Bridged metallocene catalysts, processes for their preparation and use

Abstract

This invention provides a bridged metallocene catalyst, its preparation method, and its application, relating to the fields of chemical products and chemical product reaction engineering. The structural formula of the bridged metallocene catalyst is shown in Formula I below. In the presence of alkoxyaluminum or alkylaluminum co-catalysts, the bridged metallocene catalyst efficiently catalyzes the polymerization of ethylene or α-olefins, or the copolymerization of ethylene and α-olefins, or the copolymerization of propylene and α-olefins. The polymerization or copolymerization process can be solution polymerization, gas-phase polymerization, liquid-phase bulk polymerization, slurry polymerization, loop polymerization, or a combination of polymerization processes, efficiently preparing high-end propylene-based elastomers, vinyl elastomers, and polyolefin plasmon materials.

Description

Technical Field

[0001] This invention relates to the technical field of chemical products and chemical product reaction engineering, specifically to a bridged metallocene catalyst, its preparation method and application, and particularly to an olefin coordination polymerization catalyst, catalyst synthesis and application, specifically to a bridged metallocene catalyst, a method for synthesizing a bridged metallocene catalyst, polyolefins synthesized by the bridged metallocene catalyst, the application of the obtained metallocene polyolefins, and a process for synthesizing metallocene polyolefin materials. Background Technology

[0002] High-end polyolefin materials (including metallocene polyolefins, ultra-clean polyolefins, medical polyolefins, thermoplastic elastomers, functional group copolyolefins, and high-end pipes) are a crucial pillar of the polyolefin industry. The key technology lies in olefin coordination polymerization catalysts. The reaction conditions for free radical polymerization of olefins initiated by peroxides and other initiators are demanding; ethylene can only polymerize to prepare LDPE under high temperature (200~350℃) and high pressure (200~300 MPa). Even more challenging is that propylene cannot undergo polymerization even under high temperature and high pressure conditions.

[0003] DuPont-Dow Ellastomets utilizes metallocene catalysts with defined geometries, exhibiting high catalytic activity within a polymerization temperature range of 90–180°C, resulting in polyolefins with high molecular weights. Mitsui Petrochemicals Co., Ltd. of Japan [EP0495099 A1] uses an ethyl-bridged metallocene catalyst to catalyze the copolymerization of ethylene and α-olefins, synthesizing the polyolefin elastomer Tafmer. Propylene-based elastomers are a novel type of high-end polyolefin material with stringent requirements for catalysts. Currently, there are relatively few reports on suitable catalysts, polymerization processes, and propylene-based elastomer products for their synthesis. Invention ZL201410132466.7 discloses a highly efficient catalyst for the solution polymerization process at relatively high polymerization temperatures to synthesize high-end propylene-based elastomers.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a bridged metallocene catalyst, its preparation method, and its application. This invention aims to address the problems of insufficient catalytic activity, poor structural stability, and harsh polymerization conditions encountered by existing metallocene catalysts in the synthesis of high-end polyolefins (especially propylene-based elastomers).

[0006] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In a first aspect, the present invention provides a bridged metallocene catalyst, the structural formula of which is shown in Formula I below:

[0007] Formula I; in, R1, R2 and R3 are each independently selected from any one of the following: hydrogen atom, substituted or unsubstituted C1-C30 straight-chain or branched alkyl group, substituted or unsubstituted C3-C30 cycloalkyl group, and substituted or unsubstituted C6-C30 aryl group; X is selected from any one of the following: halogen atom, substituted or unsubstituted C1-C30 straight-chain or branched alkyl group, substituted or unsubstituted C3-C30 cycloalkyl group, and substituted or unsubstituted C6-C30 aryl group; Q is a bridging group; M is selected from transition metal elements or rare earth metal elements.

[0008] Furthermore, when R1, R2, and R3 are each independently selected from any one of substituted C1-C30 straight-chain or branched alkyl groups, substituted C3-C30 cycloalkyl groups, or substituted C6-C30 aryl groups, their substituents are each independently selected from any one of halogen atoms, nitro groups, C1-C30 straight-chain or branched alkyl groups, C1-C30 straight-chain or branched alkoxy groups, C3-C30 cycloalkyl groups, or C6-C30 aryl groups.

[0009] Furthermore, when X is selected from any one of substituted C1-C30 straight-chain or branched alkyl, substituted C3-C30 cycloalkyl, or substituted C6-C30 aryl, the substituents are each independently selected from any one of halogen atom, nitro, C1-C30 straight-chain or branched alkyl, C1-C30 straight-chain or branched alkoxy, C3-C30 cycloalkyl, or C6-C30 aryl.

[0010] Furthermore, Q is selected from any one of Si, C, Se, CC, S, and Sn.

[0011] Furthermore, M is selected from any one of Ti, Zr, Hf, Ni, Pd, Ru, Rh, Fe, Co, Nd, Y, Sc, and Sm.

[0012] Furthermore, the bridged metallocene catalyst comprises the following compounds I-1 to I-6:

[0013] I-1;

[0014] I-2;

[0015] I-3;

[0016] I-4;

[0017] I-5;

[0018] I-6.

[0019] In a second aspect, the present invention provides a method for preparing a bridged metallocene catalyst as described in the first aspect, the method comprising: (1) In the first organic solvent, the organic amine and the first dehydrogenating agent react to remove the first organic solvent and then redissolve in the first organic solvent to obtain an organic solvent solution containing the organic amine salt. (2) Add a haloindene compound to the organic solvent solution containing the organic amine salt, react, remove the first organic solvent, and redissolve it in the second organic solvent to obtain an organic solvent solution containing the intermediate. (3) Add a second dehydrogenating agent to the organic solution containing the intermediate and react to obtain an organic solvent solution containing the intermediate salt; (4) Add a compound containing a bridging group to the organic solvent solution containing the intermediate salt and react to remove the second organic solvent, then redissolve in a third organic solvent to obtain an organic solvent solution containing the ligand. (5) Add a third dehydrogenating agent to the organic solution containing the ligand and react to obtain an organic solvent solution containing the ligand salt; (6) Add a transition metal salt or a rare earth metal salt to the organic solvent solution containing the ligand salt and react to obtain the bridged metallocene catalyst.

[0020] Furthermore, the structural formula of the organic amine is shown in Formula A below:

[0021] Formula A.

[0022] Furthermore, the structural formula of the haloindene compound is shown in Formula B below:

[0023] Formula B.

[0024] Furthermore, the structural formula of the organic amine salt is shown in Formula C below:

[0025] Formula C.

[0026] Furthermore, the structural formula of the ligand is shown in equation D below: Formula D.

[0027] Furthermore, the structural formula of the ligand salt is shown in E below: Formula E.

[0028] The selection of R1, R2, R3, X, Q, and M groups is as described in the first aspect; Furthermore, the first organic solvent, the second organic solvent, and the third organic solvent are each independently selected from any one or a combination of at least two of the following: C5-C30 saturated hydrocarbons, C5-C30 alicyclic hydrocarbons, C6-C30 aromatic hydrocarbons, C3-C20 saturated heterocyclic hydrocarbons, and paraffin oil. Preferably, they are any one or a combination of at least two of the following: toluene, xylene, dioxane, hexane, heptane, octane, decane, cyclohexane, petroleum ether, paraffin oil, white oil, dodecane, tetradecane, and hexadecane.

[0029] Furthermore, the first dehydrogenating agent, the second dehydrogenating agent, and the third dehydrogenating agent are each independently selected from any one or a combination of at least two of n-butyllithium, Grignard reagent, metallic sodium, metallic potassium, and metallic lithium.

[0030] Furthermore, the transition metal salt includes any one or a combination of at least two of the following: halide salts, alkyl salts, alkoxy salts, cycloalkyl salts, and aryl salts of transition metal elements.

[0031] Furthermore, the rare earth metal salt includes any one or a combination of at least two of the following: halide salts, alkyl salts, alkoxy salts, cycloalkyl salts, and aryl salts of rare earth metal elements.

[0032] Further, in step (1), the reaction temperature is -70~100℃ and the reaction time is 0.5~20h.

[0033] Further, in step (1), the molar ratio of the organic amine to the first dehydrogenation reagent is 1:(0.90~5.0).

[0034] Furthermore, in step (2), the reaction temperature is -20~100℃ and the reaction time is 0.5~15h.

[0035] Further, in step (2), the molar ratio of the haloindene compound and the organic amine salt is 1:(0.95~2.0).

[0036] Furthermore, in step (3), the reaction temperature is -70~100℃ and the reaction time is 0.5~12h.

[0037] Further, in step (3), the molar ratio of the intermediate and the second dehydrogenation reagent is 1:(0.2~1.0).

[0038] Furthermore, in step (4), the reaction temperature is -70~100℃ and the reaction time is 0.5~12h.

[0039] Further, in step (4), the molar ratio of the intermediate salt and the compound containing the bridging group is 1:(0.25~1.0).

[0040] Furthermore, in step (5), the reaction temperature is -70~100℃ and the reaction time is 0.5~12h.

[0041] Further, in step (5), the molar ratio of the ligand to the third dehydrogenating agent is 1:(0.2~1.0).

[0042] Furthermore, in step (6), the reaction temperature is -70~100℃ and the reaction time is 0.5~12h.

[0043] Further, in step (6), the molar ratio of the ligand salt to the transition metal salt is 1:(0.25~2.5); or, the molar ratio of the ligand salt to the rare earth metal salt is 1:(0.25~2.5).

[0044] Thirdly, the present invention provides an application of the bridged metallocene catalyst as described in the first aspect in the preparation of polyolefins.

[0045] Fourthly, the present invention provides a method for preparing a polyolefin, the method comprising the following steps: In the presence of the bridged metallocene catalyst as described in the first aspect, C2-C3 olefin monomers and α-olefin monomers are polymerized to obtain the polyolefin.

[0046] Furthermore, the C2-C3 olefin monomers include ethylene and / or propylene.

[0047] Further, the α-olefin monomer includes any one or a combination of at least two of C3-C30 olefins, preferably any one or a combination of at least two of C3-C30 olefins and C6-C30 dienes, and more preferably any one or a combination of at least two of propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 3-methyl-1-butene, cyclopentene, 4-methyl-1-pentene, 1,3-butadiene, isoprene, styrene, methylstyrene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, norbornene, and ethylidene norbornene.

[0048] Furthermore, the polymerization reaction temperature is 30~150℃, the polymerization reaction time is 5~300 min, and the polymerization reaction pressure is 0.05~40 MPa.

[0049] Furthermore, the polymerization process includes any one or a combination of at least two of the following: solution polymerization, gas-phase polymerization, liquid-phase bulk polymerization, slurry polymerization, and loop polymerization.

[0050] Furthermore, the polymerization reaction is carried out in the presence of a co-catalyst.

[0051] Furthermore, the co-catalyst comprises any one or a combination of at least two of alkylaluminum, alkoxyaluminum, and organoborides, preferably any one or a combination of at least two of trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-tert-butylaluminum, trioctylaluminum, diethylaluminum chloride, diethylaluminum chloride, sesquiethylaluminum chloride, MAO, and modified MAO.

[0052] Furthermore, the molar ratio of the co-catalyst to the bridged metallocene catalyst is (5~2000):1.

[0053] Furthermore, the polymerization reaction is carried out in a solvent.

[0054] Further, the solvent includes any one or a combination of at least two of the following: C5-C30 saturated hydrocarbons, C5-C30 alicyclic hydrocarbons, C6-C30 aromatic hydrocarbons, C3-C20 saturated heterocyclic hydrocarbons, and paraffin oil; preferably, any one or a combination of at least two of the following: toluene, xylene, hexane, heptane, octane, decane, cyclohexane, petroleum ether, paraffin oil, white oil, dodecane, tetradecane, and hexadecane.

[0055]

Terminology Explanation

[0056] As used in this invention, the term "C1-C30 straight-chain or branched alkyl" refers to a monovalent substituent derived from a straight-chain or branched saturated hydrocarbon having 1 to 30 carbon atoms, including but not limited to methyl, ethyl, n-propyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, and n-hexyl.

[0057] As used in this invention, the term "C1-C30 straight-chain or branched alkoxy group" refers to a monovalent oxygen-containing substituent derived from a straight-chain or branched saturated hydrocarbon having 1 to 30 carbon atoms, having the structure "-O-alkyl", wherein the alkyl group is a straight-chain or branched alkyl group having 1 to 30 carbon atoms.

[0058] As used in this invention, the term "C3-C30 cycloalkyl" refers to a monocyclic or polycyclic hydrocarbon derived from a main chain of 3 to 30 carbon atoms, including cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc.

[0059] As used in this invention, the term "C6-C30 aryl" refers to a monocyclic, polycyclic, or fused-ring aryl group having 6 to 30 ring backbone carbon atoms, wherein the rings may be interrupted by short non-aromatic units and may contain spiro structures, including but not limited to phenyl, tetrahydronaphthyl, indenyl, biphenyl, benzyl, etc.

[0060] Compared with the prior art, the present invention has the following beneficial effects: The metallopolymer catalyst provided by this invention has a stable structure and excellent heat resistance. In the presence of alkoxyaluminum or alkylaluminum co-catalysts, it efficiently catalyzes the homopolymerization of ethylene, homopolymerization of propylene, copolymerization of ethylene and α-olefins, copolymerization of propylene and α-olefins, copolymerization of ethylene and polar olefin monomers, copolymerization of propylene and polar olefin monomers, or multi-component copolymerization of non-polar olefin monomers and polar olefin monomers, thus efficiently preparing high-end copolyolefin materials. The method of this invention is simple, safe, low-cost, and easy to operate, with low equipment requirements, low energy consumption, and minimal environmental pollution. Attached Figure Description

[0061] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0062] Figure 1 The NMR spectrum of the bridged metallocene catalyst prepared in Example 1 is shown.

[0063] Figure 2 The NMR spectrum of the bridged metallocene catalyst prepared in Example 2 is shown.

[0064] Figure 3 The NMR spectrum of the bridged metallocene catalyst prepared in Example 3 is shown.

[0065] Figure 4 The NMR spectrum of the bridged metallocene catalyst prepared in Example 4 is shown. Detailed Implementation

[0066] Unless otherwise defined herein, the scientific and technical terms used in conjunction with this invention shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0067] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] In a first aspect, the present invention provides a bridged metallocene catalyst, the structural formula of which is shown in Formula I below:

[0069] Formula I; in, R1, R2, and R3 are each independently selected from any one of the following: hydrogen atom; substituted or unsubstituted C1-C30 (e.g., C1, C2, C4, C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, etc.) straight-chain or branched alkyl groups; substituted or unsubstituted C3-C30 (e.g., C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, etc.) cycloalkyl groups; and substituted or unsubstituted C6-C30 (e.g., C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, etc.) aryl groups. X is selected from any one of the following: halogen atom; substituted or unsubstituted C1-C30 (e.g., C1, C2, C4, C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, etc.) straight-chain or branched alkyl group; substituted or unsubstituted C3-C30 (e.g., C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, etc.) cycloalkyl group; substituted or unsubstituted C6-C30 (e.g., C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, etc.) aryl group; Q is a bridging group; M is selected from transition metal elements or rare earth metal elements.

[0070] It should be noted that the bridging metallocene catalyst of this invention integrates nitrogen-containing ligands and an indenyl framework, and introduces multiple types of bridging groups, including Si, C, Se, CC, S, and Sn, to coordinate with transition metal and rare earth metal centers to construct a stable catalytic framework. The nitrogen-containing structure allows for the control of the coordination electron cloud distribution, while the rigid indenyl ring framework enhances the overall conjugation effect and spatial configuration stability of the molecule, significantly improving the catalyst's thermal stability and structural resistance to dissociation, making it less prone to deactivation under high-temperature polymerization conditions. The diverse bridging groups each offer advantages in structural control: Si and C bridging exhibit moderate rigidity, allowing for precise control of the ligand angle and steric hindrance; Se and S heteroatom bridging possess unique electron-donating and accepting characteristics, optimizing the electronic environment of the active center; CC and Sn bridging are flexible and tunable, adapting to the coordination insertion requirements of different monomers. These multiple bridging groups can flexibly modify the catalyst's spatial configuration and electronic effects, precisely matching the polymerization coordination requirements of ethylene, propylene, α-olefins, and polar olefin monomers. This structural design ensures a stable coordination environment at the catalyst's active center, resulting in high catalytic activity and excellent comonomer insertion capability. It can efficiently catalyze homopolymerization, binary copolymerization, and multi-component copolymerization of olefins. Furthermore, the structure offers strong designability, allowing for easy modification and derivatization of substituents and bridging groups. The synthetic route is simple and mild, with broad compatibility with various polymerization processes, low energy consumption, minimal pollution, and ease of industrial production. This enables the efficient mass production of high-end polyolefin plastic and elastic materials.

[0071] As an optional implementation, when R1, R2, and R3 are each independently selected from any one of substituted C1-C30 straight-chain or branched alkyl groups, substituted C3-C30 cycloalkyl groups, and substituted C6-C30 aryl groups, the substituents are each independently selected from any one of halogen atoms, nitro groups, C1-C30 straight-chain or branched alkyl groups, C1-C30 straight-chain or branched alkoxy groups, C3-C30 cycloalkyl groups, and C6-C30 aryl groups.

[0072] As an optional embodiment, when X is selected from any one of substituted C1-C30 straight-chain or branched alkyl, substituted C3-C30 cycloalkyl, or substituted C6-C30 aryl, the substituents are each independently selected from any one of halogen atom, nitro, C1-C30 straight-chain or branched alkyl, C1-C30 straight-chain or branched alkoxy, C3-C30 cycloalkyl, or C6-C30 aryl.

[0073] As an optional implementation, Q is selected from any one of Si, C, Se, CC, S, and Sn.

[0074] As an optional implementation, M is selected from any one of Ti, Zr, Hf, Ni, Pd, Ru, Rh, Fe, Co, Nd, Y, Sc, and Sm.

[0075] As an optional embodiment, the bridged metallocene catalyst comprises the following compounds I-1 to I-6:

[0076] I-1;

[0077] I-2;

[0078] I-3;

[0079] I-4;

[0080] I-5;

[0081] I-6.

[0082] In a second aspect, the present invention provides a method for preparing a bridged metallocene catalyst as described in the first aspect, the method comprising: (1) In the first organic solvent, the organic amine and the first dehydrogenating agent react to remove the first organic solvent and then redissolve in the first organic solvent to obtain an organic solvent solution containing the organic amine salt. (2) Add a haloindene compound to the organic solvent solution containing the organic amine salt, react, remove the first organic solvent, and redissolve it in the second organic solvent to obtain an organic solvent solution containing the intermediate. (3) Add a second dehydrogenating agent to the organic solution containing the intermediate and react to obtain an organic solvent solution containing the intermediate salt; (4) Add a compound containing a bridging group to the organic solvent solution containing the intermediate salt and react to remove the second organic solvent, then redissolve in a third organic solvent to obtain an organic solvent solution containing the ligand. (5) Add a third dehydrogenating agent to the organic solution containing the ligand and react to obtain an organic solvent solution containing the ligand salt; (6) Add a transition metal salt or a rare earth metal salt to the organic solvent solution containing the ligand salt and react to obtain the bridged metallocene catalyst.

[0083] The preparation method described herein is simple, safe, low-cost, easy to operate, requires minimal equipment, consumes little energy, and causes minimal environmental pollution.

[0084] As an optional implementation, the organic amine has the following structural formula A:

[0085] Formula A.

[0086] Furthermore, the structural formula of the haloindene compound is shown in Formula B below:

[0087] Formula B.

[0088] Furthermore, the structural formula of the organic amine salt is shown in Formula C below:

[0089] Formula C.

[0090] Furthermore, the structural formula of the ligand is shown in equation D below: Formula D.

[0091] Furthermore, the structural formula of the ligand salt is shown in E below: Formula E.

[0092] The selection of R1, R2, R3, X, Q, and M groups is as described in the first aspect.

[0093] As an optional implementation, the first organic solvent, the second organic solvent, and the third organic solvent are each independently selected from any one or a combination of at least two of the following: saturated hydrocarbons of C5-C30 (e.g., C5, C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, etc.), alicyclic hydrocarbons of C5-C30, aromatic hydrocarbons of C6-C30, saturated heterocyclic hydrocarbons of C3-C20, and paraffin oil.

[0094] As an optional implementation, the first organic solvent, the second organic solvent, and the third organic solvent are each independently selected from any one or a combination of at least two of toluene, xylene, dioxane, hexane, heptane, octane, decane, cyclohexane, petroleum ether, paraffin oil, white oil, dodecane, tetradecane, and hexadecane.

[0095] As an optional implementation, the first dehydrogenating agent, the second dehydrogenating agent, and the third dehydrogenating agent are each independently selected from any one or a combination of at least two of n-butyllithium, Grignard reagent, metallic sodium, metallic potassium, and metallic lithium.

[0096] As an optional implementation, the transition metal salt includes any one or a combination of at least two of the following: halide salts, alkyl salts, alkoxy salts, cycloalkyl salts, and aryl salts of transition metal elements.

[0097] As an optional implementation, the rare earth metal salt includes any one or a combination of at least two of the following: halide salts, alkyl salts, alkoxy salts, cycloalkyl salts, and aryl salts of rare earth metal elements.

[0098] As an optional implementation, in step (1), the reaction temperature is -70~100℃, for example, it can be -70℃, -65℃, -60℃, -55℃, -50℃, -45℃, -40℃, -35℃, -30℃, -25℃, -20℃, -15℃, -10℃, -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, etc., and the reaction time is 0.5~20 h, for example, it can be 0.5 h, 1.0 h, 1.5 h, 2.0 h, 2.5 h, 3.0 h, 3.5 h, 4.0 h, 4.5 h, 5.0 h, 5.5 h, etc. h, 6.0 h, 6.5 h, 7.0 h, 7.5 h, 8.0 h, 8.5 h, 9.0 h, 9.5 h, 10.0 h, 10.5 h, 11.0 h, 11.5 h, 12.0 h, 12.5 h, 13.0 h, 13.5 h, 14.0 h, 14.5 h, 15.0 h, 15.5 h, 16.0 h, 16.5 h, 17.0 h, 17.5 h, 18.0 h, 18.5 h, 19.0 h, 19.5 h, 20.0 h, etc.

[0099] As an optional implementation, in step (1), the molar ratio of the organic amine to the first dehydrogenating agent is 1:(0.90~5.0), for example, it can be 1:0.90, 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2.0, 1:2.2, 1:2.4, 1:2.6, 1:2.8, 1:3.0, 1:3.2, 1:3.4, 1:3.6, 1:3.8, 1:4.0, 1:4.2, 1:4.4, 1:4.6, 1:4.8, 1:5.0, etc.

[0100] As an optional implementation, in step (2), the reaction temperature is -20~100℃, for example, it can be -20℃, -15℃, -10℃, -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, etc., and the reaction time is 0.5~15 h, for example, it can be 0.5 h, 1.0 h, 1.5 h, 2.0 h, 2.5 h, 3.0 h, 3.5 h, 4.0 h, 4.5 h, 5.0 h, 5.5 h, 6.0 h, 6.5 h, 7.0 h, 7.5 h, 8.0 h, 8.5 h, 9.0 h, 9.5 h, 10.0 h. h, 10.5 h, 11.0 h, 11.5 h, 12.0 h, 12.5 h, 13.0 h, 13.5 h, 14.0 h, 14.5 h, 15.0 h, etc.

[0101] As an optional implementation, in step (2), the molar ratio of the haloindene compound and the organic amine salt is 1:(0.95~2.0), for example, it can be 1:0.95, 1:0.90, 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2.0, etc.

[0102] As an optional implementation, in step (3), the reaction temperature is -70~100℃, for example, it can be -70℃, -65℃, -60℃, -55℃, -50℃, -45℃, -40℃, -35℃, -30℃, -25℃, -20℃, -15℃, -10℃, -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, etc., and the reaction time is 0.5~12 h, for example, it can be 0.5 h, 1.0 h, 1.5 h, 2.0 h, 2.5 h, 3.0 h, 3.5 h, 4.0 h, 4.5 h, 5.0 h, 5.5 h, etc. h, 6.0 h, 6.5 h, 7.0 h, 7.5 h, 8.0 h, 8.5 h, 9.0 h, 9.5 h, 10.0 h, 10.5 h, 11.0 h, 11.5 h, 12.0 h, etc.

[0103] As an optional implementation, in step (3), the molar ratio of the intermediate and the second dehydrogenation reagent is 1:(0.2~1.0), for example, it can be 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, etc.

[0104] As an optional implementation, in step (4), the reaction temperature is -70~100℃, for example, it can be -70℃, -65℃, -60℃, -55℃, -50℃, -45℃, -40℃, -35℃, -30℃, -25℃, -20℃, -15℃, -10℃, -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, etc., and the reaction time is 0.5~12 h, for example, it can be 0.5 h, 1.0 h, 1.5 h, 2.0 h, 2.5 h, 3.0 h, 3.5 h, 4.0 h, 4.5 h, 5.0 h, 5.5 h, etc. h, 6.0 h, 6.5 h, 7.0 h, 7.5 h, 8.0 h, 8.5 h, 9.0 h, 9.5 h, 10.0 h, 10.5 h, 11.0 h, 11.5 h, 12.0 h, etc.

[0105] As an optional implementation, in step (4), the molar ratio of the intermediate salt and the compound containing the bridging group is 1:(0.25~1.0), for example, it can be 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, etc.

[0106] As an optional implementation, in step (5), the reaction temperature is -70~100℃, for example, it can be -70℃, -65℃, -60℃, -55℃, -50℃, -45℃, -40℃, -35℃, -30℃, -25℃, -20℃, -15℃, -10℃, -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, etc., and the reaction time is 0.5~12 h, for example, it can be 0.5 h, 1.0 h, 1.5 h, 2.0 h, 2.5 h, 3.0 h, 3.5 h, 4.0 h, 4.5 h, 5.0 h, 5.5 h, etc. h, 6.0 h, 6.5 h, 7.0 h, 7.5 h, 8.0 h, 8.5 h, 9.0 h, 9.5 h, 10.0 h, 10.5 h, 11.0 h, 11.5 h, 12.0 h, etc.

[0107] As an optional implementation, in step (5), the molar ratio of the ligand and the third dehydrogenating agent is 1:(0.2~1.0), for example, it can be 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, etc.

[0108] As an optional implementation, in step (6), the reaction temperature is -70~100℃, for example, it can be -70℃, -65℃, -60℃, -55℃, -50℃, -45℃, -40℃, -35℃, -30℃, -25℃, -20℃, -15℃, -10℃, -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, etc., and the reaction time is 0.5~12 h, for example, it can be 0.5 h, 1.0 h, 1.5 h, 2.0 h, 2.5 h, 3.0 h, 3.5 h, 4.0 h, 4.5 h, 5.0 h, 5.5 h, etc. h, 6.0 h, 6.5 h, 7.0 h, 7.5 h, 8.0 h, 8.5 h, 9.0 h, 9.5 h, 10.0 h, 10.5 h, 11.0 h, 11.5 h, 12.0 h, etc.

[0109] As an optional implementation, in step (6), the molar ratio of the ligand salt to the transition metal salt is 1:(0.25~2.5), for example, it can be 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2.0, 1:2.2, 1:2.4, 1:2.5, etc.

[0110] As an optional implementation, in step (6), the molar ratio of the ligand salt to the rare earth metal salt is 1:(0.25~2.5), for example, it can be 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2.0, 1:2.2, 1:2.4, 1:2.5, etc.

[0111] Thirdly, the present invention provides an application of the bridged metallocene catalyst as described in the first aspect in the preparation of polyolefins.

[0112] It should be noted that the application of the bridged metallocene catalyst catalyzes the polymerization of olefins to produce high-performance polyolefin plastic materials and polyolefin elastic materials. These polyolefin plastic and elastic materials are suitable for various existing processing techniques, as well as future new processing techniques, including extrusion, blow molding, uniaxial (biaxial) film stretching, wet (dry) film formation, foaming, rotational molding, casting, and other processing techniques. The resulting products are suitable for various applications, primarily in battery films, temperature and pressure resistant pipes, shoe materials, building materials, automotive materials, automotive decorative materials, fitness equipment, creep-resistant materials, ship cables, fishing nets, agricultural films, drones, home decorations, toys, non-structural materials for aircraft and high-speed rail, interior trim, stab-resistant gloves, bulletproof vests, hydrogen storage tank linings, modern communication materials, and packaging materials for intelligent robots or humanoid robots.

[0113] As an optional implementation, the bridged metallocene catalyst is used to catalyze the polymerization of ethylene or α-olefins, or the copolymerization of ethylene and α-olefins, or the copolymerization of propylene and α-olefins, in the presence of a co-catalyst.

[0114] Fourthly, the present invention provides a method for preparing a polyolefin, the method comprising the following steps: In the presence of the bridged metallocene catalyst as described in the first aspect, C2-C3 olefin monomers and α-olefin monomers are polymerized to obtain the polyolefin.

[0115] As an optional implementation, the C2-C3 olefin monomer includes ethylene and / or propylene.

[0116] As an optional implementation, the α-olefin monomer includes any one or a combination of at least two of the C3-C30 olefins.

[0117] As an optional implementation, the α-olefin monomer includes any one or a combination of at least two of C3-C30 olefins and C6-C30 dienes.

[0118] As an optional implementation, the α-olefin monomer includes any one or a combination of at least two of the following: propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 3-methyl-1-butene, cyclopentene, 4-methyl-1-pentene, 1,3-butadiene, isoprene, styrene, methylstyrene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, norbornene, and ethylidene norbornene.

[0119] As an optional implementation, the polymerization reaction temperature is 30~150℃, for example, it can be 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, etc.

[0120] As an optional implementation, the polymerization reaction time is 5 to 300 min, for example, it can be 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min, 90 min, 95 min, 100 min, 105 min, 110 min, 115 min, 120 min, 125 min, 130 min, 135 min, 140 min, 145 min, 150 min, 155 min, 160 min, 165 min, 170 min, 175 min, 180 min, 185 min, 190 min, 195 min, 200 min, 205 min, 210 min, 215 min, 220 min, 225 min, 230 min, 235 min, 240 min, 245 min, etc. min, 250 min, 255 min, 260 min, 265 min, 270 min, 275 min, 280 min, 285 min, 290 min, 295 min, 300 min, etc.

[0121] As an optional implementation, the pressure of the polymerization reaction is 0.05~40 MPa, for example, it can be 0.05 MPa, 0.1 MPa, 0.2 MPa, 0.5 MPa, 1 MPa, 5 MPa, 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, etc.

[0122] As an optional implementation, the polymerization process includes any one or a combination of at least two of the following: solution polymerization, gas-phase polymerization, liquid-phase bulk polymerization, slurry polymerization, and loop polymerization.

[0123] As an optional implementation, the polymerization reaction is carried out in the presence of a co-catalyst.

[0124] As an optional embodiment, the co-catalyst includes any one or a combination of at least two of alkylaluminum, alkoxyaluminum, and organoborides.

[0125] As an optional implementation, the co-catalyst includes any one or a combination of at least two of trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-tert-butylaluminum, trioctylaluminum, diethylaluminum chloride, diethylaluminum chloride, sesquiethylaluminum chloride, MAO, and modified MAO.

[0126] As an optional implementation, the molar ratio of the co-catalyst to the bridged metallocene catalyst is (5~2000):1, for example, it can be 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 60:1, 70:1, 80:1, 90:1, 100:1, 110:1, 120:1, 130:1. 140:1, 150:1, 160:1, 170:1, 180:1, 190:1, 200:1, 210:1, 220:1, 230:1, 240:1, 250:1, 260:1, 270:1, 280:1, 290:1, 300:1, 310:1, 320:1, 330:1, 340:1, 350:1, 360:1, 370 :1, 380:1, 390:1, 400:1, 410:1, 420:1, 430:1, 440:1, 450:1, 460:1, 470:1, 480:1, 490:1, 500:1, 550:1, 600:1, 650:1, 700:1, 750:1, 800:1, 850:1, 900:1, 950:1, 1000:1 1050:1, 1100:1, 1150:1, 1200:1, 1250:1, 1300:1, 1350:1, 1400:1, 1450:1, 1500:1, 1550:1, 1600:1, 1650:1, 1700:1, 1750:1, 1800:1, 1850:1, 1900:1, 1950:1, 2000:1, etc.

[0127] As an optional implementation, the polymerization reaction is carried out in a solvent.

[0128] As an optional implementation, the solvent includes saturated hydrocarbons of C5-C30 (e.g., C5, C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, etc.) and C5-C30 (e.g., C5, C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, etc.). The following are any one or a combination of at least two of the following: alicyclic hydrocarbons (C6-C30, such as C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, etc.); aromatic hydrocarbons (C3-C20, such as C3, C5, C7, C9, C11, C13, C15, C17, C19, C20, etc.); and paraffin oil.

[0129] As an optional implementation, the solvent includes any one or a combination of at least two of toluene, xylene, hexane, heptane, octane, decane, cyclohexane, petroleum ether, paraffin oil, white oil, dodecane, tetradecane, and hexadecane.

[0130] As an optional implementation, the method for preparing the polyolefin includes the following steps: (1) Add an organic solvent, a bridged metallocene catalyst and a co-catalyst to the polymerization reactor. The co-catalyst is an alkyl aluminum, an alkoxy aluminum or a mixture thereof. Classic co-catalysts such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-tert-butylaluminum, trioctylaluminum, diethylaluminum chloride, diethylaluminum chloride, sesquiethylaluminum chloride, MAO or modified MAO, etc., can be used alone or in combination. The molar ratio of the bridged metallocene catalyst to the co-catalyst is 1:(5-2000). Stir at 10~100℃ for 5~30 min. (2) Ethylene or α-olefin is added to the polymerization reactor for polymerization. The polymerization temperature is 30~200℃, the copolymerization time is 5~100 min, and the copolymerization pressure is 0.05~40. MPa; wherein the α-olefin is a C3-C30 olefin, preferably propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 3-methyl-1-butene, cyclopentene, 4-methyl-1-pentene, 1,3-butadiene, isoprene, styrene, methylstyrene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, norbornene, ethylidene norbornene or their derivatives; the organic solvent is selected from C5-C30 saturated hydrocarbons, C5-C30 alicyclic hydrocarbons, C6-C30 aromatic hydrocarbons or C3-C20 saturated heterocyclic hydrocarbons or paraffin oil or a mixture thereof, such as toluene, xylene, hexane, heptane, octane, decane, cyclohexane, petroleum ether, paraffin oil, white oil, dodecane, tetradecane or hexadecane, or a mixture thereof.

[0131] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0132] Example 1 This embodiment provides the preparation of a bridged metallocene catalyst (I-1) and its application as a catalyst in the preparation of polyolefins.

[0133]

[0134] I-1; The synthesis route is shown below:

[0135] The specific preparation steps of the bridged metallocene catalyst (I-1) are as follows: (1) Add 80 mL of toluene, add N-methyl-2,4,6-trimethylaniline (3 g) and n-butyllithium in an equimolar ratio, stir at -50℃ for 2 h, then heat to 50℃ for 5 h, filter, wash the filter residue 3 times with hexane (50 mL hexane each time), and vacuum dry the filter residue; then dissolve or disperse the filter residue in 60 mL of toluene solvent to obtain N-methyl-2,4,6-trimethylaniline salt toluene solution; (2) Add 7-bromoindene (7.8 g) to the N-methyl-2,4,6-trimethylaniline salt toluene solution from step (1), stir and react at -20°C for 1 h, then heat to 45°C and react for 8 h; filter to obtain the intermediate salt toluene solution; (3) At -20℃, add 16 ml of n-butyllithium solution (2.5 M) to the intermediate salt toluene solution obtained in step (2), stir, react for 6 h, wash the filter residue with hexane 3 times (50 mL of hexane each time), and vacuum dry the filter residue; then dissolve or disperse the filter residue in 60 mL of toluene solvent to obtain N-methyl-2,4,6-trimethylaniline salt toluene solution; (4) At -20℃, dimethyl silicon dichloride (1.3 g) was added to the N-methyl-2,4,6-trimethylaniline salt toluene solution obtained in step (3), stirred and reacted for 1 h, and then heated to 40℃ and reacted for 9 h; the mixture was filtered, and the toluene solvent in the filtrate was removed by vacuum to obtain the ligand (9.1 g), with a yield of 78.1%; the ligand molecular formula is C 40 H 44 N₂Si, Fm 581, elemental analysis: C 82.61, H 7.57, N 4.81, Si 4.65; the ligand was dissolved in toluene to obtain a toluene solution containing the ligand; (5) Add 2 molar ratios of n-butyllithium to the toluene solution containing the ligand obtained in step (4), stir and react at -40℃ for 1 h, then heat to 40℃ and react for 8 h, filter, wash the filter residue twice with hexane, and vacuum dry the filter residue. Then dissolve or disperse the filter residue in toluene to obtain a toluene solution containing the ligand salt; (6) At -20℃, TiCl4 (4.1 g) of transition metal salt was added to the toluene solution containing ligand salt obtained in step (5), stirred and reacted for 1 h, heated to 50℃ and reacted for 8 h, filtered, and the toluene solvent in the filtrate was removed by vacuum to obtain 11.2 g of bridged metallocene catalyst (I-1) solid powder with a yield of 80.5% and molecular formula C 40 H 42Cl2N2TiSi, Fm 696, elemental analysis: C 68.99, H 6.05, Cl 10.18, N 4.11, Ti 10.67.

[0136] like Figure 1 The specific characterization of the bridged metallocene catalyst (I-1) is shown below: 1 H NMR (400 MHz, CDCl3) δ: 7.46-7.42 (d, 2H); 7.28-7.23 (t, 2H); 7.21-7.17 (m, 2H); 7.06-7.03 (d,2H); 6.85 (s,4H); 6.19-6.15 (d,2H); 3.47 (s,6H); 2.26 (s,6H); 2.16 (s,12H); 0.51 (s,6H).

[0137] Propylene polymerization: (1) At 25°C, add 5 mL of MAO solution toluene, 150 mL of toluene and 10 mg of bridged metallocene catalyst (1) solid powder to a 500 mL polymerization reactor and stir for 15 min.

[0138] (2) At 90℃, propylene monomer was introduced into the polymerization reactor, the pressure was maintained at 0.2 MPa, and the mixture was stirred for 20 min to obtain 9.1 g of polyolefin with a polymerization activity of 1.9*10. 6 g / mol·Ti·h. Polyolefin molecular weight 197,000, melting point 154.6℃.

[0139] Example 2 This embodiment provides the preparation of a bridged metallocene catalyst (I-2) and its application as a catalyst in the preparation of polyolefins.

[0140]

[0141] Formula I-2; The specific preparation steps of the bridged metallocene catalyst (I-2) are as follows: (1) Add 80 mL of toluene, 2.15 g of N-methylaniline and 1.5 molar ratio of n-butyllithium, stir at -30 °C for 1 h, then heat to 45 °C and react for 9 h. Filter, wash the filter residue twice with hexane (50 mL hexane each time), and vacuum dry the filter residue. Dissolve or disperse the filter residue in 70 mL of toluene solvent to obtain an N-methylaniline salt toluene solution; (2) Add 7.8 g of 7-bromoindene to the N-methylaniline salt toluene solution from step (1), stir and react at -20°C for 1 h, then raise the temperature to 45°C and react for 8 h; filter to obtain toluene solution; (3) Add 16 ml of n-butyllithium solution (2.5 M) at -20℃, stir, react for 6 h, wash the filter residue with hexane 3 times (50 mL of hexane each time), and vacuum dry the filter residue; then dissolve or disperse the filter residue in 60 mL of toluene solvent to obtain the intermediate salt toluene solution; (4) Add 0.85 g of dichloromethane at -30℃, stir and react for 1 h, then raise the temperature to 30℃ and react for 8 h; filter, remove toluene solvent from the filtrate under vacuum, and obtain 6.93 g of ligand, yield 76.7%, ligand molecular formula C 33 H 28 N2, Fm 453, elemental analysis: C 87.56, H 6.25, N 6.19; the ligand was dissolved in toluene to obtain a toluene solution of the ligand; (5) Add 2 molar ratios of n-butyllithium to the ligand toluene solution, stir and react at -40℃ for 1 h, then heat to 50℃ and react for 12 h, filter, wash the filter residue twice with hexane, and vacuum dry the filter residue. Then dissolve or disperse the filter residue in toluene to obtain the ligand salt toluene solution of step (3); (6) At -20℃, 4.66 g of transition metal salt ZrCl4 was added to the ligand salt toluene solution, stirred and reacted for 1 h, heated to 50℃ and reacted for 15 h, filtered, and the toluene solvent in the filtrate was removed by vacuum to obtain 10.0 g of bridged metallocene catalyst (2) solid powder, yield 82.0%, molecular formula C 33 H 26 Cl2N2Zr, Fm 612, elemental analysis: C 64.73, H 4.29, Cl 11.57, N 4.63, Zr 14.78.

[0142] like Figure 2 The specific characterization of the bridged metallocene catalyst (I-2) is shown below: 1 H NMR (400 MHz, CDCl3) δ: 7.57-7.52 (d,2H); 7.26-7.22 (m,4H); 7.21-7.17 (m,2H); 7.09-7.06 (m,2H); 7.06-7.04 (q,2H); 7.03-7.01 (m,2H); 6.92-6.87 (m,4H); 6.23-6.17 (d,2H); 6.33 (s,6H); 3.21-3.17 (1H); 2.21-2.16 (d,1H).

[0143] Propylene copolymerization: (1) At 25°C, add 5 mL of MAO solution to toluene, 150 mL of toluene and 10 mg of bridged metallocene catalyst (2) solid powder to a 500 mL polymerization reactor and stir for 15 min.

[0144] (2) At 90℃, 10 mL of 1-octene was added to the polymerization reactor, followed by the introduction of propylene monomer. The pressure was maintained at 0.3 MPa, and the mixture was stirred for 20 min to obtain 7.8 g of polyolefin with a polymerization activity of 1.6*10. 6 The weight-average molecular weight of the polyolefin is 223,000 g / mol·M·h.

[0145] Example 3 This embodiment provides the preparation of a bridged metallocene catalyst (I-3) and its application as a catalyst in the preparation of polyolefins.

[0146]

[0147] Formula I-3; The specific preparation steps of the bridged metallocene catalyst (I-3) are as follows: (1) Add 80 mL of toluene, 3.4 g of N-methyl-2,6-dimethylaniline and methyl magnesium chloride in an equimolar ratio, stir at -50 °C for 2 h, then heat to 50 °C and react for 7 h. Filter, wash the filter residue three times with hexane (50 mL hexane each time), and vacuum dry the filter residue. Dissolve or disperse the filter residue in 60 mL of toluene solvent to obtain a toluene solution of N-methyl-2,6-dimethylaniline salt; (2) Add 4.8 g of 4-bromoindene to the N-methylaniline salt toluene solution from step (1), stir and react at -10℃ for 1 h, then heat to 55℃ and react for 10 h; filter to obtain toluene solution; (3) Add 9.8 ml of n-butyllithium solution (2.5 M) at -20℃, stir, react for 6 h, wash the filter residue with hexane 3 times (50 mL of hexane each time), and vacuum dry the filter residue; then dissolve or disperse the filter residue in 60 mL of toluene solvent to obtain the intermediate salt toluene solution; (4) Add 3.1 g of diethyltin dichloride at -10℃, stir and react for 2 h, then heat to 50℃ and react for 8 h; filter, remove toluene solvent from the filtrate under vacuum, and obtain 13.61 g of ligand, yield 81.1%, ligand molecular formula C 40 H 44 N2Sn, Fm671.5, elemental analysis: C71.56, H6.59, N4.17, Sn17.68; the ligand was dissolved in toluene to obtain a toluene solution of the ligand; (5) Add 2 molar ratios of n-butyllithium to the ligand toluene solution, stir and react at -40℃ for 1 h, then heat to 40℃ and react for 8 h, filter, wash the filter residue twice with hexane, and vacuum dry the filter residue. Then dissolve or disperse the filter residue in toluene to obtain the ligand salt toluene solution of step (3); (6) At -20℃, 6.8 g of transition metal salt HfCl4 was added to the toluene solution of the ligand salt, stirred and reacted for 1 h, then heated to 60℃ and reacted for 8 h. 1.5 g of TMA was added at room temperature, and the mixture was stirred and reacted for 6 h. The mixture was filtered, and the toluene solvent in the filtrate was removed by vacuum to obtain 11.2 g of bridged metallocene catalyst (3) solid powder, with a yield of 80.5% and molecular formula C 42 H 48 N2SnHf, Fm 877, Elemental analysis: C 57.48, H 5.51, N 3.20, Sn 13.52, Hf 20.29.

[0148] like Figure 3 The specific characterization of the bridged metallocene catalyst (I-3) is shown below: 1 H NMR (400 MHz, CDCl3) δ: 7.31-7.28 (d,2H); 7.25-7.20 (t,2H); 7.10-7.08 (t,2H); 7.07 (s,2H); 7.02-6.98(d,4H); 6.86-6.82 (m,2H); 6.60-6.56 (d,2H); 3.53-3.48 (s,6H); 2.18-2.12 (s,12H); 1.99-1.95 (s,2H); 1.93-1.84 (m,2H); 1.81-1.74 (m,2H); 1.11-1.07 (t,6H).

[0149] Propylene copolymerization: (1) At 20°C, add 3 mL of MAO solution toluene, 200 mL of toluene, and 6 mg of bridged metallocene catalyst (3) solid powder to a 500 mL polymerization reactor and stir for 10 min.

[0150] (2) At 70℃, 2 mL of norbornene was added to the polymerization reactor, followed by the introduction of ethylene and propylene monomer. The pressure was maintained at 0.4 MPa, and the mixture was stirred for 0.5 h to obtain 7.3 g of polyolefin with a polymerization activity of 1.9*10. 6 g / mol·M·h. The weight-average molecular weight of the polyolefin is 321,000.

[0151] Example 4 This embodiment provides the preparation of a bridged metallocene catalyst (I-4) and its application as a catalyst in the preparation of polyolefins.

[0152]

[0153] Formula I-4; The specific preparation steps of the bridged metallocene catalyst (I-4) are as follows: (1) Add 80 mL of toluene, 2.15 g of N-methylaniline and methyl magnesium chloride in a 2.5 molar ratio, stir at -20 °C for 2 h, then heat to 55 °C and react for 8 h. Filter, wash the filter residue three times with hexane (50 mL hexane each time), and vacuum dry the filter residue. Dissolve or disperse the filter residue in 60 mL of toluene solvent to obtain an N-methylaniline salt toluene solution; (2) Add 3.9 g of 4-bromoindene to the N-methylaniline salt toluene solution from step (1), stir and react at -10℃ for 1 h, then raise the temperature to 55℃ and react for 10 h; filter to obtain toluene solution; (3) Add 8 ml of n-butyllithium solution (2.5 M) at -20℃, stir, react for 6 h, wash the filter residue with hexane 3 times (50 mL of hexane each time), and vacuum dry the filter residue; then dissolve or disperse the filter residue in 60 mL of toluene solvent to obtain the intermediate salt toluene solution; (4) Add 2.1 g of diethylselenium dichloride at -10℃, stir and react for 2 h, then heat to 50℃ and react for 8 h; filter, remove toluene solvent from the filtrate under vacuum, and obtain 9.81 g of ligand, yield 85.1%, ligand molecular formula C 36 H 36 N₂Se, Fm 576, elemental analysis: C 75.12, H 6.31, N 4.88, Se 13.87; the ligand was dissolved in toluene to obtain a toluene solution of the ligand; (5) Add 2 molar ratios of n-butyllithium to the ligand toluene solution, stir and react at -40℃ for 1 h, then heat to 40℃ and react for 8 h, filter, wash the filter residue twice with hexane, and vacuum dry the filter residue. Then dissolve or disperse the filter residue in toluene to obtain the ligand salt toluene solution of step (3); (6) At -20℃, 4.9 g of transition metal salt NdCl4 was added to the ligand salt toluene solution, stirred and reacted for 1 h, then heated to 60℃ and reacted for 8 h. 1.4 g of TMA was added at room temperature, and the mixture was stirred and reacted for 6 h. The mixture was filtered, and the toluene solvent in the filtrate was removed by vacuum extraction to obtain 10.5 g of bridged metallocene catalyst (4) solid powder, with a yield of 83.1% and molecular formula C 38 H 40 N2SeNd, Fm 748, elemental analysis: C 60.99, H 5.37, N 3.76, Se 10.41, Hf 19.47.

[0154] like Figure 4 The specific characterization of the bridged metallocene catalyst (I-4) is shown below: 1 H NMR (400 MHz, CDCl3) δ: 7.42-7.38 (d,2H); 7.37-7.33 (t,2H); 7.27-7.20 (m,4H); 7.08-7.05 (m,2H); 7.04-7.01 (m,2H); 6.92-6.89 (1,4H); 6.89-6.87 (d,2H); 6.80-6.76 (d,2H); 3.36-3.32(s,6H); 3.15-3.02 (m,2H); 2.09-2.06 (s,6H); 1.35-1.31 (t,6H).

[0155] Propylene copolymerization: (1) At 20°C, add 4 mL of MAO solution toluene, 200 mL of toluene, and 8 mg of bridged metallocene catalyst (4) solid powder to a 500 mL polymerization reactor and stir for 10 min.

[0156] (2) Add 20 mL of 1-butene to the polymerization reactor, then add ethylene and propylene monomer, maintain a pressure of 0.4 MPa, and stir at 90℃ for 0.5 h to obtain 12.5 g of polyolefin with a polymerization activity of 2.9*10. 6 g / mol·M·h. The weight-average molecular weight of the polyolefin is 215,000.

[0157] Example 5 This embodiment provides the preparation of a bridged metallocene catalyst (I-5) and its application as a catalyst in the preparation of polyolefins.

[0158]

[0159] Formula I-5; (1) The operation is the same as in Example 1; (2) The operation is the same as in Example 1; (3) The operation is the same as in Example 1; (4) The operation is the same as in Example 1; (5) The operation is the same as in Example 1; (6) At -10℃, 2.9 g of transition metal salt ScCl4 was added to the toluene solution of the ligand salt, stirred, and reacted for 1 h. The temperature was then raised to 60℃ and reacted for 8 h. After filtration, the toluene solvent in the filtrate was removed by vacuum extraction to obtain 9.3 g of bridged metallocene catalyst (5) solid powder, with a yield of 86.5% and molecular formula C 40 H 44Cl2N2SiSc, Fm 696, Elemental analysis: C 68.99, H 6.33, N 4.03, Si 4.02, Sc 16.63.

[0160] Propylene copolymerization: (1) At 20°C, add 5 mL of MAO solution toluene, 200 mL of toluene, and 10 mg of bridged metallocene catalyst (5) solid powder to a 500 mL polymerization reactor and stir for 20 min.

[0161] (2) Add 20 mL of 1,7-octadiene to the polymerization reactor, then add ethylene and propylene monomer, maintain a pressure of 0.4 MPa, and stir at 90 °C for 0.5 h to obtain 13.8 g of polyolefin with a polymerization activity of 2.9 × 10⁻⁶. 6 g / mol·M·h. The weight-average molecular weight of the polyolefin is 237,000.

[0162] Example 6 This embodiment provides the preparation of a bridged metallocene catalyst (I-6) and its application as a catalyst in the preparation of polyolefins.

[0163]

[0164] Formula I-6; (1) The operation is the same as in Example 2; (2) The operation is the same as in Example 2; (3) The operation is the same as in Example 2; (4) The operation is the same as in Example 2; (5) The operation is the same as in Example 2; (6) At -10℃, 2.9 g of transition metal salt VCl4 was added to the toluene solution of the ligand salt, stirred, and reacted for 1 h. The temperature was then raised to 70℃ and reacted for 10 h. After filtration, the toluene solvent in the filtrate was removed by vacuum extraction to obtain 7.8 g of bridged metallocene catalyst (6) solid powder, with a yield of 91.0% and molecular formula C 33 H 26 Cl2N2V, Fm 572, Elemental analysis: C 69.26, H 4.58, N 4.93, Cl 12.39, V 8.84.

[0165] Olefin polymerization: (1) At 30°C, add 5 mL of MAO solution toluene, 200 mL of toluene and 10 mg of bridged metallocene catalyst (6) solid powder to a 500 mL polymerization reactor and stir for 15 min.

[0166] (2) Add 20 mL of 1-octene to the polymerization reactor, then charge with ethylene monomer, maintain a pressure of 0.4 MPa, and stir at 90 °C for 0.5 h to obtain 14.1 g of polyolefin with a polymerization activity of 2.4 × 10⁻⁶. 6 g / mol·M·h. The weight-average molecular weight of the polyolefin is 336,000.

[0167] Comparative Example 1 The only difference from Example 1 was that the bridging metallocene catalyst (I-1) was replaced with an equal mass of ethylene bis-1-indenyl titanium dichloride, thereby yielding 6.5 g of polyolefin with a polymerization activity of 8.2*10. 5 g / mol·M·h. Polyolefin molecular weight 101,000, melting point 148.2℃.

[0168] Comparative Example 2 The only difference from Example 2 is that the bridged metallocene catalyst (I-2) was replaced with an equal mass of ethylene bis-1-(2-methyl-4-phenylindenyl)zirconia dichloride, thereby yielding 5.8 g of polyolefin with a polymerization activity of 1*10. 6 g / mol·M·h. Polyolefin molecular weight 123,000, melting point 145.4 ℃.

[0169] Comparative Example 3 The only difference from Example 2 was that the bridged metallocene catalyst (I-3) was replaced with an equal mass of dimethylmethylenesilyl bis-1-(4,5,6,7-tetrahydro-1-indenyl)hafnium dichloride, thereby yielding 5.4 g of polyolefin with a polymerization activity of 7.4*10. 5 g / mol·M·h. Polyolefin molecular weight 112,000, melting point 147.2℃.

[0170] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bridged metallocene catalyst, characterized in that, The structural formula of the bridged metallocene catalyst is shown in Formula I below: Formula I; in, R1, R2 and R3 are each independently selected from any one of the following: hydrogen atom, substituted or unsubstituted C1-C30 straight-chain or branched alkyl group, substituted or unsubstituted C3-C30 cycloalkyl group, and substituted or unsubstituted C6-C30 aryl group; X is selected from any one of the following: halogen atom, substituted or unsubstituted C1-C30 straight-chain or branched alkyl group, substituted or unsubstituted C3-C30 cycloalkyl group, and substituted or unsubstituted C6-C30 aryl group; Q is a bridging group; M is selected from transition metal elements or rare earth metal elements.

2. The bridged metallocene catalyst according to claim 1, characterized in that, When R1, R2, and R3 are each independently selected from any one of substituted C1-C30 straight-chain or branched alkyl, substituted C3-C30 cycloalkyl, or substituted C6-C30 aryl, their substituents are each independently selected from any one of halogen atom, nitro, C1-C30 straight-chain or branched alkyl, C1-C30 straight-chain or branched alkoxy, C3-C30 cycloalkyl, or C6-C30 aryl; And / or, when X is selected from any one of substituted C1-C30 straight-chain or branched alkyl, substituted C3-C30 cycloalkyl, or substituted C6-C30 aryl, its substituents are each independently selected from any one of halogen atom, nitro, C1-C30 straight-chain or branched alkyl, C1-C30 straight-chain or branched alkoxy, C3-C30 cycloalkyl, or C6-C30 aryl; Preferably, Q is selected from any one of Si, C, Se, C, S, and Sn; Preferably, M is selected from any one of Ti, Zr, Hf, Ni, Pd, Ru, Rh, Fe, Co, Nd, Y, Sc, and Sm.

3. The bridged metallocene catalyst according to claim 1 or 2, characterized in that, The bridged metallocene catalyst comprises the following compounds I-1 to I-6: I-1； I-2； I-3； I-4； I-5； I-6。 4. A method for preparing a bridged metallocene catalyst according to any one of claims 1 to 3, characterized in that, The preparation method includes: (1) In the first organic solvent, the organic amine and the first dehydrogenating agent react to remove the first organic solvent and then redissolve in the first organic solvent to obtain an organic solvent solution containing the organic amine salt. (2) Add a haloindene compound to the organic solvent solution containing the organic amine salt and react to obtain an organic solvent solution containing the intermediate; (3) Add a second dehydrogenating agent to the organic solution containing the intermediate, react, remove the first organic solvent, and redissolve in the second organic solvent to obtain an organic solvent solution containing the intermediate salt; (4) Add a compound containing a bridging group to the organic solvent solution containing the intermediate salt and react to obtain an organic solvent solution containing a ligand; (5) Add a third dehydrogenating agent to the organic solution containing the ligand, react, remove the second organic solvent, and redissolve in the third organic solvent to obtain an organic solvent solution containing the ligand salt. (6) Add a transition metal salt or a rare earth metal salt to the organic solvent solution containing the ligand salt and react to obtain the bridged metallocene catalyst.

5. The method for preparing the bridged metallocene catalyst according to claim 4, characterized in that, The structural formula of the organic amine is shown in Formula A below: Formula A; And / or, the structural formula of the haloindenoid compound is shown in Formula B below: Formula B; And / or, the structural formula of the organic amine salt is shown in Formula C below: Formula C; And / or, the structural formula of the ligand is shown in formula D below: Formula D; And / or, the structural formula of the ligand salt is shown in Formula E below: Formula E; The selection of R1, R2, R3, X, Q, and M groups is as described in claim 1 or 2; Preferably, the first organic solvent, the second organic solvent, and the third organic solvent are each independently selected from any one or a combination of at least two of the following: C5-C30 saturated hydrocarbons, C5-C30 alicyclic hydrocarbons, C6-C30 aromatic hydrocarbons, C3-C20 saturated heterocyclic hydrocarbons, and paraffin oil. More preferably, they are any one or a combination of at least two of the following: toluene, xylene, dioxane, hexane, heptane, octane, decane, cyclohexane, petroleum ether, paraffin oil, white oil, dodecane, tetradecane, and hexadecane. Preferably, the first dehydrogenating agent and the second dehydrogenating agent are each independently selected from any one or a combination of at least two of n-butyllithium, Grignard reagent, sodium metal, potassium metal, and lithium metal; Preferably, the transition metal salt includes any one or a combination of at least two of the following: halide salts, alkyl salts, alkoxy salts, cycloalkyl salts, and aryl salts of transition metal elements; Preferably, the rare earth metal salt includes any one or a combination of at least two of the following: halide salts, alkyl salts, alkoxy salts, cycloalkyl salts, and aryl salts of rare earth metal elements.

6. The method for preparing the bridged metallocene catalyst according to claim 4, characterized in that, In step (1), the reaction temperature is -70~100℃, and the reaction time is 0.5~20 h; Preferably, in step (1), the molar ratio of the organic amine to the first dehydrogenating agent is 1:(0.90~5.0); Preferably, in step (2), the reaction temperature is -20~100℃ and the reaction time is 0.5~15 h; Preferably, in step (2), the molar ratio of the haloindene compound to the organic amine salt is 1:(0.95~2.0); Preferably, in step (3), the reaction temperature is -70~100℃ and the reaction time is 0.5~12 h; Preferably, in step (3), the molar ratio of the intermediate and the second dehydrogenation reagent is 1:(0.20~1.0); Preferably, in step (4), the reaction temperature is -70~100℃ and the reaction time is 0.5~12 h; Preferably, in step (4), the molar ratio of the intermediate salt to the compound containing the bridging group is 1:(0.25~1.0); Preferably, in step (5), the reaction temperature is -70~100℃ and the reaction time is 0.5~12 h; Preferably, in step (5), the molar ratio of the ligand to the third dehydrogenating agent is 1:(0.20~1.0); Preferably, in step (6), the reaction temperature is -70~100℃ and the reaction time is 0.5~12 h; Preferably, in step (6), the molar ratio of the ligand salt to the transition metal salt is 1:(0.25~1.0); or, the molar ratio of the ligand salt to the rare earth metal salt is 1:(0.90~2.5).

7. The application of a bridged metallocene catalyst according to any one of claims 1 to 3 in the preparation of polyolefins.

8. A method for preparing a polyolefin, characterized in that, The method for preparing the polyolefin includes the following steps: In the presence of any one of the bridged metallocene catalysts according to claims 1 to 3, C2-C3 olefin monomers and / or α-olefin monomers are subjected to a polymerization reaction to obtain the polyolefin.

9. The method for preparing polyolefin according to claim 8, characterized in that, The C2-C3 olefin monomers include ethylene and / or propylene; Preferably, the α-olefin monomer comprises any one or a combination of at least two of C3-C30 olefins, more preferably any one or a combination of at least two of C3-C30 olefins and C6-C30 dienes, and more preferably any one or a combination of at least two of propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 3-methyl-1-butene, cyclopentene, 4-methyl-1-pentene, 1,3-butadiene, isoprene, styrene, methylstyrene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, norbornene, and ethylidene norbornene. Preferably, the polymerization reaction temperature is 30~150℃, the polymerization reaction time is 5~300 min, and the polymerization reaction pressure is 0.05~40 MPa.

10. The method for preparing polyolefin according to claim 8, characterized in that, The polymerization process includes any one or a combination of at least two of the following: solution polymerization, gas-phase polymerization, liquid-phase bulk polymerization, slurry polymerization, and loop polymerization. Preferably, the polymerization reaction is carried out in the presence of a co-catalyst; Preferably, the co-catalyst comprises any one or a combination of at least two of alkylaluminum, alkoxyaluminum, and organoborides, and more preferably any one or a combination of at least two of trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-tert-butylaluminum, trioctylaluminum, diethylaluminum chloride, diethylaluminum chloride, sesquiethylaluminum chloride, MAO, and modified MAO. Preferably, the molar ratio of the co-catalyst to the bridged metallocene catalyst is (5~2000):1; Preferably, the polymerization reaction is carried out in a solvent; Preferably, the solvent comprises any one or a combination of at least two of the following: C5-C30 saturated hydrocarbons, C5-C30 alicyclic hydrocarbons, C6-C30 aromatic hydrocarbons, C3-C20 saturated heterocyclic hydrocarbons, and paraffin oil; more preferably, it comprises any one or a combination of at least two of the following: toluene, xylene, hexane, heptane, octane, decane, cyclohexane, petroleum ether, paraffin oil, white oil, dodecane, tetradecane, and hexadecane.

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