Linear low density polyethylene films with outstanding processability and mechanical properties

Abstract

A variety of methods and compositions are disclosed, including in one embodiment, polyethylene composition comprising: about 80 wt.% to about 99 wt.% ethylene-derived content, and about 1.0 wt.% to about 20 wt.% units derived from one or more C3 to C40 α-olefin comonomers, based on a total weight of the polyethylene composition, wherein the polyethylene composition comprises: a density of about 0.91 g / cm3 to about 0.95 g / cm3; a melt index (I2.16) of about 2 g / 10 min to about 10 g / 10 min; a melt index ratio (I21.6 / I2.16) of about 15 to about 40; a number average molecular weight, Mw (IR) of about 7,000 g / mol to 25,000 g / mol; a weight average molecular weight, Mw (IR) of about 60,000 g / mol to 100,000 g / mol: a molecular weight distribution (Mw / Mn) ratio (IR) of about 4 to about 10; a molecular weight distribution (Mz / Mn) ratio (IR) of about 5 to about 25; a ratio of z-average molecular weight to weight-average molecular weight (Mz / Mw) of about 1.5 to about 5.0; and a very low density VLD% as measured by temperature rising elution fractionation (TREF) of about 2% to about 40%.

Description

LINEAR LOW DENSITY POLYETHYLENE FILMS WITH OUTSTANDING PROCESSABILITY AND MECHANICAL PROPERTIESCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 707,143 having a filing date of October 14, 2024, the disclosure of which is incorporated herein by reference in its entirety.FIELD

[0002] The present disclosure relates to polyethylene compositions having properties suitable for casting applications.BACKGROUND

[0003] Polyolefin polymer compositions are in high demand for many applications, including various films (such as cast films, shrink films, and blown films), sheets, membranes such as geomembranes, sacks, pipes (e.g., polyethylene of raised temperature (PE-RT) pipes, utility pipes, and gas distribution pipes), roto-molded parts, blow-molded flexible bottles or other containers, and various other blow molded / extruded articles such as bottles, drums, jars, and other containers. These applications have been commonly made from polyethylenes because polyethylene compositions offer an attractive balance of mechanical strength, stress crack resistance, and flexibility. High performance polyolefins, such as linear low-density polyethylene (LLDPE), have been able to lower manufacturing costs sufficiently to justify commercial use in food packaging as well as trash bags, including heavy duty garbage bags, leaf bags, and trash can liners. Linear low-density polyethylene allows for the production of bags with remarkably thin gauge and flexibility while maintaining high strength characteristics such as dart impact and tensile strength.

[0004] Polyethylene copolymer resins are used in a variety of applications where the rheological and mechanical profiles of such materials may dictate their end use and applications. As such, it is valuable to understand the multitude of variables, processes, and parameters which affect such properties of these materials during and throughout their production and processing. In many instances, gas phase polymerization processes are utilized in the development of various polyethylene copolymer resins. In such processes, the use of Ziegler-Natta and metallocene catalysts have been well documented to produce polyethylene copolymer resins having low density, high tensile strength, high impact strength, high tear resistance, high stiffness, and high toughness. The gas phase processes have become commonplace in the production of polyethylene resins, and the resins produced can be implemented in the manufacture of multi-layer films. However, such processes and catalysts used to form polyethylene copolymer resins useful for filmare rather challenging. In some instances, it may be desirable to produce polyethylene copolymer resins having both the high mechanical properties as stiffness and toughness and the rheological profiles of resins with suitable processability.

[0005] More recently, linear low-density polyethylene (LLDPE) has been used in place of conventional highly branched low7density polyethylenes (LDPE) and stiff high-density7polyethylenes (HDPE) in many film applications, including bags. Linear low density7polyethylenes (LLDPE) is a substantially linear polymer, with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins, typically alpha-olefin comonomer, particularly yvhen made in a loyv-pressure polymerization process such as, for example, solution, slurry, and / or gas phase polymerization processes. Such polyethylene compositions may therefore be referred to as ethylene alpha-olefin copolymers.

[0006] LLDPE is widely recognized as being tougher and stronger than LDPE, thus contributing to reduced bag failures, including punctures and splitting under stress. In particular, LLDPEs made with metallocene or single site catalysts, and LLDPEs containing hexene and / or octene comonomers have been used to provide improved toughness. However, LLDPE's are difficult to process. Much effort has been placed in understanding hoyv the comonomer is distributed along the polymer carbon chain or simply polymer chain of a polyolefin polymer such as a polyethylene composition. For example, the composition distribution of an ethylene alpha-olefin copolymer refers to the distribution of comonomer (short chain branches) among the molecules that comprise the polyethylene polymer. When the amount of short chain branches varies among the polymer carbon chains of different length, the polymer or resin is said to have a Broad Composition Distribution (BCD). For example, for an ethyl ene-hexene copolymer, hexene distribution varies from low to high even among polymer chains of similar length (e.g., the polydispersity index or PDI among those chains is narrow). When the amount of comonomer per about 1000 carbons is similar among the polyethylene molecules of different polymer chain lengths or molecular weights, the composition distribution is said to be “narrow” or have a Narrow7Composition Distribution (NCD).

[0007] The composition distribution is known to influence the properties of copolymers, for example, extractables content, environmental stress crack resistance, heat sealing, dart drop impact resistance, and tear resistance or strength. The composition distribution of a polyolefin may be readily measured by methods known in the art, for example, Temperature Rising Elution Fractionation (TREF) or Crystallization Analysis Fractionation (CRYSTAF).

[0008] Polymers made with Zeigler Natta catalysts have a composition distribution which is broad but the high molecular weight fractions are higher density (i.e. , less comonomer) than the lower molecular weight fraction (high comonomer).

[0009] In contrast, metallocene catalysts typically produce a polyolefin polymer composition with an NCD. A metallocene catalyst is generally a metal complex of a transitional metal, typically, a Group 4 metal, and one or more cyclopentadienyl (Cp) ligands or rings. As stated above, NCD generally refers to the comonomer being evenly distributed or not varying much between polymer chains of different lengths.

[0010] More recently, a third distribution has been described for a polyolefin polymer composition having a Broad Orthogonal Composition Distribution (BOCD) in which the comonomer is incorporated predominantly in the high molecular weight chains. A substituted hafnocene catalyst has been noted to produce this type of distribution. This distribution has been noted for its improved physical properties, for example, ease in fabrication of end-use articles as well as stiffness and toughness in multiple applications such as films that can be measured by dart drop impact resistance and tear resistance or strength. BOCD behavior in a polymer composition has been associated with a good balance of mechanical and optical properties and has been an important goal in the development of new polymer products. BOCD has been targeted and improved in various linear PE compositions.SUMMARY

[0011] Disclosed herein is an example polyethylene composition including about 80 wt.% to about 99 wt.% ethylene-derived content, and about 1 .0 wt.% to about 20 wt.% units derived from one or more Cs to C40 a-olefin comonomers, based on a total weight of the polyethylene composition, wherein the polyethylene composition comprises: a density of about 0.91 g / cm3to about 0.95 g / cm3; a melt index (h ie) of about 2 g / 10 min to about 10 g / 10 min; a melt index ratio (I21.6 / I2.16) of about 15 to about 40; a weight average molecular weight, Mn (LS) of about 7,000 g / mol to 25,000 g / mol; a number average molecular weight, Mw (IR) of about 65,000 g / mol to 112,000 g / mol; a molecular weight distribution (Mw / Mn) ratio (IR) of about 4 to about 10; a molecular weight distribution (Mz / Mn) ratio (IR) of about 5 to about 25; a ratio of z-average molecular weight to weight-average molecular weight (Mz / Mw) of about 1.5 to about 5.0; and a very low density VLD% as measured by temperature rising elution fractionation (TREF) of about 2% to about 40%.

[0012] Further disclosed herein is an example cast polyethylene film, including: a polyethylene composition of claim 1, wherein the film has: a machine direction (MD) 1% secant modulus as measured according to ASTM D-882-18, from about 15,000 psi to about 80,000 psi., atransversedirection (TD) 1% secant modulus (psi) as measured according to ASTM D-882-18, in a range of 15,000 psi to 80.000 psi., a machine direction yield strength as measured according to ASTM D- 882-18 from about 900 psi to about 3000 psi; a transverse direction yield strength as measured according to ASTM D-882-18 from 900 psi to 3000 psi; and a dart drop as measured according to ASTM D-1709, Phenolic, Method A in a range of 200 g to 800 g.

[0013] Further disclosed herein is an example method for making a film including: producing a polymer melt comprising a polyethylene composition of claim 1; extruding a film from the polymer melt; and fabricating the film of the polymer melt, wherein the film has: a machine direction (MD) 1% secant modulus as measured according to ASTM D-882-18, from about 15,000 psi to about 80.000 psi. a transverse direction (TD) 1% secant modulus (psi) as measured according to ASTM D-882-18, in a range of 15,000 psi to 80,000 psi. a machine direction yield strength as measured according to ASTM D-882-18, from about 900 psi to about 3000 psi; a transverse direction yield strength as measured according to ASTM D-882-18, from 900 psi to 3000 psi; and a dart A as measured according to ASTM D-1709, Phenolic, Method A in a range of 200 g to 800 g.

[0014] These and other features and attributes of the disclosed methods and compositions of the present disclosure and their advantageous applications and / or uses will be apparent from the detailed description which follows.BRIEF DESCRIPTION OF THE DRAWING

[0015] To assist those of ordinary skill in the relevant art in making and using the subject matter hereof, reference is made to the appended drawings, wherein:

[0016] The FIGURE is a graph of results of gel permeation chromatography (GPC) testing for polyolefin compositions prepared in accordance with certain embodiments of the present disclosure.DETAILED DESCRIPTION

[0017] The present disclosure relates to polyolefin compositions, their methods of manufacture, and articles including and / or made from the polyolefin compositions. In an embodiment, the polyolefin compositions include polyethylene compositions. The polyethylene compositions disclosed herein have improved melt index (MI), melt index ratio (MIR), and density as compared to previous polyethylene compositions. The improved properties of the polyethylene compositions are suitable for casting applications such as cast film extrusion. The disclosed polyethylene compositions have improved processability including lower melt head pressure and higher output as compared to previously used polyethylene compositions. Products produced using the disclosedpolyethylene compositions also have improved stiffness and other desirable physical properties as compared to previously used polyethylene compositions having comparable MI and densities..Definitions

[0018] The small amplitude oscillatory shear (SAGS) measurements are made on the Ares-G2 Rheometer by TA Instruments. Samples are compression molded at 177°C for 15 minutes (including cool down under pressure) and 25mm testing disk specimen are die cut from the resulting plaques. Measurements are conducted using a 25mm parallel plate geometry. Tests are run from 0.01 to 500 rad / s and carried out at T= 190°C under 5% strain. To quantify the shearlike rheological behavior, the degree of shear thinning (DoST) parameter can be defined. The DoST is measured by the following expression: DoST= q*(0.5 rad / s)- q*(500 rad / s) / q*(0.5 rad / s) where r|*(0.5 rad / s) and q *(500 rad / s) are the complex viscosities at frequencies of 0.5 and 500 rad / s, respectively, measured at 190°C. The DoST can also be measured by using complex viscosities at different frequencies. The higher the DoST parameter is, the higher is the degree of shear thinning. Also, tan (5) at frequency= 0.5 rad / s is determined, which is the tangent of the phase angle: G" / G’, the ratio of viscous modulus (G") to elastic modulus (G') at 0.5 rad / s.

[0019] Temperature Rising Elution Fractionation (TREF) analysis was done using a Cry stallization Elution Fractionation (CEF) instrument from Polymer Char, S.A., Valencia, Spain. The principles of CEF analysis and a general description of the particular apparatus used are given in the article Monrabal, B. et al. Crystallization Elution Fractionation. A New Separation Process for Polyolefin Resins. Macromol. Symp. 2007, 257, 71. In particular, a process conforming to the “TREF separation process”, in which Fc=0 was used. Pertinent details of the analysis method and features of the apparatus used are as follows. The solvent used for preparing the sample solution and for elution was 1,2 Di chlorobenzene (ODCB) filtered using a 0. 1-pm Teflon filter (Millipore). The sample (16 mg) to be analyzed was dissolved in 8 ml of ODCB metered at ambient temperature by stirring (Medium setting) at 150°C for 90 min.

[0020] A small volume of the polymer solution was first filtered by an inline filter (stainless steel, 10 pm), which is backflushed after every' filtration. The filtrate was then used to completely fill a 200-pl injection-valve loop. The volume in the loop was then introduced near the center of the CEF column (15-cm long SS tubing, 3 / 8" o.d., 7.8 mm i.d.) packed with an inert support (SS balls) at 140°C, and the column temperature was stabilized at 125°C for 20 min. The sample volume was then allowed to cry stallize in the column by reducing the temperature to 0°C at a cooling rate of 1 °C / min. The column was kept at 0°C for 10 min before injecting the ODCB flow (1 ml / min) into the column for 10 min to elute and measure the polymer that did not crystallize (solublefraction). The wide-band channel of the infrared detector used (Polymer Char IR5) generates an absorbance signal that is proportional to the concentration of polymer in the eluting flow.

[0021] A complete TREF curve was then generated by increasing the temperature of the column from 0 to 140°C at a rate of 2°C / min while maintaining the ODCB flow at 1 ml / min to elute and measure the concentration of the dissolving polymer. The TREF curve was further processed as follows: The solvent-only response of the instrument was generated and subtracted from the TREF curve of the sample. The solvent-only response is generated by running, typically before, the same method as used for the polymer sample, but without any polymer added to the sample vial; using the same solvent reservoir as for the polymer sample and without replenishing with fresh solvent; and within a reasonable proximity of time from the run for the polymer sample. The temperature axis of the TREF curve was appropriately shifted to correct for the delay in the IR signal caused by the column-to-detector volume. This volume is obtained by first filling the injection-valve loop with a ~1 mg / ml solution of an HDPE resin; then loading the loop volume in the same location within the column where a sample is loaded for TREF analysis; then directly flowing, at a constant flow rate of 1 ml / min, the hot solution towards the detector using an isothermal method; and then measuring the time after injection for the HDPE probe's peak to appear in the IR signal. The delay volume (ml) is therefore equated to the time (min). The curve was baseline corrected and appropriate integration limits were selected. And the curve was normalized so that the area of the curve is 100 wt%.

[0022] The Composition Distribution Breadth Index (CDBI) was obtained by the method described in WO 93 / 03093 (Meka, P. et al). Similar to the correlation shown in Figure 16 of this reference, which was used for converting the temperature scale to a composition scale, twelve compositionally narrow polymer standards having Mn (number-averaged molecular weight) values greater than 20000 gm / mole were employed to generate a calibration line. For this purpose, the standards were analyzed by the same TREF method as the polymer samples for which CDBI values were calculated.

[0023] The TREF elution is carried out as described above, and a curve normalized so that area of the curve is 100 wt%. The curve is then partitioned into four bins and defined by their respective ranges of elution temperature. T. The four bins are designated the following nomenclature: very low density (VLD) for T<60°C, low density (LD) for 60<T<75°C, medium density (MD) for 75<T<87°C, and high density (HD) for T>87°C. The weight fractions of the material in each bin are readily computed from the cumulative TREF distribution by identifying the cumulative fraction at each boundary between partitions.

[0024] 1H NMR data of the polymer was collected at 120°C using a 10 mm cry oprobe on at least a 600 MHz Bruker spectrometer with l,l,2,2-tetrachloroethane-d2 (tce-d2). Samples were prepped with a concentration of 30mg / ml at 140°C. Data was recorded with a 30°pulse, 5 second delay, 512 transients. Signals were integrated and the numbers of unsaturation types per 1000 carbons and methyl branches per 1000 carbons were reported. The shift regions for unsaturations and methyl branching were in Table 1.Table 1

[0025] Gel Permeation Chromatography (GPC) is a liquid chromatography technique used to measure the molecular weight and poly dispersity of polymers.

[0026] Unless otherwise indicated, the distribution and the moments of molecular weight (e.g., Mw, Mn. Mz, Mw / Mn) and the comonomer content (e.g.. C2, C3, C6) are determined by using a high temperature Gel Permeation Chromatography (Polymer Char GPC-IR) equipped with a multiple-channel band-filter based Infrared detector IR5, an 18-angle light scattering detector and a viscometer. Three Agilent PLgel 10-pm Mixed-B LS columns are used to provide polymer separation. Aldrich reagent grade 1, 2, 4-tri chlorobenzene (TCB) with 300 ppm antioxidant butylated hydroxytoluene (BHT) is used as the mobile phase. The TCB mixture is filtered through a 0.1 -pm Teflon filter and degassed with an online degasser before entering the GPC instrument. The nominal flow rate is 1.0 ml / min. and the nominal injection volume is 200 pl. The whole system including transfer lines, columns, and detectors is contained in an oven maintained at 145°C. The polymer sample is weighed and sealed in a standard vial with 80-pl flow marker (heptane) added to it. After loading the vial in the autosampler, polymer is dissolved in the instrument with 8 ml added TCB solvent. The polymer is dissolved at 160°C with continuous shaking for about 1 hour for polyethylene samples. The TCB densities used in concentration calculation is 1.463 g / ml at room temperature and 1.284 g / ml at 145°C. The sample solutionconcentration is from 0.2 to 2.0 mg / ml, with lower concentrations being used for higher molecular weight samples. The concentration (c), at each point in the chromatogram is calculated from the baseline-subtracted IR5 broadband signal intensity (I), using the following equation: c = ? / , where P is the mass constant. The mass recover}' can be calculated from the ratio of the integrated area of the concentration chromatography over elution volume and the injection mass, which is equal to the pre-determined concentration multiplied by injection loop volume.

[0027] Conventional molecular weight (IR molecular weight): determined by combining universal calibration relationship with the column calibration, which is performed with a series of monodispersed polystyrene (PS) standards ranging from 700 to 10,000,000 gm / mole. The molecular weight at each elution volume is calculated with (1):EQ. 1 . logwhere the variables with subscript “PS” stand for polystyrene while those without a subscript are for the test samples. In this method, aPS = 0.67 and KPS = 0.000175 while a and K for other materials are as calculated and published in literature (Sun, T. et al. Macromolecules 2001, 34, 6812), except that for purposes of this invention and claims thereto, a = 0.705 and K = 0.0002288 for linear propylene polymers, a = 0.695 and K = 0.000181 for linear butene polymers, a is 0.695 and K is 0.000579*(l-0.0087*w2b+0.000018*(w2b)A2) for ethylene-butene copolymer where w2b is a bulk weight percent of butene comonomer, a is 0.695 and K is 0.000579*(l-0.0075*w2b) for ethylene-hexene copolymer where w2b is a bulk weight percent of hexene comonomer, and a is 0.695 and K is 0.000579*(l-0.0077*w2b) for ethylene-octene copolymer where w2b is a bulk weight percent of octene comonomer, and a = 0.695 and K = 0.000579 for all other linear ethylene polymers. Concentrations are expressed in g / cm3, molecular weight is expressed in g / mole, and intrinsic viscosity (hence K in the Mark-Houwink equation) is expressed in dl / g, unless otherwise noted.

[0028] Comonomer composition: determined by the ratio of the IR5 detector intensity corresponding to CH2 and CEE channel calibrated with a series of polyethylene and propylene homo / copolymer standards whose nominal value are predetermined by NMR or FTIR. In particular, this provides the methyls per 1000 total carbons (CH3 / IOOOTC) as a function of molecular weight. The short-chain branch (SCB) content per 1000TC (SCB / 1000TC) can be then computed as a function of molecular weight by applying a chain-end correction to the CH3 / IOOOTC function, assuming each chain to be linear and terminated by a methyl group at eachend. The weight % comonomer can be then obtained from the following expression in which f is 0.3, 0.4, 0.6, 0.8. and so on for C3, C4, C6, C8, and so on co-monomers, respectively:EQ. 2 iv 2 = f * SCB / 1000TC

[0029] The bulk composition of the polymer from the GPC-IR and GPC-4D analyses is obtained by considering the entire signals of the CH3 and CH2 channels between the integration limits of the concentration chromatogram. First, the following ratio is obtained.EQ. 3 Area of CH, signal within integration limitsBulk IR ratio = - — — - — : - — . - : - - — —Area of CH2signal within integration limits

[0030] Then the same calibration of the CEI3 and CH2 signal ratio, as mentioned previously in obtaining the CH3 / 1000TC as a function of molecular weight, is applied to obtain the bulk CH3 / 1000TC. A bulk methyl chain ends per 1000TC (bulk C143end / 1000TC) is obtained by weight-averaging the chain-end correction over the molecular-weight range. Then:EQ. 4 w2b = f * bulk CH3 / 1000TCEQ. 5 bulk SCB / 1000TC = bulk CH3 / 1000TC - bulk CH3end / 1000TCLastly, bulk SCB / 1000TC are converted to bulk i 2 in the same manner as described above.

[0031] LS molecular weight: The LS detector is the 18-angle Wyatt Technology High Temperature DAWN HELEOSII. The LS molecular weight (M) at each point in the chromatogram is determined by analyzing the LS output using the Zimm model for static light scattering (Light Scattering from Polymer Solutions; Huglin, M. B., Ed.; Academic Press, 1972):EQ. 6

[0032] Here, AR(0) is the measured excess Rayleigh scattering intensity at scattering angle 9, c is the polymer concentration determined from the IR5 analysis, A2 is the second virial coefficient, P(0) is the form factor for a monodisperse random coil, and Ko is the optical constant for the system:EQ. 7where NA is Avogadro’s number, and (dn / dc) is the refractive index increment for the system, n = 1.500 for TCB at 145°C, and = 665 nm. For analyzing ethylene homopolymers, ethylenehexene copolymers, and ethylene-octene copolymers, dn / dc = 0. 1048 ml / mg and A2 = 0.0015; for analyzing ethylene-butene copolymers, dn / dc = 0.1048*(l-0.00126*w2) ml / mg and A2 = 0.0015 where w2 is weight percent butene comonomer, for all other ethylene polymers dn / dc = 0.1048 ml / mg and A2 = 0.0015.

[0033] Viscosity MW: A high temperature viscometer, such as those made by Technologies. Inc. or Viscotek Corporation, which has four capillaries arranged in a Wheatstone bridge configuration with two pressure transducers, is used to determine specific viscosity. One transducer measures the total pressure drop across the detector, and the other, positioned between the two sides of the bridge, measures a differential pressure. The specific viscosity, ps, for the solution flowing through the viscometer is calculated from their outputs. The intrinsic viscosity, [ ], at each point in the chromatogram is calculated from the equation [q] = qs / c, where c is concentration and is determined from the IR5 broadband channel output. The viscosity MW at each point is calculatedwhere aPS is 0.67 and KPS is 0.000175. The average intrinsic viscosity, ([q]) of the sample is calculated by:EQ. 8where the summations are over the chromatographic slices, i. between the integration limits.

[0034] The long chain branching index (g’ECB, also referred to as g'vis) is defined asEQ. 9where (MIR) is the viscosity average molecular weight calibrated with polystyrene standards, K and a are for the reference linear polymer, which are as calculated and published in literature (Sun, T. et al. Macromolecules 2001, 34. 6812), except that for purposes of this invention and claims thereto, a = 0.705 and K = 0.0002288 for linear propylene polymers, a = 0.695 and K = 0.000181 for linear butene polymers, a is 0.695 and K is 0.000579*(l- 0.0087*w2b+0.000018*(w2b)A2) for ethylene-butene copolymer where w2b is a bulk weight percent of butene comonomer, a is 0.695 and K is 0.000579*(l-0.0075*w2b) for ethylene-hexene copolymer where w2b is a bulk weight percent of hexene comonomer, and a is 0.695 and K is 0.000579*(l-0.0077*w2b) for ethylene-octene copolymer where w2b is a bulk weight percent of octene comonomer, and a = 0.695 and K = 0.0005 for all other linear ethylene polymers.

[0035] The 1% secant modulus and tensile properties, including yield strength, and tensile strength are determined by ASTM D882-18 with gauge variations within 10%-15% range for Sample C-l along TD, Sample C-2 along TD and sample C-4 along TD. The average gauge uniformity per sample is below 10% for all other samples.Polyethylene Compositions

[0036] In various embodiments, the present disclosure describes compositions of, and / or methods for making, polyethylene compositions including polyethylene homopolymers, and / or copolymers of ethylene and one, two, three, four or more C3 to C40 olefin comonomers, for example, Cs to C20 a-olefin comonomers.

[0037] Polyethylene compositions in accordance with the present disclosure may be copolymers of majority ethylene (e.g., 80, 85, 90. 95. 98, 99 wt.% or more ethylene-derived units, for example, 98 wt.% or more) and one or more C3 to C40 comonomers (e.g., 1 -butene, 1 -hexene, 1 -octene). Such polyethylene compositions may be linear low density polyethylene (LLDPE) compositions (e.g., having density within the range from 0.900 to 0.940 g / cm3in accordance with various embodiments) that exhibit a high degree of broad orthogonal composition distribution (BOCD); that is, with a high degree of short chain branching (SCB) — also referred to as comonomer incorporation — on longer-molecular weight chains within the polyethylene composition, as compared to SCB in the lower-molecular weight chains of the polyethylene composition.

[0038] In embodiments, the polyethylene compositions include copolymers of ethy lene and one, two or three or more different C3 to C40 olefins. In particular embodiments, the polyethylene compositions comprise a majority of units derived from ethylene, and units derived from one or more C3 to C40 comonomers, for example, C3 to C20 a-olefin comonomers (e.g., propylene, 1- butene, 1 -hexene, 1 -octene, 1 -decene, or 1 -dodecene, alternatively, propylene, 1 -butene, 1- hexene, 1 -octene, or a mixture thereof, or alternatively, 1 -butene and / or 1 -hexene).

[0039] The polyethylene composition may comprise the ethylene-derived units in an amount of at least 80 wt.%, or 85 wt.%, fore example, 90, 93, 94, 95, or 96 wt.% (for instance, in a range from a low of 80, 85, 90, 91, 92, 93, 94, 95, 96, or 97 wt.%, to a high of 94, 95, 95.5, 96, 96.5, 97, 97.5, or 98 wt.%, with ranges from any foregoing low end to any foregoing high end contemplated, provided the high is greater than the low). For instance, the polyethylene composition may comprise 94 or 95 wt.% to 97 or 98 wt.% ethylene-derived units. Comonomer units (e.g., C3 to C20 a-olefin-derived units, such as units derived from butene, hexene, and / or octene) may be present in the polyethylene composition within the range from a low of 4, 4.5, 5, or 6 wt.%. to a high of 10. 12. 14 or 15 wt.%, with ranges from any foregoing low ends to any foregoing highends contemplated (provided the high is greater than the low end). For instance, the polyethylene composition may comprise 4, 4.5, or 5 wt.% to 12 or 14 wt.% comonomer units.

[0040] Several suitable comonomers are noted above, although in various embodiments, other a- olefin comonomers are contemplated. For example, the a-olefin comonomer can be linear or branched, and two or more comonomers can be used, if desired. Examples of suitable comonomers include linear C3-C20 a-olefins (such as butene, hexene, octene as already noted), and a-olefins having one or more C1-C3 alkyl branches, or an aryl group. Specific examples include propylene; 3-methyl-l -butene; 3,3-dimethyl-l-butene; 1-pentene; 1-pentene with one or more methyl, ethyl or propyl substituents; 1 -hexene with one or more methyl, ethyl or propyl substituents; 1 -heptene with one or more methyl, ethyl or propyl substituents; 1-octene with one or more methyl, ethyl or propyl substituents; 1 -nonene with one or more methyl, ethyl or propyl substituents; ethyl, methyl or dimethyl-substituted 1 -decene; 1 -dodecene; and styrene. It should be appreciated that the list of comonomers above is merely exemplary, and is not intended to be limiting. In some embodiments, comonomers include propylene, 1 -butene, 1-pentene, 4-methyl-l-pentene, 1- hexene, 1-octene and styrene.Catalyst Systems and Activators

[0041] Suitable polymerization processes employ a polymerization catalyst system, and in particular a polymerization catalyst system comprising at least one activator, at least one support and at least one catalyst composition. The catalyst composition may be a single-site catalyst, such as a metallocene catalyst.

[0042] Any suitable polymerization catalyst may be used to obtain the polyethylene compositions as described herein (e.g., Ziegler-Natta, single-site such as metallocene, etc.), but example catalyst systems employ a catalyst system comprising a mix of two metallocene catalysts: a bis- cyclopentadienyl hafnocene and a zirconocene, such as an indenylcyclopentadienyl zirconocene, such as those described in US2020 / 0071437 and / or in W02019 / 083609.

[0043] In embodiments, catalyst systems comprise a mix of a biscyclopentadienyl hafnocene and a zirconocene, the bis-cyclopentadienyl hafnocene may be in accordance with one or more of the following metallocene catalyst compositions according to formulas (Al) and / or (A2) as described in US2020 / 0071437; and the zirconocene may be in 30 accordance with one or more of the catalyst compositions of formula (B) as described in US2020 / 0071437. Further, the catalyst system may be delivered to the polymerization reactor (e.g., gas phase fluidized bed polymerization reactor; slurry loop polymerization reactor, or other suitable reactor) in a catalyst trim methodology as described in paragraphs

[0134] -

[0139] of US2020 / 0071437. Further, any of the activators and / orsupports and other catalyst additives as described in US2020 / 0071437 may be employed in connection with the catalyst system.Methods of Making Polyethylene Compositions

[0044] In embodiments, a polymerization process includes contacting monomer (such as ethylene), and optionally comonomer (e.g., any of the above-described comonomers), with a catalyst system comprising at least one activator, at least one support and at least one catalyst, such as a metallocene compound. The support, catalyst compound, and activator may be combined in any order, and are combined typically prior to contacting with the monomers.

[0045] Polymerization processes according to the present disclosure can be carried out in any manner known in the art. Any suspension, slurry, high pressure tubular or autoclave process, or gas phase polymerization process known in the art can be used under polymerizable conditions. Such processes can be run in a batch, semi-batch, or continuous mode. Heterogeneous polymerization processes (such as gas phase and slurry’ phase processes) are useful. A heterogeneous process is defined to be a process where the catalyst system is not soluble in the reaction media. Alternatively, in other embodiments, the polymerization process is not homogeneous. In embodiments, the polymerization is performed in the gas phase, in particular in a gas-phase fluidized bed reactor system. In embodiments herein, the polymerization to obtain the polyethylene composition takes place in a single reactor, or in multiple parallel reactors, as opposed to taking place in multiple series reactors. However, it is also contemplated that the polyethylene composition could, in other embodiments, be formed in multiple (two or more) series reactors. In embodiments, the polymerization process is carried out at polymerization conditions to produce the polyethylene compositions.Polyethylene Composition - Molecular Characteristics

[0046] The density’ of each of polyethylene copolymer resin was determined in accordance to ASTM D1505. A polyethylene composition according to various embodiments can have a density in a range of 0.910 to 0.950 g / cm3. Alternatively, a density’ in a range of 0.910 to 0.920 g / cm3, in a range of 0.920 to 0.930 g / cm1, in a range of 0.930 to 0.940 g / cm3, in a range of 0.940 to 0.950 g / cm3, or any ranges therebetween.

[0047] In various embodiments, the polyethylene composition has one or more, two or more, or, for example, all of the following molecular weights (determined by GPC using the infra-red (IR) detector) of weight-average molecular weight (Mw), number-average molecular weight (Mn), and Z-average molecular weight (Mz).

[0048] In embodiments, the polyethylene composition has a number-average molecular weight (Mn) (IR) in a range of from 7,000 to 25,000 g / mol. Alternatively, a number-average molecularweight (Mn) (IR) in a range of from 7,000 to 10,000 g / mol, in a range of from 10,000 to 15,000 g / mol, in a range of from 15,000 to 20,000 g / mol, in a range of from 20.000 to 25,000 g / mol. or any ranges therebetween.

[0049] In embodiments, the polyethylene composition has a weight-average molecular weight (Mw) (IR) in a range of from 60,000 to 100,000 g / mol. Alternatively, a weight-average molecular weight (Mw) (IR) in a range of from 60,000 to 70,000 g / mol, in a range of from 70,000 to 80,000 g / mol, in a range of from 80.000 to 90,000 g / mol. in a range of from 90,000 to 100,000 g / mol. or any ranges therebetween.

[0050] In embodiments, the polyethylene composition has a z-average molecular weight (Mz) (IR) in a range of from 125,000 to 350,000 g / mol. Alternatively, a z-average molecular weight (Mz) (IR) in a range of from 125.000 to 200.000 g / mol, in a range of from 200,000 to 300,000 g / mol, in a range of from 300,000 to 350,000 g / mol, or any ranges therebetween.

[0051] In embodiments, the polyethylene composition has a z+l-average molecular weight (Mz+i) (IR) in a range of from 250,000 to 700,000 g / mol. Alternatively, a z-average molecular weight (Mz+i) (IR) in a range of from 250,000 to 350,000 g / mol. in a range of from 350,000 to 450,000 g / mol, in a range of from 450,000 to 550,000 g / mol, in a range of from 550,000 to 650,000 g / mol, in a range of from 650,000 to 750,000 g / mol, or any ranges therebetween.

[0052] In various embodiments, the polyethylene composition has one or more, two or more, or, for example, all of the following molecular weights (determined by GPC using the light scattering (LS) detector) of weight-average molecular weight (Mw), number-average molecular weight (Mn), and Z-average molecular weight (Mz).

[0053] In embodiments, the polyethylene composition has a number-average molecular weight (Mn) (LS) in a range of from 9,000 to 24,000 g / mol. Alternatively, a number-average molecular weight (Mn) (LS) in a range of from 9,000 to 10,000 g / mol, in a range of from 10,000 to 15,000 g / mol, in a range of from 15,000 to 20,000 g / mol, in a range of from 20,000 to 24,000 g / mol, or any ranges therebetween.

[0054] In embodiments, the polyethylene composition has a weight-average molecular weight (Mw) (LS) in a range of from 65,000 to 112,000 g / mol. Alternatively, a weight-average molecular weight (Mw) (LS) in a range of from 65.000 to 70,000 g / mol. in a range of from 70,000 to 80,000 g / mol, in a range of from 80,000 to 90,000 g / mol, in a range of from 90,000 to 112,000 g / mol, or any ranges therebetween.

[0055] In embodiments, the polyethylene composition has a z-average molecular weight (Mz) (LS) in a range of from 125,000 to 350,000 g / mol. Alternatively, a z-average molecular weight(Mz) (LS) in a range of from 125,000 to 200,000 g / mol, in a range of from 200,000 to 300,000 g / mol, in a range of from 300,000 to 350,000 g / mol, or any ranges therebetween

[0056] In embodiments, the polyethylene composition has a comonomer content (Cn) wt.% in a range of 2 wt.% to 12 wt.%. Alternatively, a comonomer content (Cn) wt.% in a range of 2 wt.% to 5 wt.%, in a range of 5 wt.% to 8 wt.%, in a range of 8 wt.% to 12 wt.%, or any ranges therebetween.

[0057] In embodiments, the polyethylene composition has a Mw / Mn ratio as measured by (IR), also referred to polydispersity index, PDI, in a range of 4 to 10. Alternatively, the polyethylene composition has a Mw / Mn ratio as measured by (IR) in a range of 4 to 5, in a range of 5 to 6, in a range of 6 to 7, in a range of 7 to 8, in a range of 8 to 9, in a range of 9 to 10, or any ranges therebetween.

[0058] In embodiments, the polyethylene composition has a Mz / Mw ratio as measured by (IR) in a range of 1.5 to 5.0. Alternatively, the polyethylene composition has a Mw / Mn ratio as measured by (IR) in a range of 1.5 to 2.5, in a range of 2.5 to 3.5, in a range of 4.5 to 5.0, or any ranges therebetween.

[0059] In embodiments, the polyethylene composition has a Mz / Mn ratio as measured by (IR) in arange of 5.0 to 25.0. Alternatively, the polyethylene composition has a Mz / Mn ratio as measured by (IR) in a range of 5.0 to 10.0, in a range of 10.0 to 15.0, in a range of 15.0 to 20.0, in a range of 20.0 to 25.0. or any ranges therebetween.

[0060] Furthermore the polyethylene compositions of various embodiments described herein exhibit unimodal distribution with respect to molecular weight of polymer chains, meaning that there is a single distinguishable peak in a molecular weight distribution curve of the composition (as determined using gel permeation chromatography (GPC) or other recognized analytical technique, noting that if there is any conflict between or among analytical techniques, a molecular weight distribution determined by GPC, as described below, shall control). This is in contrast with a ‘‘multimodal” molecular weight distribution, which means that there are at least two distinguishable peaks in a molecular weight distribution curve (again, as determined by GPC or any other recognized analytical technique, with GPC controlling in the event of any conflict). For example, if there are two distinguishable peaks in the molecular weight distribution curve such composition may be referred to as bimodal composition.

[0061] As noted, polyethylene compositions of the present disclosure exhibit BOCD characteristics. Several methods can illustrate the high degree of preferential comonomer incorporation along the high molecular-weight chains of the polyethylene composition.Other Resin Properties

[0062] In various embodiments, the polyethylene compositions have a melt index, (MI, also referred to as h or I2.16 in recognition of the 2.16 kg loading used in the ASTM D1238 test procedure) within the range from 2 g / 10 min to 10 g / 10 min. Alternatively, an I2.16 in a range of from 2 g / 10 min to 4 g / 10 min, in a range of from 4 g / 10 min to 6 g / 10 min, in a range of from 6 g / 10 min to 8 g / 10 min, in a range of from 8 g / 10 min to 10 g / 12 min, or any ranges therebetw een.

[0063] Moreover, polyethylene compositions of various embodiments can have a high load melt index (HLMI) (also referred to as I21 or I21.6 in recognition of the 21.6 kg loading used in the ASTM D1238 test procedure) within the range of from 60 g / 10 min to 180 g / 10 min. Alternatively, an I21.6 in a range of from 60 g / 10 min to 80 g / 10 min, 80 g / 10 min to 100 g / 10 min, 100 g / 10 min to 125 g / 10 min. 125 g / 10 min to 150 g / 10 min. 150 g / 10 min to 180 g / 10 min. or any ranges therebetween.

[0064] Polyethylene compositions according to various embodiments have a melt index ratio (MIR, defined as I21.6 / I2. ie) in a range of 15 to 40. Alternatively, a MIR in a range of 15 to 25, in a range of 25 to 35, in a range of 30 to 40, or any ranges therebetween.

[0065] Polyethylene compositions according to various embodiments have a very low- density VLD % as measured by temperature rising elution fractionation (TREF) in a range of 2 % to 40 %. Alternatively, the polyethylene compositions according to various embodiments have a very low density VLD % 2% to 10%, 10% to 20%, 20% to 30%, 30% to 40%, or any ranges therebetween.

[0066] Polyethylene compositions according to various embodiments have a low-density LD % as measured by temperature rising elution fractionation (TREF) in a range of 5 % to 35 %. Alternatively, the polyethylene compositions according to various embodiments have a very low- density LD % 5% to 10%, 10% to 20%, 20% to 30%, 30% to 35%, or any ranges therebetween.

[0067] Polyethylene compositions according to various embodiments have a medium density MD % as measured by temperature rising elution fractionation (TREF) in a range of 10 % to 35 %. Alternatively, the polyethylene compositions according to various embodiments have a medium density MD % 10% to 20%, 20% to 30%, 30% to 35%, or any ranges therebetween.

[0068] Polyethylene compositions according to various embodiments have a high-density HD % as measured by temperature rising elution fractionation (TREF) in a range of 5 % to 80 %. Alternatively, the polyethylene compositions according to various embodiments have a high- density HD % 5% to 25%, 25% to 50%, 50% to 80%, or any ranges therebetween.

[0069] Polyethylene compositions according to various embodiments have a main peak temperature as measured by temperature rising elution fractionation (TREF) in a range of 75 °Cto 100 °C. Alternatively, the polyethylene compositions according to various embodiments have a main peak temperature in a range of 75 °C to 85 °C. in a range of 85 °C to 95 °C, in a range of 95 °C to 100 °C, or any ranges therebetween.

[0070] Polyethylene compositions according to various embodiments have a composition distribution breadth index (CBDI %) as measured by temperature rising elution fractionation (TREF) in a range of 25 % to 75 %. Alternatively, a composition distribution breadth index in a range of 25 % to 45 %, in a range of 45 % to 65 %, in a range of 65 % to 75 %. or any ranges therebetween.

[0071] Polyethylene compositions according to various embodiments have a Degree of Shear Thinning (DoST) determined using SAOS in a range of 0.6 to 0.9. Alternatively, DoST in a range of 0.6 to 0.7, 0.7 to 0.8, 0.8 to 0.9. or any ranges therebetween.

[0072] Polyethylene compositions according to various embodiments have a Viscosity, r|500(Pa*s) determined using SAOS in arange of 250 Pa*s to 550 Pa*s. Alternatively, a Viscosity, r|500(Pa*s) in a range of 250 Pa*s to 300 Pa*s, in a range of 300 Pa*s to 400 Pa*s, in a range of 400 Pa*s to 500 Pa*s, in a range of 500 Pa*s to 600 Pa*s, in a range of 600 Pa*s to 550 Pa*s, or any ranges therebetween.

[0073] Polyethylene compositions according to various embodiments have a Viscosity, r|0.5(Pa*s) determined using SAOS in a range of 1000 Pa*s to 3500 Pa*s. Alternatively, a Viscosity, r|0.5(Pa*s) in a range of 1000 Pa*s to 1500 Pa*s, in arange of 1500 Pa*s to 2000 Pa*s, in a range of 2000 Pa*s to 2500 Pa*s. in a range of 2500 Pa*s to 3000 Pa*s, in a range of 3000 Pa*s to 3500 Pa*s, or any ranges therebetween.

[0074] Polyethylene compositions according to various embodiments have a methyl content (methyl / lOOOC) as determined by nuclear magnetic resonance (NMR) in a range of 3 to 30. Alternatively, a methyl content (methyl / 1000C) in a range of 3 to 5, 5to 10, 10 to 15, 15 to 20, 20 to 25, 25 to 30, or any ranges therebetween.

[0075] Polyethylene compositions according to various embodiments have a vinylenes content (vinylenes / lOOOC) as determined by nuclear magnetic resonance (NMR) in a range of 0.01 to 0.4. Alternatively, a vinylenes content (vinylenes / 1000C) in a range of 0.01 to 0.05. 0.05 to 0.1, 0.1 to 0.15. 0.15 to 0.20. 0.20 to 0.25, 0.25 to 0.3. 0.3 to 0.4, or any ranges therebetween.

[0076] Polyethylene compositions according to various embodiments have a trisubstituted olefins content (trisubstituted olefins / 1000C) as determined by nuclear magnetic resonance (NMR) in a range of 0.01 to 0.40. Alternatively, a trisubstituted olefins content (trisubstituted olefins / 1000C) in a range of 0.01 to 0.05, 0.05 to 0.1. 0.1 to 0.15, 0.15 to 0.20, 0.20 to 0.25. 0.25 to 0.30. 0.3 to 0.4, or any ranges therebetween.

[0077] Polyethylene compositions according to various embodiments have a vinyl content (vinyl / 1000C) as determined by nuclear magnetic resonance (NMR) in a range of 0.00 to 0.1. Alternatively, a vinyl content (vinyl / 1000C) in a range of 0.00 to 0.01, 0.01 to 0.05, 0.05 to 0.075, 0.075 to 0.1, or any ranges therebetween.

[0078] Polyethylene compositions according to various embodiments have a vinylidenes content (vinylidenes / lOOOC) as determined by nuclear magnetic resonance (NMR) in a range of 0.01 to 0. 15. Alternatively, a vinylidenes content (vinylidenes / 1000C) in a range of 0.00 to 0.01, 0.01 to 0.04, 0.04 to 0.070, 0.07 to 0.1, 0.1 to 0.15 or any ranges therebetween.Films and Methods

[0079] In addition to the polyethylene, the films may include one or more additives. Examples of additives include, but are not limited to, stabilization agents (e.g.. antioxidants or other heat or light stabilizers), anti-static agents, crosslink agents or co-agents, crosslink promoters, release agents, adhesion promoters, plasticizers, anti-agglomeration agents (e.g., oleamide, stearamide, erucamide or other derivatives with the same activity), and fillers.

[0080] When present, the amount of the additives cumulatively can range from 0.01 wt.% to 1 wt.% (or 0.01 wt.% to 0.1 wt.%. or 0.1 wt.% to 1 wt.%).

[0081] In embodiments, polyethylene films produced from the polyethylene compositions disclosed herein have a machine direction (MD) 1% secant modulus (psi) as measured according to ASTM D-882-18, in a range of 15,000psi to 80,000psi. Alternatively, a machine direction 1% secant modulus (psi) in a range of 15,000 psi to 25,000 psi, in a range of 25,000 psi to 50,000 psi, in a range of 50,000 psi to 65,000 psi, in a range of 65,000 psi to 80,000 psi, or any ranges therebetween.

[0082] In embodiments, polyethylene films produced from the polyethylene compositions disclosed herein have a transverse direction (TD) 1% secant modulus (psi) as measured according to ASTM D-882-18, in a range of 15,000 psi to 80,000 psi. Alternatively, a transverse direction 1% secant modulus (psi) in a range of 15,000 psi to 25,000 psi, in a range of 25,000 psi to 50,000 psi, in a range of 50,000 psi to 65,000 psi, in a range of 65,000 psi to 80,000 psi, or any ranges therebetween.

[0083] In embodiments, polyethylene films produced from the polyethylene compositions disclosed herein have a dart drop as measured according to ASTM D-1709, Phenolic, Method A in a range of 200 g to 800 g. Alternatively, a dart drop as measured according to ASTM DI 709 in a range 200 g to 400 g, in a range of 400 g to 600 g, in a range of 600 g to 800 g, or any ranges therebetween.

[0084] In embodiments, polyethylene films produced from the polyethylene compositions disclosed herein have a machine direction tear strength as measured according to ASTM DI 922- 09 in a range of 20 g to 400 g. Alternatively, a machine direction tear strength in a range 20 g to 50 g, in a range of 50 g to 100 g, in a range of 100 g to 200 g, in a range of 200 g to 300 g, in a range of 300 g to 400 g, or any ranges therebetween.

[0085] In embodiments, polyethylene films produced from the polyethylene compositions disclosed herein have a transverse direction tear strength as measured according to ASTM D 1922- 09 in a range of 90 g to 500 g. Alternatively, a machine direction tear strength in a range 90 g to 100 g, in a range of 100 g to 200 g, in a range of 200 g to 300 g, in a range of 300 g to 400 g, in a range of 400 g to 500 g, or any ranges therebetween.

[0086] In embodiments, polyethylene films produced from the polyethylene compositions disclosed herein have a machine direction yield strength as measured according to ASTM D-882- 18, in a range of 900 psi to 3000 psi. Alternatively, a machine direction yield strength in a range 900 psi to 1500 psi, in a range of 1500 psi to 2000 psi, in a range of 2000 psi to 2500 psi, 2500 psi to 3000 psi or any ranges therebetween.

[0087] In embodiments, polyethylene films produced from the polyethylene compositions disclosed herein have a transverse direction yield strength as measured according to ASTM D- 882-18, in a range of 900 psi to 3000 psi. Alternatively, a transverse direction yield strength in a range 900 psi to 1500 psi, in a range of 1500 psi to 2000 psi, in a range of 2000 psi to 2500 psi. in a range of 2500 psi to 3000 psi or any ranges therebetween.

[0088] In embodiments, polyethylene films produced from the polyethylene compositions disclosed herein have a machine direction tensile strength as measured according to ASTM D- 882-18, in a range of 4000 psi to 9500 psi. Alternatively, a machine direction tensile strength in a range 4000 psi to 5000 psi. in a range of 5000 psi to 6000 psi, in a range of 6000 psi to 7000 psi, 7000 psi to 8000 psi, 8000 psi to 9500 psi, or any ranges therebetween.

[0089] In embodiments, polyethylene films produced from the polyethylene compositions disclosed herein have a transverse direction tensile strength as measured according to ASTM D- 882-18, in a range of 4000 psi to 10000 psi. Alternatively, a transverse direction tensile strength in a range 4000 psi to 5000 psi, in a range of 5000 psi to 6000 psi, in a range of 6000 psi to 7000 psi, in a range of 7000 psi to 8000 psi, in a range of 8000 psi to 9000 psi, in a range of 9000 psi to 10000 psi, or any ranges therebetween.

[0090] In embodiments, polyethylene films produced from the polyethylene compositions disclosed herein have a haze as measured according to ASTM D-1003 in a range of 1% to 15%. Alternatively, a haze in a range of 1 % to 5%, 5% to 10%, 10% to 15%, or any ranges therebetween.End Uses

[0091] The cast polyethylene films described herein may be used as monolayer films or as one or more layers of a multilayer film. Examples of other layers include, but are not limited to, blown polymer films, cast polymer films, MDO polymer films, and biaxially-oriented polymer films of polymers like polyethylene, polypropylene, polyethylene terephthalate, polysty rene, polyamide, and the like.

[0092] The polyethylene films described herein (alone or as part of a multilayer film) are useful in end use applications that include, but are not limited to, film-based products, shrink film, cling film, stretch film, sealing films, snack packaging, heavy-duty' bags, grocery sacks, baked and frozen food packaging, diaper backsheets, housewrap, medical packaging (e.g., medical films and intravenous (IV) bags), industrial liners, membranes, and the like.

[0093] In one embodiment, multilayer films or multiple-layer films may be formed by methods well known in the art. The total thickness of multilayer films may vary based upon the application desired. A total film thickness of about 5-100 pm, more ty pically about 10-50 pm, is suitable for most applications. Those skilled in the art will appreciate that the thickness of individual layers for multilayer films may be adjusted based on desired end-use performance, resin or copolymer employed, equipment capability, and other factors. The materials forming each layer may be coextruded through a coextrusion feedblock and die assembly to yield a film with two or more layers adhered together but differing in composition. Coextrusion can be adapted for use in both cast film or blown film processes. Exemplary multilayer films have at least two, at least three, or at least four layers. In one embodiment, the multilayer films are composed of five to ten layers.

[0094] To facilitate discussion of different film structures, the following notation is used herein. Each layer of a film is denoted "A" or "B". Where a film includes more than one A layer or more than one B layer, one or more prime symbols (', ", etc.) are appended to the A or B symbol to indicate layers of the same t pe that can be the same or can differ in one or more properties, such as chemical composition, density, melt index, thickness, etc. Finally, the symbols for adjacent layers are separated by a slash ( / ). Using this notation, a three-layer film having an inner layer disposed between two outer layers would be denoted A / B / A'. Similarly, a five-layer film of alternating layers would be denoted A / B / A7B7A". Unless otherwise indicated, the left-to-right or right-to-left order of layers does not matter, nor does the order of prime symbols; e g., an A / B film is equivalent to a B / A film, and an A / A7B / A" film is equivalent to an A / B / A7A" film, for purposes described herein. The relative thickness of each film layer is similarly denoted, with the thickness of each layer relative to a total film thickness of 100 (dimensionless) indicated numerically andseparated by slashes; e.g., the relative thickness of an A / B / A' film having A and A' layers of 10 pm each and a B layer of 30 pm is denoted as 20 / 60 / 20.

[0095] The thickness of each layer of the film, and of the overall film, is not particularly limited, but is determined according to the desired properties of the film. Typical film layers have a thickness of from about 1 to about 1,000 pm, more typically from about 5 to about 100 pm, and typical films have an overall thickness of from about 10 to about 100 pm.

[0096] In some embodiments, and using the nomenclature described above, examples provide for multilayer films with any of the following exemplary structures: (a) two-layer films, such as A / B and B / B'; (b) three-layer films, such as A / B / A', A / A7B, B / A / B' and B / B' / B"; (c) four-layer films, such as A / A7A7B, A / A7B / A", A / A7B / B', A / B / A7B1, A / B / B7A', B / A / A7B', A / B / B7B", B / A / B 7B" and B / B7B7B'"; (d) five-layer films, such as A / A7A" / A"7B, A / A7A7B / A'", A / A7B / A7A'", A / A7A7B / B', A / A7B / A7B', A / A7B / B7A", A / B / A7B7A", A / B / A7A7B, B / A / A7A7B',A / A7B / B7B", A / B / A7B7B", A / B / B7B7A', B / A / A7B7B", B / A / B7A7B", B / A / B7B7A',A / B / B7B7B'", B / A / B7B7B"', B / B7A / B7B'", and B / B7B7B"7B""; and similar structures for films having six, seven, eight, nine, twenty-four, forty-eight, sixty-four, one hundred, or any other number of layers. It should be appreciated that films having still more layers.

[0097] In any of the embodiments above, one or more A layers can be replaced with a substrate layer, such as glass, plastic, paper, metal, etc., or the entire film can be coated or laminated onto a substrate. Thus, although the discussion herein has focused on multilayer films, the films may also be used as coatings for substrates such as paper, metal, glass, plastic, and other materials capable of accepting a coating.

[0098] The films can further be embossed, or produced or processed according to other known film processes. The films can be tailored to specific applications by adjusting the thickness, materials and order of the various layers, as well as the additives in or modifiers applied to each layer.Additional Embodiments

[0099] Accordingly, the present disclosure may provide polyethylene compositions having properties suitable for casting applications. The methods and compositions may include any of the various features disclosed herein, including one or more of the following statements.

[0100] Embodiments 1. A polyethylene composition comprising: about 80 wt.% to about 99 wt.% ethylene-derived content, and about 1.0 wt.% to about 20 wt.% units derived from one or more C3 to C40 a -olefin comonomers, based on a total weight of the polyethylene composition, wherein the polyethylene composition comprises: a density of about 0.91 g / cm3to about 0.95 g / cm3; a melt index (I2.16) of about 2 g / 10 min to about 10 g / 10 min; a melt index ratio (I21.6 / I2.16) of about 15 toabout 40; a number average molecular weight, Mn (IR) of about 7,000 g / mol to 25,000 g / mol; a weight average molecular weight, Mw (IR) of about 60,000 g / mol to 100,000 g / mol; a molecular weight distribution (Mw / Mn) ratio (IR) of about 4 to about 10; a molecular weight distribution (Mz / Mn) ratio (IR) of about 5 to about 25; a ratio of z-average molecular weight to weight-average molecular weight (Mz / Mw) of about 1.5 to about 5.0; and a very low density7VLD% as measured by temperature rising elution fractionation (TREF) of about 2% to about 40%.

[0101] Embodiments 2. The polyethylene composition of embodiment 1, wherein the C3 to C40 a-olefin comonomers comprise at least one comonomer selected from the group consisting of 1 - butene; 1 -hexene, 1 -octene, and combinations thereof.

[0102] Embodiments 3. The polyethylene composition of embodiments 1 or 2, wherein the comonomer content is 2 wt.% to 12 wt.%.

[0103] Embodiments 4. The polyethylene composition of any of embodiments 1-3, wherein the comonomer content is 7 wt.% to 10 wt.% and the comonomer is 1 -hexene.

[0104] Embodiments 5. The polyethylene composition of any of embodiments 1-4, wherein the polyethylene composition has a very low density VLD% as measured by temperature rising elution fractionation (TREF) of about 2% to about 40%.

[0105] Embodiments 6. The polyethylene composition of any of embodiments 1-5, wherein the polyethylene composition has a Mz / Mn ratio as measured by (IR) from about 5.0 to about 25.0.

[0106] Embodiments 7. The polyethylene composition of any of embodiments 1-6, wherein the polyethylene composition has a number-average molecular weight (Mn) (LS) from about 9,000 g / mol to about 24,000 g / mol.

[0107] Embodiments 8. The polyethylene composition of any of embodiments 1-7, wherein the polyethylene composition has a Viscosity, r|500(Pa*s) determined using SAOS from about 250 Pa*s to about 600 Pa*s.

[0108] Embodiments 9. The polyethylene composition of any of embodiments 1-8, wherein the polyethylene composition has a Viscosity, r|0.5(Pa*s) determined using SAOS in a range of 1000 Pa*s to 4000 Pa*s.

[0109] Embodiments 10. The polyethylene composition of any of embodiments 1-9, further comprising: z-average molecular weight (Mz) (IR) in a range of from 140,000 to 300,000 g / mol; weight-average molecular weight (Mw) (IR) in a range of from 60,000 to 100,000 g / mol; and weight-average molecular weight (Mw) (LS) within the range from 65,000 to 112,000 g / mol.

[0110] Embodiments 11. A cast polyethylene film, comprising: a polyethylene composition of embodiment 1, wherein the film has: a machine direction (MD) 1% secant modulus as measured according to ASTM D-882-18, from about 15,000 psi to about 80,000 psi. a transverse direction(TD) 1% secant modulus (psi) as measured according to ASTM D-882-18, in a range of 15,000 psi to 80.000 psi. a machine direction yield strength as measured according to ASTM D-882-18 from about 900 psi to about 3000 psi; a transverse direction yield strength as measured according to ASTM D-882-18 from 900 psi to 3000 psi; and a dart drop as measured according to ASTM D-1709, Phenolic, Method A in a range of 200 g to 800 g.[OHl] Embodiments 12. The cast polyethylene film of embodiment 11. wherein the polyethylene film has a machine direction tensile strength as measured according to ASTM D-882-18 of about 4000 psi to about 9500 psi.

[0112] Embodiments 13. The cast polyethylene film of any of embodiments 11-12, wherein the polyethylene film has a transverse direction tensile strength as measured according to ASTM D- 882-18 of about 4000 psi to about 10000 psi.

[0113] Embodiments 14. The cast polyethylene film any of embodiments 1 1-13, wherein the polyethylene film has a haze as measured according to ASTM D-1003 in a range of 1% to 15%.

[0114] Embodiments 15. The cast polyethylene film any of embodiments 11-13, wherein the polyethylene film has a dart drop as measured according to ASTM D-1709, Phenolic, Method A, from about 200 g to about 800 g.

[0115] Embodiments 16. A method for making a film, comprising: producing a polymer melt comprising a polyethylene composition of embodiment 1 ; extruding a film from the polymer melt; and fabricating the film of the polymer melt, wherein the film has: a machine direction (MD) 1% secant modulus as measured according to ASTM D-882-18, from about 15,000 psi to about 80,000 psi. a transverse direction (TD) 1 % secant modulus (psi) as measured according to ASTM D-882- 18, in a range of 15,000 psi to 80,000 psi. a machine direction yield strength as measured according to ASTM D-882-18, from about 900 psi to about 3000 psi; a transverse direction yield strength as measured according to ASTM D-882-18, from 900 psi to 3000 psi; and a dart drop as measured according to ASTM D-1709, Phenolic, Method A in a range of 200 g to 800 g.

[0116] Embodiments 17. The method of embodiment 1 wherein, the polymer melt comprises at least one additive selected from the group consisting of a stabilization agent, antioxidants, a heat stabilizer, a light stabilizer, an anti-static agent, a crosslinking agent, a crosslink promoter, a release agent, an adhesion promoters, a plasticizer, an anti-agglomeration agent, a filler, and combinations thereof.

[0117] Embodiments 18. The method of any of embodiments 16-17, wherein the film has a machine direction tensile strength as measured according to ASTM D-882-18 of about 4000 psi to about 9500 psi.

[0118] Embodiments 19. The method of any of embodiments 16-17, wherein the film has a transverse direction tensile strength as measured according to ASTM D-882-18 of about 4000 psi to about 10000 psi.

[0119] Embodiments 20. The method of any of embodiments 16-17, wherein the film has a haze as measured according to ASTM D-1003 in a range of 1% to 15%.EXAMPLES

[0120] To facilitate a better understanding of the embodiments of the present invention, the following examples of preferred or representative embodiments are given. In no way should the following examples be read to limit, or to define, the scope of the invention.Example 1:

[0121] The inventive polyethylene copolymer resins were formed in a gas phase reactor using varied H2 gas concentrations, varied flow ratios of olefin comonomer (e.g., 1-hexene) and ethylene into the gas phase reactor (C6:C2), varied induced condensing agent (ICA e.g., pentane) concentration within the reactor, and varied catalyst feed rate into the reactor. Seven different polyethylene copolymer resins (e.g.. Il, 12, 13. 14, 15, and 16) were formed in accordance with the parameters and / or input values set forth in Table 2. FIGURE is a graph of results of gel permeation chromatography (GPC) testing for II, 12, 13, 14, 15, and 16.Table 2

[0122] After the polyethylene compositions were prepared, each sample was subjected to testing to determine resin properties of each of the produced polyethylene compositions. The polyethylene compositions were compared against control C-l to C-4. The results of the testing are shown in Tables 3-6. The characterization was carried out by nuclear magnetic resonance (MT NMR) and by gel permeation chromatography with 4 detectors (GPC-4D): refractive index, viscosity, multi-angle light scattering and infrared detectors. The composition distribution of thepolyolefin was measured by temperature rising elution fractionation (TREF). The rheology was measured by small amplitude oscillatory shear (SAGS) method.Table 3Table 4Table 5

[0123] It was observed that the polyethylene compositions had desirable properties It was observed that the polyethylene compositions generally had higher values of Mw / Mn (IR) ratio, Mz / Mn (IR) ratio, comonomer content, methyl, vinylenes, and trisubstituted olefins and very low- density portion (TREF) as compared to control compositions with similar basic characteristics as melt index (MI) and density. On the other hand, the Mn (IR), CDBI value (excluding C-3 vs. 1-1 i.e. comparable) and viscosity values at 500 rad / s (excluding C-3 vs. 1-1) of the inventive resins are lower than the controls. The Mn (LS) is also trending lower.Example 2:

[0124] In this example, the polyethylene compositions prepared in Example 1 were utilized in cast film extrusion. The 7 layer monomaterial film structure was divided as: first extruder (Extruder A) produced 3-layers, and the second extruder (Extruder B) produced 4-layers. Thepolyethylene compositions were compared against control C-l to C-4. The measured extruder conditions are shown in Tables 7 - 10.Table 7Table 8Table 9Table 10

[0125] The cast processing data of the 1-2. 1-3, 1-4, 1-5 and 1-6 resins highlighted a better performance over the C-l, C-2 and C-4 resins in terms of extruder melt pressure, torque load and output. The inventive resins were able to offer lower extruder pressures and torque loads which allowed to run the line efficiently and stably at high outputs. Some improvements were also observed with 1-1 but less significant.Example 3:

[0126] In this example, the cast films prepared in Example 2 were tested for physical properties. The drop dart test was performed according to ASTM DI 709. The results of the testing is shown in Table 11 - Table 14.Table 11Table 12Table 13Table 14

[0127] Overall, the mechanical properties of the inventive resins showed a better performance in terms of stiffness and in several instances also toughness as shown for 1-2, 1-3 and 1-5 (i.e. tear resistance and dart impact).

[0128] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitlyrecited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, within a range includes every point or individual value between its end points even though not explicitly recited. Thus, every' point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

[0129] All documents described herein are incorporated by reference herein, including any priority' documents and or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the present disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby. Likewise, the term “comprising” is considered synonymous with the term “including” for purposes of United States law. Likewise whenever a composition, an element or a group of elements is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0130] The phrases, unless otherwise specified, "consists essentially of' and "consisting essentially of' do not exclude the presence of other steps, elements, or materials, whether or not, specifically mentioned in this specification, so long as such steps, elements, or materials, do not affect the basic and novel characteristics of the present disclosure, additionally, they do not exclude impurities and variances normally associated with the elements and materials used.

[0131] While the present disclosure has been described with respect to a number of embodiments and examples, those skilled in the art, having the benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope and spirit of the present disclosure.

Claims

CLAIMSWhat is claimed is:

1. A polyethylene composition comprising: about 80 wt.% to about 99 wt.% ethylene-derived content, and about 1.0 wt.% to about 20 wt.% units derived from one or more Cri to C40 a-olefm comonomers, based on a total weight of the polyethylene composition, wherein the polyethylene composition comprises: a density of about 0.91 g / cm3to about 0.95 g / cm3; a melt index (I2.16) of about 2 g / 10 min to about 10 g / 10 min; a melt index ratio (I21.6 / I2.16) of about 15 to about 40; a number average molecular weight, Mn (IR) of about 7,000 g / mol to 25,000 g / mol; a weight average molecular weight, Mw (IR) of about 60,000 g / mol to 100,000 g / mol; a molecular weight distribution (Mw / Mn) ratio (IR) of about 4 to about 10; a molecular weight distribution (Mz / Mn) ratio (IR) of about 5 to about 25; a ratio of z-average molecular weight to weight-average molecular weight (Mz / Mw) of about 1.5 to about 5.0; and a very low density VLD% as measured by temperature rising elution fractionation (TREF) of about 2% to about 40%.

2. The polyethylene composition of claim 1, wherein the C3 to C40 a-olefm comonomers comprise at least one comonomer selected from the group consisting of 1 -butene; 1 -hexene. 1 -octene, and combinations thereof.

3. The polyethylene composition of claim 1 or 2, wherein the comonomer content is 2 wt.% to 12 wt.%.

4. The polyethylene composition of any of claims 1-3, wherein the comonomer content is 7 wt.% to 10 wt.% and the comonomer is 1 -hexene.

5. The polyethylene composition of any of claims 1-4, wherein the polyethylene composition has a very low density VLD% as measured by temperature rising elution fractionation (TREF) of about 2% to about 40%.

6. The polyethylene composition of any of claims 1-5, wherein the polyethylene composition has a Mz / Mn ratio as measured by (IR) from about 5.0 to about 25.0.

7. The polyethylene composition of any of claims 1-6, wherein the polyethylene composition has a number-average molecular weight (Mn) (LS) from about 9,000 g / mol to about 24,000 g / mol.

8. The polyethylene composition of any of claims 1-7, wherein the polyethylene composition has a Viscosity, r|500(Pa*s) determined using SAGS from about 250 Pa*s to about 600 Pa*s.

9. The polyethylene composition of any of claims 1-8, wherein the polyethylene composition has a Viscosity, r|0.5(Pa*s) determined using SAGS in a range of 1,000 Pa*s to 4,000 Pa*s.

10. The polyethylene composition of any of claims 1-9, further comprising: z-av erage molecular weight (Mz) (IR) in a range of from 140.000 to 300,000 g / mol; weight-average molecular weight (Mw) (IR) in a range of from 60.000 to 100,000 g / mol; and weight-average molecular weight (Mw) (LS) within the range from 65,000 to 112,000 g / mol.1 1 . A cast polyethylene film, comprising: a polyethylene composition of claim 1, wherein the cast polyethylene film has: a machine direction (MD) 1% secant modulus as measured according to ASTM D-882- 18, from about 15,000 psi to about 80.000 psi; a transverse direction (TD) 1% secant modulus as measured according to ASTM D-882- 18, in a range of 15,000 psi to 80,000 psi; a machine direction yield strength as measured according to ASTM D-882-18 from about 900 psi to about 3,000 psi; a transverse direction yield strength as measured according to ASTM D-882-18 from 900 psi to 3,000 psi; and a dart drop as measured according to ASTM D-1709, Phenolic, Method A in a range of 200 g to 800 g.

12. The cast polyethylene film of claim 11, wherein the cast polyethylene film has a machine direction tensile strength as measured according to ASTM D-882-18 of about 4.000 psi to about 9,500 psi.

13. The cast polyethylene film of any of claims 11-12, wherein the cast polyethylene film has a transverse direction tensile strength as measured according to ASTM D-882-18 of about 4,000 psi to about 10,000 psi.

14. The cast polyethylene film of any of claims 11-13, wherein the cast polyethylene film has a haze as measured according to ASTM D-1003 in a range of 1% to 15%.

15. The cast polyethylene film any of claims 11-13, wherein the cast polyethylene film has a dart drop as measured according to ASTM D-1709, Phenolic, Method A, from about 200 g to about 800 g.

16. A method for making a film, comprising: producing a polymer melt comprising a polyethylene composition of claim 1; extruding a film from the polymer melt; and fabricating the film of the polymer melt, wherein the film has: a machine direction (MD) 1% secant modulus as measured according to ASTM D- 882-18, from about 15,000 psi to about 80,000 psi. a transverse direction (TD) 1% secant modulus (psi) as measured according to ASTM D-882-18, in a range of 15,000 psi to 80,000 psi. a machine direction yield strength as measured according to ASTM D-882-18, from about 900 psi to about 3,000 psi; a transverse direction yield strength as measured according to ASTM D-882-18, from 900 psi to 3,000 psi; and a dart A as measured according to ASTM D-1709, Phenolic, Method A in a range of 200 g to 800 g.

17. The method of claim 16 wherein, the polymer melt comprises at least one additive selected from the group consisting of a stabilization agent, an antioxidant, a heat stabilizer, a light stabilizer, an anti-static agent, a crosslinking agent, a crosslink promoter, a release agent, an adhesion promoter, a plasticizer, an anti-agglomeration agent, a filler, and combinations thereof.

18. The method of any of claims 16-17, wherein the film has a machine direction tensile strength as measured according to ASTM D-882-18 of about 4,000 psi to about 9,500 psi.

19. The method of any of claims 16-17, wherein the film has a transverse direction tensile strength as measured according to ASTM D-882-18 of about 4,000 psi to about 10,000 psi.

20. The method of any of claims 16-17, wherein the film has a haze as measured according to ASTM D-1003 in a range of 1% to 15%.

Images