BR112020022914B1 - METHOD FOR SYNTHESISTING A BIMODAL ETHYLENE-CO1-HEXENE COPOLYMER AND METHOD FOR PRODUCING A BLOWN FILM - Google Patents

Abstract

BIMODAL COPOLYMER OF POLYETHYLENE AND FILM THEREOF. It is a bimodal ethylene-co-1-hexene copolymer that essentially consists of a higher molecular weight component and a lower molecular weight component and, when in molten form at 190 degrees Celsius, is characterized by a unique melt property space defined by a combination of high load melt index, melt flow ratio, and melt elasticity properties. A blown film consisting essentially of the bimodal ethylene-co-1-hexene copolymer. A method for synthesizing bimodal ethylene-co-1-hexene copolymer. A method for producing blown film. A manufactured article comprising bimodal ethylene-co-1-hexene copolymer.

Description

Field

[0001] Polyethylene copolymers, films, manufactured articles and related methods.

Introduction

[0002] Patent application publications in or about the field include applications No. US 2016/0068623 A1; US 2016/0297907 A1 and WO 2017/132092 A1. Patents in or about the field include US Application Nos. 5,332,706; US 5,882,750; US 6,989,344 B2; US 7,078,467 B1; US 7,090,927 B2; US 7,157,531 B2; US 7,223,825 B2; US 7,300,988 B2; US 8,227,552 B2 and US 8,497,329 B2.

summary

[0003] A bimodal ethylene-co-1-hexene copolymer that consists essentially of a higher molecular weight component (HMW) and a lower molecular weight component (LMW) and, when in molten form, 190 degrees Celsius (°C), is characterized by a unique melt property space defined by a combination of high-load melt index, melt flow ratio, and melt elasticity properties ("the bimodal ethylene copolymer -co-1-hexene"). With "consist essentially of", the ethylene-co-1-hexene bimodal copolymer is free of a third or more distinct components, as determined by gel permeation chromatography (GPC) measured in accordance with the GPC Test Method.

[0004] A method for synthesizing the bimodal ethylene-co-1-hexene copolymer, the method essentially consisting of polymerizing ethylene (monomer) and 1-hexene (comonomer) with a single bimodal catalyst system in a single bed fluidized, gas phase polymerization (FB-GPP) under effective operating conditions, thus producing the bimodal ethylene-co-1-hexene copolymer. With "consist essentially of", the method is free of Ziegler-Natta catalysts and chromium catalysts, and the polymerization is carried out in a single reactor (that is, in the FB-GPP reactor), and the operating conditions are effective to impart the Unique combination of high load melt index, melt flow ratio and melt elasticity properties for the bimodal ethylene-co-1-hexene copolymer. Other than that, the method is not particularly limited.

[0005] A film consisting essentially of the bimodal ethylene-co-1-hexene copolymer ("the film"). The film is characterized by enhanced (increased) hardness comprising enhanced (increased) tear resistance and enhanced (increased) dart impact. With "consist essentially of", the film is free of other polyolefin polymers, but otherwise its constituents are not particularly limited.

[0006] A method of producing a blown film, the method comprising melting the bimodal ethylene-co-1-hexene copolymer to provide a melt thereof, extruding the melt through a die configured to produce a bubble in order to produce a bubble of the bimodal ethylene-co-1-hexene copolymer and blowing (inflating) the bubble with a film blowing machine, thus producing the blown film.

[0007] A manufactured article comprising the bimodal ethylene-co-1-hexene copolymer.

Detailed Description

[0008] The Summary and Summary are incorporated into this document by way of reference. Certain embodiments are described below as numbered aspects to facilitate cross-referencing.

[0009] Aspect 1. A bimodal ethylene-co-1-hexene copolymer consisting essentially of a higher molecular weight component (HMW) and a lower molecular weight component (LMW) and, when under the molten form at 190 °C, is characterized by a melt property space defined by a combination of properties of high load melt index ("HLMI" or "I21"), melt flow ratio I21/I5 ("MFR5 ") and melt elasticity (G'/Gw at 0.1 rad/s), where the HLMI is 7.0 to 11.0 grams per 10 minutes (g/10 min), alternatively 7.3 to 10 .0 g/10 min, alternatively 7.4 to 9.5 g/10 min and is measured in accordance with ASTM D1238-13 (190 °C, 21.6 kg); the MFR5 is 22.0 to 35.0, alternatively 25 to 32, alternatively 26.6 to 30.6, wherein the I21 and I5 values used to calculate the MFR5 are each in g/10 min and are measured in accordance with ASTM D1238-13 (190 °C, 21.6 kg, "I21"; and 190 °C, 5.0 kg, "I5", respectively), and the melt elasticity is 0.5 to 0.8 pascals (Pa), alternatively 0.50 to 0.70 Pa, alternatively 0.525 to 0.684 Pa, and where melt elasticity = G7G" is determined at 0.1 radian per second (rad/s) in accordance with o Melt Elasticity Test Method (described in this document). dynamic frequency of 0.1 rad/s. This relationship is useful for evaluating polyethylene resins for film applications.

[0010] Aspect 2. The bimodal ethylene-co-1-hexene copolymer according to aspect 1, wherein the melting property space of the bimodal ethylene-co-1-hexene copolymer is further defined by any of limitations (i) to (iii): (i) a melt index I2 of 0.05 to 0.10, alternatively 0.055 to 0.084, alternatively 0.060 to 0.080 g/10 min measured in accordance with ASTM D1238-13 (190 °C, 2.16 kg, “I2”); (ii) a melt index I5 of 0.20 to 0.40, alternatively of 0.25 to 0.35, alternatively of 0.27 to 0.33 g/10 min, measured in accordance with ASTM D1238-13 ( 190 °C, 5.0 kg, "I5"); and (iii) a melt flow ratio I21/I2 ("MFR2") of 80.0 to 150.0, alternatively 99 to 140.0, alternatively 101 to 139, wherein the I21 and I2 values used to calculate the MFR2 are each in g/10 min and are measured in accordance with ASTM D1238-13 (190 °C, 21.6 kg, "I21"; and 190 °C, 2.16 kg, "I2", respectively ). In some respects, the merger property space is further defined by any of the constraints (iv) to (vii): (iv) both (i) and (ii); (v) both (i) and (iii); (vi) both (ii) and (iii); and (vii) each of (i) to (iii).

[0011] Aspect 3. The bimodal ethylene-co-1-hexene copolymer according to aspect 1 or 2, characterized by any of the resin property limitations (i) to (iv): (i) a density 0.9410 to 0.9550 grams per cubic centimeter (g/cm3), alternatively 0.9450 to 0.9530 g/cm3, alternatively 0.9480 to 0.9500 g/cm3, measured in accordance with ASTM D792-13 , Method B; (ii) a component fraction division characterized by a weight fraction of the HMW component of 50.0 to 63% by weight, alternatively of 55 to 60.0% by weight, alternatively of 57.0 to 59.4% by weight Weight; and a weight fraction of the LWM component fraction is 50.0 to 37 wt%, alternatively 45 to 40.0 wt%, alternatively 43.0 to 40.6 wt%, respectively, of the combined weight of the HMW and LMW components, measured according to the Gel Permeation Chromatography (GPC) Test Method; (iii) a molecular weight spread of the component characterized by a ratio between the weight average molecular weight of the HMW component (Mw-HMW) and the weight average molecular weight of the LMW component (Mw-LMW) (i.e., Mw-HMW) /Mw-LMW Ratio) of 30.0 to 50.0, alternatively 40.0 to 45, alternatively 40.9 to 42.5, measured in accordance with the GPC Test Method; and (iv) a molecular mass dispersion (Mw/Mn), DM, from 30.0 to 40.0, alternatively from 34 to 39, alternatively from 34.8 to 38.6, where Mw and Mn are measured from in accordance with the GPC Test Method. In some aspects, the copolymer is further characterized by any of the resin property limitations (v) to (xii): (v) both (i) and (ii); (vi) both (i) and (iii); (vii) both (i) and (iv); (viii) both (ii) and (iii); (ix) both (ii) and (iv); (x) both (iii) and (iv); (xi) any three of (i) to (iv); and (xii) each of (i) to (iv). In some aspects, the ethylene-co-1-hexene bimodal copolymer may have a transition metal content, alternatively a Zr content, of less than 10 parts by weight per million (ppm) measured according to mass spectrometry. inductively coupled plasma (ICP-MS).

[0012] Aspect 4. The bimodal ethylene-co-1-hexene copolymer, according to any one of aspects 1 to 3, wherein, when it is characterized by being in the form of a blown film and by having a thickness of 0.0127 millimeters (mm, 12.7 micrometer (μm), 0.500 mil), is characterized by any of the limitations (i) to (iv): (i) a dart impact of 250 to 400 grams (g) , alternatively 270 to 380 g, alternatively 275 to 376 g, measured in accordance with the Dart Impact Test Method; (ii) an Elmendorf tear in the transverse direction (CD) of 60.0 to 190.0 grams of force (gf), alternatively 61 to 185 gf, alternatively 83 to 182 gf, measured in accordance with the Tear Test Method of Elmendorf; (iii) an Elmendorf tear in machine direction (MD) of 15 to 35 gf, alternatively 17 to 33 gf, alternatively 18 to 32 gf, measured in accordance with the Elmendorf Tear Test Method; and (iv) gauge variation from 10.5% to 17%, alternatively from 11.0% to 16.4%, alternatively from 11.2% to 16.2%, measured in accordance with the Variation Test Method of Caliber. In some aspects, the copolymer, when characterized by being in the form of a blown film, is also characterized by any of the limitations (v) to (xii): (v) both (i) and (ii); (vi) both (i) and (iii); (vii) both (i) and (iv); (viii) both (ii) and (iii); (ix) both (ii) and (iv); (x) both (iii) and (iv); (xi) any three of (i) to (iv); and (xii) each of (i) to (iv).

[0013] Aspect 5. Method for synthesizing the bimodal ethylene-co-1-hexene copolymer, according to any of aspects 1 to 4, the method essentially consisting of copolymerizing ethylene (monomer) and 1-hexene (comonomer) with a combination of a bimodal catalyst system and an equilibrium catalyst in the presence of molecular hydrogen gas (H2) and, optionally, an induced condensation agent (ICA) in a polymerization reactor (e.g., a fluidized bed , gas phase polymerization reactor (FB-GPP reactor)) under effective polymerization conditions to provide an initial bimodal ethylene-co-1-hexene copolymer and, optionally, oxygen by adapting the bimodal ethylene-co-1-hexene copolymer initial to provide an oxygen-adapted bimodal ethylene-co-1-hexene copolymer; wherein the bimodal catalyst system is produced by contacting a first activator with bis(2-(pentamethylphenylamido)ethyl)-amine zirconium dibenzyl and a bis(butylcyclopentadienyl)zirconium dihalide; wherein the equilibrium catalyst is produced by contacting a second activator with bis(butylcyclopentadienyl)zirconium dialkyl; wherein the first and second activators are the same or different; and wherein effective polymerization conditions comprise a reaction temperature of 80 degrees (°) to 110° Celsius (C), alternatively 83° to 106°C, alternatively 83° to 87°C, alternatively 91° to 100°C , alternatively 101° to 106°C; a molar ratio of molecular hydrogen gas to ethylene (H2/C2 molar ratio) of 0.001 to 0.020, alternatively 0.002 to 0.015, alternatively 0.005 to 0.010; and a molar ratio of 1-hexene ("C6") to ethylene (C6/C2 molar ratio) of 0.005 to 0.050, alternatively 0.008 to 0.030, alternatively 0.015 to 0.025. In some aspects, bis(butylcyclopentadienyl)zirconium dihalide is bis(butylcyclopentadienyl)zirconium dichloride; and bis(butylcyclopentadienyl)zirconium dialkyl is bis(butylcyclopentadienyl)zirconium dimethyl or bis(butylcyclopentadienyl)zirconium diethyl, alternatively bis(butylcyclopentadienyl)zirconium dimethyl. In some aspects, the first activator is an alkylaluminoxane (alkylalumoxane) and the second activator is, independently, an alkylaluminoxane or an alkylaluminoxane compound.

[0014] Aspect 6. The method, according to aspect 5, which further consists essentially of removing the bimodal ethylene-co-1-hexene copolymer (initial and/or oxygen-adapted modality (or initial and/or oxygen-adapted modalities). or adapted to oxygen) of the reactor (e.g., the FB-GPP reactor) to provide a bimodal ethylene-co-1-hexene copolymer removed. In some aspects, the bimodal ethylene-co-1-hexene copolymer can be removed. the initial bimodal ethylene-co-1-hexene copolymer, the oxygen-adapted bimodal ethylene-co-1-hexene copolymer, or both. In some aspects, the removed bimodal ethylene-co-1-hexene copolymer can be purged. with an inert gas (e.g. N2) to remove entrained hydrocarbons therefrom and/or treated with a stream of humidified nitrogen (N2) to deactivate, in situ, any residual amount of the bimodal catalyst system contained therein to provide a bimodal copolymer of purged ethylene-co-1-hexene. In some aspects, the removed or purged bimodal ethylene-co-1-hexene copolymer is degassed to remove volatile organic compounds therefrom to provide a bimodal ethylene-co-1-hexene copolymer. degassed. In some aspects, the removed, purged or degassed bimodal ethylene-co-1-hexene copolymer is pelletized to provide pellets thereof (pelletized bimodal ethylene-co-1-hexene copolymer). The initial, oxygen-adapted, stripped, purged, degassed and pelletized embodiments of the bimodal ethylene-co-1-hexene copolymer are collectively referred to as "the bimodal ethylene-co-1-hexene copolymer", which may be that according to any one of aspects 1 to 4. The bimodal ethylene-co-1-hexene copolymer can be combined with one or more film additives useful in polyethylene films. The combination may comprise melt mixing one or more film additives into a bimodal ethylene-co-1-hexene copolymer melt. Alternatively, the combination may comprise soaking or injecting one or more film additives into the pellets of the pelletized ethylene-co-1-hexene bimodal copolymer.

[0015] Aspect 7. A manufactured article comprising the bimodal ethylene-co-1-hexene copolymer, according to any one of aspects 1 to 4.

[0016] Aspect 8. A film consisting essentially of the bimodal ethylene-co-1-hexene copolymer, according to any one of aspects 1 to 4 ("the film"). The transitional phrase of "consist essentially of" means that the film is free of other polyolefin polymers, but otherwise its constituents are not particularly limited. The film may be used in packaging applications to protect a substance that needs covering, wherein the film is arranged to at least partially cover the substance. Examples of substances that need covering are paper, cardboard (e.g. cardboard), food, pharmaceutical compounds, and a stack of cardboard boxes (e.g. where the film is a shrink wrap used to wrap a pallet stacked with boxes of cardboard). The film may be the blown film produced next.

[0017] Aspect 9. A method for producing a blown film, the method comprising melting the bimodal ethylene-co-1-hexene copolymer, according to any one of aspects 1 to 5, so as to provide a melt of the same, extruding the melt through a die configured to produce a bubble in order to produce a bubble of the bimodal ethylene-co-1-hexene copolymer and blowing (inflating) the bubble with a blowing machine of film, thus producing blown film. The bubble is restricted to one dimension. Blown film may be produced or manufactured without internal bubble cooling (IBC) by any suitable method, including high stem film blowing without IBC, such as with the use of a high stem film blowing manufacturing line without IBC equipment (active). The blown film essentially consists of the bimodal ethylene-co-1-hexene copolymer according to any one of aspects 1 to 5 ("the blown film"). The transitional phrase of "consist essentially of" means that the blown film is free of other polyolefin polymers, but otherwise its constituents are not particularly limited.

[0018] Aspect 10. A blown film which is produced by the method according to aspect 9 and which consists essentially of the bimodal ethylene-co-1-hexene copolymer according to any one of aspects 1 to 4 ("the blown film"). With "consist essentially of", the blown film is free of other polyolefin polymers, but otherwise its constituents are not particularly limited. The blown film may be characterized by enhanced (increased) hardness (tear or dart impact) and/or improved gauge variation (decreased film thickness variability). Blown film can be used in packaging applications.

Definitions

[0019] Activator. A substance, other than the catalyst or one of the substrates, that increases the rate of a catalyzed reaction without being consumed. Typically, the activator contains aluminum and/or boron.

[0020] Bimodal. Two, and only two, modalities or modes.

[0021] Bimodal, in reference to a copolymer (for example, the ethylene-co-1-hexene copolymer), means a composition that essentially consists of a higher molecular weight component and a lower molecular weight component, in that the higher molecular weight component consists of a first group of polymer macromolecules produced by a first catalyst in a first reactor under a first set of effective molecular weight polymerization process conditions (e.g., bed temperature of the first reactor, molar ratio of the first gas H2/C2, molar ratio of the first comonomer/monomer and/or use or not of oxygen adaptation) and the lower molecular weight component consists of a second group of polymer macromolecules produced by a second catalyst in a second reactor under a second set of effective molecular weight polymerization process conditions (e.g., second reactor bed temperature, second gas H2/C2 molar ratio, second comonomer/monomer molar ratio, and/or use or not of adaptation to oxygen), wherein at least one of the following differences is present: (a) the first catalyst is different in composition and/or catalytic metal binder than that/those of the second catalyst; (b) the first reactor is different from the second reactor or the first and second reactors are the same reactor, but the polymerization reaction that produces the higher molecular weight component is produced in a different time than the polymerization reaction that produces the lower molecular weight component; (c) at least one of the first set of effective molecular weight polymerization process conditions is different from that of the second set of effective molecular weight polymerization process conditions. Bimodal polymer compositions include post-reactor blends and reactor blends (in which the lower and higher molecular weight components are synthesized in the same reactor). The bimodal copolymer can be characterized by two peaks separated by a local minimum distinguishable between them on a plot of dW/dLog (MW) on the y-axis versus Log (MW) on the x-axis to provide a Gel Permeation Chromatography (GPC) chromatogram ), where Log (MW) and dW/dLog (MW) are as defined herein and are measured by the Gel Permeation Chromatography (GPC) Test Method described herein.

[0022] Bimodal, when referring to a catalyst system, means a catalyst system that contains two different catalysts to catalyze the same polymerization process (for example, olefin polymerization) and produce a bimodal polymer composition. Two catalysts are different if they differ from each other in at least one of the following characteristics: (a) their catalytic metals are different (Ti versus Zr, Zr versus Hf, Ti versus Hf; non-activating metals such as Al); (b) one catalyst has a functional ligand covalently bound to its catalytic metal and the other catalyst is free of functional ligands bound to its catalytic metal; (c) both catalysts have functional ligands covalently bonded to their catalytic metal and the structure of at least one of the functional ligands of one of the catalysts is different from the structure of each of the functional ligands of the other catalyst (e.g., cyclopentadienyl versus propylcyclopentadienyl or butylcyclopentadienyl versus (pentamethylphenylamido)ethyl)-amine); and (d) for catalysts disposed on a support material, the compositions of the support materials are different. Functional ligands do not include leaving groups X, as defined later. Two catalysts of a bimodal catalyst system can be disposed on the same support material, on the same particles of the same support material, or each on different particles of the same support material. The same catalyst, in terms of catalytic metal and ligands, in which a portion thereof is disposed on a support material and a different portion thereof is dissolved in an inert solvent, the different portions do not in themselves constitute a system bimodal catalyst.

[0023] Catalyst. A material that enhances the rate of a reaction (for example, the polymerization of ethylene and 1-hexene) and is not completely consumed by it.

[0024] Catalyst system. A combination of a catalyst, per se, and a complementary material, such as a modifying compound to attenuate the reactivity of the catalyst, a support material on which the catalyst is disposed, a carrier material on which the catalyst is disposed, or a combination of two or more of the same, or a reaction product of a reaction of the same.

[0025] Consist essentially of, consists (or consist) essentially of, and so on. Partially closed expressions that exclude anything that would affect the basic, novel features they describe, but otherwise allow anything else. In some aspects, either, alternatively, each “comprising” or “comprising” may be replaced by “consisting essentially of” or “consisting essentially of”, respectively; alternatively by “which consists of” or “consists of”, respectively.

[0026] Consist of and consists of. Closed expressions that exclude anything not specifically described by the limitation they modify. In some aspects, either, alternatively, each expression “consisting essentially of” or “consisting essentially of” may be replaced by the expression “consisting of” or “consists of”, respectively.

[0027] Dry. Generally, a moisture content of 0 to less than 5 parts per million based on total parts by weight. Materials that feed the reactor (or reactors) during a polymerization reaction are dried.

[0028] Food. Amount of reactant or reactant that is added or “used to feed” a reactor. In continuous polymerization operation, each feed, independently, can be continuous or intermittent. Quantities or “feeds” can be measured, for example, by dosing, to control quantities and relative amounts of the various reactants and reagents in the reactor at any given time.

[0029] Power line. A tube or conduit structure for transporting a feed.

[0030] Film: an article restricted to one dimension. The restricted dimension can be called film thickness, and the thickness (gauge variation) is substantially uniform therein. Film: Claimed film properties are measured on 13 (12.7) micrometer thick monolayer films.

[0031] Inert. Generally, it does not (noticeably) reactive or does not (noticeably) interfere with the polymerization reaction of the invention. The term “inert” as applied to purge gas or ethylene feed means a molecular oxygen (O2) content of 0 to less than 5 parts per million based on the total parts by weight of the purge gas or ethylene feed. .

[0032] Internal bubble cooling or IBC is an aspect of film blowing carried out using active special purpose IBC auxiliary equipment, such as that in document No. US 2002/0150648 A1 by RE Cree.

[0033] Metallocene catalyst. Homogeneous or heterogeneous material that contains a cyclopentadienyl metal-ligand complex and that enhances olefin polymerization reaction rates. Substantially single location or dual location. Each metal is a Ti, Zr, or Hf transition metal. Each cyclopentadienyl ligand, independently, is an unsubstituted cyclopentadienyl group or a hydrocarbyl-substituted cyclopentadienyl group. In some aspects, the metallocene catalyst has two cyclopentadienyl ligands, and at least one, alternatively both cyclopentenyl ligands are independently a hydrocarbyl-substituted cyclopentadienyl group. Each hydrocarbyl-substituted cyclopentadienyl group can independently have 1, 2, 3, 4 or 5 hydrocarbyl substituents. Each hydrocarbyl substituent may independently be a (C1-C4)alkyl.

[0034] Balance catalyst. An amount of a metallocene catalyst that is identical, except for the group X described later, to the metallocene catalyst of the bimodal catalyst system. The equilibrium catalyst is typically fed (e.g., to the FB-GPP reactor) as a solution of the catalyst dissolved in an inert liquid (nonpolar, aprotic, e.g., hydrocarbon solvent). The equilibrium catalyst is used with the bimodal catalyst system to modify at least one property of the copolymer produced in this way. Examples of this at least one property are: density, melt index I2, flow index I21, melt flow ratio (I21/I2) and molecular mass dispersion (Mw/Mn), θM.

[0035] Ziegler-Natta catalysts. Heterogeneous materials that enhance olefin polymerization reaction rates by contacting inorganic titanium compounds, such as titanium halides supported on a magnesium chloride support, with an activator.

Reactor and polymerization method

[0036] In an illustrative pilot installation process to produce the bimodal ethylene-co-1-hexene copolymer, a fluidized bed, gas phase polymerization reactor ("FB-GPP reactor") that has a reaction zone sized in 304.8 mm (twelve inches) in internal diameter and 2.4384 meters (8 feet) in straight side height and containing a fluidized bed of ethylene-co-1-hexene bimodal copolymer granules. Configure the FB-GPP reactor with a recycle gas line to produce a recycle gas stream. Set up FB-GPP reactor with gas feed inlets and polymer product outlet. Introduce gaseous feed streams of ethylene and hydrogen together with comonomer (e.g. 1-hexene) from the FB-GPP reactor bed into the recycle gas line.

[0037] Polymerization operating conditions are any variable or combination of variables that can affect a polymerization reaction in the FB-GPP reactor or a composition or property of an ethylene-co-1-hexene copolymer product produced in this way. Variables may include reactor design and size, catalyst composition and quantity; composition and amount of reagent; molar ratio of two different reagents; presence or absence of feed gases such as H2 and/or O2, molar ratio of feed versus reactive gases, absence or concentration of interfering materials (e.g. H2O), absence or presence of an induced condensing agent (ICA) , average polymer residence time in the reactor, partial pressures of constituents, monomer feed rates, reactor bed temperature (e.g., fluidized bed temperature), nature or sequence of process steps, time periods for transition between the steps. Variables other than those described or changed by the method or use may be kept constant.

[0038] When operating the polymerization method, control the individual flow rates of ethylene ("C2"), hydrogen ("H2") and 1-hexene ("C6" or "Cx" where x is 6) to maintain a fixed comonomer to ethylene monomer gas molar ratio (Cx/C2, e.g., C6/C2) equal to a described value (e.g., 0.0050), a constant molar ratio of hydrogen to ethylene gas ("H2/ C2") equal to a described value (e.g., 0.0020), and a constant ethylene partial pressure ("C2") equal to a described value (e.g., 1,000 kPa). Measure concentrations of all gases via the in-line gas chromatograph to understand and maintain the composition in the recycle gas stream. Maintain a reaction bed of growing polymer particles in a fluidized state by continuously flowing a makeup feed and recycling gas through the reaction zone. Use a superficial gas velocity of 0.49 to 0.67 meters per second (m/s) (for example, 0.49 to 0.67 m/s or 1.6 to 2.2 feet per second (ft. /s)). Operate the FB-GPP reactor at a total pressure of about 2,344 to about 2,413 kilopascals (kPa) (about 340 to about 350 pounds per square inch-gauge (psig)) and at an RBT of the first bed temperature. reactor described. Maintain the fluidized bed at a constant height by withdrawing a portion of the bed at a rate equal to the production rate of particulate form of the bimodal ethylene-co-1-hexene copolymer, from which the production rate can be 10 to 20 kilograms per hour (kg/h), alternatively from 13 to 18 kg/h. Remove bimodal ethylene-co-1-hexene copolymer semicontinuously through a series of valves in a fixed volume chamber, wherein this removed bimodal ethylene-co-1-hexene copolymer is purged to remove entrained hydrocarbons and treated with a stream of humidified nitrogen gas (N2) to deactivate any traces of residual catalyst. See the polymerization method described in this document.

[0039] The bimodal catalyst system can feed the polymerization reactor (or polymerization reactors) in "dry mode" or "wet mode", alternatively in dry mode, alternatively in wet mode. Dry mode is dry powder or granules. Wet mode is a suspension in an inert liquid such as mineral oil.

[0040] The molar ratio of comonomer/ethylene gas Cx/C2 of comonomer (1-hexene/ethylene or C6/C2) and ethylene used to feed the gas phase polymerization reactor (GPP) can be from 0.0001 to 0.1, alternatively from 0.0002 to 0.05, alternatively from 0.0004 to 0.02.

[0041] The molar ratio of comonomer gas to ethylene ("Cx/C2 gas molar ratio") is the amount of all alphaolefin comonomers (e.g., 1-hexene "C6"), in moles, being used to feed, in a gaseous or vaporous state, the GPP reactor divided by the amount of ethylene monomer (C2), in moles, being used to feed, in a gaseous state, the GPP reactor. Moles of comonomer and moles of ethylene are measured by gas flow meters or other suitable means.

[0042] Partial pressure of ethylene (e.g. C2P) in the GPP reactor. From 690 to 2,070 kilopascals (kPa, that is, from 100 to 300 psia (pounds per square inch absolute)); alternatively, from 830 to 1,655 kPa (120 to 240 psia), alternatively, from 1,300 to 1,515 kPa (190 to 220 psia). Alternatively, the partial pressure of ethylene may be 690 to 3,450 kilopascals (kPa, 100 to 500 pounds per square inch absolute (psia)), alternatively, 1,030 to 2,070 kPa (150 to 300 psia), alternatively, 1,380 to 1,720 kPa ( 200 to 250 psia), alternatively, 1,450 to 1,590 kPa (210 to 230 psia), for example, 1,520 kPa (220 psia). 1,000 psia = 6.8948 kPa.

[0043] The molar ratio of hydrogen gas to ethylene (H2/C2) in the GPP reactor can be from 0.010 to 0.100, alternatively from 0.011 to 0.094.

[0044] Induced condensation agent (ICA). An inert liquid useful for cooling materials in the polymerization reactor (or polymerization reactors) (e.g., a fluidized bed reactor); its use is optional. The ICA may be a (C5-C20)alkane, alternatively a (C11-C20)alkane, alternatively a (C5-C10)alkane, alternatively a (C5)alkane, for example pentane or 2-methylbutane; one hexane; a heptane; one octane; a nonane; a dean; or a combination of any two or more of them. The ICA may be 2-methylbutane (i.e., isopentane). Aspects of the polymerization method that use ICA can be referred to as induced condensation mode operation (ICMO). ICMO is described in documents No. US 4,453,399; US 4,588,790; US 4,994,534; US 5,352,749; US 5,462,999 and US 6,489,408. The concentration of ICA in the gas phase is measured using gas chromatography by calibrating the percentage peak area in mole percent (mol%) with a gas mixture standard of known concentrations of ad rem gas phase components. . The concentration of ICA can be 1 to 10 mol%, alternatively 3 to 8 mol%.

[0045] The concentration of oxygen (O2) in relation to ethylene (“O2/C2”, parts by volume of O2 per million parts by volume of ethylene (ppmv)) in the GPP reactor. In some embodiments, the O2/C2 is 0.0000 to 0.20 ppmv, alternatively 0.0001 to 0.200 ppmv, alternatively 0.0000 to 0.183 ppmv, alternatively 0.0000 to 0.163 ppmv.

[0046] The polymerization method uses a gas phase polymerization (GPP) reactor, such as a stirred bed gas phase polymerization reactor (SB-GPP reactor) or a fluidized bed gas phase polymerization reactor (FB reactor -GPP), to produce the bimodal ethylene-co-1-hexene copolymer. Such reactors and methods are generally well known in the art. For example, the FB-GPP reactor/method may be described in US 3,709,853; US 4,003,712; US 4,011,382; US 4,302,566; US 4,543,399; US 4,882,400; US 5,352,749; US 5,541,270; EP-A-0 802 202; and Patent No. BE 839,380. These polymerization processes and reactors SB-GPP and FB-GPP mechanically agitate or fluidize by continuous flow of gaseous monomer and polymerization medium diluent within the reactor, respectively. Other useful reactors/processes contemplated include serial or multi-stage polymerization processes, as described in US 5,627,242; US 5,665,818; US 5,677,375; EP-A-0 794 200; EP-B1-0 649 992; EP-A-0 802 202 and EP-B-634421.

[0047] The polymerization conditions may also include one or more additives, such as a chain transfer agent or a promoter. Chain transfer agents are well known and may be alkyl metal, such as diethyl zinc. Promoters are known, as in US 4,988,783, and may include chloroform, CFCl3, trichloroethane and difluorotetrachloroethane. Prior to reactor startup, a sequestering agent can be used to react with moisture, and during reactor transitions, a sequestering agent can be used to react with excess activator. The sequestering agents may be trialkylaluminum. Gas phase polymerizations can be operated free of sequestering agents (not deliberately added). The polymerization conditions for the gas phase polymerization reactor/method may additionally include an amount (e.g., 0.5 to 200 ppm based on all feeds into the reactor) of static control agent and/or continuity additive, such as aluminum stearate or polyethyleneimine. The static control agent can be added to the FB-GPP reactor to inhibit the formation or accumulation of static charge therein.

[0048] Startup or restart of the GPP reactor can be illustrated with a fluidized bed, GPP reactor. Start-up of a recommissioned FB-GPP reactor (cold start) or restart of a transitioning FB-GPP reactor (hot start) includes a period of time that is prior to reaching the steady-state polymerization conditions of the step ( The). Start-up or restart may include the use of a pre-charged or loaded polymer seed, respectively, in the fluidized bed reactor. The polymer seed may be composed of a polyethylene powder, such as a polyethylene homopolymer or that produced prior to batching the bimodal ethylene-co-1-hexene copolymer.

[0049] Startup or restart of the FB-GPP reactor may also include gas atmosphere transitions that comprise purging air or other unwanted gas (or gases) from the reactor with a dry (anhydrous) inert purge gas, followed by purging of dry inert purge gas from the FB-GPP reactor with dry ethylene gas. The dry inert purge gas may consist essentially of molecular nitrogen (N2), argon, helium or a mixture of two or more thereof. When not in operation, before initialization (cold start), the FB-GPP reactor contains an air atmosphere. The dry inert purge gas can be used to sweep air from a recommissioned FB-GPP reactor during the early stages of startup to provide an FB-GPP reactor that has an atmosphere consisting of the dry inert purge gas. Prior to restart (e.g., after a change in seedings) a transitioning FB-GPP reactor may contain an unwanted ICA atmosphere or other unwanted gas or vapor. The dry inert purge gas may be used to sweep vapor or unwanted gas from the transitioning FB-GPP reactor during the initial stages of restart to provide an atmosphere consisting of the dry inert purge gas to the FB-GPP reactor. Any dry inert purge gas can itself be swept from the FB-GPP reactor with the dry ethylene gas. The dry ethylene gas may additionally contain molecular hydrogen gas such that the dry ethylene gas is used to feed the fluidized bed reactor as a mixture thereof. Alternatively, dry molecular hydrogen gas can be introduced separately and after the fluidized bed reactor atmosphere has been transferred to ethylene. Gas atmosphere transitions can be produced before, during, or after heating the FB-GPP reactor to the reaction temperature of the polymerization conditions.

[0050] Initialization or restart of the FB-GPP reactor also includes introducing feeds of reactants and reagents into it. Reactives include ethylene and alpha-olefin (e.g., 1-hexene). The reactants used to power the fluidized bed reactor include molecular hydrogen gas and induced condensation agent (ICA) and the bimodal catalyst system (e.g., PRODIGY™ BMC-300 catalyst) and equilibrium catalyst.

[0051] In one embodiment, the method uses a pilot-scale fluidized bed gas-phase polymerization reactor (pilot reactor) comprising a reactor vessel containing a fluidized bed of a bimodal ethylene-co-1 copolymer powder. -hexene and a distributor plate disposed above a lower head, and which defines a bottom gas inlet and which has an expanded section, or cyclone system, at the top of the reactor vessel to decrease the amount of fine resin particles that can escape from the fluidized bed. The expanded section defines a gas outlet. The pilot reactor further comprises a compressor blower with sufficient power to circulate, in a closed loop or continuous cycle, gas around the gas outlet in the expanded section at the top of the reactor vessel to the lower gas inlet. from the pilot reactor and through the distributor plate and fluidized bed. The pilot reactor additionally comprises a cooling system to remove polymerization heat and maintain the fluidized bed at a target temperature. The gas compositions, such as ethylene, alpha-olefin (e.g., 1-hexene), hydrogen, and oxygen, that are used to power the pilot reactor are monitored by an in-line gas chromatograph in the closed loop loop in order to maintain specific concentrations that define and allow control of polymer properties. In some embodiments, the gases are cooled, resulting in a temperature drop below the dew point, at which time the pilot reactor is operating in condensation mode (CMO) or operating in induced condensation mode (ICMO). In CMO, liquids are present downstream of the cooler and in the lower head after the distributor plate. The bimodal catalyst system (e.g. PRODIGY™ BMC-300) can be fed with a slurry or a dry powder into the Pilot Reactor from high pressure devices, where the slurry is fed via a pump syringe and the dry powder is used to feed through a metered disc. The bimodal catalyst system typically enters the fluidized bed at the bottom 1/3 of its bed height. The pilot reactor further comprises a means of weighing the fluidized bed and isolation ports (Product Discharge System) for discharging the ethylene-co-1-hexene bimodal copolymer powder from the reactor vessel in response to a increase in fluidized bed weight as the polymerization reaction proceeds.

[0052] In some embodiments, the FB-GPP reactor is a commercial scale reactor, such as a UNIPOL™ or UNIPOL™ II reactor, which are available from Univation Technologies, LLC, a subsidiary of The Dow Chemical Company, Midland, Michigan, USA.

Catalysts, Support Materials, Activators

[0053] The bimodal catalyst system used in the method to synthesize can essentially consist of a metallocene catalyst and a non-metallocene molecular catalyst, which are different in functional ligand and/or catalytic metal M. The bimodal catalyst system can also consist, essentially, on a solid support material and/or on at least one activator and/or on at least one kind of activator, which is a by-product of the reaction of the metallocene catalyst or the non-metallocene molecular catalyst with the first activator . The metallocene catalyst of the bimodal catalyst system can be bis(butylcyclopentadienyl)zirconium dihalide and the non-metallocene molecular catalyst of the bimodal catalyst system can be bis(2-(pentamethylphenylamido)ethyl)-zirconium dibenzylamine. The bimodal catalyst system can be PRODIGY BMC-300, available from Univation Technologies LLC, Houston, Texas, USA.

[0054] Without being limited by theory, it is believed that zirconium bis(2-(pentamethylphenylamido)ethyl)-amine dibenzyl is effective for producing the HMW component of the ethylene-co-1-hexene bimodal copolymer and each of Bis(butylcyclopentadienyl)zirconium dihalide and bis(butylcyclopentadienyl)zirconium dialkyl are independently effective to produce the LMW component of the bimodal ethylene-co-1-hexene copolymer. The molar ratio of the two catalysts of the bimodal catalyst system can be based on the molar ratio of their respective catalytic metal atom contents (M, e.g. Zr), which can be calculated from the weights of the ingredients thereof or can be measured analytically.

[0055] In an alternative embodiment of the method for producing the bimodal ethylene-co-1-hexene copolymer, either or both of bis(butylcyclopentadienyl)zirconium dihalide (i.e., (butylcyclopentadienyl)2MX2, wherein each is halide) and bis(butylcyclopentadienyl)zirconium dialkyl (i.e., (butylcyclopentadienyl)2MX2, where each ; (tetramethylcyclopentadienyl)(propylcyclopentadienyl)MX2; (tetramethylcyclopentadienyl)(butylcyclopentadienyl)MX2; (CH3)2Si(indenyl)MX2 bridged; (CH3)2Si(4,5,6,7-tetrahydro-indenyl)MX2 bridged; (propylcyclopentadienyl)2MX2; (1-methyl-3-butyl-cyclopentadienyl)2MX2; wherein each M is independently zirconium (Zr) or hafnium (Hf); and wherein each .

[0056] The catalysts of the bimodal catalyst system can be disposed by spray drying on a solid support material before coming into contact with an activator. The solid support material may be uncalcined or calcined before coming into contact with the catalysts. The solid support material may be a hydrophobic fumed silica (e.g., a fumed silica treated with dimethyldichlorosilane). The bimodal catalyst system (unsupported or supported) may be in the form of a free-flowing, powdered, particulate solid.

[0057] Support material. The support material may be an inorganic oxide material. The terms "support" and "support material" are the same as those used herein and refer to a porous inorganic substance or organic substance. In some embodiments, desirable support materials may be inorganic oxides that include oxides of Group 2, 3, 4, 5, 13 or 14, alternatively Group 13 or 14 of atoms. Examples of inorganic oxide-type support materials are silica, alumina, titania, zirconia, thoria and mixtures of any two or more of these inorganic oxides. Examples of such mixtures are silica-chromium, silica-alumina and silica-titania.

[0058] The inorganic oxide support material is porous and has variable surface area, pore volume and average particle size. In some embodiments, the surface area is 50 to 1,000 square meters per gram (m2/g) and the average particle size is 20 to 300 micrometers (μm). Alternatively, the pore volume is 0.5 to 6.0 cubic centimeters per gram (cm3/g) and the surface area is 200 to 600 m2/g. Alternatively, the pore volume is 1.1 to 1.8 cm3/g and the surface area is 245 to 375 m2/g. Alternatively, the pore volume is 2.4 to 3.7 cm3/g and the surface area is 410 to 620 m2/g. Alternatively, the pore volume is 0.9 to 1.4 cm3/g and the surface area is 390 to 590 m2/g. Each of the above properties is measured using conventional techniques known in the art.

[0059] The support material may comprise silica, alternatively amorphous silica (not quartz), alternatively an amorphous silica with a large surface area (for example, from 500 to 1,000 m2/g). These silicas are commercially available from several sources, including Davison Chemical Division of WR Grace and Company (e.g., Davison 952 and Davison 955 products) and PQ Corporation (e.g., product ES70). Silica can be in the form of spherical particles, which are obtained by a spray drying process. Alternatively, product MS3050 is a silica from PQ Corporation that is not spray dried. As purchased, all of these silicas are not calcined (i.e., not dehydrated). Silica that is calcined before purchase can also be used as a support material.

[0060] Before contacting a catalyst, the support material can be pretreated by heating the support material in air to provide a calcined support material. Pre-treatment comprises heating the support material to a peak temperature of 350°C to 850°C, alternatively 400°C to 800°C, alternatively 400°C to 700°C, alternatively 500°C at 650 ° C, and for a period of time from 2 to 24 hours, alternatively from 4 to 16 hours, alternatively from 8 to 12 hours, alternatively from 1 to 4 hours, thus producing a calcined support material. In some aspects, the support material is a calcined support material.

[0061] The equilibrium catalyst can be any one of the metallocene catalysts mentioned above. For convenience, the equilibrium catalyst is fed to the reactor with a solution in a hydrocarbon solvent (e.g., mineral oil or heptane). The hydrocarbon solvent may be an alkane or a mixture of alkanes, wherein each alkane independently has from 5 to 20 carbon atoms, alternatively from 5 to 12 carbon atoms, alternatively from 5 to 10 carbon atoms. Each alkane, independently, can be acyclic or cyclic. Each acyclic alkane, independently, can be straight-chain or branched-chain. The acyclic alkane can be pentane, 1-methylbutane (isopentane), hexane, 1-methylpentane (isohexane), heptane, 1-methylhexane (isoheptane), octane, nonane, decane or a mixture of two or more of the same. The cyclic alkane can be cyclopentane, cyclicohexane, cyclicheptane, cyclooctane, cyclononane, cyclodecane, methylcyclopentane, methylcyclohexane, dimethylcyclopentane or a mixture of two or more thereof.

[0062] For solubility in the hydrocarbon solvent, typically, each of the X group of the equilibrium catalyst is, independently, hydrocarbyl (e.g., benzyl, a (C1-C5)alkyl or a (C2-C5)alkenyl; e.g. example, methyl or ethyl) or - CH2Si(CH3)3. The X groups of the equilibrium catalyst may be different from the X groups of the metallocene catalyst of the bimodal catalyst system. However, upon activation by contact thereof with an activator, the species of active catalyst resulting from the activation of the equilibrium catalyst is essentially the same as the species of active catalyst resulting from the activation of the metallocene catalyst of the bimodal catalyst system. For example, the metallocene catalyst of the bimodal catalyst system may be bis(n-butylcyclopentadienyl)zirconium dichloride (each X is Cl), and the equilibrium catalyst may be bi(n-butylcyclopentadienyl)zirconium dichloride (e.g., dimethyl, where X is CH3). After activation by treating it with a suitable activator or cocatalyst, both bis(n-butylcyclopentadienyl)zirconium dichloride and bis(n-butylcyclopentadienyl)zirconium dimethyl effectively produce the same species of activated catalyst.

[0063] Activator. Each catalyst in the bimodal catalyst system is activated by contact with the first activator. The balancing catalyst is activated upon contact with the second activator. Additional activators can be used. The activator can be the same or different from each other and, independently, can be a Lewis acid, a non-coordinating ionic activator or an ionizing activator or a Lewis base, an alkylaluminum or an alkylaluminoxane (alkylalumoxane). The alkylaluminum may be a trialkylaluminum, alkylaluminum halide or alkylaluminum alkoxide (diethylaluminum ethoxide). The trialkylaluminum can be trimethylaluminum, triethylaluminum (“TEAI”), tripropylaluminum or tris(2-methypropyl)aluminum. The alkylaluminum halide may be diethylaluminum chloride. The alkylaluminum alkoxide may be diethylaluminum ethoxide. The alkylaluminoxane can be a methylaluminoxane (MAO), ethylaluminoxane, 2-methylpropylaluminoxane or a modified methylaluminoxane (MMAO). Each alkyl of alkylaluminoxane or alkylaluminoxane can independently be a (C1-C7)alkyl, alternatively a (C1-C6)alkyl, alternatively a (C1-C4)alkyl. The molar ratio of the metal of the activator (Al) to the metal of a specific catalytic compound (catalytic metal, e.g. Zr) may be 1,000:1 to 0.5:1, alternatively 300:1 to 1:1, alternatively 150 :1 to 1:1. Suitable activators are commercially available.

[0064] Once the first activator and the (bis(2-(pentamethylphenylamido)ethyl)-amine zirconium dibenzyl and bis(butylcyclopentadienyl)zirconium dihalide) of the bimodal catalyst system come into contact, the catalysts of the catalyst system bimodal are activated and a species of the first activator can be produced in situ. Once the second activator and the equilibrium catalyst (a bis(butylcyclopentadienyl)zirconium dialkyl) come into contact, the equilibrium catalyst is activated and a second species of the activator can be produced in situ. The activator species may have a different structure or composition than the activator from which it is derived and may be a byproduct of catalyst activation or may be a derivative of the byproduct. The corresponding activator species can be a Lewis acid derivative, non-coordinating ionic activator, ionizing activator, Lewis base, alkylaluminum or alkylaluminoxane, respectively. An example of the byproduct derivative is a species of methylaluminoxane that is formed by devolatilization during spray drying of a bimodal catalyst system produced with methylaluminoxane.

[0065] Each contact step between the activator and the catalyst can be carried out independently: (a) in a separate container outside the GPP reactor (e.g. outside the FB-GPP reactor), (b) in a feed to the GPP reactor, and/or (c) inside the GPP reactor (in situ). In option (a), the bimodal catalyst system, once its catalysts are activated, can be fed to the GPP reactor with a dry powder, alternatively with a slurry in a non-polar, aprotic (hydrocarbon) solvent. In option (c), the bimodal catalyst system may be fed to the reactor prior to activation via a first feed line, the first activator may be fed to the reactor via a second feed line, the balancing catalyst may be powered by the reactor via a third supply line and the second activator may be powered by the reactor via a fourth supply line. Any one of the two from the first to the fourth power lines can be the same or different. The activator (or activators) may be fed into the polymerization reactor in “wet mode” and in the form of a solution thereof in an inert liquid, such as mineral oil or toluene, in slurry mode, as a suspension or, in dry mode, as a powder. Each contacting step may be carried out in separate vessels, feed lines or reactors at the same or different times, or in the same vessel, feed line or reactor at different times, to separately provide the bimodal catalyst system and the bimodal catalyst system. balance. Alternatively, the contacting steps can be carried out in the same vessel, feed line or reactor at the same time to provide a mixture of the bimodal catalyst system and the in situ equilibrium catalyst.

Ethylene-co-1-hexene bimodal copolymer

[0066] Ethylene. A polymerizable monomer with the formula H2C=CH2.

[0067] 1-hexene. Polymerizable monomer with the formula H2C=C(H)CH2CH2CH2CH3.

[0068] Bimodal ethylene-co-1-hexene copolymer. A macromolecule, or collection of macromolecules, composed of repeating units, wherein 50.0 to <100 mol% (mol%), alternatively 70.0 to 99.99 mol%, alternatively 95.0 to 99, 9 mol% of such repeating units are derived from ethylene monomer, and from >0 to 50.0 mol%, alternatively from 0.01 to 30.0 mol%, alternatively 0.1 to 5.0% in moles of the remaining repeating units are comonomer units derived from 1-hexene; or collection of such macromolecules. The collection of macromolecules is characterized by two distinct peaks (not bumps) on a plot of dW/dLog (MW) on the y-axis versus Log (MW) on the x-axis to provide a Gel Permeation Chromatography (GPC) chromatograph in Log (MW) and dW/dLog (MW) are as defined below and measured by the Gel Permeation Chromatography (GPC) Test Method described herein.

[0069] The bimodal ethylene-co-1-hexene copolymer is a high-density, higher-molecular-weight polyethylene (HMW HDPE). The bimodal ethylene-co-1-hexene copolymer may further be characterized by any of the following limitations: a weight average molecular weight (Mw) of 200,000.0 to 400,000.0 grams per mole (g/mol), alternatively 250,000.0 to 320,000.0 g/mol; a number average molecular weight (Mn) of 6,000.0 to 11,000.0 g/mol, alternatively 7,000.0 to 9,000.0 g/mol; a z-average molecular weight (Mz) of 1,200,000.0 to 2,500,000.0 g/mol; a combination of any two of the same; and a combination of all three of the same; all measured according to the Gel Permeation Chromatography (GPC) Test Method.

[0070] The melt elasticity of the bimodal ethylene-co-1-hexene copolymer can be considered as the behavior of a copolymer melt during a shaping process, such as extrusion or film formation. It is one of the determinants of viscoelastic melt behavior, in which viscosity decreases with increasing shear rate. Poor melt elasticity can cause undesirable die swelling during extrusion or problems with bubble stability during film blowing. A measure of, or surrogate for, melt elasticity used herein is a ratio of the value of the melt storage modulus (G') to the melt loss modulus (G") that is measured using DMA (Dynamic Mechanical Analysis) in polymer melts at 190 °C, carrying out oscillatory shear of small deformation (10%) at a variable frequency of 100 radians per second (rad/s) at about 0.1 rad/s with the use of an ARES-G2 Advanced Rheometric Expansion System, from TA Instruments, with parallel plate geometry to obtain the G'/G" ratio value at a dynamic frequency equal to 0.1 rad/s.

[0071] The bimodal ethylene-co-1-hexene copolymer, film and manufacturing methods are free of Ti and Cr metals.

[0072] The polymerization conditions in the method for synthesizing are effective to produce the bimodal ethylene-co-1-hexene copolymer characterized by the previously described melt space and, optionally, by the properties of the resin and/or properties of the film.

Film

[0073] The film. The film cannot be non-embossed or embossed. The film can be adapted for specific uses by adjusting the film thickness, combination with other films or additives, or not. In some embodiments, the film may be a monolayer film. The film may have a thickness of 0.0051 to 0.051 mm (0.200 mil to 2 mils), alternatively from 0.0077 mm to 0.051 mm (0.300 mil to 2 mils), alternatively from 0.0077 mm to 0.0254 mm ( 0.300 mil to 1.00 mils), alternatively from 0.0077 mm to 0.0203 mm (0.300 mil to 0.80 mils), alternatively from 0.0077 mm to 0.0152 mm (0.300 mil to 0.6 mils) .

[0074] The film can be produced using extrusion or coextrusion methods, including blown, slanted and cast film methods. Blown film can be produced using any blown film line machine configured to produce polyethylene films. The machine may be configured with a feed hopper in fluid communication with an extruder in heating communication with a heating device capable of heating a polyethylene in the extruder to a temperature of up to 500 °C. (e.g., 430°C), and wherein the extruder is in fluid communication with a die that has an interior diameter of 12 centimeters (4.72 inches) and a fixed die gap (e.g., 1. 2 millimeters (47 mils)), a blow ratio of 4.0:1 and a Neck Height (NH) of 96 centimeters (38 inches) of the die. Step (a) can be performed in the feed hopper.

[0075] The film can be unoriented, uniaxially oriented or biaxially oriented. The film uniaxially can be oriented in the extrusion direction (machine direction or MD), alternatively in the direction transverse to the extrusion direction (transverse direction or TD). The biaxially oriented film can be oriented in both MD and TD by stretching or pulling in the MD, simultaneously or followed by stretching or pulling in the TD.

[0076] The film may have one or more improved properties, such as improved (increased) bubble stability, improved (increased) Elmendorf MD and/or TD Tear performance, improved (increased) MD tensile strength and/or resistance to TD traction, enhanced (increased) dart impact performance, or a combination of any two or more thereof.

[0077] The film may constitute one layer of a multilayer or laminated film.

[0078] The (blown) film may optionally contain zero, one or more film additives. The "film additive" is a compound or material other than a polyolefin polymer that imparts one or more properties and/or enhances one or more properties of the blown film. Examples of film additives are antimicrobial agents, antioxidants, catalyst neutralizers (from single-site catalysts), dyes and light stabilizers. The film additive (or film additives), when present, may be premixed with the bimodal ethylene-co-1-hexene copolymer prior to the melting step in the blown film manufacturing method. Alternatively, the film additive (or film additives) may be added to the ethylene-co-1-hexene bimodal copolymer melt during or after the melting step and before the extrusion step in the blown film manufacturing method. When two or more film additives are used, one or more film additives may be premixed with the bimodal ethylene-co-1-hexene copolymer prior to the melting step in the method for producing the blown film and one or more additives. of film may be added to the ethylene-co-1-hexene bimodal copolymer melt during or after the melting step and before the extrusion step in the blown film manufacturing method. In some aspects, the blown film consists essentially of the bimodal ethylene-co-1-hexene copolymer, at least one antioxidant, and at least one catalyst neutralizer.

[0079] The film is useful for producing wraps and casings that have improved puncture resistance. Examples of such wraps are bags, such as ice packs and grocery bags. Examples of such casings are stretch films, meat casings and food casings. The inventive mixture and composition are also useful in a variety of non-film applications, including vehicle parts.

[0080] Alternatively, a different modality is preceded. ASTM means ASTM International Standards Organization, West Conshohocken, Pennsylvania, USA. Any comparative example is used for illustration purposes only and need not relate to the prior art. Free from or lacking means a complete absence of; alternatively, not detectable. IUPAC is the International Union of Pure and Applied Chemistry (IUPAC Secretariat, Research Triangle Park, North Carolina, USA). "May" confers a permissible choice, not an imperative choice. Operative means functionally capable or effective. Optional(mind) means to be absent (or excluded), alternatively, to be present (or included). Properties can be measured using standard test methods and conditions. Ranges include endpoints, subranges, and integer and/or fractional values included therein, except that an integer range does not include fractional values. Ambient temperature: 23 °C. ± 1°C.

Examples

[0081] Bimodality Test Method: determines the presence or absence of resolved bimodality by plotting dWf/dLogM (mass detector response) on the y-axis versus LogM on the x-axis to obtain a GPC chromatogram curve that contains maximum values log(MW) locations for LMW and HMW polyethylene component peaks, and observe the presence or absence of a local minimum between the LMW and HMW polyethylene component peaks. The dWf is the change in weight fraction, dLogM is also referred to as dLog(MW) and is the change in the logarithm of the molecular weight, and LogM is also referred to as Log(MW) and is the logarithm of the molecular weight.

[0082] Dart Impact Test Method: measured in accordance with Method A, ASTM D1709-16a, Standard Test Methods for Impact Resistivity of Plastic Film by Free Fall Dart Test Method. Method A employs a dart with a hemispherical head 38.10 ± 0.13 mm (1.500 ± 0.005 in) in diameter thrown from a height of 0.66 ± 0.01 m (26.0 ± 0.4 in). .). This test method can be used for films whose impact resistibilities require masses of about 50 g or less to about 6 kg to fracture. Results expressed in grams (g).

[0083] Deconvolution Test Method: segments the chromatogram obtained using the Bimodality Test Method into nine (9) Schulz-Flory molecular weight distributions. Such a deconvolution method is described in document No. US 6,534,604. Assign the four lowest Mw distributions to the LMW polyethylene component and the five highest Mw distributions to the HMW polyethylene component. Determine the respective weight percentages (wt%) for each of the LMW and HMW polyethylene components in the bimodal ethylene-co-1-hexene composition using summed values of the weight fractions (Wf) of the LMW polyethylene components and HMW and the corresponding numerical weight molecular weights (Mn) and weight-average molecular weights (Mw) by the known mathematical treatment of the Schulz-Flory aggregate Mw distributions.

[0084] Density is measured in accordance with ASTM D792-13, Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement, Method B (for testing solid plastics in liquids other than water, e.g. in liquid 2-propanol). Report results in units of grams per cubic centimeter (g/cm3).

[0085] Elmendorf Tear Test Method: measured in accordance with ASTM D1922-09, Standard Test Methods for Tear Resistance of Plastic Film Spread and Thin Sheet Formation by Pendulum Method, Type B (constant radius) . (Technically equivalent to ISO 6383-2.) Report results as normalized tear in cross direction (CD) or machine direction (MD) in gram-force (gf).

[0086] Film Puncture Test Method: ASTM D5748 - 95(2012), Standard Test Method for Stretch Film Bulge Puncture Resistance. Determines the puncture resistance of a film, such as the resistance to penetration of the film by a probe impinging on the film at a standard speed, such as 250 millimeters per minute (mm/min). The probe is coated with a polytetrafluoroethylene and has an outer diameter of 1.905 cm (0.75 inch). The film is stuck during testing. The probe eventually penetrates or breaks through the trapped film. The peak force at rupture, that is, the maximum force, energy (work) until breaking or penetrating the stuck film, and the distance at which the probe penetrated the rupture, are recorded using mechanical testing software. The probe imparts a biaxial tension to the trapped film that is representative of the type of tension encountered by films in many end-use product applications. This resistance is a measure of the energy absorption capacity of a film to resist puncture under these conditions.

[0087] Gauge Variation Test Method: Determined in accordance with ASTM D8136-17, Standard Test Method for Determining Plastic Film Thickness and Thickness Variation Using a Non-contact Capacitance Thickness Gauge. Before testing, samples are conditioned at 23° ± 2°C and 50% ± 10% relative humidity (RH) for at least 40 hours (per ASTM D618), and then tested under the same conditions. The caliber variation is calculated using the following equation: (Standard deviation of thickness/average thickness) x 100%.

[0088] Gel Permeation Chromatography (GPC) Method: Weight Average Molecular Weight Test Method: determine Mw, average numerical molecular weight (Mn) and Mw/Mn using chromatograms obtained on a Permeation Chromatography instrument in High Temperature Gel (HTGPC, Polymer Laboratories). The HTGPC is equipped with transfer lines, a differential refractive index (DRI) detector, and three 10 μm Polymer Laboratories PLgel Mixed-B columns, all contained in an oven maintained at 160 °C. The method uses a solvent composed of TCB treated with BHT at a nominal flow rate of 1.0 milliliter per minute (ml/min) and a nominal injection volume of 300 microliters (μ l). Prepare the solvent by dissolving 6 grams of butylated hydroxytoluene (BHT, antioxidant) in 4 liters (l) of 1,2,4-trichlorobenzene (TCB) reagent grade and filtering the resulting solution through a Teflon filter of 0.1 micrometer (μ m) to supply the solvent. Degas the solvent with an in-line degasser before entering the HTGPC instrument. Calibrate the columns with a series of monodisperse polystyrene (PS) standards. Separately, prepare known concentrations of test polymer dissolved in solvent by heating known amounts thereof in known volumes of solvent to 160 °C with continuous stirring for 2 hours to provide the solutions. (Measure all quantities gravimetrically). Target solution concentrations, c, of test polymer of 0.5 to 2.0 milligrams of polymer per milliliter of solution (mg/ml), where lower concentrations, c, are used for higher molecular weight polymers. Before passing each sample, purge the DRI detector. Then increase the flow rate in the device to 1.0 ml/minute and let the DRI detector stabilize for 8 hours before injecting the first sample. Calculate Mw and Mn using universal calibration relationships with column calibrations. Calculate the MW in each elution volume with the following equation: where the subscript "X" represents the test sample, the subscript "PS" represents PS standards, APS = 0.67, KPS = 0.000175, and AX and KX are obtained from published literature. For polyethylenes, ax/Kx = 0.695/0.000579. For polypropylenes, ax/Kx = 0.705/0.0002288. At each point in the resulting chromatogram, calculate the concentration, c, from a DRI signal subtracted from the reference base, IDRI, using the following equation: c = KDRIIDRI/(dn/dc), where KDRI is a constant determined by calibrating the DRI, / indicates division and dn/dc is the refractive index increment for the polymer. For polyethylene, dn/dc = 0.109. Calculate the mass recovery from the ratio of the integrated area of the concentration chromatography chromatogram over the elution volume and the injection mass that is equal to the predetermined concentration multiplied by the injection closed circuit volume. Report all molecular weights in grams per mole (g/mol) unless otherwise noted. Additional details regarding methods for determining Mw, Mn, MWD are described in document No. US 2006/0173123, pages 24 to 25, paragraphs [0334] to [0341]. Plot dW/dLog (MW) on the y axis versus Log(MW) on the x axis to provide a GPC chromatogram, where Log(MW) and dW/dLog (MW) are as defined above.

[0089] Load Melt Index (HLMI) Test Method I21: use ASTM D1238-13, Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Platomer, using conditions of 190 ° C/ 21.6 kilograms (kg). Report results in units of grams eluted for 10 minutes (g/10 min).

[0090] Melt Index Test Method (“I2”): for ethylene-based (co)polymer is measured in accordance with ASTM D1238-13, using conditions of 190 °C/2.16 kg , previously known as “Condition E”.

[0091] Melt Indicator Test Method (“I5”): use ASTM D1238-13, using conditions of 190 °C/5.0 kg. Report results in units of grams eluted for 10 minutes (g/10 min).

[0092] Melt Flow Ratio Test Method MFR5 (“I21/I5”): calculated by dividing the value of the HLMI Test Method I21 by the value of the Melt Ratio Test Method I5.

[0093] Melt Elasticity Test Method: On polymers melted at 190 °C, perform oscillatory shear of small deformation (10%) at a variable frequency of 100 radians per second (rad/s) at about 0.1 rad/s s using a TA Instruments ARES-G2 Advanced Rheometric Expansion System with parallel plate geometry to obtain the G7G" ratio value at a dynamic frequency equal to 0.1 rad/s.

[0094] Antioxidants: 1. Pentaerythritol tetracis (3-(3,5-di(1',1'-dimethylethyl)-4-hydroxyphenyl)propionate); obtained as IRGANOX 1010 from BASF. 2. Tris(2,4-di(1‘,1‘- dimethylethyl)-phenyl)phosphite. Obtained as IRGAFOS 168 from BASF.

[0095] Catalyst neutralizers: 1. Calcium Stearate. 2. Zinc Stearate.

[0096] Bimodal catalyst system: the PRODIGY™ BMC-300 catalyst system. Obtained from Univation Technologies LLC, Houston, Texas, USA.

[0097] Equilibrium catalyst: bis(butylcyclopentadienyl)zirconium dimethyl obtained as UT-TR-300 equilibrium catalyst from Univation Technologies LLC, Houston, Texas, USA.

[0098] Comonomer: 1-hexene. See below for the molar ratio of Cθ/C2 gas.

[0099] Ethylene (“C2”): See below for the partial pressure of C2.

[0100] Molecular hydrogen gas (“H2”): See below for H2/C2 gas molar ratio.

[0101] Molecular oxygen gas (“O2”): See below for O2/C2 gas volume ratio.

[0102] Inventive examples 1 to 7 (IE1 to IE7): polymerization procedure: executions began with PRODIGY™ BMC-300 Bimodal Catalyst and 1-hexene comonomer, according to the Pilot Reactor and method described previously, to provide, in different parts, as described below, different embodiments of the bimodal ethylene-co-1-hexene copolymer as granular resins and having targeted properties of high load melt index (I21) 8.0 to 10.0 g/10 minutes, melt flow ratio I21/I5 of 26.6 to 30.6, a melt index I5 of 0.25 to 0.35 g/10 min, melt elasticity 0.50 to 0.70 and density 0.948 at 0.950 g/cm3. The polymerization operating conditions are reported below in Table 1 (IE1 to IE4) or Table 2 (IE5 to IE7). Table 1: Operating conditions from IE1 to IE4 *S, CM, PP, FB, GPP: simple, continuous mode, pilot installation, gas phase polymerization in fluidized bed. ARx pressure (kPa): total reactor pressure in kilopascals. Table 2: Operating conditions from IE5 to IE7 *S, CM, PP, FB, GPP: simple, continuous mode, pilot installation, gas phase polymerization in fluidized bed. ARx pressure (kPa): total reactor pressure in kilopascals.

[0103] As shown in Tables 1 and 2, the operating conditions used to produce the bimodal ethylene-co-1-hexene copolymers of IE1 to IE7 comprising a bed temperature of 90.0 ° C; an ethylene partial pressure (C2) of 1,520 kpa; an H2/C2 molar ratio of 0.0040 to 0.0042; a C6/C2 molar ratio of 0.0054 to 0.0055; and a superficial gas velocity of 0.616 to 0.671 m/s (meter per second). In certain embodiments, the method for synthesizing the bimodal ethylene-co-1-hexene copolymer employs the aforementioned operating conditions.

[0104] Formulation and pelletization procedure: Each of the different granular resins from IE1 to IE7 was mixed separately with 800 parts per million weight/weight (ppm) of Antioxidant 1, 200 ppm of Antioxidant 2, 1,000 ppm of Neutralizer of Catalyst 1 and 500 ppm of Catalyst 2 Neutralizer in a ribbon mixer and then combined into strand-cut pellets using an LCM100 twin-screw extruder in accordance with the methods described in documents No. US 5,728. 335; US 6,456,976 and US 6,989,423. The resulting pellets of each resin were tested for HLMI (I21), MFR5 (I21/I5), melt elasticity and density according to their respective test methods mentioned above. The results are reported below. In certain embodiments, the bimodal ethylene-co-1-hexene copolymer further comprises at least one antioxidant selected from Antioxidants 1 and 2; at least one catalyst neutralizer selected from Catalyst Neutralizers 1 and 2; or a combination thereof. The results are reported below in Table 3, which also includes the oxygen adaptation level (O2) again for convenience. Table 3: Fusion properties of IE1 to IE7.

[0105] As shown in Table 3, the melting properties of the bimodal ethylene-co-1-hexene copolymers of IE1 to IE7 comprise a high load melt index I21 (190 ° C, 21.6 kg) of 7. 4 to 9.5 g/10 min; an MFR5 melt flow ratio (I21/I5) of 26.6 to 30.6; a melt elasticity (G'/G" at 0.1 rad/s) of 0.53 to 0.68 Pa; a melt index I2 (190 °C, 2.16 kg) of 0.06 to 0, 08 g/10 min; and a melt index I5 (190 °C, 5.0 kg) of 0.27 to 0.33 g/10 min). Hexene is characterized by any, alternatively all but one, alternatively each of the aforementioned melting properties.

[0106] The melting properties data in Table 3 for the bimodal ethylene-co-1-hexene copolymer were analyzed to find out which reactor/process operating conditions the melting properties depend on. The following operating conditions were found to influence the melting properties of the bimodal ethylene-co-1-hexene copolymer produced in this way: Increasing the molar ratio of H2/C2 gas in the process produced the bimodal ethylene-co-1- inventive hexene having an improved beneficial melting property space for use in blown film processes and for the production of blown films.

[0107] Granular resins from IE1 to IE7 were characterized by density; propagation of the molecular weight of the component (Mw-HMW/Mw-LMW ratio); division of component fractions; molecular weights; and molecular mass dispersion (Mw/Mn), DM. The results are reported below in Table 4. Table 4: Resin properties from IE1 to IE7

[0108] As shown in Table 4, the resin properties of the bimodal ethylene-co-1-hexene copolymers from IE1 to IE7 comprise a density of 0.949 g/cm3; a division of the higher molecular weight (HMW) component at 57.6 to 59.4% by weight; a division of the lower molecular weight (LMW) component by 42.4 to 40.6% by weight; a number-average molecular weight of 7,470 to 7,920 g/mol; a weight average molecular weight of 268,800 to 295,300 g/mol; a molecular mass dispersion Mw/Mn (MD) of 34.8 to 38.6; and a z-average molecular weight of 1,835,000 to 2,110,000 g/mol. In certain embodiments, the bimodal ethylene-co-1-hexene copolymer is characterized by any one, alternatively all but one, alternatively each of the aforementioned resin properties.

[0109] Film Formation Procedure: Granular resin pellets of the bimodal ethylene-co-1-hexene copolymer of IE1 to IE7 are melted separately at the melting temperature described herein and separately blown into films using a barrier single-screw extruder sized 25:1 length to diameter (L/D) of 50 millimeters (mm), Alpine, a 120 mm inner diameter die, a 1.2 mm die gap, without IBC (internal bubble cooling). Gauge variation, dart impact and Elmendorf tear properties were measured on films with a thickness of 0.0127 millimeters (mm) = 12.7 micrometers (μm) and in accordance with the above-mentioned test methods. See Table 5 below. Table 5: Film properties from IE1 to IE7 N/a means not applicable. As shown in Table 5, the film properties of blown films of the bimodal ethylene-co-1-hexene copolymers of IE1 to IE7 comprise a gauge range of 11.2% to 16.2%, an average Elmendorf tear in the direction transverse tear (CD) of 61 to 181 gf, a medium Elmendorf tear in the machine direction (MD) of 18 to 32 gf, and a dart impact of 276 to 375 g. In certain embodiments, the bimodal ethylene-co-1-hexene copolymer and blown films thereof are independently characterized by any, alternatively all but one, alternatively each of the aforementioned film properties.

Claims (8)

1. Method for synthesizing a bimodal ethylene-CO-1-hexene copolymer, consisting essentially of a higher molecular weight component (HMW) and a lower molecular weight component (LMW) and, when in molten form, 190 °C, is characterized by having a melt property space defined by a combination of properties of high load melt index ("HLMI" or "I21"), melt flow ratio I21/I5 (" MFR5") and melt elasticity (G'/Gw at 0.1 rad/s), with the HLMI being 7.0 to 11.0 grams per 10 minutes (g/10 min) and is measured according with ASTM D1238-13 (190 °C, 21.6 kg); the MFR5 is 22.0 to 35.0, and the I21 and I5 values used to calculate the MFR5 are each in g/10 min and are measured in accordance with ASTM D1238-13 (190 °C, 21 .6 kg, "I21"; and 190 °C, 5.0 kg, "I5", respectively), and the melt elasticity is 0.5 to 0.8 pascals (Pa), where melt elasticity = G7G" is determined at 0.1 radian per second (rad/s) in accordance with the Melt Elasticity Test Method, the method essentially consisting of copolymerizing ethylene and 1-hexene with a combination of a bimodal catalyst system and of an equilibrium catalyst in the presence of molecular hydrogen gas (H2) and optionally an induced condensation agent (ICA) in a polymerization reactor under effective polymerization conditions to provide an initial ethylene-CO-1-hexene bimodal copolymer and, optionally, oxygen adapting the initial bimodal ethylene-CO-1-hexene copolymer to provide an oxygen-adapted bimodal ethylene-CO-1-hexene copolymer, the bimodal catalyst system being produced by contacting a first activator with; bis(2-(pentamethylphenylamido)ethyl)-amine zirconium dibenzyl and a bis(butylcyclopentadienyl)zirconium dihalide; wherein the equilibrium catalyst is produced by contacting a second activator with bis(butylcyclopentadienyl)zirconium dialkyl; the first and second activators being the same or different; and wherein effective polymerization conditions comprise a reaction temperature of 80 degrees (°) to 110° Celsius (C); a molar ratio of molecular hydrogen gas to ethylene (H2/C2 molar ratio) of 0.001 to 0.020; and a molar ratio of 1-hexene ("C6") to ethylene (C6/C2 molar ratio) of 0.005 to 0.050. 2. Method according to claim 1, characterized in that the melting property space of the bimodal ethylene-CO-1-hexene copolymer is further defined by any of the limitations (i) to (iii): (i) a melt index I2 of 0.05 to 0.10, measured in accordance with ASTM D1238-13 (190 °C, 2.16 kg, “I2”); (ii) a melt index I5 of 0.20 to 0.40 g/10 min, measured in accordance with ASTM D1238-13 (190 °C, 5.0 kg, “I5”); and (iii) a melt flow ratio I21/I2 ("MFR2") of 80.0 to 150.0, with the I21 and I2 values used to calculate the MFR2 each being in g/10 min and are measured in accordance with ASTM D1238-13 (190 °C, 21.6 kg, "I21"; and 190 °C, 2.16 kg, "I2", respectively). 3. Method according to claim 1 or 2, wherein the bimodal ethylene-CO-1-hexene copolymer is characterized by the fact that it has any of the resin property limitations (i) to (iv): (i ) a density of 0.9410 to 0.9550 g/cm3, measured in accordance with ASTM D79213, Method B; (ii) a component fraction division defined by a weight fraction of the HMW component of 50.0 to 63% by weight; and a weight fraction of the LWM component fraction is 50.0 to 37 wt%, respectively, of the combined weight of the HMW and LMW components, measured in accordance with the Gel Permeation Chromatography (GPC) Test Method; (iii) a component molecular weight distribution defined by a ratio between the weight-average molecular weight of the HMW component (Mw-HMW) and the weight-average molecular weight of the LMW component (Mw-LMW) (i.e., Mw-HMW) /Mw-LMW Ratio) from 30.0 to 50.0, measured according to the GPC Test Method; and (iv) a molecular mass dispersity (Mw/Mn), DM, of 30.0 to 40.0, with Mw and Mn being measured in accordance with the GPC Test Method. 4. Method according to claim 1 or 2, wherein the bimodal ethylene-CO-1-hexene copolymer is characterized by the fact that it has any of the resin property limitations (i) to (iv): (i ) a density of 0.9450 to 0.9530 g/cm3, measured in accordance with ASTM D79213, Method B; (ii) a component fraction division defined by a weight fraction of the HMW component of 55 to 60.0% by weight; and a weight fraction of the LWM component fraction is 45 to 40.0 wt%, respectively, of the combined weight of the HMW and LMW components, measured in accordance with the Gel Permeation Chromatography (GPC) Test Method; (iii) a component molecular weight distribution defined by a ratio between the weight-average molecular weight of the HMW component (Mw-HMW) and the weight-average molecular weight of the LMW component (Mw-LMW) (i.e., Mw-HMW) /Mw-LMW Ratio) from 40.0 to 45, measured according to the GPC Test Method; and (iv) a molecular mass dispersity (Mw/Mn), DM, of 34 to 39, with Mw and Mn being measured in accordance with the GPC Test Method. 5. Method according to claim 1 or 2, wherein the bimodal ethylene-CO-1-hexene copolymer is characterized by the fact that it has any of the resin property limitations (i) to (iv): (i ) a density of 0.9480 to 0.9500 g/cm3, measured in accordance with ASTM D79213, Method B; (ii) a component fraction division defined by a weight fraction of the HMW component of 57.0 to 59.4% by weight; and a weight fraction of the LWM component fraction is 43.0 to 40.6 wt%, respectively, of the combined weight of the HMW and LMW components, measured in accordance with the Gel Permeation Chromatography (GPC) Test Method ); (iii) a component molecular weight distribution defined by a ratio between the weight-average molecular weight of the HMW component (Mw-HMW) and the weight-average molecular weight of the LMW component (Mw-LMW) (i.e., Mw-HMW) /Mw-LMW Ratio) from 40.9 to 42.5, measured according to the GPC Test Method; and (iv) a molecular mass dispersity (Mw/Mn), DM, of 34.8 to 38.6, with Mw and Mn being measured in accordance with the GPC Test Method. 6. Method according to any one of claims 1 to 5, wherein the bimodal ethylene-CO-1-hexene copolymer when defined in the form of a blown film and having a thickness of 0.0127 millimeters, is characterized by having any of the limitations (i) to (iv): (i) a dart impact of 250 to 400 grams (g), measured in accordance with the Dart Impact Test Method in accordance with Method A , ASTM D1709-16a; (ii) an Elmendorf tear in the transverse direction (CD) of 60.0 to 190.0 grams of force (gf), measured in accordance with the Elmendorf Tear Test Method in accordance with ASTM D1922-09; (iii) a machine direction (MD) Elmendorf tear of 15 to 35 gf, measured in accordance with the Elmendorf Tear Test Method in accordance with ASTM D1922-09; and (iv) a gauge variation of 10.5% to 17%, measured in accordance with the Gauge Variation Test Method in accordance with ASTM D8136-17. 7. Method according to any one of claims 1 to 6, characterized in that it further essentially consists of removing the bimodal ethylene-CO-1-hexene copolymer from the reactor to provide a bimodal ethylene-co-1-hexene copolymer. 1-hexene removed. 8. Method for producing a blown film, the method being characterized by the fact that it comprises melting the bimodal ethylene-CO-1-hexene copolymer, as defined in any one of claims 1 to 7, so as to provide a melt thereof, extrude the melt through a die configured to form a bubble so as to produce a bubble of bimodal ethylene-CO-1-hexene copolymer and blow the bubble with a film blowing machine, thereby producing the blown film.