Asymmetric hafnium metallocene

Abstract

SUMMARY OF THE DISCLOSURE Embodiments of the present disclosure relate to asymmetric hafnium metallocenes, compositions comprising these asymmetric hafnium metallocenes, and methods of utilizing compositions comprising asymmetric hafnium metallocenes.

Description

[Technical Field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present disclosure relate to asymmetric hafnium metallocenes, catalyst compositions comprising asymmetric hafnium metallocenes, methods of making and using the same, and polyolefins made thereby. [Background technology]

[0002] Metallocenes can be used in a variety of applications, including polymerization catalysts. Polymers can be utilized in many articles, including, among others, films. Polymers can be formed by reacting one or more monomers in a polymerization reaction. The industry continues to focus on developing new and improved materials and / or processes that can be utilized in growth media. Summary of the Invention

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

[0004] An asymmetric hafnium metallocene represented by structure (I):

[0005] [ka] In the formula, R 1 is a (C1-C8) alkyl and each X is independently a leaving group.

[0006] A metallocene catalyst composition comprising an asymmetric hafnium metallocene and an activator.

[0007] A method for producing a metallocene catalyst composition comprising contacting an asymmetric hafnium metallocene with an activator.

[0008] A method for producing a polyolefin polymer, comprising polymerizing at least one olefin monomer with a metallocene catalyst composition to produce the polyolefin polymer. [Brief explanation of the drawings]

[0009] [Figure 1] 1 shows a data plot utilized to determine the Molecular Weight Comonomer Distribution Index (MWCDI) according to some embodiments of the present disclosure. [Figure 2] 1 shows a data plot utilized to determine the Molecular Weight Comonomer Distribution Index (MWCDI) according to some embodiments of the present disclosure. [Figure 3A] 1 shows a data plot utilized to determine the Molecular Weight Comonomer Distribution Index (MWCDI) according to some embodiments of the present disclosure. [Figure 3B] 1 shows a data plot utilized to determine the Molecular Weight Comonomer Distribution Index (MWCDI) according to some embodiments of the present disclosure. [Figure 4] 1 shows a data plot utilized to determine the Molecular Weight Comonomer Distribution Index (MWCDI) according to some embodiments of the present disclosure. [Figure 5] 1 shows a data plot utilized to determine the Molecular Weight Comonomer Distribution Index (MWCDI) according to some embodiments of the present disclosure. [Figure 6] 1 shows a data plot of molecular weight comonomer distribution index (MWCDI) versus density according to some embodiments of the present disclosure. [Figure 7] 1 shows a data plot of molecular weight comonomer distribution index (MWCDI) versus density according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Asymmetric hafnium metallocenes are discussed herein. Advantageously, these asymmetric metallocenes can be utilized, for example, to produce catalyst compositions. These catalyst compositions can be utilized to produce polymers having improved, i.e., higher, molecular weight comonomer distribution index (MWCDI) compared to other polymers produced from other metallocenes. These polymers are desirable for many applications, including, in particular, films. Therefore, it would be advantageous to provide improved MWCDIs. Such polymers would be advantageous for many applications.

[0011] The asymmetric hafnium metallocene may be represented by structure (I):

[0012] [ka] In the formula, R 1 is a (C1-C8) alkyl and each X is independently a leaving group. As shown in structure (I), the upper cyclopentadienyl ring is R 1 The cyclopentadienyl ring is substituted with an R group, and the lower cyclopentadienyl ring is unsubstituted. 1 Because one cyclopentadienyl ring is substituted with a group and the other cyclopentadienyl ring is unsubstituted, the metallocene may be referred to as an asymmetric metallocene.

[0013] One or more embodiments of the present disclosure may comprise R 1 is (C1-C8) alkyl. One or more embodiments of the present disclosure provide that R 1 is (C1-C7) alkyl. One or more embodiments of the present disclosure provide that R 1 is (C1-C6) alkyl. One or more embodiments of the present disclosure provide that R 1 is (C2-C5) alkyl. One or more embodiments of the present disclosure provide that R 1 is (C-C) alkyl. One or more embodiments of the present disclosure provide that R 1is (C3) alkyl. The (C3) alkyl may be branched or linear. As used herein, "Pr" and "n-Pr" refer to -CH2CH2CH3. One or more embodiments of the present disclosure provide that R 1 is a (C4) alkyl. The (C4) alkyl may be an isobutyl substituent.

[0014] 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 halogen, (C1-C5) alkyl, CH2SiMe3, and benzyl. One or more embodiments provide that X is selected from alkyl and halogen. One or more embodiments provide that X is Cl. One or more embodiments provide that X is methyl.

[0015] Examples of X include halogen ions, hydrides, (C1-C 12 ) Alkyl, (C2-C 12 ) alkenyl, (C6-C 12 ) Aryl, (C7-C 20 Alkylaryl, (C1-C 12 )Alkoxy, (C6-C 16 )aryloxy, (C7-C8)alkylaryloxy, (C1-C 12 Fluoroalkyl, (C6-C 12 Fluoroaryl, and (C1-C 12 ) heteroatom-containing hydrocarbons, and their substituted derivatives. One or more embodiments include hydrides, halides, (C1-C6) alkyls, (C2-C6) alkenyls, (C7-C 18 Alkylaryl, (C1-C6)alkoxy, (C6-C 14 ) Aryloxy, (C7-C 16 ) alkylaryloxy, (C1-C6) alkyl carboxylate, (C1-C6) fluorinated alkyl carboxylate (C6-C 12 ) Aryl carboxylate (C7-C18 Alkylarylcarboxylates, (C1-C6 fluoroalkyl, (C2-C6) fluoroalkenyl, and (C7-C 18 )fluoroalkylaryl. One or more embodiments include hydride, chloride, fluoride, methyl, phenyl, phenoxy, benzoxy, tosyl, fluoromethyl, and fluorophenyl. One or more embodiments include (C1-C 12 ) Alkyl, (C2-C 12 ) alkenyl, (C6-C 12 ) Aryl, (C7-C 20 ) Alkylaryl, substituted (C1-C 12 ) Alkyl, substituted (C6-C 12 Aryl, substituted (C7-C 20 Alkylaryl, and (C1-C 12 Heteroatom-containing alkyl, (C1-C 12 ) heteroatom-containing aryl, and (C1-C 12 ) heteroatom-containing alkylaryl. One or more embodiments include chloride, fluoride, (C1-C6) alkyl, (C2-C6) alkenyl, (C7-C 18 ) alkylaryl, halogenated (C1-C6) alkyl, halogenated (C2-C6) alkenyl, and halogenated (C7-C 18 ) alkylaryl. One or more embodiments include fluoride, methyl, ethyl, propyl, phenyl, methylphenyl, dimethylphenyl, trimethylphenyl, fluoromethyl (mono-, di-, and trifluoromethyl), and fluorophenyl (mono-, di-, tri-, tetra-, and pentafluorophenyl).

[0016] Other non-limiting examples of X groups include amines, phosphines, ethers, carboxylates, dienes, hydrocarbon groups having 1 to 20 carbon atoms, fluorinated hydrocarbon groups such as -CF (pentafluorophenyl), fluorinated alkyl carboxylates such as CF C(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, methylidene, methyoxy, ethoxy, propoxy, phenoxy, bis(N-methylanilide), dimethylamide, and dimethylphosphide groups, among others. In one embodiment, two or more Xs form part of a fused ring or ring system. In one or more embodiments, X can be a chloride ion, a bromide ion, a (C1-C2) ion, a methyl ... 10 ) Alkyl, (C2-C 12 ) may be a leaving group selected from the group consisting of alkenyl, carboxylate, acetylacetonate, and alkoxide. In one or more embodiments, X is methyl.

[0017] The asymmetric hafnium metallocenes discussed herein can be produced by contacting a hafnium complex with an alkali metal complex to produce the asymmetric hafnium metallocene. The asymmetric hafnium metallocenes discussed herein can be produced by processes using, for example, conventional solvents, reaction conditions, reaction times, and isolation procedures used to produce known metallocenes.

[0018] The alkali metal complex may be represented by one of the following structures:

[0019] [ka] where M' is lithium, sodium, or potassium, and R 1 is as defined as discussed herein.

[0020] One or more embodiments provide that the hafnium complex may be represented by one of the following structures:

[0021] [ka] In the formula, R 1 is defined as discussed herein.

[0022] One or more embodiments provide, for example, a method for producing an asymmetric metallocene where 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 an organomagnesium halide of formula R2Mg(halide), where R is (C1-C5)alkyl, CH2SiMe3, or benzyl, and the halide is Cl or Br, to produce an asymmetric metallocene of structure (I), wherein each X is (C1-C5)alkyl, CH2SiMe3, or benzyl. One or more embodiments provide that X is (C1-C5)alkyl, CH2SiMe3, or benzyl. As used herein, all references to the Periodic Table of the Elements and its Groups, unless they refer to the previous IUPAC system designated by Roman numerals (which are also designated similarly), or unless otherwise stated, are references to the NEW NOTATION published in HAWLEY'S CONDENSED CHEMICAL DICTIONARY, Thirteenth Edition, John Wiley & Sons, Inc., (1997) (reproduced with permission of IUPAC).

[0023] As used herein, "alkyl" includes straight-chain, branched-chain, and cyclic paraffinic groups that are deficient by one hydrogen. Thus, for example, CH ("methyl") and CHCH ("ethyl") are examples of alkyl.

[0024] As used herein, "alkenyl" includes straight-chain, branched-chain, and cyclic olefinic groups that are deficient by one hydrogen. Alkynyl groups include straight-chain, branched-chain, and cyclic acetylenic groups that are deficient by one hydrogen.

[0025] As used herein, "aryl" groups include phenyl, naphthyl, pyridyl, and other groups whose molecules have ring structures characteristic of benzene, naphthylene, phenanthrene, anthracene, etc. "Aryl" groups include C6-C 20 It is understood that the aromatic group may be an aryl group. For example, a C6H5 aromatic structure is "phenyl" and a C6H42 aromatic structure is "phenylene." An "arylalkyl" group is an alkyl group having an aryl group pendant therefrom. An "aralkyl" group is an alkyl group having a C7-C 20 It is understood that it may also be an aralkyl group. An "alkylaryl" is an aryl group having one or more alkyl groups pendant therefrom.

[0026] As used herein, "alkylene" includes straight-chain, branched-chain, and cyclic hydrocarbon groups deficient by two hydrogens. Thus, CH ("methylene") and CHCH ("ethylene") are examples of alkylene groups. Other groups deficient by two hydrogens include "arylene" and "alkenylene."

[0027] 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 a heteroatom, which in certain embodiments may contain one or more of the same or different heteroatoms, and from one to three heteroatoms. Non-limiting examples of heteroatom-containing groups include imine, amine, oxide, phosphine, ether, ketone, oxoazoline complex cyclic compound, oxazoline, and thioether groups (monoradical and diradical).

[0028] As used herein, the term "substituted" means that one or more hydrogen atoms in a parent structure are independently replaced by a substituent atom or group.

[0029] The asymmetric hafnium metallocenes discussed herein can be utilized to prepare catalyst compositions. These compositions include the asymmetric hafnium metallocenes discussed herein and an activator. One or more embodiments provide that the activator is an alkylaluminoxane, such as methylaluminoxane. As used herein, "activator" refers to any compound or combination of compounds, supported or unsupported, that can activate a complex or catalyst component, for example, by generating a cationic species of the catalyst component. For example, this can include abstraction of at least one leaving group, such as an "X" group described herein, from the metal center of the complex / catalyst component, e.g., an asymmetric hafnium metallocene of structure (I). The activator is sometimes referred to as a "cocatalyst." As used herein, "leaving group" refers to one or more chemical moieties that are bonded to a metal atom and capable of abstraction by an activator, thus generating a species active for olefin polymerization. Various catalyst compositions, e.g., olefin polymerization catalyst compositions, are known in the art, and different known catalyst composition components may be utilized. Varying amounts of the catalyst composition components may be utilized for different applications.

[0030] The asymmetric hafnium metallocenes discussed herein can be utilized to produce spray-dried compositions. As used herein, "spray-dried composition" refers to a composition containing several components that has undergone a spray-drying process. Various spray-drying processes are known in the art and are suitable for forming the spray-dried compositions disclosed herein. One or more embodiments provide that the spray-dried composition comprises a trim composition.

[0031] In one or more embodiments, the spray-drying process may include atomizing a composition comprising the asymmetric hafnium metallocene discussed herein. Several other known components may be utilized in the spray-drying process. For example, a spray or dispersion of droplets of the composition may be created using an atomizer, such as an atomizing nozzle or a centrifugal high-speed disk. The droplets of the composition may then be rapidly dried by contacting them with an inert drying gas. The inert drying gas may be any gas that is non-reactive under the conditions employed during atomization, such as nitrogen. The inert drying gas may contact the composition in an atomizer that continuously generates a droplet stream. Dried particles of the composition may be captured from the process in a separator, such as a cyclone, which may separate the formed solids from the gaseous mixture of the drying gas, solvent, and other volatile components.

[0032] The spray-dried composition may, for example, have the form of a free-flowing powder. After the spray-drying process, the spray-dried composition and certain known ingredients may be utilized to form a slurry. The spray-dried composition may be utilized with a diluent to form a slurry suitable for use in, for example, olefin polymerization. In one or more embodiments, the slurry may be combined with one or more additional catalysts or other known ingredients before being delivered to a polymerization reactor.

[0033] In one or more embodiments, the spray-dried composition may be formed by contacting spray-dried activator particles, such as spray-dried MAO, with a solution of the asymmetric hafnium metallocene discussed herein. Such a solution may typically be prepared, for example, in an inert hydrocarbon solvent and may also be referred to as a trim solution. Such a spray-dried composition, consisting of contacting a trim solution of the asymmetric hafnium metallocene with spray-dried activator particles, such as spray-dried MAO, may be prepared in situ in the feed line to the gas-phase polymerization reactor by contacting the trim solution with a slurry of spray-dried activator particles, typically in mineral oil.

[0034] Various spray drying conditions may be utilized for different applications. For example, the spray drying process may utilize a drying temperature of 75 to 185°C. Other drying temperatures are possible, and may depend on the metallocene and activator particles. Various sizes of orifices in the atomizing nozzle employed during the spray drying process may be utilized to obtain different particle sizes. Alternatively, in other types of atomizers, such as disks, the rotation speed, disk size, and number / size of holes may be adjusted to obtain different particle sizes. One or more embodiments provide that a filler may be utilized in the spray drying process. Different amounts of additives may be utilized for various applications.

[0035] Catalyst compositions such as the asymmetric hafnium metallocenes discussed herein, e.g., spray-dried hafnium metallocene compositions, may be utilized to produce polymers. For example, the asymmetric hafnium metallocene may be activated, i.e., an activator may be used to produce the catalyst. One or more embodiments provide that the spray-dried composition includes an activator. As used herein, "activator" refers to any compound or combination of compounds, supported or unsupported, that can activate a complex or catalyst component, for example, by generating a cationic species of the catalyst component to provide the catalyst. Activators are sometimes referred to as "cocatalysts." Activators can include Lewis acids or non-coordinating ionic activators or ionizing activators, or any other compounds, including Lewis bases, aluminum alkyls, and / or conventional cocatalysts. Activators include, among others, methylaluminoxane (MAO) and modified methylaluminoxane (MMAO). One or more embodiments provide that the activator is methylaluminoxane. Activation conditions are well known in the art. Known activation conditions may be utilized.

[0036] The molar ratio of the metal in the activator, e.g., aluminum to hafnium in the asymmetric hafnium metallocene, may be from 1500:1 to 0.5:1, from 300:1 to 1:1, or from 150:1 to 1:1. One or more embodiments provide that the molar ratio of the activator to hafnium in the asymmetric hafnium metallocene is at least 75:1. One or more embodiments provide that the molar ratio of the activator to hafnium in the asymmetric hafnium metallocene is at least 100:1. One or more embodiments provide that the molar ratio of the activator to hafnium in the asymmetric hafnium metallocene is at least 150:1.

[0037] The asymmetric hafnium metallocenes discussed herein, as well as some other components, may be supported on the same or separate supports, or one or more components may be used in unsupported form. Using a support can be achieved by any technique used in the art. One or more embodiments provide that a spray drying process is utilized. The support may be functionalized. One or more embodiments provide that the spray-dried composition includes a support.

[0038] "Support", which may also be referred to as "carrier", refers to any support material, including porous support materials such as talc, inorganic oxides, and inorganic chlorides. Other support materials include resinous support materials, functionalized or crosslinked organic supports such as polystyrene, polystyrene divinylbenzene polyolefins, or polymeric compounds, zeolites, clays, or any other organic or inorganic support material, or mixtures thereof.

[0039] Support materials include inorganic oxides, including Group 2, 3, 4, 5, 13, or 14 metal oxides. Some preferred supports include silica, fumed silica, alumina, silica-alumina, and mixtures thereof. Other supports include magnesia, titania, zirconia, magnesium chloride, montmorillonite, phyllosilicates, zeolites, talc, clay, and the like. Combinations of these support materials, such as silica-chromium, silica-alumina, and silica-titania, can also be used. One or more embodiments provide that the support is silica. One or more embodiments provide that the support is hydrophobic fumed silica. One or more embodiments provide that the support is dehydrated silica. Additional support materials include porous acrylic polymers, nanocomposites, aerogels, spherulites, and polymer beads. Additional support materials may include porous acrylic polymers, nanocomposites, aerogels, spherulites, and polymer beads. An example of a support is fumed silica available under the trade name Cabosil™ TS-610 or other TS or TG series supports available from Cabot Corporation. Fumed silica is typically silica with particles 7 to 30 nanometers in size that have been treated with dimethylsilyl dichloride so that most of the surface hydroxyl groups are capped.

[0040] The asymmetric hafnium metallocenes described herein, e.g., catalyst compositions / spray-dried compositions, can be contacted with olefins under polymerization conditions to produce polymers, e.g., polyolefin polymers. The polymerization process can be a solution polymerization process, such as a suspension polymerization process, a slurry polymerization process, and / or a gas phase polymerization process. The polymerization process can be used using known equipment and reaction conditions, e.g., known polymerization conditions. The polymerization process is not limited to any particular type of polymerization system. The polymers can be utilized in many articles, such as films, fibers, nonwoven and / or woven fabrics, extruded articles, and / or molded articles.

[0041] One or more embodiments provide that the polymer is produced using a gas-phase reactor system. For example, one or more embodiments provide that a single gas-phase reactor is utilized, as opposed to a series of reactors. In other words, the polymerization reaction occurs only in one reactor. For example, the polymer may be produced using a fluidized bed reactor. Gas-phase reactors are known, and known components may be utilized in a fluidized bed reactor.

[0042] As used herein, "olefin," which may be referred to as "alkene," refers to a linear, branched, or cyclic compound containing carbon and hydrogen and having at least one double bond. As used herein, when a polyolefin, polymer, and / or copolymer is referred to as comprising, e.g., produced from, an olefin, the olefin present in such a polymer or copolymer is the polymerized form of the olefin. For example, when a copolymer is said to have an ethylene content of 75% to 95% by weight, it is understood that the polymer units in the copolymer are derived from ethylene in the polymerization reaction(s), and the derived units are present in 75% to 95% by weight, based on the total weight of the polymer. Higher α-olefin refers to an α-olefin having three or more carbon atoms.

[0043] Polyolefins produced using the compositions discussed herein can be produced from olefin monomers such as ethylene (i.e., polyethylene) or propylene (i.e., polypropylene), among others provided herein, and the polyolefins are homopolymers produced solely from olefin monomers (e.g., 100% by weight ethylene or 100% by weight propylene). Alternatively, polyolefins produced using the compositions discussed herein can include polymers produced from olefin monomers such as ethylene, i.e., polyethylene, and linear or branched higher α-olefin monomers containing 3 to 20 carbon atoms. Examples of higher α-olefin monomers include, but are not limited to, propylene, butene, pentene, 1-hexene, and 1-octene. Examples of polyolefins include, among others, ethylene-based polymers having at least 50% by weight ethylene, such as ethylene-1-butene, ethylene-1-hexene, and ethylene-1-octene copolymers. One or more embodiments provide that the polymer can comprise 50 to 99.9 wt. % ethylene-derived units, based on the total weight of the polymer. All individual values and subranges between 50 and 99.9 wt. % are included, for example, the polymer can comprise from a lower limit of 50, 60, 70, 80, or 90 wt. % ethylene-derived units to an upper limit of 99.9, 99.7, 99.4, 99, 96, 93, 90, or 85 wt. % ethylene-derived units, based on the total weight of the polymer. The polymer can comprise 0.1 to 50 wt. % comonomer-derived units, based on the total weight of the polymer. One or more embodiments provide that ethylene is utilized as the monomer and hexene is utilized as the comonomer.

[0044] As noted above, polymers produced using the compositions disclosed herein can be produced in a fluidized bed reactor. The fluidized bed reactor can have a reaction temperature of 10 to 130° C. All individual values and subranges between 10 and 130° C. are included. For example, the fluidized bed reactor can have a reaction temperature from a lower limit of 10, 20, 30, 40, 50, or 55° C. to an upper limit of 130, 120, 110, 100, 90, 80, 70, or 60° C.

[0045] The fluidized bed reactor can have an ethylene partial pressure of from 30 to 250 pounds per square inch (psi), including all individual values and subranges between 30 and 250, for example, the fluidized bed reactor can have an ethylene partial pressure from a lower limit of 30, 45, 60, 75, 85, 90, or 95 psi to an upper limit of 250, 240, 220, 200, 150, or 125 psi.

[0046] One or more embodiments provide that ethylene is utilized as the monomer and hexene is utilized as the comonomer. The fluidized bed reactor may have a comonomer to ethylene molar ratio, e.g., C6 / C2, of 0.0001 to 0.100. All individual values and subranges from 0.0001 to 0.100 are included, for example, the fluidized bed reactor may have a comonomer to ethylene molar ratio from a lower limit of 0.0001, 0.0005, 0.0007, 0.001, 0.0015, 0.002, 0.007, 0.010, 0.016, or 0.024 to an upper limit of 0.100, 0.080, or 0.050. One or more embodiments provide that no comonomer is utilized.

[0047] If hydrogen is utilized in the polymerization process, the fluidized bed reactor may 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 may have a H2 / C2 from 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 no hydrogen is utilized.

[0048] Many polymer properties may be determined using conventional compositional gel permeation chromatography. For example, weight-average molecular weight (Mw), number-average molecular weight (Mn), Z-average molecular weight (Mz), and Mw / Mn (PDI) were determined using a chromatographic system consisting of a PolymerChar GPC-IR (Valencia, Spain) high-temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5). The autosampler oven compartment was set to 160°C, and the column compartment was set to 150°C. The columns used were four Agilent "Mixed A" 30 cm, 20 micron linear mixed-bed columns. The chromatographic solvent used was 1,2,4-trichlorobenzene containing 200 ppm butylated hydroxytoluene (BHT). The solvent source was nitrogen sparged. The injection volume used was 200 microliters, and the flow rate was 1.0 milliliters / minute.

[0049] Calibration of the GPC column set was performed using 21 narrow molecular weight distribution polystyrene standards ranging from 580 to 8,400,000 g / mol, arranged in six "cocktail" mixtures with at least one decade between individual molecular weights. Standards were purchased from Agilent Technologies. Polystyrene standards were prepared at 0.025 grams in 50 milliliters of solvent for molecular weights above 1,000,000 and 0.05 grams in 50 milliliters of solvent for molecular weights below 1,000,000. The polystyrene standards were predissolved at 80°C with gentle agitation for 30 minutes, then cooled, and the room temperature solution was transferred to an autosampler dissolving oven at 160°C for 30 minutes to cool. The peak molecular weights of the polystyrene standards were converted to polyethylene molecular weights using Equation 1 (as described in Williams and Ward, J. Polym. Sci., Polym. Let., 6, 621 (1968)). M ポリエチレン =A×(M ポリスチレン ) B (Formula 1) where M is the molecular weight, A has a value of 0.4061, and B is equal to 1.0.

[0050] A fifth order polynomial was used to fit each polyethylene equivalent calibration point.

[0051] A total plate count for the GPC column set was performed using decane as a blank sample introduced via a micropump controlled using a PolymerChar GPC-IR system. The plate count for the chromatography system should exceed 18,000 for four Agilent "Mixed A" 30 cm 20 micron linear mixed-bed columns.

[0052] Samples were prepared in a semi-automated fashion using PolymerChar's "Instrument Control" software, with a target sample weight of 2 mg / ml, by adding the solvent (containing 200 ppm BHT) via a PolymerChar high-temperature autosampler to a pre-nitrogen-sparged, septum-capped vial. The sample was dissolved at 160°C under "slow" shaking for 2 hours.

[0053] Mn (GPC) , Mw (GPC) , and Mz (GPC) The calculation was based on GPC results using the internal IR5 detector (measurement channel) of the PolymerChar GPC-IR chromatograph according to Equations 2-4 using PolymerChar's GPCONE software, baseline-subtracted IR chromatograms at each equally spaced data collection point (i), and polyethylene equivalent molecular weights obtained from a narrow standard calibration curve for point (i) of Equation 1.

[0054]

number

[0055] To monitor deviations over time, a flow marker (decane) was introduced into each sample via a micropump controlled by the PolymerChar GPC-IR system. This flow marker (FM) was aligned with the respective decane peak (RV) in the sample. (FM試料) ) to narrow standard calibration (RV (FM較正済み) The pump flow rate (flow rate) of each sample was calculated by matching the RV with the decane peak in the (公称) ) was used to linearly calibrate the flow rate (flow rate). Any change in the time of the decane marker peak was then correlated with the flow rate (flow rate (有効) ) is assumed to be related to a linear shift in the apparent flow rate. After calibrating the system based on the flow rate marker peaks, the effective flow rate (for a narrow standard calibration) is calculated as per Equation 5. Processing of the flow rate marker peaks was performed via PolymerChar's GPCONE software. An acceptable flow rate correction is such that the effective flow rate should be within ±0.5% of the apparent flow rate. Flow rate (effective) = Flow rate (nominal) * (RV(FM calibrated) / RV(FM sample)) (Equation 5)

[0056] IR5 GPC Octene Composition Calibration. Quantitative calibration of the IR5 detector is based on a narrow SCB distribution ranging from homopolymer (0 SCB / 1000 total carbons) to approximately 40 SCB / 1000 total carbons (where total C = carbons in the main chain + carbons in the branches) and known comonomer content ( 13 A study was conducted using at least 10 ethylene-based polymer standards (octene as a comonomer) produced by single-site metallocene catalysis from a single reactor (polyethylene homopolymer and ethylene / octene copolymer) in a solution process (measured by C NMR Method, Qiu et al., Anal. Chem. 2009, 81, 8585-8589). Each standard had a weight average molecular weight (Mw) of 36,000 g / mol to 126,000 g / mol as measured by GPC. Each standard had a molecular weight distribution (Mw / Mn) of 2.0 to 2.5. The polymer properties of the SCB standards are shown in Table A.

[0057] [Table 1]

[0058] The "IR5 area ratio" (or "IR5 area ratio") of the "baseline-subtracted area response of the IR5 methyl channel sensor" to the "baseline-subtracted area response of the IR5 measurement channel sensor" メチルチャネル面積 / IR5 測定チャネル面積 ")" (Standard filters and filter wheel supplied by PolymerChar: Part Number IR5_FWM01 included as part of the GPC-IR instrument) were calculated for each of the "copolymer" standards. A linear fit of wt% comonomer frequency versus "IR5 area ratio" was constructed in the form of Equation 6 below. Wt% Comonomer = A0 + [A1 × (IR5 メチルチャネル面積 / IR5 測定チャネル面積 )] (Equation 6) where A0 is the "wt% comonomer" at an "IR5 area ratio" of zero, and A1 is the slope of "wt% comonomer" vs. "IR5 area ratio," representing the increase in wt% comonomer as a function of "IR5 area ratio." The IR5 area ratio is equal to the IR5 height ratio for the narrow PDI and narrow SCBD standard material.

[0059] Melt strength measurements were performed on a Goettfert Rheotens 71.97 (Goettfert Inc., Rock Hill, SC) attached to a Goettfert Rheotester 2000 capillary rheometer. The molten sample (approximately 25-30 grams) was fed into the Goettfert Rheotester 2000 capillary rheometer with a length of 30 mm, a diameter of 2.0 mm, and a flat entrance angle (180 degrees) with an aspect ratio (length / diameter) of 15. After equilibrating the sample at 190°C for 10 minutes, the piston was run at a constant piston speed of 0.265 mm / sec. The standard test temperature was 190°C. The sample was accelerated at 2.4 mm / sec against a set of acceleration wheels located 100 mm below the die. 2 The force applied to the wheel was recorded as a function of the wheel winding speed.

[0060] The following conditions were used in the melt strength measurements: plunger speed = 0.265 mm / s, wheel acceleration = 2.4 mm / s, capillary diameter = 2.0 mm, capillary length = 30 mm; and barrel diameter = 12 mm. Melt strength was reported as the average plateau force (cN) before the strand broke.

[0061] The rheology of each composition was analyzed by dynamic mechanical spectroscopy (DMS) using an Advanced Rheometric Expansion System (ARES) equipped with 25 mm stainless steel parallel plates under a nitrogen purge. Constant-temperature dynamic frequency sweeps ranging from 0.1 to 100 rad / s were performed at 190°C under nitrogen (see Tables 9 and 10). Samples approximately 25 mm in diameter and 3.3 mm thick were cut from compression-molded disks (see below). The samples were placed on the lower plate and allowed to equilibrate for 5 minutes. The plates were then closed to a 2.0 mm gap, and the samples were trimmed to a 25 mm diameter. Before testing began, the samples were allowed to equilibrate at 190°C for 5 minutes. The complex viscosity was measured at a constant strain amplitude of 10%. The stress response was analyzed in terms of amplitude and phase, from which the storage modulus (G'), loss modulus (G"), and dynamic viscosity η were calculated. * The viscosity (V0.1 and V100) was recorded, where V0.1 is the complex viscosity at 0.1 rad / s (190°C) and V100 is the complex viscosity at 100 rad / s (190°C). Viscosity is reported in Pascal-seconds (Pa s).

[0062] For each composition, samples were prepared by compression molding approximately 2.3 g of material in a 2 in x 3 in x 3 mm thick TEFLON-coated chase at 190°C for 5 minutes at 10 MPa pressure, followed by quenching between cooled platens (15-20°C) for 2 minutes.

[0063] The comonomer distribution or short-chain branching distribution in ethylene / α-olefin copolymers can be characterized as either normal (also referred to as having a Ziegler-Natta distribution), inverted, or flat. Several reported methods are used to quantify broad orthogonal composition distributions (BOCDs). Herein, a simple line fit is used so that the normal or inverted 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 obtained from compositional GPC measurements, where the x-axis is Log(MW) and the y-axis is the weight percent comonomer. Figure 1 shows the data plots used to determine the MWCDI for Example 1-2 (MWCDI = 6.58) and Comparative Example A-2 (MWCDI = 3.60), as shown in Table 1 in the Examples section of this application. An inverted comonomer distribution is defined when the MWCDI is greater than 0, and a normal comonomer distribution is defined when the MWCDI is less than 0. When MWCDI=0, the comonomer distribution is said to be flat. In addition, MWCDI quantifies the magnitude of the comonomer distribution. When comparing two polymers with MWCDI>0, the polymer with the larger MWCDI value is defined as having a larger, i.e., increased BOCD. In other words, the polymer with the larger MWCDI value has a more inverse comonomer distribution. For example, as reported in Table 1, the polymers produced in Examples 1-2 each have an increased BOCD compared to the polymer produced in Comparative Example A-2. Polymers with a relatively large MWCDI, i.e., BOCD, may provide improved physical properties, such as improved film properties, compared to polymers with a relatively small MWCDI.

[0064] Polymers made with the compositions disclosed herein can have an MWCDI of 0.10 to 10.00, including all individual values and subranges between 0.10 and 10.00, for example, polymers can have a MWCDI from 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.

[0065] The polymers produced with the compositions disclosed herein have a viscosity of 0.8700 to 0.9700 g / cm 3 It may have a density of 0.8700 to 0.9700 g / cm 3 All individual values and subranges are included, for example, a polymer may have a viscosity of 0.8700, 0.9000, 0.9100, 0.9150, 0.9200, or 0.9250 g / cm 3 from the lower limit of 0.9700, 0.9600, 0.9500, 0.9450, 0.9350, or 0.9300 g / cm 3 The density may be determined according to ASTM D792.

[0066] Polymers made with the compositions disclosed herein may have a melt index (I2) of 0.0 to 1500 dg / min. I2 may be determined according to ASTM D1238 (190°C, 2.16 kg). Note that an I2 of 0.0 dg / min may be referred to as "no flow." All individual values and subranges between 0.0 and 1500 dg / min are included; for example, the polymers may have an I2 from lower limits of 0.0, 0.05, 0.07, 0.10, 0.20, 0.30, or 0.50 dg / min to upper limits of 1500, 1200, 1000, 500, 200, 120, or 100 dg / min.

[0067] Polymers produced with the compositions disclosed herein can have a weight average molecular weight (Mw) of 10,000 to 1,000,000 g / mol. All individual values and subranges between 10,000 and 1,000,000 g / mol are included. For example, polymers can have Mw from lower limits of 10,000, 50,000, or 100,000 g / mol to upper limits of 1,000,000, 750,000, or 500,000 g / mol. Mw can be determined by gel permeation chromatography (GPC), as known in the art. GPC is discussed herein.

[0068] Polymers produced with the compositions disclosed herein can have a number average molecular weight (Mn) of 5,000 to 300,000 g / mol. All individual values and subranges between 5,000 and 300,000 g / mol are included. For example, the polymers can have Mn from lower limits of 5,000, 20,000, or 40,000 g / mol to upper limits of 300,000, 250,000, or 200,000 g / mol. Mn can be determined by GPC, as described below.

[0069] Polymers produced using the compositions disclosed herein can have a Z-average molecular weight (Mz) of 40,000 to 2,000,000 g / mol. All individual values and subranges between 40,000 and 2,000,000 g / mol are included. For example, the polymers can have a Z-average molecular weight (Mz) from lower limits of 40,000, 100,000, or 250,000 g / mol to upper limits of 2,000,000, 1,800,000, or 1,650,000 g / mol. Mz can be determined by GPC.

[0070] Polymers produced using the compositions disclosed herein can have a weight average molecular weight to number average molecular weight ratio (Mw / Mn) of 2.00 to 6.00, including all individual values and subranges between 2.00 and 6.00, for example, polymers can have Mw / Mn from lower limits of 2.00, 2.50, or 3.00 to upper limits of 6.00, 5.50, or 4.50.

[0071] Some aspects of the present disclosure are provided below.

[0072] Embodiment 1 is an asymmetric hafnium metallocene represented by structure (I):

[0073] [ka] In the formula, R 1 is (C1-C8) alkyl and each X is independently a leaving group.

[0074] Embodiment 2 provides the asymmetric hafnium metallocene of embodiment 1, wherein each X is independently a leaving group selected from halogen, (C1-C5) alkyl, CH2SiMe3, and benzyl.

[0075] Aspect 3 is R 1 is (C3-C4) alkyl and each X is Cl, or each X is CH3.

[0076] Aspect 4 is Structure (II)~(V):

[0077] [ka] The asymmetric hafnium metallocene of embodiment 1 is selected from the group consisting of hafnium asymmetric metallocenes represented by

[0078] Aspect 5 is Structure (II)~(III):

[0079] [ka] The asymmetric hafnium metallocene of embodiment 1 is selected from the group consisting of hafnium asymmetric metallocenes represented by

[0080] Aspect 6 is Structure (IV)~(V):

[0081] [ka] The asymmetric hafnium metallocene of embodiment 1 is selected from the group consisting of hafnium asymmetric metallocenes represented by

[0082] Embodiment 7 is a method of synthesizing the asymmetric hafnium metallocene of any one of Embodiments 1-6, wherein each X is Cl, comprising: contacting the hafnium complex with an alkali metal complex, wherein the alkali metal complex is represented by the following structure:

[0083] [ka] M' is lithium, sodium, or potassium; The hafnium complex is represented by one of the following structures:

[0084] [ka] In the formula, R 1 is as defined in the above aspects, or contacting the hafnium complex with an alkali metal complex, wherein the alkali metal complex is represented by the following structure:

[0085] [ka] wherein M' is lithium, sodium, or potassium; R 1 is as defined in the above embodiment, the hafnium complex is represented by the following structure:

[0086] [ka] A method for producing an asymmetric hafnium metallocene is provided.

[0087] Embodiment 8 provides the method of embodiment 7, comprising contacting the asymmetric hafnium metallocene with two molar equivalents of an organomagnesium halide of formula RMg(halide) or one molar equivalent of R2Mg, where R is (C1-C5) alkyl, CH2SiMe3, or benzyl, and the halide is Cl or Br, to produce the asymmetric hafnium metallocene of structure (I), wherein each X is (C1-C5) alkyl, CH2SiMe3, or benzyl.

[0088] Aspect 9 is a metallocene catalyst composition comprising: A metallocene catalyst composition is provided that includes the asymmetric hafnium metallocene of any one of embodiments 1-6, or the asymmetric metallocene produced by the method of embodiment 7 or embodiment 8, and an activator (e.g., an alkylaluminoxane such as methylaluminoxane).

[0089] Embodiment 10 provides the metallocene catalyst composition of embodiment 8, further comprising a support (e.g., silica, such as hydrophobic fumed silica or dehydrated silica).

[0090] Embodiment 11 provides the metallocene catalyst composition of embodiment 10, wherein the composition is a spray-dried metallocene catalyst composition.

[0091] Embodiment 12 provides a method of making the metallocene catalyst composition of any one of Embodiments 9-11, comprising contacting an asymmetric hafnium metallocene with an activator rather than a support to obtain the metallocene catalyst composition of Embodiment 9 without a support; or contacting an asymmetric hafnium metallocene with an activator and a support to obtain the metallocene catalyst composition of Embodiment 10 with a support; or contacting an asymmetric hafnium metallocene with an activator and a support in an inert solvent to obtain the metallocene catalyst composition of Embodiments 10-11; or contacting an asymmetric hafnium metallocene with an activator and a support in an inert solvent to obtain a suspension thereof and spray drying the suspension to obtain the spray-dried metallocene catalyst composition of Embodiment 11; or contacting an asymmetric hafnium metallocene in an inert solvent with a supported or spray-dried activator (or a slurry thereof) to obtain the spray-dried metallocene catalyst composition of Embodiment 11.

[0092] Example 13 is a method of producing a polyolefin polymer, comprising polymerizing at least one olefin monomer with the metallocene catalyst composition of any one of Examples 9-11, or with the metallocene catalyst composition produced by the method of Example 12, to produce a polyolefin polymer, preferably the at least one olefin monomer is ethylene and, optionally, propene and (C4-C 20 and a comonomer selected from the group consisting of: α-olefins.

[0093] Example 14 provides the method of example 13, wherein the at least one olefin monomer comprises ethylene and a comonomer, and the polyolefin polymer has a Molecular Weight Comonomer Distribution Index (MWCDI) of 0.10 to 10.00, as measured by the MWCDI test method described herein, and preferably the comonomer is selected from the group consisting of 1-butene, 1-hexene, and 1-octene.

[0094] Aspect 15 provides a polyolefin polymer produced by the method of any one of aspects 13-14.

[0095] Aspect 16 is a method for producing a polyolefin polymer having an MWCDI of >-133. * 16. The polyolefin polymer of embodiment 15 is provided having a MWCDI to density relationship such that density is +126.75.

[0096] Aspect 17 is a polyolefin polymer having an MWCDI > -157.75 * 16. The polyolefin polymer of embodiment 15 is provided having a MWCDI to density relationship such that density is +150.62.

[0097] Embodiment 18 is a method of producing a polyolefin polymer, comprising polymerizing at least one olefin monomer with a spray-dried asymmetric hafnium metallocene catalyst composition to produce a polyolefin polymer, wherein the at least one olefin monomer is ethylene and, optionally, propene and (C4-C 20 and a comonomer selected from the group consisting of α-olefins, wherein the polyolefin polymer has a molecular weight comonomer distribution index (MWCDI) of 0.10 to 10.00 and a MWCDI > -133. * The method has a MWCDI to density relationship such that density is +126.75.

[0098] Aspect 19 is a polyolefin polymer having an MWCDI > -157.75 * 20. The method of embodiment 18, wherein the MWCDI to density relationship is such that density is +150.62. [Example]

[0099] Hafnium complex I, which can be represented by the following structure: (n-propylcyclopentadienyl) hafnium trichloride, dimethoxyethane adduct

[0100] [ka] (n-Propylcyclopentadienyl)hafnium trichloride, dimethoxyethane adduct was synthesized as follows (e.g., by adapting the procedure described in WO 2016 / 168448(A1) by Harlan): Bis-(n-propylcyclopentadienyl)hafnium dichloride was commercially obtained from TCI. Bis(n-propylcyclopentadienyl)hafnium dichloride (25.1 g, 54.1 mmol) was heated to 140 °C in a 100 mL round-bottom flask until melted. HfCl4 (17.5 g, 54.6 mmol) was added to the flask as a solid powder. The contents of the flask were heated at 140 °C for approximately 30 minutes, forming a brown, viscous liquid. The 100 mL round-bottom flask was attached to a short-path distillation apparatus consisting of glass tubing (90° bend) attached to a Schlenk flask. Vacuum was applied through the stopper of the Schlenk flask. Distillation was carried out at 105-110°C under a vacuum of 0.4 Torr. After approximately 1 hour, it was observed that most of the material had either distilled / sublimed into the Schlenk flask or remained in the glass tube. The solid material in the U-tube was scraped off and combined with the material in the Schlenk flask. Toluene (50 mL) and dimethoxyethane (50 mL) were added to the solid. This was heated to reflux to form a solution, and additional toluene (50 mL) was added. Upon cooling, colorless needles formed. Pentane (200 mL) was added, causing further formation of a solid precipitate. The solid was isolated by filtration, washed with pentane (2 x 50 mL), and dried under vacuum to give (n-propylcyclopentadienyl)hafnium trichloride, dimethoxyethane adduct (42.2 g). The combined supernatant and washings were cooled to yield an additional 2.6 g of product, which was isolated.

[0101] Example 1-1 is an asymmetric hafnium metallocene that can be represented by the following structure (II):

[0102] [ka] It was synthesized as follows: In the above formula, R 1is (C3) alkyl(n-propyl), as discussed above. In a glovebox, (n-propylcyclopentadienyl)hafnium trichloride dimethoxyethane adduct (0.75 g, 1.56 mmol) was added to a vessel (oven-dried 4 oz. glass jar). A Teflon-coated stir bar and 40 mL of dry toluene (40 mL) were added to the vessel, and the contents were stirred. The contents were observed to be gray and cloudy. Cyclopentadienyllithium (1 molar equivalent) was slowly added to the vessel. The vessel contents were then stirred at about 20°C for about 12 hours. NMR spectra indicated the formation of Example 1-1, as well as some unreacted starting material. The vessel contents were further stirred at about 20°C for about 120 hours. The vessel contents were then filtered, and volatiles were removed under reduced pressure. The solid was recrystallized from warm hexane and toluene. The resulting solid (Example 1-1) was isolated (63.9% overall yield after recrystallization). Example 1-1 was confirmed by 1H and 13C NMR spectra. 1 H NMR(400MHz,C6D6)δ5.86(s,3H),5.77-5.72(m,2H),5.57(t,J=2.7Hz,2H),2.63-2.54(m,2H),1.48-1.35(m,2H),0.80(t,J=7.3Hz,3H). 13 C NMR(101MHz,C6D6)δ132.81,115.78,114.13,110.86,32.38,24.34,14.00.

[0103] Spray-dried composition Example 1-2 was prepared as follows: In a nitrogen-purged glovebox, hydrophobic fumed silica (CABOSIL TS-610, 1.325 grams) and toluene (37.5 grams) were added to a container and mixed, followed by the addition of a 10 wt% solution of methylaluminoxane (MAO) in toluene (11 grams). The contents of the container were stirred for approximately 15 hours. Example 1-1 (0.054 grams) was then added to the container, and the contents of the container were stirred for approximately 45 minutes. The contents of the container were then spray-dried using a Buchi Mini Spray Dryer B-290 (set temperature 185°C, reaction temperature 100°C, pump speed 150 rpm) to provide Example 1-2.

[0104] Examples 1-3 are asymmetric hafnium metallocenes that can be represented by the following structure (III):

[0105] [ka] It was synthesized as follows.

[0106] Example 1-1 (8.5 g, 20.2 mmol) was dissolved in ether (80 mL) in a vessel. Methylmagnesium bromide (13.4 mL, 3.0 M in EtO, 40.3 mmol) was added dropwise to the contents of the vessel via syringe. The contents of the vessel were then stirred at about 20° C. for about 12 hours. The volatiles were then removed by vacuum, and hexane (30 mL) was added to the contents of the vessel. The contents were then filtered through Celite to remove insoluble by-products. The contents and Celite filter were washed with additional hexane (30 mL). The solvent was removed from the filtrate in vacuo to give Example 1-3, which was observed to be an off-white solid (7.11 g, 93%). 1 H NMR(400MHz,C6D6):δ5.70(s,4H),5.57(t,J=2.6Hz,2H),5.41(t,J=2.7Hz,2H),2. 33-2.26(m,2H),1.48(dq,J=14.8,7.4Hz,2H),0.87(t,J=7.3Hz,3H),-0.30(s,6H). 13 C NMR (101MHz, C6D6): δ127.08, 110.65, 109.89, 107.39, 36.43, 32.35, 25.22, 14.12.

[0107] 5-(2-methylpropylidene)cyclopenta-1,3-diene, which can be represented by the following structure:

[0108] [ka] The synthesis was carried out as follows: In a glovebox, pyrrolidine (1.45 g, 10 mol%) was added to a glass vessel containing a solution of isobutyraldehyde (14.6 g, 203 mmol) and cyclopentadiene (13.4 g, 203 mmol) in MeOH-HO (200 mL 4 / 1). The contents of the vessel were transferred to an ice-cold mixture of brine solution and 10 mol% AcOH in a narrow graduated cylinder. The organic phase was isolated and dried over molecular sieves. The product (5-(2-methylpropylidene)cyclopenta-1,3-diene) was filtered to give a bright yellow oil, which was subsequently used without further purification (16.0 g, 65%). 1 H 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). 13 C NMR(101MHz, CDCl3)δ:149.88,143.69,133.08,130.87,126.06,119.36,30.58,23.24.

[0109] Iso-butylcyclopentadienyllithium, which can be represented by the following structure:

[0110] [ka] It was synthesized as follows.

[0111] Et2O (250 mL) was added to the vessel. 5-(2-methylpropylidene)cyclopenta-1,3-diene (16.0 g, 133 mmol) was added to the contents of the vessel with stirring. LiAlH4 (33 mL, 4 M Et2O solution) was added dropwise to the contents of the vessel with stirring. Bubbling was observed. A white solid precipitated during the addition, and the yellow color gradually disappeared as the addition of LiAlH4 continued. The addition was stopped when the solution turned a very faint yellow color. The product, iso-butylcyclopentadienyllithium, observed to be a white solid, was collected by filtration, rinsed with Et2O, and dried under vacuum (13.7 g, 80%).

[0112] Hafnium complex II, which can be represented by the following structure:

[0113] [ka] It was synthesized as follows.

[0114] Iso-butylcyclopentadienyllithium (0.150 g, 1.17 mmol) and hafnium tetrachloride (0.187 g, 0.585 mmol) were added to a vessel along with THF and stirred at about 20° C. for about 12 hours. The contents of the vessel were then concentrated to give an off-white residue. The residue was extracted with dichloromethane and then filtered. The resulting solution was placed under vacuum to give hafnium complex II (0.276 g, 96%). 1 H NMR(400MHz,C6D6)δ:5.83(t,J=2.7Hz,4H),5.72-5.61(m,4H),2.57(d,J=7.0Hz,4H),1.62(dq,J=13.5,6.8Hz,2H),0.80(d,J=6.6Hz,12H). 13 C NMR(101MHz,C6D6)δ:130.67,116.15,110.24,39.50,30.32,22.09.

[0115] Hafnium complex III, which can be represented by the following structure:

[0116] [ka] It was synthesized as follows.

[0117] Hafnium tetrachloride (0.33 g, 1.0 mmol) and hafnium complex II bis(iso-butylcyclopentadienyl)hafnium dichloride (0.50 g, 1.0 mmol) were mixed in a large screw-cap container. The contents of the container turned to a viscous brown liquid upon heating. Colorless vapor began to appear on the side of the container at approximately 150 °C. At this point, the heat was adjusted to 150 °C. A white solid began to form with a colorless vapor line. After approximately 5 minutes, the container was removed from the heat and allowed to cool under a nitrogen atmosphere. The white solid was manually scraped from the container and transferred to a second container. After removing most of the white solid, the container was placed under vacuum and reheated to 150 °C for 5 minutes. A second crop of white solid was obtained and combined with the first set of isolated material to give hafnium complex III (0.59 g, 72%). 1 H NMR(400MHz,C6D6)δ5.81(t,J=2.7Hz,2H),5.75(t,J=2.7Hz,2H),2.27(d,J=7.0Hz,3H),1.35(dq,J=13.5,6.7Hz,1H),0.59(d,J=6.6Hz,8H). 13 C NMR(101MHz,C6D6)δ134.94,116.61,116.04,38.83,30.18,21.67.

[0118] Example 2-1, an asymmetric hafnium metallocene, can be represented by the following structure:

[0119] [ka] The synthesis was carried out as follows: Hafnium Complex III (0.100 g, 246 mmol) and cyclopentadienyllithium (0.021 g, 0.246 mmol) were added to a vessel. EtO was then added to the vessel, and the contents of the vessel were stirred at about 20° C. for about 12 hours. The contents of the vessel were filtered and then concentrated under vacuum to give Example 2-1 (0.098 g, 88%). 1 H NMR(400MHz,C6D6)δ5.79(t,J=2.7Hz,2H),5.75-5.70(m,1H),5.62(t,J=2.7Hz,1H),5.60(t,J=2.7Hz,1H),2 .54(d,J=7.0Hz,2H),2.25(d,J=2.5Hz,1H),2.18(s,3H),1.60(dq,J=13.5,6.7Hz,1H),0.78(d,J=6.7Hz,6H). 13 C NMR(101MHz,C6D6)δ116.43,116.23,110.71,110.66,39.86,30.71,22.46.

[0120] Spray-dried composition Example 2-2 was prepared as follows: In a nitrogen-purged glovebox, hydrophobic fumed silica (CABOSIL TS-610, 0.665 grams) and toluene (19 grams) were added to a container and mixed, followed by the addition of a 10 wt% solution of methylaluminoxane (MAO) in toluene (5.5 grams). The contents of the container were stirred for approximately 15 hours. Example 2-1 (0.022 grams) was then added to the container, and the contents of the container were stirred for approximately 45 minutes. The contents of the container were then spray-dried using a Buchi Mini Spray Dryer B-290 (set temperature 185°C, reaction temperature 100°C, pump speed 150 rpm) to provide Example 2-2.

[0121] Comparative Example A-1, a hafnium metallocene having two substituted cyclopentadienyl rings, can be represented by the following structure:

[0122] [ka] It was synthesized as follows: Bis-(n-propylcyclopentadienyl)hafnium dichloride was obtained commercially from TCI and is readily converted to bis-(n-propylcyclopentadienyl)hafnium dimethyl by reaction with a methylating agent, such as a Grignard reagent, for example, methylmagnesium bromide, by one skilled in the art.

[0123] The spray-dried composition, Comparative Example A-2, was prepared as follows: In a nitrogen-purged glovebox, hydrophobic fumed silica (CABOSIL TS-610, 2.65 grams) and toluene (75 grams) were added to a container and mixed, followed by the addition of a 10 wt % solution of methylaluminoxane (MAO) in toluene (22 grams). The contents of the container were stirred for approximately 15 hours. Comparative Example A-1 (0.105 grams) was then added to the container, and the contents of the container were stirred for approximately 45 minutes. The contents of the container were then spray-dried using a Buchi Mini Spray Dryer B-290 (set temperature 185°C, reaction temperature 100°C, pump speed 150 rpm) to provide Comparative Example A-2.

[0124] Comparative Example B-1, a hafnium metallocene having two substituted cyclopentadienyl rings, can be represented by the following structure:

[0125] [ka] The synthesis was carried out as follows: In a glovebox, (n-propylcyclopentadienyl)hafnium trichloride, dimethoxyethane adduct (0.75 grams, 1.56 mmol) was added to a glass jar (4 oz) containing dry toluene (40 mL) while stirring with a Teflon-coated stir bar. The contents of the jar were observed to be gray and cloudy. Methylcyclopentadienyllithium (MeCpLi) (1 molar equivalent) was then slowly added to the contents of the jar, and the contents of the jar were stirred at room temperature (approximately 20°C) for approximately 12 hours. The contents of the jar were then filtered, and volatiles were removed from the filtrate under reduced pressure to yield Comparative Example B-1 (0.618 g, 91.2%). The product was confirmed by H and C NMR spectroscopy. 1 H NMR(400MHz,C6D6)δ5.80-5.68(m,3H),5.61(dt,J=5.5,2.7Hz,3H),2.64-2 .55(m,2H),2.17(d,J=0.6Hz,3H),1.49-1.36(m,2H),0.80(t,J=7.4Hz,3H). 13 C NMR(101MHz,C6D6)δ132.51,116.18,115.40,110.75,110.71,32.42,24.39,15.37,14.01.

[0126] The spray-dried composition, Comparative Example B-2, was prepared as follows: In a nitrogen-purged glovebox, hydrophobic fumed silica (CABOSIL TS-610, 1.325 grams) and toluene (37.5 grams) were added to a container and mixed, followed by the addition of a 10 wt % solution of methylaluminoxane (MAO) in toluene (11 grams). The contents of the container were stirred for approximately 15 hours. Comparative Example B-1 (0.056 grams) was then added to the container, and the contents of the container were stirred for approximately 45 minutes. The contents of the container were then spray-dried using a Buchi Mini Spray Dryer B-290 (set temperature 185°C, reaction temperature 100°C, pump speed 150 rpm) to provide Comparative Example B-2.

[0127] A spray-dried composition, Comparative Example C-1, was prepared as follows: In a nitrogen-purged glovebox, hydrophobic fumed silica (CABOSIL TS-610, 1.33 grams) and toluene (37.5 grams) were added to a container and mixed, followed by the addition of a 10 wt % solution of methylaluminoxane (MAO) in toluene (11 grams). The contents of the container were stirred for approximately 15 hours. Hafnium Complex II (0.049 grams) was then added to the container, and the contents of the container were stirred for approximately 45 minutes. The contents of the container were then spray-dried using a Buchi Mini Spray Dryer B-290 (set temperature 185°C, reaction temperature 100°C, pump speed 150 rpm) to provide Comparative Example C-1.

[0128] Polymerizations were conducted as follows. For each polymerization, dry NaCl (200 g) was charged to a laboratory-scale gas-phase polymerization reactor (a 2-liter stainless steel autoclave equipped with a variable-speed mechanical stirrer) and heated to 100°C under a nitrogen stream for 1 hour. The reactor was then purged with nitrogen, silica-supported methylaluminoxane was added to the reactor as a scavenger, the reactor temperature was adjusted to approximately the desired temperature, the reactor was sealed, and the reactor contents were stirred. The reactor was precharged with hydrogen, ethylene, and 1-hexene to the desired pressure. Once steady state was reached, the catalyst was charged to the reactor (at the temperature indicated below) to initiate the polymerization. The reactor temperature was maintained at the desired temperature for 60 minutes of polymerization. The hydrogen, C6 / C2 ratio, and ethylene pressure were maintained constant. At the end of the 60-minute polymerization, the reactor was cooled, vented, and opened. The resulting mixture was washed with water and methanol and dried. The polymerization conditions are listed in Tables 1–4.

[0129] Several properties were determined for the polymers produced in Examples 1-2, 2-2, Comparative Examples A-2, B-2, and C-1. The results are reported in Tables 1-4. Catalyst productivity (grams of polymer / grams of catalyst-hours) was determined as the ratio of polymer produced to the amount of catalyst added to the reactor. Melt index (I2) was determined according to ASTM D1238 (190°C, 2.16 kg), melt index (I5) was determined according to ASTM D1238 (190°C, 5 kg), and melt index (I 21 ) was determined according to ASTM D1238 (190°C, 21.6 kg). Melting temperature was determined using differential scanning calorimetry according to ASTM D 3418-08, using a scan rate of 10°C / min on a 10 mg sample, and T using a second heating cycle. m M w , M n , M z , M w / M n (PDI), and M z / M w was determined as described above in the detailed description. The comonomer content incorporated into the polymer, e.g., 1-hexene, was determined by fast FT-IR spectroscopy on the dissolved polymer in a GPC measurement, as described above in the detailed description. The molecular weight comonomer distribution index (MWCDI) was determined as discussed herein.

[0130] [Table 2]

[0131] The data in Table 1 show that the polymer produced by Example 1-2 had an improved, i.e., higher, molecular weight comonomer distribution index (MWCDI) compared to the polymers produced by both Comparative Examples A-2 and B-2. In addition, the polymer produced by Example 1-2 had a higher Mw at the same conditions, as indicated by no flow melt index (I2), compared to 0.863 and 0.761 for the polymers produced by Comparative Examples A-2 and B-2, and a much lower flow index than the polymers produced by either Comparative Example A-2 or B-2. Catalyst Example 1-2 also incorporates more comonomer as the polymer produced, as a higher wt. % hexene than either Comparative Example, at the same conditions as Comparative Examples A-2 and B-2.

[0132] FIG. 1 shows the data plot used to determine the MWCDI for the polymer produced in Example 1-2 (MWCDI=6.58) and the data plot used to determine the MWCDI for the polymer produced in Comparative Example A-2 (MWCDI=3.60), as reported in Table 1.

[0133] [Table 3]

[0134] The data in Table 2 show that the polymer produced in Example 1-2 had an improved, i.e., higher, molecular weight comonomer distribution index (MWCDI) compared to the polymers produced in both Comparative Example A-2 and Comparative Example B-2. The polymer produced in Example 1-2 also had a higher Mw, as indicated by a lower flow index (I21) than the polymers produced by either Comparative Example A-2 or B-2. Catalyst Example 1-2 also incorporated more comonomer as the polymer produced, as a higher weight percent hexene, than either Comparative Example under the same conditions as Comparative Examples A-2 and B-2.

[0135] [Table 4]

[0136] The data in Table 3 show that the polymer produced in Example 2-2 had an improved, i.e., higher, molecular weight comonomer distribution index (MWCDI) compared to the polymers produced in both Comparative Example A-2 and Comparative Example C-1. Additionally, in Tables 3 and 4, Example 2-2 is shown to have a higher Mw under the same conditions; this higher Mw capability is a desirable feature of the catalysts disclosed herein.

[0137] FIG. 2 shows the data plot used to determine the MWCDI for the polymer produced in Example 2-2 (MWCDI=7.38) and the data plot used to determine the MWCDI for the polymer produced in Comparative Example A-2 (MWCDI=3.60), as reported in Table 3.

[0138] [Table 5]

[0139] The data in Table 4 show that the polymer produced in Example 2-2 had an improved, i.e., higher, molecular weight comonomer distribution index (MWCDI) compared to the polymers produced in both Comparative Example A-2 and Comparative Example C-1.

[0140] The polymers were produced utilizing a gas phase continuous polymerization reactor, and some polymerizations utilized a trim component (having a concentration of 0.04 wt %) as follows:

[0141] Spray-dried MAO slurry (SDMAO)—14 wt. % SDMAO, 10 wt. % hexane, 76 wt. % Hydrobite 380 mineral oil (obtained from Sonneborn, LLC). Spray-dried MAO was prepared as a dry powder by adapting the procedure described in U.S. Pat. No. 8,497,330 (B2), column 22, lines 48-67. In the adapted procedure, the addition of the metallocene compound was omitted. Toluene, methylaluminoxane (MAO can be obtained from AkzoNobel), and Cabosil slurry were instead introduced into the atomizer to produce SDMAO as a dry powder. The polymerization conditions are reported in Tables 5, 7, and 8.

[0142] Spray-dried compositions Examples 1-4 were prepared as follows: In a 13-gallon mixing tank, 2.38 pounds of Cabosil TS-610 hydrophobic fumed silica and 37.0 pounds of 10 wt. % MAO in toluene were slurried, followed by 80.0 g of (propylcyclopentadineyl)(cyclopentadienyl)hafnium(IV) dichloride (Example 1-1) with an additional 20 pounds of toluene. The mixture was spray-dried using the following operating parameters: inlet temperature 146°C, outlet temperature 84°C, slurry inlet feed of 13 pounds / hour, and atomizer speed 20,000 revolutions per minute (rpm), yielding 4.1 pounds of Examples 1-4 as a powder.

[0143] Spray-dried composition Example A-3 was prepared as described above (same procedure as Examples 1-4) by adapting the procedure according to U.S. Patent No. 8,497,330(B2), column 22, lines 48-67. Example A-1 was slurried with hydrophobic fumed silica, MAO in toluene, and additional toluene, and then introduced into the atomization device described for Examples 1-4 to obtain Example A-3 as a powder.

[0144] Many properties were determined for the polymers. The results are reported in Tables 6, 9, 10, and 11. Catalyst productivity (grams of polymer / grams of catalyst-hours) was determined as the ratio of polymer produced to the amount of catalyst added to the reactor. Melt index (I2) was determined according to ASTM D1238 (190°C, 2.16 kg), melt index (I5) was determined according to ASTM D1238 (190°C, 5 kg), and melt index (I21) was determined according to ASTM D1238 (190°C, 21.6 kg). Mw, Mn, Mz, and Mw / Mn were determined by GPC, and molecular weight comonomer distribution index (MWCDI) was determined as discussed herein.

[0145] The polymerization method used a pilot-scale fluidized-bed gas-phase polymerization reactor comprising a reactor vessel containing a fluidized bed of ethylene / α-olefin copolymer powder, a distributor plate positioned above the bottom head, a bottom gas inlet defined, and an expansion section or cyclone system at the top of the reactor to reduce the amount of resin fines that may escape from the fluidized bed. The expansion section defined a gas outlet. The reactor was further equipped with a compressor blower used to continuously circulate gas from the gas outlet of the expansion section at the top of the reactor vessel through a cycle loop to the bottom gas inlet of the reactor, and through the distributor plate and the fluidized bed. The reactor was also equipped with a cooling system to remove polymerization heat and maintain the fluidized bed at a target temperature. The composition of gases, such as ethylene, α-olefin, hydrogen, and oxygen, fed to the reactor was monitored by an in-line gas chromatograph in the cycle loop to maintain specific concentrations used to control polymer properties. Spray-dried catalyst was fed to the reactor from a high-pressure device as a slurry or dry powder; the slurry was fed via a syringe pump, and the dry powder was fed via a metering disk. The active catalyst entered the fluidized bed in the lower third of its bed height. The polymerization system included an isolation port that metered the fluidized bed and discharged polymerization product from the reactor in response to an increase in bed weight as the polymerization reaction progressed.

[0146] [Table 6]

[0147] [Table 7]

[0148] Tables 5 and 6 refer to polymers produced using Examples 1-3 as trim on SDMAO. Each of the gas-phase continuous polymers 1-3 had the same density and an I of 0.5. 21 The goal was to have similar molecular weights.

[0149] Gas-phase continuous polymer 2, produced in Comparative Example A-2, was only able to produce polymer at 3 FI (approximately 218 kMw), the upper limit of its catalyst molecular weight capability. Gas-phase continuous polymer 1 and gas-phase continuous polymer 2 have similar FI and Mw (with a small difference due to the slightly higher H2 / C2 for gas-phase continuous polymer 1) and density. The density is approximately the same for each polymer, and the polymers in Tables 5 and 6 can be said to have medium density.

[0150] Comparing the gas-phase continuous polymer 1 produced in Examples 1-3 with the gas-phase continuous polymers 2-3, Examples 1-3 exhibited a high molecular weight (I 21 The data in Table 6 show that advantageous BOCD polymers can be produced with a molecular weight comonomer distribution index (MWCDI) of 100,000 or less (Mw<1, Mw>300,000). The data in Table 6 show that the polymers produced in Examples 1-3 had improved, i.e., higher, molecular weight comonomer distribution indices (MWCDI) compared to the polymers produced in both Comparative Examples A-3 and C-1.

[0151] FIG. 3A shows the data plot used to determine the MWCDI for Gas-Continuous Polymer 1 (MWCDI=1.58) and the data plot used to determine the MWCDI for Gas-Continuous Polymer 2 (MWCDI=0.03), as reported in Table 6.

[0152] FIG. 3B shows the data plot used to determine the MWCDI for Gas-Continuous Polymer 1 (MWCDI=1.58) and the data plot used to determine the MWCDI for Gas-Continuous Polymer 3 (MWCDI=0.82), as reported in Table 6.

[0153] [Table 8]

[0154] [Table 9]

[0155] Gas-phase continuous polymers 10-13 were produced using XCAT VP-100 obtained from Univation Technologies, LLC, utilized herein as a comparative catalyst. VP-100 is a supported catalyst consisting of the symmetric hafnium metallocene Example A-1.

[0156] [Table 10]

[0157] The gas phase continuous polymers of Table 9 can be referred to as linear low density polymers.

[0158] The data in Table 9 show that the polymers produced using Examples 1-4 and 1-3 / SDMAO each had an improved, i.e., higher, molecular weight comonomer distribution index (MWCDI) compared to the polymer produced using Comparative Example A-3 at comparable densities and MI.

[0159] FIG. 4 shows the data plot used to determine the MWCDI for gas-phase continuous polymer 4 (MWCDI=7.34) and the data plot used to determine the MWCDI for gas-phase continuous polymer 9 (MWCDI=2.51), as reported in Table 9.

[0160] Gas-phase continuous polymers 4 and 5 produced in Examples 1-4 and 1-3 / SDMAO, respectively, had improved melt strengths, i.e., greater melt strengths of 14.2 cN and 13.8 cN, respectively, compared to the melt strength of 9.5 cN for gas-phase continuous polymer 9 produced by Comparative Example A-1. Gas-phase continuous polymers 4 and 5 also had improved melt flow ratios (I21 / I2), i.e., greater melt flow ratios (I21 / I2), and broader PDIs than comparative gas-phase continuous polymer 9 produced by Comparative Example A-3. Both gas-phase continuous polymers 4 and 5 had improved high-shear viscosities (V100), i.e., reduced high-shear viscosities (V100), despite having significantly higher low-shear viscosities (V0.1) than comparative gas-phase continuous polymer 9. Lower high-shear viscosities (V100) are typically associated with improved processing speeds, which is advantageous. The rheological ratios (RR) of gas-continuous polymers 4 and 5 produced using the catalysts of Examples 1-4 and 1-3 / SDMAO are significantly greater than the RR of gas-continuous polymer 9 produced by Comparative Example A-3. A higher RR indicates a higher degree of shear thinning of the polymer. Taken together, the improved melt strength, increased shear thinning, greater MFR, broader PDI, and lower high-shear viscosity (V100) for gas-continuous polymers 4 and 5 produced using the catalysts of Examples 1-4 and 1-3 / SDMAO all indicate improved processability for applications in this density range, such as film, compared to gas-continuous polymer 9 produced by Comparative Example A-3.

[0161] The data in Table 9 show that Catalysts Ex. 1-4 and Ex. 1-3 / SDMAO can produce polymers with both improved mechanical properties and improved processability, which is a very advantageous balance of properties.

[0162] [Table 11]

[0163] The gas-phase continuous polymers in Table 10 may be referred to as medium density polymers.

[0164] The data in Table 10 show that the polymers produced in Examples 1-4 had improved, i.e., higher, molecular weight comonomer distribution index (MWCDI) compared to the polymers produced with VP-100.

[0165] FIG. 5 shows the data plot used to determine the MWCDI for gas-phase continuous polymer 6 (MWCDI=5.36) and the data plot used to determine the MWCDI for gas-phase continuous polymer 10 (MWCDI=1.17), as reported in Table 9.

[0166] Gas-continuous polymer 6 has an improved high-shear viscosity (V100), i.e., a reduced high-shear viscosity (V100), despite having a significantly higher low-shear viscosity (V0.1) than comparative gas-continuous polymers 10 and 12. Gas-continuous polymer 6 produced by utilizing Examples 1-4 also has an improved rheology ratio (RR), i.e., a rheology ratio (RR) greater than that of gas-continuous polymers 10 and 12 produced by comparative catalyst VP-100.

[0167] [Table 12]

[0168] The gas-phase continuous polymers in Table 11 may be referred to as high density polymers.

[0169] The data in Table 11 show that the polymers produced using Example 1-1 had improved, i.e., higher, molecular weight comonomer distribution index (MWCDI) values compared to the polymers produced using VP-100 at a given density range. For example, gas-continuous polymer 7 produced in Examples 1-4 has a higher MWCDI (2.65) than gas-continuous polymer 11 produced with VP-100 (MWCDI = 0.34), and both polymers have densities of 0.942-0.943 g / cc. Similarly, at a higher density, gas-continuous polymer 8 produced in Examples 1-4 has a higher MWCDI (0.26) at 0.9551 g / cc than gas-continuous polymer 13 produced with VP-100 (MWCDI = 0.34) at 0.952 g / cc.

[0170] Figure 6 shows a data plot of molecular weight comonomer distribution index (MWCDI) versus density according to some embodiments of the present disclosure. Figure 6 is a plot of molecular weight comonomer distribution index (MWCDI) versus density for inventive gas-phase continuous polymers 4-8 and comparative gas-phase continuous polymers 9-13. Gas-phase continuous polymers 4-8 were all produced with a spray-dried catalyst (Trim or otherwise) containing an asymmetric hafnium metallocene with one n-propylcyclopentadienyl ligand and one unsubstituted cyclopentadienyl ligand, i.e., Examples 1-1 and 1-3. Gas-phase continuous polymers 9-13 were all produced with a spray-dried catalyst or supported commercial catalyst VP-100, and all contained a comparative symmetric hafnium metallocene with two n-propylcyclopentadienyl ligands, i.e., Example A-1.

[0171] The data in Figure 6 show that the polymers produced by the catalysts of Examples 1-1 and 1-3 have improved MWCDI, i.e., greater MWCDI at a given density, than the polymer produced by the catalyst of Comparative Example A-1.

[0172] In Examples 1-1 and 1-3, MWCDI = -182.51 *The comparative catalyst produced a polymer with a MWCDI vs. density relationship of +174.5. * A polymer was produced with a MWCDI vs. density relationship such that the density was +78.235.

[0173] In some embodiments, the catalyst of the present invention has an MWCDI > -133 * This results in a MWCDI vs. density relationship of +126.75.

[0174] FIG. 7 shows a data plot of molecular weight comonomer distribution index (MWCDI) versus density according to some embodiments of the present disclosure. FIG. 7 is a plot of molecular weight comonomer distribution index (MWCDI) versus density for inventive gas-phase continuous polymers 4-8 and comparative gas-phase continuous polymers 9-13. Gas-phase continuous polymers 4-8 were all produced with a spray-dried catalyst (Trim or otherwise) containing an asymmetric hafnium metallocene with one n-propylcyclopentadienyl ligand and one unsubstituted cyclopentadienyl ligand, i.e., Examples 1-1 and 1-3. Gas-phase continuous polymers 9-13 were all produced with a spray-dried catalyst or supported commercial catalyst VP-100, and all contained a comparative symmetric hafnium metallocene with two n-propylcyclopentadienyl ligands, i.e., Example A-1. One or more embodiments demonstrate that the catalysts of the present invention, as shown in FIG. 7, exhibit MWCDIs > -157.75. * Provided that the MWCDI vs. density relationship is given such that density is +150.62.

Claims

1. Asymmetric hafnium metallocene represented by structure (I), 【Chemistry 1】 In the formula, R １ However, (C １ ~C ８ ) an alkyl group, where each X is an independently leaving group, and is an asymmetric hafnium metallocene.

2. Each X independently produces a halogen, (C １ ~C ５ ) alkyl, CH ２ SiMe ３ The asymmetric hafnium metallocene according to claim 1, wherein the leaving group is selected from and benzyl.

3. R １ is (C ３ ~C ４ ) alkyl, and each X is Cl or each X is CH ３ ; the asymmetric hafnium metallocene according to claim 2.

4. Structures (II) to (V): 【Chemistry 2】 The asymmetric hafnium metallocene according to claim 1, selected from the group consisting of hafnium asymmetric metallocenes represented by

5. Structures (II) to (III): 【Transformation 3】 The asymmetric hafnium metallocene according to claim 1, selected from the group consisting of hafnium asymmetric metallocenes represented by

6. Structure (IV) to (V): 【Chemistry 4】 The asymmetric hafnium metallocene according to claim 1, selected from the group consisting of hafnium asymmetric metallocenes represented by

7. A method for synthesizing the asymmetric hafnium metallocene according to claim 1, wherein each X is Cl, The process involves contacting a hafnium complex with an alkali metal complex, wherein the alkali metal complex is represented by the following structure: 【Transformation 5】 In the formula, M' is lithium, sodium, or potassium. The aforementioned hafnium complex is represented by one of the following structures: 【Transformation 6】 In the formula, R １ However, as defined in the above claim, or The process involves contacting a hafnium complex with an alkali metal complex, wherein the alkali metal complex is represented by the following structure: 【Transformation 7】 In the formula, M' is lithium, sodium, or potassium, and R １ However, as defined in the above claim, The hafnium complex is represented by any of the following structures: 【Transformation 8】 A method for producing asymmetric hafnium metallocene.

8. The aforementioned asymmetric hafnium metallocene is replaced with 2 molar equivalents of an organomagnesium halide of formula RMg (halide) or 1 molar equivalent of R ２ When brought into contact with Mg (in the formula, R is (C １ ~C ５ ) alkyl, CH ２ SiMe ３ , or benzyl, and the halide is Cl or Br), to produce the asymmetric hafnium metallocene of structure (I), where each X is (C １ ~C ５ ) alkyl, CH ２ SiMe ３ The method according to claim 7, comprising being benzyl or otherwise.

9. A metallocene catalyst composition, Asymmetric hafnium metallocene according to any one of claims 1 to 6, or asymmetric metallocene produced by the method described in claim 7 or claim 8, and A metallocene catalyst composition containing an activator.

10. The metallocene catalyst composition according to claim 9, further comprising a support.

11. The metallocene catalyst composition according to claim 10, wherein the composition is a spray-dried metallocene catalyst composition.

12. A method for producing the metallocene catalyst composition according to claim 9, comprising contacting the asymmetric hafnium metallocene with the activator instead of a support to obtain the metallocene catalyst composition according to claim 9 without a support.

13. A method for producing polyolefin polymers, The process includes polymerizing at least one olefin monomer with the metallocene catalyst composition described in claim 9 to produce the polyolefin polymer, preferably the at least one olefin monomer being ethylene and optionally propene and (C ４ ~C ２０ A method for producing a polyolefin polymer comprising a comonomer selected from the group consisting of α-olefins.

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

15. A polyolefin polymer produced by the method described in Claim 13.

16. The aforementioned polyolefin polymer has MWCDI > -133 ＊ The polyolefin polymer according to claim 15, having an MWCDI-to-density relationship such that the density is +126.

75.

17. The aforementioned polyolefin polymer has MWCDI > -157.75 ＊ The polyolefin polymer according to claim 15, having an MWCDI-to-density relationship such that the density is +150.

62.

18. A method for producing polyolefin polymers, The process involves polymerizing at least one olefin monomer with a spray-dried asymmetric hafnium metallocene catalyst composition to produce a polyolefin polymer, wherein the at least one olefin monomer is ethylene and optionally propene and (C ４ ~C ２０ ) comprising a comonomer selected from the group consisting of α-olefins, wherein the polyolefin polymer has a molecular weight comonomer distribution index (MWCDI) of 0.10 to 10.00 and an MWCDI > -133 ＊ A method for producing a polyolefin polymer having an MWCDI-to-density relationship such that the density is +126.

75.

19. The aforementioned polyolefin polymer has MWCDI > -157.75 ＊ The method according to claim 18, having an MWCDI-to-density relationship such that the density is +150.62.

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