Polyethylene and film comprising same

Abstract

The present invention provides: a polyethylene having excellent low-temperature sealing properties, sealing stability, and process reliability; and a film comprising same.

Description

Polyethylene and films containing the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0073747, filed June 5, 2024, and Korean Patent Application No. 10-2025-0073933, filed June 5, 2025, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to polyethylene having excellent low-temperature sealing properties, high hot-tack strength, and drop impact strength, and to a film comprising the same.

[0004]

[0005] Linear low density polyethylene (LLDPE) is a resin manufactured by copolymerizing ethylene and alpha-olefin at low pressure using a polymerization catalyst. It has a narrow molecular weight distribution, short-chain branches of a certain length, and no long-chain branches.

[0006] Linear low-density polyethylene film has the characteristics of general polyethylene, as well as high breaking strength and elongation, excellent film processability and transparency, and superior tear strength and drop impact strength, so its use is increasing in industrial films such as food packaging and industrial laminated films, heavy-duty films, and stretch wrap films, where conventional low-density polyethylene or high-density polyethylene is difficult to apply.

[0007] Linear low-density polyethylene (LPE) is generally known to exhibit increased drop impact strength as density decreases. However, the use of large amounts of comonomers to manufacture LPE can lead to increased fouling during the slurry polymerization process, and the resulting film can become sticky, necessitating increased use of anti-blocking agents. Furthermore, production processes can become unstable, and the resulting polyethylene morphology can deteriorate, resulting in a decrease in bulk density.

[0008] Due to recent market trends in sustainability and D4R (Design For Recyclability), the demand for down-gauging (D / G) is increasing, and accordingly, the demand for linear low-density polyethylene with excellent molding processability and drop impact strength is also increasing.

[0009] Before COVID-19, D / G focused on reducing the thickness of the polyethylene layer in multilayer films from a cost perspective. However, after COVID-19, with the increased interest in environmental issues, the demand for downgauging from a recycling perspective and energy consumption issues for carbon reduction have emerged.

[0010] In addition, the D4R design from the recycling perspective is attracting attention to promote and activate the transition to a resource circular economy, and the demand for improved sealing properties of the sealant layer during co-extrusion or bonding in the manufacturing process of BOPE (Biaxially Oriented Polyethylene) film and MDO (Machine Direction Orientation) film applied to single-material All-PE film is increasing.

[0011]

[0012] In order to solve the problems of the above prior art, the present invention aims to provide polyethylene having excellent low-temperature sealing properties, high hot-tack strength and drop impact strength.

[0013] In addition, the present invention seeks to provide a film comprising the polyethylene.

[0014]

[0015] According to the present invention, there is provided polyethylene that satisfies the following equation 1, and the x value of the following equation 1 is 9.17 or more:

[0016] [Formula 1]

[0017] 0.3309 * x - 3.014 ≤ y ≤ 0.3309 * x - 1.614

[0018] In the above equation 1,

[0019] y is ln(hot-tack strength), where hot-tack strength is the hot-tack strength (unit: N / 25.4 mm) measured according to ASTM F 1921,

[0020] x is ln(Mw Te≥80℃ )+ln(T m,1st - Tc)-ln(W peak≥80℃ ) and,

[0021] At this time Mw Te≥80℃ is the weight average molecular weight (unit: g / mol) of the polymer fraction eluted at an elution temperature of 80℃ or higher based on the total weight of polyethylene during temperature rising elution fractionation (TREF) of cross-fractionation chromatography (CFC).

[0022] T m,1stWhen the first heating curve of polyethylene DSC (Differential Scanning Calorimeter) graph is deconvoluted, it is the temperature (unit: ℃) of the highest endothermic peak among the deconvolution peaks.

[0023] Tc is the temperature (unit: ℃) of the highest exothermic peak when the DSC graph of polyethylene is deconvoluted.

[0024] W peak≥80℃ When the DSC graph of polyethylene is deconvoluted, it is the sum (unit: %) of the integral area of ​​the deconvolution curves in which the temperature of the exothermic peak is 80℃ or higher with respect to the total sum of the areas of the entire deconvolution curves.

[0025]

[0026] In addition, according to the present invention, a film including the polyethylene is provided.

[0027]

[0028] The polyethylene according to the present invention exhibits excellent low-temperature sealing and hot-tack properties. Furthermore, the polyethylene exhibits excellent drop impact strength and rigidity, along with improved moldability. Accordingly, downgauging is possible during film production using the polyethylene, making it advantageous for D4R applications.

[0029] In addition, the polyethylene according to the present invention can exhibit reliability of the sealing portion, interlayer adhesion stability, and high-strength sealing properties.

[0030] The above polyethylene can be usefully used in multipurpose films such as food, agricultural, general industrial films, or stretch films, and can be applied to a sealant layer during coextrusion or bonding in the manufacturing process of BOPE (Biaxially Oriented Polyethylene) film and MDO (Machine Direction Orientation) film applied to a single-material All-PE film.

[0031] Additionally, it is advantageous in responding to PPWR as it does not contain PFAS (Per- and Polyfluoroalkyl Substances), which are subject to the Packaging and Packaging Waste Regulation (PPWR) implemented by the European Union (EU).

[0032]

[0033] Figure 1 is a DSC deconvolution analysis graph of Example 1.

[0034] Figure 2 is a DSC deconvolution analysis graph of Example 2.

[0035] Figure 3 is a DSC deconvolution analysis graph of Example 3.

[0036] Figure 4 is a DSC deconvolution analysis graph of Comparative Example 1.

[0037] Figure 5 is a DSC deconvolution analysis graph of Comparative Example 2.

[0038] Figure 6 is a DSC deconvolution analysis graph of Comparative Example 3.

[0039]

[0040] In the present invention, terms such as first, second, etc. are used to describe various components, and the terms are used only for the purpose of distinguishing one component from another.

[0041] Furthermore, the terminology used herein is merely for the purpose of describing exemplary embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprise," "include," or "have" indicate the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0042] Additionally, the term “to” used in describing a numerical range in this specification includes both the upper and lower limits. For example, “1 to 3” means 1 or more and 3 or less.

[0043] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated and described in detail below. However, this is not intended to limit the present invention to specific disclosed forms, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0044] Hereinafter, the polyethylene of the present invention and the film containing the same will be described in detail.

[0045]

[0046] Polyethylene according to one embodiment of the present invention satisfies the following formula 1, and the x value of the following formula 1 satisfies 9.17 or more:

[0047] [Formula 1]

[0048] 0.3309 * x - 3.014 ≤ y ≤ 0.3309 * x - 1.614

[0049] In the above equation 1,

[0050] y is ln(hot-tack strength), where hot-tack strength is the hot-tack strength (unit: N / 25.4 mm) measured according to ASTM F 1921,

[0051] x is ln(Mw Te≥80℃ )+ln(T m,1st - Tc)-ln(W peak≥80℃ ) and,

[0052] At this time Mw Te≥80℃ is the weight average molecular weight (unit: g / mol) of the polymer fraction eluted at an elution temperature of 80℃ or higher based on the total weight of polyethylene during temperature rising elution fractionation (TREF) of cross-fractionation chromatography (CFC).

[0053] T m,1st When the first heating curve of polyethylene DSC (Differential Scanning Calorimeter) graph is deconvoluted, it is the temperature (unit: ℃) of the highest endothermic peak among the deconvolution peaks.

[0054] Tc is the temperature (unit: ℃) of the highest exothermic peak when the DSC graph of polyethylene is deconvoluted.

[0055] W peak≥80℃ When the DSC graph of polyethylene is deconvoluted, it is the sum (unit: %) of the integral area of ​​the deconvolution curves in which the temperature of the exothermic peak is 80℃ or higher with respect to the total sum of the areas of the entire deconvolution curves.

[0056]

[0057] Polyethylene resins are widely used in packaging films, particularly heat sealing films, due to their excellent processability, mechanical properties, and economic efficiency. These films are sealed through heating, and the physical properties and thermal stability of the sealing area are directly related to the film's reliability.

[0058] In order to secure low-temperature sealing and hot-tack characteristics, conventional polyethylene resins have mainly been made by lowering the density to lower the melting point to secure low-temperature sealing characteristics based on the melting point (Tm) and crystallization temperature (Tc), or by controlling the recrystallization behavior with a single distribution crystal. However, in the sealing process of an actual packaging line, there are cases where polyethylene resins with low density cannot be applied depending on the sealing temperature change due to external conditions and the packaging temperature of the packaged material, such as hot-fill due to sterilization / sterilization. The sealing characteristics of polyethylene resins are affected by complex factors such as recrystallization behavior, the influence of molecular weight distribution, and crystallizable fraction.

[0059] Accordingly, the present invention proposes a recrystallization factor, a new concept parameter that comprehensively considers not only the difference between the melting point and crystallization temperature, but also the weight average molecular weight and content ratio of the polymer fraction existing at a temperature higher than the crystallization temperature of polyethylene, thereby providing an index of polyethylene resin that can quantitatively measure performance in actual processing and sealing processes.

[0060] More specifically, in the above formula 1, x has a technical significance as a recrystallization factor of polyethylene, and is a comprehensive parameter reflecting the high-temperature crystallization tendency of polyethylene, entanglement of molecular chains, and crystallization speed, and the present invention was completed based on the observation that it shows a high correlation with hot-tack strength.

[0061]

[0062] The above recrystallization factor is a sealing-specific parameter that comprehensively considers the structural characteristics, thermal characteristics, and crystallization ratio (high-temperature crystallization region) of polyethylene, and reflects how individual factors such as the weight-average molecular weight of the polymer fraction, thermal characteristics, and the content of the polymer fraction in the high-temperature crystallization region interact and affect the sealing performance.

[0063] Polyethylene resins with a high recrystallization factor retain a high molecular weight component even at temperatures above their crystallization temperature (Tc), increasing the likelihood of recrystallization upon cooling and enabling the formation of a uniform crystal structure. This leads to improved sealing strength and thermal stability.

[0064] The above recrystallization factor comprehensively reflects the internal microstructure and crystallization potential of polyethylene resin, and thus serves as a useful design indicator that can quantitatively express the recrystallization tendency, which is difficult to explain simply by melting point, crystallization temperature, or molecular weight.

[0065] According to one embodiment of the present invention, by designing a resin based on the recrystallization factor and providing a polyethylene resin having the recrystallization factor above a certain standard, reliability of the sealing portion, interlayer adhesion stability, and high-strength sealing characteristics can all be satisfied simultaneously.

[0066] In addition, according to one embodiment of the present invention, it was experimentally confirmed that when the recrystallization factor x value in the above formula 1 is 9.17 or more, the hot-tack strength is secured as 3.0 N / 15mm or more. This greatly contributes to improving the sealing stability in the high-speed packaging process. More specifically, the recrystallization factor x value in the above formula 1 may be 9.17 or more, or 9.18 or more, or 9.20 or more, or 9.30 or more, or 9.40 or more, or 9.50 or more, or 9.60 or more, or 9.70 or more, or 9.80 or more, or 9.90 or more, or 10.0 or more, or 10.3 or more, or 10.5 or more, or 10.7 or more, or 11.0 or more, or 11.3 or more. The upper limit of the above x value is not particularly limited, but may be, for example, 20.0 or less, or 19.5 or less, or 19.0 or less, or 18.5 or less, or 18.0 or less, or 17.5 or less, or 17.0 or less, or 16.5 or less, or 16.0 or less, or 15.5 or less, or 15.0 or less.

[0067] More specifically, ln(Mw) among the recrystallization factors in Equation 1 Te≥80℃ ) in Mw Te≥80℃ Considering the contribution of crystal structure stability and chain entanglement to initial adhesion, Mw Te≥80℃ It refers to the weight average molecular weight (unit: g / mol) of the polymer fraction eluted at an elution temperature of 80℃ or higher based on the total weight of polyethylene during temperature rising elution fractionation (TREF) of cross-fractionation chromatography (CFC).

[0068] In this way, the weight average molecular weight of the polymer fraction eluted at high temperatures above 80℃ has a major influence on the entanglement between polyethylene chains. Therefore, the higher the weight average molecular weight of these polymer fractions, the more entanglement there is between the polyethylene chains, the stronger the intermolecular physical interaction occurs in the sealed state, the more favorable it is for the formation and growth of crystal nuclei upon cooling, and the more likely it is to obtain a high-strength / high-crystallinity film. More specifically, from the perspective of the mechanism of sealing by a heat bar, the initial seal initiation temperature (Hot-tack Seal Initiation Temperature) is determined by the partial melting of polymer chains at the surface between the two films due to the heat and pressure of the heat bar, and at a temperature near or above the melting temperature, the polymer between the films melts, causing polymer diffusion, and the Hot-tack strength is formed and increased by the bridge points of the dispersed polymers or the polymers that become entangled. Under the conditions for measuring the hot-tack strength, since sufficient cooling time is insufficient, the dispersion state of the polymer chains between the two films to be sealed and the mobility of the polymer are important along with the recrystallization temperature (Tc), and the weight average molecular weight of the polymer fraction eluted at the elution temperature of 80°C or higher was reflected as the recrystallization factor.

[0069] In addition, polyethylene according to one embodiment of the present invention, Mw Te≥80℃This can be more than 65,000 g / mol. More specifically, 65,000 g / mol or more, or 70,000 g / mol or more, or 80,000 g / mol or more, or 85,000 g / mol or more, or 90,000 g / mol or more, or 95,000 g / mol or more, or 100,000 g / mol or more, or 105,000 g / mol or more, or 110,000 g / mol or more, or 115,000 g / mol or more, or 120,000 g / mol or more, but 300,000 g / mol or less, or 290,000 g / mol or less, or 280,000 g / mol or less, or 270,000 g / mol or less, or 269,000 g / mol or less, or 268,000 g / mol or less, or 267,000 g / mol or less, or 266,000 g / mol or less, or 265,000 g / mol or less, or 264,000 g / mol or less, or 263,000 g / mol or less, or 262,000 g / mol or less, or 261,000 g / mol or less, or 260,000 g / mol or less.

[0070] Polyethylene according to one embodiment of the present invention has a weight average molecular weight (Mw) in the high crystallinity region Te≥80℃ ) can exhibit excellent hot-tack strength by satisfying the above-mentioned range conditions.

[0071]

[0072] In addition, the polyethylene according to one embodiment of the present invention can satisfy a content of a polymer fraction eluted at a temperature of 80°C or higher (Te≥80°C) in temperature rising elution fractionation analysis (TREF) of cross-sectional chromatography (CFC) of 10 to 50 wt% based on the total weight of polyethylene. More specifically, the content of the polymer fraction eluted at the elution temperature of 80° C. or higher may be 10 wt% or more, or 11 wt% or more, or 12 wt% or more, or 13 wt% or more, or 14 wt% or more, or 15 wt% or more, or 16 wt% or more, or 17 wt% or more, or 18 wt% or more, or 19 wt% or more, or 20 wt% or more, and 50 wt% or less, or 49 wt% or less, or 48 wt% or less, or 47 wt% or less, or 46 wt% or less, or 45 wt% or less, or 44 wt% or less, or 43 wt% or less, or 42 wt% or less, or 41 wt% or less, or 40 wt% or less.

[0073] The polymer fraction eluted at the elution temperature of 80°C or higher affects the stiffness of a film made of polyethylene, and the lower the fraction content, the lower the stiffness. On the other hand, if the fraction content is excessively high, the low-temperature sealing properties of the polyethylene may actually deteriorate. The polyethylene according to the present invention can exhibit excellent stiffness by including the polymer fraction eluted at the elution temperature of 80°C or higher within the above content range.

[0074]

[0075] Meanwhile, in the present invention, temperature rising elution fractionation (TREF) analysis of cross-fraction chromatography (CFC) can be performed by dissolving and stabilizing polyethylene in a trichlorobenzene solvent, cooling the temperature to crystallize it, and heating the crystallized polyethylene sample to the fraction temperature at a constant heating rate while measuring the content of the eluted polymer. A more detailed measurement method is described in the examples described below.

[0076]

[0077] Among the recrystallization factors in Equation 1, ln(T m,1st -Tc) reflects the ease of recrystallization and structural fixation due to rapid crystallization.

[0078] In general, the melting point (Tm) is the temperature at which a crystalline polymer breaks down its crystal structure and transitions to a liquid state when heated. This appears as an endothermic peak on a DSC graph. Tc is the crystallization temperature, which is the temperature at which a polymer begins to form a crystalline structure during cooling. This appears as an exothermic peak on a DSC graph, and can be used to determine the crystallization rate or degree of crystallinity of a polymer.

[0079] However, when multiple crystal structures or molecular weight distributions are mixed, multiple peaks resulting from each crystal structure appear as a single fused form on the DSC graph, making it difficult to accurately reflect crystal characteristics.

[0080] Accordingly, in the present invention, in order to more accurately reflect the thermal properties of polyethylene, the DSC graph is mathematically decomposed and deconvoluted to obtain the temperature of the highest endothermic peak among the deconvolution peaks of the first heating curve as T m,1stwas defined as Tc. In addition, when the DSC graph was deconvoluted, the temperature of the highest exothermic peak was defined as Tc.

[0081] For reference, in the present invention, deconvolution is performed according to the Gaussian-Lorentzian method using a known method, and a more detailed method is described in the examples described below.

[0082] T m,1st The difference between Tc and T m,1st -Tc) reflects the crystallization rate, and the smaller it is, the faster the recrystallization rate is in terms of recrystallization kinetics, which reduces the possibility of defects occurring, and the hot-tack strength can be improved as inter-diffusion and bonding between molecules occur well. However, T m,1st The difference between Tc and T m,1st -Tc) is too small, the gap between the melting temperature and the recrystallization temperature of the film will be very small, resulting in a narrow effective sealing temperature range. For example, T m,1st The difference between Tc and T m,1st - If Tc) is close to 0 and there is no difference, it means that the crystal is completed at the same time as the melting. This can improve the packaging speed because the cooling time is eliminated in the high-speed packaging line, but sealing is only possible at a certain temperature, and additional problems may occur during film manufacturing and forming. Therefore, T m,1st Both hot-tack strength and process reliability can be secured when the difference between Tc and Tc is within an appropriate range.

[0083] In addition, polyethylene according to one embodiment of the present invention, the T m,1st The difference between Tc and T m,1st -Tc) may be 15°C to 25°C. More specifically, the T m,1st The difference between Tc and T m,1st-Tc) may be 15°C or higher, or 16°C or higher, or 17°C or higher, or 18°C ​​or higher, and 25°C or lower, or 24°C or lower, or 23°C or lower, or 22°C or lower, or 21°C or lower.

[0084] The above T m,1st The difference between Tc and T m,1st -Tc) is lower, the possibility of occurrence of weak defects due to rapid crystallization immediately after sealing is lower, and inter-diffusion and bonding between molecules can occur well, which can improve hot-tack strength. In addition, T m,1st -If Tc is too large, the recrystallization rate slows down during cooling, which slows down the recrystallization rate of the film, which means the cooling time becomes long, so when hot-filling or packaging heavy objects, a long cooling time is required, which may cause peeling or poor bonding before the seal is completely formed during the packaging process. However, T m,1st The difference between Tc and T m,1st -If Tc) is too small, the gap between the melting temperature and the recrystallization temperature of the film will be very small, resulting in a narrow effective sealing temperature range.

[0085] Therefore, T m,1st When Tc satisfies a certain range, sealing can be completed within a sufficient amount of time during the heating and cooling cycles, significantly reducing sealing defects. Consequently, the effective hot-tack window range in the sealing process is expanded, enabling stable sealing under a variety of conditions. This increases the process tolerance of the production process and improves the film's packaging processability, i.e., its packaging suitability.

[0086] Polyethylene according to one embodiment of the present invention is T as follows. m,1st By controlling the temperature difference between Tc and Tc within a predetermined range, the sealing properties of the film can be comprehensively improved, and can be particularly usefully applied to the packaging film field where hot-tack strength and sealing stability are important.

[0087]

[0088] In addition, polyethylene according to one embodiment of the present invention, the T m,1st This can be over 120℃.

[0089] As explained earlier, T m,1st is a value derived from a deconvoluted DSC graph, which more accurately reflects the thermal properties of polyethylene. More specifically, the T m,1st The polyethylene according to one embodiment of the present invention may have a high T of 120°C or more, or 121°C or more, or 122°C or more, or 123°C or more, and 130°C or less, or 129°C or less, or 128°C or less, or 127°C or less, or 126°C or less. As described above, the polyethylene according to one embodiment of the present invention has a high T of 120°C or more. m,1st By having it, it can exhibit excellent heat resistance and hot tack strength.

[0090] In the present invention specification, DSC analysis can be performed under the same conditions as the general polyethylene resin analysis process with reference to ASTM D 3418, for example, 1 st Heating can be performed by heating polyethylene from 50℃ to 190℃ at a rate of 10℃ / min, then cooling it to -50℃ at a rate of 10℃ / min, and then heating it again. A more detailed measurement method is described in the examples described below.

[0091]

[0092] Among the recrystallization factors in Equation 1, W peak≥80℃ When the DSC graph of polyethylene is deconvoluted, it is the sum of the integrated areas of the deconvolution curves with an exothermic peak temperature of 80℃ or higher relative to the total sum of the areas of the entire deconvolution curves, and reflects the proportion of polymers capable of high-temperature crystallization in the entire polyethylene and the contribution to crystallization at high temperatures.

[0093] The more components that can be crystallized in the high-temperature region, the more highly crystalline components that contribute to structural stabilization even at high temperatures immediately after sealing. Therefore, if this value is large, the polyethylene resin maintains its crystallization ability even at high processing temperatures, and it can be advantageous in thermal stability and interlayer lamination stability. However, W peak≥80℃ If this is too large, the ratio of high crystallinity increases significantly, causing the crystal lamella to become large, which may lead to a problem of reduced low-temperature sealing properties. Therefore, including it within an appropriate range may be advantageous for the recrystallization and crystallization speed.

[0094] In addition, polyethylene according to one embodiment of the present invention, the W peak≥80℃ This can be more than 50%. More specifically, the above W peak≥80℃ is 50% or more, or 51% or more, or 52% or more, or 53% or more, or 54% or more, or 55% or more, or 56% or more, or 57% or more, or 58% or more, or 59% or more, or 60% or more, but may be 80% or less, or 79% or less, or 78% or less, or 77% or less. The polyethylene according to the present invention may be W peak≥80℃ By including the content range mentioned above, high crystallinity and excellent rigidity can be exhibited.

[0095]

[0096] In the above equation 1, the characteristic variables were applied by reducing excessive sensitivity to the overall recrystallization factor through natural log (ln) transformation and reflecting the actual contribution.

[0097] The recrystallization factor x described above reflects the high-temperature crystallization tendency of polyethylene, the entanglement of molecular chains, and the crystallization speed, and shows a high correlation with the hot-tack strength y. Accordingly, the polyethylene according to one embodiment of the present invention is characterized by satisfying the above equation 1.

[0098] In the above equation 1, y is ln(hot-tack strength), and the hot-tack strength is a value measured according to ASTM F 1921 (sealing time 0.5 seconds, sealing pressure 0.3 MPa, delay time 0.1 seconds, tensile speed 200 mm / second, Sealing machine J&B 5000 Model) by molding a composition containing polyethylene at 95 wt% or more, or 96 wt% or more, or 97 wt% or more, or 98 wt% or more, or 99 wt% or more, or 99.9 wt% or more based on the total composition into a single-layer film having a thickness of 45 to 55 μm, or 48 to 52 μm, more specifically, 50 μm, using a blown film extruder (die diameter 120 mm, die gap 2.0 mm, BUR 2.5, Dual air-ring system).

[0099]

[0100] In addition, polyethylene according to one embodiment of the present invention, when the first heating curve DSC graph of the polyethylene is deconvoluted, the highest endothermic peak (T) among the deconvolution peaks m,1st ) may be 5 to 30% of the total sum of the areas of the entire deconvolution curves. More specifically, the area may be 5% or more, or 6% or more, or 7% or more, or 8% or more, or 9% or more, or 10% or more, but 30% or less, or 29% or less, or 28% or less, or 27% or less, or 26% or less, or 25% or less, or 24% or less, or 23% or less, or 22% or less, or 21% or less, or 20% or less. T m,1stSince the integral area of ​​the deconvolution curve representing the above-described range is shown, the polyethylene according to the present invention can exhibit excellent hot tack strength.

[0101] In addition, polyethylene according to one embodiment of the present invention has a density of 0.900 to 0.925 g / cm as measured according to ASTM D 1505 standard. 3 am.

[0102] If the density of polyethylene is too low, it is difficult to ensure stability in the slurry polymerization process. In addition, there is a trade-off relationship between density and drop impact strength, and density and low-temperature sealing properties. If the density of polyethylene is too high, it is difficult to down-gauge during film production due to the decrease in drop impact strength and low-temperature sealing properties. More specifically, the polyethylene according to the present invention has a density of 0.900 g / cm. 3 or 0.901 g / cm 3 or 0.902 g / cm 3 or 0.903 g / cm 3 or 0.904 g / cm 3 or 0.905 g / cm 3 or 0.906 g / cm 3 or 0.907 g / cm 3 or 0.908 g / cm 3 or 0.909 g / cm 3 or 0.910 g / cm 3 or 0.911 g / cm 3 or 0.912 g / cm 3 or 0.913 g / cm 3 or 0.914 g / cm 3 or 0.915 g / cm 3 Ideally, 0.925 g / cm 3 or less, or 0.924 g / cm 3 or less, or 0.923 g / cm 3 or less, or 0.922 g / cm 3or less, or 0.921 g / cm 3 or less, or 0.920 g / cm 3 or less, or 0.919 g / cm 3 or less, or 0.918 g / cm 3 It could be as follows:

[0103]

[0104] According to one embodiment of the present invention, the polyethylene has a significantly lower sealing initiation temperature than conventional polyethylene having a similar density, and thus can exhibit excellent low-temperature sealing properties and improved stiffness. As a product having a balanced sealing property and stiffness, when a low-density product is used to improve the existing low-temperature sealing properties, the waste of resources that are not used due to blocking problems that occur during actual application for packaging in roll form after lamination can be prevented, and additives such as anti-blocking agents used to lower the coefficient of friction can be reduced.

[0105]

[0106] In addition, the polyethylene according to one embodiment of the present invention has a molecular weight distribution (MWD, Mw / Mn) of 2.0 to 5.0.

[0107] If the molecular weight distribution is narrow, less than 2.0, the mechanical properties such as toughness are excellent, but there is a risk that the molding processability may deteriorate. If the molecular weight distribution exceeds 5.0, the molding processability is excellent, but there is a risk that the mechanical properties may deteriorate. More specifically, the polyethylene has a molecular weight distribution (MWD) of 2.0 or more, or 2.1 or more, or 2.2 or more, or 2.3 or more, or 2.4 or more, or 2.5 or more, or 2.6 or more, or 2.7 or more, or 2.8 or more, or 2.9 or more, or 3.0 or more, or 3.1 or more, or 3.2 or more, or 3.3 or more, or 3.4 or more, or 3.5 or more, or 3.6 or more, or 3.65 or more, or 3.7 or more, or 3.8 or more, and 5.0 or less, or 4.9 or less, or 4.8 or less, or 4.7 or less, or 4.6 or less, or 4.5 or less, or 4.4 or less, or 4.3 or less, or 4.25 or less, or 4.2 or less, or 4.15 or less, or 4.1 or less, or It may be 4.0 or less, or 3.9 or less. The polyethylene according to the present invention can exhibit well-balanced improved molding processability and mechanical properties by satisfying the above-mentioned molecular weight distribution conditions.

[0108]

[0109] Meanwhile, in the present invention, the weight average molecular weight (Mw) and number average molecular weight (Mn) of polyethylene were measured using gel permeation chromatography (GPC), and then the molecular weight distribution was calculated as the ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn). Here, the weight average molecular weight (Mw) and number average molecular weight (Mn) are polystyrene-converted molecular weights analyzed by GPC.

[0110] Specifically, a sample of polyethylene was analyzed using a PolymerChar GPC-IR using a Polymer Laboratories PLgel MIX-B 300 mm length column. ®The evaluation was performed using a device. The evaluation temperature was 160℃, 1,2,4-trichlorobenzene was used as a solvent, and the flow rate was measured at a rate of 1 mL / min. The polyethylene sample was prepared at a concentration of 16 mg / 8 mL and then supplied in an amount of 200 μL. The values ​​of Mw and Mn were measured using a calibration curve formed using polystyrene standards. The molecular weights of the polystyrene standards were 9 types: 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000.

[0111]

[0112] In addition, the polyethylene according to one embodiment of the present invention has a melt index (MI) measured under a temperature of 190°C and a load of 2.16 kg according to ASTM D1238 standard. 2.16) is 0.5 to 5.0 g / 10 min. More specifically, 0.5 g / 10 min or more, or 0.6 g / 10 min or more, or 0.7 g / 10 min or more, or 0.8 g / 10 min or more, or 0.9 g / 10 min or more, or 1.0 g / min or more, or 1.1 g / 10 min or more, or 1.2 g / min or more, or 1.3 g / min or more, or 1.4 g / min or more, or 1.5 g / min or more, and 5.0 g / 10 min or less, or 4.9 g / 10 min or less, or 4.8 g / 10 min or less, or 4.7 g / 10 min or less, or 4.6 g / 10 min or less, or 4.5 g / 10 min or less, or 4.4 g / 10 min or less, or 4.3 g / 10 min or less, or 4.2 g / 10 min or less, or 4.1 g / 10 min or less, or 4.0 g / 10min or less, or 3.9 g / 10min or less, or 3.8 g / 10min or less, or 3.7 g / 10min or less, or 3.6 g / 10min or less, or 3.5 g / 10min or less, or 3.4 g / 10min or less, or 3.3 g / 10min or less, or 3.2 g / 10min or less, or 3.1 g / 10min or less, or 3.0 g / 10min or less, or 2.9 g / 10min or less, or 2.8 g / 10min or less, or 2.7 g / 10min or less, or 2.6 g / 10min or less, or 2.5 g / 10min or less, or 2.4 g / 10min or less, or 2.3 g / 10min or less, or 2.2 g / 10min or less, or 2.1 g / 10min or less, or It may be 2.0 g / 10 min or less, or 1.9 g / 10 min or less, or 1.8 g / 10 min or less, or 1.7 g / 10 min or less, or 1.6 g / 10 min or less.

[0113]

[0114] In addition to the aforementioned crystal distribution characteristics and molecular weight distribution characteristics, the polyethylene according to the present invention can exhibit improved molding processability and mechanical properties as well as excellent sealing properties and drop impact strength characteristics by satisfying the conditions of low density and optimal range molecular weight distribution and melting index.

[0115]

[0116] In addition, the polyethylene according to one embodiment of the present invention may be a copolymer of ethylene and alpha-olefin, specifically including an alpha-olefin repeating unit derived from an alpha-olefin monomer together with an ethylene repeating unit.

[0117] The above alpha-olefin monomer may specifically be an alpha-olefin monomer having 3 to 20 carbon atoms. Specific examples thereof include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, etc., and more preferably, it may be 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, or 1-octene. Preferably, the polyethylene according to one embodiment of the present invention may be a type of copolymer of ethylene and 1-hexene, rather than a mixture with another polyethylene.

[0118] Polyethylene having the above properties can be produced by a production method including, for example, a step of polymerizing an ethylene monomer and an alpha-olefin monomer in the presence of a hybrid supported metallocene catalyst comprising a first transition metal compound represented by the following chemical formula 1; and a second transition metal compound represented by the following chemical formula 2. The above production method is merely an example for implementing the polyethylene according to the present invention, and the polyethylene of the present invention is not limited to the above production method.

[0119] [Chemical Formula 1]

[0120]

[0121] In the above chemical formula 1,

[0122] M1 is a group 4 transition metal,

[0123] X 11 and X 12 are each independently, C 1-20 Alkyl or halogen,

[0124] A1 is carbon, silicon, or germanium,

[0125] Q 11 and Q 12 are each independently hydrogen, halogen, C 1-20 Alkyl, or C 2-20 It is an alkoxyalkyl,

[0126] R 11 Inland R 15 are each independently hydrogen or C 1-20 It is alkyl,

[0127] [Chemical Formula 2]

[0128]

[0129] In the above chemical formula 2,

[0130] M2 is a group 4 transition metal,

[0131] X 21 and X 22 are each independently, C 1-20 Alkyl or halogen,

[0132] R 21 Inland R 25 are each independently, C 1-20 It is alkyl,

[0133] R 26 is hydrogen or C 1-20 It is alkyl,

[0134] R 27 Silver hydrogen, C 1-20 Alkyl, C 2-20 Alkoxy, or C 2-20 It is an alkoxyalkyl.

[0135]

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

[0137] The halogen can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0138] C 1-20 The alkyl of may be straight-chain, branched-chain or cyclic alkyl. Specifically, the C 1-20 The alkyl may be a straight chain alkyl having 1 to 20 carbon atoms; a straight chain alkyl having 1 to 10 carbon atoms; a straight chain alkyl having 1 to 5 carbon atoms; a branched chain or cyclic alkyl having 3 to 20 carbon atoms; a branched chain or cyclic alkyl having 3 to 15 carbon atoms; or a branched chain or cyclic alkyl having 3 to 10 carbon atoms. More specifically, the alkyl having 1 to 20 carbon atoms may be a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, or a cyclohexyl group.

[0139] C 2-20 The alkenyl of may be a straight-chain, branched-chain or cyclic alkenyl. Specifically, the C 2-20 The alkenyl may be a straight chain alkenyl having 2 to 20 carbon atoms, a straight chain alkenyl having 2 to 10 carbon atoms, a straight chain alkenyl having 2 to 5 carbon atoms, a branched chain alkenyl having 3 to 20 carbon atoms, a branched chain alkenyl having 3 to 15 carbon atoms, a branched chain alkenyl having 3 to 10 carbon atoms, a cyclic alkenyl having 5 to 20 carbon atoms or a cyclic alkenyl having 5 to 10 carbon atoms. More specifically, C 2-20 The alkenyl may be ethenyl, propenyl, butenyl, pentenyl or cyclohexenyl.

[0140] C 1-20 The alkoxy of may be a straight-chain, branched-chain or cyclic alkoxy group. Specifically, the C 1-20The alkoxy may be a straight chain alkoxy group having 1 to 20 carbon atoms; a straight chain alkoxy group having 1 to 10 carbon atoms; a straight chain alkoxy group having 1 to 5 carbon atoms; a branched chain or cyclic alkoxy group having 3 to 20 carbon atoms; a branched chain or cyclic alkoxy group having 3 to 15 carbon atoms; or a branched chain or cyclic alkoxy group having 3 to 10 carbon atoms. More specifically, the alkoxy group having 1 to 20 carbon atoms may be a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, an iso-butoxy group, a tert-butoxy group, an n-pentoxy group, an iso-pentoxy group, a neo-pentoxy group, or a cyclohexene group.

[0141] C 2-20 Alkoxyalkyl of -R y -OR z Alkyl (-R) with a structure containing y ) is one or more hydrogens of alkoxy (-OR z ) may be a substituent substituted with. Specifically, the alkoxyalkyl having C2 to C20 carbon atoms may be a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an iso-propoxymethyl group, an iso-propoxyethyl group, an iso-propoxyhectyl group, a tert-butoxymethyl group, a tert-butoxyethyl group, or a tert-butoxyhexyl group.

[0142] Also, group 4 transition metals can include titanium, zirconium, and hafnium.

[0143]

[0144] The hybrid supported metallocene catalyst used in the production of polyethylene according to the present invention is a hybrid catalyst comprising a first transition metal compound with high molecular weight and high polymerizability, and a second transition metal compound with low molecular weight and low polymerizability.

[0145] Specifically, the first transition metal compound represented by the above chemical formula 1 contributes to producing a high molecular weight copolymer having a high SCB content, and the second transition metal compound represented by the above chemical formula 2 contributes to producing a low molecular weight copolymer having a low SCB content. Accordingly, the hybrid supported metallocene catalyst can exhibit high copolymerizability in the high molecular weight region of polyethylene due to the first transition metal compound, while exhibiting low copolymerizability in the low molecular weight region of polyethylene due to the action of the second transition metal compound. As a result, the polyethylene produced using the hybrid supported metallocene catalyst can easily produce polyethylene that satisfies the above-described physical property requirements through tie-molecule formation due to strong low crystallinity expression in the high molecular weight region.

[0146] Specifically, in the hybrid supported metallocene catalyst, the first transition metal compound represented by the chemical formula 1 contributes to the production of a high molecular weight copolymer and exhibits a relatively high comonomer incorporation rate compared to the second transition metal compound.

[0147] Specifically, in the above chemical formula 1, M1 may be zirconium (Zr) or titanium (Ti).

[0148] Also, X 11 and X 12 are each independently halogen, and more specifically, may be chloro.

[0149] Also, in the above chemical formula 1, A1 is silicon, and Q 11 and Q 12 are each independently hydrogen, halogen, C 1-20 Alkyl, or C 2-20 Alkoxyalkyl, Q 11 and Q 12 Either one of C 2-20 It may be a tether group of an alkoxyalkyl. More specifically, Q 11 and Q 12 One of them is C2-20 One is alkoxyalkyl, and the other is C 1-20 It could be an alkyl.

[0150] As a bridging group connecting two ligands, Q 11 and Q 12 Either one of C 2-20 When the tether group of the alkoxyalkyl is included, the atomic size becomes larger and the available angle increases compared to the carbon bridge in the conventional metallocene compound, so that the monomer can easily approach during the polymerization reaction, thereby exhibiting excellent catalytic activity. In addition, the leaching of the catalyst precursor is prevented during the polymerization reaction, and as a result, fouling due to the reaction of the leached catalyst precursor and the cocatalyst can be prevented. Such an effect is described in the above Q 11 and Q 12 Either of them is -(CH2)nR b (Above R b is C 1-6 Alkoxy group, more specifically C 1-6 Straight chain alkoxy group or C 3-6 C, such as a branched alkoxy group, more specifically a tert-butoxy group 3-6 Branched alkoxy, n is an integer from 2 to 10, or from 3 to 9, and the remainder is C 1-4 It can be further increased in the case of alkyl. More specifically, Q 11 and Q 12 One of them may be tert-butoxyhexyl and the other may be methyl.

[0151] Also, in the above chemical formula 1, R 11 Inland R 14 are each independently, C 1-10 Alkyl, more specifically C 1-4 Alkyl, more specifically methyl. In this way, the cyclopentadienyl ligand in formula 1 is R 11 Inland R 14By being substituted, it can exhibit better catalytic activity due to the inductive effect that can supply sufficient electrons.

[0152] Also, in the above chemical formula 1, R 15 is C 1-6 It can be alkyl, more specifically C 1-4 Straight chain alkyl or C 3-6 It may be a branched alkyl, more specifically tert-butyl.

[0153] Specific examples of the first transition metal compound represented by the above chemical formula 1 include compounds having the following structures, but the present invention is not limited thereto.

[0154]

[0155]

[0156] The first transition metal compound represented by the above chemical formula 1 can be synthesized by applying known reactions, and a more detailed synthesis method can be found in the examples.

[0157] Meanwhile, in the hybrid supported metallocene catalyst, the second transition metal compound represented by the chemical formula 2 has a non-crosslinked structure of a hydrogenated indene ligand, specifically, a 4,5,6,7-tetrahydro-1-indene ligand and a cyclopentadiene ligand. Accordingly, the electronic / steric environment around the transition metal can be easily controlled, and as a result, the chemical structure, molecular weight distribution, and mechanical properties of the synthesized polyethylene can be easily controlled.

[0158] Specifically, in the above chemical formula 2, M2 may be zirconium (Zr). When the second transition metal compound includes Zr as a central metal, it has more orbitals capable of accepting electrons compared to when it includes other Group 14 elements such as Hf, and thus can easily bind to the monomer with higher affinity, resulting in a superior catalytic activity improvement effect.

[0159] Also, X 21 and X 22 can each independently be a halogen, and more specifically, a chloro.

[0160] Also, in the above chemical formula 2, R 21 Inland R 25 are each independently, C 1-10 Alkyl, more specifically C 1-4 Alkyl, more specifically methyl. Thus, the cyclopentadienyl ligand in formula 2 is R 21 Inland R 25 By being substituted, it can exhibit better catalytic activity due to the inductive effect that can supply sufficient electrons. In addition, by being used in combination with the first transition metal compound represented by the above chemical formula 1, the distribution of the comonomer in the polyethylene produced is appropriately controlled, so that polyethylene satisfying the above-described physical property requirements can be easily produced.

[0161] In addition, the second transition metal compound includes a hydrogenated indene ligand, i.e., a 4,5,6,7-tetrahydro-1-indene ligand, thereby exhibiting superior hydrogen reactivity compared to a case in which an indene group is included in the prior art. Accordingly, the amount of hydrogen input and the amount of wax generated during the polymerization reaction can be reduced, and as a result, process stability can be improved. In addition, by being used in combination with the first transition metal compound represented by the above chemical formula 1, the distribution of comonomers in the final polyethylene produced is concentrated toward a high molecular weight, and as a result, the impact strength properties of the polyethylene can be significantly improved.

[0162] In addition, the 1st and 3rd positions of the above 4,5,6,7-tetrahydro-1-indene ligand are unsubstituted, or R 26 and R 27 Each of which can be replaced by R 26 is specifically hydrogen or C 1-20 Alkyl, R 27 Silver hydrogen, C 1-20 Alkyl, C 2-20 Alkoxy, or C 2-20 It may be an alkoxyalkyl. More specifically, the R 26 is hydrogen or C 1-6 Alkyl, R 27 Silver hydrogen, C 1-6 Alkyl, or -(CH2) n -R b (Above R b is C 1-6 Alkoxy group, more specifically C 1-6 Straight chain alkoxy group or C 3-6 It may be an alkoxyalkyl group having a branched alkoxy group, and n is an integer from 2 to 10. In addition, the above -(CH2) n -R b In R b is C 3-6 C, such as a branched alkoxy group, more specifically a tert-butoxy group 3-6 Branched alkoxy, and n may be an integer from 3 to 9. More specifically, the R 26is hydrogen, or methyl, and R 27 may be hydrogen, methyl, ethyl, or tert-butoxyhexyl.

[0163] Specific examples of the second transition metal compound represented by the above chemical formula 2 include compounds having the following structures, but the present invention is not limited thereto.

[0164] .

[0165] The second transition metal compound represented by the above chemical formula 2 can be synthesized by applying known reactions, and a more detailed synthesis method can be found in the examples.

[0166] In addition, the hybrid supported metallocene catalyst can increase catalytic activity and more easily implement the properties of the polymer produced by controlling the molar ratio of the first and second transition metal compounds.

[0167] For example, the hybrid supported metallocene catalyst may include the first and second transition metal compounds in a molar ratio of 1:1 to 10:1. When the above-described mixing ratio conditions are satisfied, the catalytic activity is excellently maintained, while the high and low copolymerizabilities of the polyethylene produced from the hybrid supported catalyst are optimized, thereby further improving the sealing properties, drop impact strength properties, rigidity, and molding processability. More specifically, the molar ratio of the first and second transition metal compounds may be 2:1 to 8:1, or 2:1 to 5:1.

[0168] Additionally, the hybrid supported metallocene catalyst may include a cocatalyst.

[0169] Hybrid supported metallocene catalysts exhibit improved process stability along with high catalytic activity when they include a cocatalyst.

[0170] Specifically, the cocatalyst may include at least one compound represented by the following chemical formula 3.

[0171] [Chemical Formula 3]

[0172] -[Al(R 41 )-O]a-

[0173] In the above chemical formula 3,

[0174] R 41 is a halogen; or C substituted or unsubstituted with a halogen 1-20 It is hydrocarbyl;

[0175] a is an integer greater than or equal to 2.

[0176] Meanwhile, in the present specification, a hydrocarbyl group is a monovalent functional group in the form of removing a hydrogen atom from a hydrocarbon, and may include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an aralkenyl group, an aralkynyl group, an alkylaryl group, an alkenylaryl group, and an alkynylaryl group. In addition, the hydrocarbyl group having 1 to 20 carbon atoms may be a hydrocarbyl group having 1 to 15 carbon atoms or 1 to 10 carbon atoms. Specifically, the hydrocarbyl group having 1 to 20 carbon atoms is a straight-chain, branched-chain, or cyclic alkyl group such as a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, or a cyclohexyl group; Or it may be an aryl group such as a phenyl group, a naphthyl group, or anthracenyl group.

[0177] Examples of compounds represented by the above chemical formula 3 include alkylaluminoxane compounds such as methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, or butylaluminoxane, and any one of these or a mixture of two or more thereof may be used. Among the above compounds, the cocatalyst may be more specifically methylaluminoxane.

[0178] The above alkylaluminoxane cocatalyst can further enhance catalytic activity by including a metal element that stabilizes the first and second transition metal compounds and acts as a Lewis acid to form a bond through a Lewis acid-base interaction with a functional group introduced to a bridge group of the first transition metal compound.

[0179] In addition, the amount of the cocatalyst used can be appropriately adjusted depending on the properties or effects of the desired catalyst and polyethylene. For example, when silica is used as the carrier described below, the cocatalyst can be supported in an amount of 100 g or more, 1000 g or more, or 2000 g or more, and 6000 g or less, or 5500 g or less, or 5400 g or less, based on the weight of the carrier, for example, 1,000 g of silica.

[0180] In addition, the hybrid supported metallocene catalyst may include a carrier. When the hybrid supported metallocene catalyst includes a carrier, the first and second transition metal compounds are used in the form of a supported catalyst supported on the carrier.

[0181] As the carrier, a carrier having a highly reactive hydroxyl group, silanol group, or siloxane group on the surface can be used. For this purpose, a carrier whose surface has been modified by calcination or whose surface has had moisture removed by drying can be used. For example, silica such as silica manufactured by calcining silica gel, or silica dried at high temperature, silica-alumina, and silica-magnesia can be used, and these can typically contain oxides, carbonates, sulfates, and nitrate components such as Na2O, K2CO3, BaSO4, and Mg(NO3)2.

[0182] When used in a supported catalyst state, the particle shape and bulk density of the polymer produced are excellent, and it can be suitably used in conventional slurry polymerization, bulk polymerization, and gas phase polymerization processes. In addition, among various supports, the silica support is supported by chemical bonding of the functional group of the transition metal compound, so that almost no catalyst is liberated from the surface of the support during the ethylene polymerization process, and as a result, fouling caused by adhesion of the reactor wall or polymer particles to each other can be minimized when producing polyethylene by slurry or gas phase polymerization.

[0183] The above-mentioned carrier may have an average particle diameter (D50) of 20 to 40 μm. When the above-mentioned particle size is present, the transition metal compound can be supported with superior efficiency, and as a result, the catalytic activity can be enhanced. More specifically, the carrier may have an average particle diameter of 20 μm or more, or 25 μm or more, and 40 μm or less, or 30 μm or less.

[0184] Meanwhile, in the present invention, the average particle diameter (D50) of the carrier refers to the particle diameter at the 50% point of the cumulative distribution of the number of particles according to particle size (particle diameter). The D50 can be measured using a laser diffraction method. Specifically, the target carrier is dispersed in a dispersion medium such as deionized water, and then introduced into a commercially available laser diffraction particle size measuring device (e.g., Microtrac S3500), and when the particles pass through the laser beam, the difference in the diffraction pattern according to the particle size is measured to calculate the particle size distribution. The particle size at the point where it becomes 50% of the cumulative distribution of the number of particles according to the particle diameter in the measuring device is calculated, and this is taken as the average particle size.

[0185] In addition, when supported on the carrier, the first and second transition metal compounds may be supported in an amount of, for example, 1 mmol or more, 1.5 mmol or more, or 2 mmol or more, and 100 mmol or less, or 50 mmol or less, or 30 mmol or less, or 10 mmol or less, or 5 mmol or less, based on 1,000 g of the silica carrier. When supported in the above content range, it may exhibit appropriate supported catalytic activity, which may be advantageous in terms of maintaining the activity of the catalyst and economic efficiency.

[0186] The hybrid supported metallocene catalyst having the above-described configuration can be produced by a production method including a step of supporting a promoter compound on a support, and a step of supporting the first and second transition metal compounds on the support. In this case, the supporting order of the promoter and the first and second transition metal compounds can be changed as needed, and the supporting order of the first and second transition metal compounds can also be changed as needed. The first and second transition metal compounds can be supported simultaneously. Considering the effect of the supported catalyst having a structure determined according to the supporting order, among these, supporting the promoter on the support and then sequentially supporting the first and second transition metal compounds can enable the produced supported catalyst to realize high catalytic activity and better process stability in the process of producing polyethylene.

[0187] Meanwhile, in the polymerization reaction, specific examples of alpha-olefin monomers include, as described above, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, etc., and two or more of these may be used. More specifically, the alpha-olefin monomer may be 1-hexene.

[0188] The amount of the alpha-olefin monomer added may be determined depending on the properties of the polyethylene to be manufactured. For example, considering the properties of the polyethylene to be implemented in the present invention, the alpha-olefin monomer may be added in an amount of 4 to 30 wt%, more specifically, 4 wt% or more, or 8 wt% or more, or 10 wt% or more, or 12 wt% or more, and 30 wt% or less, or 25 wt% or less, or 20 wt% or less, based on the total weight of monomers including ethylene and the alpha-olefin monomer.

[0189] In addition, the above polymerization reaction is performed under the condition of hydrogen input.

[0190] Specifically, hydrogen may be introduced in an amount of 10 to 50 ppm, more specifically 10 ppm or more, or 15 ppm or more, or 20 ppm or more, or 25 ppm or more, and 50 ppm or less, or 45 ppm or less, or 40 ppm or less, or 38 ppm or less, or 35 ppm or less, based on the total weight of monomers including ethylene monomers and alpha-olefin monomers. When introduced in the above range, it is easier to implement the physical properties of the polyethylene described above. When the polymerization reaction is performed under conditions without introducing hydrogen, the melt index (MI) of the polyethylene produced may be significantly lowered.

[0191] Additionally, the above polymerization reaction can be carried out as a slurry polymerization reaction.

[0192] In the case of solution polymerization, since the catalyst is activated by a high temperature and high pressure reaction, catalyst decomposition and chain transfer are promoted, and the resulting resin composition has a narrow molecular weight distribution (MWD) and a low high molecular weight tail content. Accordingly, the resin composition manufactured by solution polymerization exhibits deteriorated moldability when manufacturing a film. However, in the case of the slurry polymerization process of the present invention, since polymerization is performed at a relatively low temperature, it is possible to secure a molecular structure containing a wide MWD and a large amount of high molecular weight tail, which is required for a polyethylene resin composition for manufacturing a transparent film. As a result, excellent moldability can be exhibited.

[0193] In the above slurry polymerization reaction, it can be performed using a single continuous slurry polymerization reactor or a loop slurry reactor.

[0194] In addition, during the above slurry polymerization reaction, the hybrid supported catalyst can be dissolved or diluted and injected in an aliphatic hydrocarbon solvent having 4 to 12 carbon atoms, such as isobutane, pentane, hexane, heptane, nonane, decane, and isomers thereof, an aromatic hydrocarbon solvent such as toluene and benzene, a hydrocarbon solvent substituted with a chlorine atom such as dichloromethane and chlorobenzene, etc. It is preferable to use the solvent used here after removing a small amount of water or air, etc. that act as catalyst poisons, by treating it with a small amount of alkyl aluminum, and it is also possible to carry out the reaction using an additional cocatalyst.

[0195] In addition, the polymerization reaction may be carried out at a temperature of 40°C or higher, or 60°C or higher, or 80°C or higher, and 110°C or lower, or 100°C or lower, or 90°C or lower. In addition, when the pressure conditions during the polymerization reaction are further controlled, the polymerization reaction may be carried out under a pressure of 5 bar or higher, or 10 bar or higher, or 20 bar or higher, or 30 bar or higher, and 50 bar or lower, or 45 bar or lower, or 40 bar or lower. When polymerization is carried out under such temperature and pressure, the desired physical properties of polyethylene can be more easily realized.

[0196] The polyethylene produced by the above-described production method has the crystal distribution characteristics, molecular weight distribution characteristics, rheological characteristics, and processing characteristics described above. Accordingly, the polyethylene can exhibit excellent low-temperature sealing characteristics and hot-tack characteristics, and can also exhibit well-balanced improved molding processability along with excellent drop impact strength characteristics and rigidity. As a result, downgauging is possible when producing a film using the polyethylene, and the polyethylene is advantageous for D4R applications. In addition, the polyethylene can be usefully used in multi-purpose films such as food, agricultural, and general industrial films, or stretch films, and can be particularly used in the sealant layer of All-PE.

[0197] Accordingly, the present invention provides a resin composition comprising the polyethylene, specifically a composition for forming a film.

[0198] In addition, the present invention provides a film manufactured using the polyethylene or the resin composition.

[0199] The above film can be manufactured according to a conventional film manufacturing method, except that the above-mentioned polyethylene is used. For example, the film can be manufactured according to an inflation method in which a film-forming composition is manufactured by mixing only the above-mentioned polyethylene or optionally by mixing additives such as antioxidants and processing aids, and then extruding the film into a film using an extruder.

[0200] More specifically, the resin composition containing the polyethylene may be applied for a sealant layer, and co-extruded with a composition for forming another film layer, or extruded with a blown film extruder or a cast film extruder, or a film may be separately manufactured with the resin composition containing the polyethylene using extrusion coating on a substrate such as paper, and then the manufactured film may be laminated with another film. However, the present invention is not limited thereto, and any known manufacturing method may be applied to manufacture various films.

[0201]

[0202] The above film exhibits excellent low-temperature sealing properties, sealing stability and process reliability by including the above polyethylene.

[0203]

[0204] Specifically, when the film is a single-layer film having a thickness of 45 to 55 μm, or 48 to 52 μm, more specifically 50 μm, the Hot-tack Strength measured according to ASTM F 1921 is 3.00 N / 25.4 mm or more. More specifically, when measured according to ASTM F 1921, the Hot-tack Strength, which is the highest strength measured, is 3.00 N / 25.4mm or more, or 3.02 N / 25.4mm or more, or 3.03 N / 25.4mm or more, or 3.05 N / 25.4mm or more, or 3.10 N / 25.4mm or more, or 3.15 N / 25.4mm or more, or 3.20 N / 25.4mm or more, or 3.25 N / 25.4mm or more, or 3.30 N / 25.4mm or more, or 3.35 N / 25.4mm or more, or 3.40 N / 25.4mm or more, or 3.45 N / 25.4mm or more, or 4.00 N / 25.4mm or more.

[0205] Hot-tack Strength refers to the sealing strength between two films before they are sufficiently cooled when sealed using the hot-bar jaw method. The higher the value, the better the molding processability. Accordingly, it is advantageous for VFFS packaging that enables high-speed production of hot-fill products such as ramen soup or liquid sauce. In addition, the higher the Hot-tack Strength, the advantageous for packaging heavy products. Accordingly, the upper limit of Hot-tack Strength is not particularly limited, but may be 10.00 N / 25.4mm or less, or 9.00 N / 25.4mm or less, or 8.00 N / 25.4mm or less, or 7.00 N / 25.4mm or less, or 6.00 N / 25.4mm or less, or 5.00 N / 25.4mm or less.

[0206] Meanwhile, in the present invention, in the unit of hot-tack strength, N / 25.4 mm, “25.4 mm” means the width of the film sample for measuring sealing.

[0207]

[0208] For reference, the above hot tack strength is the highest strength measured when the tack strength is measured at each temperature at intervals of 5°C between 60°C and 130°C using a J&B Hot tack tester (Hot tacker 5000) under the conditions of a sealing time of 0.5 seconds, a sealing pressure of 0.3 MPa, a delay time of 0.1 seconds, and a tensile speed of 200 mm / sec when the film thickness is 45 to 55 μm, or 48 to 52 μm, more specifically, a single-layer film of 50 μm.

[0209]

[0210] In addition, the polyethylene film can exhibit improved drop impact strength properties in addition to the sealing properties.

[0211] Specifically, when the film is a single-layer film having a film thickness of 45 to 55 μm, or 48 to 52 μm, more specifically 50 μm, the drop impact strength measured according to ASTM D 1709 [Method A] is 900 gf or more, or 950 gf or more, or 970 gf or more, or 1,000 gf or more, or 1,100 gf or more, or 1,200 gf or more, or 1,250 gf or more, or 1,300 gf or more, or 1,350 gf or more, or 1,400 gf or more. The drop impact strength is not particularly limited because the higher it is, the better it is, but for example, it may be 2,000 gf or less, or 1,900 gf or less, or 1,800 gf or less, or 1,700 gf or less.

[0212]

[0213] In addition, when the film is a single-layer film having a film thickness of 45 to 55 μm, or 48 to 52 μm, more specifically 50 μm, the 1% secant modulus in the MD direction of the film, measured according to ASTM D882 using a Universal Testing Machine (UTM), is 1,500 kg / cm. 2 or more than 1,600 kg / cm 2 or more than 1,700 kg / cm 2 or more than 1,800 kg / cm 2 And the 1% secant modulus in the TD direction is 1,800 kg / cm 2 or more than 1,900 kg / cm 2 or more than 2,000 kg / cm 2 or more than 2,100 kg / cm 2 That's all.

[0214] The secant modulus is defined in ASTM D882 and represents the stiffness of a film. The secant modulus is related to density, and the higher the density, the higher the secant modulus and stiffness. In addition, the higher the secant modulus, the better the openability, visibility, and coefficient of friction (COF). Accordingly, the upper limit of the secant modulus is not particularly limited, but as an example, the 1% secant modulus in the MD and TD directions of the film is 3,000 kg / cm each. 2 or less, or 2,900 kg / cm 2 or less, or 2,800 kg / cm 2 or less, or 2,700 kg / cm 2 or less, or 2,600 kg / cm 2 or less, or 2,500 kg / cm 2 or less, or 2,400 kg / cm 2 It could be as follows:

[0215]

[0216] For reference, the Hot-tack Strength, drop impact strength, and secant modulus were measured for a film formed into a single-layer film having a thickness of 45 to 55 μm, or 48 to 52 μm, more specifically, 50 μm, using a blown film extruder (die diameter 120 mm, die gap 2.0 mm, BUR 2.5, Dual air-ring system) from a composition containing 95 wt% or more, or 96 wt% or more, or 97 wt% or more, or 98 wt% or more, or 99 wt% or more, of the polyethylene of the present invention based on the total composition.

[0217]

[0218] Hereinafter, preferred examples are presented to aid understanding of the present invention. However, the following examples are provided solely to facilitate understanding of the present invention and are not intended to limit the scope of the present invention.

[0219] Meanwhile, in this specification, room temperature means 23±2℃.

[0220]

[0221] <Preparation of Transition Metal Compounds>

[0222] Synthesis Example 1

[0223]

[0224] Preparation of ligands

[0225] Tetramethylcyclopentadiene (TMCP, 1 equiv) was dissolved in THF (0.3 M), and n-BuLi (1.05 eq) was slowly added dropwise at -25°C, followed by stirring at room temperature for 3 hours. t-BuOHexSiMeCl2 (1.00 eq) was added to the resulting reaction mixture at -10°C, followed by stirring at room temperature overnight. The solvent was completely vacuum-dried, and tBuNH2 (10 eq) was added and stirred at room temperature overnight. Afterwards, the mixture was worked up with water and dried to obtain the ligand.

[0226]

[0227] Preparation of transition metal compounds

[0228] The above-mentioned ligand was dissolved in toluene (0.3 M), n-BuLi (2.05 eq) was added at -25°C, and stirred at room temperature for 3 hours. In a glove box, TiCl4(THF)2 (titanium tetrachloride tetrahydrofuran adduct, 1 eq) was prepared in another flask, added to the ligand-Li flask using a cannula at -25°C, and washed and added using toluene (1.0 M).

[0229] Upon completion of the reaction, the solvent was vacuum-dried, DCM was re-introduced, LiCl was removed through a filter, and the filtrate was vacuum-dried to obtain a liquid transition metal compound (Cat 1).

[0230] 1 H NMR (500 MHz, CDCl3) δ 3.34 (t, 2H), 2.24 (d, J = 1.7 Hz, 6H), 2.13 (d, J = 3.2 Hz, 6H), 1.57 - 1.45 (m, 6H), 1.42 (s, 9H), 1.32 - 1.22 (m, 4H), 1.18 (s, 9H), 0.67 (s, 3H).

[0231]

[0232] Synthesis Example 2-1

[0233] (Cat 2-1)

[0234] Indene (1 eq) was dissolved in THF (0.3 M), and n-BuLi (1.05 eq) was slowly added dropwise at -25°C, and the mixture was stirred at room temperature for 3 hours. Then, CH3-I (1.05 eq) was added at -10°C, and the mixture was stirred overnight at room temperature, worked up with water, and dried to obtain 3-MethylIndene. 3-MethylIndene (1 eq) thus synthesized was dissolved in THF (0.3 M), and n-BuLi (1.05 eq) was slowly added dropwise at -25°C, and the mixture was stirred at room temperature for 3 hours. Then, CH3-I (1.05 eq) was added at -10°C, and the mixture was stirred overnight at room temperature, worked up with water, and dried to obtain 1,3-dimethyl-Indene.

[0235]

[0236] Preparation of transition metal compounds

[0237] The above-mentioned ligand was dissolved in Ether (0.3 M), n-BuLi (1.05 eq) was added at -25°C, and stirred at room temperature for 3 hours. In a glove box, PMCpZrCl3 (Pentamethylcyclopentadienylzirconium trichloride) (1 eq) was prepared in another flask, added to the ligand-Li flask using a cannula at -25°C, and washed and added using Ether (1.0 M).

[0238] Upon completion of the reaction, the solvent was vacuum-dried, DCM was reintroduced, LiCl was removed through a filter, the filtrate was vacuum-dried, and slurry was formed using hexane. The resulting solid was then filtered and vacuum-dried to obtain a solid metallocene compound intermediate.

[0239]

[0240] In a glove box, the above metallocene compound intermediate was placed in a mini parr, and 5 mol% of Pd / C (10 wt%) was added. A magnetic bar was inserted here and moved outside the glove box using a closing system. DCM (0.5 M) was added to the parr, and H2 gas (10 barg) was added. After repeating the vent-charge cycle three times, the mixture was placed in a 40°C oil bath and stirred. When the pressure of the parr decreased below 5 barg, the previous charging process was repeated, and the reaction was continued until there was no more consumption of H2 gas. Upon completion of the reaction, the remaining H2 gas was vented and replaced with Ar gas. After cooling to room temperature, the mixture was filtered using a cannula, and the filtrate was vacuum-dried. The dried filtrate was slurried using hexane, and this was filtered to obtain a solid transition metal compound (Cat 2-1).

[0241] 1 H NMR (500 MHz, CDCl3) δ 5.60 (s, 1H), 2.90 (dt, J = 16.4, 6.3 Hz, 2H), 2.32 (dt, J = 16.3, 6.0 Hz, 2H), 2.04 (s, 15H), 1.79 - 1.66 (m, 2H), 1.67 (s, 6H), 1.64 - 1.54 (m, 2H).

[0242]

[0243] Synthesis Example 2-2

[0244] (Cat 2-2)

[0245] Indene (1 eq) was dissolved in THF (0.3 M), and n-BuLi (1.05 eq) was slowly added dropwise at -25°C, followed by stirring at room temperature for 3 hours. Afterwards, CH3-I (1.05 eq) was added at -10°C, and stirred overnight at room temperature, worked up with water, and dried to obtain 3-MethylIndene. 3-MethylIndene (1 eq) thus synthesized was dissolved in THF (0.3 M), and n-BuLi (1.05 eq) was slowly added dropwise at -25°C, followed by stirring at room temperature for 3 hours. Afterwards, tert-butoxyhexyl-I (1.05 eq) was added at -10°C, stirred overnight at room temperature, worked up using water, and dried to obtain 1-methyl-3-(tert-butoxyhexyl)-Indene.

[0246]

[0247] Preparation of transition metal compounds

[0248] The above-mentioned ligand was dissolved in Ether (0.3 M), n-BuLi (1.05 eq) was added at -25°C, and stirred at room temperature for 3 hours. In a glove box, PMCpZrCl3 (Pentamethylcyclopentadienylzirconium trichloride) (1 eq) was prepared in another flask, added to the ligand-Li flask using a cannula at -25°C, and washed and added using Ether (1.0 M).

[0249] Upon completion of the reaction, the solvent was vacuum-dried, DCM was reintroduced, LiCl was removed through a filter, the filtrate was vacuum-dried, and slurry was formed using hexane. The resulting solid was then filtered and vacuum-dried to obtain a solid metallocene compound intermediate.

[0250]

[0251] In a glove box, the above metallocene compound intermediate was placed in a mini parr, and 5 mol% of Pd / C (10 wt%) was added. A magnetic bar was inserted here and moved outside the glove box using a closing system. DCM (0.5 M) was added to this parr, and H2 gas (10 barg) was added. After repeating the vent-charge cycle three times, the mixture was placed in a 40°C oil bath and stirred. When the pressure of the parr decreased below 5 barg, the previous charging process was repeated, and the reaction was continued until there was no more consumption of H2 gas. When the reaction was complete, the remaining H2 gas was vented and replaced with Ar gas. After cooling to room temperature, the mixture was filtered using a cannula, and the filtrate was vacuum-dried. The dried filtrate was slurried using hexane, and this was filtered to obtain a solid transition metal compound (Cat 2-2).

[0252] 1 H NMR (500 MHz, CDCl3) δ 5.57 (s, 1H), 3.31 (t, J = 6.7 Hz, 2H), 2.95 - 2.85 (m, 2H), 2.37 - 2.28 (m, 2H), 2.18 - 2.03 (m, 2H), 2.02 (s, 15H), 1.96 - 1.88 (m, 1H), 1.82 - 1.77 (m, 1H), 1.75 (s, 3H), 1.71 - 1.55 (m, 3H), 1.53 - 1.36 (m, 4H), 1.36 - 1.20 (m, 3H), 1.18 (s, 9H).

[0253]

[0254] Synthesis Example 2-3

[0255] (Cat 2-3)

[0256] Preparation of ligands

[0257] Indene (1 eq) was dissolved in THF (0.3 M), n-BuLi (1.05 eq) was slowly added dropwise at -25°C, and the mixture was stirred at room temperature for 3 hours. Then, CH3-CH2-I (1.05 eq) was added at -10°C, stirred overnight at room temperature, worked up with water, and dried to obtain 3-Ethyl-Indene.

[0258]

[0259] Preparation of transition metal compounds

[0260] The above-mentioned ligand was dissolved in Ether (0.3 M), n-BuLi (1.05 eq) was added at -25°C, and stirred at room temperature for 3 hours. In a glove box, PMCpZrCl3 (Pentamethylcyclopentadienylzirconium trichloride) (1 eq) was prepared in another flask, added to the ligand-Li flask using a cannula at -25°C, and washed and added using Ether (1.0 M).

[0261] Upon completion of the reaction, the solvent was vacuum-dried, DCM was reintroduced, LiCl was removed through a filter, the filtrate was vacuum-dried, and slurry was formed using hexane. The resulting solid was then filtered and vacuum-dried to obtain a solid metallocene compound intermediate.

[0262] In a glove box, the above metallocene compound intermediate was placed in a mini parr, and 5 mol% of Pd / C (10 wt%) was added. A magnetic bar was inserted here and moved outside the glove box using a closing system. DCM (0.5 M) was added to this parr, and H2 gas (10 barg) was added. After repeating the vent-charge cycle three times, the mixture was placed in a 40°C oil bath and stirred. When the pressure of the parr decreased below 5 barg, the previous charging process was repeated, and the reaction was continued until there was no more consumption of H2 gas. When the reaction was complete, the remaining H2 gas was vented and replaced with Ar gas. After cooling to room temperature, the mixture was filtered using a cannula, and the filtrate was vacuum-dried. The dried filtrate was slurried using hexane, and this was filtered to obtain a solid transition metal compound (Cat 2-3).

[0263] 1 H NMR (500 MHz, CDCl3) δ 5.60 (d, J = 2.7 Hz, 2H), 5.20 (d, J = 2.7 Hz, 2H), 2.83 - 2.71 (m, 2H), 2.49 - 2.36 (m, 3H), 2.21 (dd, J = 15.1, 7.6 Hz, 1H), 2.01 (s, 15H), 1.98 - 1.80 (m, 2H), 1.66 - 1.51 (m, 2H), 1.03 (t, J = 7.6 Hz, 3H).

[0264]

[0265] Synthesis Example 3

[0266] (Cat 3)

[0267] A transition metal compound having the above structure was prepared using the same method as Manufacturing Example 2-3 of Korean Patent Publication No. 10-2016-0029718.

[0268]

[0269] Synthesis Example 4

[0270] (Cat 4)

[0271] A transition metal compound having the above structure was prepared according to the method disclosed in J. Am. Chem. Soc. 2004, VOL. 126, No. 46, pp.15231-15244.

[0272]

[0273] <Catalyst Manufacturing>

[0274] Manufacturing Example 1

[0275] 2.0 kg of toluene and 1000 g of silica (SP2410, Grace Davision) were charged into a 20L SUS high-pressure reactor, and the reactor temperature was raised to 40°C while stirring. 5.4 kg of methylaluminoxane (10 wt% in toluene, Albemarle) was charged into the reactor, the temperature was raised to 70°C, and the reactor was stirred at about 200 rpm for about 12 hours. Thereafter, the temperature of the reactor was lowered to 40°C, and stirring was stopped. The reaction product was allowed to stand for about 10 minutes and then decantated. 2.0 kg of toluene was again charged into the reaction product, stirred for about 10 minutes, stopped, and the reactor was allowed to stand for about 30 minutes before decantation.

[0276] 2.0 kg of toluene was charged into the reactor, and then the compound (Cat 1) (50 mmol) prepared in Synthesis Example 1 as the first transition metal compound, the compound (Cat 2-2) (10 mmol) prepared in Synthesis Example 2-2 as the second transition metal compound, and 1000 mL of toluene were charged. The temperature of the reactor was raised to 85°C, and stirring was performed for approximately 90 minutes.

[0277] Afterwards, the temperature of the reactor was lowered to room temperature, stirring was stopped, the reaction product was allowed to stand for about 30 minutes, and the reaction product was decantated. Next, 3 kg of hexane was added to the reactor, and the hexane slurry solution was transferred to a 20 L filter dryer, the solution was filtered, and dried under reduced pressure at 50 °C for about 4 hours to obtain 1.5 kg of a hybrid metallocene catalyst.

[0278] (Cat 1) (Cat 2-2)

[0279]

[0280]

[0281] Manufacturing Examples 2 to 3, Comparative Manufacturing Example 1

[0282] As described in Table 1 below, a hybrid supported metallocene catalyst was prepared in the same manner as in Preparation Example 1, except that the types of the first and second transition metal compounds were changed.

[0283]

[0284] Catalyst 1 Transition metal compound 2 Transition metal compound Mixing molar ratio Preparation example 1 Cat 1, 50 mmol Cat 2-2, 10 mmol 5:1 Preparation example 2 Cat 1, 20 mmol Cat 2-3, 10 mmol 2:1 Preparation example 3 Cat 1, 55 mmol Cat 2-1, 10 mmol 5.5:1 Comparative Preparation example 1 Cat 1, 40 mmol Cat 4, 10 mmol 4:1

[0285] <Manufacturing of polyethylene>

[0286] Examples 1-1 to 3-1 and Comparative Example 3-1

[0287] A 140 L continuous polymerizer capable of performing an isobutene slurry loop process with a polymerization reactor and operating at a reaction velocity of approximately 7 m / s was prepared. The reactants required for polyethylene polymerization were continuously fed into the reactor as described in Table 2. The catalysts used in each polymerization reaction were those prepared in the manufacturing examples described in Table 1, and the catalysts were mixed with the isobutene slurry and fed. Furthermore, the polymerization reaction was performed at a pressure of approximately 40 bar and a temperature of approximately 85°C, and other key conditions for the polymerization reaction are shown in Table 2 below.

[0288]

[0289] Comparative Example 1-1

[0290] LF100A, a copolymer of ethylene and 1-octene manufactured by LG Chem, was used.

[0291]

[0292] Comparative Example 2-1

[0293] XM3108, a copolymer of ethylene and 1-hexene manufactured by LG Chem, was used.

[0294]

[0295] Catalytic ethylene input (kg / hr)1-hexene input 1 (wt%) hydrogen input 2 (ppm)Activity (kgPE / kgSiO2·hr)Example 1-1 Manufacturing Example 12618385.2Example 2-1 Manufacturing Example 226.520406.0Example 3-1 Manufacturing Example 327.517387.0Comparative Example 3-1 Comparative Manufacturing Example 123.7754.1

[0296] In Table 2 above, the activity (Activity, kgPE / kgSiO2·hr) was calculated as the ratio of the polymer weight (kgPE) produced per the catalyst weight (kg) used per unit time (hr).

[0297] Also, the 1-hexene input amount (wt%) is calculated as a percentage of the 1-hexene input amount based on the total weight of monomers containing ethylene and 1-hexene, and the hydrogen input amount (ppm) is calculated as a percentage of the total weight of monomers containing ethylene and 1-hexene.

[0298]

[0299] Film Manufacturing

[0300] A film was manufactured using the polyethylene manufactured in the examples and comparative examples using the following method.

[0301]

[0302] Examples 1-2 to 3-2, Comparative Examples 1-2 to 3-2

[0303] Based on the total weight of the polyethylene manufactured in the above examples or comparative examples, 1200 ppm of an antioxidant (Songnox 1076 (Songwon): Songnox 1680 (Songwon) = 1:2 in weight ratio) was added and mixed, and a twin screw extruder (Twin screw extruder; TEK 30 MHS, manufactured by SMPLATECH CO., diameter 32 pi, L / D = 40) was used to extrude at an extrusion temperature of 190°C at an extrusion rate of 35 kg / hr, thereby manufacturing a composition for forming a pellet-shaped film weighing about 18 kg.

[0304] A film was manufactured by inflation molding the film-forming composition manufactured above under the following film extrusion conditions.

[0305]

[0306] <Film forming conditions>

[0307] Single Screw Extruder (Eugene Engineering Single Screw Extruder, Blown Film M / C, 50 pi, L / D=32)

[0308] Melting temperature (or extrusion temperature): 185℃

[0309] Die Gap: 2.0mm

[0310] Die diameter: 120mm

[0311] Blown-Up Ratio: 2.5

[0312] Maintain Frost Line Height at 200~250mm

[0313] Sample extrusion rate: 300~500g / min

[0314] Cooling: Uses dual air-ring

[0315] Film thickness: 50㎛

[0316]

[0317] Experimental Example 1

[0318] The physical properties of the polyethylene manufactured in the above examples and comparative examples were measured as follows, and the results are shown in Tables 3 and 5 below.

[0319]

[0320] (1) Melt Index (MI) 2.16 ): Measured according to ASTM D1238 (Condition E, 190 ℃, 2.16 kg load).

[0321]

[0322] (2) Density: Measured according to ASTM D1505 standard.

[0323]

[0324] (3) Molecular weight distribution (MWD)

[0325] For the polyethylene according to the above examples and comparative examples, the weight average molecular weight (Mw, g / mol) and number average molecular weight (Mn, g / mol) were measured through gel permeation chromatography (GPC) analysis, and the molecular weight distribution (MWD, Mw / Mn) was obtained by dividing the weight average molecular weight measured above by the number average molecular weight.

[0326] Specifically, the gel permeation chromatography (GPC) device is Polymer Char GPC-IR. ®The device was used, and a Polymer Laboratories PLgel MIX-B 300 mm long column was used. The measurement temperature was 160°C, 1,2,4-trichlorobenzene was used as a solvent, and the flow rate was 1 mL / min. Each sample of polyethylene manufactured in the examples and comparative examples was analyzed by GPC analysis equipment (Polymer Char GPC-IR). ® ) was dissolved in 1,2,4-trichlorobenzene containing 0.03% BHT at 160℃ for 2 hours, pretreated, and then prepared at a concentration of 16 mg / 8 mL and supplied in an amount of 200 μL. The values ​​of Mw and Mn were calculated using a calibration curve formed using polystyrene standard specimens. The weight-average molecular weights of the polystyrene standard specimens were 9 types: 2000 g / mol, 10000 g / mol, 30000 g / mol, 70000 g / mol, 200000 g / mol, 700000 g / mol, 2000000 g / mol, 4000000 g / mol, and 10000000 g / mol.

[0327]

[0328] (4) DSC analysis

[0329] Analysis was performed using a differential scanning calorimeter (DSC) with reference to ASTM D 3418.

[0330] More specifically, as a differential scanning calorimeter (DSC), the polyethylene of the above examples and comparative examples was measured by using Q20 V24.11 (manufactured by TA instrument) to determine the first order transition (1 stFor heating, a preliminary thermal cycle was performed and recorded by heating the sample from 50 to 190°C at a rate of 10°C / min under an inert purge gas (N2) atmosphere. After heating, it was maintained for 10 min, cooled to -50°C at a rate of 10°C / min, and the cooling curve was recorded. The heating was repeated at a rate of 10°C / min under an inert purge gas as quickly as possible, and the heating curve was recorded. Typically, Tm is measured at the second temperature rise section, and Tc is measured on the cooling curve obtained after cooling after the first transition.

[0331] For the purposes of the present invention, a general Tm is 2 nd It is measured from the heating curve, but to see the sealing characteristics in more detail, 1 with the previous thermal history remaining st The distribution of the crystals was confirmed through the heating curve.

[0332] The DSC curve derived from these analysis results was deconvoluted according to the Gaussian-Lorentzian method using the peak analyzer of the OriginPro 2024 program (see P.Yu, Spectroscopy 20(2006), 229-251).

[0333] The DSC deconvolution curve of Example 1 is shown in FIG. 1, the DSC deconvolution curve of Example 2 is shown in FIG. 2, the DSC deconvolution curve of Example 3 is shown in FIG. 3, the DSC deconvolution curve of Comparative Example 1 is shown in FIG. 4, the DSC deconvolution curve of Comparative Example 2 is shown in FIG. 5, and the DSC deconvolution curve of Comparative Example 6 is shown in FIG. 6.

[0334] In each of Figures 1 to 6, the upper graph is an endothermic curve graph, and the lower graph is an exothermic curve graph.

[0335] Also, in the endothermic / exothermic deconvolution curve graph of each graph, the deconvolution curves indicated by the arrows are each T m,1st This is a curve measuring Tc, and the table on the right shows the area and peak temperature of each endothermic / exothermic deconvolution curve.

[0336]

[0337] (5) Analysis of crystal distribution and molecular weight distribution

[0338] Cross fraction chromatography (CFC) analysis was performed on the polyethylene manufactured in the above examples and comparative examples using the following method.

[0339]

[0340] [Cross-fractionation chromatography measurement conditions (including TREF and GPC analysis)]

[0341] - Analysis equipment: Polymer Char CFC - 7890B (G3440D)

[0342] (Detector: Integrated Detector IR5 MCT)

[0343] - Sample preparation and loading: 32 mg of polyethylene manufactured in the above examples or comparative examples was placed in a 10 mL vial and placed in an autosampler, 8 mL of 1,2,4-trichlorobenzene (TCB) was added, dissolved at 160°C for 90 minutes, and stabilized at 140°C for 20 minutes. After nitrogen purge, extraction was performed and loaded onto a temperature rising elution fractionation column (TREF column).

[0344] - Crystallization: The temperature of the sample previously loaded onto the TREF column was adjusted to 140℃, then cooled from 140℃ to 35℃ at a rate of 0.5℃ / min and maintained for 15 minutes.

[0345] The detailed conditions for the above stabilization and crystallization are as follows:

[0346]

[0347]

[0348] - Temperature Rising Elution Fractionation (TREF) Analysis: The previously crystallized sample was heated from 30°C to 120°C at a rate of 1°C / min to the fraction temperature shown below, then fixed. The concentrations of the fractions eluted at that temperature for 5 minutes were measured. A TREF analysis graph was derived from the concentration measurement results.

[0349] From the TREF graph, the content ratio of the polymer fraction eluted in the region of the elution temperature 80°C or higher (Te≥80°C) was calculated (weight%) based on the total weight of the entire eluted fraction.

[0350] <fraction temperature>

[0351] 30℃ / 35℃ / 40℃ / 43℃ / 46℃ / 49℃ / 52℃ / 55℃ / 58℃ / 61℃ / 64℃ / 67℃ / 70℃ / 73℃ / 76℃ / 79℃ / 82℃ / 85℃ / 88℃ / 91℃ / 94℃ / 97℃ / 100℃ / 105℃ / 120℃

[0352]

[0353] <Measurement conditions>

[0354]

[0355]

[0356] - GPC analysis: The fractions eluted for each temperature range in the previous TREF analysis were analyzed by GPC equipment (Polymer Char GPC-IR) ® ) After moving to the GPC column provided, GPC analysis was performed according to the following conditions.

[0357]

[0358] <Sample Preparation>

[0359] The polyethylene fraction is pretreated by dissolving it in 1,2,4-trichlorobenzene at 160°C for 10 hours, and then prepared at a concentration of 10 mg / 10 mL, and supplied in an amount of 200 μL.

[0360] <GPC 분석 조건>

[0361] GPC Device: Polymer Char GPC-IR ®

[0362] GPC Column: Polymer Laboratories PLgel MIX-B 300 mm long column

[0363] Measurement temperature: 160℃

[0364] Solvent: 1,2,4-Trichlorobenzene

[0365] Flow rate: 1 mL / min

[0366] Standard specimen: Polystyrene standard specimen

[0367] (Weight average molecular weight of polystyrene standard specimens: 9 types: 2000 g / mol, 10000 g / mol, 30000 g / mol, 70000 g / mol, 200000 g / mol, 700000 g / mol, 2000000 g / mol, 4000000 g / mol, 10000000 g / mol)

[0368]

[0369] <Measurement conditions>

[0370]

[0371]

[0372] Experimental Example 2

[0373] The physical properties of the films manufactured in the examples and comparative examples were measured as follows, and the results are shown in Tables 4 and 6 below.

[0374]

[0375] (1) Dart drop impact strength

[0376] For the films of the examples and comparative examples manufactured above, the drop impact strength was measured according to the ASTM D1709 [Method A] standard, and the average value was taken by measuring at least 5 sets (20 times / 1 set) per film sample.

[0377]

[0378] (2) Hot-tack strength (N / 25.4mm)

[0379] According to ASTM F 1921, when the tack strength was measured at each temperature at 5℃ intervals between 60℃ and 130℃ using a J&B Hot tack tester (Hot tacker 5000) under the conditions of a sealing time of 0.5 seconds, a sealing pressure of 0.3 MPa, a delay time of 0.1 seconds, and a tensile speed of 200 mm / sec, the highest strength measured was taken as the hot-tack strength (N / 25.4 mm).

[0380]

[0381] (3) Secant modulus

[0382] For the films of the above examples and comparative examples, the 1% secant modulus in the machine direction (MD) and transverse direction (TD) of the films was measured according to ASTM D882 using an Instron UTM (Universal Testing Machine).

[0383]

[0384] Example 1-1 Example 2-1 Example 3-1 MI (g / 10 min) 1.387 1.59 1.31 Density (g / cm3) 0.9169 0.9163 0.9184 Comonomer 1-hexene 1-hexene 1-hexene MWD 3.76 4.16 4.24 T m,1st (℃)1 24.1124.8123.7Tc (℃)105.2104.5106.6T m,1st - Tc (℃)18.820.317.1Wpeak≥80℃ (%)61.6076.2150.51Crystal propertiesTe ≥ 80℃(wt%)36.134.4536.68Mw Te≥80℃ (g / mol)268,000121,207131,809T m,1st Deconvolution curve integral area (%) 6.7610.2210.94 X value: ln(Mw Te≥80℃ )+ln(T m,1st - Tc)-ln(W peak≥80℃ )11.3110.3810.71hot-tack strength (unit: N / 25.4mm)4.153.033.49Y value: ln(hot-tack strength)1.421.111.25

[0385] Example 1-2 Example 2-2 Example 3-2 Drop impact strength (gf) 972 1, 700 1, 400 1% Secant, MD (kg / cm 2 )1,7461,8751,6821% Secant, TD (kg / cm 2 )2,1192,0512,050

[0386] Comparative Example 1-1 Comparative Example 2-1 Comparative Example 3-1 MI (g / 10 min) 1.2 0.95 0.67 Density (g / cm3) 0.90 20.91 78 0.92 66 Comonomer 1-octene 1-hexene 1-hexene MWD 2.4 13.0 8 4.34 T m,1st (℃)101.4122.3124.2Tc (℃)84.2105.6110.1T m,1st - Tc (℃)17.216.714.1W peak≥80℃ (%)59.8266.1776.37Crystal propertiesTe ≥ 80℃(wt%)0.341.8150.1Mw Te≥80℃ (g / mol)12,82537,57651,079T m,1st Deconvolution curve integral area (%) 34.6410.697.76 X value: ln(Mw Te≥80℃ )+ln(T m,1st - Tc)-ln(W peak≥80℃)8.219.169.15hot-tack strength (unit: N / 25.4mm)2.892.82.14Y value: ln(hot-tack strength)1.061.030.76

[0387] Comparative Example 1-2 Comparative Example 2-2 Comparative Example 3-2 Drop impact strength (gf) 1,900 1,900 448 1% Secant, MD (kg / cm 2 )6391,6602,9781% Secant, TD (kg / cm 2 )6871,8203,624

[0388] Referring to Tables 3 to 6, it was confirmed that the polyethylene of Examples 1 to 3 of the present invention exhibited a recrystallization factor (X value) reflecting high-temperature crystallization tendency, molecular chain entanglement, and crystallization speed above a certain standard, thereby exhibiting improved hot tack strength.

Claims

1. Satisfies the following equation 1, Polyethylene, where the value of x in the following equation 1 is 9.17 or greater: [Formula 1] 0.3309 * x - 3.014 ≤ y ≤ 0.3309 * x - 1.614 In the above equation 1, y is ln(hot-tack strength), where hot-tack strength is the hot-tack strength (unit: N / 25.4 mm) measured according to ASTM F 1921, x is ln(Mw Te≥80℃ )+ln(T m,1st - Tc)-ln(W peak≥80℃ ) and, At this time Mw Te≥80℃ is the weight average molecular weight (unit: g / mol) of the polymer fraction eluted at an elution temperature of 80℃ or higher based on the total weight of polyethylene during temperature rising elution fractionation (TREF) of cross-fractionation chromatography (CFC). T m,1st When the first heating curve of polyethylene DSC (Differential Scanning Calorimeter) graph is deconvoluted, it is the temperature (unit: ℃) of the highest endothermic peak among the deconvolution peaks. Tc is the temperature (unit: ℃) of the highest exothermic peak when the DSC graph of polyethylene is deconvoluted. W peak≥80℃ When the DSC graph of polyethylene is deconvoluted, it is the sum (unit: %) of the integral area of ​​the deconvolution curves with an exothermic peak temperature of 80℃ or higher relative to the total sum of the areas of the entire deconvolution curves.

2. In paragraph 1, Polyethylene, wherein the value of x in the above formula 1 is 10 or more.

3. In paragraph 1, In x of the above equation 1, T m,1st Polyethylene having a difference between Tc and Tc of 15 to 25°C.

4. In paragraph 1, In x of the above equation 1, T m,1st This is over 120℃, Polyethylene.

5. In paragraph 1, In x of the above equation 1, Mw Te≥80℃ is 65,000 g / mol or more, Polyethylene.

6. In paragraph 1, In x of the above equation 1, W peak≥80℃ Polyethylene, which is more than 50%.

7. In paragraph 1, Polyethylene, wherein the content of a polymer fraction (Te ≥80°C) eluted at an elution temperature of 80°C or higher is 10 to 50 wt% based on the total weight of polyethylene during temperature rising elution fractionation (TREF) analysis of cross-fraction chromatography (CFC).

8. In paragraph 1, When the first heating curve DSC graph of the above polyethylene was deconvoluted, the highest endothermic peak (T) among the deconvolution peaks m,1st ) of the integral area of ​​the deconvolution curve representing the polyethylene, which is 5 to 30% of the total area of ​​the entire deconvolution curve.

9. In paragraph 1, A density of 0.900 to 0.925 g / cm as measured according to ASTM D1505. 3 person, Polyethylene.

10. In paragraph 1, Polyethylene having a molecular weight distribution (MWD) of 2.0 to 5.

0.

11. In paragraph 1, The above polyethylene is a polyethylene having a melting index of 0.5 to 5.0 g / 10 min, measured at a temperature of 190°C and a load of 2.16 kg according to ASTM D1238.

12. In paragraph 1, The above polyethylene is a type of copolymer of ethylene and alpha olefin.

13. In paragraph 11, The above alpha olefin is 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, or 1-octene, Polyethylene.

14. A film containing polyethylene according to paragraph 1.

15. In paragraph 14, A hot-tack strength of 3 N / 25.4 mm or more as measured according to ASTM F 1921, film.

16. In paragraph 14, When the film thickness is 45 to 55 ㎛, the drop impact strength measured according to ASTM D 1709 is 900 gf or more. film.

17. In paragraph 14, When the film thickness is 45 to 55 ㎛, the 1% secant modulus in the MD direction measured according to ASTM D882 is 1,500 kg / cm 2 And the 1% secant modulus in the TD direction is 1,800 kg / cm 2 Lee Sang-in, film.

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