Polyethylene composition

Abstract

The present invention provides a polyethylene composition comprising virgin polyethylene and recycled polyethylene (post-consumer waste polyethylene (PCW PE)), and having excellent mechanical properties along with improved environmental stress cracking resistance.

Description

polyethylene composition

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

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0188267, filed December 21, 2023, and Korean Patent Application No. 10-2024-0192758, filed December 20, 2024, the entire contents of which are incorporated herein by reference.

[0003]

[0004] The present invention relates to a polyethylene composition comprising virgin polyethylene and recycled polyethylene (PCW PE, Post-consumer waste polyethylene), and having excellent mechanical properties and improved environmental stress crack resistance.

[0005]

[0006] The demand for polyethylene resin is increasing and it is being used in a variety of applications.

[0007]

[0008] Recently, with growing environmental concerns, regulations to curb carbon dioxide emissions are being strengthened. In particular, with environmental pollution caused by the increased use of plastics emerging as a serious problem, regulations at the manufacturing stage are being strengthened, including mandating the use of recycled resin, primarily in the United States. Accordingly, manufacturers are required to add a certain amount of recycled resin to products such as resin molded products, and eco-friendliness ratings are assigned based on the amount of recycled resin present.

[0009]

[0010] However, since recycled resin is already processed, its properties have already changed during the high-temperature processing process, resulting in significantly lower impact strength, tensile strength, chemical resistance, and thermal stability compared to virgin resin. To address this issue, attempts have been made to incorporate a certain level of virgin resin into compositions containing recycled resin. However, this method requires an excessive amount of virgin resin to minimize the deterioration of mechanical properties, and major property degradation issues such as environmental stress cracking resistance (ESCR) remain unresolved. Furthermore, this problem becomes more severe as the number of processing cycles increases.

[0011]

[0012] The present invention includes virgin polyethylene and recycled polyethylene (PCW PE, Post consumer waste polyethylene), and aims to provide a polyethylene composition having excellent mechanical properties and improved environmental stress crack resistance.

[0013]

[0014] According to one embodiment of the invention, a polyethylene composition comprising virgin polyethylene and recycled polyethylene (PCW PE, Post consumer waste polyethylene) is provided, which satisfies the following (a) to (c).

[0015] (a) Density 0.949 g / cm 3 more,

[0016] (b) According to ASTM D 1709, using the Dart drop method A, a weight is dropped on a disk specimen (diameter 50 mm, thickness 2 mm) of a polyethylene composition with a drop energy of 4.2 J, and the number of drops before a crack of 1 mm or more in length occurs is measured to be 7 or more, and

[0017] (c) Environmental stress cracking resistance (ESCR) of 200 hours or more as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%).

[0018]

[0019] According to the present invention, a polyethylene composition having improved environmental stress cracking resistance (ESCR) along with high density and drop impact strength can be provided, while containing virgin polyethylene and recycled polyethylene (PCW PE, Post-consumer waste polyethylene) together, and having excellent mechanical properties.

[0020]

[0021] In the present invention, terms such as first, second, etc. are used to describe various components, and the terms are used only for the purpose of distinguishing one component from another.

[0022]

[0023] Furthermore, the terminology used herein is merely for the purpose of describing exemplary embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprise," "include," or "have" indicate the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0024]

[0025] 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.

[0026]

[0027] In addition, 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.

[0028]

[0029] In addition, "% 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 exemplified 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. In this case, the total content of each component does not exceed 100% by weight.

[0030]

[0031] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated and described in detail below. However, this is not intended to limit the present invention to specific disclosed forms, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0032]

[0033] Hereinafter, the present invention will be described in more detail.

[0034]

[0035] According to one embodiment of the invention, a polyethylene composition is provided which includes virgin polyethylene and recycled polyethylene (PCW PE, Post-consumer waste polyethylene), and which enhances the entanglement between the recycled raw material having polar groups due to oxidation and the non-polar virgin polyethylene, thereby increasing environmental stress cracking resistance (ESCR) along with high density and drop impact strength, thereby realizing high loading strength with excellent mechanical properties when used as a blow container, while simultaneously securing excellent processability.

[0036]

[0037] Specifically, the polyethylene composition of the present invention includes virgin polyethylene and recycled polyethylene (PCW PE, Post consumer waste polyethylene), and satisfies the following (a) to (c).

[0038] (a) Density 0.949 g / cm 3 more,

[0039] (b) According to ASTM D 1709, using the Dart drop method A, a weight is dropped on a disk specimen (diameter 50 mm, thickness 2 mm) of a polyethylene composition with a drop energy of 4.2 J, and the number of drops before a crack of 1 mm or more in length occurs is measured to be 7 or more, and

[0040] (c) Environmental stress cracking resistance (ESCR) of 200 hours or more as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%).

[0041]

[0042] Hereinafter, the polyethylene composition of the present invention will be described in more detail.

[0043]

[0044] The polyethylene composition of the present invention comprises virgin polyethylene and recycled polyethylene (PCW PE, Post-consumer waste polyethylene), and is characterized by having high density and drop impact strength, as well as increased environmental stress cracking resistance (ESCR), by strengthening the entanglement between the recycled raw material having polar groups due to oxidation and the non-polar virgin polyethylene.

[0045]

[0046] In particular, the polyethylene composition has a density of 0.949 g / cm 3 and for example, 0.949 g / cm 3Above 0.954 g / cm 3 The polyethylene composition of the present invention can secure excellent density while containing recycled polyethylene (PCW PE, Post consumer waste polyethylene), thereby realizing sufficient loading strength when used as a blow container, etc.

[0047]

[0048] Meanwhile, the polyethylene composition of the present invention is characterized by simultaneously securing high drop strength along with the density described above.

[0049]

[0050] Specifically, the polyethylene composition has a drop impact strength of 7 or more times, which is measured by the number of times a disk specimen with a diameter of 50 mm and a thickness of 2 mm is manufactured using a polyethylene composition using a Dart drop method A according to ASTM D 1709, and a weight is dropped by fixing the disk specimen with a drop energy of 4.2 J before a crack of 1 mm or more in length occurs. For example, the drop impact strength may be 7 or more and 30 or less times.

[0051]

[0052] For example, the drop impact strength of the polyethylene composition is measured by manufacturing a disc based on a polyethylene composition (PCR Compound) as shown below, dropping a weight on the disc and measuring the number of drops before a crack occurs in the disc, and measuring the number of drops before a crack of 1 mm or more in length occurs.

[0053]

[0054] <Manufacturing of Drop Impact Discs>

[0055] - Discs are manufactured using an injection molding machine, and can be manufactured by setting a temperature gradient of 210 to 230 ℃ and then injecting PCR Compound.

[0056] - Disc size (Φ 50 mm, thickness 2 mm).

[0057]

[0058] <Drop impact strength evaluation>

[0059] - According to ASTM D 1709, the Dart drop method A utilizes the Instron 9450 (Impact Drop Tower) product. After fixing the disc, a weight is dropped to measure the number of times cracks occur. Here, the drop energy is fixed at 4.2 J.

[0060]

[0061] In addition, the polyethylene composition of the present invention is characterized by optimizing density and drop impact strength as described above and increasing environmental stress cracking resistance (ESCR).

[0062]

[0063] The polyethylene composition has an environmental stress cracking resistance (ESCR) of 200 hours or more, as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%), and may be, for example, 200 hours or more and 500 hours or less. Preferably, the ESCR of the polyethylene composition may be 203 hours or more, or 210 hours or more, or 215 hours or more, or 220 hours or more, or 250 hours or more, or 260 hours or more, or 270 hours or more, or 280 hours or more, and may also be 400 hours or less, or 350 hours or less, or 320 hours or less, or 300 hours or less, or 288 hours or less. The polyethylene composition of the present invention, with the excellent ESCR characteristics described above, can simultaneously secure excellent mechanical properties, excellent processability, and high drop strength when used as a blow container.

[0064]

[0065] In particular, the polyethylene composition according to the present invention optimizes the density and drop impact strength as described above and increases the environmental stress cracking resistance (ESCR), thereby increasing the content of recycled polyethylene while achieving high load strength with excellent mechanical properties when used as a blow container, such as excellent impact strength, tensile strength, chemical resistance and thermal stability close to that of virgin resin, while simultaneously securing excellent processability and high drop strength.

[0066]

[0067] Meanwhile, the polyethylene composition of the present invention can simultaneously secure excellent processability and high drop strength by optimizing the melting index along with the density described above.

[0068]

[0069] The above polyethylene composition has a melt index (MI) 2.16 , ASTM D 1238, 190 ℃, 2.16 kg) is 0.25 g / 10 min or more, and for example, it may be 0.25 g / 10 min or more and 0.8 g / 10 min or less. Preferably, the melt index (MI) of the polyethylene composition 2.16 , ASTM D 1238, 190 ℃, 2.16 kg) may be 0.7 g / 10 min or less, or 0.65 g / 10 min or less, or 0.6 g / 10 min or less, or 0.55 g / 10 min or less, or 0.5 g / 10 min or less, or 0.45 g / 10 min or less, or 0.42 g / 10 min or less, or 0.4 g / 10 min or less, or 0.38 g / 10 min or less, and may be 0.26 g / 10 min or more, or 0.27 g / 10 min or more, or 0.28 g / 10 min or more, or 0.29 g / 10 min or more. The polyethylene composition of the present invention may have a melt index (MI) as described above. 2.16 ) can simultaneously secure excellent mechanical properties that can exhibit high loading strength, as well as excellent processability and high drop strength.

[0070]

[0071] Meanwhile, according to the present invention, the polyethylene composition includes virgin polyethylene and recycled polyethylene (PCW PE, Post-consumer waste polyethylene), and as described above, the entanglement between the recycled raw material having polar groups due to oxidation and the non-polar virgin polyethylene is strengthened, so as to increase the environmental stress cracking resistance (ESCR) along with high density and drop impact strength, and as described below, the polyethylene is optimized for the ratio of low molecular weight regions while strengthening the ratio of high molecular weight regions in the molecular structure, as a virgin resin.

[0072]

[0073] Specifically, the new polyethylene may be an ethylene homopolymer or an ethylene / alpha-olefin copolymer, and may be a dry blend of one or more or two or more of the above-described ethylene homopolymers or ethylene / alpha-olefin copolymers.

[0074]

[0075] For example, when one or more kinds of the above-described ethylene homopolymer and the ethylene / alpha-olefin copolymer are mixed (dry blended), the weight ratio of one or more kinds of the ethylene homopolymer and one or more kinds of the ethylene / alpha-olefin copolymer may be 1:99 to 99:1, or 5:95 to 95:5, or 10:90 to 90:10, or 15:85 to 85:15, or 20:80 to 80:20, or 25:75 to 75:25, or 30:70 to 70:30, or 35:65 to 65:35, or 40:60 to 60:40, or 45:55 to 55:45.

[0076]

[0077] The above alpha-olefin may be at least one 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.

[0078]

[0079] For example, when the new polyethylene is a copolymer, it may contain about 0.45 mol or less, or about 0.1 mol to about 0.45 mol, or about 0.4 mol or less, or about 0.2 mol to about 0.4 mol, or about 0.35 mol or less, or about 0.25 mol to about 0.35 mol, of alpha-olefin based on 1 mol of ethylene.

[0080]

[0081] Specifically, when the new polyethylene comprises an ethylene / alpha-olefin copolymer, 1-hexene can be used as the alpha-olefin copolymerized with ethylene.

[0082]

[0083] For example, the new polyethylene may be an ethylene homopolymer that does not include a separate copolymer, an ethylene / 1-hexene copolymer, or a dry blend of the above-described ethylene homopolymer and ethylene / 1-hexene copolymer.

[0084]

[0085] Meanwhile, the new polyethylene comprises at least one of the ethylene homopolymers or ethylene / alpha-olefin copolymers described above, and may further comprise at least one of various polar copolymers containing ethylene.

[0086]

[0087] For example, the new polyethylene may be an ethylene homopolymer that does not include a separate copolymer, or an ethylene / 1-hexene copolymer, or a dry blend of the above-described ethylene homopolymer and the ethylene / 1-hexene copolymer, or a melt blend of an ethylene homopolymer that does not include a separate copolymer and a polar copolymer containing ethylene, or a melt blend of an ethylene / 1-hexene copolymer and a polar copolymer containing ethylene, or a melt blend of a dry blend of the above-described ethylene homopolymer and the ethylene / 1-hexene copolymer and a polar copolymer containing ethylene.

[0088]

[0089] The polar copolymer is a copolymer containing ethylene and containing at least one polar functional group selected from the group consisting of a carboxyl group, a hydroxyl group, a carbonyl group, a nitrile group, and an amide group. Preferably, the polar functional group of the polar copolymer may be a carboxyl group, a hydroxyl group, or a carbonyl group. For example, it may be a vinyl acetate group (VA).

[0090]

[0091] Meanwhile, the polar copolymer preferably has a higher polar functional group content in order to maintain the physical properties of the ethylene homopolymer or ethylene / alpha-olefin copolymer when melt-mixed with the ethylene homopolymer or ethylene / alpha-olefin copolymer. Specifically, the polar functional group content of the polar copolymer may be 20 wt% or more and 50% or less based on the total weight of the polar copolymer.

[0092]

[0093] For example, the polar functional group content can be measured by any one of Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible absorption spectroscopy (UV-Vis spectroscopy). As a specific measuring method, a conventional method known to be applicable to polyethylene or an ethylene copolymer can be applied.

[0094]

[0095] As a specific implementation example among these, when using Fourier transform infrared (FTIR) spectroscopy, the absorbance is measured over various wavelengths (e.g., 4000 cm¹ - 400 cm¹), and after obtaining a spectrum including an absorption band related to the polar functional group, the area of ​​the peak region for the polar functional group such as ethylene and vinylacetate (VA) is converted into a mass fraction together with the area of ​​the total peaks, thereby calculating the content of the polar functional group such as vinylacetate (VA).

[0096]

[0097] In another specific implementation example, when using nuclear magnetic resonance spectroscopy (NMR, e.g., Bruker 500 MHz), chromium acetylacetonate (Cr(acac)3, Chromium(III) acetylacetonate) as a relaxation agent is dissolved in tetrachloroethane-d2 (TCE-d2, tetrachloroethane-d2) as an organic solvent to prepare a stock solution with a concentration of 0.001 M. Then, 11 mg of the above-mentioned ethylene polar copolymer sample is added to 0.6 mL of the stock solution and heated in a heating block at a temperature of 393 K for 40 minutes. Then, after confirming that the sample is uniformly melted, it is transferred to an NMR tube and heated at a temperature of 393 K. 1 By measuring the H NMR spectrum, the area of ​​the total peaks and the area of ​​the proton (H) peaks present in polar functional groups such as ethylene and vinylacetate (VA) can be converted into mass fraction to calculate the content of polar functional groups such as vinylacetate (VA).

[0098]

[0099] Preferably, the polar functional group content of the polar copolymer may be 22 wt% or more, or 24 wt% or more, or 26 wt% or more, or 28 wt% or more, or 30 wt% or more, or 32 wt% or more, or 34 wt% or more, or 36 wt% or more, or 38 wt% or more, or 40 wt% or more, but 48 wt% or less, or 46 wt% or less, or 45 wt% or less, or 44 wt% or less, or 43 wt% or less, or 42 wt% or less, based on the total weight of the polar copolymer.

[0100]

[0101] Specifically, such polar copolymers may be copolymers containing ethylene, for example, ethylene vinyl acetate copolymers.

[0102]

[0103] At this time, it may be a melt blended mixture of at least one of the ethylene homopolymer or ethylene / alpha-olefin copolymer as described above and the polar copolymer described above. For example, when the ethylene homopolymer described above and at least one of the ethylene / alpha-olefin copolymer and at least one of the polar copolymer described above are melt blended, the weight ratio between the total weight of the ethylene homopolymer and at least one of the ethylene / alpha-olefin copolymer and the total weight of the at least one polar copolymer, that is, the ratio between the total weight of the ethylene homopolymer and at least one of the ethylene / alpha-olefin copolymer: the total weight of the at least one polar copolymer may be 70:30 to 99:1.

[0104]

[0105] Preferably, the weight ratio of at least one of the ethylene homopolymer and the ethylene / alpha-olefin copolymer and at least one of the polar copolymers may be 70:30 to 97:3, or 70:30 to 95:5, or 70:30 to 93:7, or 70:30 to 90:10, or 72:28 to 90:10, or 75:25 to 90:10, or 78:22 to 90:10, or 80:20 to 90:10, or 83:17 to 90:10, or 85:15 to 90:10, or 87:13 to 90:10. For example, the weight ratio of at least one of the ethylene homopolymer and the ethylene / alpha-olefin copolymer and at least one of the polar copolymers may be 70:30 or 80:20, or 87:13 or 90:10 or 99:1.

[0106]

[0107] Meanwhile, the new polyethylene has a density (ASTM D1505, 23 ℃) of 0.944 g / cm 3 or 0.944 g / cm 3 0.954 g / cm3 It can be high density polyethylene (HDPE) that satisfies .

[0108]

[0109] More specifically, the density of the new polyethylene is 0.945 g / cm 3 or 0.946 g / cm 3 and 0.954 g / cm 3 or less, or 0.953 g / cm 3 It could be as follows:

[0110]

[0111] When the density of the above-mentioned virgin polyethylene satisfies the above-mentioned range, compatibility with recycled polyethylene can be improved, and when mixed with recycled polyethylene, deterioration of major physical properties such as ESCR can be minimized without using an excessive amount of virgin polyethylene resin.

[0112]

[0113] Meanwhile, in the GPC curve graph where the x-axis is log Mw and the y-axis is dw / dlogMw, the integral value of the region where Log Mw is 5.5 or more is 15% or less, or 5% or more to 15% or less, of the total integral value.

[0114]

[0115] Specifically, the integral value of the region where the Log Mw is 5.5 or more may be 14.5% or less, or 14% or less, or 13.8% or less, or 13.5% or less, or 13% or less, so as to secure excellent processability and high drop impact strength when mixing the virgin polyethylene and recycled polyethylene. However, when considering excellent mechanical properties at a high density after mixing with recycled polyethylene, the integral value of the region where the Log Mw is 5.5 or more may be 6% or more, or 8% or more, or 10% or more, or 11.0% or more.

[0116]

[0117] For example, the GPC graph of the above-mentioned new polyethylene can be measured using gel permeation chromatography (GPC), and a specific measurement method can be applied to a conventional method known to be applicable in relation to polyethylene.

[0118]

[0119] By having an integral value in the region where the Log Mw is 5.5 or more as described above, the ratio of the polymer region in the molecular structure of virgin polyethylene can be strengthened, and mechanical properties such as environmental stress cracking resistance (ESCR) can be improved along with excellent compatibility with recycled polyethylene.

[0120]

[0121] In addition, the new polyethylene has an entanglement molecular weight (Me) of less than 10,000 g / mol or 50 g / mol or more and less than 10,000 g / mol. For example, the entanglement molecular weight (Me) of the virgin polyethylene may be 9,990 g / mol or less, or 9,950 g / mol or less, or 9,900 g / mol or less, or 9,800 g / mol or less, or 9,700 g / mol or less, or 9,600 g / mol or less, or 9,555 g / mol or less, and together with 50 g / mol or more, or 100 g / mol or more, or 300 g / mol or more, 500 g / mol or more, or 800 g / mol or more, or 1,000 g / mol or more, or 1,500 g / mol or more, or 2,000 g / mol or more, or 3,000 g / mol or more, or 4,000 g / mol or more, or 5,000 g / mol or more, or 6,000 g / mol or more, or It may be 6,500 g / mol or more, or 7,000 g / mol or more, or 7,500 g / mol or more, or 8,000 g / mol or more, or 8,500 g / mol or more, or 9,000 g / mol or more.

[0122]

[0123] Entanglement molecular weight (Me) represents the average molecular weight between entanglement points between polyethylene, i.e., ethylene (co)polymer chains. The lower the entanglement molecular weight, the higher the degree of entanglement of ethylene (co)polymer chains, which means superior resistance to deformation by external force and crack resistance. Therefore, the new polyethylene of the present invention has the characteristic of being able to realize a high level of mechanical properties such as durability due to a low entanglement molecular weight.

[0124]

[0125] The above entanglement molecular weight (Me) can be derived according to the following equation 1 and can be measured using a hybrid rheometer (DHR-2, Discovery Hybrid Rheometer-2), for example.

[0126] [Formula 1]

[0127] Me = ρRT / G 0 N

[0128] In the above equation 1, G 0 N is the plateau modulus, ρ is the melt density, R is the gas constant, and T is the absolute temperature.

[0129]

[0130] Meanwhile, the plateau elastic modulus G 0 N J is the intercept value of the creep compliance coefficient. o It is inversely proportional to , and can be obtained from the following equation 2:

[0131] [Formula 2]

[0132] G 0 N = 6 / (5J o )

[0133] In the above equation 2, J o can be measured using a 25 mm diameter flat plate from DHR-2 (TA Instruments) as follows:

[0134]

[0135] First, melt the ethylene (co)polymer sample under a nitrogen atmosphere at 190 ℃, and place it between 25 mm flat plates so that the thickness of the ethylene (co)polymer sample becomes 2 mm. Wait for 2 minutes to stabilize the temperature and remove the vertical stress generated when the sample is compressed. Apply a shear stress of 1 Pa to the molten sample for 1,000 seconds. After the measurement is completed, the creep compliance J, which is the value obtained by dividing the amount of deformation of the ethylene (co)polymer by the applied shear stress, is plotted on the y-axis, and time (t) is plotted on the x-axis. J0 is obtained by using the tangent line in the section where the steady state is reached and the slope is constant.

[0136]

[0137] Here, for a polyethylene resin specimen, the maximum stress value at which permanent deformation occurs under specific conditions can be measured, and the above-described entanglement molecular weight can be measured.

[0138]

[0139] Meanwhile, in the polyethylene composition according to one embodiment of the present invention, the new polyethylene described above may be manufactured using various catalysts, and preferably may be manufactured using a catalyst composition including a metallocene compound, but is not limited thereto.

[0140]

[0141] For example, the new polyethylene may be manufactured by introducing hydrogen gas in the presence of a catalyst composition including a first metallocene compound represented by the following chemical formula 1 and a second metallocene compound represented by the following chemical formula 2.

[0142] [Chemical Formula 1]

[0143] (Cp 1 R a ) n (Cp 2 R b )M 1 Z 1 3-n

[0144] In the above chemical formula 1,

[0145] M 1 is a group 4 transition metal;

[0146] Cp 1 and Cp 2 are each cyclopentadienyl, and these are C 1-20 Substituted or unsubstituted with hydrocarbons;

[0147] 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 C containing one or more heteroatoms selected from the group consisting of alkynyl, or N, O and S 2-20 It is heteroaryl;

[0148] Z 1 Silver 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;

[0149] n is 1 or 0;

[0150] [Chemical Formula 2]

[0151]

[0152] In the above chemical formula 2,

[0153] C1 is any one of the ligands represented by the following chemical formulas 3 to 6,

[0154] [Chemical Formula 3]

[0155]

[0156] [Chemical Formula 4]

[0157]

[0158] [Chemical Formula 5]

[0159]

[0160] [Chemical Formula 6]

[0161]

[0162] In the above chemical formulas 3 to 6,

[0163] R1 to R6 are the same or different and are each independently hydrogen, C 1-30 Alkyl, C 1-30 Alkoxy, C 2-30 Alkoxyalkyl, C 6-30 Aryl, C 6-30 Aryloxy, C 2-30 Alkenyl, C 2-30 alkynyl, C 3-30 Cycloalkyl, C 7-40 Alkylaryl of C 8-40 Alkenylaryl, C 8-40 Alkynylaryl, C 7-40 Arylalkyl of C 8-40 Arylalkenyl of, or C 8-40 is arylalkynyl,

[0164] M is Ti, Zr or Hf,

[0165] Z is -O-, -S-, -NR7-, or -PR7-,

[0166] R7 is hydrogen, C 1-30 Alkyl, C 6-30 Aryl, C 2-30 Alkenyl, C 2-30 alkynyl, C 3-30 Cycloalkyl, C 7-40 Alkylaryl of C 8-40Alkenylaryl, C 8-40 Alkynylaryl, C 7-40 Arylalkyl of C 8-40 Arylalkenyl, C 8-40 Arylalkynyl, C 1-30 Alkoxysilyl group, C 6-30 Aryloxysilyl, C 1-30 Alkylsilyl group, or C 1-30 It is a silylalkyl group,

[0167] X1 and X2 are the same or different and each independently represent 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 arylalkoxy,

[0168] T is or And,

[0169] T1 is C, Si, Ge, Sn or Pb,

[0170] Y1 is hydrogen, hydrogen, C 1-30 Alkyl, C 1-30 Alkoxy, C 2-30 Alkoxyalkyl, C 6-30 Aryl, C 6-30 Aryloxy, C 2-30 Alkenyl, C 2-30 alkynyl, C 3-30 Cycloalkyl, C 7-40 Alkylaryl of C 8-40 Alkenylaryl, C 8-40 Alkynylaryl, C 7-40 Arylalkyl of C 8-40 Arylalkenyl of, or C 8-40 Aryl alkynyl, silyl group (-SiH3), C 1-30 Alkoxysilyl group, C 2-30 Alkoxyalkylsilyl group, C 6-30 Aryloxysilyl, C 1-30 Haloalkyl, C6-30 Haloaryl, or -NR9R 10 And,

[0171] Y2 is C 2-30 Alkoxyalkyl, or C 7-40 Aryloxyalkyl,

[0172] R9 and R 10 are each independently hydrogen, C 1-30 Alkyl, C 6-30 Aryl, C 2-30 Alkenyl, C 2-30 alkynyl, C 3-30 Cycloalkyl, C 7-40 Alkylaryl of C 8-40 Alkenylaryl, C 8-40 Alkynylaryl, C 7-40 Arylalkyl of C 8-40 Arylalkenyl of, or C 8-40 arylalkynyl, or are linked to each other to form an aliphatic or aromatic ring.

[0173]

[0174] Meanwhile, in this specification, unless otherwise specifically limited, the following terms may be defined as follows:

[0175]

[0176] The halogen can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0177]

[0178] 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 3-10It may be a branched 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.

[0179]

[0180] C 2-30 The alkenyl group may 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 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.

[0181]

[0182] C 6-30 Aryl can mean a monocyclic, bicyclic, or tricyclic aromatic hydrocarbon. Specifically, C 6-30 Aryl can be a phenyl group, a naphthyl group, or anthracenyl group.

[0183]

[0184] 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.

[0185]

[0186] C 7-40Arylalkyl 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.

[0187]

[0188] C above 1-20 Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, phenyloxy, and cyclohexyloxy.

[0189]

[0190] C above 2-20 An alkoxyalkyl group is a functional group in which at least one hydrogen atom of an alkyl group as described above is replaced with an alkoxy group, and specifically, examples thereof include, but are not limited to, 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, and a tert-butoxyhexyl group; or an aryloxyalkyl group such as a phenoxyhexyl group.

[0191]

[0192] 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.

[0193]

[0194] C above 1-20A 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.

[0195]

[0196] 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.

[0197]

[0198] The above heteroaryl is C containing at least one of N, O, and S as a heteroatom. 2-20 As 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, Examples thereof include, but are not limited to, phenanthroline, isoxazolyl, thiadiazolyl, phenothiazinyl, and dibenzofuranyl groups.

[0199]

[0200] 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.

[0201]

[0202] 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.

[0203]

[0204] Also, group 4 transition metals include, but are not limited to, titanium (Ti), zirconium (Zr), and hafnium (Hf).

[0205]

[0206] For example, the first metallocene compound represented by the above chemical formula 1 is Cp 1 and Cp 2 As a non-bridged compound containing a ligand of Cp 1 and Cp 2 The ligands may be the same or different, each being cyclopentadienyl, and C 1-10 It may be substituted with one or more alkyl groups or with one to three alkyl groups.

[0207]

[0208] 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 olefin polymer 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 C containing one or more heteroatoms selected from the group consisting of arylalkyl, or N, O and S 2-12 It may be heteroaryl, more specifically C 1-10 Alkyl, C 2-10 Alkoxyalkyl, C 7-20 C containing one or more heteroatoms selected from the group consisting of arylalkyl, or N, O and S 4-12 Heteroaryl; may be.

[0209]

[0210] Also, the above Cp 1 and Cp 2 There is a M between the ligands of 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 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 1may be Ti, Zr or Hf; may be Zr or Hf; or may be Zr.

[0211]

[0212] Among the first transition metal compounds, Cp in the 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 the compounds may be a substituent of an alkoxyalkyl group such as a t-butoxyhexyl group, more specifically -(CH2)n-OR (wherein R is a straight or branched alkyl group having 1 to 6 carbon atoms, and n is an integer of 2 to 4).

[0213]

[0214] 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.

[0215]

[0216]

[0217] In addition, the second metallocene compound includes an aromatic ring compound containing thiophene as a different ligand and a base compound containing a group 14 or 15 atom, and the different ligands are bridged by -T- and have a structure in which M(X1)(X2) exists between the different ligands.

[0218]

[0219] More specifically, in the above chemical formula 2, M may be Ti, Zr or Hf, and more specifically, Ti.

[0220]

[0221] Also, R1 to R4 are each independently hydrogen, or C 1-20 It is alkyl, and more specifically, it can be hydrogen or methyl.

[0222]

[0223] Also, R5 and R6 are each independently C 1-10 is alkyl, and more specifically, both R5 and R6 can be methyl.

[0224]

[0225] Also, Z is -NR7-, and the above R7 is C 1-10 C, such as alkyl, more specifically t-butyl 3-10 It may be a branched alkyl.

[0226]

[0227] 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 Aryl, C 7-30 Alkylaryl, C 7-30 Arylalkyl, C 6-20 Aryloxy, or C 7-30 Aryloxyalkyl, and Y2 is C 2-20 Alkoxyalkyl, or C 7-30 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 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.

[0228]

[0229] Also, X1 and X2 are each independently halogen or C1-20 It may be alkyl, or more specifically chloro.

[0230]

[0231] As an example, as the second metallocene compound, compounds represented by the following chemical formulas 2a to 2d can be exemplified.

[0232] [Chemical Formula 2a]

[0233]

[0234] [Chemical Formula 2b]

[0235]

[0236] [Chemical Formula 2c]

[0237]

[0238] [Chemical formula 2d]

[0239]

[0240] In the above chemical formulas 2a to 2d, R1 to R7, M, X1, X2, T1, Y1 and Y2 are as defined above.

[0241]

[0242] More specifically, the second metallocene compound is, in the chemical formulas 2a to 2d, M is Ti, Zr or Hf, more specifically Ti; R1 to R4 are each independently hydrogen, or C 1-20 alkyl, more specifically hydrogen or methyl; R5 and R6 are each independently C 1-10 is alkyl, and more specifically, both R5 and R6 are methyl; wherein R7 is C 1-10 Alkyl, more specifically C, such as t-butyl 3-10 Branched alkyl; wherein T1 is C or Si, and Y1 is C 1-20 Alkyl, C 1-20 Alkoxy, C 2-20 Alkoxyalkyl, C 6-20 Aryl, C 7-30 Alkylaryl, C7-30 Arylalkyl, C 6-20 Aryloxy, or C 7-30 Aryloxyalkyl, and Y2 is C 2-20 Alkoxyalkyl, or C 7-30 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 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 halogen or C 1-20 It may be an alkyl compound, more specifically a chloro compound.

[0243]

[0244] More specifically, specific examples of the second metallocene compound include, but are not limited to, compounds having the following structures:

[0245] .

[0246]

[0247] In addition, the content ratio of the first and second metallocene compounds in the catalyst composition may be included in a molar ratio of 1:1.1 to 1:5, and more specifically, may be 1:1.1 or more, or 1:1.2 or more, or 1:1.3 or more, and 1:5 or less, or 1:3 or less.

[0248]

[0249] 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.

[0250]

[0251] 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.

[0252]

[0253] In addition, the catalyst composition may additionally include a cocatalyst to improve high activity and process stability, and the cocatalyst may be, more specifically, an alkylaluminoxane-based cocatalyst such as methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, or butylaluminoxane.

[0254]

[0255] Meanwhile, in the polyethylene composition according to one embodiment of the present invention, the virgin polyethylene described above is manufactured by polymerizing ethylene using the catalyst composition described above, and the polymerization process can be performed as a monomodal (or unimodal) polymerization process in which a polymerization reaction is performed under a single polymerization reaction condition using a single catalyst in one reactor, and more specifically, it can be performed in the presence of the hybrid supported catalyst described above in one loop-type slurry reactor.

[0256]

[0257] At this time, the polymerization temperature may be 25 to 500°C, preferably 25 to 200°C, and more preferably 50 to 150°C. In addition, the polymerization pressure may be 1 to 100 Kgf / ㎠, preferably 1 to 50 Kgf / ㎠, and more preferably 5 to 30 Kgf / ㎠.

[0258]

[0259] Meanwhile, according to the present invention, the polyethylene composition includes recycled polyethylene (PCW PE, Post consumer waste polyethylene) together with the virgin polyethylene described above.

[0260]

[0261] Specifically, the polyethylene composition of the present invention may contain 10 wt% to 90 wt% of recycled polyethylene (PCW PE). In particular, in order to enhance the carbon dioxide emission suppression effect of the polyethylene composition and reduce costs, the content of the recycled polyethylene (PCW PE) may be 20 wt% or more, or 30 wt% or more, or 35 wt% or more, or 40 wt% or more, or 45 wt% or more, or 50 wt% or more, or 55 wt% or more. In addition, in order to enhance the mechanical properties of the polyethylene composition, such as impact strength, tensile strength, chemical resistance, and thermal stability, and to minimize the virgin resin content, the content of the recycled polyethylene (PCW PE) may be 85 wt% or less, or 80 wt% or less, or 75 wt% or less, or 70 wt% or less, or 65 wt% or less, or 60 wt% or less.

[0262]

[0263] The above recycled polyethylene (PCW PE) has a melt index (MI) 2.16 , 190 o C, measured under a load of 2.16 kg) may be 0.10 g / 10 min to 0.3 g / 10 min, specifically 0.12 g / 10 min to 0.28 g / 10 min, or 0.13 g / 10 min to 0.25 g / 10 min, or 0.15 g / 10 min to 0.2 g / 10 min.

[0264]

[0265] In addition, the above recycled polyethylene (PCW PE) has a density of 0.951 g / cm 3 0.953 g / cm 3 It can be expressed as a characteristic of a person.

[0266]

[0267] Additionally, the recycled polyethylene (PCW PE) may have an environmental stress cracking resistance (ESCR) of 40 to 50 hours as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%).

[0268]

[0269] The polyethylene composition according to the present invention uses recycled polyethylene together with virgin polyethylene as described above, optimizes density and drop impact strength, and increases environmental stress cracking resistance (ESCR), thereby enabling the production of a molded product having high mechanical properties along with excellent processability.

[0270]

[0271] In particular, the polyethylene composition according to the present invention can secure excellent impact strength, tensile strength, chemical resistance, and thermal stability close to those of virgin resin while increasing the content of recycled polyethylene.

[0272]

[0273] Hereinafter, preferred examples are presented to aid understanding of the present invention. However, the following examples are provided solely to facilitate understanding of the present invention and are not intended to limit the scope of the present invention.

[0274]

[0275] <Example>

[0276] Example 1: Preparation of polyethylene composition

[0277] A polyethylene composition (PCR Compound) was manufactured by dry blending 40 wt% of virgin polyethylene and 60 wt% of recycled polyethylene (PCW PE, Post consumer waste polyethylene), and then extruding through a twin screw extruder.

[0278]

[0279] The recycled polyethylene used at this time (Baeksan Natural product of Baeksan Plastic Co., Ltd.) has a melting index of MI 2.16 (190 according to ASTM D 1238 (Condition E) o (measured under 2.16 kg load under C) is 0.15 to 0.2 g / 10 min, and the density (measured according to ASTM D 1505 standard) is 0.951 to 0.953 g / cm 3 , ESCR (time to F50 (50% destruction) measured under temperature conditions of 50℃ using 10% Igepal CO-630 Solution according to ASTM D 1693) is at the level of 40 to 50 hours.

[0280]

[0281] In addition, the virgin polyethylene used at this time was copolymerized by injecting isobutane 15 kg / h, ethylene 33 kg / h, hydrogen 6.4 g / hr, and comonomer (1-hexene) 0.9 wt% in the presence of a catalyst (molar ratio of the first metallocene compound and the second metallocene compound = 1:1.3) in which the first metallocene compound (1) and the second metallocene compound (2) are hybrid-supported on a silica carrier (Grace Davison, SP2212) in a single slurry loop reactor, and then dry blending the obtained high-density ethylene / 1-hexene copolymer in powder form through a solvent removal facility and a dryer to produce high-density polyethylene (HDPE, polyethylene) in powder form. At this time, the reactor was maintained at 93 ℃, and the pressure was 42 kg / cm 2The polyethylene thus manufactured and the ethylene vinyl acetate copolymer (EVA, manufactured by LG Chemical, product name: ES28005, VA content 28 wt%) as a polar copolymer were melt blended at a weight ratio of 90:10 to manufacture new polyethylene, and the specific physical properties are as shown in Table 1 below.

[0282] (1) (2).

[0283]

[0284] Example 2: Preparation of polyethylene composition

[0285] A polyethylene composition (PCR Compound) was prepared in the same manner as in Example 1, but a polyethylene resin having the properties shown in Table 1 below was used as virgin polyethylene together with the above-described recycled polyethylene (Baeksan Natural product of Baeksan Plastic Co., Ltd.), to prepare a polyethylene composition of Example 2.

[0286]

[0287] At this time, the virgin polyethylene used was manufactured in the same manner as in Example 1, but was melt blended with the polar copolymer (EVA, manufacturer: LG Chemical, product name: ES28005) at a weight ratio of 87.5:12.5 to manufacture virgin polyethylene (HDPE, Virgin polyethylene).

[0288]

[0289] Comparative Example 1: Preparation of polyethylene composition

[0290] A polyethylene composition (PCR Compound) was manufactured in the same manner as in Example 1, but a polyethylene resin having the properties shown in Table 1 below was used as virgin polyethylene together with the above-described recycled polyethylene (Baeksan Natural product of Baeksan Plastic Co., Ltd.), thereby manufacturing a polyethylene composition of Comparative Example 1.

[0291]

[0292] At this time, the virgin polyethylene used was manufactured by polymerization in the same manner as in Example 1, but was used as virgin polyethylene without melt blending of the polar copolymer.

[0293]

[0294] Comparative Example 2: Preparation of polyethylene composition

[0295] A polyethylene composition (PCR Compound) was prepared in the same manner as in Example 1, but a polyethylene resin having the properties shown in Table 1 below was used as virgin polyethylene together with the above-described recycled polyethylene (Baeksan Plastic, Baeksan Natural), thereby preparing a polyethylene composition of Comparative Example 2.

[0296]

[0297] At this time, the virgin polyethylene used was manufactured in the same manner as in Example 1, but the hydrogen content was changed to 4.7 g / hr and the comonomer (1-hexene) content to 0.8 wt% in the polymerization process of the ethylene / 1-hexene copolymer, and was used as virgin polyethylene without melt blending of the polar copolymer.

[0298]

[0299] Comparative Example 3: Preparation of polyethylene composition

[0300] A polyethylene composition (PCR Compound) was prepared in the same manner as in Example 1, but a polyethylene resin having the properties shown in Table 1 below was used as virgin polyethylene together with the above-described recycled polyethylene (Baeksan Natural product of Baeksan Plastic Co., Ltd.), to prepare a polyethylene composition of Comparative Example 3.

[0301]

[0302] At this time, the virgin polyethylene used was manufactured in the same manner as Example 1, but the hydrogen content was changed to 7.9 g / hr and the comonomer (1-hexene) content was changed to 2.9 wt% in the polymerization process of the ethylene / 1-hexene copolymer, and virgin polyethylene (virgin polyethylene) was used without melt blending of the polar copolymer.

[0303]

[0304] Comparative Example 4: Preparation of polyethylene composition

[0305] A polyethylene composition (PCR Compound) was prepared in the same manner as in Example 1, but a polyethylene resin having the properties shown in Table 1 below was used as virgin polyethylene together with the above-described recycled polyethylene (Baeksan Natural product of Baeksan Plastic Co., Ltd.), thereby preparing a polyethylene composition of Comparative Example 4.

[0306]

[0307] At this time, the virgin polyethylene used was manufactured in the same manner as in Example 1, but instead of the polar copolymer (EVA, LG Chemical ES28005), modified polypropylene (manufacturer: Lotte Chemical. Product name: MB300) was used as a polar copolymer in a melt blend ratio of 87.5:12.5 to manufacture virgin polyethylene (HDPE, Virgin polyethylene).

[0308]

[0309] Comparative Example 5: Preparation of polyethylene composition

[0310] A polyethylene composition (PCR Compound) was prepared in the same manner as in Example 1, but a polyethylene resin having the properties shown in Table 1 below was used as virgin polyethylene together with the above-described recycled polyethylene (Baeksan Natural product of Baeksan Plastic Co., Ltd.), thereby preparing a polyethylene composition of Comparative Example 5.

[0311]

[0312] At this time, the virgin polyethylene used was manufactured in the same manner as in Example 1, but instead of the polar copolymer (EVA, LG Chemical ES28005), modified polyethylene (manufacturer: Lotte Chemical. Product name: TU-300TL) was used as a polar copolymer, and melt blended at a weight ratio of 87.5:12.5 to manufacture virgin polyethylene (HDPE, Virgin polyethylene).

[0313]

[0314] Comparative Example 6: Preparation of polyethylene composition

[0315] A polyethylene composition (PCR Compound) was prepared in the same manner as in Example 1, but a polyethylene resin having the properties shown in Table 1 below was used as virgin polyethylene together with the above-described recycled polyethylene (Baeksan Natural product of Baeksan Plastic Co., Ltd.), to prepare a polyethylene composition of Comparative Example 6.

[0316]

[0317] At this time, the virgin polyethylene used was a commercially available high-density polyethylene product (HDPE, manufacturer: Lotte Chemical, product name: M7100) and was used as virgin polyethylene without melt blending of polar copolymers.

[0318]

[0319] Comparative Example 7: Preparation of polyethylene composition

[0320] A polyethylene composition (PCR Compound) was prepared in the same manner as in Example 1, but a polyethylene resin having the properties shown in Table 1 below was used as virgin polyethylene together with the above-described recycled polyethylene (Baeksan Natural product of Baeksan Plastic Co., Ltd.), to prepare a polyethylene composition of Comparative Example 6.

[0321]

[0322] At this time, the virgin polyethylene used was a commercially available high-density polyethylene product (HDPE, manufacturer: LG Chemical, product name: CE2080) and was used as virgin polyethylene without melt blending of polar copolymers.

[0323]

[0324] <Example of an exam>

[0325] The physical properties of virgin polyethylene (HDPE, Virgin polyethylene) used in the examples and comparative examples and the polyethylene composition (PCR Compound) manufactured thereby were evaluated using the following method, and the measurement results are shown in Table 1 below.

[0326]

[0327] (1) Density

[0328] Density (g / cm) of virgin polyethylene (HDPE) and polyethylene composition (PCR Compound) according to ASTM D 1505 standard of the American Society for Testing and Materials 3 ) was measured.

[0329]

[0330] (2) Weight average molecular weight and molecular weight distribution (PDI, polydispersity index, Mw / Mn) and Log MW (5.5 or higher) ratio according to GPC analysis

[0331] For virgin polyethylene (HDPE), the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polymer were measured using gel permeation chromatography (GPC, manufactured by Water), and the molecular weight distribution (PDI, Mw / Mn) was calculated by dividing the weight-average molecular weight by the number-average molecular weight.

[0332]

[0333] Specifically, a Waters PL-GPC220 gel permeation chromatography (GPC) device was used, and a Polymer Laboratories PLgel MIX-B 300 mm column was used. The measurement temperature was 160°C, 1,2,4-trichlorobenzene was used as a solvent, and the flow rate was 1 mL / min. The polymer samples according to the examples and comparative examples were each pretreated by dissolving in trichlorobenzene (1,2,4-trichlorobenzene) containing 0.0125% butylated hydroxytoluene (BHT) at 160°C for 10 hours using a GPC analysis device (PL-GP220), and then preparing a concentration of 10 mg / 10 mL, and then supplying in an amount of 200 μL. The values ​​of Mw and Mn were derived using a calibration curve formed using polystyrene standard specimens. 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 nine types.

[0334]

[0335] In addition, the logarithmic graph for the weight average molecular weight (Mw) of virgin polyethylene (HDPE) measured through GPC analysis, i.e., the GPC curve graph in which the x-axis is log MW and the y-axis is dw / dlogMw, was calculated as the ratio of the integral value of the region in which the Log MW value is 5.5 or more to the total integral value (LogMw≥5.5, unit: %), and is shown in Table 1 below.

[0336]

[0337] (3) Entanglement molecular weight (Me)

[0338] The entanglement molecular weight (Me, g / mol) of virgin polyethylene (HDPE) was measured using a hybrid rheometer (DHR-2, Discovery Hybrid Rheometer-2) according to the following equation 1.

[0339] [Formula 1]

[0340] Me = ρRT / G 0 N

[0341] In the above equation 1, G 0 N is the plateau modulus, ρ is the melt density, R is the gas constant, and T is the absolute temperature.

[0342]

[0343] Here, G 0 N is inversely proportional to J0, the intercept value of creep compliance, and can be obtained from the following equation 2.

[0344] [Formula 2]

[0345] G 0 N = 6 / 5J0

[0346] In the above equation 2, J0 is the intercept value of creep compliance.

[0347]

[0348] In addition, the above J0 can be measured using a 25 mm diameter flat plate from DHR-2 (TA Instrument) in the following manner.

[0349]

[0350] For example, an ethylene (co)polymer sample is melted under a nitrogen atmosphere at a temperature of 190 ℃, and the ethylene (co)polymer sample is placed between 25 mm flat plates so that the thickness of the ethylene (co)polymer sample is 1 mm. Wait for 2 minutes to stabilize the temperature and to remove the vertical stress generated when the sample is compressed. A shear stress of 10 Pa is applied to the molten sample for 1,000 seconds. After the measurement is completed, the creep compliance J, which is the value obtained by dividing the amount of deformation of the ethylene (co)polymer by the applied shear stress, is plotted on the y-axis, and time (t) is plotted on the x-axis. J0 can be obtained by using the tangent line in the section where the steady state is reached and the slope is constant.

[0351]

[0352] (4) Drop impact strength

[0353] According to ASTM D 1709, using the Dart drop method A, a weight was dropped with a drop energy of 4.2 J on a disk specimen (diameter 50 mm, thickness 2 mm) of a polyethylene composition, and the number of drops before a crack of 1 mm or more in length occurred was measured, and the drop impact (times) is shown in Table 1 below.

[0354]

[0355] Specifically, a disc was manufactured based on a polyethylene composition (PCR Compound) as shown below, and the number of drops before a crack occurred in the disc was measured by dropping a weight on the disc. The number of drops before a crack of 1 mm or more in length occurred was measured.

[0356]

[0357] 4-1. Drop Impact Disc Manufacturing

[0358] - The disc was manufactured using an injection molding machine, and was manufactured by injecting PCR Compound after setting the temperature gradient to 210~230℃.

[0359] - Disc size (Φ 50 mm, thickness 2 mm).

[0360]

[0361] 4-2. Drop impact evaluation

[0362] - According to ASTM D 1709, Dart drop method A, using Instron 9450 (Impact Drop Tower), fix the disc and drop the weight to measure the number of times cracks occur (fixed drop energy of 4.2 J).

[0363]

[0364] (5) ESCR

[0365] According to the method of ASTM D 1693-07, the time to F50 (50% destruction) was measured for a polyethylene composition (PCR Compound) under the conditions of 50 ℃ and Condition B using 10% Igepal CO-630 Solution, and the time is shown as ESCR (hr) in Table 1 below.

[0366]

[0367] Properties of virgin polyethylene (Virgin Resin) Properties of polyethylene composition (PCR product, recycled raw material + Virgin Resin) Density (g / cm) 3 )LogMw>5.5(%)Me(g / mol)Density(g / cm 3 ) Drop impact (times) ESCR (hr) Example 10.947214.19,5540.94957217 Example 20.947714.29,0410.94977242 Comparative example 10.947414.315,5740.94977107 Comparative example 20.947018.99,5470.94924230 Comparative example 30.942910.29,7870.946910147 Comparative example 40.942514.010,1050.94797140 Comparative example 50.942813.910,8740.94777135 Comparative example 60.954220.79,8740.95413185Comparative example 70.958013.219,6870.9555553

[0368] Referring to Table 1 above, the polyethylene compositions of Examples 1 and 2 of the present invention have an excellent effect of enhancing the entanglement between the recycled raw material having polar groups due to oxidation and the non-polar virgin polyethylene, thereby increasing the environmental stress cracking resistance (ESCR) along with high density and drop impact strength, thereby simultaneously securing excellent processability while realizing high loading strength with excellent mechanical properties when used as a blow container even when recycled polyethylene (PCW PE) is blended in an excess of 60 wt%.

Claims

1. A polyethylene composition comprising virgin polyethylene and recycled polyethylene (PCW PE, Post consumer waste polyethylene), The above polyethylene composition satisfies the following (a) to (c): Polyethylene composition: (a) Density 0.949 g / cm 3 more, (b) The drop impact strength is 7 or more times measured by dropping a weight with a drop energy of 4.2 J on a disk specimen (diameter 50 mm, thickness 2 mm) of a polyethylene composition using the Dart drop method A according to ASTM D 1709, before a crack of 1 mm or more in length occurs. (c) Environmental stress cracking resistance (ESCR) of 200 hours or more as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%).

2. In paragraph 1, The above polyethylene composition has a density of (a) 0.949 g / cm 3 Above 0.954 g / cm 3 Below, Polyethylene composition.

3. In paragraph 1, The polyethylene composition above has a drop impact strength of 7 to 30 times, Polyethylene composition.

4. In paragraph 1, The above polyethylene composition has an environmental stress cracking resistance (ESCR) of 200 hours or more and 500 hours or less, Polyethylene composition.

5. In paragraph 1, The above polyethylene composition has a melting index (MI) of (d) 2.16 , ASTM D 1238, 190 ℃, 2.16 kg) is 0.25 g / 10min or more and 0.8 g / 10min or less, Polyethylene composition.

6. In paragraph 1, The above-mentioned new polyethylene is at least one selected from the group consisting of ethylene homopolymer and ethylene / alpha-olefin copolymer. Polyethylene composition.

7. In paragraph 6, The above alpha-olefin is at least one 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. Polyethylene composition.

8. In paragraph 6, The above new polyethylene is, Additionally comprising at least one polar copolymer containing ethylene, The above polar copolymer comprises at least one polar functional group selected from the group consisting of a carboxyl group, a hydroxyl group, a carbonyl group, a nitrile group, and an amide group. Polyethylene composition.

9. In paragraph 8, The polar copolymer has a content of the polar functional group of 20 wt% or more and 50 wt% or less based on the total weight of the polar copolymer. Polyethylene composition.

10. In paragraph 8, The above polar copolymer is an ethylene vinyl acetate copolymer. Polyethylene composition.

11. In paragraph 8, The above-mentioned new polyethylene has a ratio between the total weight of at least one of ethylene homopolymer and ethylene / alpha-olefin copolymer and the total weight of at least one of polar copolymers of 70:30 to 99:

1. Polyethylene composition.

12. In paragraph 1, The above new polyethylene has a density of 0.944 g / cm 3 Strange person, Polyethylene composition.

13. In paragraph 1, The above-mentioned new polyethylene is a polyethylene GPC curve graph in which the x-axis is log Mw and the y-axis is dw / dlogMw, in which the integral value of the region in which the log Mw is 5.5 or more is 15% or less of the total integral value. Polyethylene composition.

14. In paragraph 1, The above-mentioned new polyethylene has an entanglement molecular weight (Me) of less than 10,000 g / mol. Polyethylene composition.

15. In paragraph 1, Containing 10 wt% or more and 90 wt% or less of the above recycled polyethylene (PCW PE, Post consumer waste polyethylene), Polyethylene composition.

16. In paragraph 1, The above recycled polyethylene (PCW PE, Post consumer waste polyethylene) has a melt index (MI) measured at 190°C and 2.16 kg load according to ASTM D 1238. 2.16 ) is 0.15 g / 10min or more and 0.2 g / 10min or less, Polyethylene composition.

17. In paragraph 1, The above recycled polyethylene (PCW PE, Post consumer waste polyethylene) has a density of 0.951 g / cm 3 Above 0.953 g / cm 3 Below, Polyethylene composition.

18. In paragraph 1, The above recycled polyethylene (PCW PE, Post consumer waste polyethylene) has an environmental stress cracking resistance (ESCR) of 40 hours or more and 50 hours or less as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%). Polyethylene composition.

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