Metallocene-catalyzed polyethylene and articles made therefrom

Abstract

The present invention relates to a polyethylene blend comprising a Ziegler-Natta catalyzed linear low density polyethylene and a metallocene catalyzed polyethylene, wherein the metallocene catalyzed polyethylene has a melt index (MI) of 0.1 g / 10 min to 30 g / 10 min, a density of 0.890 g / cm<supgt;3< / supgt> to 0.940 g / cm<supgt;3< / supgt>, a molecular weight distribution (MWD) of 2 to 12, and a compositional distribution breadth index of 10 to 50, and the roughness gray scale of the polyethylene blend is decreased by 35 - 70% relative to the pure Ziegler-Natta catalyzed linear low density polyethylene and / or decreased by 12 - 58% relative to the pure metallocene catalyzed polyethylene.

Description

Technical Field

[0001] The disclosure of the present application relates to a polyethylene blend comprising Ziegler-Natta catalyzed linear low density polyethylene and metallocene catalyzed polyethylene, wherein the metallocene catalyzed polyethylene has a melt index (MI) of 0.1 g / 10 min to 30 g / 10 min, a density of 0.890 g / cm 3 to 0.940 g / cm 3 , a molecular weight distribution (MWD) of 2 to 12, and a compositional distribution breadth index of 10 to 50, wherein the compositional distribution refers to the distribution of comonomers (short chain branches) in the molecules comprising the polyethylene polymer, and the roughness gray scale of the polyethylene blend is decreased by 35 - 70% relative to pure Ziegler-Natta catalyzed linear low density polyethylene and / or decreased by 12 - 58% relative to pure metallocene catalyzed polyethylene. Further, the polyethylene blend achieves a roughness gray scale standard deviation (STD) of <11, preferably 7.5 - 3.5, more preferably 6.5 - 4.5 in a two-step extrusion process. Background Art

[0002] For applications involving polyolefins, particularly polyethylene blends, such as pipe extrusion, profile extrusion, etc., a two-step extrusion process is typically employed. That is, the polyolefin polymer and other additives, etc. are first melt-mixed in a screw and pelletized, and then these blend particles are further melt-plasticized by a screw and extruded into pipes or profiles. In these applications, surface quality is a rather important consideration, especially for production scenarios with high extrusion line speeds. In such applications, linear low density polyethylene (“LLDPE”), particularly linear low density polyethylene prepared by the Ziegler-Natta process, is a commonly used component.

[0003] Linear low density polyethylene (“LLDPE”) is a substantially linear macromolecule composed of ethylene monomer units and α-olefin comonomer units. Typical comonomer units used commercially are derived from 1-butene, 1-hexene, or 1-octene. LLDPE can be distinguished from conventional low density polyethylene (“LDPE”) in many ways. Their respective manufacturing processes are different. LLDPE has substantially no detectable long chain branching per 1,000 carbon atoms, while conventional LDPE contains long chain branching. The MWD of LLDPE is narrower than that of LDPE.

[0004] However, after the two-step extrusion process, the linear low density polyethylene prepared by the Ziegler-Natta process shows poor surface smoothness, and thus customers need to solve such problems to provide technical solutions with improved surface smoothness.

[0005] WO94 / 12568A1 discloses the use of an effective amount of low weight average molecular weight polyethylene having a density greater than or equal to 0.900 g / cm 3 , for example, having a polydispersity index greater than 3.5. This solution shows that improved surface properties are achieved after higher shear processing of the blend, thereby greatly eliminating or effectively minimizing the occurrence of surface distortion. The amount of low weight average molecular weight polyethylene is from about 30 wt% to about 80 wt%.

[0006] US5,344,714A discloses a linear low density polyethylene film composite formed by coextrusion without melt fracture, comprising A) a layer of linear low density polyethylene (LLDPE) blended with polystyrene, which layer constitutes at least 70 wt% of the composite, wherein the blend contains 0.5 to 5 wt% polystyrene; and B) a second thin layer constituting less than 30 wt% of the composite and containing a resin selected from high density polyethylene, low density polyethylene, and mixtures thereof.

[0007] US5,925,448A discloses a film prepared in a two-step extrusion process, the film comprising a blend of component (i) linear low density polyethylene and an in-situ blend of component (ii) a copolymer of ethylene and one or more α-olefins having 3 to 8 carbon atoms, wherein the weight ratio of component (i) to component (ii) is in the range of about 0.01:1 to about 6:1; (b) the blend is extruded at an extrusion condition, at a die rate in the range of about 6 to about 20 pounds per hour per inch of die circumference and at a die gap of about 0.020 to about 0.075 inches; and (c) the film substantially does not show melt fracture.

[0008] US2022 / 0176592A1 discloses a method for extruding a melt of linear low density polyethylene (LLDPE) to form an LLDPE extrudate without surface melt fracture, the method comprising heating a melt of polyethylene to 200.0 to 260.0 °C; and extruding the heated melt through a die at a shear rate of 1,101 to 7,000 per second (s -1 ) and at a shear stress greater than 0.41 megapascals (MPa), thereby forming an LLDPE extrudate without surface melt fracture; and cutting the LLDPE extrudate into pellets having a surface without surface melt fracture. SUMMARY OF THE INVENTION

[0009] In one class of embodiments, the present invention provides a polyethylene blend comprising a Ziegler-Natta catalyst-catalyzed linear low density polyethylene and a metallocene-catalyzed polyethylene, wherein the melt index (MI) of the metallocene-catalyzed polyethylene is 0.1 g / 10 min to 30 g / 10 min and the density is 0.890 g / cm 3to 0.940 g / cm 3 with a molecular weight distribution (MWD) of 2 to 12 and a compositional distribution breadth index of 10 to 50, the roughness gray scale of the polyethylene blend is decreased by 35 - 70% relative to the linear low density polyethylene catalyzed by a pure Ziegler - Natta catalyst, and / or decreased by 12 - 58% relative to the polyethylene catalyzed by a pure metallocene catalyst. In addition, the polyethylene blend achieves a roughness gray scale STD of < 11, preferably 7.5 - 3.5, more preferably 6.5 - 4.5 in a two - step extrusion process.

[0010] In another class of embodiments, the present invention provides the use of the metallocene - catalyzed polyethylene to improve the surface quality, particularly the surface smoothness, of the linear low density polyethylene catalyzed by a Ziegler - Natta catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is the surface quality of pure LL7042 after a two - step extrusion process.

[0012] Figure 2 is the surface quality of LL7042 + 25% S9333 after a two - step extrusion process.

[0013] Figure 3 is the surface quality of LL7042 + 50% S9333 after a two - step extrusion process.

[0014] Figure 4 is the surface quality of LL7042 + 75% S9333 after a two - step extrusion process.

[0015] Figure 5 is the surface quality of pure S9333 after a two - step extrusion process.

[0016] Figure 6 is a schematic diagram describing the measurement of gray scale values. DETAILED DESCRIPTION OF THE INVENTION

[0017] Before disclosing and describing the compounds, components, compositions and / or methods of the present invention, it should be understood that, unless otherwise specified, the present invention is not limited to specific compounds, components, compositions, reactants, reaction conditions, ligands, metallocene structures, catalyst structures, or the like, as these can vary unless otherwise provided. It should also be understood that the various terms used herein are for the purpose of describing specific embodiments only and are not intended to be limiting.

[0018] In several embodiments of the present invention, the present application disclosure relates to polyethylene blends comprising Ziegler-Natta catalyzed linear low density polyethylene and metallocene catalyzed polyethylene, wherein the metallocene catalyzed polyethylene has a melt index (MI) of 0.1 g / 10 min to 30 g / 10 min, a density of 0.890 g / cm 3 to 0.940 g / cm 3 , a molecular weight distribution (MWD) of 2 to 12, and a compositional distribution breadth index of 10 to 50, and the roughness gray scale of the polyethylene blend is decreased by 35 - 70% relative to pure Ziegler-Natta catalyzed linear low density polyethylene and / or decreased by 12 - 58% relative to pure metallocene catalyzed polyethylene. In addition, the polyethylene blend achieves a roughness gray scale STD of <11, preferably 7.5 - 3.5, more preferably 6.5 - 4.5 in a two-step extrusion process.

[0019] Ziegler-Natta catalyzed linear low density polyethylene

[0020] Linear low density polyethylene prepared with a Ziegler-Natta catalyst is also referred to as ZN-LLDPE. ZN-LLDPE is manufactured by copolymerizing ethylene with an α-olefin comonomer in the presence of a Ziegler-Natta catalyst such as TiCl4 disposed on a particulate MgCl2 support. Ziegler-Natta catalysts are well known and include Ziegler-Natta catalyst components and systems in column 12, rows 13 to 49; column 12, row 58 to column 13, row 25; and a cocatalyst in column 13, row 31 to column 14, row 28 of Robert O. Hagerty et al.'s US7,122,607B2. Copolymerization methods are generally well known and can be slurry phase, solution phase or gas phase methods. For example, suitable gas phase methods are in column 25, row 59 to column 26, row 21 and column 33, row 32 to column 35, row 56 of US 7,122,607 B2.

[0021] The α-olefin comonomer used to prepare ZN-LLDPE can be (C3-C 20 ) α-olefin, alternatively (C 11 -C 20 ) α-olefin, alternatively (C3 to C 10)α-olefins, alternatively (C4-C8) α-olefins, alternatively 1-butene or 1-hexene, alternatively 1-butene, alternatively 1-hexene, alternatively 1-octene. ZN-LLDPE can be characterized by its monomer content (i.e., ethylene monomer content) and comonomer content (i.e., α-olefin comonomer content). The α-olefin comonomer units of ZN-LLDPE can be 1-butene comonomer units, alternatively 1-hexene comonomer units, alternatively 1-octene comonomer units.

[0022] The density of ZN-LLDPE can be from 0.905 to 0.930 g / cm 3 , alternatively from 0.915 to 0.926 g / cm 3 , alternatively from 0.920 to 0.926 g / cm 3 , alternatively 0.918 ± 0.003 g / cm 3 , alternatively 0.918 ± 0.002 g / cm 3 , alternatively 0.918 ± 0.001 g / cm 3 , alternatively 0.918 g / cm 3 , all measured according to ASTM D792-13. The melt index I2 of ZN-LLDPE can be from 0.5 to 2.5 g / 10 min, alternatively from 0.5 to 2.04 g / 10 min, alternatively from 0.5 to 1.99 g / 10 min, alternatively from 0.6 to 1.4 g / 10 min, alternatively from 0.9 to 1.1 g / 10 min, all measured according to ASTM D1238-04. The Mw of ZN-LLDPE can be from 1,000 to 1,000,000 grams per mole (g / mol), alternatively from 10,000 to 500,000 g / mol, alternatively from 20,000 to 200,000 g / mol.

[0023] Examples of ZN-LLDPE are commercially available and include LL1001 from EXXONMOBIL, LLDPEDFDA7042 from Sinopec, DOW LLDPEDFDA 7047NT 7; FORMOLENE L42022B from Formosa Plastics Corporation, Taiwan, China; HIFOR LF1021 and NOVAPOL TD-9022 from Westlake Chemical Corporation; and MARFLEX 7109 polyethylene from Chevron Phillips Company.

[0024] Metallocene-catalyzed polyethylene

[0025] Definition

[0026] For the purposes of the present invention and its claims, the numbering scheme for the groups of the periodic table follows the new notation of the IUPAC periodic table.

[0027] As used herein, the term "olefin polymerization catalyst(s)" refers to any catalyst capable of coordination polymerization addition, typically an organometallic complex or compound, in which successive monomers are added to the monomer chain at an organometallic active center.

[0028] The terms "substituent", "radical", "group" and "moiety" are used interchangeably.

[0029] When used herein and unless otherwise specified, the term "C n " refers to a hydrocarbon(s) containing n carbon atom(s) per molecule, where n is a positive integer.

[0030] When used herein and unless otherwise specified, the term "hydrocarbon" refers to a class of compounds containing hydrogen bonded to carbon and encompasses (i) saturated hydrocarbon compounds, (ii) unsaturated hydrocarbon compounds, and (iii) mixtures of hydrocarbon compounds (saturated and / or unsaturated), including mixtures of hydrocarbon compounds having different values of n.

[0031] The terms "hydrocarbyl radical", "hydrocarbyl", "hydrocarbyl group", "alkyl radical" and "alkyl" are used interchangeably throughout the document. Similarly, the terms "group", "radical" and "substituent" are also used interchangeably in this document. For the purposes of the disclosure of the present application, a "hydrocarbyl group" is defined as a C1-C 100 group, which may be linear, branched or cyclic, and when cyclic, is aromatic or non-aromatic. Examples of such groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, hexyl, octyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, etc., including their substituted analogs. A substituted hydrocarbyl is one in which at least one hydrogen atom of the hydrocarbyl has been replaced by at least one heteroatom or heteroatom-containing group, such as a halogen (e.g., Br, Cl, F or I) or at least one functional group such as NR*2, OR*, SeR*, TeR*, PR*2, AsR*2, SbR*2, SR*, BR*2, SiR*3, GeR*3, SnR*3, PbR*3, etc., or one in which at least one heteroatom has been inserted into the hydrocarbyl ring.

[0032] As used herein and unless otherwise specified, the term "alkyl" refers to a saturated hydrocarbon group having 1 to 12 carbon atoms (i.e., C1-C 12 alkyl), particularly 1 to 8 carbon atoms (i.e., C 1- C8 alkyl), particularly 1 to 6 carbon atoms (i.e., C1-C6 alkyl), particularly 1 to 4 carbon atoms (i.e., C1-C4 alkyl). Examples of alkyl include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, and the like. Alkyl can be linear, branched, or cyclic. "Alkyl" is intended to cover all structural isomeric forms of alkyl. For example, when used herein propyl covers n-propyl and isopropyl; butyl covers n-butyl, sec-butyl, isobutyl, and tert-butyl, and the like. When used herein "C1 alkyl" refers to methyl (-CH3), "C2 alkyl" refers to ethyl (-CH2CH3), "C3 alkyl" refers to propyl (-CH2CH2CH3), and "C4 alkyl" refers to butyl (e.g., -CH2CH2CH2CH3, -(CH3)CHCH2CH3, -CH2CH(CH3)2, etc.). Additionally, when used herein "Me" refers to methyl, "Et" refers to ethyl, "i-Pr" refers to isopropyl, "t-Bu" refers to tert-butyl, and "Np" refers to neopentyl.

[0033] As used herein and unless otherwise specified, the term "alkylene" refers to a divalent alkyl structural moiety having 1 to 12 carbon atoms in length (i.e., C1-C 12 alkylene) and refers to the alkylene structural moiety being connected to the remainder of the molecule at both ends of the alkyl unit. For example, alkylene includes, but is not limited to, -CH2-, -CH2CH2-, -CH(CH3)CH2-, -CH2CH2CH2-, etc. Alkylene can be linear or branched.

[0034] As used herein and unless otherwise specified, the term "alkenyl" refers to an unsaturated hydrocarbon group having 2 to 12 carbon atoms (i.e., C2-C 12 alkenyl), particularly 2 to 8 carbon atoms (i.e., C2-C8 alkenyl), particularly 2 to 6 carbon atoms (i.e., C2-C6 alkenyl) and having one or more (e.g., 2, 3, etc.) carbon-carbon double bonds. Alkenyl can be linear, branched, or cyclic. Examples of alkenyl include, but are not limited to, ethenyl (vinyl), 2-propenyl, 3-propenyl, 1,4-pentadienyl, 1,4-butadienyl, 1-butenyl, 2-butenyl, and 3-butenyl. "Alkenyl" is intended to cover all structural isomeric forms of alkenyl. For example, butenyl covers 1,4-butadienyl, 1-butenyl, 2-butenyl, and 3-butenyl, etc.

[0035] As used herein and unless otherwise specified, the term "alkenylene" refers to a divalent alkenyl structural moiety having from 2 to about 12 carbon atoms in length (i.e., C2-C 12 alkenylene) and means that the alkylene structural moiety is attached to the remainder of the molecule at both ends of the alkyl unit. For example, alkenylene includes, but is not limited to, -CH=CH-, -CH=CHCH2-, -CH=CH=CH-, -CH2CH2CH=CHCH2-, etc. Alkenylene can be linear or branched.

[0036] As used herein and unless otherwise specified, the term "alkynyl" refers to an unsaturated hydrocarbon group having from 2 to 12 carbon atoms (i.e., C2-C 12 alkynyl), especially from 2 to 8 carbon atoms (i.e., C2-C8 alkynyl), especially from 2 to 6 carbon atoms (i.e., C2-C6 alkynyl) and having one or more (e.g., 2, 3, etc.) carbon-carbon triple bonds. Alkynyl can be linear, branched or cyclic. Examples of alkynyl include, but are not limited to, ethynyl, 1-propynyl, 2-butynyl, and 1,3-butadiynyl. "Alkynyl" is intended to cover all structural isomeric forms of alkynyl. For example, butynyl covers 2-butynyl and 1,3-butadiynyl, and propynyl covers 1-propynyl and 2-propynyl (propargyl).

[0037] As used herein and unless otherwise specified, the term "alkynylene" refers to a divalent alkynyl structural moiety having from 2 to about 12 carbon atoms in length (i.e., C2-C 12 alkynylene) and means that the alkylene structural moiety is attached to the remainder of the molecule at both ends of the alkyl unit. For example, alkenylene includes, but is not limited to, -C≡C-, -C≡CCH2-, -C≡CCH2C≡C-, -CH2CH2C≡CCH2-. Alkynylene can be linear or branched.

[0038] As used herein and unless otherwise specified, the term "alkoxy" refers to --O--alkyl having from 1 to about 10 carbon atoms. Alkoxy can be straight-chain or branched-chain. Non-limiting examples include methoxy, ethoxy, propoxy, butoxy, isobutoxy, tert-butoxy, pentyloxy, and hexyloxy. "C1 alkoxy" means methoxy, "C2 alkoxy" means ethoxy, "C3 alkoxy" means propoxy, and "C4 alkoxy" means butoxy. Additionally, as used herein "OMe" means methoxy and "OEt" means ethoxy.

[0039] As used herein and unless otherwise specified, the term "aromatic" refers to having a delocalized conjugated π-system and containing from 5 to 20 carbon atoms (aromatic C5-C 20 hydrocarbon), especially from 5 to 12 carbon atoms (aromatic C5-C 12hydrocarbons), especially those having 5 to 10 carbon atoms (aromatic C5-C 12 unsaturated cyclic hydrocarbons. Exemplary aromatic compounds include, but are not limited to, benzene, toluene, xylene, mesitylene, ethylbenzene, cumene, naphthalene, methylnaphthalene, dimethylnaphthalene, ethylnaphthalene, acenaphthylene, anthracene, phenanthrene, tetraphene, tetracene, benzanthracene, fluoranthene, pyrene, (chrysene), benzophenanthrene, etc., and combinations thereof.

[0040] Unless otherwise specified, when isomers of an enumerated alkyl, alkenyl, alkoxy, or aryl group are present (e.g., n-butyl, isobutyl, sec-butyl, and tert-butyl), one member of the group (e.g., n-butyl) should explicitly disclose the remaining isomers in the class (e.g., isobutyl, sec-butyl, and tert-butyl). Similarly, a reference to an alkyl, alkenyl, alkoxide, or aryl group without specifying a particular isomer (e.g., butyl) deliberately discloses all isomers (e.g., n-butyl, isobutyl, sec-butyl, and tert-butyl).

[0041] The term "hydroxyl" as used herein refers to the -OH group.

[0042] The "oxygenate" as used herein refers to a saturated, unsaturated, or polycyclic cyclized hydrocarbon group containing 1 to 40 carbon atoms and further containing one or more heteroatoms of oxygen.

[0043] The "alkylaluminum adduct" as used herein refers to the reaction product of an alkylaluminum and / or an aluminoxane with a quenching agent such as water and / or methanol.

[0044] "Olefin", or "olefinic hydrocarbon", is a linear, branched, or cyclic compound of carbon and hydrogen having at least one double bond. For the purposes of this specification and the appended claims, when a polymer or copolymer is said to contain an olefin, the olefin present in such polymer or copolymer is the polymerized form of the olefin. For example, when a copolymer is said to have an "ethylene" content of 35 wt% - 55 wt%, it should be understood that the monomer units in the copolymer are derived from ethylene in the polymerization reaction and the derived units are present at 35 wt% - 55 wt%, based on the weight of the copolymer.

[0045] "Polymer" has two or more identical or different monomer units. "Homopolymer" is a polymer containing identical monomer units. "Copolymer" is a polymer having two or more monomer units that are different or distinct from one another. "Terpolymer" is a polymer having three monomer units that are different or distinct from one another. The use of "different" or "distinct" to refer to monomer units indicates that the monomer units differ from one another by at least one atom or are isomerically different. Thus, the definition of copolymer used herein includes terpolymers and the like. "Ethylene polymer" or "ethylene copolymer" is a polymer or copolymer containing at least 50 mol% of ethylene-derived units, "propylene polymer" or "propylene copolymer" is a polymer or copolymer containing at least 50 mol% of propylene-derived units, and so on.

[0046] "Polymerizable conditions" as used herein refers to those conditions, including temperature, pressure, reactant concentration, optional solvent / diluent, reactant mixing / addition parameters, selected by one of ordinary skill in the art, and other conditions that facilitate the reaction of one or more olefin monomers to form the desired polyolefin polymer typically via coordination polymerization when contacted with an activated olefin polymerization catalyst in at least one polymerization reactor.

[0047] The term "continuous" refers to a system that operates without interruption or cessation. For example, a continuous process for preparing a polymer would be one in which reactants are continuously introduced into one or more reactors and the polymer product is continuously withdrawn.

[0048] "Catalyst composition" or "catalyst system" is a combination of at least one catalyst compound, a support material, optional activator, and optional co-activator. For the purposes of the present invention and its claims, when a catalyst system or composition is described as containing the neutral stable form of the components, one of ordinary skill in the art will understand that the ionic form of the components is the form that reacts with monomers to produce a polymer. When it is used to describe such a combination after activation, it refers to the support, the activation complex, and the activator or other charge-balancing structural moieties. The transition metal compound can be neutral, as in a pre-catalyst, or a charged species having a counterion, as in an activated catalyst system.

[0049] Coordination polymerization is an addition polymerization in which a continuous monomer is added to or into an organometallic active center to cause the formation and / or growth of a polymer chain.

[0050] The terms "cocatalyst" and "activator" are used interchangeably herein and are defined as any compound capable of activating any of the above catalyst compounds by converting a neutral catalyst compound into a catalytically active catalyst compound cation.

[0051] The term "contact product" or "product of combination" is used herein to describe a composition in which the components are brought into contact with each other in any order, in any manner, for any length of time. For example, the components can be brought into contact by blending or mixing. Additionally, the contact of any component can occur in the presence or absence of any other component of the compositions described herein. The combination of additional materials or components can be effected by any suitable method. Additionally, the term "contact product" includes mixtures, blends, solutions, slurries, reaction products, etc., or combinations thereof. Although a "contact product" can include a reaction product, it is not required that the corresponding components react with each other or react in the manner postulated. Similarly, the term "contact" is used herein to refer to materials that can be blended, mixed, slurried, dissolved, reacted, treated, or otherwise contacted in some other manner.

[0052] "BOCD" refers to broad orthogonal composition distribution, in which the comonomers of a copolymer are predominantly incorporated in the high molecular weight chains or fractions of a polyolefin polymer or composition. For example, the distribution of short chain branches can be measured using temperature rising elution fractionation (TREF) together with a light scattering (LS) detector to determine the weight average molecular weight of the molecules eluting from the TREF column at a given temperature. The combination of TREF and LS (TREF-LS) gives information about the width of the composition distribution and whether the comonomer content increases, decreases, or is uniform along the different molecular weight chains of the polymer chain. BOCD has been described, for example, in U.S. Patent No. 8,378,043, column 3, line 34 to column 4, line 19; and 8,476,392, line 43 to column 16, line 54.

[0053] The width of the composition distribution is characterized by the T 75 -T 25 value, where T 25 is the temperature at which 25% of the eluted polymer is obtained in the TREF experiment described herein, and T 75 is the temperature at which 75% of the eluted polymer is obtained in the TREF experiment described herein. The composition distribution is further characterized by the F 80 value, which is the fraction of the polymer eluting below 80 °C in the TREF-LS experiment described herein. A higher F 80 value indicates a higher proportion of comonomer in the polymer molecules. Orthogonal composition distribution is defined by an M 60 / M 90 value greater than 1, where M 60 is the molecular weight of the polymer fraction eluting at 60 °C in the TREF-LS experiment, and M 90 is the molecular weight of the polymer fraction eluting at 90 °C in the TREF-LS experiment described herein.

[0054] In one class of embodiments, the polymers described herein can have a characteristic T75 -T 25 The value is 1 or greater, 2.0 or greater, 2.5 or greater, 4.0 or greater, 5.0 or greater, 7.0 or greater, 10.0 or greater, 11.5 or greater, 15.0 or greater, 17.5 or greater, 20.0 or greater, or 25.0 or greater, 30.0 or greater, 35.0 or greater, 40.0 or greater, or 45.0 or greater for BOCD, where T 25 is the temperature at which 25% of the eluted polymer is obtained in the TREF experiment described herein, T 75 is the temperature at which 75% of the eluted polymer is obtained.

[0055] The polymers described herein may further have a feature characterized by M 60 / M 90 The value is 1.5 or greater, 2.0 or greater, 2.25 or greater, 2.50 or greater, 3.0 or greater, 3.5 or greater, 4.0 or greater, 4.5 or greater, or 5.0 or greater for BOCD, where M 60 is the molecular weight of the polymer fraction eluted at 60 °C in the TREF-LS experiment described herein, M 90 is the molecular weight of the polymer fraction eluted at 90 °C in the TREF-LS experiment described herein.

[0056] In addition, the polymers described herein may further have a feature characterized by F 80 The value is 1% or greater, 2% or greater, 3% or greater, 4% or greater, 5% or greater, 6% or greater, 7% or greater, 10% or greater, 11% or greater, 12% or greater, or 15% or greater for BOCD, where F 80 is the proportion of the polymer eluted at a temperature below 80 °C.

[0057] Olefin polymerization catalyst

[0058] Metallocene catalyst

[0059] In one class of embodiments, the catalyst system can be a mixed metallocene catalyst system (i.e., comprising more than one catalyst) and comprises two or more of the following catalysts, such as the catalyst represented by formula (A):

[0060]

[0061] Wherein:

[0062] M is Hf or Zr;

[0063] Each R 1 、R 2 and R 4Independently is hydrogen, an alkoxide, or a C1-C 40 substituted or unsubstituted hydrocarbon group (preferably C1-C 20 substituted or unsubstituted hydrocarbon group);

[0064] R 3 Independently is hydrogen, an alkoxide, or a C1-C 40 substituted or unsubstituted hydrocarbon group (preferably C1-C 20 substituted or unsubstituted hydrocarbon group), or is -R 20 -SiR'3 or -R 20 -CR'3, where R 20 is hydrogen, or a C1-C4 hydrocarbon group, and each R' is independently a C1-C 20 substituted or unsubstituted hydrocarbon group, provided that at least one R' is not H;

[0065] Each R 7 、R 8 and R 10 Independently is hydrogen, an alkoxide, or a C1-C 40 substituted or unsubstituted hydrocarbon group (preferably C1-C 20 substituted or unsubstituted hydrocarbon group);

[0066] R 9 is -R 20 -SiR'3 or -R 20 -CR'3 where R 20 is hydrogen or a C1-C4 hydrocarbon group (preferably R 20 is CH2), and each R' is independently a C1-C 20 substituted or unsubstituted hydrocarbon group, (preferably R' is an alkyl group such as Me, or an aryl group such as phenyl), provided that at least one R' is not H, or 2 R's are not H, or 3 R's are not H;

[0067] T is a bridging group, such as CR 21 R 22 ,where R 21 and R 22 Independently are hydrogen, a halogen, or a hydrocarbon group containing C1-C 20 (such as, a linear hydrocarbon group), a substituted hydrocarbon group, optionally, R 21 and R 22 join to form a substituted or unsubstituted, saturated, partially unsaturated, or aromatic, cyclic or polycyclic substituent, optionally, R 21 and R 22 are the same or different; and

[0068] Each X is independently a monovalent anionic ligand, or two X's are joined and bonded to the metal atom to form a metallocycle ring, or two X's are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand (preferably, a halogen or a C1-C 12 alkyl or aryl, such as Cl, Me, Et, Ph).

[0069] In a preferred embodiment of the present invention, M is Hf, or M is Zr.

[0070] In a preferred embodiment of the present invention, each R 1 、R 2 and R 4 is independently hydrogen, or a substituted C1-C 12 hydrocarbyl or an unsubstituted C1-C 12 hydrocarbyl, preferably hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl or their isomers.

[0071] In a preferred embodiment of the present invention, each R 3 is independently hydrogen, or a substituted C1-C 12 hydrocarbyl or an unsubstituted C1-C 12 hydrocarbyl, preferably hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl or their isomers or R 3 is -R 20 -SiR'3 or -R 20 -CR'3, where R 20 is a C1-C4 hydrocarbyl (preferably methyl, ethyl, propyl, butyl), and R' is a C1-C 20 substituted or unsubstituted hydrocarbyl, preferably a substituted C1-C 12 hydrocarbyl or an unsubstituted C1-C 12 hydrocarbyl, preferably methyl, ethyl, propyl, butyl, pentyl, hexyl or their isomers.

[0072] In a preferred embodiment of the present invention, each R 7 、R 8 and R 10 is independently hydrogen, or a substituted C1-C 12 hydrocarbyl or an unsubstituted C1-C 12 hydrocarbyl, preferably hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl or their isomers.

[0073] In a preferred embodiment of the present invention, R 9 is -R 20 -SiR'3 or -R 20 -CR'3, where R 20is a C1-C4 hydrocarbyl (preferably methyl, ethyl, propyl, butyl), R' is a substituted or unsubstituted hydrocarbyl, preferably a substituted C1-C 20 hydrocarbyl or an unsubstituted C1-C 12 hydrocarbyl, preferably methyl, ethyl, propyl, butyl, pentyl, hexyl or their isomers. 12

[0074] Alternatively, R 9 and optionally, R 3 independently is -R 20 -CMe3 or -R 20 -SiMe3, where R 20 is a C1-C4 hydrocarbyl (preferably methyl, ethyl, propyl, butyl), preferably -CH2-CMe3 or -CH2-SiMe3.

[0075] Alternatively, each X can independently be a halide, a hydride, an alkyl, an alkenyl or an aralkyl.

[0076] Alternatively, each X independently is selected from hydrocarbyls having 1-20 carbon atoms, aryls, hydrides, amides, alkoxys, sulfides, phosphides, halides, dienes, amines, phosphines, ethers and combinations thereof (two Xs can form part of a fused ring or a ring system), preferably, each X independently is selected from halides, aryls and C1-C5 alkyls, preferably each X is phenyl, methyl, ethyl, propyl, butyl, pentyl, bromine or chlorine.

[0077] ​Preferably, T is a bridging group containing at least one Group 13, 14, 15 or 16 element, especially boron or a Group 14, 15 or 16 element. Examples of suitable bridging groups include P(=S)R', P(=Se)R', P(=O)R', R'2C, R'2Si, R'2Ge, R'2CCR'2, R'2CCR'2CR'2, R'2CCR'2CR'2CR'2, R'C=CR', R'C=CR'CR'2, R'2CCR'=CR'CR'2, R'C=CR'CR'=CR', R'C=CR'CR'2CR'2, R'2CSiR'2, R'2SiSiR'2, R'2SiOSiR'2, R'2CSiR'2CR'2, R'2SiCR'2SiR'2, R'C=CR'SiR'2, R'2CGeR'2, R'2GeGeR'2, R'2CGeR'2CR'2, R'2GeCR'2GeR'2, R'2SiGeR'2, R'C=CR'GeR'2, R'B, R'2C-BR', R'2C-BR'-CR'2, R'2C-O-CR'2, R'2CR'2C-O-CR'2CR'2, R'2C-O-CR'2CR'2, R'2C-O-CR'=CR', R'2C-S-CR'2, R'2CR'2C-S-CR'2CR'2, R'2C-S-CR'2CR'2, R'2C-S-CR'=CR', R'2C-Se-CR'2, R'2CR'2C-Se-CR'2CR'2, R'2C-Se-CR'2CR'2, R'2C-Se-CR'=CR', R'2C-N=CR', R'2C-NR'-CR'2, R'2C-NR'-CR'2CR'2, R'2C-NR'-CR'=CR', R'2CR'2C-NR'-CR'2CR'2, R'2C-P=CR', R'2C-PR'-CR'2, O, S, Se, Te, NR', PR', AsR', SbR', O-O, S-S, R'N-NR', R'P-PR', O-S, O-NR', O-PR', S-NR', S-PR' and R'N-PR', where R' is hydrogen or contains C1-C 20a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl or germylcarbyl substituent, optionally, two or more adjacent R' may be joined to form a substituted or unsubstituted, saturated, partially unsaturated or aromatic, cyclic or polycyclic substituent. Preferred examples of the bridging group T include CH2, CH2CH2, SiMe2, SiPh2, SiMePh, Si(CH2)3, Si(CH2)4, O, S, NPh, PPh, NMe, PMe, NEt, NPr, NBu, PEt, PPr, Me2SiOSiMe2 and PBu.

[0078] In a preferred embodiment of the present invention, in any embodiment of any of the formulas described herein, T is of the formula R a 2J or (R a 2J)2, where J is C, Si or Ge, each R a is independently hydrogen, halogen, C1-C 20 hydrocarbyl (such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl or dodecyl) or C1-C 20 substituted hydrocarbyl, and two R a may form a cyclic structure including an aromatic, partially saturated or saturated cyclic or fused ring system. Preferably, T is a carbon- or silicon-containing bridging group, such as a dialkylsilyl, and preferably T is selected from CH2, CH2CH2, C(CH3)2, SiMe2, SiPh2, SiMePh, silylcyclobutyl (Si(CH2)3), (Ph)2C, (p-(Et)3SiPh)2C, Me2SiOSiMe2 and cyclopentasilylene (Si(CH2)4).

[0079] In a preferred embodiment of the present invention, the molar ratio of racemic to meso in the catalyst compound is from 1:1 to 100:1, preferably from 5:1 to 90:1, preferably from 7:1 to 80:1, preferably 5:1 or greater, or 7:1 or greater, or 20:1 or greater, or 30:1 or greater or 50:1 or greater. In one embodiment of the present invention, the metallocene catalyst comprises greater than 55 mol% of the racemic isomer, or greater than 60 mol% of the racemic isomer, or greater than 65 mol% of the racemic isomer, or greater than 70 mol% of the racemic isomer, or greater than 75 mol% of the racemic isomer, or greater than 80 mol% of the racemic isomer, or greater than 85 mol% of the racemic isomer, or greater than 90 mol% of the racemic isomer, or greater than 92 mol% of the racemic isomer, or greater than 95 mol% of the racemic isomer, or greater than 97 mol% of the racemic isomer, based on the total amount of racemic and meso isomers formed if any. In a particular embodiment of the present invention, the metallocene transition metal compound formed consists essentially of the racemic isomer.

[0080] The amounts of the racemic and meso isomers are determined by proton NMR. The 1H NMR data are collected at 23 °C using a 400 MHz Bruker spectrometer with a 5 mm probe and deuterated dichloromethane. (It should be noted that deuterated benzene can be used in some of the examples here, but for claim purposes, dichloromethane should be used.) The data are recorded using a maximum pulse width of 45°, 5 seconds between pulses and 16 averaged transients. The spectrum is normalized to protonated dichloromethane in deuterated dichloromethane, which is expected to show a peak at 5.32 ppm. 1 H NMR data. (It should be noted that deuterated benzene can be used in some of the examples here, but for claim purposes, dichloromethane should be used.) The data are recorded using a maximum pulse width of 45°, 5 seconds between pulses and 16 averaged transients. The spectrum is normalized to protonated dichloromethane in deuterated dichloromethane, which is expected to show a peak at 5.32 ppm.

[0081] Catalyst compounds particularly useful in the present invention include one or more of the following: racemic / meso-Me2Si(Me3SiCH2Cp)2HfMe2; racemic Me2Si(Me3SiCH2Cp)2HfMe2; racemic / meso-Ph2Si(Me3SiCH2Cp)2HfMe2; racemic / meso-(CH2)3Si(Me3SiCH2Cp)2HfMe2; racemic / meso-(CH2)4Si(Me3SiCH2Cp)2HfMe2; racemic / meso-(C6F5)2Si(Me3SiCH2Cp)2HfMe2; racemic / meso-(CH2)3Si(Me3SiCH2Cp)2ZrMe2; racemic / meso-Me2Ge(Me3SiCH2Cp)2HfMe2; racemic / meso-Me2Si(Me2PhSiCH2Cp)2HfMe2; racemic / meso-Ph2Si(Me2PhSiCH2Cp)2HfMe2; Me2Si(Me4Cp)(Me2PhSiCH2Cp)HfMe2; racemic / meso-(CH2)3Si(Me2PhSiCH2Cp)2HfMe2; racemic / meso-(CH2)4Si(Me2PhSiCH2Cp)2HfMe2; racemic / meso-(C6F5)2Si(Me2PhSiCH2Cp)2HfMe2; racemic / meso-Me2Ge(Me2PhSiCH2Cp)2HfMe2; racemic / meso-Me2Si(MePh2SiCH2Cp)2HfMe2; racemic / meso-Ph2Si(MePh2SiCH2Cp)2HfMe2; racemic / meso-Me2Si(MePh2SiCH2Cp)2ZrMe2; racemic / meso-(CH2)3Si(MePh2SiCH2Cp)2HfMe2; racemic / meso-(CH2)4Si(MePh2SiCH2Cp)2HfMe2; racemic / meso-(C6F5)2Si(MePh2SiCH2Cp)2HfMe2; racemic / meso-Me2Ge(MePh2SiCH2Cp)2HfMe2; racemic / meso-Me2Si(Ph3SiCH2Cp)2HfMe2; racemic / meso-Ph2Si(Ph3SiCH2Cp)2HfMe2; racemic / meso-Me2Si(Ph3SiCH2Cp)2ZrMe2; racemic / meso-(CH2)3Si(Ph3SiCH2Cp)2HfMe2; racemic / meso-(CH2)4Si(Ph3SiCH2Cp)2HfMe2; racemic / meso-(C6F5)2Si(Ph3SiCH2Cp)2HfMe2; racemic / meso-Me2Ge(Ph3SiCH2Cp)2HfMe2;Racemic / meso-Me2Si(Cy3SiCH2Cp)2HfMe2; racemic Me2Si(Cy3SiCH2Cp)2HfMe2; racemic / meso-Ph2Si(Cy3SiCH2Cp)2HfMe2; racemic / meso-Me2Si(Cy3SiCH2Cp)2ZrMe2; racemic / meso-(CH2)3Si(Cy3SiCH2Cp)2HfMe2; racemic / meso-(CH2)4Si(Cy3SiCH2Cp)2HfMe2; racemic / meso-(C6F5)2Si(Cy3SiCH2Cp)2HfMe2; racemic / meso-Me2Ge(Cy3SiCH2Cp)2HfMe2; racemic / meso-Me2Si(Cy2MeSiCH2Cp)2HfMe2; racemic / meso-Ph2Si(Cy2MeSiCH2Cp)2HfMe2; Me2Si(Me4Cp)(Cy2MeSiCH2Cp)HfMe2; racemic / meso-(CH2)3Si(Cy2MeSiCH2Cp)2HfMe2; racemic / meso-(CH2)4Si(Cy2MeSiCH2Cp)2HfMe2; racemic / meso-(C6F5)2Si(Cy2MeSiCH2Cp)2HfMe2; racemic / meso-Me2Ge(Cy2MeSiCH2Cp)2HfMe2; racemic / meso-Me2Si(CyMe2SiCH2Cp)2HfMe2; racemic / meso-Ph2Si(CyMe2SiCH2Cp)2HfMe2; racemic / meso-(CH2)3Si(CyMe2SiCH2Cp)2HfMe2; racemic / meso-(CH2)4Si(CyMe2SiCH2Cp)2HfMe2; racemic / meso-(C6F5)2Si(CyMe2SiCH2Cp)2HfMe2; racemic / meso-Me2Ge(CyMe2SiCH2Cp)2HfMe2; racemic / meso-Me2Si(Cy2PhSiCH2Cp)2HfMe2; racemic / meso-Ph2Si(Cy2PhSiCH2Cp)2HfMe2; racemic / meso-(CH2)3Si(Cy2PhSiCH2Cp)2HfMe2; racemic / meso-(CH2)4Si(Cy2PhSiCH2Cp)2HfMe2; racemic / meso-(C6F5)2Si(Cy2PhSiCH2Cp)2HfMe2; racemic / meso-Me2Ge(Cy2PhSiCH2Cp)2HfMe2; racemic / meso-Me2Si(CyPh2SiCH2Cp)2HfMe2; racemic / meso-Ph2Si(CyPh2SiCH2Cp)2HfMe2;Racemic / meso-(CH2)3Si(CyPh2SiCH2Cp)2HfMe2; Racemic / meso-(CH2)4Si(CyPh2SiCH2Cp)2HfMe2; Racemic / meso-(C6F5)2Si(CyPh2SiCH2Cp)2HfMe2; and Racemic / meso-Me2Ge(CyPh2SiCH2Cp)2HfMe2.

[0082] In a preferred embodiment, in any of the methods described herein, a catalyst compound is used, such that the catalyst compounds are not different. For the purposes of this invention, catalyst compounds are considered different if one differs from another by at least one atom. For example, "zirconium dichloride bis(indenyl)" is different from "zirconium dichloride (indenyl)(2-methylindenyl)", which is different from "hafnium dichloride (indenyl)(2-methylindenyl)". Catalyst compounds that differ only by isomers are considered the same for the purposes of this invention, for example, racemic-dimethyl dimethylsilyl bis(2-methyl-4-phenylindenyl)hafnium is considered the same as meso-dimethyl dimethylsilyl bis(2-methyl-4-phenylindenyl)hafnium.

[0083] Other useful olefin polymerization catalysts include metallocene catalyst compounds represented by the following formula (B):

[0084] T y Cp m M 6 G n X 5 q (B),

[0085] where each Cp is independently a cyclopentadienyl that may be substituted or unsubstituted (such as cyclopentadiene, indene, or fluorene), M 6 is a Group 4 transition metal, such as titanium, zirconium, hafnium, G is a heteroatom group represented by the formula JR* z where J is N, P, O, or S, and R* is a C1-C 20 hydrocarbyl group, z is 1 or 2, T is a bridging group, y is 0 or 1, X 5 is a leaving group (such as a halogen group, hydrogen group, alkyl group, alkenyl group, or aralkyl group), and m = 1 or 2, n = 0, 1, 2, or 3, q = 0, 1, 2, or 3, and the sum of m + n + q is equal to the oxidation state of the transition metal. See, for example, WO 2016 / 094843.

[0086] In one embodiment, each Cp is a cyclopentadiene, indene, or fluorene that may be substituted or unsubstituted, each M 6 is titanium, zirconium, or hafnium, and each X 5Independently is a halogen group, a hydrogen group, an alkyl group, an alkenyl group or an aralkyl group. In any of the embodiments described herein, y can be 1, m can be 1, n can be 1, J can be N, and R* can be methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, cyclooctyl, cyclododecyl, decyl, undecyl, dodecyl, adamantyl or their isomers.

[0087] In yet another embodiment, one or more olefin polymerization catalysts can comprise one or more of the following metallocene catalysts: bis(tetrahydroindenyl)Hf Me2; bis(1-butyl,3-methylcyclopentadienyl)ZrCl2; bis-(n-butylcyclopentadienyl)ZrCl2; (dimethylsilyl)2O bis(indenyl)ZrCl2; dimethylsilyl(3-(3-methylbutyl)cyclopentadienyl)(2,3,4,5-tetramethylcyclopentadienyl)ZrCl2; dimethylsilyl·bis(tetrahydroindenyl)ZrCl2; dimethylsilyl-(3-phenyl-indenyl)(tetramethylcyclopentadienyl)ZrCl2; dimethylsilyl(3-neopentylcyclopentadienyl)(tetramethylcyclopentadienyl)HfCl2; tetramethyldisilylene bis(4-(3,5-di-tert-butylphenyl)-indenyl)ZrCl2; cyclopentadienyl(1,3-diphenylcyclopentadienyl)ZrCl2; dichloro·bis(cyclopentadienyl)zirconium; dichloro·bis(pentamethylcyclopentadienyl)zirconium; dimethyl·bis(pentamethylcyclopentadienyl)zirconium; dichloro·bis(pentamethylcyclopentadienyl)hafnium; dimethyl·bis(pentamethylcyclopentadienyl)zirconium; dichloro·bis(1-methyl-3-n-butylcyclopentadienyl)zirconium; dimethyl·bis(1-methyl-3-n-butylcyclopentadienyl)zirconium; dichloro·bis(1-methyl-3-n-butylcyclopentadienyl)hafnium; dimethyl·bis(1-methyl-3-n-butylcyclopentadienyl)zirconium; dichloro·bis(indenyl)zirconium; dimethyl·bis(indenyl)zirconium; dichloro·bis(tetrahydro-1-indenyl)zirconium; dimethyl·bis(tetrahydro-1-indenyl)zirconium; dichloro·dimethylsilyl·bis(tetrahydroindenyl)zirconium; dimethyl·dimethylsilyl·bis(tetrahydroindenyl)zirconium; dimethylsilyl·bis(indenyl)dichloro·zirconium; dimethyl·dimethylsilyl(bisindenyl)zirconium; dichloro·dimethylsilyl·bis(cyclopentadienyl)zirconium; or dimethyl·dimethylsilyl·bis(cyclopentadienyl)zirconium.

[0088] In another embodiment, one or more olefin polymerization catalyst compounds can comprise a first metallocene catalyst and a second metallocene catalyst independently selected from the following: SiMe2(Me4Cp)(cC 12 N)TiMe2 and bis(1-Bu,3-Me-Cp)ZrCl2; SiMe2(Me4Cp)(cC 12(N)TiMe2 and (SiMe2) bis(indenyl)ZrCl2; SiMe2(Me4Cp)(cC 12 (N)TiMe2 and (SiMe2)2O bis(indenyl)ZrCl2; SiMe2(Me4Cp)(cC 12 (N)TiMe2 and SiMe2)2O bis(indenyl)ZrMe2; SiMe2(Me4Cp)(cC 12 (N)TiMe2 and SiMe2(3-neopentylCp)((Me4Cp)HfCl2; SiMe2(Me4Cp)(cC 12 (N)TiMe2 and SiMe2(3-neopentylcyclopentadienyl)(Me4Cp)HfMe2; SiMe2(Me4Cp)(1-adamantylamino)TiMe2 and bis(1-Bu,3-MeCp)ZrCl2; and SiMe2(Me4Cp)(1-tert-butylamino)TiMe2 and bis(1-Bu,3-MeCp)ZrCl2.

[0089] In one class of embodiments, one or more metallocene catalysts can include dichloro·(4-propyl,1,2-dimethylcyclopentadienyl)(cyclopentadienyl)hafnium; dimethyl·(tetramethylcyclopentadienyl)(propylcyclopentadienyl)hafnium; dimethyl·(tetramethylcyclopentadienyl)(propylcyclopentadienyl)zirconium; dimethyl·(3,4-dipropyl,1,2-dimethylcyclopentadienyl)(cyclopentadienyl)hafnium; dimethyl·(propylcyclopentadienyl)(methylcyclopentadienyl)hafnium; dimethyl·(propylcyclopentadienyl)(cyclopentadienyl)hafnium; dimethyl·(tetramethylcyclopentadienyl)(benzylcyclopentadienyl)zirconium; dichloro·silylcyclopentyl(tetramethylcyclopentadienyl)(cyclopentadienyl)zirconium; dichloro·dimethylsilyl(tetramethylcyclopentadienyl)(3-(1-hexenyl)cyclopentadienyl)zirconium; or dimethyl·dimethylsilyl(tetramethylcyclopentadienyl)(3-trimethylsilylmethylcyclopentadienyl)hafnium.

[0090] In another class of embodiments, one or more metallocene catalysts can include zirconium dichloride bis(cyclopentadienyl), zirconium dimethyl bis(cyclopentadienyl), zirconium dichloride bis(n-butylcyclopentadienyl), zirconium dimethyl bis(n-butylcyclopentadienyl), zirconium dichloride bis(pentamethylcyclopentadienyl), zirconium dimethyl bis(pentamethylcyclopentadienyl), hafnium dichloride bis(pentamethylcyclopentadienyl), zirconium dimethyl bis(pentamethylcyclopentadienyl), zirconium dichloride bis(1-methyl-3-n-butylcyclopentadienyl), zirconium dimethyl bis(1-methyl-3-n-butylcyclopentadienyl), zirconium dichloride bis(1-methyl-3-phenylcyclopentadienyl), zirconium dimethyl bis(1-methyl-3-phenylcyclopentadienyl), hafnium dichloride bis(1-methyl-3-n-butylcyclopentadienyl), zirconium dimethyl bis(1-methyl-3-n-butylcyclopentadienyl), zirconium dichloride bis(indenyl), zirconium dimethyl bis(indenyl), zirconium dichloride bis(tetrahydro-1-indenyl), zirconium dimethyl bis(tetrahydro-1-indenyl), zirconium dichloride (n-propylcyclopentadienyl)(pentamethylcyclopentadienyl), zirconium dimethyl (n-propylcyclopentadienyl)(pentamethylcyclopentadienyl), zirconium dichloride rac / mes-(1-ethylindenyl), zirconium dimethyl rac / mes-(1-ethylindenyl), zirconium dichloride rac / mes-(1-methylindenyl), zirconium dimethyl rac / mes-(1-methylindenyl), zirconium dichloride rac / mes-(1-propylindenyl), zirconium dimethyl rac / mes-(1-propylindenyl), zirconium dichloride rac / mes-(1-butylindenyl), zirconium dimethyl rac / mes-(1-butylindenyl), zirconium dichloride meso-(1-ethylindenyl), zirconium dimethyl meso-(1-ethylindenyl), zirconium dichloride (1-methylindenyl)(pentamethylcyclopentadienyl), zirconium dimethyl (1-methylindenyl)(pentamethylcyclopentadienyl), or combinations thereof.

[0091] In yet another class of embodiments, one or more metallocene catalysts can include dichloro·rac / meso-(1-ethylindenyl)zirconium, dimethyl·rac / meso-(1-ethylindenyl)zirconium, dichloro·rac / meso-(1-methylindenyl)zirconium, dimethyl·rac / meso-(1-methylindenyl)zirconium, dichloro·rac / meso-(1-propylindenyl)zirconium, dimethyl·rac / meso-(1-propylindenyl)zirconium, dichloro·rac / meso-(1-butylindenyl)zirconium, dimethyl·rac / meso-(1-butylindenyl)zirconium, dichloro·meso-(1-ethylindenyl)zirconium, dimethyl·meso-(1-ethylindenyl)zirconium, dichloro·(1-methylindenyl)(pentamethylcyclopentadienyl)zirconium, dimethyl·(1-methylindenyl)(pentamethylcyclopentadienyl)zirconium, or combinations thereof.

[0092] One or more of the above or below metallocene catalysts can be used in a mixed catalyst system, also known as a dual catalyst system, which includes, for example, two or three metallocene catalysts or any catalyst described herein or known in the art that can be used for olefin polymerization. They can be co-supported, i.e., disposed on the same support material, and optionally and additionally, separately (with or without a support) or together in different combinations and ratios are injected into the reactor(s) to "trim" or adjust the polymer product properties according to their target specifications. This method is very suitable for controlling polymer product properties and ensuring uniformity in the mass production of polyolefin polymers.

[0093] For example, catalyst combinations such as dichloro·rac-ethylidene-bis(indenyl)zirconium and dichloro·diphenylmethylene{η 5 -[3-(penten-4-yl)cyclopentadien-1-ylidene]}[η 5 -(2,7-di-tert-butylfluoren-9-ylidene)]zirconium, and other catalysts disclosed in U.S. Patent No. 9,181,370 can be used in a catalyst system or a mixed catalyst system, which is sometimes also called a dual catalyst system if only two catalysts are used. In another example, Me2Si(H4Ind)2ZrCl2 and (Me5 Cp)PrCpZrCl2, and (Cp)IndZrCl2 and meso-O(Me2SiInd)2ZrCl2 can be used in a mixed catalyst system and other catalysts disclosed in U.S. Patent No. 6,828,394. In yet another example, the catalysts represented by "MTE-A" and "MTE-B" disclosed in U.S. Patent No. 9,181,369 can be used in a mixed catalyst system.

[0094] In another class of embodiments, the following catalysts can be used in a mixed catalyst system: dichloro·phenyl-3-butenylmethylene(η5 -Cyclopentadienyl)(η 5 -9,2-7-Di-tert-butylfluorenyl)zirconium, dichloro-bis(indenyl)zirconium, dichloro-diphenylmethylene{η 5 -[3-(Pent-4-enyl)cyclopentadien-1-ylidene]}[η 5 -(2,7-Di-tert-butylfluorene-9-ylidene)]hafnium, [dichloro-[η 5 -1-(Prop-2-enyl)indenyl][η 5 -n-butylcyclopentadienyl]zirconium, dichloro-rac-ethylidene-bis(indenyl)zirconium, dichloro-diphenylmethylene{η 5 -[3-(Pent-4-enyl)cyclopentadien-1-ylidene]}[η 5 -(2,7-Di-tert-butylfluorene-9-ylidene)]zirconium, and other catalysts disclosed in U.S. Patent No. 9,006,367, or any catalyst disclosed in U.S. Patent No. 9,217,049, such as those represented by the following structures:

[0095]

[0096]

[0097] Activator

[0098] The catalyst composition can be combined with an activator in any manner known in the art, including loading them for use in slurry or gas phase polymerization. An activator is generally a compound that can activate any of the above catalyst compounds by converting a neutral metal compound into a catalytically active metal compound cation. Non-limiting activators include, for example, aluminoxanes, alkyl aluminums, ionizing activators (which can be neutral or ionic), and conventional types of cocatalysts. Preferred activators typically include aluminoxane compounds, modified aluminoxane compounds, and ionizing anion precursor compounds, which abstract a reactive, σ-bonded metal ligand, thereby cationizing the metal compound and providing a non-coordinating or weakly coordinating anion to balance the charge.

[0099] Aluminoxane activator

[0100] The aluminoxane activator is used as an activator in the catalyst composition described herein. Aluminoxanes are generally oligomeric compounds containing -Al(R 1 )-O- subunits, where R 1is an alkyl group. Examples of aluminoxanes include methylaluminoxane (MAO), modified methylaluminoxane (MMAO), ethylaluminoxane, and isobutylaluminoxane. Alkylaluminoxanes and modified alkylaluminoxanes are suitable as catalyst activators, especially when the ligand that can be abstracted is an alkyl, halo, alkoxy, or amino group. Mixtures of different aluminoxanes and modified aluminoxanes can also be used. Visually transparent methylaluminoxane can be preferably used. Turbid or gelled aluminoxane can be filtered to prepare a transparent solution or transparent aluminoxane can be decanted from the turbid solution. A useful aluminoxane is modified methylaluminoxane (MMAO) cocatalyst type 3A covered by U.S. Patent No. US 5,041,584 (commercially available from Akzo Chemicals, Inc. under the trade name Modified Methylaluminoxane 3A).

[0101] When the activator is an aluminoxane (modified or unmodified), some embodiments select a maximum activator dose typically up to 5000-fold molar excess (Al / M) relative to the catalyst compound (per metal catalytic site). The minimum activator to catalyst compound ratio is a 1:1 molar ratio. Alternative preferred ranges include 1:1 - 500:1, or 1:1 - 200:1, or 1:1 - 100:1, or 1:1 - 50:1.

[0102] In one class of embodiments, little or no aluminoxane is used in the polymerization processes described herein. Preferably, the aluminoxane is present at 0 mol%, or the aluminoxane is present at an Al to transition metal of the catalyst compound molar ratio less than 500:1, preferably less than 300:1, preferably less than 100:1, preferably less than 1:1.

[0103] In another class of embodiments, at least one activator contains aluminum and the ratio of the aluminum to a transition metal, e.g., hafnium or zirconium, is at least 150:1; at least one activator contains aluminum and the ratio of the aluminum to a transition metal, e.g., hafnium or zirconium, is at least 250:1; or at least one activator contains aluminum and the ratio of the aluminum to a transition metal, e.g., hafnium or zirconium, is at least 1,000:1.

[0104] Ionizing / noncoordinating anion activators

[0105] The term "non-coordinating anion" (NCA) refers to an anion that does not coordinate to the cation or only weakly coordinates to the cation, thus remaining sufficiently labile to be replaced by a neutral Lewis base. "Compatible" non-coordinating anions are those that do not degrade to neutral when the initially formed complex decomposes. Further, the anion does not transfer anionic substituents or fragments to the cation such that it forms a neutral transition metal compound and a neutral by-product from the anion. Non-coordinating anions that can be used in accordance with the present invention are anions that are compatible, stabilize the transition metal cation at +1 in the sense of balancing its ionic charge, and still remain sufficiently labile to permit displacement during the polymerization process. Ionizing activators useful herein typically comprise NCAs, particularly compatible NCAs.

[0106] Use of neutral or ionic ionizing activators is within the scope of the present invention, such as tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate, triarylboron precursors such as trisperfluorophenylboron or trisperfluoronaphthylboron, polyhalogenated heteroborane anions (WO 98 / 43983), boric acid (US 5,942,459), or combinations thereof. Use of neutral or ionic activators alone or in combination with alumoxane or modified alumoxane activators is also within the scope of the present invention.

[0107] For a description of useful activators, see US 8,658,556 and US 6,211,105.

[0108] Preferred activators include N,N-dimethylanilinium tetrakis(perfluoronaphthyl)borate, N,N-dimethylanilinium tetrakis(perfluorobiphenyl)borate, N,N-dimethylanilinium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, N,N-dimethylanilinium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, trityl tetrakis(perfluoronaphthyl)borate trityl tetrakis(perfluorobiphenyl)borate trityl tetrakis(3,5-bis(trifluoromethyl)phenyl)borate trityl tetrakis(perfluorophenyl)borate [Me3NH + [B(C6F5)4 - ; 1-(4-(tris(pentafluorophenyl)borato)-2,3,5,6-tetrafluorophenyl)pyrrolidine salt; and tetrakis(pentafluorophenyl)borate salts, 4-(tris(pentafluorophenyl)borato)-2,3,5,6-tetrafluoropyridine.

[0109] In a preferred embodiment, the activator comprises a triarylcarbon (such as trityl tetraphenylborate trityl tetrakis(pentafluorophenyl)borate Triphenylcarbenium tetrakis(2,3,4,6-tetrafluorophenyl)borate Triphenylcarbenium tetrakis(perfluoronaphthyl)borate Triphenylcarbenium tetrakis(perfluorobiphenyl)borate Triphenylcarbenium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate )。

[0110] In another embodiment, the activator comprises one or more of the following: trialkylammonium tetrakis(pentafluorophenyl)borate, N,N-dialkylanilinium tetrakis(pentafluorophenyl)borate, N,N-dimethyl-(2,4,6-trimethylanilinium) tetrakis(pentafluorophenyl)borate, trialkylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate, N,N-dialkylanilinium tetrakis(2,3,4,6-tetrafluorophenyl)borate, trialkylammonium tetrakis(perfluoronaphthyl)borate, N,N-dialkylanilinium tetrakis(perfluoronaphthyl)borate, trialkylammonium tetrakis(perfluorobiphenyl)borate, N,N-dialkylanilinium tetrakis(perfluorobiphenyl)borate, trialkylammonium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, N,N-dialkylanilinium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, N,N-dialkyl-(2,4,6-trimethylanilinium) tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, di(isopropyl)ammonium tetrakis(pentafluorophenyl)borate, (wherein the alkyl group is methyl, ethyl, propyl, n-butyl, sec-butyl or tert-butyl).

[0111] Typical activator to catalyst ratios, e.g., for all NCA activators to catalyst, are molar ratios of about 1:1. Alternative preferred ranges include 0.1:1 - 100:1, or 0.5:1 - 200:1, or 1:1 - 500:1, or 1:1 - 1000:1. A particularly useful range is 0.5:1 - 10:1, preferably 1:1 - 5:1.

[0112] Support material

[0113] The catalyst composition may optionally contain at least one "carrier" or sometimes also referred to as a "support". The terms may be interchangeable unless otherwise distinguished. Suitable carriers include, but are not limited to, silica, alumina, silica - alumina, zirconia, titania, silica - alumina, ceria, magnesia, or combinations thereof. The catalyst may optionally contain a carrier or be disposed on at least one carrier. Suitable carriers include, but are not limited to, active and inactive materials, synthetic or naturally occurring zeolites, and inorganic materials such as clays and / or oxides such as silica, alumina, zirconia, titania, silica - alumina, ceria, magnesia, or combinations thereof. In particular, the carrier may be silica - alumina, alumina, and / or zeolite, especially alumina. Silica - alumina may be naturally occurring or in the form of a gel - like precipitate or gel comprising a mixture of silica and metal oxides.

[0114] In one class of embodiments, at least one carrier may comprise an organosilica material. The organosilica material carrier may be a polymer formed from at least one monomer. In certain embodiments, the organosilica material may be a polymer formed from a plurality of distinct monomers. Methods of preparing organosilica materials, materials, and characterization descriptions can be found, for example, in WO 2016 / 094770 and WO 2016 / 094774.

[0115] Scavengers, chain transfer agents, and / or co - activators

[0116] Scavengers, chain transfer agents, or co - activators may also be used. Alkylaluminum compounds that can be used as scavengers or co - activators include, for example, one or more of those represented by the formula AlR3, where each R is independently a C1 - C8 aliphatic group, preferably methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, or their isomers), especially trimethylaluminum, triethylaluminum, triisobutylaluminum, tri - n - hexylaluminum, tri - n - octylaluminum, or mixtures thereof.

[0117] Useful chain transfer agents that can also be used here are typically compounds represented by the formula AlR 20 3, ZnR 20 2 (where each R 20 is independently a C1 - C8 aliphatic group, preferably methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, or their isomers) or combinations thereof, such as diethylzinc, trimethylaluminum, triisobutylaluminum, trioctylaluminum, or combinations thereof.

[0118] Polymerization methods

[0119] In the embodiments herein, the present invention relates to a polymerization process in which a monomer (such as propylene and / or ethylene), and optionally, a comonomer are contacted with a catalyst system comprising at least one activator, at least one support and at least one catalyst, such as a metallocene compound, as described above. The support, catalyst compound and activator can be combined in any order and are typically combined prior to contact with the monomer.

[0120] Monomers useful herein include substituted or unsubstituted C2-C 40 α-olefins, preferably C2-C 20 α-olefins, preferably C2-C 12 α-olefins, preferably ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene and their isomers.

[0121] In one embodiment of the present invention, the monomer comprises propylene and an optional comonomer, the comonomer comprising one or more ethylene or C4-C 40 olefins, preferably C4-C 20 olefins, or preferably C6-C 12 olefins. The C4-C 40 olefin monomers can be linear, branched or cyclic. The C4-C 40 cyclic olefins can be strained or unstrained, monocyclic or polycyclic, and can optionally include heteroatoms and / or one or more functional groups.

[0122] In another embodiment of the present invention, the monomer comprises ethylene and an optional comonomer, the comonomer comprising one or more C3-C 40 olefins, preferably C4-C 20 olefins, or preferably C6-C 12 olefins. The C3-C 40 olefin monomers can be linear, branched or cyclic. The C3-C 40 cyclic olefins can be strained or unstrained, monocyclic or polycyclic, and can optionally include heteroatoms and / or one or more functional groups.

[0123] Exemplary C2-C 40Examples of the olefin monomer and optional comonomers include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, norbornene, norbornadiene, dicyclopentadiene, cyclopentene, cycloheptene, cyclooctene, cyclooctadiene, cyclododecene, 7-oxanorbornene, 7-oxanorbornadiene, their substituted derivatives and their isomers, preferably hexene, heptene, octene, nonene, decene, dodecene, cyclooctene, 1,5-cyclooctadiene, 1-hydroxy-4-cyclooctene, 1-acetoxy-4-cyclooctene, 5-methylcyclopentene, cyclopentene, dicyclopentadiene, norbornene, norbornadiene and their corresponding homologues and derivatives, preferably norbornene, norbornadiene and dicyclopentadiene.

[0124] In a preferred embodiment, one or more dienes are present in the polymers prepared herein at up to 10 wt%, preferably at 0.00001 - 1.0 wt%, preferably 0.002 - 0.5 wt%, even more preferably 0.003 - 0.2 wt%, based on the total weight of the composition. In some embodiments, 500 ppm or less of diene, preferably 400 ppm or less, preferably 300 ppm or less of diene is added to the polymerization. In other embodiments, at least 50 ppm of diene, or 100 ppm or more, or 150 ppm or more is added to the polymerization.

[0125] Diene monomers useful in the present invention include any hydrocarbon structure having at least two unsaturated bonds, preferably C4-C 30, wherein at least two of the unsaturated bonds are readily introduced into the polymer by a stereospecific or non-stereospecific catalyst(s). Further preferably, the diene monomer is selected from α,ω-diene monomers (i.e., divinyl monomers). More preferably, the diolefin monomer is a linear divinyl monomer, and very preferably those containing 4 to 30 carbon atoms. Examples of preferred dienes include butadiene, pentadiene, hexadiene, heptadiene, octadiene, nonadiene, decadiene, undecadiene, dodecadiene, tridecadiene, tetradecadiene, pentadecadiene, hexadecadiene, heptadecadiene, octadecadiene, nonadecadiene, eicosadiene, heneicosadiene, docosadiene, tricosadiene, tetracosadiene, pentacosadiene, hexacosadiene, heptacosadiene, octacosadiene, nonacosadiene, triacontadiene, and particularly preferred dienes include 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, 1,11-dodecadiene, 1,12-tridecadiene, 1,13-tetradecadiene, and low molecular weight polybutadiene (Mw less than 1000 g / mol). Preferred cyclic dienes include cyclopentadiene, vinylnorbornene, norbornadiene, ethylidene norbornene, divinylbenzene, dicyclopentadiene, or diolefins with higher rings with or without substituents at various ring positions.

[0126] The polymerization process according to the disclosure of the present application can be carried out in any manner known in the art. Any suspension, slurry, high-pressure tubular or autoclave process or gas-phase polymerization process known in the art can be used under polymerizable conditions. These processes can be operated in batch, semi-batch or continuous mode. Heterogeneous polymerization processes (such as gas-phase and slurry-phase processes) are useful. A multiphase process is defined as a process in which the catalyst system is insoluble in the reaction medium. Alternatively, in other embodiments, the polymerization process is heterogeneous.

[0127] A homogeneous polymerization process is defined as a process in which at least 90 wt% of the preferred product is soluble in the reaction medium. Alternatively, a polymerization process that is not a bulk process is particularly preferred. In one class of embodiments, a bulk process is defined as a process in which the monomer concentration in all feeds to the reactor is preferably 70 vol% or higher. Alternatively, no solvent or diluent is present in or added to the reaction medium (except for a small amount used as a carrier for the catalyst system or other additives, or an amount that is normally co-existent with the monomer, such as propane in propylene). In another embodiment, the process is a slurry process. As used herein, the term "slurry polymerization process" refers to a polymerization process in which a supported catalyst is used and the monomer is polymerized on the supported catalyst particles. At least 95 wt% of the polymer product derived from the supported catalyst is in the form of solid particles (insoluble in the diluent) in granular form.

[0128] Suitable diluents / solvents for the polymerization include non-coordinating inert liquids. Examples include straight-chain and branched hydrocarbons such as isobutane, butane, pentane, isopentane, hexane, isohexane, heptane, octane, dodecane, and mixtures thereof; cyclic and cycloaliphatic hydrocarbons such as cyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane, and mixtures thereof such as those commercially available (Isopar TM ); perhalogenated hydrocarbons such as perfluorinated C 4-10 alkanes, chlorobenzene, and aromatic and alkyl-substituted aromatic compounds such as benzene, toluene, mesitylene, and xylene. Suitable solvents also include liquid olefins that can act as monomers or comonomers, including ethylene, propylene, 1-butene, 1-hexene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-octene, 1-decene, and mixtures thereof. In a preferred embodiment, aliphatic hydrocarbon solvents are used as solvents, such as isobutane, butane, pentane, isopentane, hexane, isohexane, heptane, octane, dodecane, and mixtures thereof; cyclic and cycloaliphatic hydrocarbons, such as cyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane, and mixtures thereof. In another embodiment, the solvent is a non-aromatic solvent, preferably with aromatic compounds present in the solvent at less than 1 wt%, preferably less than 0.5 wt%, preferably less than 0 wt%, based on the weight of the solvent.

[0129] In a preferred embodiment, the feed concentration of monomers and comonomers for the polymerization is 60 vol% solvent or less, preferably 40 vol% or less, preferably 20 vol% or less, based on the total volume of the feed stream. Preferably, the polymerization is run in a bulk process.

[0130] The preferred polymerization can be run at any temperature and / or pressure suitable for obtaining the desired ethylene polymer and as described above. In some embodiments, typical pressures include from about 0.35 MPa to about 10 MPa, preferably from about 0.45 MPa to about 6 MPa, or preferably from about 0.5 MPa to about 4 MPa.

[0131] In some embodiments, hydrogen is present in the polymerization reactor at a partial pressure of 0.001 - 50 psig (0.007 - 345 kPa), preferably 0.01 - 25 psig (0.07 - 172 kPa), more preferably 0.1 - 10 psig (0.7 - 70 kPa).

[0132] In one class of embodiments, the polymerization is carried out in the gas phase, preferably, in a fluidized bed gas phase process. Generally, in a fluidized bed gas phase process for preparing polymers, a gaseous stream containing one or more monomers is continuously circulated through a fluidized bed in the presence of a catalyst under reactive conditions. The gaseous stream is withdrawn from the fluidized bed and recycled back to the reactor. At the same time, the polymer product is withdrawn from the reactor and fresh monomers are added to replace the polymerized monomers. See, for example, U.S. Patent Nos. 4,543,399; 4,588,790; 5,028,670; 5,317,036; 5,352,749; 5,405,922; 5,436,304; 5,453,471; 5,462,999; 5,616,661; and 5,668,228; which are all incorporated herein by reference in their entirety.

[0133] In another embodiment of the present invention, the polymerization is carried out in the slurry phase. Slurry polymerization processes generally operate in the range of 1 to about 50 atmospheres (15 psi - 735 psi, 103 kPa - 5068 kPa) or even greater and the above temperatures. In slurry polymerization, a suspension of solid, particulate polymer is formed in a liquid polymerization diluent medium in which monomers and comonomers are added along with the catalyst. The suspension including the diluent is intermittently or continuously removed from the reactor, in which the volatile components are separated from the polymer and recycled (optionally, after distillation) to the reactor. The liquid diluent for the polymerization medium is typically an alkane having 3 to 7 carbon atoms, preferably a branched alkane. The medium employed should be liquid and relatively inert under the polymerization conditions. When using a propane medium, the process is typically operated above the critical temperature and pressure of the reaction diluent. Usually, hexane or isobutane media are used.

[0134] In one embodiment, a preferred polymerization technique useful in the present invention is called particle forming polymerization, or the slurry process, in which the temperature is maintained below the temperature at which the polymer goes into solution. Such techniques are well known in the art and are described, for example, in U.S. Patent No. 3,248,179. The preferred temperature in the particle forming process is in the range of about 85°C to about 110°C. Two preferred polymerization methods of the slurry process are those employing a loop reactor and those using multiple stirred reactors in series, parallel, or combinations thereof. Non-limiting examples of slurry processes include continuous loop or stirred tank processes. In addition, other examples of slurry processes are described in U.S. Patent No. 4,613,484, which is incorporated herein by reference in its entirety.

[0135] In another embodiment, the slurry process is carried out continuously in a loop reactor. The catalyst (as a slurry in isobutane or as a dry free-flowing powder) is injected periodically into the reactor loop which is itself filled with a circulating slurry of growing polymer particles in a diluent of isobutane containing monomer and comonomer. Optionally, hydrogen can be added as a molecular weight control. In one embodiment, 500 ppm or less of hydrogen is added, or 400 ppm or less or 300 ppm or less. In other embodiments, at least 50 ppm of hydrogen is added, or 100 ppm or more, or 150 ppm or more.

[0136] The heat of reaction is removed through the loop reactor wall since most of the reactor is in the form of a double-jacketed tube. The slurry is allowed to leave the reactor periodically or continuously and is passed in sequence to a hot low-pressure flash vessel, a rotary dryer, and a nitrogen purge column to remove the isobutane diluent and all unreacted monomer and comonomer. The resulting hydrocarbon-free powder is then compounded for use in various applications.

[0137] In a preferred embodiment, the catalyst system used in the polymerization comprises at most one catalyst compound. The "reaction zone", also referred to as the "polymerization zone", is the vessel in which the polymerization takes place, such as a batch reactor. When multiple reactors are used in a series or parallel configuration, each reactor is considered a separate polymerization zone. For multi-stage polymerization in both batch and continuous reactors, each polymerization stage is considered a separate polymerization zone. In a preferred embodiment, the polymerization takes place in one reaction zone.

[0138] Useful reactor types and / or processes for preparing polyolefin polymers include, but are not limited to, UNIPOL TM gas phase reactors (available from Univation Technologies); INEOS TM gas phase reactors and processes; continuous flow stirred tank (CSTR) reactors (solution and slurry); plug flow tubular reactors (solution and slurry); slurry: (e.g., slurry loop (single or double loop)) (available from Chevron Phillips Chemical Company) and (series reactors) (available from Mitsui Chemicals)); BORSTAR TM processes and reactors (slurry combined with gas phase); and multi-zone circulation reactors (MZCR), such as SPHERIZONE available from LyondellBasell TM reactors and processes.

[0139] In several embodiments, the catalyst activity of the polymerization reaction is at least 4,250 g / g*catalyst or greater, at least 4,750 g / g*catalyst or greater, at least 5,000 g / g*catalyst or greater, at least 6,250 g / g*catalyst or greater, at least 8,500 g / g*catalyst or greater, at least 9,000 g / g*catalyst or greater, at least 9,500 g / g*catalyst or greater, or at least 9,700 g / g*catalyst or greater.

[0140] Product

[0141] In one embodiment, the method described herein prepares metallocene-catalyzed polyethylene, and the composition includes one, two, three, four or more C2-C 40 olefin monomers, e.g., C2-C 20 homopolymers and copolymers of α-olefin monomers.

[0142] For example, metallocene-catalyzed polyethylene includes C2-C 40 olefins and copolymers of one, two or three or more different C2-C 40 olefins (wherein the C2-C 40 olefins are preferably C3-C 20 olefins, preferably C3-C 12 α-olefins, preferably propylene, butene, hexene, octene, decene, dodecene, preferably propylene, butene, hexene, octene or mixtures thereof).

[0143] Metallocene-catalyzed polyethylene can contain at least 65 wt%, 99.0 - about 80.0 wt%, 99.0 - 85.0 wt%, 99.0 - 87.5 wt%, 99.0 - 90.0 wt%, 99.0 - 92.5 wt%, 99.0 - 95.0 wt%, or 99.0 - 97.0 wt% of polymer units derived from ethylene and 0.5 - 20 wt%, about 1.0 - about 20.0 wt%, 1.0 - 15.0 wt%, 0.5 - 12.5 wt%, 1.0 - 10.0 wt%, 1.0 - 7.5 wt%, 1.0 - 5.0 wt%, or 1.0 - 3.0 wt% of polymer units derived from one or more C3-C 20 α-olefin comonomers, preferably C3-C 12 α-olefins, preferably C3-C 10 α-olefins, more preferably C4-C8 α-olefins, such as polymer units of hexene and octene. The α-olefin comonomer can be linear or branched, and if desired, two or more comonomers can be used.

[0144] Examples of suitable comonomers include propylene, butene, 1-pentene; 1-pentene having one or more methyl, ethyl or propyl substituents; 1-hexene; 1-hexene having one or more methyl, ethyl or propyl substituents; 1-heptene; 1-heptene having one or more methyl, ethyl or propyl substituents; 1-octene; 1-octene having one or more methyl, ethyl or propyl substituents; 1-nonene; 1-nonene having one or more methyl, ethyl or propyl substituents; 1-decene substituted with ethyl, methyl or dimethyl; 1-dodecene and styrene. Particularly suitable comonomers include 1-butene, 1-hexene and 1-octene, 1-hexene and mixtures thereof.

[0145] Metallocene-catalyzed polyethylene can have a melt index (MI) of ≥ about 0.10 g / 10 min, 0.1 g / 10 min - 30 g / 10 min, 0.1 g / 10 min - 6 g / 10 min according to the following test methods, or for example, a melt index I of ≥ about 0.15 g / 10 min, ≥ about 0.18 g / 10 min, ≥ about 0.20 g / 10 min, ≥ about 0.22 g / 10 min, ≥ about 0.25 g / 10 min, ≥ about 0.28 g / 10 min, or ≥ about 0.30 g / 10 min 2.16 and in addition ≤ about 3.00 g / 10 min, for example, ≤ about 2.00 g / 10 min, ≤ about 1.00 g / 10 min, ≤ about 0.70 g / 10 min, ≤ about 0.50 g / 10 min, ≤ about 0.40 g / 10 min or ≤ about 0.30 g / 10 min of melt index (I 2.16 ). The ranges specifically disclosed include, but are not limited to, the ranges formed by combinations of any of the values listed above, such as about 0.10 - about 0.30, about 0.15 - about 0.25, about 0.18 - about 0.22 g / 10 min, etc.

[0146] Metallocene-catalyzed polyethylene can have a high load melt index (HLMI) of 1 - 60 g / 10 min, 5 - 40 g / 10 min, 15 - 40 g / 10 min, or 18 - 39.5 g / 10 min according to the following test methods (I 21.6 ).

[0147] Metallocene-catalyzed polyethylene can have a melt index ratio (MIR) of 10 - 90, 20 - 45, 25 - 60, alternatively, 30 - 55, alternatively, 35 - 50, alternatively 40 - 46. MIR is defined as I 21.6 / I 2.16 .

[0148] Metallocene-catalyzed polyethylene can have 0.900 g / cm3 -0.930 g / cm 3 density; or having a density of about 0.890 g / cm 3 , about 0.918 g / cm 3 , ≥ about 0.920 g / cm 3 , for example, ≥ about 0.922 g / cm 3 , ≥ about 0.928 g / cm 3 , ≥ about 0.930 g / cm 3 , ≥ about 0.932 g / cm 3 density. In addition, the metallocene-catalyzed polyethylene can have ≤ about 0.945 g / cm 3 , for example ≤ about 0.940 g / cm 3 , ≤ about 0.937 g / cm 3 , ≤ about 0.935 g / cm 3 , ≤ about 0.933 g / cm 3 or ≤ about 0.930 g / cm 3 density. The specifically disclosed ranges include, but are not limited to, ranges formed by any combination of the values listed above, for example, about 0.920 - about 0.945 g / cm 3 , 0.920 - 0.930 g / cm 3 , 0.925 - 0.935 g / cm 3 , 0.920 - 0.940 g / cm 3 etc. The density is determined according to the following test method.

[0149] The metallocene-catalyzed polyethylene can have a molecular weight distribution (MWD, defined as Mw / Mn) of about 2 - about 12, about 5 - about 10.5 or 11, about 2.5 - about 5.5, preferably 4.0 - 5.0 and about 4.4 - 5.0.

[0150] In one class of embodiments, the metallocene-catalyzed polyethylene comprises at least 65 wt% of ethylene-derived units and 0 - 35 wt% of C3 - C 12 olefin comonomer-derived units, based on the total weight of the metallocene-catalyzed polyethylene; wherein the metallocene-catalyzed polyethylene has:

[0151] a) An RCI,m of 100 kg / mol or greater, alternatively 110 kg / mol or greater, alternatively 125 kg / mol or greater, alternatively 150 kg / mol or greater, alternatively 170 kg / mol or greater, alternatively 185 kg / mol or greater; where RCI,m represents the reversed-co-monomer index, and its definition and test method can be found in the disclosure of the prior art document US20190119417A1.

[0152] And one or both of the following:

[0153] b) A Tw of -16 to -38 °C 1- The Tw2 value, alternatively the Tw1 - Tw2 value of -23 to -36 °C, alternatively the Tw1 - Tw2 value of -23 to -33 °C; and

[0154] c) An Mw1 / Mw2 value of at least 0.9, alternatively 0.9 - 4, alternatively 1.25 - 4;

[0155] And one or more of the following:

[0156] d) A density of 0.890 g / cm 3 - 0.940 g / cm 3 ;

[0157] e) A melt index (MI) of 0.1 g / 10min - 30 g / 10min, alternatively 0.1 g / 10min - 6 g / 10min;

[0158] f) A melt index ratio (I 21 / I2) of 10 - 90;

[0159] g) An Mw / Mn of 2 - 12;

[0160] h) An Mz / Mw of 2.5 - 5.0;

[0161] i) An Mz / Mn of 10 - 40; and

[0162] j) A g' of 0.900 or greater, alternatively 0.930 or greater, alternatively 0.940 or greater, alternatively 0.994 or greater (vis) ;

[0163] The measurement of the parameters described in this application can be specifically referred to the disclosure of US20190119417A1. In particular, Tw1, Tw2, Mw1, and Mw2 are measured by CFC. In any of the embodiments described herein, the metallocene-catalyzed polyethylene can be a multimodal metallocene-catalyzed polyethylene, such as a bimodal metallocene-catalyzed polyethylene. As used herein, "multimodal" means that there are at least two resolvable peaks in the molecular weight distribution curve of the metallocene-catalyzed polyethylene (determined using gel permeation chromatography (GPC) or other approved analytical techniques). For example, if there are two resolvable peaks in the molecular weight distribution curve, such a composition can be referred to as a bimodal composition. Typically, if there is only one peak (e.g., unimodal), there is no obvious valley between the peaks, neither of the peaks is considered a resolvable peak, or the two peaks are not considered resolvable peaks, such a composition can be referred to as a non-bimodal composition. For example, in U.S. Patent Nos. 8,846,841 and 8,691,715, Figures 1-5 show representative bimodal molecular weight distribution curves. In these figures, there is a valley between the peaks, and the peaks can be independent or deconvoluted. Generally, the bimodal molecular weight distribution is characterized as having a distinguishable high molecular weight component (or distribution) and a distinguishable low molecular weight component (or distribution). In contrast, in U.S. Patent Nos. 8,846,841 and 8,691,715, Figure 6-1 1 shows representative non-bimodal molecular weight distribution curves. They include unimodal molecular weight distributions and distribution curves with two peaks that cannot be easily distinguished, separated, or deconvoluted.

[0164] In any of the embodiments described herein, the metallocene-catalyzed polyethylene can have more than 0.2 total internal unsaturation moieties per 1000 carbon atoms, alternatively, more than 0.3 total internal unsaturation moieties per 1000 carbon atoms, alternatively, more than 0.32 total internal unsaturation moieties per 1000 carbon atoms, alternatively, more than 0.38 total internal unsaturation moieties per 1000 carbon atoms, alternatively, more than 0.4 total internal unsaturation moieties per 1000 carbon atoms of internal unsaturation moieties measured by 1 1H NMR (see Test Methods below).

[0165] Blend

[0166] As used herein, "blend" can refer to a dry or extruder blend of two or more different polymers, and an in-reactor blend, including blends produced by using a multiple or mixed catalyst system in a single reactor zone, and blends produced by using one or more catalysts in one or more reactors under the same or different conditions (e.g., blends produced in series reactors (same or different), where each reactor operates under different conditions and / or with different catalysts). The blend may also contain at least one additive component (C) to (M): (C) lubricant; (D) polymer processing aid; (E) antioxidant; (F) metal deactivator; (G) ultraviolet degradation inhibitor as a UV stabilizer; (H) slip agent; (I) hindered amine stabilizer; (J) anti-caking agent; (K) colorant; (L) anti-fogging agent; and (M) antistatic agent; provided that the total amount of the at least one additive is >0 to 5 wt% of the polyolefin composition.

[0167] In a preferred embodiment of the present application, the polyethylene blend comprises 50 wt% to 75 wt% metallocene-catalyzed polyethylene and 50 wt% to 25 wt% Ziegler-Natta catalyst-catalyzed linear low density polyethylene, based on the total weight of the polyethylene blend, wherein the melt index (MI) of the metallocene-catalyzed polyethylene is 0.1 - 6 g / 10 min, preferably 2 g / 10 min, the density is 0.900 - 0.930 g / cm 3 , preferably 0.925 g / cm 3 , the molecular weight distribution (MWD) is 5 - 10.5, preferably 5.35, and the composition distribution breadth index is 10 to 50, preferably 39.53, wherein the melt index (MI) of the Ziegler-Natta catalyst-catalyzed linear low density polyethylene is 0.5 - 2.5 g / 10 min, preferably 2 g / 10 min and the density is 0.905 - 0.930 g / cm 3 , preferably 0.918 g / cm 3 .

[0168] End use

[0169] Any of the above polymers and compositions in combination with non-essential additives (see, e.g., U.S. Patent Application Publication No. 2016 / 0060430, paragraphs

[0082] -

[0093] ) can be used in a variety of end-use applications. These end-uses can be prepared by methods known in the art. End-uses include polymer products and products with specific end-uses. Exemplary end-uses can include, but are not limited to, films, film-based products, diaper backsheets, industrial filter cloths, wire and cable coating compositions, articles formed by molding techniques such as injection molding or blow molding, extrusion coating, foaming, casting, and combinations thereof. End-uses also include products made from films, such as bags, packaging, and personal care films, pouches, medical products such as medical films and intravenous (IV) bags.

[0170] Film

[0171] Films include single-layer or multi-layer films. Films include those film structures and film applications known to those skilled in the art. Specific end-use films include, for example, blown films, cast films, stretched films, stretch / cast films, stretch-adhesive films, stretch hand-rolled films, mechanically stretched wraps, shrink films, shrink-wrap films, greenhouse films, laminates, and laminated films. Exemplary films can be prepared by any conventional method known to those skilled in the art, such as by techniques used to prepare blown, extruded, and / or cast stretch and / or shrink films (including shrink-on-shrink applications).

[0172] In one embodiment, multi-layer or multiple-layer films can be formed by methods well known in the art. The total thickness of the multi-layer film can vary based on the desired application. A total film thickness of about 5-100 μm, more typically about 10-50 μm, is suitable for most applications. Those skilled in the art will appreciate that the thickness of the individual layers of the multi-layer film can be adjusted according to the desired end-use properties, the resin or copolymer used, the equipment production capacity, and other factors. The materials forming each layer can be co-extruded through a co-extrusion feed block and die assembly to produce a film having two or more layers that are adhered together but have different compositions. Co-extrusion can be suitably used in both cast film or blown film processes. Exemplary multi-layer films have at least two, at least three, or at least four layers. In one embodiment, the multi-layer film consists of five to ten layers.

[0173] For the sake of facilitating the discussion of different membrane structures, the following symbols are used in this article. Each layer of the membrane is denoted as "A" or "B". When the cast film includes more than one A layer or more than one B layer, one or more prime symbols (', ", '", etc.) are appended to the A or B symbol to denote the same type of layer, which may be the same or may be different in one or more properties such as chemical composition, density, melt index, thickness, etc. Finally, the symbols of adjacent layers are separated by a slash ( / ). Using this notation, a three-layer film with an inner layer disposed between two outer layers will be denoted as A / B / A'. Similarly, a five-layer film with alternating layers will be denoted as A / B / A' / B' / A". Unless otherwise specified, for the purposes described herein, the left-to-right or right-to-left order of the layers is immaterial, and the order of the prime symbols is also immaterial; for example, an A / B film is equivalent to a B / A film, and an A / A' / B / A'' film is equivalent to an A / B / A' / A'' film. The relative thickness of each membrane layer is represented similarly, where the thickness (dimensionless) of each layer relative to the total membrane thickness of 100 is represented numerically and separated by a slash; for example, the relative thickness of an A / B / A' film with A and A' layers (each 10 μm) and a B layer of 30 μm is represented as 20 / 60 / 20.

[0174] The thickness of each layer of the membrane, and of the entire membrane, is not particularly limited but is determined according to the desired properties of the membrane. Typical membrane layers have a thickness of about 1 - about 1000 μm, more usually about 5 - about 100 μm, and typical membranes have a total thickness of about 10 - about 100 μm.

[0175] In some embodiments, and using the above nomenclature, the present invention provides multilayer films having any of the following exemplary structures: (a) bilayer films, such as A / B and B / B'; (b) trilayer films, such as A / B / A', A / A' / B, B / A / B' and B / B' / B"; (c) four-layer films, such as A / A' / A" / B, A / A' / B / A", A / A' / B / B', A / B / A' / B', A / B / B' / A', B / A / A' / B', A / B / B' / B", B / A / B' / B" and B / B' / B" / B'"; (d) five-layer films, such as A / A' / A" / A'" / B, A / A' / A" / B / A'", A / A' / B / A" / A'", A / A' / A" / B / B', A / A' / B / A" / B', A / A' / B / B' / A", A / B / A' / B' / A", A / B / A' / A" / B, B / A / A' / A" / B', A / A' / B / B' / B", A / B / A' / B' / B", A / B / B' / B" / A', B / A / A' / B' / B", B / A / B' / A' / B", B / A / B' / B" / A', A / B / B' / B" / B'", B / A / B' / B" / B'", B / B' / A / B" / B'" and B / B' / B" / B'" / B""; and similar structures for films having 6, 7, 8, 9, 24, 48, 64, 100 or any other number of layers. It is understood that films having even more layers can also be used.

[0176] In any of the above embodiments, one or more A layers can be replaced with a substrate layer, such as glass, plastic, paper, metal, etc., or the entire film can be coated or laminated onto a substrate. Thus, while the discussion here focuses on multilayer films, the films can also be used as coatings for substrates such as paper, metal, glass, plastic and other materials capable of accepting coatings.

[0177] The film can be further embossed, or produced, or processed according to other known film methods. The film can be customized for a specific application by adjusting the thickness, materials and the order of the individual layers, as well as additives in each layer or modifiers applied to each layer.

[0178] Stretch film

[0179] The above polymers and compositions can be used to prepare stretch films. Stretch films are widely used in various bundling and packaging applications. The term "stretch film" refers to a film capable of being stretched and applying a bundling force and includes films that are stretched at the time of application and "pre-stretched" films, i.e., films provided in a pre-stretched form for use without additional stretching. Stretch films can be single-layer or multilayer films and can include conventional additives, such as adhesion enhancing additives such as tackifiers, and non-adhesive or slip additives to customize the slip / adhesion properties of the film.

[0180] Shrink film

[0181] The above polymers and compositions can be used to prepare shrink films. Shrink films (also known as heat - shrinkable films) are widely used in industrial and retail bundling and packaging applications. Such films are capable of shrinking upon application of heat to relieve the stress imparted to the film during or after extrusion. The shrinkage can occur in one direction or simultaneously in the longitudinal and transverse directions. Conventional shrink films are described, for example, in WO 2004 / 022646.

[0182] Industrial shrink films are often used to bundle products on pallets. Typical industrial shrink films are formed to a thickness of about 80 - 200 μm in a single - film - bubble blow - up extrusion process and provide shrinkage in two directions, typically with a longitudinal (MD) to transverse (TD) ratio of about 60:40. Retail films are often used to package and / or bundle products for consumer use, such as for supermarket goods. Such films are typically formed to a thickness of about 35 - 80 μm in a single - film - bubble blow - up extrusion process and have a typical MD:TD shrink ratio of about 80:20.

[0183] The film can be used in “shrink - on - shrink” applications. As used herein, “shrink - on - shrink” refers to a method of applying an outer shrink - wrap layer around one or more articles that have already been individually shrink - wrapped (here, the “inner layer” that is wrapped). In these methods, it is desirable for the film used to wrap the individual articles to have a higher melt (or shrink) point than the film used for the outer layer. When using such a configuration, the desired level of shrinkage can be achieved in the outer layer while preventing the inner layer from melting, further shrinking, or otherwise distorting during the shrinkage of the outer layer. Some of the films described herein have been observed to have a sharp shrinkage point when subjected to heat from a heat gun with high heat - setting, indicating that they may be particularly suitable as the inner layer in various shrink - on - shrink applications.

[0184] Greenhouse film

[0185] The polymers and compositions as described above can be used to prepare stretch for the preparation of greenhouse films. Greenhouse films are generally insulating films that retain different amounts of heat depending on the climate requirements. Films with less insulation requirement are used in warmer regions or for spring - time applications. Films with a greater insulation requirement are used in winter months and in colder regions.

[0186] Bag

[0187] Bags include those bag structures and bag applications known to those skilled in the art. Exemplary bags include shipping bags, grocery bags and liners, industrial liners, production bags, and heavy - duty bags.

[0188] Packaging

[0189] The packaging includes those packaging structures and packaging applications known to those skilled in the art. Exemplary packaging includes flexible packaging, food packaging, such as fresh cut produce packaging, frozen food packaging, bundling, packaging, and unitizing various products. Applications of such packaging include various foods, carpet rolls, liquid containers, and various similar merchandise that are containerized and / or palletized for shipping, storage, and / or display.

[0190] Blown articles

[0191] The above polymers and compositions can also be used in blow molding methods and applications. Such methods are well known in the art and include methods of blowing a hot, hollow thermoplastic preform (or parison) inside a closed mold. In this way, the shape of the parison conforms to the shape of the mold cavity, enabling the preparation of a wide variety of hollow parts and containers.

[0192] In a typical blow molding method, a parison is formed between the half - molds and the mold is closed around the parison. One end of the parison is sealed and the parison is closed around a core mold at the other end. Then air is blown through the core mold (or through a needle) to blow up the parison inside the mold. Then the mold is cooled and the part formed inside the mold is solidified. Finally, the mold is opened and the molded part is ejected. The method is applicable to any design having a hollow shape, including but not limited to bottles, jars, toys, consumer goods, automotive parts, and other hollow containers and / or parts.

[0193] Blow molding methods can include extrusion and / or injection blow molding. Extrusion blow molding is typically suitable for forming articles having a relatively heavy weight, such as greater than about 12 ounces, including but not limited to food, clothing, or waste containers. Injection blow molding is typically used to obtain precise and uniform wall thicknesses, high - quality neck finishes, and to process polymers that cannot be extruded. Typical injection blow molding applications include, but are not limited to, pharmaceuticals, cosmetics, and single - serve containers, typically weighing less than 12 ounces.

[0194] Injection - molded articles

[0195] The above polymers and compositions can also be used in injection molding applications. Injection molding is a method commonly known in the art and is a method that typically occurs in a cyclic manner. The cycle time is typically 10 - 100 seconds and is controlled by the cooling time of the polymer or polymer blend used. In a typical injection molding cycle, polymer pellets or powder are fed from a hopper and melted in a reciprocating screw-type injection molding machine. The screw in the machine rotates forward, fills the mold with the melt, and holds the melt under high pressure. As the melt cools and shrinks in the mold, the machine adds more melt to the mold to compensate. Once the mold is filled, it is separated from the injection unit and the melt cools and solidifies. The solidified part is ejected from the mold, and then the mold is closed to prepare for the next injection of melt from the injection unit. The injection molding method provides high productivity, good reproducibility, minimized scrap loss, and little to no need for part trimming. Injection molding is suitable for a wide variety of applications, including containers, consumer goods, automotive components, electronic parts, and many other solid products.

[0196] Extrusion coating

[0197] The above polymers and compositions can be used in extrusion coating methods and applications. Extrusion coating is a plastics manufacturing method in which a molten polymer is extruded and applied to a non-plastic carrier or substrate, such as paper or aluminum, in order to obtain a multi-material composite structure. Such a composite structure typically combines the toughness, sealing, and impedance properties of the polymer formulation with the barrier, stiffness, or aesthetic properties of the non-polymer substrate. In this method, the substrate is typically fed into the molten polymer from a roll as the polymer is extruded from a slot die, which is similar to the cast film method. The resulting structure is cooled, typically with a cooling roll, and wound into a finished roll. Extrusion coated materials are typically used in food and non-food packaging, pharmaceutical packaging, and in the manufacture of goods for construction (insulating elements) and the photographic industry (paper).

[0198] Foamed products

[0199] The above polymers and compositions can be used in foaming applications. In the extrusion foaming method, a blowing agent, such as carbon dioxide, nitrogen, or a compound that decomposes to form carbon dioxide or nitrogen, is injected into the polymer melt using a metering unit. The blowing agent is then dissolved in the polymer in the extruder, and the pressure is maintained throughout the period in the extruder. A rapid pressure drop rate upon leaving the extruder produces a foamed polymer with a homogeneous pore structure. The resulting foamed products are typically lightweight, strong, and suitable for a wide range of applications in industries such as packaging, automotive, aerospace, transportation, electrical and electronic instruments, and manufacturing.

[0200] Wire and cable applications

[0201] Also provided are electrical articles and devices including one or more layers formed from or comprising the above polymers and compositions. Such devices include, for example, electronic instrument cables, computers and computer-related equipment, marine cables, power cables, communication cables or data transmission cables, and hybrid power / communication cables.

[0202] The electrical articles described herein can be formed by methods well known in the art, such as by one or more extrusion coating steps in a reactor / extruder equipped with a cable die. Such cable extrusion equipment and methods are well known. In a typical extrusion method, via a hot extrusion die, typically a right-angle die, a non-necessarily heated conductive core is pulled, and a layer of the molten polymer composition is applied. Multiple layers can be applied by consecutive extrusion steps, where additional layers are added, or, with a suitable type of die, multiple layers can be added simultaneously. The cable can be placed in a wet curing environment or allowed to cure under ambient conditions.

[0203] Involved in the test method 1 1H NMR, TREF method, GPC method, Cross-Fractionation Chromatograph (CFC) are well known in the art and can be referred to, for example, the disclosure of the prior art document US20190119417A1.

[0204] Additional test methods include the following.

[0205]

[0206] Examples

[0207] It should be understood that although the present invention has been described in connection with specific embodiments of the present invention, the above description is intended to be illustrative and not restrictive of the scope of the present invention. Other aspects, advantages, and improvements will be apparent to those skilled in the art to which the present invention pertains.

[0208] Therefore, the following examples are given to provide a complete disclosure and description to those skilled in the art and are not intended to limit what the inventors regard as their invention.

[0209] Components used in the examples:

[0210] LL7042, a Ziegler-Natta catalyst-catalyzed linear low-density polyethylene, having a melt index (MI) of 2 g / 10 min and a density of 0.918 g / cm 3 , from Sinopec LLDPE DFDA7042.

[0211] ExceedTM S9333, metallocene-catalyzed polyethylene, with a melt index (MI) of 2 g / 10 min, a density of 0.925 g / cm 3 , a molecular weight distribution (MWD) of 5.35, and a compositional distribution breadth index of 39.53, from ExxonMobil.

[0212] The polymers used in the examples were first extruded and pelletized at 195 °C using a TSE-40 without adding any additives to obtain pellets. Then, the pellets obtained above were used for laboratory capillary rheometer (LCR) testing at 190 °C. Such an operation process simulates a two-step extrusion process. All the following are mass fractions.

[0213] Example 1

[0214] 100% LL7042 was subjected to a two-step extrusion process and its surface quality was evaluated, as Figure 1 shown.

[0215] Example 2

[0216] A blend of 75% LL7042 and 25% S9333 was subjected to a two-step extrusion process and its surface quality was evaluated, as Figure 2 shown.

[0217] Example 3

[0218] A blend of 50% LL7042 and 50% S9333 was subjected to a two-step extrusion process and its surface quality was evaluated, as Figure 3 shown.

[0219] Example 4

[0220] A blend of 25% LL7042 and 75% S9333 was subjected to a two-step extrusion process and its surface quality was evaluated, as Figure 4 shown.

[0221] Example 5

[0222] 100% Exceed TM S9333 was subjected to a two-step extrusion process and its surface quality was evaluated, as Figure 5 shown.

[0223] In order to meet the requirements for evaluating the surface quality of the blends, especially the surface smoothness as described above, the applicant has developed a test method by using image analysis. This test method is called surface roughness test and the process is as follows.

[0224] 1. Use the image analysis software ImageJ (NIH, Bethesda, MD, USA; https: / / imagej.nih.gov / ij / , version 4.53e) to measure the gray values (yellow) along the middle line of the sample. The specific operation method is as follows:

[0225] 1. Draw a reference line on the extruded spline with the line drawing tool. Note that this line should reflect the surface topography of the overall spline and should be kept on the same non-reflective side of the spline. If unavoidable, the length of the reference line can be appropriately shortened.

[0226] 2. In the software, use the Plot profile function to draw the distribution graph of the image along the reference line and read the gray data from it.

[0227] 3. Calculate the standard deviation of the gray data.

[0228] In addition, in the test, the shear rate of 800S-1 measured by LCR is uniformly used to compare the surface roughness. The test conditions of LCR are 195 degrees, L / D = 20 / 1, and the conclusions are as follows:

[0229]

[0230] 2. Calculate the standard deviation of the data. A smaller value indicates better smoothness.

[0231] Results and Discussion

[0232] The test data of the above examples are shown in Table 1 below.

[0233] Test Data

[0234]

[0235]

[0236] As shown in the above table, by gradually increasing the content of S9333 in the blend, the obtained blend roughness gray scale STD gradually decreases, showing good descent consistency. Specifically, when 25% of S9333 is added, the roughness gray scale of the blend decreases by (11.5 - 10.6) / 11.5 = 7.83% relative to pure LL7042; when 50% of S9333 is added, the roughness gray scale of the blend decreases by (11.5 - 5.5) / 11.5 = 52.17% relative to pure LL7042; when 75% of S9333 is added, the roughness gray scale of the blend decreases by (11.5 - 3.9) / 11.5 = 66.09% relative to pure LL7042. Additionally, when 50% of S9333 is added, the roughness gray scale of the blend decreases by (8.5 - 5.5) / 8.5 = 35.29% relative to pure S9333; when 75% of S9333 is added, the roughness gray scale of the blend decreases by (8.5 - 3.9) / 8.5 = 54.12% relative to pure S9333. The decrease in the blend roughness gray scale STD in the technical solution of this application is unpredictable.

[0237] Figure 1 shows the surface quality of pure LL7042. After the two-step extrusion process, the surface smoothness is poor, especially for high shear rate conditions (high line speed). When S9333 is added to the formulation, the applicant unexpectedly finds that the surface smoothness can be greatly improved.

[0238] Figure 2 , 3 and 4 show the surface quality at different S9333 addition levels. When the S9333 addition level is 25%, the LCR results clearly show that the improvement in surface quality begins to appear. From the results, it is found that a higher S9333 addition amount can result in a better improvement in surface quality. However, when using pure Exceed S9333 ( Figure 5 ), the obtained surface quality cannot be as good as that of the corresponding blend. Such results indicate that the combination of Ziegler-Natta catalyzed linear low density polyethylene and metallocene catalyzed polyethylene in the technical solution of this invention, such as S9333 + LL7042, is an ideal solution to achieve both surface quality and cost effectiveness. Although the surface smoothness is not as good as that of 100% S9333 after adding 25% of S9333, considering cost factors, blending 25% of S9333 is still an economical option to improve surface smoothness and maintain other mechanical properties.

[0239] Unless otherwise specified, the phrase "consisting essentially of" does not exclude the presence of other steps, elements or materials (whether or not specifically mentioned in the specification), provided that these steps, elements or materials do not affect the basic and novel characteristics of the invention, and further provided that they do not exclude impurities and variations normally associated with the elements and materials used.

[0240] For the sake of simplicity, only certain numerical ranges are explicitly disclosed herein. However, a lower limit may be combined with any other upper limit to define a range not explicitly recited, and similarly, a lower limit may be combined with any other lower limit to define a range not explicitly recited, and likewise, an upper limit may be combined with any other upper limit to define a range not explicitly recited. Additionally, every point or individual value between the endpoints is included within the range even if not explicitly recited. Thus, each point or individual value by itself may be used as a lower or upper limit in combination with other points or individual values or other lower or upper limits to define a range not explicitly recited.

[0241] All prior art documents are incorporated herein by reference, provided that their disclosures are not inconsistent with the description of the present invention. Additionally, all documents and references cited herein (including experimental procedures, publications, patents, journal articles, etc.) are incorporated herein by reference, provided that their disclosures are not inconsistent with the description of the present invention.

[0242] Although the invention has been described in terms of many embodiments and examples, those skilled in the art will understand that other embodiments can be designed without departing from the scope and spirit of the invention disclosed herein after reading the disclosure of this application.

Claims

1. Use of metallocene-catalyzed polyethylene for improving the surface roughness of a polyethylene blend comprising Ziegler-Natta-catalyzed linear low density polyethylene, wherein the melt index (I2) of the metallocene-catalyzed polyethylene is from 0.1 g / 10 min to 30 g / 10 min, the density is from 0.890 g / cm 3 to 0.940 g / cm 3 , the molecular weight distribution (MWD) is from 2 to 12, and the compositional distribution breadth index is from 10 to 50, wherein the content of the metallocene-catalyzed polyethylene is from 40 wt% to 80 wt%, based on the total weight of the polyethylene blend, and the roughness gray scale of the polyethylene blend is reduced by 35 - 70% relative to pure Ziegler-Natta-catalyzed linear low density polyethylene and / or by 12 - 58% relative to pure metallocene-catalyzed polyethylene.

2. Use according to claim 1, wherein the metallocene-catalyzed polyethylene comprises at least 65 wt% of units derived from ethylene and 0 - 35 wt% of units derived from C3-C 12 olefin comonomers, based on the total weight of the metallocene-catalyzed polyethylene; wherein the metallocene-catalyzed polyethylene further has: a) An RCI,m of 100 kg / mol or greater; and one or both of the following: b) A Tw1 - Tw2 value of -16 to -38 °C; and c) An Mw1 / Mw2 value of at least 0.9; and one or more of the following: d) Melt index ratio (I 21 / I2) of 10 - 90; 21 / I2); e) A Mz / Mw of 2.5 - 5.0; f) A Mz / Mn of 10 - 40; and g) g' of 0.900 or greater (vis) .

3. Use according to claim 1, wherein the metallocene-catalyzed polyethylene comprises from 0.5 to 20 wt% of units derived from C3-C 12 olefin comonomer, based on the total weight of the metallocene-catalyzed polyethylene.

4. The use according to claim 1, wherein the metallocene-catalyzed polyethylene comprises units derived from 1 - 10 wt% of C4 - C8 α-olefin comonomer, based on the total weight of the metallocene-catalyzed polyethylene.

5. The use according to claim 1, wherein the metallocene-catalyzed polyethylene has a melt index (I2) of 0.1 g / 10min - 6 g / 10min.

6. Use according to claim 1, wherein the metallocene-catalyzed polyethylene has a melt index ratio (I 21 / I2) of 20-45.

7. Use according to claim 1, wherein the metallocene-catalyzed polyethylene has a high load melt index (I 21 ) of 5 - 40 g / 10 min.

8. The use according to claim 1, wherein the metallocene-catalyzed polyethylene has an Mw / Mn of 5 - 10.

5.

9. The use according to claim 1, wherein the metallocene-catalyzed polyethylene has a g'(vis) of 0.940 or greater.

10. The use according to claim 1, wherein the metallocene-catalyzed polyethylene has a density of 0.900 g / cm 3 - 0.930 g / cm 3 .

11. The use according to claim 1, wherein the metallocene-catalyzed polyethylene has a melt index (I2) of 2 g / 10 min, a density of 0.925 g / cm 3 , a molecular weight distribution (MWD) of 5.35, and a compositional distribution breadth index of 39.

53.

12. The use according to claim 1, wherein the linear low density polyethylene catalyzed by the Ziegler-Natta catalyst has a melt index (I2) of 2 g / 10 min and a density of 0.918 g / cm 3 .

13. The use according to claim 1, wherein the content of the metallocene-catalyzed polyethylene is 45 wt% to 75 wt%, based on the total weight of the polyethylene blend.

14. The use according to claim 1, wherein the content of the metallocene-catalyzed polyethylene is 50 wt% to 75 wt%, based on the total weight of the polyethylene blend.

15. The use according to claim 1, wherein the content of the metallocene-catalyzed polyethylene is 55 wt% to 70 wt%, based on the total weight of the polyethylene blend.

16. The use according to any one of claims 1 - 15, wherein the content of the Ziegler - Natta catalyst-catalyzed linear low density polyethylene is 60 wt% to 20 wt%, based on the total weight of the polyethylene blend.

17. The use according to claim 16, wherein the content of the Ziegler - Natta catalyst-catalyzed linear low density polyethylene is 55 wt% to 25 wt%, based on the total weight of the polyethylene blend.

18. The use according to claim 17, wherein the content of the Ziegler - Natta catalyst-catalyzed linear low density polyethylene is 50 wt% to 25 wt%, based on the total weight of the polyethylene blend.

19. The use according to claim 18, wherein the content of the Ziegler - Natta catalyst-catalyzed linear low density polyethylene is 45 wt% to 30 wt%, based on the total weight of the polyethylene blend.

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