Supported metallocene catalyst, preparation method thereof, ethylene homopolymerization method and ethylene and alpha-olefin copolymerization method

Abstract

The invention provides a supported metallocene catalyst, a preparation method of the supported metallocene catalyst, an ethylene homopolymerization reaction method and an ethylene and alpha-olefin copolymerization reaction method. The supported metallocene catalyst comprises a carrier, and a metallocene compound and a cocatalyst which are supported on the carrier, the carrier is selected from silicon dioxide and / or aluminum oxide; the metallocene compound has a structure as shown in a formula I. Formula I. The polymer particles are regular, and the phenomenon that the reactor adheres to the kettle is relieved; in addition, when the supported metallocene catalyst is used for copolymerization of ethylene and alpha-olefin by adopting a slurry polymerization process, the polymerization activity can be improved, the cost is reduced, and the dosage of methylaluminoxane is reduced.

Description

Technical Field

[0001] This invention relates to supported metallocene catalysts and their preparation methods, methods for ethylene homopolymerization and copolymerization of ethylene with α-olefins, and belongs to the field of polyolefin catalysis technology. Background Technology

[0002] In the 1950s, Breslow and Natta independently used metallocene compounds to achieve olefin polymerization. Their homogeneous catalytic systems consisted of Cp₂TiCl₂ / Et₂AlCl, but due to the Ti active center… 4+ It is easily deactivated by excessive reduction, resulting in low overall catalytic efficiency. Until the 1980s, Kaminsky et al. developed the metallocene / methylaluminoxane system for olefin polymerization catalysis.

[0003] In recent years, metallocene compounds have undergone diverse evolutions, from non-bridged to bridged structures, from dimetallocenes to monometallocenes, from carbon-bridged to silicon-bridged structures, and bridged heteroatom structures. Various substituted cadmium compounds, functionalized cadmium compounds, and the design and synthesis of heteroatoms containing B, N, and P have significantly advanced the synthetic strategies, structural analysis, and catalytic performance studies of transition metal complexes. In reactions involving transition metal complexes, the electronic effects brought by ligand heteroatoms can directly regulate the stereoselectivity of olefin polymerization.

[0004] CN102245620A discloses a metallocene complex with a substituent at the 5-position of an indenyl group and optional furan or thiophene groups at the 2-position. This type of structure can improve the absorption efficiency of ethylene or α-olefins, enabling the production of high molecular weight rubber components, especially ethylene / propylene copolymers, and also facilitating the preparation of high-melting-point propylene homopolymers. CN105985372A describes metallocene catalysts containing S or O heterocycles for the copolymerization of long-chain α-olefins, but their activity is generally low and the insertion rate is limited when copolymerizing with ethylene.

[0005] While homogeneous metallocene catalysts possess advantages such as high catalytic activity and mild reaction conditions, they still suffer from several drawbacks: the polymer particle morphology is difficult to control, leading to severe reactor sticking and low bulk density of the resulting polymer. To address these issues and better adapt to existing industrial olefin polymerization plants (slurry and gas-phase polymerization processes), metallocene catalysts can be supported. This involves loading the metallocene catalyst onto a particulate support using physical or chemical methods. Although loading typically reduces catalyst activity and increases the types of active sites, it yields polyolefin powders with regular morphology and high apparent density, thus improving catalyst stability.

[0006] Therefore, it is of great significance to develop a novel supported catalyst for metallocene compounds. Summary of the Invention

[0007] To address the aforementioned problems, the present invention aims to provide a supported metallocene catalyst and its preparation method, as well as methods for ethylene homopolymerization and copolymerization of ethylene with α-olefins. The polymer particles of the present invention are regular, reducing reactor sticking and improving polymerization activity.

[0008] To achieve the above objectives, in a first aspect, the present invention provides a supported metallocene catalyst, wherein the supported metallocene catalyst comprises a support and a metallocene compound and a cocatalyst supported on the support; The carrier is selected from silicon dioxide and / or aluminum oxide; The metallocene compound has a structure as shown in Formula I: Formula I; In Equation I, M is selected from Zr, Ti, or Hf; X 1 X 2 The substituents are the same or different, each independently selected from halogens, C1-C. 10 Straight-chain alkyl, C3-C 10 Branched alkyl groups, C2-C 10 alkenyl, unsubstituted or heteroatom-substituted C7-C 20 Aryl groups, unsubstituted or heteroatom-substituted C6-C 20 One or more combinations of aryl groups; B is C, Si, Ge, or Sn; R 1 and R 2 The substituents are the same or different, each independently selected from H, unsubstituted or heteroatom-substituted C6-C. 20 aryl, unsubstituted or heteroatom-substituted C1-C 10 Straight-chain alkyl, unsubstituted or heteroatom-substituted C3-C 10 Branched alkyl groups, unsubstituted or heteroatom-substituted C3-C 20 cycloalkyl, unsubstituted or heteroatom-substituted C2-C 10 alkenyl, unsubstituted or heteroatom-substituted C7-C 20 One or more combinations of aralkyl groups, or R 1 and R 2 The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to 12-membered cyclic alkyl groups; R 3 R 4 R 5 R 6 R 7 R 8 R 9The substituents are the same or different, each independently selected from H, unsubstituted or heteroatom-substituted C6-C. 20 aryl, unsubstituted or heteroatom-substituted C1-C 12 Straight-chain alkyl, unsubstituted or heteroatom-substituted C3-C 12 Branched alkyl groups, unsubstituted or heteroatom-substituted C3-C 20 cycloalkyl, unsubstituted or heteroatom-substituted C2-C 10 alkenyl, unsubstituted or heteroatom-substituted C7-C 20 One or more combinations of aralkyl groups; optionally, wherein R 3 R 4 R 5 R 6 R 7 R 8 R 9 Any two adjacent groups in the carbon atom to which they are attached together form an unsubstituted or heteroatom-substituted C3-C group. 20 cycloalkyl or unsubstituted or heteroatom-substituted C6-C 20 aryl; The heteroatoms are selected from one or more combinations of nitrogen, oxygen, sulfur, silicon, halogens, and phosphorus.

[0009] According to a specific embodiment of the present invention, preferably, X 1 X 2 The substituents are either the same or different, and are each independently selected from F, Cl, Br, I, C1-C5 straight-chain alkyl, C3-C5 branched alkyl, C2-C6 alkenyl, unsubstituted or heteroatom-substituted C7-C 15 Aryl groups, unsubstituted or heteroatom-substituted C6-C 15 One or more combinations of aryl groups; B is either C or Si; R 1 and R 2 The substituents are the same or different, each independently selected from H, unsubstituted or heteroatom-substituted C6-C. 10 aryl, unsubstituted or heteroatom-substituted C1-C5 straight-chain alkyl, unsubstituted or heteroatom-substituted C3-C5 branched alkyl, unsubstituted or heteroatom-substituted C3-C 10 Cycloalkyl, unsubstituted or heteroatom-substituted C2-C6 alkenyl, unsubstituted or heteroatom-substituted C7-C 15 One or more combinations of aralkyl groups, or R 1 and R 2The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to decacyclic alkyl groups; R 3 R 4 R 5 R 6 R 7 R 8 R 9 The substituents are the same or different, each independently selected from H, unsubstituted or heteroatom-substituted C6-C. 10 Aryl, unsubstituted or heteroatom-substituted C1-C8 straight-chain alkyl, unsubstituted or heteroatom-substituted C3-C8 branched alkyl, unsubstituted or heteroatom-substituted C3-C 10 Cycloalkyl, unsubstituted or heteroatom-substituted C2-C6 alkenyl, unsubstituted or heteroatom-substituted C7-C 15 One or more combinations of aralkyl groups; optionally, wherein R 3 R 4 R 5 R 6 R 7 R 8 R 9 Any two adjacent groups in the carbon atom to which they are attached together form an unsubstituted or heteroatom-substituted C3-C group. 10 cycloalkyl or unsubstituted or heteroatom-substituted C6-C 10 The aryl group. The heteroatom-substituted group in this invention refers to a substituent containing a heteroatom.

[0010] According to a specific embodiment of the present invention, preferably, In Equation I, M is selected from Zr or Hf; X 1 X 2 The substituents are the same or different, and are each independently selected from one or more combinations of Cl, Br, I, C1-C5 straight-chain alkyl, C3-C5 branched alkyl, and unsubstituted or heteroatom-substituted C7-C9 aralkyl. B is either C or Si; R 1 and R 2 The substituents are the same or different, each independently selected from one or more combinations of H, unsubstituted or heteroatom-substituted C6-C8 aryl groups, unsubstituted or heteroatom-substituted C1-C5 straight-chain alkyl groups, unsubstituted or heteroatom-substituted C3-C5 branched alkyl groups, and unsubstituted or heteroatom-substituted C3-C8 cycloalkyl groups, or R. 1 and R 2The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to octagonal cyclic alkyl groups; R 3 R 4 R 5 R 6 R 7 R 8 R 9 The substituents are the same or different, each independently selected from one or more combinations of H, unsubstituted or heteroatom-substituted C6-C8 aryl groups, unsubstituted or heteroatom-substituted C1-C8 straight-chain alkyl groups, unsubstituted or heteroatom-substituted C3-C8 branched alkyl groups, and unsubstituted or heteroatom-substituted C3-C8 cycloalkyl groups; optionally, wherein R 3 R 4 R 5 R 6 R 7 R 8 R 9 Any two adjacent groups in the compound, together with the carbon atom to which they are attached, form an unsubstituted or heteroatom-substituted C3-C8 cycloalkyl group or an unsubstituted or heteroatom-substituted C6-C8 aryl group; The heteroatoms are selected from one or more combinations of nitrogen, oxygen, sulfur, silicon, fluorine, chlorine, bromine, iodine, and phosphorus.

[0011] According to a specific embodiment of the present invention, preferably, In equation I, X 1 X 2 The substituents are the same or different, and each is independently selected from one or more combinations of Cl, Br, I, C1-C3 straight-chain alkyl, and C3-C5 branched alkyl; B is either C or Si; R 1 and R 2 The substituents are the same or different, each independently selected from one or more combinations of H, unsubstituted or heteroatom-substituted C6-C8 aryl groups, unsubstituted or heteroatom-substituted C1-C3 straight-chain alkyl groups, unsubstituted or heteroatom-substituted C3-C5 branched alkyl groups, and unsubstituted or heteroatom-substituted C3-C6 cycloalkyl groups, or R. 1 and R 2 The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to six-membered cyclic alkyl groups; R 3 R 4 R 5 R 6 R 7 R 8 R9 The substituents are the same or different, each independently selected from one or more combinations of H, unsubstituted or heteroatom-substituted C6-C8 aryl groups, unsubstituted or heteroatom-substituted C1-C5 straight-chain alkyl groups, unsubstituted or heteroatom-substituted C3-C5 branched alkyl groups, and unsubstituted or heteroatom-substituted C3-C8 cycloalkyl groups; optionally, wherein R 3 R 4 R 5 R 6 R 7 R 8 R 9 Any two adjacent groups in the compound, together with the carbon atom to which they are attached, form an unsubstituted or heteroatom-substituted C3-C8 cycloalkyl group or an unsubstituted or heteroatom-substituted C6-C8 aryl group; The heteroatoms are selected from one or more combinations of nitrogen, oxygen, and sulfur.

[0012] According to a specific embodiment of the present invention, preferably, In equation I, X 1 X 2 The substituents are the same or different, and each is independently selected from one or more combinations of C1, C1-C3 straight-chain alkyl, and C3-C5 branched alkyl; B is Si; R 1 and R 2 The substituents are the same or different, each independently selected from one or more combinations of H, unsubstituted or heteroatom-substituted C6-C8 aryl groups, and unsubstituted or heteroatom-substituted C3-C6 cycloalkyl groups, or R. 1 and R 2 The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to six-membered cyclic alkyl groups; R 3 R 4 R 5 R 6 R 7 R 8 R 9 The substituents are the same or different, each independently selected from one or more combinations of H, unsubstituted or heteroatom-substituted C6-C8 aryl groups, unsubstituted or heteroatom-substituted C1-C3 straight-chain alkyl groups, unsubstituted or heteroatom-substituted C3-C5 branched alkyl groups, and unsubstituted or heteroatom-substituted C3-C6 cycloalkyl groups; optionally, wherein R 3 R 4 R 5 R 6 R 7R 8 R 9 Any two adjacent groups in the compound, together with the carbon atom to which they are attached, form an unsubstituted or heteroatom-substituted C3-C6 cycloalkyl group or an unsubstituted or heteroatom-substituted C6-C8 aryl group; The heteroatoms are selected from one or more combinations of nitrogen, oxygen, and sulfur.

[0013] According to a specific embodiment of the present invention, preferably, In equation I, X 1 X 2 The substituents are the same or different, and each is independently selected from one or more combinations of C1, C1-C3 straight-chain alkyl, and C3-C5 branched alkyl; B is Si; R 1 and R 2 The substituents are the same or different, each independently selected from one or more combinations of H, C6-C8 aryl, and C3-C6 cycloalkyl, or R. 1 and R 2 The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to six-membered cyclic alkyl groups; R 3 R 4 R 5 R 6 R 7 R 8 R 9 The substituents are the same or different, each independently selected from one or more combinations of H, C6-C8 aryl, C1-C3 straight-chain alkyl, C3-C5 branched alkyl, and C3-C6 cycloalkyl; optionally, wherein R 3 R 4 R 5 R 6 R 7 R 8 R 9 Any two adjacent groups in the group and the carbon atom to which they are attached can form a C3-C6 cycloalkyl or a C6-C8 aryl group; More preferably, X 1 X 2 For Cl. According to a specific embodiment of the present invention, preferably, the metallocene compound represented by Formula I has one of the following structures: .

[0014] According to a specific embodiment of the present invention, preferably, the co-catalyst is selected from methylaluminoxane and / or modified methylaluminoxane.

[0015] According to a specific embodiment of the present invention, preferably, the molar ratio of the metallocene compound to the cocatalyst is (50-1000):1. More preferably, it is (100-500):1.

[0016] According to a specific embodiment of the present invention, preferably, the mass ratio of the support to the co-catalyst is 1:(0.2-0.8).

[0017] According to a specific embodiment of the present invention, preferably, the silica can be silicone, such as SYLOPOL®2408, manufactured by Changzhou Haohua Chemical Co., Ltd.

[0018] Secondly, the present invention also provides a method for preparing the above-mentioned supported metallocene catalyst, comprising the following steps: Under a protective atmosphere, the support, co-catalyst, and solvent are mixed to obtain a dispersion. The dispersion was reacted with the metallocene compound at 20-70 °C, and after post-treatment, a supported metallocene catalyst was obtained.

[0019] According to a specific embodiment of the present invention, preferably, the support, co-catalyst and solvent are mixed at 25-100 °C for 2-12 h.

[0020] According to a specific embodiment of the present invention, preferably, the carrier is first activated at 200-800 °C for 1-7 h, and then mixed with an organic solvent at a weight ratio of 1:(15-25) at room temperature (e.g., 20-30 °C) for 5-15 minutes.

[0021] According to a specific embodiment of the present invention, preferably, under a protective atmosphere, the support, co-catalyst A, and solvent are mixed and stirred, then cooled, allowed to settle, the supernatant is removed, washed, allowed to settle again, the supernatant is removed, and then a solvent is added to obtain a dispersion. The solvent is further preferably toluene.

[0022] According to a specific embodiment of the present invention, preferably, the present invention does not require the post-processing steps, but may include, for example, allowing the catalyst to stand, removing the solvent, washing, and vacuum drying to obtain a powdered catalyst for subsequent ethylene polymerization reaction.

[0023] According to a specific embodiment of the present invention, preferably, the protective atmosphere is selected from nitrogen, helium, and argon.

[0024] According to a specific embodiment of the present invention, preferably, the method for preparing the metallocene compound represented by Formula I includes preparing it using ligand I and a metal precursor as raw materials; Ligand I; The metal precursor is a metal halide.

[0025] In the above-described method for preparing metallocene compounds, preferably, the metal precursor is zirconium tetrachloride and / or hafnium tetrachloride.

[0026] In the above-described method for preparing metallocene compounds, preferably, the method for preparing the metallocene compound represented by Formula I satisfies at least one of the following conditions: (1) The molar ratio of ligand I to the metal precursor is 1:(0.5-2); (2) The ligand I and the metal precursor react at 20-30 °C for 3-7 h.

[0027] In the above-mentioned method for preparing metallocene compounds, preferably, the solvent used in the preparation of metallocene compounds is selected from one or more combinations of diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, ethyl acetate, dichloromethane, trichloromethane, and carbon tetrachloride; more preferably, it is selected from one or more combinations of diethyl ether, toluene, and n-hexane.

[0028] In the above-mentioned method for preparing metallocene compounds, preferably, the method includes preparing ligand I using compound G and compound H as raw materials; Compound G; Compound H; In compound H, X 3 It is selected from halogens, more preferably from F, Cl, Br, I, and even more preferably Cl.

[0029] In the above-described method for preparing metallocene compounds, preferably, the method for preparing ligand I satisfies at least one of the following conditions: (1) The molar ratio of compound G to compound H is (1.5-2.5):1; (2) The compound G and compound H are reacted at -20 to 0 °C for 2-7 h, and then at 20-30 °C for 2-7 h.

[0030] In the above-mentioned method for preparing metallocene compounds, preferably, the solvent used in the preparation of ligand I is selected from one or more combinations of diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, ethyl acetate, dichloromethane, trichloromethane, and carbon tetrachloride; more preferably, it is selected from one or more combinations of diethyl ether, tetrahydrofuran, and toluene.

[0031] In the above-mentioned method for preparing metallocene compounds, preferably, the method includes preparing compound G using compound D and compound F as raw materials; Compound D; Compound F.

[0032] In the above-described method for preparing metallocene compounds, preferably, the method for preparing compound G satisfies at least one of the following conditions: (1) The molar ratio of compound D to compound F is 1:(0.1-10); (2) The quaternary ammonium salts of compounds D and F are heated at 60-100 °C for 5-12 h under the action of alkali, and then reacted at 20-30 °C for 2-7 h.

[0033] In the above-described method for preparing metallocene compounds, preferably, the solvent used in the preparation of compound G is selected from one or more combinations of acetone, diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, ethyl acetate, dichloromethane, chloroform, and carbon tetrachloride; more preferably, it is selected from one or more combinations of acetone, acetonitrile, and dichloromethane.

[0034] In the above-mentioned method for preparing metallocene compounds, preferably, the method includes using compound E as a raw material to prepare compound F; Compound E.

[0035] In the above-mentioned method for preparing metallocene compounds, preferably, the reaction conditions for preparing compound F are: stirring at 20-30 °C for 18-30 h.

[0036] In the above-mentioned method for preparing metallocene compounds, preferably, the solvent used in the preparation of compound F is selected from one or more combinations of diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, ethyl acetate, dichloromethane, trichloromethane, and carbon tetrachloride; more preferably, it is selected from one or more combinations of acetonitrile, dichloromethane, and carbon tetrachloride.

[0037] In the above-described method for preparing metallocene compounds, preferably, the method includes using compound A and O=CR 9 Using [the raw material], compound D was prepared; Compound A.

[0038] In the above-described method for preparing metallocene compounds, preferably, the solvent used in the preparation of compound D is selected from one or more combinations of diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, ethyl acetate, dichloromethane, and chloroform; more preferably, it is selected from one or more combinations of acetonitrile, diethyl ether, tetrahydrofuran, dichloromethane, and ethyl acetate.

[0039] This invention does not impose special requirements on the specific operations used in the purification process of preparing compounds, ligands, and metallocene compounds, such as concentration, washing, recrystallization, and silica gel column chromatography. Those skilled in the art can perform these operations according to conventional techniques in the field. These will not be elaborated upon here, and should not be construed as limiting the invention.

[0040] Thirdly, the present invention also provides a method for homopolymerization of ethylene, wherein the method includes: Ethylene is homopolymerized in the presence of organic solvent A, supported metallocene catalyst, and co-catalyst A. The supported metallocene catalyst is the supported metallocene catalyst described above or the supported metallocene catalyst prepared by the above preparation method.

[0041] According to a specific embodiment of the present invention, preferably, the homopolymerization reaction is carried out at a temperature of 20-150 °C for a time of 0.5-3 h.

[0042] According to a specific embodiment of the present invention, preferably, the ethylene inlet pressure is 5-30 atm.

[0043] According to a specific embodiment of the present invention, preferably, the cocatalyst A is selected from one or more combinations of alkylaluminoxane A, alkylaluminum compound A, and organoboron compound A.

[0044] According to a specific embodiment of the present invention, preferably, the alkylaluminoxane A is selected from methylaluminoxane and / or modified methylaluminoxane.

[0045] According to a specific embodiment of the present invention, preferably, the alkyl aluminum compound A is selected from one or more combinations of diethylaluminum chloride (AlEt2Cl), sesquiethylaluminum chloride (EASC), sesqui-monochlorodiethylaluminum (CAS: 96-10-6), diethylaluminum dichloride, trimethylaluminum, triethylaluminum, triisobutylaluminum, and tributylaluminum.

[0046] According to a specific embodiment of the present invention, preferably, the organoboron compound A is selected from one or more combinations of N,N-dimethylaniline-tetrafluorophenylborate, triphenyltetrafluorophenylborate, and triphenylphenylboron.

[0047] According to a specific embodiment of the present invention, preferably, the organic solvent A is selected from one or more combinations of toluene, xylene, chlorobenzene, benzene, hexane, pentane, heptane, and dichloromethane.

[0048] Fourthly, the present invention also provides a method for copolymerizing ethylene with α-olefins, wherein the method comprises: In the presence of organic solvent B, supported metallocene catalyst, and co-catalyst B, ethylene and α-olefins are copolymerized. The supported metallocene catalyst is the supported metallocene catalyst described above or the supported metallocene catalyst prepared by the above preparation method.

[0049] According to a specific embodiment of the present invention, preferably, the copolymerization reaction satisfies at least one of the following conditions: (1) The temperature of the copolymerization reaction is 40-100 ℃; (2) The copolymerization reaction takes 0.5-3 h; (3) The ethylene is introduced at a pressure of 5-30 atm.

[0050] According to a specific embodiment of the present invention, preferably, the cocatalyst B is selected from one or more combinations of alkylaluminoxane B, alkylaluminum compound B, and organoboron compound B.

[0051] According to a specific embodiment of the present invention, preferably, the alkylaluminoxane B is selected from methylaluminoxane and / or modified methylaluminoxane.

[0052] According to a specific embodiment of the present invention, preferably, the alkyl aluminum compound B is selected from one or more combinations of diethylaluminum chloride (AlEt2Cl), sesquiethylaluminum chloride (EASC), sesqui-monochlorodiethylaluminum (CAS: 96-10-6), diethylaluminum dichloride, trimethylaluminum, triethylaluminum, triisobutylaluminum, and tributylaluminum.

[0053] According to a specific embodiment of the present invention, preferably, the organoboron compound B is selected from one or more combinations of N,N-dimethylaniline (dimethylanilium)-tetrafluorophenylborate, triphenyltetrafluorophenylborate, and triphenylphenylboron.

[0054] According to a specific embodiment of the present invention, preferably, the organic solvent B is selected from one or more combinations of toluene, xylene, chlorobenzene, benzene, hexane, pentane, heptane, and dichloromethane.

[0055] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a slurry polymerization process to use a supported metallocene catalyst for the homopolymerization of ethylene. Compared with solution polymerization, the polymer particles of this invention are more regular, and the reactor sticking phenomenon is reduced. In addition, when this supported metallocene catalyst is used for the copolymerization of ethylene and α-olefins using the slurry polymerization process, the polymerization activity can be improved and the amount of methylaluminoxane used can be reduced, thus reducing costs. Detailed Implementation

[0056] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0057] Unless otherwise specified, the analytical and testing methods described in the following examples and comparative examples are conventional methods.

[0058] Elemental analysis: Results obtained using organic elemental analyzer methods; Catalytic activity: expressed as "g of g (Cat)·h", which is the mass of polymer that can be produced per gram of supported metallocene catalyst per unit time.

[0059] I. Synthesis of Metallocene Compounds

[0060] Preparation Example 1

[0061] The preparation method of metallocene compound N-3 is as follows: (a) Synthesis of pyridine derivative D-2: To a THF (50 mL) solution of compound A-2 (25 mmol, 3.95 g) and tetramethylethylenediamine (37.5 mmol, 5.5 mL), n-butyllithium (n-BuLi, 37.5 mmol, 37.5 mL in 1 M THF solution) was added at -78 °C. After reacting for 1 hour, benzaldehyde B-2 (50 mmol, 5.0 mL) was added. The reaction solution was gradually raised to room temperature and stirred for 12 hours. The reaction was then quenched with H2O. The product was extracted three times with CH2Cl2 (250 mL each time). The organic phases were combined, the solvent was evaporated, and the residue was purified by silica gel column chromatography (eluent: ethyl acetate, n-hexane, volume ratio 1:3) to give an oily compound C-2 (3.70 g, yield 80%). Compound A-2; Benzaldehyde B-2; Compound C-2.

[0062] Compound C-2 (17.5 mmol, 3.24 g) was dissolved in ethyl acetate (25 mL), and palladium hydroxide (Pd(OH)₂, 1.50 g, 20% supported on activated carbon) was added, followed by hydrogenation at room temperature for 12 hours. The reaction mixture was filtered, and the filtrate was evaporated to dryness. The remaining oily residue was dissolved in dichloroethane (25 mL), followed by the addition of trifluoroacetic acid (46.5 mmol, 3.55 mL) and triethylsilane (Et₃SiH, 31.0 mmol, 12.5 mL). The mixture was heated to 50 °C and reacted for 12 hours. After evaporation of the solvent, the residue was purified by silica gel column chromatography (eluent: ethyl acetate, n-hexane, v / v) to give the oily compound D-2 (1.75 g, 59% yield). LC-MS (ESI) of product D-2, [M+1] + 170.2. Compound D-2.

[0063] (II) Preparation of compound F-1: Under stirring, TMS·OTf (trimethylsilyl trifluoromethanesulfonate, 600 mg, 2.5 mmol) was added to an acetonitrile (MeCN, 300 mL) solution of E-1 (4.11 g, 50.0 mmol) and NBS (N-bromosuccinimide, 9.80 g, 55.0 mmol). The resulting mixture was stirred at 25 °C for 24 h, then diluted with diethyl ether, washed with water, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography to give an oily compound F-1 (6.85 g, 85% yield). The GC-MS (EI) of product F-1 was 160.4 m / z. Compound E-1; Compound F-1.

[0064] (III) Preparation of compound G-3: Compounds D-2 (10 mmol, 1.69 g) and F-1 (10 mmol, 1.61 g) were dissolved in acetone (50 mL) and heated under reflux for 4 hours. The reaction mixture was separated by filtration to obtain the quaternary ammonium salt, which was then redissolved in hot (70 °C) water (50 mL). Potassium carbonate (10 mmol, 1.38 g) was added, and the mixture was heated at 80 °C for 8 hours. The product was extracted three times with CH2Cl2 (250 mL each time). The organic phases were combined, the solvent was evaporated, and the residue was purified by rapid column chromatography to give the oily compound G-3 (1.85 g, 80% yield). The GC-MS (EI) of product G-3 was 231.4 m / z. Compound G-3.

[0065] (iv) Preparation of bridging ligand I-3: Compound G-3 (7.0 mmol, 1.62 g) was dissolved in tetrahydrofuran solution, and n-butyllithium (n-BuLi, 7 mmol, 7 mL of 1 M THF solution) was added dropwise to deprotonate compound G-3. The reaction was carried out at room temperature for 5 h. Dichlorodimethylsilane H-1 (0.42 mL, 3.5 mmol) was slowly injected using a syringe, and the reaction was maintained at -10 °C for 3 h, followed by a 3 h reaction at room temperature. After the reaction was completed, 60 mL of n-hexane was added, the solvent was evaporated under reduced pressure, and the solution was concentrated to obtain oily dimethylsilane-bridged ligand I-3 (3.5 mmol, 1.81 g).

[0066] 1H NMR data for ligand I-3: 1 H-NMR (300M, CDCl3): δ7.38-7.55 (m, 12H), 7.11 (dd, 7.5 Hz, 1.5 Hz, 2H), 6.68 (t, 7.5 Hz, 7.5 Hz, 1.5 Hz, 2H), 6.41 (m, 7.5 Hz, 7.5 Hz, 1.5 Hz, 2H), 6.35 (dd, 10.9 Hz, 1.0 Hz, 2H), 5.63 (dd, 10.9Hz, 6.2 Hz, 2H), 3.21 (dd, 6.2 Hz, 1.0 Hz 2H), 0.20 (s, 6H). Compound H-1; Ligand I-3.

[0067] (V) Preparation of metallocene compound N-3: Dimethylsilyl-bridged ligand I-3 (3.5 mmol, 1.81 g) was dissolved in diethyl ether (50 mL). The reaction system was cooled to 0 °C, and n-butyllithium (n-BuLi, 7.0 mmol, 2.8 mL of 2.5 M diethyl ether solution) was slowly added dropwise. After the addition was complete, the reaction system was allowed to react at 25 °C for 5 h. Subsequently, zirconium tetrachloride (ZrCl4, 3.5 mmol, 815 mg) was added and reacted for 6 h. The mixture was filtered to obtain crude product N-3, which was then recrystallized from toluene / n-hexane to obtain yellow solid product N-3 (1.0 g, 42%).

[0068] Elemental analysis of product N-3: Elem. Anal. Calcd. For C 36 H 28Cl2N2SiZr: C, 63.70%; H, 4.16%; N, 4.13%. Found: C, 63.72%; H, 4.18%; N, 4.15%. Metallocene compound N-3.

[0069] Preparation Examples 2 to 11: Preparation Examples 2 to 11 correspond to the preparation of metallocene compounds N-1, N-2, N-4, N-5, N-6, N-7, N-8, N-9, N-10, and N-11, respectively. The methods are the same as those for the preparation of N-3 in Preparation Example 1, except that the raw materials and products are different in each step. The compounds involved in the preparation process and the test results are shown in Tables 1 to 5 (3). Among them, the NMR data of the main catalyst N-1 in Preparation Example 2 1 H NMR (300M, Benzene-) d 6 ): δ 7.42 (m,2H), 7.01-7.12 (m, 2H), 6.58-6.70 (m, 4H), 6.41 (m, 2H), 6.35 (d, J = 3 Hz,2H), 5.63 (d, J = 3 Hz, 2H), 0.51 (s, 6H).

[0070] Preparation Example 12: The preparation method of metallocene compound N-12 is the same as that of N-3 in preparation example 1, except that the metal precursor used is hafnium tetrachloride (HfCl4). The test results are shown in Table 5 (3).

[0071] Table 1 shows the specific structures of compounds A, B, and D in the corresponding preparation examples, as well as the test results for compound D.

[0072] Table 1

[0073] Table 2 shows the specific structures of compounds E and F in the corresponding preparation examples, as well as the test results for compound F.

[0074] Table 2

[0075] Table 3 shows the specific structures of compound G obtained from compounds D and F in the preparation examples, as well as the test results of compound G.

[0076] Table 3

[0077] Tables 4(1) and 4(2) show the specific structures of ligands I prepared from compounds G and H in Preparation Examples 1 to 11, as well as the test results of ligands I.

[0078] Table 4(1)

[0079] Table 4(2)

[0080] Tables 5(1), 5(2), and 5(3) show the specific structures of ligand I and metallocene compound N in preparation examples 1 to 12, as well as the yield and elemental analysis results of metallocene compound N.

[0081] Table 5(1)

[0082] Table 5(2)

[0083] Table 5(3)

[0084] Example 1

[0085] This embodiment provides a method for preparing a supported metallocene catalyst, specifically including the following steps: In a reaction flask, 2 g of silica gel (SYLOPOL® 2408, activated at 600 °C for 2 h) was added to 10 mL of toluene and dispersed at room temperature for 10 min at 400 rpm / min. Then, 11.2 mL of a toluene solution with a concentration of 0.1 g / mL of MAO was slowly added dropwise, and the reaction was carried out at 45 °C for 3 h. After the reaction was completed, the temperature was lowered, and the mixture was allowed to settle for 1 h. The upper toluene solution was removed. The mixture was washed with 20 mL of toluene, allowed to settle for 30 min, and the upper toluene solution was removed again. Then, 10 mL of toluene was added to disperse the mixture, resulting in a dispersion. 0.081 g of a toluene solution (10 mL) of metallocene compound N-3 was added to the above dispersion, and the reaction was carried out at 45 °C for 3 h. After the reaction was completed, the temperature was lowered, the mixture was allowed to settle, and the upper toluene solution was removed. The mixture was washed three times with 20 mL of toluene, and then washed once with 20 mL of n-hexane. Finally, the solvent was dried under vacuum to obtain the supported metallocene catalyst M-3 (2.56 g).

[0086] Example 2

[0087] This embodiment provides a method for preparing a catalyst, which differs from Example 1 only in that: Metallocene compound N-4 was added to the dispersion to obtain supported metallocene catalyst M-4 (2.61 g).

[0088] Example 3

[0089] This embodiment provides a method for preparing a catalyst, which differs from Example 1 only in that: Metallocene compound N-7 was added to the dispersion to obtain supported metallocene catalyst M-7 (2.43 g).

[0090] Example A1

[0091] This embodiment provides the application of the supported metallocene catalyst M-3 in the homopolymerization reaction of ethylene, specifically including the following steps: The 2 L stainless steel polymerization reactor was purged with high-purity nitrogen at least three times, and then purged with ethylene three times. After the gas purging was completed, 400 mL of n-hexane was added to the reactor, stirring was started, and 0.25 mL of AlEt3 (1M n-hexane solution) was added. The reactor was then flushed with 200 mL of n-hexane to ensure that AlEt3 was completely incorporated into the reactor. Subsequently, 60 mg of the supported metallocene catalyst M-3 was added in the same manner, and the catalyst was completely flushed into the reactor with 200 mL of n-hexane. The polymerization reaction was initiated by adjusting the rotation speed of the polymerization apparatus to 400 rpm, the temperature to 70 ℃, and maintaining the ethylene pressure at 10 atm. The reaction was terminated after 1 h, and the product was dried in a vacuum oven to constant weight. 35.5 g of polyethylene was obtained, with a polymerization activity of 592 g PE / (g of Cat M-3·h).

[0092] Example A2

[0093] This embodiment provides the application of the supported metallocene catalyst M-4 in the homopolymerization reaction of ethylene, and the only difference from Example A1 is: Use the supported metallocene catalyst M-4; The obtained polymer weighed 41.7 g and had a polymerization activity of 695 g PE / (g of Cat M-4·h).

[0094] Example A3

[0095] This embodiment provides the application of the supported metallocene catalyst M-7 in the homopolymerization reaction of ethylene, and the only difference from Example A1 is: Use the supported metallocene catalyst M-7; The obtained polymer weighed 44.1 g and had a polymerization activity of 735 g PE / (g of Cat M-7·h).

[0096] Example B1

[0097] This embodiment provides the application of the supported metallocene catalyst M-7 in the copolymerization reaction of ethylene and 1-octene, specifically including the following steps: The 2 L stainless steel polymerization reactor was purged with high-purity nitrogen at least three times, and then purged with ethylene three times. After the gas purging was completed, 400 mL of n-hexane and 20 mL of 1-octene solution (0.20 mol / L n-hexane solution) were added to the reactor, stirring was started, and 0.25 mL of AlEt3 (1M n-hexane solution) was added. The reactor was then flushed with 200 mL of n-hexane to ensure that AlEt3 was completely incorporated into the reactor. Subsequently, 60 mg of the supported metallocene catalyst M-7 was added in the same manner, and the catalyst was completely flushed into the reactor with 200 mL of n-hexane. The polymerization apparatus was adjusted to 400 rpm, the temperature was 70 ℃, and the ethylene pressure was maintained at 10 atm to initiate the polymerization reaction. The reaction was terminated after 1 h, and the polymer was dried in a vacuum oven to constant weight. 49.1 g of polymer was obtained, and the polymerization activity was 818 g PE / (g of Cat M-7·h).

[0098] Comparative Example B1

[0099] This comparative example provides the application of the supported metallocene catalyst M-Cmp-3 in the copolymerization reaction of ethylene and propylene, and differs from Example B1 only in that: The metallocene compound used was Cmp-3; Cmp-3 was prepared according to the experimental steps disclosed in patent CN108250252A.

[0100] A copolymer with a polymer mass of 32.4 g was obtained, and the polymerization activity was 540 g PE / (g of Cat M-7·h).

[0101] Metallocene compound Cmp-3.

[0102] In the copolymerization reaction of ethylene and 1-octene, the supported metallocene catalyst of the present invention exhibits higher catalytic activity than M-Cmp-3 of Comparative Example B1.

Claims

1. A supported metallocene catalyst, characterized in that, The supported metallocene catalyst includes a support and a metallocene compound and a co-catalyst supported on the support; The carrier is selected from silicon dioxide and / or aluminum oxide; The metallocene compound has a structure as shown in Formula I: Formula I; In Equation I, M is selected from Zr, Ti, or Hf; X 1 X 2 The substituents are the same or different, each independently selected from halogens, C1-C. 10 Straight-chain alkyl, C3-C 10 Branched alkyl groups, C2-C 10 alkenyl, unsubstituted or heteroatom-substituted C7-C 20 Aryl groups, unsubstituted or heteroatom-substituted C6-C 20 One or more combinations of aryl groups; B is C, Si, Ge, or Sn; R 1 and R 2 The substituents are the same or different, each independently selected from H, unsubstituted or heteroatom-substituted C6-C. 20 aryl, unsubstituted or heteroatom-substituted C1-C 10 Straight-chain alkyl, unsubstituted or heteroatom-substituted C3-C 10 Branched alkyl groups, unsubstituted or heteroatom-substituted C3-C 20 cycloalkyl, unsubstituted or heteroatom-substituted C2-C 10 alkenyl, unsubstituted or heteroatom-substituted C7-C 20 One or more combinations of aralkyl groups, or R 1 and R 2 The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to 12-membered cyclic alkyl groups; R 3 R 4 R 5 R 6 R 7 R 8 R 9 The substituents are the same or different, each independently selected from H, unsubstituted or heteroatom-substituted C6-C. 20 aryl, unsubstituted or heteroatom-substituted C1-C 12 Straight-chain alkyl, unsubstituted or heteroatom-substituted C3-C 12 Branched alkyl groups, unsubstituted or heteroatom-substituted C3-C 20 cycloalkyl, unsubstituted or heteroatom-substituted C2-C 10 alkenyl, unsubstituted or heteroatom-substituted C7-C 20 One or more combinations of aralkyl groups; optionally, wherein R 3 R 4 R 5 R 6 R 7 R 8 R 9 Any two adjacent groups in the carbon atom to which they are attached together form an unsubstituted or heteroatom-substituted C3-C group. 20 cycloalkyl or unsubstituted or heteroatom-substituted C6-C 20 aryl; The heteroatoms are selected from one or more combinations of nitrogen, oxygen, sulfur, silicon, halogens, and phosphorus.

2. The supported metallocene catalyst according to claim 1, characterized in that, X 1 X 2 The substituents are either the same or different, and are each independently selected from F, Cl, Br, I, C1-C5 straight-chain alkyl, C3-C5 branched alkyl, C2-C6 alkenyl, unsubstituted or heteroatom-substituted C7-C 15 Aryl groups, unsubstituted or heteroatom-substituted C6-C 15 One or more combinations of aryl groups; B is either C or Si; R 1 and R 2 The substituents are the same or different, each independently selected from H, unsubstituted or heteroatom-substituted C6-C. 10 aryl, unsubstituted or heteroatom-substituted C1-C5 straight-chain alkyl, unsubstituted or heteroatom-substituted C3-C5 branched alkyl, unsubstituted or heteroatom-substituted C3-C 10 Cycloalkyl, unsubstituted or heteroatom-substituted C2-C6 alkenyl, unsubstituted or heteroatom-substituted C7-C 15 One or more combinations of aralkyl groups, or R 1 and R 2 The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to decacyclic alkyl groups; R 3 R 4 R 5 R 6 R 7 R 8 R 9 The substituents are the same or different, each independently selected from H, unsubstituted or heteroatom-substituted C6-C. 10 Aryl, unsubstituted or heteroatom-substituted C1-C8 straight-chain alkyl, unsubstituted or heteroatom-substituted C3-C8 branched alkyl, unsubstituted or heteroatom-substituted C3-C 10 Cycloalkyl, unsubstituted or heteroatom-substituted C2-C6 alkenyl, unsubstituted or heteroatom-substituted C7-C 15 One or more combinations of aralkyl groups; optionally, wherein R 3 R 4 R 5 R 6 R 7 R 8 R 9 Any two adjacent groups in the carbon atom to which they are attached together form an unsubstituted or heteroatom-substituted C3-C group. 10 cycloalkyl or unsubstituted or heteroatom-substituted C6-C 10 Aryl groups.

3. The supported metallocene catalyst according to claim 1, characterized in that, In Equation I, M is selected from Zr or Hf; X 1 X 2 The substituents are the same or different, and are each independently selected from one or more combinations of Cl, Br, I, C1-C5 straight-chain alkyl, C3-C5 branched alkyl, and unsubstituted or heteroatom-substituted C7-C9 aralkyl. B is either C or Si; R 1 and R 2 The substituents are the same or different, each independently selected from one or more combinations of H, unsubstituted or heteroatom-substituted C6-C8 aryl groups, unsubstituted or heteroatom-substituted C1-C5 straight-chain alkyl groups, unsubstituted or heteroatom-substituted C3-C5 branched alkyl groups, and unsubstituted or heteroatom-substituted C3-C8 cycloalkyl groups, or R. 1 and R 2 The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to octagonal cyclic alkyl groups; R 3 R 4 R 5 R 6 R 7 R 8 R 9 The substituents are the same or different, each independently selected from one or more combinations of H, unsubstituted or heteroatom-substituted C6-C8 aryl groups, unsubstituted or heteroatom-substituted C1-C8 straight-chain alkyl groups, unsubstituted or heteroatom-substituted C3-C8 branched alkyl groups, and unsubstituted or heteroatom-substituted C3-C8 cycloalkyl groups; optionally, wherein R 3 R 4 R 5 R 6 R 7 R 8 R 9 Any two adjacent groups in the compound, together with the carbon atom to which they are attached, form an unsubstituted or heteroatom-substituted C3-C8 cycloalkyl group or an unsubstituted or heteroatom-substituted C6-C8 aryl group; The heteroatoms are selected from one or more combinations of nitrogen, oxygen, sulfur, silicon, fluorine, chlorine, bromine, iodine, and phosphorus.

4. The supported metallocene catalyst according to claim 1, characterized in that, In equation I, X 1 X 2 The substituents are the same or different, and each is independently selected from one or more combinations of Cl, Br, I, C1-C3 straight-chain alkyl, and C3-C5 branched alkyl; B is either C or Si; R 1 and R 2 The substituents are the same or different, each independently selected from one or more combinations of H, unsubstituted or heteroatom-substituted C6-C8 aryl groups, unsubstituted or heteroatom-substituted C1-C3 straight-chain alkyl groups, unsubstituted or heteroatom-substituted C3-C5 branched alkyl groups, and unsubstituted or heteroatom-substituted C3-C6 cycloalkyl groups, or R. 1 and R 2 The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to six-membered cyclic alkyl groups; R 3 R 4 R 5 R 6 R 7 R 8 R 9 The substituents are the same or different, each independently selected from one or more combinations of H, unsubstituted or heteroatom-substituted C6-C8 aryl groups, unsubstituted or heteroatom-substituted C1-C5 straight-chain alkyl groups, unsubstituted or heteroatom-substituted C3-C5 branched alkyl groups, and unsubstituted or heteroatom-substituted C3-C8 cycloalkyl groups; optionally, wherein R 3 R 4 R 5 R 6 R 7 R 8 R 9 Any two adjacent groups in the compound, together with the carbon atom to which they are attached, form an unsubstituted or heteroatom-substituted C3-C8 cycloalkyl group or an unsubstituted or heteroatom-substituted C6-C8 aryl group; The heteroatoms are selected from one or more combinations of nitrogen, oxygen, and sulfur.

5. The supported metallocene catalyst according to any one of claims 1-4, characterized in that, The metallocene compound represented by Formula I has one of the following structures: 。 6. The supported metallocene catalyst according to claim 1, characterized in that, The cocatalyst is selected from methylaluminoxane and / or modified methylaluminoxane.

7. The supported metallocene catalyst according to claim 1, characterized in that, The molar ratio of the metallocene compound to the cocatalyst is (50-1000):

1.

8. The supported metallocene catalyst according to claim 1, characterized in that, The mass ratio of the support to the co-catalyst is 1:(0.2-0.8).

9. A method for preparing a supported metallocene catalyst according to any one of claims 1-8, characterized in that, Includes the following steps: Under a protective atmosphere, the support, co-catalyst, and solvent are mixed to obtain a dispersion. The dispersion was reacted with the metallocene compound at 20-70 °C, and after post-treatment, a supported metallocene catalyst was obtained.

10. The method for preparing the supported metallocene catalyst according to claim 9, characterized in that, Mix the support, co-catalyst, and solvent at 25-100 °C for 2-12 h.

11. A method for homopolymerization of ethylene, characterized in that, The method includes: Ethylene is homopolymerized in the presence of organic solvent A, supported metallocene catalyst, and co-catalyst A. The supported metallocene catalyst is the supported metallocene catalyst according to any one of claims 1-8 or the supported metallocene catalyst prepared by the method of claim 9 or 10.

12. The method for homopolymerization of ethylene according to claim 11, characterized in that, The homopolymerization reaction is carried out at a temperature of 20-150 °C for a time of 0.5-3 h.

13. The method for homopolymerization of ethylene according to claim 11, characterized in that, The ethylene is introduced at a pressure of 5-30 atm.

14. A method for copolymerizing ethylene with α-olefins, characterized in that, The method includes: In the presence of organic solvent B, supported metallocene catalyst, and co-catalyst B, ethylene and α-olefins are copolymerized. The supported metallocene catalyst is the supported metallocene catalyst according to any one of claims 1-8 or the supported metallocene catalyst prepared by the method of claim 9 or 10.

15. The method for copolymerizing ethylene with α-olefins according to claim 14, characterized in that, The copolymerization reaction satisfies at least one of the following conditions: (1) The temperature of the copolymerization reaction is 40-100 ℃; (2) The copolymerization reaction takes 0.5-3 h; (3) The ethylene is introduced at a pressure of 5-30 atm.

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