Asymmetric zirconium metallocenes with isobutyl cyclopentadienyl ligands

Abstract

Embodiments of the present disclosure relate to asymmetric zirconium metallocenes having an isobutyl cyclopentadienyl ligand, compositions comprising those asymmetric zirconium metallocenes having an isobutyl cyclopentadienyl ligand, and methods of utilizing the compositions comprising the asymmetric zirconium metallocenes having an isobutyl cyclopentadienyl ligand.

Description

Technical Field

[0001] Embodiments of the present disclosure are directed to asymmetric zirconium metallocenes having isobutylcyclopentadienyl ligands, catalyst compositions comprising the same, methods of making and using the same, and polyolefins made therefrom. Background Art

[0002] Metallocenes can be used in a variety of applications, including as polymerization catalysts. Polymers can be used in a variety of products, including membranes, etc. Polymers can be formed by reacting one or more types of monomers in a polymerization reaction. The industry is constantly working to develop new and improved materials and / or methods that can be used to form polymers. Summary of the invention

[0003] The present disclosure provides various embodiments including the following.

[0004] An asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand, the asymmetric zirconium metallocene is represented by structure (I):

[0005]

[0006] wherein each X is independently a leaving group.

[0007] A metallocene catalyst composition comprises: an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand; and an activator.

[0008] A method for preparing an asymmetric metallocene catalyst composition comprises contacting an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand with an activator.

[0009] A method for preparing a polyolefin polymer comprises polymerizing at least one olefin monomer with an asymmetric zirconium metallocene catalyst composition having an isobutylcyclopentadienyl ligand to prepare the polyolefin polymer. DETAILED DESCRIPTION

[0010] Asymmetric zirconium metallocenes with isobutylcyclopentadienyl ligands are discussed herein. Advantageously, these asymmetric zirconium metallocenes with isobutylcyclopentadienyl ligands can be used to prepare, for example, catalyst compositions. These catalyst compositions can be used to prepare polymers with reverse comonomer distribution (e.g., molecular weight comonomer distribution index (MWCDI)>0), as further discussed herein. These polymers are desired for many applications (including films, etc.). Therefore, it is advantageous to provide a reverse comonomer distribution. Such polymers are advantageous for many applications. In addition, the polymer may have a reverse short chain branching distribution (rSCBD) (also referred to as a broad orthogonal composition distribution (BOCD)), which is unexpected for Zr catalysts. In addition, these catalyst compositions can be used to prepare such polymers, which have improved (i.e., larger) comonomer incorporation (C6 weight %) compared to polymers prepared by other metallocenes.

[0011] As discussed herein, asymmetric zirconium metallocenes with isobutylcyclopentadienyl ligands can also be used to provide polymers with improved reverse short chain branching distribution. The defining feature of polymers (such as poly (ethylene-to-1-olefin) resins) is short chain branching distribution (SCBD) or comonomer distribution. In order to improve product performance in many applications, it is desirable to have reverse SCBD or reverse comonomer distribution, wherein the weight percentage (wt%) of the comonomer in the polymer increases as the molecular weight (MW) of the polymer chain increases. This is also referred to as a polymer with a wide orthogonal composition distribution (BOCD). Such distribution is typically achieved using a dual reactor configuration and a single or dual catalyst process. In a dual reactor process, a single catalyst can be used to prepare a high MW lower density component (with a higher wt % comonomer) and a low MW high density (lower wt % comonomer) component in an independent reactor via independent process control in two reactors. The result is a bimodal resin with reverse SCBD. In the case of a dual catalyst single reactor process, a catalyst prepares a high MW low density component, and another prepares a low MW high density component, thereby producing a bimodal product with reverse SCBD.

[0012] A more ideal way to achieve polymers with reverse SCBD is to use a single catalyst that can prepare such BOCD resins in a single reactor. As discussed herein, the asymmetric zirconium metallocenes with isobutylcyclopentadienyl ligands disclosed herein provide the ability to produce polymers with improved BOCD resins in a single reactor, especially those with a measurable greater tendency for comonomers to link in higher MW fractions and maintain significant BOCD characteristics across a wide range of process conditions. In addition, low melt index resins with wide molecular weight distributions and high BOCD compositions for films and other applications are needed in the industry. Without wishing to be bound by theory, it is believed that the isobutyl group of the asymmetric zirconium metallocenes with isobutylcyclopentadienyl ligands disclosed herein increases the primary C (sp 3 )-H bonds, thereby increasing the frequency of the reaction and increasing the tendency of the asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand catalyst toward multisiteness and forming a polymer with BOCD.

[0013] An asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand and can be represented by structure (I):

[0014]

[0015] wherein each X is independently a leaving group. As shown in structure (I), the upper cyclopentadienyl ring is substituted with an isobutyl group (also known as a 2-methylpropyl group) having a monovalent structure -CH2CH(CH3)2; the lower cyclopentadienyl ring is unsubstituted.

[0016] Embodiments of the present disclosure provide that X is a leaving group. One or more embodiments provide that X is selected from alkyl, aryl, hydride, and halogen. One or more embodiments provide that X is selected from alkyl and halogen. One or more embodiments provide that X is chlorine. One or more embodiments provide that X is methyl. One or more embodiments provide that X is selected from halogen, (C1-C5) alkyl, CH2SiMe3, and benzyl.

[0017] Examples of X include halogen ions, hydrides, (C1 to C 12 ) alkyl, (C2 to C 12 )alkenyl, (C6 to C 12 ) aryl, (C7 to C 20 ) alkylaryl, (C1 to C 12 ) alkoxy, (C6 to C 16 )aryloxy, (C7 to C8)alkylaryloxy, (C1 to C 12 ) fluoroalkyl, (C6 to C 12 ) fluoroalkyl and (C1 to C 12) heteroatom-containing hydrocarbons and their substituted derivatives; one or more embodiments include hydrides, halides, (C1 to C6) alkyls, (C2 to C6) alkenyls, (C7 to C 18 )alkylaryl, (C1 to C6)alkoxy, (C6 to C 14 ) aryloxy, (C7 to C 16 ) alkyl aryloxy, (C1 to C6) alkyl carboxylate, (C1 to C6) fluorinated alkyl carboxylate, (C6 to C 12 ) aryl carboxylate, (C7 to C 18 )alkylaryl carboxylates, (C1 to C6)fluoroalkyl, (C2 to C6)fluoroalkenyl and (C7 to C 18 ) fluoroalkylaryl; one or more embodiments include hydride, chloride, fluoride, methyl, phenyl, phenoxy, benzoyloxy, tosyl, fluoromethyl and fluorophenyl; one or more embodiments include (C1 to C 12 ) alkyl, (C2 to C 12 )alkenyl, (C6 to C 12 ) aryl, (C7 to C 20 ) alkylaryl, substituted (C1 to C 12 ) alkyl, substituted (C6 to C 12 ) aryl, substituted (C7 to C 20 ) alkylaryl and (C1 to C 12 ) containing heteroatom alkyl, (C1 to C 12 ) containing heteroatom aromatic groups and (C1 to C 12 ) containing heteroatom alkylaryl; one or more embodiments include chloride, fluoride, (C1 to C6) alkyl, (C2 to C6) alkenyl, (C7 to C 18 ) alkylaryl, halogenated (C1 to C6) alkyl, halogenated (C2 to C6) alkenyl and halogenated (C7 to C 18 ) alkylaryl; one or more embodiments include fluoride, methyl, ethyl, propyl, phenyl, methylphenyl, dimethylphenyl, trimethylphenyl, fluoromethyl (monofluoromethyl, difluoromethyl and trifluoromethyl) and fluorophenyl (monofluorophenyl, difluorophenyl, trifluorophenyl, tetrafluorophenyl and pentafluorophenyl).

[0018] Other non-limiting examples of X groups include amines, phosphines, ethers, carboxylates, dienes, hydrocarbon groups with 1 to 20 carbon atoms, fluorinated hydrocarbon groups (e.g., -C6F5(pentafluorophenyl)), fluorinated alkyl carboxylates (e.g., CF3C(O)O-), hydrides, halogen ions, and combinations thereof. Other examples of X ligands include alkyl groups such as cyclobutyl, cyclohexyl, methyl, heptyl, tolyl, trifluoromethyl, tetramethylene, pentamethylene, methylene, methoxy, ethoxy, propoxy, phenoxy, bis(N-methylaniline), dimethylamido, and dimethylphosphoryl, etc. In one embodiment, two or more X form a part of a fused ring or ring system. In one or more embodiments, X can be a leaving group selected from the group consisting of chloride, bromide, (C1 to C5), thiazolyl, ... 10 ) alkyl, (C2 to C 12 ) alkenyl, carboxylate, acetylacetonate, and alcoholate. In one or more embodiments, X is methyl.

[0019] The asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand discussed herein can be prepared by contacting a Zr complex with an alkali metal complex to prepare an asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand. For example, the alkali metal complex can be a lithium complex, such as isobutylcyclopentadienyl lithium. The asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand discussed herein can be prepared by methods for preparing known metallocenes (e.g., using conventional solvents, reaction conditions, reaction times, and separation procedures).

[0020] Alkali metal complexes can be represented by the following structures:

[0021]

[0022] Wherein M' is lithium, sodium or potassium, and R 1 For H.

[0023] One or more embodiments provide that the zirconium complex may be represented by one of the following structures:

[0024]

[0025] Where R 1 For H.

[0026] One or more embodiments provide for a method of preparing an asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand (e.g., wherein each X is Cl) comprising: contacting the asymmetric metallocene with two molar equivalents of an organomagnesium halide of formula RMg(halide) or one molar equivalent of R2Mg, wherein R is (C1-C5)alkyl, CH2SiMe3, or benzyl; and the halide is Cl or Br, to prepare an asymmetric metallocene of structure (I), wherein each X is a halogen, (C1-C5)alkyl, CH2SiMe3, or benzyl. One or more embodiments provide for X to be (C1-C5)alkyl, CH2SiMe3, or benzyl.

[0027] As used herein, all references to the Periodic Table of the Elements and its Groups refer to the NEW NOTATION as published in HAWLEY'S CONDENSED CHEMICAL DICTIONARY, Thirteenth Edition, John Wiley & Sons, Inc. (1997) (reproduced with permission from IUPAC), unless reference is made to the previous IUPAC form marked with Roman numbering (which also appears therein) or unless otherwise mentioned.

[0028] As used herein, "alkyl" includes straight chain, branched chain, and cyclic alkane radicals lacking one hydrogen. Thus, for example, CH3 ("methyl") and CH2CH3 ("ethyl") are examples of alkyl radicals.

[0029] As used herein, "alkenyl" includes straight chain, branched chain, and cyclic alkene groups lacking one hydrogen group; alkynyl includes straight chain, branched chain, and cyclic ethynyl groups lacking one hydrogen group.

[0030] As used herein, "aryl" groups include phenyl, naphthyl, pyridyl and other groups whose molecules have ring structures characteristic of benzene, naphthylene, phenanthrene, anthracene, etc. It should be understood that "aryl" groups can be C6 to C 20 Aryl groups. For example, a C6H5 aromatic structure is a "phenyl" and a C6H42 aromatic structure is a "phenylene". An "aralkyl" group is an alkyl group with a pendant aryl group. It should be understood that an "aralkyl" group can be (C7 to C 20 ) aralkyl groups. "Alkaryl" is an aryl group having one or more pendant alkyl groups.

[0031] As used herein, "alkylene" includes straight chain, branched, and cyclic hydrocarbon groups lacking two hydrogens. Thus, CH2 ("methylene") and CH2CH2 ("ethylene") are examples of alkylene groups. Other groups lacking two hydrogen groups include "arylene" and "alkenylene".

[0032] As used herein, the term "heteroatom" includes any atom selected from the group consisting of B, Al, Si, Ge, N, P, O and S. A "heteroatom-containing group" is a hydrocarbon group containing heteroatoms and may contain one or more of the same heteroatoms or different heteroatoms, and may contain 1 to 3 heteroatoms in a particular embodiment. Non-limiting examples of heteroatom-containing groups include groups (monovalent and divalent) of imines, amines, oxides, phosphines, ethers, ketones, oxazoline heterocycles, oxazolines and thioethers.

[0033] As used herein, the term "substituted" means that one or more hydrogen atoms in the parent structure have been independently replaced with a substituent atom or group.

[0034] The asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand discussed herein can be used to prepare catalyst compositions. These asymmetric metallocene compositions include: an asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand; and an activator. One or more embodiments provide that the activator is an alkylaluminoxane, such as methylaluminoxane. As used herein, "activator" refers to any supported or unsupported compound or combination of compounds, which can activate the complex or catalyst component, for example, by generating a cationic species of the catalyst component. For example, this can include capturing at least one leaving group, for example, the "X" group described herein, from the metal center of the complex / catalyst component (e.g., the asymmetric metallocene of structure (I)). The activator may also be referred to as a "co-catalyst". As used herein, "leaving group" refers to one or more chemical moieties that are combined with a metal atom and can be captured by an activator, thereby generating a substance that is active for olefin polymerization. Various catalyst compositions, such as olefin polymerization catalyst compositions are known in the art, and different known catalyst composition components can be used. Different amounts of known catalyst composition components can be used for different applications.

[0035] The asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand discussed herein can be used to prepare a spray-dried composition. As used herein, a "spray-dried composition" refers to a composition comprising a plurality of components that has undergone a spray-drying process. Various spray-drying methods are known in the art and are suitable for forming the spray-dried compositions disclosed herein. One or more embodiments provide for the spray-dried composition to include a modified composition.

[0036] In one or more embodiments, the spray drying process may include atomizing a composition comprising an asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand. Many other known components may be used in the spray drying process. Atomizers such as atomizing nozzles or centrifugal high-speed disks may be used, for example, to produce a spray or dispersion of composition droplets. The droplets of the composition may then be rapidly dried by contact with an inert dry gas. The inert dry gas may be any gas, such as nitrogen, that is not reactive under the conditions employed during atomization. The inert dry gas may encounter the composition at the atomizer, which produces a stream of droplets on a continuous basis. The dried composition particles may be captured from the process in a separator, such as a cyclone separator, which may separate the formed solid from a gas mixture of a drying gas, a solvent, and other volatile components.

[0037] For example, the spray-dried composition can have a free-flowing powder form. After the spray-drying process, the spray-dried composition and many known components can be used to form a slurry. The spray-dried composition can be used together with a diluent to form a slurry suitable for, for example, olefin polymerization. In one or more embodiments, the slurry can be merged with one or more other catalysts or other known components before being delivered in a polymerization reactor.

[0038] In one or more embodiments, a spray-dried composition can be formed by contacting spray-dried activator particles (such as spray-dried MAO) with a solution of an asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand. Such solutions can be prepared, for example, in an inert hydrocarbon solvent, and are sometimes referred to as adjustment solutions. Such spray-dried compositions including contacting an adjustment solution of an asymmetric metallocene with spray-dried activator particles (such as spray-dried MAO) can be prepared in situ by contacting the adjustment solution with a slurry of spray-dried activator particles (usually in mineral oil) in a feed pipe to a gas phase polymerization reactor. Alternatively, a spray-dried composition can be formed by contacting a slurry of spray-dried activator particles (such as a mineral oil slurry of spray-dried activator particles) with an asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand discussed herein.

[0039] Various spray drying conditions can be used for different applications. For example, the spray drying process can utilize a drying temperature of 115° C. to 185° C. Other drying temperatures are also possible, wherein the temperature may depend on the metallocene and activator particles. Various sizes of orifices of the atomizing nozzles employed during the spray drying process can be used to obtain different particle sizes. Alternatively, for other types of atomizers such as disks, the rotation speed, disk size, and number / size of holes can be adjusted to obtain different particle sizes. One or more embodiments provide that fillers can be used in the spray drying process. Different fillers and their amounts can be used for various applications.

[0040] The asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand discussed herein (e.g., catalyst composition, such as spray-dried asymmetric metallocene composition) can be used to prepare polymers. For example, the asymmetric metallocene can be activated (i.e., with an activator) to prepare an asymmetric metallocene catalyst. One or more embodiments provide that the spray-dried composition comprises an activator. As used herein, "activator" refers to any supported or unsupported compound or combination of compounds, which can activate the complex or catalyst component, such as by generating a cationic species of the catalyst component, for example, to provide a catalyst. The activator may also be referred to as a "cocatalyst". The activator may include a Lewis acid or a non-coordinating ion activator or an ionizing activator, or any other compound including a Lewis base, an alkyl aluminum and / or a conventional cocatalyst. The activator includes methylaluminoxane (MAO) and modified methylaluminoxane (MMAO), etc. One or more embodiments provide that the activator is methylaluminoxane. Activation conditions are well known in the art. Known activation conditions can be used.

[0041] The molar ratio of the metal (e.g., aluminum) in the activator to the Zr in the asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand can be 1500: 1 to 0.5: 1, 300: 1 to 1: 1, or 150: 1 to 1: 1. One or more embodiments provide that the molar ratio of the activator to the Zr in the asymmetric metallocene is at least 75: 1. One or more embodiments provide that the molar ratio of the activator to the Zr in the asymmetric metallocene is at least 100: 1. One or more embodiments provide that the molar ratio of the activator to the Zr in the asymmetric metallocene is at least 150: 1.

[0042] Asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand and many other components discussed herein can be loaded on the same or independent carrier, or one or more of these components can be used in the form of non-loaded. The utilization of carrier can be realized by any technology used in the art. One or more embodiments provide that spray drying process is utilized. For example, an asymmetric metallocene with isobutylcyclopentadienyl ligand in an inert solvent can be contacted with a loaded or spray-dried activator (or its slurry) to obtain a spray-dried metallocene catalyst composition. Alternatively, the supported asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand of the present disclosure and many other components can be formed by drying the slurry of the component under vacuum or reduced pressure. The carrier can be functionalized. One or more embodiments provide that the spray-dried composition comprises a carrier.

[0043] "Carrier" may also be referred to as "support", and refers to any carrier material, including porous carrier materials (such as talc), inorganic oxides and inorganic chlorides. Other carrier materials include resin carrier materials (such as polystyrene), functionalized or cross-linked organic carriers (such as polystyrene divinyl benzene polyolefins or polymeric compounds), zeolites, clays or any other organic or inorganic carrier materials, etc., or mixtures thereof.

[0044] The support material includes an inorganic oxide including a Group 2, 3, 4, 5, 13 or 14 metal oxide. Some preferred supports include silica, fumed silica, alumina, silica-alumina and mixtures thereof. Some other supports include magnesium oxide, titanium dioxide, zirconium oxide, magnesium chloride, montmorillonite, phyllosilicates, zeolites, talc, clays and the like. Moreover, combinations of these support materials may be used, such as silica-chromium, silica-alumina, silica-titania and the like. One or more embodiments provide that the support is a hydrophobic fumed silica. Additional support materials may include porous acrylic polymers, nanocomposites, aerogels, spherulites and polymer beads. An example of a support is available under the trade name Cabosil TM Fumed silica is obtained from TS-610, or other TS-series or TG-series supports available from Cabot Corporation. Fumed silica is typically silica having a particle size of 7 to 30 nanometers that has been treated with dimethylsilyl dichloride such that most of the surface hydroxyl groups are capped.

[0045] The asymmetric zirconium metallocene with isobutylcyclopentadienyl ligand discussed herein (e.g., catalyst composition / spray-dried asymmetric metallocene composition) and olefins can be contacted under polymerization conditions to prepare polymers, e.g., polyolefin polymers. The polymerization process can be a solution polymerization process, a suspension polymerization process, a slurry polymerization process, and / or a gas phase polymerization process. The polymerization process can utilize known equipment and reaction conditions, e.g., known polymerization conditions. The polymerization process is not limited to any particular type of polymerization system. The polymer can be used in many articles, such as films, fibers, nonwoven fabrics and / or woven fabrics, extruded articles, and / or molded articles.

[0046] One or more embodiments provide for the use of a gas phase reactor system to prepare the polymer. One or more embodiments provide for the use of a single gas phase reactor, for example as opposed to a series of reactors. In other words, the polymerization reaction occurs in only one reactor. For example, a fluidized bed reactor may be used to prepare the polymer. Gas phase reactors are known, and known components may be used in fluidized bed reactors.

[0047] As used herein, "olefins" which may be referred to as "alkenes" refer to linear, branched or cyclic compounds comprising carbon and hydrogen and having at least one double bond. As used herein, when polyolefins, polymers and / or copolymers are referred to as comprising olefins (e.g., prepared by olefins), the olefins present in such polymers or copolymers are olefins in polymerized form. For example, when it is said that the ethylene content of a copolymer is 75% to 95% by weight, it is understood that the polymer units in the copolymer are derived from ethylene in the polymerization reaction, and based on the gross weight of the polymer, the derived units are present in 75% to 95% by weight. Higher alpha-olefins refer to alpha-olefins having 3 or more carbon atoms.

[0048] The polyolefins prepared with the compositions discussed herein can be prepared from olefin monomers, such as ethylene (i.e., polyethylene) or propylene (i.e., polypropylene), and other substances specified herein, wherein the polyolefin is a homopolymer prepared only from olefin monomers (e.g., prepared from 100% by weight ethylene or 100% by weight propylene). Alternatively, the polyolefins prepared with the compositions discussed herein can be prepared from olefin monomers, such as ethylene (i.e., polyethylene), and straight or branched higher alpha-olefin monomers containing 3 to 20 carbon atoms. Examples of higher alpha-olefin monomers include, but are not limited to, propylene, butene, pentene, 1-hexene, and 1-octene. Examples of polyolefins include ethylene-based polymers having at least 50% by weight ethylene, including ethylene-1-butene, ethylene-1-hexene, and ethylene-1-octene copolymers, etc. One or more embodiments provide that, based on the total weight of the polymer, the polymer may include 50% by weight to 99.9% by weight of units derived from ethylene. All individual values ​​and subranges of 50 wt % to 99.9 wt % are included; for example, based on the total weight of the polymer, the polymer may include a lower limit of 50 wt %, 60 wt %, 70 wt %, 80 wt % or 90 wt % of units derived from ethylene to an upper limit of 99.9 wt %, 99.7 wt %, 99.4 wt %, 99 wt %, 96 wt %, 93 wt %, 90 wt % or 85 wt % of units derived from ethylene. Based on the total weight of the polymer, the polymer may include 0.1 wt % to 50 wt % of units derived from comonomers. One or more embodiments provide that ethylene is used as a monomer and hexene is used as a comonomer.

[0049] As mentioned, polymers prepared with the compositions disclosed herein can be prepared in a fluidized bed reactor. The fluidized bed reactor can have a reaction temperature of 10°C to 130°C. All individual values ​​and subranges from 10°C to 130°C are included; for example, the fluidized bed reactor can have a reaction temperature of 10°C, 20°C, 30°C, 40°C, 50°C, or 55°C to an upper limit of 130°C, 120°C, 110°C, 100°C, 90°C, 80°C, 70°C, or 60°C.

[0050] The fluidized bed reactor can have an ethylene partial pressure of 30 pounds per square inch (psi) to 250 psi, including all individual values ​​and subranges from 30 to 250; for example, the fluidized bed reactor can have an ethylene partial pressure of 30 psi, 45 psi, 60 psi, 75 psi, 85 psi, 90 psi, or 95 psi on the lower limit and 250 psi, 240 psi, 220 psi, 200 psi, 150 psi, or 125 psi on the upper limit.

[0051] One or more embodiments provide that ethylene is used as a monomer and hexene is used as a comonomer. The fluidized bed reactor can have a comonomer to ethylene molar ratio of 0.0001 to 0.100, for example C6 / C2. All individual values ​​and subranges from 0.0001 to 0.100 are included; for example, the fluidized bed reactor can have a comonomer to ethylene molar ratio of 0.0001, 0.0005, 0.0007, 0.001, 0.0015, 0.002, 0.007, or 0.010 to an upper limit of 0.100, 0.080, or 0.050.

[0052] When hydrogen is used in the polymerization process, the fluidized bed reactor can have, for example, a hydrogen to ethylene molar ratio (H2 / C2) of 0.00001 to 0.90000. All individual values ​​and subranges from 0.00001 to 0.90000 are included; for example, the fluidized bed reactor can have a H2 / C2 with a lower limit of 0.00001, 0.00005, or 0.00008 to an upper limit of 0.90000, 0.500000, 0.10000, 0.01500, 0.00700, or 0.00500. One or more embodiments provide that hydrogen is not utilized.

[0053] Conventional gel permeation chromatography can be used to determine multiple polymer properties. For example, a chromatographic system consisting of a PolymerChar GPC-IR (Valencia, Spain) high temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5) is used to determine weight average molecular weight (Mw), number average molecular weight (Mn), Z average molecular weight (Mz) and Mw / Mn (PDI). The autosampler oven chamber is set to 160°C, and the column chamber is set to 150°C. The column used is 4 Agilent "MixedA" 30cm 20 micron linear mixed bed columns. The chromatographic solvent used is 1,2,4 trichlorobenzene and contains 200ppm of butylated hydroxytoluene (BHT). The solvent source is nitrogen sparged. The injection volume used is 200 microliters, and the flow rate is 1.0 ml / min.

[0054] The calibration of the GPC column set was performed with 21 narrow molecular weight distribution polystyrene standards, ranging in molecular weight from 580 g / mol to 8,400,000 g / mol, and arranged in 6 "mixed liquid" mixtures with at least ten times intervals between individual molecular weights. The standards were purchased from Agilent Technologies. For molecular weights equal to or greater than 1,000,000, 0.025 grams of polystyrene standards were prepared in 50 milliliters of solvent, and for molecular weights less than 1,000,000, 0.05 grams of polystyrene standards were prepared in 50 milliliters of solvent. The polystyrene standards were pre-dissolved at 80°C under gentle stirring for 30 minutes, then cooled, and the room temperature solution was transferred to a 160°C autosampler dissolution oven to cool for 30 minutes. The polystyrene standard peak molecular weight was converted to polyethylene molecular weight using equation 1 (as described in Williams and Ward, J. Polym. Sci., Polym. Let.), 6, 621 (1968)):

[0055] M 聚乙烯 =A×(M 聚苯乙烯 ) B (Equation 1)

[0056] Where M is the molecular weight, A has a value of 0.4061, and B equals 1.0.

[0057] A fifth-order polynomial was used to fit the calibration points to the corresponding polyethylene equivalents.

[0058] Total plate counts for the GPC column set were performed with decane, which was introduced into the blank sample via a micro pump controlled by the PolymerChar GPC-IR system. The plate count of the chromatography system should be greater than 18,000 for 4 Agilent "Mixed A" 30 cm 20 micron linear mixed bed columns.

[0059] The samples were prepared semi-automatically using the PolymerChar "Instrument Control" software, where the target weight of the sample was set to 2 mg / ml, and the solvent (containing 200 ppm BHT) was added to a septum-capped vial previously sparged with nitrogen via the PolymerChar high temperature autosampler. The samples were dissolved at 160 degrees Celsius for 2 hours under "slow" shaking.

[0060] Mn was determined based on GPC results using the internal IR5 detector (measurement channel) of a PolymerChar GPC-IR spectrometer according to Equations 2-4 using the PolymerChar GPCONE software, the baseline-subtracted IR chromatogram at each equally spaced data collection point (i), and the polyethylene equivalent molecular weight obtained from the narrow standard calibration curve at point (i) according to Equation 1. (GPC) 、Mw (GPC) and Mz (GPC) Calculation:

[0061]

[0062] To monitor the deviation over time, a flow rate marker (decane) was introduced into each sample via a micropump controlled by the PolymerChar GPC-IR system. This flow rate marker (FM) was used to linearly calibrate the pump flow rate (flow rate) for each sample by the following method: (标称) ): The RV of the corresponding decane peak in the sample (RV (FM样品) ) and the retention volume (RV (FM校准) ). It is then assumed that any changes in the decane marker peak time are related to the flow rate (flow rate) during the entire run. (有效) ). After calibrating the system based on the flow marker peak, the effective flow rate (relative to the narrow standard calibration) is calculated according to Equation 5. Processing of the flow marker peak is completed by PolymerChar GPCONE software. An acceptable flow rate correction is such that the effective flow rate should be within + / - 0.5% of the nominal flow rate.

[0063] Flow rate (effective) = flow rate (nominal) × (RV (FM calibration) / RV (FM sample)) (Equation 5)

[0064] IR5 GPC Octene Composition Calibration. Calibration for IR5 detector dosing is performed using at least ten ethylene-based polymer standards (octene as comonomer) produced in a solution process (polyethylene homopolymer and ethylene / octene copolymer) from a single reactor over a single site metallocene catalyst with narrow SCB distribution and known comonomer content (e.g., by 13 C NMR method, Qiu et al., Anal. Chem.) 2009, 81, 8585-8589) in a solution process (polyethylene homopolymer and ethylene / octene copolymer) from a single reactor by a single-site metallocene catalyst, the known monomer content is in the range of from homopolymer (0 SCB / 1000 total C) to about 40 SCB / 1000 total C, where total C = carbon in the main chain + carbon in the branch chain. Each SCB standard has a weight average molecular weight of 36,000 g / mole to 126,000 g / mole, as measured by GPC. The molecular weight distribution (Mw / Mn) of each standard is 2.0 to 2.5. The SCB standard polymer properties are shown in Table A.

[0065] Table A: "Copolymer" Standards

[0066] Comonomer weight % IR5 Area Ratio SCB / 1000Total C M Mw / Mn 23.1 0.2411 28.9 37,300 2.22 14.0 0.2152 17.5 36,000 2.19 0.0 0.1809 0.0 38,400 2.20 35.9 0.2708 44.9 42,200 2.18 5.4 0.1959 6.8 37,400 2.16 8.6 0.2043 10.8 36,800 2.20 39.2 0.2770 49.0 125,600 2.22 1.1 0.1810 1.4 107,000 2.09 14.3 0.2161 17.9 103,600 2.20 9.4 0.2031 11.8 103,200 2.26

[0067] The “IR5 Area Ratio” (or “IR5 Area Response”) of the “Baseline-Subtracted Area Response of the IR5 Methyl Channel Sensor” to the “Baseline-Subtracted Area Response of the IR5 Measurement Channel Sensor” was calculated for each of the “Copolymer” standards. 甲基通道面积 / IR5 测量通道面积 ”)” (including standard filters and filter wheels supplied by PolymerChar: Part No. IR5_FWM01 as part of the GPC-IR instrument). A linear fit of comonomer wt% frequency versus “IR5 Area Ratio” was constructed in the form of Equation 6 below:

[0068] Comonomer weight % = A0 + [A1 × (IR5 甲基通道面积 / IR5 测量通道面积 )] (Equation 6)

[0069] Where A0 is the "Comonomer wt%" intercept at "IR5 Area Ratio" of zero, and A1 is the slope of "Comonomer wt%" relative to "IR5 Area Ratio" and represents the increase in comonomer wt% as a function of "IR5 Area Ratio". For narrow PDI and narrow SCBD standard materials, the IR5 Area Ratio is equal to the IR5 Height Ratio.

[0070] The comonomer distribution or short chain branching distribution in ethylene / α-olefin copolymers can be characterized as normal (also referred to as having a Ziegler-Natta distribution), reversed or flat. Several reported methods are used to quantify a broad orthogonal composition distribution (BOCD). In this article, a simple straight line fit is used so that the normal or reverse nature of the comonomer distribution can be quantified by the molecular weight comonomer distribution index (MWCDI), which is the slope of the linear regression of the comonomer distribution measured by the composition GPC, where the x-axis is Log (MW) and the y-axis is the weight percentage of the comonomer. Reverse comonomer distribution is defined when MWCDI>0, and normal comonomer distribution is defined when MWCDI<0. When MWCDI=0, the comonomer distribution is said to be flat. In addition, MWCDI quantifies the magnitude of the comonomer distribution. Comparing two polymers with MWCDI>0, the polymer with a larger MWCDI value is defined as having a larger, i.e., increased BOCD; in other words, the polymer with a larger MWCDI value has a larger reverse comonomer distribution. For example, as reported in Tables 1 to 3, respectively, Examples 1-2 have increased BOCD compared to Comparative Example A-2. Polymers with relatively large MWCDI (ie, BOCD) can provide improved physical properties, such as improved film performance, compared to polymers with relatively small MWCDI.

[0071] Polymers prepared with the compositions disclosed herein can have a MWCDI of 0.10 to 10.00, including all individual values ​​and subranges from 0.10 to 10.00; for example, a polymer can have a MWCDI of a lower limit of 0.10, 0.50, or 1.00 to an upper limit of 10.00, 9.00, 8.00, 8.50, or 8.35.

[0072] The polymers prepared using the compositions disclosed herein may have a hardness of 0.8700 g / cm 3 Up to 0.9700g / cm 3 Density. Including 0.8700g / cm 3 Up to 0.9700g / cm 3 All individual values ​​and subranges of; for example, a polymer may have a lower limit of 0.8700 g / cm 3 , 0.9000g / cm 3 、0.9100g / cm 3 、0.9150g / cm 3 , 0.9200g / cm 3 or 0.9250g / cm 3 The upper limit is 0.9700g / cm 3 , 0.9600g / cm 3 , 0.9500g / cm3 、0.9450g / cm 3 、0.9350g / cm 3 or 0.9300g / cm 3 Density. Density can be determined according to ASTM D792.

[0073] The polymer prepared with the composition disclosed herein can have a weight average molecular weight (Mw) of 10,000 g / mol to 1,000,000 g / mol. All individual values ​​and subranges of 10,000 g / mol to 1,000,000 g / mol are included; for example, the polymer can have a Mw with a lower limit of 10,000 g / mol, 50,000 g / mol, or 100,000 g / mol to an upper limit of 1,000,000 g / mol, 750,000 g / mol, or 500,000 g / mol. As known in the art, Mw can be determined by gel permeation chromatography (GPC). GPC is discussed herein.

[0074] The polymers prepared with the compositions disclosed herein can have a number average molecular weight (Mn) of 5,000 g / mol to 300,000 g / mol. All individual values ​​and subranges of 5,000 g / mol to 300,000 g / mol are included; for example, the polymer can have a Mn with a lower limit of 5,000 g / mol, 20,000 g / mol, or 40,000 g / mol to an upper limit of 300,000 g / mol, 250,000 g / mol, or 200,000 g / mol. Mn can be determined by GPC.

[0075] The polymers prepared with the compositions disclosed herein can have a Z-average molecular weight (Mz) of 40,000 g / mol to 2,000,000 g / mol. All individual values ​​and subranges of 40,000 g / mol to 2,000,000 g / mol are included; for example, the polymer can have a Mz with a lower limit of 40,000 g / mol, 100,000 g / mol, or 250,000 g / mol to an upper limit of 2,000,000 g / mol, 1,800,000 g / mol, or 1,650,000 g / mol. Mz can be determined by GPC.

[0076] The polymers prepared with the compositions disclosed herein can have a ratio of weight average molecular weight to number average molecular weight (Mw / Mn) from 2.00 to 6.00. All individual values ​​and subranges from 2.00 to 6.00 are included; for example, the polymer can have a Mw / Mn with a lower limit of 2.00, 2.50, or 3.00 and an upper limit of 6.00, 5.50, or 4.50.

[0077] Various aspects of the disclosure are provided as follows.

[0078] Aspect 1 provides an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand, wherein the asymmetric zirconium metallocene is represented by structure (I):

[0079]

[0080] wherein each X is independently a leaving group.

[0081] Aspect 2 provides an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand according to aspect 1, wherein each X is independently a leaving group selected from halogen, (C1-C5) alkyl, CH2SiMe3 and benzyl.

[0082] Aspect 3 provides an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand according to any one of aspects 1 to 2, wherein each X is Cl, and the asymmetric zirconium metallocene is represented by structure (II):

[0083]

[0084] Aspect 4 provides an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand according to any one of claims 1 to 2, wherein each X is CH3, and the asymmetric zirconium metallocene is represented by structure (III):

[0085]

[0086] Aspect 5 provides a method for synthesizing an asymmetric metallocene according to any one of aspects 1 to 3, wherein each X is Cl, the method comprising:

[0087] The zirconium complex is contacted with an alkali metal complex, wherein the alkali metal complex is

[0088] The structure is expressed as:

[0089]

[0090] Wherein M' is lithium, sodium or potassium, and R 1 is H; and

[0091] The zirconium complex is represented by the following structure:

[0092]

[0093] To prepare an asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand.

[0094] Aspect 5 provides a method for synthesizing an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand according to any one of aspects 1 to 3, wherein each X is Cl, the method comprising:

[0095] The zirconium complex is contacted with an alkali metal complex, wherein the alkali metal complex is

[0096] The structure is expressed as:

[0097]

[0098] wherein M' is lithium, sodium or potassium, and

[0099] The zirconium complex is represented by the following structure:

[0100]

[0101] Where R 1 is H to prepare an asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand.

[0102] Aspect 6 provides a method for synthesizing an asymmetric metallocene according to any one of aspects 1 to 3, wherein each X is Cl, the method comprising:

[0103] The zirconium complex is contacted with an alkali metal complex, wherein the alkali metal complex is

[0104] The structure is expressed as:

[0105]

[0106] Wherein M' is lithium, sodium or potassium, and R 1 is H; and

[0107] The zirconium complex is represented by the following structure:

[0108]

[0109] To prepare an asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand.

[0110] Aspect 7 provides a method according to any one of Aspects 5 to 6, comprising: contacting an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand with two molar equivalents of an organic magnesium halide of formula RMg(halide) or one molar equivalent of R2Mg, wherein R is (C1-C5)alkyl, CH2SiMe3 or benzyl; and the halide is Cl or Br, to prepare an asymmetric metallocene of structure (I), wherein each X is (C1-C5)alkyl, CH2SiMe3 or benzyl.

[0111] Aspect 8 provides a metallocene catalyst composition, which comprises: an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand according to any one of Aspects 1 to 4, or an asymmetric metallocene prepared by the method according to any one of the aspects; and an activator (e.g., an alkylaluminoxane, such as methylaluminoxane).

[0112] Aspect 9 provides the metallocene catalyst composition according to aspect 8, further comprising a support (eg, silica, such as hydrophobic fumed silica or dehydrated silica).

[0113] Aspect 10 provides the metallocene catalyst composition according to aspect 9, wherein the composition is a spray-dried metallocene catalyst composition.

[0114] Aspect 11 provides a method for preparing a metallocene catalyst composition according to any one of Aspects 9 to 10, the method comprising any one of the following: contacting an asymmetric metallocene with an activator but not with a support to obtain a metallocene catalyst composition without a support; or contacting an asymmetric metallocene with an activator and a support to obtain a metallocene catalyst composition containing a support; or contacting an asymmetric metallocene with an activator and a support in an inert solvent to obtain a suspension thereof, and spray-drying the suspension to obtain a spray-dried metallocene catalyst composition; or contacting an asymmetric metallocene in an inert solvent with a supported or spray-dried activator (or its slurry) to obtain a spray-dried metallocene catalyst composition.

[0115] Aspect 12 provides a method for preparing a polyolefin polymer, the method comprising: polymerizing at least one olefin monomer with the metallocene catalyst composition according to any one of aspects 8 to 10 or the metallocene catalyst composition prepared by the method according to aspect 11 to prepare a polyolefin polymer; wherein preferably, the at least one olefin monomer comprises ethylene and an optional comonomer selected from the group consisting of propylene and (C4-C 20 )α-olefins.

[0116] Aspect 13 provides a method according to aspect 12, wherein the at least one olefin monomer comprises ethylene and a comonomer; and wherein the polyolefin polymer has a molecular weight comonomer distribution index (MWCDI) from 0.10 to 10.00, as measured by the MWCDI test method described herein; wherein preferably, the comonomer is selected from the group consisting of: 1-butene, 1-hexene and 1-octene.

[0117] Aspect 14 provides a polyolefin polymer prepared by the method according to any one of aspects 12 to 13.

[0118] Example

[0119] 5-(2-methylpropylene)cyclopenta-1,3-diene, which can be represented by the following formula:

[0120]

[0121] Synthesized as follows. In a glove box, pyrrolidine (1.45 g, 10 mol%) was added to a glass container containing a solution of isobutyraldehyde (14.6 g, 203 mmol) and cyclopentadiene (13.4 g, 203 mmol) in MeOH-H2O (200 mL 4 / 1). The contents of the container were transferred to an ice-cold mixture of a saline solution and 10 mol% AcOH in a narrow graduated cylinder. The organic phase was separated and dried over molecular sieves. The product (5-(2-methylpropylidene)cyclopenta-1,3-diene) was filtered to obtain a bright yellow oil, which was then used without further purification (16.0 g, 65%). 1H NMR (400MHz, CDCl3) δ: 6.54 (tdd, J = 5.4, 3.8, 2.5Hz, 2H), 6.51-6.44 (m, 1H), 6.29-6.17 (m, 2H), 3.02 (dp, J = 10.0, 6.6Hz, 1H), 1.15 (d, J = 6.6Hz, 6H). 13C NMR (101MHz, CDCl3) δ: 149.88, 143.69, 133.08, 130.87, 126.06, 119.36, 30.58, 23.24.

[0122] Isobutylcyclopentadienyllithium, which can be represented by the following formula:

[0123]

[0124] are synthesized as follows.

[0125] Et2O (250 mL) was added to the container. 5-(2-methylpropylidene)cyclopenta-1,3-diene (16.0 g, 133 mmol) was added to the contents of the container while stirring. LiAlH4 (33 mL, 4M Et2O solution) was added dropwise to the contents of the container while stirring. Bubbling was observed. A white solid precipitated during the addition, and the yellow color gradually faded as the LiAlH4 was continued to be added. Addition was stopped once the solution turned only light yellow. The product, isobutylcyclopentadienyllithium, observed as a white solid, was collected by filtration, rinsed with Et2O, and dried under vacuum (13.7 g, 80%).

[0126] Example 1-1 (Cyclopentadienyl)(isobutylcyclopentadienyl)zirconium dichloride, an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand, can be represented by the following formula:

[0127]

[0128] was synthesized as follows. A solution of isobutylcyclopentadienyllithium (0.11 g, 0.76 mmol) in THF (5 mL) was slowly added to a flask containing CpZrC l3 (zirconium complex, 0.2 g, 0.76 mmol; purchased from Boulder Scientific Company) in THF (5 mL) in a vial and stirred at room temperature for about 12 hours. The solvent was then removed by vacuum, and the residue was redissolved in toluene (10 mL) and filtered through a syringe filter. The solution was concentrated to about 2 mL by vacuum; pentane (10 mL) was added, causing the formation of a white precipitate. The solid was collected, washed with pentane (2 x 5 mL), and dried by vacuum to give Example 1-1 (0.21 g, 80%). 1 H NMR (400MHz, benzene-d6) δ5.94 (s, 4H), 5.85 (t, J = 2.76Hz, 2H), 5.66 (t, J = 2.67Hz, 2H), 2.51 (d, J = 7.18Hz, 2H), 1.60 (tq, 1H), 0.78 (d, J = 6.65Hz, 6H).

[0129] Comparative Example A-1 (cyclopentadienyl)(n-butylcyclopentadienyl)zirconium dichloride, which can be represented by the following formula:

[0130]

[0131] Prepared as follows. A solution of n-butylcyclopentadienyl lithium (0.098 g, 0.76 mmol) in THF (5 mL) was slowly added to a vial containing a solution of CpZrCl3 (0.2 g, 0.76 mmol) in THF (5 mL) and stirred at room temperature for about 12 hours. The solvent was then removed by vacuum and the residue was redissolved in toluene (10 mL) and filtered through a syringe filter. The solution was then concentrated to about 2 mL by vacuum; pentane (10 mL) was added to cause the formation of a white precipitate. The solid was collected, washed with pentane (2 x 5 mL), and dried under vacuum to obtain Comparative Example A-1 (0.21 g, 79%). 1H NMR (400MHz, benzene-d6) δ5.94(s,4H),5.86(t,J=2.6Hz,2H),5.66(t,J=2.7Hz,2 H), 2.61 (t, J = 7.93Hz, 2H), 1.40 (m, 2H), 1.21 (m, 2H), 0.83 (t, J = 7.3Hz, 3H).

[0132] Example 1-2, a spray dried composition, was prepared as follows. In a nitrogen purged glove box, Cabosil TS-610 hydrophobic fumed silica (1.34 g) was slurried in toluene (34 g) until well dispersed. Then 10.7 g of a 10 wt % solution of MAO in toluene was added. The mixture was stirred for 15 minutes. Example 1-1 (0.028 g) was then added. The mixture was stirred for about 45 minutes. A 100% slurry was used with the following operating parameters. Mini Spray Dryer B-290 was used to spray dry the mixture to provide Example 1-2: set temperature 185°C, outlet temperature 100°C, aspirator 95, and pump speed 150 revolutions per minute (rpm).

[0133] Comparative Example A-2 (spray dried composition) was prepared as follows. In a nitrogen purged glove box, Cabosil TS-610 hydrophobic fumed silica (1.34 g) was slurried in toluene (34 g) until well dispersed. Then 10.7 g of a 10 wt % solution of MAO in toluene was added. The mixture was stirred for 15 minutes. Comparative Example A-1 (0.028 g) was then added. The mixture was stirred for about 45 minutes. A spray dried silica was used with the following operating parameters: The mixture was spray dried using a Mini Spray Dryer B-290 to provide Comparative Example A-2: set temperature 185°C, outlet temperature 100°C, aspirator 95, and pump speed 150 revolutions per minute (rpm).

[0134] Polymerization is performed as follows. For the corresponding polymerization, dry NaCl (200 g) is loaded into a laboratory-level gas phase polymerization reactor (equipped with a 2-liter stainless steel autoclave with a variable speed mechanical stirrer) and heated to 100 ° C for one hour under a nitrogen stream. The reactor is then purged with nitrogen, methylaluminoxane supported by silica is added to the reactor as a scavenger, the reactor temperature is adjusted to an approximately desired temperature, the reactor is sealed, and the contents of the stirring reactor are stirred. The reactor is preloaded to the desired pressure with hydrogen, ethylene and 1-hexene. When steady state is reached, the catalyst is loaded into the reactor (at the temperature indicated below) to start polymerization. The reactor temperature is maintained at the desired temperature for 60 minutes of polymerization, wherein hydrogen, C6 / C2 ratio and ethylene pressure are kept constant. At the end of 60 minutes of polymerization, the reactor is cooled, vented and opened. The resulting mixture is washed with water and methanol and dried. The polymerization conditions are reported in Table 1 to Table 3.

[0135] A number of properties of the polymers prepared using Examples 3-9 and Comparative Example CO, respectively, were determined. The results are reported in Tables 2 and 3. The polymerization productivity (gram polymer / gram catalyst-hour) was determined as the ratio of the polymer produced to the amount of catalyst added to the reactor. The melt index (I2) was determined according to ASTM D1238 (190°C, 2.16 kg), the melt index (I5) was determined according to ASTM D1238 (190°C, 5 kg), and the melt index (I 21 ) is determined according to ASTM D1238 (190°C, 21.6 kg); the molecular weight comonomer distribution index (MWCDI) is determined as discussed herein. Melt temperature is determined using differential scanning calorimetry according to ASTM D 3418-08, using a scan rate of 10°C / min for a 10 mg sample and a second heating cycle to determine T m . M w 、M n 、M z 、M w / M n (PDI) and M z / M w Determined as discussed above in the Detailed Description.The comonomer content (eg, 1-hexene) incorporated into the polymer is determined by fast FT-IR spectroscopy of the dissolved polymer in a GPC measurement, as discussed above in the Detailed Description.

[0136] Table 1

[0137]

[0138]

[0139] Table 2

[0140] Example 1-2 Comparative Example A-2 Reaction temperature (℃) 90 90 <![CDATA[C6 / C2]]> 0.016 0.016 <![CDATA[H2 / C2]]> 0.0005 0.0005 <![CDATA[Partial pressure of C2 (psi)]]> 220 220 Catalyst loading (mg) 5.4 5.3 Yield (g) 95.59 106.14 Catalyst productivity 17,702 20,026 Mn 29,237 39,981 M 798,585 127,447 Mw / Mn 27.31 3.19 <![CDATA[C6 (% by weight)]]> 4.55 4.06 <![CDATA[Melt Index (I2)]]> 4.78 0.42 <![CDATA[Melt Index (I5)]]> 11.60 1.41 <![CDATA[Melt Index (I 21 )]]> 73.06 10.16 <![CDATA[I 21 / I2]]> 15.28 24.19 <![CDATA[I 21 / I5]]> 6.30 7.21 Melt temperature(℃) 119.8 120.4 MWCDI 1.34 0.88

[0141] Table 3

[0142]

[0143]

[0144] The data in Tables 1 to 3 illustrate that the polymers prepared with Examples 1-2 have improved (i.e., greater) molecular weight comonomer distribution indexes (MWCDI) compared to the polymers prepared with Comparative Example A-2. The data in Tables 1 to 3 illustrate that the polymers prepared with Examples 1-2 have molecular weight comonomer distribution indexes (MWCDI) > 0.

[0145] Additionally, the data in Tables 1-3 illustrate that the polymers prepared using Examples 1-2 have improved (ie, greater) comonomer incorporation (C6 wt %) compared to the polymer prepared using Comparative Example A-2.

Claims

1. An asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand, wherein the asymmetric zirconium metallocene is represented by structure (I): wherein each X is independently a leaving group.

2. An asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand according to claim 1, wherein each X is independently a leaving group selected from halogen, (C1-C5) alkyl, CH2SiMe3 and benzyl.

3. The asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand according to any one of claims 1 to 2, wherein each X is Cl, and the asymmetric zirconium metallocene is represented by structure (II):

4. The asymmetric zirconium metallocene with an isobutylcyclopentadienyl ligand according to any one of claims 1 to 2, wherein each X is CH3, and the asymmetric zirconium metallocene is represented by structure (III):

5. A method for synthesizing an asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand according to any one of claims 1 to 3, wherein each X is Cl, the method comprising: The zirconium complex is contacted with an alkali metal complex, wherein the alkali metal complex is represented by the following structure: wherein M' is lithium, sodium or potassium, and The zirconium complex is represented by the following structure: Where R 1 is H to prepare the asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand.

6. A method for synthesizing an asymmetric metallocene according to any one of claims 1 to 3, wherein each X is Cl, the method comprising: The zirconium complex is contacted with an alkali metal complex, wherein the alkali metal complex is represented by the following structure: Wherein M' is lithium, sodium or potassium, and R 1 is H; and The zirconium complex is represented by the following structure: To prepare the asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand.

7. The method according to any one of claims 5 to 6, comprising: The asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand is contacted with two molar equivalents of an organomagnesium halide of formula RMg(halide) or one molar equivalent of R2Mg, wherein R is (C1-C5)alkyl, CH2SiMe3 or benzyl; and the halide is Cl or Br, to prepare an asymmetric metallocene of structure (I), wherein each X is (C1-C5)alkyl, CH2SiMe3 or benzyl.

8. A metallocene catalyst composition, comprising: An asymmetric zirconium metallocene having an isobutylcyclopentadienyl ligand according to any one of claims 1 to 4, or the asymmetric metallocene prepared by the method according to any one of claims 5 to 7; and Activator. 9 . The metallocene catalyst composition according to claim 8 , further comprising a carrier.

10. The metallocene catalyst composition of claim 9, wherein the composition is a spray-dried metallocene catalyst composition.

11. A method for preparing a metallocene catalyst composition according to any one of claims 9 to 10, the method comprising any one of the following: contacting the asymmetric metallocene with the activator but not with the support to obtain the metallocene catalyst composition without the support; or contacting the asymmetric metallocene with the activator and the support to obtain the metallocene catalyst composition containing the support; Alternatively, the asymmetric metallocene is contacted with the activator and the support in an inert solvent to obtain a suspension thereof, and the suspension is spray-dried to obtain the spray-dried metallocene catalyst composition; or the asymmetric metallocene in an inert solvent is contacted with a supported or spray-dried activator (or its slurry) to obtain the spray-dried metallocene catalyst composition; or the asymmetric metallocene having an isobutylcyclopentadienyl ligand in an inert solvent is contacted with a supported or spray-dried activator (or its slurry) to obtain the spray-dried metallocene catalyst composition.

12. A method for preparing a polyolefin polymer, the method comprising: at least one olefin monomer is polymerized with the metallocene catalyst composition according to any one of claims 8 to 10 or the metallocene catalyst composition prepared by the method according to claim 11 to prepare the polyolefin polymer; wherein preferably, the at least one olefin monomer comprises ethylene and optionally a comonomer selected from the group consisting of propylene and (C4-C 20 )α-olefins.

13. The method of claim 12, wherein the at least one olefin monomer comprises ethylene and the comonomer; and wherein the polyolefin polymer has a molecular weight comonomer distribution index (MWCDI) from 0.10 to 10.00 as measured by the MWCDI test method described herein; wherein preferably, the comonomer is selected from the group consisting of: 1-butene, 1-hexene and 1-octene.

14. A polyolefin polymer prepared by the process according to any one of claims 12 to 13.

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