Polyethylene and composition comprising same

Abstract

The present invention provides polyethylene having improved processability and resistance to environmental stress cracking as well as retaining excellent mechanical properties when combined with recycled polyethylene, and a polyethylene composition comprising same.

Description

Polyethylene and compositions containing the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0133315 filed September 30, 2024 and Korean Patent Application No. 10-2025-0141601 filed September 29, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0003] The present invention relates to polyethylene that improves processability and environmental stress crack resistance while maintaining excellent mechanical properties when combined with recycled polyethylene, and a polyethylene composition containing the same.

[0004]

[0005] The demand for polyethylene resin is steadily increasing and it is being used in various applications.

[0006] Recently, as environmental concerns have intensified, regulations aimed at curbing carbon dioxide emissions have been strengthened. In particular, as environmental pollution caused by the increased use of plastics has emerged as a serious issue, regulations at the manufacturing stage are being tightened, such as mandating the use of recycled resins, primarily in the United States. Consequently, manufacturers are required to add a certain amount of recycled resin when producing resin molded products, and eco-friendliness ratings are assigned based on the recycled resin content.

[0007] However, since recycled resin is already processed, its properties have already changed during the high-temperature processing, resulting in significantly lower impact strength, tensile strength, chemical resistance, and thermal stability compared to conventional virgin resin. To address this problem, methods have been attempted to include a certain level of virgin resin in compositions containing recycled resin. However, this requires an excessive amount of virgin resin to minimize the degradation of mechanical properties, and issues regarding the deterioration of key properties, such as environmental stress cracking resistance (ESCR), remain unresolved. Furthermore, this problem becomes more severe as the number of processing cycles increases.

[0008] In addition, in the case of polyethylene resin products using recycled resin, there is a problem in that it is difficult to satisfy both mechanical properties and processability due to a trade-off relationship.

[0009] Accordingly, there is an urgent need for research and development of polyethylene with improved resistance to environmental stress cracking and excellent mechanical properties as a virgin resin to be blended with such recycled resins. To achieve this, it is necessary to have an enhanced bimodal structure along with a broad molecular weight distribution; however, there have been difficulties in providing a polyethylene resin that simultaneously satisfies these requirements.

[0010]

[0011] The present invention aims to provide polyethylene and a polyethylene composition containing the same, which improves processability and resistance to environmental stress cracking while maintaining excellent mechanical properties such as drop impact strength and compressive strength when blended with recycled polyethylene.

[0012]

[0013] According to one embodiment of the invention, polyethylene is provided that satisfies (1) to (5) below.

[0014] (1) Density of 0.940 g / cm³ measured according to ASTM D 1505, 23 ℃ 3 more;

[0015] (2) The low molecular weight ratio represented by the following formula 1 is 3.5 to 5.5;

[0016] [Equation 1]

[0017] Low molecular weight ratio = (Integral value of the region where log Mw is 4.5 or less on a GPC curve graph with log Mw on the x-axis and dw / dlogMw on the y-axis) / (Integral value of the region where log Mw is 5.5 or greater on a GPC curve graph with log Mw on the x-axis and dw / dlogMw on the y-axis);

[0018] (3) Molecular weight distribution (PDI, Mw / Mn) is 20 to 50;

[0019] (4) SCB content is 3.0 to 5.0 pieces / 1000C;

[0020] (5) The BOCD index (Broad Orthogonal Co-monomer Distribution Index) expressed by Equation 2 below is 2.0 or higher;

[0021] [Equation 2]

[0022] BOCD Index =

[0023] In the above Equation 2,

[0024] When the weight-average molecular weight, molecular weight distribution, and SCB content are measured simultaneously and continuously using a GPC-IR device, and a molecular weight distribution curve is plotted with the log value of the weight-average molecular weight (Mw) (log Mw) as the x-axis and the molecular weight distribution (dwt / dlog Mw) for the log value as the y-axis, the SCB content on the high molecular weight side and the SCB content on the low molecular weight side refer to the SCB content values ​​at the right boundary and the left boundary, respectively, within the middle 60% range excluding the left and right ends of 20%.

[0025]

[0026] In addition, the present invention provides a polyethylene composition comprising virgin polyethylene (or Booster PE) and recycled polyethylene (PCW PE, Post consumer waste polyethylene), wherein the virgin polyethylene comprises the polyethylene described above.

[0027]

[0028] According to the present invention, by optimizing the molecular structure along with density, the ratio of the low molecular weight region, molecular weight distribution, SCB content, BOCD, etc., are all optimized, thereby improving the environmental stress cracking resistance (ESCR) and impact strength (IZOD) of the polyethylene. Through these characteristics, it is possible to provide polyethylene that improves processability and environmental stress cracking resistance while maintaining excellent mechanical properties such as drop impact strength and compressive strength when blended with recycled polyethylene.

[0029] Accordingly, when the above polyethylene is blended with a recycled resin using a virgin resin, a recycled polyethylene composition with improved processability and resistance to environmental stress cracking, along with excellent mechanical properties, can be provided.

[0030]

[0031] In the present invention, terms such as first, second, etc. are used to describe various components, and these terms are used solely for the purpose of distinguishing one component from another.

[0032] Furthermore, the terms used herein are used merely to describe exemplary embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “comprising,” or “having” are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0033] Additionally, terms such as "approximately" and "substantially" used throughout this specification are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the stated meaning, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure in which precise or absolute values ​​are mentioned to aid in understanding the invention.

[0034] In addition, in this specification, "part by weight" refers to a relative concept in which the weight of one substance is expressed as a ratio to the weight of another 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.

[0035] In addition, "weight % (% by weight)" refers to an absolute concept in which the weight of a substance is expressed as a percentage of the total weight. In the mixture given as an example above, the content of substance A, substance B, and substance C is 50 weight%, 20 weight%, and 30 weight%, respectively, out of 100% of the total weight of the mixture. At this time, the total content of each component does not exceed 100 weight%.

[0036] The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0037]

[0038] The present invention will be described in more detail below.

[0039]

[0040] According to one embodiment of the invention, polyethylene is provided in which the molecular structure is optimized along with the density to improve the ratio of the low molecular weight region, molecular weight distribution, and SCB content, etc., so as to improve processability and environmental stress cracking resistance (ESCR) while maintaining excellent mechanical properties even when combined with recycled polyethylene.

[0041]

[0042] Specifically, the polyethylene of the present invention has a density of 0.940 g / cm³ as measured according to ASTM D 1505, 23 ℃. 3 The above is the case, the low molecular weight ratio is 3.5 to 5.5, the molecular weight distribution (PDI, Mw / Mn) is 20 to 50, and the SCB content is 3.0 to 5.0 pieces / 1000C.

[0043]

[0044] The polyethylene of the present invention will be described in more detail below.

[0045]

[0046] Specifically, the polyethylene according to one embodiment of the present invention may be an ethylene homopolymer or an ethylene / alpha-olefin copolymer.

[0047] The above alpha-olefin may be one or more 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-eicocene, and mixtures thereof.

[0048] For example, the polyethylene according to the present invention may not contain the aforementioned alpha-olefin or may contain it in an amount of 10 weight% or less. That is, the alpha-olefin may be contained in an amount of 0 to 10 weight% or less. Specifically, the alpha-olefin may be 10 weight% or less, or 9.5 weight% or less, or 9 weight% or less, or 8.5 weight% or less, or 8 weight% or less, 7.5 weight% or less, or 7 weight% or less, or 6.5 weight% or less, or 6 weight% or less, or 5.5 weight% or less, or 5 weight% or less, or 4.5 weight% or less, or 4 weight% or less, or 3.5 weight% or less, or 3 weight% or less, or 2.5 weight% or less, or 2.2 weight% or less, or 2 weight% or less, or 1.8 weight% or less, or 1.5 weight% or less, but is not limited thereto. In addition, when the polyethylene is an ethylene / alpha-olefin copolymer, the alpha-olefin may be 0.1 wt% or more, or 0.2 wt% or more, or 0.3 wt% or more, or 0.4 wt% or more, or 0.5 wt% or more, or 0.6 wt% or more, or 0.7 wt% or more, or 0.85 wt% or more, or 0.9 wt% or more, or 1.0 wt% or more, or 1.1 wt% or more, or 1.2 wt% or more, but is not limited thereto.

[0049] For example, when the polyethylene according to the present invention is a copolymer, 1-hexene or 1-butene can be used as the alpha-olefin copolymerized with ethylene, and more specifically, 1-hexene can be used.

[0050] In addition, the polyethylene may be a dry blend of one or more or two or more ethylene homopolymers as described above, or a dry blend of one or more or two or more ethylene / alpha-olefin copolymers.

[0051]

[0052] Polyethylene according to one embodiment of the present invention has a density of 0.940 g / cm³ as measured according to ASTM D 1505, 23 ℃. 3 Satisfies the ideal.

[0053] More specifically, the density of the polyethylene is 0.940 g / cm³ 3 Above, or 0.941 g / cm³ 3 Above, or 0.942 g / cm³ 3 Above, or 0.943 g / cm³ 3 Above, or 0.944 g / cm³ 3 Above, or 0.945 g / cm³ 3 Above, or 0.946 g / cm³ 3 Above, 0.965 g / cm³ 3 Less than or equal to 0.964 g / cm³ 3 Less than or equal to 0.963 g / cm³ 3 Less than or equal to 0.962 g / cm³ 3 Less than or equal to 0.961 g / cm³ 3 Less than or equal to 0.960 g / cm³ 3 Less than or equal to 0.959 g / cm³ 3 Less than or equal to 0.958 g / cm³ 3 Less than or equal to 0.957 g / cm³ 3 Less than or equal to 0.956 g / cm³ 3 Less than or equal to 0.955 g / cm³ 3 It is as follows.

[0054] In the present invention, density can be measured according to ASTM D 1505 standards, for example, and may be a value measured at 23°C. As an example, the method for measuring such density is as described in the experimental examples described below.

[0055] When the density of the above-mentioned polyethylene satisfies the aforementioned range, when mixed with recycled polyethylene, it is possible to improve processability and environmental stress cracking resistance (ESCR) while minimizing the degradation of mechanical properties such as drop impact.

[0056]

[0057] In addition, the above polyethylene has a low molecular weight ratio represented by the following formula 1 of 3.5 to 5.5:

[0058] [Equation 1]

[0059] Low molecular weight ratio = (Integral value of the region where log Mw is 4.5 or less on a GPC curve graph with log Mw on the x-axis and dw / dlogMw on the y-axis) / (Integral value of the region where log Mw is 5.5 or greater on a GPC curve graph with log Mw on the x-axis and dw / dlogMw on the y-axis)

[0060] Preferably, the low molecular weight ratio of the polyethylene may be 3.5 or more, or 3.6 or more, or 3.7 or more, or 3.8 or more, or 3.9 or more, or 4.0 or more, and 5.5 or less, or 5.4 or less, or 5.3 or less.

[0061] As described above, by having a relatively high low molecular weight ratio, when blended with recycled polyethylene, it is possible to improve environmental stress cracking resistance (ESCR) while maintaining excellent mechanical properties and processability, such as drop impact resistance.

[0062] In the above Equation 1, the integral value of the region where the log Mw value is 4.5 or less and the integral value of the region where the log Mw value is 5.5 or more are measured using gel permeation chromatography (GPC). Specifically, the values ​​can be measured using the polystyrene conversion assay method via gel permeation chromatography, and a more specific measurement method is as described in the experimental examples below.

[0063]

[0064] In addition, the above polyethylene has a molecular weight distribution (PDI, Mw / Mn) of 20 to 50. Preferably, the molecular weight distribution (Mw / Mn) of the above polyethylene may be 20 or more, or 21 or more, or 22 or more, or 23 or more, or 24 or more, and may be 50 or less, or 49 or less, or 48 or less, or 47 or less, or 46 or less, or 45 or less, or 44 or less, or 43 or less, or 42 or less, or 41 or less, or 40 or less, or 39 or less, or 38 or less, or 37 or less, or 36 or less, or 35 or less, or 34 or less, or 33 or less, or 32 or less, or 31 or less, or 30 or less, or 29 or less, or 28 or less, or 27 or less, or 26 or less.

[0065] As described above, the polyethylene according to one embodiment of the present invention can have a bimodal structure by having a very broad molecular weight distribution while reinforcing the proportion of the low molecular weight region within the molecular structure. Accordingly, when blended with recycled polyethylene, it can maintain excellent mechanical properties such as drop impact strength and flexural modulus, while improving processability and environmental stress crack resistance (ESCR).

[0066] The above molecular weight distribution is measured using gel permeation chromatography (GPC). Specifically, it can be measured using the polystyrene conversion assay method via gel permeation chromatography.

[0067] Here, the molecular weight distribution can be calculated by measuring the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polyethylene and dividing the weight-average molecular weight by the number-average molecular weight.

[0068] Specifically, the Polymer Char GPC-IR instrument can be used as the gel permeation chromatography (GPC) device, and a Polymer Laboratories PLgel MIX-B 300 mm long column can be used. At this time, the measurement temperature is 160 ℃, 1,2,4-trichlorobenzene can be used as the solvent, and the flow rate can be applied at 1 mL / min. The polyethylene sample can be pretreated by dissolving it in trichlorobenzene containing 0.0125% butylated hydroxytoluene (BHT) at 160 ℃ for 10 hours using a GPC analyzer (PL-GP220), prepared to a concentration of 10 mg / 10 mL, and then supplied in an amount of 200 microliters (μL). The values ​​of Mw and Mn can be derived using a calibration curve formed using a polystyrene standard specimen. Nine types of polystyrene standard specimens with weight-average molecular weights can be used: 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.

[0069]

[0070] In addition, the above polyethylene has an SCB content of 3.0 to 6.0 pieces / 1,000C.

[0071] Preferably, the SCB content of the polyethylene may be 3.0 or more, or 3.1 or more, or 3.2 or more, or 3.3 or more, or 3.4 or more, or 3.5 or more, or 3.6 or more, or 3.7 or more, or 3.8 or more, and 6.0 or less, or 5.9 or less, or 5.8 or less, or 5.7 or less, or 5.6 or less, or 5.5 or less, or 5.4 or less, or 5.3 or less, or 5.2 or less.

[0072] In the present invention, SCB (Short Chain Branch) refers to a short chain bonded to the polymer main chain in a branch-like form in polyethylene; specifically, it refers to a short branched chain having 2 to 7 carbon atoms bonded to the main chain of polyethylene. It is a short branched chain formed when an alpha-olefin having 4 or more carbon atoms, such as 1-butene, 1-hexene, or 1-octene, is used as a comonomer, and its content may be proportional to the content of the α-olefin monomers contained in the polymer chains. The SCB content refers to the number of branched chains having 2 to 7 carbon atoms per 1,000 carbon atoms (unit: number / 1,000 C), and can be calculated through analysis using gel permeation chromatography (GPC). In the present invention, measurements were taken at 160 ℃ using GPC-IR equipment and calculated through FT-IR analysis, and the specific analysis method is described in detail in the experimental examples below.

[0073]

[0074] Meanwhile, the polyethylene according to the present invention may be one in which the BOCD index, BMI, weight average molecular weight (Mw), and melt index are also controlled while optimizing the molecular structure, such as the ratio of the low molecular weight region, molecular weight distribution, and SCB content, along with the density as described above.

[0075]

[0076] Specifically, the polyethylene may have a weight average molecular weight (Mw) of 100,000 g / mol to 500,000 g / mol. Preferably, the weight average molecular weight of the polyethylene may be 100,000 g / mol or more, or 105,000 g / mol or more, or 110,000 g / mol or more, or 115,000 g / mol or more, or 120,000 g / mol or more, or 121,000 g / mol or more, or 122,000 g / mol or more, or 123,000 g / mol or more, or 124,000 g / mol or more, or 125,000 g / mol or more.However, considering compatibility with recycled polyethylene, the weight average molecular weight is 500,000 g / mol or less, or 490,000 g / mol or less, or 480,000 g / mol or less, or 470,000 g / mol or less, or 460,000 g / mol or less, or 450,000 g / mol or less, or 440,000 g / mol or less, or 430,000 g / mol or less, or 420,000 g / mol or less, or 410,000 g / mol or less, or 400,000 g / mol or less, or 390,000 g / mol or less, or 380,000 g / mol or less, or 370,000 g / mol or less, or 360,000 g / mol or less, or 350,000 g / mol or less. 340,000 g / mol or less, or 330,000 g / mol or less, or 320,000 g / mol or less, or 310,000 g / mol or less, or 300,000 g / mol or less, or 290,000 g / mol or less, or 280,000 g / mol or less, or 270,000 g / mol or less, or 260,000 g / mol or less, or 250,000 g / mol or less, or 240,000 g / mol or less, or 230,000 g / mol or less, or 220,000 g / mol or less, or 210,000 g / mol or less, or 200,000 g / mol or less, or 190,000 g / mol or less, or 180,000 g / mol or less, or 170,000 It may be g / mol or less, or 160,000 g / mol or less, or 150,000 g / mol or less, or 140,000 g / mol or less.

[0077] The above weight-average molecular weight is measured using gel permeation chromatography (GPC). Specifically, it can be measured using the polystyrene conversion assay method via gel permeation chromatography.

[0078] By having the weight average molecular weight as described above, the molecular weight distribution of the polyethylene is optimized, and when combined with recycled polyethylene, environmental stress crack resistance (ESCR) can be improved along with excellent mechanical properties.

[0079]

[0080] In addition, the above polyethylene has a melt index (MI). 2.16 (ASTM D 1238, 190 ℃, 2.16 kg) may be 0.1 to 1.5 g / 10 min. Preferably, the melt index (MI) of the polyethylene 2.16 ) may be 0.1 g / 10min or more, or 0.2 g / 10min or more, or 0.3 g / 10min or more, or 0.4 g / 10min or more, or 0.5 g / 10min or more, and 1.5 g / 10min or less, or 1.4 g / 10min or less, or 1.3 g / 10min or less, or 1.2 g / 10min or less, or 1.1 g / 10min or less, or 1.0 g / 10min or less.

[0081] As described above, the melt index (MI) of polyethylene 2.16 By having ), it has excellent compatibility with recycled polyethylene, optimizes the molecular weight distribution of polyethylene, and can improve processability and environmental stress crack resistance (ESCR) along with excellent mechanical properties when combined with recycled polyethylene.

[0082]

[0083] In addition, the above polyethylene may have a BOCD index (Broad Orthogonal Co-monomer Distribution Index) represented by Formula 2 below of 2.0 or higher:

[0084] [Equation 2]

[0085] BOCD =

[0086] In the above Equation 2,

[0087] The high molecular weight SCB content and low molecular weight SCB content refer to the SCB content values ​​at the right boundary and left boundary, respectively, within the middle 60% range excluding the left and right ends, when a molecular weight distribution curve is plotted with the logarithm of the weight-average molecular weight (Mw) (log Mw) as the x-axis and the molecular weight distribution (dwt / dlog Mw) for the logarithm as the y-axis, when the weight-average molecular weight (Mw) log value (log Mw) is simultaneously and continuously measured using a GPC-IR device and a molecular weight distribution curve is plotted with the log value (dwt / dlog Mw) corresponding to the log value as the y-axis.

[0088] Preferably, the BOCD index of the polyethylene may be 2.0 or higher, or 2.1 or higher, or 2.2 or higher, or 2.3 or higher, or 2.4 or higher, or 2.5 or higher, or 2.6 or higher, or 2.7 or higher, or 2.8 or higher, or 2.9 or higher, or 3.0 or higher, or 3.1 or higher, or 3.2 or higher, or 3.3 or higher, or 3.4 or higher, or 3.5 or higher, or 3.6 or higher, or 3.7 or higher, and may be 8.0 or lower, or 7.5 or lower, or 7.0 or lower, or 6.5 or lower, or 6.0 or lower, or 5.8 or lower, or 5.5 or lower, or 5.4 or lower, or 5.3 or lower.

[0089] The BOCD structure used in this specification refers to a structure in which the content of short chain branches (SCBs) in polyethylene is concentrated in the high molecular weight main chain, for example, a structure in which the content of comonomers such as alpha olefins is concentrated in the high molecular weight main chain, that is, a structure in which the SCB content increases as the molecular weight increases.

[0090] In this case, if the BOCD index is 0 or less, it is not a polymer with a BOCD structure, and if it is greater than 0, it is considered to be a polymer with a BOCD structure; the larger the value, the more it has a structure with a high SCB content in the high molecular weight region.

[0091] The polyethylene according to one embodiment of the invention has a high BOCD index of 2.0 or higher, thereby having a high comonomer content in the high molecular weight portion, and as a result, can exhibit high environmental stress crack resistance (ESCR) along with excellent mechanical properties.

[0092]

[0093] In addition, the above polyethylene may have a BMI (bimodality index) of 2.0 or higher, represented by the following Formula 3:

[0094] [Equation 3]

[0095]

[0096] In the above Equation 3,

[0097] Peaks A and B are the peaks of the low molecular weight fraction (peak A) and the high molecular weight fraction (peak B), respectively, when the peaks forming the low molecular weight fraction and the high molecular weight fraction are separated using peak deconvolution (Gaussian Probability Function) on a GPC curve graph for polyethylene with the x-axis being log Mw and the y-axis being dw / dlogMw.

[0098] logMw(peak A) and logMw(peak B) are the logMw values ​​at the maximum dw / dlogMw for each peak, and

[0099] AR(peak A) and AR(peak B) are the area ratio (AR) of each peak relative to the total area of ​​the derived GPC curve graph of peaks A and B.

[0100] In other words, the above BMI refers to the interval between the peak forming the low molecular weight fraction (peak A) and the peak forming the high molecular weight fraction (peak B) when a molecular weight distribution curve is plotted with the logarithm of the weight-average molecular weight (Mw) (log Mw) on the x-axis and the molecular weight distribution for said logarithm (dwt / dlog M) on the y-axis. If the above BMI index is greater than 0, it can be considered as a polymer having a bimodal molecular weight distribution, and the higher the value, the higher the bimodality of the structure.

[0101] Preferably, the BMI of the polyethylene may be 2.0 or higher, or 2.1 or higher, or 2.2 or higher, or 2.3 or higher, or 2.4 or higher, or 2.5 or higher, or 2.6 or higher, and 3.0 or lower, or 2.9 or lower, or 2.8 or lower, or 2.75 or lower.

[0102] According to one embodiment of the invention, the polyethylene has a high BMI of 2.0 or higher, and can exhibit high environmental stress crack resistance (ESCR) along with excellent processability due to its reinforced bimodal structure.

[0103]

[0104] In addition, the above polyethylene may have an environmental stress cracking resistance (ESCR) of 20,000 hours or more as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%).

[0105] More specifically, the polyethylene may have an environmental stress crack resistance (ESCR) of 20,000 hours or more, or 25,000 hours or more, or 30,000 hours or more, or 32,000 hours or more, or 35,000 hours, and 100,000 hours or less, or 90,000 hours or less, or 80,000 hours or less, or 70,000 hours or less, or 60,000 hours or less.

[0106]

[0107] In addition, the above polyethylene may have an Izod impact strength of 4.0 kgf·cm / cm or more as measured according to ASTM D256.

[0108] More specifically, the polyethylene may have an Izod impact strength measured according to ASTM D256 of 4.0 kgf·cm / cm or more, or 4.1 kgf·cm / cm or more, or 4.2 kgf·cm / cm or more, or 4.3 kgf·cm / cm or more, or 4.4 kgf·cm / cm or more, or 4.5 kgf·cm / cm or more, or 4.6 kgf·cm / cm or more, or 4.7 kgf·cm / cm or more, or 4.8 kgf·cm / cm or more, or 4.9 kgf·cm / cm or more, or 5.0 kgf·cm / cm or more, and 10.0 kgf·cm / cm or less, or 9.0 kgf·cm / cm or less, or 8.5 kgf·cm / cm or less.

[0109]

[0110] In addition, the above polyethylene may have a complex viscosity of 400 Pa.s or less when measured at 190 ℃ and 500 rad / s using an ARES-G2 instrument.

[0111] More specifically, the polyethylene may have a complex viscosity measured at 190°C and 500 rad / s using an ARES-G2 instrument of 400 Pa.s or less, or 390 Pa.s or less, or 380 Pa.s or less, or 370 Pa.s or less, or 360 Pa.s or less, or 350 Pa.s or less, and 200 Pa.s or more, or 210 Pa.s or more, or 220 Pa.s or more, or 230 Pa.s or more, or 240 Pa.s or more, or 250 Pa.s or more.

[0112]

[0113] Meanwhile, the polyethylene of the present invention can be produced by homopolymerizing ethylene in the presence of a metallocene catalyst in a slurry loop process, or by copolymerizing ethylene with a comonomer such as an alpha-olefin, and a more detailed synthesis method can be referenced in the examples.

[0114]

[0115] For example, the above-mentioned novel polyethylene may be manufactured by introducing hydrogen gas in the presence of a catalyst composition comprising one first metallocene compound represented by the following chemical formula 1 and two or more second metallocene compounds represented by the following chemical formula 2.

[0116] [Chemical Formula 1]

[0117] (Cp 1 R a ) n (Cp 2 R b )M 1 Z 1 3-n

[0118] In the above chemical formula 1,

[0119] M 1 It is a Group 4 transition metal;

[0120] Cp 1 and Cp 2 are respectively cyclopentadiennyl, and these are C1-20 Substituted with or unsubstituted with hydrocarbons;

[0121] R a and R b are identical or different from each other, and independently hydrogen, C 1-20 Alkyl, C 1-20 Alkoxy, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 6-20 Aryloxy, C 2-20 Alkenyl, C 7-40 alkylaryl of, C 7-40 arylalkyl of, C 8-40 of Arylalkenil, C 2-20 C comprising alkynyl, or one or more heteroatoms selected from the group consisting of N, O, and S. 2-20 It is heteroaryl, provided that R a and R b At least one of them is C 1-20 alkyl or C 7-20 is an arylalkyl, and the other one is C 2-20 It is an alkoxyalkyl;

[0122] Z 1 Silver is a 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 It is an aryl alkoxy;

[0123] n is 1 or 0 and;

[0124] [Chemical Formula 2]

[0125]

[0126] In the above chemical formula 2,

[0127] C1 is any one of the ligands represented by the following chemical formulas 3 to 6, and

[0128] [Chemical Formula 3]

[0129]

[0130] [Chemical Formula 4]

[0131]

[0132] [Chemical Formula 5]

[0133]

[0134] [Chemical Formula 6]

[0135]

[0136] In the above chemical formulas 3 to 6,

[0137] R1 to R6 are identical or different from one another, and each independently contains hydrogen, C 1-30 Alkyl, C 1-30 Alkoxy, C 2-30 Alkoxyalkyl, C 6-30 Aril, C 6-30 Aryloxy, C 2-30 Alkenyl, C 2-30 Alkinyl, C 3-30 Cycloalkyl, C 7-40 alkylaryl of, C 8-40 alkenylaryl of, C 8-40 alkynylaryl of, C 7-40 arylalkyl of, C 8-40 aryl alkenyl of, or C 8-40 It is an aryl alkinil of, and

[0138] M is Ti, Zr, or Hf, and

[0139] Z is -O-, -S-, -NR7- or -PR7-, and

[0140] R7 is hydrogen, C 1-30 Alkyl, C 6-30 Aril, C 2-30 Alkenyl, C 2-30 Alkinyl, C 3-30 Cycloalkyl, C 7-40 alkylaryl of, C 8-40 alkenylaryl of, C 8-40 alkynylaryl of, C 7-40 arylalkyl of, C 8-40of Arylalkenil, C 8-40 arylalkinyl of, C 1-30 Alkoxysilyl group, C 6-30 Aryloxysilyl, C 1-30 Alkylsilyl group, or C 1-30 It is a silylalkyl group, and

[0141] X1 and X2 are identical or different from each other and each independently halogen, C 1-30 Alkyl, C 2-30 Alkenyl, C 7-30 Alkylaryl, C 7-30 Arylalkyl, C 6-20 Aryl, substituted or unsubstituted C 1-30 Alkylidene, substituted or unsubstituted amino group, C 2-30 Alkylalkoxy, or C 7-30 It is an aryl alkoxy, and

[0142] T is or And,

[0143] T1 is C, Si, Ge, Sn, or Pb, and

[0144] Y1 is hydrogen, hydrogen, C 1-30 Alkyl, C 1-30 Alkoxy, C 2-30 Alkoxyalkyl, C 6-30 Aril, C 6-30 Aryloxy, C 2-30 Alkenyl, C 2-30 Alkinyl, C 3-30 Cycloalkyl, C 7-40 alkylaryl of, C 8-40 alkenylaryl of, C 8-40 alkynylaryl of, C 7-40 arylalkyl of, C 8-40 aryl alkenyl of, or C 8-40 arylalkinyl, silyl group (-SiH3), C 1-30 Alkoxysilyl group, C 2-30 Alkoxyalkylsilyl group, C 6-30 Aryloxysilyl, C 1-30 Haloalkyl, C 6-30 Haloaryl, or -NR9R 10 And,

[0145] Y2 is C2-30 Alkoxyalkyl, or C 7-40 It is an aryloxyalkyl, and

[0146] R9 and R 10 Each independently hydrogen, C 1-30 Alkyl, C 6-30 Aril, C 2-30 Alkenyl, C 2-30 Alkinyl, C 3-30 Cycloalkyl, C 7-40 alkylaryl of, C 8-40 alkenylaryl of, C 8-40 alkynylaryl of, C 7-40 arylalkyl of, C 8-40 aryl alkenyl of, or C 8-40 It is an arylalkynyl, or connected to form an aliphatic or aromatic ring.

[0147]

[0148] Meanwhile, unless otherwise specifically limited in this specification, the following terms may be defined as follows.

[0149]

[0150] Halogens can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0151]

[0152] C 1-30 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-chain or cyclic alkyl group. More specifically, the C1-20 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, etc.

[0153]

[0154] C 2-30 The alkenyl group can be a straight-chain, branched-chain, or cyclic alkenyl group. Specifically, C 2-30 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 The cyclic alkenyl group or C 5-10 It may be a cyclic alkenyl group. More specifically, C 2-20 The alkenyl group of may be an ethenyl group, a propenyl group, a butenyl group, a pentenyl group, or a cyclohexanyl group, etc.

[0155]

[0156] C 6-30 Aryl can refer to monocyclic, bicyclic, or tricyclic aromatic hydrocarbons. Specifically, C 6-30 The aryl group can be a phenyl group, a naphthyl group, or anthracenyl group, etc.

[0157]

[0158] C 7-40 Alkylaryl may refer to a substituent in which one or more hydrogens of an aryl are substituted by an alkyl group. Specifically, C 7-40 The alkylaryl may be methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl, or cyclohexylphenyl, etc.

[0159]

[0160] C 7-40 Arylalkyl may refer to a substituent in which one or more hydrogens of an alkyl group are substituted by an aryl group. Specifically, C 7-40 The arylalkyl group may be a benzyl group, phenylpropyl or phenylhexyl, etc.

[0161]

[0162] The above C1-20 Examples of alkoxy groups include methoxy groups, ethoxy groups, phenyloxy groups, cyclohexyloxy groups, etc., but are not limited to these.

[0163]

[0164] The above C 2-20 The alkoxyalkyl group is a functional group in which one or more hydrogens of the alkyl group described above are substituted with an alkoxy group, specifically, alkoxyalkyl groups such as methoxymethyl group, methoxyethyl group, ethoxymethyl group, iso-propoxymethyl group, iso-propoxyethyl group, iso-propoxyhexyl group, tert-butoxymethyl group, tert-butoxyethyl group, tert-butoxyhexyl group; or aryloxyalkyl groups such as phenoxyhexyl group, but is not limited thereto.

[0165]

[0166] The above C 1-20 alkylsilyl group or C 1-20 The alkoxysilyl group is a functional group in which 1 to 3 hydrogens of -SiH3 are substituted with 1 to 3 alkyl groups or alkoxy groups as described above, and specifically, examples include 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, but are not limited thereto.

[0167]

[0168] The above C 1-20 The silylalkyl group is a functional group in which one or more hydrogens of the alkyl group described above are substituted with a silyl group, and specifically, examples include -CH2-SiH3, methylsilylmethyl group or dimethylethoxysilylpropyl group, but are not limited thereto.

[0169]

[0170] The above sulfonate group has the structure -O-SO2-R', where R' is C1-20 It may be an alkyl group. Specifically, C 1-20 Sulfonate groups include methanesulfonate groups or phenylsulfonate groups, but are not limited to these.

[0171]

[0172] The above heteroaryl comprises one or more of N, O, and S as heteroelements, C 2-20 As heteroaryls, 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, quinazolinyl group, quinoxalinyl group, phthalazinyl group, pyridopyrimidinyl group, pyridopyrazinyl group, pyrazinopyrazinyl group, isoquinoline group, indole group, carbazole group, benzoxazole group, benzimidazole group, benzothiazole group, benzocarbazole group, benzothiophen group, dibenzothiophen group, benzofuranyl group, phenanthroline, There are isooxazolyl groups, thiadiazolyl groups, phenothiazinyl groups and dibenzofuranyl groups, but are not limited to these.

[0173]

[0174] The substituents described above may be optionally substituted with one or more substituents selected from the group consisting of hydroxyl groups; halogens; alkyl groups or alkenyl groups, aryl groups, alkoxy groups; alkyl groups or alkenyl groups, aryl groups, alkoxy groups comprising one or more heteroatoms of groups 14 to 16; silyl groups; alkylsilyl groups or alkoxysilyl groups; phosphine groups; phosphide groups; sulfonate groups; and sulfone groups, within the range of producing the same or similar effects as the desired effect.

[0175]

[0176] Furthermore, the fact that two adjacent substituents are connected to form an aliphatic or aromatic ring means that the atom(s) of the two substituents and the valence (atoms) to which the two substituents are bonded are connected to form a ring. Specifically, -NR9R 10 R9 and R 10 Examples of these interconnected groups forming an aliphatic ring include piperidinyl groups, and -NR9R 10 R9 and R 10 Examples of groups connected to form an aromatic ring include pyrrolyl groups.

[0177]

[0178] In addition, group 4 transition metals include titanium (Ti), zirconium (Zr), hafnium (Hf), etc., but are not limited to these.

[0179]

[0180] For example, the first metallocene compound represented by the above chemical formula 1 is Cp 1 and Cp 2 As a non-crosslinked compound containing a ligand of, Cp 1 and Cp 2 The ligands of may be identical or different from each other, and are each cyclopentadiennyl, and C 1-10 It can be substituted with 1 or more alkyl groups or 1 to 3.

[0181]

[0182] Also, the above Cp 1 and Cp 2 The ligand of can easily control characteristics such as the chemical structure, molecular weight, molecular weight distribution, mechanical properties, and transparency of the olefin polymer produced by adjusting the degree of steric hindrance effect according to, for example, the type of substituted functional group. Specifically, the above Cp 1 and Cp 2 The ligands of are R, respectively. a and R b It is replaced with, at this time, the above Ra and R b are identical or different from each other, and independently, hydrogen, C 1-20 Alkyl, C 2-20 Alkoxyalkyl, C 7-40 C comprising an arylalkyl, or one or more heteroatoms selected from the group consisting of N, O, and S. 2-12 It can be heteroaryl, and more specifically, C 1-10 Alkyl, C 2-10 Alkoxyalkyl, C 7-20 C comprising an arylalkyl, or one or more heteroatoms selected from the group consisting of N, O, and S. 4-12 It can be heteroaryl. However, R a and R b At least one of them is C 1-20 alkyl or C 7-20 is an arylalkyl, and the rest R a and R b At least one of them is C 2-20 It is an alkoxyalkyl.

[0183]

[0184] Also, the above Cp 1 and Cp 2 Between the ligands of , M 1 Z 1 3-n This exists, M 1 Z 1 3-n can affect the storage stability of metal complexes. To ensure this effect more effectively, Z 1 Each independently is a halogen or C 1-20 It may be an alkyl group, and more specifically, it may be F, Cl, Br, or I independently. Also, the above M 1 It may be Ti, Zr or Hf; Zr or Hf; or Zr.

[0185]

[0186] Among the first transition metal compounds above, Cp in Chemical Formula 11 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, but R a and R b At least one of them is an alkyl such as methyl or butyl, or an aryl alkyl such as phenylpropyl, and the remainder R a and R b At least one of them may be a compound having an alkoxyalkyl group such as a t-butoxyhexyl group, more specifically -(CH2)n-OR (wherein R is a straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms, and n is an integer from 2 to 4).

[0187]

[0188] The first metallocene compound represented by the above chemical formula 1 may be, for example, a compound represented by one of the following structural formulas, but is not limited thereto.

[0189]

[0190]

[0191] In addition, the second metallocene compound comprises an aromatic ring compound containing thiophene as a different ligand and a base compound containing a group 14 or 15 atom, the different ligands are cross-linked by -T-, and has a structure in which M(X1)(X2) exists between the different ligands.

[0192]

[0193] More specifically, in the above chemical formula 2, M is Ti, Zr, or Hf, and more specifically, may be Ti.

[0194]

[0195] Also, R1 to R4 are each independently hydrogen, or C 1-20It is an alkyl, and more specifically, it can be hydrogen or methyl.

[0196]

[0197] Also, R5 and R6 each independently C 1-10 It is alkyl, and more specifically, both R5 and R6 can be methyl.

[0198]

[0199] Also, Z is -NR7-, and the above R7 is C 1-10 Alkyl, more specifically C such as t-butyl 3-10 It can be a branched alkyl.

[0200]

[0201] Also, T is And, the above T1 is C or Si, and Y1 is C 1-20 Alkyl, C 1-20 Alkoxy, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-30 Alkylaryl, C 7-30 Arylalkyl, C 6-20 Aryloxy, or C 7-30 It is aryloxyalkyl, and Y2 is C 2-20 Alkoxyalkyl, or C 7-30 It is an aryloxyalkyl, and more specifically, Y1 can be any one of a methyl group, an ethyl group, an n-propyl group, and an n-butyl group, and Y2 is C 2-20 Alkoxyalkyl, or C 7-30 It is an aryloxyalkyl, and more specifically, Y2 may be any one of 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, a tert-butoxyhexyl group, and a phenoxyhexyl group.

[0202]

[0203] Also, X1 and X2 are each independently halogen or C 1-20 It is an alkyl, and more specifically, it can be chloro or methyl.

[0204]

[0205] For example, as the second metallocene compound, compounds represented by the following chemical formulas 2a to 2d may be exemplified, and among the compounds represented by the following chemical formulas 2a to 2d, two or more compounds of different structures are included.

[0206] According to one embodiment of the present invention, as the second metallocene compound, a combination of two compounds represented by the following formula 2a and two compounds represented by the following formula 2b, or a combination of two compounds represented by the following formula 2a and two compounds represented by the following formula 2c, or a combination of two compounds represented by the following formula 2a and two compounds represented by the following formula 2d, or a combination of two compounds represented by the following formula 2b and two compounds represented by the following formula 2c, or a combination of two compounds represented by the following formula 2b and two compounds represented by the following formula 2d, or a combination of two compounds represented by the following formula 2c and two compounds represented by the following formula 2d may be used.

[0207] In this way, by mixing and using two or more compounds with different structures among the compounds represented by the following chemical formulas 2a to 2d as the second metallocene compound together with one first metallocene compound, it is possible to produce polyethylene with optimized density, low molecular weight ratio, molecular weight distribution, SCB content, and BOCD index.

[0208] [Chemical Formula 2a]

[0209]

[0210] [Chemical Formula 2b]

[0211]

[0212] [Chemical Formula 2c]

[0213]

[0214] [Chemical Formula 2d]

[0215]

[0216] In the above chemical formulas 2a to 2d, R1 to R7, M, X1, X2, T1, Y1, and Y2 are as previously defined.

[0217]

[0218] More specifically, in the second metallocene compound of the above formulas 2a to 2d, M is Ti, Zr, or Hf, more specifically Ti; and R1 to R4 are each independently hydrogen, or C 1-20 It is alkyl, more specifically hydrogen or methyl; R5 and R6 are each independently C 1-10 It is alkyl, more specifically, both R5 and R6 are methyl; and the above R7 is C 1-10 It is an alkyl, and more specifically, C such as t-butyl. 3-10 It is a branched alkyl; above, T1 is C or Si, and Y1 is C 1-20 Alkyl, C 1-20 Alkoxy, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-30 Alkylaryl, C 7-30 Arylalkyl, C 6-20 Aryloxy, or C 7-30 It is aryloxyalkyl, and Y2 is C 2-20 Alkoxyalkyl, or C 7-30 It is an aryloxyalkyl, more specifically, Y1 is any one of a methyl group, an ethyl group, an n-propyl group, and an n-butyl group, and Y2 is C 2-20 Alkoxyalkyl, or C 7-30 It is an aryloxyalkyl, more specifically, Y2 is any one of 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, a tert-butoxyhexyl group, and a phenoxyhexyl group, and X1 and X2 are each independently a halogen or C 1-20 It may be a compound that is alkyl, and more specifically, chloro or methyl.

[0219]

[0220] More specifically, specific examples of the second metallocene compound may include compounds having the following structures, but are not limited thereto:

[0221]

[0222] .

[0223] In addition, the first and second metallocene compounds in the catalyst composition may be included in a molar ratio of 1:0.3 to 1:3, and more specifically, in a molar ratio of 1:0.3 or higher, or 1:0.4 or higher, or 1:0.5 or higher, and in a molar ratio of 1:3 or lower, or 1:2 or lower.

[0224] In addition, two types of second metallocene compounds of different structures in the catalyst composition may be included in a molar ratio of 1:0.1 to 1:1, and more specifically, in a molar ratio of 1:0.1 or higher, or 1:0.2 or higher, or 1:0.4 or higher, and in a molar ratio of 1:1 or lower, or 1:0.8 or lower.

[0225]

[0226] Meanwhile, the catalyst composition may further include a carrier, in which case the first and second metallocene compounds are used in a state supported on the carrier.

[0227]

[0228] Specific examples of the above carriers 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.

[0229]

[0230] In addition, the catalyst composition may further include a co-catalyst to improve high activity and process stability, and the co-catalyst may be, more specifically, an alkylaluminoxan-based co-catalyst such as methylaluminoxan, ethylaluminoxan, isobutylaluminoxan, or butylaluminoxan.

[0231]

[0232] Meanwhile, in a polyethylene composition according to one embodiment of the present invention, the aforementioned novel polyethylene is prepared by polymerizing ethylene using the aforementioned catalyst composition, and the polymerization process can be carried out as a monomodal (or unimodal) polymerization process in which a polymerization reaction is performed under single polymerization reaction conditions using a single catalyst in a single reactor, and more specifically, it can be carried out in a single loop-type slurry reactor in the presence of the aforementioned hybrid supported catalyst.

[0233]

[0234] At this time, the polymerization temperature may be 25 ℃ to 500 ℃, preferably 25 ℃ to 200 ℃, and more preferably 50 ℃ to 150 ℃. 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 / ㎠.

[0235] For example, the polyethylene may be a dry blend of one or more ethylene homopolymers or two or more ethylene copolymers prepared in the presence of a metallocene catalyst as described above, or a dry blend of one or more ethylene / alpha-olefin copolymers or two or more ethylene / alpha-olefin copolymers.

[0236]

[0237] Meanwhile, according to another embodiment of the invention, a polyethylene composition is provided comprising virgin polyethylene (or Booster PE) and recycled polyethylene (PCW PE, Post consumer waste polyethylene), wherein the virgin polyethylene is the polyethylene of the above-described embodiment or a mixture thereof.

[0238]

[0239] In particular, the polyethylene composition according to the present invention uses polyethylene in which the molecular structure, including density, the proportion of the low molecular weight region, molecular weight distribution, and SCB content, is all optimized as described above. This allows for the improvement of environmental stress crack resistance (ESCR) while maintaining excellent mechanical properties when combined with recycled polyethylene, thereby ensuring excellent drop impact strength and environmental stress crack resistance comparable to that of virgin resin even when combined with recycled polyethylene.

[0240]

[0241] For example, in a polyethylene composition, the virgin polyethylene may be included in an amount of 30 to 70 parts by weight based on 100 parts by weight of the total composition, and the recycled polyethylene may be included in an amount of 30 to 70 parts by weight based on 100 parts by weight of the total composition.

[0242] More specifically, in terms of improving the ESCR of the polyethylene composition, enhancing the effect of suppressing carbon dioxide emissions, and achieving physical properties equivalent to those of virgin resin, the content of the virgin polyethylene may be 30 parts by weight or more, or 40 parts by weight or more, and 70 parts by weight or less, or 60 parts by weight or less, and the content of the recycled polyethylene resin (PCW PE) may be 30 parts by weight or more, or 40 parts by weight or more, and 70 parts by weight or less, or 60 parts by weight or less.

[0243]

[0244] Meanwhile, the above-mentioned recycled polyethylene (PCW PE) has a density of 0.940 to 0.960 g / cm³ as measured according to ASTM D 1505, 23 ℃. 3 It may be. More specifically, the density of the recycled polyethylene (PCW PE) is 0.943 g / cm³ 3 Above, or 0.945 g / cm³ 3 Above, or 0.948 g / cm³ 3 Above, 0.950 g / cm³ 3 It may be greater than 0.958 g / cm³ 3 Less than or equal to 0.956 g / cm³ 3 Less than or equal to 0.955 g / cm³ 3 Less than or equal to 0.953 g / cm³ 3 It may be less than.

[0245] In addition, the above recycled polyethylene (PCW PE) has a melt index (MI 2.16 , measured at 190 ℃, under a 2.16 kg load) may be 0.1 g / 10 min to 0.7 g / 10 min.

[0246] In addition, the above recycled polyethylene (PCW PE) may have an environmental stress crack resistance (ESCR) of 20 to 60 hours as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%).

[0247]

[0248] Meanwhile, the polyethylene composition according to the present invention can secure excellent ESCR close to that of virgin resin while increasing the recycled polyethylene content.

[0249] For example, the above polyethylene composition may have an environmental stress cracking resistance (ESCR) of 300 hours or more as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%).

[0250] More specifically, the polyethylene composition may have an environmental stress crack resistance (ESCR) of 300 hours or more, or 350 hours or more, or 400 hours or more, or 440 hours or more, or 500 hours or more, and 1,000 hours or less, or 950 hours or less, or 900 hours or less, or 800 hours or less.

[0251] In addition, the polyethylene composition has a density of 0.940 g / cm³ as measured according to ASTM D 1505, 23 ℃. 3 The above is true, and more specifically, 0.940 to 0.960 g / cm³ 3 It could be

[0252] At this time, the measurement method for the density, ESCR, etc. of the polyethylene composition is as described above with respect to polyethylene, and the polyethylene composition can be measured instead of polyethylene using this method, and specific details are omitted.

[0253]

[0254] In addition, the above polyethylene composition may have a flexural modulus of 13,400 kg / ㎠ or more as measured according to ASTM D256.

[0255] More specifically, the polyethylene composition may have a flexural modulus measured according to ASTM D256 of 13,400 kg / ㎠ or more, or 13,500 kg / ㎠ or more, or 13,800 kg / ㎠ or more, and 20,000 kg / ㎠ or less, or 18,000 kg / ㎠ or less, or 17,000 kg / ㎠ or less, or 16,000 kg / ㎠ or less, or 15,000 kg / ㎠ or less.

[0256]

[0257] In addition, the above polyethylene composition may have a complex viscosity of 350 Pa.s or less when measured at 190 ℃ and 500 rad / s using an ARES-G2 instrument.

[0258] More specifically, the polyethylene composition may have a complex viscosity measured at 190°C and 500 rad / s using an ARES-G2 instrument that is 350 Pa.s or less, or 330 Pa.s or less, or 320 Pa.s or less, or 310 Pa.s or less, and 200 Pa.s or more, or 210 Pa.s or more, or 220 Pa.s or more.

[0259]

[0260] Preferred embodiments are presented below to aid in understanding the present invention. However, the following embodiments are provided merely to facilitate a better understanding of the invention and do not limit the scope of the invention.

[0261]

[0262] <Example>

[0263] Manufacture of Polyethylene

[0264] Example 1-1

[0265] High-density new polyethylene was manufactured through a single slurry polymerization process as follows.

[0266] First, 25 kg / h of isobutane and 30 kg / h of ethylene were injected into a single slurry loop reactor, and hydrogen was injected at a flow rate of 245 ppm, respectively. Then, the following first metallocene compound (1), second metallocene compound (2), and second metallocene compound (3) were hybridly supported on a silica carrier (Grace Davison, SP2212) and a catalyst (molar ratio of first metallocene compound (1), second metallocene compound (2), and second metallocene compound (3) = 1:0.41:0.2) and a comonomer (1-hexene) were injected. The comonomer used here was 1-hexene, and the input amount was 5.4 wt% relative to the ethylene input amount. At this time, the reactor was maintained between 90 and 93 ℃, and the pressure was 42 kg / cm². 3 Virgin polyethylene (HDPE), a high-density ethylene / 1-hexene copolymer in powder form, was produced by maintaining the copolymerization process and then passing it through a solvent removal facility and a dryer.

[0267] (1) (2)

[0268] (3)

[0269]

[0270] Examples 1-2

[0271] In Example 1-1, high-density new polyethylene was prepared in the same manner as in Example 1, except that the hydrogen flow rate was changed to 390 ppm and the amount of 1-hexene added was changed to 2.7 wt%.

[0272]

[0273] Examples 1-3

[0274] In Example 1-1, high-density new polyethylene was prepared in the same manner as in Example 1, except that the hydrogen flow rate was changed to 415 ppm and the amount of 1-hexene added was changed to 3.1 wt%.

[0275]

[0276] Examples 1-4

[0277] High-density new polyethylene was prepared in the same manner as in Example 1-1, except that the hydrogen flow rate was changed to 430 ppm and the amount of 1-hexene added was changed to 2.3 wt%.

[0278]

[0279] Examples 1-5

[0280] High-density new polyethylene was prepared in the same manner as in Example 1-1, except that the hydrogen flow rate was changed to 350 ppm and the amount of 1-hexene added was changed to 1.9 wt%.

[0281]

[0282] Examples 1-6

[0283] High-density new polyethylene was prepared in the same manner as in Example 1-1, except that the hydrogen flow rate was changed to 415 ppm and the amount of 1-hexene added was changed to 2.0 wt%.

[0284]

[0285] Comparative Example 1-1

[0286] A commercially available high-density polyethylene (HDPE) product manufactured using a metallocene catalyst (LG Chem product, product name SP4701) was prepared as Comparative Example 1-1.

[0287]

[0288] Comparative Example 1-2

[0289] For a commercially available high-density polyethylene (HDPE) product (LG Chem product, product name SP4701) manufactured using a metallocene catalyst, a density of 0.957 g / cm³ 3 , Melt Index (MI 2.16 A high-density polyethylene product (LG Chem’s ME8000 product) with a density of 8 g / 10 min was dry-blended and prepared as Comparative Example 1-2.

[0290]

[0291] Comparative Examples 1-3

[0292] The same polymerization process as in Example 1 was performed, but the following first metallocene compound (1) and second metallocene compound (2) were copolymerized and supported on a silica carrier (Grace Davison, SP2212) and a catalyst was added (molar ratio of the first metallocene compound to the second metallocene compound = 2:1), and the composition was changed to 200 ppm hydrogen and 2.2 wt% coconomer(1-hexene), after which homopolymerization was performed with a density of 0.957 g / cm³ 3 , Melt Index (MI 2.16 Comparative Examples 1-3 were prepared by dry blending with a high-density polyethylene product (LG Chem’s ME8000 product) with a density of 8 g / 10 min.

[0293] (1) (2)

[0294]

[0295] Comparative Examples 1-4

[0296] The same polymerization process as in Comparative Example 1-3 was performed, but with the hydrogen content changed to 220 ppm and the coconomer (1-hexene) content to 1.5 wt% to homopolymerize, thereby producing the high-density new polyethylene of Comparative Example 1-4.

[0297]

[0298] Comparative Examples 1-5

[0299] The same polymerization process as in Comparative Example 1-3 was performed, but with hydrogen changed to 150 ppm and coconomer(1-hexene) to 1.92 wt% to homopolymerize, thereby producing the high-density new polyethylene of Comparative Example 1-5.

[0300]

[0301] Comparative Examples 1-6

[0302] The same polymerization process as in Comparative Example 1-3 was performed, but with hydrogen changed to 80 ppm and Commonomer (1-hexene) to 1.87 wt% to homopolymerize, thereby producing the high-density new polyethylene of Comparative Example 1-6.

[0303]

[0304] Comparative Examples 1-7

[0305] The same polymerization process as in Comparative Example 1-3 was performed, but with the hydrogen content changed to 300 ppm and the coconomer (1-hexene) content to 1.21 wt% to homopolymerize, thereby producing the high-density new polyethylene of Comparative Example 1-7.

[0306]

[0307] Comparative Example 1-8

[0308] The same polymerization process as in Comparative Example 1-3 was performed, but with the hydrogen content changed to 220 ppm and the coconomer (1-hexene) content to 1.99 wt% to homopolymerize, thereby producing the high-density new polyethylene of Comparative Example 1-8.

[0309]

[0310] Comparative Example 1-9

[0311] The same polymerization process as in Comparative Example 1-3 was performed, but with the hydrogen content changed to 290 ppm and the coconomer (1-hexene) content to 2.07 wt% to homopolymerize, thereby producing the high-density new polyethylene of Comparative Example 1-9.

[0312]

[0313] Comparative Example 1-10

[0314] The same polymerization process as in Comparative Examples 1-3 was performed, but with the hydrogen content changed to 120 ppm and the coconomer (1-hexene) content to 2.22 wt% to homopolymerize, thereby producing the high-density new polyethylene of Comparative Examples 1-10.

[0315]

[0316] <Preparation of Polyethylene Composition>

[0317] Example 2-1

[0318] 50 wt% of the polyethylene prepared in Example 1-1 using virgin polyethylene and 50 wt% of recycled polyethylene (PCW PE, Post consumer waste polyethylene) were dry blended, and then extruded through a twin screw extruder to prepare a polyethylene composition (PCR Compound).

[0319] Recycled polyethylene is as follows:

[0320] BSN Hakusan natural color product from Hakusan Plastic Co., Ltd., Melt Index MI 2.16 (Measured under a 2.16 kg load at 190 ℃ according to ASTM D 1238 (Condition E)) 0.15–0.2 g / 10 min, and the density (measured according to ASTM D 1505 standard) is 0.951–0.953 g / cm³ 3 , ESCR (time to F50 (50% destruction) measured under 50°C conditions using 10% Igepal CO-630 Solution according to ASTM D 1693) is 40~50 hours.

[0321]

[0322] Example 2-2

[0323] A polyethylene composition was prepared in the same manner as in Example 2-1, except that the polyethylene prepared in Example 1-2 was used instead of the polyethylene prepared in Example 1-1 using new polyethylene.

[0324]

[0325] Examples 2-3

[0326] A polyethylene composition was prepared in the same manner as in Example 2-1, except that the polyethylene prepared in Example 1-3 was used instead of the polyethylene prepared in Example 1-1 using new polyethylene.

[0327]

[0328] Examples 2-4

[0329] A polyethylene composition was prepared in the same manner as in Example 2-1, except that the polyethylene prepared in Example 1-4 was used instead of the polyethylene prepared in Example 1-1 using new polyethylene.

[0330]

[0331] Examples 2-5

[0332] A polyethylene composition was prepared in the same manner as in Example 2-1, except that the polyethylene prepared in Example 1-5 was used instead of the polyethylene prepared in Example 1-1 using new polyethylene.

[0333]

[0334] Examples 2-6

[0335] A polyethylene composition was prepared in the same manner as in Example 2-1, except that polyethylene prepared in Example 1-6 was used instead of polyethylene prepared in Example 1-1 using new polyethylene.

[0336]

[0337] Comparative Example 2-1

[0338] A polyethylene composition was prepared in the same manner as in Example 2-1, except that the polyethylene prepared in Comparative Example 1-1 was used instead of the polyethylene prepared in Example 1-1 using new polyethylene.

[0339]

[0340] Comparative Example 2-2

[0341] A polyethylene composition was prepared in the same manner as in Example 2-1, except that polyethylene prepared in Comparative Example 1-2 was used instead of polyethylene prepared in Example 1-1 using new polyethylene.

[0342]

[0343] Comparative Example 2-3

[0344] A polyethylene composition was prepared in the same manner as in Example 2-1, except that polyethylene prepared in Comparative Example 1-3 was used instead of polyethylene prepared in Example 1-1 using new polyethylene.

[0345]

[0346] Comparative Example 2-4

[0347] A polyethylene composition was prepared in the same manner as in Example 2-1, except that polyethylene prepared in Comparative Example 1-4 was used instead of polyethylene prepared in Example 1-1 using new polyethylene.

[0348]

[0349] Comparative Example 2-5

[0350] A polyethylene composition was prepared in the same manner as in Example 2-1, except that polyethylene prepared in Comparative Example 1-5 was used instead of polyethylene prepared in Example 1-1 using new polyethylene.

[0351]

[0352] Comparative Example 2-6

[0353] A polyethylene composition was prepared in the same manner as in Example 2-1, except that polyethylene prepared in Comparative Example 1-6 was used instead of polyethylene prepared in Example 1-1 using new polyethylene.

[0354]

[0355] Comparative Example 2-7

[0356] A polyethylene composition was prepared in the same manner as in Example 2-1, except that polyethylene prepared in Comparative Example 1-7 was used instead of polyethylene prepared in Example 1-1 using new polyethylene.

[0357]

[0358] Comparative Example 2-8

[0359] A polyethylene composition was prepared in the same manner as in Example 2-1, except that polyethylene prepared in Comparative Example 1-8 was used instead of polyethylene prepared in Example 1-1 using new polyethylene.

[0360]

[0361] Comparative Example 2-9

[0362] A polyethylene composition was prepared in the same manner as in Example 2-1, except that polyethylene prepared in Comparative Example 1-9 was used instead of polyethylene prepared in Example 1-1 using new polyethylene.

[0363]

[0364] Comparative Example 2-10

[0365] A polyethylene composition was prepared in the same manner as in Example 2-1, except that polyethylene prepared in Comparative Example 1-10 was used instead of polyethylene prepared in Example 1-1 using new polyethylene.

[0366]

[0367] <Experimental Example: Evaluation of Physical Properties of Polyethylene>

[0368] The physical properties of the polyethylene or polyethylene compositions of the examples and comparative examples were evaluated in the following manner, and the measurement results are shown in Tables 1 and 2 below, respectively.

[0369]

[0370] (1) Density

[0371] Density of polyethylene at 23°C according to ASTM D 1505 (g / cm³) 3 ) was measured.

[0372]

[0373] (2) Weight average molecular weight (Mw) and molecular weight distribution (PDI, Mw / Mn)

[0374] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polyethylene were measured using gel permeation chromatography (GPC, manufactured by Polymer Char), and the molecular weight distribution (PDI, Mw / Mn) was calculated by dividing the weight-average molecular weight by the number-average molecular weight.

[0375] Specifically, a Polymer Char GPC-IR instrument was used as the gel permeation chromatography (GPC) device, and a Polymer Laboratories PLgel MIX-B 300 mm long column was used. The measurement temperature was 160 ℃, 1,2,4-trichlorobenzene was used as the solvent, and the flow rate was 1 mL / min. Polyethylene samples according to the examples and comparative examples were each pretreated by dissolving them in trichlorobenzene (1,2,4-trichlorobenzene) containing 0.0125% butylated hydroxytoluene (BHT) at 160 ℃ for 2 hours using a GPC analyzer (GPC-IR), prepared at a concentration of 10 mg / 10 mL, and supplied in an amount of 200 μL. The values ​​of Mw and Mn were derived using a calibration curve formed using polystyrene standard specimens. Nine types of polystyrene standard specimens with weight-average molecular weights were used: 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.

[0376]

[0377] (3) Low molecular weight ratio

[0378] In the GPC curve graph where the x-axis is log Mw and the y-axis is dw / dlogMw obtained through the GPC analysis described in (2), the integral value of the region where the log Mw value is 5.5 or higher and the integral value of the region where the log Mw value is 4.5 or lower were obtained, and the low molecular weight ratio was calculated according to the following Equation 1.

[0379] [Equation 1]

[0380] Low molecular weight ratio = (Integral value of the region where log Mw is 4.5 or less on a GPC curve graph with log Mw on the x-axis and dw / dlogMw on the y-axis) / (Integral value of the region where log Mw is 5.5 or greater on a GPC curve graph with log Mw on the x-axis and dw / dlogMw on the y-axis)

[0381]

[0382] (4) SCB content

[0383] SCB (units / 1000C) for polyethylene was measured using GPC-IR equipment at 160 ℃.

[0384] Specifically, the sample was pretreated by melting it in 1,2,4-Trichlorobenzene containing 0.0125% BHT at 160°C for 2 hours, and then measured at 160°C using IR4 and IR6 connected to a high-temperature GPC (GPC-IR).

[0385]

[0386] (5) BOCD Index (Broad Orthogonal Co-monomer Distribution Index)

[0387] In the GPC curve graph where the x-axis is log Mw and the y-axis is dw / dlogMw obtained through the GPC analysis described in (2), the SCB (Short Chain branch) content was measured at the left and right boundaries of the middle 60% excluding the left and right ends relative to the total area, and the BOCD index was calculated as shown in Equation 2 below.

[0388] [Equation 2]

[0389] BOCD Index =

[0390] In the above Equation 2,

[0391] The high molecular weight SCB content and low molecular weight SCB content refer to the SCB content values ​​at the right and left boundaries, respectively, within the middle 60% range excluding the left and right ends, when a molecular weight distribution curve is plotted with the logarithm of the weight-average molecular weight (Mw) (log Mw) on the x-axis and the molecular weight distribution corresponding to said log value (dwt / dlog Mw) on the y-axis, after simultaneously and continuously measuring the weight-average molecular weight, molecular weight distribution, and SCB content using a GPC-IR device.

[0392]

[0393] (6) BMI (bimodality index)

[0394] BMI was calculated from the GPC curve graph with x-axis log Mw and y-axis dw / dlogMw obtained through the GPC analysis as described in (2), as shown in Equation 3 below.

[0395] [Equation 3]

[0396]

[0397] In the above Equation 3,

[0398] Peaks A and B are the peaks of the low molecular weight fraction (peak A) and the high molecular weight fraction (peak B), respectively, when the peaks forming the low molecular weight fraction and the high molecular weight fraction are separated using peak deconvolution (Gaussian Probability Function) on a GPC curve graph for polyethylene with the x-axis being log Mw and the y-axis being dw / dlogMw.

[0399] logMw(peak A) and logMw(peak B) are the logMw values ​​at the maximum dw / dlogMw for each peak, and

[0400] AR(peak A) and AR(peak B) are the area ratio (AR) of each peak relative to the total area of ​​the derived GPC curve graph of peaks A and B.

[0401]

[0402] (7) Melt Index (MI) 2.16 )

[0403] It was measured according to ASTM D 1238, 190 ℃, 2.16 kg.

[0404]

[0405] (8) Environmental stress crack resistance (ESCR)

[0406] According to the method of ASTM D 1693-07, the time to F50 (50% destruction) for a polyethylene composition (PCR Compound) was measured using 10% Igepal CO-630 Solution at a temperature of 50 ℃ under Condition B.

[0407]

[0408] (9) Falling impact

[0409] A disc was manufactured based on a polyethylene resin composition (PCR Compound) using the following method.

[0410] More specifically, the disc was manufactured using an injection molding machine, and after setting the temperature gradient to 210–230 ℃, a polyethylene resin composition was injected and injected under conditions of an injection speed of 11 mm / s and a holding pressure of 450 bar to produce a disc with a diameter of 50 mm and a thickness of 2 mm.

[0411] For the manufactured disc, the drop impact strength corresponding to the face impact strength was measured using the ASTM D 3763 method. Specifically, using the Instron 9440 (Impact Drop Tower) product (Impact energy 15.5 J, Impact velocity 4.55 m / s, Temperature 5 ℃), the disc was fixed and a weight was dropped to measure the number of times a crack occurred.

[0412]

[0413] (10) Izod impact strength (kgf·cm / cm)

[0414] According to ASTM D256, a 3.0 mm thick specimen with a V-shaped notch was fixed to an Izod impact tester, and the notch surface was fractured by impact with a pendulum (0.461 kgf), and the impact strength was measured by the energy required for fracture.

[0415]

[0416] (11) Flexural modulus (kg / cm²)

[0417] According to ASTM D790, the strength (kg / cm²) was measured when a load of 28 mm / min was applied using a Loading Nose after the specimen was placed on and fixed to a support. The flexural modulus, which represents stiffness, was measured based on the initial slope value according to the bending force.

[0418]

[0419] (12) Complex Viscosity

[0420] Complex Viscosity (500 rad / s, Pa.s) was measured for a polyethylene composition (PCR Compound) at 190 ℃ and 500 rad / s using an ARES-G2 instrument.

[0421]

[0422] MI (g / 10 min) Density (g / cm³) 3 )Mw (g / mol) Molecular weight distribution SCB (pieces / 1000C) BOCD index BMI Low molecular weight ratio Izod impact strength (kgf·cm / cm) ESCR (hr) Complex viscosity (Pa·s) Example 1-10.5 50.9 4614 9,000 24.3 5.2 6.1 72.5 54.0 8.3 5515 7332 Example 1-20.5 10.9 4613 2,000 24.9 4.6 4.1 92.7 34.3 5.2 386 06312 Example 1-30.5 50.9 4813 1,000 24.9 3.7 3.3 32.7 34.6 5.0 334 71298 Example 1-4 1.000.95 117,000 23.5 4.1 3.2 7 2.5 9 5.3 4.1 28 250 211 Example 1-50.46 0.95 147,000 25.2 3.8 3.2 4 2.72 3.8 5.8 37 25 23 57 Example 1-60.58 0.949 121,000 31.6 4.1 4.01 2.5 05.05.1 31 78 9 245 Comparative Example 1-10.16 0.947 210,000 21.3 2.3 0.91 88 2.1 3.3 10 23 76 78 Comparative Example 1-20.290.948168,00015.04.10.861.664.02.96038351 Comparative Example 1-30.550.946138,00015.13.01.882.083.64.19950435 Comparative Example 1-40.530.945119,00012.84.13.051.874.44.811814411 Comparative Example 1-50.40.954157,00018.520.94UNI3.42.5250531 Comparative Example 1-60.200.954175,00020.35.31.112.153.953.77805465 Comparative Example 1-71.30.947123,00024.84.32.671.015.62.45600295 Comparative Example 1-80.60.956127,00031.42.00.81.215.82.72605247 Comparative Example 1-90.720.948148,00025.63.11.762.233.34.38750486 Comparative Example 1-100.320.945197,00017.83.32.781.942.53.29876579

[0423] MI (g / 10 min) Density (g / cm³) 3)ESCR(hr) Drop Impact (Times) Flexural Modulus (kg / cm²) Complex Viscosity (Pa.s) Example 2-10.25 0.949 887 8.314 410288 Example 2-20.32 0.949 762 8.613 460262 Example 2-30.31 0.950 660 8.413 970259 Example 2-40.41 0.951 445 9.214 013207 Example 2-50.30 0.951 598 8.113 878301 Example 2-60.33 0.949 713 8.413 879249 Comparative Example 2-10.190.9502885.411,215578 Comparative Example 2-20.240.9501505.411,300270 Comparative Example 2-30.300.9492267.313,358368 Comparative Example 2-40.290.94918010.312,967361 Comparative Example 2-50.260.9521104.210,900110 Comparative Example 2-60.220.9511605.311,115241 Comparative Example 2-70.420.9492006.210,836300 Comparative Example 2-80.320.9501907.112,645245 Comparative Example 2-90.340.9482694.311,793305 Comparative Example 2-100.260.9481454.612,465211

[0424] Referring to Tables 1 and 2 above, it can be seen that when using the polyethylene of Examples 1-1 to 1-6, in which the molecular structure including density, the ratio of the low molecular weight region, molecular weight distribution, and SCB content is all optimized according to the present invention, excellent mechanical properties such as drop impact strength and flexural modulus are maintained when combined with recycled polyethylene (PCW PE), and at the same time, environmental stress crack resistance (ESCR) can be significantly improved to over 300 hours.

Claims

Polyethylene satisfying (1) to (5) below: (1) Density of 0.940 g / cm³ measured according to ASTM D 1505, 23 ℃ 3 more; (2) The low molecular weight ratio represented by the following formula 1 is 3.5 to 5.5; [Equation 1] Low molecular weight ratio = (Integral value of the region where log Mw is 4.5 or less on a GPC curve graph with log Mw on the x-axis and dw / dlogMw on the y-axis) / (Integral value of the region where log Mw is 5.5 or greater on a GPC curve graph with log Mw on the x-axis and dw / dlogMw on the y-axis); (3) Molecular weight distribution (PDI, Mw / Mn) is 20 to 50; (4) SCB content is 3.0 to 6.0 pieces / 1000C; (5) The BOCD index (Broad Orthogonal Co-monomer Distribution Index) expressed by Equation 2 below is 2.0 or higher; [Equation 2] BOCD Index = In the above Equation 2, When the weight-average molecular weight, molecular weight distribution, and SCB content are measured simultaneously and continuously using a GPC-IR device, and a molecular weight distribution curve is plotted with the log value of the weight-average molecular weight (Mw) (log Mw) as the x-axis and the molecular weight distribution (dwt / dlog Mw) for the log value as the y-axis, the SCB content on the high molecular weight side and the SCB content on the low molecular weight side refer to the SCB content values ​​at the right boundary and the left boundary, respectively, within the middle 60% range excluding the left and right ends of 20%. In paragraph 1, The above polyethylene is an ethylene homopolymer or an ethylene / alpha-olefin copolymer, Polyethylene. In paragraph 2, The above alpha-olefin is one or more 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-eicocene, and mixtures thereof. Polyethylene. In paragraph 1, The above polyethylene has a BOCD index (Broad Orthogonal Co-monomer Distribution Index) of 3.0 or higher, Polyethylene. In paragraph 1, The above polyethylene has a BMI (bimodality index) of 2.0 or higher, represented by Formula 3 below, Polyethylene: [Equation 3] In the above Equation 3, Peaks A and B are the peaks of the low molecular weight fraction (peak A) and the high molecular weight fraction (peak B), respectively, when the peaks forming the low molecular weight fraction and the high molecular weight fraction are separated using peak deconvolution (Gaussian Probability Function) on a GPC curve graph for polyethylene with the x-axis being log Mw and the y-axis being dw / dlogMw. logMw(peak A) and logMw(peak B) are the logMw values ​​at the maximum dw / dlogMw for each peak, and AR(peak A) and AR(peak B) are the area ratio (AR) of each peak relative to the total area of ​​the derived GPC curve graph of peaks A and B. In paragraph 1, The above polyethylene has a weight-average molecular weight of 100,000 g / mol or more. Polyethylene. In paragraph 1, The above polyethylene has a melt index (MI) measured at 190°C and a 2.16 kg load according to ASTM D 1238. 2.16 ) having 0.1 g / 10 min to 1.5 g / 10 min, Polyethylene. A polyethylene composition comprising virgin polyethylene and recycled polyethylene (PCW PE, Post consumer waste polyethylene), The above-mentioned novel polyethylene is polyethylene or a mixture thereof according to any one of claims 1 to 7, Polyethylene composition. In paragraph 8, The above-mentioned novel polyethylene is included in an amount of 30 to 70 parts by weight based on 100 parts by weight of the total composition, and The above recycled polyethylene is included in an amount of 30 to 70 parts by weight based on 100 parts by weight of the total composition, Polyethylene composition. In paragraph 8, The above polyethylene composition has an environmental stress crack resistance (ESCR) of 300 hours or more as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%), Polyethylene composition. In paragraph 8, The above polyethylene composition has a flexural modulus of 13,400 kg / ㎠ or more as measured according to ASTM D256, Polyethylene composition. In paragraph 8, The above polyethylene composition has a complex viscosity of 350 Pa.s or less, measured at 190 ℃ and 500 rad / s using an ARES-G2 instrument. Polyethylene composition.

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