Polyethylene composition and biaxially-oriented film comprising same

Abstract

The present invention relates to a polyethylene composition and a biaxially-oriented film comprising same, the polyethylene composition having excellent film processability and productivity as well as excellent mechanical properties and stretching stability, thereby enabling a biaxially-oriented film with high shrinkage resistance, printability and transparency to be manufactured.

Description

Polyethylene composition and biaxially oriented film comprising the same

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

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0013787, filed January 30, 2024, and Korean Patent Application No. 10-2025-0011592, filed January 24, 2025, the entire contents of which are incorporated herein by reference.

[0003]

[0004] The present invention provides a polyethylene composition capable of producing a biaxially oriented film having high shrinkage resistance, printability and transparency, with excellent film processability and productivity, along with excellent mechanical properties and stretching stability, and a biaxially oriented 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, shrink film is primarily used to preserve the shape of the product while protecting it from touch during display.

[0007]

[0008] In particular, among these shrink films, biaxially oriented polymer films are widely used for packaging purposes due to their excellent mechanical properties, productivity, and printability. Commercialized packaging films generally use biaxially oriented polypropylene (BOPP), biaxially oriented polyethylene terephthalate (BOPET), or biaxially oriented polyamide (BOPA) for the print layer, and LLDPE film for the sealing layer. These composite material forms are not 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 phenomena such as fracture and melting occur during stretching, making biaxial stretching difficult to apply. To ensure stretching stability, products in the form of 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 polyethylene resins for biaxially oriented films. Furthermore, high processing viscosity can negatively affect film productivity, and high processing pressure can cause micro-patterning, which can negatively affect the film's appearance.

[0011]

[0012] Accordingly, a method is required to provide a polyethylene composition for biaxial stretching, which selects a polyethylene resin having a molecular structure advantageous for stretching, selects an appropriate composition, and thereby exhibits excellent stretching stability and excellent mechanical properties during biaxial stretching, while also having low processing viscosity and thus excellent film processability and productivity.

[0013]

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

[0015]

[0016] In one embodiment of the present invention

[0017] The Bimodal Triangula Area (BMTA) derived from GPC analysis is 0.05 or greater,

[0018] The complex viscosity (η*(ω500), complex viscosity) measured at a frequency (ω) of 500 rad / s is 650 Paㆍs or less,

[0019] When cross fractionation chromatography (CFC) is analyzed, the molecular weight / low-scb molecular content (C) is 150,000 g / mol or more and the number of short-chain branches (scb) is 10 or less / 1000C. high Mw, low SCB ) is 15% by weight or more,

[0020] A polyethylene composition is provided.

[0021]

[0022] In addition, in another embodiment of the present invention, a biaxially oriented film comprising the polyethylene composition of the above embodiment is provided.

[0023]

[0024] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention.

[0025]

[0026] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0027]

[0028] 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.

[0029]

[0030] 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.

[0031]

[0032] Additionally, in the present invention, (co)polymer means both a homopolymer and a copolymer.

[0033]

[0034] 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.

[0035]

[0036] 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.

[0037]

[0038] Hereinafter, the present invention will be described in detail.

[0039]

[0040] (polyethylene composition)

[0041] According to one aspect of the present invention, there is provided a polymer composition comprising at least one ethylene-alphaolefin copolymer, wherein the Bimodal Triangula Area (BMTA) derived from GPC analysis is 0.05 or more, the complex viscosity (η*(ω500)) measured at a frequency (ω) of 500 rad / s is 650 Paㆍs or less, and the weight average molecular weight (Mw) is 150000 g / mol or more and the number of short-chain branches (scb) is 10 / 1000C or less when analyzed by cross fractionation chromatography (CFC), and the high molecular weight / low scb molecular content (C) high Mw, low SCB ) is provided, wherein the polyethylene composition comprises 15 wt% or more.

[0042]

[0043] 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.

[0044]

[0045] 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.

[0046]

[0047] In the present invention, the polyethylene composition is blended with a first ethylene-alpha olefin copolymer having excellent flowability and stretchability, which can be imparted by applying a specific metallocene catalyst described below, and a second ethylene-alpha olefin copolymer having excellent mechanical properties, thereby controlling the balance between mechanical properties and stretchability, thereby maintaining mechanical properties, productivity, and stretching stability equivalent to or superior to those of the prior art, and having characteristics suitable for manufacturing a biaxially oriented film having high shrinkage resistance, printability, and transparency.

[0048]

[0049] Preferably, the polyethylene composition may comprise two or more ethylene-alphaolefin copolymers. More preferably, the polyethylene composition may comprise two ethylene-alphaolefin copolymers.

[0050]

[0051] The polyethylene composition may have a Bimodal Triangular Area (BMTA) of 0.05 or more derived from GPC analysis. A larger Bimodal Triangular Area (BMTA) value indicates a higher degree of binary separation between low-molecular fractions and high-molecular fractions in the GPC curve, indicating a larger low-molecular region. Therefore, the value may preferably be 0.06 or more, or 0.07 or more, or 0.08 or more, or 0.09 or more. However, an excessively large Bimodal Triangular Area (BMTA) value makes it difficult to form a crystalline framework during the production of a biaxially oriented film, resulting in poor mechanical properties. Therefore, the value may preferably be 0.3 or less, or 0.25 or less, or 0.2 or less, 0.15 or less, or 0.12 or less. More preferably, the polyethylene composition may have a Bimodal Triangular Area (BMTA) of 0.09 or more to 0.11 or less derived from GPC analysis.

[0052]

[0053] In the present invention, the Bimodal Triangula Area (BMTA) is measured by using gel permeation chromatography (GPC, gel permeation chromatography, manufactured by Water) in accordance with the American Society for Testing and Materials ASTM D 6474 standard, and then measuring the area of ​​the BMTA (Bimodality triangular area) region in a logarithmic graph for the weight average molecular weight (Mw) of polyethylene thus measured, i.e., a GPC curve graph in which the x-axis is log MW and the y-axis is dw / dlogMw, so that the ratio (wt%) to the total integral of the GPC curve graph can be calculated. For example, the method for measuring the Bimodal Triangula Area (BMTA) is as described in Test Example 2 described below.

[0054]

[0055] Specifically, the BMTA (Bimodality triangular area) region is the peak with the widest area among the low molecular weight fractions with a log Mw of less than 5.0 of the peak maximum intensity in the GPC curve graph. low ) and the maximum intensity coordinates (X-axis: a, Y-axis: d) of the peak, and the peak with the largest area among the polymer fractions with a log Mw of 5.0 or more of the peak maximum intensity (Peak high ) defines the maximum intensity coordinate (X-axis: b, Y-axis: e), and the peak (Peak low ) and the low molecular weight fraction containing the peak (Peak high ) is defined as the coordinates of the intersection point (X-axis: c, Y-axis: f) where the high molecular weight fractions intersect, and corresponds to the triangular area connecting these three coordinates. That is, the low molecular weight fraction peak (Peak low ) and the maximum intensity coordinates (X-axis: a, Y-axis: d) of the polymer fraction peak (Peak high ) of the maximum intensity coordinates (X-axis: b, Y-axis: e) and the area of ​​the BMTA (Bimodality triangular area) region connecting the intersection coordinates (X-axis: c, Y-axis: f) can be measured by the method shown in Equation 1 below.

[0056] [Formula 1]

[0057]

[0058] In equation 1

[0059] ae represents the product of the maximum intensity X-axis coordinate value of the low-molecular fraction and the maximum intensity Y-axis coordinate value of the high-molecular fraction,

[0060] bf is the product of the maximum intensity X-axis coordinate value of the polymer fraction and the Y-axis coordinate value of the intersection point,

[0061] cd represents the product of the X-axis coordinate value of the intersection point and the Y-axis coordinate value of the maximum intensity of the low-molecular fraction,

[0062] db represents the product of the maximum intensity Y-axis coordinate value of the low-molecular fraction and the maximum intensity X-axis coordinate value of the high-molecular fraction.

[0063] ec represents the product of the maximum intensity Y-axis coordinate value of the polymer fraction and the X-axis coordinate value of the intersection point,

[0064] fa represents the product of the Y-axis coordinate value of the intersection point and the X-axis coordinate value of the maximum intensity of the low-molecular fraction.

[0065]

[0066] When the BMTA ratio (wt%) is high, the degree of binary separation of the GPC curve is high, which means that there is a large amount of low-molecular weight region, and thus, it can be seen that the processability is excellent.

[0067]

[0068] In addition, the polyethylene composition may have a complex viscosity (η*(ω500)) measured at a frequency (ω) of 500 rad / s of 650 Paㆍs or less. The smaller the complex viscosity value, the lower the viscosity in the processing region when manufacturing a biaxially oriented film, resulting in excellent processability and productivity. Therefore, it may be preferably 645 Paㆍs or less, or 640 Paㆍs or less, or 635 Paㆍs or less, or 630 Paㆍs or less, or 625 Paㆍs or less. However, if the complex viscosity value is excessively small, it is difficult to form a crystalline framework when manufacturing a biaxially oriented film, resulting in poor mechanical properties. Therefore, it may be preferably 400 Paㆍs or more, or 430 Paㆍs or more, or 450 Paㆍs or more, or 480 Paㆍs or more, or 500 Paㆍs or more, or 550 Paㆍs or more, or 560 Paㆍs or more. More preferably, the polyethylene composition may have a complex viscosity (η*(ω500), complex viscosity) measured at a frequency (ω) of 500 rad / s of 560 Paㆍs or more and 625 Paㆍs or less.

[0069]

[0070] In the present invention, the complex viscosity (Pa·s, 500 rad / s) is measured at 190 using a rotational rheometer (ARES Rheometer). o It can be measured under conditions of frequency (ω) from 0.05 rad / s to 500 rad / s in C. For example, the method for measuring this complex viscosity (Pa·s, 500 rad / s) is as described in Test Example 2 described below.

[0071]

[0072] Specifically, the complex viscosity of polyethylene is measured as the complex viscosity η*(ω0.05) and η*(ω500) depending on the frequency using a rotational rheometer ARES (Advanced Rheometric Expansion System, ARES G2) of TA Instruments (New Castle, Delaware, USA). A certain amount of polyethylene is placed in the ARES-G2 equipment and a 25 mm parallel plate and ring, and the sample is placed in the 190 o At C, press with the fixtures above and below to use parallel plates with a diameter of 25.0 mm so that the gap becomes 2.0 mm. Measurements are made in dynamic strain frequency sweep mode, with a strain of 5% and a frequency (angular frequency) from 0.05 rad / s to 500 rad / s, measuring 10 points per decade for a total of 41 points, and among these, the complex viscosity measured at a frequency (ω) of 500 rad / s can be confirmed.

[0073]

[0074] In addition, the polyethylene composition has a high molecular weight / low scb molecular content (C) of 150,000 g / mol or more and 10 short-chain branches / 1000 C or less when analyzed by cross fractionation chromatography (CFC). high Mw, low SCB ) may be greater than 15 wt%. This high molecular weight / low scb molecular content (C high Mw, low SCB ) value increases, it means that the proportion of molecules that can form a crystalline elongation framework increases, so it can be preferably 15.5 wt% or more, or 16 wt% or more, 16.5 wt% or more, or 17 wt% or more, or 17.5 wt% or more, or 18 wt% or more. However, the high molecular weight / low scb molecule content (C high Mw, low SCB ) value is excessively large, the formation of a crystalline framework is difficult during the production of a biaxially stretched film, and the mechanical properties deteriorate, so it may preferably be 35 wt% or less, or 30 wt% or less, or 25 wt% or less. More preferably, the polyethylene composition has the above-described high molecular weight / low scb molecular content (C high Mw, low SCB ) may be 18 wt% or more and 25 wt% or less.

[0075]

[0076] In the present invention, cross fractionation chromatography (CFC) analysis can be specifically performed by the following method. For example, such cross fractionation chromatography (CFC) analysis is as described in Test Example 2 described below.

[0077]

[0078] Cross-fractionation chromatography (CFC) measurement conditions (including TREF and GPC-IR analysis)

[0079] - Analysis equipment: Polymer Char CFC (Detector: Integrated Detector IR5 MCT)

[0080]

[0081] - Sample preparation and loading: Place 32 mg of polyethylene composition in a 10 mL vial and place in an autosampler, add 8 mL of 1,2,4-trichlorobenzene (TCB), dissolve at 160°C for 90 minutes, extract after nitrogen purge, and load onto a temperature rising elution temperature column (TREF column: temperature rising elution temperature column).

[0082]

[0083] - Crystallization: After adjusting the sample previously loaded onto the TREF column to 100 ℃, cool it from 100 ℃ to 35 ℃ at a rate of 0.5 ℃ / min.

[0084]

[0085] - Temperature-rising elution temperature (TREF) analysis: The temperature of the previously crystallized sample was increased from 35°C to 125°C in 3°C intervals and fixed, and the fractions eluted at each temperature for 25 minutes were analyzed. Specifically, extraction and analysis were performed at 35°C for 25 minutes, then the temperature was increased in 3°C intervals for extraction and analysis, and finally, extraction and analysis were performed at 125°C for 25 minutes.

[0086]

[0087] - GPC-IR analysis: In the TREF analysis above, the fractions eluted at each temperature are transferred to the GPC column of the GPC (PL-GPC220) device, the molecular weight of the eluted molecules is measured, and the number of short-chain branches (scb) of the eluted molecules at each temperature is measured using the PerkinElmer Spectrum 100 FT-IR connected to the GPC (PL-GPC220) (number of branches with 2 to 7 carbon atoms per 1,000 carbon atoms, unit: branches / 1,000C).

[0088]

[0089] - High molecular weight molecular scb index (C high Mw, low SCB Measurement): The fraction (wt%) of molecules with a molecular weight of 150,000 g / mol or more and having a "scb count of 10 or less on 1000 carbon atoms" is measured from the results confirmed through CFC analysis. A higher value indicates a greater amount of high-molecular-weight / low-scb-content molecules.

[0090]

[0091] Here, the high molecular weight molecular scb index can be derived using the following method as in Equation 2.

[0092] [Formula 2]

[0093]

[0094] In the above equation 2,

[0095] C Mw,i is the concentration of each fraction corresponding to a specific molecular weight (Mw) and a specific scb(i) number at each temperature through the previous CFC analysis.

[0096]

[0097] Meanwhile, the polyethylene composition has a density of 0.925 g / cm 3 Ideally 0.950 g / cm 3 It may be less than or equal to 0.927 g / cm. Preferably, the density is 0.927 g / cm. 3 Above, 0.929 g / cm 3Above, 0.931 g / cm 3 Above, 0.934 g / cm 3 or 0.935 g / cm 3 Ideally, 0.949 g / cm 3 Below, 0.948 g / cm 3 Below, 0.947 g / cm 3 Below, 0.946 g / cm 3 or less, or 0.945 g / cm 3 It may be less than or equal to 0.935 g / cm. More preferably, the density of the polyethylene composition is 0.935 g / cm. 3 Ideally 0.945 g / cm 3 It could be as follows:

[0098] In the present invention, the density (g / cm 3 ) can be measured using a density gradient pipe according to the American Society for Testing and Materials ASTM D 1505 standard. For example, this density (g / cm 3 ) is as described in Test Examples 1 and 2 described below.

[0099]

[0100] In addition, the polyethylene composition has a melt index (MI) 2.16 , 190 ℃, 2.16 kg load) may be 0.1 g / 10 min to 2.0 g / 10 min. Preferably, the melting index (MI 2.16, 190 ℃, 2.16 kg load) may be 0.2 g / 10 min or more, 0.3 g / 10 min or more, 0.5 g / 10 min or more, 0.8 g / 10 min or more, 0.1 g / 10 min or more, 0.15 g / 10 min or more, or 0.19 g / 10 min or more, and 1.5 g / 10 min or less, 1.35 g / 10 min or less, 1.2 g / 10 min or less, 1.1 g / 10 min or less, 1.0 g / 10 min or less, 0.8 g / 10 min or less, 0.7 g / 10 min or less, or 0.5 g / 10 min or less, 0.45 g / 10 min or less, 0.42 g / 10 min or less, 0.4 g / 10 min or less, or 0.38 g / 10 min or less. More preferably, the melting index (MI) of the polyethylene composition 2.16 , 190 ℃, 2.16 kg load) may be 0.19 g / 10 min or more and 0.38 g / 10 min or less.

[0101]

[0102] 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, this melt index (MI) 2.16 ) is as described in Test Examples 1 and 2 described below.

[0103]

[0104] In addition, the polyethylene composition has a melt flow rate (MFRR, MI) 21.6 kg / MI 2.16 kg , here MI 21.6 The value measured at 190 ℃ and 21.6 kg is MI 2.16 The melt flow rate (MFRR, MI) measured at 190 ℃ and 2.16 kg may be 60 or more. Preferably, the melt flow rate (MFRR, MI) 21.6 kg / MI 2.16 kg) may be 63 or more, or 65.0 or more, or 70.0 or more, or 72 or more, or 75 or more, or 78 or more, or 80 or more, or 85 or more, or 87 or more, or 89 or more, and 110 or less, or 105 or less, or 100 or less, or 98 or less, or 95 or less, or 92 or less. More preferably, the melt flow rate (MFRR, MI) of the polyethylene composition 21.6 kg / MI 2.16 kg ) can be 89 or more and 92 or less.

[0105]

[0106] In addition, the polyethylene composition may have a number average molecular weight (Mn) of 15,000 g / mol or more, 17,000 g / mol or more, or 19,000 g / mol or more to 500,000 g / mol or less, 300,000 g / mol or less, 100,000 g / mol or less, 50,000 g / mol or less, or 31,000 g / mol or less, and a weight average molecular weight (Mw) of 100,000 g / mol or more, or 106,000 g / mol or more to 1,000,000 g / mol or less, 500,000 g / mol or less, 300,000 g / mol or less, or 158,000 g / mol or less.

[0107]

[0108] The molecular weight distribution (Mw / Mn) of the polyethylene composition may be 5.0 or more and 11.5 or less. More preferably, the molecular weight distribution (Mw / Mn) of the polyethylene composition may be 11.4 or less, 11.3 or less, 11.2 or less, 11.0 or less, 10.8 or less, 10.7 or less, 10.6 or less, 10.5 or less, 10.2 or less, or 10.0 or less. In addition, the molecular weight distribution (Mw / Mn) may be 5.2 or more, 5.5 or more, 5.8 or more, 6.0 or more, 6.2 or more, 6.5 or more, 6.8 or more, 7.0 or more, 7.1 or more, 7.2 or more, 7.5 or more, 7.6 or more, or 7.8 or more. In particular, the molecular weight distribution (Mw / Mn) of the polyethylene composition should be 5.0 or more to strengthen the bimodal molecular structural characteristics and increase the degree of GPC peak diffusion, thereby lowering the processing viscosity. However, if the molecular weight distribution (Mw / Mn) of the polyethylene composition is too high, exceeding 11.5, it may have a negative effect on the film properties or appearance. More preferably, the molecular weight distribution (Mw / Mn) of the polyethylene composition may be 7.8 or more and 10.0 or less.

[0109]

[0110] 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 is not limited thereto and may be measured by other methods known in the art 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 Examples 1 and 2 described below.

[0111]

[0112] In addition, the polyethylene composition may have a melting point (Tm) of 127°C or more and 130°C or less, or 127.2°C or more and 129.8°C or less, or 127.5°C or more and 129.5°C or less, a crystallization temperature (Tc) of 111°C or more and 115°C or less, or 112°C or more and 114.5°C or less, or 112.5°C or more and 114°C, or 112.8°C or more and 113.7°C or less, and a crystallinity (Xc) of 55% or more and 70% or less, or 58% or more and 68% or less, or 60% or more and 67.8% or less, or 60.4% or more and 67.5% or less. More preferably, the polyethylene composition may have a melting point (Tm) of 127.6°C or more and 129.3°C or less, a crystallization temperature (Tc) of 112.8°C or more and 113.7°C or less, and a crystallinity (Xc) of 60.4% or more and 67.5%.

[0113]

[0114] In the present invention, the melting point Tm, the crystallization temperature Tc, and the crystallinity Xc can be measured using a differential scanning calorimeter (DSC, device name: DSC Q20, manufacturer: TA instrument). For example, the method for measuring the melting point Tm, the crystallization temperature Tc, and the crystallinity Xc is as described in Test Example 2 described below.

[0115]

[0116] Meanwhile, a polyethylene composition according to one embodiment of the present invention,

[0117] (a) Density is 0.930 g / cm 3 0.960 g / cm 3 and the melting index (MI) 2.16, 190 ℃, 2.16 kg load) of 0.15 g / 10 min to 2.0 g / 10 min, and molecular weight distribution (Mw / Mn) of 8.8 or more to 12.5 or less, a first ethylene-alpha olefin copolymer; and

[0118] (b) Density is 0.870 g / cm 3 0.920 g / cm 3 and the melting index (MI) 2.16 , 190 ℃, 2.16 kg load) is 3.0 g / 10 min to 10.0 g / 10 min, and the molecular weight distribution (Mw / Mn) is 2.0 or more to 4.0 or less, and may include a second ethylene-alpha olefin copolymer;

[0119] The first ethylene-alphaolefin copolymer (a) may be included in an amount of 60 wt% or more and 90 wt% or less,

[0120] The second ethylene-alpha olefin copolymer (b) may be included in an amount of 10 wt% or more and 40 wt% or less.

[0121]

[0122] Preferably, the first ethylene-alphaolefin copolymer (a) may be included in an amount of 65 wt% or more, 67 wt% or more, or 70 wt% or more, and 85 wt% or less, 83 wt% or less, or 80 wt% or less.

[0123]

[0124] Additionally, the second ethylene-alphaolefin copolymer (b) may be included in an amount of 15 wt% or more, 17 wt% or more, or 20 wt% or more, but 35 wt% or less, 33 wt% or less, or 30 wt% or less.

[0125]

[0126] Preferably, in the polyethylene composition, the first ethylene-alphaolefin copolymer (a) may be an ethylene / 1-hexene copolymer, and the second ethylene-alphaolefin copolymer (b) may be an ethylene / 1-octene copolymer.

[0127]

[0128] (First ethylene-alpha olefin copolymer (a))

[0129] In a polyethylene composition according to one embodiment of the present invention, the first ethylene-alphaolefin copolymer (a) has excellent mechanical properties and can provide characteristics suitable for manufacturing a biaxially oriented film having excellent stretchability and high mechanical properties with an appropriate balance between crystallinity and processability.

[0130]

[0131] Specifically, the first ethylene-alpha olefin copolymer (a) has a density of 0.930 g / cm 3 0.960 g / cm 3 and the melting index (MI) 2.16 , 190 ℃, 2.16 kg load) is 0.15 g / 10 min to 2.0 g / 10 min, and 8.8 or more to 12.5 or less.

[0132]

[0133] Preferably, the first ethylene-alpha olefin copolymer (a) has a density of 0.933 g / cm 3 Above, 0.935 g / cm 3 Above, 0.938 g / cm 3 or 0.941 g / cm 3 Ideally, 0.955 g / cm 3 Below, 0.950 g / cm 3 or less, or 0.948 g / cm 3 It could be as follows:

[0134]

[0135] In addition, the first ethylene-alpha olefin copolymer (a) has a melt index (MI) 2.16 , 190 o C, 2.16 kg load) may be 0.2 g / 10 min or more, 1.5 g / 10 min or less, 1.0 g / 10 min or less, or 0.6 g / 10 min or less.

[0136]

[0137] The above first ethylene-alpha olefin copolymer (a) has a molecular weight distribution (Mw / Mn) of 8.8 or more and 12.5 or less.

[0138]

[0139] In addition, the first ethylene-alpha olefin copolymer (a) may have a number average molecular weight (Mn) of 12,000 g / mol or more and 50,000 g / mol or less, and a weight average molecular weight (Mw) of 100,000 g / mol or more and 250,000 g / mol or less.

[0140]

[0141] Preferably, the number average molecular weight Mn of the first ethylene-alphaolefin copolymer (a) may be 13000 g / mol or more, 13500 g / mol or more, 14000 g / mol or more, 14500 g / mol or more, or 15000 g / mol or more, and may be 40000 g / mol or less, 35000 g / mol or less, 30000 g / mol or less, 28000 g / mol or less, 25000 g / mol or less, 23000 g / mol or less, or 20000 g / mol or less.

[0142]

[0143] In addition, the weight average molecular weight Mw of the first ethylene-alpha olefin copolymer (a) may be 105000 g / mol or more, 110000 g / mol or more, 114000 g / mol or more, 118000 g / mol or more, 120000 g / mol or more, 123000 g / mol or more, 125000 g / mol or more, 140000 g / mol or more, 145000 g / mol or more, 150000 g / mol or more, 155000 g / mol or more, 158000 g / mol or more, or 160000 g / mol or more, and 230000 g / mol or less, 210000 g / mol or less, 200000 g / mol or less, 185000 g / mol or less, 180000 g / mol or less, 175000 g / mol or less, or 168000 g / mol or less.

[0144]

[0145] In addition, the molecular weight distribution (Mw / Mn) of the first ethylene-alphaolefin copolymer (a) may be 8.8 or more and 12.5 or less. More preferably, the molecular weight distribution (Mw / Mn) of the first ethylene-alphaolefin copolymer (a) may be 8.85 or more, 8.9 or more, 9.0 or more, 9.2 or more, 9.5 or more, 9.8 or more, 10 or more, 10.2 or more, 10.5 or more, 10.8 or more, or 11 or more, and 12.4 or less, 12.3 or less, 12.1 or less, 12.0 or less, 11.8 or less, 11.5 or less, or 11.3 or less.

[0146]

[0147] The above first ethylene-alpha olefin copolymer (a) may have at least one of the above-described properties, and may have all of the above-described properties to exhibit excellent mechanical strength.

[0148]

[0149] The above first ethylene-alpha-olefin copolymer (a) may include at least one alpha-olefin selected from the group consisting of 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, together with ethylene.

[0150]

[0151] Preferably, the first ethylene-alphaolefin copolymer (a) may be an ethylene / 1-hexene copolymer.

[0152]

[0153] The above first ethylene-alpha-olefin copolymer (a) can more easily realize the above-described properties when it is the above-described copolymer. However, the type of the above-described first ethylene-alpha-olefin copolymer (a) is not limited to the above-described types, and various types known in the technical field to which the present invention pertains can be provided as long as they can exhibit the above-described properties.

[0154]

[0155] Meanwhile, the first ethylene-alpha olefin copolymer (a) having the above-described physical properties may be produced in the presence of a metallocene catalyst.

[0156]

[0157] Specifically, the first ethylene-alphaolefin copolymer (a) can be produced by copolymerizing ethylene and a comonomer while introducing hydrogen gas in the presence of a catalyst composition comprising a first metallocene compound represented by the following chemical formula 1 and a second metallocene compound represented by the following chemical formula 2 in a molar ratio of 1:1 to 1:8.

[0158] [Chemical Formula 1]

[0159] (Cp 1 R a ) m (Cp 2 R b )M 2 Z2 3-m

[0160] In the above chemical formula 1,

[0161] M 2 is a group 4 transition metal;

[0162] Cp 1 and Cp 2 are each cyclopentadienyl, and these are C 1-20 Substituted or unsubstituted with hydrocarbons;

[0163] R a and R b are identical or different from each other, and each independently represents hydrogen, C 1-20 Alkyl, C 1-20 Alkoxy, C 2-20 Alkoxyalkyl, C 6-20 Aryl, C 6-20 Aryloxy, C 2-20 Alkenyl, C 7-40 Alkylaryl of C 7-40 Arylalkyl of C 8-40 Arylalkenyl, C 2-20 alkynyl, or substituted or unsubstituted C containing one or more heteroatoms selected from the group consisting of N, O and S; 2-20 Heteroaryl, and R a and R b At least one of which is not hydrogen;

[0164] Z 2 are each independently halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 7-40 Alkylaryl, C 7-40 Arylalkyl, C 6-20 Aryl, substituted or unsubstituted C 1-20 Alkylidene, substituted or unsubstituted amino group, C 2-20 Alkylalkoxy, or C 7-40 Aryl alkoxy;

[0165] m is 1 or 0;

[0166] [Chemical Formula 2]

[0167]

[0168] In the above chemical formula 2,

[0169] M 3 is a group 4 transition metal,

[0170] T 2 is carbon, silicon or germanium,

[0171] X 3 and X 4 are the same or different from each other, and each independently represents a halogen, or C 1-20 is alkyl,

[0172] R 11 Inland R 14 are identical or different from each other, and each independently represents hydrogen, C 1-20 Alkyl of C 2-20 Alkenyl, C 6-20 Aryl of C 7-20 Alkylaryl of C 7-20 is arylalkyl, or R 11 Inland R 14 Two or more adjacent rings are connected to each other to form a substituted or unsubstituted aliphatic ring, an aromatic ring, or a heteroaromatic ring including at least one selected from the group consisting of N, O, and S,

[0173] Q 3 and Q 4 are identical or different from each other, and each is independently C 1-20 Alkyl, C 2-20 Alkenyl, C 6-30 Aryl, or C 2-20 It is an alkoxy alkyl,

[0174] R 15 Silver C 1-20 Alkyl, C 2-20 Alkenyl, or C 6-30 It's Aryl.

[0175]

[0176] Meanwhile, in this specification, unless otherwise specifically limited, the following terms may be defined as follows:

[0177] The halogen can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0178]

[0179] C 1-20 The alkyl group may be a straight-chain, branched-chain or cyclic alkyl group. Specifically, C 1-20 The alkyl group is C 1-15 straight chain alkyl group; C 1-10 straight chain alkyl group; C 1-5 straight chain alkyl group; C 3-20 Branched or cyclic alkyl group; C 3-15 Branched or cyclic alkyl group; or C 3-10 It may be a branched or cyclic alkyl group. More specifically, C 1-20 The alkyl group 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, a neo-pentyl group, or a cyclohexyl group.

[0180]

[0181] C 2-20 The alkenyl group may be a straight-chain, branched-chain, or cyclic alkenyl group. Specifically, C 2-20 The alkenyl group is C 2-20 Straight-chain alkenyl group, C 2-10 Straight-chain alkenyl group, C 2-5 Straight-chain alkenyl group, C 3-20 Branched-chain alkenyl group, C 3-15 Branched-chain alkenyl group, C 3-10 Branched-chain alkenyl group, C 5-20 Cyclic alkenyl group or C 5-10 It may be a cyclic alkenyl group. More specifically, C 2-20 The alkenyl group may be an ethenyl group, a propenyl group, a butenyl group, a pentenyl group, or a cyclohexenyl group.

[0182]

[0183] C 6-20Aryl refers to a monocyclic, bicyclic or tricyclic aromatic hydrocarbon, including aryl of a single ring or condensed ring. Specifically, C 6-20 Aryl can be a phenyl group, a biphenyl group, a naphthyl group, anthracenyl group, a phenanthrenyl group, or a fluorenyl group.

[0184]

[0185] C 7-40 Alkylaryl may refer to a substituent in which one or more hydrogens of aryl are replaced by alkyl. Specifically, C 7-40 The alkylaryl may be methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl or cyclohexylphenyl.

[0186]

[0187] C 7-40 Arylalkyl may refer to a substituent in which one or more hydrogens of alkyl are replaced by aryl. Specifically, C 7-40 Arylalkyl can be benzyl, phenylpropyl or phenylhexyl.

[0188]

[0189] C 6-20 Examples of aryloxy include, but are not limited to, phenoxy, biphenoxy, and naphthoxy.

[0190]

[0191] C above 1-20 Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, phenyloxy, and cyclohexyloxy.

[0192]

[0193] C above 2-20An alkoxyalkyl group is a functional group in which one or more hydrogen atoms of the alkyl group described above are replaced with an alkoxy group, and specifically, examples thereof include, but are not limited to, alkoxyalkyl groups such as a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an iso-propoxymethyl group, an iso-propoxyethyl group, an iso-propoxyhexyl group, a tert-butoxymethyl group, a tert-butoxyethyl group, and a tert-butoxyhexyl group.

[0194]

[0195] C above 1-20 Alkylsilyl group or C 1-20 The alkoxysilyl group is a functional group in which 1 to 3 hydrogens of -SiH3 are replaced by 1 to 3 alkyl groups or alkoxy groups as described above, and specifically, examples thereof include, but are not limited to, alkylsilyl groups such as methylsilyl, dimethylsilyl, trimethylsilyl, dimethylethylsilyl, diethylmethylsilyl, or dimethylpropylsilyl; alkoxysilyl groups such as methoxysilyl, dimethoxysilyl, trimethoxysilyl, or dimethoxyethoxysilyl; and alkoxyalkylsilyl groups such as methoxydimethylsilyl, diethoxymethylsilyl, or dimethoxypropylsilyl.

[0196]

[0197] C above 1-20 A silylalkyl group is a functional group in which one or more hydrogens of the alkyl group described above are replaced with a silyl group, and specifically, examples thereof include, but are not limited to, -CH2-SiH3, a methylsilylmethyl group, or a dimethylethoxysilylpropyl group.

[0198]

[0199] The above sulfonate group has the structure -O-SO2-R', where R' is C 1-20 It can be an alkyl group. Specifically, C 1-20 Sulfonate groups include, but are not limited to, methanesulfonate groups or phenylsulfonate groups.

[0200]

[0201] The above heteroaryl is C containing at least one of N, O, and S as a heteroatom. 2-20 As a heteroaryl, it includes a monocyclic or condensed ring heteroaryl. Specific examples include xanthene, thioxanthen, thiophene group, furan group, pyrrole group, imidazole group, thiazole group, oxazole group, oxadiazole group, triazole group, pyridyl group, bipyridyl group, pyrimidyl group, triazine group, acridyl group, pyridazine group, pyrazinyl group, quinolinyl group, quinazoline group, quinoxalinyl group, phthalazinyl group, pyrido pyrimidinyl group, pyrido pyrazinyl group, pyrazino pyrazinyl group, isoquinoline group, indole group, carbazole group, benzoxazole group, benzimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuranyl group, phenanthroline group, Examples thereof include, but are not limited to, isoxazolyl group, thiadiazolyl group, phenothiazinyl group, and dibenzofuranyl group.

[0202]

[0203] And, the group 4 transition metal may be titanium (Ti), zirconium (Zr), hafnium (Hf), or rutherfordium (Rf), specifically titanium (Ti), zirconium (Zr), or hafnium (Hf), more specifically zirconium (Zr) or hafnium (Hf), but is not limited thereto.

[0204]

[0205] Additionally, the group 13 element may be boron (B), aluminum (Al), gallium (Ga), indium (In), or thallium (Tl), specifically, but not limited to, boron (B) or aluminum (Al).

[0206]

[0207] The above-described substituents may be optionally substituted with one or more substituents selected from the group consisting of a hydroxy group; a halogen; an alkyl group or alkenyl group, an aryl group, an alkoxy group; an alkyl group or alkenyl group, an aryl group, an alkoxy group containing one or more heteroatoms of Groups 14 to 16; a silyl group; an alkylsilyl group or an alkoxysilyl group; a phosphine group; a phosphide group; a sulfonate group; and a sulfone group, within a range that exhibits the same or similar effect as the desired effect.

[0208]

[0209] Also, when two adjacent substituents are linked to form an aliphatic or aromatic ring, it means that the atom(s) of the two substituents and the atom(s) to which the two substituents are linked to form a ring. Specifically, -NR9R 10 R9 and R of 10 Examples of these linked to form aliphatic rings include the piperidinyl group, -NR9R 10 R9 and R of 10 An example of these interconnected groups forming an aromatic ring is the pyrrolyl group.

[0210]

[0211] In the above catalyst composition, the first metallocene compound represented by the chemical formula 1 is Cp 1 and Cp 2 As a non-crosslinked compound containing a ligand, it is advantageous in producing a low molecular weight copolymer having mainly a low short-chain branch (SCB) content.

[0212]

[0213] Specifically, in the above chemical formula 1, Cp 1 and Cp 2 The ligands may be the same or different, each being cyclopentadienyl, and C 1-10It may be substituted with 1 or more or 1 to 3 alkyl groups. In this way, the Cp 1 and Cp 2 The ligand of Cp can exhibit high polymerization activity by having an unshared electron pair that can act as a Lewis base, and in particular, the Cp 1 and Cp 2 Since the ligand is cyclopentadienyl, which has relatively less steric hindrance, it exhibits high polymerization activity and low hydrogen reactivity, allowing for high-activity polymerization of low-molecular-weight polyethylene.

[0214]

[0215] Also, the above Cp 1 and Cp 2 The ligand of Cp can easily control the chemical structure, molecular weight, molecular weight distribution, mechanical properties, transparency, etc. of the polyethylene produced by controlling the degree of steric hindrance effect depending on the type of substituted functional group, for example. Specifically, the Cp 1 and Cp 2 The ligands of each R a and R b is replaced by , and at this time, the R a and R b are identical or different from each other, and each independently represents hydrogen, C 1-20 Alkyl, C 2-20 Alkoxyalkyl, C 7-40 Arylalkyl, or substituted or unsubstituted C containing one or more heteroatoms selected from the group consisting of N, O and S 2-12 It may be heteroaryl, more specifically, C 1-10 Alkyl, C 2-10 Alkoxyalkyl, C 7-20 Arylalkyl, or substituted or unsubstituted C containing one or more heteroatoms selected from the group consisting of N, O and S 4-12 Heteroaryl; may be.

[0216]

[0217] Also, the above Cp1 and Cp 2 There is a M between the ligands of 2 Z 2 3-m This exists, M 2 Z 2 3-m can affect the storage stability of silver metal complexes. To ensure this effect more effectively, Z 1 are each independently halogen or C 1-20 It may be an alkyl, and more specifically, each independently may be F, Cl, Br or I. Also, the above M 2 may be Ti, Zr or Hf; may be Zr or Hf; or may be Zr.

[0218]

[0219] Among the above first metallocene compounds, Cp in the above chemical formula 1 1 and Cp 2 are each an unsubstituted or substituted cyclopentadienyl group, and R a and R b Each independently hydrogen, C 1-10 Alkyl, C 2-10 Alkoxyalkyl, or C 7-20 Arylalkyl of R a and R b At least one of which is an alkoxyalkyl group such as t-butoxyhexyl group, more specifically, -(CH2) p -OR c (At this time, R c is a straight or branched alkyl group having 1 to 6 carbon atoms, and p is an integer from 2 to 4.) may be a compound having a substituent. In this case, when producing polyethylene using a comonomer, it exhibits a lower conversion rate for the comonomer compared to other Cp-based catalysts that do not include the substituent, so that low molecular weight polyethylene with controlled copolymerization degree or comonomer distribution can be produced. In addition, when the first metallocene compound having the above structure is supported on a carrier, -(CH2) among the substituents p -ORc Stable support polymerization is possible because covalent bonds can be formed through close interaction with the silanol groups on the silica surface used as a carrier.

[0220]

[0221] The first metallocene compound represented by the above chemical formula 1 may be, for example, a compound represented by one of the structural formulas below, but is not limited thereto.

[0222] .

[0223]

[0224] The first metallocene compound represented by the above chemical formula 1 can be synthesized by applying known reactions, and a more detailed synthesis method can be found in the examples.

[0225]

[0226] Meanwhile, in one embodiment of the invention, the second metallocene compound represented by the chemical formula 2 includes an aromatic ring compound including cyclopentadienyl or a derivative thereof and a nitrogen atom, and the aromatic ring compound and the nitrogen atom are T bridging groups. 2 Q 3 Q 4 It has a structure that is cross-linked by . The second metallocene compound having this specific structure can be applied to the polymerization reaction of polyethylene, exhibiting high activity and copolymerizability, and can provide an olefin copolymer having a high molecular weight.

[0227]

[0228] In particular, the second metallocene compound represented by the above chemical formula 2 has a well-known CGC (constrained geometry catalyst) structure within its structure, thereby facilitating the introduction of a comonomer, and furthermore, the distribution of the comonomer is controlled by the electronic and steric properties of the ligand. From these properties, the average ethylene sequence length (ASL) is controlled, thereby increasing the mid-molecular region in the molecular weight distribution, thereby increasing the entanglement of polymer chains, thereby facilitating the production of an ethylene-alpha-olefin copolymer having high resistance to film tearing and puncture, such as tensile properties and puncture strength, during film processing, while exhibiting excellent extensibility and processability.

[0229]

[0230] M of the metallocene compound represented by the above chemical formula 2 3 A group 4 transition metal can be used, preferably titanium (Ti), zirconium (Zr), or hafnium (Hf).

[0231]

[0232] Preferably, T in the above chemical formula 2 2 may be silicone.

[0233]

[0234] Preferably, X in the above chemical formula 2 3 and X 4 can each independently be methyl or chlorine (Cl).

[0235]

[0236] Preferably, R in the above chemical formula 2 11 Inland R 14 are the same or different, and each independently may be methyl or phenyl.

[0237]

[0238] Preferably, R in the above chemical formula 2 11 Inland R 14Two or more adjacent ones may be connected to each other to form a substituted or unsubstituted aliphatic ring, an aromatic ring, or a heteroaromatic ring including at least one selected from the group consisting of N, O, and S. For example, in the above chemical formula 2, R 11 Inland R 14 When two or more adjacent groups are connected to each other to form an aliphatic ring, an aromatic ring, or a heteroaromatic ring, a cyclopentadiene-fused indenyl group, a fluorenyl group, a benzothiophene group, or a dibenzothiophene group can be formed. In addition, the indenyl group, the fluorenyl group, the benzothiophene group, or the dibenzothiophene group can be substituted with one or more substituents.

[0239]

[0240] Preferably, R in the above chemical formula 2 15 Inland R 16 are the same or different, and each independently may be methyl, ethyl, phenyl, propyl, hexyl, or tert-butoxyhexyl.

[0241]

[0242] Preferably, R in the above chemical formula 2 17 can be methyl, ethyl, n-propyl, iso-propyl, n-butyl, or tert-butyl.

[0243]

[0244] A second metallocene compound capable of providing an ethylene-alphaolefin copolymer exhibiting excellent mechanical properties along with excellent stretching stability during biaxial stretching through a further increased intermediate molecular region, wherein the metallocene compound of the above chemical formula 2 may be any one selected from the group consisting of the following compounds, but the present invention is not limited thereto:

[0245] .

[0246]

[0247] The second metallocene compound represented by the above chemical formula 2 can be synthesized by applying known reactions. Specifically, it can be synthesized by connecting a nitrogen compound and a cyclopentadiene derivative with a bridge compound to prepare a ligand compound, and then introducing a metal precursor compound to perform metallation, but is not limited thereto. For more detailed synthetic methods, refer to the examples.

[0248]

[0249] The second metallocene compound of the above chemical formula 2 has excellent activity and can polymerize a high molecular weight ethylene-alpha olefin copolymer. In particular, when used by being supported on a carrier, it exhibits high polymerization activity, enabling the production of an ultra-high molecular weight ethylene-alpha olefin copolymer.

[0250]

[0251] In addition, even when a polymerization reaction is carried out including hydrogen to produce an ethylene-alpha-olefin copolymer having both a high molecular weight and a broad molecular weight distribution, the second metallocene compound of chemical formula 2 according to the present invention exhibits low hydrogen reactivity, so that polymerization of an ethylene-alpha-olefin copolymer having an ultra-high molecular weight is still possible with high activity. Therefore, even when used in combination with a catalyst having different characteristics, an ethylene-alpha-olefin copolymer satisfying the characteristics of a high molecular weight can be produced without a decrease in activity, so that an ethylene-alpha-olefin copolymer including a high molecular weight ethylene-alpha-olefin copolymer and having a broad molecular weight distribution can be easily produced.

[0252]

[0253] As described above, in the catalyst composition, the first metallocene compound represented by the chemical formula 1 mainly contributes to forming a low-molecular-weight copolymer having a low SCB content, and the second metallocene compound represented by the chemical formula 2 mainly contributes to forming a high-molecular-weight copolymer having a high SCB content. More specifically, the catalyst composition exhibits high copolymerizability toward a comonomer in a high-molecular-weight region copolymer due to the second metallocene compound, and exhibits low copolymerizability toward a comonomer in a low-molecular-weight region copolymer due to the first metallocene compound. As a result, an ethylene-alpha-olefin copolymer having excellent mechanical properties as well as a bimodal molecular weight distribution and thus excellent heat resistance can be produced.

[0254]

[0255] In particular, the above-described properties can be achieved by controlling the content ratio of the first and second metallocene compounds in the catalyst composition of the present invention, and the resulting improvement effect can be further enhanced. Specifically, by including the second metallocene compound in the catalyst composition at a higher content than the first metallocene compound, the intramolecular medium-molecular region can be increased, thereby increasing the entanglement of polymer chains and optimizing the ratio of high-molecular-weight regions to low-molecular-weight regions.

[0256]

[0257] Specifically, the first and second metallocene compounds should be included in a molar ratio of 1:1 to 1:8. Preferably, the first and second metallocene compounds may be included in a molar ratio of 1:1 to 1:7, 1:1 to 1:6, or 1:1 to 1:5.5. When the first metallocene compound and the second metallocene compound are in the molar ratio as described above, the ethylene-alphaolefin copolymer manufactured using the same can control the balance between mechanical properties and stretchability, thereby maintaining mechanical properties, productivity, and stretchability equivalent to or superior to those of the prior art, and can improve high shrinkage resistance, printability, and transparency.

[0258]

[0259] Meanwhile, the first and second metallocene compounds have the structural characteristics described above and can be stably supported on the carrier.

[0260]

[0261] In this case, the first and second metallocene compounds are used in a supported state on the carrier. When used in the supported catalyst state, the resulting polymer has excellent particle shape and bulk density, and can be suitably used in conventional slurry polymerization, bulk polymerization, and gas phase polymerization processes.

[0262]

[0263] Specific examples of the above carrier include silica, alumina, magnesia, silica-alumina, silica-magnesia, etc., and these may further include oxide, carbonate, sulfate, and nitrate components, such as Na2O, K2CO3, BaSO4, and Mg(NO3)2. Among these, when a silica carrier is used, the transition metal compound is supported by chemically bonding with a reactive functional group, such as a siloxane group, existing on the surface of the silica carrier, so that almost no catalyst is liberated from the surface of the carrier during the propylene polymerization process, and as a result, fouling, in which the reactor wall or polymer particles stick together, can be minimized when manufacturing polypropylene by slurry or gas phase polymerization.

[0264]

[0265] Additionally, the carrier may be surface-modified through a calcination or drying process to enhance the loading efficiency and minimize leaching and fouling. Through the surface modification step described above, moisture on the carrier surface that inhibits reaction with the loading components is removed, and instead, the content of reactive functional groups capable of chemical bonding with the loading components, such as hydroxyl groups and siloxane groups, can be increased.

[0266]

[0267] Specifically, the calcination or drying process for the carrier may be performed at a temperature ranging from a temperature at which moisture disappears from the surface of the carrier to a temperature below which reactive functional groups, particularly hydroxyl groups (OH groups), present on the surface completely disappear. Specifically, the temperature may be 150 to 600°C, or 200 to 500°C. If the temperature during calcination or drying of the carrier is lower than 150°C, the moisture removal efficiency is low, and as a result, there is a concern that moisture remaining in the carrier may react with the cocatalyst, thereby reducing the support efficiency. On the other hand, if the drying or calcination temperature is excessively high, exceeding 600°C, the pores present on the surface of the carrier may merge, reducing the specific surface area, and also many reactive functional groups, such as hydroxyl groups or silanol groups, present on the surface may disappear, leaving only siloxane groups, which may reduce the reaction sites with the cocatalyst.

[0268]

[0269] When the above-mentioned first and second metallocene compounds are supported on a carrier, for example, when the carrier is silica, the first and second metallocene compounds may be supported in a total amount of 40 μmol or more, or 80 μmol or more, and 240 μmol or less, or 160 μmol or less, based on 1 g of silica. When supported in the above-mentioned 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.

[0270]

[0271] In addition, the catalyst composition may additionally include a cocatalyst to improve high activity and process stability.

[0272]

[0273] In the hybrid supported metallocene catalyst of the present invention, the type and content of the additionally included cocatalyst are as described above with respect to the first ethylene-alpha olefin copolymer (a), and specific details are omitted.

[0274] For example, among the above compounds, the cocatalyst may be, more specifically, an alkylaluminoxane cocatalyst such as methylaluminoxane.

[0275]

[0276] In addition, the alkylaluminoxane-based cocatalyst can further enhance catalytic activity by including a metal element that stabilizes the metallocene compounds, acts as a Lewis acid, and can form a bond through a Lewis acid-base interaction with a functional group introduced into a bridge group of the second metallocene compound.

[0277]

[0278] In addition, the amount of the cocatalyst used can be appropriately adjusted depending on the properties or effects of the desired catalyst and resin composition. For example, when silica is used as the carrier, the cocatalyst can be supported in an amount of 8 mmol or more, or 10 mmol or more, and 25 mmol or less, or 20 mmol or less, based on the weight of the carrier, for example, 1 g of silica.

[0279]

[0280] In addition, the above-described catalyst composition may be used for polymerization as is, or may be used in a prepolymerized state through contact with an ethylene monomer prior to use in the polymerization reaction. In this case, the manufacturing method according to one embodiment of the invention may further include a step of prepolymerizing (or prepolymerizing) the catalyst composition by contacting it with an ethylene monomer prior to producing polyethylene through a polymerization reaction.

[0281]

[0282] In addition, the above catalyst composition can be dissolved or diluted in an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, such as pentane, hexane, heptane, nonane, decane, and isomers thereof, an aromatic hydrocarbon solvent such as toluene and benzene, a hydrocarbon solvent substituted with a chlorine atom such as dichloromethane and chlorobenzene, and then introduced into the polymerization reaction described below. It is preferable to use the solvent used here after removing a small amount of water or air, which 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.

[0283]

[0284] Meanwhile, the polymerization process can be carried out by contacting ethylene and a comonomer in the presence of the above-described catalyst composition. In particular, the polymerization reaction can be carried out in a bimodal manner using two or more multiple reactors, or in a single polymerization reactor.

[0285]

[0286] And, the polymerization temperature may be 25°C to 500°C, preferably 25°C to 200°C, and more preferably 50°C to 150°C. In addition, the polymerization pressure may be 1 kgf / ㎠ to 100 kgf / ㎠, preferably 1 kgf / ㎠ to 50 kgf / ㎠, and more preferably 5 kgf / ㎠ to 30 kgf / ㎠.

[0287]

[0288] In addition, when alpha-olefin is introduced as a comonomer in the copolymerization process, the amount of alpha-olefin introduced may be about 3.0 wt% or more to about 6.0 wt% or less based on the total weight of ethylene introduced. More specifically, the amount of the alpha-olefin input may be about 3.1 wt% or more, or about 3.2 wt% or more, or about 3.3 wt% or more, or about 3.4 wt% or more, or about 3.5 wt% or more, or about 3.53 wt% or more, or about 3.55 wt% or more, or about 3.58 wt% or more, or about 3.6 wt% or more, and about 5.9 wt% or less, or about 5.8 wt% or less, or about 5.6 wt% or less, or about 5.4 wt% or less, or about 5.2 wt% or less, or about 5.0 wt% or less, or about 4.5 wt% or less, or about 4.2 wt% or less, or about 4 wt% or less, or about 3.8 wt% or less, or about 3.75 wt% or less, or about 3.7 wt% or less, based on the total weight of the ethylene input.

[0289]

[0290] Specifically, when 1-hexene is introduced as a comonomer in the copolymerization process, the amount of 1-hexene introduced may be about 3.55 wt% or more, or about 3.58 wt% or more, or about 3.6 wt%, and about 5.2 wt% or less, or about 5.0 wt% or less, or about 4.5 wt% or less, or about 4.2 wt% or less, or about 4 wt% or less, or about 3.8 wt% or less, or about 3.75 wt% or less, or about 3.7 wt% or less, based on the total weight of the ethylene introduced.

[0291]

[0292] For example, the copolymerization process can be performed at an ethylene input of 10.0 kg / hr and an input of 1-hexene, which is a comonomer, of 5.5 mL / min or more and 6.2 mL / min or less, or 5.8 mL / min or more and less than 6.2 mL / min.

[0293]

[0294] Meanwhile, the first ethylene-alpha-olefin copolymer according to the present invention can be produced by copolymerizing ethylene and a comonomer by introducing hydrogen gas in the presence of the above-described catalyst composition. The amount of hydrogen gas and the alpha-olefin comonomer introduced can be determined depending on the physical properties of the first ethylene-alpha-olefin copolymer to be produced.

[0295] Specifically, the hydrogen gas may be introduced in an amount of about 5 ppm or more to about 120 ppm based on the total weight of ethylene. More specifically, based on the total weight of ethylene, about 5.5 ppm or more, or about 7 ppm or more, or about 8.5 ppm or more, or about 10 ppm or more, or about 12 ppm or more, or about 15 ppm or more, or about 16 ppm or more, or about 17.5 ppm or more, or about 17.8 ppm or more, or about 18 ppm or more, or about 18.3 ppm or more, or about 18.5 ppm or more, and about 100 ppm or less, or about 80 or less, or about 65 ppm or less, or about 50 ppm or less, or about 40 ppm or less, or about 35 ppm or less, or about 34 ppm or less, or about 32 ppm or less, or about 30 ppm or less, or about 25 ppm or less, or about 25 ppm or less, or about 20 ppm or less, or about 19 ppm or less, or about It can be administered in amounts of 18.8 ppm or less.

[0296]

[0297] For example, in the copolymerization process, the ethylene input amount may be 10.0 kg / hr, and the hydrogen input amount may be about 1.83 g / hr or more to about 35 g / hr or less, or about 1.83 g / hr or more to about 34 g / hr or less, and preferably, the ethylene input amount may be about 1.83 g / hr or more, but about 32 g / hr or less, or about 25 g / hr or less, or about 20 g / hr or less, or about 19 g / hr or less, or about 18.8 g / hr or less.

[0298]

[0299] In the step of supporting the catalyst precursor on the above-mentioned catalyst-supporting carrier, the first and second transition metal compounds are added to the catalyst-supporting carrier, stirred, and then a catalyst is additionally added to produce a supported catalyst.

[0300]

[0301] The contents of the carrier, cocatalyst, cocatalyst-supported carrier, and transition metal compound used in the hybrid supported metallocene catalyst according to the above embodiment can be appropriately adjusted depending on the desired properties or effects of the supported catalyst.

[0302]

[0303] Meanwhile, if the molar ratio of the first transition metal compound and the second transition metal compound (first transition metal compound: second transition metal compound) is less than 1:0.3, there is a disadvantage in that it is difficult to produce ultra-low density polyethylene as copolymerization is reduced, and if it exceeds 1:5.5, there is a problem in that it is difficult to reproduce the molecular structure of the desired polymer.

[0304]

[0305] At this time, the amount of the metallocene compound supported on the silica carrier by the above step may be 0.01 to 1 mmol / g based on 1 g of the carrier. That is, it is preferable to control the amount so as to fall within the aforementioned range in consideration of the contribution effect of the catalyst by the metallocene compound.

[0306]

[0307] When preparing the above hybrid supported catalyst, a hydrocarbon solvent such as pentane, hexane, heptane, etc., or an aromatic solvent such as benzene, toluene, etc. may be used as a reaction solvent.

[0308]

[0309] The specific manufacturing method of the supported catalyst described above can be referenced in the examples described below. However, the manufacturing method of the supported catalyst is not limited to the contents described herein. The manufacturing method may additionally employ steps commonly employed in the technical field to which the present invention pertains, and the step(s) of the manufacturing method may be modified by step(s) that are typically changeable.

[0310]

[0311] Meanwhile, a polyethylene copolymer as described above can be produced through a method including a step of copolymerizing ethylene and alpha-olefin in the presence of the hybrid supported metallocene catalyst.

[0312]

[0313] The above-described hybrid supported catalyst can exhibit excellent supporting performance, catalytic activity and high copolymerizability, and can produce a polyethylene copolymer capable of producing a biaxially oriented film having excellent expandable processing area characteristics and mechanical properties.

[0314]

[0315] The method for producing the above first ethylene-alpha-olefin copolymer (a) can be carried out by a slurry polymerization method using ethylene and alpha-olefin as raw materials in the presence of the above-described hybrid supported catalyst, using a conventional device and contact technology.

[0316]

[0317] The method for producing the above first ethylene-alpha-olefin copolymer (a) may copolymerize ethylene and alpha-olefin using a continuous slurry polymerization reactor, a loop slurry reactor, or the like, but is not limited thereto.

[0318]

[0319] That is, in the case of the hybrid supported metallocene catalyst of the present invention in which the first metallocene compound and the second metallocene compound are supported at the molar ratio, the mechanical properties of the polyethylene copolymer as well as the processability and shrinkage rate can all be further improved due to the interaction of two or more types of catalysts.

[0320]

[0321] In the hybrid supported metallocene catalyst of the present invention, the polymerization process, including the carrier for supporting the first metallocene compound and the second metallocene compound and the additionally included cocatalyst, etc., are as described above with respect to the first ethylene-alphaolefin copolymer (a), and specific details are omitted.

[0322]

[0323] In this way, the first ethylene-alpha-olefin copolymer (a) according to the present invention can be produced by copolymerizing ethylene and alpha-olefin using the supported metallocene catalyst described above.

[0324]

[0325] By the above-described manufacturing method, a first ethylene-alpha olefin copolymer (a) having the above-described physical properties can be manufactured.

[0326]

[0327] (Second ethylene-alpha olefin copolymer (b))

[0328] According to one embodiment of the present invention, a polyethylene composition can be blended with the first ethylene-alpha olefin copolymer (a) described above and a second ethylene-alpha olefin copolymer (b) having excellent flowability and excellent stretching stability and shrinkage resistance to control the balance between mechanical properties and stretching properties, thereby maintaining mechanical properties, productivity, and stretching stability equivalent to or superior to those of the prior art, and imparting characteristics suitable for manufacturing a biaxially oriented film having high shrinkage resistance, printability, and excellent transparency.

[0329]

[0330] Specifically, the second ethylene-alpha olefin copolymer (b) has a density of 0.870 g / cm 3 0.920 g / cm 3 and the melting index (MI) 2.16 , 190 ℃, 2.16 kg load) is 3.0 g / 10 min to 10.0 g / 10 min, and the molecular weight distribution (Mw / Mn) is 2.0 or more and 4.0 or less.

[0331]

[0332] Preferably, the second ethylene-alpha olefin copolymer (b) has a density of 0.880 g / cm 3 Above, 0.890 g / cm 3 or 0.895 g / cm 3 Ideally, 0.915 g / cm 3 Below, 0.910 g / cm 3 or less, or 0.905 g / cm 3 It could be as follows:

[0333]

[0334] In addition, the second ethylene-alpha olefin copolymer (b) has a melting index (MI) 2.16, 190 ℃, 2.16 kg load) may be 4.0 g / 10 min or more, 5.0 g / 10 min or more, or 5.5 g / 10 min or more, and 9.0 g / 10 min or less, 8.0 g / 10 min or less, or 7.0 g / 10 min or less.

[0335]

[0336] The above second ethylene-alpha olefin copolymer (b) has a molecular weight distribution (Mw / Mn) of 2.0 or more and 4.0 or less.

[0337]

[0338] In addition, the second ethylene-alpha olefin copolymer (b) may have a number average molecular weight (Mn) of 20,000 g / mol or more and 50,000 g / mol or less, and a weight average molecular weight (Mw) of 50,000 g / mol or more and 100,000 g / mol or less.

[0339]

[0340] Preferably, the number average molecular weight (Mn) of the second ethylene-alpha olefin copolymer (b) may be 23000 g / mol or more, 25000 g / mol or more, or 28000 g / mol or more, and 45000 g / mol or less, 40000 g / mol or less, or 35000 g / mol or less.

[0341]

[0342] In addition, the weight average molecular weight (Mw) of the second ethylene-alpha olefin copolymer (b) may be 55,000 g / mol or more, 60,000 g / mol or more, or 65,000 g / mol or more, and may be 90,000 g / mol or less, 80,000 g / mol or less, or 70,000 g / mol or less.

[0343]

[0344] In addition, the molecular weight distribution (Mw / Mn) of the second ethylene-alpha olefin copolymer (b) may be 2.1 or more, 2.2 or more, or 2.3 or more, and 3.5 or less, 3.0 or less, or 2.5 or less.

[0345]

[0346] The above second ethylene-alpha olefin copolymer (b) may have at least one of the above-described properties, and may have all of the above-described properties to exhibit excellent mechanical strength.

[0347]

[0348] The second ethylene-alpha-olefin copolymer (b) may include at least one alpha-olefin selected from the group consisting of 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, together with ethylene.

[0349]

[0350] Preferably, the second ethylene-alphaolefin copolymer (b) may be an ethylene 1-octene copolymer.

[0351]

[0352] The above second ethylene-alpha-olefin copolymer (b) can more easily realize the above-described properties when it is the above-described copolymer. However, the type of the above-described second ethylene-alpha-olefin copolymer (b) is not limited to the above-described types, and various types known in the technical field to which the present invention pertains can be provided as long as they can exhibit the above-described properties.

[0353]

[0354] And, the second ethylene-alpha olefin copolymer (b) is produced in the presence of a metallocene catalyst.

[0355]

[0356] Specifically, the second ethylene-alphaolefin copolymer (b) can be produced by copolymerizing ethylene and a comonomer in the presence of a catalyst composition including a metallocene compound represented by the following chemical formula 3.

[0357] [Chemical Formula 3]

[0358]

[0359] In the above chemical formula 3,

[0360] M 1 is a group 4 transition metal;

[0361] X 1 and X 2 are the same or different from each other, and each independently represents a halogen, a nitro group, an amido group, a phosphine group, a phosphide group, a hydrocarbyl group having 1 to 30 carbon atoms, a hydrocarbyloxy group having 1 to 30 carbon atoms, a hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms, -SiH3, a hydrocarbyl(oxy)silyl group having 1 to 30 carbon atoms, a sulfonate group having 1 to 30 carbon atoms, or a sulfone group having 1 to 30 carbon atoms;

[0362] Z is -O-, -S-, -NR a -, or -PR a - and,

[0363] R a is any one of hydrogen, a hydrocarbyl group having 1 to 20 carbon atoms, a hydrocarbyl(oxy)silyl group having 1 to 20 carbon atoms, and a silylhydrocarbyl group having 1 to 20 carbon atoms;

[0364] T is or And,

[0365] T 1 is C, Si, Ge, Sn or Pb,

[0366] Q 1 and Q 2 are the same or different from each other, and each independently represents hydrogen, a hydrocarbyl group having 1 to 30 carbon atoms, a hydrocarbyloxy group having 1 to 30 carbon atoms, a hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms, -SiH3, a hydrocarbyl(oxy)silyl group having 1 to 30 carbon atoms, a hydrocarbyl group having 1 to 30 carbon atoms substituted with a halogen, and -NR b R cOne of them,

[0367] R b and R c are each independently hydrogen and a hydrocarbyl group having 1 to 30 carbon atoms, or are connected to each other to form an aliphatic or aromatic ring;

[0368] C 1 is any one of the ligands represented by the following chemical formulas 3a to 3d,

[0369] [Chemical Formula 3a]

[0370]

[0371] [Chemical Formula 3b]

[0372]

[0373] [Chemical formula 3c]

[0374]

[0375] [Chemical formula 3d]

[0376]

[0377] In the above chemical formulas 3a to 3d,

[0378] Y is O or S,

[0379] R 1 Inland R 6 are the same or different from each other, and each independently represents hydrogen, a hydrocarbyl group having 1 to 30 carbon atoms, or a hydrocarbyloxy group having 1 to 30 carbon atoms.

[0380]

[0381] Unless otherwise specified in this specification, the following terms may be defined as follows:

[0382]

[0383] A hydrocarbyl group is a monovalent functional group in which a hydrogen atom is removed 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, a hydrocarbyl group having 1 to 30 carbon atoms may be a hydrocarbyl group having 1 to 20 carbon atoms or 1 to 10 carbon atoms. For example, the hydrocarbyl group may be a straight-chain, branched-chain, or cyclic alkyl. More specifically, the hydrocarbyl group having 1 to 30 carbon atoms may be a straight-chain, branched-chain or cyclic alkyl group such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, cyclohexyl, or the like; or an aryl group such as phenyl, biphenyl, naphthyl, anthracenyl, phenanthrenyl, or fluorenyl. In addition, it may be an alkylaryl such as methylphenyl, ethylphenyl, methylbiphenyl, or methylnaphthyl, or an arylalkyl such as phenylmethyl, phenylethyl, biphenylmethyl, or naphthylmethyl. In addition, it may be an alkenyl such as allyl, allyl, ethenyl, propenyl, butenyl, or pentenyl.

[0384]

[0385] A hydrocarbyloxy group is a functional group in which a hydrocarbyl group is bonded to oxygen. Specifically, the hydrocarbyloxy group having 1 to 30 carbon atoms may be a hydrocarbyloxy group having 1 to 20 carbon atoms or 1 to 10 carbon atoms. For example, the hydrocarbyloxy group may be a straight-chain, branched-chain, or cyclic alkyl. More specifically, the hydrocarbyloxy group having 1 to 30 carbon atoms may be a straight-chain, branched-chain, or cyclic alkoxy group such as 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 n-heptoxy group, an n-heptoxy group, or a cycloheptoxy group; or an aryloxy group such as a phenoxy group or a naphthalenoxy group.

[0386]

[0387] A hydrocarbyloxyhydrocarbyl group is a functional group in which at least one hydrogen atom of a hydrocarbyl group is replaced by at least one hydrocarbyloxy group. Specifically, the hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms may be a hydrocarbyloxyhydrocarbyl group having 2 to 20 carbon atoms or a hydrocarbyloxyhydrocarbyl group having 2 to 15 carbon atoms. For example, the hydrocarbyloxyhydrocarbyl group may be a straight-chain, branched-chain or cyclic alkyl. More specifically, the hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms may be an alkoxyalkyl group such as a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an iso-propoxymethyl group, an iso-propoxyethyl group, an iso-propoxyhexyl group, a tert-butoxymethyl group, a tert-butoxyethyl group, or a tert-butoxyhexyl group; Or it may be an aryloxyalkyl group such as a phenoxyhexyl group.

[0388]

[0389] A hydrocarbyl(oxy)silyl group is a functional group in which 1 to 3 hydrogen atoms of -SiH3 are replaced by 1 to 3 hydrocarbyl groups or hydrocarbyloxy groups. Specifically, the hydrocarbyl(oxy)silyl group having 1 to 30 carbon atoms may be a hydrocarbyl(oxy)silyl group having 1 to 20 carbon atoms, 1 to 15 carbon atoms, 1 to 10 carbon atoms, or 1 to 5 carbon atoms. More specifically, the hydrocarbyl(oxy)silyl group having 1 to 30 carbon atoms may be an alkylsilyl group such as a methylsilyl group, a dimethylsilyl group, a trimethylsilyl group, a dimethylethylsilyl group, a diethylmethylsilyl group, or a dimethylpropylsilyl group; an alkoxysilyl group such as a methoxysilyl group, a dimethoxysilyl group, a trimethoxysilyl group, or a dimethoxyethoxysilyl group; It may be an alkoxyalkylsilyl group such as a methoxydimethylsilyl group, a diethoxymethylsilyl group, or a dimethoxypropylsilyl group.

[0390]

[0391] A silylhydrocarbyl group having 1 to 20 carbon atoms is a functional group in which at least one hydrogen atom of the hydrocarbyl group is replaced with a silyl group. The silyl group may be -SiH3 or a hydrocarbyl(oxy)silyl group. Specifically, the silylhydrocarbyl group having 1 to 20 carbon atoms may be a silylhydrocarbyl group having 1 to 15 carbon atoms or 1 to 10 carbon atoms. More specifically, the silylhydrocarbyl group having 1 to 20 carbon atoms may be a silylalkyl group such as -CH2-SiH3; an alkylsilylalkyl group such as a methylsilylmethyl group, a methylsilylethyl group, a dimethylsilylmethyl group, a trimethylsilylmethyl group, a dimethylethylsilylmethyl group, a diethylmethylsilylmethyl group, or a dimethylpropylsilylmethyl group; or an alkoxysilylalkyl group such as a dimethylethoxysilylpropyl group.

[0392]

[0393] The halogen can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0394]

[0395] The sulfonate group is -O-SO2-R d R in the structure of d may be a hydrocarbyl group having 1 to 30 carbon atoms. Specifically, the sulfonate group having 1 to 30 carbon atoms may be a methanesulfonate group or a phenylsulfonate group.

[0396]

[0397] A sulfonic acid group having 1 to 30 carbon atoms is -R e' -SO2-R e" Here R is the structure of e' and R e" are the same or different and can each independently be any one of hydrocarbyl groups having 1 to 30 carbon atoms. Specifically, the sulfone group having 1 to 30 carbon atoms can be a methylsulfonylmethyl group, a methylsulfonylpropyl group, a methylsulfonylbutyl group, or a phenylsulfonylpropyl group.

[0398]

[0399] In this specification, when two adjacent substituents are linked to each other to form an aliphatic or aromatic ring, it means that the atom(s) of the two substituents and the atom(s) to which the two substituents are bound are linked to each other to form a ring. Specifically, -NR b R c or -NR b' R c' R of b and R c or R b' and R c' Examples of groups that are linked to each other to form an aliphatic ring include the piperidinyl group, and -NR b R c or -NR b' R c' R of b and R c or R b' and R c' An example of a group that is connected to each other to form an aromatic ring is the pyrrolyl group.

[0400]

[0401] And, the group 4 transition metal may be titanium (Ti), zirconium (Zr), hafnium (Hf), or rutherfordium (Rf), specifically titanium (Ti), zirconium (Zr), or hafnium (Hf), more specifically zirconium (Zr), or hafnium (Hf), but is not limited thereto.

[0402]

[0403] Additionally, the group 13 element may be boron (B), aluminum (Al), gallium (Ga), indium (In), or thallium (Tl), specifically, but not limited to, boron (B) or aluminum (Al).

[0404]

[0405] The above-described substituents may be optionally substituted with one or more substituents selected from the group consisting of a hydroxy group; a halogen; a hydrocarbyl group; a hydrocarbyloxy group; a hydrocarbyl group or hydrocarbyloxy group containing at least one heteroatom from groups 14 to 16; a silyl group; a hydrocarbyl(oxy)silyl group; a phosphine group; a phosphide group; a sulfonate group; and a sulfone group, within a range that exhibits the same or similar effect as the desired effect.

[0406]

[0407] In this specification, <@ <000013.tif> @> indicates a bond that connects to another substituent.

[0408]

[0409] Specifically, in the above chemical formula 3, Z is -NR a - and the above R a may be a hydrocarbyl group having 1 to 10 carbon atoms, and specifically, the R a It may be a straight-chain or branched alkyl group having 1 to 6 carbon atoms, and more specifically, it may be a tert-butyl group.

[0410]

[0411] And, in the above chemical formula 3, T is And, T 1 is carbon (C) or silicon (Si), and Q 1 and Q 2 Each independently may be hydrogen, a hydrocarbyl group having 1 to 30 carbon atoms, or a hydrocarbyloxy group having 1 to 30 carbon atoms. Specifically, Q 1 and Q 2 Each of may be a hydrocarbyl group having 1 to 10 carbon atoms, or a hydrocarbyloxyhydrocarbyl group having 2 to 12 carbon atoms. More specifically, Q 1 and Q 2Each of may be an alkyl group having 1 to 6 carbon atoms, or an alkoxy-substituted alkyl group having 1 to 6 carbon atoms. For example, Q 1 and Q 2 may each independently be hydrogen, methyl, ethyl, or tert-butoxy substituted hexyl. More specifically, T 1 is silicon (Si), and Q 1 and Q 2 are all methyl, or Q 1 and Q 2 One of them may be methyl and the other may be tert-butoxy substituted hexyl.

[0412]

[0413] Specifically, the metallocene compound represented by the above chemical formula 3 may be represented by any one of the following chemical formulas 3-1 to 3-4.

[0414] [Chemical Formula 3-1]

[0415]

[0416] [Chemical Formula 3-2]

[0417]

[0418] [Chemical Formula 3-3]

[0419]

[0420] [Chemical Formula 3-4]

[0421]

[0422] In the above chemical formulas 3-1 to 3-4, M 1 , X 1 , X 2 , R a , T 1 , Q 1 , Q 2 , Y, and R 1 Inland R 6 is as defined in the above chemical formula 3.

[0423]

[0424] And, in the above chemical formula 3, R 1 Inland R 4 are each hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms, and R 5 and R 6 Each of R may be a hydrocarbyl group having 1 to 10 carbon atoms. Specifically, R 1 Inland R 4 are each hydrogen or alkyl having 1 to 10 carbon atoms, and R 5 and R 6 Each of R may be an alkyl having 1 to 10 carbon atoms. More specifically, R 1 Inland R 4 are hydrogen or methyl, respectively, and R 5 and R 6 can be methyl.

[0425]

[0426] And, in the above chemical formula 3, M 1 is titanium (Ti), zirconium (Zr), or hafnium (Hf), and preferably titanium (Ti).

[0427]

[0428] And, in the above chemical formula 3, X 1 and X 2 Each may be a halogen or an alkyl group having 1 to 10 carbon atoms or an alkyl group having 1 to 6 carbon atoms, and specifically may be chlorine or methyl.

[0429]

[0430] And, in the above chemical formula 3, the metallocene compound may be represented by one of the following structural formulas.

[0431]

[0432]

[0433] Metallocene compounds represented by the above structural formulas can be synthesized by applying known reactions, and more detailed synthesis methods can be referred to the examples and synthesis examples described below.

[0434]

[0435] As described above, the transition metal compound represented by the chemical formula 3 used in the present invention controls the degree of introduction of alpha-olefin monomers in the copolymerization process due to the structural characteristics of the catalyst, and exhibits the density as described above, and as a result, can secure excellent flowability and elongation processability.

[0436]

[0437] In the present invention, the polymerization reaction can be carried out by continuously introducing hydrogen in the presence of a catalyst composition including at least one transition metal compound represented by Chemical Formula 3 to continuously polymerize ethylene and alpha-olefin monomers, and specifically, it can be carried out while introducing hydrogen at a rate of 5 cc / min to 100 cc / min.

[0438]

[0439] The hydrogen gas suppresses the rapid reaction of the transition metal compound in the early stage of polymerization and terminates the polymerization reaction. Accordingly, by controlling the use and amount of hydrogen gas, an ethylene / alpha-olefin copolymer with a narrow molecular weight distribution can be effectively produced.

[0440]

[0441] For example, the hydrogen may be introduced at 5 cc / min or more, or 7 cc / min or more, or 8.5 cc / min or more, or 10 cc / min or more, or 12 cc / min or more, or 15 cc / min or more, and may be introduced at 100 cc / min or less, or 50 cc / min or less, or 45 cc / min or less, or 35 cc / min or less, or 30 cc / min or less, or 29 cc / min or less, or 25 cc / min or less, or 20 cc / min or less, or 18 cc / min or less, or 16 cc / min or less. When introduced under the above conditions, the produced ethylene / alpha-olefin copolymer can implement the physical properties of the present invention.

[0442]

[0443] If the hydrogen gas content is less than 5 cc / min, the polymerization reaction may not be completed uniformly, making it difficult to produce an ethylene / alpha-olefin copolymer with desired properties. If it is more than 100 cc / min, there is a concern that the termination reaction may occur too quickly, resulting in the production of an ethylene / alpha-olefin copolymer with very low molecular weight.

[0444]

[0445] Meanwhile, the second ethylene-alpha-olefin copolymer according to the present invention can be produced by copolymerizing ethylene and a comonomer by introducing hydrogen gas in the presence of the above-described catalyst composition. The amount of hydrogen gas and the alpha-olefin comonomer introduced can be determined depending on the properties of the second ethylene-alpha-olefin copolymer to be produced.

[0446]

[0447] When alpha-olefin is introduced as a comonomer in the above copolymerization process, the amount of alpha-olefin introduced may be about 10 wt% or more to about 48 wt% or less based on the total weight of ethylene introduced. More specifically, the amount of the alpha-olefin input may be about 12 wt% or more, or about 15 wt% or more, or about 18 wt% or more, or about 20 wt% or more, or about 22 wt% or more, or about 25 wt% or more, or about 28 wt% or more, or about 30 wt% or more, or about 32 wt% or more, or about 35 wt% or more, but about 46 wt% or less, or about 45 wt% or less, or about 43.5 wt% or less, or about 42 wt% or less, or about 40 wt% or less, or about 38.5 wt% or less, or about 38 wt% or less, or about 37.5 wt% or less, or about 37 wt% or less, or about 36.5 wt% or less, or about 36 wt% or less, based on the total weight of the ethylene input.

[0448]

[0449] Specifically, when 1-octene is introduced as a comonomer in the copolymerization process, the amount of 1-octene introduced may be about 28 wt% or more, or about 30 wt% or more, or about 32 wt% or more, or about 35 wt% or more, and about 40 wt% or less, or about 38.5 wt% or less, or about 38 wt% or less, or about 37.5 wt% or less, or about 37 wt% or less, or about 36.5 wt% or less, or about 36 wt% or less, based on the total weight of the introduced ethylene.

[0450]

[0451] For example, when the copolymerization process is performed using 1-octene as a comonomer, the amount of 1-octene input can be 0.25 kg / hr or more and 0.35 kg / hr or less, or 0.28 kg / hr or more and 0.32 kg / hr or less, based on an ethylene input of 0.87 kg / hr.

[0452]

[0453] In addition, the polymerization reaction can be carried out at 100°C to 200°C, and by controlling the polymerization temperature together with the above-mentioned hydrogen input amount, the crystallinity distribution and molecular weight distribution within the ethylene / alpha-olefin copolymer can be more easily controlled. Specifically, the polymerization reaction can be carried out at 100°C to 200°C, 120°C to 180°C, 130°C to 170°C, and 140°C to 160°C, but is not limited thereto.

[0454]

[0455] In the present invention, a cocatalyst may be additionally used in the catalyst composition to activate the transition metal compound of the above chemical formula 3. The cocatalyst is an organometallic compound containing a Group 13 metal, and specifically may include at least one selected from the following chemical formulas 4 to 4.

[0456] [Chemical Formula 4]

[0457] R8-[Al(R7)-O] n -R9

[0458] In the above chemical formula 4,

[0459] R7, R8 and R9 are each independently hydrogen, halogen, C 1-20 C substituted with a hydrocarbyl group or halogen 1-20 It is a hydrocarbyl group,

[0460] n is an integer greater than or equal to 2,

[0461] [Chemical Formula 5]

[0462] D(R 10 )3

[0463] In the above chemical formula 5,

[0464] D is aluminum or boron,

[0465] R 10 are each independently halogen, C 1-20 hydrocarbyl group, C 1-20C substituted with a hydrocarbyloxy group or halogen 1-20 It is a hydrocarbyl group,

[0466] [Chemical Formula 6]

[0467] [LH] + [W(A)4] - or [L] + [W(A)4] -

[0468] In the above chemical formula 6,

[0469] L is a neutral or cationic Lewis base,

[0470] H is a hydrogen atom,

[0471] W is a group 13 element,

[0472] A is independently C 1-20 hydrocarbyl group; C 1-20 hydrocarbyloxy group; and one or more hydrogen atoms of these substituents are halogen, C 1-20 Hydrocarbyloxy group and C 1-20 Any one of the substituents substituted with one or more substituents among the hydrocarbyl(oxy)silyl groups.

[0473]

[0474] Specifically, in the chemical formula 6, [LH] + is the Bronsted Mountain.

[0475]

[0476] For example, the above [LH] + is trimethylammonium; triethylammonium; tripropylammonium; tributylammonium; diethylammonium; trimethylphosphonium; or triphenylphosphonium, and the above [L] + is N,N-diethylanilinium; or triphenylcarbonium.

[0477]

[0478] Also, in the above chemical formula 6, W is B 3+ or Al 3+ It could be.

[0479]

[0480] The compound represented by the above chemical formula 4 can act as an alkylating agent and an activator, the compound represented by the above chemical formula 5 can act as an alkylating agent, and the compound represented by the above chemical formula 6 can act as an activator.

[0481]

[0482] More specifically, the compound of the above chemical formula 4 may be an alkylaluminoxane compound in which repeating units are bonded in a linear, circular or network shape, and specific examples thereof include methylaluminoxane (MAO), ethylaluminoxane, isobutylaluminoxane or tert-butylaluminoxane. Non-limiting examples of the compound represented by the above chemical formula 4 include methylaluminoxane, ethylaluminoxane, isobutylaluminoxane or tert-butylaluminoxane.

[0483]

[0484] And, non-limiting examples of the compound represented by Chemical Formula 5 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.

[0485]

[0486] Finally, non-limiting examples of compounds represented by the formula 6 include trimethylammonium tetrakis(pentafluorophenyl)borate, triethylammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium n-butyltris(pentafluorophenyl)borate, N,N-dimethylanilinium benzyltris(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(4-(t-butyldimethylsilyl)-2,3,5,6-tetrafluorophenyl)borate, N,N-dimethylanilinium tetrakis(4-(triisopropylsilyl)-2,3,5,6-tetrafluorophenyl)borate, N,N-dimethylanilinium pentafluorophenoxytris(pentafluorophenyl)borate, Examples thereof include N,N-dimethyl-2,4,6-trimethylanilinium tetrakis(pentafluorophenyl)borate, trimethylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate, N,N-dimethylanilinium tetrakis(2,3,4,6-tetrafluorophenyl)borate, hexadecyldimethylammonium tetrakis(pentafluorophenyl)borate, N-methyl-N-dodecylanilinium tetrakis(pentafluorophenyl)borate, or methyldi(dodecyl)ammonium tetrakis(pentafluorophenyl)borate.

[0487]

[0488] Among the above compounds, the cocatalyst may be, more specifically, an alkylaluminoxane cocatalyst such as methylaluminoxane.

[0489]

[0490] The amount of the above cocatalyst used can be appropriately adjusted depending on the properties or effects of the desired hybrid supported metallocene catalyst.

[0491]

[0492] The above cocatalyst may be used in an appropriate amount so that the activation of the transition metal compound of the above chemical formula 3 can proceed sufficiently. The amount of the cocatalyst used may be appropriately adjusted depending on the properties or effects of the desired hybrid supported metallocene catalyst.

[0493]

[0494] In the present invention, the transition metal compound of the above chemical formula 3 can be used in an unsupported form not supported on a carrier or in a form supported on a carrier.

[0495]

[0496] When the transition metal compound of the above chemical formula 3 is supported on a carrier, the weight ratio of the transition metal compound and the carrier may be 1:10 to 1:1000, more specifically 1:10 to 1:500. When the carrier and the transition metal compound are included in the weight ratio within the above range, an optimal shape can be exhibited. In addition, when the cocatalyst is supported on the carrier together, the weight ratio of the cocatalyst to the carrier may be 1:1 to 1:100, more specifically 1:1 to 1:50. When the cocatalyst and the carrier are included in the above weight ratio, the catalytic activity can be improved and the microstructure of the polymer produced can be optimized.

[0497]

[0498] Meanwhile, silica, alumina, magnesia, or a mixture thereof may be used as the carrier, or these materials may be dried at high temperature to remove moisture from the surface, thereby allowing the material to be used in a state in which it contains highly reactive hydroxyl or siloxane groups on the surface. In addition, the carriers dried at high temperature may further contain oxides, carbonates, sulfates, or nitrates such as Na2O, K2CO3, BaSO4, and Mg(NO3)2.

[0499]

[0500] The drying temperature of the carrier is preferably 200 to 800°C, more preferably 300 to 600°C, and most preferably 300 to 400°C. If the drying temperature of the carrier is less than 200°C, the moisture content is too high, causing the moisture on the surface to react with the cocatalyst. If the drying temperature is more than 800°C, the pores on the surface of the carrier merge, reducing the surface area. In addition, many hydroxyl groups on the surface disappear, leaving only siloxane groups, reducing the reaction sites with the cocatalyst, which is not preferable.

[0501]

[0502] In addition, the amount of hydroxyl groups on the surface of the carrier is preferably 0.1 to 10 mmol / g, and more preferably 0.5 to 5 mmol / g. The amount of hydroxyl groups on the surface of the carrier can be controlled by the manufacturing method and conditions of the carrier or drying conditions, such as temperature, time, vacuum or spray drying.

[0503]

[0504] In addition, during the polymerization reaction, an organoaluminum compound may be further added to remove moisture in the reactor, and the polymerization reaction may proceed in its presence. Specific examples of such organoaluminum compounds include trialkylaluminum, dialkylaluminum halides, alkylaluminum dihalides, aluminum dialkyl hydrides, or alkylaluminum sesquihalides, and more specific examples thereof include Al(C2H5)3, Al(C2H5)2H, Al(C3H7)3, Al(C3H7)2H, Al(i-C4H9)2H, Al(C8H 17 )3, Al(C 12 H 25 )3, Al(C2H5)(C 12 H 25 )2, Al(i-C4H9)(C 12 H 25 )2, Al(i-C4H9)2H, Al(i-C4H9)3, (C2H5)2AlCl, (i-C3H9)2AlCl or (C2H5)3Al2 Cl3, etc. can be mentioned. These organic aluminum compounds can be continuously introduced into the reactor, and can be introduced at a ratio of about 0.1 to 10 moles per 1 kg of the reaction medium introduced into the reactor to ensure proper moisture removal.

[0505]

[0506] Additionally, the polymerization pressure is about 1 to about 100 Kgf / cm 2 , preferably from about 1 to about 50 Kgf / cm 2 , more preferably about 5 to about 30 Kgf / cm 2 It could be.

[0507]

[0508] In addition, when a transition metal compound is used in a form supported on a carrier, the transition metal compound may be dissolved or diluted in an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, such as pentane, hexane, heptane, nonane, decane, and isomers thereof, an aromatic hydrocarbon solvent such as toluene and benzene, a hydrocarbon solvent substituted with a chlorine atom such as dichloromethane and chlorobenzene, and then introduced. It is preferable to use the solvent used here after removing a small amount of water or air, which act as a catalyst poison, by treating it with a small amount of alkyl aluminum, and it is also possible to carry out the process using an additional cocatalyst.

[0509]

[0510] In this way, the second ethylene-alpha-olefin copolymer (b) can be produced by copolymerizing ethylene and alpha-olefin using the metallocene catalyst described above.

[0511]

[0512] Specifically, the method for producing the second ethylene-alpha-olefin copolymer (b) can be carried out by a solution polymerization method using ethylene and alpha-olefin as raw materials in the presence of a catalyst composition including the above-described metallocene compound, applying a conventional device and contact technique.

[0513]

[0514] In addition, the above catalyst composition can be dissolved or diluted in an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, such as pentane, hexane, heptane, nonane, decane, and isomers thereof, an aromatic hydrocarbon solvent such as toluene and benzene, a hydrocarbon solvent substituted with a chlorine atom such as dichloromethane and chlorobenzene, and then introduced into the polymerization reaction described below. It is preferable to use the solvent used here after removing a small amount of water or air, which act as catalyst poisons, by treating it with a small amount of alkyl aluminum, and it is also possible to carry out the reaction by further using a cocatalyst as described above.

[0515]

[0516] The method for producing the above second ethylene-alpha-olefin copolymer (b) may be a method for copolymerizing ethylene and alpha-olefin using a continuous polymerization reactor or the like, but is not limited thereto.

[0517]

[0518] By the above-described manufacturing method, a second ethylene-alpha olefin copolymer (b) having the above-described physical properties can be manufactured.

[0519]

[0520] (biaxially oriented film)

[0521] The polyethylene composition having the above-described physical properties maintains excellent mechanical properties, productivity and stretching stability, and can stably form a biaxially stretched film having high shrinkage resistance, printability and transparency.

[0522]

[0523] Meanwhile, the above biaxially oriented film can be manufactured by a conventional film manufacturing method, except that the above polyethylene composition is used.

[0524]

[0525] For example, a polyethylene biaxially oriented film according to the present invention can be manufactured into a polyethylene composition sheet with a thickness of 0.75 mm using a Bruckner lab extruder line (L / D ratio: 42, Screw diameter: 25 mm, Melt / T-Die temperature: 220°C). Thereafter, a polyethylene biaxially oriented film can be manufactured by performing biaxial stretching on a polyethylene composition sheet having a width x length of 90 mm x 90 mm using a KARO 5.0 device. The specific film manufacturing method and conditions are as described in Test Example 3 described below.

[0526]

[0527] In addition, the polyethylene biaxially 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, and foaming agents. The types of the additives are not particularly limited, and general additives known in the art can be used.

[0528]

[0529] A polyethylene biaxially oriented 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.

[0530]

[0531] The above polyethylene biaxially oriented film may have a haze of 0.5% or more, 1.0% or more, 1.5% or more, or 1.6% or more, and 8.5% or less, 8.2% or less, 8.0% or less, 7.8% or less, 7.7% or less, 7.5% or less, 7.0% or less, 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, or 1.9% or less, as measured according to ASTM 1003.

[0532]

[0533] The above polyethylene biaxially oriented film has a gloss of 45 as measured according to ASTM 2457. o ) may be 65 GU or more, or 65 GU or more to 100 GU or less, preferably 66 GU or more, 68 GU or more, 70 GU or more, 75 GU or more, 80 GU or more, 82 GU or more, 84 GU or more, 85 GU or more, 88 GU or more, 90 GU or more, or 93 GU or more, and may also be 98 GU or less, or 95 GU or less.

[0534]

[0535] In particular, the above polyethylene biaxially stretched film satisfies an MD stretch ratio of 4 or more, or 5 or more, and a TD stretch ratio of 7 or more, or 8 or more.

[0536]

[0537] The above polyethylene biaxially oriented film may have a tensile strength in the MD direction of 100 MPa or more, 110 MPa or more, or 120 MPa or more, and may also be 150 MPa or less, as measured according to ASTM D 882, and a tensile strength in the TD direction of 160 MPa or more, 180 MPa or more, 190 MPa or more, or 200 MPa or more, and may also be 250 MPa or less.

[0538]

[0539] Accordingly, the average of the MD tensile strength and the TD tensile strength of the biaxially stretched film measured according to ASTM D 882 may be 130 MPa or more, preferably 140 MPa or more, 150 MPa or more, or 160 MPa or more, and may also be 200 MPa or less.

[0540]

[0541] In addition, the polyethylene biaxially oriented film may have a tensile modulus in the MD direction measured according to ASTM D 882 of 600 MPa or more, 610 MPa or more, 620 MPa or more, 630 MPa or more, 640 MPa or more, 645 MPa or more, or 650 MPa or more, and may also be 1000 MPa or less, and a tensile modulus in the TD direction of 800 MPa or more, 820 MPa or more, 850 MPa or more, 900 MPa or more, 920 MPa or more, 930 MPa or more, or 940 MPa or more, and may also be 1500 MPa or less.

[0542]

[0543] Accordingly, the average of the MD tensile modulus and the TD tensile modulus of elasticity of the biaxially stretched film measured according to ASTM D 882 may be 700 MPa or more, preferably 710 MPa or more, 730 MPa or more, 750 MPa or more, 770 MPa or more, 785 MPa or more, or 795 MPa or more, and may also be 1000 MPa or less.

[0544]

[0545] The above polyethylene biaxially oriented film may have a tensile elongation in the MD direction of 150% to 250%, or 160% to 230%, as measured according to ASTM D 882, and a tensile elongation in the TD direction of 50% to 100%, or 65% to 90%.

[0546]

[0547] The above polyethylene biaxially oriented film may have a tear strength in the MD direction measured according to ASTM 1922 standards of 5 N / mm or more, or 5 N / mm or more to 13.1 N / mm or less, or 5.3 N / mm or more to 11.5 N / mm or less, and a tear strength in the TD direction may be 1.2 N / mm or more, or 1.2 N / mm or more to 12 N / mm or less, or 1.4 N / mm or more to 11.7 N / mm or less. Preferably, the polyethylene biaxially oriented film may have a tear strength in the MD direction of 5.3 N / mm or more to 7.8 N / mm or less, or 5.3 N / mm or more to 7.1 N / mm or less, and a tear strength in the TD direction of 1.4 N / mm or more to 11.7 N / mm or less, or 1.4 N / mm or more to 1.6 N / mm or less.

[0548]

[0549] In addition, the polyethylene biaxially oriented film may have a puncture strength of 300 N / mm or more, measured according to EN 14477. Preferably, it may be 315 N / mm or more, 320 N / mm or more, 340 N / mm or more, 345 N / mm or more, 350 N / mm or more, or 355 N / mm or more, and may also be 400 N / mm or less.

[0550]

[0551] In the present invention, the physical properties of a biaxially stretched film can be measured according to the above-described standard, and the specific method is as described in Test Example 3 described below.

[0552]

[0553] In the present invention, by blending a first ethylene-alpha olefin copolymer having excellent flowability and extensibility as described above with a second ethylene-alpha olefin copolymer having excellent mechanical properties, the balance between mechanical properties and extensibility is controlled, thereby maintaining excellent mechanical properties, productivity, and extensibility stability, and stably producing a biaxially oriented film having high shrinkage resistance, printability, and transparency.

[0554]

[0555] The polyethylene according to the present invention has an excellent effect of being able to produce a biaxially oriented film having high shrinkage resistance, printability and transparency, with excellent film processability and productivity, along with excellent mechanical properties and stretching stability.

[0556]

[0557] 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.

[0558]

[0559] [Example]

[0560] <Preparation of metallocene compounds>

[0561] Synthesis Example 1

[0562]

[0563] t-butyl-O-(CH2)6-Cl was prepared using 6-chlorohexanol by the method described in the literature (Tetrahedron Lett. 2951(1988)), and t-butyl-O-(CH2)6-C5H5 was obtained by reacting it with Na(C5H5) [NaCp] (yield 60%, bp 80 o C / 0.1 mmHg).

[0564]

[0565] Also, -78 oAt C, t-butyl-O-(CH2)6-C5H5 was dissolved in tetrahydrofuran (THF), n-BuLi was slowly added, the temperature was raised to room temperature, and the reaction was carried out for 8 hours. The solution was then cooled to -78 o The above-synthesized lithium salt solution was slowly added to a suspension solution of ZrCl4(THF)2 (170 g, 4.50 mmol) / THF (30 mL) at C and further reacted at room temperature for 6 hours. All volatile substances were removed by vacuum drying, and hexane was added to the obtained oily liquid substance and filtered. After vacuum drying the filter solution, hexane was added and the solution was cooled to -20 o C) A precipitate was derived. The obtained precipitate was filtered at low temperature to obtain a white solid compound [t-butyl-O-(CH2)6-C5H4]2ZrCl2 (yield 92%).

[0566]

[0567] 1 H-NMR (300 MHz, CDCl3): δ 6.28 (t, J=2.6 Hz, 2H), 6.19 (t, J=2.6 Hz, 2H), 3.31 (t, 6.6 Hz, 2H), 2.62 (t, J=8 Hz), 1.7 - 1.3 (m, 8H), 1.17(s, 9H).

[0568]

[0569] 13 C-NMR (CDCl3): δ 135.09, 116.66, 112.28, 72.42, 61.52, 30.66, 30.31, 30.14, 29.18, 27.58, 26.00.

[0570]

[0571] Synthesis Example 2

[0572]

[0573] At room temperature, 50 g of Mg(s) was added to a 10 L reactor, and then 300 mL of THF was added. After adding approximately 20.5 g of I, the reactor temperature was maintained at 50°C. After the reactor temperature stabilized, 250 g of 6-t-butoxyhexyl chloride was added to the reactor at a rate of 5 mL / min using a feeding pump. As 6-t-butoxyhexyl chloride was added, the reactor temperature was observed to rise by approximately 4 to 5°C. 6-t-butoxyhexyl chloride was continuously added and stirred for 12 hours. After 12 hours of reaction, a black reaction solution was obtained. 2 mL of the resulting black solution was taken, and water was added to obtain an organic layer. 1 6-t-butoxyhexane was confirmed through H-NMR. It was found that the Grignard reaction proceeded well from the 6-t-butoxyhexane. Thus, 6-t-butoxyhexyl magnesium chloride was synthesized.

[0574]

[0575] After adding 500 g of trichloromethylsilane (MeSiCl3) and 1 L of THF to the reactor, the reactor temperature was cooled to -20°C. 560 g of the synthesized 6-t-butoxyhexyl magnesium chloride was added to the reactor at a rate of 5 mL / min using a feeding pump. After the feeding of the Grignard reagent was completed, the reactor temperature was slowly raised to room temperature and stirred for 12 hours. After 12 hours of reaction, it was confirmed that a white MgCl2 salt was produced. 4 L of hexane was added, and the salt was removed through a labdori to obtain a filter solution. The obtained filter solution was added to the reactor, and the hexane was removed at 70°C to obtain a pale yellow liquid. The obtained liquid 1The desired compound, methyl(6-t-butoxy hexyl)dichlorosilane, was confirmed through H-NMR.

[0576]

[0577] 1 H-NMR (300 MHz, CDCl3): δ 3.3(t, 2H), 1.5(m, 3H), 1.3(m, 5H), 1.2(s, 9H), 1.1(m, 2H), 0.7(s, 3H).

[0578]

[0579] 1.2 mol (150 g) of tetramethylcyclopentadiene and 2.4 L of THF were added to the reactor, and the reactor temperature was cooled to -20 ℃. 480 mL of n-BuLi was added to the reactor at a rate of 5 mL / min using a feeding pump. After adding n-BuLi, the reactor temperature was slowly raised to room temperature and stirred for 12 hours. After 12 hours of reaction, an equivalent amount of methyl(6-t-butoxy hexyl)dichlorosilane (326 g, 350 mL) was rapidly added to the reactor. The reactor temperature was slowly raised to room temperature and stirred for 12 hours, then cooled to 0 ℃ and 2 equivalents of t-BuNH2 were added. The reactor temperature was slowly raised to room temperature and stirred for 12 hours. After 12 hours of reaction, THF was removed, and 4 L of hexane was added to obtain a filter solution with salt removed through a labdori. After adding the filter solution back to the reactor, hexane was removed at 70°C to obtain a yellow solution. The obtained yellow solution was confirmed to be a compound of methyl(6-t-butoxyhexyl)-(tetramethylCpH)t-butylaminosilane through 1H-NMR.

[0580]

[0581] TiCl3(THF)3 (10 mmol) was rapidly added to the dilithium salt of the ligand synthesized from n-BuLi and the ligand dimethyl(tetramethylCpH)t-butylaminosilane in a THF solution at -78°C. The reaction solution was slowly warmed from -78°C to room temperature and stirred for 12 hours. After stirring for 12 hours, an equivalent amount of PbCl2 (10 mmol) was added to the reaction solution at room temperature and stirred for 12 hours. After stirring for 12 hours, a dark black solution with a bluish tint was obtained. After removing THF from the resulting reaction solution, hexane was added, and the product was filtered. After removing hexane from the obtained filter solution, it was confirmed from 1H-NMR that the desired ([methyl(6-t-buthoxyhexyl)silyl(η5-tetramethylCp)(t-Butylamido)]TiCl2) was (tBu-O-(CH2)6)(CH3)Si(C5(CH3)4)(tBu-N)TiCl2.

[0582]

[0583] 1 H-NMR (300 MHz, CDCl3): δ 3.3 (s, 4H), 2.2 (s, 6H), 2.1 (s, 6H), 1.8 - 0.8 (m), 1.4 (s, 9H), 1.2 (s, 9H), 0.7 (s, 3H).

[0584]

[0585] Synthesis Example 3

[0586] (1) Preparation of ligand A

[0587] 1-Benzothiophene 4.0 g (30 mmol) was dissolved in THF to prepare a 1-benzothiophene solution. Then, 14 mL (36 mmol, 2.5 M in hexane) of n-BuLi solution and 1.3 g (15 mmol) of CuCN were added to the 1-benzothiophene solution. Subsequently, 3.6 g (30 mmol) of tigloyl chloride was slowly added to the solution at -80 °C, and the resulting solution was stirred at room temperature for about 10 hours. Afterwards, 10% HCl was poured into the solution to quench the reaction, and the organic layer was separated with dichloromethane to obtain (2E)-1-(1-benzothien-2-yl)-2-methyl-2-buten-1-one as a beige solid.

[0588]

[0589]

[0590]

[0591] 1 H NMR (CDCl3): 7.85-7.82 (m, 2H), 7.75 (m, 1H), 7.44-7.34 (m, 2H), 6.68 (m, 1H), 1.99 (m, 3H), 1.92 (m, 3H)

[0592]

[0593] 5.0 g (22 mmol) of (2E)-1-(1-benzothien-2-yl)-2-methyl-2-buten-1-one prepared above was dissolved in 5 mL of chlorobenzene, and 34 mL of sulfuric acid was slowly added to the solution while stirring vigorously. Then, the solution was stirred at room temperature for about 1 hour. Afterwards, ice water was poured into the solution, and the organic layer was separated with ether solvent to obtain 4.5 g (91% yield) of 1,2-dimethyl-1,2-dihydro-3H-benzo[b]cyclopenta[d]thiophene-3-one as a yellow solid.

[0594]

[0595]

[0596] 1 H NMR (CDCl3): 7.95-7.91 (m, 2H), 7.51-7.45 (m, 2H), 3.20 (m, 1H), 2.63 (m, 1H), 1.59 (d, 3H), 1.39 (d, 3H)

[0597]

[0598] To a solution of 2.0 g (9.2 mmol) of 1,2-dimethyl-1,2-dihydro-3H-benzo[b]cyclopenta[d]thiophene-3-one in a mixed solvent of 20 mL of THF and 10 mL of methanol, 570 mg (15 mmol) of NaBH4 was added at 0°C. The solution was stirred at room temperature for about 2 hours. Afterwards, HCl was added to the solution to adjust the pH to 1, and the organic layer was separated with an ether solvent to obtain an alcohol intermediate.

[0599]

[0600] The alcohol intermediate was dissolved in toluene to prepare a solution. Then, 190 mg (1.0 mmol) of p-toluenesulfonic acid was added to the solution, and refluxed for about 10 minutes. The resulting reaction mixture was separated by column chromatography to obtain 1.8 g (9.0 mmol, 98% yield) of 1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophene (ligand A) in a liquid form with an orange-brown color.

[0601]

[0602]

[0603]

[0604] 1 H NMR (CDCl3): 7.81(d, 1H), 7.70(d, 1H), 7.33(t, 1H), 7.19(t, 1H), 6.46(s, 1H), 3.35(q, 1H), 2.14(s, 3H), 1.14(d, 3H)

[0605]

[0606] (2) Preparation of ligand B

[0607] 13 mL (120 mmol) of t-butylamine and 20 mL of ether solvent were added to a 250 mL schlenk flask, and 16 g (60 mmol) of (6-tert-butoxyhexyl)dichloro(methyl)silane and 40 mL of ether solvent were added to a 250 mL schlenk flask and a different 250 mL schlenk flask to prepare t-butylamine solution and (6-tert-butoxyhexyl)dichloro(methyl)silane solution, respectively. Then, the t-butylamine solution was cooled to -78 °C, and the (6-tert-butoxyhexyl)dichloro(methyl)silane solution was slowly injected into the cooled solution, which was stirred at room temperature for about 2 hours. The resulting white suspension was filtered to obtain 1-(6-(tert-butoxy)hexyl)-N-(tert-butyl)-1-chloro-1-methylsilanamine (ligand B), which was ivory in color and in liquid form.

[0608]

[0609]

[0610]

[0611] 1 H NMR (CDCl3): 3.29 (t, 2H), 1.52-1.29 (m, 10H), 1.20 (s, 9H), 1.16 (s, 9H), 0.40 (s, 3H)

[0612]

[0613] (3) Cross-linking of ligands A and B

[0614] A 250 mL Schlenk flask was charged with 1.7 g (8.6 mmol) of 1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophene (ligand A), and 30 mL of THF was added to prepare a ligand A solution. After cooling the ligand A solution to -78 °C, 3.6 mL (9.1 mmol, 2.5 M in hexane) of n-BuLi solution was added to the ligand A solution, and the mixture was stirred at room temperature overnight to obtain a purple-brown solution. The solvent of the purple-brown solution was replaced with toluene, and a solution of 39 mg (0.43 mmol) of CuCN dispersed in 2 mL of THF was injected into the solution to prepare solution A.

[0615]

[0616] Meanwhile, 1-(6-(tert-butoxy)hexyl)-N-(tert-butyl)-1-chloro-1-methylsilanamine (ligand B) and toluene were injected into a 250 mL Schlenk flask, and the prepared solution B was cooled to -78 °C. The previously prepared solution A was slowly injected into the cooled solution B. Then, the mixture of solutions A and B was stirred at room temperature overnight. Then, the produced solid was filtered and removed to obtain 4.2 g (> 99% yield) of 1-(6-(tert-butoxy)hexyl)-N-(tert-butyl)-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1-methylsilanamine (crosslinked product of ligands A and B) as a viscous liquid with a brown color.

[0617]

[0618]

[0619]

[0620] In order to confirm the structure of the crosslinked product of the above ligands A and B, the crosslinked product was lithiated at room temperature, and then a H-NMR spectrum was obtained using a sample dissolved in a small amount of pyridine-D5 and CDCl3.

[0621]

[0622] 1 H NMR (pyridine-D5 and CDCl3): 7.81 (d, 1H), 7.67 (d, 1H), 7.82-7.08 (m, 2H), 3.59 (t, 2H), 3.15 (s, 6H), 2.23-1.73 (m, 10H), 2.15 (s, 9H), 1.91(s, 9H), 1.68(s, 3H)

[0623]

[0624] (4) Preparation of transition metal compounds

[0625] A 250 mL Schlenk flask was charged with 4.2 g (8.6 mmol) of 1-(6-(tert-butoxy)hexyl)-N-(tert-butyl)-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1-methylsilanamine (crosslinked product of ligands A and B), and 14 mL of toluene and 1.7 mL of n-hexane were added to the flask to dissolve the crosslinked product. After cooling the solution to -78 °C, 7.3 mL (18 mmol, 2.5 M in hexane) of n-BuLi solution was added to the cooled solution. The solution was stirred at room temperature for about 12 hours. Next, 5.3 mL (38 mmol) of trimethylamine was added to the above solution, and the solution was stirred at about 40°C for about 3 hours to prepare solution C.

[0626]

[0627] Meanwhile, 22.3 g (8.6 mmol) of TiCl4(THF) and 10 mL of toluene were added to a separately prepared 250 mL Schlenk flask to prepare a solution D in which TiCl4(THF)2 was dispersed in toluene. The previously prepared solution C was slowly injected into the solution D at -78 °C, and the mixture of solutions C and D was stirred at room temperature for about 12 hours. Thereafter, the solution was depressurized to remove the solvent, and the obtained solute was dissolved in toluene. Then, the solid that was not dissolved in toluene was filtered off, and the solvent was removed from the filtered solution to obtain 4.2 g (83% yield) of a transition metal compound in the form of a brown solid.

[0628]

[0629]

[0630] 1 H NMR (CDCl3): 8.01 (d, 1H), 7.73 (d, 1H), 7.45-7.40 (m, 2H), 3.33 (t, 2H), 2.71 (s, 3H), 2.33 (d, 3H), 1.38 (s, 9H), 1.18 (s, 9H), 1.80-0.79(m, 10H), 0.79(d, 3H)

[0631]

[0632] Synthesis Example 4

[0633]

[0634] (1) Preparation of ligand compound: Synthesis of N-tert-butyl-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-dimethylsilanamine

[0635] 4.65 g (15.88 mmol) of the compound of chemical formula 3 was weighed and added to a 100 mL Schlenk flask, and 80 mL of THF was added. tBuNH2 (4 eq, 6.68 mL) was added at room temperature, and the mixture was reacted at room temperature for 3 days. After the reaction, THF was removed and the mixture was filtered with hexane. After drying the solvent, 4.50 g (yield: 86%) of a yellow liquid was obtained.

[0636]

[0637] 1 H-NMR (500 MHz, CDCl3): δ 7.99(d, 1H), 7.83(d, 1H), 7.35(dd, 1H), 7.24(dd, 1H), 3.49(s, 1H), 2.37(s, 3H), 2.17(s, 3H), 1.27(s, 9H), 0.19(s, 3H), -0.17(s, 3H).

[0638]

[0639] (2) Preparation of transition metal compounds

[0640] The above ligand compound (1.06 g, 3.22 mmol / 1.0 eq) and MTBE 16.0 mL (0.2 M) were placed in a 50 mL Schlenk flask and stirred first. n-BuLi (2.64 mL, 6.60 mmol / 2.05 eq, 2.5 M in THF) was added at -40 °C and reacted overnight at room temperature. After that, MeMgBr (2.68 mL, 8.05 mmol / 2.5 eq, 3.0 M in diethyl ether) was slowly added dropwise at -40 °C, followed by TiCl4 (2.68 mL, 3.22 mmol / 1.0 eq, 1.0 M in toluene) and reacted overnight at room temperature. After that, the reaction mixture was filtered through Celite using hexane. After drying the solvent, 1.07 g (yield: 82%) of a brown solid was obtained.

[0641]

[0642] 1H-NMR (500 MHz, CDCl3): δ 7.99(d, 1H), 7.68(d, 1H), 7.40(dd, 1H), 7.30(dd, 1H), 3.22(s, 1H), 2.67(s, 3H), 2.05(s, 3H), 1.54(s, 9H), 0.58(s, 3H), 0.57(s, 3H), 0.40(s, 3H), -0.45(s, 3H).

[0643]

[0644] <Manufacture of supported catalysts>

[0645] Catalyst Preparation Example 1: Preparation of Hybrid Supported Metallocene Catalyst 1

[0646] 3.0 kg of toluene solution was placed in a 20 L sus high-pressure reactor, and the reactor temperature was maintained at 40°C. 500 g of silica (Grace Davison, SP2212), dehydrated by applying vacuum at 600°C for 12 hours, was placed in the reactor, and after sufficient dispersion, 2.78 kg of 10 wt% methylaluminoxane (MAO) / toluene solution was placed, and the mixture was stirred at 80°C and 200 rpm for more than 15 hours.

[0647]

[0648] After lowering the reactor temperature to 40°C, 200 g of the first metallocene compound / toluene solution (7.8 wt% in toluene) prepared in Synthesis Example 1 was added to the reactor and stirred at 200 rpm for 1 hour. Next, 250 g of the second metallocene compound (b) / toluene solution (7.8 wt% in toluene) prepared in Synthesis Example 3 was added to the reactor and stirred at 200 rpm for 1 hour (molar ratio of the first metallocene compound and the second metallocene compound = 1:1.3).

[0649]

[0650] 70 g of cocatalyst (anilinium tetrakis(pentafluorophenyl)borate) was diluted in toluene and added to the reactor, followed by stirring at 200 rpm for more than 15 hours. After lowering the reactor temperature to room temperature, stirring was stopped, and the reaction solution was allowed to settle for 30 minutes before decantation.

[0651]

[0652] The toluene slurry was transferred to a filter dryer and filtered. 3.0 kg of toluene was added and stirred for 10 minutes, then stirring was stopped and filtered. 3.0 kg of hexane was added to the reactor and stirred for 10 minutes, then stirring was stopped and filtered. The mixture was dried under reduced pressure at 50°C for 4 hours to produce 500 g of a SiO2 hybrid supported catalyst 1.

[0653]

[0654] Catalyst Preparation Example 2: Preparation of Hybrid Supported Metallocene Catalyst 2

[0655] 5.0 kg of toluene solution was placed in a 20 L sus high-pressure reactor, and the reactor temperature was maintained at 40°C. 1,000 g of silica (SYLOPOL 948, manufactured by Grace Davison) dehydrated under vacuum at 600°C for 12 hours was placed in the reactor, and after sufficiently dispersing the silica, 80 g of the metallocene compound of Synthesis Example 1 dissolved in toluene was added, and the mixture was stirred at 40°C for 2 hours at 200 rpm for reaction. Afterwards, stirring was stopped, and the reaction solution was allowed to settle for 30 minutes, and then decantated.

[0656]

[0657] 2.5 kg of toluene was charged into the reactor, and 9.4 kg of a 10 wt% methylaluminoxane (MAO) / toluene solution was added, followed by stirring at 200 rpm at 40°C for 12 hours. After the reaction, stirring was stopped, the reaction solution was allowed to settle for 30 minutes, and then decanted. 3.0 kg of toluene was added, stirred for 10 minutes, stopped, and the reaction solution was allowed to settle for 30 minutes, and then decanted.

[0658]

[0659] 3.0 kg of toluene was charged into the reactor, and 314 mL of a 29.2 wt% metallocene compound / toluene solution of Synthesis Example 2 was charged into the reactor, and the mixture was stirred at 200 rpm at 40°C for 2 hours to allow for reaction. At this time, the molar ratio of the first metallocene compound to the second metallocene compound was 1:5 (number of moles of the first metallocene compound: number of moles of the second metallocene compound). After the reactor temperature was lowered to room temperature, stirring was stopped, and the mixture was allowed to settle for 30 minutes, after which the reaction solution was decantated.

[0660]

[0661] 2.0 kg of toluene was added to the reactor and stirred for 10 minutes. After stopping the stirring and allowing it to settle for 30 minutes, the reaction solution was decanted.

[0662]

[0663] 3.0 kg of hexane was added to the reactor, the hexane slurry was transferred to a filter dryer, and the hexane solution was filtered. The hexane solution was dried under reduced pressure at 40°C for 4 hours to produce a 910 g-SiO2 hybrid supported catalyst 2.

[0664]

[0665] <Manufacture of ethylene-alphaolefin copolymer>

[0666] Manufacturing Example 1: Manufacturing of ethylene / 1-hexene copolymer (PE-a)

[0667] An ethylene / 1-hexene copolymer (PE-a) was slurry polymerized through a monomodal polymerization process in the presence of the hybrid supported catalyst 1 prepared in the above catalyst preparation example 1.

[0668]

[0669] Specifically, the ethylene supply was 10.0 kg / hr, the comonomer 1-hexene input was 6.0 ml / min, and the hydrogen input was 1.85 g / hr, using the hybrid supported metallocene catalyst 1 manufactured in the catalyst manufacturing example 1, and using a hexane slurry stirred tank process polymerizer, polymerization reaction was performed in one loop reactor (polymerization temperature 93 ℃, polymerization pressure 7.7 kgf / cm 2 ) was used to prepare ethylene / 1-hexene copolymer (PE-a).

[0670]

[0671] After measuring the weight of the catalyst used in the polymerization reaction and the weight of the polymer produced from the polymerization reaction, the activity of the catalyst calculated as the weight ratio of the produced polymer to the weight of the catalyst used was 9.9 kgPE / gCat.hr.

[0672]

[0673] Manufacturing Example 2: Manufacturing of ethylene / 1-hexene copolymer (PE-b)

[0674] An ethylene / 1-hexene copolymer (PE-b) was slurry polymerized in the presence of the hybrid supported catalyst 2 prepared in the above catalyst preparation example 2.

[0675]

[0676] At this time, the polymerization reactor was a continuous polymerizer of isobutane (i-C4) slurry loop process, with a reactor volume of 140 L and a reaction flow rate of approximately 7 m / s. The gases (ethylene, hydrogen) required for polymerization and the comonomer 1-hexene were continuously fed continuously and the individual flow rates were adjusted to suit the target product. At this time, the ethylene feed amount was 31.1 kg / hr, the 1-hexene input amount was adjusted to 3.0 wt% relative to ethylene, and the hydrogen input amount was adjusted to 56 ppm relative to ethylene. In addition, the concentrations of all gases and the comonomer 1-hexene of Manufacturing Example 2 were confirmed by an on-line gas chromatograph. The supported catalyst was prepared as an isobutane slurry with a concentration of 4 wt% and introduced, the reactor pressure was maintained at approximately 40 bar, and the polymerization temperature was performed at approximately 80°C.

[0677]

[0678] Manufacturing Example 3: Manufacturing of ethylene / 1-hexene copolymer (PE-c)

[0679] An ethylene / 1-hexene copolymer (PE-c) was prepared in the same manner as in Preparation Example 3, except that the ethylene / 1-hexene copolymer was slurry polymerized as described in Preparation Example 2, but the 1-hexene input was adjusted to 2.5 wt% relative to ethylene, and the hydrogen input was adjusted to 70 ppm relative to ethylene.

[0680]

[0681] Manufacturing Example 4: Manufacturing of ethylene / 1-hexene copolymer (PE-d)

[0682] An ethylene / 1-hexene copolymer (PE-d) was prepared in the same manner as in Manufacturing Example 1, except that the ethylene / 1-hexene copolymer was slurry polymerized as described in Manufacturing Example 1, but the hydrogen input was adjusted to 3.10 g / hr relative to ethylene.

[0683]

[0684] Manufacturing Example 5: Manufacturing of ethylene / 1-octene copolymer (PE-e)

[0685] A 1.5 L continuous process reactor was preheated to 120°C while introducing 5 kg / h of hexane solvent and 0.31 kg / h of 1-octene. Triisobutylaluminum (Tibal, 0.045 mmol / min), the transition metal compound obtained in Synthesis Example 4, and dimethylanilinium tetrakis(pentafluorophenyl)borate cocatalyst (2.6 μmol / min) were simultaneously introduced into the reactor. Subsequently, 0.87 kg / h of ethylene and 10 cc / min of hydrogen gas were introduced into the reactor, and the copolymerization reaction was carried out at 160.0°C for more than 60 minutes in a continuous process at a pressure of 89 bar to obtain an ethylene / 1-octene copolymer (PE-e).

[0686]

[0687] Manufacturing Example 6

[0688] ME1000™ (manufactured by LG Chemical Co., Ltd.), a commercially available ethylene / 1-butene copolymer polyethylene product manufactured using a Zigler-Natta catalyst, was used as Manufacturing Example 6 (PE-f).

[0689]

[0690] Manufacturing Example 7

[0691] ME2500™ (manufactured by LG Chemical Co., Ltd.), a commercially available ethylene / 1-butene copolymer polyethylene product manufactured using a Zigler-Natta catalyst, was used as Manufacturing Example 7 (PE-g).

[0692]

[0693] <Test Example 1: Evaluation of the physical properties of polyethylene>

[0694] The physical properties of the ethylene-alphaolefin copolymers manufactured in the above manufacturing examples 1 to 7 were measured by the method described below and are shown in Table 1.

[0695]

[0696] (1) Density

[0697] According to the American Society for Testing and Materials ASTM D 1505 standard, density (g / cm) is measured using a density gradient pipe. 3 ) was measured.

[0698]

[0699] (2) Melting index

[0700] 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 polymer melted for 10 minutes was expressed.

[0701]

[0702] (3) Number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn)

[0703] For the ethylene-alphaolefin copolymers manufactured in the above Manufacturing Examples 1 to 7, the weight average molecular weight (Mw, g / mol) and number average molecular weight (Mn, g / mol) were measured using gel permeation chromatography (GPC, manufactured by Water) 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.

[0704]

[0705] 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 the solvent, and the flow rate was 1 mL / min. Each sample of the ethylene-alphaolefin copolymers prepared in Preparation Examples 1 to 5 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.

[0706]

[0707] Catalytic polymerization process monomer density (g / cm) 3 )MI 2.16kg(g / 10min)Mn(g / mol)Mw(g / mol)Mw / MnPreparation Example 1 (PE-a)MetalloceneSlurry1-Hexene0.9480.161500016100011.0Preparation Example 2 (PE-b)MetalloceneSlurry1-Hexene0.9380.64270001160004.3Preparation Example 3 (PE-c)MetalloceneSlurry1-Hexene0.9410.62290001060003.7Preparation Example 4 (PE-d)MetalloceneSlurry1-Hexene0.9430.63140001250008.9Preparation Example 5(PE-e)MetalloceneSolution1-Octene0.9006.0830000680002.3Preparation Example 6(PE-f)Zigler-Natta-1-Butene0.9520.91000013700014.1Preparation Example 7(PE-g)Zigler-Natta-1-Butene0.9522.0190001000005.3

[0708]

[0709] <Manufacture of polyethylene composition>

[0710] Examples 1 to 4 and Comparative Examples 1 to 76

[0711] Using the ethylene-alphaolefin copolymers of the above-described Manufacturing Examples 1 to 7, polyethylene compositions of Examples 1 to 4 and Comparative Examples 1 to 6 were prepared, respectively, with the compositions shown in Table 2 below.

[0712]

[0713] Specifically, a polyethylene composition was manufactured by extruding and granulating using Twin extruder equipment under the conditions of hopper 18 rpm, screw 350 rpm, and 220 ℃ (extruder: SMPLATEK TEK30MHS, L / D ratio: 40, die diameter: 4 mm).

[0714]

[0715] <Test Example 2: Evaluation of Physical Properties of Polyethylene Composition>

[0716] The physical properties of the polyethylene compositions manufactured in Examples 1 to 4 and Comparative Examples 1 to 6 were measured by the methods described below and are shown in Table 2.

[0717]

[0718] First, the melt index (MI) for the polyethylene composition 2.16 , MI 21.6 , MFRR = MI 21.6 / MI 2.16 ), density, weight average molecular weight (Mw, g / mol), number average molecular weight (Mn, g / mol), and molecular weight distribution (Mw / Mn, PDI) were measured using the same method as in Test Example 1.

[0719]

[0720] (4) Melting temperature (Tm), crystallization temperature (Tc) and crystallinity (Xc)

[0721] Using a differential scanning calorimeter (DSC, device name: DSC Q20, manufacturer: TA instrument), the melting temperature (Tm), crystallization temperature (Tc), and crystallinity (Xc) of the polyethylene compositions of Examples 1 to 4 and Comparative Examples 1 to 6 were measured.

[0722]

[0723] Specifically, the polyethylene composition was heated to 180 ℃ at 10 ℃ / min by increasing the temperature (Cycle 1), isothermalized at 180 ℃ for 5 minutes, cooled to 0 ℃ at 10 ℃ / min, isothermalized at 30 ℃ for 5 minutes, and then heated again to 180 ℃ at 10 ℃ / min (Cycle 2). In the DSC curve obtained through this, the temperature at the maximum point of the endothermic peak was measured as the melting temperature (Tm, ℃), and the temperature at the maximum point of the exothermic peak was measured as the crystallization temperature (Tc, ℃). At this time, the melting temperature (Tm) and the crystallization temperature (Tc) are expressed as the results measured in the second temperature increasing and decreasing section (Cycle 2), respectively.

[0724]

[0725] In addition, the Heat of Fusion △Hm was calculated as the area of ​​the melting peak in the second temperature-rising section (Cycle 2), and the crystallinity (Xc, %) was calculated by dividing this by the theoretical value of H0m = 293.6 J / g when the crystallinity is 100%.

[0726]

[0727] (3) Bimodality triangular area (BMTA)

[0728] Bimodality triangular area (BMTA) was measured for the polyethylene compositions of Examples 1 to 4 and Comparative Examples 1 to 6 using the following method.

[0729]

[0730] Specifically, using gel permeation chromatography (GPC, manufactured by Water) as described above, the weight average molecular weight (Mw, g / mol) was measured in accordance with the American Society for Testing and Materials ASTM D 6474 standard, and the area of ​​the BMTA (Bimodality triangular area) region in the logarithmic graph for the weight average molecular weight (Mw) of polyethylene thus measured, i.e., the GPC curve graph in which the x-axis is log MW and the y-axis is dw / dlogMw, was measured to calculate the ratio (wt%) to the total starch value of the GPC curve graph, which is shown in Table 2 below.

[0731]

[0732] Here, the BMTA (Bimodality triangular area) area is the peak with the widest area among the low molecular weight fractions with a log Mw of less than 5.0 of the peak maximum intensity in the GPC curve graph. low ) and the maximum intensity coordinates (X-axis: a, Y-axis: d) of the peak, and the peak with the largest area among the polymer fractions with a log Mw of 5.0 or more of the peak maximum intensity (Peak high ) defines the maximum intensity coordinate (X-axis: b, Y-axis: e), and the peak (Peak low ) and the low molecular weight fraction containing the peak (Peak high ) is defined as the coordinates of the intersection point (X-axis: c, Y-axis: f) where the high molecular weight fractions intersect, and corresponds to the triangular area connecting these three coordinates. That is, the low molecular weight fraction peak (Peak low ) and the maximum intensity coordinates (X-axis: a, Y-axis: d) of the polymer fraction peak (Peak high) and the area of ​​the BMTA (Bimodality triangular area) region connecting the maximum intensity coordinates (X-axis: b, Y-axis: e) and their intersection coordinates (X-axis: c, Y-axis: f) was measured using the method in Equation 1 below.

[0733] [Formula 1]

[0734]

[0735] In equation 1

[0736] ae represents the product of the maximum intensity X-axis coordinate value of the low-molecular fraction and the maximum intensity Y-axis coordinate value of the high-molecular fraction,

[0737] bf is the product of the maximum intensity X-axis coordinate value of the polymer fraction and the Y-axis coordinate value of the intersection point,

[0738] cd represents the product of the X-axis coordinate value of the intersection point and the Y-axis coordinate value of the maximum intensity of the low-molecular fraction,

[0739] db represents the product of the maximum intensity Y-axis coordinate value of the low-molecular fraction and the maximum intensity X-axis coordinate value of the high-molecular fraction.

[0740] ec represents the product of the maximum intensity Y-axis coordinate value of the polymer fraction and the X-axis coordinate value of the intersection point,

[0741] fa represents the product of the Y-axis coordinate value of the intersection point and the X-axis coordinate value of the maximum intensity of the low-molecular fraction.

[0742]

[0743] The specific method is as follows.

[0744]

[0745] - Peak deconvolution was performed from the Mw curve obtained through GPC analysis (Agilent PL-GPC 220).

[0746] : Curve fitting using Gaussian probability function

[0747] : Peak separation into low molecular weight fraction (log Mw 5.0 or less of peak maximum intensity) and high molecular weight fraction (log Mw 5.0 or more of peak maximum intensity)

[0748] : Selection of the peak with the largest area among the low-molecular fractions and the peak with the largest area among the high-molecular fractions

[0749]

[0750] - The area is calculated from the triangle derived by drawing a line connecting the point corresponding to the maximum intensity of each of the selected low-molecular fractions and high-molecular fractions and the point corresponding to the intersection of each curve, and this is defined as BMTA.

[0751] - If the maximum intensity coordinates of the above low molecular fraction are defined as (a, d), the maximum intensity coordinates of the high molecular fraction as (b, e), and the coordinates of the intersection point as (c, f), the calculation formula for BMTA is as shown in Equation 1 described above.

[0752]

[0753] Here, if the low molecular weight fraction and high molecular weight fraction are not separated in the GPC curve graph of the polyethylene composition, or the log Mw value of the intersection point is not between the log Mw values ​​of the maximum intensities of the low molecular weight fraction and the high molecular weight fraction (c > a, b or c < a, b), BMTA is defined as 0.

[0754]

[0755] The BMTA value measured in this way is calculated as a ratio (wt%) to the total starch value of the GPC curve graph and is shown in Table 2 below. When the BMTA ratio (wt%) is high, the degree of binary separation of the GPC curve is high, meaning that there is a large low-molecular-weight region, and accordingly, it can be seen that the processability is excellent.

[0756]

[0757] (6) Complex viscosity (Pa·s, 500rad / s)

[0758] The complex viscosity (Pa·s, measured under conditions of 190°C and 500 / s) of the polyethylene compositions of Examples 1 to 4 and Comparative Examples 1 to 6 was measured using the following method.

[0759]

[0760] Specifically, using a rotational rheometer (ARES Rheometer), 190 o The complex viscosity of the polyethylene compositions according to Examples 1 to 4 and Comparative Examples 1 to 6 was measured under conditions of a frequency (ω) of .05 rad / s to 500 rad / s in C.

[0761]

[0762] At this time, the complex viscosity of polyethylene was measured as the complex viscosity η*(ω0.05) and η*(ω500) according to frequency using a rotational rheometer ARES (Advanced Rheometric Expansion System, ARES G2) of TA Instruments (New Castle, Delaware, USA). A certain amount of polyethylene was placed in the ARES-G2 equipment and a 25 mm parallel plate and ring, and the sample was placed at 190 o At C, the gap was made 2.0 mm using parallel plates with a diameter of 25.0 mm by pressing them with fixtures above and below. Measurements were performed in dynamic strain frequency sweep mode, with a strain of 5% and a frequency (angular frequency) from 0.05 rad / s to 500 rad / s, with 10 points per decade for a total of 41 points. Among these, the complex viscosity measured at a frequency (ω) of 500 rad / s is shown in Table 2 below.

[0763]

[0764] (5) Cross Fractionation Chromatography (CFC) Analysis

[0765] Cross Fractionation Chromatography (CFC) analysis was performed on the polyethylene compositions of Examples 1 to 4 and Comparative Examples 1 to 6 by the following method, and the main chain weight average molecular weight (Mwmain, T≥90℃) of the high-crystalline fraction eluted at 90℃ or higher, the content ratio of the high-crystalline fraction eluted at 90℃ or higher (TREF, T≥90℃), and the content ratio of the medium- to low-crystalline fraction eluted at less than 90℃ (TREF, T<90℃) were measured.

[0766]

[0767] Cross-fractionation chromatography (CFC) measurement conditions (including TREF and GPC-IR analysis)

[0768] - Analysis equipment: Polymer Char CFC (Detector: Integrated Detector IR5 MCT)

[0769]

[0770] - Sample preparation and loading: Place 32 mg of polyethylene composition in a 10 mL vial and place in an autosampler, add 8 mL of 1,2,4-trichlorobenzene (TCB), dissolve at 160°C for 90 minutes, extract after nitrogen purge, and load onto a temperature rising elution temperature column (TREF column: temperature rising elution temperature column).

[0771]

[0772] - Crystallization: After adjusting the sample previously loaded onto the TREF column to 100 ℃, cool it from 100 ℃ to 35 ℃ at a rate of 0.5 ℃ / min.

[0773]

[0774] - Temperature rising elution temperature (TREF) analysis: The temperature of the previously crystallized sample was increased from 35°C to 125°C in 3°C intervals and fixed, and the fractions eluted at each temperature for 25 minutes were analyzed. Specifically, extraction was performed at 35°C for 25 minutes and analyzed, and then the temperature was increased in 3°C intervals for extraction and analysis, and finally, extraction was performed at 125°C for 25 minutes and analyzed.

[0775]

[0776] - GPC-IR analysis: In the TREF analysis above, the fractions eluted at each temperature were transferred to the GPC column of the GPC (PL-GPC220) device, the molecular weight of the eluted molecules was measured, and the number of short-chain branches (scb) of the eluted molecules at each temperature (branch content of 2 to 7 carbon atoms per 1,000 carbon atoms, unit: branches / 1,000C) was measured using the PerkinElmer Spectrum 100 FT-IR connected to the GPC (PL-GPC220).

[0777]

[0778] - High molecular weight molecular scb index (C high Mw, low SCB Measurement): From the results confirmed through CFC analysis, the fraction (wt%) of molecules satisfying a molecular weight of 150,000 g / mol or more and having a "scb number on 1000 carbon atoms or less" was measured. A higher value indicates a greater amount of high-molecular-weight / low-scb content molecules. The scb index of high-molecular-weight molecules was derived using the following method: Equation 2.

[0779] [Formula 2]

[0780]

[0781] In the above equation 2,

[0782] C Mw,i is the concentration of each fraction corresponding to a specific molecular weight (Mw) and a specific scb(i) number at each temperature through the previous CFC analysis.

[0783]

[0784] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Composition PE-a (70 wt%) + PE-e (30 wt%) PE-a (80 wt%) + PE-e (20 wt%) PE-a (90 wt%) + PE-e (10 wt%) PE-d (70 wt%) + PE-e (30 wt%) PE-b (70 wt%) + PE-e (30 wt%) PE-c (70 wt%) + PE-e (30 wt%) PE-c (90 wt%) + PE-e (10 wt%) PE-f (70 wt%) + PE-e (30 wt%) PE-a 100 wt% PE-g 100 wt% Density (g / cm) 3 )0.9350.9400.9450.9360.9290.9320.9390.9400.9480.952Bimodal Triangula Area, BMTA0.090.100.110.070.040.0100.070.120.02MI 2.16kg (g / 10min)0.380.250.191.111.081.260.751.570.162.0MFRR(MI 21.6 kg / MI 2.16 kg )91.888.289.663.634.736.338.535.2100.965.8Complex viscosity(complex viscosityat 190 ℃ 500 / s (Pa·s)568.6571.8622.5433.2682.7713.6750.7473.5766.3382.8High molecular weight / low scb molecular content(wt %,C high Mw, low SCB)18.221.324.115.86.412.114.211.224.020.9Tm(℃)127.6128.5129.3127.0126.5126.7127.6130.3129. 9134.3Tc(℃)112.8113.3113.7111.3113111.9112.8116.1114.2115.6Xc(%)60.464.767.460.655.258.46 4.351.872.266.7Mn(g / mol)1800017000160001400025000320002800089001500019000Mw(g / mol)1430001 4700015600098000104000101000112800115000161000100000Mw / Mn7.88.710.07.14.23.44.012.910.95.3

[0785]

[0786] <Test Example 3: Manufacturing and Property Evaluation of Biaxially Stretched Film>

[0787] Biaxially stretched films were manufactured using the polyethylene compositions manufactured in Examples 1 to 4 and Comparative Examples 1 to 6 by the following method, and the respective physical properties were measured and shown in Table 3.

[0788]

[0789] Manufacturing of biaxially oriented films

[0790] - Manufacture of polyethylene composition sheet with a thickness of 0.75 mm using Bruckner's lab extruder line (L / D ratio: 42, Screw diameter: 25 mm, Melt / T-Die temperature: 220 ℃)

[0791] - Biaxial stretching is performed on a polyethylene composition sheet measuring 90 mm x 90 mm in length and width using KARO 5.0 equipment.

[0792] - Sequential stretching (MD→TD) was performed after preheating for 80 seconds under the following conditions (Example 1 and Comparative Example 1: preheating and stretching at 122°C, Example 2 and Comparative Example 2: preheating and stretching at 124°C, Example 3, Comparative Example 3 and Comparative Example 4: preheating and stretching at 126°C)

[0793]

[0794] Biaxially stretched film property evaluation

[0795] - Haze (%): Measured according to ASTM 1003 standard

[0796] - Gloss (gloss 45) o ): Measured according to ASTM 2457 standard

[0797] - Tensile strength (MPa), tensile modulus (MPa), and tensile elongation (%): Measured in each MD / TD direction according to ASTM D 882 standard

[0798] - Tear strength (N / mm): Measured in each MD / TD direction according to ASTM 1922 standard

[0799] - Shrinkage rate (%): According to ASTM D 1204 standard, the length change rate is measured after shrinkage for 7 minutes at 100 ℃ or 120 ℃. Specifically, the shrinkage rate (%) is measured as [(1 - length after shrinkage) / length before shrinkage] * 100.

[0800] - Puncture strength (N / mm): Measured according to EN 14477 standard

[0801]

[0802] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Maximum Stretch Ratio (MD*TD) 5 * 85 * 85 * 85 * 85 * 85 * 85 * 84 * 65 * 8 Not Stretchable Haze (%) 1.9 5.6 7.7 3.4 2.7 2.9 13.6 9.5 8.4 - Gloss (45 o)938068848987566164-Tensile strength (Mpa)MD123125133114931036962146-TD203214233162150170112102266-MD, TD average163169.5183138121.5136.590.582206-Tensile modulus (Mpa)MD65380711016134866027696571465-TD9401207149682073591010496892048-MD, TD Average 796.5 100 71 298.5 7 16.5 6 10.5 7 5 6 9 0 9 7 3 1 7 5 7 - Tensile Elongation (%) MD 16 4 1 4 8 1 7 3 1 6 2 0 6 2 1 0 1 7 6 3 2 9 1 3 4 - TD 6 5 4 7 5 6 4 3 8 7 7 4 3 9 1 5 5 4 3 - MD, TD Average 114.5 9 7.5 114.5 102.5 1 4 6 5 1 4 2 1 0 7.5 2 4 2 8 9 - Tear Strength (N / mm) MD 6 5 7.15 3 7.89.111.88.615.40.6 - TD 1.6 1.4 1.4 1.11.72.42.37.67.00.3 - MD, TD Average 4.054.253.359.755.757.058.17.70.5-Shrinkage (@100, %)MD3.1000.83.12.80.30.80-TD8.343.82.87.56.82.22.14.2-MD+TD11.443.83.610.69.62.52.94.2-Shrinkage (@120, %)MD10.9656.312.99.141.73.5-TD25.5151412.329.322.611.57.111.7-MD+TD36.4211918.642.231.715.58.815.2-Puncture strength (N / mm)362355397.1315243259.2208.3211.4346-

[0803]

[0804] According to the results in Tables 2 and 3 above, it can be confirmed that the biaxially stretched films manufactured using the polyethylene compositions of Examples 1 to 4 having high molecular weight / low scb molecule content and bimodal molecular structural characteristics have significantly higher tensile strength and puncture strength than those of Comparative Examples 1 to 6. This can be inferred to be because, as in the polyethylene compositions of Examples 1 to 4, the higher the molecular weight / low scb content, the higher the content of molecules capable of forming a crystalline stretched framework, making it easier to form a stretched structure.

[0805]

[0806] Accordingly, the polyethylene composition of the present invention can effectively produce a biaxially oriented film having excellent stretching stability and mechanical properties, and at the same time, when produced as a biaxially oriented film, it exhibits low viscosity in the processing area, so that it can be said to be 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, The Bimodal Triangula Area (BMTA) derived from GPC analysis is 0.05 or greater, The complex viscosity (η*(ω500), complex viscosity) measured at a frequency (ω) of 500 rad / s is 650 Paㆍs or less, When cross fractionation chromatography (CFC) is analyzed, the molecular weight / low-scb molecular content (C) is 150,000 g / mol or more and the number of short-chain branches (scb) is 10 or less / 1000C. high Mw, low SCB ) is 15% by weight or more, Polyethylene composition.

2. In paragraph 1, Density measured according to ASTM D 1505 is 0.925 g / cm 3 Ideally 0.950 g / cm 3 Below, MI (MI) measured according to ASTM D 1238 2.16 , 190 ℃, 2.16 kg) is 0.1 g / 10 min or more and 2.0 g / 10 min or less, Polyethylene composition.

3. In paragraph 1, MFRR (MI) measured according to ASTM D 1238 21.6 kg / MI 2.16 kg , here MI 21.6 The value measured at 190 ℃ and 21.6 kg is MI 2.16 (measured at 190 ℃, 2.16 kg) is 60.0 or more, Polyethylene composition.

4. In paragraph 1, The number average molecular weight (Mn) is 14000 g / mol or more, The weight average molecular weight (Mw) is 980000 g / mol or more, Molecular weight distribution (Mw / Mn) is 5.0 or more and 11.5 or less, Polyethylene composition.

5. In paragraph 1, The melting point (Tm) is 127 ℃ or higher and 130 ℃ or lower, The crystallization temperature (Tc) is 111 ℃ or higher and 115 ℃ or lower, The crystallinity (Xc) is 55% or more and 70% or less, Polyethylene composition.

6. In paragraph 1, The above polyethylene composition (a) Density is 0.930 g / cm 3 0.960 g / cm 3 and the melting index (MI) 2.16 , 190 ℃, 2.16 kg load) of 0.15 g / 10 min to 2.0 g / 10 min, and molecular weight distribution (Mw / Mn) of 8.8 or more to 12.5 or less, a first ethylene-alpha olefin copolymer; and (b) Density is 0.870 g / cm 3 0.920 g / cm 3 and the melting index (MI) 2.16 , 190 ℃, 2.16 kg load) is 3.0 g / 10 min to 10.0 g / 10 min, and the molecular weight distribution (Mw / Mn) is 2.0 or more to 4.0 or less, and includes a second ethylene-alpha olefin copolymer; Containing 60 wt% or more and 90 wt% or less of the above first ethylene-alpha olefin copolymer (a), Containing 10 wt% or more and 40 wt% or less of the second ethylene-alpha olefin copolymer (b), Polyethylene composition.

7. In paragraph 6, The above first ethylene-alpha olefin copolymer (a) The number average molecular weight (Mn) is 12000 g / mol or more and 50000 g / mol or less, A weight average molecular weight (Mw) of 100,000 g / mol or more and 250,000 g / mol or less, Polyethylene composition.

8. In paragraph 6, The above first ethylene-alphaolefin copolymer (a) is an ethylene / 1-hexene copolymer, Polyethylene composition.

9. In paragraph 6, The above second ethylene-alphaolefin copolymer (b) The number average molecular weight (Mn) is 20,000 g / mol or more and 50,000 g / mol or less, A weight average molecular weight (Mw) of 50,000 g / mol or more and 100,000 g / mol or less, Polyethylene composition.

10. In paragraph 6, The above second ethylene-alphaolefin copolymer (b) is an ethylene / 1-octene copolymer, Polyethylene composition.

11. Comprising the polyethylene composition of paragraph 1, Biaxially oriented film.

12. In paragraph 11. MD elongation ratio is 4 or more, and TD elongation ratio is 7 or more, Biaxially oriented film.

13. In paragraph 11. The average of MD tensile strength and TD tensile strength measured according to ASTM D 882 is 130 MPa or more. Biaxially oriented film.

14. In paragraph 11. The average of MD tensile modulus and TD tensile modulus measured according to ASTM D 882 is 700 MPa or more. Biaxially oriented film.

15. In paragraph 11. A puncture strength of 300 N / mm or more as measured according to EN 14477, Biaxially oriented film.

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