High-density polyethylene and film comprising same

Abstract

High-density polyethylene according to the present invention can improve both processability and excellent moisture barrier properties, without degradation of physical properties during film processing and without blending with low-density polyethylene or the like, through fine control of a melt flow index, a polydispersity index (PDI), and elongation viscosity, in addition to having a high density.

Description

High-density polyethylene and films containing the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0152544 filed October 31, 2024 and Korean Patent Application No. 10-2025-0151703 filed October 20, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0003]

[0004] The present invention relates to high-density polyethylene having excellent processability along with moisture barrier properties, and a film containing the same.

[0005]

[0006] Polyethylene is a general-purpose polymer widely used in various applications such as packaging films, pipes, and containers, and is broadly classified into high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE) depending on its density.

[0007]

[0008] Recently, in order to increase the recycling rate of various packaging films for food, household use, and electronic products, there is growing interest in films made entirely of polyethylene, such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE), instead of the conventionally used aluminum foil (Al foil), nylon, or ethylene vinyl alcohol (EVOH).

[0009]

[0010] In addition, to replace other materials used for barrier applications, it is necessary to ensure the moisture and oxygen barrier properties of 100% polyethylene films (All-PE films). Among polyethylenes, HDPE has a high density and a large number of crystalline regions, so it offers superior moisture and oxygen barrier properties compared to other polyethylenes such as low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE). Accordingly, HDPE can serve as a barrier film that blocks moisture penetration. However, because HDPE is non-polar, its oxygen barrier properties are inferior to those of conventionally used materials such as aluminum foil, nylon, and EVOH.

[0011]

[0012] Accordingly, in order to increase the recycling rate of various packaging films, there is a need to develop a method that utilizes HDPE films applicable to fields requiring stiffness, such as VFFS (vertical form fill seal), while also significantly improving processability through excellent moisture barrier properties and superior bubble stability at low resin pressures and process temperatures during film processing.

[0013]

[0014] The present invention aims to provide high-density polyethylene capable of improving processability through excellent moisture barrier properties and excellent bubble stability at low resin pressure and process temperature during film processing.

[0015]

[0016] In addition, the present invention aims to provide a film with improved processability by manufacturing using the aforementioned high-density polyethylene, which exhibits excellent moisture barrier properties and excellent bubble stability at low resin pressure and process temperature during film processing.

[0017]

[0018] According to one embodiment of the invention, the density is 0.965 g / cm³ or more and 0.975 g / cm³ or less, and the melt flow index (MI 2.16 High-density polyethylene is provided, wherein the polydispersity index (PDI, Mw / Mn) measured at 190 ℃ and 2.16 kg load is 0.1 g / 10 min or more and 5.0 g / 10 min or less, the polydispersity index is 20 or more and 60 or less, and the elongational viscosity (@strain 2.5) is 30,000 Pa·S or more and 90,000 Pa·S or less.

[0019]

[0020] In addition, the high-density polyethylene is characterized by being manufactured by performing ethylene homopolymerization in a unimodal slurry loop process in the presence of a hybrid supported metallocene catalyst comprising one or more first metallocene compounds represented by the following chemical formula 1 as catalytic active components; and one or more second metallocene compounds selected from compounds represented by the following chemical formula 2.

[0021] [Chemical Formula 1]

[0022]

[0023] In the above chemical formula 1,

[0024] At least one of R1 to R8 is -(CH2) n -OR and here, R is C 1-6 It is a straight-chain or branched-chain alkyl, where n is an integer from 2 to 6, and

[0025] The remainders of R1 to R8 are identical or different from one another and each independently hydrogen, halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 6-20 Aril, C 7-40 Alkylaryl, and C 7-40 It is a functional group selected from the group consisting of arylalkyls, or two or more adjacent groups connected to each other, C 1-10C substituted or unsubstituted with a hydrocarbyl group 6-20 It can form an aliphatic or aromatic ring,

[0026] Q1 and Q2 are identical or different from each other, and each independently hydrogen, halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is an arylalkyl;

[0027] A1 is carbon (C), silicon (Si), or germanium (Ge);

[0028] M1 is a group 4 transition metal;

[0029] X1 and X2 are identical or different from each other, and each independently halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 6-20 Aryl, Nitrogi, Amidogi, C 1-20 Alkylsilyl, C 1-20 Alkoxy, or C 1-20 It is a sulfonate group; and

[0030] m is 0 or 1, and

[0031] [Chemical Formula 2]

[0032]

[0033] In the above chemical formula 2,

[0034] Q5 and Q6 are identical or different from each other, and each independently hydrogen, halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is an arylalkyl;

[0035] A3 is carbon (C), silicon (Si), or germanium (Ge);

[0036] M3 is a group 4 transition metal;

[0037] X5 and X6 are identical or different from each other, and each independently halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 6-20 Aryl, Nitrogi, Amidogi, C 1-20 Alkylsilyl, C 1-20 Alkoxy, or C 1-20 It is a sulfonate group;

[0038] One of C3 and C4 is represented by one of the following chemical formulas 2a, 2b, or 2c, provided that the case where both C3 and C4 are chemical formula 2c is excluded;

[0039] [Chemical Formula 2a]

[0040]

[0041] [Chemical Formula 2b]

[0042]

[0043] [Chemical Formula 2c]

[0044]

[0045] In the above chemical formulas 2a and 2b, R 40 to R 47 and R 40 ' or R 47 ' are identical or different from each other, and each independently hydrogen, halogen, C 1-20 Alkyl, C 1-20 Haloalkyl, C 2-20 Alkenyl, C 1-20 Alkylsilyl, C 1-20 Alkylsilylalkylene, C 1-20 Alkoxysilyl, C 1-20 Alkoxy, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is an arylalkyl, and

[0046] R 48 and R 48 ' are identical or different from each other, and each independently C 1-20 Alkyl, C 1-20 Alkylsilyl, C1-20 Alkylsilylalkylene, C 1-20 Alkoxysilyl, or C 1-20 It is an alkoxy;

[0047] In the above chemical formula 2c, R 49 to R 56 They are identical or different from each other, and each independently hydrogen, halogen, and C 1-20 Alkyl, C 1-20 Haloalkyl, C 2-20 Alkenyl, C 1-20 Alkylsilyl, C 1-20 Alkylsilylalkylene, C 1-20 Alkoxysilyl, C 1-20 Alkoxy, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is an arylalkyl, and the above R 49 to R 56 Two or more adjacent rings may be connected to each other to form a substituted or unsubstituted aliphatic or aromatic ring; and

[0048] * indicates the region that combines with A3 and M3.

[0049]

[0050] In addition, the present invention provides a film comprising the high-density polyethylene.

[0051]

[0052] According to the present invention, by fine-tuning the melt flow index, polydispersity index (PDI), and tensile viscosity along with the high density of high-density polyethylene (HDPE), excellent moisture barrier properties and excellent bubble stability at low resin pressure and process temperature during film processing can be improved.

[0053]

[0054] Figure 1 shows a GPC graph measured for high-density polyethylene of Examples 1 and 3 and Comparative Example 1 according to one embodiment of the present invention.

[0055]

[0056] FIG. 2 shows a graph of the ARES analysis results measured for high-density polyethylene of Examples 1 and 3 and Comparative Example 1 according to one embodiment of the present invention.

[0057]

[0058] FIG. 3 shows a graph of the elongation viscosity measured for high-density polyethylene of Examples 1 and 3 and Comparative Example 1 according to one embodiment of the present invention.

[0059]

[0060] 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.

[0061]

[0062] 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.

[0063]

[0064] 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.

[0065]

[0066] 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.

[0067]

[0068] 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%.

[0069]

[0070] 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.

[0071]

[0072] The present invention will be described in more detail below.

[0073]

[0074] According to one embodiment of the invention, high-density polyethylene is provided that can improve both processability and excellent moisture barrier properties without degradation of physical properties during film processing, even without blending with low-density polyethylene, by finely controlling the melt flow index, polydispersity index (PDI), and tensile viscosity along with high density.

[0075]

[0076] Specifically, the high-density polyethylene (HDPE) of the present invention has a density of 0.965 g / cm³ or more and 0.975 g / cm³ or less, and a melt flow index (MI 2.16 (measured at 190 ℃, 2.16 kg load) is 0.1 g / 10 min or more and 5.0 g / 10 min or less, polydispersity index (PDI, Mw / Mn) is 20 or more and 60 or less, and elongational viscosity (@strain 2.5) is 30,000 Pa·S or more and 90,000 Pa·S or less.

[0077]

[0078] In particular, the high-density polyethylene in the present invention is an all-PE single material based on advantages such as ease of recycling and excellent physical properties, and is characterized by having a high density to enable excellent moisture barrier, heat resistance, and excellent stiffness characteristics for VFFS (vertical form fill seal) processing, having a wide molecular weight distribution to enable low processing pressure for stable film production, and having high tensile viscosity to ensure excellent bubble stability during film processing.

[0079]

[0080] The high-density polyethylene according to the present invention is an ethylene homopolymer that does not include a separate copolymer.

[0081]

[0082] The above high-density polyethylene has a wide polydispersity index (PDI, Mw / Mn) and a melt flow rate ratio (MFRR, MI 21.6 / MI 2.16 The large size of the resin pressure during processing results in excellent processability. In addition, the large portions of molecular weights of 1,000 g / mol or less and 10,000 g / mol or less have a wide crystal distribution and high tensile viscosity, resulting in excellent bubble stability.

[0083]

[0084] Specifically, the density of the high-density polyethylene (ASTM D 1505, 23 ℃) is 0.965 g / cm³ 3 Above 0.975 g / cm³ 3 It is less than or equal to. Preferably, the density is 0.966 g / cm³. 3 Above, 0.967 g / cm³ 3 Above, 0.968 g / cm³ 3 Above, 0.969 g / cm³ 3 Above, or 0.970 g / cm³ 3 Above, 0.974 g / cm³ 3 Less than or equal to 0.973 g / cm³ 3 It may be less than or equal to this. Such high density implies a high content of the crystalline structure of high-density polyethylene; accordingly, as the crystalline region increases in the entire film, the amorphous region decreases, which can effectively block water and oxygen molecules and significantly improve the moisture and oxygen barrier properties of the film.

[0085]

[0086] Meanwhile, the high-density polyethylene of the present invention has a high density and an optimized melt flow index as described above.

[0087]

[0088] The above high-density polyethylene has a melt flow index (MI 2.16 , ASTM D 1238, 190 ℃, 2.16 kg) is 0.1 g / 10 min or more and 5.0 g / 10 min or less. Preferably, the melt flow index (MI) 2.16(ASTM D 1238, 190 ℃, 2.16 kg) may be 0.5 g / 10 min or more, 0.8 g / 10 min or more, 0.9 g / 10 min or more, 1.0 g / 10 min or more, 1.05 g / 10 min or more, or 1.1 g / 10 min or more, and 2.5 g / 10 min or less, 2.2 g / 10 min or less, 2.0 g / 10 min or less, 1.8 g / 10 min or less, 1.6 g / 10 min or less, 1.5 g / 10 min or less, 1.4 g / 10 min or less, 1.35 g / 10 min or less, or 1.3 g / 10 min or less. The melt flow index (MI) of the above high-density polyethylene 2.16 ) refers to the melt flow index (MI) within the aforementioned range in terms of securing excellent moisture barrier and heat resistance during film processing. 2.16 has ).

[0089]

[0090] In addition, the above high-density polyethylene has a high-load melt flow index (MI 21.6 , ASTM D 1238, 190 ℃, 21.6 kg) may be 180 g / 10 min or more and 300 g / 10 min or less. Preferably, the above high-load melt flow index (MI 21.6 (ASTM D 1238, 190 ℃, 21.6 kg) may be 185 g / 10 min or more, 190 g / 10 min or more, 195 g / 10 min or more, 198 g / 10 min or more, or 200 g / 10 min or more, and 290 g / 10 min or less, 285 g / 10 min or less, 280 g / 10 min or less, 275 g / 10 min or less, 270 g / 10 min or less, or 265 g / 10 min or less. The high-load melt flow index (MI) of the above high-density polyethylene 21.6 ) refers to the high-load melt flow index (MI) within the aforementioned range in terms of ensuring excellent moisture barrier and heat resistance during film processing. 21.6 Can have ).

[0091]

[0092] In addition, the above high-density polyethylene has a melt flow rate ratio (MFRR, MI 21.6 / MI 2.16 ) may be 150 or more and 250 or less. Preferably, the melt flow rate ratio (MFRR) may be 155 or more, 160 or more, 165 or more, 170 or more, 175 or more, or 178 or more, and 245 or less, 240 or less, 235 or less, 230 or less, 225 or less, 220 or less, 215 or less, 210 or less, or 205 or less. The high-load melt flow rate ratio (MFRR) of the high-density polyethylene may have a large melt flow rate ratio within the above-described range in terms of securing excellent processability with low processing pressure during film processing.

[0093]

[0094] The high-density polyethylene of the present invention, in terms of excellent thermal stability, has a melting point (T m The melting point (T) may be 130°C or higher and 140°C or lower. Preferably, the melting point (T m ) may be 131 ℃ or higher, 132 ℃ or higher, 132.5 ℃ or higher, 133 ℃ or higher, 133.5 ℃ or higher, or 134 ℃ or higher, and 139 ℃ or lower, 138.5 ℃ or lower, 138 ℃ or lower, 137.5 ℃ or lower, 137 ℃ or lower, 136.5 ℃ or lower, or 136 ℃ or lower. For example, the melting point (T) of the high-density polyethylene is m ) can be measured using a differential scanning calorimeter (DSC). More specifically, the method for measuring the melting point (Tm) of the high-density polyethylene will be explained in detail in the test examples described below.

[0095]

[0096] Meanwhile, the high-density polyethylene of the present invention is optimized with a wide molecular weight distribution along with high density and melt flow index as described above.

[0097]

[0098] Specifically, the polydispersity index (PDI, Mw / Mn) of the high-density polyethylene is 20 or higher and 60 or lower. Preferably, the polydispersity index (PDI, Mw / Mn) may be 25 or higher, 28 or higher, 30 or higher, 32 or higher, 35 or higher, or 38 or higher, and 58 or lower, 55 or lower, 53 or lower, 50 or lower, 48 or lower, 45 or lower, 43 or lower, or 40 or lower. The polydispersity index (PDI, Mw / Mn) of the high-density polyethylene satisfies the above-mentioned range by optimizing it with a wide molecular weight distribution to ensure excellent processability with low processing pressure during film processing.

[0099]

[0100] For example, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polyethylene (PDI, polydispersity index, Mw / Mn) can be measured using gel permeation chromatography (GPC, gel permeation chromatography, manufactured by Polymer Char).

[0101]

[0102] Specifically, a high-temperature GPC instrument from Polymer Char is used as the gel permeation chromatography (GPC) apparatus, and one guard column and three separation columns can be used. In this case, the measurement temperature is 160 oC, 1,2,4-trichlorobenzene is used as the solvent, and the 'default 50 min' method from Polymer Char can be applied. Polyethylene samples according to the examples and comparative examples can be weighed at 8–16 mg, placed in a 10 mL vial, and capped. The capped vials are placed in an autosampler, and after adding 8 mL of 1,2,4-trichlorobenzene to the vials, 160 o It can be dissolved at C for 2 hours under middle shaking conditions to prepare a solution at a concentration of 1–2 mg / mL, and then supplied in an amount of 200 μL. Mn, Mw, and PDI values ​​can be derived using a calibration curve formed using a polystyrene standard specimen. Sixteen types of polystyrene standard specimens with molecular weights of 266 g / mol, 672 g / mol, 1,810 g / mol, 3,220 g / mol, 5,180 g / mol, 12,600 g / mol, 19,700 g / mol, 34,800 g / mol, 61,400 g / mol, 127,000 g / mol, 238,000 g / mol, 526,000 g / mol, 1,500,000 g / mol, 3,080,000 g / mol, 5,150,000 g / mol, and 12,900,000 g / mol can be used.

[0103]

[0104] The weight-average molecular weight (Mw) of the above high-density polyethylene may be 120,000 g / mol to 200,000 g / mol. In particular, the above high-density polyethylene may have a weight-average molecular weight within the range described above within the same molecular weight distribution in terms of improving moisture barrier properties during film processing. Preferably, the weight average molecular weight (Mw) may be 123,000 g / mol or more, 125,000 g / mol or more, 128,000 g / mol or more, 130,000 g / mol or more, 132,000 g / mol or more, 134,000 g / mol or more, or 136,000 g / mol or more, and 190,000 g / mol or less, 180,000 g / mol or less, 160,000 g / mol or less, 155,000 g / mol or less, 150,000 g / mol or less, 148,000 g / mol or less, 145,000 g / mol or less, or 142,000 or less.

[0105]

[0106] The number average molecular weight (Mn) of the above high-density polyethylene may be 1,000 g / mol to 5,500 g / mol. In particular, the above high-density polyethylene may have a high number average molecular weight in terms of improving moisture barrier properties during film processing. Preferably, the number average molecular weight (Mn) may be 1,500 g / mol or more, 2,000 g / mol or more, 2,500 g / mol or more, 2,800 g / mol or more, 3,000 g / mol or more, 3,200 g / mol or more, or 3,500 g / mol or more, and 5,000 g / mol or less, 4,800 g / mol or less, 4,500 g / mol or less, 4,300 g / mol or less, 4,200 g / mol or less, or 4,000 g / mol or less.

[0107]

[0108] In addition, the high-density polyethylene can secure excellent bubble stability during film processing by optimizing the GPC curve graph measured using gel permeation chromatography (GPC, manufactured by Polymer Char Co., Ltd.) as described above, that is, the GPC curve graph where the x-axis is Log Mw and the y-axis is dw / dlogMw, the region of molecular weight 100 g / mol or more and 1,000 g / mol or less, the region of molecular weight 100 g / mol or more and 10,000 g / mol or less, and the region of molecular weight 1,000,000 g / mol or more and 10,000,000 g / mol or less, i.e., the region where the Log Mw value is 2 or more and 3 or less, 2 or more and 4 or less, and 6 or more and 7 or less, respectively.

[0109]

[0110] Specifically, in the GPC curve graph of the high-density polyethylene where the x-axis is Log Mw and the y-axis is dw / dlogMw, the integral value of the region with a molecular weight of 100 g / mol or more and 1,000 g / mol or less, that is, the region with a Log Mw value of 2 or more and 3 or less, may be 3% or more and 10% or less of the total integral value. Preferably, the region with a molecular weight of 100 g / mol or more and 1,000 g / mol or less may be 3.5% or more, 4% or more, 4.5% or more, 4.8% or more, 5% or more, 5.2% or more, 5.4% or more, or 5.6% or more, and 9% or less, 8.5% or less, 8% or less, 7.5% or less, 7% or less, 6.8% or less, or 6.5% or less. The molecular weight range of the above high-density polyethylene, ranging from 100 g / mol to 1,000 g / mol, is advantageous in terms of securing excellent moisture barrier properties and excellent processability during film processing.

[0111]

[0112] In addition, in the GPC curve graph of the high-density polyethylene where the x-axis is Log Mw and the y-axis is dw / dlogMw, the integral value of the region with a molecular weight of 100 g / mol or more and 10,000 g / mol or less, that is, the region with a Log Mw value of 2 or more and 4 or less, may be 38% or more and 50% or less of the total integral value. Preferably, the region with a molecular weight of 100 g / mol or more and 10,000 g / mol or less may be 38.5% or more, 39% or more, 39.5% or more, 40% or more, 40.5% or more, 41% or more, or 41.5% or more, and 48% or less, 47% or less, 46% or less, 45% or less, 44.5% or less, or 44% or less.

[0113]

[0114] In addition, in the GPC curve graph of the high-density polyethylene where the x-axis is Log Mw and the y-axis is dw / dlogMw, the integral value of the region with a molecular weight of 1,000,000 g / mol or more and 10,000,000 g / mol or less, that is, the region with a Log Mw value of 6 or more and 7 or less, may be 1% or more and 5% or less of the total integral value. Preferably, the region with a molecular weight of 1,000,000 g / mol or more and 10,000,000 g / mol or less may be 1.2% or more, 1.5% or more, 1.8% or more, 2.0% or more, 2.2% or more, or 2.3% or more, and 4.5% or less, 4% or less, 3.8% or less, 3.5% or less, 3.2% or less, 3% or less, or 2.8% or less.

[0115]

[0116] Along with the molecular weight range of 100 g / mol or more and 1,000 g / mol or less of the above high-density polyethylene, the molecular weight range of 100 g / mol or more and 10,000 g / mol or less, and the molecular weight range of 1,000,000 g / mol or more and 10,000,000 g / mol or less can be optimized to the aforementioned ranges in terms of securing excellent processability and excellent bubble stability with low processing pressure, along with excellent moisture barrier properties during film processing.

[0117]

[0118] Meanwhile, the high-density polyethylene of the present invention has a structure that optimizes the melt flow index and polydispersity index (PDI) along with high density as described above, and has high tensile viscosity.

[0119]

[0120] Specifically, the elongational viscosity (@strain 2.5) of the high-density polyethylene is 30,000 Pa·S or more and 90,000 Pa·S or less. Preferably, the above-mentioned elongation viscosity may be 32,000 Pa·S or more, 35,000 Pa·S or more, 38,000 Pa·S or more, 40,000 Pa·S or more, 42,000 Pa·S or more, 45,000 Pa·S or more, 48,000 Pa·S or more, 50,000 Pa·S or more, or 52,000 Pa·S or more, and 80,000 Pa·S or less, 78,000 Pa·S or less, 75,000 Pa·S or less, 73,000 Pa·S or less, 70,000 Pa·S or less, 68,000 Pa·S or less, 65,000 Pa·S or less, or 64,000 Pa·S or less. The tensile viscosity of the above-mentioned high-density polyethylene is optimized to the aforementioned range in terms of securing excellent bubble stability during film processing along with excellent moisture barrier properties during film processing.

[0121]

[0122] For example, elongation viscosity can be measured using TA Instruments’ ARES G2 instrument and EVF (Elongation Viscosity Fixture) accessory. Specifically, after measuring the elongation viscosity from strain 0 to 3 under conditions of 170 ℃ and a Henki strain rate of 0.1 / s, the elongation viscosity value at strain 2.5 can be extracted.

[0123]

[0124] Meanwhile, the high-density polyethylene of the present invention has a high elongational viscosity (@strain 2.5) as described above, and by optimizing the ratio of the complex viscosity at an angular velocity of 0.1 rad / s to the complex viscosity at an angular velocity of 100 rad / s, it is possible to secure both excellent bubble stability and excellent processability during film processing.

[0125]

[0126] Specifically, the complex viscosity (η*(0.1 rad / s)) of the high-density polyethylene measured at an angular velocity of 0.1 rad / s may be 10,000 Pa·s or more and 16,000 Pa·s or less. Preferably, the complex viscosity (η*(0.1 rad / s)) may be 10,500 Pa·s or more, 11,000 Pa·s or more, or 11,500 Pa·s or more, and 15,500 Pa·s or less, 15,000 Pa·s or less, 14,800 Pa·s or less, or 14,500 Pa·s or less. The complex viscosity (η*(0.1 rad / s)) of the high-density polyethylene may be optimized to the above-described range in terms of ensuring excellent bubble stability during film processing.

[0127]

[0128] In addition, the complex viscosity (η*(100 rad / s)) of the high-density polyethylene measured at an angular velocity of 100 rad / s may be 600 Pa·s or more and 900 Pa·s or less. Preferably, the complex viscosity (η *(100 rad / s)) may be 620 Pa·s or more, 640 Pa·s or more, 650 Pa·s or more, or 680 Pa·s or more, and 880 Pa·s or less, 850 Pa·s or less, 840 Pa·s or less, or 830 Pa·s or less. The complex viscosity (η*(100 rad / s)) of the high-density polyethylene may be optimized to the above-described range in terms of securing excellent processability with a low processing load during film processing, along with excellent moisture barrier properties during film processing.

[0129]

[0130] In addition, the ratio of the complex viscosity measured at an angular velocity of 0.1 rad / s to the complex viscosity measured at an angular velocity of 100 rad / s of the high-density polyethylene (η* (0.1 rad / s)) / η* (100 rad / s)) may be 10 or more and 30 or less. Preferably, the complex viscosity ratio ((η* (0.1 rad / s)) / η* (100 rad / s)) may be 12 or more, 14 or more, 15 or more, or 16 or more, and 28 or less, 25 or less, 22 or less, 20 or less, or 18 or less. The complex viscosity ratio ((η* (0.1 rad / s)) / η*(100 rad / s)) of the above high-density polyethylene can be optimized to the aforementioned range in terms of securing excellent moisture barrier properties during film processing, as well as excellent bubble stability and excellent processability during film processing.

[0131]

[0132] For example, complex viscosity was measured using TA Instruments’ ARES (Advanced Rheometric Expansion System) G2. Polyethylene specimens with a diameter of 25 mm and a gap of 2.0 mm were prepared at 190°C using the parallel plates of the ARES instrument, and then complex viscosity was measured in dynamic strain frequency sweep mode at a strain of 5% and an angular frequency from 0.05 rad / s to 500 rad / s.

[0133]

[0134] Meanwhile, the high-density polyethylene according to the present invention is characterized by being produced by homopolymerizing ethylene in the presence of a metallocene catalyst using a unimodal slurry loop process. A specific example of the ethylene homopolymerization process can be referenced in the examples described below.

[0135]

[0136] Specifically, the high-density polyethylene is characterized by being manufactured by performing an ethylene homopolymerization process in a unimodal slurry loop process in the presence of a hybrid supported metallocene catalyst comprising one or more first metallocene compounds represented by the following chemical formula 1 as catalytic active components; and one or more second metallocene compounds selected from compounds represented by the following chemical formula 2. A specific example of the ethylene homopolymerization process may be referenced in the examples described below.

[0137] [Chemical Formula 1]

[0138]

[0139] In the above chemical formula 1,

[0140] At least one of R1 to R8 is -(CH2) n -OR and here, R is C 1-6 It is a straight-chain or branched-chain alkyl, where n is an integer from 2 to 6, and

[0141] The remainders of R1 to R8 are identical or different from one another and each independently hydrogen, halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 6-20 Aril, C 7-40 Alkylaryl, and C 7-40 It is a functional group selected from the group consisting of arylalkyls, or two or more adjacent groups connected to each other, C 1-10 C substituted or unsubstituted with a hydrocarbyl group 6-20It can form an aliphatic or aromatic ring,

[0142] Q1 and Q2 are identical or different from each other, and each independently hydrogen, halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is an arylalkyl;

[0143] A1 is carbon (C), silicon (Si), or germanium (Ge);

[0144] M1 is a group 4 transition metal;

[0145] X1 and X2 are identical or different from each other, and each independently halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 6-20 Aryl, Nitrogi, Amidogi, C 1-20 Alkylsilyl, C 1-20 Alkoxy, or C 1-20 It is a sulfonate group; and

[0146] m is 0 or 1, and

[0147] [Chemical Formula 2]

[0148]

[0149] In the above chemical formula 2,

[0150] Q5 and Q6 are identical or different from each other, and each independently hydrogen, halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is an arylalkyl;

[0151] A3 is carbon (C), silicon (Si), or germanium (Ge);

[0152] M3 is a group 4 transition metal;

[0153] X5 and X6 are identical or different from each other, and each independently halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 6-20 Aryl, Nitrogi, Amidogi, C 1-20 Alkylsilyl, C 1-20 Alkoxy, or C 1-20 It is a sulfonate group;

[0154] One of C3 and C4 is represented by one of the following chemical formulas 2a, 2b, or 2c, provided that the case where both C3 and C4 are chemical formula 2c is excluded;

[0155] [Chemical Formula 2a]

[0156]

[0157] [Chemical Formula 2b]

[0158]

[0159] [Chemical Formula 2c]

[0160]

[0161] In the above chemical formulas 2a and 2b, R 40 to R 47 and R 40 ' or R 47 ' are identical or different from each other, and each independently hydrogen, halogen, C 1-20 Alkyl, C 1-20 Haloalkyl, C 2-20 Alkenyl, C 1-20 Alkylsilyl, C 1-20 Alkylsilylalkylene, C 1-20 Alkoxysilyl, C 1-20 Alkoxy, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is an arylalkyl, and

[0162] R 48 and R 48 ' are identical or different from each other, and each independently C 1-20 Alkyl, C 1-20 Alkylsilyl, C 1-20Alkylsilylalkylene, C 1-20 Alkoxysilyl, or C 1-20 It is an alkoxy;

[0163] In the above chemical formula 2c, R 49 to R 56 They are identical or different from each other, and each independently hydrogen, halogen, and C 1-20 Alkyl, C 1-20 Haloalkyl, C 2-20 Alkenyl, C 1-20 Alkylsilyl, C 1-20 Alkylsilylalkylene, C 1-20 Alkoxysilyl, C 1-20 Alkoxy, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is an arylalkyl, and the above R 49 to R 56 Two or more adjacent rings may be connected to each other to form a substituted or unsubstituted aliphatic or aromatic ring; and

[0164] * indicates the region that combines with A3 and M3.

[0165]

[0166] In addition, the high-density polyethylene in the present invention is characterized by being produced by performing ethylene homopolymerization while introducing hydrogen gas in the presence of the aforementioned hybrid supported metallocene catalyst.

[0167]

[0168] Specifically, the homopolymerization step described above is performed by introducing hydrogen gas at a concentration of about 350 ppm to about 850 ppm based on ethylene content. Preferably, hydrogen gas may be introduced at a concentration of about 380 ppm or more, or about 400 ppm or more, 420 ppm or more, or about 450 ppm or more, 480 ppm or more, or about 500 ppm or more, 520 ppm or more, or about 550 ppm or more, or about 580 ppm or more, or about 600 ppm or more, and at the same time, may be introduced at a concentration of about 820 ppm or less, or about 800 ppm or less, or about 780 ppm or less, or about 750 ppm or less, or about 700 ppm or less, or about 680 ppm or less, or about 660 ppm or less, or about 650 ppm or less.

[0169]

[0170] In this way, by performing an ethylene homopolymerization process in a unimodal slurry loop process in the presence of the aforementioned first metallocene compound and second metallocene compound, while optimizing the hydrogen gas input amount, high-density polyethylene with optimized melt flow index, polydispersity index (PDI), and tensile viscosity can be produced along with high density.

[0171]

[0172] Meanwhile, unless otherwise specifically limited in this specification, the following terms may be defined as follows.

[0173]

[0174] Halogens can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0175]

[0176] The hydrocarbyl group is a monovalent functional group in which a hydrogen atom has been removed from a hydrocarbon, and may include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, aralkyl groups, aralkenyl groups, aralkynyl groups, alkylaryl groups, alkenylaryl groups, and alkynylaryl groups. Additionally, the hydrocarbyl group having 1 to 30 carbon atoms may be a hydrocarbyl group having 1 to 20 carbon atoms or 1 to 10 carbon atoms. For example, the hydrocarbyl group may be a straight-chain, branched-chain, or cyclic alkyl group. More specifically, the hydrocarbyl group having 1 to 30 carbon atoms may be a straight-chain, branched-chain, or cyclic alkyl group such as a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, or a cyclohexyl group; or an aryl group such as phenyl, biphenyl, naphthyl, anthracenyl, phenanthrenyl, or fluorenyl. Additionally, it may be an alkylaryl such as methylphenyl, ethylphenyl, methylbiphenyl, methylnaphthyl, etc., or an arylalkyl such as phenylmethyl, phenylethyl, biphenylmethyl, naphthylmethyl, etc. Additionally, it may be an alkenyl such as allyl, ethenyl, propenyl, butenyl, pentenyl, etc.

[0177]

[0178] In addition, carbon atoms numbering 1 to 20 (C 1-20 The alkyl of ) may be a straight-chain, branched-chain, or cyclic alkyl. Specifically, the alkyl having 1 to 20 carbon atoms may be a straight-chain alkyl having 1 to 20 carbon atoms; a straight-chain alkyl having 1 to 15 carbon atoms; a straight-chain alkyl having 1 to 5 carbon atoms; a branched-chain or cyclic alkyl having 3 to 20 carbon atoms; a branched-chain or cyclic alkyl having 3 to 15 carbon atoms; or a branched-chain or cyclic alkyl having 3 to 10 carbon atoms. For example, the above alkyl having 1 to 20 carbon atoms (C 1-20The alkyl groups of ) include methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc., but are not limited to these.

[0179]

[0180] Number of carbon atoms 2 to 20 (C 2-20 Alkenyls of ) include straight-chain or branched-chain alkenyls, specifically allyl, ethenyl, propenyl, butenyl, fentenyl, etc., but are not limited to these.

[0181]

[0182] 1 to 20 carbon atoms (C 1-20 Examples of alkoxy groups include methoxy, ethoxy, isopropoxy, n-butoxy, tert-butoxy, cyclohexyloxy, etc., but are not limited to these.

[0183]

[0184] Number of carbon atoms 2 to 20 (C 2-20 The alkoxyalkyl group of the above-described alkyl is a functional group in which one or more hydrogens are substituted with an alkoxy group, and specifically, examples include alkoxyalkyls such as methoxymethyl, methoxyethyl, ethoxymethyl, iso-propoxymethyl, iso-propoxyethyl, iso-propoxypropyl, iso-propoxyhexyl, tert-butoxymethyl, tert-butoxyethyl, tert-butoxypropyl, and tert-butoxyhexyl, but are not limited thereto.

[0185]

[0186] 6 to 40 carbon atoms (C 6-40 Examples of aryloxys include phenoxy, biphenoxy, and naphthoxy, but are not limited to these.

[0187]

[0188] 7 to 40 carbon atoms (C 7-40The aryloxyalkyl group of the above-mentioned alkyl is a functional group in which one or more hydrogens of the alkyl are substituted with aryloxy, and specifically, examples include phenoxymethyl, phenoxyethyl, phenoxyhexyl, etc., but are not limited thereto.

[0189]

[0190] 1 to 20 carbon atoms (C 1-20 ) alkylsilyl or carbon atoms 1 to 20 (C 1-20 The alkoxysilyl group of ) is a functional group in which 1 to 3 hydrogens of -SiH3 are substituted with 1 to 3 alkyl or alkoxy groups as described above, and specifically, examples include alkylsilyls such as methylsilyl, dimethylsilyl, trimethylsilyl, dimethylethylsilyl, diethylmethylsilyl, or dimethylpropylsilyl; alkoxysilyls such as methoxysilyl, dimethoxysilyl, trimethoxysilyl, or dimethoxyethoxysilyl; and alkoxyalkylsilyls such as methoxydimethylsilyl, diethoxymethylsilyl, or dimethoxypropylsilyl, but are not limited thereto.

[0191]

[0192] 1 to 20 carbon atoms (C 1-20 The silylalkyl group of ) is a functional group in which one or more hydrogens of the alkyl group described above are substituted with silyl, and specifically, examples include -CH2-SiH3, methylsilylmethyl or dimethylethoxysilylpropyl, but are not limited thereto.

[0193]

[0194] In addition, carbon atoms numbering 1 to 20 (C 1-20 The alkylenes of ) are the same as the alkyls described above except that they are divalent substituents, specifically methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene, etc., but are not limited to these.

[0195]

[0196] 6 to 20 carbon atoms (C 6-20The aryl of ) may be a monocyclic, bicyclic, or tricyclic aromatic hydrocarbon. For example, the above 6 to 20 carbon atoms (C 6-20 Examples of aryls of ) include phenyl, biphenyl, naphthyl, anthracenyl, phenanthrenyl, fluorenyl, etc., but are not limited to these.

[0197]

[0198] 7 to 20 carbon atoms (C 7-20 The alkylaryl of ) may refer to a substituent in which one or more hydrogens of the aromatic ring are substituted by the aforementioned alkyl group. For example, the above 7 to 20 carbon atoms (C 7-20 Examples of alkylaryls include methylphenyl, ethylphenyl, methylbiphenyl, methylnaphthyl, etc., but are not limited to these.

[0199]

[0200] The above carbon atoms numbering 7 to 20 (C 7-20 The arylalkyl of ) may refer to a substituent in which one or more hydrogens of the above-described alkyl are substituted by the above-described aryl. For example, the above 7 to 20 carbon atoms (C 7-20 Examples of arylalkyls of ) include phenylmethyl, phenylethyl, biphenylmethyl, naphthylmethyl, etc., but are not limited to these.

[0201]

[0202] In addition, 6 to 20 carbon atoms (C 6-20 The arylenes of ) are identical to the aryls described above except that they are divalent substituents, specifically phenylene, biphenylene, naphthylene, anthracenylene, phenanthrenylene, fluorenylene, etc., but are not limited to these.

[0203]

[0204] And, the group 4 transition metal may be titanium (Ti), zirconium (Zr), hafnium (Hf), or rutherfordium (Rf), specifically titanium (Ti), zirconium (Zr), or hafnium (Hf), more specifically zirconium (Zr) or hafnium (Hf), but is not limited thereto.

[0205]

[0206] In addition, the Group 13 elements may be boron (B), aluminum (Al), gallium (Ga), indium (In), or thallium (Tl), and specifically may be boron (B) or aluminum (Al), but are not limited thereto.

[0207]

[0208] Meanwhile, the first metallocene compound may be represented by any one of the following chemical formulas 1-1 to 1-4.

[0209] [Chemical Formula 1-1]

[0210]

[0211] [Chemical Formula 1-2]

[0212]

[0213] [Chemical Formula 1-3]

[0214]

[0215] [Chemical Formula 1-4]

[0216]

[0217] In the above chemical formulas 1-1 to 1-4, Q1, Q2, A1, M1, X1, X2, and R1 to R8 are as defined in the above chemical formula 1, and R' and R'' are identical or different from each other and each independently hydrogen or C 1-10 It is the hydrocarbyl group.

[0218]

[0219] Preferably, the first metallocene compound has a structure including a bis-cyclopentadienyl ligand, and more preferably, the cyclopentadienyl ligand may be symmetrically arranged around a transition metal. More preferably, the first metallocene compound may be represented by the chemical formula 1-1.

[0220]

[0221] In the above Chemical Formula 1 and Chemical Formulas 1-1 to 1-4, at least one of R1 to R8 is -(CH2) n -OR and here, R is C 1-6 It is a straight-chain or branched-chain alkyl, and n is an integer from 2 to 6. Specifically, R is C 1-4 It is a straight-chain or branched-chain alkyl, and n is an integer from 4 to 6. For example, at least one of R1 to R8 is or C 1-6 Alkoxy-substituted C 2-6 alkyl, or C 1-4 Alkoxy-substituted C 4-6 It can be an alkyl.

[0222]

[0223] In the above Chemical Formula 1 and Chemical Formulas 1-1 to 1-4, the remainders among R1 to R8 are identical or different from each other and are each independently hydrogen, halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 6-20 Aril, C 7-40 Alkylaryl, C 7-40 It is a functional group selected from the group consisting of arylalkyls, or two or more adjacent groups connected to each other, C 1-10 C substituted or unsubstituted with a hydrocarbyl group 6-20 It can form aliphatic or aromatic rings.

[0224]

[0225] Specifically, the remainder of the above R1 to R8 are each hydrogen, or C 1-20 alkyl, or C 1-10alkyl, or C 1-6 alkyl, or C 1-6 Alkoxy-substituted C 2-6 alkyl, or C 1-4 Alkoxy-substituted C 4-6 It may be an alkyl group. Alternatively, two or more adjacent groups among R1 to R8 are connected to each other, such that C 1-3 C substituted with 6-20 It may form an aliphatic or aromatic ring.

[0226]

[0227] Preferably, in the above Formula 1 and Formulas 1-1 to 1-4, R3 and R6 are each C 1-6 alkyl, or C 1-6 Alkoxy-substituted C 2-6 It is an alkyl, provided that at least one of the above R3 and R6 is C 1-6 Alkoxy-substituted C 2-6 It is an alkyl. Or, the above R3 and R6 are each C 4-6 alkyl, or C 1-4 Alkoxy-substituted C 4-6 It may be an alkyl group, provided that at least one of R3 and R6 is C 1-4 Alkoxy-substituted C 4-6 It is an alkyl. For example, R3 and R6 may each be n-butyl, n-pentyl, n-hexyl, tert-butoxybutyl, or tert-butoxyhexyl, provided that at least one of R3 and R6 is tert-butoxybutyl or tert-butoxyhexyl. Preferably, R3 and R6 are identical to each other and may be tert-butoxybutyl or tert-butoxyhexyl.

[0228]

[0229] And, in the above chemical formulas 1 and 1-1 to 1-4, R1, R2, R4, R5, R7, and R8 may be hydrogen.

[0230]

[0231] In the above Chemical Formulas 1, 1-2, and 1-4, Q1 and Q2 are identical or different from each other, and each independently hydrogen, halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is an arylalkyl.

[0232]

[0233] Specifically, the above Q1 and Q2 are each C 1-12 alkyl, or C 1-6 alkyl, or C 1-3 It may be an alkyl. Preferably, Q1 and Q2 are identical to each other, and C 1-3 They may be alkyl. More preferably, Q1 and Q2 may be methyl.

[0234]

[0235] In the above chemical formulas 1 and 1-1 to 1-4, A1 is carbon (C), silicon (Si), or germanium (Ge). Specifically, A1 may be silicon (Si).

[0236]

[0237] In the above chemical formulas 1 and 1-1 to 1-4, M1 is a group 4 transition metal. Specifically, M1 may be zirconium (Zr) or hafnium (Hf), and preferably may be zirconium (Zr).

[0238]

[0239] In the above Chemical Formula 1 and Chemical Formulas 1-1 to 1-4, X1 and X2 are identical or different from each other, and each independently halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 6-20 Aryl, Nitrogi, Amidogi, C 1-20 Alkylsilyl, C 1-20 Alkoxy, or C 1-20It is a sulfonate group. Specifically, X1 and X2 may each be a halogen, and may each be chloro, iodine, or bromine. Preferably, X1 and X2 may be chloro.

[0240]

[0241] In the above chemical formula 1, m is 0 or 1, and preferably m is 0.

[0242]

[0243] The 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.

[0244]

[0245]

[0246]

[0247]

[0248]

[0249]

[0250]

[0251]

[0252]

[0253]

[0254] Preferably, the first metallocene compound may be a compound represented by one of the following structural formulas.

[0255]

[0256] .

[0257]

[0258] More preferably, the first metallocene compound may be a compound represented by one of the following structural formulas.

[0259] , .

[0260]

[0261] The first metallocene compound represented by the above structural formulas can be synthesized by applying known reactions, and a more detailed synthesis method can be referenced in the examples.

[0262]

[0263] The method for manufacturing polyethylene according to the present invention uses one or more first metallocene compounds represented by Chemical Formula 1 or Chemical Formulas 1-1, 1-2, 1-3, and 1-4 as described above, together with one or more second metallocene compounds described below, thereby maintaining excellent moisture barrier properties and low extrusion loads through fine control of the melt flow index, polydispersity index (PDI), and tensile viscosity along with the high density of polyethylene, and securing excellent bubble stability and excellent processability without lowering the process temperature during film processing.

[0264]

[0265] Meanwhile, the second metallocene compound may be represented by the following chemical formula 2-1.

[0266] [Chemical Formula 2-1]

[0267]

[0268] In the above chemical formula 2-1, Q5, Q6, A3, M3, X5, X6, R 45 , R 48 , and R 49 to R 56 It is as defined in Chemical Formula 2 above.

[0269]

[0270] In the above chemical formulas 2 and 2-1, Q5 and Q6 are identical or different from each other, and each independently hydrogen, halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-40Alkylaryl, or C 7-40 It is an arylalkyl. Specifically, Q5 and Q6 are each C 1-12 alkyl, or C 1-8 alkyl, or C 1-3 alkyl, or C 2-18 Alkoxyalkyl, or C 2-14 Alkoxyalkyl, or C 2-12 They may be alkoxyalkyl, and more specifically, Q5 and Q6 are each C 1-3 alkyl, or C 2-12 It may be an alkoxyalkyl. Preferably, Q5 and Q6 are different from each other, and one of Q5 and Q6 is C 1-3 It is alkyl, and the rest is C 2-12 It may be an alkoxyalkyl. More preferably, one of Q5 and Q6 may be methyl and the other tert-butoxyhexyl.

[0271]

[0272] In the above chemical formulas 2 and 2-1, A3 is carbon (C), silicon (Si), or germanium (Ge). Specifically, A3 may be silicon (Si).

[0273]

[0274] In the above chemical formulas 2 and 2-1, M3 is a group 4 transition metal. Specifically, M3 may be zirconium (Zr) or hafnium (Hf), and preferably may be zirconium (Zr).

[0275]

[0276] In the above chemical formulas 2 and 2-1, X5 and X6 are identical or different from each other, and each independently halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 6-20 Aryl, Nitrogi, Amidogi, C 1-20 Alkylsilyl, C 1-20 Alkoxy, or C 1-20It is a sulfonate group. Specifically, X5 and X6 may each be a halogen, and may each be chloro, iodine, or bromine. Preferably, X5 and X6 may be chloro.

[0277]

[0278] In the above chemical formula 2, C1 and One of C2 is represented by the above chemical formula 2a or chemical formula 2b, and C1 and The remaining one of C2 may be represented by the above chemical formula 2c.

[0279]

[0280] In the above chemical formulas 2 and 2-1, R 40 to R 47 and R 40 ' or R 47 ' are identical or different from each other, and each independently hydrogen, halogen, C 1-20 Alkyl, C 1-20 Haloalkyl, C 2-20 Alkenyl, C 1-20 Alkylsilyl, C 1-20 Alkylsilylalkylene, C 1-20 Alkoxysilyl, C 1-20 Alkoxy, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is an arylalkyl.

[0281]

[0282] Also, R 48 and R 48 ' are identical or different from each other, and each independently C 1-20 Alkyl, C 1-20 Alkylsilyl, C 1-20 Alkylsilylalkylene, C 1-20 Alkoxysilyl, or C 1-20 It is an alkoxy.

[0283]

[0284] Specifically, in the above chemical formula 2, R 40 to R 44 and R 46 to R47 and R 40’ to R 44’ and R 46’ to R 47’ It can be hydrogen.

[0285]

[0286] Specifically, in the above chemical formulas 2 and 2-1, R 45 and R 45’ are hydrogen, halogen, and C, respectively. 1-6 alkyl, or C 1-6 It can be an alkoxy, or hydrogen, halogen, C 1-3 alkyl, or C 1-3 It may be an alkoxy. For example, the above R 45 and R 45’ Each can be hydrogen, bromine, methyl, or methoxy, and preferably methyl.

[0287]

[0288] In addition, in the above chemical formulas 2 and 2-1, the R 48 and R 48’ are C 1-6 Alkyl, C 1-6 Alkylsilyl, C 1-6 Alkylsilylalkylene, or C 6-12 It could be aryl, and more specifically, C 1-6 straight-chain or branched-chain alkyl, C 1-6 straight-chain or branched-chain alkylsilyl, C 1-6 straight-chain or branched-chain alkylsilylalkylene, or C 6-12 It can be aryl. For example, the above R 48 and R 48’ Each can be methyl, trimethylsilyl, trimethylsilylmethylene, or phenyl, and preferably methyl.

[0289]

[0290] In the above chemical formulas 2 and 2-1, R 49 to R 56 They are identical or different from each other, and each independently hydrogen, halogen, and C 1-20 Alkyl, C 1-20Haloalkyl, C 2-20 Alkenyl, C 1-20 Alkylsilyl, C 1-20 Alkylsilylalkylene, C 1-20 Alkoxysilyl, C 1-20 Alkoxy, C 6-20 Aril, C 7-40 Alkylaryl, or C 7-40 It is arylalkyl, or R 49 to R 56 Among them, two or more adjacent items are connected to each other C 1-10 C substituted or unsubstituted with a hydrocarbyl group 6-20 It can form aliphatic or aromatic rings.

[0291]

[0292] Specifically, the above R 49 to R 56 are hydrogen, or C, respectively. 1-20 alkyl, or C 1-10 alkyl, or C 1-6 alkyl, or C 1-3 It may be an alkyl. Or, the above R 49 to R 56 Among them, two or more adjacent items are connected to each other C 1-3 C substituted with 6-20 It may form an aliphatic or aromatic ring. For example, the above R 49 to R 56 It is hydrogen, tert-butyl, or n-hexyl, or R 49 to R 56 Among them, two or more adjacent ones may be connected to each other to form a 1,1',4,4'-methyl-substituted cyclohexyl ring. Preferably, the R 49 to R 56 It can be hydrogen.

[0293]

[0294] In the above chemical formulas 2 and 2-1, the R 49 , R 52 , R 53 , and R 56 All of it can be hydrogen.

[0295]

[0296] Specifically, according to one embodiment of the present invention, specific examples of the compound represented by Chemical Formula 2a include a compound represented by one of the following structural formulas, but the present invention is not limited thereto.

[0297] , , ,

[0298] , , ,

[0299] , , ,

[0300] , , ,

[0301] , ,

[0302]

[0303] According to one embodiment of the present invention, specific examples of the compound represented by Chemical Formula 2b include a compound represented by one of the following structural formulas, but the present invention is not limited thereto.

[0304] , , ,

[0305] , , ,

[0306] , , ,

[0307] , , ,

[0308] , ,

[0309]

[0310] According to one embodiment of the present invention, specific examples of the compound represented by the chemical formula 2c include a compound represented by one of the following structural formulas, but the present invention is not limited thereto.

[0311] , ,

[0312] , ,

[0313] .

[0314]

[0315] According to one embodiment of the present invention, specific examples of the second metallocene compound represented by Chemical Formulas 2 and 2-1 may include compounds represented by one of the following structural formulas, but are not limited thereto.

[0316] , ,

[0317] , ,

[0318] , ,

[0319] , ,

[0320] , ,

[0321] , ,

[0322] , ,

[0323] , ,

[0324] , ,

[0325] .

[0326]

[0327] Preferably, the compound represented by the above chemical formula 2 may be, for example, a compound represented by the following structural formula, but is not limited thereto.

[0328] .

[0329]

[0330] The second metallocene compound represented by the above structural formula can be synthesized by applying known reactions, and a more detailed synthesis method can be referenced in the examples.

[0331]

[0332] In addition, the method for manufacturing the metallocene compounds described above is specifically described in the examples below.

[0333]

[0334] The metallocene catalyst used in the present invention may be supported on a carrier together with a co-catalyst compound.

[0335]

[0336] The metallocene catalyst used in the present invention may be supported on a carrier together with a co-catalyst compound.

[0337]

[0338] In the supported metallocene catalyst according to the present invention, the co-catalyst supported on the carrier to activate the metallocene compound is an organometallic compound including a Group 13 metal, and is not particularly limited as long as it can be used when polymerizing olefins under a general metallocene catalyst.

[0339]

[0340] The above co-catalyst is an organometallic compound containing a Group 13 metal, and is not particularly limited as long as it can be used when polymerizing ethylene under a general metallocene catalyst.

[0341]

[0342] Specifically, the co-catalyst may be one or more selected from the group consisting of compounds represented by the following chemical formulas 3 to 5:

[0343] [Chemical Formula 3]

[0344] -[Al(R 60 )-O] c -

[0345] In the above chemical formula 3,

[0346] R 60 Each is independently a halogen; or C substituted or unsubstituted with a halogen 1-20 It is hydrocarbil, and

[0347] c is an integer greater than or equal to 2, and

[0348] [Chemical Formula 4]

[0349] D(R 61 )3

[0350] In the above chemical formula 4,

[0351] D is aluminum or boron, and

[0352] R 61 are, respectively, hydrogen, halogen; or C substituted or unsubstituted with halogen. 1-20 It is hydrocarbil, and

[0353] [Chemical Formula 5]

[0354] [LH] + [Q(E)4] - or [L] + [Q(E)4] -

[0355] In the above chemical formula 5,

[0356] L is a neutral or cationic Lewis base, and

[0357] H is a hydrogen atom;

[0358] Q is a Group 13 element, and

[0359] E is independently C 6-20 Aryl or C1-20 It is an alkyl, and here, the above C 6-20 Aryl or C 1-20 Alkyl groups are halogens, C 1-20 Alkyl, C 1-20 Alkoxy, and C 6-20 It is substituted or unsubstituted with one or more substituents selected from the group consisting of aryloxy.

[0360]

[0361] Specifically, [LH] in the above chemical formula 5 + is Brønsted acid.

[0362]

[0363] In addition, in the above Chemical Formula 5, Q is Br 3+ or Al 3+ It could be.

[0364]

[0365] The compound represented by Chemical Formula 3 above can act as an alkylating agent and an activating agent, the compound represented by Chemical Formula 4 above can act as an alkylating agent, and the compound represented by Chemical Formula 5 above can act as an activating agent.

[0366]

[0367] The compound represented by the above chemical formula 3 is not particularly limited to alkylaluminoxan, but may be, for example, methylaluminoxan, ethylaluminoxan, isobutylaluminoxan, butylaluminoxan, etc., and preferably may be methylaluminoxan.

[0368]

[0369] The compound represented by the above chemical formula 4 is not particularly limited as long as it is an alkyl metal compound, but, for example, may be trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, triisopropylaluminum, tri-s-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylaluminum methoxide, dimethylaluminum ethoxide, trimethylboron, triethylboron, triisobutylboron, tripropylboron, tributylboron, etc., and preferably trimethylaluminum, triethylaluminum, It can be selected from triisobutyl aluminum.

[0370]

[0371] Examples of compounds represented by the above chemical formula 5 include triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium tetra(p-tolyl)boron, tripropylammonium tetra(p-tolyl)boron, triethylammonium tetra(o,p-dimethylphenyl)boron, trimethylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, trimethylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetrapentafluorophenylboron, N,N-dimethylanilinium tetraphenylboron, N,N-diethylanilinium tetraphenylboron, N,N-diethylanilinium tetrapentafluorophenylboron, diethylammonium tetrapentafluorophenylboron, triphenylphosphonium tetraphenylboron, Trimethylphosphonium tetraphenylboron, triethylammonium tetraphenylaluminum, tributylammonium tetraphenylaluminum, trimethylammonium tetraphenylaluminum, tripropylammonium tetraphenylaluminum, trimethylammonium tetra(p-tolyl)aluminum, tripropylammonium tetra(p-tolyl)aluminum, triethylammonium tetra(o,p-dimethylphenyl)aluminum, tributylammonium tetra(p-trifluoromethylphenyl)aluminum, trimethylammonium tetra(p-trifluoromethylphenyl)aluminum, tributylammonium tetrapentafluorophenylaluminum, N,N-dimethylanilinium tetraphenylaluminum, N,N-diethylanilinium tetraphenylaluminum, N,N-diethylanilinium tetrapentafluorophenylaluminum, diethylammonium tetrapentafluorophenylaluminum, Examples include triphenylphosphonium tetraphenylaluminum, trimethylphosphonium tetraphenylaluminum, triphenylcarbonium tetraphenylboron, triphenylcarbonium tetraphenylaluminum, triphenylcarbonium tetra(p-trifluoromethylphenyl)boron, and triphenylcarbonium tetrapentafluorophenylboron.

[0372]

[0373] Meanwhile, in the metallocene catalyst according to the present invention, the total amount of the co-catalyst and the metallocene compounds of Formulas 1 and 2 may each be included in a molar ratio of about 1:1 to about 1:10000, preferably in a molar ratio of about 1:1 to about 1:1000, and more preferably in a molar ratio of about 1:10 to about 1:100. At this time, if the molar ratio is less than about 1, the metal content of the co-catalyst is too low, so the catalytic active species are not formed well, and the activity may be lowered, and if the molar ratio exceeds about 10000, there is a risk that the metal of the co-catalyst may act as a catalyst poison.

[0374]

[0375] The loading amount of such co-catalyst may be about 3 mmol to about 25 mmol, or about 5 mmol to about 20 mmol, based on 1 g of the carrier.

[0376]

[0377] In the supported metallocene catalyst according to the present invention, the carrier may be a carrier having hydroxyl groups on its surface, and preferably, a carrier having highly reactive hydroxyl groups and siloxane groups that has been dried to remove moisture from its surface may be used.

[0378]

[0379] For example, silica dried at high temperatures, silica-alumina, and silica-magnesia may be used, and these may typically contain oxide, carbonate, sulfate, and nitrate components such as Na2O, K2CO3, BaSO4, and Mg(NO3)2.

[0380]

[0381] The drying temperature of the above carrier is approximately 200 o C to about 800 o C is preferable, and about 300 o C to about 600 o C is more preferable, and about 300 oC to 400 o C is most preferable. The drying temperature of the carrier is approximately 200 o If it is below C, there is too much moisture, so the surface moisture reacts with the co-catalyst, and about 800 o When C is exceeded, the pores on the surface of the carrier merge, reducing the surface area, and also many hydroxyl groups are removed from the surface, leaving only siloxane groups, which reduces the number of reaction sites with the co-catalyst, so it is undesirable.

[0382]

[0383] The amount of hydroxyl groups on the surface of the carrier is preferably about 0.1 mmol / g to about 10 mmol / g, and more preferably about 0.5 mmol / g to about 5 mmol / g. The amount of hydroxyl groups on the surface of the carrier can be controlled by the manufacturing method and conditions of the carrier or drying conditions, such as temperature, time, vacuum, or spray drying.

[0384]

[0385] If the amount of the above hydroxyl group is less than about 0.1 mmol / g, there are few reaction sites with the co-catalyst, and if it exceeds about 10 mmol / g, it is undesirable because there is a possibility that it is caused by moisture in addition to the hydroxyl groups present on the surface of the carrier particles.

[0386]

[0387] In the supported metallocene catalyst according to the present invention, the mass ratio of the total transition metal to the support included in the metallocene catalyst may be about 1:10 to about 1:1000. When the support and the metallocene compound are included in the above mass ratio, an optimal shape can be exhibited. In addition, the mass ratio of the co-catalyst compound to the support may be about 1:1 to about 1:100.

[0388]

[0389] For example, a metallocene catalyst according to the present invention may be manufactured by a manufacturing method comprising the steps of: supporting a co-catalyst on a carrier; supporting first and second metallocene compounds respectively on the carrier on which the co-catalyst is supported; and supporting the carrier on which the co-catalyst and the metallocene compounds are supported.

[0390]

[0391] In the above method, the loading conditions are not particularly limited and can be performed within a range well known to those skilled in the art. For example, high-temperature loading and low-temperature loading can be appropriately utilized, for example, the loading temperature is approximately -30°C o C to about 150 o It is possible within the range of C, preferably about 50 o C to about 98 o C, or about 55 o C to about 95 o C can be used. The loading time can be appropriately adjusted according to the amount of the first and second metallocene compounds to be loaded. The loaded catalyst can be used as is after removing the reaction solvent by filtering or vacuum distillation, or if necessary, it can be used after Soxhlet filtering with an aromatic hydrocarbon such as toluene.

[0392]

[0393] In addition, the preparation of the supported catalyst can be carried out in a solvent or solvent-free environment. When a solvent is used, usable solvents include aliphatic hydrocarbon solvents such as hexane or pentane, aromatic hydrocarbon solvents such as toluene or benzene, hydrocarbon solvents substituted with chlorine atoms such as dichloromethane, ether-based solvents such as diethyl ether or tetrahydrofuran (THF), and most organic solvents such as acetone and ethyl acetate, and hexane, heptane, toluene, or dichloromethane are preferred.

[0394]

[0395] Meanwhile, polyethylene according to one embodiment of the present invention can be produced by a method for producing polyethylene comprising the step of polymerizing ethylene in the presence of a catalyst comprising the first and second metallocene compounds.

[0396]

[0397] For example, the above ethylene polymerization reaction can be carried out using a continuous slurry polymerization reactor, a loop slurry reactor, a gas phase reactor, or a solution reactor, and for example, it can be a slurry polymerization reaction using a continuous slurry polymerization reactor or a loop slurry reactor.

[0398]

[0399] In particular, polyethylene according to the present invention can be produced by homopolymerizing ethylene in the presence of a hybrid supported metallocene catalyst comprising one or more first metallocene compounds represented by Formula 1; and one or more second metallocene compounds selected from compounds represented by Formula 2.

[0400]

[0401] Meanwhile, in a method for manufacturing high-density polyethylene according to one embodiment of the present invention, the molar ratio of the first metallocene compound and the second metallocene compound can be adjusted to a range that ensures excellent moisture barrier properties and low extrusion loads through fine control of the melt flow index, polydispersity index (PDI), and elongation viscosity along with the high density of polyethylene, bubble stability without lowering the process temperature during film processing, and excellent processability.

[0402]

[0403] Specifically, the molar ratio of the first metallocene compound based on the moles of the second metallocene compound may be 1:1 to 1:10. More specifically, the molar ratio of the first metallocene compound based on the moles of the second metallocene compound may be 1:3 to 1:8, or 1:4 to 1:6.

[0404]

[0405] The molar ratio of the above catalyst precursors can be as described above in terms of securing excellent processability while maintaining low extrusion load and excellent moisture barrier properties without degradation of physical properties during film processing, even without blending with low-density polyethylene, etc., through fine control of the melt flow index, polydispersity index (PDI), and tensile viscosity along with the ratio of low molecular weight, medium-low molecular weight, and high molecular weight regions and high density.

[0406]

[0407] Meanwhile, high-density polyethylene according to one embodiment of the present invention is characterized by being produced by performing ethylene homopolymerization in a unimodal slurry loop, i.e., a single reactor slurry loop process, in the presence of the aforementioned hybrid supported metallocene catalyst.

[0408]

[0409] Specifically, the ethylene homopolymerization process can be carried out as a monomodal (or unimodal) polymerization process in which the polymerization reaction is carried out under single polymerization reaction conditions using the hybrid supported metallocene 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 hybrid supported catalyst.

[0410]

[0411] Conventional multimodal polymerization methods with a wide molecular weight distribution use two or more reactors depending on the number of catalysts, and perform a polymerization reaction by introducing a catalyst into each reactor to produce polymers with different molecular weights, and then mix them. However, in this case, there is a problem in that the uniformity of the polymer is reduced due to the different molecular weights. In contrast, the present invention uses a hybrid supported catalyst in which two or more metallocene compounds are supported on a single carrier, and performs a polymerization reaction in a single reactor under single polymerization conditions, thereby enabling the production of high-density polyethylene with high density as described above, while simultaneously optimizing the melt flow index, polydispersity index (PDI), and tensile viscosity.

[0412]

[0413] And, the above polymerization temperature is about 25 o C to about 500 o C, approximately 25 o C to about 300 o C, approximately 30 o C to about 200 o C, about 50 o C to about 150 o C, or about 60 o C to about 120 o C may be. In addition, the polymerization pressure may be about 1 bar to about 100 bar, about 1 bar to about 70 bar, about 3 bar to about 60 bar, about 5 bar to about 50 bar, about 7 bar to about 45 bar, or about 10 bar to about 42 bar. For example, the polymerization process is about 90 o C to about 95 o It can be performed under conditions of about 38 bar to about 42 bar in C.

[0414]

[0415] The catalyst comprising the first and second metallocene compounds according to the present invention may be dissolved or diluted and injected in an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, such as pentane, hexane, heptane, nonane, decane, and their isomers, an aromatic hydrocarbon solvent such as toluene and benzene, or a hydrocarbon solvent substituted with chlorine atoms such as dichloromethane and chlorobenzene. It is preferable to use a solvent that removes small amounts of water or air, which act as catalyst poisons, by treating it with a small amount of alkyl aluminum, and it is also possible to carry out the process using a co-catalyst.

[0416]

[0417] In the present invention, in the process of manufacturing a metallocene compound or a supported catalyst or in the ethylene polymerization reaction, the equivalent (eq) means the molar equivalent (eq / mol).

[0418]

[0419] In addition, in the present invention, the high-density polyethylene can be manufactured under a metallocene catalyst as described above while introducing hydrogen gas. At this time, the hydrogen gas [is used to [add] the melt flow index (MI) of the polyethylene obtained after polymerization. 2.16 ), High-load Melt Flow Index (MI 21.6 It can be used by adjusting the melt flow rate ratio (MFRR), etc., to an optimized range.

[0420]

[0421] Due to the aforementioned characteristics, the high-density polyethylene can maintain low extrusion loads and excellent moisture barrier properties through fine control of the melt flow index, polydispersity index (PDI), and tensile viscosity, along with high density. Furthermore, it possesses bubble stability without lowering the process temperature during film processing and ensures excellent processability. Accordingly, this high-density polyethylene is useful for manufacturing films requiring high moisture barrier properties, particularly food packaging films and electronic product packaging films.

[0422]

[0423] According to another embodiment of the invention, a film comprising the high-density polyethylene of the above-described embodiment is provided, such as a film requiring high moisture barrier properties, particularly a food packaging film.

[0424]

[0425] As the above film comprises the aforementioned high-density polyethylene, it can exhibit significantly improved processability and moisture barrier properties without degradation of film properties through fine control of the melt flow index, polydispersity index (PDI), and tensile viscosity along with high density.

[0426]

[0427] Meanwhile, the polyethylene film according to the present invention has a water vapor transmission rate (WVTR) of 1 g / m² per day under the condition of a film thickness of 50 μm. 2 Less than ㆍday or 0.001 g / m² 2 ㆍday or more 1 g / m² 2 It may be less than 1 day. Here, the smaller the water vapor transmission value (WVTR) of the film, the better the water barrier performance.

[0428]

[0429] Specifically, for a high-density polyethylene film with a thickness of 50 μm, the water vapor transmission rate (WVTR, g / m²) was determined by the following method. 2 It is possible to measure (day). For example, the water vapor transmission rate (WVTR) of the above film is, at a film thickness of 50 μm, based on 1 day of film 1 m 2 The amount of water vapor permeated per day (g) can be measured under the following conditions using the Mocon AquaTran of Modern Controls Inc. in accordance with ASTM F 1249-90.

[0430]

[0431] <Film WVTR Measurement Conditions>

[0432] Film thickness: 50 µm

[0433] Film width: 50 cm 2

[0434] Humidity: 100%

[0435] Pressure: 1 bar

[0436] Temperature: 37.8 ℃.

[0437]

[0438] The above film can be manufactured according to a general film-making method, except that the aforementioned high-density polyethylene is used. Further detailed explanation regarding this is omitted.

[0439]

[0440] Specifically, the polyethylene film according to the present invention can be manufactured using a film-making extruder with a polyethylene composition obtained by melt-extruding the high-density polyethylene described above. For example, the high-density polyethylene described above is fed into a single-screw extruder, such as a single-screw extruder with a diameter of 35 mm (L / D=20), and melt-kneaded and reactive-extruded at a temperature of about 220 °C, after which it is cooled to obtain high-density polyethylene pellets. Furthermore, each of the pellets obtained in this way can be used to manufacture a film with a thickness of 50 μm using a blown film-making machine (die diameter 100 mm) of Eugene Engineering. At this time, the specific processing conditions are a film-making machine temperature of 230 °C, a Frost Line Height (FLH) of 160 mm, and a BUR of 2.5. For such a film with a thickness of 50 µm, resin pressure (bar), bubble stability, and water vapor transmission rate (WVTR, mg / m²) during film processing 2 Can measure ㆍday).

[0441]

[0442] In addition, the polyethylene film has excellent “bubble stability”, such that when the film is formed at 230°C or higher and 240°C or lower, or 225°C or higher and 238°C, or 228°C or higher and 235°C without lowering the normal film forming temperature as described above when manufacturing a blown film, the bubble diameter above the frost line is maintained at a constant level, for example, the bubble diameter is maintained at 240 mm or higher and 260 mm or lower for 10 minutes or more.

[0443]

[0444] Specifically, as described above, when manufacturing a film with a thickness of 50 μm under conditions of a die diameter of 100 mm, an extruder temperature of 230 ℃, a Frost Line Height (FLH) of 160 mm, and a BUR of 2.5, if the bubble diameter above the frost line does not decrease to 240 mm or lower or rise to 260 mm within 10 minutes, it can be said that the “bubble stability” is excellent.

[0445]

[0446] Meanwhile, the polyethylene film according to the present invention can secure excellent processability by lowering the pressure measured in the blown film making machine in the manner described above. For example, when manufacturing a blown film with a thickness of 50 μm, the resin pressure (bar) of the polyethylene film may be 80 bar or less or 30 bar to 80 bar, and preferably 78 bar or less, or 75 bar or less, or 72 bar or less, or 70 bar or less, or 68 bar or less.

[0447]

[0448] The high-density polyethylene according to the present invention is characterized by being able to significantly improve processability with excellent bubble stability at low resin pressure and process temperature during film processing, along with high density, through fine control of the melt flow index, polydispersity index (PDI), and elongation viscosity, while simultaneously improving the moisture barrier properties of the film.

[0449]

[0450] 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.

[0451]

[0452] <Example>

[0453] [Preparation of catalyst precursors]

[0454] Synthesis Example 1: Preparation of the first metallocene compound

[0455]

[0456] t-butyl-O-(CH2)6-Cl was prepared using 6-chlorohexanol by the method described in the literature (Tetrahedron Lett. 2951 (1988)), and t-butyl-O-(CH2)6-C5H5 was obtained by reacting it with sodium cyclopentadienyl (NaCp) (yield 60%, bp 80 o C / 0.1 mmHg).

[0457]

[0458] Also, -78 o t-butyl-O-(CH2)6-C5H5 was dissolved in tetrahydrofuran (THF) at C, n-butyllithium (n-BuLi) was slowly added, the temperature was raised to room temperature, and the reaction was carried out for 8 hours. The above solution was then again -78 oThe synthesized lithium salt solution was slowly added to a suspension solution of ZrCl4(THF)2 (170 g, 4.50 mmol) / THF (30 mL) at C and reacted for 6 hours at room temperature. All volatile substances were removed by vacuum drying, and the resulting oily liquid substance was filtered after adding hexane. After vacuum drying the filtered solution, hexane was added and the mixture was subjected to low temperature (-20°C). o Precipitation was induced in C). The obtained precipitate was filtered at low temperature to obtain [t-butyl-O-(CH2)6-C5H4]2ZrCl2] in the form of a white solid (yield 92%).

[0459]

[0460] 1 H-NMR (300 MHz, CDCl3): 6.28 (t, J=2.6 Hz, 2H), 6.19 (t, J=2.6 Hz, 2H), 3.31 (t, 6.6 Hz, 2H), 2.62 (t, J=8 Hz), 1.7 - 1.3 (m, 8H), 1.17 (s, 9H).

[0461]

[0462] 13 C-NMR (CDCl3): 135.09, 116.66, 112.28, 72.42, 61.52, 30.66, 30.31, 30.14, 29.18, 27.58, 26.00.

[0463]

[0464] Synthesis Example 2

[0465]

[0466] 2-1 Preparation of Ligand Compounds

[0467] 2 g of fluorene was dissolved in 5 mL of MTBE and 100 mL of hexane, and 5.5 mL of 2.5 M n-BuLi hexane solution was added dropwise in a dry ice / acetone bath and stirred overnight at room temperature. 3.6 g of (6-(tert-butoxy)hexyl)dichloro(methyl)silane was dissolved in 50 mL of hexane, and the fluorene-Li slurry was transferred over 30 minutes in a dry ice / acetone bath and stirred overnight at room temperature. At the same time, 5,8-dimethyl-5,10-dihydroindeno[1,2-b]indole (12 mmol, 2.8 g) was also dissolved in 60 mL of THF, and 5.5 mL of 2.5 M n-BuLi hexane solution was added dropwise in a dry ice / acetone bath and stirred overnight at room temperature. After confirming the completion of the reaction by NMR sampling of the reaction solution between fluorene and (6-(tert-butoxy)hexyl)dichloro(methyl)silane, the 5,8-dimethyl-5,10-dihydroindeno[1,2-b]indole-Li solution was transferred under a dry ice / acetone bath. The mixture was stirred overnight at room temperature. After the reaction, extraction with ether / water was performed to remove residual moisture from the organic layer with MgSO4, and the ligand compound (Mw 597.90, 12 mmol) was obtained.

[0468]

[0469] 1H NMR (500 MHz, d6-benzene): -0.30 - -0.18 (3H, d), 0.40 (2H, m), 0.65 - 1.45 (8H, m), 1.12 (9H, d), 2.36 - 2.40 (3H, d), 3.17 (2H, m), 3.41 - 3.43 (3H, d), 4.17 - 4.21 (1H, d), 4.34 - 4.38 (1H, d), 6.90 - 7.80 (15H, m).

[0470]

[0471] 2-2 Preparation of Metallocene Compounds

[0472] 7.2 g (12 mmol) of the ligand compound synthesized in Section 2-1 above was dissolved in 50 mL of diethylether, and 11.5 mL of 2.5 M n-BuLi hexane solution was added dropwise in a dry ice / acetone bath and stirred overnight at room temperature. A brown sticky oil was obtained by vacuum drying. A slurry was obtained by dissolving it in toluene. ZrCl4(THF)2 was prepared and 50 mL of toluene was added to make a slurry. The 50 mL toluene slurry of ZrCl4(THF)2 was transferred in a dry ice / acetone bath. As it was stirred overnight at room temperature, it changed to a violet color. The reaction solution was filtered to remove LiCl. After removing the toluene from the filtrate by vacuum drying, hexane was added and sonicated for 1 hour. The slurry was filtered to obtain 6 g of a dark violet metallocene compound (Mw 758.02, 7.92 mmol, yield 66 mol%), which was a filtered solid. 1 Two isomers were observed on the H-NMR.

[0473]

[0474] 1H NMR (500 MHz, CDCl3): 1.19 (9H, d), 1.71 (3H, d), 1.50 - 1.70(4H, m), 1.79(2H, m), 1.98 - 2.19(4H, m), 2.58(3H, s), 3.38 (2H, m), 3.91 (3H, d), 6.66 - 7.88 (15H, m).

[0475]

[0476] [Hybrid Supported Catalyst]

[0477] Preparation Example 1: Preparation of a supported catalyst

[0478] Add 6.0 kg of toluene solution to a 20 L stainless steel (SUS) high-pressure reactor and set the reactor temperature to 40 o Maintained at C. 600 o 1000 g of silica (manufactured by Grace Davison, SYLOPOL 948), dehydrated by applying vacuum at a temperature of C for 12 hours, was introduced into a reactor and, after sufficiently dispersing the silica, 50 g of the first metallocene compound of Synthesis Example 1 dissolved in toluene was introduced, and 40 o The reaction was carried out at C with stirring at 200 rpm for 2 hours. Afterward, stirring was stopped, the mixture was settled for 30 minutes, and the reaction solution was decanted.

[0479]

[0480] 2.5 kg of toluene was added to the reactor, and after adding 6.8 kg of a 10 wt% methylaluminoxan (MAO) / toluene solution, 40 o Stirring was performed at 200 rpm at C for 12 hours. After the reaction, stirring was stopped, the mixture was settled for 30 minutes, and the reaction solution was decanted. 3.0 kg of toluene was added and stirred for 10 minutes, then stirring was stopped, the mixture was settled for 30 minutes, and the toluene solution was decanted.

[0481]

[0482] 3.0 kg of toluene was added to the reactor, 11 g of the second metallocene compound of Synthesis Example 2 was dissolved in 1 L of toluene solution and added to the reactor, and 40 o The reaction was carried out by stirring at 200 rpm at C for 2 hours. After lowering the reactor temperature to room temperature, stirring was stopped, the mixture was settled for 30 minutes, and the reaction solution was decanted. At this time, the first metallocene compound of Synthesis Example 1 and the second metallocene compound of Synthesis Example 2 were used in a molar ratio of 4:1.

[0483]

[0484] 2.0 kg of toluene was added to the reactor and stirred for 10 minutes, then the stirring was stopped, the mixture was settled for 30 minutes, and the reaction solution was decanted.

[0485]

[0486] 3.0 kg of hexane was added to the reactor, the hexane slurry was transferred to a filter dryer, and the hexane solution was filtered. 40 o A 1 kg-SiO2 hybrid supported catalyst was prepared by drying under reduced pressure at C for 4 hours.

[0487]

[0488] Comparative Preparation Example 1: Preparation of Supported Catalyst

[0489] Add 6.0 kg of toluene solution to a 20 L stainless steel (SUS) high-pressure reactor and set the reactor temperature to 40 o Maintained at C. 600 o 1000 g of silica (manufactured by Grace Davison, SYLOPOL 948), dehydrated by applying vacuum at a temperature of C for 12 hours, was introduced into a reactor and, after sufficiently dispersing the silica, 25 g of the first metallocene compound of Synthesis Example 1 dissolved in toluene was introduced, and 40 o The reaction was carried out at C with stirring at 200 rpm for 2 hours. Afterward, stirring was stopped, the mixture was settled for 30 minutes, and the reaction solution was decanted.

[0490]

[0491] 2.5 kg of toluene was added to the reactor, and after adding 6.8 kg of a 10 wt% methylaluminoxan (MAO) / toluene solution, 40 o Stirring was performed at 200 rpm at C for 12 hours. After the reaction, stirring was stopped, the mixture was settled for 30 minutes, and the reaction solution was decanted. 3.0 kg of toluene was added and stirred for 10 minutes, then stirring was stopped, the mixture was settled for 30 minutes, and the toluene solution was decanted.

[0492]

[0493] 3.0 kg of toluene was added to the reactor, 11 g of the second metallocene compound of Synthesis Example 2 was dissolved in 1 L of toluene solution and added to the reactor, and 40 o The reaction was carried out by stirring at 200 rpm at C for 2 hours. After lowering the reactor temperature to room temperature, stirring was stopped, the mixture was settled for 30 minutes, and the reaction solution was decanted. At this time, the first metallocene compound of Synthesis Example 1 and the second metallocene compound of Synthesis Example 2 were used in a molar ratio of 2:1.

[0494]

[0495] 2.0 kg of toluene was added to the reactor and stirred for 10 minutes, then the stirring was stopped, the mixture was settled for 30 minutes, and the reaction solution was decanted.

[0496]

[0497] 3.0 kg of hexane was added to the reactor, the hexane slurry was transferred to a filter dryer, and the hexane solution was filtered. 40 o A 1 kg-SiO2 hybrid supported catalyst was prepared by drying under reduced pressure at C for 4 hours.

[0498]

[0499] Example 1: Preparation of Polyethylene

[0500] High-density polyethylene of Example 1 was prepared by performing ethylene homopolymerization in a single reactor unimodal slurry loop process as follows in the presence of the hybrid supported metallocene catalyst of Preparation Example 1.

[0501]

[0502] Polyethylene was prepared by injecting ethylene, isobutane, hydrogen, and the hybrid supported catalyst solution of Preparation Example 1 (4 wt% isobutane solution) at 40 bar into a 140 L slurry loop reactor. The catalyst input cycle was adjusted to maintain an ethylene content of 6.5 mol%. While maintaining the reactor temperature at 93 ℃, the input rates of ethylene and isobutane were adjusted to 30 kg / h and 30 kg / hr, respectively, resulting in a slurry density of 550 kg / m³. 3 It was made so that... In addition, the melt flow index (MI) of the polyethylene pellet 2.16 High-density polyethylene in powder form was prepared by adjusting the hydrogen input amount to 630 ppm so that the (measured at 190 ℃, 2.16 kg load) would be 1.12 g / 10 min. After adding an antioxidant to the obtained high-density polyethylene in powder form, the mixture was melt-kneaded and reactively extruded at a temperature of approximately 220 ℃ using a single-screw extruder (die diameter 35 mm, L / D=20), and then cooled and extruded in the form of pellets.

[0503]

[0504] Example 2

[0505] The same ethylene homopolymerization process as in Example 1 was performed, but the catalyst input cycle was adjusted so that ethylene was maintained at 8.5 mol% on the GC, and the melt flow index (MI) of the polyethylene pellet 2.16 The high-density polyethylene of Example 2 was prepared by adjusting the hydrogen input amount to 650 ppm so that the (measured at 190 ℃, 2.16 kg load) would be 1.27 g / 10 min.

[0506]

[0507] Example 3

[0508] High-density polyethylene of Example 3 was prepared by performing an ethylene homopolymerization process in a single reactor as a unimodal slurry loop process in the presence of the hybrid supported metallocene catalyst of Preparation Example 1.

[0509]

[0510] 70 m 3 Polyethylene was prepared by injecting ethylene, isobutane, hydrogen, and the hybrid supported catalyst solution of Preparation Example 1 (4.0 wt% isobutane solution) at 40 bar into a loop slurry continuous polymerization reactor. The catalyst input cycle was adjusted to maintain an ethylene content of 7.5 mol%. While maintaining the reactor temperature at 93 ℃, the input amounts of ethylene and isobutane were controlled to 12.5 ton / h and 15 ton / hr, respectively, to achieve a slurry density of 550 kg / m³. 3 It was made so that... In addition, the melt flow index (MI) of the polyethylene pellet 2.16 High-density polyethylene in powder form was prepared by adjusting the hydrogen input amount to 600 ppm so that the (measured at 190 ℃, 2.16 kg load) would be 1.13 g / 10 min. After adding an antioxidant to the obtained high-density polyethylene in powder form, the mixture was melt-kneaded and reactively extruded at a temperature of approximately 220 ℃ using a single-screw extruder (die diameter 35 mm, L / D=20), and then cooled and extruded in the form of pellets.

[0511]

[0512] Example 4

[0513] The same polymerization process as in Example 3 was performed, except that the polyethylene pellet melt flow index (MI 2.16The high-density polyethylene of Example 4 was prepared by adjusting the hydrogen input amount to 630 ppm so that the (measured at 190 ℃, 2.16 kg load) would be 1.3 g / 10 min.

[0514]

[0515] Comparative Example 1

[0516] High-density polyethylene (Manufacturer Dow, Product name AT6900, MI 2.16 : 1.17 g / min, Density : 0.969 g / cm³ 3 ) was prepared as Comparative Example 1.

[0517]

[0518] Comparative Example 2: Preparation of Polyethylene

[0519] High-density polyethylene of Comparative Example 2 was prepared by performing ethylene homopolymerization in a single reactor slurry loop process as follows in the presence of the hybrid supported metallocene catalyst of Comparative Example 1.

[0520]

[0521] Polyethylene was prepared by injecting ethylene, isobutane, hydrogen, and the hybrid supported catalyst solution of Comparative Example 1 (4 wt% isobutane solution) at 40 bar into a 140 L slurry loop reactor. The catalyst input cycle was adjusted to maintain an ethylene content of 6.5 mol%. While maintaining the reactor temperature at 93 ℃, the input rates of ethylene and isobutane were controlled to 30 kg / h and 30 kg / hr, respectively, resulting in a slurry density of 550 kg / m³. 3 It was made so that... In addition, the melt flow index (MI) of the polyethylene pellet 2.16High-density polyethylene in powder form was prepared by adjusting the hydrogen input amount to 620 ppm so that the (measured at 190 ℃, 2.16 kg load) would be 0.89 g / 10 min. After adding an antioxidant to the obtained high-density polyethylene in powder form, the mixture was melt-kneaded and reactively extruded at a temperature of approximately 220 ℃ using a single-screw extruder (die diameter 35 mm, L / D=20), and then cooled and extruded in the form of pellets.

[0522]

[0523] Comparative Example 3

[0524] The same polymerization process as in Example 1 was performed, but the catalyst addition cycle was adjusted so that ethylene was maintained at 6.5 mol% on the GC, and the melt flow index (MI) of the polyethylene pellet 2.16 High-density polyethylene of Comparative Example 3 was prepared by adjusting the hydrogen input amount to 300 ppm so that the (measured at 190 ℃, 2.16 kg load) would be 0.21 g / 10 min.

[0525]

[0526] Comparative Example 4

[0527] The same polymerization process as in Example 1 was performed, but the catalyst addition cycle was adjusted so that ethylene was maintained at 6.5 mol% on the GC, and the melt flow index (MI) of the polyethylene pellet 2.16 The high-density polyethylene of Comparative Example 4 was prepared by adjusting the hydrogen input amount to 890 ppm so that the (measured at 190 ℃, 2.16 kg load) could be 3.8 g / 10 min.

[0528]

[0529] Comparative Example 5

[0530] The same polymerization process as in Example 1 was performed, but the catalyst addition cycle was adjusted so that ethylene was maintained at 6.5 mol% on the GC, and the melt flow index (MI) of the polyethylene pellet 2.16High-density polyethylene of Comparative Example 5 was prepared by adjusting the hydrogen input amount to 150 ppm so that the (measured at 190 ℃, 2.16 kg load) would be 0.02 g / 10 min.

[0531]

[0532] Comparative Example 6

[0533] The same polymerization process as in Example 1 was performed, but the catalyst addition cycle was adjusted so that ethylene was maintained at 6.5 mol% on the GC, and the melt flow index (MI) of the polyethylene pellet 2.16 High-density polyethylene of Comparative Example 6 was prepared by adjusting the hydrogen input amount to 1000 ppm so that the (measured at 190 ℃, 2.16 kg load) would be 5.2 g / 10 min.

[0534]

[0535] Comparative Example 7: Preparation of Polyethylene

[0536] High-density polyethylene of Comparative Example 7 was prepared by performing ethylene / 1-hexene copolymerization in a single reactor slurry loop process as follows in the presence of the hybrid supported metallocene catalyst of Preparation Example 1.

[0537]

[0538] Polyethylene was prepared by injecting ethylene, isobutane, hydrogen, 1-hexene, and the hybrid supported catalyst solution of Preparation Example 1 (4 wt% isobutane solution) at 40 bar into a 140 L slurry loop reactor. The catalyst input cycle was adjusted to maintain an ethylene content of 6.5 mol%. While maintaining the reactor temperature at 93 ℃, the input rates of ethylene and isobutane were controlled to 30 kg / h, resulting in a slurry density of 550 kg / m³. 3 It was made so that... In addition, the melt flow index (MI) of the polyethylene pellet 2.16High-density polyethylene in powder form was prepared by adjusting the hydrogen input amount to 600 ppm so that the density (measured at 190 ℃, 2.16 kg load) would be 1.07 g / 10 min, and adjusting the 1-C6 input amount to 0.8 wt% so that the density would be 0.955 g / cm³. After adding an antioxidant to the obtained high-density polyethylene in powder form, the mixture was melt-kneaded and reactive-extruded at a temperature of approximately 220 ℃ using a single-screw extruder (die diameter 35 mm, L / D=20), and then cooled and extruded in the form of pellets.

[0539]

[0540] <Evaluation of Physical Properties of High-Density Polyethylene and Films>

[0541] Test Example 1

[0542] The physical properties of the high-density polyethylene prepared in the examples and comparative examples were measured in the following manner, and the results are shown in Table 1 below.

[0543]

[0544] (1) Melt index (MI)

[0545] 190 according to the American Society for Testing Materials standard ASTM D 1238 (Condition E) o The respective melt flow index (MI) under C with loads of 2.16 kg and 21.6 kg 2.16 ) and high-load melt flow index (MI 21.6 ) was measured and expressed as the weight (g) of the polymer that melted out over 10 minutes.

[0546]

[0547] (2) Melt Flow Rate Ratio (MFRR)

[0548] Melt flow index (MI) measured by the above-described method 2.16 ) and high-load melt flow index (MI 21.6 Measure ) and the melt flow index (MI 2.16 ) High-load melt flow index (MI21.6 Divided by ) to form the melt flow rate ratio (MFRR, MI 21.6 / MI 2.16 ) calculated.

[0549]

[0550] (3) Melting point (Tm, ℃)

[0551] The melting point (Tm) of the high-density polyethylene prepared in the examples and comparative examples was measured using a differential scanning calorimeter (DSC, device name: DSC 2920, manufacturer: TA instrument).

[0552]

[0553] Specifically, high-density polyethylene was heated from 50 ℃ to 190 ℃ at a rate of 10 ℃ / min using a Differential Scanning Calorimeter (DSC, TA2000) from TA Instruments (New Castle, Delaware, USA), maintained at this temperature for 1 minute, then lowered from 190 ℃ to 50 ℃ at a rate of 10 ℃ / min and maintained for 1 minute. Then, while increasing the temperature again from 50 ℃ to 190 ℃ at a rate of 10 ℃ / min (2 nd The melting point (Tm, °C) was measured during the heating cycle.

[0554]

[0555] (4) Density

[0556] Density of high-density polyethylene (g / cm³) according to the ASTM D 1505 method 3 ) was measured.

[0557]

[0558] (5) Molecular weight (Mw, Mn) and polydispersity index (PDI)

[0559] The weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity index (PDI, Mw / Mn) of high-density polyethylene were measured using gel permeation chromatography (GPC, manufactured by Polymer Char).

[0560]

[0561] Specifically, a high-temperature GPC instrument from Polymer Char was used for gel permeation chromatography (GPC), employing one guard column and three separation columns. The measurement temperature was 160°C. o C, 1,2,4-trichlorobenzene was used as the solvent, and the 'default 50 min' method from Polymer Char was applied. 8–16 mg of high-density polyethylene samples according to the examples and comparative examples were weighed, placed in 10 mL vials, and capped. The capped vials were placed in an autosampler, and after adding 8 mL of 1,2,4-trichlorobenzene to the vials, 160 o It was dissolved at C for 2 hours under middle shaking conditions, prepared at a concentration of 1–2 mg / mL, and supplied in an amount of 200 μL. Mn, Mw, and PDI values ​​were derived using a calibration curve formed using a polystyrene standard specimen. Sixteen types of polystyrene standard specimens were used, with molecular weights of 266 g / mol, 672 g / mol, 1,810 g / mol, 3,220 g / mol, 5,180 g / mol, 12,600 g / mol, 19,700 g / mol, 34,800 g / mol, 61,400 g / mol, 127,000 g / mol, 238,000 g / mol, 526,000 g / mol, 1,500,000 g / mol, 3,080,000 g / mol, 5,150,000 g / mol, and 12,900,000 g / mol.

[0562]

[0563] Among these, the GPC graphs measured for the high-density polyethylene of Examples 1 and 3 and Comparative Example 1 are shown in FIG. 1. As shown in FIG. 1, it can be seen that the high-density polyethylene of Examples 1 and 3 has a wider molecular weight distribution compared to Comparative Example 1 and can have excellent processability with low resin pressure during film processing.

[0564]

[0565] (6) Content of the GPC area

[0566] For the polyethylene of the Examples and Comparative Examples, using gel permeation chromatography (GPC, manufactured by Polymer Char) in the manner described above, among the total area of ​​the y-axis (dw / dlogMw) and x-axis (logMw) curves obtained through GPC analysis, the regions corresponding to the molecular weight of 100 g / mol to 1,000 g / mol [MW 100-1,000 g / mol], 100 g / mol to 10,000 g / mol [MW 100-10,000 g / mol], and 1,000,000 g / mol to 10,000,000 g / mol [MW 1,000,000~10,000,000 g / mol], respectively, where the Log Mw value is 2 to 3 (2≤LogMw≤3) and the Log MW value is 2 to 4, are respectively. The area of ​​regions with Log MW values ​​of 6 or higher and 7 or lower (6 ≤ Log Mw ≤ 7) was expressed as a percentile (%).

[0567]

[0568] (7) Complexity

[0569] Complex viscosity was measured for high-density polyethylene prepared in the examples and comparative examples at angular frequencies from 0.05 rad / s to 500 rad / s using an ARES (Advanced Rheometric Expansion System, manufactured by TA instruments).

[0570]

[0571] Specifically, the complex viscosity of high-density polyethylene was measured using TA Instruments’ ARES (Advanced Rheometric Expansion System) G2. Polyethylene specimens with a diameter of 25 mm and a gap of 2.0 mm were prepared at 190°C using the parallel plates of the ARES instrument, and the complex viscosity was measured in dynamic strain frequency sweep mode at a strain of 5% and an angular frequency from 0.05 rad / s to 500 rad / s.

[0572]

[0573] Among these, the complex viscosity for high-density polyethylene at angular frequencies of 0.1 rad / s and 100 rad / s is shown in Table 1 below.

[0574]

[0575] In addition, the graph of the ARES analysis results of the high-density polyethylene of Examples 1 and 3 and Comparative Example 1, obtained by measurement as described above, is shown in FIG. 2. As shown in FIG. 2, the ratio of the complex viscosity at an angular velocity of 0.1 rad / s and the complex viscosity at an angular velocity of 100 rad / s is optimized for the high-density polyethylene of Examples 1 and 3 compared to Comparative Example 1, and it can be seen that excellent processability along with excellent bubble stability can be secured without lowering the process temperature during film processing.

[0576]

[0577] (8) Extensible viscosity (@strain 2.5)

[0578] The elongation viscosity of the high-density polyethylene prepared in the examples and comparative examples was measured using the ARES (Advanced Rheometric Expansion System, manufactured by TA instruments) G2 instrument and EVF (Elongation Viscosity Fixture) accessory.

[0579]

[0580] Specifically, elongation viscosity was measured using TA Instruments' ARES G2 instrument and EVF (Elongation Viscosity Fixture) accessory. Specifically, the elongation viscosity was measured from strain 0 to 3 under conditions of 170 ℃ and a Henki strain of 0.1 / s, and then the elongation viscosity value at strain 2.5 was extracted.

[0581]

[0582] In addition, the graphs of the elongation viscosity of the high-density polyethylene of Examples 1 and 3 and Comparative Example 1, obtained by measurement as described above, are shown in FIG. 3. As shown in FIG. 3, the high-density polyethylene of Examples 1 and 3 has a higher elongation viscosity compared to Comparative Example 1, and it can be seen that processability can be significantly improved with excellent bubble stability without lowering the process temperature during film processing.

[0583]

[0584] Item Unit Example 1 Example 2 Example 3 Example 4 MI 2.16 g / min 1.12 1.27 1.13 1.30 MI 21.6 g / dmin201227225265MFRR(MI 21.6 / MI 2.16 )-181179199204 Density g / cm³ 3 0.9700.9710.9700.970Mnx10 3 g / mol 3.7 3.6 3.7 3.5 Mw x 10 3g / mol140139141136PDI(Mw / Mn)-38383839Tm℃13413513413410 2 ≤MW≤10 3 %5.65.85.76.210 2 ≤MW≤10 4 %41.942.442.243.610 6 ≤MW≤10 7 %2.52.62.62.5η*(0.1 rad / s)Pa.s14,33512,68513,05311,698η*(100 rad / s)Pa.s830786748692η*(0.1 rad / s) / η*(100 rad / s)-17.316.117.516.9 Elongation viscosity (@strain 2.5)Pa.s62,01755,52960,39553,908

[0585]

[0586] Item-by-item Comparison Example 1 Comparison Example 2 Comparison Example 3 Comparison Example 4 Comparison Example 5 Comparison Example 6 Comparison Example 7 MI 2.16 g / min1.170.890.213.80.025.21.07MI 21.6 g / dmin15711532-2.96-191MFRR(MI 21.6 / MI 2.16 )-134129152-148-178 density g / cm³ 3 0.9690.9650.9650.9720.9580.9740.955Mnx10 3 g / mol7.69.35.42.18.41.53.7Mwx10 3 g / mol1051491898828767139PDI(Mw / Mn)-14163542344538Tm℃13413213213713113713010 2 ≤MW≤10 3 %1.62.33.27.81.58.55.710 2 ≤MW≤10 4 %34.440.041.643.937.847.341.910 6 ≤MW≤10 7%0.4 1.8 2.9 1.9 3.2 1.1 2.5η*(0.1 rad / s)Pa.s7,239 8,359 20,2176,12322,542 4,852 13,857η*(100 rad / s)Pa.s1,006 1,217 1,425 52 11,621 418 799η*(0.1 rad / s) / η*(100 rad / s)-7.20 6.8 71 4.2 12.0 1 3.9 11.6 17.3 Extensibility Viscosity(@strain 2.5)Pa.s19,908 30,271 92,113 13,212 113,218 10,1176 1,247

[0587]

[0588] Test Example 2

[0589] The physical properties of films prepared using high-density polyethylene according to the examples and comparative examples were measured in the following manner, and the results are shown in Tables 3 and 4 below, respectively.

[0590]

[0591] Specifically, the high-density polyethylene of the examples and comparative examples were each fed into a single-screw extruder (L / D=20) with a diameter of 35 mm, melt-kneaded and reactive-extruded at a temperature of approximately 220 °C, and then cooled to obtain the respective pellet compositions. Furthermore, each of the obtained pellet compositions was used to manufacture a film with a thickness of 50 μm using a blown film extruder (die diameter 100 mm) from Eugene Engineering. At this time, the specific processing conditions were an extruder temperature of 230 °C, a Frost Line Height (FLH) of 160 mm, and a BUR of 2.5. When processing these films with a thickness of 50 μm using the following method, the resin pressure (bar), bubble stability, and water vapor transmission rate (WVTR, water vapor transmission rate, mg / m²) 2 Measured ㆍday).

[0592]

[0593] (1) Processing pressure

[0594] The resin pressure (bar) during film processing was measured through the pressure measured by the blown film machine.

[0595]

[0596] (2) Film bubble stability

[0597] When manufacturing a film with a thickness of 50 μm using the above-described film-making machine under conditions of a die diameter of 100 mm, a film-making machine temperature of 230 ℃, a FLH (Frost Line Height) of 160 mm, and a BUR of 2.5, if the bubble diameter above the frost line does not decrease to less than 240 mm or increase to more than 260 mm within 10 minutes, it is indicated as “bubble stable,” and if the bubble diameter decreases to 240 mm or less or increases to 260 mm or more within 10 minutes, it is indicated as “bubble unstable.”

[0598]

[0599] (3) Film moisture permeability (WVTR)

[0600] WVTR is based on a film thickness of 50 µm and a film length of 50 cm per day. 2 The amount of water vapor permeated per gram was measured in accordance with ASTM F 1249-90 using a Mocon AquaTran from Modern Controls Inc. under the following conditions. A smaller WVTR value indicates improved moisture barrier performance.

[0601]

[0602] <Film WVTR Measurement Conditions>

[0603] Film thickness: 50 µm

[0604] Film width: 50 cm 2

[0605] Humidity: 100%

[0606] Pressure: 1 bar

[0607] Temperature: 37.8 ℃.

[0608]

[0609] Specifically, according to 'Barrier classification of films based on OTR and WVTR values' in Platt 2013a, the WVTR value is 6–100 g / m² 2 Indicate as "Medium" for / day, and 1~5 g / m² 2 Indicate as "High" if it is / day, and 1 g / m² 2 If less than / day, it was marked as "Very high".

[0610]

[0611] Item Unit Example 1 Example 2 Example 3 Example 4 Resin Pressure bar 67636260 Bubble Stability (@230℃) - Stable Stable Stable Stable WVTR - Very high Very high Very high Very high

[0612]

[0613] Item Unit Comparison Example 1 Comparison Example 2 Comparison Example 3 Comparison Example 4 Comparison Example 5 Comparison Example 6 Comparison Example 7 Resin Pressure bar 91829551974864 Bubble Stability (@230℃) - Unstable Unstable Unstable Unstable Unstable Unstable Unstable Stable WVTR - Very high high high Very high Medium Very high Medium

[0614]

[0615] As shown in Table 3 above, the high-density polyethylene of Examples 1 to 4, which implements an optimized molecular structure through fine control of the melt flow index, polydispersity index (PDI), and tensile viscosity along with high density according to the present invention, maintains excellent processability compared to Comparative Examples 1 to 7 and can be confirmed to have excellent bubble stability and significantly superior film moisture barrier properties at film processing temperatures.

[0616]

[0617] On the other hand, as shown in Table 4 above, in the case of Comparative Examples 1 to 7, where the density, melt flow index, polydispersity index (PDI), or elongation viscosity of polyethylene is not optimized, it can be confirmed that the resin pressure increases during film processing, bubble stability decreases at the film processing temperature, or the moisture barrier properties of the final manufactured film are insufficient.

Claims

1. The density is 0.965 g / cm³ or greater and 0.975 g / cm³ or less, and Melt Flow Index (MI) 2.16 , measured at 190 ℃ and a load of 2.16 kg) is 0.1 g / 10 min or more and 5.0 g / 10 min or less, and The polydispersity index (PDI, Mw / Mn) is between 20 and 60, and Elongational viscosity (@strain 2.5) of 30,000 Pa·S or more and 90,000 Pa·S or less, High-density polyethylene.

2. In Paragraph 1, The above polyethylene is an ethylene homopolymer, High-density polyethylene.

3. In Paragraph 1, High-load Melt Flow Index (MI) 21.6 , measured at 190 ℃, 21.6 kg load, having a value of 180 g / 10 min or more and 300 g / 10 min or less, High-density polyethylene.

4. In Paragraph 1, Melt flow rate ratio (MI) 21.6 / MI 2.16 ) being 150 or more and 250 or less, High-density polyethylene.

5. In Paragraph 1, melting points (Tm) of 130 ℃ or higher and 140 ℃ or lower, High-density polyethylene.

6. In Paragraph 1, A weight-average molecular weight (Mw) of 120,000 g / mol to 200,000 g / mol, High-density polyethylene.

7. In Paragraph 1, In a GPC curve graph where the x-axis is Log Mw and the y-axis is dw / dlogMw, the integral value in the region where the Log Mw value is between 2 and 3 (inclusive) is between 3% and 10% of the total integral value, High-density polyethylene.

8. In Paragraph 1, In a GPC curve graph where the x-axis is Log Mw and the y-axis is dw / dlogMw, the integral value in the region where the Log Mw value is between 2 and 4 is between 38% and 50% of the total integral value, High-density polyethylene.

9. In Paragraph 1, In a GPC curve graph where the x-axis is Log Mw and the y-axis is dw / dlogMw, the integral value in the region where the Log Mw value is 6 or greater and 7 or less is 1% or greater and 5% or less of the total integral value, High-density polyethylene.

10. In Paragraph 1, Complex viscosity measured at an angular frequency of 0.1 rad / s is 10,000 Pa·s or more and 16,000 Pa·s or less, High-density polyethylene.

11. In Paragraph 1, High-density polyethylene having a complex viscosity of 600 Pa·s or more and 900 Pa·s or less, measured at an angular velocity of 100 rad / s.

12. In Paragraph 1, The ratio of the complex viscosity measured at an angular velocity of 0.1 rad / s to the complex viscosity measured at an angular velocity of 100 rad / s (η* (0.1 rad / s)) / η*(100 rad / s)) is between 10 and 30, High-density polyethylene.

13. A high-density polyethylene according to claim 1, having a water vapor transmission rate (WVTR) of 1 g / m² based on a film thickness of 50 μm. 2 / day or less, Polyethylene film.

14. In Paragraph 13, When manufacturing a blown film with a thickness of 50 μm under conditions of a temperature of 230℃, FLH (Frost Line Height) of 160 mm, and BUR 2.5, the resin pressure is 80 bar or less, Polyethylene film.

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