] Afterwards, the temperature of the reactor was lowered to room temperature, stirring was stopped, the reaction product was allowed to stand for about 30 minutes, and the reaction product was decantated. Next, 3 kg of hexane was added to the reactor, and the hexane slurry solution was transferred to a 20 L filter dryer, the solution was filtered, and dried under reduced pressure at 50 °C for about 4 hours to obtain about 1.5 kg of a hybrid supported metallocene catalyst.

[0531]

[0532] Manufacturing Example 3

[0533] 2.0 kg of toluene and 1000 g of silica (Grace Davison, SP2410) were charged into a 20L SUS high-pressure reactor, and stirred while raising the temperature of the reactor to 40°C. 5.4 kg of methylaluminoxane (10 wt% in toluene, manufactured by Albemarle) was charged into the reactor, and the temperature was raised to 70°C, followed by stirring at about 200 rpm for about 12 hours. Thereafter, the temperature of the reactor was lowered to 40°C, and stirring was stopped. The reaction product was allowed to stand for about 10 minutes and then decantated. 2.0 kg of toluene was then added to the reaction product, stirred for about 10 minutes, stopped, allowed to stand for about 30 minutes, and then decantated.

[0534]

[0535] 2.0 kg of toluene was charged into the reactor, and then the first transition metal compound of structural formula Cat 1-2 (40.0 mmol) prepared in Synthesis Example 1-2, the second transition metal compound of structural formula Cat 2-2 (20.0 mmol) prepared in Synthesis Example 2-2, and 1000 mL of toluene were charged. The temperature of the reactor was raised to 85°C, and stirring was performed for approximately 90 minutes.

[0536]

[0537] Afterwards, the temperature of the reactor was lowered to room temperature, stirring was stopped, the reaction product was allowed to stand for about 30 minutes, and the reaction product was decantated. Next, 3 kg of hexane was added to the reactor, and the hexane slurry solution was transferred to a 20 L filter dryer, the solution was filtered, and dried under reduced pressure at 50 °C for about 4 hours to obtain about 1.5 kg of a hybrid supported metallocene catalyst.

[0538]

[0539] The types and molar ratios of the hybrid supported metallocene catalysts of the above manufacturing examples 1 to 3 are shown in Table 1 below.

[0540]

[0541] Catalyst 1st transition metal compound (A) 2nd transition metal compound (B) Molar ratio (A:B) Manufacturing example 1 Cat 1-1 Cat 2-12:1 Manufacturing example 2 Cat 1-1 Cat 2-13.5:1 Manufacturing example 3 Cat 1-2 Cat 2-22:1

[0542] <Manufacturing of polyethylene>

[0543] Example 1

[0544] Ethylene-1-hexene was slurry polymerized in the presence of the hybrid supported catalyst prepared in Manufacturing Example 1 above.

[0545]

[0546] At this time, the polymerization reactor was a continuous polymerizer of isobutane (i-C4) slurry loop process, with a reactor volume of 140 L and a reaction flow rate of approximately 7 m / s. In addition, the gases (ethylene, hydrogen) required for polyethylene polymerization and 1-hexene, a comonomer, were continuously fed into the reactor as described in Table 2, and the individual flow rates were adjusted according to the target product. At this time, the hydrogen input amount was adjusted to 5.0 ppm relative to ethylene. In addition, the concentrations of all gases and 1-hexene, a comonomer, in Example 1 were confirmed by an on-line gas chromatograph. The supported catalyst was fed mixed into the isobutene slurry. The polymerization reaction was performed at a pressure of approximately 40 bar and a temperature of approximately 85°C.

[0547]

[0548] Examples 2 to 4

[0549] Ethylene-1-hexene was slurry polymerized using the same method as in Example 1, but using the hybrid supported catalyst polymer prepared in the manufacturing example as described in Table 2, while varying the input amounts of reactants required for polyethylene polymerization.

[0550]

[0551] The main conditions of the polymerization reaction in Examples 1 to 4 are shown in Table 2.

[0552] Catalytic ethylene input (kg / hr)1-Hexene input 1 (wt%) hydrogen input 2 (ppm)Activity (kgPE / kgSiO2·hr)Example 1 Manufacturing Example 128.1151602.0Example 2 Manufacturing Example 128.1161301.9Example 3 Manufacturing Example 228.114.21501.9Example 4 Manufacturing Example 32516.0405.2

[0553] In Table 2 above, the activity (Activity, kgPE / kgSiO2·hr) was calculated as the ratio of the weight of polymer (kg PE) produced per weight of supported catalyst (kg) used per unit time (hr).

[0554]

[0555] In addition, the 1-Hexene input amount (wt%) is calculated as a percentage of the 1-Hexene input amount based on the total weight of monomers including ethylene and 1-hexene, and the hydrogen input amount (ppm) is calculated as a percentage of the total weight of monomers including ethylene and 1-hexene.

[0556]

[0557] Comparative Example 1

[0558] HP1018, an ethylene-1-hexene copolymer manufactured by LG Chem, was used.

[0559]

[0560] Comparative Example 2

[0561] EP2010, an ethylene-1-hexene copolymer manufactured by LG Chem, was used.

[0562]

[0563] Comparative Example 3

[0564] XM1605, an ethylene-1-hexene copolymer manufactured by LG Chem, was used.

[0565]

[0566] Comparative Example 4

[0567] BF315, a low density polyethylene manufactured by LG Chem, was used.

[0568]

[0569] Comparative Example 5

[0570] LF2003, a low density polyethylene manufactured by LG Chem, was used.

[0571]

[0572] <Evaluation of physical properties of polyethylene and films>

[0573] Test Example 1

[0574] The physical properties of the polyethylene of the examples and comparative examples were measured using the methods described below and are shown in Tables 3 and 4.

[0575]

[0576] (1) Density

[0577] Density of polyethylene (g / cm) 3 ) was measured according to the American Society for Testing and Materials ASTM D 1505 standard.

[0578]

[0579] (2) Melting index

[0580] American Society for Testing and Materials Standard ASTM D 1238 (Condition E, 190 o 190 according to C, 2.16 kg) o Melt index (MI) under a load of 2.16 kg under C 2.16 ) was measured and expressed as the weight (g) of the polymer melted over 10 minutes.

[0581]

[0582] (3) Melt flow index

[0583] American Society for Testing and Materials Standard ASTM D 1238 (Condition E, 190 o 190 according to C, 2.16 kg) o High load melt index (MI) under loads of 21.6 kg and 2.16 kg, respectively, under C 21.6 ) and melting index (MI) 2.16 ) after measuring each, MI 21.6 MI 2.16 Divide by melt flow rate ratio (MFRR, Melt Flow Rate Ratio, MI) 21.6 / MI 2.16 ) was calculated.

[0584]

[0585] (4) Molecular weight (Mw, Mn, Mz, Mp) and molecular weight distribution

[0586] For the polyethylene of the examples and comparative examples, the weight-average molecular weight (Mw, g / mol), number-average molecular weight (Mn, g / mol), Z-average molecular weight (Mz, g / mol), and peak molecular weight (Mp, g / mol) were measured using gel permeation chromatography (GPC, manufactured by Water), and the ratio of the Z-average molecular weight to the number-average molecular weight measured above (Mz / Mn) was calculated. In addition, the molecular weight distribution (Mw / Mn, PDI, polydispersity index) was calculated by dividing the weight-average molecular weight by the number-average molecular weight, and in addition, the Z-average molecular weight was divided by the number-average molecular weight to measure the molecular weight distribution (Mz / Mn, Mw / Mn), weight-average molecular weight (Mw), and number-average molecular weight (Mn).

[0587]

[0588] Specifically, the gel permeation chromatography (GPC) device is Polymer Char GPC-IR. ® The device was used, and a Polymer Laboratories PLgel MIX-B 300 mm long column was used. The measurement temperature was 160°C, 1,2,4-trichlorobenzene was used as a solvent, and the flow rate was 1 mL / min. Each sample of polyethylene manufactured in the examples and comparative examples was analyzed by GPC analysis device (Polymer Char GPC-IR). ®) was dissolved in 1,2,4-trichlorobenzene containing 0.03% BHT at 160℃ for 2 hours, pretreated, and then prepared at a concentration of 16 mg / 8 mL and supplied in an amount of 200 μL. The values ​​of Mw and Mn were calculated using a calibration curve formed using polystyrene standard specimens. The weight-average molecular weights of the polystyrene standard specimens were 9 types: 2000 g / mol, 10000 g / mol, 30000 g / mol, 70000 g / mol, 200000 g / mol, 700000 g / mol, 2000000 g / mol, 4000000 g / mol, and 10000000 g / mol.

[0589]

[0590] (5) Melt strength (mN)

[0591] Melt strength was measured for the polyethylenes of the examples and comparative examples using a Goettfert Rheotens 71.97 equipped with a Model 3211 Instron capillary rheometer.

[0592]

[0593] Specifically, the specific measurement conditions for measuring melt strength for the polyethylene of the examples and comparative examples were as follows a) to d):

[0594]

[0595] a) Capillary die L / D: 30 / 2, 180°

[0596] b) Capillary shear rate: 200 / s

[0597] c) Leotens starting speed: 50 mm / s

[0598] d) Leotens acceleration: 12 mm / s2

[0599]

[0600] At this time, the melting strength was measured at each speed under the above acceleration, and the measurement results (melting strength was derived as an average value) are shown in Tables 3 and 4.

[0601]

[0602] (6) Maximum take-off velocity

[0603] Under the conditions described above, the maximum take-off velocity (Max V) was measured for the polyethylene of the examples and comparative examples using a Goettfert Rheotens 71.97 equipped with a Model 3211 Instron capillary rheometer.

[0604]

[0605] Specifically, the speed at which processing defects, such as buckling, breaking, stretching, thickness unevenness, and fracture, first occur when pulling polyethylene was measured. The maximum take-off velocity was defined as the maximum speed at which the polyethylene could be reliably pulled without such defects.

[0606]

[0607] (7) Decision distribution analysis

[0608] Cross fraction chromatography (CFC) analysis was performed on the polyethylene manufactured in the above examples and comparative examples using the following method.

[0609]

[0610] [Cross-fractionation chromatography measurement conditions (including TREF and GPC analysis)]

[0611] - Analysis equipment: Polymer Char CFC - 7890B (G3440D)

[0612] (Detector: Integrated Detector IR5 MCT)

[0613] - Sample preparation and loading: 32 mg of polyethylene manufactured in the above examples or comparative examples was placed in a 10 mL vial and placed in an autosampler, 8 mL of 1,2,4-trichlorobenzene (TCB) was added, dissolved at 160°C for 90 minutes, and stabilized at 140°C for 20 minutes. After nitrogen purge, extraction was performed and loaded onto a temperature rising elution fractionation column (TREF column).

[0614] - Crystallization: The temperature of the sample previously loaded onto the TREF column was adjusted to 140℃, then cooled from 140℃ to 35℃ at a rate of 0.5℃ / min and maintained for 15 minutes.

[0615]

[0616] The detailed conditions for the above stabilization and crystallization are as follows:

[0617]

[0618]

[0619] - Temperature Rising Elution Fractionation (TREF) Analysis: The previously crystallized sample was heated from 35°C to 120°C at a rate of 1°C / min to the fraction temperature shown below, then fixed. The concentrations of the fractions eluted at that temperature for 5 minutes were measured. A TREF analysis graph was derived from the concentration measurement results.

[0620]

[0621] From the TREF graph, the content ratio of the soluble fraction (SF) eluted in the region of the elution temperature 35°C or lower (Te≤35°C) based on the total weight of the entire elution fraction, the content ratio of the polymer fraction eluted in the region of the elution temperature exceeding 35°C and less than 60°C (35°C <Te<60℃), 용리 온도 30 ℃ 이상이고 60 ℃ 미만의 영역에서 용출되는 중합체 분획의 함량 비율(30℃≤Te<60℃), 용리 온도 60 ℃ 이상이고 80 ℃ 미만의 영역에서 용출되는 중합체 분획의 함량 비율(60℃≤Te<80℃), 그리고 용리 온도 80 ℃ 이상의 영역에서 용출되는 중합체 분획의 함량 비율(80℃≤Te)을 각각 산출하였다(중량%).

[0622]

[0623] In addition, from the TREF analysis results, the elution temperature (Te) when the content of the eluted polymer is 50 wt% ,50 ) was measured.

[0624] <fraction temperature>

[0625] 35℃ / 40℃ / 43℃ / 46℃ / 49℃ / 52℃ / 55℃ / 58℃ / 61℃ / 64℃ / 67℃ / 70℃ / 73℃ / 76℃ / 79℃ / 82℃ / 85℃ / 88℃ / 91℃ / 94℃ / 97℃ / 100℃ / 105℃ / 120℃

[0626]

[0627] <Measurement conditions>

[0628]

[0629] Example 1 Example 2 Example 3 Example 4 Density (g / cm3) 0.918 10.917 20.919 40.918 7 MI (190 ℃, 2.16 kg, g / 10 min) 10.56 0.93 1.13 MFRR 3 0.53 34.14 30.43 28.29 Comonomer 1-hexene 1-hexene 1-hexene 1-hexene Molecular weight and molecular weight distribution Mn (g / mol) 28,400 31,800 27,300 20,700 Mw (g / mol) 98,300 111,200 104,400 96,600 Mz (g / mol) 276,000 341,300 381,400 303,100 Mp (g / mol)62,100,66,800,65,600,73,600,Mz / Mn9.7,10.7,14.0,14.6,Mw / Mn3.4,63.5,03.8,24.67,Tensile test,Melt Strength (mN),145,180,105,96,Take-off velocity (mm / sec),50,33,155,265,73,TREF analysis,30 ≤ Te <60, wt%,13.95,14.0,22.0,92,4.3,600,Te <80, wt%,55,195,2.9,35.4,39.5,Te ≥80, wt%,30.8,53,33.0,44,2.53,36.0,T e,50 (℃)71.972.275.872.8

[0630] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Density (g / cm3) 0.918 0.920 90.916 0.922 0.921 MI (190 ℃, 2.16 kg, g / 10 min) 10.99 40.5 0.93 50.723 MFRR 16.37 38.45 40.86 72.81 66 7.926 Molecular weight and molecular weight distribution Mn (g / mol) 42,100 27,500 29,000 16,200 20,400 Mw (g / mol) 103,100 80,800 93,100 90,400 142,000 Mz (g / mol)185,900157,300190,200246,800459,400Mp (g / mol)78,30063,90071,50063,90081,000Mz / Mn4.45.76.615.222.5Mw / Mn2.452.943.215.586.96Tensile TestMelt Strength (mN)6682106140228Take-off velocity(mm / sec)892595495235204TREF analysis30≤Te<60 (wt%)5.32.94.31513.760≤Te<80 (wt%)50.66884.184.786Te≥80 (wt%)44.129.111.60.30.3T e,50 (℃)77.677.175.172.271.9

[0631]

[0632] Test Example 2

[0633] For the polyethylene of the above examples and comparative examples, the absolute molecular weight (M) of the polyethylene sample was determined using IR6 MCT, a Polymer Char GPC-IR® equipped with a triple detector (refractive index detector, viscosity detector, and light scattering detector) as follows. abs ) was measured for the branching index g'(vis,bulk), and the measurement results are shown in Tables 5 and 6.

[0634]

[0635] (1) Sample preparation

[0636] - Dissolve the polyethylene sample to be analyzed in a solvent (1,2,4-trichlorobenzene (TCB)).

[0637] - Dissolution conditions: For example, stirring for 2 to 6 hours at 140 to 160°C with a concentration of 0.1 to 2% w / v.

[0638]

[0639] (2) GPC-Triple Detector System Configuration

[0640] - Column: GPC column for polymer separation (PLgel Olexis, Mixed-B, 300×7.5mm, 2~4 in series)

[0641] - Detectors: (a) refractive index detector (RI), (b) light scattering detector (LS), (c) viscosity detector (VIS)

[0642] - Mobile phase: TCB, Temperature: 140~160°C, Flow rate: 1.0 mL / min

[0643]

[0644] (3) Measurement and data processing

[0645] a) Calculating the branching parameters (g'(vis,bulk):

[0646] - Calculate the intrinsic viscosity ([η]) for each molecular weight band from the viscosity detector signal.

[0647] - The absolute molecular weight (M) of polyethylene according to the following mathematical formula 5 abs ) to calculate the branching index g'(vis,bulk)

[0648] [Equation 5]

[0649]

[0650] In the above mathematical expression 5,

[0651] ηb is the intrinsic viscosity of the polyethylene,

[0652] ηl is the absolute molecular weight (M) equal to that of the polyethylene abs ) is the intrinsic viscosity of linear polyethylene, and is a value calculated according to the following mathematical formula 6.

[0653] [Equation 6]

[0654] ηl =KM α

[0655] In the above mathematical expression 6,

[0656] M is the absolute molecular weight (M) of the linear polyethylene abs ) and,

[0657] K is 0.000523,

[0658] α is 0.708.

[0659]

[0660] Here, the absolute molecular weight of polyethylene (M abs ) is the molecular weight measured directly without a reference material, and was measured using the 15°, 90° light scattering detector of IR6 MCT, a Polymer Char GPC-IR®.

[0661]

[0662] Also, g'(vis,bulk) is the absolute molecular weight (M abs ) is the arithmetic mean g'(vis) value for the whole.

[0663]

[0664] Example 1 Example 2 Example 3 Example 4 g'(vis,bulk) 0.79 0 7 0.70 9 3 0.80 8 3 0.79 6 7

[0665] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 g'(vis,bulk) 0.91 3 9 0.87 24 0.84 6 9 0.38 8 5 0.26 40 "-" is not measurable, not measured

[0666] Test Example 3

[0667] After measuring the rheological properties of the polyethylene of the examples and comparative examples, the relaxation time spectrum was analyzed using the results, and the ER (Polydispersity at the High MW) and PDR (overall polydispersity) of the polyethylene of the examples and comparative examples were obtained using the rheological property measurement results.

[0668]

[0669] (1) Sample manufacturing

[0670] For each of the polyethylenes of the above examples and comparative examples, samples for measuring rheological properties were prepared by compression molding at 182°C for 3 minutes.

[0671]

[0672] Specifically, the polyethylene of the examples and comparative examples was melted at 182°C under a pressure of 2 bar for 1 minute, then a pressure of 100 bar was additionally applied for 2 minutes, and quenched in a cooling press to manufacture a press mold sample in the shape of a disk with a thickness of 2 mm x a diameter of 25.4 mm.

[0673]

[0674] Meanwhile, in the case of the polyethylene of the examples and comparative examples, when manufacturing the above samples, since it is in powder form, in order to easily load it into the rheometer and minimize sample deterioration or crosslinking during measurement, 1200 ppm of an antioxidant (Songnox 1076 (Songwon): Songnox 1680 (Songwon) = 1:2 weight ratio) was added and mixed based on the total weight of polyethylene, and pelletized by extrusion at an extrusion temperature of 190℃ at an extrusion amount of 35 kg / hr using a twin screw extruder (TEK 30 MHS, manufactured by SMPLATECH CO., diameter 32 pi, L / D = 40). However, for samples that may already contain an antioxidant and processing aid during commercial pelletization, such as the polyethylene of Comparative Example 3, an antioxidant was not added.

[0675]

[0676] (2) Measurement of rheological properties

[0677] The storage modulus (G') and loss modulus (G") of the polyethylene of the examples and comparative examples were measured in frequency sweep mode using a rotational rheometer (ARES-G2 Rheometer, manufactured by TA Instruments), respectively.

[0678]

[0679] Specifically, the test chamber of the rheometer was purged with nitrogen to minimize polyethylene degradation, and the rheometer was preheated to an initial temperature of 190°C. After sample loading and oven thermal equilibration, the sample prepared above was placed between the parallel plates of the rheometer (plate diameter: 25.4 mm, gap between plates: 2 mm) and pressed to a thickness of 2.0 mm. Vacuum shear flow was applied at a strain of 5% over each frequency range from 0.05 to 500 rad / s under a nitrogen atmosphere. At this time, the strain was kept within 5% to satisfy the linear viscoelasticity condition. A total of 8 minutes elapsed between the time the sample was inserted between the plates and the time the frequency sweep (0.03-100 rad / s) was initiated, and the measurements were performed at 190°C. Meanwhile, a new sample was used at each temperature, and nitrogen (N2) was circulated within the test chamber for each measurement.

[0680]

[0681] Through the above measurements, the storage modulus (G') and loss modulus (G") for frequency (ω) were obtained.

[0682]

[0683] (3) ER and PDR measurements

[0684] Using the rheological property measurement results of the above (2), the ER (Polydispersity at the High MW) and PDR (overall polydispersity) for the polyethylene of the examples and comparative examples were obtained, respectively, by the method described in the literature “New measures of polydispersity from rheological data on polymer melts”, Journal of Appied Polymer Science, vol. 57, 1605-1626 (1995).

[0685]

[0686] Specifically, using the storage elastic modulus (G') and loss elastic modulus (G") obtained as the measurement results in (2) above, the graph was plotted as in Fig. 6 with Log(G") as the X-axis and log (G') as the Y-axis, and the plotted graph was curve-fitted using data analysis software (Origin Pro). As a result, the following linear relationship (5) was obtained.

[0687] logG' = k1+ k2log G" (5)

[0688] In the above mathematical equation, k1 and k2 are constants for curve fitting.

[0689]

[0690] Next, ER was obtained by interpolating the G' value corresponding to G"ref, as in the following mathematical expression 1.

[0691] [Mathematical Formula 1]

[0692]

[0693] In the above mathematical formula 1,

[0694] C1 is a constant, 1.781x10 -3 And,

[0695] G' is the storage modulus of polyethylene (dyne / cm 2 ) and

[0696] G"ref is the loss modulus of polyethylene, a small elastic modulus value corresponding to the low frequency range, 5000 dyne / cm 2 am.

[0697] Minimum G" value is 5000 dyne / cm 2 If it is larger, extrapolate to obtain ER.

[0698]

[0699] Additionally, PDR (Overall Polydispersity) was calculated according to the following mathematical equation 2.

[0700] [Equation 2]

[0701]

[0702] In the above mathematical expression 2,

[0703] η*1, η*2, and η*3 are the reference complex modulus G, respectively. * ref1 , G * ref2 , and G * ref3 As the complex viscosity in , G * ref1 =1.95x10 4 dyn / cm 2 And, G * ref2 = (G * ref1 G * ref3 ) 1 / 2 , and for linear polymers, log10(G * ref3 / G * ref1 )=2 were used as the standard to obtain η*1, η*2, and η*3.

[0704]

[0705] (4) Relaxation time spectrum analysis

[0706] Based on the rheological property measurement results of (2) above, the relaxation time spectrum is analyzed, and using the relaxation time spectrum analysis results thus obtained, the zero shear viscosity (η) is calculated according to the following mathematical equation 3. 0 ) (Pa·s) was obtained.

[0707] [Equation 3]

[0708]

[0709] In the above mathematical formula 3,

[0710] N is the number of modes in the mode distribution of the relaxation time spectrum, and τi is the relaxation time (s), and G i is the elastic modulus (dyne / cm) corresponding to the relaxation time. 2 )am.

[0711]

[0712] As described above, the results of rheological property measurements for the polyethylene of the examples and comparative examples are shown in Tables 7 and 8.

[0713]

[0714] Example 1 Example 2 Example 3 Example 5 Rheological properties ER (dyn / cm 2 )1.892.211.171.19PDR8.9711.536.876.59η0 (Pa·s)12,48224,4509,4098,999

[0715] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Rheological Characteristics ER (dyn / cm 2 )0.132.042.722.282.34PDR2.217.826.0305.7304.3η0 (Pa·s)7,33713,81234,60015,13119,540

[0716] Test Example 4

[0717] To evaluate the processing characteristics of the polyethylene of the above examples and comparative examples, the processing pressure (Head Pressure), extrusion amount (Output), and Output index were each measured.

[0718]

[0719] (1) Machining pressure

[0720] When manufacturing polyethylene film using a blown extruder, a pressure device was installed at the die and screen pack front end of the blown extruder to measure the processing pressure (head pressure, bar) of polyethylene.

[0721]

[0722] Specifically, first, based on the total weight of the polyethylene manufactured in the above examples or comparative examples, 1200 ppm of an antioxidant (Songnox 1076 (Songwon): Songnox 1680 (Songwon) = 1:2 in weight ratio) was added and mixed, and a twin screw extruder (Twin screw extruder; TEK 30 MHS, manufactured by SMPLATECH CO., diameter 32 pi, L / D = 40) was used to extrude at an extrusion temperature of 190°C at an extrusion rate of 35 kg / hr, thereby manufacturing a composition for forming a pellet-like film weighing about 18 kg.

[0723]

[0724] The film-forming composition manufactured above was manufactured into a film by adjusting the take-off speed from 8 m / min to 10 m / min at an extrusion temperature of 130°C to 180°C using a single-screw extruder (Eugene Engineering Single Screw Extruder, Blown Film M / C, 50 pi, L / D=32) as a blown extruder so as to obtain a final thickness of 50 μm. At this time, the die gap was 2.0 mm, the die diameter was 120 mm, and the blown-up ratio was 2.5.

[0725]

[0726] A laboratory-scale blown film manufacturing line was constructed with an extruder die diameter of 120 mm, a die gap of 1.5 mm (0.060 in), a 50-pi diameter baler screw and a mixer at the screw tip. Extrusion was performed at a screw speed of 40 rpm, a frost line height (FLH) of 200 to 250 mm, barrel and die set temperatures of 170°C, and a melt temperature of 185 to 190°C. Cooling was performed at 20°C using a dual-lip air ring. These specific processing conditions were chosen because the film properties obtained in this manner are representative of those obtained under larger commercial-scale film blowing conditions.

[0727]

[0728] During the production of blown film under the above conditions, the processing pressure (head pressure, bar) was measured by a pressure device installed at the die and screen pack front end of the blown extruder.

[0729]

[0730] (2) Extrusion amount

[0731] In addition, the film manufacturing process was performed in the same manner as above, but the screw speed in the blown extruder was fixed at 40 rpm, and the take-off speed was adjusted so that the film thickness was 50 ㎛. When the steady state was reached, the extrusion amount (Output) (g / min) discharged from the blown extruder for 1 minute was measured.

[0732]

[0733] (3) Output Index

[0734] Using the results of the processing pressure and extrusion amount measured in (1) and (2) above, the Output Index g / (min·bar) was calculated according to the following mathematical formula 4.

[0735] [Equation 4]

[0736]

[0737]

[0738] As described above, the results of measuring the processing characteristics of the polyethylene of the examples and comparative examples are shown in Tables 9 and 10.

[0739]

[0740] Example 1 Example 2 Example 3 Example 5 Processing characteristics Processing pressure (bar) 18 4 2 2 5 2 1 4 2 0 2 Output Index, g / (min bar) 2.5 0 1.9 6 2.1 0 2.2 3 Extrusion amount (g / min) 46 0 44 0 45 0 45 0

[0741] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Processing Characteristics Processing Pressure (bar) 290 174 249 127 152 Output Index, g / (min bar) 1.43 2.53 1.62 2.65 2.36 Extrusion Amount (g / min) 415 440 40 3336 359

[0742] Test Example 5

[0743] The rheological properties of the polyethylene of the above examples and comparative examples were measured as follows, and the measurement results are shown in Tables 11 and 12.

[0744]

[0745] (1) Activation energy (Ea) according to change in phase angle (δ)

[0746] Using ARES, a Dynamic Frequency Sweep Test was performed to measure the activation energy (Ea) according to changes in phase angle (δ).

[0747]

[0748] Specifically, the ARES analysis was performed at temperatures of 170 ℃, 190 ℃, and 210 ℃, with a frequency of 0.05–500 and a strain of 5% using a parallel plate. After measuring ARES at different temperatures (170 ℃, 190 ℃, and 210 ℃), Ea can be determined from the phase angle δ measured as a function of ω at different temperatures, and is calculated according to Equation 1 below. For example, if ω at different δ is plotted semilogarithmically against the reciprocal absolute temperature 1 / T, a straight line is obtained. Then, Ea can be calculated from the slope of the linear fit (see Macromolecules 2010, 43, 7341–7350):

[0749] [Formula 1]

[0750]

[0751] In the above equation 1,

[0752] ω(T) is the frequency (in radians / second) at which the phase angle δ has a certain value (e.g. δ=60°) at temperature T,

[0753] ω(T) is the frequency at which the same δ value is obtained at the reference temperature (T),

[0754] Ea is the activation energy (J / mol),

[0755] R is the gas constant (8.314 J / mol K),

[0756] T is the absolute temperature (K),

[0757] exp(-Ea / RT) represents the temperature sensitivity according to activation energy.

[0758]

[0759] Tables 11 and 12 below show the maximum Ea(δ) values ​​of the polyethylenes of the examples and comparative examples measured in this way, and the average Ea(δ) values ​​are indicated in parentheses. In particular, in the case of comparative examples 1, 4, and 5, only the average Ea(δ) values ​​are shown because there were no maximum values ​​as linear LLDPE or LDPE.

[0760]

[0761] (2) Phase angle

[0762] The measurement was performed using a Dynamic Frequency Sweep Test using ARES. The measurement temperature was 190 ℃, the frequency was 0.05 - 500, and the strain was 5%, and the measurement was performed using a parallel plate.

[0763]

[0764] For the polyethylene of the examples and comparative examples, the phase angles were measured when |G*| was 0.01 MPa and 0.1 MPa, respectively, by the Van Gurp-Palmen method (refer to M. Van Gurp and J. Palmen, 67 Rheology Bulletin 5 (1998)). More specifically, the phase angle (δ) is the arctangent of the ratio of the storage modulus (G', Pa) and the loss modulus (G'', Pa), i.e., δ = arctan -1 It is calculated as (G'' / G'), and the absolute value of the complex elastic modulus |G*| is (G' 2 + G'' 2 ) 1 / 2 It was calculated as .

[0765]

[0766] As described above, the results of measuring the rheological properties of the polyethylene of the examples and comparative examples are shown in Tables 11 and 12.

[0767]

[0768] Rheological properties Unit Example 1 Example 2 Example 3 Example 4 Ea(δ) kJ / mol 37.237 33.83 4.8 phase angle (@0.01Mpa)° 68.2667 2.57 2.7 phase angle (@0.1Mpa)° 54.15 3.55 3.154

[0769] Rheological properties unit comparison example 1 comparison example 2 comparison example 3 comparison example 4 comparison example 5 Ea(δ) kJ / mol-(30)82(59)130(82)-(60.9)-(69)phase angle (@0.01Mpa)°83.861.958.65151.2phase angle (@0.1Mpa)°6551.451.532.532.2

[0770] Meanwhile, a graph in which the phase angle (δ) is plotted on the x-axis and the activation energy (Ea) according to the change in the phase angle (δ) is plotted on the y-axis, obtained through the advanced rheometric expansion system (ARES) analysis by temperature for the polyethylene of Examples and Comparative Examples, is shown in FIG. 1. As shown in FIG. 1, in the graph in which the phase angle (δ) is plotted on the x-axis and the activation energy (Ea) according to the change in the phase angle (δ) is plotted on the y-axis, when the polyethylene of Examples 1 to 4 is analyzed by the advanced rheometric expansion system (ARES) by temperature, there is no inflection point in which the phase angle (δ) shows the maximum value of Ea when the phase angle (δ) is 45° or higher, and it can be seen from the graph that the maximum value of Ea is 20 kJ / mol or more and 60 kJ / mol or less.

[0771]

[0772] In addition, on the other hand, a Dynamic Frequency Sweep Test was performed on the polyethylene of Examples and Comparative Examples using an advanced rheometric expansion system (ARES) at different temperatures, and a vGP plot graph with the complex shear modulus as the x-axis and the phase angle (δ) as the y-axis, obtained through the above-described method, is shown in Fig. 2. As shown in Fig. 2, it can be seen that the polyethylene of Examples 1 to 3 has a phase angle (δ) of 63° or more and 75° or less when the absolute value (|G*|) of the complex shear modulus is 0.01 MPa in the vGP plot graph.

[0773]

[0774] Film Manufacturing

[0775] A film was manufactured using the polyethylene manufactured in the above examples and comparative examples using the following method.

[0776]

[0777] Based on the total weight of each polyethylene manufactured in the above examples or comparative examples, 1200 ppm of an antioxidant (Songnox 1076 (Songwon): Songnox 1680 (Songwon) = 1:2 in weight ratio) was added and mixed, and extruded at an extrusion temperature of 190°C at an extrusion rate of 35 kg / hr using a twin screw extruder (TEK 30 MHS, manufactured by SMPLATECH CO., diameter 32 pi, L / D = 40), to manufacture a composition for forming a pellet-shaped film weighing about 18 kg.

[0778]

[0779] A film was manufactured by inflation molding the film-forming composition manufactured above under the following film extrusion conditions.

[0780]

[0781] Film forming conditions

[0782] Single Screw Extruder (Eugene Engineering Single Screw Extruder, Blown Film M / C, 50 pi, L / D=32)

[0783] Melting temperature (or extrusion temperature): 185 ℃

[0784] Die Gap: 2.0 mm

[0785] Die diameter: 120 mm

[0786] Blown-Up Ratio: 2.5

[0787] Maintain Frost Line Height at 200~250 mm

[0788] Sample extrusion rate: 300~500 g / min

[0789] Cooling: Uses dual air-ring

[0790] Film thickness: 50 ㎛

[0791]

[0792] <Evaluation of the physical properties of polyethylene film>

[0793] Test Example 2: Evaluation of physical properties of polyethylene film

[0794] The drop impact strength of films manufactured using polyethylene was measured and shown in Tables 13 and 14.

[0795]

[0796] (1) Dart drop impact strength

[0797] For the films of the examples and comparative examples manufactured above, the drop impact strength was measured according to the ASTM D1709 [Method A] standard, and the average value was taken by measuring at least 5 sets (20 times / 1 set) per film sample.

[0798]

[0799] Example 1 Example 2 Example 3 Example 4 Drop impact strength (gf) 155918911,1291,147

[0800] Comparison Example 1 Comparison Example 2 Comparison Example 3 Comparison Example 4 Comparison Example 5 Drop Impact Strength (gf) 1,200 5,53 1,200 < 200 < 200

[0801]

[0802] As shown in Tables 13 and 14 above, the examples according to the present invention have a density and a melt index (MI) 2.16 ), melt flow index (MI) 21.6 / MI 2.16 ) and temperature-dependent ARES (advanced rheometric expansion system) analysis, both the Ea(δ) graph characteristics, i.e., the phase angle(δ) value when the Ea maximum value and the G* absolute value are 0.01 MPa, were optimized to significantly improve the melt strength without significantly reducing the melt index or increasing the zero shear viscosity, and it was confirmed that the processability and drop impact strength that can be applied to All-PE(Uni) materials in wide-width agricultural films, shrink films, and MDO films were both excellent.

[0803]

[0804] From the above experimental results, it was confirmed that the polyethylene according to the present invention having controlled rheological properties exhibits drop impact strength characteristics, rigidity, and molding processability by minimizing processing load while significantly improving melt strength at low zero shear viscosity.

Claims

1. Density measured according to ASTM D 1505 standard is 0.915 g / cm 3 Above 0.940 g / cm 3 Below, Melt index MI measured under a load of 2.16 kg at a temperature of 190 ℃ according to ASTM D 1238 2.16 is 0.7 g / 10 min or more and 1.6 g / 10 min or less, Melt index (MI) measured under a load of 21.6 kg and 2.16 kg at a temperature of 190 ℃ according to ASTM D 1238 standard 21.6 and melting index MI 2.16 The melt flow rate (MFRR, MI) is the ratio of 21.6 / MI 2.16 ) is 25 or more and 35 or less, Polyethylene satisfying the conditions (a1) and (a2) below when analyzed by ARES (advanced rheometric expansion system) according to temperature: (a1) In a graph where the phase angle (δ) is on the x-axis and the activation energy (Ea) according to the change in the phase angle (δ) is on the y-axis, there is no inflection point where the phase angle (δ) shows the maximum value of Ea when it is 45° or more, and the maximum value of Ea in the graph is 20 kJ / mol or more and 60 kJ / mol or less, (a2) When the absolute value of the complex shear modulus (|G*|) is 0.01 MPa, the phase angle (δ) is 63° or more and 75° or less.

2. In paragraph 1, The above polyethylene, when analyzed by ARES (advanced rheometric expansion system) at different temperatures, has a phase angle (δ) of 50° or more and 65° or less when the absolute value (|G*|) of the complex shear modulus is 0.1 MPa. Polyethylene.

3. In paragraph 1, The above polyethylene has a melt index MI measured under a load of 21.6 kg at a temperature of 190°C according to ASTM D 1238. 21.6 12.5 g / 10min or more and 56 g / 10min or less, Polyethylene.

4. In paragraph 1, The above polyethylene has a Z-average molecular weight of 250,000 g / mol or more. Polyethylene.

5. In paragraph 1, The above polyethylene has a weight average molecular weight of 60,000 g / mol or more and 120,000 g / mol or less. Polyethylene.

6. In paragraph 1, The above polyethylene has a molecular weight distribution (Mw / Mn) of 3.0 or more and 5.0 or less. Polyethylene.

7. In paragraph 1, The above polyethylene satisfies at least one of the conditions (b1) to (b3) below. Polyethylene: (b1) ER calculated according to the following mathematical formula 1: 1.00 dyn / cm 2 More than 2.5 dyn / cm 2 below, (b2) PDR calculated according to the following mathematical formula 2: 3.0 or more and 15 or less, (b3) The zero shear viscosity η calculated according to the following mathematical formula 3 0 : 25,000 Pa·s or less, [Mathematical Formula 1] In the above mathematical formula 1, C1 is a constant, 1.781x10 -3 And, G' is the storage modulus of polyethylene (dyne / cm 2 ) and G"ref is the loss modulus of polyethylene, 5000 dyne / cm 2 And, [Equation 2] In the above mathematical formula 2, η*1, η*2, and η*3 are the reference complex elastic moduli G, respectively. * ref1 , G * ref2 , and G * ref3 As the complex viscosity in , G * ref1 =1.95x10 4 dyne / cm 2 And, G * ref2 =(G * ref1 G * ref3 ) 1 / 2 , and log10(G * ref3 / G * ref1 )=2 is used as a standard, [Equation 3] In the above mathematical formula 3, N is the number of modes, and G i is the elastic modulus (dyne / cm) corresponding to the relaxation time. 2 ), and τ i is the relaxation time (s).

8. In paragraph 1, The above polyethylene satisfies at least one of the conditions (c1) and (c2) below. Polyethylene: (c1) Working pressure: 155 bar or more and 235 bar or less, (c2) Output Index calculated according to the following mathematical formula 4: 0.75 g / (min·bar) or more and 2.80 g / (min·bar) or less, [Equation 4] 9. In paragraph 1, The above polyethylene has a melt strength of 95 mN or more as measured by a capillary rheometer. Polyethylene.

10. In paragraph 1, The above polyethylene has a maximum take-off velocity of 300 mm / sec or more. Polyethylene.

11. In paragraph 1, The above polyethylene has a branching index g'(vis,bulk) of 0.81 or less for the total absolute molecular weight of polyethylene calculated according to the following mathematical formula 5. Polyethylene: [Equation 5] In the above mathematical expression 5, ηb is the intrinsic viscosity of the polyethylene, ηl is the absolute molecular weight (M) equal to that of the polyethylene abs ) is the intrinsic viscosity of linear polyethylene, and is a value calculated according to the following mathematical formula 6. [Equation 6] ηl =KM α In the above mathematical expression 6, M is the absolute molecular weight (M) of the linear polyethylene abs ) and, K is 0.000523, α is 0.

708.

12. In paragraph 1, The above polyethylene comprises at least one copolymer of ethylene and alpha olefin. Polyethylene.

13. In paragraph 1, The above polyethylene is a copolymer of ethylene and 1-hexene. Polyethylene.

14. A film comprising the polyethylene of paragraph 1.

15. In paragraph 14, The above film has a drop impact strength of 1,000 gf or more as measured according to the American Society for Testing and Materials ASTM D 1709 [Method A]. film.

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