Polyethylene copolymers

Abstract

The present invention relates to a metallocene-catalyzed polyethylene copolymer having: a density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured according to the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C; a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw being the weight-average molecular weight and Mn being the number-average molecular weight; an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min and / or an MI2 of at least 0.40 g / 10 min to at most 6.00 g / 10 min wherein MI2 is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm, and HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2): (1) X is greater than - 0.026 ln(MI 2 ) + 0.0498 (2) X is greater than - 0.026 ln(HLMI) + 0.1334 a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by 13C NMR; wherein said polyethylene copolymer is an ethylene-1-hexene polymer, and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support. The present invention also relates to an article, such as a film, comprising the metallocene-catalyzed polyethylene copolymer as defined herein. The present invention also relates to a process for the preparation of a metallocene-catalyzed polyethylene copolymer as defined herein.

Description

[0001]Polyethylene copolymers Field of invention This invention relates to new polyethylene copolymers and to articles, such as films, comprising said polyethylene copolymers. Background of the inventionIn the field of polyethylene, constant mechanical, optics and process-ability improvement ismandatory. Good melt processing of polyethylene is generally associated among others with high melt strength and low extruder head pressure.There are many types of polyethylene resins. Not many of them, however, combineprocessing-ease and good mechanical properties. It was achieved in the last few years using metallocene catalyst combined with cascade reactor to make tailor made bimodal resins. However, the requirement of multiple reactors leads to some drawbacks like increased costs, inhomogeneity of resins or inaccessibility of some designs, and this can be overcome using dual-site catalysts in one single loop reactor. However, in several examples in the literature, some combinations suffer of a lack of reactivity, work only in specific conditions or are able to produce only specific resins. There is thus still a need for resins that can be processed easily and offer simultaneously good mechanical properties. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide new metallocene-catalyzedpolyethylene copolymers that have good melt strength and which can be easily processed,while displaying good mechanical and optical properties and good sealing performances.In a first aspect, the present invention provides a metallocene-catalyzed polyethylenecopolymer having a density ranging from at least 0.900 g / cm3to at most 0.913 g / cm3, as measured according to the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C; a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw being the weight-average molecular weight and Mn being the number-average molecular weight; a melt index ranging from an HLMI of at least 1.2 g / 10 min to an MI2 of at most 6.00 g / 10 min wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm, and melt index HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2): (1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; and wherein said polyethylene copolymer is an ethylene-1-hexene polymer, and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support. Preferably, the present invention provides a metallocene-catalyzed polyethylene copolymer having a density ranging from at least 0.900 g / cm3to at most 0.913 g / cm3, as measured according to the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C; a molecular weight distribution Mw / Mnranging from at least 2.50 to at most 3.50, with Mwbeing the weight-average molecular weight and Mnbeing the number-average molecular weight; an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min and / or an MI2of at least 0.40 g / 10 min to at most 6.00 g / 10 min wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm, and HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C,and a 21.6 kg load using a die of 2.096 mm;a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2): (1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2(also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; and wherein said polyethylene copolymer is an ethylene-1-hexene polymer, and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support; optionally having a zero shear viscosity η0 in Pa.s of at least 5000, preferably at least 6000, preferably at least 7000, preferably at least 8000. In a second aspect, the present invention also encompasses an article comprising the metallocene-catalyzed polyethylene copolymers according to the first aspect. In a third aspect, the present invention also encompasses a film comprising the metallocene- catalyzed polyethylene copolymers according to the first aspect.In a fourth aspect, the present invention provides a process for the preparation of metallocene-catalyzed polyethylene copolymers according to the first aspect, the process comprising:contacting at least one metallocene catalyst composition with ethylene and 1-hexene as co-monomer, optionally hydrogen, and polymerizing the ethylene, and 1-hexene, in the presenceof said at least one metallocene catalyst composition, and optional hydrogen, thereby obtaining the polyethylene copolymer.The invention overcomes the drawbacks of the aforementioned strategies. The presentinvention provides polyethylene copolymers having very low densities, with densities below0.913 g / cm3. These copolymers can be produced in a slurry process, preferably in a slurry loopprocess. After the copolymers are produced, they may be formed into various articles,including but not limited to, film products, and yarns such grass yarns. The articles obtained with such copolymers have clarity, softness, strain recovery, and toughness. They have flexibility at low temperatures, sealing and hot-tack properties, and good optical properties.These copolymers offer the value chain a combination of attributes — including levels ofelasticity and holding force, puncture resistance, and low haze — currently unavailable in asingle resin. Film formulation is simple and therefore contributes to an improved recyclability. The independent and dependent claims set out particular and preferred features of the invention. Features from the dependent claims may be combined with features of the independent or other dependent claims as appropriate. The present invention will now be further described. In the following passages, different aspects of the invention are defined in more detail. Each aspect so defined may be combinedwith any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature or statement indicated as being preferred or advantageous may be combined with any other features or statements indicated as being preferred or advantageous. Brief description of the figures Figure 1 represents a graph plotting the13C{1H} NMR spectrum of a metallocene ethylene 1- hexene copolymer.Figure 2 represents a graph plotting the melting temperature Tm (melting peak at the highesttemperature in °C) of copolymers according to embodiments of the invention and ofcomparative examples as a function of the 1-hexene content C (in weight %).Figure 3 represents a graph plotting the 1-hexene content C (in weight %) of the copolymers as a function of the density (in g / cm3). Figure 4 represents a graph plotting the TREF (temperature rising elution fractionation) profilesof copolymers according to embodiments of the invention and profiles of comparativeexamples. Figure 5 represents a graph plotting heat seal curves for films produced with copolymers according to embodiments of the invention. Detailed description of the invention Before the present copolymers, processes, articles, and uses encompassed by the invention are described, it is to be understood that this invention is not limited to particular copolymers, processes, articles, and uses described, as such copolymers, processes, articles, and uses may, of course, vary. It is also to be understood that the terminology used herein is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims. Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, definitions for the terms used in the description are included to better appreciate the teaching of the present invention. When describing the polyethylene copolymers, processes, articles, and uses of the invention, the terms used are to be construed in accordance with the following definitions, unless the context dictates otherwise. As used herein, the singular forms "a", "an", and "the" include both singular and plural referents unless the context clearly dictates otherwise. By way of example, "a copolymer" means one copolymer or more than one copolymer. The terms "comprising", "comprises" and "comprised of" as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. The terms "comprising", "comprises" and "comprised of" also include the term “consisting of”. The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1, 2, 3, 4 whenreferring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80,when referring to, for example, measurements). The recitation of end points also includes the end point values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein. Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims and statements, any of the embodiments can be used in any combination. Whenever the term “substituted” is used herein, it is meant to indicate that one or more hydrogen atoms on the atom indicated in the expression using “substituted” is replaced with a selection from the indicated group, provided that the indicated atom’s normal valence is not exceeded, and that the substitution results in a chemically stable compound, i.e. a compound that is sufficiently robust to survive isolation from a reaction mixture. Preferred substituents for the indenyl, tetrahydroindenyl, cyclopentadienyl and fluorenyl groups, can be selected from the group comprising alkyl, alkenyl, cycloalkyl, aryl, alkoxy, alkylaryl, arylalkyl, halogen, Si(R10)3, heteroalkyl; wherein each R10is independently hydrogen, alkyl, or alkenyl. Preferably, substituents for the tetrahydroindenyl, cyclopentadienyl and fluorenyl groups, can be selected from the group comprising alkyl, alkenyl, cycloalkyl, aryl, alkoxy, alkylaryl, arylalkyl, halogen, Si(R10)3, heteroalkyl; wherein each R10is independently hydrogen, alkyl, or alkenyl. The term “halo” or “halogen” as a group or part of a group is generic for fluoro, chloro, bromo, iodo. The term "alkyl" as a group or part of a group, refers to a hydrocarbyl group of formula CnH2n+1wherein n is a number greater than or equal to 1. Alkyl groups may be linear or branched and may be substituted as indicated herein. Generally, alkyl groups of this invention comprise from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 6 carbon atoms, more preferably from 1 to 4 carbon atoms. When a subscript is used herein following a carbon atom, the subscript refers to the number of carbon atoms that the named group may contain. For example, the term "C1-20alkyl", as a group or part of a group, refers to a hydrocarbyl group of formula -CnH2n+1wherein n is a number ranging from 1 to 20. Thus, for example, “C1-8alkyl” includes all linear or branched alkyl groups with between 1 and 8 carbon atoms, and thus includes methyl, ethyl, n-propyl, i-propyl, butyl and its isomers (e.g. n-butyl, i-butyl and t- butyl); pentyl and its isomers, hexyl and its isomers, etc. A “substituted alkyl" refers to an alkyl group substituted with one or more substituent(s) (for example 1 to 3 substituent(s), for example 1, 2, or 3 substituent(s)) at any available point of attachment. When the suffix "ene" is used in conjunction with an alkyl group, i.e. “alkylene”, this is intended to mean the alkyl group as defined herein having two single bonds as points of attachment toother groups. As used herein, the term “alkylene” also referred as “alkanediyl”, by itself or aspart of another substituent, refers to alkyl groups that are divalent, i.e., with two single bonds for attachment to two other groups. Alkylene groups may be linear or branched and may be substituted as indicated herein. Non-limiting examples of alkylene groups include methylene (-CH2-), ethylene (-CH2-CH2-), methylmethylene (-CH(CH3)-), 1-methyl-ethylene (-CH(CH3)- CH2-), n-propylene (-CH2-CH2-CH2-), 2-methylpropylene (-CH2-CH(CH3)-CH2-), 3- methylpropylene (-CH2-CH2-CH(CH3)-), n-butylene (-CH2-CH2-CH2-CH2-), 2-methylbutylene (- CH2-CH(CH3)-CH2-CH2-), 4-methylbutylene (-CH2-CH2-CH2-CH(CH3)-), pentylene and its chain isomers, hexylene and its chain isomers. The term “alkenyl” as a group or part of a group, refers to an unsaturated hydrocarbyl group, which may be linear, or branched, comprising one or more carbon-carbon double bonds. Generally, alkenyl groups of this invention comprise from 3 to 20 carbon atoms, preferably from 3 to 10 carbon atoms, preferably from 3 to 8 carbon atoms. When a subscript is used herein following a carbon atom, the subscript refers to the number of carbon atoms that the named group may contain. Examples of C3-20alkenyl groups are ethenyl, 2-propenyl, 2-butenyl, 3-butenyl, 2-pentenyl and its isomers, 2-hexenyl and its isomers, 2,4-pentadienyl, and the like. The term “alkoxy" or “alkyloxy”, as a group or part of a group, refers to a group having the formula –ORbwherein Rbis alkyl as defined herein above. Non-limiting examples of suitable alkoxy include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert- butoxy, pentyloxy and hexyloxy. The term “cycloalkyl”, as a group or part of a group, refers to a cyclic alkyl group, that is a monovalent, saturated, hydrocarbyl group having 1 or more cyclic structure, and comprisingfrom 3 to 20 carbon atoms, more preferably from 3 to 10 carbon atoms, more preferably from3 to 8 carbon atoms; more preferably from 3 to 6 carbon atoms. Cycloalkyl includes all saturated hydrocarbon groups containing 1 or more rings, including monocyclic, bicyclic groups or tricyclic. The further rings of multi-ring cycloalkyls may be either fused, bridged and / or joined through one or more spiro atoms. When a subscript is used herein following a carbon atom, the subscript refers to the number of carbon atoms that the named group may contain. For example, the term “C3-20cycloalkyl”, a cyclic alkyl group comprising from 3 to 20 carbon atoms. For example, the term “C3-10cycloalkyl”, a cyclic alkyl group comprising from 3 to 10 carbon atoms. For example, the term “C3-8cycloalkyl”, a cyclic alkyl group comprising from 3 to 8 carbon atoms. For example, the term “C3-6cycloalkyl”, a cyclic alkyl group comprising from 3 to 6 carbon atoms. Examples of C3-12cycloalkyl groups include but are not limited to adamantly, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, bicycle[2.2.1]heptan-2yl, (1S,4R)-norbornan-2-yl, (1R,4R)-norbornan-2-yl, (1S,4S)-norbornan- 2-yl, (1R,4S)-norbornan-2-yl. When the suffix "ene" is used in conjunction with a cycloalkyl group, i.e. cycloalkylene, this is intended to mean the cycloalkyl group as defined herein having two single bonds as points of attachment to other groups. Non-limiting examples of "cycloalkylene" include 1,2- cyclopropylene, 1,1-cyclopropylene, 1,1-cyclobutylene, 1,2-cyclobutylene, 1,3-cyclopentylene, 1,1-cyclopentylene, and 1,4-cyclohexylene. Where an alkylene or cycloalkylene group is present, connectivity to the molecular structure of which it forms part may be through a common carbon atom or different carbon atom. To illustrate this applying the asterisk nomenclature of this invention, a C3alkylene group may be for example *-CH2CH2CH2-*, *-CH(-CH2CH3)-* or *-CH2CH(-CH3)-*. Likewise a C3cycloalkylene group may be * * . The term “cycloalkenyl” as a group or part of a group, refers to a non-aromatic cyclic alkenyl group, with at least one site (usually 1 to 3, preferably 1) of unsaturation, namely a carbon- carbon, sp2 double bond; preferably having from 5 to 20 carbon atoms more preferably from 5 to 10 carbon atoms, more preferably from 5 to 8 carbon atoms, more preferably from 5 to 6 carbon atoms. Cycloalkenyl includes all unsaturated hydrocarbon groups containing 1 or more rings, including monocyclic, bicyclic or tricyclic groups. The further rings may be either fused, bridged and / or joined through one or more spiro atoms. When a subscript is used herein following a carbon atom, the subscript refers to the number of carbon atoms that the named group may contain. For example, the term “C5-20cycloalkenyl”, a cyclic alkenyl group comprising from 5 to 20 carbon atoms. For example, the term “C5-10cycloalkenyl”, a cyclic alkenyl group comprising from 5 to 10 carbon atoms. For example, the term “C5-8cycloalkenyl”, a cyclic alkenyl group comprising from 5 to 8 carbon atoms. For example, the term “C5-6cycloalkyl”, a cyclic alkenyl group comprising from 5 to 6 carbon atoms. Examples include but are not limited to: cyclopentenyl (-C5H7), cyclopentenylpropylene, methylcyclohexenylene and cyclohexenyl (-C6H9). The double bond may be in the cis or trans configuration. The term "cycloalkenylalkyl", as a group or part of a group, means an alkyl as defined herein, wherein at least one hydrogen atom is replaced by at least one cycloalkenyl as defined herein. The term “cycloalkoxy”, as a group or part of a group, refers to a group having the formula – ORhwherein Rhis cycloalkyl as defined herein above. The term “aryl”, as a group or part of a group, refers to a polyunsaturated, aromatic hydrocarbyl group having a single ring (i.e. phenyl) or multiple aromatic rings fused together (e.g. naphthyl), or linked covalently, typically containing 6 to 20 atoms; preferably 6 to 10, wherein at least one ring is aromatic. The aromatic ring may optionally include one to two additional rings (either cycloalkyl, heterocyclyl or heteroaryl) fused thereto. Examples of suitable aryl include C6-20aryl, preferably C6-10aryl, more preferably C6-8aryl. Non-limiting examples of aryl comprise phenyl,biphenylyl, biphenylenyl, or 1-or 2-naphthanelyl; 1-, 2-, 3-, 4-, 5- or 6-tetralinyl (also known as“1,2,3,4-tetrahydronaphtalene); 1-, 2-, 3-, 4-, 5-, 6-, 7- or 8-azulenyl, 4-, 5-, 6 or 7-indenyl; 4-or 5-indanyl; 5-, 6-, 7- or 8-tetrahydronaphthyl; 1,2,3,4-tetrahydronaphthyl; and 1,4-dihydronaphthyl; 1-, 2-, 3-, 4- or 5-pyrenyl. A “substituted aryl” refers to an aryl group havingone or more substituent(s) (for example 1, 2 or 3 substituent(s), or 1 to 2 substituent(s)), at any available point of attachment. The term “aryloxy”, as a group or part of a group, refers to a group having the formula –ORgwherein Rgis aryl as defined herein above. The term "arylalkyl", as a group or part of a group, means an alkyl as defined herein, wherein at least one hydrogen atom is replaced by at least one aryl as defined herein. Non-limiting examples of arylalkyl group include benzyl, phenethyl, dibenzylmethyl, methylphenylmethyl, 3- (2-naphthyl)-butyl, and the like. The term “alkylaryl” as a group or part of a group, means an aryl as defined herein wherein at least one hydrogen atom is replaced by at least one alkyl as defined herein. Non-limitingexamples of alkylaryl group include p-CH3-Rg-, wherein Rg is aryl as defined herein above.The term “arylalkyloxy” or “aralkoxy” as a group or part of a group, refers to a group having the formula -O-Ra-Rgwherein Rgis aryl, and Rais alkylene as defined herein above. The term “heteroalkyl” as a group or part of a group, refers to an acyclic alkyl wherein one or more carbon atoms are replaced by at least one heteroatom selected from the group comprising O, Si, S, B, and P, with the proviso that said chain may not contain two adjacent heteroatoms. This means that one or more -CH3of said acyclic alkyl can be replaced by –OHfor example and / or that one or more -CR2- of said acyclic alkyl can be replaced by O, Si, S, B, and P. The term “aminoalkyl” as a group or part of a group, refers to the group -Rj-NRkRlwherein Rjis alkylene, Rkis hydrogen or alkyl as defined herein, and Rlis hydrogen or alkyl as defined herein. The term "heterocyclyl" as a group or part of a group, refers to non-aromatic, fully saturated or partially unsaturated cyclic groups (for example, 3 to 7 member monocyclic, 7 to 11 member bicyclic, or containing a total of 3 to 10 ring atoms) which have at least one heteroatom in at least one carbon atom-containing ring. Each ring of the heterocyclic group containing a heteroatom may have 1, 2, 3 or 4 heteroatoms selected from N, S, Si, Ge, where the nitrogen and sulfur heteroatoms may optionally be oxidized and the nitrogen heteroatoms may optionally be quaternized. The heterocyclic group may be attached at any heteroatom or carbon atom of the ring or ring system, where valence allows. The rings of multi-ring heterocycles may be fused, bridged and / or joined through one or more spiro atoms. Non limiting exemplary heterocyclic groups include aziridinyl, oxiranyl, thiiranyl, piperidinyl, azetidinyl, 2-imidazolinyl, pyrazolidinyl imidazolidinyl, isoxazolinyl, oxazolidinyl, isoxazolidinyl, thiazolidinyl, isothiazolidinyl, piperidinyl, succinimidyl, 3H-indolyl, indolinyl, isoindolinyl, 2H- pyrrolyl, 1-pyrrolinyl, 2-pyrrolinyl, 3-pyrrolinyl, pyrrolidinyl, 4H-quinolizinyl, 2-oxopiperazinyl, piperazinyl, homopiperazinyl, 2-pyrazolinyl, 3-pyrazolinyl, tetrahydro-2H-pyranyl, 2H-pyranyl, 4H-pyranyl, 3,4-dihydro-2H-pyranyl, oxetanyl, thietanyl, 3-dioxolanyl, 1,4-dioxanyl, 2,5- dioximidazolidinyl, 2-oxopiperidinyl, 2-oxopyrrolodinyl, indolinyl, tetrahydropyranyl, tetrahydrofuranyl, tetrahydrothiophenyl, tetrahydroquinolinyl, tetrahydroisoquinolin-1-yl, tetrahydroisoquinolin-2-yl, tetrahydroisoquinolin-3-yl, tetrahydroisoquinolin-4-yl, thiomorpholin-4-yl, thiomorpholin-4-ylsulfoxide, thiomorpholin-4-ylsulfone, 1,3-dioxolanyl, 1,4- oxathianyl, 1,4-dithianyl, 1,3,5-trioxanyl, 1H-pyrrolizinyl, tetrahydro-1,1-dioxothiophenyl, N- formylpiperazinyl, and morpholin-4-yl. Whenever used in the present invention the term “compounds” or a similar term is meant to include the compounds of general formula (I) and / or (II) and any subgroup thereof, includingall polymorphs and crystal habits thereof, and isomers thereof (including optical, geometric andtautomeric isomers) as hereinafter defined. The compounds of formula (I) and / or (II) or any subgroups thereof may comprise alkenyl group, and the geometric cis / trans (or Z / E) isomers are encompassed herein. Where structural isomers are interconvertible via a low energy barrier, tautomeric isomerism ('tautomerism') can occur. This can take the form of proton tautomerism in compounds of formula (I) containing, for example, a keto group, or so-called valence tautomerism in compounds which contain an aromatic moiety. It follows that a single compound may exhibit more than one type of isomerism. Cis / trans isomers may be separated by conventional techniques well known to those skilled in the art, for example, chromatography and fractional crystallization. Preferred statements (features) and embodiments of the compositions, processes, polymers, articles, and uses of this invention are set herein below. Each statement and embodiment of the invention so defined may be combined with any other statement and / or embodiment, unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other features or statements indicated as being preferred or advantageous. Hereto, the present invention is in particular captured by any one or any combination of one or more of the below numbered statements and embodiments, with any other aspect and / or embodiment.1. A metallocene-catalyzed polyethylene copolymer having:a density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured accordingto the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C; amolecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mwbeing the weight-average molecular weight and Mn being the number-average molecular weight; a melt index ranging from an HLMI of at least 1.2 g / 10 min to an MI2 of at most 6.00 g / 10 min wherein MI2 is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm, and melt index HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably a melt index ranging from an HLMIof at least 5.0 g / 10 min to an MI2 of at most 3.0 g / 10 min; for example a melt index MI2 of at least 0.10 g / 10 min to at most 6.00 g / 10 min, preferably a melt index MI2 of at least 0.10 g / 10 min to at most 3.00 g / 10 min, and / or a melt index HLMI of at least 1.2 g / 10 min to at most 150.0 g / 10 min, preferably an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min; preferably an HLMI of at least 5.0 g / 10 min to at most 50.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2): (1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; and wherein said polyethylene copolymer is an ethylene-1-hexene polymer; and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support.A metallocene-catalyzed polyethylene copolymer having:a density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured accordingto the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C;a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mwbeing the weight-average molecular weight and Mnbeing the number-average molecular weight; a melt index MI2 of at least 0.10 g / 10 min to at most 6.00 g / 10 min, wherein MI2 is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm; preferably a melt index MI2 of at least 0.10 g / 10 min to at most 3.00 g / 10 min, a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equation (1): (1) X is greater than - 0.026 ln(MI2) + 0.0498a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; and wherein said polyethylene copolymer is an ethylene-1-hexene polymer; and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support.A metallocene-catalyzed polyethylene copolymer having:a density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured accordingto the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C;a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mwbeing the weight-average molecular weight and Mnbeing the number-average molecular weight; an HLMI of at least 1.2 g / 10 min to at most 150.0 g / 10 min wherein HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min; preferably an HLMI of at least 5.0 g / 10 min to at most 50.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equation (2): (2) X is greater than – 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; and wherein said polyethylene copolymer is an ethylene-1-hexene polymer; and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support.A metallocene-catalyzed polyethylene copolymer having:a density ranging from at least 0.900 g / cm3to at most 0.913 g / cm3, as measured according to the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C; a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw being the weight-average molecular weight and Mn being the number-average molecular weight; an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min and / or an MI2of at least 0.40 g / 10 min to at most 6.00 g / 10 min wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm, and melt index HLMI is determined according to ISO 1133:2005 Method B, conditionG, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably an MI2of at least 0.50 g / 10 min, preferably at least 0.60 g / 10 min, preferably at least 0.40 g / 10min to at most 3.00 g / 10 min, preferably at least 0.50 g / 10 min to at most 3.00 g / 10 min, preferably at least 0.60 g / 10 min to at most 2.00 g / 10 min, preferably at least 0.40 g / 10 minto at most 1.50 g / 10 min, preferably at least 0.50 g / 10min to at most 1.50 g / 10 min, and / orpreferably an HLMI of at 6.0 g / 10 min, preferably least 7.0 g / 10 min to at most 100.0 g / 10 min, preferably an HLMI of at least 8.0 g / 10 min to at most 80.0 g / 10 min, preferably an HLMI of at least 9.0 g / 10 min to at most 60.0 g / 10 min, preferably an HLMI of at least 10.0 g / 10 min to at most 50.0 g / 10 min, preferably an HLMI of at least 11.0 g / 10 min to at most 40.0 g / 10 min, preferably an HLMI of at least 12.0 g / 10 min to at most 30.0 g / 10 min, preferably an HLMI of at least 13.0 g / 10 min to at most 30.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2): (1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2(also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; and wherein said polyethylene copolymer is an ethylene-1-hexene polymer, and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support; optionally having a zero shear viscosity η0 in Pa.s of at least 5000, preferably at least 6000, preferably at least 7000, preferably at least 8000.5. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-4, having a melting temperature Tmsatisfying the following equation (3): (3) Tm ≤ -2.2 x C +120Tm being defined as the melting peak at the lowest temperature in °C as determined by DSC (measured on the copolymer in the absence of any nucleating agent), and C beingthe 1-hexene content in weight % as determined by13C NMR.6. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-5, having a 1-hexene content C in weight % satisfying the following equation (4):(4) C ≤ (-708 x density (in g / cm3))+656.7. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-6, having a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 24.5, preferably at most 24.0, preferably at most 23.5, preferably at most 23.0.8. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-7, having a melt index ratio HLMI / MI2 of at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0.9. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-8, wherein the Temperature Rising Elution Fractionation (TREF) distribution curve of the metallocene-catalyzed polyethylene copolymer comprises only one peak.10. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-9, wherein the Temperature Rising Elution Fractionation (TREF) distribution curve of the metallocene-catalyzed polyethylene copolymer comprises only one peak and wherein said peak appears at a temperature of at least 65.0 °C to at most 75.0°C.11. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-10, having a fraction of material that is eluted in Temperature Rising Elution Fractionation (TREF) at a temperature below 35.0°C of at most 2.0 % by weight, preferably at most 1.9 % by weight, preferably at most 1.8 % by weight, preferably at most 1.7 % by weight, preferably at most 1.6 % by weight, preferably at most 1.5 % by weight, based on the total amount of the copolymer.12. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-11, having a molecular weight distribution Mz / Mw of at most 2.80, with Mz being the z average molecular weight, preferably at most 2.75, preferably at most 2.70, preferably at most 2.65.13. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-12, having a molecular weight distribution Mz / Mw of at least 2.00, with Mz being the z average molecular weight, preferably at least 2.10, preferably at least 2.20.14. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-13, having a molecular weight distribution Mz / Mn of at least 5.00, preferably at least 6.00, preferably at least 6.50, preferably at least 7.00, with Mz being the z average molecular weight and Mn being the number-average molecular weight.15. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-14, having a molecular weight distribution Mz / Mn of at most 11.00, preferably at most 10.50, preferably at most 10.00, preferably at most 9.50, preferably at most 9.00, with Mz being the z average molecular weight and Mn being the number-average molecular weight.16. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-15, having a Mnof at least 23000 Da, preferably at least 24000 Da, preferably at least 25000 Da, preferably at least 26000 Da, preferably at least 27000 Da, with Mnbeing the number-average molecular weight.17. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-16, having a molecular weight distribution Mw / Mnof at least 2.55, preferably at least 2.60, preferably at least 2.65, preferably at least 2.70, preferably at least 2.75, preferably at least 2.80, preferably at least 2.85, with Mwbeing the weight-average molecular weight and Mnbeing the number-average molecular weight.18. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-17, having a molecular weight distribution Mw / Mnof at most 3.45, preferably at most 3.40, preferably at most 3.35, with Mw being the weight-average molecular weight and Mn beingthe number-average molecular weight.19. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-18, having a molecular weight distribution Mw / Mn of at least 2.55 to at most 3.50, preferablyat least 2.60 to at most 3.50, preferably at least 2.70 to at most 3.50, preferably at least2.80 to at most 3.50, preferably at least 2.50 to at most 3.40, preferably at least 2.50 to atmost 3.50, preferably at least 2.60 to at most 3.40, preferably at least 2.70 to at most 3.40,with Mw being the weight-average molecular weight and Mn being the number-average molecular weight.20. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-19, having a density of at most 0.913 g / cm3as measured according to the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C.21. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-20, having a density of at least 0.901 g / cm3, preferably of at least 0.902 g / cm3, preferably of at least 0.903 g / cm3, preferably of at least 0.904 g / cm3, preferably of at least 0.905 g / cm3, preferably of at least 0.906 g / cm3, preferably of at least 0.907 g / cm3, as measured according to the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C.22. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-3, 5-21, having a melt index MI2 ranging from at least 0.10 g / 10 min to at most 5.00 g / 10min, preferably at most 4.00 g / 10 min, preferably at most 3.00 g / 10 min, preferably at most 2.00 g / 10 min, preferably at most 1.75 g / 10 min, preferably at most 1.50 g / 10 min, whereinMI2 is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm.23. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-3, 5-22, having a melt index MI2from at least 0.10 g / 10 min, preferably at least 0.20 g / 10 min, preferably at least 0.30 g / 10 min, preferably at least 0.40 g / 10 min, preferably at least 0.50 g / 10 min, preferably at least 0.60 g / 10 min, for example at least 0.10 g / 10 min to at most 5.00 g / 10 min, preferably from at least 0.20 g / 10 min to at most 4.00 g / 10 min, preferably from at least 0.30 g / 10 min to at most 3.00 g / 10 min, preferably from at least 0.30 g / 10 min to at most 2.00 g / 10 min, preferably at least 0.30 g / 10 min to at most 1.75 g / 10 min, preferably at least 0.40 g / 10 min to at most 1.50 g / 10 min, preferably at least 0.50 g / 10 min to at most 1.50 g / 10 min, wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm.24. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-3, 5-23, having a melt index HLMI ranging from at least 5.0 g / 10 min to at most 150.0 g / 10min wherein melt index HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm, preferably an HLMI of at most 100.0 g / 10 min, preferably an HLMI of at most 50.0 g / 10 min, preferably an HLMI of at most 30.0 g / 10 min, preferably an HLMI of at most 25.0 g / 10 min.25. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1--24, having a melt index MI2 ranging from at least 0.40 g / 10 min to at most 5.00 g / 10 min, preferably at most 4.00 g / 10 min, preferably at most 3.00 g / 10 min, preferably at most 2.00 g / 10 min, preferably at most 1.75 g / 10 min, preferably at most 1.50 g / 10 min, wherein MI2 is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm.26. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-3, 5-25, having a melt index MI2 from at least 0.50 g / 10 min, preferably at least 0.60 g / 10 min, for example at least 0.50 g / 10 min to at most 5.00 g / 10 min, preferably from at least 0.50 g / 10 min to at most 4.00 g / 10 min, preferably from at least 0.50 g / 10 min to at most 3.00 g / 10 min, preferably from at least 0.50 g / 10 min to at most 2.00 g / 10 min, preferably at least 0.50 g / 10 min to at most 1.75 g / 10 min, preferably at least 0.50 g / 10 min to at most 1.50 g / 10 min, wherein MI2 is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm.27. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-3, 5-26, having a melt index HLMI ranging from at least 5.0 g / 10 min to at most 50.0 g / 10 min wherein melt index HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm, preferably an HLMI of at most 30.0 g / 10 min, preferably an HLMI of at most 25.0 g / 10 min.28. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-27, having a melt index HLMI from at least 6.0 g / 10 min, wherein melt index HLMI isdetermined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm, preferably an HLMI of at least 7.0 g / 10 min, preferably an HLMI of at least 8.0 g / 10 min, preferably an HLMI of at least 9.0 g / 10 min, preferably an HLMI of at least 10.0 g / 10 min, preferably an HLMI of at least 11.0 g / 10 min, preferably an HLMI of at least 12.0 g / 10 min, preferably an HLMI of at least 13.0 g / 10 min.29. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-28, having a melt index HLMI from at least 6.0 g / 10 min, wherein melt index HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm, preferably an HLMI of at least 7.0 g / 10 min to at most 100.0 g / 10 min, preferably an HLMI of at least 8.0 g / 10 min to at most 80.0 g / 10 min, preferably an HLMI of at least 9.0 g / 10 min to at most 60.0 g / 10 min, preferably an HLMI of at least 10.0 g / 10 min to at most 50.0 g / 10 min, preferably an HLMI of at least 11.0g / 10 min to at most 40.0 g / 10 min, preferably an HLMI of at least 12.0 g / 10 min to at most 30.0 g / 10 min, preferably an HLMI of at least 13.0 g / 10 min to at most 30.0 g / 10 min.30. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-29, having a melt index MI5 of at least 0.5 g / 10 min to 15.0 g / 10 min, wherein MI5 is determined according to ISO 1133:2005 Method B, condition T, at a temperature 190 °C, and a 5 kg load using a die of 2.096 mm, preferably at least 0.7 g / 10 min, preferably at least 1.0 g / 10 min, preferably at least 1.5 g / 10 min, preferably at least 2.0 g / 10 min.31. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-30, having a melt index MI5 of at most 15.0 g / 10 min, wherein MI5 is determined accordingto ISO 1133:2005 Method B, condition T, at a temperature 190 °C, and a 5 kg load using a die of 2.096 mm, preferably of at most 10.0 g / 10 min, preferably of at most 9.0 g / 10 min, preferably of at most 8.0 g / 10 min, preferably of at most 5.0 g / 10 min, preferably of at most4.0 g / 10 min.32. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-31, having a melt index MI5 ranging from 0.5 g / 10 min to 15.0 g / 10 min, wherein MI5 is determined according to ISO 1133:2005 Method B, condition T, at a temperature 190 °C, and a 5 kg load using a die of 2.096 mm, preferably from 0.7 g / 10 min to 10.0 g / 10 min, preferably from 1.0 g / 10 min to 9.0 g / 10 min, preferably from 1.5 g / 10 min to 8.0 g / 10 min,preferably from 2.0 g / 10 min to 5.0 g / 10 min.33. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-32, having a melt index ratio HLMI / MI5 of at least 3.0, preferably at least 4.0, preferably atleast 5.0, preferably at least 6.0, preferably at least 6.5.34. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-33, having a melt index ratio HLMI / MI5 of at most 15.0; preferably at most 10.0, preferablyat most 8.5, preferably at most 8.0, preferably of at least 3.0 to at most 15.0; preferably at least 4.0 to at most 9.0, preferably at least 5.0 to at most 8.0.35. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-34, having a melt index ratio MI5 / MI2 of at most 10.0, preferably at most 7.0, preferably atmost 5.0, preferably at most 4.0, preferably at most 3.5, preferably at least 1.0, preferably at least 1.5, preferably at least 2.0, preferably at least 1.0 to at most 10.0, preferably at least 1.0 to at most 5.0, preferably at least 1.5 to at most 5.0.36. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-35, having at least one melting temperature Tm determined by DSC of at most 115.0 °C,for example at most 112.0 °C, for example at most 111.0 °C, preferably at most 110.0 °C,preferably in the range of at least 100.0 °C to at most 111.0 °C, more preferably in the range of at least 105.0 °C to at most 110.0 °C, when measured on the copolymer in theabsence of any nucleating agent.37. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-36, having a total 1-hexene content, relative to the total weight of the polyethylene copolymer of at least 5.0 % by weight, as determined by13C NMR analysis, preferably at least 6.0 % by weight, preferably at least 6.5% by weight, preferably at least 6.9 % by weight, preferably at least 7.0 % by weight, preferably at least 8.0 % by weight, preferablyat least 9.0 % by weight.38. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-37, having a total 1-hexene content, relative to the total weight of the polyethylenecopolymer of at most 15.0 % by weight, as determined by13C NMR analysis, preferably at most 14.0 % by weight, preferably at most 13.0 % by weight.39. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-38, having a total 1-hexene content, relative to the total weight of the polyethylene copolymer of at least 6.0 % by weight to at most 15.0 % by weight, as determined by13C NMR analysis, preferably at least 6.0 % by weight to at most 14.0 % by weight, preferably at least 7.0% by weight to at most 14.0 % by weight, preferably at least 8.0 % by weight toat most 14.0 % by weight, preferably at least 9.0 % by weight to at most 13.0 % by weight.40. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-39, having a zero shear viscosity η0 in Pa.s of at least 5000, preferably at least 6000, preferably at least 7000, preferably at least 8000.41. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-40, having a rheology long chain branching index grheoof at least 0.80, preferably at least 0.83, preferably at least 0.85.42. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-41, having a (HLMI / MI2) / (Mw / Mn) (~LCB) of at least 6.0, preferably at least 6.1, preferably atmost 8.0, preferably at most 7.5.43. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-42, wherein said metallocene is a zirconium based metallocene.44. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-43, having at least 0.1 ppm of residual zirconium by weight of copolymer.45. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-44, wherein said metallocene is a metallocene catalyst composition comprising two metallocene catalysts, and an optional activator.46. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-45, wherein the catalyst composition comprises a catalyst component A and a catalyst component B, an optional activator; an optional support; and an optional co-catalyst;wherein catalyst component A comprises a bridged metallocene compound with two groups independently selected from indenyl or tetrahydroindenyl, each group being unsubstituted or substituted; and catalyst component B comprises a bridged metallocene compound with a substituted or unsubstituted cyclopentadienyl group and a substituted orunsubstituted fluorenyl group.47. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-46, wherein said catalyst composition comprises a catalyst component A and a catalystcomponent B, an optional activator; an optional support; and an optional co-catalyst; wherein catalyst component A comprises a bridged metallocene compound with two tetrahydroindenyl groups, each group being unsubstituted or substituted; and catalyst component B comprises a bridged metallocene compound with a substituted or unsubstituted cyclopentadienyl group and a substituted or unsubstituted fluorenyl group.48. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-47, wherein the weight ratio of catalyst component A to catalyst component B is in a range of from 5:95 to 30:70, preferably 10:90 to 25:75, preferably 15:85 to 25:75, preferably 20:80.49. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-48, wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst, with a catalyst component A and a catalyst component B on a single support (i.e. with two metallocene active sites on a single support), and an optional activator.50. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-49, wherein said metallocene is a metallocene catalyst composition comprising analuminoxane activator; and a titanated silica solid support or a silica solid support; and an optional co-catalyst.51. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1- 50, prepared using a continuous process.52. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-51, prepared using a process, wherein said continuous process is performed in slurryphase, preferably in at least one slurry loop reactor.53. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-52, prepared using a process comprising: contacting at least one metallocene catalystcomposition, with ethylene, 1-hexene as comonomer, and optionally hydrogen, andpolymerizing the ethylene and 1-hexene, in the presence of said at least one metallocene catalyst composition, and optional hydrogen, thereby obtaining the polyethylene copolymer.54. The metallocene-catalyzed polyethylene copolymer according to any one of statements 1-53, wherein the at least one metallocene-catalyzed polyethylene copolymer is prepared using a process comprising the steps of: feeding ethylene monomer, a diluent, at least onemetallocene catalyst composition, 1-hexene and optionally hydrogen into at least oneslurry loop reactor; polymerizing the ethylene monomer and the 1-hexene, in the presence of the metallocene catalyst composition, and optional hydrogen, in said slurry loop reactor thereby producing the metallocene catalyzed-polyethylene copolymer.55. An article comprising the metallocene-catalyzed polyethylene copolymer according to anyone of statements 1-54.56. The article according to statement 55, wherein the article is a film.57. A film comprising the metallocene-catalyzed polyethylene copolymer according to any oneof statements 1-54.58. The film according to statements 57, having a relative tear resistance (N / mm) in themachine direction of at least 50 N / mm, preferably of at least 55 N / mm, preferably at least 58 N / mm, as measured according to ASTM D 1922:2015, on a blown film 40 µm thickprepared using a blown film line equipment having a low neck configuration with an extrusion screw diameter of 45 mm, a length to diameter ratio of the screw of 30, a die diameter of 120 mm, a blow-up ratio (BUR) of 2.5, a die gap of 1.6 mm, cooling air at a temperature of 20 °C, and a throughput of 20 kg / h.59. The film according to any one of statements 57-58, having a relative tear resistance (N / mm)in the transverse direction can be preferably of at least 70 N / mm, preferably at least 75 N / mm, preferably at least 80 N / mm, preferably at least 85 N / mm, preferably at least 90 N / mm, as measured according to ASTM D 1922:2015, on a blown film 40 µm thick prepared using a blown film line equipment having a low neck configuration with an extrusion screw diameter of 45 mm, a length to diameter ratio of the screw of 30, a die diameter of 120 mm, a blow-up ratio (BUR) of 2.5, a die gap of 1.6 mm, cooling air at a temperature of 20 °C, and a throughput of 20 kg / h.60. The film according to any one of statements 57-59, having a gloss of at least 50 measuredaccording to ASTM D-2457:2013 at an angle of 45°, at a thickness of 40 µm, more preferably a gloss of at least 60, preferably at least 65, preferably at least 70, preferably atleast 75, measured on a blown film 40 µm thick prepared using a blown film line equipmenthaving a low neck configuration with an extrusion screw diameter of 45 mm, a length todiameter ratio of the screw of 30, a die diameter of 120 mm, a blow-up ratio (BUR) of 2.5, adie gap of 1.6 mm, cooling air at a temperature of 20 °C, and a throughput of 20 kg / h.61. The film according to any one of statements 57-60, having a haze average of less than10.0 % measured according to ISO 14782:1999, at a thickness of 40 µm, more preferably ahaze of less than 8.0 %, preferably less than 7.0 %, preferably less than 5.0 %, preferablyless 4.5 %, preferably less than 4.0 %, measured on a blown film 40 µm thick preparedusing a blown film line equipment having a low neck configuration with an extrusion screwdiameter of 45 mm, a length to diameter ratio of the screw of 30, a die diameter of 120 mm, ablow-up ratio (BUR) of 2.5, a die gap of 1.6 mm, cooling air at a temperature of 20 °C,and a throughput of 20 kg / h.62. A process for the preparation of a metallocene-catalyzed polyethylene copolymeraccording to any one of statements 1-54, the process comprising: contacting at least one metallocene catalyst composition, with ethylene, 1-hexene as comonomer, and optionally hydrogen, and polymerizing the ethylene and the 1-hexene, in the presence of the at leastone metallocene catalyst composition, and optional hydrogen, thereby obtaining the polyethylene copolymer.63. Use of a metallocene-catalyzed polyethylene copolymer according to any one ofstatements 1-54, in film applications. As stated before, the present invention provides a metallocene-catalyzed polyethylene copolymer as defined herein (including all embodiments thereof as described herein), whereinsaid polyethylene copolymer is an ethylene-1-hexene copolymer having:a density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured according tothe method of standard ISO 1183-1:2012 method A at a temperature of 23 °C, preferably a density of at least 0.901 g / cm3to at most 0.913 g / cm3, preferably a density of at least 0.902g / cm3 to at most 0.913 g / cm3, preferably of at least 0.903 g / cm3 to at most 0.913 g / cm3,preferably of at least 0.905 g / cm3to at most 0.913 g / cm3, preferably of at least 0.906 g / cm3to at most 0.913 g / cm3, preferably of at least 0.907 g / cm3to at most 0.913 g / cm3;a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw beingthe weight-average molecular weight and Mnbeing the number-average molecular weight; a melt index ranging from an HLMI of at least 1.2 g / 10 min to an MI2of at most 6.00 g / 10 min wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm, and melt index HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably a melt index ranging from an HLMI of atleast 5.0 g / 10 min to an MI2 of at most 3.0 g / 10 min; for example a melt index MI2 of at least0.10 g / 10 min to at most 6.00 g / 10 min, preferably a melt index MI2of at least 0.10 g / 10 min to at most 3.00 g / 10 min, and / or an HLMI of at least 1.2 g / 10 min to at most 150.0 g / 10 min, preferably an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min; preferably an HLMI of at least 5.0 g / 10 min to at most 50.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2):(1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regardto the total weight of the polyethylene copolymer measured by 13C NMR. Preferably, saidmetallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support. The present invention also provides a metallocene-catalyzed polyethylene copolymer as defined herein (including all embodiments thereof as described herein), wherein said polyethylene copolymer is an ethylene-1-hexene copolymer having:a density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured according tothe method of standard ISO 1183-1:2012 method A at a temperature of 23 °C, preferably a density of at least 0.901 g / cm3to at most 0.913 g / cm3, preferably a density of at least 0.902 g / cm3to at most 0.913 g / cm3, preferably of at least 0.903 g / cm3to at most 0.913 g / cm3, preferably of at least 0.904 g / cm3to at most 0.913 g / cm3, preferably of at least 0.905 g / cm3to at most 0.913 g / cm3, preferably of at least 0.906 g / cm3to at most 0.913 g / cm3, preferably of at least 0.907 g / cm3to at most 0.913 g / cm3;a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw beingthe weight-average molecular weight and Mnbeing the number-average molecular weight; a melt index MI2of at least 0.10 g / 10 min to at most 6.00 g / 10 min, wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm; preferably a melt index MI2of at least 0.10 g / 10 min to at most 3.00 g / 10 min, and / or an HLMI of at least 1.2 g / 10 min to at most 150.0 g / 10 min wherein HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min; preferably an HLMI of at least 5.0 g / 10 min to at most 50.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2):(1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR. In some embodiments, the metallocene-catalyzed polyethylene copolymer as defined herein(including all embodiments thereof as described herein), is an ethylene-1-hexene copolymerhaving:a density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured according tothe method of standard ISO 1183-1:2012 method A at a temperature of 23 °C, preferably a density of at least 0.901 g / cm3to at most 0.913 g / cm3, preferably a density of at least 0.902g / cm3 to at most 0.913 g / cm3, preferably of at least 0.903 g / cm3 to at most 0.913 g / cm3,preferably of at least 0.904 g / cm3 to at most 0.913 g / cm3, preferably of at least 0.905 g / cm3 toat most 0.913 g / cm3, preferably of at least 0.906 g / cm3to at most 0.913 g / cm3, preferably of at least 0.907 g / cm3to at most 0.913 g / cm3;a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw beingthe weight-average molecular weight and Mnbeing the number-average molecular weight; a melt index MI2of at least 0.10 g / 10 min to at most 6.00 g / 10 min, wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm; preferably a melt index MI2of at least 0.10 g / 10 min to at most 3.00 g / 10 min, and / oran HLMI of at least 1.2 g / 10 min to at most 150.0 g / 10 min wherein HLMI is determinedaccording to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min; preferably an HLMI of at least 5.0 g / 10 min to at most 50.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2):(1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0, preferably at least 16.5 to at most 25.0, preferably at least 17.0 to at most 24.0, preferably at least 17.5 to at most 23.0, preferably at least 18.0 to at most 23.0, preferably at least 18.5 to at most 23.0, preferably at least 19.0 to at most 23.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; optionally a melting temperature Tm satisfying the following equation (3): (3) Tm ≤ -2.2 x C +120Tm being defined as the melting peak at the lowest temperature in °C as determined by DSC(measured on the copolymer in the absence of any nucleating agent), and C being the 1-hexene content in weight % as determined by13C NMR;and optionally a 1-hexene content C in weight % satisfying the following equation (4):(4) C ≤ (-708 x density (in g / cm3))+656optionally having a Temperature Rising Elution Fractionation (TREF) distribution curve comprising only one peak and preferably wherein said peak appears at a temperature of at least 65.0 °C to at most 75.0°C; optionally having a fraction of material that is eluted in Temperature Rising Elution Fractionation (TREF) at a temperature below 35.0°C of at most 2.0 % by weight, preferably at most 1.9 % by weight, preferably at most 1.8 % by weight, preferably at most 1.7 % by weight, preferably at most 1.6 % by weight, preferably at most 1.5 % by weight, based on the total amount of the copolymer. In some embodiments, the metallocene-catalyzed polyethylene copolymer as defined herein(including all embodiments thereof as described herein), is an ethylene-1-hexene copolymerhaving: a density ranging from at least 0.900 g / cm3to at most 0.913 g / cm3, as measured according to the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C, preferably a density of at least 0.901 g / cm3to at most 0.913 g / cm3, preferably a density of at least 0.902 g / cm3to at most 0.913 g / cm3, preferably of at least 0.903 g / cm3to at most 0.913 g / cm3, preferably of at least 0.904 g / cm3to at most 0.913 g / cm3, preferably of at least 0.905 g / cm3to at most 0.913 g / cm3, preferably of at least 0.906 g / cm3to at most 0.913 g / cm3, preferably of at least 0.907 g / cm3to at most 0.913 g / cm3; a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw being the weight-average molecular weight and Mn being the number-average molecular weight;an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min wherein HLMI is determinedaccording to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably an HLMI of at least 5.0 g / 10 min to at most 50.0 g / 10 min; preferably an HLMI of at 6.0 g / 10 min, preferably least 7.0 g / 10 min to at most 100.0 g / 10 min, preferably an HLMI of at least 8.0 g / 10 min to at most 80.0 g / 10 min, preferably an HLMI of at least 9.0 g / 10 min to at most 60.0 g / 10 min, preferably an HLMI of at least 10.0 g / 10 min to at most 50.0 g / 10 min, preferably an HLMI of at least 11.0 g / 10 min to at most 40.0 g / 10 min, preferably an HLMI of at least 12.0 g / 10 min to at most 30.0 g / 10 min, preferably an HLMI of at least 13.0 g / 10 min to at most 30.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus,190 °C, as described in the Experimental section, satisfying the following equation (2):(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0, preferably at least 16.5 to at most 25.0, preferably at least 17.0 to at most 24.0, preferably at least 17.5 to at most 23.0, preferably at least 18.0 to at most 23.0, preferably at least 18.5 to at most 23.0, preferably at least 19.0 to at most 23.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; optionally having a zero shear viscosity η0 in Pa.s of at least 5000, preferably at least 6000, preferably at least 7000, preferably at least 8000; optionally a melting temperature Tmsatisfying the following equation (3):(3) Tm ≤ -2.2 x C +120Tmbeing defined as the melting peak at the lowest temperature in °C as determined by DSC(measured on the copolymer in the absence of any nucleating agent), and C being the 1-hexene content in weight % as determined by13C NMR;and optionally a 1-hexene content C in weight % satisfying the following equation (4):(4) C ≤ (-708 x density (in g / cm3))+656optionally having a Temperature Rising Elution Fractionation (TREF) distribution curve comprising only one peak and preferably wherein said peak appears at a temperature of at least 65.0 °C to at most 75.0°C; optionally having a fraction of material that is eluted in Temperature Rising Elution Fractionation (TREF) at a temperature below 35.0°C of at most 2.0 % by weight, preferably at most 1.9 % by weight, preferably at most 1.8 % by weight, preferably at most 1.7 % by weight, preferably at most 1.6 % by weight, preferably at most 1.5 % by weight, based on the total amount of the copolymer; and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support. In some embodiments, the metallocene-catalyzed polyethylene copolymer as defined herein(including all embodiments thereof as described herein), is an ethylene-1-hexene copolymerhaving: a density ranging from at least 0.900 g / cm3to at most 0.913 g / cm3, as measured according to the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C, preferably a density of at least 0.901 g / cm3to at most 0.913 g / cm3, preferably a density of at least 0.902 g / cm3to at most 0.913 g / cm3, preferably of at least 0.903 g / cm3to at most 0.913 g / cm3, preferably of at least 0.904 g / cm3to at most 0.913 g / cm3, preferably of at least 0.905 g / cm3to at most 0.913 g / cm3, preferably of at least 0.906 g / cm3to at most 0.913 g / cm3, preferably of at least 0.907 g / cm3to at most 0.913 g / cm3; a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw being the weight-average molecular weight and Mnbeing the number-average molecular weight; a melt index MI2of at least 0.40 g / 10 min to at most 6.00 g / 10 min, wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm; preferably a melt index MI2of at least 0.50 g / 10 min to at most3.00 g / 10 min, preferably at least 0.60 g / 10 min to at most 2.00 g / 10 min, preferably at least0.40 g / 10 min to at most 1.50 g / 10 min, preferably at least 0.50 g / 10min to at most 1.50 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equation (1):(1) X is greater than - 0.026 ln(MI2) + 0.0498a melt index ratio HLMI / MI2(also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0, preferably at least 16.5 to at most 25.0, preferably at least 17.0 to at most 24.0, preferably at least 17.5 to at most 23.0, preferably at least 18.0 to at most 23.0, preferably at least 18.5 to at most 23.0, preferably at least 19.0 to at most 23.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; optionally having a zero shear viscosity η0 in Pa.s of at least 5000, preferably at least 6000, preferably at least 7000, preferably at least 8000; optionally a melting temperature Tm satisfying the following equation (3):(3) Tm ≤ -2.2 x C +120Tm being defined as the melting peak at the lowest temperature in °C as determined by DSC(measured on the copolymer in the absence of any nucleating agent), and C being the 1-hexene content in weight % as determined by13C NMR;and optionally a 1-hexene content C in weight % satisfying the following equation (4):(4) C ≤ (-708 x density (in g / cm3))+656optionally having a Temperature Rising Elution Fractionation (TREF) distribution curve comprising only one peak and preferably wherein said peak appears at a temperature of at least 65.0 °C to at most 75.0°C; optionally having a fraction of material that is eluted in Temperature Rising Elution Fractionation (TREF) at a temperature below 35.0°C of at most 2.0 % by weight, preferably at most 1.9 % by weight, preferably at most 1.8 % by weight, preferably at most 1.7 % by weight, preferably at most 1.6 % by weight, preferably at most 1.5 % by weight, based on the total amount of the copolymer; and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support. In some embodiments, the metallocene-catalyzed polyethylene copolymer as defined herein(including all embodiments thereof as described herein), has a molecular weight distributionMz / Mwof at least 2.00 to at most 2.80, with Mzbeing the z average molecular weight, preferablyof at least 2.00 to at most 2.75, preferably of at least 2.00 to at most 2.70, preferably of at least2.00 to at most 2.65, preferably of at least 2.10 to at most 2.75, preferably of at least 2.20 to at most 2.70, preferably of at least 2.30 to at most 2.65. In some embodiments, the metallocene-catalyzed polyethylene copolymer as defined herein(including all embodiments thereof as described herein), has a molecular weight distributionMz / Mnof at least 5.00 to at most 11.00, preferably of at least 6.00 to at most 11.00, preferably of at least 6.50 to at most 11.00, preferably of at least 7.00 to at most 11.00, preferably of atleast 5.00 to at most 10.50, preferably of at least 6.00 to at most 10.00, preferably of at least6.50 to at most 9.50, preferably of at least 6.50 to at most 9.00, with Mz being the z averagemolecular weight and Mn being the number-average molecular weight. In some embodiments, the metallocene-catalyzed polyethylene copolymer as defined herein(including all embodiments thereof as described herein), has a melt index MI2 ranging from atleast 0.10 g / 10 min to at most 5.00 g / 10 min, preferably from at least 0.10 g / 10 min to at most4.00 g / 10 min, preferably from at least 0.10 g / 10 min to at most 3.00 g / 10 min, preferably fromat least 0.10 g / 10 min to at most 2.00 g / 10 min, preferably at least 0.20 g / 10 min to at most5.00 g / 10 min, preferably at least 0.30 g / 10 min to at most 4.00 g / 10 min, preferably at least0.40 g / 10 min to at most 3.00 g / 10 min, preferably at least 0.50 g / 10 min to at most 3.00 g / 10min, preferably at least 0.60 g / 10 min to at most 2.00 g / 10 min, wherein MI2 is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm. In some embodiments, the metallocene-catalyzed polyethylene copolymer as defined herein(including all embodiments thereof as described herein), is an ethylene-1-hexene copolymerhaving:a density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured according tothe method of standard ISO 1183-1:2012 method A at a temperature of 23 °C, preferably a density of at least 0.901 g / cm3to at most 0.913 g / cm3, preferably a density of at least 0.902g / cm3 to at most 0.913 g / cm3, preferably of at least 0.903 g / cm3 to at most 0.913 g / cm3,preferably of at least 0.904 g / cm3to at most 0.913 g / cm3, preferably of at least 0.905 g / cm3to at most 0.913 g / cm3, preferably of at least 0.906 g / cm3to at most 0.913 g / cm3, preferably of at least 0.907 g / cm3to at most 0.913 g / cm3;a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw beingthe weight-average molecular weight and Mnbeing the number-average molecular weight; a melt index MI2of at least 0.10 g / 10 min to at most 6.00 g / 10 min, wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm; preferably a melt index MI2of at least 0.10 g / 10 min to at most 3.00 g / 10 min, and / or an HLMI of at least 1.2 g / 10 min to at most 150.0 g / 10 min wherein HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min; preferably an HLMI of at least 5.0 g / 10 min to at most 50.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2):(1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0, preferably at least 16.5 to at most 25.0, preferably at least 17.0 to at most 24.0, preferably at least 17.5 to at most 23.0, preferably at least 18.0 to at most 23.0, preferably at least 18.5 to at most 23.0, preferably at least 19.0 to at most 23.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; a melting temperature Tm satisfying the following equation (3): (3) Tm ≤ -2.2 x C +120Tmbeing defined as the melting peak at the lowest temperature in °C as determined by DSC(measured on the copolymer in the absence of any nucleating agent), and C being the 1-hexene content in weight % as determined by13C NMR;a 1-hexene content C in weight % satisfying the following equation (4):(4) C ≤ (-708 x density (in g / cm3))+656optionally having a Temperature Rising Elution Fractionation (TREF) distribution curve comprising only one peak and preferably wherein said peak appears at a temperature of at least 65.0 °C to at most 75.0°C; optionally having a fraction of material that is eluted in Temperature Rising Elution Fractionation (TREF) at a temperature below 35.0°C of at most 2.0 % by weight, preferably at most 1.9 % by weight, preferably at most 1.8 % by weight, preferably at most 1.7 % by weight, preferably at most 1.6 % by weight, preferably at most 1.5 % by weight, based on the total amount of the copolymer;Optionally having a molecular weight distribution Mz / Mw of at least 2.00 to at most 2.80, withMz being the z average molecular weight, preferably of at least 2.00 to at most 2.75, preferablyof at least 2.00 to at most 2.70, preferably of at least 2.00 to at most 2.65, preferably of at least 2.10 to at most 2.75, preferably of at least 2.20 to at most 2.70, preferably of at least 2.30 to at most 2.65;Optionally having a molecular weight distribution Mz / Mn of at least 5.00 to at most 11.00,preferably of at least 6.00 to at most 11.00, preferably of at least 6.50 to at most 11.00, preferably of at least 7.00 to at most 11.00, preferably of at least 5.00 to at most 10.50,preferably of at least 6.00 to at most 10.00, preferably of at least 6.50 to at most 9.50, preferablyof at least 6.50 to at most 9.00, with Mz being the z average molecular weight and Mn being the number-average molecular weight. Polyethylene copolymers described herein can, in some aspects, have a non-conventional(reverse or inverse) co-monomer distribution, i.e., the higher molecular weight portions of thepolymer have higher co-monomer incorporation than the lower molecular weight portions. Preferably, there is an increasing co-monomer incorporation with increasing molecular weight. As used herein, the term “monomodal polyethylene” or “polyethylene with a monomodal molecular weight distribution” refers to polyethylene having one maximum in their molecular weight distribution curve, which is also defined as a unimodal distribution curve. As used herein, the term “polyethylene with a bimodal molecular weight distribution” or “bimodal polyethylene” it is meant, polyethylene having a distribution curve being the sum of two unimodal molecular weight distribution curves, and refers to a polyethylene product having two distinct but possibly overlapping populations of polyethylene macromolecules each having different weight average molecular weights. By the term “polyethylenes with a multimodal molecular weight distribution” or “multimodal polyethylenes” it is meant polyethylenes with a distribution curve being the sum of at least two, preferably more than two unimodal distribution curves, and refers to a polyethylene product having two or more distinct but possibly overlapping populations of polyethylene macromolecules each having different weight average molecular weights. The multimodal polyethylene can have an “apparent monomodal” molecular weight distribution, which is a molecular weight distribution curve with a single peakand no shoulder. Nevertheless, the polyethylene will still be multimodal if it comprises two ormore distinct populations of polyethylene macromolecules each having a different weightaverage molecular weights, as defined above, for example when the two distinct populations were prepared in different reactors and / or under different conditions and / or with different catalysts.According to the invention, the polyethylene copolymer is a metallocene-catalyzedpolyethylene copolymer. According to this invention the terms “metallocene-catalyzed polyethylene copolymer", "polyethylene copolymer prepared using at least one metallocene catalyst composition", and the term "polyethylene copolymer prepared in the presence of at least one metallocene catalyst", are synonyms. As used herein, the term “catalyst” refers to a substance that causes a change in the rate of a polymerization reaction. It is especially applicable to catalysts suitable for the polymerization of ethylene to polyethylene. The present invention therefore concerns polyethylene copolymers prepared preferably in the presence of at least one metallocene catalyst composition. As used herein, the terms “metallocene-catalyzed polyethylene copolymer”, and “metallocene-catalyzed polyethylene” are synonymous and used interchangeably and refers to a polyethylene copolymer prepared in the presence of a metallocene catalyst composition. The term "metallocene catalyst" or “metallocene” for short is used herein to describe any transition metal complexes comprising metal atoms bonded to one or more ligands. The preferred metallocene catalysts are compounds of Group IV transition metals of the Periodic Table such as titanium, zirconium, hafnium, etc., and have a coordinated structure with a metal compound and ligands composed of one or two groups of cyclopentadienyl, indenyl, fluorenyl or their derivatives. The structure and geometry of the metallocene can be varied to adapt tothe specific need of the producer depending on the desired polymer. Metallocene catalyststypically comprise a single metal site, which allows for more control of branching and molecular weight distribution of the polymer. Monomers are inserted between the metal and the growing chain of polymer. In a preferred embodiment, the metallocene used for preparing metallocene-catalyzed polyethylene copolymer is a dual metallocene catalyst composition comprising two metallocene catalysts, and an optional activator. Preferably, the metallocene catalyst composition comprises a dual catalyst which means a catalyst particle with two metallocene active sites on a single support. For example, catalyst “A” can produce short chains without co-monomer while catalyst “B” can produce longer chains with high concentration of co- monomer. The catalyst composition can be used in single reactor processes or even in multi- reactors processes.In an embodiment, the dual metallocene catalyst composition for preparing metallocene-catalyzed polyethylene copolymer comprises: at least one catalyst component A and at least one catalyst component B, an optional activator; an optional support; and an optional co- catalyst; wherein catalyst component A comprises a bridged metallocene compound with two groups independently selected from indenyl or tetrahydroindenyl, each group being unsubstituted or substituted; preferably catalyst component A comprises a bridgedmetallocene compound with two tetrahydroindenyl groups, each group being unsubstituted orsubstituted; catalyst component B comprises a bridged metallocene compound with a substituted or unsubstituted cyclopentadienyl group and a substituted or unsubstituted fluorenyl group. In an embodiment, the dual metallocene catalyst composition comprises a catalyst component A and a catalyst component B, an optional activator; an optional support; and an optional co- catalyst; wherein catalyst component A comprises a bridged metallocene compound with two tetrahydroindenyl groups, each group being unsubstituted or substituted; and catalyst component B comprises a bridged metallocene compound with a substituted or unsubstituted cyclopentadienyl group and a substituted or unsubstituted fluorenyl group. In an embodiment, the metallocene which can be used for metallocene-catalyzed ethylene polymer A is a dual metallocene catalyst composition comprising a catalyst component A and a catalyst component B, an optional activator; an optional support; and an optional co-catalyst;wherein the weight ratio of catalyst component A to catalyst component B is in a range of from5:95 to 30:70, preferably 10:90 to 25:75, preferably 15:85 to 25:75, preferably 20:80. In an embodiment, the bridged metallocene compound of catalyst component B comprises at least one alkenyl, cycloalkenyl, or cycloalkenylalkyl substituent, preferably at least one C3- 20alkenyl, C5-20cycloalkenyl, or C6-20cycloalkenylalkyl substituent, more preferably at least one C3-8alkenyl, C5-8cycloalkenyl, or C6-8cycloalkenylalkyl substituent. In one embodiment, the bridged metallocene catalyst can be represented by formula (III) for catalyst A, and formula (IV) for catalyst B: wherein L1(Ar1)2M1Q1Q2(III), L2(Ar2)(Ar3)M2Q3Q4(IV), each Ar1is independently indenyl or tetrahydroindenyl, optionally substituted with one or more substituents each independently selected from the group consisting of alkyl, alkenyl, cycloalkyl, aryl, alkoxy, alkylaryl, arylalkyl, halogen, Si(R10)3, heteroalkyl; wherein each R10is independently hydrogen, alkyl, or alkenyl. Each indenyl or tetrahydroindenyl component may be substituted in the same way or differently from one another at one or more positions of either of the fused rings, each substituent can be independently chosen. Preferably, each Ar1is tetrahydroindenyl, optionally substituted with one or more substituents each independently selected from the group consisting of alkyl, alkenyl, cycloalkyl, aryl, alkoxy, alkylaryl, arylalkyl, halogen, Si(R10)3, heteroalkyl; wherein each R10is independently hydrogen, alkyl, or alkenyl; Ar2is cyclopentadienyl, optionally substituted with one or more substituents each independently selected from the group consisting of alkyl, alkenyl, cycloalkyl, cycloalkenyl, or cycloalkenylalkyl, aryl, alkoxy, alkylaryl, arylalkyl, halogen, Si(R10)3, heteroalkyl; wherein each R10is independently hydrogen, alkyl, or alkenyl; Ar3is fluorenyl, optionally substituted with one or more substituents each independently selected from the group consisting of alkyl, alkenyl, cycloalkyl, cycloalkenyl, or cycloalkenylalkyl, aryl, alkoxy, alkylaryl, arylalkyl, halogen, Si(R10)3, heteroalkyl; wherein each R10is independently hydrogen, alkyl, or alkenyl; each of M1and M2is a transition metal selected from the group consisting of zirconium, hafnium, titanium, and vanadium; and preferably is zirconium; Q1and Q2are each independently selected from the group consisting of halogen, alkyl, -N(R11)2, alkoxy, cycloalkoxy, aralkoxy, cycloalkyl, aryl, alkylaryl, aralkyl, and heteroalkyl;wherein R11is hydrogen or alkyl; Q3and Q4are each independently selected from the group consisting of halogen, alkyl, -N(R11)2, alkoxy, cycloalkoxy, aralkoxy, cycloalkyl, aryl, alkylaryl, aralkyl, and heteroalkyl;wherein R11is hydrogen or alkyl; L1is a divalent group or moiety bridging the two Ar1groups, preferably selected from -[CR8R9]h- , SiR8R9, GeR8R9, or BR8; wherein h is an integer selected from 1, 2, or 3; each of R8, and R9are independently selected from the group consisting of hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aminoalkyl, and arylalkyl; or R8and R9together with the atom to which they are attached form a cycloalkyl, cycloalkenyl or heterocyclyl; preferably L1is -[CR8R9]h- ;L2is a divalent group or moiety bridging Ar2and Ar3groups, preferably selected from -[CR8R9]h- , SiR8R9, GeR8R9, or BR8; wherein h is an integer selected from 1, 2, or 3; each of R8, and R9are independently selected from the group consisting of hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aminoalkyl, and arylalkyl; or R8and R9together with the atom to which they are attached form a cycloalkyl, cycloalkenyl or heterocyclyl. In some embodiments, each Ar1is tetrahydroindenyl, optionally substituted with one or more substituents each independently selected from the group consisting of C1-20alkyl, C3-20alkenyl, C3-20cycloalkyl, C5-20cycloalkenyl, C6-20cycloalkenylalkyl, C6-20aryl, C1-20alkoxy, C7-20alkylaryl, C7-20arylalkyl, halogen, Si(R10)3, and heteroC1-12alkyl; wherein each R10is independently hydrogen, C1-20alkyl, or C3-20alkenyl. Preferably each Ar1is tetrahydroindenyl, optionally substituted with one or more substituents each independently selected from the group consisting of C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, C6-12aryl, C1-8alkoxy, C7-12alkylaryl, C7-12arylalkyl, halogen, Si(R10)3, and heteroC1-8alkyl; wherein each R10is independently hydrogen, C1-8alkyl, or C3-8alkenyl. Preferably each Ar1is tetrahydroindenyl, optionally substituted with one or more substituents each independently selected from the group consisting of C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C6-12aryl, and halogen. In some embodiments, Ar2is cyclopentadienyl, optionally substituted with one or more substituents each independently selected from the group consisting of C1-20alkyl, C3-20alkenyl, C3-20cycloalkyl, C5-20cycloalkenyl, C6-20cycloalkenylalkyl, C6-20aryl, C1-20alkoxy, C7-20alkylaryl, C7-20arylalkyl, halogen, Si(R10)3, and heteroC1-12alkyl; wherein each R10is independently hydrogen, C1-20alkyl, or C3-20alkenyl. Preferably Ar2is cyclopentadienyl, optionally substituted with one or more substituents each independently selected from the group consisting of C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, C6-12aryl, C1-8alkoxy, C7-12alkylaryl, C7-12arylalkyl, halogen, Si(R10)3, and heteroC1-8alkyl; wherein each R10is independently hydrogen, C1-8alkyl, or C3-8alkenyl. Preferably Ar2is cyclopentadienyl, optionally substituted with one or more substituents each independently selected from the group consisting of C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C6-12aryl, and halogen. In some embodiments, Ar3is fluorenyl, optionally substituted with one or more substituents each independently selected from the group consisting of C1-20alkyl, C3-20alkenyl, C3- 20cycloalkyl, C5-20cycloalkenyl, C6-20cycloalkenylalkyl, C6-20aryl, C1-20alkoxy, C7-20alkylaryl, C7- 20arylalkyl, halogen, Si(R10)3, and heteroC1-12alkyl; wherein each R10is independently hydrogen, C1-20alkyl, or C3-20alkenyl. Preferably Ar2is fluorenyl, optionally substituted with one or more substituents each independently selected from the group consisting of C1-8alkyl, C3- 8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, C6-12aryl, C1-8alkoxy, C7- 12alkylaryl, C7-12arylalkyl, halogen, Si(R10)3, and heteroC1-8alkyl; wherein each R10isindependently hydrogen, C1-8alkyl, or C3-8alkenyl. Preferably, Ar3 is fluorenyl, optionallysubstituted with one or more substituents each independently selected from the group consisting of C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C6-12aryl, and halogen. In some embodiments, L1is -[CR8R9]h-, SiR8R9, GeR8R9, or BR8; wherein h is an integer selected from 1, 2, or 3; each of R8, and R9are independently selected from the group consisting of hydrogen, C1-20alkyl, C3-20alkenyl, C3-20cycloalkyl, C5-20cycloalkenyl, C6- 20cycloalkenylalkyl, C6-12aryl, and C7-C20arylalkyl; or R8and R9together with the atom to which they are attached form a C3-20cycloalkyl, C5-20cycloalkenyl or heterocyclyl. Preferably L1is - [CR8R9]h-, SiR8R9, GeR8R9, or BR8; wherein h is an integer selected from 1, 2, or 3; each of R8, and R9are independently selected from the group consisting of hydrogen, C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, C6-12aryl, and C7-C12arylalkyl; or R8and R9together with the atom to which they are attached form a C3-8cycloalkyl, C5-8cycloalkenyl or heterocyclyl. Preferably, L1is -[CR8R9]h-, or SiR8R9; wherein h is an integer selected from 1, or 2; each of R8, and R9are independently selected from the group consisting of hydrogen, C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, and C6-12aryl. Preferably, L1is -[CR8R9]h-; wherein h is an integer selected from 1, or 2; each of R8, and R9are independently selected from the group consisting of hydrogen, C1-8alkyl, preferably hydrogen. In some embodiments, Q1and Q2are each independently selected from the group consistingof halogen, C1-20alkyl, -N(R11)2, C1-20alkoxy, C3-20cycloalkoxy, C7-20aralkoxy, C3-20cycloalkyl, C6-20aryl, C7-20alkylaryl, C7-20aralkyl, and heteroC1-20alkyl; wherein R11is hydrogen or C1-20alkyl. Preferably Q1and Q2are each independently selected from the group consisting of halogen,C1-8alkyl, -N(R11)2, C1-8alkoxy, C3-8cycloalkoxy, C7-12aralkoxy, C3-8cycloalkyl, C6-12aryl, C7-12alkylaryl, C7-12aralkyl, and heteroC1-8alkyl; wherein R11 is hydrogen or C1-8alkyl. Preferably,Q1and Q2are each independently selected from the group consisting of halogen, C1-8alkyl, - N(R11)2, C6-12aryl, and C7-12aralkyl; wherein R11is hydrogen or C1-8alkyl, preferably Q1and Q2are each independently selected from the group consisting of Cl, F, Br, I, methyl, benzyl, and phenyl. In some embodiments, L2is -[CR8R9]h-, SiR8R9, GeR8R9, or BR8; wherein h is an integer selected from 1, 2, or 3; each of R8, and R9are independently selected from the group consisting of hydrogen, C1-20alkyl, C3-20alkenyl, C3-20cycloalkyl, C5-20cycloalkenyl, C6- 20cycloalkenylalkyl, C6-12aryl, and C7-C20arylalkyl; or R8and R9together with the atom to which they are attached form a C3-20cycloalkyl, C5-20cycloalkenyl or heterocyclyl. Preferably L2is - [CR8R9]h-, SiR8R9, GeR8R9, or BR8; wherein h is an integer selected from 1, 2, or 3; each of R8, and R9are independently selected from the group consisting of hydrogen, C1-8alkyl, C3- 8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, C6-12aryl, and C7-C12arylalkyl; or R8and R9together with the atom to which they are attached form a C3-8cycloalkyl, C5- 8cycloalkenyl or heterocyclyl. Preferably, L2is -[CR8R9]h-, or SiR8R9; wherein h is an integer selected from 1, or 2; each of R8, and R9are independently selected from the group consisting of hydrogen, C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, and C6-12aryl. In some embodiments, Q3and Q4are each independently selected from the group consistingof halogen, C1-20alkyl, -N(R11)2, C1-20alkoxy, C3-20cycloalkoxy, C7-20aralkoxy, C3-20cycloalkyl, C6-20aryl, C7-20alkylaryl, C7-20aralkyl, and heteroC1-20alkyl; wherein R11is hydrogen or C1-20alkyl. Preferably Q3and Q4are each independently selected from the group consisting of halogen,C1-8alkyl, -N(R11)2, C1-8alkoxy, C3-8cycloalkoxy, C7-12aralkoxy, C3-8cycloalkyl, C6-12aryl, C7-12alkylaryl, C7-12aralkyl, and heteroC1-8alkyl; wherein R11 is hydrogen or C1-8alkyl. Preferably,Q3and Q4are each independently selected from the group consisting of halogen, C1-8alkyl, - N(R11)2, C6-12aryl, and C7-12aralkyl; wherein R11is hydrogen or C1-8alkyl, preferably Q1and Q2are each independently selected from the group consisting of Cl, F, Br, I, methyl, benzyl, and phenyl. In some preferred embodiments, catalyst component A comprises a bridged metallocenecatalyst of formula (Ia) or (Ib), more preferably catalyst component A comprises a bridgedmetallocene catalyst of formula (Ia); wherein each of R1, and R3, are independently selected from the group comprising alkyl, alkenyl, cycloalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, alkoxy, alkylaryl, arylalkyl, halogen, Si(R10)3, and heteroalkyl; wherein each R10is independently hydrogen, alkyl, or alkenyl; and m, p, are each independently an integer selected from 0, 1, 2, 3, or 4; each of R2, and R4, are independently selected from the group comprising alkyl, alkenyl, cycloalkyl, cycloalkenyl, cycloalkenylalkyl, phenyl, alkoxy, alkylaryl, arylalkyl, halogen, Si(R10)3, and heteroalkyl; wherein each R10is independently hydrogen, alkyl, or alkenyl; and n, q are each independently an integer selected from 0, 1, 2, 3, or 4; L1is -[CR8R9]h-, SiR8R9, GeR8R9, or BR8; wherein h is an integer selected from 1, 2, or 3; each of R8, and R9are independently selected from the group comprising hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aminoalkyl, and arylalkyl; or R8and R9together with the atom to which they are attached form a cycloalkyl, cycloalkenyl or heterocyclyl; M1is a transition metal selected from the group comprising zirconium, titanium, hafnium, and vanadium; and preferably M is zirconium; and Q1and Q2are each independently selected from the group comprising halogen, alkyl, -N(R11)2, alkoxy, cycloalkoxy, aralkoxy, cycloalkyl, aryl, alkylaryl, aralkyl, and heteroalkyl; wherein R11is hydrogen or alkyl.In some embodiments, catalyst component A contains a -[CR8R9]h- bridging group; wherein his an integer selected from 1, 2, or 3; preferably 1 or 2, preferably 2, each of R8, and R9are independently selected from the group comprising hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aminoalkyl, and arylalkyl, preferably hydrogen; or R8and R9together with the atom to which they are attached form a cycloalkyl, cycloalkenyl or heterocyclyl. In some embodiments, catalyst component A comprises a bridged metallocene of formula (Ia), wherein1 3 each of R , R are independently group comprising C1-20alkyl, C3-20alkenyl, C3-20cycloalkyl, C5-20cycloalkenyl, C6-20cycloalkenylalkyl, C6-20aryl, C1-20alkoxy, C7-20alkylaryl, C7-20arylalkyl, halogen, Si(R10)3, and heteroC1-12alkyl; wherein each R10is independently hydrogen, C1-20alkyl, or C3-20alkenyl; and m, p, are each independently an integer selected from 0, or 1; each of R2, R4are independently selected from the group comprising C1-20alkyl, C3-20alkenyl, C3-20cycloalkyl, C5-20cycloalkenyl, C6-20cycloalkenylalkyl, C6-20aryl, C1-20alkoxy, C7-20alkylaryl, C7-20arylalkyl, halogen, Si(R10)3, and heteroC1-12alkyl; wherein each R10is independently hydrogen, C1-20alkyl, or C3-20alkenyl; and n, q are each independently an integer selected from 0, or 1;L1 is -[CR8R9]h- wherein h is an integer selected from 1, 2, or 3; each of R8, and R9 areindependently selected from the group comprising hydrogen, C1-20alkyl, C3-20alkenyl, C3-20cycloalkyl, C5-20cycloalkenyl, C6-20cycloalkenylalkyl, C6-10aryl, aminoC1-6alkyl, and C7- C20arylalkyl; or R8and R9together with the atom to which they are attached form a C3-20cycloalkyl, C5-20cycloalkenyl or heterocyclyl; M1is a transition metal selected from the group comprising zirconium, titanium, hafnium, and vanadium; and preferably M is zirconium; and Q1and Q2are each independently selected from the group consisting of halogen, C1-20alkyl, - N(R11)2, C1-20alkoxy, C3-20cycloalkoxy, C7-20aralkoxy, C3-20cycloalkyl, C6-20aryl, C7-20alkylaryl, C7- 20aralkyl, and heteroC1-20alkyl; wherein R11is hydrogen or C1-20alkyl. In some embodiments, each of R1, and R3are independently selected from the group comprising C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, C6- 10aryl, C1-8alkoxy, C7-12alkylaryl, C7-12arylalkyl, halogen, Si(R10)3, and heteroC1-8alkyl; wherein each R10is independently hydrogen, C1-8alkyl, or C3-8alkenyl; and m, p, are each independently an integer selected from 0, or 1; each of R2, and R4, are independently selected from the group comprising C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, C6-10aryl, C1-8alkoxy, C7-12alkylaryl, C7- 12arylalkyl, halogen, Si(R10)3, and heteroC1-8alkyl;wherein each R10is independently hydrogen, C1-8alkyl, or C3-8alkenyl; and n, q are each independently an integer selected from 0, or 1; L1is -[CR8R9]h-; wherein h is an integer selected from 1, or 2; each of R8, and R9are independently selected from the group consisting of hydrogen, C1-8alkyl, preferably hydrogen; M1is a transition metal selected from the group comprising zirconium, titanium, hafnium, and vanadium; and preferably M is zirconium; and Q1and Q2are each independently selected from the group comprising halogen, C1-8alkyl, - N(R11)2, C1-8alkoxy, C3-8cycloalkoxy, C7-12aralkoxy, C3-8cycloalkyl, C6-10aryl, C7-12alkylaryl, C7-12aralkyl, and heteroC1-8alkyl; wherein R11is hydrogen or C1-8alkyl. In some embodiments, each of R1, and R3are independently selected from the group comprising C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C6-10aryl, and halogen; and m, p, are each independently an integer selected from 0, or 1; preferably 0; each of R2, and R4, are independently selected from the group comprising C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C6-10aryl, and halogen; and n, q are each independently an integer selected from 0, or 1; preferably 0; L1is -[CR8R9]h-; wherein h is an integer selected from 1, or 2, preferably 2; each of R8, and R9are independently selected from the group consisting of hydrogen, C1-8alkyl, preferably hydrogen; M1is a transition metal selected from zirconium, or hafnium; and preferably M is zirconium; and Q1and Q2are each independently selected from the group comprising halogen, C1-8alkyl, - N(R11)2, C6-10aryl, and C7-12aralkyl; wherein R11is hydrogen or C1-8alkyl, preferably Q1and Q2are each independently selected from the group comprising Cl, F, Br, I, methyl, benzyl, and phenyl. In some embodiments, catalyst component A comprises a bridged metallocene of formula (Ic) wherein R3, R4, L1, M1, Q1, Q2, p and q have the same meaning as that defined herein, preferably p and q are 0. In some embodiments, catalyst component A comprises bridged metallocene of formula (Id) erein L1, M1 wh , Q1, and Q2, have the defined herein. In some embodiments, catalyst component A comprises bridged metallocene of formula (Ie) wherein M1, Q1, and Q2, have the same meaning as that defined herein. A bridged metallocene catalyst component can appear in two stereo-isomeric forms: a racemic form and a meso form. In some preferred embodiments, catalyst component A is a racemic bridged bis-tetrahydroindenyl metallocene compound, preferably component A has formula (Ia). Non-limiting examples of catalyst A are shown below . Preferred examples of catalyst A are shown below . In some preferred embodiments, catalyst component B comprises a bridged metallocene catalyst of formula (II), each of R5, R6, and R7, are independently selected from the group comprising alkyl, alkenyl, cycloalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, alkoxy, alkylaryl, arylalkyl, halogen, Si(R10)3, and heteroalkyl; wherein each R10is independently hydrogen, alkyl, or alkenyl; and r, s, t are each independently an integer selected from 0, 1, 2, 3, or 4; L2is -[CR8R9]h-, SiR8R9, GeR8R9, or BR8; wherein h is an integer selected from 1, 2, or 3; each of R8, and R9are independently selected from the group comprising hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aminoalkyl, and arylalkyl; or R8and R9together with the atom to which they are attached form a cycloalkyl, cycloalkenyl or heterocyclyl; M2is a transition metal selected from the group comprising zirconium, titanium, hafnium, and vanadium; and preferably is zirconium; and Q3and Q4are each independently selected from the group comprising halogen, alkyl, -N(R11)2, alkoxy, cycloalkoxy, aralkoxy, cycloalkyl, aryl, alkylaryl, aralkyl, and heteroalkyl; wherein R11is hydrogen or alkyl. In some embodiments, catalyst component B comprises a bridged metallocene of formula (II), wherein each of R5, R6, and R7 , are group consisting of C1-20alkyl, C3-20alkenyl, C3-20cycloalkyl, C5-20cycloalkenyl, C6-20cycloalkenylalkyl, C6-20aryl, C1-20alkoxy, C7-20alkylaryl, C7-20arylalkyl, halogen, Si(R10)3, and heteroC1-20alkyl; wherein each R10is independently hydrogen, C1-20alkyl, or C3-20alkenyl; and r, s, t are each independently an integer selected from 0, 1, 2, 3, or 4; L2is -[CR8R9]h-, SiR8R9, GeR8R9, or BR8; wherein h is an integer selected from 1, 2, or 3; each of R8, and R9are independently selected from the group consisting of hydrogen, C1-20alkyl, C3- 20alkenyl, C3-20 cycloalkyl, C5-20cycloalkenyl, C6-20cycloalkenylalkyl, C6-10aryl, aminoC1-6alkyl, and C7-C20arylalkyl; or R8and R9together with the atom to which they are attached form a C3- 20cycloalkyl, C5-20cycloalkenyl or heterocyclyl; M2is a transition metal selected from the group comprising zirconium, titanium, hafnium, and vanadium; and preferably is zirconium; and Q3and Q4are each independently selected from the group comprising halogen, C1-20alkyl, - N(R11)2, C1-20alkoxy, C3-20cycloalkoxy, C7-20aralkoxy, C3-20cycloalkyl, C6-20aryl, C7-20alkylaryl, C7- 20aralkyl, and heteroC1-20alkyl; wherein R11is hydrogen or C1-20alkyl. In some embodiments, each of R5, R6, and R7, are independently selected from the group comprising C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, C6- 10aryl, C1-8alkoxy, C7-12alkylaryl, C7-12arylalkyl, halogen, Si(R10)3, and heteroC1-8alkyl; wherein each R10is independently hydrogen, C1-8alkyl, or C3-8alkenyl; and r, s, t are each independently an integer selected from 0, 1, 2, 3, or 4; L2is -[CR8R9]h-, SiR8R9, GeR8R9, or BR8; wherein h is an integer selected from 1, 2, or 3; each of R8, and R9are independently selected from the group comprising hydrogen, C1-8alkyl, C3- 8alkenyl, C3-8cycloalkyl, C5-8cycloalkenyl, C6-8cycloalkenylalkyl, C6-10aryl, aminoC1-6alkyl, and C7-C12arylalkyl; or R8and R9together with the atom to which they are attached form a C3- 8cycloalkyl, C5-8cycloalkenyl or heterocyclyl; M2is a transition metal selected from the group comprising zirconium, titanium, hafnium, and vanadium; and preferably is zirconium; and Q3and Q4are each independently selected from the group comprising halogen, C1-8alkyl, - N(R11)2, C1-8alkoxy, C3-8cycloalkoxy, C7-12aralkoxy, C3-8cycloalkyl, C6-10aryl, C7-12alkylaryl, C7-12aralkyl, and heteroC1-8alkyl; wherein R11is hydrogen or C1-8alkyl. In some embodiments, each of R5, R6, and R7, is independently selected from the group comprising C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl, C6-10aryl, and halogen; and r, s, t are each independently an integer selected from 0, 1, 2, 3, or 4; preferably 0, 1, 2, or 3, preferably 0, 1, or 2; preferably 0, or 1; L2is -[CR8R9]h-, or SiR8R9; wherein h is an integer selected from 1, or 2; each of R8, and R9are independently selected from the group comprising hydrogen, C1-8alkyl, C3-8alkenyl, C3-8cycloalkyl; C5-8cycloalkenyl, C6-8cycloalkenylalkyl, and C6-10aryl; M2is a transition metal selected from zirconium, or hafnium; and preferably zirconium; and Q3and Q4are each independently selected from the group comprising halogen, C1-8alkyl, - N(R11)2, C6-10aryl, and C7-12aralkyl; wherein R11is hydrogen or C1-8alkyl, preferably Q1and Q2are each independently selected from the group comprising Cl, F, Br, I, methyl, benzyl, and phenyl. In some preferred embodiments, catalyst component B comprises a bridged metallocene catalyst of formula (IIa), wherein R5, R6, R7, L2, M2, Q3, Q4, and r have the same meaning as that defined herein, preferably each R6and R7is C1-8alkyl. In some embodiments, catalyst B a metallocene of formula (IIb), (IIb) wherein R6, R7, L2, M2, Q3, Q4, have the same meaning as that defined herein, preferably each R6and R7is C1-8alkyl. In some embodiments, catalyst component B comprises a bridged metallocene of formula (IIc), in R6, R7, R8, R9 where , M2, Q3, same as that defined herein, preferably each R6and R7is C1-8alkyl. Non-limiting examples of catalyst B are shown below: . Preferably the metallocene catalyst composition comprises dichloro[rac-ethylenebis(4,5,6-5 tetrahydro-1-indenyl)]zirconium and (Butenyl)MeC(Cp)(2,7-tBu2-Flu)ZrCl2. In a preferred embodiment, the weight ratio of catalyst component A to catalyst component B is in a range of from 5:95 to 30:70, preferably 10:90 to 25:75, preferably 15:85 to 25:75, preferably 20:80. The catalyst components A and B herein are preferably provided on a solid support, preferably both catalysts are provided on a single solid support, thereby forming a dual catalyst system. The support can be an inert organic or inorganic solid, which is chemically unreactive with any of the components of the conventional bridged metallocene catalyst. Suitable support materials for the supported catalyst include solid inorganic oxides, such as silica, alumina, magnesium oxide, titanium oxide, thorium oxide, as well as mixed oxides of silica and one or more Group 2 or 13 metal oxides, such as silica-magnesia and silica-alumina mixed oxides. Silica, alumina, and mixed oxides of silica and one or more Group 2 or 13 metal oxides are preferred supportmaterials. Preferred examples of such mixed oxides are the silica-aluminas. For example thesolid oxide comprises titanated silica, silica, alumina, silica-alumina, silica-coated alumina, aluminum phosphate, aluminophosphate, heteropolytungstate, titania, zirconia, magnesia, boria, zinc oxide, a mixed oxide thereof, or any mixture thereof, preferably silica, titanated silica, silica treated with fluoride, silica-alumina, alumina treated with fluoride, sulfated alumina, silica-alumina treated with fluoride, sulfated silica-alumina, silica-coated alumina, silica treated with fluoride, sulfated silica-coated alumina, or any combination thereof. Most preferred is a titanated silica, or a silica compound. In a preferred embodiment, the bridged metallocene catalysts are provided on a solid support, preferably a titanated silica support, or a silica support. The support may be in granular, agglomerated, fumed or other form.In some embodiments, the support is a porous support, and preferably a porous titanated silica,or silica support having a surface area comprised between 200 and 900 m² / g. In another embodiment, the support of the polymerization catalyst is a porous support, and preferably a porous titanated silica, or silica support having an average pore volume comprised between 0.5 and 4 mL / g. In yet another embodiment, the support of the polymerization catalyst is a porous support, and preferably a porous titanated silica, or silica support having an averagepore diameter comprised between 50 and 300 Å, and preferably between 75 and 220 Å.In some embodiments, the support has a D50 of at most 150 µm, preferably of at most 100 µm, preferably of at most 75 µm, preferably of at most 50 µm, preferably of at most 40 µm, preferably of at most 30 µm. The D50 is defined as the particle size for which fifty percent by weight of the particles has a size lower than the D50. The measurement of the particle size can be made according to the International Standard ISO 13320:2009 ("Particle size analysis -Laser diffraction methods"). For example, the D50 can be measured by sieving, by BET surface measurement, or by laser diffraction analysis. For example, Malvern Instruments' laser diffraction systems may advantageously be used. The particle size may be measured by laser diffraction analysis on a Malvern type analyzer. The particle size may be measured by laser diffraction analysis on a Malvern type analyzer after having put the supported catalyst in suspension in cyclohexane. Suitable Malvern systems include the Malvern 2000, Malvern MasterSizer (such as MasterSizer S), Malvern 2600 and Malvern 3600 series. Such instruments together with their operating manual meet or even exceed the requirements set- out within the ISO 13320:2009 Standard. The Malvern MasterSizer ( such as MasterSizer S) may also be useful as it can more accurately measure the D50 towards the lower end of the range e.g. for average particle sizes of less 8 µm, by applying the theory of Mie, using appropriate optical means. Preferably, the catalyst components are activated by an activator. The activator can be any activator known for this purpose such as an aluminum-containing activator, a boron-containing activator, or a fluorinated activator. The aluminum-containing activator may comprise analumoxane, an alkyl aluminum, a Lewis acid and / or a fluorinated catalytic support.In some embodiments, alumoxane is used as an activator. The alumoxane can be used in conjunction with a catalyst in order to improve the activity of the catalyst during the polymerization reaction.As used herein, the term “alumoxane” and “aluminoxane” are used interchangeably, and referto a substance, which is capable of activating the bridged metallocene catalyst. In some embodiments, alumoxanes comprise oligomeric linear and / or cyclic alkyl alumoxanes. In a further embodiment, the alumoxane has formula (V) or (VI) Ra-(Al(Ra)-O)x-AlRa2 (V) for oligomeric, linear alumoxanes; or (-Al(Ra)-O-)y (VI) for oligomeric, cyclic alumoxanes wherein x is 1-40, and preferably 10-20; wherein y is 3-40, and preferably 3-20; and wherein each Rais independently selected from a C1-8alkyl, and preferably is methyl. In a preferred embodiment, the alumoxane is methylalumoxane (MAO). The catalyst composition may comprise a co-catalyst. One or more aluminumalkyl represented by the formula AIRbx can be used as additional co-catalyst, wherein each Rbis the same or different and is selected from halogens or from alkoxy or alkyl groups having from 1 to 12 carbon atoms and x is from 1 to 3. Non-limiting examples are Tri-Ethyl Aluminum (TEAL), Tri- Iso-Butyl Aluminum (TIBAL), Tri-Methyl Aluminum (TMA), and Methyl-Methyl-Ethyl Aluminum (MMEAL). Especially suitable are trialkylaluminums, the most preferred being triisobutylaluminum (TIBAL) and triethylaluminum (TEAL). In an embodiment, said metallocene is a metallocene catalyst composition comprising an alumoxane activator; and a titanated silica or silica solid support; and an optional co-catalyst. The present invention also encompasses a process for the preparation of a metallocene-catalyzed polyethylene copolymer as defined herein (including all embodiments thereof asdescribed herein), the process comprising: contacting a catalyst composition with ethylene, 1- hexene as comonomer, and optionally hydrogen, and polymerizing the ethylene and the 1- hexene, in the presence of the at least one catalyst composition, and optional hydrogen, thereby obtaining the polyethylene copolymer. The copolymer can be prepared out in bulk, gas, solution and / or slurry phase. The process can be conducted in one or more batch reactors, slurry reactors, gas-phase reactors, solution reactors, high pressure reactors, tubular reactors, autoclave reactors, or a combinationthereof. In some embodiments, said copolymer is not prepared in solution. In someembodiments, said copolymer is not prepared in gas phase. The polymerization can be carried out batchwise or in a continuous process. In a preferred embodiment of the present invention, the polymerization is carried out in a continuous process. The term “continuous” means a system that operates without interruption or cessation. For example, a continuous process to produce a polymer would be one where the reactants are continually introduced into one or more reactors and polymer product is continually withdrawn. By this it is meant herein that the reactors, when operating, are run in continuous mode, that is at least one feed stream is predominantly fed continuously to the reactor, while at least one stream is predominantly withdrawn continuously. More preferably, the process comprises the step of comprising: contacting a metallocenecatalyst composition with ethylene, 1-hexene, and optionally hydrogen, and polymerizing theethylene and the 1-hexene, in the presence of the at least one metallocene catalystcomposition, and optional hydrogen, thereby obtaining the polyethylene copolymer of theinvention; preferably wherein said metallocene catalyst composition comprises a catalyst component A and a catalyst component B, wherein catalyst component A comprises a bridged metallocene compound with two tetrahydroindenyl groups, each group being unsubstituted or substituted; and catalyst component B comprises a bridged metallocene compound with a substituted or unsubstituted cyclopentadienyl group and a substituted or unsubstituted fluorenyl group; and an optional activator; an optional support; and an optional co-catalyst. More preferably, the process comprises the step of comprising: contacting a metallocenecatalyst composition with ethylene, 1-hexene, and optionally hydrogen, and polymerizing theethylene and 1-hexene, in the presence of the at least one metallocene catalyst composition,and optional hydrogen, thereby obtaining the polyethylene copolymer of the invention; whereinsaid metallocene catalyst composition comprises a catalyst component A and a catalyst component B, wherein catalyst component A comprises a bridged metallocene compound with two tetrahydroindenyl groups, each group being unsubstituted or substituted; and catalyst component B comprises a bridged metallocene compound with a substituted or unsubstituted cyclopentadienyl group and a substituted or unsubstituted fluorenyl group; and an alumoxane activator; a support; and an optional co-catalyst. The metallocene-catalyzed polyethylene copolymer can be prepared out in gas, solution and / or slurry phase. The process can be conducted in one or more slurry loop reactors, gas- phase reactors, continuously stirred tank reactors or a combination thereof. Slurry polymerization is preferably used to prepare the polyethylene resin composition, preferably in a slurry loop reactor or a continuously stirred reactor. In some embodiments, said process is not conducted in solution. In some embodiments, said process is not conducted in gas phase.Preferably, the metallocene-catalyzed polyethylene copolymer is prepared in a loop reactor,more preferably slurry loop reactor, most preferably liquid full loop reactor in the presence of same or different metallocene catalysts. The most preferred polymerization process is carriedout in a slurry loop reactor, advantageously liquid full loop reactor.As used herein, the terms “loop reactor” and “slurry loop reactor” may be used interchangeably herein. In certain embodiments, each loop reactor may comprise interconnected pipes, defining a reactor path. In certain embodiments, each loop reactor may comprise at least two vertical pipes, at least one upper segment of reactor piping, at least one lower segment of reactor piping, joined end to end by junctions to form a complete loop, one or more feed lines, one or more outlets, one or more cooling jackets per pipe, and one pump, thus defining a continuous flow path for a polymer slurry. The vertical sections of the pipe segments are preferably provided with cooling jackets. Polymerization heat can be extracted by means ofcooling water circulating in these jackets of the reactor. The loop reactor preferably operatesin a liquid full mode. The term "slurry" or "polymerization slurry" or "polymer slurry", as used herein refers to substantially a multi-phase composition including at least polymer solids and a liquid phase, the liquid phase being the continuous phase. The solids may include the catalyst and polymerized monomer. The catalyst is preferably added to the loop reactor as catalyst slurry. As used herein, the term “catalyst slurry” refers to a composition comprising catalyst solid particles and a diluent. The solid particles can be suspended in the diluent, either spontaneously or by homogenization techniques, such as mixing. The solid particles can be non-homogeneously distributed in a diluent and form sediment or deposit. In some embodiments, the liquid phase comprises a diluent. As used herein, the term “diluent” refers to any organic diluent, which does not dissolve the synthesized polyolefin. As used herein, the term “diluent” refers to diluents in a liquid state, liquid at room temperature and preferably liquid under the pressure conditions in the loop reactor. Suitable diluents comprise but are not limited to hydrocarbon diluents such as aliphatic, cycloaliphatic and aromatic hydrocarbon solvents, or halogenated versions of such solvents. Preferred solvents are C12or lower, straight chain or branched chain, saturated hydrocarbons, C5to C9saturated alicyclic or aromatic hydrocarbons or C2to C6halogenated hydrocarbons. Non-limiting illustrative examples of solvents are butane, isobutane, pentane, hexane, heptane, cyclopentane, cyclohexane, cycloheptane, methyl cyclopentane, methyl cyclohexane, isooctane, benzene, toluene, xylene, chloroform, chlorobenzenes, tetrachloroethylene, dichloroethane and trichloroethane, preferably isobutane or hexane. The polymerization steps can be performed over a wide temperature range. In certain embodiments, the polymerization steps may be performed at a temperature from 20 °C to 125 °C, preferably from 60 °C to 100 °C, preferably from 65 °C to 90 °C. Preferably, the temperaturerange may be within the range from 70 °C to 80 °C and most preferably from 70 °C to 76 °C.Said temperature may fall under the more general term of polymerization conditions. In certain embodiments, in slurry conditions, the polymerization steps may be performed at a pressure from about 20 bar to about 100 bar, preferably from about 30 bar to about 50 bar, and more preferably from about 37 bar to about 45 bar. Said pressure may fall under the more general term of polymerization conditions. The term “metallocene-catalyzed polyethylene copolymer”, “polyethylene copolymer”, “ethylene copolymer” or “polyethylene” as used herein refers to the polyethylene copolymer fluff or powder that is extruded, and / or melted, and / or pelleted and can be prepared through compounding and homogenizing of the polyethylene copolymer as taught herein, for instance, with mixing and / or extruder equipment. Unless otherwise stated, all parameters used to define the metallocene-catalyzed polyethylene copolymer, are as measured on polyethylene copolymer pellets. The term “fluff” or “powder” as used herein refers to the polyethylene copolymer material with the solid catalyst particle at the core of each grain and is defined as the polymer material after it exits the polymerization reactor (or final polymerization reactor in the case of multiple reactors connected in series). The term “pellets” refers to the polyethylene copolymer that has been pelletized, for example through melt extrusion. As used herein, the terms “extrusion” or “extrusion process”, “pelletization” or “pelletizing” are used herein as synonyms and refer tothe process of transforming polyethylene copolymer into a “polyolefin product” or into “pellets”after pelletizing. The process of pelletization preferably comprises several devices connected in series, including one or more rotating screws in an extruder, a die, and means for cutting the extruded filaments into pellets. The present invention also encompasses a polyethylene composition comprising themetallocene-catalyzed polyethylene copolymer as defined herein (including all embodimentsthereof as described herein) and one or more additives.The additives can be for example antioxidants, UV stabilizers, pigments, processing aids, acid scavengers, lubricants, antistatic agents, fillers, nucleating agents, or clarifying agents, or combination thereof. An overview of useful additives is given in Plastics Additives Handbook, ed. H. Zweifel, 5thedition, Hanser Publishers. These additives may be present in quantities generally between 0.01 and 10 weight % based on the weight of the polyethylene composition.After the polyethylene copolymer is produced, it may be formed into various articles. In viewof its melt strength properties, the polyethylene copolymer is particularly suited for articles suchas film products, etc. The present invention therefore also encompasses an article comprising a polyethylenecopolymer as defined herein (including all embodiments thereof as described herein); orobtained according to a process as defined herein. In some embodiments, said article can be film products, preferably a film. The invention also encompasses a process for preparing an article as defined herein (including all embodiments thereof as described herein). Preferred embodiments as described above are also preferred embodiments for the present process.In some preferred embodiment, the metallocene-catalyzed polyethylene copolymer as definedherein (including all embodiments thereof as described herein) is particularly suitable for filmapplications i.e. to prepare films. In particular, it provides a good balance in both mechanical and optical properties. The present invention therefore also encompasses a film comprising or consisting essentiallyof a metallocene-catalyzed polyethylene copolymer as defined herein (including allembodiments thereof as described herein). The film can be a cast or blown film. The inventionalso encompasses the process of preparing the films. The process for making a film cancomprise the steps of providing a metallocene-catalyzed polyethylene copolymer as defined herein (including all embodiments thereof as described herein), and forming a film as defined herein.In some embodiments, the film comprises or consist essentially of a metallocene-catalyzedpolyethylene copolymer as defined herein (including all embodiments thereof as described herein), said polyethylene copolymer being an ethylene-1-hexene polymer havinga density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured according tothe method of standard ISO 1183-1:2012 method A at a temperature of 23 °C, preferably adensity of at least 0.901 g / cm3 to at most 0.913 g / cm3, preferably of at least 0.902 g / cm3 to atmost 0.913 g / cm3, preferably of at least 0.903 g / cm3 to at most 0.913 g / cm3, preferably of at least 0.904 g / cm3to at most 0.913 g / cm3, preferably of at least 0.905 g / cm3to at most 0.913 g / cm3, preferably of at least 0.906 g / cm3to at most 0.913 g / cm3, preferably of at least 0.907 g / cm3to at most 0.913 g / cm3;a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw beingthe weight-average molecular weight and Mnbeing the number-average molecular weight; a melt index ranging from an HLMI of at least 1.2 g / 10 min to an MI2of at most 6.0 g / 10 min wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm, and melt index HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, anda 21.6 kg load using a die of 2.096 mm; preferably a melt index ranging from an HLMI of atleast 5.0 g / 10 min to an MI2 of at most 3.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2):(1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support. In some embodiments, the film comprises or consist essentially of a metallocene-catalyzed polyethylene copolymer as defined herein (including all embodiments thereof as described herein), said polyethylene copolymer being an ethylene-1-hexene polymer havinga density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured according tothe method of standard ISO 1183-1:2012 method A at a temperature of 23 °C, preferably a density of at least 0.901 g / cm3to at most 0.913 g / cm3, preferably a density of at least 0.902g / cm3 to at most 0.913 g / cm3, preferably of at least 0.903 g / cm3 to at most 0.913 g / cm3,preferably of at least 0.904 g / cm3to at most 0.913 g / cm3, preferably of at least 0.905 g / cm3to at most 0.913 g / cm3, preferably of at least 0.906 g / cm3to at most 0.913 g / cm3, preferably of at least 0.907 g / cm3to at most 0.913 g / cm3; a molecular weight distribution Mw / Mnranging from at least 2.5 to at most 3.50, with Mwbeing the weight-average molecular weight and Mnbeing the number-average molecular weight; a melt index MI2of at least 0.10 g / 10 min to at most 6.00 g / 10 min, wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm; preferably a melt index MI2of at least 0.10 g / 10 min to at most 3.00 g / 10 min, and / or a melt index HLMI of at least 1.2 g / 10 min to at most 150.0 g / 10 min wherein melt index HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min; preferably an HLMI of at least 5.0 g / 10 min to at most 50.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2):(1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR. In some embodiments, the film comprises or consist essentially of a metallocene-catalyzed polyethylene copolymer as defined herein (including all embodiments thereof as described herein), said polyethylene copolymer being an ethylene-1-hexene polymer havinga density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured according tothe method of standard ISO 1183-1:2012 method A at a temperature of 23 °C, preferably adensity of at least 0.901 g / cm3 to at most 0.913 g / cm3, preferably a density of at least 0.902g / cm3 to at most 0.913 g / cm3, preferably of at least 0.903 g / cm3 to at most 0.913 g / cm3,preferably of at least 0.904 g / cm3to at most 0.913 g / cm3, preferably of at least 0.905 g / cm3to at most 0.913 g / cm3, preferably of at least 0.906 g / cm3to at most 0.913 g / cm3, preferably of at least 0.907 g / cm3to at most 0.913 g / cm3; a molecular weight distribution Mw / Mnranging from at least 2.5 to at most 3.50, with Mwbeing the weight-average molecular weight and Mnbeing the number-average molecular weight; a melt index MI2of at least 0.10 g / 10 min to at most 6.00 g / 10 min, wherein MI2is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm; preferably a melt index MI2of at least 0.10 g / 10 min to at most 3.00 g / 10 min, and / oran HLMI of at least 1.2 g / 10 min to at most 150.0 g / 10 min wherein HLMI is determinedaccording to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min; preferably an HLMI of at least 5.0 g / 10 min to at most 50.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2):(1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0, preferably at least 16.5 to at most 25.0, preferably at least 17.0 to at most 24.0, preferably at least 17.5 to at most 23.0, preferably at least 18.0 to at most 23.0, preferably at least 18.5 to at most 23.0, preferably at least 19.0 to at most 23.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; optionally a melting temperature Tm satisfying the following equation (3): (3) Tm ≤ -2.2 x C +120Tm being defined as the melting peak at the lowest temperature in °C as determined by DSC(measured on the copolymer in the absence of any nucleating agent), and C being the 1-hexene content in weight % as determined by13C NMR;and optionally a 1-hexene content C in weight % satisfying the following equation (4):(4) C ≤ (-708 x density (in g / cm3))+656optionally having a Temperature Rising Elution Fractionation (TREF) distribution curve comprising only one peak and preferably wherein said peak appears at a temperature of at least 65.0 °C to at most 75.0°C; optionally having a fraction of material that is eluted in Temperature Rising Elution Fractionation (TREF) at a temperature below 35.0°C of at most 2.0 % by weight, preferably at most 1.9 % by weight, preferably at most 1.8 % by weight, preferably at most 1.7 % by weight, preferably at most 1.6 % by weight, preferably at most 1.5 % by weight, based on the total amount of the copolymer; and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support. In some embodiments, the film comprises or consist essentially of a metallocene-catalyzed polyethylene copolymer as defined herein (including all embodiments thereof as described herein), said polyethylene copolymer being an ethylene-1-hexene polymer havinga density ranging from at least 0.900 g / cm3 to at most 0.913 g / cm3, as measured according tothe method of standard ISO 1183-1:2012 method A at a temperature of 23 °C, preferably adensity of at least 0.901 g / cm3 to at most 0.913 g / cm3, preferably a density of at least 0.902g / cm3 to at most 0.913 g / cm3, preferably of at least 0.903 g / cm3 to at most 0.913 g / cm3,preferably of at least 0.904 g / cm3to at most 0.913 g / cm3, preferably of at least 0.905 g / cm3to at most 0.913 g / cm3, preferably of at least 0.906 g / cm3to at most 0.913 g / cm3, preferably of at least 0.907 g / cm3to at most 0.913 g / cm3;a molecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mw beingthe weight-average molecular weight and Mn being the number-average molecular weight; a melt index MI2 of at least 0.10 g / 10 min to at most 6.00 g / 10 min, wherein MI2 is determined according to ISO 1133:2005 Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm; preferably a melt index MI2 of at least 0.10 g / 10 min to at most 3.00 g / 10 min, and / or an HLMI of at least 1.2 g / 10 min to at most 150.0 g / 10 min wherein HLMI is determined according to ISO 1133:2005 Method B, condition G, at a temperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; preferably an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min; preferably an HLMI of at least 5.0 g / 10 min to at most 50.0 g / 10 min; a melt strength of X in Newtons, as determined by Göttfert Rheotens Melt Strength Apparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2):(1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2 (also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0, preferably at least 16.5 to at most 25.0, preferably at least 17.0 to at most 24.0, preferably at least 17.5 to at most 23.0, preferably at least 18.0 to at most 23.0, preferably at least 18.5 to at most 23.0, preferably at least 19.0 to at most 23.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; a melting temperature Tmsatisfying the following equation (3): (3) Tm ≤ -2.2 x C +120Tm being defined as the melting peak at the lowest temperature in °C as determined by DSC(measured on the copolymer in the absence of any nucleating agent), and C being the 1-hexene content in weight % as determined by13C NMR;a 1-hexene content C in weight % satisfying the following equation (4):(4) C ≤ (-708 x density (in g / cm3))+656optionally having a Temperature Rising Elution Fractionation (TREF) distribution curve comprising only one peak and preferably wherein said peak appears at a temperature of at least 65.0 °C to at most 75.0°C; optionally having a fraction of material that is eluted in Temperature Rising Elution Fractionation (TREF) at a temperature below 35.0°C of at most 2.0 % by weight, preferably at most 1.9 % by weight, preferably at most 1.8 % by weight, preferably at most 1.7 % by weight, preferably at most 1.6 % by weight, preferably at most 1.5 % by weight, based on the total amount of the copolymer;optionally having a molecular weight distribution Mz / Mw of at least 2.00 to at most 2.80, with Mzbeing the z average molecular weight, preferably of at least 2.00 to at most 2.75, preferably ofat least 2.00 to at most 2.70, preferably of at least 2.00 to at most 2.65, preferably of at least 2.10 to at most 2.75, preferably of at least 2.20 to at most 2.70, preferably of at least 2.30 to at most 2.65;optionally having a molecular weight distribution Mz / Mn of at least 5.00 to at most 11.00,preferably of at least 6.00 to at most 11.00, preferably of at least 6.50 to at most 11.00, preferably of at least 7.00 to at most 11.00, preferably of at least 5.00 to at most 10.50,preferably of at least 6.00 to at most 10.00, preferably of at least 6.50 to at most 9.50, preferablyof at least 6.50 to at most 9.00, with Mzbeing the z average molecular weight and Mnbeing the number-average molecular weight.In some embodiments, the film can have a relative tear resistance (N / mm) in the machinedirection of at least 50 N / mm, preferably of at least 55 N / mm, preferably at least 58 N / mm as measured according to ASTM D 1922:2015, on a blown film 40 µm thick prepared using ablown film line equipment having a low neck configuration with an extrusion screw diameter of 45 mm, a length to diameter ratio of the screw of 30, a die diameter of 120 mm, a blow-up ratio(BUR) of 2.5, a die gap of 1.6 mm, cooling air at a temperature of 20 °C, and a throughput of20 kg / h.In some embodiments, the relative tear resistance (N / mm) of the film in the transverse directioncan be preferably of at least 70 N / mm, preferably at least 75 N / mm, preferably at least 80 N / mm, preferably at least 85 N / mm, and preferably at least 90 N / mm, as measured according to ASTM D 1922:2015, on a blown film 40 µm thick prepared using a blown film line equipmenthaving a low neck configuration with an extrusion screw diameter of 45 mm, a length todiameter ratio of the screw of 30, a die diameter of 120 mm, a blow-up ratio (BUR) of 2.5, adie gap of 1.6 mm, cooling air at a temperature of 20 °C, and a throughput of 20 kg / h.In some embodiments, the film has a gloss of at least 50 measured according to ASTM D-2457:2013 at an angle of 45°, at a thickness of 40 µm, more preferably a gloss of at least 60, preferably at least 65, preferably at least 70, preferably at least 75.In some embodiments, the film has a haze average of less than 8.0 % measured according toISO 14782:1999, at a thickness of 40 µm, more preferably a haze of less than 7.0 %, preferablyless than 6.0 %, preferably less than 5.0 %, preferably less than 4.5.0 %, preferably less 4.0%. Blown films may include, for example, films used as geoliners, i.e., in-ground liners used to prevent contamination of surrounding soil and groundwater by materials found in, and leaching from, for example, trash collection and chemical dump sites. Other blown film applications include apparel bags and / or coverings, bread bags, produce bags and the like. The polyethylene copolymers may be used in a wide variety of thicknesses and as one or more layers of a multi-layer film construction. In other embodiments they may be used as coatings or may, as films, be coated or subjected to fluorination or other treatments to increase their barrier potential for these and other uses. The films are also suitable for use in or as articles designed for packaging in particular food packaging, construction, insulation, and as laminating films etc. Any known film blowing line equipment can be used to prepare blown films comprising thecopolymer composition of this invention, for example Macchi®’s COEX FLEX®, or Windmöller& Hölscher VAREII, or Windmöller & Hölscher OPTIMEX Blown Film Lines. The process parameters which can be used are well-known to the person skilled in the art depending on the desired application of the film. For example: The die diameter can vary from 50 to 2000 mm. For example, 50 mm would be used for smaller film applications e.g. pouches for instance for medical purposes, and on the other hand 2000 mm would be used for larger applications, such as agricultural film applications. The blow-up ratio (BUR) can be of 1 to 5. The die-gap can be of 0.8 to 2.6 mm. The throughput can be of 10 kg / h to 2000 kg / h. The extrusion screw can have a diameter of from 30 mm to 150 mm. Preferably, the screw is a barrier screw. The copolymers can also be used to prepare cast films. Typical cast film equipment can be provided by Dolci, SML, Windmöller & Hölscher, or COLINES, etc. Again, the skilled person would know how to run the cast film line to obtain the best possible results. In some embodiments, the film can be 10 µm to 500 µm thick, more preferably 10 to 100 µm, most preferably 10 to 75 µm. The polyethylene copolymers according to the invention can be used to prepare films, which can be monolayer or multilayer films Monolayer films can be prepared essentially from thepolyethylene copolymer according to the invention i.e. the film can comprise at least 70 % byweight of the polyethylene copolymer of the invention based on the total weight of the film. Ina multilayer film, the polyethylene copolymer composition according to the invention can beused in one or several layers, in varying concentrations, alone or combination with other resins.The invention also encompasses the use of a polyethylene copolymer according to theinvention, in film applications, such as blown film and cast films, grass yarn applications, etc.The invention will now be illustrated by the following, non-limiting illustrations of particular embodiments of the invention. EXAMPLES Test methods The properties cited herein and cited below were determined in accordance with the following test procedures. Where any of these properties is referenced in the appended claims, it is to be measured in accordance with the specified test procedure. Density The density of the polyolefin was measured according to the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C (weight of displaced fluid (Buoyancy) at 23°C inisopropanol). Melt flow index The melt flow index MI2 was determined according to ISO 1133:2005 Method B, condition D, at a temperature of 190 °C, and a 2.16 kg load using a die of 2.096 mm. The melt flow rate MI5 was determined according to ISO 1133:2005, Method B, condition T, at 190 °C and under a load of 5 kg, using a die of 2.096 mm. The high load melt flow index (HLMI) or MI21was determined according to ISO 1133:2005 Method B, condition G, at a temperature of 190 °C, and a 21.6 kg load using a die of 2.096 mm. Molecular weight, molecular distribution The molecular weight (Mn(number average molecular weight), Mw(weight average molecular weight) and molecular weight distributions D (Mw / Mn), and D’ (Mz / Mw) were determined by size exclusion chromatography (SEC) and in particular by IR-detected gel permeation chromatography (GPC) at high temperature (145 °C). Briefly, a GPC-IR5MCT from Polymer Char was used: 8 mg polymer sample was dissolved at 160 °C in 8 mL of trichlorobenzene stabilized with 1000 ppm by weight of butylhydroxytoluene (BHT) for 1 hour (h). Injection volume: about 400 µl, automatic sample preparation and injection temperature: 160 °C. Column temperature: 145 °C. Detector temperature: 160 °C.. Column set: three PL gel Olexis (Agilent) columns were used with a flow rate of 1 mL / min. Detector: Infrared detector (2800- 3000 cm-1) to collect all C-H bonds and two narrow band filters tuned to the absorption region assigned to CH3 and CH2 groups. Calibration: narrow standards of polystyrene (PS) (commercially available). Calculation of molecular weight Mi of each fraction i of eluted polymeris based on the Mark-Houwink relation (log10(MPE) = 0.965909 x log10(MPS) – 0.28264) (cut offon the low molecular weight end at MPE = 1000). The molecular weight averages used in establishing molecular weight / property relationships are the number average (Mn), weight average (Mw) and z average (Mz) molecular weight. These averages are defined by the following expressions and are determined form the calculated Mi: Here Niand Wiare the number and weight, respectively, of molecules having molecular weight Mi. The third representation in each case (farthest right) defines how one obtains these averages from SEC chromatograms. hi is the height (from baseline) of the SEC curve at the ithelution fraction and Miis the molecular weight of species eluting at this increment. Differential Scanning Calorimetry (DSC) for Determination of Melting Temperatures. Melting temperature (Tm) was determined via Differential Scanning according to ISO 11357- 3:2018 on a DSC Q2000 instrument by TA Instruments, calibrated with indium and using T zero mode. To erase any prior thermal and crystallization history the samples were first heated to 220 °C at a heating rate of 10°C / min and kept at 220 °C for 5 minutes. The polymer was then cooled with a constant cooling rate of -10 °C / min up to 0 °C and kept isothermal at 0 °C for 5 minutes. The polymer was then heated to 220 °C at a constant heating rate of 10 °C / min. and the melting temperature was determined during this heating step. The melting temperature corresponds to the temperature of the extremum of the spectrogram presenting the heat flux associated with the polymer as a function of the temperature during its melting. In some cases, the thermogram can present two melting peaks. The extremum associated to the lowest temperature is labelled as Tm1and the extremum associated to the highest temperature is labelled as Tm2. Long chain branching index grheoRheology long chain branching index grheowas measured according to the formula, as described in WO 2008 / 113680: ^ wherein Mw (SEC) is the weight average molecular weight obtained from size exclusion chromatography expressed in kDa; and wherein Mw (η0, MWD, SCB) is determined according to the following, also expressed in kDa: Mw(^o,MWD,SCB)=exp(1.7789+0.199769LnMn+0.209026(Ln^o)+0.955(lnρ)- 0.007561(LnMz)(Ln^o)+0.02355(lnMz)2) wherein the zero shear viscosity η0 in Pa.s is obtained from a frequency sweep experiment combined with a creep experiment, in order to extend the frequency range to values down to 10-4s-1or lower, and taking the usual assumption of equivalence of angular frequency (rad / s) and shear rate; wherein zero shear viscosity η0 is estimated by fitting with Carreau-Yasuda flow curve (η-W) at a temperature of 190°C, obtained by oscillatory shear rheology on ARES- G2 equipment (manufactured by TA Instruments) in the linear viscoelasticity domain; wherein circular frequency (W in rad / s) varies from 0.1 rad / s to 300 rad / s, and the shear strain is typically 10 %. In practice, the creep experiment was carried out at a temperature of 190 °C under nitrogen atmosphere with a stress level such that after 1000 s the total strain was less than 25 %. Comonomer content The 1-hexene content (wt.% C6-) relative to the total weight of the polyethylene copolymer was determined from a13C{1H} NMR spectrum. Ethyl branches content, expressed in terms of equivalent wt.% C4-, was also determined from a13C{1H} NMR spectrum. The sample was prepared by dissolving a sufficient amount of polymer in 1,2,4- trichlorobenzene (TCB 99% spectroscopic grade) at 130 °C and occasional agitation to homogenize the sample, followed by the addition of hexadeuterobenzene (C6D6, spectroscopic grade) and a minor amount of hexamethyldisiloxane (HMDS, 99.5+%), with HMDS serving as internal standard. To give an example, about 220 mg of polymer were dissolved in 2.0 mL of TCB, followed by addition of 0.5 mL of C6D6and 2 to 3 drops of HMDS.13C{1H} NMR signal was recorded on a Bruker 500 MHz with a 10 mm probe (or 10mm cryoprobe) with the following conditions: Pulse angle: 90° Pulse repetition time: 30s Spectral width: 25000 Hz centered at 95 ppm Data points: 64K Temperature: 130 °C + / -2 °C Rotation: 15 HzScan numbers: 2000 – 4000 (240 scans with 10 mm cryoprobe)Decoupling sequence: inverse-gated decoupling sequence to avoid NOE effect13C{1H} NMR spectrum was obtained by Fourier Transform on 131K points after a light Gaussian multiplication. Spectrum was phased, baseline corrected, and chemical shift scale was referenced to the internal standard HMDS at 2.03 ppm. Chemical shifts of signals were peak picked, and peaks were integrated as mentioned on Figure 1 and in the following Table A. Table A: integration regions of13C{1H} NMR spectrum Peak position High Integral limit Low Integral limit(ppm) (ppm) (ppm)Vinylidene 1 150.13 150.2 149.98Tv1 139.13 139.18 139.05Tv2 114.26 114.34 114.19Vinylidene 2 108.96 109.05 108.85CH2 40.3 40.45 40.2CH B2 39.76 39.88 39.61CH B4 38.22 38.4 38.03CH2(a) B1 37.58 37.7 37.5CH B4 high 35.97 36.05 35.86CH2(a) + 35.2 34Tv3 33.93 34 33.8CH B1 33.29 33.3 33.23Ts3 32.21 32.35 32.07CH2n 30.03 31.6 28.49CH2(b) 27.34 27.66 26.96CH2 (2) B2 26.8 26.96 26.62CH2 24.71 24.48CH2(2) B4 23.41 23.55 23.2Ts2 22.89 23.02 22.79CH3 B1 20 20.06 19.92CH3 B4 + Ts1 14.1 14.32 13.86CH3 B2 11.21 11.34 11.06Small adjustments on integration limits can be applied if necessary. Chemical shifts are given at ± 0.05 ppm.The wt.% C6- and wt.% C4- contents are obtained by the following areas (A) combinations:AC3 = 0.5 x ACH2(a) B1 AC4 = ACH3 B2 AC6 = ACH2(2) B4AC2 = 0.5 x (ATv1 + ATv2 + ATv3 + AVinylidene1 + AVinylidene2 + 0.5 x ACH2(a) B1 + ATs3 + 2x ATs2 + ACH2n -AC6+ ACH2(b) )wt.% C6- = (84 * AC6) / (28 * AC2 + 42 * AC3 + 56 * AC4+ 84 * AC6) x 100wt.% C4- = (56 * AC6) / (28 * AC2 + 42 * AC3 + 56 * AC4+ 84 * AC6) x 100Melt strength The melt strength (also referred as strength at break) was measured with a Göttfert Rheotens Melt Strength device, model 71-97, in combination with Rheograph Göttfert RG50, both manufactured by Göttfert under the following testing conditions: Rheograph Göttfert (RG50)= Die geometry (L / D): 30 mm / 2 mm, 180° entrance angle; barrel + die temperature: 190 °C; Piston diameter 12 mm, Piston speed: 0.25 mm / s. Rheotens (model 71-97) Wheels: standard (ridged wheels); Wheel gap: 0.4 mm ; Wheel acceleration: 2 mm / s2, Strand length: 100.0 mm, Wheel initial speed Vo: 9.0 mm / s. In the Rheotens test, the tensile force required for extension / stretching of an extruded melt filament exiting a capillary die was measured as a function of the wheel take-up velocity that increased continuously at a constant acceleration speed. The tensile force typically increased as the wheel (roller) velocity was increased and above a certain take-up velocity the force remained constant until the filament (strand) broke. For each material, Rheotens curves were generated to verify data reproducibility. Polymer was loaded into the barrel and allowed to melt for 360 seconds at 190 °C before beginning the testing. In fact, the complete amount of material present in the barrel of the Rheograph was extruded through the die and was being picked up by the wheels of the Rheotens device. The strand was let to stabilize between the wheels turning at 9 mm / s, once the strand was stabilized, the force was calibrated to 0 N and the acceleration of the wheels was started. Once the test was started, the speed of the wheels was increased with a 2.0 mm / s2acceleration and the tensile force was measured for each given speed. After each strand break, or strand slip between the wheels, the measurement was stopped and the material was placed back between the wheels for a new measurement. A new Rheotens curve was recorded. Measuring continued until all material in the barrel was consumed. In this invention, the average of the tensile force vs. draw ratio for each material was reported. TREF Temperature Rising Elution Fractionation analysis (TREF analysis) was performed using the method similar to as described in Soares and Hamielec, Polymer, 36 (10), 19951639-1654, incorporated herein in its entirety by reference. The TREF analysis was performed on a TREF model 200 TF series instrument equipped with Infrared detector from Polymer Char, (Valencia,Spain). The samples were dissolved in 1,2-dichlorobenzene at 150 °C for 1 h. The followingparameters as shown in Table B were used. Table B METHOD INFORMATION Name DefaultDissolution Rate(ºC / min) 20Stabilization Rate(ºC / min) 20Crystallization Rate 1(ºC / min) 0.5Elution Rate (ºC / min) 1Cleaning rate (ºC / min) 30Dissolution temperature (ºC) 150Stabilization temperature (ºC) 95Crystallization temperature (ºC) 35Elution init temp (ºC) 35Elution temperature (ºC) 130Post elution temperature (ºC) 150Cleaning temperature (ºC) 150Dissolution time (min) 60Stabilization time (min) 45Crystallization time (min) 10Pre-injection time (min) 10Soluble Fraction time (min) 10post elution time (min) 10Cleaning time (min) 30Cleaning cycles 1High rpm 200Low rpm 100T on 5T off (s) 120Dissolution stirring HighStabilization stirring HighCleaning stirring HighFilling vessels volume 20Filling vessels pick up speed 40Filling vessels pump speed 15Analysis discarded sample volume 2Analysis discarded waste volume 6Analysis sample volume 0.3Column load volume 1.9Analysis waste volume 5Analysis returned volume 1Analysis pick up rate 8Analysis dispensing rate 3 Cleaning volume 30Cleaning pick up speed 40Cleaning pump speed 15Top oven temperature 140Pump Flow (ml / min) 0.5The soluble fraction is the amount of material eluted below 35 °C in % by weight.Determination of Zr residual contents in the copolymersThe Zr content was determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES) after mineralization of the sample and recovery of the residues in an acid medium. The spectrometer used was ICP-AES ARCOS, by Spectro. The elements were determined by nebulizing the solution in an argon plasma, measuring the intensities of the most sensitive and interference-free emission lines, and comparing these intensities with those of calibration solutions (external calibration method). Preparation of the solution to be analyzed (test solution): In a platinum crucible was added 10 g of polymer and placed in a microwave oven to perform a thermal treatment (calcination) at 600°C for 1 hour. After calcination, 1 mL of concentrated HCl, 0.5 mL of concentrated HF, and Milli-Q® deionized water were added while agitating the mixture under heat to achieve full dissolution. After cooling the mixture was transferred to a 50 mL polypropylene tube and the volume made up to 50 mL with Milli-Q® deionized water.Preparation of calibration standards and control solutions: Standard solutions were preparedby dilution of commercial single-element solutions of certified concentrations. The standard solutions were prepared by transferring the required volume of the certified solution to a 50 mL polypropylene tube, then rinsing the sides of the tube with Milli-Q® deionized water, and adding 1 mL of concentrated HCl and 0.5 mL of concentrated HF per 50 mL to obtain the same acid content in solution as in the sample solutions, and finalizing the dilution with Milli-Q® deionized water. Control solutions were prepared by dilution of commercial multi-element solutions of certified concentrations. The presence of other elements in solution allowed verification of the presence / absence of possible interferences. Seal strengthSeal strength has been measured according to standards ASTM F88 / F88M-21(Technique A).Prior to cutting, 40µm blown films were conditioned for a minimum of 40 hours at 23 °C ± 2 °Cand 50 % ± 10 % relative humidity (R.H.) per ASTM D-618 (procedure A). Specimens werethen cut in the machine direction to a length of approximately 150 mm x 100 mm. The specimens were heat sealed across the machine direction on a Brugger HSG-C sealer over a range of temperatures under the following conditions: Sealing pressure: 300 N Sealing time: 3 secSealing jaws dimension: 150 x 10 mmSealing jaws shape: smooth Sealing jaws coating: Teflon Sealing temperature: ambient 23 °C Sealing temperature interval: 5 °C Start temperature: 85 °CThree 15 mm width x 100 length strips were cut in the Machine Direction and conditioned for24 hours at 23 °C ± 2 °C at 50 % ± 10 % R.H. Technique A of the standard was used to achievetraction. The specimens were peeled in a Zwicky Z2.5 (200 N) at 200 mm / min with an initialdistance between the two jaws of 10 mm. Compared to a reference sample (unsealed specimen), at each sealing temperature 3 specimens were tested. The force / displacementcurves of the sealed specimens at the different temperatures were recorded and averagedacross the three specimens. By plotting the seal strength versus the sealing temperature, asealing curve was produced. Tear resistance Tear resistance (determined as Elmendorf tear [N]): Applies for the measurement both in machine direction (MD) and in transverse direction (TD). The tear strength is measured usingthe ASTM D 1922:2015 method. The force required to propagate tearing across a film sampleis measured using a pendulum device. The pendulum swings under gravity through an arc, tearing the specimen from pre-cut slit. The specimen is fixed on one side by the pendulum and on the other side by a stationary clamp. The tear resistance is the force required to tear thespecimen. The relative tear resistance (N / mm) is then calculated by dividing the tear resistance by the thickness of the film. The measurements of Elmendorf tear strength were carried out according to ASTM D 1922:2015, on a blown film 40 µm thick prepared using a blown film lineequipment having a low neck configuration with an extrusion screw diameter of 45 mm, alength to diameter ratio of the screw of 30, a die diameter of 120 mm, a blow-up ratio (BUR) of2.5, a die gap of 1.6 mm, cooling air at a temperature of 20 °C, and a throughput of 20 kg / h.Haze and Gloss Haze in % was measured according to ISO 14782:1999, at a thickness of 40 µm. Gloss was measured according to ASTM D-2457:2013 at an angle of 45°. It was measured using a Byk- Gardner micro-gloss reflectometer. Both gloss and haze were measured on 40 µm thick blown film prepared using a blown film line equipment having a low neck configuration with an extrusion screw diameter of 45 mm, a length to diameter ratio of the screw of 30, a die diameterof 120 mm, a blow-up ratio (BUR) of 2.5, a die gap of 1.6 mm, cooling air at a temperature of20 °C, and a throughput of 20 kg / h. Structure of 1. Metallocene 1: Dichloro[rac-ethylenebis(4,5,6-tetrahydro-1-indenyl)]zirconium (Met1) Dichloro[rac-ethylenebis(4,5,6-tetrahydro-1-indenyl)]zirconium was purchased from Boulder Scientific Company (CAS 100163-29-9).2. Metallocene 2: (Butenyl)MeC(Cp)(2,7-tBu2-Flu)ZrCl2 (Met2)Metallocene 2 was prepared as described below, following the synthesis described in Journal of Organometallic Chemistry vol.553, 1998, p.205–220: Met2 Step 1: N Into a 200 mL 3-neck flask equipped with a gas inlet tube and a magnetic stirring bar was charged, under nitrogen, 2.5 eq of freshly cracked cyclopentadiene and 1 eq of 5-hexene-2- one in 60 mL of methanol. Then, 2 eq of pyrrolidine was added dropwise at 0 °C and the mixture was stirred overnight at room temperature. The reaction was quenched with 50 mL of HCl 1M and extracted with Et2O (3 x 50 mL). Organic fractions were dried over MgSO4and solvent was removed under reduced pressure. The fulvene was obtained as a yellow oil and used without further purification (Yield = 65%). Step 2: In a 3-neck flask, 1 eq of di-tert-butylfluorene was added under flow of nitrogen and dissolvedin 70 mL of Et2O.1.1 eq of n-BuLi (1.6 M in hexane) was added dropwise at 0 °C to this solutionand the mixture was stirred overnight at room temperature. A solution of 3.5 g of fulvene prepared in the previous step, dissolved in 30 mL of Et2O was added dropwise. The reactionmixture was allowed to stir overnight. The reaction was quenched with water and extractedwith Et2O (3 x 50 mL). Combined organic fractions were dried over MgSO4and solvent was removed under reduced pressure. The product was crystallized in pentane / MeOH at 0 °C to afford a white solid (Yield = 85%). Step 3: 1. nBuLi, Et2O, r.t., overnight 2. ZrCl4, Pentane, r.t., overnight In a round-bottomed flask, 1 g of ligand was introduced and dissolved in 40 mL of Et2O. 2.1eq. of nBuLi was added dropwise and the mixture was stirred overnight at room temperature. Solvent was removed under vacuum and 40 mL of dry pentane was added. Then 1 eq of ZrCl4 was added in small portions at room temperature. The reaction was stirred over 2 days and filtered. The resulting precipitate was diluted in DCM and centrifuged to eliminate lithium chloride. Solvent was removed under vacuum to afford a pink-red powder (Yield = 70%).1H NMR (500 MHz, CD2Cl2) δ 1.34 (s, 9 H, CH3tBu); 1.36 (s, 9 H, CH3tBu); 2.30 (m, CH2alk); 2.43 (s, 3 H, CH3); 2.55 (m, 1 H, CH2alk.); 2.65 (m, 1 H, CH2alk.); 3.25 (m, 1 H, CH2alk.); 5.13 (m; 1 H, CHvinyl); 5.18 (m; 1 H, CHvinyl); 5.70 (m, 2 H, CHcp); 6.10 (m; 1 H, CHvinyl); 6.29 (m, 2 H, CHcp); 7.55 (s, 1 H, CHflu), 7.63-7.68 (m, 2 H, CHflu); 7.72 (s, 1 H, CHflu); 8.00- 8.04 (m, 2 H, CHflu)3. Synthesis of supported catalystsAll catalyst and co-catalyst experimentations were carried out in a glove box under nitrogenatmosphere. Methylaluminoxane (30 wt%) (MAO) in toluene from Grace was used as theactivator. Supported metallocene catalysts were prepared in two steps using the following method: 1. Impregnation of MAO on silica:Ten grams of dry silica (dried at 450 °C under nitrogen during 6 h) was introduced into a round- bottomed flask equipped with a mechanical stirrer and a slurry was formed by adding 100 mlof toluene. MAO (21 ml) was added dropwise with a dropping funnel. The reaction mixture wasstirred at 110 °C for 4 hours. The reaction mixture was filtered through a glass frit (POR3) andthe powder was washed with dry toluene (3 x 20 ml) and with dry pentane (3 x 20 ml). Thepowder was dried under reduced pressure overnight to obtain a free flowing grey powder. 2. Deposition of metallocene on silica / MAO support:Silica / MAO (10 g) was suspended in toluene (100 ml) under nitrogen. Metallocenes 1 and 2 (total amount of metallocene = 0.2 g) were introduced and the mixture was stirred 2 hours at room temperature. The reaction mixture was filtered through a glass frit and the powder waswashed with dry toluene (3 x 20 ml) and with dry pentane (3x 20 ml). The powder was driedunder reduced pressure overnight to obtain a free flowing grey powder. The catalyst compositions prepared are shown in Table 1. Table 1 Catalyst Composition catalysts Silica Ratio Met1:Met21 Met1 / Met2 PD12052 purchased from1:4 Ecovyst 2Met1 / Met2 PD12052 purchased from1:1 Ecovyst4. PolymerizationsPolymerization reactions for preparing polymers A to D were performed using the catalystcomposition 1 shown in Table 1, in a slurry single loop reactor with isobutane as diluent. Polymerization reactions for preparing comparative polymers Comp A, Comp B wereperformed using the catalyst composition 2 shown in Table 1, in a slurry single loop reactorwith isobutane as diluent. The polymerizations were performed under the operating conditionsdepicted in Table 2. Analytical results on pellets are also shown in Table 2. Table 2 Polymers A B C D Comp A Comp BTEMP. °C 75 73 75 75 75 75Ethylene C2 kg / h 30.5 30.5 30.0 30.0 30.0 30.01-Hexene C6 kg / h 6.2 6.8 5.2 5.0 5.3 5.5LoopHydrogen H2 Nl / h 20.0 20.0 19.5 17.0 46.6 35.0reactorIsobutane kg / h 45.0 45.0 42.0 42.0 42.0 42.0operatingC2- Off Gaz wt% 6.5 6.4 6.3 6.6 6.3 6.3conditionsC6- Of Gaz wt% 4.78 5.07 3.93 3.83 4.55 4.70C6- / C2- Off Gaz0.7 0.8 0.6 0.6 0.7 0.7Residence timemin 57 57 60 60 60 60The copolymers properties are shown in Table 3.Table 3 Polymers Comp A Comp B Pol A Pol B Pol C Pol DDensity g / cm³ 0.915 0.916 0.910 0.908 0.912 0.912MI2 g / 10 min 2.60 1.32 1.00 1.15 0.95 0.73MI5 g / 10 min 7.50 3.85 2.90 3.22 2.90 2.26HLMI g / 10 min 63.0 32.0 22.2 23.0 20.1 15.9Mn 18501 20852 29295 28991 32761 34617Mw 74485 87773 96132 93931 95718 102896Mz 209645 259769 233883 224390 241568 266858Mw / Mn(MW) 4.03 4.21 3.28 3.24 2.92 2.97Mz / Mw 2.81 2.96 2.43 2.39 2.52 2.59Mz / Mn 11.33 12.46 7.98 7.74 7.37 7.71Melt StrengthN 0.030 0.045 0.052 0.050 0.064 0.079mm / s 127 110 152 146 121 125Right side calculation of claim equation (1)0.025 0.043 0.050 0.046 0.051 0.058Right side calculation of claim equation (2)0.026 0.043 0.053 0.052 0.055 0.0611-Hexene (C) wt% 9.9 9.9 11.2 12.4 10.1 9.7Ethyl branches (C4) wt% 0.2 0.1 0.2 0.1 0.1 0.1Tm1 °C 100.7 99.6 95.3 93.0 98.8 98.8Tm2 °C 111.5 111.7 109.0 108.1 107.9 107.9Right side calculation of claim equation (3)98.2 98.2 95.4 92.7 97.8 98.7MI5 / MI2 2.9 2.9 2.9 2.8 3.1 3.1HLMI / MI2(SR2) 24.2 24.2 22.2 20.0 21.2 21.8HLMI / MI5 8.4 8.3 7.7 7.1 6.9 7.0Residual Zr ppm >0.1 >0.1 >0.1 >0.1 >0.1 >0.1Polymers Comp A Comp B Pol A Pol B Pol C Pol DRight side calculation of claim equation (4)6.6 7.8 11.2 12.9 10.4 10.6C-Y C1 (η°) 4894 10234 9562 8168 12937 17257ghreo 0.93 0.90 0.95 0.96 0.87 0.86SR2 / MWD (~LCB) 6.0 5.8 6.8 6.2 7.2 7.3NM: not measuredEquation (1): Melt strength is greater than - 0.026 ln(MI2) + 0.0498Equation (2): Melt strength is greater than - 0.026 ln(HLMI) + 0.1334Equation (3): Tm1 ≤ -2.2 x C +120Equation (4): C ≤ (-708 x density)+656 Figure 2 represents a graph plotting the Tm1 of the copolymers as a function of the 1-hexene content C (in weight %). Figure 3 represents a graph plotting the 1-hexene content C (in weight %) of the copolymers as a function of the density (in g / cm3). TREF analysis: Copolymers were fractionated by a Temperature Rising Elution Fractionation(TREF) process. The results are shown in Figure 4. For each of the copolymer tested, thetemperature of each of the peaks observed in the TREF distribution curves, the percentage ofthe area under said peaks, and the soluble fraction are displayed in Table 4.Table 4 Polymer Pol C Comp A Comp BSoluble Fraction (%) 1.0 3.0 2.1Peak Tlow (°C) / / / Area Tlow (%) / / / Peak Thigh (°C) 73.8 74.4 73.1Area Thigh (%) 99.0 97.0 97.9The polyethylene copolymer were transformed into 40 µm thick blown films using a blown filmline equipment from Macchi® having a low neck configuration with an extrusion screw diameterof 45 mm, a length to diameter ratio of the screw of 30, a die diameter of 120 mm, a blow-upratio (BUR) of 2.5, a die gap of 1.6 mm, cooling air at a temperature of 20 °C, and a throughputof 20 kg / h. The mechanical and optical properties of the films can be found in Table 5.Table 5Polymer Comp A Comp B Pol C Pol DTear MD N / mm 116 98 72 60Tear TD N / mm 144 145 115 91Gloss @ 45° 66 71 76 77Haze_average % 6.8 5.7 3.9 3Thickness_average µm 46 40 40 41The results show that the polyethylene copolymers according to the invention give films having a good balance of optical and mechanical properties.Sealing strength was determined as described herein and the results are shown in Figure 5.

Claims

Claims1. A metallocene-catalyzed polyethylene copolymer having:a density ranging from at least 0.900 g / cm3to at most 0.913 g / cm3, as measured according to the method of standard ISO 1183-1:2012 method A at a temperature of 23 °C; amolecular weight distribution Mw / Mn ranging from at least 2.50 to at most 3.50, with Mwbeing the weight-average molecular weight and Mnbeing the number-average molecular weight; an HLMI of at least 5.0 g / 10 min to at most 100.0 g / 10 min and / or an MI2 of at least 0.40g / 10 min to at most 6.00 g / 10 min wherein MI2 is determined according to ISO 1133:2005Method B, condition D, at a temperature 190 °C, and a 2.16 kg load using a die of 2.096 mm, and HLMI is determined according to ISO 1133:2005 Method B, condition G, at atemperature 190 °C, and a 21.6 kg load using a die of 2.096 mm; amelt strength of X in Newtons, as determined by Göttfert Rheotens Melt StrengthApparatus, 190 °C, as described in the Experimental section, satisfying the following equations (1) and / or (2): (1) X is greater than - 0.026 ln(MI2) + 0.0498(2) X is greater than - 0.026 ln(HLMI) + 0.1334a melt index ratio HLMI / MI2(also referred as MI21 / MI2) of at most 25.0, preferably at most 24.0, preferably at most 23.0, preferably at least 16.5, preferably at least 17.0, preferably at least 17.5, preferably at least 18.0, preferably at least 18.5, preferably at least 19.0; said polyethylene copolymer having less than 0.30 % by weight of ethyl branching with regard to the total weight of the polyethylene copolymer measured by13C NMR; and wherein said polyethylene copolymer is an ethylene-1-hexene polymer, and preferably wherein said metallocene is a metallocene catalyst composition comprising a dual catalyst with two metallocene active sites on a single support.

2. The metallocene-catalyzed polyethylene copolymer according to claim 1, having a zeroshear viscosity η0 in Pa.s of at least 5000, preferably at least 6000, preferably at least 7000, preferably at least 8000.

3. The metallocene-catalyzed polyethylene copolymer according to claim 1 or 2, having amelting temperature Tm satisfying the following equation (3): (3) Tm ≤ -2.2 x C +120Tm being defined as the melting peak at the lowest temperature in °C as determined byDSC (measured on the copolymer in the absence of any nucleating agent), and C being the 1-hexene content in weight % as determined by13C NMR.

4. The metallocene-catalyzed polyethylene copolymer according to any one of claims 1-3,having a 1-hexene content C in weight % satisfying the following equation (4): (4) C ≤ (-708 x density)+656.

5. The metallocene-catalyzed polyethylene copolymer according to any one of claims 1-4,wherein the Temperature Rising Elution Fractionation (TREF) distribution curve of the metallocene-catalyzed polyethylene copolymer comprises only one peak.

6. The metallocene-catalyzed polyethylene copolymer according to any one of claims 1-5,wherein the Temperature Rising Elution Fractionation (TREF) distribution curve of the metallocene-catalyzed polyethylene copolymer comprises only one peak and wherein said peak appears at a temperature of at least 65.0 °C to at most 75.0°C.

7. The metallocene-catalyzed polyethylene copolymer according to any one of claims 1-6,having a Mn of at least 23000 Da, preferably at least 24000 Da, preferably at least 25000 Da, with Mn being the number-average molecular weight.

8. The metallocene-catalyzed polyethylene copolymer according to any one of claims 1-7,having a melt index MI5 of at least 0.5 g / 10 min to 15.0 g / 10 min, wherein MI5 is determined according to ISO 1133:2005 Method B, condition T, at a temperature 190 °C, and a 5 kg load using a die of 2.096 mm, preferably at least 0.7 g / 10 min, preferably at least 1.0 g / 10 min, preferably at least 1.5 g / 10 min, preferably at least 2.0 g / 10 min.

9. The metallocene-catalyzed polyethylene copolymer according to any one of claims 1-8,having a melt index ratio HLMI / MI5 of at most 10.0.

10. The metallocene-catalyzed polyethylene copolymer according to any one of claims 1-9,having a melt index ratio HLMI / MI5 of at least 3.0 to at most 8.0; preferably at least 4.0 to at most 8.0, preferably at least 5.0 to at most 8.0.

11. The metallocene-catalyzed polyethylene copolymer according to any one of claims 1-10,having a melt index ratio MI5 / MI2 of at most 10.0, preferably at most 7.0, preferably at most5.0, preferably at most 4.0, preferably at least 1.0, preferably at least 2.0.

12. The metallocene-catalyzed polyethylene copolymer according to any one of claims 1-11,wherein said metallocene is a metallocene catalyst composition comprising a dual catalystwith two metallocene active sites on a single support, and an optional activator.

13. The metallocene-catalyzed polyethylene copolymer according to any one of claims 1-12,wherein the catalyst composition comprises a catalyst component A and a catalyst component B, wherein catalyst component A comprises a bridged metallocene compoundwith two groups independently selected from indenyl or tetrahydroindenyl, each group being unsubstituted or substituted; and catalyst component B comprises a bridged metallocene compound with a substituted or unsubstituted cyclopentadienyl group and a substituted or unsubstituted fluorenyl group; and an optional activator; an optional support; and an optional co-catalyst.

14. An article comprising the metallocene-catalyzed polyethylene copolymer according to anyone of claims 1-13.

15. The article according to claim 14, wherein the article is a film.

16. A film comprising the metallocene-catalyzed polyethylene copolymer according to any oneof claims 1-13.

17. A process for the preparation of a metallocene-catalyzed polyethylene copolymeraccording to any one of claims 1-13, the process comprising: contacting at least one metallocene catalyst composition, with ethylene, 1-hexene as comonomer; and optionally hydrogen, and polymerizing the ethylene and the 1-hexene, in the presence of the at least one metallocene catalyst composition, and optional hydrogen, thereby obtaining the polyethylene copolymer.

18. Use of a metallocene-catalyzed polyethylene copolymer according to any one of claims 1-13, in film applications.

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