Ethylene-based polymers, articles made therefrom, and methods of making same

Abstract

The present disclosure relates to ethylene-based polymers, articles made therefrom, and methods of making the same. The ethylene-based polymer may include polymer units derived from ethylene and polymer units derived from one or more C3-C18 alpha-olefin monomers. The ethylene-based polymer may have a melt index (I2) from 0.1 g / 10 min to 10 g / 10 min, a density from 0.890 g / cm < 3 > to 0.910 g / cm < 3 >, a CDBI from 60% to 80%, a number average molecular weight from 25,000 g / mol to 53,000 g / mol, and an intrinsic viscosity from 1.3 dL / g to 1.9 dL / g. In some embodiments, the ethylene-based polymer may also have one or more of the following properties: a compositional distribution width T75-T25 value of 16.5 DEG C to 21 DEG C as determined by TREF, a complex viscosity of 5, 700 Pa.s to 8, 700 Pa.s as determined at a shear rate of 10 rad / s, and a complex viscosity of 11, 100 Pa.s to 14, 100 Pa.s as determined at a shear rate of 0.1 rad / s.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 366,426, filed on June 15, 2022, entitled “ETHYLENE-BASED POLYMERS, ARTICLES MADE THEREFROM, AND METHODS OF MAKING THE SAME,” the entire contents of which are incorporated herein by reference.

[0003] field

[0004] The present disclosure relates to ethylene-based polymers, articles made therefrom, and methods of making the same.

[0005] background

[0006] Polymer films are suitable for many applications. Historically, such films have been made from blends of various materials, particularly blends including propylene-based polymers. The strength and success of polypropylene films is attributed to their excellent processability (broad stretch temperature profile, slow crystallization), good overall properties, attractive cost (high production speeds), and good yield (low density).

[0007] Recently, however, there has been increasing interest in developing simplified film solutions utilizing polyethylene, preferably with substantially no polymers other than polyethylene or polyethylene-based polymers present in the film layers (meaning that, for each polymer used in the film, the majority (e.g., 75% or more or 90% or more) of the polymers used in the film are polyethylene or polyethylene-based copolymers). However, polyethylene tends to be more crystalline than polypropylene, which makes it more difficult to down-gauge and maintain the proper balance of stiffness and toughness properties.

[0008] Therefore, there is a need for improved ethylene-based polymers and articles made therefrom. The present disclosure satisfies this need and others.

[0009] Overview

[0010] The present disclosure provides ethylene-based polymers, articles made therefrom, and methods of making the same. In some embodiments, the ethylene-based polymer may include about 90 mol% to about 99 mol% of polymer units derived from ethylene and about 1 mol% to about 10 mol% of polymer units derived from one or more C 3 -C 18 The ethylene-based polymer may have a melt index (I) of about 0.1 g / 10 min to about 10 g / 10 min. 2 , 190℃), about 0.890g / cm 3 -About 0.910g / cm 3The ethylene-based polymer may further have one or more of the following properties: a composition distribution width T of at least 16.5°C to 21°C as measured by TREF; ... 75 -T 25 Values, a complex viscosity of at least 5,700 Pa·s to about 8,700 Pa·s measured at a shear rate of 10 rad / s, and a complex viscosity of at least 11,100 Pa·s to about 14,100 Pa·s measured at a shear rate of 0.1 rad / s.

[0011] In some embodiments, a method of preparing an ethylene-based polymer may include reacting ethylene and one or more C 3 -C 18 An α-olefin monomer is introduced into a reactor and the ethylene and the at least one other comonomer are polymerized in the reactor at a temperature of about 50° C. to about 110° C. and a pressure of about 750 kPa absolute to about 7,000 kPa absolute to produce the ethylene-based polymer. The ethylene-based polymer may include about 90 mol % to about 99 mol % of polymer units derived from ethylene and about 1 mol % to about 10 mol % of polymer units derived from one or more C 3 -C 18 The ethylene-based polymer may have a melt index (I) of about 0.1 g / 10 min to about 10 g / 10 min. 2 , 190℃), about 0.890g / cm 3 -About 0.910g / cm 3 The ethylene-based polymer may have a density of about 100%, a composition distribution width index of about 60% to about 80%, a number average molecular weight of about 25,000 g / mol to about 53,000 g / mol, and an intrinsic viscosity of about 1.3 dL / g to about 1.9 dL / g. In some embodiments, the ethylene-based polymer may also have one or more of the following properties: a composition distribution width T of at least 16.5°C to 21°C as measured by TREF; 75 -T 25 Values, a complex viscosity of at least 5,700 Pa·s to about 8,700 Pa·s measured at a shear rate of 10 rad / s, and a complex viscosity of at least 11,100 Pa·s to about 14,100 Pa·s measured at a shear rate of 0.1 rad / s.

[0012] Detailed Description

[0013] As used herein, the indefinite article "a" or "an" shall mean "at least one", unless otherwise specified or the context clearly indicates otherwise. Thus, embodiments using "an α-olefin" include embodiments in which one, two or more α-olefins are used, unless otherwise specified or the context clearly indicates that only one α-olefin is used.

[0014] Unless otherwise indicated, all numerical values ​​indicating quantities in this disclosure are to be understood in all cases as being modified by the term "about". It should also be understood that the precise numerical values ​​used in this specification and claims constitute specific embodiments. Efforts have been made to ensure the accuracy of the data in the examples. However, it should be understood that any measured data inherently contain a certain level of error due to the limitations of the techniques and / or equipment used to make the measurements.

[0015] As used herein, "wt%" means percent by weight, "vol%" means percent by volume, "mol%" means mole percent, "ppm" means parts per million, and "ppmwt" and "wppm" are used interchangeably to refer to parts per million by weight. Unless otherwise indicated, all concentrations herein are expressed on a total weight basis of the composition in question.

[0016] "Olefins" (or "alkenes") are linear, branched or cyclic compounds of carbon and hydrogen having at least one double bond. For purposes of this specification and the appended claims, when a polymer or copolymer is referred to as comprising olefins, the olefins present in such polymer or copolymer are the polymerized form of the olefins. For example, when a copolymer is said to have an "ethylene" content of 50 wt% to 55 wt%, it is understood that the mer units in the copolymer are derived from ethylene in the polymerization reaction and the derived units are present in an amount of 50 wt% to 55 wt%, based on the weight of the copolymer.

[0017] "Polymer" has two or more identical or different repeating units / mer units (or simply units). "Homopolymer" is a polymer with identical units. "Copolymer" is a polymer with two or more units that are different from each other. "Terpolymer" is a polymer with three units that are different from each other. The term "different" when used to refer to units means that the units differ from each other by at least one atom or are different isomers. The definition of copolymer used herein includes terpolymers, etc. Similarly, the definition of polymer used herein includes homopolymers, copolymers, etc. Moreover, the terms "ethylene-based polymer", "polyethylene copolymer", "polyethylene", "ethylene polymer" and "ethylene copolymer" are used interchangeably to refer to copolymers of polymer units derived from ethylene including at least 50 mol% of polymer units derived from ethylene, such as 90 mol%-99 mol%.

[0018] The term "alpha olefin" or "α-olefin" refers to an olefin having a terminal carbon-carbon double bond in its structure. 1 R 2 C=CH 2 , where R 1 and R 2 can be independently hydrogen or any hydrocarbon group; for example, R 1 is hydrogen and R 2 A "linear alpha-olefin" is one in which R 1 is hydrogen and R 2 It is hydrogen or a linear alkyl alpha-olefin.

[0019] The nomenclature of elements and their groups used herein follows the periodic table used by the International Union of Pure and Applied Chemistry after 1988. An example of a periodic table is shown on the inside cover of Advanced Inorganic Chemistry, 6th edition, edited by F. Albert Cotton et al. (John Wiley & Sons, Inc., 1999).

[0020] Ethylene-based polymers

[0021] Composition, density, molecular weight

[0022] The ethylene-based polymer disclosed herein refers to a polyethylene copolymer, which may include 90 mol%, 91 mol%, 92 mol%, 93 mol%, or 94 mol% to 95 mol%, 96 mol%, 97 mol%, 98 mol%, or 99 mol% of polymer units derived from ethylene and about 1 mol%, 2 mol%, 3 mol%, 4 mol%, or 5 mol% to 6 mol%, 7 mol%, 8 mol%, 9 mol%, or 10 mol% of polymer units derived from one or more C 3-C 18 α-olefin comonomers, preferably one or more C 3 -C 10 α-olefins, more preferably one or more C 4 -C 8 Polymer units of alpha-olefins. The alpha-olefin comonomers may be linear or branched, and two or more comonomers may be used if desired. Examples of suitable comonomers may be or may include, but are not limited to, propylene; 1-butene; 1-pentene; 1-pentene with one or more methyl, ethyl or propyl substituents; 1-hexene; 1-hexene with one or more methyl, ethyl or propyl substituents; 1-heptene; 1-heptene with one or more methyl, ethyl or propyl substituents; 1-octene; 1-octene with one or more methyl, ethyl or propyl substituents; 1-nonene; 1-nonene with one or more methyl, ethyl or propyl substituents; 1-decene substituted with ethyl, methyl or dimethyl; 1-dodecene; and styrene. In some embodiments, particularly suitable comonomers may be or may include 1-butene, 1-hexene and 1-octene.

[0023] The ethylene mole percentage and the comonomer mole percentage can be used 13 C NMR determination. More specifically, 13 CNMR samples can be dissolved in deuterated 1,1,2,2-tetrachloroethane (TCE-D2) at a concentration of 67 mg / mL at 140°C. Spectra can be recorded at 120°C using a Bruker NMR spectrometer of at least 600 MHz and a 10 mm cryogenic probe. Measurements can be made using 90° pulses, 10 second delay, 512 transients, and gated decoupling. 13 C NMR. The polymer resonance peaks can be referenced to the polyethylene major peak at 29.98 ppm. The calculations involved in characterizing the polymers by NMR follow the work published by J. Randall in "Polymer Sequence Determination, 13C-NMR Method", Academic Press, New York, 1977.

[0024] In some embodiments, the ethylene-based polymer may have a 3 、0.880g / cm 3 、0.890g / cm 3 , 0.900g / cm 3 , 0.903g / cm 3 or 0.905 g / cm 3 To 0.907g / cm 3 , 0.908g / cm3 , 0.909g / cm 3 、0.910g / cm 3 , 0.912g / cm 3 , 0.914g / cm 3 , 0.916g / cm 3 , 0.918 or 0.920 g / cm 3 In other embodiments, the ethylene-based polymer may have a density of 0.900 g / cm 3 -0.910g / cm 3 , 0.903g / cm 3 -0.908g / cm 3 , 0.904g / cm 3 -0.906g / cm 3 , or 0.904 g / cm 3 -9.905g / cm 3 The density of the ethylene-based polymer can be determined according to ASTM D1505-18 column density, wherein the sample is molded according to ASTM D-4703-16 Procedure C and then conditioned at ASTM D-618-21 (23° C. + / - 2° C. and 50 + / - 10% relative humidity) for 40 hours before testing.

[0025] In some embodiments, the ethylene-based polymer can have a number average molecular weight (Mn) from 20,000 g / mol, 23,000 g / mol, 25,000 g / mol, 27,000 g / mol, 30,000 g / mol, 33,000 g / mol, or 35,000 g / mol to 37,000 g / mol, 40,000 g / mol, 42,000 g / mol, 45,000 g / mol, 50,000 g / mol, 53,000 g / mol, or 55,000 g / mol. In other embodiments, the ethylene-based polymer may have a number average molecular weight of 42,000 g / mol to 55,000 g / mol, 44,000 g / mol to 53,000 g / mol, 46,000 g / mol to 51,000 g / mol, or 47,000 g / mol to 50,000 g / mol. In other embodiments, the ethylene-based polymer may have a number average molecular weight of greater than 42,000 g / mol, greater than 43,000 g / mol, greater than 44,000 g / mol, or greater than 45,000 g / mol to 49,000 g / mol, 50,000 g / mol, 51,000 g / mol, 52,000 g / mol, or 53,000 g / mol.

[0026] In some embodiments, the ethylene-based polymer may have a weight average molecular weight (Mw) ranging from 90,000 g / mol, 100,000 g / mol, 110,000 g / mol, or 115,000 g / mol to 125,000 g / mol, 130,000 g / mol, 135,000 g / mol, or 140,000 g / mol. In other embodiments, the ethylene-based polymer may have a weight average molecular weight of greater than 100,000 g / mol, greater than 110,000 g / mol, greater than 115,000 g / mol, greater than 117,000 g / mol, or greater than 119,000 g / mol to 130,000 g / mol, 135,000 g / mol, or 140,000 g / mol.

[0027] In some embodiments, the ethylene-based polymer may have a z-average molecular weight (Mz) in the range of 180,000 g / mol, 190,000 g / mol, or 200,000 g / mol to 220,000 g / mol, 230,000 g / mol, or 240,000 g / mol. In other embodiments, the ethylene-based polymer may have a weight average molecular weight of greater than 200,000 g / mol, greater than 205,000 g / mol, or greater than 207,000 g / mol to less than 240,000 g / mol, less than 230,000 g / mol, less than 220,000 g / mol, or less than 215,000 g / mol.

[0028] In some embodiments, the ethylene-based polymers may have Mw / Mn values ​​ranging from 2.0, 2.1, 2.2, 2.3, or 2.4 to 2.5, 2.6, 2.7, 2.8, 2.9, or 3.0. In some embodiments, the ethylene-based polymers may have Mz / Mw values ​​ranging from 1.3, 1.4, 1.5, 1.6, or 1.7 to 1.8, 1.9, 2.0, or 2.1. In some embodiments, the ethylene-based polymers may have Mz / Mn values ​​ranging from 3.9, 4.0, 4.1, 4.2, or 4.3 to 4.4, 4.5, 4.6, 4.7, or 4.8.

[0029] For the ethylene-based polymers described herein, molecular weight distribution and moments (Mw, Mn, Mz, Mw / Mn, Mz / Mn, etc.) and monomer / comonomer content (C ) were determined by using high temperature gel permeation chromatography (Polymer CharGPC-IR) equipped with a multi-channel bandpass filter based infrared detector IR5, an 18-angle light scattering detector and a viscometer. 2 , C 4 , C 6 and / or C 8 and / or other monomers, etc.) and branching index (g'). Three Agilent PLgel 10μm Mixed-B LS columns were used to provide polymer separation. PCT Publication No. WO2019 / 246069A1, paragraphs

[0044] -

[0051] , describe the detailed analytical principles and methods for molecular weight determination and g'(vis) (note that the formula c= / / / for the concentration (c) at each point in the chromatogram cited in paragraph

[0044] is c=βI, where β is a mass constant and I is the IR5 broadband signal intensity (I) minus the baseline). Unless otherwise noted, all molecular weight moments used or referred to in this disclosure are determined according to conventional molecular weight (IR molecular weight) determination methods (e.g., as described in paragraphs

[0044] -

[0045] of the publication just mentioned), noting that for the formula in paragraph

[0044] , a=0.695 and K=0.000579 (1-0.75 Wt) are used, where Wt is the weight fraction of the comonomer, and further noting that the comonomer composition is composed of the corresponding CH 2 and CH 3 The ratio of the IR5 detector intensities of the 100 channels is determined by calibration with a series of PE and PP homopolymer / copolymer standards whose nominal values ​​are pre-determined by NMR or FTIR (providing the number of methyl groups (CH 3 / 1000TC)), as described in paragraph

[0045] of the PCT publication just mentioned). The other parameters required can be found in the reference paragraphs in the publication WO2019 / 246069A1, but some parameters are included here for convenience: n = 1.500 for TCB at 145°C; I = 665nm; dn / dc = 0.1048ml / mg.

[0030] Composition distribution and crystallinity

[0031] Composition distribution (or comonomer distribution) refers to the distribution of comonomers or short chain branches (SCB) in polymer chains of different lengths (different molecular weights). The ethylene-based polymers of the present disclosure exhibit a relatively constant or uniform distribution of comonomers along chains of different lengths, but show some variation.

[0032] For example, the ethylene-based polymer can have a composition distribution breadth index (CDBI) in the range of from any lower limit of 50%, 55%, 60%, 65%, 70%, 73%, or 74% to any upper limit of 75%, 76%, 77%, 80%, 85%, 90%, or 95%, wherein ranges from any of the foregoing lower limits to any of the foregoing upper limits are contemplated (e.g., 60%-80%, 65%-80%, 70%-80%, 73%-77%, or 74%-76% CDBI). CDBI is defined as the weight percent of copolymer molecules having a comonomer content within 50% of the median total molar comonomer content (i.e., within + / - 25% of the median), and is referred to, for example, in U.S. Pat. No. 5,382,630. In general, a broader distribution of copolymers (meaning a greater difference between (i) comonomer incorporation on high molecular weight polymer chains and (ii) comonomer incorporation on low molecular weight polymer chains) results in a lower CDBI, whereas a theoretical copolymer having exactly the same relative comonomer content on all polymer chains of different lengths within + / - 25% of the average length (average molecular weight) would have a CDBI of 100%. The CDBI of a copolymer can be readily determined using techniques for separating the individual fractions of a sample of the copolymer. One such technique is to generate a solubility distribution curve using temperature rising elution fractionation (TREF), as described in WO 1993003093 (which in turn cites Wild et al., J. Poly. Sci., Poly. Phys. Ed., vol. 20, p. 441 (1982) and U.S. Pat. No. 5,008,204 (in this regard)). All three of the above publications are incorporated herein by reference.

[0033] A solubility distribution curve for the copolymer can first be generated using data obtained from the TREF technique (as described, for example, in the publication just cited). The solubility distribution curve is a plot of the weight fraction of the copolymer dissolved versus temperature. This can be converted into a curve of weight fraction versus composition distribution. To simplify the correlation of composition to elution temperature, weight fractions less than 15,000 can be ignored. These low weight fractions generally account for only a very small portion of the ethylene-based polymers disclosed herein.

[0034] Alternatively or additionally, the composition or comonomer distribution may be referred to as T 75 -T 25 The value is understood as T 25 is the temperature at which 25% of the eluted polymer is obtained, and T 75is the temperature at which 75% of the eluted polymer is obtained, both of which are obtained in a TREF experiment (and a plot of weight percent eluted polymer versus elution temperature), as described in US2019 / 0119413 (particularly paragraphs

[0055] -

[0058] therein, which description is incorporated herein by reference). A narrow distribution is caused by a relatively small T 75 -T 25 The broad distribution is indicated by the relatively large T 75 -T 25 The difference in values ​​(especially in combination with a smaller CDBI value) indicates that there is a large difference in crystallinity between the fractions of the polymer composition. It is also noted that if there is a difference between the actual TREF procedure described in US2019 / 0119413 and the TREF procedure described in WO1993003093, US5,382,630 and / or US5,008,204, the TREF procedure described in US2019 / 0119413 should be used. It is also noted that the curves generated according to the TREF procedure - the solubility distribution curve used to obtain CDBI and the solubility distribution curve used to obtain T 75 -T 25 The relationship between the elution weight percentage and elution temperature is shown in their generation and CDBI and T 75 -T 25 Finally, with T 75 -T 25 The resulting TREF curve (eluted polymer weight percent versus elution temperature curve) from the measurement correlation can be further processed as follows:

[0035] 1. A solvent-only response of the instrument can be generated and subtracted from the TREF curve of the sample. The solvent-only response can be generated by running (usually before) the same method as the polymer sample, but without adding any polymer to the sample bottle; using the same solvent reservoir as the polymer sample, without replenishing fresh solvent; and in a time that is reasonably close to the polymer sample run time.

[0036] 2. The temperature axis of the TREF curve can be appropriately shifted to correct for the delay in the IR signal caused by the volume from the column to the detector. This volume can be obtained by first filling the injection valve loop with about 1 mg / ml HDPE resin solution; then loading the loop volume into the column at the same location as the sample for TREF analysis; then using an isothermal method to flow the hot solution directly to the detector at a constant flow rate of 1 ml / min; and then measuring the time after injection when the HDPE probe peak appears in the IR signal. Therefore, the delay volume (ml) is equal to the time (min).

[0037] 3. The curve can be baseline corrected and appropriate integration limits can be selected. The curve can also be normalized so that the curve area is 100 wt%.

[0038] In particular, the ethylene-based polymer may have a T in a range from any lower limit of 16.5°C, 17°C, 17.5°C, 18°C, 18.5°C or 19°C to any upper limit of 19.5°C, 20°C, 20.5°C or 21°C. 75 -T 25 Values, ranges from any aforementioned lower limit to any aforementioned upper limit are contemplated herein, and ranges greater than or less than any aforementioned endpoint values ​​are also contemplated herein (e.g., greater than 16.5°C, greater than 16.7°C, greater than 16.9°C, or greater than 17°C to less than 21°C, less than 20.5°C, less than 20°C, less than 19.5°C, or less than 19°C).

[0039] Similarly, the known cryogenic cross fractionation (cryo CFC) aliquot analysis technique can be used to determine T W1 , T W2 、Mw 1 and Mw 2 Value. The cryo CFC method and the determination of Tw1, Tw2, Mw1, and Mw2 are described in U.S. Patent Application Publication No. US2022 / 0048016 (paragraphs 622-634 and Figures 2-3 therein), which is incorporated herein by reference. To summarize the publication, Twl and Tw2 represent: the average temperature at which the first half of the polymer is eluted (Twl) and the average temperature at which the second half is eluted (Tw2) during the CFC experiment, noting that a higher elution temperature implies a greater degree of crystallinity; therefore, the temperatures Twl and Tw2 can be used to infer the presence of two distinct crystalline fractions, and the difference between them can be used to infer the difference in crystallinity between these fractions. Mwl and Mw2 represent the average weight-average molecular weights of the first fraction (Mwl) and the second fraction (Mw2) of the eluted polymer, which can be used to infer the relative amounts of low-crystalline fractions and high-crystalline fractions in the polymer.

[0040] In some embodiments, the ethylene-based polymer may have a T of 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C to 57°C, 58°C, 59°C, 60°C, or 61°C. W1 In some embodiments, the ethylene-based polymer may have a T of 74°C, 75°C, 76°C, 77°C, or 78°C to 79°C, 80°C, 81°C, 82°C, or 83°C. W2In some embodiments, the ethylene-based polymer may have a Tw of -7°C, -9°C, -11°C, -13°C, -15°C, or -17°C to -19°C, -21°C, -22°C, -23°C, -24°C, or -25°C. 1 -Tw 2 In some embodiments, the Tw 1 -Tw 2 The value may be less than -21.5°C, less than -21.7°C or less than -22°C and greater than -23°C, greater than -22.7°C or greater than -22.5°C.

[0041] In some embodiments, the ethylene-based polymer may have an M of 160,000 g / mol, 165,000 g / mol, 170,000 g / mol, or 175,000 g / mol to 180,000 g / mol, 185,000 g / mol, 190,000 g / mol, or 195,000 g / mol. W1 In some embodiments, the ethylene-based polymer may have an M of 170,000 g / mol, 175,000 g / mol, 180,000 g / mol, or 185,000 g / mol to 190,000 g / mol, 195,000 g / mol, 200,000 g / mol, or 205,000 g / mol. W2 In some embodiments, the ethylene-based polymer may have an Mw of 0.6, 0.7, 0.8, 0.9, or 1 to 1.3, 1.4, 1.5, 1.6, or 1.7. 1 / Mw 2 value.

[0042] Rheology of Ethylene-Based Polymers

[0043] In some embodiments, the ethylene-based polymer may have a melt index (MI, or I ) from 0.1 g / 10 min, 0.2 g / 10 min, 0.4 g / 10 min, 0.6 g / 10 min, 0.8 g / 10 min, or 1 g / 10 min to 2 g / 10 min, 4 g / 10 min, 6 g / 10 min, 8 g / 10 min, or 10 g / 10 min. 2 ), measured according to ASTM D-1238-20 at a temperature of 190°C under a load of 2.16 kg (I 2, 190° C.). In other embodiments, the ethylene-based polymer may have a melt index (I) from 0.1 g / 10 min, 0.2 g / 10 min, 0.3 g / 10 min, 0.4 g / 10 min, 0.5 g / 10 min, or 0.6 g / 10 min to 0.7 g / 10 min, 0.8 g / 10 min, 0.85 g / 10 min, 0.9 g / 10 min, or 1 g / 10 min. 2 In other embodiments, the ethylene-based polymer may have a melt index (MI) of 0.1 g / 10 min to less than 0.8 g / 10 min. 2 In some embodiments, the ethylene-based polymer may have a high load melt index (HLMI, or I HLMI) of 5 g / 10 min, 7 g / 10 min, 9 g / 10 min, or 11 g / 10 min to 13 g / 10 min, 14 g / 10 min, 15 g / 10 min, or 16 g / 10 min. 21 ), measured according to ASTM D-1238-20 at a temperature of 190°C under a load of 21.6 kg (I 21 , 190°C). The melt index ratio (MIR) of the ethylene-based polymer is defined as the ratio I 21.6 / I 2.16 ) can be in the range of 10, 12 or 14 to 16, 18 or 20.

[0044] The ethylene-based polymer may also or alternatively have an intrinsic viscosity of from 1.3 dL / g, 1.35 dL / g, 1.4 dL / g, 1.45 dL / g, 1.5 dL / g, 1.55 dL / g, 1.6 dL / g or 1.65 dL / g to 1.7 dL / g, 1.75 dL / g, 1.8 dL / g, 1.85 dL / g or 1.9 dL / g. In other embodiments, the ethylene-based polymer may have an intrinsic viscosity of greater than 1.4 dL / g, greater than 1.5 dL / g, greater than 1.6 dL / g or greater than 1.7 dL / g to 1.75 dL / g, 1.8 dL / g, 1.85 dL / g or 1.9 dL / g. The intrinsic viscosity of the ethylene-based polymer can be determined according to the procedure described in Macromolecules, 2000, 33, pp. 7489-7499. The intrinsic viscosity can be determined by dissolving linear and branched polymers in a suitable solvent such as trichlorobenzene, usually measured at 135°C. Another method for measuring the intrinsic viscosity of the ethylene-based polymer can include ASTM D-5225-98 standard test method "Measurement of polymer solution viscosity using a differential viscometer". If the results obtained by the two methods conflict, the result obtained by the method following ASTM D-5225-98 shall prevail.

[0045] The ethylene-based polymer may have a Dow Rheology Index (DRI) / Melt Index (MI) of at least 0.060, at least 0.061, at least 0.062, or at least 0.063 to less than 0.070, less than 0.075, or less than 0.080. 2 The Dow Rheology Index can be measured according to the well-known technique described in PCT Publication No. WO2013 / 087531A1.

[0046] Further rheological properties can be characterized using small angle oscillatory shear (SAOS) measurements, recording the viscosity at different shear rates.

[0047] For example, the ethylene-based polymer can have a complex viscosity of from 1,500 Pa·s, 1,600 Pa·s, 1,800 Pa·s, 2,000 Pa·s, 2,300 Pa·s, or 2,500 Pa·s to 2,700 Pa·s, 2,900 Pa·s, 3,100 Pa·s, 3,300 Pa·s, or 3,500 Pa·s, as measured at a shear rate of 100 rad / s (again, ranges from any of the foregoing lower limits to any of the foregoing upper limits are contemplated herein). Alternatively, the ethylene-based polymer can be characterized by a minimum complex viscosity at a shear rate of 100 rad / s, without necessarily requiring a maximum value; for example, the complex viscosity at a shear rate of 100 rad / s can be at least 2,600 Pa·s, at least 2,700 Pa·s, at least 2,800 Pa·s, or at least 2,900 Pa·s to 3,100 Pa·s, 3,300 Pa·s, or 3,500 Pa·s.

[0048] The ethylene-based polymer may also or instead be characterized by a complex viscosity at other shear rates. For example, the complex viscosity measured at a shear rate of 10 rad / s may be in a range from any lower limit of 5,700 Pa·s, 6,000 Pa·s, 6,300 Pa·s, 6,500 Pa·s, 6,700 Pa·s, or 7,000 Pa·s to any upper limit of 7,300 Pa·s, 7,500 Pa·s, 7,700 Pa·s, 8,000 Pa·s, 8,300 Pa·s, 8,500 Pa·s, or 8,700 Pa·s. Additionally or alternatively, the complex viscosity measured at a shear rate of 1 rad / s may be in a range from any lower limit of 3,600 Pa·s, 4,000 Pa·s, 5,000 Pa·s, 6,000 Pa·s, 7,000 Pa·s, 8,000 Pa·s or 9,000 Pa·s to any upper limit of 10,000 Pa·s, 11,000 Pa·s, 12,00 Pa·s, 13,000 or 13,300 Pa·s. Similarly, the complex viscosity at a shear rate of 1 rad / s can be characterized by a minimum value rather than a range, for example, the ethylene-based polymer can have a complex viscosity of at least 7,100 Pa·s, at least 7,500 Pa·s, at least 8,000 Pa·s, at least 8,500 Pa·s, at least 9,000 Pa·s, or at least 9,500 Pa·s to 10,000 Pa·s, 11,000 Pa·s, 12,00 Pa·s, 13,000 or 13,300 Pa·s measured at a shear rate of 1 rad / s. Finally, in addition to or in lieu of any one or more of the foregoing properties, the ethylene-based polymer can have a complex viscosity measured at a shear rate of 0.1 rad / s in a range from any lower limit of 11,100 Pa·s, 11,150 Pa·s, 11,200 or 11,250 Pa·s to any upper limit of 11,500 Pa·s, 12,000 Pa·s, 12,500 Pa·s, 13,00 Pa·s, 13,500 or 14,100 Pa·s.

[0049] As described above, the complex viscosity of the ethylene-based polymer can be measured by varying the shear rate (particularly at 10 x For example, η*10 2It is the complex viscosity measured at a shear rate of 100 rad / s. Small angle oscillatory shear ("SAOS") frequency sweep melt rheology experiments were performed at 190°C on a MCR301 controlled strain / stress rheometer (Anton Paar GmbH) using a 25 mm cone (1°) and plate configuration. Sample test discs (25 mm in diameter, 1 mm in thickness) were prepared by compression molding of pellets (which can be made of fiber samples if necessary) using a SchwabenThan laboratory press (200T) at 190°C. A typical cycle for sample preparation is 1 minute without pressure, then 1.5 minutes under pressure (50 bar), and then 5 minutes of cooling between water-cooled plates. The sample was first equilibrated at 190°C for 13 minutes to eliminate any previous thermal and crystallization history. Next, an angular frequency sweep from 500 rad / s to 0.0232 rad / s was performed, using 6 points / decade, and the strain value was 10% within the linear viscoelastic region determined by the strain sweep experiment. All experiments were performed in a nitrogen atmosphere to minimize any degradation of the samples during rheological testing.

[0050] Process for preparing the ethylene-based polymer

[0051] While any suitable polymerization process may be used, including solution or slurry polymerization processes, the ethylene-based polymers disclosed herein can be readily obtained by continuous gas phase polymerization using a supported catalyst, which may include an activated molecular discrete catalyst, in the substantial absence of alkylaluminum-based scavengers (e.g., triethylaluminum (TEAL), trimethylaluminum (TMAL), triisobutylaluminum (TIBAL), tri-n-hexylaluminum (TNHAL), and the like).

[0052] In some embodiments, the ethylene-based polymer can be made with a zirconium transition metal metallocene-type catalyst system. Non-limiting examples of metallocene catalysts and catalyst systems that can be used to make the ethylene-based polymer can include those described in U.S. Pat. Nos. 5,466,649, 6,476,171, 6,225,426, and 7,951,873, and references cited therein.

[0053] The polymerization catalyst may be deposited, bonded, contacted, bound to, adsorbed or absorbed in or on a support or carrier. In another embodiment, the metallocene may be introduced to the support by slurrying the preloaded activator in an oil, a hydrocarbon such as pentane, a solvent or a non-solvent and then adding the metallocene as a solid while stirring. The metallocene may be a finely divided solid. Although the solubility of the metallocene in the diluent medium is generally very low, the metallocene may be distributed on the support and have polymerization activity. A medium with very low solubility, such as mineral oil (e.g., Kay do TMor Drakol TM ) or pentane. The diluent can be filtered off and the remaining solids exhibit polymerization capabilities very similar to those expected if the catalyst is prepared by conventional methods (e.g., contacting the catalyst with methylaluminoxane in toluene, contacting with the support, and then removing the solvent). If the diluent is volatile, such as pentane, it can be removed under vacuum or by nitrogen purge to provide an active catalyst. Mixing times can exceed 4 hours, but shorter times are also suitable.

[0054] Typically, a continuous cycle is employed in a gas phase polymerization process, wherein a circulating gas stream (also referred to as a recycle stream or fluidizing medium) is heated in the reactor by the heat of polymerization in one portion of the reactor cycle. This heat can be removed in another portion of the cycle by a cooling system external to the reactor. See, for example, U.S. Pat. Nos. 4,543,399, 4,588,790, 5,028,670, 5,317,036, 5,352,749, 5,405,922, 5,436,304, 5,453,471, 5,462,999, 5,616,661, and 5,668,228.

[0055] Typically, in a gas phase fluidized bed process for producing a polymer, a gaseous stream containing one or more monomers is continuously circulated through a fluidized bed in the presence of a catalyst under reaction conditions. A gaseous stream is taken out of the fluidized bed, and at least a portion of the gaseous stream taken out of the fluidized bed can be recycled back into the reactor. At the same time, a polymer product can be taken out of the reactor, and fresh monomers can be added to replace the polymerized monomers. The reactor pressure can be in the range of 680 kPa absolute pressure, 750 kPa absolute pressure, 1,000 kPa absolute pressure, 1,500 kPa absolute pressure, or 2,000 kPa absolute pressure to 4,000 kPa absolute pressure, 5,500 kPa absolute pressure, or 7,000 kPa absolute pressure. The reactor can be operated at a temperature in the range of 50°C, 60°C, 70°C, 75°C, or 80°C to 85°C, 90°C, 95°C, 100°C, 110°C, or 120°C. The productivity of the catalyst or catalyst system can be affected by the partial pressure of the main monomers. The molar percentage of the main monomer, i.e., ethylene, can be in the range of 25 mol%, 50 mol% or 70 mol% to 80 mol%, 85 mol% or 90 mol%, and the monomer partial pressure can be in the range of 500 kPa absolute, 690 kPa absolute, 1,025 kPa absolute or 1,375 kPa absolute to 1,700 kPa absolute, 1,800 kPa absolute, 1,900 kPa absolute or 2,100 kPa absolute, which are typical conditions in gas phase polymerization processes.

[0056] Other gas phase processes useful for making the ethylene-based polymers may include those described in U.S. Patent Nos. 5,627,242, 5,665,818, and 5,677,375 and European Patent Application Nos. EP-A-0 794 200, EP-A-0 802 202, and EP-B-634 421.

[0057] In some embodiments, in a slurry or gas phase process, it may be beneficial to operate in the substantial absence or absence of any scavenger, such as triethylaluminum, trimethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, and diethylaluminum chloride, etc. Such a process is described in PCT Publication No. WO 96 / 08520.

[0058] Additionally, although not required, it may be desirable to use a process continuity aid in any of the above processes. Such continuity aids are well known to those skilled in the art and include, for example, metal stearates.

[0059] End-use applications

[0060] Some properties of the ethylene-based polymers described herein can be characterized by their performance in films. End-use applications of such films include, for example, monolayer and multilayer blown, extruded and / or cast films. Films comprising the ethylene-based polymers can also be used as cling film, sealing film, oriented film, snack packaging, heavy-duty bags, grocery bags, baked and frozen food packaging, pharmaceutical packaging, industrial liners, films, etc., for food contact and non-food contact applications. The combination of properties provided by the ethylene-based polymers particularly allows films made therefrom (particularly blown films) to be used for sealing film applications.

[0061] The total thickness of monolayer and multilayer films can vary depending on the desired application. A total film thickness of 5 μm to 100 μm, more typically 10 μm to 25 μm, is suitable for most applications. Those skilled in the art will appreciate that the thickness of the individual layers of the multilayer film can be adjusted based on the desired end-use performance, the resin or copolymer used, equipment capabilities and other factors. The materials forming the layers can be coextruded through a coextrusion feed block and die assembly to produce a film having two or more layers bonded together but of different composition. Coextrusion can be suitable for cast film or blown film processes.

[0062] Specific embodiments disclosed herein include monolayer films containing ethylene-based polymers disclosed herein. When used in multilayer films, the ethylene-based polymers can be used in any layer of the film or in multiple layers of the film as desired. When multiple layers of a film include ethylene-based polymers, each such layer can be formulated separately; that is, the chemical composition, density, melt index, thickness, etc. of the layers including the ethylene-based polymer can be the same or different, depending at least in part on the desired properties of the film.

[0063] Such films can be formed by a variety of well-known extrusion or coextrusion techniques discussed below. The film can be unoriented, uniaxially oriented or biaxially oriented. As described below, the film can be a cast film or a blown film. The film can also be embossed, or produced or processed according to other known film processes. The film can be customized according to a specific application by adjusting the thickness, material and sequence of the individual layers and the additives or modifiers used in each layer.

[0064] Films can be formed using casting techniques (e.g., cold roll casting processes). For example, a composition in a molten state can be extruded through a flat die and then cooled to form a film. As a specific example, a cast film production line machine can be used to prepare cast films as follows. In order to cast ethylene-based polymers, polymer particles are melted at a temperature of typically about 250°C to about 300°C (depending on the specific resin used), and the selection of the specific melting temperature is to match the melt viscosity of the specific resin layer. For multilayer cast films, two or more different melts are conveyed to a coextrusion adapter that combines the two or more melt streams into a multilayer coextrusion structure. The stratified stream is distributed to the desired width through a single manifold film extrusion die. The die gap opening is typically about 600 μm. The material is then stretched to the final specification. For a 20 μm film, the material stretch ratio is typically about 21:1. A vacuum box, an edge holder, an air knife, or a combination of the above equipment can be used to fix the melt leaving the die opening to a main cooling roll maintained at about 32°C. The resulting polymer film is collected on a winder. Film thickness can be monitored by a measuring instrument, and the film can be edged by a trimmer. Typical casting line speeds are about 76.2 meters per minute to about 609.6 meters per minute. Those skilled in the art will appreciate that higher rates can be used for similar processes (e.g., extrusion coating). If desired, one or more optional processors can be used to surface treat the film. Such chill roll casting processes and equipment are well known in the art and are described in, for example, Wiley-Encyclopedia of Packaging Technology, Second Edition, AL Brody and KS Marsh, Ed., John Wiley and Sons, Inc., New York (1997). Although chill roll casting is an example, other forms of casting can also be used.

[0065] Films containing ethylene-based polymers described herein can be formed using blow molding techniques, i.e., forming blown films. For example, the composition in a molten state can be extruded through an annular die, then inflated and cooled to form a tubular blown film, which can then be axially cut and unfolded to form a flat film. As a specific example, a blown film can be prepared as follows. The polymer composition is introduced into the feed hopper of an extruder, such as a 63.5 mm Egan extruder with a water-cooled, resistance-heated, and length-to-diameter ratio of 24:1. A 15.24 cm Sano die with a 2.24 mm die gap and a Sano double-hole non-rotating, non-adjustable air ring can be used to produce the film. The film is extruded into a film through the die and cooled by blowing air on the surface of the film. The film is pulled out of the die, usually forming a cylindrical film, which is then cooled, shrunk, and optionally subjected to the desired auxiliary processes such as slitting, processing, sealing or printing. The typical melting temperature is about 175°C to about 225°C. The film blowing rate is generally about 2.27 kg to about 13.61 kg / hour / 2.54 cm die circumference. The finished film can be rolled into a roll for subsequent processing, or can be fed into a bag making machine and made into a bag. U.S. Patent No. 5,569,693 describes a specific blown film process and equipment suitable for forming a film according to the embodiments described herein. Of course, other blown film forming methods can also be used.

[0066] Some films including the ethylene-based polymers described herein may be characterized by unique properties that are particularly suitable for heat sealing applications. The properties of blown films made from the ethylene-based polymers may be measured on blown films having a thickness of about 25.4 μm. Therefore, the properties of blown films made from the ethylene-based polymers disclosed herein are applicable to blown films having a thickness of about 25.4 μm.

[0067] In some embodiments, the blown film made from the ethylene-based polymer may have a hot adhesion of greater than 4N / 25mm, greater than 4.5N / 25mm, greater than 5N / 25mm, greater than 5.5N / 25mm, greater than 6N / 25mm, greater than 6.5N / 25mm, greater than 7N / 25mm, greater than 7.5N / 25mm, or greater than 8N / 25mm at a temperature between 85°C and 90°C. In some embodiments, the blown film made from the ethylene-based polymer may have a hot adhesion of greater than 4N / 25mm to 8.5N / 25mm at a temperature between 85°C and 90°C. The hot adhesion of the blown film made from the ethylene-based polymer can be measured according to the following procedure. A 2.54 cm strip of film can be subjected to a 0.5 N / mm 2The sealed sample was sealed under a pressure of 0.5 seconds. After a delay of 0.4 seconds, the sealed sample was pulled apart at a speed of 200 mm / min in a T-joint peeling mode.

[0068] In some embodiments, the blown film made from the ethylene-based polymer may have a seal strength of greater than 2N, greater than 3N, greater than 4N, greater than 5N, greater than 6N, greater than 7N, greater than 8N, or greater than 9N at a sealing temperature of about 70°C to about 100°C. In other embodiments, the blown film made from the ethylene-based polymer may have a seal strength of greater than 2N, greater than 3N, greater than 4N, greater than 5N, greater than 6N, greater than 7N, or greater than 8N to 8.3N, 8.5N, 8.7N, or 9N at a sealing temperature of about 70°C to about 100°C. In other embodiments, the blown film made from the ethylene-based polymer may have a seal strength of greater than 2N, greater than 2.3N, greater than 2.5N, greater than 2.7N, greater than 3N, greater than 3.3N, greater than 3.5N, or greater than 4N at a sealing temperature of about 72°C to about 75°C. In other embodiments, the blown film made from the ethylene-based polymer can have a seal strength of greater than 2, greater than 2.3N, greater than 2.5N, greater than 2.7N, greater than 3N, greater than 3.3N, or greater than 3.5N to 3.7N, 4N, 4.2N, 4.4N, 4.6N, or 5N at a sealing temperature of about 72°C to about 75°C. The seal strength of the blown film made from the ethylene-based polymer can be determined according to the following procedure. A 2.54 cm strip of film can be subjected to a 0.5 N / mm 2 The film can then be conditioned at 23°C + / - 2°C and 50 + / - 10% relative humidity for 40 hours in accordance with ASTM D618-21. The conditioned seal sample can then be tested in a T-joint peel mode at a pull-off speed of 50.8 cm / min.

[0069] In some embodiments, the blown film made from the ethylene-based polymer can have a longitudinal tensile strength at break of 50MPa, 55MPa, 60MPa, 65MPa or 70MPa to 75MPa, 80MPa or 85MPa. In other embodiments, the longitudinal tensile strength at break of the blown film made from the ethylene-based polymer can be greater than 77MPa, greater than 78MPa, greater than 79MPa or greater than 80MPa to 81MPa, 82MPa, 83MPa, 84MPa or 85MPa. In some embodiments, the blown film made from the ethylene-based polymer can have a transverse tensile strength at break of 50MPa, 55MPa, 60MPa, 65MPa or 70MPa to 75MPa, 80MPa, 85MPa or 90MPa. In other embodiments, the transverse tensile break strength of the blown film made from the ethylene-based polymer can be greater than 65 MPa, greater than 67 MPa, greater than 70 MPa, greater than 72 MPa, or greater than 74 MPa to 75 MPa, 80 MPa, 85 MPa, or 90 MPa. The tensile break strength can be determined according to a modified ASTM D-822-18, using a 2.54 mm x 17.78 cm strip at a speed of 50.8 cm / min.

[0070] In some embodiments, the blown film made from the ethylene-based polymer can have a longitudinal tensile yield strength of 4.5MPa, 4.7MPa, 5.0MPa, 5.1MPa or 5.3MPa to 5.5MPa, 5.7MPa, 6MPa or 6.3MPa. In some embodiments, the blown film made from the ethylene-based polymer can have a transverse tensile yield strength of 4.3MPa, 4.5MPa, 4.7MPa or 4.9MPa to 5.1MPa, 5.3MPa, 5.4MPa or 5.5MPa. The tensile yield strength can be measured according to modified ASTM D-822-18, using a 2.54mm x 17.78cm strip at a speed of 50.8cm / min.

[0071] In some embodiments, the blown film made from the ethylene-based polymer can have a haze of 1%, 1.5%, 2%, 2.5%, 3% or 4% to 8%, 10%, 12%, 14%, 16%, 18% or 20%. In other embodiments, the blown film made from the ethylene-based polymer can have a haze of 1% to less than 2%, less than 1.9%, less than 1.8%, less than 1.7%, less than 1.6% or less than 1.5%. The haze of the blown film can be measured according to ASTM D-1003-13.

[0072] In some embodiments, the blown film made from the ethylene-based polymer can have an average gloss of 10GU, 15GU, 20GU, 25GU, 30GU, 35GU or 40GU to 50GU, 55GU, 60GU, 65GU, 70GU, 75GU, 80GU, 85GU or 90GU. In some other embodiments, the blown film made from the ethylene-based polymer can have an average gloss of greater than 80GU, greater than 82GU, greater than 83GU or greater than 84GU to 86GU, 88GU or 90GU. The gloss of blown film can be measured according to ASTM D2457-13. The gloss of the blown film sample can be measured in longitudinal (MD) and transverse (TD) directions, and the average value is the MD value plus the TD value divided by 2.

[0073] In some embodiments, the blown films made from the ethylene-based polymers can have a puncture peak force / 25.4 μm from 1,800 kN / m, 1,900 kN / m, 2,000 kN / m, 2,100 kN / m, 2,200 kN / m, 2,300 kN / m, 2,400 kN / m, 2,500 kN / m, or 2,600 kN / m to 2,700 kN / m, 2,800 kN / m, 2,900 kN / m, or 3,000 kN / m. In other embodiments, the blown film made from the ethylene-based polymer may have a puncture peak force / 25.4 μm of greater than 2,400 kN / m, greater than 2,500 kN / m, greater than 2,600 kN / m, or greater than 2,670 kN / m to 2,800 kN / m, 2,900 kN / m, or 3,000 kN / m. The puncture peak force of the blown film may be determined in accordance with a modified ASTM D5748-19, using a 19.05 mm stainless steel uncoated probe and two 6.35 μm HDPEW slides at a test speed of 25.4 cm / min.

[0074] In some embodiments, the blown film made from the ethylene-based polymer can have a puncture energy of 130 kJ / m, 150 kJ / m, 175 kJ / m or 200 kJ / m to 210 kJ / m, 230 kJ / m, 250 kJ / m or 260 kJ / m. In other embodiments, the blown film made from the ethylene-based polymer can have a puncture energy of greater than 252 kJ / m or greater than 253 kJ / m to 255 kJ / m, 257 kJ / m or 260 kJ / m. The puncture energy can be measured according to ASTM D5748-19.

[0075] In some embodiments, the blown film made from the ethylene-based polymer can have a machine direction (MD) Elmendorf Tear of 30 kN / m, 40 kN / m, 50 kN / m, 60 kN / m, or 70 kN / m to 80 kN / m, 90 kN / m, 100 kN / m, or 110 kN / m. In some other embodiments, the blown film made from the ethylene-based polymer can have a machine direction (MD) Elmendorf Tear of 30 kN / m, 33 kN / m, 35 kN / m, 37 kN / m, or 39 kN / m to 42 kN / m, 43 kN / m, 44 kN / m, 45 kN / m, 46 kN / m, or 47 kN / m. In some embodiments, the blown film made from the ethylene-based polymer can have a longitudinal Elmendorf tear of less than 48 kN / m, less than 47 kN / m, less than 46 kN / m, or less than 45 kN / m. In some embodiments, the blown film made from the ethylene-based polymer can have a transverse (TD) Elmendorf tear of 50 kN / m, 60 kN / m, 70 kN / m, or 80 kN / m to 90 kN / m, 95 kN / m, 100 kN / m, or 110 kN / m. In some other embodiments, the blown film made from the ethylene-based polymer can have a transverse Elmendorf tear of 50 kN / m, 60 kN / m, 70 kN / m, or 80 kN / m to 85 kN / m, 87 kN / m, 90 kN / m, 93 kN / m, or 95 kN / m. In some embodiments, the blown film made from the ethylene-based polymer can have a transverse Elmendorf tear of less than 95 kN / m, less than 93 kN / m, less than 90 kN / m, or less than 87 kN / m. The Elmendorf tear of the blown film can be determined according to ASTM D1922-15 on a blown film specimen that has been conditioned for 40 hours at a temperature of 23° C.+ / -2° C. and a relative humidity of 50+ / -10%.

[0076] In some embodiments, the blown film made from the ethylene-based polymer can have a longitudinal (MD) yield elongation of 6.0%, 6.3%, 6.5%, 6.7% or 7% to 7.5%, 7.7%, 8.0%, 8.3% or 8.5%. In some embodiments, the blown film made from the ethylene-based polymer can have a transverse (TD) yield elongation of 5.0%, 5.3%, 5.5%, 5.7% or 6% to 6.5%, 6.7%, 7.0%, 7.3% or 7.5%. In some embodiments, the blown film made from the ethylene-based polymer can have a longitudinal (MD) break elongation of 375%, 385%, 395% or 405% to 415%, 425%, 435% or 445%. In some embodiments, the blown film made from the ethylene-based polymer can have a transverse (TD) elongation at break of 525%, 545%, 560%, or 570% to 590%, 600%, 615%, 630%, or 640%. The elongation at yield and elongation at break can be determined according to a modified ASTM D-822-18, using a 2.54 mm x 17.78 cm strip at a speed of 50.8 cm / min.

[0077] In some embodiments, the blown film made from the ethylene-based polymer can have a dart impact strength of 33 g / μm, 35 g / μm, 37 g / μm, 39 g / μm, 41 g / μm or 43 g / μm to 45 g / μm, 47 g / μm, 49 g / μm, 51 g / μm or 53 g / μm. In some other embodiments, the blown film made from the ethylene-based polymer can have a dart impact strength of greater than 37 g / μm, greater than 39 g / μm, greater than 41 g / μm or greater than 42 g / μm to less than 53 g / μm, less than 52 g / μm, less than 50 g / μm, less than 48 g / μm or less than 46 g / μm. The dart impact strength can be determined according to ASTM D-1709-16, Phenolic, Method A.

[0078] Blends of ethylene-based polymers

[0079] In some embodiments, the ethylene-based polymer described herein can be blended with another polymer component, particularly other α-olefin polymers such as polyethylene homopolymers and copolymer compositions (e.g., LLDPE, HDPE, MDPE, LDPE, and other differentiated polyethylenes) and / or polypropylene. In such a blend, the amount of the ethylene-based polymer can be 0.1wt%-99.9wt%. In such a blend, the upper limit of the amount of the ethylene-based polymer can be 99.5wt%, 99wt%, 98wt%, 97wt%, 96wt%, 95wt%, 90wt%, 85wt%, 80wt%, 75wt%, 70wt%, 60wt%, 50wt%, 40wt%, 30wt%, 25wt%, 20wt%, 15wt%, 10wt%, 5wt%, 4wt%, 3wt%, 2wt%, 1wt% or 0.5wt%. In such a blend, the lower limit of the amount of ethylene-based polymer can be 99.5 wt%, 99 wt%, 98 wt%, 97 wt%, 96 wt%, 95 wt%, 90 wt%, 85 wt%, 80 wt%, 75 wt%, 70 wt%, 60 wt%, 50 wt%, 40 wt%, 30 wt%, 25 wt%, 20 wt%, 15 wt%, 10 wt%, 5 wt%, 4 wt%, 3 wt%, 2 wt%, 1 wt% or 0.5 wt%. Blend compositions including any upper and any lower limits of the ethylene-based polymer are contemplated (e.g., 0.5 wt%-99.5 wt%, 10 wt%-90 wt%, 20 wt%-80 wt%, 25 wt%-75 wt%, 40 wt%-60 wt%, 45 wt%-55 wt%, 5 wt%-50 wt%, 10 wt%-40 wt%, 20 wt%-30 wt%, 50 wt%-95 wt%, 60 wt%-90 wt%, 70 wt%-80 wt%, 1 wt%-15 wt%, 1 wt%-10 wt%, 1 wt%-5 wt%, 85 wt%-99 wt%, 90 wt%-99 wt%, or 95-99 wt%). The amount of ethylene-based polymer is based on the total weight of the polymer blend.

[0080] In some embodiments, the ethylene-based polymer can be blended with one or more propylene-based polymers (e.g., homopolymers, copolymers, or impact copolymers comprising>50 mol% of polymer units derived from propylene). In addition to the blends having the above compositional limitations, particularly useful blends containing polypropylene can include less than 50 wt% (e.g., 2 wt%-49.5 wt%, 5 wt%-45 wt%, 7.5 wt%-42.5 wt%, 10 wt%-40 wt%, 20 wt%-30 wt%, 25 wt%-49.5 wt%, 30 wt%-49.5 wt%, 35 wt%-45 wt%) of propylene-based polymers.

[0081] In some embodiments, the polypropylene homopolymer or copolymer that can be used can have a certain level of isotacticity or syndiotacticity. In one embodiment, the polypropylene can be isotactic polypropylene, and in another embodiment, the polypropylene is highly isotactic polypropylene. In another embodiment, the propylene polymer can be a random copolymer (also called "RCP"), which can include propylene and up to 20 mol% of ethylene or C 4 -C 20 Olefins, preferably up to 20 mol% ethylene, preferably 1 to 10 mol% ethylene.

[0082] The blend can be formed using conventional equipment and methods, for example, by dry blending the components and subsequently melt mixing in a mixer, or by mixing the components together directly in a mixer such as a Banbury mixer, a Haake mixer, a Brabender internal mixer, or a single or twin screw extruder (which may include mixing extruders and side arm extruders used directly downstream of the polymerization process). In addition, additives may be included in the blend, in one or more components of the blend, and / or in products such as films formed from the blend, as desired. Such additives are well known in the art and may include, for example: fillers; antioxidants (e.g., hindered phenols such as IRGANOX available from BASF); TM 1010 or IRGANOX TM 1076); phosphites (e.g., IRGAFOS available from BASF TM 168); tackifiers such as polybutene, terpene resins, aliphatic and aromatic hydrocarbon resins, alkali metal and glyceryl stearate, and hydrogenated rosin; UV stabilizers; heat stabilizers; antiblocking agents; pigments; colorants; dyes; waxes; silica; fillers; talc. Example

[0083] The foregoing discussion may be further described with reference to the following non-limiting examples.

[0084] One inventive example (Example 1) and nine commercially available comparative examples (C1-C9) were evaluated, which are ethylene-based polymers comprising from about 90 mol% to about 99 mol% of polymer units derived from ethylene and from about 1 mol% to about 10 mol% of polymer units derived from one or more C 3 -C 18 The polymer units are α-olefin monomers. C1-C4 are Exact TM 3236、Exceed TM 1012, Exceed TM 2012 and Exceed TM 1018 ethylene-hexene copolymer. C5, C6 and C7 are Elite 1018 ethylene-hexene copolymers available from Dow Chemicals. TM AT6401N、Elite TM 5400 and Affinity TM PL1880G ethylene-octene copolymer. C8 and C9 are Evolue available from Mitsui TM SP0510 and SP1510 ethylene-hexene copolymers. The measured properties of the examples are shown in Table 1 below. Blown films having a thickness of 25.4 μm were made from the ethylene-based polymers of Example 1 and C1-C9, and the measured properties of the blown films are shown in Tables 2-4 below. The blown films were made on a 160 mm blown film line with a blow-up ratio of 2.5:1, a melt temperature of 233°C, a die gap of 1.52 mm, and a rate of 1.79 kg / hr / cm.

[0085]

[0086]

[0087] As shown in Table 1, the number average molecular weight (Mn) of the ethylene-based polymer of Example 1 is significantly greater than all comparative examples. Similarly, the weight average molecular weight (Mw) of Example 1 is greater than all comparative examples. Compared with all comparative examples, the ethylene-based polymer of Example 1 also has a greater complex viscosity at shear rates of 100 rad / s, 10 rad / s, 1 rad / s, and 0.1 rad / s.

[0088]

[0089]

[0090]

[0091] As can be seen from Tables 2-4, the blown films made from the polyethylene-based polymer of Example 1 have peak heat seal strength at significantly lower temperatures (e.g., 75° C.) than C1-C9 of similar density, while also maintaining satisfactory strength such as puncture and tensile properties. Among all examples, the blown films made from the polyethylene-based polymer of Example 1 also have the lowest haze, the highest average gloss, the highest tensile break strength (MD), and the highest puncture energy.

[0092] For the reason of brevity, only some scope is clearly disclosed in this article.However, the scope starting from any lower limit can be combined with any upper limit to describe the scope not clearly mentioned, and the scope starting from any lower limit can be combined with any other lower limit to describe the scope not clearly mentioned. Similarly, the scope starting from any upper limit can be combined with any other upper limit to describe the scope not clearly mentioned. In addition, each point or each value included between its endpoints in a scope, even if not clearly mentioned. Therefore, each point or each value can be used as its own lower limit or upper limit, with any other point or each value or any other lower limit or upper limit combination, to describe the scope not clearly mentioned.

[0093] All documents described herein, including any priority documents and / or test procedures, are incorporated herein by reference to the extent that they are not inconsistent with this article. As can be clearly known by the aforementioned general description and specific embodiments, although the form of the present disclosure has been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Therefore, it is not desired that the present disclosure be limited thereby. Similarly, when there is a transition phrase "comprising" before a composition, an element or an element group, it should be understood that we have also thought of identical compositions or element groups, wherein the composition, the element or the element group is guided by the transition phrase "essentially consisting of ... ", "consisting of ... ", "selected from the group consisting of ... " or "is", and vice versa.

[0094] While the disclosure has been described with reference to a number of embodiments and examples, those skilled in the art having the benefit of this disclosure will appreciate that other embodiments may be devised which do not depart from the spirit and scope of the disclosure.

Claims

1. An ethylene-based polymer comprising 90 mol% to about 99 mol% of polymer units derived from ethylene and 1 mol% to 10 mol% of polymer units derived from one or more C3-C 18 Polymer units of alpha-olefin monomers, wherein the ethylene-based polymer has: Melt index of 0.1g / 10min-10g / 10min (I2, 190℃), 0.890g / cm 3 -0.910g / cm 3 The density, 60%-80% Composition Distribution Width Index (CDBI), Number average molecular weight (Mn) of 25,000 g / mol-53,000 g / mol, Intrinsic viscosity of 1.3dL / g-1.9dL / g, and One or more of the following properties: The composition distribution width T is at least 16.5℃-21℃ 75 -T 25 Values, determined by temperature rising elution fractionation (TREF), A complex viscosity of at least 5,700 Pa·s to 8,700 Pa·s at a shear rate of 10 rad / s, and The complex viscosity of at least 11,100 Pa·s to 14,100 Pa·s is measured at a shear rate of 0.1 rad / s.

2. The ethylene-based polymer of claim 1, wherein the ethylene-based polymer has a Mw1 / Mw2 value of 0.6 to 1.

7.

3. The ethylene-based polymer of claim 1 or claim 2, wherein the ethylene-based polymer has a Tw1-Tw2 value of -7°C to -25°C.

4. The ethylene-based polymer of claim 3, wherein the Tw1-Tw2 value is less than -22°C.

5. The ethylene-based polymer of any of the preceding claims, wherein the ethylene-based polymer has the following properties: The complex viscosity of 1,500 Pa·s-3,300 Pa·s was measured at a shear rate of 100 rad / s, and The complex viscosity of 3,600 Pa·s to 13,000 Pa·s was measured at a shear rate of 1 rad / s.

6. The ethylene-based polymer of any of the preceding claims, wherein the ethylene-based polymer has a Dow Rheology Index (DRI) / Melt Index (I2, 190°C) ratio of greater than 0.060 to less than 0.

080.

7. The ethylene-based polymer of any of the preceding claims, having one or more of the following properties: (a) a melt index (I2, 190°C) in the range of 0.5 g / 10 min to 1 g / 10 min; (b) at 0.900 g / cm 3 -0.910g / cm 3 Density within the range of (c) CDBI in the range of 70%-80%; (d) Mn in the range of greater than 42,000 to less than 50,000; and (e) An intrinsic viscosity in the range of greater than 1.6 dL / g to 1.9 dL / g.

8. The ethylene-based polymer of claim 7 having all of properties (a)-(e).

9. The ethylene-based polymer of any of the preceding claims, wherein the ethylene-based polymer has the following properties: The composition distribution width T is at least 16.5℃-19℃ 75 -T 25 Value, determined by TREF, The complex viscosity is greater than 2,700 Pa·s to 3,100 Pa·s at a shear rate of 100 rad / s. The complex viscosity is greater than 5,700 Pa·s to 8,200 Pa·s at a shear rate of 10 rad / s. Determine complex viscosity from greater than 8,700 Pa·s to 12,000 Pa·s at a shear rate of 1 rad / s. Determination of complex viscosity greater than 11,100 Pa·s to 13,500 Pa·s at a shear rate of 0.1 rad / s, and Dow Rheology Index (DRI) / Melt Index (I2, 190°C) ratio greater than 0.060 and less than 0.

080.

10. The ethylene-based polymer of any one of the preceding claims, wherein a blown film made from the ethylene-based polymer has a hot tack greater than 4 N / 25 mm at a temperature between 85°C and 90°C.

11. The ethylene-based polymer of any one of the preceding claims, wherein a blown film made from the ethylene-based polymer has a seal strength greater than 3N at a sealing temperature of 70°C to 75°C.

12. An article comprising the ethylene-based polymer of any of the preceding claims.

13. The article of claim 12, wherein the article is in the form of a film or a pellet.

14. A blown film made from the ethylene-based polymer of any one of the preceding claims, wherein the blown film has a seal strength greater than 2 Newtons at a sealing temperature of 70°C to 100°C or at a sealing temperature of 72°C to 75°C.

15. The blown film of claim 14, wherein the blown film has a hot tack greater than 4 N / 25 mm at a temperature between 85°C and 90°C.

16. The blown film of claim 14 or claim 15, wherein the blown film has one or more of the following properties: (A) a longitudinal tensile strength at break of 50 MPa to 85 MPa or greater than 78 MPa to 85 MPa; (B) haze of 1%-20%; (C) Average glossiness of 10GU-90GU; (D) a peak penetration force / 25.4 μm of 1,800 kN / m to 3,000 kN / m or greater than 2,670 kN / m to 3,000 kN / m; (E) a piercing energy of 130 kJ / m to 260 kJ / m or greater than 252 kJ / m to 260 kJ / m; and (F) MD Elmendorf Tear of 30 kN / m to 110 kN / m or 30 kN / m to less than 45 kN / m.

17. The blown film of claim 16 having all of the properties (A) to (F).

18. The blown film of claim 16 or claim 17, having one or more of the following properties: (A1) a machine direction (MD) tensile strength at break of greater than 78 MPa to 85 MPa; (B1) a haze of 1% to less than 2%; (C1) average gloss greater than 84 GU to 90 GU; (D1) a peak penetration force / 25.4 μm of greater than 2,670 kN / m to 3,000 kN / m; (E1) a piercing energy of greater than 252 kJ / m to 260 kJ / m; and (F1) MD Elmendorf tear of 30 kN / m to less than 45 kN / m.

19. The blown film of claim 18, having all of the properties (A1) to (F1).

20. A method for preparing an ethylene-based polymer, the method comprising: Ethylene and one or more C3-C 18 an alpha-olefin monomer is introduced into a reactor; and The ethylene and the at least one other comonomer are polymerized in the reactor at a temperature of 50° C. to 110° C. and a pressure of 750 kPa to 7,000 kPa absolute to produce the ethylene-based polymer, wherein the ethylene-based polymer comprises 90 mol% to 99 mol% of polymer units derived from ethylene and 1 mol% to 10 mol% of polymer units derived from the one or more C3-C 18 polymer units of α-olefin monomers, and wherein the ethylene-based polymer has: Melt index of 0.1g / 10min-10g / 10min (I2, 190℃), 0.890g / cm 3 -0.910g / cm 3 The density, 60%-80% composition distribution width index, Number average molecular weight of 25,000 g / mol-53,000 g / mol, Intrinsic viscosity of 1.3dL / g-1.9dL / g, and One or more of the following properties: The composition distribution width T is at least 16.5℃-21℃ 75 -T 25 Value, determined by TREF, A complex viscosity of at least 5,700 Pa·s to 8,700 Pa·s at a shear rate of 10 rad / s, and The complex viscosity of at least 11,100 Pa·s to 14,100 Pa·s is measured at a shear rate of 0.1 rad / s.

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