Process for producing branched polyolefins

Abstract

The present disclosure provides a method. In one embodiment, the process includes contacting a first polymerization catalyst and a first co-catalyst with (i) an ethylene monomer and optionally an alpha-olefin comonomer and (ii) a double-ended aluminum-alkyl chain transfer agent at a temperature of less than 150 DEG C in a first polymerization reactor under first polymerization conditions. The process includes first forming one or more telechelic aluminum-terminated polymer chains and feeding the one or more telechelic aluminum-terminated polymer chains to a second polymerization reactor. The second polymerization reactor has second polymerization conditions, a second polymerization catalyst, a second co-catalyst, and a temperature of 160 DEG C to 250 DEG C. The process comprises contacting (iii) an ethylene monomer and optionally an olefin comonomer and (iv) the one or more telechelic aluminum terminated polymer chains in the second polymerization reactor. The method includes forming an ethylene-based polymer having an I10 / I2 of greater than 8.0 and a vinyl content of greater than 20 / 1000000C.

Description

Background Technology

[0001] Long-chain branched (LCB) olefin-based polymers are olefin-based polymers containing one or more side chain branches whose lengths are comparable to or longer than the critical entanglement length. It is known that incorporation of long-chain branching (LCB) enhances the processability of olefin-based polymers and increases melt strength.

[0002] Compared to linear olefin-based polymers of the same molecular weight, olefin-based polymers with LCB exhibit higher shear sensitivity, higher zero-shear viscosity, greater melt elasticity, greater impact strength, and higher melt strength ("melt strength" is the tensile resistance during the elongation period of molten olefin-based polymers). High melt strength is a desirable mechanical property in thermoforming, extrusion coating, and blow molding processes involving olefin-based polymers.

[0003] Furthermore, compared to olefin-based linear polymers with the same molecular weight, olefin-based polymers with LCB exhibit higher viscosity at low shear rates and lower viscosity at high shear rates. Shear thinning is advantageous in polymer processing, such as under high shear conditions.

[0004] For linear low-density polyethylene (LLDPE), a common mechanism for LCB formation during olefin coordination polymerization (a form of addition polymerization mediated by transition metal catalysts) is the insertion of vinyl-terminated polymer chains, generated by thermal termination, at the transition metal catalyst sites. Due to the small population size of vinyl-terminated polymer chains, the level of LCB formed via this mechanism is typically low. In contrast, low-density polyethylene (LDPE) produced via radical polymerization is known for its excellent processability due to its unique "tree-like" branch-branch structure. It is known to add α,ω-dienes, such as decadiene, during olefin polymerization to bridge the two polymer chains. The α,ω-diene approach is disadvantageous because it increases the risk of gelation in reactor systems and imposes logistical burdens due to the limited supply and high cost of industrial-scale α,ω-diene.

[0005] There is a recognition in the art of the need for alternative methods to generate long-chain branching in olefin-based polymers. Specifically, there is a need for a method to generate long-chain branching in olefin-based polymers (and especially ethylene-based polymers) via coordination polymerization of olefins. Summary of the Invention

[0006] This disclosure provides a method. In one embodiment, the method includes contacting a first polymerization catalyst and a first co-catalyst with (i) an ethylene monomer and optionally an α-olefin comonomer and (ii) a bis-ended aluminum-alkyl chain transfer agent in a first polymerization reactor at a temperature below 150°C under first polymerization conditions. The method includes first forming one or more distally chelated aluminum-terminated polymer chains and feeding the one or more distally chelated aluminum-terminated polymer chains into a second polymerization reactor. The second polymerization reactor has second polymerization conditions, a second polymerization catalyst, a second co-catalyst, and a temperature of 160°C to 250°C. The method includes contacting (iii) the ethylene monomer and optionally an olefin comonomer and (iv) the one or more distally chelated aluminum-terminated polymer chains in the second polymerization reactor. The method includes forming an Ig with a value greater than 8.0. 10 Ethylene-based polymers with a vinyl content of / I2 and greater than 20 / 1,000,000C. Attached Figure Description

[0007] Figure 1 is a diagram showing the chemical structures of different types of carbon-carbon double bonds (unsaturated groups in polymer chains) of vinylidene, trisubstituted, vinyl, and vinylidene.

[0008] Figure 2 is a schematic diagram of the aggregation method according to an embodiment of the present disclosure.

[0009] Figure 3 is a schematic diagram of a dual-reactor polymerization system according to an embodiment of the present disclosure.

[0010] Figure 4 is a graph showing the DMS viscosity coverage of comparative sample 6 and embodiments 6-13 of the invention.

[0011] Figure 5 is a graph showing the DMS tanδ coverage plots of comparative sample 6 and embodiments 6-13 of the invention.

[0012] definition

[0013] Any reference to the periodic table is as in the version published by CRC Press, Inc. in 1990–1991. A group of elements in the table is referred to using a new notation for numbering the groups.

[0014] For the purposes of U.S. patent practice, any reference to the contents of a patent, patent application, or publication, particularly disclosures relating to the definitions (limited to not being inconsistent with any definition specifically provided in this disclosure) and general knowledge in the art, is incorporated, in its entirety, by reference (or its equivalent U.S. version thereof).

[0015] The numerical ranges disclosed herein include all values ​​from the lower limit to the upper limit, and include both the lower limit and the upper limit. For a range containing definite values ​​(e.g., 1 or 2, or 3 to 5, or 6, or 7), any subrange between any two definite values ​​is included (e.g., the range 1 to 7 above includes subranges 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6, etc.).

[0016] Unless otherwise stated or implied by the context, all parts and percentages are by weight, and all test methods are current methods as of the date of this disclosure.

[0017] As used in this article, "alkyl group" refers to a saturated hydrocarbon group.

[0018] As used herein, the term "blend" or "polymer blend" is a blend of two or more polymers. Such a blend may or may not be miscible (not phase-separated at the molecular level). Such blends may or may not contain one or more domain configurations, as determined by transmission electron spectroscopy, light scattering, X-ray scattering, and other methods known in the art.

[0019] The term "composition" refers to a mixture of materials comprising the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0020] The terms “comprising,” “including,” “having,” and their derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether or not such components, steps, or procedures are specifically disclosed. For the avoidance of any doubt, unless stated to the contrary, all compositions claimed using the term “comprising” may include any additional additives, adjuvants, or compounds, whether in polymeric or other forms. In contrast, the term “consistently comprising” excludes any other components, steps, or procedures (except those not essential to operability) from the scope of any subsequent statements. The term “consisting of” excludes any components, steps, or procedures not specifically described or listed. Unless otherwise stated, the term “or” refers to the listed members individually and in any combination. Use of the singular includes use of the plural, and vice versa.

[0021] "Ethylene-based polymer" and similar terms refer to a polymer containing, by weight a majority percentage of ethylene-derived units in a polymeric form. Non-limiting examples of ethylene-based polymers include low-density polyethylene (or "LDPE"), which is an ethylene homopolymer; or containing at least one C3-C... 10α-olefins, preferably C3-C4 ethylene / α-olefin copolymers with a density of 0.915 g / cc to 0.940 g / cc and containing long-chain branching with a wide MWD, typically produced by high-pressure free radical polymerization; linear low-density polyethylene (or "LLDPE"), a linear ethylene / α-olefin copolymer containing a heterogeneous distribution of short-chain branching (the heterogeneous short-chain branching distribution comprises units derived from ethylene and units derived from at least one C3-C4 ethylene / α-olefin). 10 α-olefin comonomer or at least one C4-C8 α-olefin comonomer or at least one C6-C8 α-olefin comonomer unit); LLDPE is characterized by very little long-chain branching (if present) compared to conventional LDPE; LLDPE has a density of 0.880 g / cc, or 0.890 g / cc, or 0.900 g / cc, or 0.910 g / cc, or 0.915 g / cc, or 0.920 g / cc, or 0.925 g / cc to 0.930 g / cc, or 0.935 g / cc, or 0.940 g / cc; very low density polyethylene (VLDPE), ultra-low density polyethylene (ULDPE), medium density polyethylene (or "MDPE" - ethylene homopolymer, or containing at least one C3-C4 α-olefin comonomer unit); 10 Ethylene / α-olefin copolymers of α-olefins or C3-C4 α-olefins, having a density of 0.926 g / cc to 0.940 g / cc; high-density polyethylene (or "HDPE") is an ethylene homopolymer or has at least one C4-C4 α-olefin. 10 Ethylene / α-olefin copolymers of α-olefin comonomers or C4-C8 α-olefin comonomers, and having a density greater than 0.94 g / cc, or 0.945 g / cc, or 0.95 g / cc, or 0.955 g / cc to 0.96 g / cc, or 0.97 g / cc, or 0.98 g / cc.

[0022] A "heteroatom" is an atom other than carbon or hydrogen. Heteroatoms can be non-carbon atoms from Groups IV, V, VI, and VII of the periodic table. Non-limiting examples of heteroatoms include F, N, O, P, B, S, and Si.

[0023] Hydrocarbons are compounds containing only hydrogen and carbon atoms. A hydrocarbon group (or hydrocarbon alkyl group) is a hydrocarbon with a valence (usually a monovalent valence). Hydrocarbons can have straight-chain, cyclic, or branched structures.

[0024] "Mixomers" are polymers prepared by polymerizing at least two different monomers. This general term includes copolymers, which are generally used to refer to polymers prepared from two different monomers, as well as polymers prepared from more than two different monomers, such as terpolymers, tetrpolymers, etc.

[0025] The terms "long-chain branching," "LCB," and similar terms refer to side chains extending from the polymer backbone that contain more than one carbon atom. If the polymer is a copolymer (such as an ethylene / α-olefin copolymer), the LCB contains one carbon atom, which is more than two carbon atoms shorter than the total length of the longest comonomer copolymerized with ethylene. For example, in an ethylene / octene copolymer, the LCB is at least seven carbon atoms long. In practice, the LCB is longer than the side chains created by incorporating comonomers into the polymer backbone. The polymer backbone of HPLDPE contains coupled ethylene units.

[0026] "Olefin-based polymers" or "polyolefins" are polymers containing more than 50% by weight of polymerizable olefin monomers (based on the total amount of polymerizable monomers) and optionally containing at least one comonomer. Non-limiting examples of olefin-based polymers include ethylene-based polymers and propylene-based polymers.

[0027] A "polymer" is a compound prepared by polymerizing the same or different types of monomers, which provide, in polymeric form, multiple and / or repeating "units" or "monomer units" constituting the polymer. Therefore, the general term polymer encompasses the term homopolymer, which is generally used to refer to polymers prepared from only one type of monomer, and the term copolymer, which is generally used to refer to polymers prepared from at least two types of monomers. It also encompasses all forms of copolymers, such as random copolymers, block copolymers, etc. The terms "ethylene / α-olefin polymer" and "propylene / α-olefin polymer" refer to copolymers prepared as described above by polymerizing ethylene or propylene and one or more additional polymerizable α-olefin monomers, respectively. It should be noted that although polymers are generally referred to as being "made from" one or more specified monomers, "based on" a specified monomer or monomer type, "containing" a specified monomer content, etc., in this context, the term "monomer" should be understood to refer to the polymer residue of the specified monomer rather than the unpolymerized material. Generally, polymers herein are referred to as "units" based on the polymeric form of the corresponding monomer.

[0028] Test methods

[0029] 1 H NMR . 1 H nuclear magnetic resonance (H nuclear magnetic resonance) 1H NMR is used to detect the following types of carbon-carbon double bonds (“unsaturated groups”) in polymers. “Metene” is a carbon-carbon double bond with the formula R1–CH=CH–R2, where R1 and R2 are each a carbon atom or a heteroatom selected from N, O, P, B, S, and Si. “Trisubstituent” is a carbon-carbon double bond where the double-bonded carbon is bonded to a total of three carbon atoms, and where R1, R2, and R3 (in Figure 1) are each a carbon atom. “Vinyl” is a carbon-carbon double bond with the formula R–CH=CH2, where R is a carbon atom or a heteroatom selected from N, O, P, B, S, and Si. “Vinylene” is a carbon-carbon double bond with the formula C=CH2. “Total unsaturated groups” (“total”) is the sum of metene, trisubstituents, vinyl groups, and vinylene in the polymer. The chemical structures of metene, trisubstituents, vinyl groups, and vinylene are shown in Figure 1.

[0030] The sample was prepared by adding 130 mg of the sample to 3.25 g of 50 / 50 tetrachloroethane-d2 / perchloroethylene with 0.001 M Cr(AcAc)3 in a 10 mm NMR tube. 1 Polymer samples were analyzed by 1H NMR. The sample was purged by bubbling N2 through the solvent for approximately 5 minutes via a pipette inserted into the tube to prevent oxidation, capped, and sealed with Teflon tape. The sample was heated and vortexed at 115°C to ensure homogeneity.

[0031] The measurements were performed on a Bruker AVANCE 400 / 600MHz spectrometer equipped with a Bruker high-temperature CryoProbe and a sample temperature of 120°C. 1 H NMR. Two experiments were performed to obtain spectra, a control spectrum for quantifying total polymer protons, and a double presaturation experiment, which suppressed strong polymer backbone peaks and enabled highly sensitive spectra for quantifying end groups. The control was run with ZG pulses, 4 scans, SWH 10,000 Hz, AQ 1.64 s, D1 14 s. The control was run with a modified pulse sequence lc1prf2.zz1, TD 32768, 100 scans, DS 4, SWH 10,000 Hz, AQ 1.64 s, D1 1 s, D... 13 Double presaturation experiments were performed in 13s. Results were reported as the number of vinyl groups per 1,000,000 carbon atoms or per 1,000,000 C atoms (as well as the number of methemethylene, trisubstituents, vinylides and total groups).

[0032] density Measured according to ASTM D792 Method B. Results are recorded in grams per cubic centimeter (g / cc).

[0033] Differential scanning calorimetry (DSC)Differential scanning calorimetry (DSC) can be used to measure the melting, crystallization, and glass transition behavior of polymers over a wide temperature range. Testing was performed using a DSC2500 from TA Instruments with a refrigerator cooling system. An aluminum DSC-sealed sample pan was used, with 5 mg to 8 mg of sample added. Testing was conducted in a nitrogen atmosphere.

[0034] At the start of the test, the temperature was equilibrated to 180°C and held isothermally for 5 minutes to remove thermal history. Next, the temperature was decreased to -40°C at a rate of 10°C / min to determine the crystallization temperature. Upon reaching the final temperature, it was held for 5 minutes. Finally, the temperature was increased back to 180°C at a rate of 10°C / min to determine the polymer's melting point.

[0035] Triple detector GPC (TD-GPC) The chromatographic system used for triple detector gel permeation chromatography (TD-GPC) consisted of a PolymerChar GPC-IR (Valencia, Spain) high-temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5). The autosampler chamber was set to 160°C and the column chamber to 150°C. The columns used were four Agilent “Mixed A” 30cm 20µm linear mixed-bed columns and a 20µm pre-column. The chromatographic solvent used was 1,2,4-trichlorobenzene containing 200ppm of butylated hydroxytoluene (BHT). The solvent source was nitrogen injection. The injection volume used was 200µL, and the flow rate was 1.0mL / min.

[0036] The GPC column assembly was calibrated using 21 polystyrene standards with narrow molecular weight distributions, ranging from 580 to 8,400,000, arranged in a six-cocktail mixture, with individual molecular weights spaced at least tenfold apart. The standards were purchased from Agilent Technologies. For molecular weights equal to or greater than 1,000,000, 0.025 g of polystyrene standard was prepared in 50 mL of solvent; for molecular weights less than 1,000,000, 0.05 g of polystyrene standard was prepared in 50 mL of solvent. The polystyrene standards were dissolved at 80°C and gently stirred for 30 minutes. 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)).

[0037] (Equation 1)

[0038] Where M is the molecular weight, A has a value of 0.4315, and B equals 1.0.

[0039] A fifth-order polynomial was used to fit the calibration point for the corresponding polyethylene equivalent. A small adjustment to A (approximately 0.375 to 0.445) was made to correct for column resolution and band broadening effects, resulting in linear homopolymer polyethylene standards at 120,000 Mw.

[0040] Total plate counts were performed on the GPC column assembly using decane (prepared as 0.04 g in 50 mL TCB and dissolved under slow stirring for 20 min). Plate counts and symmetry were measured at 200 μL injections according to the following equations: (Equation 2) and (Equation 3):

[0041] (Equation 2)

[0042] Where RV is the retention volume in milliliters, and peak width is in milliliters, peak maximum is the position of the peak value, one-tenth height is 1 / 10 of the height of the peak maximum, and a subsequent peak refers to the tail of a peak whose retention volume is later than the peak maximum, while a preceding peak refers to the front of a peak whose retention volume is earlier than the peak maximum. The plate count of the chromatographic system should be greater than 18,000, and the symmetry should be between 0.98 and 1.22.

[0043] Samples were prepared semi-automatically using PolymerChar Instrument Control software, with a target sample weight of 2 mg / ml. Solvent (containing 200 ppm BHT) was added to a pre-bubbled, diaphragm-capped vial via a PolymerChar high-temperature autosampler. The sample was then dissolved at 160°C for 2 hours with low-speed shaking.

[0044] Based on the GPC results, using the internal IR5 detector (measurement channel) of the PolymerChar GPC-IR chromatograph, according to Equations 4-6, the PolymerChar GPCOne was used. ™ The software calculates the Mn content based on the baseline-subtracted IR chromatograms at each equidistant 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) The calculation.

[0045] (Equation 4)

[0046] (Equation 5)

[0047] (Equation 6)

[0048] To monitor deviations over time, a flow rate marker (decane) was introduced into each sample via a micropump controlled by a PolymerChar GPC-IR system. This flow rate marker (FM) was used to linearly correct the pump flow rate (nominal flow rate) for each sample by comparing the RV (RV(FM sample)) of the corresponding decane peak within the sample with the RV (RV(FM calibrated)) of the decane peak within the narrow standard calibration. It was then assumed that any variation in the decane marker peak time was linearly related to the flow rate (effective flow rate) over the entire run. To facilitate the highest accuracy in RV measurement of the flow marker peak, a least-squares fitting procedure was used to fit the peak values ​​of the flow marker concentration chromatogram to a quadratic equation. The first derivative of the quadratic equation was then used to solve for the true peak position. After calibration based on the flow marker peak, the effective flow rate (relative to the narrow standard calibration) was calculated according to Equation 7. (via PolymerChar GPCOne) ™ The software processes the flow marker peaks. Acceptable flow rate correction ensures that the effective flow rate is within + / -1% of the nominal flow rate.

[0049] Flow rate (effective) = Flow rate (nominal) * (RV (FM calibrated) / RV (FM sample)) (Equation 7)

[0050] Melt flow index (I2, I) was measured according to ASTM method D1238. 10 I2 and I 10 Measurements were taken at 190℃ / 2.16kg and 190℃ / 10kg, respectively. Results are reported as grams eluted per 10 minutes or g / 10 minutes.

[0051] Dynamic mechanical analysis (DMA) was performed using an ARES-G2 rheometer with two parallel plates of 25 mm diameter. Tests were conducted at 190 °C with a 1.8 mm gap, at frequency intervals ranging from 0.1 rad / s to 100 rad / s, and with a strain of 10%. By applying this deformation and measuring the resulting torque with a transducer, parameters such as complex viscosity, storage modulus, and loss modulus under certain shear conditions were determined. Detailed Implementation

[0052] This disclosure provides a method. In one embodiment, a method is provided, comprising contacting a first polymerization catalyst and a first co-catalyst with (i) an ethylene monomer and optionally an α-olefin comonomer and (ii) a bis-ended aluminum-alkyl chain transfer agent at a temperature below 150°C in a first polymerization reactor under first polymerization conditions; initially forming one or more distally chelated aluminum-terminated polymer chains; feeding one or more distally chelated aluminum-terminated polymer chains into a second polymerization reactor having second polymerization conditions, a second polymerization catalyst, a second co-catalyst, and a temperature of 160°C to 250°C. The method further comprises contacting (iii) an ethylene monomer and optionally an olefin comonomer and (iv) one or more distally chelated aluminum-terminated polymer chains in the second polymerization reactor; and forming an Ig with a value greater than 8.0. 10 Ethylene-based polymers with a vinyl content of / I2 and greater than 20 / 1,000,000C.

[0053] The method comprises contacting a first polymerization catalyst and a first co-catalyst with (i) an olefin monomer and optionally an olefin comonomer and (ii) a bis-headed aluminum-alkyl chain transfer agent at a temperature below 150°C in a first polymerization reactor under first polymerization conditions. As used herein, the term “polymerization conditions” refers to process parameters for copolymerizing ethylene (and optionally an olefin comonomer) in the presence of a catalyst system. First polymerization conditions include, for example, polymerization reactor conditions (reactor type), reactor pressure, reactor temperature, concentrations of reagents and polymers, solvents, supports, residence time, and distribution, thereby affecting molecular weight distribution and polymer structure. As used herein, the term first polymerization conditions includes polymerization temperatures below 150°C, or 85°C to 150°C, or 90°C to 140°C, or 100°C to 135°C, or 110°C to 130°C.

[0054] In one embodiment, the first polymerization catalyst has formula (1)

[0055] Equation (1)

[0056]

[0057] Where X 1 Each occurrence is a halide ion, an N,N-dimethylamide group, or a C1-4 alkyl group, and preferably X each time it appears. 1 It is methyl; and

[0058] R1-R7 are each independently hydrogen, halogen, or C1-C. 20 Alkyl or C6-C 20 Aryl groups, or two adjacent R groups, can bond together to form a ring.

[0059] In one embodiment, the first polymerization catalyst has formula (2).

[0060] Equation (2)

[0061]

[0062] The first polymerization conditions include providing a first co-catalyst. Non-limiting examples of suitable first co-catalysts include boron compounds that can be used as activating co-catalysts in the preparation of the modified catalysts of this disclosure, including trisubstituted ammonium salts such as trimethylammonium tetra(pentafluorophenyl)borate, triethylammonium tetra(pentafluorophenyl)borate, tripropylammonium tetra(pentafluorophenyl)borate, tri(n-butyl)ammonium tetra(pentafluorophenyl)borate, tri(sec-butyl)ammonium tetra(pentafluorophenyl)borate, N,N-dimethylphenylammonium tetra(pentafluorophenyl)borate, and n-butyltri(pentafluorophenyl)borate. N,N-dimethylphenylammonium (phenyl)boronic acid, N,N-dimethylphenylammonium benzyltris(pentafluorophenyl)boronic acid, N,N-dimethylphenylammonium tetra(4-(tert-butyldimethylsilyl)-2,3,5,6-tetrafluorophenyl)boronic acid, N,N-dimethylphenylammonium tetra(4-(triisopropylsilyl)-2,3,5,6-tetrafluorophenyl)boronic acid, N,N-dimethylphenylammonium pentafluorophenoxytris(pentafluorophenyl)boronic acid, N,N-diethylphenylammonium tetra(pentafluorophenyl)boronic acid, N,N-dimethyl-2,4,6-trimethylaniline tetra(pentafluorophenyl)borate, dimethyl octadecylammonium tetra(pentafluorophenyl)borate, methyl bis(octadecylammonium tetra(pentafluorophenyl)borate; various dialkylammonium salts, such as: di(isopropyl)ammonium tetra(pentafluorophenyl)borate, methyl octadecylammonium tetra(pentafluorophenyl)borate, methyl octadecylammonium tetra(pentafluorophenyl)borate and bis(octadecylammonium tetra(pentafluorophenyl)borate; various trisubstituted phosphonium salts, such as: tetra(pentafluorophenyl) Triphenylphosphonium tetra(pentafluorophenyl)borate, methyl bis(octadecyl)phosphonium tetra(pentafluorophenyl)borate, and tri(2,6-dimethylphenyl)phosphonium tetra(pentafluorophenyl)borate; disubstituted oxonium salts, such as diphenyloxonium tetra(pentafluorophenyl)borate, di(o-tolyl)oxonium tetra(pentafluorophenyl)borate, and bis(octadecyl)oxonium tetra(pentafluorophenyl)borate; and disubstituted sulfonium salts, such as di(o-tolyl)sulfonium tetra(pentafluorophenyl)borate and methyl octadecylsulfonium tetra(pentafluorophenyl)borate.

[0063] (i) The ethylene monomer and (ii) optionally an olefin comonomer are polymerized under the first polymerization conditions. Non-limiting examples of suitable olefin comonomers include α-olefins having 3 to 30 carbon atoms, or 3 to 20 carbon atoms, or 3 to 10 carbon atoms, or 4 to 8 carbon atoms. In one embodiment, an olefin comonomer is present, and the olefin comonomer is selected from propylene, butene, hexene, and octene, or selected from butene, hexene, and octene.

[0064] In one embodiment, the method includes contacting a first polymerization catalyst and a first co-catalyst with only the following in a first polymerization reactor at a temperature below 150°C under polymerization conditions: (i) ethylene monomers and (ii) one or more C3-C8 α-olefin comonomers, excluding dienes, and / or excluding branching agents.

[0065] The method comprises contacting a first polymerization catalyst and a first co-catalyst with (i) an olefin monomer and optionally an olefin comonomer and (ii) a bis-headed aluminum-alkyl chain transfer agent at a temperature below 150°C under first polymerization conditions. As used herein, a "chain transfer agent" refers to a compound capable of exchanging a polymeric group (e.g., an alkyl group) on the chain transfer agent with a growing polymer chain on the catalyst, such exchange resulting in termination of polymer chain growth under the first polymerization conditions. As used herein, a "bis-headed aluminum-alkyl chain transfer agent" is a chain transfer agent that is a compound having formula A.

[0066] Formula (A)

[0067]

[0068] in

[0069] n is a number from 1 to 100;

[0070] R1 is a divalent linear, branched, or cyclic C4 to C1 chain. 100 A hydrocarbon group, which optionally contains at least one heteroatom and is aliphatic or aromatic; and

[0071] R2, R3, R4, and R5 are each independently hydrogen, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. R2 and R3, R4 and R5 can combine with each other to form a divalent C4-C100 ring. Non-limiting examples of bis-headed aluminum-alkyl chain transfer agents include structures (B), (C), (D), and (E) shown below:

[0072] Structure (B)

[0073] ; and / or

[0074] Structure (C)

[0075] ; and / or

[0076] Structure (D)

[0077]

[0078] Where m is an integer from 1 to 100 or from 1 to 10; and / or

[0079] Structure (E)

[0080]

[0081] Where m is an integer from 1 to 100 or from 1 to 10.

[0082] Figure 2 is a schematic diagram of the method of the present invention. Under first polymerization conditions, in a first polymerization reactor (“reactor-1”), contact occurs between a first polymerization catalyst, a first co-catalyst, an ethylene monomer (and optionally an olefin comonomer) or octene, and a bis-ended aluminum-alkyl chain transfer agent at a temperature below 150°C (or 135°C). Alkyl groups on the aluminum are transferred to the catalyst, growing into polymer chains from both ends, and are transferred back to the aluminum to form one or more distally chelated aluminum-terminated polymer chains 12. As used herein, a “distally chelated aluminum-terminated polymer chain” is a polymer or prepolymer chain having at least two ends and capable of entering further polymerization or other reactions through its reactive end groups, the polymer or prepolymer containing aluminum metal at at least two ends of the chain.

[0083] The second polymerization catalyst is flexible for olefin polymerization at high temperatures or temperatures between 160°C and 250°C. In one embodiment, the second polymerization catalyst has the formula (3).

[0084] Equation (3)

[0085]

[0086] in

[0087] M represents titanium, zirconium, or hafnium;

[0088] Each Y 1 and Y 2 Choose independently the following groups: (C1-C 40 ) hydrocarbon group, (C1-C 40 Trialkylsilyl hydrocarbon group, halogen, alkoxide or amine, or two Y groups together are divalent hydrocarbon group, hydrocarbon diene or trialkylsilyl group;

[0089] Each Ar 1 and Ar 2 Choose independently the following groups: (C6-C) 40 ) aryl, substituted (C6-C 40 )Aryl, (C3-C 40 Heteroaryl and substituted (C3-C) 40 ) heteroaryl;

[0090] T 1 Each time it appears, it is independently a divalent bridging group of 2 to 20 carbon atoms, optionally containing heteroatoms including Si, Ge, O, N, S, and P; and

[0091] Each R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 R 10 R 11 R 12 R 13 and R 14 Independently select from the following groups: hydrogen, halogens, (C1-C) 40 ) hydrocarbon group, substituted (C1-C) 40 ) hydrocarbon group, (C1-C 40 Heterohydrocarbon groups, substituted (C1-C) 40 (C6-C) heterohydrocarbon group, (C6-C) 40 ) aryl, substituted (C6-C 40 )Aryl, (C3-C 40 Heteroaryl and substituted (C3-C) 40 ) heteroaryl and nitro (NO2).

[0092] In one embodiment, the second polymerization catalyst has formula (4).

[0093] Equation (4)

[0094]

[0095] The second polymerization conditions include the provision of a second co-catalyst. Non-limiting examples of suitable second co-catalysts include co-catalysts suitable for the first polymerization catalyst.

[0096] (i) The ethylene monomer and (ii) optionally an olefin comonomer are polymerized under a second polymerization condition. Non-limiting examples of suitable olefin comonomers include α-olefins having 3 to 30 carbon atoms, or 3 to 20 carbon atoms, or 3 to 8 carbon atoms, or 4 to 8 carbon atoms. In one embodiment, an olefin comonomer is present, and the olefin comonomer is selected from propylene, 1-butene, 1-hexene, and 1-octene, or selected from 1-butene, 1-hexene, and 1-octene.

[0097] The method involves feeding or otherwise transferring one or more distally chelated aluminum-terminated polymer chains 12 (from a first polymerization reactor) to a second polymerization reactor. The distally chelated aluminum-terminated polymer 12 is fed directly into the second polymerization reactor or enters the second polymerization reactor directly. The second polymerization reactor has second polymerization conditions, a second polymerization catalyst, a second co-catalyst, and a temperature of 160°C to 250°C. As used herein, the term "second polymerization conditions" refers to the process parameters for copolymerizing ethylene (and optionally olefin comonomers) in the second polymerization reactor in the presence of a second catalyst system, which differ from the first polymerization conditions. Specifically, the second polymerization conditions include, for example, parameters such as polymerization reactor conditions (reactor type), reactor pressure, reactor temperature, concentration of reagents and polymers, solvent, carrier, residence time, and distribution, wherein one or more parameters in the second polymerization conditions differ from the corresponding parameters in the first polymerization conditions. The second polymerization conditions affect the molecular weight distribution and polymer structure. As used herein, the term "second polymerization conditions" includes polymerization temperatures of 160°C to 250°C, or 180°C to 230°C, or 190°C to 220°C.

[0098] Referring to Figure 2, in a second polymerization reactor (the “main reactor” in Figure 2), under second polymerization conditions at a temperature of 160°C to 250°C (or 190°C), the method involves contacting a plurality of aluminum-terminated polymer chains 12 with an ethylene monomer (and optionally an olefin comonomer or octene) to form one or more grown polymer chains 14. With the first polymerization catalyst effectively carrying out chain transfer with a bis-headed aluminum-alkyl chain transfer agent, the second polymerization catalyst provides (1) flexibility for polymerization at high temperatures (160°C–250°C) and (2) the ability to incorporate vinyl-terminated polymer chains.

[0099] In one embodiment, ethylene (“C2=") and an optional olefin comonomer, octene (“C8="), are present, as shown in Figure 2. The grown polymer chain 14 is an ethylene / octene copolymer. As the polymer chain 14 grows simultaneously or substantially simultaneously, multiple aluminum-terminated polymer chains 12 are converted into one or more polymer-based chains or polymer-based dienes 12a. Without being bound by any particular theory, it is believed that under the second polymerization conditions (and a second polymerization temperature of 160°C to 250°C), the aluminum-terminated polymer chains 12 undergo β-hydride elimination to form divinyl-terminated polymer-based chains 12a (or “polymer-based dienes”). In the second polymerization reactor and under the second polymerization conditions, the vinyl-terminated polymer-based chains 12a are incorporated into or otherwise inserted into the grown polymer chain 14, thereby forming an olefin-based polymer 16 with H-shaped long-chain branching. In one embodiment, the grown polymer chain is an ethylene / octene copolymer, and the vinyl-terminated polymer base chain 12a is incorporated into or otherwise inserted into the grown ethylene / octene copolymer chain to form an ethylene / octene copolymer with H-shaped long-chain branching.

[0100] In one embodiment, the method includes contacting a first polymerization catalyst and a first co-catalyst having the structure of formula (1) with the following in a first polymerization reactor at a temperature of 120°C to 150°C (or 135°C) under first polymerization conditions.

[0101] (i) Ethylene monomers and C3-C8 α-olefin comonomers (e.g., octene), and

[0102] (ii) Bi-headed aluminum-alkyl chain transfer agents (e.g., IPRA);

[0103] First, one or more polymer chains with distal aluminum end caps are formed;

[0104] One or more distal chelate aluminum-terminated polymer chains are fed into a second polymerization reactor having a second polymerization condition, a second polymerization catalyst having the structure of formula (2), a second co-catalyst, and a temperature of 180°C to 230°C (or 190°C).

[0105] In the second polymerization reactor, the following items are brought into contact:

[0106] (iii) Ethylene monomers and C3-C8 α-olefin comonomers (e.g., octene), and

[0107] (iv) the one or more distally chelated aluminum-terminated polymer chains; and

[0108] Forming an ethylene-based polymer having the following characteristics

[0109] (i) I of 8.5 to 20.0, or 9.0 to 15.0, or 9.3 to 13.2 10 / I2; and / or

[0110] (ii) Vinyl content of 25 / 1,000,000C to 100 / 1,000,000C, or 30 / 1,000,000C to 90 / 1,000,000C, or 35 / 1,000,000C to 80 / 1,000,000C; and / or

[0111] (iii) Mw / Mn of 2.4 to 4.0, or 2.5 to 3.5, or 2.6 to 3.4.

[0112] Some embodiments of this disclosure are described in detail in the following examples, not as limiting ones.

[0113] Example

[0114] Table 1 below provides the catalysts, co-catalysts, and dialuminum-alkyl chain transfer agents used in the preparation of comparative sample (CS) AC and inventive examples (IE) 1-5.

[0115] Table 1 - Materials

[0116] Catalyst 1 (First polymerization catalyst formula (2)) [N-[6-(butylimino-κ.N)-1-cyclohexen-1-yl]-2,6-bis(1-methylethyl)aniline-κ.N]trimethylhafnium Catalyst 2 (Second polymerization catalyst formula (4)) [[rel-2',2'''-[(1R,2R)-1,2-cyclohexanediylbis(methyleneoxy-.κ.O)]bis[3-(9H-carbazol-9-yl)-5-methyl[1,1'-biphenyl]-2-olato-.κ.O]](2-)]dimethylhafnium, <![CDATA[Promoter 1 R2MeNH + (R = hydrogenated tallow alkyl group) > Bis(hydrogenated tallow alkyl)methyltetra(pentafluorophenyl)borateamine (1-) Co-catalyst 2 (MMAO-3A) Modified methylaluminoxane (MMAO) type 3A (unpurified) (AkzoNobel) Bi-headed aluminum-alkyl chain transfer agent Isoprene aluminum (IPRA)

[0117] Polymerization of ethylene / octene copolymers with LCB

[0118] Ethylene-based polymers with H-shaped long-chain branching were synthesized using a first polymerization reactor and a second polymerization reactor. The first polymerization reactor was a well-mixed high-pressure autoclave reactor, and the second polymerization reactor was a well-mixed high-pressure autoclave reactor. The first and second polymerization reactors were configured in series (hereinafter referred to interchangeably as the "dual reactor system"), as shown in Figure 3. Purified solvent Isopar-E, ethylene monomer, and octene comonomer were mixed with a chain transfer agent (CTA) and injected into the 5-liter first polymerization reactor.

[0119] The first polymerization catalyst (catalyst 1), borate activator, bi-ended aluminum-alkyl chain transfer agent (IPRA), ethylene monomer and octene comonomer are introduced into the first polymerization reactor to produce distal aluminum-terminated polymer chains.

[0120] The distally chelated aluminum-terminated polymer chains are fed into a second polymerization reactor. A second polymerization catalyst (catalyst 2), a borate activator, ethylene, octene, and hydrogen are fed into the second polymerization reactor to generate growth chains of the ethylene / octene copolymer. The distally chelated aluminum-terminated polymer chains undergo β-hydride elimination at a high temperature in the second polymerization reactor (190°C) to form divinyl polymer-based chains or polymer-based dienes.

[0121] By incorporating divinyl polymer base chains to bridge the grown ethylene / octene polymer chains, ethylene / octene copolymers with long-chain branching and ethylene / octene copolymers with H-shaped branching are formed.

[0122] The effluent from the second polymerization reactor consists of polymer, solvent, and unreacted reagents such as monomers, comonomers, hydrogen, aluminum-alkyl chain transfer agents (IPRAs), and catalyst components. The effluent from the second polymerization reactor is sent to a devolatilization unit to remove the solvent and unreacted monomers. Water or isopropanol (IPA) is added to the effluent to neutralize the remaining catalyst components and metallic alkyl groups.

[0123] In comparative sample 1 (CS1), the first polymerization reactor was not used. CS1 polymer was prepared solely in the second polymerization reactor using catalyst 2. IE1-5 was prepared using the aforementioned "dual reactor system". Polymerization conditions are provided in Tables 2 and 3 below, where "R1" is the first polymerization reactor and "R2" is the second polymerization reactor.

[0124]

[0125] Table 2. Properties of C-ethylene / octene polymers

[0126]

[0127] Invention Examples (IE) IE1-5 are prepared by feeding an increased amount of the product from the first reactor (aluminum-terminated polymer chains) into the second reactor. 10 The increased I2 / I2 ratio indicates the formation of branched polymers. The distally chelated aluminum-terminated polymer chains are transformed into polymer dienes in the second reactor, as evidenced by the significantly higher amounts of vinyl groups in the IE1-IE5 samples.

[0128] DMS analysis of the products is shown in Figure 4. Compared with the linear polymer prepared by CS1, the polymers of the present invention prepared by IE1-5 exhibit significantly different rheological behavior, such as higher shear thinning and lower tan-δ values. This is consistent with the behavior of branched polymers.

[0129] It is particularly desirable that this disclosure is not limited to the embodiments and descriptions contained herein, but includes modifications of those embodiments, including portions of embodiments appearing within the scope of the following claims and combinations of elements of different embodiments.

Claims

1. A method, the method comprising: Under the first polymerization conditions, the first polymerization catalyst and the first co-catalyst are contacted with the following in the first polymerization reactor at a temperature below 150°C. (i) ethylene monomers and optional α-olefin comonomers, and (ii) Bi-headed aluminum-alkyl chain transfer agent; First, one or more polymer chains with distal aluminum end caps are formed; One or more distally chelated aluminum-terminated polymer chains are fed into a second polymerization reactor having second polymerization conditions, a second polymerization catalyst, a second co-catalyst, and a temperature of 160°C to 250°C. In the second polymerization reactor, the following items are brought into contact: (iii) Ethylene monomers and optional olefin comonomers, and (iv) the one or more distally chelated aluminum-terminated polymer chains; as well as Forming an I with a value greater than 8.0 10 Ethylene-based polymers with a vinyl content of / I2 and greater than 20 / 1,000,000C.

2. The method of claim 1, wherein the contact in the second polymerization reactor includes One or more polymer chains are formed as they grow; The one or more double-ended aluminum-terminated polymer chains are converted into one or more divinyl polymer-based chains; Incorporating one or more divinyl polymer-based chains into the grown polymer chain; and Forming an I with a value greater than 8.0 10 Ethylene-based polymers with a vinyl content of / I2 and greater than 20 / 1,000,000C.

3. The method according to any one of claims 1 to 2, wherein the first polymerization catalyst has the following structure Equation (1) Where X 1 Each time it appears, it is a halide ion, an N,N-dimethylamide group, or a C1-4 alkyl group; and R1-R7 are each independently hydrogen, halogen, or C1-C. 20 Alkyl or C6-C 20 Aryl groups, or two adjacent R groups, can bond together to form a ring.

4. The method according to any one of claims 1 to 3, wherein the first polymerization catalyst has the structure of formula (2). Equation (2) 5. The method according to any one of claims 1 to 4, wherein the dialuminum-alkyl chain transfer agent has a structure selected from the group consisting of: Structure (B) ， Structure (C) ， Structure (D) Where m is an integer from 1 to 100, Structure (E) Where m is an integer from 1 to 100, and Their combination.

6. The method according to any one of claims 1 to 5, wherein the second polymerization catalyst has the structure of formula (3). Equation (3) in M represents titanium, zirconium, or hafnium; Each Y 1 and Y 2 Choose independently the following groups: (C1-C 40 ) hydrocarbon group, (C1-C 40 Trialkylsilyl hydrocarbon group, halogen, alkoxide or amine, or two Y groups together are divalent hydrocarbon group, hydrocarbon diene or trialkylsilyl group; Each Ar 1 and Ar 2 Choose independently the following groups: (C6-C) 40 ) aryl, substituted (C6-C 40 )Aryl, (C3-C 40 Heteroaryl and substituted (C3-C) 40 ) heteroaryl; T 1 Each time it appears, it is independently a divalent bridging group of 2 to 20 carbon atoms, optionally containing heteroatoms including Si, Ge, O, N, S, and P; and Each R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 R 10 R 11 R 12 R 13 and R 14 Independently select from the following groups: hydrogen, halogens, (C1-C) 40 ) hydrocarbon group, substituted (C1-C) 40 ) hydrocarbon group, (C1-C 40 Heterohydrocarbon groups, substituted (C1-C) 40 (C6-C) heterohydrocarbon group, (C6-C) 40 ) aryl, substituted (C6-C 40 )Aryl, (C3-C 40 Heteroaryl and substituted (C3-C) 40 ) heteroaryl and nitro (NO2).

7. The method according to any one of claims 1 to 6, wherein the second polymerization catalyst has the structure of formula (4). Equation (4) 8. The method according to any one of claims 1 to 7, wherein the optional α-olefin comonomer is present and is a C4-C8 α-olefin comonomer, the method comprising forming an ethylene / C4-C8 α-olefin copolymer having (i) I from 8.5 to 20.0 10 / I2, and (ii) Vinyl content from 25 / 1,000,000C to 100 / 1,000,000C.

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