Polyethylene composition and stretched film comprising same

Abstract

The present invention relates to a polyethylene composition and a stretched film comprising same, wherein the polyethylene composition enables producing a stretched film that has excellent mechanical properties and stretching stability as well as good film processability and productivity, and accordingly exhibits high shrink resistance, high thickness uniformity, and excellent printability and transparency.

Description

Polyethylene composition and stretched film comprising the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0086287, filed July 1, 2024, and Korean Patent Application No. 10-2025-0087740, filed July 1, 2025, the entire contents of which are incorporated herein by reference.

[0003]

[0004] The present invention provides a polyethylene composition capable of producing a stretched film having high shrinkage resistance, uniform thickness variation, and excellent printability and transparency, along with excellent mechanical properties and stretching stability, and a stretched film comprising the same.

[0005]

[0006] Thin film products manufactured from linear low-density polyethylene (LLDPE) and / or high-density polyethylene (HDPE) are widely used in packaging applications such as merchandise bags, grocery bags, food and specialty packaging, and industrial liners. In these applications, packaging films are primarily used to preserve the shape of the product while protecting it from touch during display.

[0007]

[0008] In particular, among these packaging films, biaxially oriented polymer films are widely used for packaging purposes due to their excellent mechanical properties, productivity, and printability. Commercialized packaging films typically use biaxially oriented polypropylene (BOPP), biaxially oriented polyethylene terephthalate (BOPET), or biaxially oriented polyamide (BOPA) in the print layer, and LLDPE film in the sealing layer. These composite material forms are non-recyclable, and the demand for single-material products is increasing due to the expansion of packaging material recycling regulations. Therefore, research and development is being conducted to manufacture single-material packaging films by replacing the print layer film with biaxially oriented polyethylene (BOPE) film.

[0009]

[0010] However, commercial polyethylene (PE) resins lack sufficient stretching stability, and fracture and melting occur during stretching, making biaxial stretching difficult. To ensure stretching stability, polyethylene compositions containing resins with low density and high melt index are being developed. However, such compositions exhibit low rigidity, shrinkage, and impact resistance, making them unsuitable as PE resins for uniaxial or biaxially stretched films.

[0011]

[0012] Accordingly, a method is required to provide a PE composition for uniaxial or biaxial stretching by selecting a polyethylene resin having a molecular structure advantageous for stretching, selecting an appropriate composition, and thereby exhibiting excellent stretching stability and excellent mechanical properties during biaxial stretching, while also exhibiting satisfactory film processability and productivity.

[0013]

[0014] The present invention provides a polyethylene composition capable of producing a stretched film having high shrinkage resistance, printability and transparency, with excellent mechanical properties and stretching stability, and with good film processability and productivity, and a stretched film comprising the same.

[0015]

[0016] In one embodiment of the present invention

[0017] Comprising one or more ethylene-alphaolefin copolymers,

[0018] Melting index (MI) 2.16 , 190 ℃, 2.16 kg) is 0.7 g / 10 min or more and 2.0 g / 10 min or less,

[0019] Density is 0.940 g / cm 3 Above 0.965 g / cm 3 Below,

[0020] The SCB content is 4.5 (units / 1000C) or more and 13 (units / 1000C) or less,

[0021] When the relative ratio of the crystal fraction peak area eluted according to temperature (℃) was measured using the crystallization elution fractionation (CEF) analysis method, the ratio of the crystal fraction peak area eluted above 90 ℃ to the total peak area (CEF) ≥90℃ ) is 40% or more and 85% or less, and the ratio of the peak area of ​​the crystal fraction eluting at 50 ℃ or more and less than 80 ℃ (CEF) <80℃and≥50℃ ) is 8% or more and 30% or less,

[0022] A polyethylene composition is provided.

[0023]

[0024] In addition, in another embodiment of the present invention, a stretched film comprising the polyethylene composition of the above embodiment is provided.

[0025]

[0026] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention.

[0027]

[0028] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0029]

[0030] 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.

[0031]

[0032] 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.

[0033]

[0034] Additionally, in the present invention, (co)polymer means both a homopolymer and a copolymer.

[0035]

[0036] 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.

[0037]

[0038] 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.

[0039]

[0040] Hereinafter, the present invention will be described in detail.

[0041]

[0042] (polyethylene composition)

[0043] According to one aspect of the present invention, there is provided a composition comprising at least one ethylene-alphaolefin copolymer and having a melt index (MI) measured according to ASTM D 1238. 2.16 , 190 ℃, 2.16 kg) is 0.7 g / 10 min or more and 2.0 g / 10 min or less, and the density measured according to ISO 1183-2 is 0.940 g / cm 3 Above 0.965 g / cm 3 Below, the SCB content derived from FT-IR analysis is 4.5 (units / 1000C) or more and 13 (units / 1000C) or less, and when the relative ratio of the crystal fraction peak area eluted according to the temperature (℃) was measured using the crystallization elution fractionation (CEF) analysis method, the ratio of the crystal fraction peak area eluted at 90 ℃ or more to the total peak area (CEF ≥90℃ ) is 40% or more and 85% or less, and the ratio of the peak area of ​​the crystal fraction eluting at 50 ℃ or more and less than 80 ℃ (CEF) <80℃and≥50℃ ) is provided, a polyethylene composition having an amount of 8% or more and 30% or less.

[0044]

[0045] 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.

[0046]

[0047] 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.

[0048]

[0049] In the present invention, the polyethylene composition maintains mechanical properties, productivity, and stretching stability equivalent to or superior to those of conventional polyethylene compositions by optimizing the bimodal slurry polymerization process in the presence of a Ziegler-Natta catalyst or a metallocene catalyst to control the balance between mechanical properties and stretching properties, and has characteristics suitable for manufacturing a stretched film having high shrinkage resistance, printability, and transparency.

[0050]

[0051] Preferably, the polyethylene composition may comprise one or more ethylene-alphaolefin copolymers. More preferably, the polyethylene composition may comprise two ethylene-alphaolefin copolymers.

[0052]

[0053] The above polyethylene composition has a melt index (MI) 2.16, 190 ℃, 2.16 kg load) is 0.7 g / 10 min or more and 2.0 g / 10 min or less. The melting index of the polyethylene resin composition affects the film processability and dimensional stability during the production of a stretched film. MI 2.16 If it is less than 0.70 g / 10 min, there is a risk that the processing pressure will increase and the processability will deteriorate, and if it exceeds 2.0 g / 10 min, the bubble stability will deteriorate due to high fluidity, which may cause film thickness deviation. Preferably, the melting index (MI) of the polyethylene resin composition 2.16 , 190 ℃, 2.16 kg load) may be 0.72 g / 10 min or more, 0.75 g / 10 min or more, 0.72 g / 10 min or more, 0.75 g / 10 min or more, 0.8 g / 10 min or more, 0.85 g / 10 min or more, 0.9 g / 10 min or more, 0.95 g / 10 min or more, or 1.0 g / 10 min or more, but 1.9 g / 10 min or less, 1.8 g / 10 min or less, 1.7 g / 10 min or less, 1.6 g / 10 min or less, 1.5 g / 10 min or less, or 1.4 g / 10 min or less.

[0054]

[0055] In the present invention, the melt index (MI) 2.16 ) can be measured under a load of 2.16 kg at 190 ℃ according to the American Society for Testing and Materials standard ASTM D 1238 (condition E, 190 ℃, 2.16 kg). For example, the melt index (MI) 2.16 ) is as described in Test Example 1 described below.

[0056]

[0057] In addition, the polyethylene composition has a density of 0.940 g / cm 3 Above 0.965 g / cm 3Below. The density of the polyethylene resin composition affects the rigidity of the stretched film. If the density of the polyethylene resin composition is 0.940 g / cm 3 If it is less than 0.965 g / cm, there is a risk that the rigidity of the stretched film will decrease, and if ... 3 If it exceeds , the extensibility of the film may be reduced due to excessively high density. Preferably, the density of the polyethylene resin composition is 0.941 g / cm 3 Above, 0.942 g / cm 3 Above, 0.943 g / cm 3 Below, 0.944 g / cm 3 or 0.945 g / cm 3 Ideally, 0.964 g / cm 3 Below, 0.963 g / cm 3 Below, 0.960 g / cm 3 Below, 0.958 g / cm 3 Below, 0.955 g / cm 3 Below, 0.953 g / cm 3 or less, or 0.950 g / cm 3 It could be as follows:

[0058]

[0059] In the present invention, the density (g / cm 3 ) can be measured according to ISO 1183-2 standard, and can be, for example, a value measured at 23 ℃. For example, this density (g / cm 3 ) is as described in Test Example 1 described below.

[0060]

[0061] Meanwhile, the polyethylene composition has an SCB content derived from FT-IR analysis relative to the total mole number of the entire composition, which is the number of short chain branches per 1000 carbon atoms, i.e., the number of short branch chains having 2 to 7 carbon atoms ( / 1000C), of 4.5 (numbers / 1000C) or more and 13 (numbers / 1000C) or less. Preferably, the SCB content may be 4.6 (pieces / 1000C) or more, 4.8 (pieces / 1000C) or more, 5.0 (pieces / 1000C) or more, 5.5 (pieces / 1000C) or more, 5.8 (pieces / 1000C) or more, 6.0 (pieces / 1000C) or more, 6.5 (pieces / 1000C) or more, 6.8 (pieces / 1000C) or more, or 7 (pieces / 1000C) or more, and 12.5 (pieces / 1000C) or less, 12 (pieces / 1000C) or less, 11.5 (pieces / 1000C) or less, 11 (pieces / 1000C) or less, 10.5 (pieces / 1000C) or less, or 10 (pieces / 1000C) or less.

[0062]

[0063] Meanwhile, in the present invention, SCB (Short Chain Branch) means a short chain bonded to the main chain of a polymer in polyethylene in a branch-like form, specifically, a short branch chain having 2 to 7 carbon atoms bonded to the main chain of polyethylene. It is a short branch chain formed when an alpha olefin having 4 or more carbon atoms, such as 1-butene, 1-hexene, or 1-octene, is used as a comonomer, and its content may be proportional to the content of the α-olefin monomer included in the polymer chains. The SCB content means the number of branch chains having 2 to 7 carbon atoms per 1,000 carbon atoms (unit: number / 1,000C), and can be calculated through analysis using proton nuclear magnetic resonance (1H-NMR) or Fourier transform infrared spectroscopy (FT-IR). In the present invention, it was calculated through FT-IR analysis, and the specific analysis method is described in detail in the experimental examples below.

[0064]

[0065] Meanwhile, when the polyethylene composition was measured for the relative ratio of the crystal fraction peak area eluted according to the temperature (℃) using the crystallization elution fractionation (CEF) analysis method, the ratio of the crystal fraction peak area eluted at 90 ℃ or higher to the total peak area (CEF) ≥90℃ ), that is, the high crystal content is 40% or more and 85% or less. Preferably, the high crystal content (CEF ≥90℃) may be 42% or more, 43.5% or more, 45% or more, 46.5% or more, 48% or more, 50% or more, or 52% or more, but not more than 82%, not more than 80%, not more than 78%, not more than 75%, not more than 73.5%, not more than 72%, not more than 70%, not more than 68%, not more than 65%, not more than 63.5%, not more than 62%, or not more than 60%.

[0066]

[0067] In addition, when the polyethylene composition is measured for the relative ratio of the crystal fraction peak area eluted according to the temperature (℃) using the crystallization elution fractionation (CEF) analysis method, the ratio of the crystal fraction peak area eluted at 50 ℃ or more and less than 80 ℃ to the total peak area (CEF) <80℃and≥50℃ ), that is, the low-crystalline content is 8% or more and 30% or less. Preferably, the low-crystalline content (CEF <80℃and≥50℃ ) may be 8.2% or more, 8.5% or more, 8.8% or more, 9% or more, 9.2% or more, 9.5% or more, 9.8% or more, 10% or more, 10.5% or more, 11% or more, 11.5% or more, 12% or more, 12.5% ​​or more, 13% or more, 13.5% or more, 14% or more, 14.5% or more, 15% or more, 15.5% or more, 16% or more, 16.5% or more, 17% or more, 17.5% or more, or 18% or more, but may be 27.5% or less, 27% or less, 26.5% or less, 26% or less, 26.5% or less, 26% or less, 25.5% or less, 25% or less, 24.5% or less, or 24% or less. there is.

[0068]

[0069] In particular, the polyethylene composition optimizes the content of the low-crystallinity fraction among the polymer molecular structures according to the crystallization elution fractionation (CEF) analysis method, so that when processed into a film, not only can the film be manufactured without breakage during high-magnification stretching, but also can secure high mechanical properties along with excellent stretching processability. In particular, the low-crystallinity fraction content of the polyethylene composition has a low crystallization temperature and fast relaxation, so that the film provides fluidity during stretching, enabling stretching up to a high ratio without breakage. If the low-crystallinity fraction content is insufficient, breakage may occur during high-magnification stretching, and thickness variation may increase, which may cause plate-out, poor appearance, etc. In addition, if the low-crystallinity fraction content is too high, the film may sag during stretching or draw without orientation, and mechanical properties such as stiffness may also decrease.

[0070]

[0071] The ratio of the contents of the two crystal fractions described above, i.e., the low crystallinity content (CEF) <80℃and≥50℃ ) high crystallinity content (CEF) ≥90℃ ) ratio (CEF) ≥90℃ / CEF <80℃and≥50℃ ) may be 2 times or more and 11 times or less, and preferably 2.1 times or more, 2.15 times or more, 2.2 times or more, 2.25 times or more, 2.3 times or more, 2.35 times or more, 2.4 times or more, 2.45 times or more, 2.5 times or more, 2.55 times or more, 2.6 times or more, 2.65 times or more, 2.7 times or more, 2.75 times or more, or 2.8 times or more, and 10.8 times or less, 10.5 times or less, 10.3 times or less, 10 times or less, 9.8 times or less, 9.5 times or less, 9.3 times or less, 9 times or less, 8.8 times or less, 8.5 times or less, 8.3 times or less, 8 times or less, 7.8 times or less, 7.5 times or less, 7.3 times or less, or 7 times or less.

[0072]

[0073] In addition, the polyethylene composition may exhibit crystal fraction peaks eluting at less than 50°C and at 80°C or more and less than 90°C in addition to the high-crystallinity fraction peak and low-crystallinity fraction peak described above. That is, when the relative ratio of crystal fraction peak areas eluting according to temperature (°C) is measured using a crystallization elution fractionation (CEF) analysis method, the ratio of the residual area of ​​crystal fraction peaks eluting at less than 50°C and at 80°C or more and less than 90°C to the total peak area (CEF) <50℃,<90℃and≥80℃ ) is the content of the two crystal fractions mentioned above in the total crystal fraction amount of 100%, i.e., the high crystal content (CEF). ≥90℃ ) and low crystallinity content (CEF <80℃and≥50℃ ) can be the content excluding the sum of the

[0074]

[0075] For example, the ratio of the residual areas of the crystal fraction peaks eluting below 50 ℃ and above 80 ℃ and below 90 ℃ (CEF) <50℃,<90℃and≥80℃ ) may be 52% or less or 0 to 52% or less. Preferably, the medium crystal content (CEF <90℃and≥80℃ ) may be 0.1% or more, 0.5% or more, 1% or more, 1.5% or more, 2% or more, 3% or more, 4% or more, 5% or more, 6% or more, 8% or more, 10% or more, 12% or more, or 15% or more, but may be 50% or less, 48% or less, 45% or less, 43% or less, 40% or less, 38% or less, 35% or less, 33% or less, 30% or less, 28% or less, 26.5% or less, 25% or less, 24.5% or less, or 23% or less.

[0076]

[0077] In the present invention, the crystal fraction content of the polyethylene composition described above, i.e., the high crystal content (CEF) ≥90℃) and low crystallinity content (CEF <80℃and≥50℃ ), medium crystal content (CEF) <90℃and≥80℃ ) is measured by the Crystallization Elution Fractionation (CEF) analysis method. For example, the crystal fraction content by the Crystallization Elution Fractionation (CEF) analysis of a polyethylene composition can be obtained using an Agilent Technologies 7890A instrument from PolymerChar. For example, after dissolving the sample in 20 mL of 1,2,4-trichlorobenzene at a concentration of 1.5 mg / mL, the sample is stirred for 30 o 150 in C o 40 to C o After melting by increasing the temperature at a rate of C / min, 35 o 0.5 to C o Recrystallize by lowering the temperature at a rate of C / min, and then again at 140 o 1 to C o A crystallization elution fractionation (CEF) graph can be obtained by going through the process of eluting while increasing the temperature at a rate of C / min. The crystallization elution fractionation (CEF) graph obtained in this way shows the relative ratio of the peak area of ​​the eluted crystal fraction according to the temperature (℃), and the x-axis is the elution temperature (temperature, o C) and the y-axis can be a CEF curve graph with dW / dt. In this CEF curve graph, the total peak area is 100% and the temperature is 90 o The ratio of the peak area in the region above C is the high crystal content (CEF) ≥90℃ ) and the ratio of the peak area in the region of 50 ℃ or more and less than 80 ℃ is expressed as the low crystallinity content (CEF). <80℃and≥50℃ ) and the ratio of the peak area in the region of 80 ℃ or more and less than 90 ℃ is the crystalline content (CEF). <90℃and≥80℃ ) can be expressed as. Specifically, the crystal fraction content by this crystallization elution fractionation (CEF) analysis is measured using the method described in Test Example 1 described below.

[0078]

[0079] Meanwhile, the polyethylene composition may have a number average molecular weight (Mn) of 5000 g / mol or more and 20000 g / mol or less, preferably 5200 g / mol or more, 5500 g / mol or more, 5800 g / mol or more, 6000 g / mol or more, 6200 g / mol or more, 6500 g / mol or more, 6800 g / mol or more, 7000 g / mol or more, 8200 g / mol or more, 8500 g / mol or more, 8800 g / mol or more, 9000 g / mol or more, 9200 g / mol or more, 9500 g / mol or more, 9800 g / mol or more, 10000 g / mol or more, or 10500 g / mol or more, and 19500 g / mol or less, 19000 g / mol or less, 18500 g / mol or less, 18000 g / mol or less, 17500 g / mol or less, 17000 g / mol or less, 16500 g / mol or less, 16000 g / mol or less, 15500 g / mol or less, 15000 g / mol or less, 14500 g / mol or less, 14000 g / mol or less, or 13500 g / mol or less.

[0080]

[0081] In addition, the polyethylene composition may have a weight average molecular weight (Mw) of 80,000 g / mol or more and 160,000 g / mol or less, preferably 82,000 g / mol or more, 85,000 g / mol or more, 88,000 g / mol or more, 90,000 g / mol or more, 92,000 g / mol or more, 95,000 g / mol or more, 98,000 g / mol or more, 100,000 g / mol or more, or 105,000 g / mol or more, and 158,000 g / mol or less, 155,000 g / mol or less, 153,000 g / mol or less, 150,000 g / mol or less, 148,000 g / mol or less, 145,000 g / mol or less, 143,000 g / mol or less, 140,000 g / mol or less, It may be 138000 g / mol or less, 135000 g / mol or less, 133000 g / mol or less, 130000 g / mol or less, 128000 g / mol or less, or 125000 g / mol or less.

[0082]

[0083] The molecular weight distribution Mw / Mn of the polyethylene composition may be 8 or more and 20 or less. Preferably, the molecular weight distribution Mw / Mn of the polyethylene composition may be 8 or more, 8.2 or more, 8.5 or more, 8.7 or more, 9 or more, 9.2 or more, 9.3 or more, 9.5 or more, 9.7 or more, or 10 or more, and 19.5 or less, 19 or less, 18.5 or less, 18 or less, 17.5 or less, 17 or less, 16.5 or less, or 16 or less, 15.5 or less, 15 or less, 14.5 or less, 14 or less, 13.5 or less, 13 or less, 12.5 or less, or 12 or less, 11.5 or less, 11 or less, or 10.5 or less.

[0084]

[0085] For example, the polyethylene composition exhibits a bimodal molecular weight distribution. This bimodal molecular weight distribution means that the molecular weight distribution curve on the GPC graph has two peaks. In this case, if the two peaks each have independent peak shapes and do not exist separately, but partially overlap and exist as a shoulder peak with no minimum value between the maximum values ​​of the two peaks, this is also included as a peak. In other words, if it is not interpreted as a single peak forming a normal distribution, but can be deconvoluted into two distributions, it is defined as a bimodal structure.

[0086]

[0087] This bimodal molecular weight distribution signifies an increase in the distribution of low and high molecular weights within the polyethylene resin composition. This molecular weight distribution structure can exhibit improved physical properties, and in particular, compared to polyethylene resin compositions exhibiting a unimodal molecular weight distribution, it can strengthen the molecular structure morphology that favors biaxial stretching, thereby exhibiting superior extensibility.

[0088]

[0089] The polyethylene composition of the present invention optimizes the bimodal slurry polymerization process in the presence of a Ziegler-Natta catalyst or a metallocene catalyst, for example, by optimizing not only the total input amount of comonomer but also the ratio of comonomers input to each reactor, thereby controlling the balance between mechanical properties and extensibility, thereby maintaining mechanical properties, productivity, and extensibility that are equivalent to or superior to those of the prior art, and has characteristics suitable for producing an extensible film having high shrinkage resistance, printability, and transparency.

[0090]

[0091] In the present invention, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are conversion values ​​for standard polystyrene measured using gel permeation chromatography (GPC, manufactured by Water). However, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are not limited thereto and may be measured by other methods known in the technical field to which the present invention pertains. For example, the method for measuring the weight-average molecular weight (Mw) and number-average molecular weight (Mn) is as described in Test Example 1 described below.

[0092]

[0093] A polyethylene composition according to one embodiment of the present invention optimizes both the melt index and density, the SCB content, and the high crystallinity content as described above to obtain two types of loss modulus (G" a : loss modulus @ alpha relaxation and G" b : loss modulus @ beta relaxation) is formed in a balanced manner, so that a stretched film can be manufactured that has excellent stretching processability, transparency, stiffness, shrinkage, and other post-stretch film qualities.

[0094]

[0095] Here, beta relaxation appears in a lower temperature range than alpha relaxation, and is mainly caused by branches attached to the polymer backbone. In the case of polyethylene, it appears in the range of -50 ℃ to 20 ℃. Alpha relaxation appears in a higher temperature range than beta relaxation, and is caused by crystal relaxation. It is a transition that appears due to defects within crystals or slip between crystals, and mainly appears in the range of 30 ℃ to 100 ℃.

[0096]

[0097] Specifically, the polyethylene composition has a loss modulus G" of alpha relaxation that appears in the range of 30°C or more and 100°C or less in a dynamic viscoelasticity curve measured using DMA (Dynamic Mecahnical Analysis). a (loss modulus @ alpha relaxation) may be 95 MPa or more and 180 MPa or less. Alpha Relaxation (Crystal Relaxation) is a movement within a crystal region (Chain Folds, Crystal Slip, etc.). As the alpha relaxation peak increases, the ductility and Haze decrease, but the Modulus, etc. may improve. Preferably, the loss modulus G" of the alpha relaxation a (loss modulus @ alpha relaxation) may be 95 MPa or more, 100 MPa or more, 110 MPa or more, 120 MPa or more, or 130 MPa or more, but 180 MPa or less, 175 MPa or less, 170 MPa or less, 165 MPa or less, or 160 MPa or less.

[0098]

[0099] The polyethylene composition has a loss modulus G" of beta relaxation that appears in the range of -50°C to 20°C in the dynamic viscoelasticity curve measured using DMA (Dynamic Mecahnical Analysis). b(loss modulus @ beta relaxation) may be 95 MPa or more and 180 MPa. Beta relaxation represents the movement of side chains within the amorphous region, and the larger the beta relaxation peak, the better the smoothness and haze of the uniform thickness deviation along with excellent ductility. Preferably, the loss modulus G" of the beta relaxation b (loss modulus @ beta relaxation) may be 95 MPa or more, 100 MPa or more, 105 MPa or more, or 110 MPa or more, but not more than 180 MPa, not more than 170 MPa, not more than 160 MPa, not more than 150 MPa, not more than 140 MPa, or not more than 130 MPa.

[0100]

[0101] In addition, the loss modulus G" of alpha relaxation as described above a (loss modulus @ alpha relaxation) and loss modulus G" of beta relaxation b The ratio (G) of (loss modulus @ beta relaxation) a / G" b ) may be 0.95 or more and 1.65 or less. Preferably, the loss modulus G" a / G" b The ratio may be 1.0 or more, 1.05 or more, or 1.1 or more, and 1.60 or less, 1.55 or less, 1.50 or less, 1.45 or less, or 1.4 or less. The polyethylene composition can control the beta and alpha relaxation modulus by controlling the SCB content, and the larger the beta relaxation peak, the better the extensibility, and the larger the alpha relaxation peak, the lower the extensibility and Haze, but the better the modulus, etc.

[0102]

[0103] In the present invention, the loss modulus G" of alpha relaxation a (loss modulus @ alpha relaxation) and loss modulus G" of beta relaxation b (loss modulus @ beta relaxation) can be measured using DMA (Dynamic Mecahnical Analysis). For example, using TA instruments' Q800 DMA (Dynamic Mecahnical Analysis), the modulus according to temperature change is measured while oscillating at a heating rate of 5 ℃ / min, strain 0.1%, and frequency 1 Hz from -90 ℃ to 140 ℃ to obtain a dynamic viscoelasticity curve, and then the loss modulus G" of alpha relaxation that appears in the range of 30 ℃ to 100 ℃ a (loss modulus @ alpha relaxation) and loss modulus G" of beta relaxation appearing in the range of -50 ℃ to 20 ℃ b (loss modulus @ beta relaxation) is a value calculated. Here, the polyethylene composition can be measured by pressing it using a hot press at 180° C. to 200° C., for example, 190° C., to produce a sheet having a thickness of 10 μm to 1000 μm, for example, 20 μm to 800 μm, or 50 μm to 650 μm, or 100 μm to 600 μm, or about 500 μm.

[0104]

[0105] However, the solid rheological properties related to the above dynamic viscoelasticity, i.e., the loss modulus G" of alpha relaxation a(loss modulus @ alpha relaxation) and loss modulus G" of beta relaxation b (loss modulus @ beta relaxation) is not limited thereto and can be measured by other methods known in the art to which the present invention pertains. For example, the loss modulus G" of this alpha relaxation a (loss modulus @ alpha relaxation) and loss modulus G" of beta relaxation b The method for measuring (loss modulus @ beta relaxation) is as described in Test Example 2 below.

[0106]

[0107] Meanwhile, a polyethylene composition according to one embodiment of the present invention may include at least one ethylene-alpha-olefin copolymer. The ethylene-alpha-olefin copolymer may include at least one alpha-olefin selected from the group consisting of ethylene and 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, and mixtures thereof. Preferably, the ethylene-alpha-olefin copolymer may be at least one selected from the group consisting of ethylene / 1-hexene copolymer and ethylene / 1-butene copolymer.

[0108]

[0109] The polyethylene composition described above, when it is a copolymer, can more easily achieve the above-described properties. However, the type of polyethylene composition is not limited to the above-described types, and any of a variety of types known in the technical field to which the present invention pertains can be provided as long as it can exhibit the above-described properties.

[0110]

[0111] Meanwhile, the ethylene-alphaolefin copolymer included in the polyethylene composition having the above-described physical properties may be manufactured using a Ziegler-Natta catalyst or a metallocene catalyst, and preferably may be manufactured in the presence of a metallocene catalyst.

[0112]

[0113] Specifically, the ethylene-alpha-olefin copolymer may be an ethylene-alpha-olefin copolymer prepared by polymerizing an olefin monomer in the presence of a hybrid supported metallocene catalyst, comprising: at least one first metallocene compound selected from compounds represented by the following chemical formula 1; at least one second metallocene compound selected from compounds represented by the following chemical formula 2; and a carrier supporting the first and second metallocene compounds.

[0114] [Chemical Formula 1]

[0115]

[0116] In the above chemical formula 1,

[0117] M1 is a group 4 transition metal,

[0118] X 11 , X 12 are each independently substituted or unsubstituted C 1-20 Alkyl or halogen,

[0119] R1 to R5 and R7 to R 12 are each independently hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 6-60 Aryl, or -(CH2) n1 -OR 13 And,

[0120] R6 is substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 6-60 Aryl, or -(CH2) n1 -OR 13 However,

[0121] R1 to R12 At least one of them is -(CH2) n1 -OR 13 And,

[0122] R 13 Silver substituted or unsubstituted C 1-20 It is alkyl,

[0123] n1 is an integer from 0 to 10,

[0124] [Chemical Formula 2]

[0125]

[0126] In the above chemical formula 2,

[0127] M2 is a group 4 transition metal,

[0128] X 21 , X 22 are each independently substituted or unsubstituted C 1-20 Alkyl or halogen,

[0129] T2 is C (carbon) or Si (silicon),

[0130] Q 21 and Q 22 are each independently substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 6-60 Aryl, or -(CH2) n2 -OR 32 This or Q 21 and Q 22 C, which is substituted or unsubstituted by combining with each other 3-20 Forming a cycloalkyl ring,

[0131] R 20 Inland R 31 are each independently hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 6-60 Aryl, or -(CH2) n2 -OR 32 This or R 20 Inland R 31 C, which is substituted or unsubstituted, is formed by combining two adjacent C's. 3-20 Forming a cycloalkyl ring,

[0132] R 20 Inland R 31 , Q 21 and Q 22 At least one of them is -(CH2) n2 -OR 32 And,

[0133] R 32 is substituted or unsubstituted C 1-20 It is alkyl,

[0134] n2 is an integer from 0 to 10.

[0135]

[0136] In the present invention, the substituents of the chemical formula are described more specifically as follows.

[0137]

[0138] The halogen can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0139]

[0140] C above 1-20 Alkyl 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.

[0141]

[0142] C 3-20The cycloalkyl ring may be a ring composed of carbon atoms. It may be a hydrocarbon ring having 3 to 20 carbon atoms; a hydrocarbon ring having 3 to 15 carbon atoms; or a hydrocarbon ring having 3 to 10 carbon atoms. More specifically, C 3-20 The cycloalkyl ring may be a cyclopropene ring, a cyclobutene ring, a cyclopentene ring, or a cyclohexene ring.

[0143]

[0144] C 2-20 Alkenyl may be straight-chain, branched-chain or cyclic alkenyl. Specifically, the above C 2-20 The alkenyl may be a straight chain alkenyl having 2 to 20 carbon atoms, a straight chain alkenyl having 2 to 10 carbon atoms, a straight chain alkenyl having 2 to 5 carbon atoms, a branched chain alkenyl having 3 to 20 carbon atoms, a branched chain alkenyl having 3 to 15 carbon atoms, a branched chain alkenyl having 3 to 10 carbon atoms, a cyclic alkenyl having 5 to 20 carbon atoms or a cyclic alkenyl having 5 to 10 carbon atoms. More specifically, C 2-20 The alkenyl may be ethenyl, propenyl, butenyl, pentenyl or cyclohexenyl.

[0145]

[0146] C 1-20 Alkoxy may be a straight-chain, branched-chain or cyclic alkoxy group. Specifically, the above 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.

[0147]

[0148] C 2-20 Alkoxyalkyl is -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 C2 to C20 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.

[0149]

[0150] C 6-60 Aryl may refer to a monocyclic, bicyclic, or tricyclic aromatic hydrocarbon. Specifically, the C6 to C60 aryl may be a phenyl group, a naphthyl group, an anthracenyl group, or the like.

[0151]

[0152] C 7-20 Alkylaryl may mean a substituent in which one or more hydrogens of aryl are replaced by alkyl. Specifically, the above C 7-20 The alkylaryl may be methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl or cyclohexylphenyl.

[0153]

[0154] C 7-20 Arylalkyl may mean a substituent in which one or more hydrogens of alkyl are replaced by aryl. Specifically, the above C 7-20 The arylalkyl group may be benzyl, phenylpropyl or phenylhexyl.

[0155]

[0156] Also, group 4 transition metals can include titanium, zirconium, and hafnium.

[0157]

[0158] The above hybrid supported metallocene catalyst is a hybrid catalyst comprising a first metallocene compound having a high molecular weight and high crystallinity and a second metallocene compound having a low molecular weight and low crystallinity.

[0159]

[0160] In copolymerization in a single reactor using a hybrid supported metallocene catalyst, it is important to control the expression of differences in polymerization characteristics between the metallocene compounds constituting the hybrid supported metallocene catalyst under a single copolymerization condition. In particular, to obtain a polyethylene copolymer suitable for biaxial stretching, a high molecular weight, high crystallinity component and a low molecular weight, low crystallinity component must be composed together. Accordingly, the present invention has invented a polyethylene copolymer that expresses each characteristic under a single copolymerization condition by using a hybrid supported metallocene catalyst obtained by combining the first metallocene compound and the second metallocene compound.

[0161]

[0162] The first metallocene compound represented by the above chemical formula 1 has the characteristics of a lower polymerization rate of the comonomer and a higher polymerization rate of the ethylene monomer compared to the second metallocene compound due to the structure of the non-bridged ligand bonded to the central metal. As a result, under ethylene / 1-hexene copolymerization conditions, it can express a high molecular weight, high crystallinity polyethylene with a small number of SCBs and a high Mw.

[0163]

[0164] Meanwhile, the second metallocene compound represented by Chemical Formula 2 has a higher polymerization rate of the comonomer and a lower polymerization rate of the ethylene monomer compared to the first metallocene compound due to the bridge-type ligand structure bonded to the central metal. As a result, it can express a low molecular weight, low crystallinity polyethylene with a high SCB and a low Mw under ethylene / 1-hexene copolymerization conditions.

[0165]

[0166] Preferably, the central metal (M1) of the chemical formula 1 may be a Group 4 transition metal, specifically Ti, Zr, or Hf, and more specifically Hf or Zr.

[0167]

[0168] Preferably, X 11 , X 12 can each independently be methyl or chloro, more preferably X 11 , X 12 can be all methyl or all chloro.

[0169]

[0170] Preferably, R1 to R5 and R7 to R 12 are each independently hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 6-20 Aryl, or -(CH2) n1 -OR 13 , and R6 is substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 6-20 Aryl, or -(CH2) n1 -OR 13 However, R1 to R 12 One or both of them are -(CH2) n1 -OR 13 It could be.

[0171]

[0172] Preferably, either R7 or R8 is -(CH2) n1 -OR 13 And the rest of R1 to R5 and R9 to R 12 are each independently hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 6-60 Aryl, or -(CH2) n1 -OR 13 , and R6 is substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C6-60 Aryl, or -(CH2) n1 -OR 13 It could be.

[0173]

[0174] Preferably, R1 to R5 are each independently hydrogen, methyl, isopropyl, n-butyl, phenyl, or -(CH2) n1 -OR 13 may be. More preferably, R1 to R5 may each independently be hydrogen, methyl, n-butyl, phenyl, or tertbutoxyhexyl.

[0175]

[0176] Preferably, R6 is unsubstituted or C 6-10 C substituted with aryl or Si(R')3 1-20 Alkyl, or C 6-20 It can be aryl, where R' is C 1-20 Alkyl or C 6-10 It may be aryl. More preferably, R6 is C unsubstituted or substituted with phenyl, trimethylsilyl, or triphenylsilyl. 1-20 Alkyl, or C 6-20 It can be aryl. Most preferably, R6 can be methyl, ethyl, isopropyl, benzyl, trimethylsilyl methyl, or phenyl.

[0177]

[0178] Preferably, either R7 or R8 is -(CH2) n1 -OR 13 And the rest of R9 to R 12 Each of R7 and R8 may be hydrogen. More preferably, one of R7 or R8 is tert-butoxy hexyl, and the other and R9 to R 12 Each can be hydrogen.

[0179]

[0180] Preferably, R 13 It may be tert-butyl.

[0181]

[0182] Preferably, n1 may be an integer from 4 to 10, more preferably, n1 may be an integer from 4 to 7, and most preferably, n1 may be 6.

[0183]

[0184] Preferably, the first metallocene compound represented by the above chemical formula 1 may be any one selected from the group consisting of:

[0185]

[0186] .

[0187]

[0188] Meanwhile, the method for producing the first metallocene compound represented by the above chemical formula 1 is not particularly limited, but may be produced by a method such as the following reaction scheme 1, for example.

[0189]

[0190] The compound represented by the above chemical formula 1 is difficult to synthesize due to the steric hindrance of the indene ligand, but the compound represented by the above chemical formula 1 can be produced in high yield and high purity according to a method such as the following reaction scheme 1.

[0191]

[0192] Accordingly, according to one embodiment of the present invention, the compound represented by the chemical formula 1 is

[0193] A step of preparing a ligand of chemical formula 1-3 by reacting a compound represented by chemical formula 1-1 with a compound represented by chemical formula 1-2; and

[0194] It can be produced by a production method including a step of reacting a ligand of chemical formula 1-3, a compound represented by chemical formula 1-4, and a halogen salt of a transition metal represented by chemical formula 1-5:

[0195] [Reaction Formula 1]

[0196]

[0197] In the above reaction formula 1,

[0198] M1, X 11 , X 12 and R1 to R 12 is as defined in the above chemical formula 1,

[0199] X' is each independently a halogen.

[0200]

[0201] Preferably, the central metal (M2) of chemical formula 2 may be a Group 4 transition metal, specifically Ti, Zr, or Hf, and more specifically Zr.

[0202]

[0203] Preferably, X 21 , X 22 can each independently be methyl or chloro, more preferably X 21 , X 22 Each can be chloro.

[0204]

[0205] Preferably, T2 may be C (carbon).

[0206]

[0207] Preferably, R 20 Inland R 31 , Q 21 and Q 22 At least one of them is -(CH2) n2 -OR 32 It can be. More preferably, R 20 Inland R 25 , Q 21 and Q 22 At least one of them is -(CH2) n2 -OR 32 It can be. More preferably, R 20 Inland R 31 , Q 21 and Q 22 One or both of them are -(CH2) n2 -OR 32 It can be. More preferably, R 20Inland R 25 , Q 21 and Q 22 One or both of them are -(CH2) n2 -OR 32 It can be. Most preferably, R 20 Inland R 25 , Q 21 and Q 22 Either one or both may be tert-butoxyhexyl.

[0208]

[0209] Preferably, Q 21 and Q 22 are each independently substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 6-20 Aryl, or -(CH2) n2 -OR 32 This or Q 21 and Q 22 C, which is substituted or unsubstituted by combining with each other 3-20 A cycloalkyl ring can be formed. More preferably, Q 21 and Q 22 are each independently methyl, ethyl, isopropyl, phenyl, or -(CH2) n2 -OR 32 This or Q 21 and Q 22 can combine with each other to form a cyclopentene ring or a cyclohexene ring.

[0210]

[0211] Preferably, R 20 Inland R 23 are each independently hydrogen, C 1-20 Alkyl, C 6-20 Aryl, or -(CH2) n2 -OR 32 It may be, and more preferably, R 20 Inland R 23 Each independently may be hydrogen, methyl, n-butyl, phenyl, or tertbutoxyhexyl. More preferably, R 20 Inland R23 One of them is tert-butoxyhexyl or n-butyl, and the other is hydrogen, or R 20 Inland R 23 Two of them can be independently methyl, n-butyl, or phenyl, and the remainder can be hydrogen.

[0212]

[0213] Preferably, R 24 Inland R 31 are each independently hydrogen, C 1-10 Alkyl, C 6-20 Aryl, or -(CH2) n2 -OR 32 This or R 24 Inland R 31 C, which is substituted or unsubstituted, is formed by combining two adjacent C's. 3-10 A cycloalkyl ring can be formed. More preferably, R 24 Inland R 31 are each independently hydrogen, tert-butyl or tert-butoxyhexyl, or R 24 Inland R 31 Two adjacent ones can combine to form a cyclohexane ring substituted with four methyl groups.

[0214]

[0215] Preferably, R 32 may be tertbutyl.

[0216]

[0217] Preferably, n2 may be an integer from 4 to 10, more preferably, n2 may be an integer from 4 to 7, and most preferably, n2 may be 6.

[0218]

[0219] Preferably, the metallocene compound represented by the above chemical formula 2 may be any one selected from the group consisting of:

[0220]

[0221] .

[0222]

[0223] Meanwhile, the method for producing the second metallocene compound represented by the above chemical formula 2 is not particularly limited, but may be produced by a method such as the following reaction formula 2, for example.

[0224] The compound represented by the above chemical formula 2 is difficult to synthesize due to the steric hindrance of the indene ligand, but the compound represented by the above chemical formula 2 can be produced in high yield and high purity according to a method such as the following reaction scheme 2.

[0225]

[0226] Accordingly, according to one embodiment of the present invention, the compound represented by the chemical formula 2 is

[0227] A step of producing a compound represented by chemical formula 2-3 by reacting a compound represented by chemical formula 2-1 with a compound represented by chemical formula 2-2;

[0228] A step of preparing a ligand of chemical formula 2-5 by reacting a compound represented by chemical formula 2-3 with a compound represented by chemical formula 2-4; and

[0229] It can be produced by a production method including a step of reacting a ligand of Chemical Formula 2-5 with a halogen salt of a transition metal represented by Chemical Formula 2-6:

[0230] [Reaction Formula 2]

[0231]

[0232] In the above reaction formula 2,

[0233] M2, X 21 , X 22 , T2, Q 21 , Q 22 and R 20 Inland R 31 is as defined in the above chemical formula 2,

[0234] X" is each independently a halogen.

[0235]

[0236] In the hybrid supported metallocene catalyst of the present invention, the first metallocene compound and the second metallocene compound may be supported at a molar ratio of 1:1 to 25:1, or 2:1 to 25:1, or 3:1 to 25:1, or 3:1 to 23:1, or 3:1 to 20:1, or 5:1 to 18:1, or 8:1 to 15:1, or 10:1 to 13:1. When the ratio of the first metallocene compound to the second metallocene compound is less than 1:1, the high crystallinity content is low, making it difficult for the stretched film to have heat resistance, and when the ratio of the first metallocene compound to the second metallocene compound exceeds 25:1, the low crystallinity content is low, making biaxial stretching processability difficult.

[0237]

[0238] In the hybrid supported metallocene catalyst of the present invention, a carrier containing a hydroxyl group on the surface can be used as a carrier for supporting the first metallocene compound and the second metallocene compound. Preferably, the carrier can be a carrier having a highly reactive hydroxyl group, silanol group, or siloxane group on the surface. For this purpose, a carrier whose surface has been modified by calcination or whose surface has had moisture removed by drying can be used.

[0239]

[0240] 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.

[0241]

[0242] 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, when producing an ethylene-alphaolefin copolymer by slurry or gas phase polymerization, fouling caused by adhesion of the reactor wall or polymer particles to each other can be minimized.

[0243]

[0244] The above-mentioned carrier may have an average particle diameter (D50) of 20 to 60 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 60 μm or less, or 50 μm or less.

[0245]

[0246] Meanwhile, in the present invention, the average particle diameter (D50) of the carrier refers to the particle diameter at the 50% point of the cumulative distribution of the number of particles according to particle size (particle diameter). The D50 can be measured using a laser diffraction method. Specifically, the target carrier is dispersed in a dispersion medium such as deionized water, and then introduced into a commercially available laser diffraction particle size measuring device (e.g., Microtrac S3500), and when the particles pass through the laser beam, the difference in the diffraction pattern according to the particle size is measured to calculate the particle size distribution. The particle size at the point where it becomes 50% of the cumulative distribution of the number of particles according to the particle diameter in the measuring device is calculated, and this is taken as the average particle size.

[0247]

[0248] In addition, when supported on the carrier, the first and second metallocene compounds may be supported in an amount of, for example, 1 mmol or more, 10 mmol or more, 15 mmol or more, 20 mmol or more, 25 mmol or more, or 30 mmol or more, and 500 mmol or less, 400 mmol or less, 300 mmol or less, 200 mmol or less, 100 mmol or less, 80 mmol or less, 60 mmol or less, or 52.5 mmol or less, based on 1000 g of the 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.

[0249]

[0250] In addition, the above hybrid metallocene catalyst may further include a cocatalyst in order to improve high activity and process stability.

[0251]

[0252] The above cocatalyst is an organometallic compound containing a Group 13 metal, and specifically may contain at least one of the compounds represented by the following chemical formula 3.

[0253] [Chemical Formula 3]

[0254] -[Al(R 41 )-O] a -

[0255] In the above chemical formula 3,

[0256] R 41 is a halogen; or C substituted or unsubstituted with a halogen 1-20 It is hydrocarbyl;

[0257] a is an integer greater than or equal to 2.

[0258]

[0259] 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.

[0260]

[0261] 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.

[0262]

[0263] Among the above compounds, the cocatalyst may be, more specifically, an alkylaluminoxane cocatalyst such as methylaluminoxane.

[0264]

[0265] The above alkylaluminoxane cocatalyst can further enhance catalytic activity by including a metal element that stabilizes the first and second metallocene 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 metallocene compounds.

[0266]

[0267] In addition, the amount of the cocatalyst used can be appropriately adjusted depending on the properties or effects of the desired catalyst and the polyethylene copolymer. For example, when silica is used as the carrier, the cocatalyst can be supported in an amount of 100 g or more, or 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 1000 g of silica.

[0268]

[0269] The hybrid metallocene catalyst according to the present invention 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. At this time, 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 first and second transition metal compounds sequentially after supporting the promoter on the support can enable the produced supported catalyst to realize high catalytic activity and better process stability in the production process of an ethylene-alphaolefin copolymer.

[0270]

[0271] As described above, the hybrid supported metallocene catalyst can exhibit excellent catalytic activity by including first and second metallocene compounds having specific structures. Accordingly, the hybrid supported metallocene catalyst can be suitably used for the polymerization of ethylene and olefin monomers.

[0272]

[0273] Meanwhile, alpha-olefins may be used as the olefin monomer polymerized with ethylene. Specific examples of such alpha-olefins include 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, or 1-eicosene, and one or more of these monomers or two or more of them may be mixed and copolymerized. More specifically, the olefin monomer may be at least one of 1-butene and 1-hexene.

[0274]

[0275] The amount of the olefin monomer added may be determined depending on the properties of the polyethylene copolymer to be manufactured. For example, considering the properties of the polyethylene copolymer to be implemented in the present invention, the olefin monomer may be added in an amount of 0.1 wt% to 10.0 wt% relative to the total weight of ethylene. More specifically, the olefin monomer may be introduced in an amount of 0.2 wt% or more, 0.5 wt% or more, 0.8 wt% or more, 1.0 wt% or more, 1.2 wt% or more, 1.5 wt% or more, 1.6 wt% or more, 1.8 wt% or more, 2.0 wt% or more, or 2.1 wt% or more, and 9.8 wt% or less, 9.5 wt% or less, 9.0 wt% or less, 8.5 wt% or less, 8.0 wt% or less, 7.5 wt% or less, 7.0 wt% or less, or 6.5 wt% or less, 6 wt% or less, 5.5 wt% or less, 5 wt% or less, 4.5 wt% or less, 4 wt% or less, 3.5 wt% or less, or 3.0 wt% or less, based on the total weight of ethylene.

[0276]

[0277] The above polymerization reaction can be carried out under conditions of hydrogen input.

[0278]

[0279] Specifically, the hydrogen may be introduced in an amount of 600 ppm or less or 0 to 600 ppm based on the total weight of ethylene, which is a monomer. More specifically, the hydrogen may be introduced in an amount of 0.3 ppm or more, 0.5 ppm or more, 1 ppm or more, 3 ppm or more, 5 ppm or more, 10 ppm or more, 15 ppm or more, 20 ppm or more, 25 ppm or more, 28 ppm or more, 30 ppm or more, 32 ppm or more, or 33 ppm or more, and 580 ppm or less, 550 ppm or less, 500 ppm or less, 450 ppm or less, 400 ppm or less, 380 ppm or less, 360 ppm or less, 350 ppm or less, 340 ppm or less, 335 ppm or less, or 333 ppm or less, based on the total weight of ethylene.

[0280]

[0281] When injected within the above range, it is easier to implement the properties of the polyethylene copolymer described above.

[0282]

[0283] The above polymerization reaction can be carried out as a gas phase polymerization reaction or a slurry polymerization reaction.

[0284]

[0285] Accordingly, it can be performed using a single gas phase polymerization reactor, a continuous slurry polymerization reactor, or a loop slurry reactor.

[0286]

[0287] Preferably, the polymerization reaction can be carried out using a bimodal continuous slurry polymerization reactor, and for example, a bimodal slurry polymerization process can be carried out using two continuous stirred tank reactors (CSTRs) consisting of a first reactor and a second reactor. Here, the first reactor and the second reactor can be connected in series.

[0288]

[0289] In particular, the polyethylene composition is manufactured by a bimodal slurry polymerization process, and can be manufactured by performing a first polymerization reaction using a first reactor to manufacture first polyethylene, and then moving to a second reactor to perform a second polymerization reaction.

[0290]

[0291] In this bimodal slurry polymerization process, the first reactor and the second reactor can be operated under different conditions with respect to the input amounts of ethylene monomer, one or more alpha-olefin comonomers, and hydrogen gas.

[0292]

[0293] Specifically, in a bimodal slurry polymerization process, a first reactor may perform a polymerization process by introducing an ethylene monomer and one or more alpha-olefin comonomers in the presence of hydrogen gas, and a second reactor may perform a polymerization process of an ethylene monomer and one or more alpha-olefin comonomers without introducing hydrogen gas.

[0294]

[0295] For example, the polyethylene composition can be produced by performing a bimodal slurry polymerization process using two continuous stirred tank reactors (CSTRs) consisting of a first reactor and a second reactor in the presence of the above-described hybrid supported metallocene catalyst. At this time, the first reactor can perform a first polymerization reaction by introducing an ethylene monomer and one or more alpha-olefin comonomers in the presence of hydrogen gas to produce the first polyethylene. In this first reactor, triethylaluminum (TEAL) or the like can be additionally introduced together with the above-described hybrid supported catalyst. Thereafter, the first polyethylene polymerized in the first reactor can be transferred to a second reactor connected in series with the first reactor, and a second polymerization reaction can be performed by introducing an ethylene monomer and one or more alpha-olefin comonomers without introducing hydrogen gas.

[0296]

[0297] The above bimodal slurry polymerization process can be performed by injecting hydrogen gas into a first reactor to perform a first polymerization reaction to produce a first polyethylene, and then moving the first polyethylene to a second reactor connected in series with the first reactor, and then performing a second polymerization reaction without injecting hydrogen gas.

[0298]

[0299] Specifically, in the first reactor of the bimodal slurry polymerization process, hydrogen gas may be introduced in an amount of 600 ppm or less or 0 to 600 ppm based on the total weight of ethylene, which is a monomer. More specifically, it may be introduced in an amount of 0.3 ppm or more, 0.5 ppm or more, 1 ppm or more, 3 ppm or more, 5 ppm or more, 10 ppm or more, 15 ppm or more, 20 ppm or more, 25 ppm or more, 28 ppm or more, 30 ppm or more, 32 ppm or more, or 33 ppm or more, and 580 ppm or less, 550 ppm or less, 500 ppm or less, 450 ppm or less, 400 ppm or less, 380 ppm or less, 360 ppm or less, 350 ppm or less, 340 ppm or less, 335 ppm or less, or 333 ppm or less, based on the total weight of ethylene.

[0300]

[0301] Additionally, in the first reactor of the bimodal slurry polymerization process, the olefin monomer may be introduced in an amount of 0.1 wt% to 9.9 wt% relative to the total weight of ethylene. More specifically, the olefin monomer may be introduced in an amount of 0.2 wt% or more, 0.5 wt% or more, 0.8 wt% or more, 1.0 wt% or more, 1.2 wt% or more, 1.5 wt% or more, 1.6 wt% or more, 1.8 wt% or more, 2.0 wt% or more, or 2.1 wt% or more, and 9.8 wt% or less, 9.5 wt% or less, 9.0 wt% or less, 8.5 wt% or less, 8.0 wt% or less, 7.5 wt% or less, 7.0 wt% or less, or 6.5 wt% or less, 6 wt% or less, 5.5 wt% or less, 5 wt% or less, 4.5 wt% or less, 4 wt% or less, 3.5 wt% or less, or 3.0 wt% or less, based on the total weight of ethylene.

[0302]

[0303] In the second reactor of the above bimodal slurry polymerization process, the olefin monomer can be introduced in an amount of 0.1 wt% to 9.9 wt% relative to the total weight of ethylene. More specifically, the olefin monomer may be introduced in an amount of 0.2 wt% or more, 0.3 wt% or more, 0.4 wt% or more, 0.5 wt% or more, 0.6 wt% or more, 0.7 wt% or more, or 0.8 wt% or more, and 9.8 wt% or less, 9.0 wt% or less, 6.0 wt% or less, 5.0 wt% or less, 4.0 wt% or less, 3.0 wt% or less, 2.5 wt% or less, 2.0 wt% or less, 1.8 wt% or less, 1.5 wt% or less, 1.3 wt% or less, 1.2 wt% or less, or 1.0 wt% or less, relative to the total weight of ethylene.

[0304]

[0305] For example, the bimodal slurry polymerization process is a process in which hydrogen gas is introduced into a first reactor at 15 g / hr or less, or 0 to 15 g / hr, or 0.1 g / hr to 14 g / hr, or 0.2 to 13 g / hr, or 0.5 g / hr to 12 g / hr, or 0.7 g / hr to 11 g / hr, or 0.9 g / hr to 10.5 g / hr, or 1 g / hr to 10 g / hr, ethylene monomer is introduced at 300 mL / min to 700 mL / min, or 320 mL / min to 600 mL / min, or 350 mL / min to 580 mL / min, or 380 mL / min to 550 mL / min, or 400 mL / min to 500 mL / min, and one or more alpha-olefins. A first polymerization reaction is performed by introducing a comonomer at 20 mL / min or less, or 0 to 20 mL / min, or 0.1 mL / min to 18 mL / min, or 0.5 mL / min to 16 mL / min, or 1 mL / min to 15 mL / min, or 2 mL / min to 14 mL / min, or 3 mL / min to 13 mL / min, or 5 mL / min to 12 mL / min, to manufacture a first polyethylene, and then the first polyethylene is transferred to a second reactor connected in series with the first reactor, and then the ethylene monomer is introduced at 300 mL / min to 700 mL / min, or 320 mL / min to 600 mL / min, or 300 mL / min to 550 mL / min, or 320 mL / min to 500 mL / min, or 340 mL / min to 450 mL / min, or 350 mL / min to 400 mL / min, and one or more alpha-olefin comonomers are introduced at 20 mL / min or less, or 0 to 20 mL / min, or 0.1 mL / min to 18 mL / min, or 0.2 mL / min to 15 mL / min, or 0.The secondary polymerization reaction can be performed by injecting at 3 mL / min to 12 mL / min, or 0.4 mL / min to 10 mL / min, or 0.5 mL / min to 8 mL / min, or 0.8 mL / min to 6 mL / min, or 1 mL / min to 4 mL / min.

[0306]

[0307] Meanwhile, in the polymerization reaction, the above-described 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 carry out the reaction using an additional cocatalyst.

[0308]

[0309] Non-limiting examples of such alkyl aluminum compounds include trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, triisopropylaluminum, tri-sec-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylaluminum methoxide, or dimethylaluminum ethoxide.

[0310]

[0311] In addition, the polymerization reaction may be carried out at a temperature of 40°C or higher, or 50°C or higher, or 60°C or higher, or 70°C or higher, or 75°C or higher, or 80°C or higher, and 120°C or lower, or 115°C or lower, or 110°C or lower, or 105°C or lower, or 100°C or lower, or 95°C or lower, or 90°C or lower, or 88°C or lower, or 85°C or lower, or 82°C or lower. In addition, when the pressure conditions during the polymerization reaction are further controlled, the polymerization reaction may be carried out under a pressure of 2 bar or higher, 3 bar or higher, 5 bar or higher, or 6 bar or higher, and 50 bar or lower, or 40 bar or lower, or 30 bar or lower, or 20 bar or lower, or 15 bar or lower, or 12 bar or lower, or 10 bar or lower, or 8 bar or lower. When polymerization is carried out under such temperature and pressure, the desired properties of the ethylene-alphaolefin copolymer can be more easily achieved.

[0312]

[0313] Preferably, the polymerization reaction can be performed using a bimodal continuous slurry polymerization reactor, and in the first reactor of the bimodal slurry polymerization process, the polymerization reaction temperature is 40°C or higher, or 50°C or higher, or 60°C or higher, or 70°C or higher, or 75°C or higher, or 80°C or higher, and 120°C or lower, or 115°C or lower, or 110°C or lower, or 105°C or lower, or 100°C or lower, or 95°C or lower, or 90°C or lower, or 88°C or lower, or 85°C or lower. In addition, when the pressure conditions during the polymerization reaction of the first reactor are further controlled, it can be performed under a pressure of 2 bar or more, 3 bar or more, 5 bar or more, or 6 bar or more, and 50 bar or less, or 40 bar or less, or 30 bar or less, or 20 bar or less, or 15 bar or less, or 12 bar or less, or 10 bar or less, or 8 bar or less.

[0314]

[0315] In addition, the polymerization reaction temperature in the second reactor during the bimodal slurry polymerization process may be performed at a lower range than the polymerization reaction temperature of the first reactor described above, for example, the polymerization process of the second reactor may be performed with a temperature difference of at least 1°C, or 2°C, or 5°C. Preferably, the polymerization reaction temperature of the second reactor is 40°C or higher, or 50°C or higher, or 60°C or higher, or 70°C or higher, or 75°C or higher, and 115°C or lower, or 110°C or lower, or 105°C or lower, or 100°C or lower, or 95°C or lower, or 90°C or lower, or 85°C or lower, or 80°C or lower, or 78°C or lower. In addition, the pressure conditions during the polymerization reaction of the second reactor may be performed in a range lower than the polymerization reaction pressure of the first reactor described above, for example, the polymerization process of the second reactor may be performed with a pressure difference of at least 1 bar, or 2 bar, or 3 bar, or 4 bar. The polymerization reaction pressure in the second reactor may be performed under a pressure of 2 bar or more, or 3 bar or more, and 49 bar or less, or 40 bar or less, or 30 bar or less, or 20 bar or less, or 15 bar or less, or 12 bar or less, or 10 bar or less, or 8 bar or less, or 5 bar or less, or 4 bar or less.

[0316]

[0317] The above ethylene-alpha-olefin copolymer is produced using a catalyst in which a metallocene compound exhibiting high molecular weight and high crystallinity and a metallocene compound exhibiting low molecular weight and low crystallinity are hybrid-supported, thereby having a high crystallinity content of 45 wt% or more and improving the main chain average molecular weight of the high crystallinity fraction. Accordingly, when producing a stretched film using a polyethylene composition including at least one of the above ethylene-alpha-olefin copolymers, the heat resistance, such as tensile modulus and shrinkage rate, of the stretched film can be improved.

[0318]

[0319] Accordingly, the present invention provides a uniaxially or biaxially oriented film comprising a polyethylene composition comprising at least one of the ethylene-alphaolefin copolymers.

[0320]

[0321] (extension film)

[0322] The polyethylene composition having the above-described physical properties can stably form a uniaxially or biaxially stretched film having excellent mechanical properties, productivity and stretching stability, and having high shrinkage resistance, uniform thickness variation, and excellent printability and transparency.

[0323]

[0324] Meanwhile, the above-mentioned stretched film can be manufactured by a conventional film manufacturing method, except that the above-mentioned polyethylene composition is used.

[0325]

[0326] The above-mentioned stretched film exhibits improved transparency and strength properties along with excellent stretchability by including the above-mentioned polyethylene.

[0327]

[0328] Specifically, the stretched film may be a uniaxially stretched film having a machine direction (MD) or transverse direction (TD) stretch ratio of 5 or more, or 5 to 10, when the thickness is 10 to 100 μm. Alternatively, the stretched film may be a biaxially stretched film having a machine direction (MD) stretch ratio of 5 or more, or 5 to 8, and a transverse direction (TD) stretch ratio of 8 or more, or 8 to 10.

[0329]

[0330] Here, the stretching ratio of the stretched film may be a measured value when the thickness of the film is 10 to 100 μm, for example, 20 to 95 μm, or 30 to 90 μm, or 40 to 85 μm.

[0331]

[0332] For example, a polyethylene stretched film according to the present invention can be manufactured into a polyethylene composition sheet having a thickness of 0.6 mm to 0.9 mm, for example, a thickness of 0.8 mm, using a Bruckner lab extruder line (L / D ratio: 42, Screw diameter: 25 mm, Melt / T-Die temperature: 220° C.). Thereafter, a polyethylene stretched film can be manufactured by performing biaxial stretching using a KARO 5.0 device into a polyethylene composition sheet having a width and length of 80 mm to 100 mm, for example, a width x length of 90 mm x 90 mm. The specific film manufacturing method and conditions are as described in Test Example 3 described below.

[0333]

[0334] In addition, the polyethylene oriented film according to the present invention may further include additives well known in the art in addition to the polyethylene copolymer 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, foaming agents, and the like. The types of the additives are not particularly limited, and general additives known in the art can be used.

[0335]

[0336] The polyethylene stretch film according to one embodiment of the present invention manufactured by the above method can improve performance in terms of extensibility processing area characteristics and excellent mechanical properties.

[0337]

[0338] The above polyethylene stretched film may have a tensile modulus in the MD direction measured according to ASTM D 882 of 1000 MPa or more, 1050 MPa or more, 1100 MPa or more, 1130 MPa or more, 1150 MPa or more, 1200 MPa or more, 1250 MPa or more, or 1300 MPa or more. However, in terms of simultaneously implementing excellent stretching processability or transparency of the final film, the modulus may be 5000 MPa or less, 4500 MPa or less, 4000 MPa or less, 3500 MPa or less, 3000 MPa or less, 2500 MPa or less, 2200 MPa or less, or 2000 MPa or less.

[0339]

[0340] Here, the physical properties of the stretched film may be measured values ​​when the thickness of the film is 10 μm to 100 μm, for example, 12 μm to 85 μm, or 15 μm to 50 μm, or 18 μm to 45 μm, or 20 μm to 30 μm. Specifically, the stretched film may be stretched at a stretching ratio (MD X TD) of 5X8, and the measured thickness may be about 20 μm to about 30 μm.

[0341]

[0342] In addition, the polyethylene stretched film may have a tensile modulus in the TD direction measured according to ASTM D 882 of 1000 MPa or more, 1100 MPa or more, 1200 MPa or more, 1300 MPa or more, 1400 MPa or more, 1450 MPa or more, 1500 MPa or more, 1550 MPa or more, 1580 MPa or more, 1600 MPa or more, 1620 MPa or more, or 1635 MPa or more. However, in terms of simultaneously implementing excellent stretching processability and transparency of the final film, it may be 5000 MPa or less, 4500 MPa or less, 4000 MPa or less, 5000 MPa or less, 4500 MPa or less, 4000 MPa or less, 3800 MPa or less, 3500 MPa or less, 3200 MPa or less, 3000 MPa or less, 2800 MPa or less, or 2500 MPa or less.

[0343]

[0344] The above polyethylene stretch film may have a haze of 9% or less, 8.8% or less, 8.5% or less, 8.3% or less, 8% or less, 7.8% or less, 7.5% or less, 7.3% or less, or 7% or less as measured according to ASTM 1003.

[0345]

[0346] The above polyethylene stretched film may have a smoothness of the stretched film, that is, a thickness deviation ratio of the stretched film, calculated by calculating the standard deviation values ​​for 20 or more thickness measurements at 20 or more non-overlapping points of the stretched film when the size is 210 mm in width and 297 mm in length, of 7% or less, or 0.001% or more and 7% or less. Preferably, the smoothness of the stretched film may be 6.8% or less, 6.5% or less, 6.2% or less, 6% or less, 5.8% or less, 5.5% or less, 5.2% or less, 5% or less, 4.8% or less, 4.5% or less, 4.2% or less, 4% or less, or 3.8% or less, and considering the limitations of the actual process, it may be 0.001% or more, or 0.01% or more. At this time, the thickness of the film can be measured using a Mitutoyo 547-401A thickness measuring instrument. However, the thickness measurement method is not limited to this, and the thickness can be measured using other methods known in the technical field to which the present invention pertains.

[0347]

[0348] In the present invention, the physical properties of the stretched film can be measured according to the above-described standard, and the specific method is as described in Test Example 3 described below.

[0349]

[0350] In the present invention, by controlling the balance between mechanical properties and stretchability through a bimodal slurry polymerization process using a Ziegler-Natta catalyst or a metallocene catalyst so as to realize excellent mechanical properties along with stretchability with excellent flowability as described above, it is possible to stably manufacture a stretched film having high shrinkage resistance, printability, and transparency while maintaining excellent mechanical properties, productivity, and stretching stability.

[0351]

[0352] The polyethylene according to the present invention has excellent mechanical properties and stretching stability, as well as excellent film processability and productivity, and has an excellent effect of being able to produce a stretched film having high shrinkage resistance, uniform thickness variation, and excellent printability and transparency.

[0353]

[0354] 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.

[0355]

[0356] [Example]

[0357] <Preparation of metallocene compounds>

[0358] Synthesis Example 1: Preparation of the first metallocene compound

[0359]

[0360] (1) Synthesis of ligands

[0361] Under Ar, 120 g (440 mmol) of 3-(6-tert-butoxyhexyl)-1H-indene and 1.1 L of n-hexane were added to a dried 2 L Schlenk flask. After cooling to -78 °C, 185 mL (1.05 eq., 462.5 mmol) of 2.5 M n-BuLi in hexane was added dropwise. The reaction mixture was slowly warmed to room temperature and stirred for 8 h. After cooling again to -78 °C, 82.8 g (1.1 eq., 484 mmol) of benzyl bromide was added dropwise. After slowly warming to room temperature and stirring for 24 hours, the organic layer was separated using water and diethyl ether and dried over MgSO4 to obtain 137 g (377 mmol, 85.7% yield) of 3-(6-tert-butoxyhexyl)-1-benzyl-1H-indene.

[0362]

[0363] 1 H NMR (500 MHz, CDCl3): 1.22 (9H, s), 1.32 (4H, m), 1.44 (2H, m), 1.57 (2H, m), 1.73 (2H, m), 2.59 (2H, m), 3.38 (2H, t), 3.75 (1H, m), 6.14 (1H, brs), 7.14-7.45 (9H, m).

[0364]

[0365] (2) Synthesis of metallocene compounds

[0366] Under Ar, 9.06 g (25 mmol) of the ligand synthesized above and 90 mL of diethyl ether were added to a dried 250 mL Schlenk flask. After cooling to -78 °C, 11 mL (1.05 eq., 27.5 mmol) of 2.5 M n-BuLi in hexane was added dropwise. The reaction mixture was slowly warmed to room temperature and stirred for 8 hours. After cooling again to -78 °C, 10.6 g (1.0 eq., 25 mmol) of (1-n-butyl-3-methylcyclopentadienyl)ZrCl3dimethoxyethane complex and 30 mL of diethyl ether were added. After slowly warming to room temperature and stirring for 24 hours, the reaction mixture was dried under reduced pressure, and dichloromethane was added. The resulting suspension was filtered under Ar to remove LiCl, the filtrate was dried under reduced pressure, and n-hexane was added. The resulting suspension was filtered under Ar to obtain 8.76 g (13.3 mmol, 53.2% yield) of the first metallocene compound having the above-described structure in solid form.

[0367]

[0368] 1H NMR (500 MHz, CDCl3): 0.88-0.91 (3H, m), 1.22 (9H, s), 1.29-1.40 (8H, m), 1.52-1.76 (4H, m), 2.06 (3H, s), 2.11-2.22 (2H, m), 2.59-2.68 (2H, m), 2.99-3.07 (2H, m), 3.34 (2H, t), 4.43 (1H, dt), 5.21 (1H, dt), 5.78 (1H, t), 6.47 (1H, brs), 7.11-7.63 (9H, m).

[0369]

[0370] Synthesis Example 2: Preparation of a Second Metallocene Compound

[0371]

[0372] (1) Synthesis of ligands

[0373] Under Ar, 100 g (450 mmol) of 2-(6-tert-butoxyhexyl)cyclopentadiene, 103 g (2.0 eq., 900 mmol) of 2,4-dimethyl-3-pentanone, and 1 L of ethanol were added to a dried 250 mL Schlenk flask. After cooling to 0 °C, 48.0 g (1.5 eq., 675 mmol) of pyrrolidine was added dropwise. The reaction mixture was slowly warmed to room temperature and stirred for 24 h. After cooling the reaction mixture to 0 °C, 1 L of 10 vol% aq. acetic acid was added and stirred for 30 min. The organic layer was separated using water and diethyl ether and dried over MgSO4 to obtain 44.9 g (141 mmol, 31.3% yield) of 2-(6-tert-butoxyhexyl)-5-(2,4-dimethylpentan-3-ylidene)-cyclopenta-1,3-diene.

[0374]

[0375] Then, under Ar, 5.01 g (18 mmol) of 2,7-di-tert-butylfluorene and 80 mL of tetrahydrofuran were added to another dried 250 mL Schlenk flask. After cooling to -78 °C, 8.6 mL (1.2 eq., 21.5 mmol) of 2.5 M n-BuLi in hexane was added dropwise. The reaction mixture was slowly warmed to room temperature and stirred for 8 hours. After cooling to -78 °C, 5.73 g (1.0 eq., 18 mmol) of 2-(6-tert-butoxyhexyl)-5-(2,4-dimethylpentan-3-ylidene)-cyclopenta-1,3-diene synthesized above was added together with 10 mL of tetrahydrofuran. After slowly warming to room temperature and stirring for 24 hours, the organic layer was separated using water and diethyl ether and dried over MgSO4 to obtain 6.92 g (11.6 mmol, 64.4% yield) of ligand.

[0376]

[0377] 1 H NMR (500 MHz, CDCl3): 0.85 (12H, d), 1.14 (9H, s), 1.27 (18H, s), 1.31-1.60 (10H, m), 2.22 (2H, m), 2.92 (2H, m), 3.33 (2H, t), 3.76 (1H, brs), 6.11 (1H, m), 6.35 (1H, brs), 7.40 (2H, m), 7.49-7.62 (2H, m), 7.78-7.91 (2H, m).

[0378]

[0379] (2) Synthesis of metallocene compounds

[0380] ​Under Ar, 6.92 g (11.6 mmol) of the ligand synthesized above, 10 mL of methyl t-butyl ether, and 40 mL of toluene were added to a dried 250 mL Schlenk flask. After cooling to -78 °C, 10.2 mL (2.2 eq., 25.5 mmol) of a 2.5 M n-BuLi in hexane solution was added dropwise. The reaction mixture was slowly warmed to room temperature and stirred for 8 hours. After cooling to -78 °C, 24.38 g (1.0 eq., 11.6 mmol) of ZrCl4(THF) and 10 mL of methyl t-butyl ether were added. After slowly warming to room temperature and stirring for 24 hours, the reaction mixture was dried under reduced pressure at room temperature to remove methyl t-butyl ether. The resulting toluene suspension was filtered under Ar to remove LiCl, and the filtrate was dried under reduced pressure at 50°C and n-hexane was added. The resulting suspension was filtered under Ar to obtain 4.12 g (5.44 mmol, 46.9% yield) of the second metallocene compound having the above-described structure in solid form.

[0381]

[0382] 1 H NMR (500 MHz, C6D6): 0.90 (12H, d), 1.12 (9H, s), 1.15-1.38 (24H, m), 1.44-1.55 (6H, m), 3.21 (2H, t), 5.30-6.15 (3H, m), 7.44 (2H, dd), 7.65 (2H, d), 7.91 (2H, d).

[0383]

[0384] <Manufacture of supported catalysts>

[0385] Catalyst Preparation Example 1: Preparation of Hybrid Supported Metallocene Catalyst 1

[0386] Silica (SP 952, manufactured by Grace Davision) was dehydrated and dried under vacuum at 200°C for 12 hours.

[0387]

[0388] 800 g of dried silica was placed in a 20 L sus reactor, and 6 kg of methylaluminoxane (MAO) solution (10 wt% in toluene) in toluene solution was added, and the mixture was slowly reacted with stirring at 70 ° C. for 1 hour. After the reaction was completed, the mixture was washed several times with a sufficient amount of toluene until the unreacted aluminum compound was completely removed. A solution prepared by dissolving 30.1 g of the first metallocene compound of Synthesis Example 1 and 3.0 g of the second metallocene compound of Synthesis Example 2 in toluene was sequentially added to the reactor, and the mixture was reacted with stirring at 40 ° C. for 4 hours. At this time, the ratio of (the number of moles of the first metallocene compound of Synthesis Example 1) / (the number of moles of the second metallocene compound of Synthesis Example 2) became 12. Then, after completing the reaction and washing with a sufficient amount of toluene, the mixture was vacuum-dried to obtain a hybrid supported metallocene catalyst 1 as a solid powder.

[0389]

[0390] <Manufacture of polyethylene composition>

[0391] Example 1: Preparation of polyethylene composition A

[0392] Polyethylene composition A was slurry polymerized through a bimodal polymerization process using two 100 L continuous stirred tank reactors (CSTR) in the presence of the hybrid supported metallocene catalyst 1 prepared in the above catalyst preparation example 1.

[0393]

[0394] Specifically, in the first reactor, the first polymerization reaction was performed by controlling the hydrogen and comonomer input under the conditions described in Table 1 below, and the first polyethylene was manufactured. At this time, 75 mL / hr of triethylaluminum (TEAL) at a concentration of 0.3 mM was used as a cocatalyst. Here, the first polymerization reaction was performed under the conditions of a temperature of 80°C and a pressure of 6 to 8 bar. After the first polyethylene polymerized in the first reactor was transferred to a second reactor connected in series, the second polymerization reaction was performed by controlling the comonomer input without hydrogen input under the conditions described in Table 1 below. Here, the second polymerization reaction was performed under the conditions of a temperature of 75°C and a pressure of 3 to 4 bar.

[0395]

[0396] Based on the total weight of the polymerization product obtained as a result of the secondary polymerization reaction, 200 ppm of Irganox 1010 from BASF as a primary antioxidant, 400 ppm of Irgafos 168 from BASF as a secondary antioxidant, and 500 ppm of calcium stearate (Ca-St) or DHT4A as a neutralizer were added and mixed, and then extruded at an extrusion temperature of 190°C using a twin screw extruder (TEK 30 MHS, manufactured by SMPLATECH CO., diameter 32 pi, L / D=40) to produce a polyethylene composition A in the form of pellets.

[0397]

[0398] Examples 2 to 6: Preparation of polyethylene compositions B to F

[0399] Polyethylene compositions B to F were each manufactured in the same manner as in Example 1, except that slurry polymerization was performed through a bimodal polymerization process in the same manner as in Example 1, and the hydrogen and comonomer input amounts were adjusted differently under the conditions described in Table 1 below.

[0400]

[0401] Comparative Examples 1 to 10 Preparation of polyethylene compositions G to P

[0402] Polyethylene compositions G to N were each manufactured in the same manner as in Example 1, except that slurry polymerization was performed through a bimodal polymerization process in the same manner as in Example 1, and the input amounts of ethylene monomer, hydrogen gas, and comonomers (1-butene, 1-hexene) were adjusted differently under the conditions described in Table 1 below.

[0403]

[0404] In particular, the polyethylene composition O of Comparative Example 9 was manufactured by performing the slurry polymerization process of the first reactor without using the second reactor, and the polyethylene composition P of Comparative Example 10 was manufactured by performing the slurry polymerization process using the second reactor but by injecting hydrogen gas.

[0405]

[0406] Polyethylene composition First reactor Second reactor Ethylene [ml / min] 1-Butene [ml / min] 1-Hexene [ml / min] Hydrogen [g / hr] Pressure [bar] Ethylene [ml / min] 1-Butene [ml / min] 1-Hexene [ml / min] Hydrogen [g / hr] Pressure [bar] Example 1A 500 10 None 107 400 2 None None 3.5 Example 2B 500 12 None 107.1 400 2 None None 3.5 Example 3C 500 105 87.1 400 11 None 3.5 Example 4D 500 None 1066.8 400 None 2 None 3.5 Example 5E 500 None 826.5 400 None 4 None 3.6 Example 6F500None 816.4400None 2None 3.5Comparative Example 1G5004None 106.84002None None 3.5Comparative Example 2H5005None 46.44002None None 3.5Comparative Example 3I5006None 66.74002None None 3.5Comparative Example 4J500101086.740022None 3.6Comparative Example 5K5006846.540011None 3.5Comparative Example 6L500None 546.4400None 2None 3.5Comparative Example 7M50015None 66.94005None None 3.6Comparative Example 8N50010546.840032None 3.6Comparative Example 9O70013None 127.5NoneNoneNoneNoneNoneComparison Example 10P50015None 107.14001None 23.7

[0407]

[0408] <Test Example 1: Primary Property Evaluation of Polyethylene Composition>

[0409] The primary property evaluation of the polyethylene compositions manufactured in the examples and comparative examples was performed by the method described below and is shown in Table 2.

[0410]

[0411] (1) Melting index

[0412] Melt index (MI) at 190 ℃ under a load of 2.16 kg according to ASTM D 1238 (Condition E, 190 ℃, 2.16 kg) of the American Society for Testing and Materials. 2.16 ) was measured (measuring equipment: Gottfert MI-4), and the weight (g) of the polyethylene composition melted for 10 minutes was expressed.

[0413]

[0414] (2) Density

[0415] According to ISO 1183-2, density (g / cm) at 23 ℃ 3 ) was measured.

[0416]

[0417] (3) Number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn)

[0418] For the polyethylene compositions manufactured in the examples and comparative examples, gel permeation chromatography (GPC, manufactured by Water) was used to measure the weight average molecular weight (Mw, g / mol) and number average molecular weight (Mn, g / mol) according to the American Society for Testing and Materials standard ASTM D 6474, and the molecular weight distribution (Mw / Mn, PDI, polydispersity index) was calculated by dividing the weight average molecular weight by the number average molecular weight.

[0419]

[0420] Specifically, a Waters PL-GPC220 gel permeation chromatography (GPC) device and a Polymer Laboratories PLgel MIX-B 300 mm column were 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 the polyethylene composition manufactured in the above examples and comparative examples was pretreated by dissolving in 1,2,4-trichlorobenzene containing 0.0125% BHT at 160°C for 3 hours using a GPC analysis device (PL-GP220), preparing a concentration of 32 mg / 10 mL, and then supplying it in an amount of 200 μL. The values ​​of Mw and Mn were derived using a calibration curve formed using a polystyrene standard sample. The weight average molecular weights of the polystyrene standard specimens were 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, which were 9 types.

[0421]

[0422] (4) SCB content

[0423] According to the FT-IR analysis method, the SCB content of the polyethylene compositions of the examples and comparative examples was measured as the number of short branch chains having 2 to 7 carbon atoms per 1000 carbon atoms ( / 1000C), and the specific measurement conditions are as follows.

[0424]

[0425] <FT-IR 측정 기기 및 측정 조건>

[0426] Measuring instrument: PerkinElmer Spectrum 100

[0427] Measurement temperature: 160℃

[0428] Wavenumber: 2700 cm -1 3000 cm inland -1

[0429] Number of scans: 8

[0430] Resolution: 8 cm -1

[0431] Detector: DTGS

[0432]

[0433] (5) High crystal content and low crystal content

[0434] For the polyethylene compositions of the examples and comparative examples, the content of crystal fractions eluted at 90°C or higher, i.e., high crystal content, and the content of crystal fractions eluted at 50°C or higher but lower than 80°C, i.e., low crystal content, were measured by crystallization elution fractionation (CEF) analysis.

[0435]

[0436] Specifically, the crystal fraction content at different temperatures was measured by crystallization elution fractionation (CEF) analysis using an Agilent Technologies 7890A instrument from PolymerChar. First, the sample was dissolved in 20 mL of 1,2,4-trichlorobenzene at a concentration of 1.5 mg / mL, and then incubated for 30 o 150 in C o 40 to C o After melting by increasing the temperature at a rate of C / min, 35 o 0.5 to C o Recrystallize by lowering the temperature at a rate of C / min, and then again at 140 o 1 to C o A crystallization elution fractionation (CEF) graph was obtained through a process of eluting while increasing the temperature at a rate of C / min.

[0437]

[0438] The crystallization elution fractionation (CEF) graph obtained in this way shows the relative ratio of the peak area of ​​the crystal fraction eluted according to the temperature (℃), and the x-axis is the elution temperature (temperature, o C) and the y-axis is a CEF curve graph with dW / dt. In this CEF curve graph, the total peak area is 100% and the temperature is 90 o The ratio of the peak area in the region above C is the high crystal content (CEF) ≥90℃ ) and the ratio of the peak area of ​​the crystal fraction eluted at 50 ℃ or higher and less than 80 ℃ is expressed as the low crystal content (CEF). <80℃and≥50℃ ) was expressed as .

[0439]

[0440] Polyethylene Composition MI [2.16 kg load, g / 10 min] Density [g / cm 3 ]Mw[g / mol]Mn[g / mol]PDI(Mw / Mn)SCB[ / 1000C]High crystal content[90 o C or more, %] low crystal content [50 o C or higher~80 oLess than C, %] Example 1A1.590.9488106700950011.2376215.9 Example 2B1.590.94711062001050010.118.257.218.4 Example 3C1.320.94671220001199510.171053.823.2 Example 4D1.170.94951087001040010.456.961.816.3 Example 5E0.80.962140500151109.306.181.69.4 Example 6F1.240.95120200670017.944.656.316.6Comparative Example 1G1.450.9527107000970011.033.271.24.5Comparative Example 2H1.090.95391280001220010.494.272.25.1Comparative Example 3I0.640.941122000289804.215.773.46.2Comparative Example 4J1.570.94115000900012.782157.331Comparative Example 5K1.130.931106000310003.4214.148.228.1Comparative Example 6L0.90.952137000970014.122.474.63.7Comparative Example 7M10.920102600390002.6311.58.558.1Comparative Example 8N0.90.925119600269954.4311.430.420.2Comparative Example 9O1.90.952101300206304.917.283.24.2Comparative Example 10P2.00.94099900113508.8011.047.631.0

[0441]

[0442] <Test Example 2: Secondary Property Evaluation of Polyethylene Composition>

[0443] The solid rheological properties of the polyethylene compositions manufactured in the examples and comparative examples were evaluated in a secondary physical property evaluation manner using the method described below, and are shown in Table 3.

[0444]

[0445] - Production of samples for evaluating solid rheological properties

[0446] The polyethylene compositions manufactured in the examples and comparative examples were pressed at 190°C using a hot press to manufacture sheets having a thickness of 0.5 mm.

[0447]

[0448] - Evaluation of solid rheological properties

[0449] Using TA instruments' Q800 DMA (Dynamic Mecahnical Analysis), the modulus according to temperature change was measured while oscillating at a heating rate of 5 ℃ / min, strain 0.1%, and frequency 1 Hz from -90 ℃ to 140 ℃ to obtain a dynamic viscoelasticity curve, and then the loss modulus G" of alpha relaxation that appears in the range of 30 ℃ to 100 ℃ was obtained. a (loss modulus @ alpha relaxation) and loss modulus G" of beta relaxation appearing in the range of 50 ℃ to 20 ℃ b (loss modulus @ beta relaxation) was calculated and shown in Table 3 below.

[0450]

[0451] [Correction under Rule 91 04.09.2025] Specifically, a 0.5 mm thick sheet manufactured at 190 ℃ using a pressure press is cut into a 6 mm wide specimen, then loaded into the DMA film geometry, and the temperature is raised from -90 ℃ to 150 ℃ while oscillating in the vertical direction at a frequency of 1 Hz, a heating rate of 5 ℃ / min, and a strain of 0.1% (strain within the linear region), and the modulus is measured. G' (or E'), G" (or E") are automatically measured in the DMA, and the calculation method is as shown in Fig. 1.

[0452] [Correction pursuant to Rule 91 04.09.2025][Deleted]

[0453]

[0454] Polyethylene composition G" b @ beta relaxation temp[MPa]G" a @ alpha relaxation temp[MPa]G" a / G" b Example 1A1311641.25 Example 2B1141431.25 Example 3C1231411.15 Example 4D1221561.28 Example 5E1251801.44 Example 6F1101691.54 Comparative Example 1G1081911.77 Comparative Example 2H1151951.70 Comparative Example 3I821311.60 Comparative Example 4J1261030.82 Comparative Example 5K112790.71 Comparative Example 6L1101931.75 Comparative Example 7M93530.57 Comparative Example 8N100720.72 Comparative Example 9O Unmeasurable (broken) Unmeasurable (broken) Unmeasurable (broken) Comparative example 10P130920.71

[0455]

[0456] <Test Example 3: Manufacturing and Property Evaluation of Biaxially Stretched Film>

[0457] Biaxially oriented films were manufactured using the polyethylene compositions manufactured in the examples and comparative examples by the following method, and the respective physical properties were measured and shown in Table 4.

[0458]

[0459] Manufacturing of biaxially oriented films

[0460] - Manufacture of polyethylene composition sheet with a thickness of 0.8 mm using Bruckner's lab extruder line (L / D ratio: 42, Screw diameter: 25 mm, Melt / T-Die temperature: 220 ℃)

[0461] - Biaxial stretching is performed on a polyethylene composition sheet measuring 90 mm x 90 mm in length and width using KARO 5.0 equipment.

[0462] - Sequential stretching (MD→TD) was performed after preheating for 80 seconds under the following conditions (Examples 1 to 6 and Comparative Examples 1 to 10: preheating and stretching at 124°C, stretching film thickness of about 20 μm to about 30 μm)

[0463]

[0464] Biaxially stretched film property evaluation

[0465] - Haze (%): Measured according to ASTM 1003 standard

[0466] - Tensile modulus (MPa): Measured in MD / TD directions according to ASTM D 882 standard

[0467] - Smoothness: For a stretched film measuring 210 mm in width and 297 mm in height, the standard deviation values ​​for 20 thickness measurements taken at 20 non-overlapping film points were calculated and presented as smoothness values ​​in Table 4 below. At this time, the thickness of the film was measured using a Mitutoyo 547-401A thickness measuring device (stretched film thickness: approximately 25 μm).

[0468]

[0469] Specifically, the smoothness of the stretched film was calculated by calculating the thickness sample average and sample standard deviation, then converting the value into a % by multiplying the thickness sample standard deviation (um) / thickness sample average X 100, and calculating the sample average and sample standard deviation as follows.

[0470]

[0471]

[0472] Maximum Elongation Ratio (MDXTD) Haze [%] Tensile Modulus [Mpa] Smoothness [%] MDTD Example 15X84.1125016101.99 Example 25X83.7118016203.54 Example 35X83.5113015900.50 Example 45X83.9127016001.00 Example 55X84.9160021002.94 Example 65X88.4123716384.76 Comparative Example 14X67.1155019107.33 Comparative Example 24X66.4165019808.88 Comparative Example 35X87.91017117410.76Comparative example 45X85.26576898.96Comparative example 55X81.66459448.17Comparative example 64X65.41617199513.77Comparative example 75X82.45206896.03Comparative example 85X82.75427105.45Comparative example 9Not measurable (broken)Not measurable (broken)Not measurable (broken)Not measurable (broken)Comparative example 105X84.57458516.97

[0473]

[0474] According to the results in Table 4 above, the polyethylene compositions of Examples 1 to 6, which have a high melting index, density, and high crystallinity while optimizing the SCB content to form two types of loss moduli in a balanced manner, can effectively produce a stretched film having high shrinkage resistance, uniform thickness deviation, and excellent printability and transparency compared to the comparative examples, with excellent stretching stability and film processability without breakage even when applying a maximum draw ratio of 5 X 8 (MD X TD).

[0475]

[0476] On the other hand, it can be confirmed that the polyethylene compositions of Comparative Examples 1 to 10 have not been optimized in terms of melt index, density, high crystal content, and SCB content, and in particular, the high crystal content is lowered and the low crystal content is increased, or the density is low or the SCB content is low, so that when the film is stretched, it is not stretched up to 5X8 and a break occurs, and the stretch ratio has to be applied as 4X6, or the thickness deviation after stretching increases, or the tensile modulus of the film is lowered.

[0477]

[0478] Accordingly, the polyethylene composition of the present invention can effectively produce a stretched film having excellent stretching stability and mechanical properties, and at the same time, when produced as a stretched film, it exhibits low viscosity in the processing area, so that it is very advantageous for commercializing products such as single-material packaging films having high shrinkage resistance, printability, and transparency with excellent processability and productivity.

Claims

1. Containing at least one ethylene-alphaolefin copolymer, Melting index (MI) 2.16 , 190 ℃, 2.16 kg) is 0.7 g / 10 min or more and 2.0 g / 10 min or less, Density is 0.940 g / cm 3 Above 0.965 g / cm 3 Below, The SCB content is 4.5 ( / 1000C) or more and 13 ( / 1000C) or less, When the relative ratio of the crystal fraction peak area eluted according to temperature (℃) was measured using the crystallization elution fractionation (CEF) analysis method, the ratio of the crystal fraction peak area eluted above 90 ℃ to the total peak area (CEF) ≥90℃ ) is 40% or more and 85% or less, and the ratio of the peak area of ​​the crystal fraction eluting at 50 ℃ or more and less than 80 ℃ (CEF) <80℃and≥50℃ ) is 8% or more and 30% or less, Polyethylene composition.

2. In paragraph 1, According to the above crystallization elution fractionation (CEF) analysis method, the ratio of the peak area of ​​the crystal fraction eluting at 90°C or higher (CEF ≥90℃ ) and the ratio of the peak area of ​​the crystal fraction eluting at 50 ℃ or higher and less than 80 ℃ (CEF <80℃and≥50℃ ) and the ratio (CEF) ≥90℃ / CEF <80℃and≥50℃ ) is 2 times or more and 11 times or less, Polyethylene composition.

3. In paragraph 1, The number average molecular weight (Mn) is 5000 g / mol or more and 20000 g / mol or less, The weight average molecular weight (Mw) is 80,000 g / mol or more and 160,000 g / mol or less, Molecular weight distribution (Mw / Mn) is 8 or more and 20 or less, Polyethylene composition.

4. In paragraph 1, In the dynamic viscoelasticity curve measured using DMA (Dynamic Mecahnical Analysis), the loss modulus G" of alpha relaxation that appears in the range of 30 ℃ to 100 ℃ a (loss modulus @ alpha relaxation) is 95 MPa or more and 180 MPa or less, Polyethylene composition.

5. In paragraph 1, In the dynamic viscoelasticity curve measured using DMA (Dynamic Mecahnical Analysis), the loss modulus G" of beta relaxation that appears in the range of -50 ℃ to 20 ℃ b (loss modulus @ beta relaxation) is greater than or equal to 95 MPa and greater than or equal to 180 MPa, Polyethylene composition.

6. In paragraph 1, In the dynamic viscoelasticity curve measured using DMA (Dynamic Mecahnical Analysis), the loss modulus G" of alpha relaxation that appears in the range of 30 ℃ to 100 ℃ a (loss modulus @ alpha relaxation) and loss modulus G" of beta relaxation appearing in the range of -50 ℃ to 20 ℃ b The ratio (G) of (loss modulus @ beta relaxation) a / G" b ) is 0.95 or more and 1.65 or less, Polyethylene composition.

7. In paragraph 1, The above ethylene-alphaolefin copolymer is at least one selected from the group consisting of ethylene / 1-hexene copolymer and ethylene / 1-butene copolymer. Polyethylene composition.

8. A stretched film comprising the polyethylene composition of paragraph 1.

9. In paragraph 8. The elongation ratio in the MD direction or TD direction is 5 or more, or The elongation ratio in the MD direction is 5 or more, and the elongation ratio in the TD direction is 8 or more, Stretch film.

10. In paragraph 8. The MD tensile modulus and TD tensile modulus measured according to ASTM D 882 are each 1000 MPa or more. Stretch film.

11. In paragraph 8. A haze of 9% or less as measured according to ASTM 1003; Stretch film.

12. In paragraph 8. The smoothness of the stretched film is 7% or less, calculated by calculating the standard deviation of 20 or more thickness measurements taken at 20 or more non-overlapping points on the stretched film. Stretch film.

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