Supported metallocene catalysts and methods of making, ethylene homopolymerization and ethylene with alpha-olefin copolymerization

Abstract

The application provides a supported metallocene catalyst and a preparation method, an ethylene homopolymerization method and an ethylene and alpha-olefin copolymerization method. The supported metallocene catalyst comprises a carrier and a metallocene compound and a cocatalyst supported on the carrier; the carrier is selected from silica and / or alumina; the metallocene compound has a structure as shown in formula I. Formula I. The polymer particles of the application are regular, and the reactor sticking phenomenon is reduced; in addition, when the supported metallocene catalyst is used for ethylene and alpha-olefin copolymerization by using a slurry polymerization process, the polymerization activity can be improved, the cost is reduced, and the amount of methylaluminoxane is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to a supported metallocene catalyst and a preparation method, a method for ethylene homopolymerization and a method for ethylene and alpha-olefin copolymerization, and belongs to the technical field of polyolefin catalysis. BACKGROUND

[0002] In the 1950s, Breslow and Natta independently used metallocene compounds to achieve olefin polymerization, and the homogeneous catalytic system used by them was composed of Cp2TiCl2 / Et2AlCl, but because the active center Ti 4+ was easily over-reduced to cause deactivation, the overall catalytic efficiency was not high. Until the 1980s, Kaminsky et al. developed a metallocene / methylaluminoxane system for olefin polymerization catalysis.

[0003] In recent years, metallocene compounds have evolved from non-bridged to bridged structure, from double metallocene to single metallocene, from carbon bridge to silicon bridge, and from bridged heteroatom structure. The design and synthesis of various substituted metallocenes, functional group modified metallocenes, and heteroatoms containing B, N and P significantly promote the synthesis strategy, structure analysis and catalytic performance research of transition metal complexes. In the reaction involving transition metal complexes, the electronic effect of the ligand heteroatom can directly regulate the stereoselectivity of olefin polymerization.

[0004] CN102245620A provides a metallocene complex with a substituent group at the 5-position of indenyl and an optional furan or thiophene group at the 2-position. This structure can improve the absorption efficiency of ethylene or alpha-olefin, and can obtain high molecular weight rubber components, especially ethylene / propylene copolymer, and also helps to prepare high melting point propylene homopolymer; CN105985372A describes a metallocene catalyst containing S or O heterocycle for long-chain alpha-olefin copolymerization, but its activity is ordinary and the insertion rate is limited when copolymerized with ethylene.

[0005] Although homogeneous metallocene catalysts have high catalytic activity and mild reaction conditions, there are still some problems: the morphology of the polymer particles is difficult to control, which leads to serious reactor sticking and low bulk density of the obtained polymer. In order to solve the above problems and better adapt to the existing olefin polymerization industrialization device (slurry and gas phase polymerization process), the metallocene can be supported, that is, the metallocene catalyst is supported on a particulate carrier by physical or chemical methods. Although the activity of the catalyst may be reduced after being supported, the type of active sites is increased, but the morphology of the obtained polyolefin powder is regular and the apparent density is high, and the stability of the catalyst is improved.

[0006] Therefore, it is of great significance to develop a new type of supported metallocene catalyst. SUMMARY

[0007] To solve the above problems, the present application aims to provide a supported metallocene catalyst and a preparation method, a method for ethylene homopolymerization and a method for ethylene and α-olefin copolymerization, the polymer particles of which are regular, the reactor is less likely to be stuck, and the polymerization activity can be improved.

[0008] To achieve the above-mentioned purpose, in a first aspect, the present application provides a supported metallocene catalyst, wherein the supported metallocene catalyst comprises a carrier and a metallocene compound and a cocatalyst supported on the carrier;

[0009] The carrier is selected from silica and / or alumina;

[0010] The metallocene compound has a structure as shown in Formula I:

[0011] Formula I;

[0012] In Formula I, M is selected from Zr, Ti or Hf;

[0013] X 1 , X 2 are the same or different substituents, each independently selected from halogen, C1-C 10 linear alkyl, C3-C 10 branched alkyl, C2-C 10 alkenyl, C7-C 20 aralkyl, C6-C 20 aryl unsubstituted or substituted with a heteroatom;

[0014] B is C, Si, Ge or Sn;

[0015] R 1 and R 2 are the same or different substituents, each independently selected from H, C6-C 20 aryl unsubstituted or substituted with a heteroatom, C1-C 10 linear alkyl unsubstituted or substituted with a heteroatom, C3-C 10 branched alkyl unsubstituted or substituted with a heteroatom, C3-C 20 cycloalkyl unsubstituted or substituted with a heteroatom, C2-C 10 alkenyl unsubstituted or substituted with a heteroatom, C7-C 20 aralkyl unsubstituted or substituted with a heteroatom, or R 1 and R 2 are bonded to each other and B together to form a three- to twelve-membered cyclic alkyl unsubstituted or substituted with a heteroatom;

[0016] R3 4 5 6 7 8 9 are identical or different substituents, each independently selected from the group consisting of H, unsubstituted or heteroatom-substituted C6-C 20 aryl, unsubstituted or heteroatom-substituted C1-C 12 linear alkyl, unsubstituted or heteroatom-substituted C3-C 12 branched alkyl, unsubstituted or heteroatom-substituted C3-C 20 cycloalkyl, unsubstituted or heteroatom-substituted C2-C 10 alkenyl, unsubstituted or heteroatom-substituted C7-C 20 aralkyl, in one or more combinations; optionally, wherein R 3 4 5 6 7 8 9 any two adjacent groups of R 20 , R 20 form together with the carbon atoms to which they are attached an unsubstituted or heteroatom-substituted C3-C 1 cycloalkyl or an unsubstituted or heteroatom-substituted C6-C 2 aryl;

[0017] said heteroatom is selected from the group consisting of nitrogen, oxygen, sulfur, silicon, halogen, phosphor, in one or more combinations.

[0018] According to the specific embodiment of the present application, preferably, X 1 2 are identical or different substituents, each independently selected from the group consisting of F, Cl, Br, I, C1-C5 linear alkyl, C3-C5 branched alkyl, C2-C6 alkenyl, unsubstituted or heteroatom-substituted C7-C 15 aralkyl, unsubstituted or heteroatom-substituted C6-C 15 aryl, in one or more combinations;

[0019] B is C or Si;

[0020] R 1 and R 2 are identical or different substituents, each independently selected from the group consisting of H, unsubstituted or heteroatom-substituted C6-C 10 aryl, unsubstituted or heteroatom-substituted C1-C5 linear 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;

[0021] 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.

[0022] According to a specific embodiment of the present invention, preferably,

[0023] In Equation I, M is selected from Zr or Hf;

[0024] 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.

[0025] B is either C or Si;

[0026] R 1 and R 2are the same or different substituents, each independently selected from the group consisting of H, unsubstituted or heteroatom-substituted C6-C8 aryl, unsubstituted or heteroatom-substituted C1-C5 straight-chain alkyl, unsubstituted or heteroatom-substituted C3-C5 branched-chain alkyl, unsubstituted or heteroatom-substituted C3-C8 cycloalkyl, or a combination of one or more of the foregoing; 1 and R 2 together with B to which they are bound form an unsubstituted or heteroatom-substituted three- to eight-membered cyclic alkyl group;

[0027] R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 are the same or different substituents, each independently selected from the group consisting of H, unsubstituted or heteroatom-substituted C6-C8 aryl, unsubstituted or heteroatom-substituted C1-C8 straight-chain alkyl, unsubstituted or heteroatom-substituted C3-C8 branched-chain alkyl, unsubstituted or heteroatom-substituted C3-C8 cycloalkyl, or a combination of one or more of the foregoing; optionally, wherein any two adjacent groups of R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 together with the carbon atoms to which they are bound form an unsubstituted or heteroatom-substituted C3-C8 cycloalkyl group or an unsubstituted or heteroatom-substituted C6-C8 aryl group;

[0028] the heteroatom is selected from the group consisting of nitrogen, oxygen, sulfur, silicon, fluorine, chlorine, bromine, iodine, phosphorus, or a combination of one or more of the foregoing.

[0029] According to the specific embodiment of the present application, preferably,

[0030] in formula I, X 1 , X 2 are the same or different substituents, each independently selected from the group consisting of Cl, Br, I, C1-C3 straight-chain alkyl, C3-C5 branched-chain alkyl, or a combination of one or more of the foregoing;

[0031] B is C or Si;

[0032] R 1 and R 2are the same or different substituents, each independently selected from the group consisting of H, C6-C8 aryl unsubstituted or substituted by a heteroatom, C1-C3 linear alkyl unsubstituted or substituted by a heteroatom, C3-C5 branched alkyl unsubstituted or substituted by a heteroatom, C3-C6 cycloalkyl unsubstituted or substituted by a heteroatom, or R 1 and R 2 together with B to which they are attached form a three- to six-membered cyclic alkyl unsubstituted or substituted by a heteroatom;

[0033] R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 are the same or different substituents, each independently selected from the group consisting of H, C6-C8 aryl unsubstituted or substituted by a heteroatom, C1-C5 linear alkyl unsubstituted or substituted by a heteroatom, C3-C5 branched alkyl unsubstituted or substituted by a heteroatom, C3-C8 cycloalkyl unsubstituted or substituted by a heteroatom; optionally, wherein any two adjacent groups of R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 form together with the carbon atoms to which they are attached a C3-C8 cycloalkyl unsubstituted or substituted by a heteroatom or a C6-C8 aryl unsubstituted or substituted by a heteroatom;

[0034] the heteroatom is selected from the group consisting of nitrogen, oxygen, sulfur, or combinations of two or more thereof.

[0035] According to the specific embodiment of the present application, preferably,

[0036] in formula I, X 1 , X 2 are the same or different substituents, each independently selected from the group consisting of Cl, C1-C3 linear alkyl, C3-C5 branched alkyl, or combinations of two or more thereof;

[0037] B is Si;

[0038] R 1 and R 2 are the same or different substituents, each independently selected from the group consisting of H, C6-C8 aryl unsubstituted or substituted by a heteroatom, C3-C6 cycloalkyl unsubstituted or substituted by a heteroatom, or R 1 and R2 The B atoms bonded to each other together form unsubstituted or heteroatom-substituted ternary to six-membered cyclic alkyl groups;

[0039] 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 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-C6 cycloalkyl group or an unsubstituted or heteroatom-substituted C6-C8 aryl group;

[0040] The heteroatoms are selected from one or more combinations of nitrogen, oxygen, and sulfur.

[0041] According to a specific embodiment of the present invention, preferably,

[0042] 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;

[0043] B is Si;

[0044] 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;

[0045] R 3 R 4 R 5 R 6 R 7 R 8 R9 each independently selected from H, C6-C8 aryl, C1-C3 linear alkyl, C3-C5 branched alkyl, C3-C6 cycloalkyl, or a combination of two or more thereof; optionally, wherein R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 any two adjacent groups of R

[0046] More preferably, X 1 , X 2 is Cl. According to the specific embodiments of the present application, preferably, the metallocene compound of formula I is one of the following structures:

[0047] .

[0048] According to the specific embodiments of the present application, preferably, the co-catalyst is selected from methylaluminoxane and / or modified methylaluminoxane.

[0049] According to the specific embodiments of the present application, preferably, the molar ratio of the metallocene compound to the co-catalyst is (50-1000):1. More preferably, (100-500):1.

[0050] According to the specific embodiments of the present application, preferably, the mass ratio of the carrier to the co-catalyst is 1:(0.2-0.8).

[0051] According to the specific embodiments of the present application, preferably, the silica can be silica gel, such as SYLOPOL®2408, Changzhou Haohua Chemical Co., Ltd.

[0052] In a second aspect, the present application also provides a preparation method of the supported metallocene catalyst as described above, comprising the following steps:

[0053] mixing the carrier with the co-catalyst and the solvent under a protective atmosphere to obtain a dispersion liquid;

[0054] reacting the dispersion liquid with the metallocene compound at 20-70 ℃, and obtaining the supported metallocene catalyst after post-treatment.

[0055] According to the specific embodiments of the present application, preferably, the carrier is mixed with the co-catalyst and the solvent at 25-100 ℃ for 2-12 h.

[0056] According to the embodiment of the present application, preferably, the carrier is activated at 200-800 ℃ for 1-7 h, and then mixed with the organic solvent at a weight ratio of 1:(15-25) at room temperature (e.g. 20-30 ℃) for 5-15 min.

[0057] According to the embodiment of the present application, preferably, after the carrier is mixed with the promoter A and the solvent under a protective atmosphere, the mixture is stirred, cooled, and then allowed to stand and settle, the supernatant is removed, the mixture is washed, and then allowed to stand and settle again, the supernatant is removed, and then the solvent is added to obtain a dispersion. The solvent is further preferably toluene.

[0058] According to the embodiment of the present application, preferably, the present application does not require the step of post-treatment, which can include, for example, standing, removing the solvent, washing, vacuum drying, and obtaining a powder catalyst for use in the subsequent ethylene polymerization reaction.

[0059] According to the embodiment of the present application, preferably, the protective atmosphere is selected from one of nitrogen, helium, and argon.

[0060] According to the embodiment of the present application, preferably, the preparation method of the metallocene compound of formula I comprises using ligand I and a metal precursor as raw materials to prepare the metallocene compound of formula I.

[0061] The ligand I is as follows:

[0062] The metal precursor is a metal halide.

[0063] In the above preparation method of the metallocene compound, preferably, the metal precursor is zirconium tetrachloride and / or hafnium tetrachloride.

[0064] In the above preparation method of the metallocene compound, preferably, the preparation method of the metallocene compound of formula I satisfies at least one of the following conditions:

[0065] (1) the molar ratio of the ligand I to the metal precursor is 1:(0.5-2);

[0066] (2) the ligand I and the metal precursor are reacted at 20-30 ℃ for 3-7 h.

[0067] In the above preparation method of the metallocene compound, preferably, in the process of preparing the metallocene compound, the solvent used is selected from one or more than two combinations of ethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, ethyl acetate, dichloromethane, chloroform, carbon tetrachloride; more preferably, one or more than two combinations of ethyl ether, toluene, and n-hexane.

[0068] In the above-mentioned preparation method of the metallocene compound, preferably, the preparation method comprises preparing the ligand I using compound G and compound H as raw materials;

[0069] Compound G; Compound H;

[0070] In the compound H, X 3 is selected from halogen, more preferably one of F, Cl, Br, I, and further preferably Cl.

[0071] In the above-mentioned preparation method of the metallocene compound, preferably, the preparation method of the ligand I satisfies at least one of the following conditions:

[0072] (1) the molar ratio of the compound G to the compound H is (1.5-2.5):1;

[0073] (2) the compound G and the compound H are reacted at -20 to 0 ℃ for 2-7 h, and then reacted at 20-30 ℃ for 2-7 h.

[0074] In the above-mentioned preparation method of the metallocene compound, preferably, in the preparation of the ligand I, the solvent used is selected from one or more than two combinations of ethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, ethyl acetate, dichloromethane, trichloromethane, carbon tetrachloride; more preferably one or more than two combinations of ethyl ether, tetrahydrofuran, toluene.

[0075] In the above-mentioned preparation method of the metallocene compound, preferably, the preparation method comprises preparing the compound G using compound D and compound F as raw materials;

[0076] Compound D; Compound F.

[0077] In the above-mentioned preparation method of the metallocene compound, preferably, the preparation method of the compound G satisfies at least one of the following conditions:

[0078] (1) the molar ratio of the compound D to the compound F is 1:(0.1-10);

[0079] (2) the compound D and the compound F are prepared into a quaternary ammonium salt, heated at 60-100 ℃ for 5-12 h under the action of a base, and then reacted at 20-30 ℃ for 2-7 h.

[0080] In the above-mentioned method for preparing the metallocene compound, preferably, in the process of preparing the compound G, the solvent used is selected from one or more than two combinations of acetone, diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, ethyl acetate, dichloromethane, trichloromethane, carbon tetrachloride; more preferably one or more than two combinations of acetone, acetonitrile, dichloromethane.

[0081] In the above-mentioned method for preparing the metallocene compound, preferably, the method comprises preparing the compound F from the compound E;

[0082] The compound E.

[0083] In the above-mentioned method for preparing the metallocene compound, preferably, the reaction condition for preparing the compound F is stirring at 20-30 ℃ for 18-30 h.

[0084] In the above-mentioned method for preparing the metallocene compound, preferably, in the process of preparing the compound F, the solvent used is selected from one or more than two combinations of diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, ethyl acetate, dichloromethane, trichloromethane, carbon tetrachloride; more preferably one or more than two combinations of acetonitrile, dichloromethane, carbon tetrachloride.

[0085] In the above-mentioned method for preparing the metallocene compound, preferably, the method comprises preparing the compound D from the compound A and O=C-R 9 ; and

[0086] The compound A.

[0087] In the above-mentioned method for preparing the metallocene compound, preferably, in the process of preparing the compound D, the solvent used is selected from one or more than two combinations of diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, ethyl acetate, dichloromethane, trichloromethane; more preferably one or more than two combinations of acetonitrile, diethyl ether, tetrahydrofuran, dichloromethane, ethyl acetate.

[0088] The present application does not have special requirements for the specific operations such as concentration, washing, recrystallization, silica gel column chromatography used in the process of purifying the preparation of compounds, ligands and metallocene compounds, and those skilled in the art can perform according to the conventional technical means in the art, which will not be repeated here, and those skilled in the art should not be construed as a limitation of the present application.

[0089] In a third aspect, the present application also provides a method for ethylene homopolymerization, wherein the method comprises:

[0090] ethylene is subjected to a homopolymerization reaction in the presence of an organic solvent A, a supported metallocene catalyst, and a cocatalyst A;

[0091] The supported metallocene catalyst is the supported metallocene catalyst described above or the supported metallocene catalyst prepared by the preparation method described above.

[0092] According to the specific embodiment of the present application, preferably, the temperature of the homopolymerization reaction is 20-150 ℃, and the time is 0.5-3 h.

[0093] According to the specific embodiment of the present application, preferably, the pressure of the ethylene is 5-30 atm.

[0094] According to the specific embodiment of the present application, preferably, the cocatalyst A is selected from one or a combination of two or more of an alkyl aluminoxane A, an alkyl aluminum compound A, and an organic boron compound A.

[0095] According to the specific embodiment of the present application, preferably, the alkyl aluminoxane A is selected from methyl aluminoxane and / or modified methyl aluminoxane.

[0096] According to the specific embodiment of the present application, preferably, the alkyl aluminum compound A is selected from one or a combination of two or more of diethyl aluminum chloride (AlEt2Cl), ethyl aluminum sesquichloride (EASC), hemi-monochlorodiethyl aluminum (CAS: 96-10-6), ethyl aluminum dichloride, trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, and tributyl aluminum.

[0097] According to the specific embodiment of the present application, preferably, the organic boron compound A is selected from one or a combination of two or more of N,N-dimethylanilium-tetra-pentafluorophenyl borate, triphenyl-tetra-pentafluorophenyl borate, and tri-pentafluorophenyl boron.

[0098] According to the specific embodiment of the present application, preferably, the organic solvent A is selected from one or a combination of two or more of toluene, xylene, chlorobenzene, benzene, hexane, pentane, heptane, and dichloromethane.

[0099] In a fourth aspect, the present application further provides a method for copolymerization of ethylene and an α-olefin, wherein the method comprises:

[0100] ethylene and an α-olefin are subjected to a copolymerization reaction in the presence of an organic solvent B, a supported metallocene catalyst, and a cocatalyst B;

[0101] The supported metallocene catalyst is the supported metallocene catalyst described above or the supported metallocene catalyst prepared by the preparation method described above.

[0102] According to the specific embodiment of the present application, preferably, the copolymerization reaction satisfies at least one of the following conditions:

[0103] (1) the temperature of the copolymerization reaction is 40-100 ℃;

[0104] (2) the time of the copolymerization reaction is 0.5-3 h;

[0105] (3) the pressure of the ethylene is 5-30 atm.

[0106] According to the specific embodiment of the present application, preferably, the co-catalyst B is selected from one or more than two combinations of alkyl aluminoxane B, alkyl aluminum compound B, and organic boron compound B.

[0107] According to the specific embodiment of the present application, preferably, the alkyl aluminoxane B is selected from methyl aluminoxane and / or modified methyl aluminoxane.

[0108] According to the specific embodiment of the present application, preferably, the alkyl aluminum compound B is selected from one or more than two combinations of diethyl aluminum chloride (AlEt2Cl), ethyl aluminum sesquichloride (EASC), diethyl aluminum sesquichloride (CAS: 96-10-6), ethyl aluminum dichloride, trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, and tributyl aluminum.

[0109] According to the specific embodiment of the present application, preferably, the organic boron compound B is selected from one or more than two combinations of N,N-dimethylanilium)-tetrapentafluorophenyl borate, triphenyltetrapentafluorophenyl borate, and tri-pentafluorophenyl boron.

[0110] According to the specific embodiment of the present application, preferably, the organic solvent B is selected from one or more than two combinations of toluene, xylene, chlorobenzene, benzene, hexane, pentane, heptane, and dichloromethane.

[0111] Compared with the prior art, the present application has the following beneficial effects:

[0112] The present application uses a slurry polymerization process to use a supported metallocene catalyst for ethylene homopolymerization. Compared with solution polymerization, the polymer particles of the present application are regular, and the reactor sticking phenomenon is reduced. In addition, when the slurry polymerization process is used to use the supported metallocene catalyst for ethylene and α-olefin copolymerization, the polymerization activity can be improved, and the amount of methyl aluminoxane is reduced, and the cost is reduced. DETAILED DESCRIPTION

[0113] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present application, the technical solutions of the present application will be described in detail below, but it cannot be understood as limiting the scope of the present application.

[0114] In the following examples and comparative examples, the analytical test methods are conventional methods unless otherwise specified.

[0115] Elemental analysis: The obtained was tested by organic elemental analyzer method;

[0116] Catalytic activity: expressed as "g of g (Cat) h", i.e. the mass of polymer that can be produced per gram of supported metallocene catalyst per hour.

[0117] I. Synthesis of metallocene compounds

[0118] Preparation Example 1

[0119] The preparation method of the metallocene compound N-3 is as follows:

[0120] (I) Synthesis of pyridine derivative D-2:

[0121] To a solution of compound A-2 (25 mmol, 3.95 g) and tetramethylethylenediamine (37.5 mmol, 5.5 mL) in THF (50 mL) was added n-butyllithium (n-BuLi, 37.5 mmol, 37.5 mL of 1 M THF solution) at -78 °C. After 1 h, benzaldehyde B-2 (50 mmol, 5.0 mL) was added, and the reaction was gradually warmed to room temperature. After stirring for 12 h, the reaction was quenched with H2O, and the product was extracted with CH2Cl2(250 mL each time) three times. The organic phases were combined and the solvent was evaporated. The residue was purified by silica gel flash column chromatography (eluent: ethyl acetate / n-hexane, volume ratio 1:3) to obtain compound C-2 (3.70 g, yield 80%) as an oil;

[0122] Compound A-2; Benzaldehyde B-2; Compound C-2.

[0123] Compound C-2 (17.5 mmol, 3.24 g) was dissolved in ethyl acetate (25 mL), palladium hydroxide (Pd(OH)2, 1.50 g, 20% on activated carbon) was added, and the mixture was hydrogenated at room temperature for 12 h; the reaction mixture was filtered, and the filtrate was evaporated to dryness, the residual oil 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 for 12 h. After evaporation of the solvent, the residue was purified by flash column chromatography on silica gel (eluent: ethyl acetate, n-hexane, volume ratio 1:5) to give compound D-2 (1.75 g, yield 59%) as an oil. LC-MS (ESI), [M+1] + : 170.2.

[0124] Compound D-2.

[0125] (ii) Preparation of compound F-1:

[0126] To a solution of E-1 (4.11 g, 50.0 mmol) and NBS (N-bromosuccinimide, 9.80 g, 55.0 mmol) in acetonitrile (MeCN, 300 mL) was added TMS OTf (trimethylsilyl trifluoromethanesulfonate, 600 mg, 2.5 mmol) with stirring, and the 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 give a crude product. The crude product was purified by flash column chromatography on silica gel to give compound F-1 (6.85 g, yield 85%) as an oil. GC-MS (EI), m / z: 160.4.

[0127] Compound E-1; Compound F-1.

[0128] (iii) Preparation of compound G-3:

[0129] Compound D-2 (10 mmol, 1.69 g) and compound F-1 (10 mmol, 1.61 g) were dissolved in acetone (50 mL) and heated to reflux for 4 hours. The reaction was separated by filtration to obtain a quaternary ammonium salt, which was 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 resulting product was extracted with CH2Cl2(250 mL each time) three times. The organic phases were combined, and the solvent was evaporated. The residue was purified by flash column chromatography to obtain compound G-3 (1.85 g, yield 80%) as an oil. GC-MS (EI), m / z: 231.4.

[0130] Compound G-3.

[0131] (Four) Preparation of bridged ligand I-3:

[0132] 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, and the reaction was allowed to proceed at room temperature for 5 hours. Dichlorodimethylsilane H-1 (0.42 mL, 3.5 mmol) was slowly injected with a syringe, and the reaction was maintained at -10 °C for 3 h, and then allowed to proceed at room temperature for 3 h. After the reaction was completed, 60 mL of n-hexane was added, and the solvent was evaporated under reduced pressure. The solution was concentrated to obtain oil dimethylsilicon bridged ligand I-3 (3.5 mmol, 1.81 g).

[0133] NMR data of ligand I-3: 1 H-NMR (300M, CDC13): δ 7.38-7.55 (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, 10.9 Hz, 6.2 Hz, 2H), 3.21 (dd, 6.2 Hz, 1.0 Hz 2H), 0.20 (s, 6H).

[0134] Compound H-1; Ligand I-3.

[0135] (Five) Preparation of metallocene compound N-3:

[0136] Dimethyl silicon 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, n-butyllithium (n-BuLi, 7.0 mmol, 2.8 mL of 2.5 M diethyl ether solution) was slowly added dropwise, and after the dropwise addition was completed, the reaction system was allowed to react at 25 °C for 5 h. Then zirconium tetrachloride (ZrCl4, 3.5 mmol, 815 mg) was added and reacted for 6 h, filtered to obtain the crude product N-3, which was recrystallized from toluene / n-hexane to obtain yellow solid product N-3 (1.0 g, 42%).

[0137] Elemental analysis test of product N-3: Elem. Anal. Calcd. For C 36 H 28 Cl2N2SiZr: C, 63.70%;H, 4.16%; N, 4.13%. Found: C, 63.72%; H, 4.18%; N, 4.15%.

[0138] Metallocene compound N-3.

[0139] Preparation Examples 2 to 11:

[0140] Preparation Examples 2 to 11 respectively 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, N-11, the method of which is the same as the preparation method of N-3 in Preparation Example 1, the difference being only the raw materials and products of each step, and the compounds involved in the preparation process and test results are referred to Tables 1 to 5 (3);

[0141] The NMR data of the main catalyst N-1 of Preparation Example 2 are as follows: 1 H NMR (300 M, 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).

[0142] Preparation Example 12:

[0143] The preparation method of metallocene compound N-12 is the same as that of N-3 in Preparation Example 1, the difference being only that hafnium tetrachloride (HfCl4) is used as the metal precursor, and the test results are referred to Table 5 (3).

[0144] Table 1 corresponds to the specific structures of Compound A, Compound B and Compound D in the preparation examples, and the test results of Compound D.

[0145] Table 1

[0146]

[0147] Table 2 corresponds to the specific structures of Compound E and Compound F in the preparation examples, and the test results of Compound F.

[0148] Table 2

[0149]

[0150] Table 3 corresponds to the specific structures of Compound D and Compound F in the preparation examples, and the test results of Compound G.

[0151] Table 3

[0152]

[0153] Table 4(1), Table 4(2) correspond to the specific structures of Compound G and Compound H in the preparation examples 1 to 11, and the test results of Ligand I.

[0154] Table 4(1)

[0155]

[0156] Table 4(2)

[0157]

[0158] Table 5(1), Table 5(2), Table 5(3) correspond to the specific structures of Ligand I and metallocene compound N in the preparation examples 1 to 12, and the yield and elemental analysis test results of metallocene compound N.

[0159] Table 5(1)

[0160]

[0161] Table 5(2)

[0162]

[0163] Table 5(3)

[0164]

[0165] Example 1

[0166] The embodiment provides a preparation method of a supported metallocene catalyst, and specifically comprises the following steps.

[0167] In a reaction bottle, 2 g of silica gel (SYLOPOL® 2408, activated at 600 ℃ for 2 h) is dispersed in 10 mL of toluene at room temperature for 10 min at a rotation speed of 400 rpm / min; then 11.2 mL of a toluene solution of MAO with a concentration of 0.1 g / mL is slowly added dropwise, and the reaction is carried out at 45 ℃ for 3 h; after the reaction is completed, the temperature is lowered, and the reaction mixture is allowed to stand and settle for 1 h; the upper toluene solution is removed; 20 mL of toluene is used for washing, the reaction mixture is allowed to stand and settle for 30 min, the upper toluene solution is removed again, and then 10 mL of toluene is added to disperse the reaction mixture, so that a dispersion liquid is obtained;

[0168] The dispersion liquid is added with 0.081 g of a toluene solution (10 mL) of the metallocene compound N-3, and the reaction is carried out at 45 ℃ for 3 h; after the reaction is completed, the temperature is lowered, the reaction mixture is allowed to stand and settle, and the upper toluene solution is removed; after the reaction mixture is washed with 20 mL of toluene for three times and then washed with 20 mL of n-hexane for one time, the solvent is finally dried by vacuum extraction, so that a supported metallocene catalyst M-3 (2.56 g) is obtained.

[0169] Example 2

[0170] The embodiment provides a preparation method of a catalyst, and the difference from the embodiment 1 is only that:

[0171] The dispersion liquid is added with the metallocene compound N-4, so that a supported metallocene catalyst M-4 (2.61 g) is obtained.

[0172] Example 3

[0173] The embodiment provides a preparation method of a catalyst, and the difference from the embodiment 1 is only that:

[0174] The dispersion liquid is added with the metallocene compound N-7, so that a supported metallocene catalyst M-7 (2.43 g) is obtained.

[0175] Example A1

[0176] The embodiment provides an application of the supported metallocene catalyst M-3 in an ethylene homopolymerization reaction, and specifically comprises the following steps:

[0177] A 2 L stainless steel polymerization reactor was purged with high purity nitrogen for at least 3 times, and then purged with ethylene for 3 times. After the completion of the gas purging, 400 mL of n-hexane was added into the reactor, the stirring was started, 0.25 mL of AlEt3 (1 M n-hexane solution) was added, 200 mL of n-hexane was used to flush to make sure the AlEt3 was completely introduced into the reactor, then 60 mg of supported metallocene catalyst M-3 was added in the same way, and 200 mL of n-hexane was used to flush the catalyst into the reactor completely.

[0178] The rotation speed of the polymerization device was adjusted to 400 rpm, the temperature was 70 °C, and the ethylene polymerization reaction was initiated under the condition that the ethylene pressure was kept at 10 atm, the reaction was terminated after 1 h, and the vacuum oven was dried to constant weight, and 35.5 g of polyethylene was weighed, and the polymerization activity was 592 g PE / (g of Cat M-3·h).

[0179] Example A2

[0180] This example provides the application of supported metallocene catalyst M-4 in ethylene homopolymerization, which is only different from Example A1 in that:

[0181] The supported metallocene catalyst M-4 was used;

[0182] The mass of the prepared polymer was 41.7 g, and the polymerization activity was 695 g PE / (g of Cat M-4·h).

[0183] Example A3

[0184] This example provides the application of supported metallocene catalyst M-7 in ethylene homopolymerization, which is only different from Example A1 in that:

[0185] The supported metallocene catalyst M-7 was used;

[0186] The mass of the prepared polymer was 44.1 g, and the polymerization activity was 735 g PE / (g of Cat M-7·h).

[0187] Example B1

[0188] This example provides the application of supported metallocene catalyst M-7 in ethylene and 1-octene copolymerization, which specifically includes the following steps:

[0189] A 2 L stainless steel polymerization reactor was purged with high purity nitrogen for at least 3 times, and then purged with ethylene for 3 times. After the completion of the gas purging, 400 mL of n-hexane and 20 mL of 1-octene solution (0.20 mol / L n-hexane solution) were added into the reactor, the stirring was started, 0.25 mL of AlEt3 (1M n-hexane solution) was added, 200 mL of n-hexane was used to flush to make sure the AlEt3 was completely introduced into the reactor, then 60 mg of supported metallocene catalyst M-7 was added in the same way, and 200 mL of n-hexane was used to flush the catalyst into the reactor completely.

[0190] The rotation speed of the polymerization device was adjusted to 400 rpm, the temperature was 70 ℃, and the polymerization of ethylene was initiated under the condition that the ethylene pressure was kept at 10 atm, the reaction was terminated after 1 h, and the vacuum oven was dried to constant weight, and 49.1 g of polymer was obtained by weighing, and the polymerization activity was 818 g PE / (g of Cat M-7·h).

[0191] Comparative Example B1

[0192] This comparative example provides the application of the supported metallocene catalyst M-Cmp-3 in the copolymerization of ethylene and propylene, and the difference from Example B1 is only that:

[0193] The metallocene compound used is Cmp-3; Cmp-3 is prepared according to the experimental steps disclosed in patent CN108250252A.

[0194] The 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).

[0195] The metallocene compound Cmp-3.

[0196] In the copolymerization of ethylene and 1-octene, the catalytic activity of the supported metallocene catalyst of the application is higher than that of M-Cmp-3 of Comparative Example B1.

Claims

1. A supported metallocene catalyst characterized in that, The supported metallocene catalyst comprises a carrier and a metallocene compound and a cocatalyst supported on the carrier; The carrier is selected from silica and / or alumina; The metallocene compound has a structure as shown in Formula I: Formula I; In Formula I, M is selected from Zr, Ti or Hf; X 1 , X 2 are identical or different substituents each independently selected from one of the group consisting of halogen, Ci-C 10 straight-chain alkyl, C3-C 10 branched-chain alkyl, unsubstituted C7-C 20 aralkyl, unsubstituted C6-C 20 aryl; B is C or Si; R 1 and R 2 are identical or different substituents, each independently selected from one of H, unsubstituted C6-C 20 aryl, unsubstituted C1-C 10 straight-chain alkyl, unsubstituted C3-C 10 branched-chain alkyl, unsubstituted C3-C 20 cycloalkyl, unsubstituted C7-C 20 aralkyl, or R 1 and R 2 are bonded to one another together with the B to which they are attached to form an unsubstituted three- to twelve-membered cyclic alkyl group; R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 are identical or different substituents, each independently selected from one of H, unsubstituted C6-C 20 aryl, unsubstituted C1-C 12 straight-chain alkyl, unsubstituted C3-C 12 branched-chain alkyl, unsubstituted C3-C 20 cycloalkyl, unsubstituted C7-C 20 aralkyl; optionally, wherein any two adjacent groups of R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 together with the carbon atoms to which they are attached form an unsubstituted C3-C 20 cycloalkyl or unsubstituted C6-C 20 aryl.

2. The supported metallocene catalyst according to claim 1, wherein, X 1 , X 2 are identical or different substituents, each independently selected from F, Cl, Br, I, a straight-chain alkyl group of C1-C5, a branched-chain alkyl group of C3-C5, an unsubstituted aralkyl group of C7-C 15 , an unsubstituted aryl group of C6-C 15 ; B is C or Si; R 1 and R 2 are the same or different substituents, each independently selected from the group consisting of H, unsubstituted C6-C 10 aryl, unsubstituted C1-C5straight chain alkyl, unsubstituted C3-C5branched chain alkyl, unsubstituted C3-C 10 cycloalkyl, unsubstituted C7-C 15 aralkyl, or R 1 and R 2 bonded to each other together with the B to which they are attached form an unsubstituted three- to ten-membered cyclic alkyl group; R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 are identical or different substituents, each independently selected from the group consisting of H, unsubstituted C6-C 10 aryl, unsubstituted C1-C8straight-chain alkyl, unsubstituted C3-C8branched-chain alkyl, unsubstituted C3-C 10 cycloalkyl, unsubstituted C7-C 15 aralkyl; optionally, wherein any two adjacent groups of R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 together with the carbon atoms to which they are attached form an unsubstituted C3-C 10 cycloalkyl or unsubstituted C6-C 10 aryl.

3. The supported metallocene catalyst according to claim 1, wherein, In Formula I, M is selected from Zr or Hf; X 1 , X 2 are identical or different substituents, each independently selected from the group consisting of CI, Br, I, a straight-chain alkyl group of C1-C5, a branched alkyl group of C3-C5, an unsubstituted aralkyl group of C7-C9; B is C or Si; R 1 and R 2 are the same or different substituents, each independently selected from one of H, unsubstituted C6-C8aryl, unsubstituted C1-C5straight chain alkyl, unsubstituted C3-C5branched chain alkyl, unsubstituted C3-C8cycloalkyl, or R 1 and R 2 are bonded to each other and B together with which they are attached form an unsubstituted three- to eight-membered cyclic alkyl group; R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 are the same or different substituents, each independently selected from one of H, unsubstituted C6-C8aryl, unsubstituted C1-C8straight chain alkyl, unsubstituted C3-C8branched chain alkyl, unsubstituted C3-C8cycloalkyl; optionally, wherein any two adjacent groups of R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and the carbon atoms to which they are attached together form an unsubstituted C3-C8cycloalkyl or unsubstituted C6-C8aryl.

4. The supported metallocene catalyst according to claim 1, wherein, In formula I, X 1 , X 2 are identical or different substituents, each independently selected from one of CI, Br, I, a straight-chain alkyl group of C1-C3, a branched alkyl group of C3-C5; B is C or Si; R 1 and R 2 are the same or different substituents, each independently selected from one of H, unsubstituted C6-C8aryl, unsubstituted C1-C3straight chain alkyl, unsubstituted C3-C5branched chain alkyl, unsubstituted C3-C6cycloalkyl, or R 1 and R 2 are bonded to each other and B together with which they are attached form an unsubstituted three- to six-membered cyclic alkyl group; R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 are the same or different substituents, each independently selected from one of H, unsubstituted C6-C8aryl, unsubstituted C1-C5straight chain alkyl, unsubstituted C3-C5branched alkyl, unsubstituted C3-C8cycloalkyl; optionally, wherein any two adjacent groups of R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and the carbon atoms to which they are attached together form an unsubstituted C3-C8cycloalkyl or unsubstituted C6-C8aryl.

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

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

1.

8. The supported metallocene catalyst of claim 1, wherein, The mass ratio of the carrier to the cocatalyst is 1:(0.2-0.8).

9. A process for the preparation of the supported metallocene catalyst of any one of claims 1 to 8, characterized in that, The method comprises the following steps: Mixing the carrier with the cocatalyst and a solvent under a protective atmosphere to obtain a dispersion; Reacting the dispersion with the metallocene compound at 20-70 ℃, and post-treating to obtain the supported metallocene catalyst.

10. The method for preparing a supported metallocene catalyst according to claim 9, characterized by, Mixing the carrier with the cocatalyst and a solvent at 25-100 ℃ for 2-12 h.

11. A process for the homopolymerization of ethylene, characterized in that, The method comprises: Homopolymerizing ethylene in the presence of an organic solvent A, a supported metallocene catalyst, and a cocatalyst A; The supported metallocene catalyst is the supported metallocene catalyst according to any one of claims 1-8 or prepared by the method for preparing a supported metallocene catalyst according to claim 9 or 10.

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

13. The process for the homopolymerization of ethylene according to claim 11, characterized in that, The pressure for introducing ethylene is 5-30 atm.

14. A process for the copolymerization of ethylene with an α-olefin, characterized in that, The method comprises: Copolymerizing ethylene and an α-olefin in the presence of an organic solvent B, a supported metallocene catalyst, and a cocatalyst B; The supported metallocene catalyst is the supported metallocene catalyst according to any one of claims 1-8 or prepared by the method for preparing a supported metallocene catalyst according to claim 9 or 10.

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

Images