A method for preparing a COF-supported olefin polymerization catalyst

Abstract

The present invention relates to a method for preparing a COF-supported olefin polymerization catalyst, which comprises the following steps: (1) activating a COF material to obtain an activated COF material; (2) first, under the protection of an inert atmosphere, reacting the activated COF material with a ligand constituting an olefin polymerization catalyst in a non-polar organic solvent at a temperature of 10-100 °C, preferably 20-100 °C, more preferably 40-80 °C, so that the ligand binds to the activated COF material; subsequently, at a temperature of 20-100 °C, preferably 30-90 °C, more preferably 40-80 °C, in a non-polar organic solvent, coordinating a metal compound constituting an olefin polymerization catalyst to the ligand, thereby forming an olefin polymerization catalyst bound to the COF material, and then performing solid-liquid separation to collect the solid phase; and (3) optionally, washing and drying the solid phase to obtain a COF-supported olefin polymerization catalyst.

Description

Technical Field

[0001] The present invention relates to a method for preparing a COF-supported olefin polymerization catalyst and a COF-supported olefin polymerization catalyst obtained by this method. Background Art

[0002] Polyolefins are one of the most important synthetic materials. The production of polyolefins accounts for 60% of the total production of synthetic resins. Therefore, the development of the polyolefin industry directly affects the national economy. The quality of polyolefin products is mainly affected by the polymerization technology and process of olefin polymerization. Among them, the performance of the catalyst has an important impact on the yield and quality of polyolefin products, and heterogeneous catalysts are more suitable for the requirements of industrial olefin polymerization. Finding suitable catalyst carriers and processes for loading catalysts is very important.

[0003] Covalent organic frameworks (COF) materials are a class of porous two-dimensional or three-dimensional polymer materials connected by covalent bonds with a periodic structure. Their pore size and framework structure can be precisely regulated by monomers and linking bonds. The uniform and adjustable pore structure of COF provides a uniform and stable chemical environment for loading catalysts, which is easy to achieve precise regulation of catalytic performance and has the potential to become a carrier for olefin polymerization catalysts.

[0004] Currently, olefin polymerization catalysts with better performance, such as metallocene catalysts and post-metallocene catalysts, have characteristics such as high activity and sensitivity to water and oxygen. During the conventional loading process, the catalyst is prone to partial deactivation due to contact with water and oxygen, resulting in a decrease in the activity of the finally loaded catalyst.

[0005] Therefore, the purpose of the present invention is to seek a new method for preparing a COF-supported olefin polymerization catalyst to reduce or avoid partial deactivation of the catalyst and increase the stability of the catalyst. Summary of the Invention

[0006] On the one hand, the present invention relates to a method for preparing a COF-supported olefin polymerization catalyst. The method first loads the ligand constituting the olefin polymerization catalyst onto the COF carrier, and then coordinates the metal constituting the olefin polymerization catalyst to the ligand. The method maximally retains the activity of the catalyst and increases the stability of the catalyst, thereby improving the efficacy of the obtained COF-supported olefin polymerization catalyst in polymerization applications.

[0007] Specifically, the method includes the following steps:

[0008] (1) Activate the COF material to obtain an activated COF material;

[0009] (2) First, under the protection of an inert atmosphere, at a temperature of 10 - 100 °C, preferably about 20 - 100 °C, more preferably about 40 - 80 °C, react the activated COF material with the ligand constituting the olefin polymerization catalyst in a non-polar organic solvent so that the ligand binds to the activated COF material;

[0010] Subsequently, at a temperature of 20 - 100 °C, preferably 30 - 90 °C, more preferably 40 - 80 °C, in a non-polar organic solvent, coordinate the metal compound constituting the olefin polymerization catalyst to the ligand, thereby forming an olefin polymerization catalyst bound to the COF material, and then perform solid-liquid separation to collect the solid phase;

[0011] (3) Optionally, wash and dry the solid phase to obtain a COF-supported olefin polymerization catalyst.

[0012] The activation in step (1) is known in the art. For example, the method for activating the COF material disclosed in WO2022 / 133849 can be adopted, and the entire content of this application is incorporated herein by reference.

[0013] Specifically, the activation of step (1) can be carried out as follows: Under the protection of an inert atmosphere or vacuum, at a temperature of 0 - 800 °C, preferably 40 - 800 °C, more preferably 50 - 500 °C, most preferably 100 - 400 °C (such as 100 °C, 120 °C, 150 °C, 180 °C, 200 °C, 230 °C, 250 °C, 280 °C, 300 °C, 350 °C, 370 °C, 400 °C), activate the COF for 0.1 - 60 hours, preferably 2 - 50 hours, more preferably 3 - 48 hours (such as 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 10 hours, 12 hours, 15 hours, 20 hours, 24 hours, 28 hours, 30 hours, 35 hours, 40 hours, 43 hours, 45 hours, 48 hours) to obtain the activated COF.

[0014] In the above method, the COF material is known in the art, including, for example, those COF materials disclosed in WO2022 / 133849, and the entire content of this application is incorporated herein by reference.

[0015] Specifically, the COF material can be selected from imine-based COFs (such as COF-LZU1, COF300, COF303), imide-based COFs, borate-based COFs (such as COF5), sp 2 -type COFs, hydrazone-based COFs, boroxine-based COFs (such as COF1), borazine-based COFs, triazine-based COFs (such as CTF1), and phenazine-based COFs. The imine-based COFs, imide-based COFs, borate-based COFs, sp 2Imine-based COF, hydrazone-based COF, boroxine-based COF, borazine-based COF, triazine-based COF, and phenazine-based COF respectively refer to covalent organic framework materials linked by structural bonds such as imine, imide, borate ester, sp 2 , hydrazone, boroxine, borazine, triazine, phenazine, etc. Among them, the bonding methods of imine-based COF, imide-based COF, borate ester-based COF, sp 2 -based COF, hydrazone-based COF, boroxine-based COF, borazine-based COF, triazine-based COF, and phenazine-based COF include but are not limited to the following several types:

[0016]

[0017] Preferably, the COF is selected from COF1, COF300, COF303, CTF1, COF5, and COF-LZU1. More preferably, the COF is selected from COF1, COF300, COF303, and COF5. The structures of these COFs are shown as follows:

[0018]

[0019]

[0020]

[0021] The above-mentioned COF can be prepared by conventional methods in the art, for example, by the method disclosed in WO2022 / 133849, and the entire content of this application is incorporated herein by reference.

[0022] In steps (1) and (2), the inert atmosphere is known, for example, including nitrogen, argon, helium, and supercritical carbon dioxide, and preferably nitrogen. The non-polar organic solvent is known in the art, including, for example, aliphatic compounds containing 5-12 carbon atoms, alicyclic compounds containing 6-12 carbon atoms, aromatic compounds containing 6-12 carbon atoms and their halogenated products, ether compounds containing 4-12 carbon atoms, and their mixtures, etc. For example, the reaction medium is selected from n-hexane, n-heptane, n-octane, n-dodecane, cyclohexane, toluene, xylene, mesitylene, chlorobenzene, 1,2,4-trichlorobenzene, diethyl ether, and their mixtures. Preferably, the reaction medium is selected from chlorobenzene, n-hexane, cyclohexane, n-heptane, isooctane, and their mixtures.

[0023] The reaction of the activated COF material with the ligand is carried out under anhydrous and anaerobic conditions. Generally, the reaction temperature is about 10 - 100 °C, preferably about 20 - 100 °C, more preferably about 40 - 80 °C (such as 10 °C, 20 °C, 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 100 °C); the reaction time is about 3 - 60 hours, preferably about 12 - 48 hours. Among them, the weight ratio of the activated COF material to the ligand is about (0.2 - 10):1, preferably about (0.5 - 5):1, such as about 0.5:1, 1:1, 2:1, 3:1, 4:1 or 5:1.

[0024] Optionally, after the reaction of the activated COF material with the ligand, the product can be post-treated, such as by filtration, washing (for example, washing with an organic solvent such as toluene) and / or vacuum drying (for example, vacuum drying at 50 °C).

[0025] Through the above reaction, the ligand is physically adsorbed onto the activated COF material, thereby forming a larger ligand unit.

[0026] The olefin polymerization catalyst is known in the art and includes, for example, those disclosed in WO2022 / 133849, the entire content of which is incorporated herein by reference. Specifically, the olefin polymerization catalyst includes, for example, metallocene catalysts and post-metallocene catalysts.

[0027] The metallocene catalysts include, for example, zirconocene dichloride, bis(cyclopentadienyl)dimethylhafnium, bis(indenyl)dimethylzirconium, rac-vinylidene-bridged bis(indenyl)zirconium dichloride, rac-dimethylsilylene-bis(2-methylindenyl)zirconium dichloride, dimethylsilylene-bis(indenyl)zirconium dichloride, diphenylmethylene-bridged cyclopentadienyl-fluorenyl zirconium dichloride, dimethylsilylene-tetramethylcyclopentadienyl-tert-butylamino-dimethyltitanium, bis(indenyl)zirconium dichloride, silyl(N-tert-butylamine)(tetramethylcyclopentadienyl)titanium dichloride, bis[2-(3',5'-di-tert-butylphenyl)-indenyl]zirconium dichloride, bis(2-methyl-4,5-phenyl-indenyl)zirconium dichloride, bis(cyclopentadienyl)-bisphenoxyzirconium, dimethylsilylene-bis(indenyl)zirconium dichloride, diphenylmethylene-bridged cyclopentadienyl-fluorenyl zirconium dichloride, diphenylmethylene-bridged cyclopentadienyl-(2-dimethylamino-fluorenyl)zirconium dichloride, dimethylsilylene-tetramethylcyclopentadienyl-tert-butylamino-dimethyltitanium, dimethylsilylene-3-pyrrolylindenyl-tert-butylamino-dimethyltitanium, rac-dimethylsilylene-bis(2-methylindenyl)zirconium dichloride, and dimethylsilylene-fluorenyl-tert-butylamino-dimethyltitanium.

[0028] The post-metallocene catalyst includes, for example, imine-amine type catalysts, ketoimine type catalysts, amidine type catalysts, diimine palladium nickel type catalysts, and phenoxyimine type catalysts.

[0029] The imine-amine type catalysts include, for example, compounds 26, 27, 28, 29a, 29b, 30a, 30b, 31a, 31b, 32, 33a, 33b shown in the following structural formulas:

[0030]

[0031] The ketoimine type catalysts include, for example, compound 40 shown in the following structural formula:

[0032]

[0033] The amidine type catalysts include, for example, compounds 41 and 42 shown in the following structural formulas:

[0034]

[0035] The diimine palladium nickel type catalysts include, for example, compounds 43 and 44 shown in the following structural formulas:

[0036]

[0037] The phenoxyimine type catalysts include, for example, compounds 45-48 shown in the following structural formulas:

[0038]

[0039] Preferably, the olefin polymerization catalyst is selected from zirconocene dichloride, bis(cyclopentadienyl)dimethylhafnium, bis(indenyl)dimethylzirconium, rac-ethylenebis(indenyl)zirconium dichloride, rac-dimethylsilyl-bis(2-methylindenyl)zirconium dichloride, diphenylmethylenecyclopentadienylfluorenylzirconium dichloride, dimethylsilyl(t-butylamido)(tetramethylcyclopentadienyl)titanium dichloride, bis(indenyl)zirconium dichloride, silyl(N-t-butylamido)(tetramethylcyclopentadienyl)titanium dichloride, bis(2-methyl-4,5-benzoindenyl)zirconium dichloride, bis(cyclopentadienyl)diphenoxyzirconium, dimethylsilylbis(indenyl)zirconium dichloride, diphenylmethylenecyclopentadienylfluorenylzirconium dichloride, imine-amine type catalysts, ketoimine type catalysts, phenoxyimine type catalysts, and diimine palladium nickel type catalysts.

[0040] More preferably, the olefin polymerization catalyst is selected from zirconocene dichloride, rac-ethylenebis(indenyl)zirconium dichloride, rac-dimethylsilylbis(2-methylindenyl)zirconium dichloride, dimethylsilyl(tetramethylcyclopentadienyl)(tert-butylamido)dimethyltitanium, silyl(N-tert-butylamido)(tetramethylcyclopentadienyl)titanium dichloride, phenoxyimine zirconium, phenoxyimine titanium, diimine palladium, and diimine nickel. Most preferably, the olefin polymerization catalyst is selected from zirconocene dichloride, dimethylsilyl(tetramethylcyclopentadienyl)(tert-butylamido)dimethyltitanium, phenoxyimine zirconium, phenoxyimine titanium, and diimine nickel.

[0041] Therefore, correspondingly, the ligands constituting the olefin polymerization catalyst are those corresponding to the above-mentioned olefin polymerization catalysts known in the art, including, for example, cyclopentadienyl anion, indenyl anion, ethylenebridged diindenyl anion, dimethylsilylbisindenyl anion, diphenylcarbyne-cyclopentadienyl-fluorenyl anion, dimethylsilyl(tetramethylcyclopentadienyl)(tert-butylamido) anion, bis[2-(3',5'-di-tert-butylphenyl)-indenyl] anion, bis(2-methyl-4,5-phenyl-indenyl) anion, diphenylcarbyne-cyclopentadienyl-(2-dimethylamino-fluorenyl) anion, dimethylsilylbis(2-methylindenyl) anion, dimethylsilylfluorenyl(tert-butylamido) anion, imine-amine type ligand, ketoimine type ligand, amidine type ligand, diimine type ligand, and phenoxyimine type ligand, etc.

[0042] Similarly, correspondingly, the metal compounds constituting the olefin polymerization catalyst are compounds of those metals corresponding to the above-mentioned olefin polymerization catalysts known in the art, including, for example, zirconium tetrachloride, hafnium tetrachloride, titanium tetrachloride, dimethylzirconium dichloride, dimethylhafnium dichloride, dimethyltitanium dichloride, nickel dichloride, and nickel dibromide, etc.

[0043] The reaction of coordinating the metal compound to the ligand is also carried out under anhydrous and anaerobic conditions, and the non-polar organic solvent used is as described above for step (1). Generally, the reaction temperature is about 20 - 100 °C, preferably about 30 - 90 °C, more preferably 40 - 80 °C; the reaction time is about 3 - 60 hours, preferably about 12 - 48 hours. The molar ratio of the metal compound to the ligand is (0.2 - 10):1, preferably about (0.5 - 5):1, such as 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1.

[0044] The solid-liquid separation process is known in the art, for example, carried out at room temperature using a suction filtration device.

[0045] The washing and drying steps in step (3) are optional and are known in the art. For example, washing is carried out using an organic solvent such as toluene, n-hexane, cyclohexane, etc., and then it can be carried out at room temperature using a glove box device.

[0046] The COF-supported olefin polymerization catalyst prepared by the above method is characterized in that the loss of catalyst activity is reduced, and the COF material combines with the ligand to form a larger ligand unit, which results in higher activity and stability of the catalyst, manifested as higher polymerization activity in polymerization. Generally, the polymerization activity of the COF-supported olefin polymerization catalyst is about 1.0×10 6 -1.0×10 8 g polymer / (g catalyst·bar·h). Among them, the polymerization activity is a common parameter known in the art, which refers to the mass (g) of the polymer produced by a unit mass (g) of the catalyst under unit pressure (bar) per unit time (h).

[0047] Therefore, on the other hand, the present invention relates to a COF-supported olefin polymerization catalyst prepared by the method described in the above first aspect. The COF-supported olefin polymerization catalyst has higher activity and stability, manifested as higher polymerization activity in polymerization. Generally, the polymerization activity of the COF-supported olefin polymerization catalyst is about 1.0×10 6 -1.0×10 8 g polymer / (g catalyst·bar·h). Examples

[0048] The embodiments of the present invention will be clearly and completely described below in conjunction with the examples. The examples are illustrative and not restrictive. All other examples obtained by those of ordinary skill in the art without creative efforts based on these examples in the present invention fall within the scope of protection of the present invention.

[0049] Example 1

[0050] (1) Preparation of COF-supported dimethylsilyl-bridged-tetramethylcyclopentadienyl-tert-butylamino-dimethyltitanium catalyst

[0051] Activate COF300 at 250°C and under vacuum conditions for 12 h to obtain activated COF300;

[0052] In a nitrogen-filled glove box, 500 mg of activated COF300 and 50 mg of dimethylsilyl-bridged-tetramethylcyclopentadienyl-sodium tert-butylamide were dispersed in 500 ml of cyclohexane. The mixture was stirred at 25 °C for 72 h, then filtered, washed with toluene, and dried under vacuum at 50 °C to obtain the dimethylsilyl-bridged-tetramethylcyclopentadienyl-sodium tert-butylamide ligand supported on COF300 as a solid; and

[0053] 100 mg of the dimethylsilyl-bridged-tetramethylcyclopentadienyl-sodium tert-butylamide ligand supported on COF300 and 20 mg of dimethyldichlorotitanium were dispersed in 100 ml of n-hexane. The mixture was stirred at 60 °C for 24 h, then filtered, washed with toluene, and dried under vacuum at 50 °C to obtain the COF300-supported dimethylsilyl-bridged-tetramethylcyclopentadienyl-tert-butylamino-dimethyltitanium catalyst as a solid.

[0054] (2) Application of the catalyst in ethylene homopolymerization

[0055] A 2-liter autoclave was evacuated at 140 °C for 2 h. 1.5 L of n-hexane was added to the autoclave, the ethylene pressure in the autoclave was adjusted to 40 bar, and the temperature in the autoclave was adjusted to 50 °C. Then, 100 mg of the above-prepared COF300-supported dimethylsilyl-bridged-tetramethylcyclopentadienyl-tert-butylamino-dimethyltitanium catalyst was added, and the reaction was carried out for 0.5 h to obtain a polyethylene product. Among them, the polymerization activity was 1.2×10 7 g polymer / (g catalyst·bar·h).

[0056] Example 2

[0057] (1) Preparation of COF-supported dichlorodicyclopentadienylzirconium catalyst

[0058] COF1 was activated at 100 °C under argon for 3 h to obtain activated COF1;

[0059] In a nitrogen-filled glove box, 200 mg of activated COF1 and 100 mg of sodium cyclopentadienide were dispersed in 100 ml of n-hexane. The mixture was stirred at 40 °C for 24 h, then filtered, washed with toluene, and dried at 50 °C to obtain the sodium cyclopentadienide ligand supported on COF1 as a solid; and

[0060] 100 mg of the sodium cyclopentadienide supported on COF1 and 50 mg of titanium tetrachloride were dispersed in 100 ml of toluene. The mixture was stirred at 70 °C for 12 h, then filtered, washed with toluene, and dried under vacuum at 70 °C to obtain the COF1-supported dichlorodicyclopentadienylzirconium catalyst as a solid.

[0061] (2) Application of the catalyst in ethylene / 1-octene copolymerization

[0062] A 2-L autoclave was evacuated at 140 °C for 3 h. 1.5 L of toluene was added to the autoclave. The ethylene pressure in the autoclave was adjusted to 35 bar, and the temperature in the autoclave was adjusted to 90 °C. Then, 5 mg of the prepared COF1-supported zirconocene dichloride catalyst, 100 mg of methylaluminoxane, and 50 ml of octene were added, and the reaction was carried out for 0.5 h to obtain an ethylene-octene copolymer. Among them, the polymerization activity was 8.1×10 6 g polymer / (g catalyst·bar·h).

[0063] Example 3

[0064] (1) Preparation of COF-supported phenoxyimine titanium catalyst

[0065] COF5 was activated at 300 °C under vacuum conditions for 6 h to obtain activated COF5;

[0066] Under the protection of a nitrogen atmosphere, 500 mg of activated COF5 and 200 mg of sodium phenoxyimine were dispersed in 200 ml of n-hexane, and the reaction was stirred at 15 °C for 48 h. Then, it was filtered, washed with toluene, and dried under vacuum at 40 °C to obtain a COF5-supported sodium phenoxyimine ligand; and

[0067] In a glove box filled with nitrogen, 100 mg of the COF5-supported sodium phenoxyimine ligand and 50 mg of titanium tetrachloride were dispersed in 100 ml of chlorobenzene, and the reaction was stirred at 55 °C for 48 h. Then, it was filtered, washed with toluene, and dried under vacuum at 50 °C to obtain a COF5-supported phenoxyimine titanium catalyst, and the structure of the phenoxyimine titanium catalyst is as follows:

[0068]

[0069] (2) Application of the catalyst in ethylene homopolymerization

[0070] A 2-L autoclave was evacuated at 140 °C for 3 h. 1.5 L of n-hexane was added to the autoclave. The ethylene pressure in the autoclave was adjusted to 40 bar, and the temperature in the autoclave was adjusted to 80 °C. Then, 5 mg of the COF5-supported phenoxyimine titanium catalyst and 200 mg of methylaluminoxane were added, and the reaction was carried out for 0.5 h to obtain a polyethylene product. Among them, the polymerization activity was 7.8×10 7 g polymer / (g catalyst·bar·h).

[0071] Example 4

[0072] (1) Preparation of COF-supported diimine nickel catalyst

[0073] COF303 was activated at 200 °C under a nitrogen atmosphere for 4 h to obtain activated COF303;

[0074] In a glove box filled with nitrogen, 100 mg of activated COF303 and 50 mg of disodium imide were dispersed in 100 ml of n-hexane, and the mixture was stirred at 40 °C for 24 h, then filtered, washed with toluene and dried under vacuum at 50 °C to obtain a disodium imide ligand supported on COF303;

[0075] In a glove box filled with nitrogen, 50 mg of the disodium imide ligand supported on COF303 and 20 mg of nickel dibromide were dispersed in 100 ml of chlorobenzene, and the mixture was stirred at 30 °C for 48 h, then filtered, washed with toluene and dried under vacuum at 35 °C to obtain a nickel imide catalyst supported on COF303. The structure of the nickel imide catalyst is as follows:

[0076]

[0077] (2) Application of the catalyst in ethylene homopolymerization

[0078] A 2-liter autoclave was evacuated at 140 °C for 3 h, 1.5 L of n-hexane was added to the autoclave, the ethylene pressure in the autoclave was adjusted to 40 bar, the temperature in the autoclave was adjusted to 70 °C, then 15 mg of the prepared nickel imide catalyst supported on COF303 and 600 mg of modified methylaluminoxane were added, and the reaction was carried out for 1 h to obtain a polyethylene product. Among them, the polymerization activity was 5.4×10 6 g polymer / (g catalyst·bar·h).

[0079] Example 5

[0080] (1) Preparation of a phenoxyimine zirconium catalyst supported on COF

[0081] COF1 was activated at 400 °C under nitrogen for 12 h to obtain activated COF1;

[0082] In a glove box filled with nitrogen, 300 mg of activated COF1 and 100 mg of sodium phenoxyimide were dispersed in 200 ml of n-hexane, and the mixture was stirred at 60 °C for 24 h, then filtered, washed with toluene and dried under vacuum at 50 °C to obtain a sodium phenoxyimide ligand supported on COF1; and

[0083] In a glove box filled with nitrogen, 100 mg of the sodium phenoxyimide supported on COF1 and 40 mg of zirconium tetrachloride were dispersed in 100 ml of toluene, and the mixture was stirred at 50 °C for 24 h, then filtered, washed with toluene and dried under vacuum at 55 °C to obtain a phenoxyimine zirconium catalyst supported on COF1.

[0084] (2) Application of the catalyst in ethylene / 1-octene solution copolymerization

[0085] The 2 L autoclave was evacuated at 140 °C for 3 h. 1.5 L of n-hexane was added to the autoclave. The ethylene pressure in the autoclave was adjusted to 25 bar, and the temperature in the autoclave was adjusted to 100 °C. 10 mg of COF1-supported phenoxyimine zirconium catalyst, 200 mg of triethylaluminum and 50 ml of octene were added, and the reaction was carried out for 1 h to obtain ethylene-octene copolymer. Among them, the polymerization activity was 6.8×10 6 g polymer / (g catalyst·bar·h).

[0086] Comparative Example 1

[0087] Application of dichlorodicyclopentadienyl zirconium catalyst in ethylene / 1-octene copolymerization

[0088] The 2 L autoclave was evacuated at 140 °C for 3 h. 1.5 L of toluene was added to the autoclave. The ethylene pressure in the autoclave was adjusted to 35 bar, and the temperature in the autoclave was adjusted to 90 °C. Then 0.8 mg of dichlorodicyclopentadienyl zirconium catalyst, 100 mg of methylaluminoxane and 50 ml of octene were added, and the reaction was carried out for 0.5 h to obtain ethylene-octene copolymer. Among them, the polymerization activity was 4.3×10 6 g polymer / (g catalyst·bar·h).

[0089] It can be clearly seen by comparison that the polymerization activity of the COF1-supported dichlorodicyclopentadienyl zirconium catalyst in Example 2 above is significantly higher than that of the non-COF-supported dichlorodicyclopentadienyl zirconium catalyst in Comparative Example 1.

[0090] Comparative Example 2

[0091] (1) The method for preparing a COF-supported catalyst disclosed in WO2022 / 133849 was used to prepare a COF-supported dichlorodicyclopentadienyl zirconium catalyst

[0092] COF1 was activated at 100 °C under argon for 3 h to obtain activated COF1;

[0093] In a glove box filled with nitrogen, 100 mg of activated COF1 and 500 mg of dichlorodicyclopentadienyl zirconium were dispersed in 500 ml of n-hexane, and the reaction was stirred at 40 °C for 72 h. Then it was filtered, washed with toluene and dried at 50 °C to obtain a COF1-supported dichlorodicyclopentadienyl zirconium catalyst.

[0094] (2) Application of the catalyst in ethylene / 1-octene solution copolymerization

[0095] A 2-L autoclave was evacuated at 140 °C for 3 h, 1.5 L of toluene was added to the autoclave, the ethylene pressure in the autoclave was adjusted to 35 bar, the temperature in the autoclave was adjusted to 90 °C, then 5 mg of COF1-supported zirconocene dichloride catalyst, 100 mg of methylaluminoxane and 50 ml of octene were added, and the reaction was carried out for 0.5 h to obtain an ethylene-octene copolymer. Among them, the polymerization activity was 6.8×10 6 g polymer / (g catalyst·bar·h).

[0096] It can be clearly seen by comparison that the polymerization activity of the COF1-supported zirconocene dichloride catalyst in Example 2 above is higher than that of the COF1-supported zirconocene dichloride catalyst in Comparative Example 2.

[0097] Comparative Example 3

[0098] (1) A method for preparing a COF-supported catalyst disclosed in WO2022 / 133849 was used to prepare a COF-supported phenoxyimine titanium catalyst

[0099] COF5 was activated at 300 °C under vacuum conditions for 6 h to obtain activated COF5;

[0100] Under the protection of a nitrogen atmosphere, 1 g of activated COF5 and 100 mg of triethylaluminum were dispersed in 500 ml of n-hexane, and the reaction was stirred at 15 °C for 48 h, then filtered, washed with toluene and dried under vacuum at 50 °C to obtain pretreated COF5; and

[0101] In a glove box filled with nitrogen, 500 mg of pretreated COF5 and 100 mg of phenoxyimine titanium were dispersed in 500 ml of chlorobenzene, and the reaction was stirred at 0 °C for 72 h, then filtered, washed with toluene and dried under vacuum at 50 °C to obtain a COF5-supported phenoxyimine titanium catalyst.

[0102] (2) Application of the catalyst in ethylene homopolymerization

[0103] A 2-L autoclave was evacuated at 140 °C for 3 h, 1.5 L of n-hexane was added to the autoclave, the ethylene pressure in the autoclave was adjusted to 40 bar, the temperature in the autoclave was adjusted to 80 °C, then 5 mg of COF5-supported phenoxyimine titanium catalyst and 200 mg of methylaluminoxane were added, and the reaction was carried out for 0.5 h to obtain a polyethylene product. Among them, the polymerization activity was 6.3×10 7 g polymer / (g catalyst·bar·h).

[0104] It can be clearly seen by comparison that the polymerization activity of the COF5-supported phenoxyimine titanium catalyst in Example 3 above is significantly higher than that of the COF5-supported phenoxyimine titanium catalyst in Comparative Example 3.

[0105] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A method for preparing a COF-supported olefin polymerization catalyst, which comprises the following steps: (1) Activating the COF material to obtain an activated COF material; (2) First, under the protection of an inert atmosphere, at a temperature of 10 - 100 °C, reacting the activated COF material with a ligand constituting an olefin polymerization catalyst in a non-polar organic solvent so that the ligand binds to the activated COF material, wherein the ligand is selected from cyclopentadienyl anion, indenyl anion, vinylene-bridged diindenyl anion, dimethylsilyl-bridged diindenyl anion, diphenylcarbonyl-bridged cyclopentadienyl-fluorenyl anion, dimethylsilyl-bridged tetramethylcyclopentadienyl-tert-butylamino anion, bis[2-(3',5'-di-tert-butylphenyl)-indenyl] anion, bis(2-methyl-4,5-phenyl-indenyl) anion, diphenylcarbonyl-bridged cyclopentadienyl-(2-dimethylamino-fluorenyl) anion, dimethylsilyl-bridged bis(2-methylindenyl) anion, dimethylsilyl-bridged fluorenyl-tert-butylamino anion, imine-amine type ligand, ketoimine type ligand, amidine type ligand, diimine type ligand, and phenoxyimine type ligand, and wherein the olefin polymerization catalyst includes metallocene catalysts and post-metallocene catalysts; Subsequently, at a temperature of 20 - 100 °C, in a non-polar organic solvent, coordinating a metal compound constituting an olefin polymerization catalyst to the ligand, thereby forming an olefin polymerization catalyst bound to the COF material, and then performing solid-liquid separation to collect the solid phase; and (3) Optionally, washing and drying the solid phase to obtain a COF-supported olefin polymerization catalyst.

2. The method according to claim 1, wherein the activation in step (1) is carried out as follows: under the protection of an inert atmosphere or vacuum, at a temperature of 0 - 800 °C, activating the COF material for 0.1 - 60 hours to obtain an activated COF material.

3. The method according to claim 1, wherein the COF material is selected from imine-based COFs, imide-based COFs, borate ester-based COFs, sp 2 -type COFs, hydrazone-based COFs, boroxine-based COFs, borazine-based COFs, triazine-based COFs, and phenazine-based COFs.

4. The method according to claim 3, wherein the COF material is selected from COF1, COF300, COF303, CTF1, COF5, and COF-LZU1 materials having the following structures:

5. The method according to claim 1, wherein the reaction time between the activated COF material and the ligand is 3 - 60 hours.

6. The method according to claim 1, wherein the weight ratio of the activated COF material to the ligand is (0.2 - 10):

1.

7. The method according to claim 6, wherein the weight ratio of the activated COF material to the ligand is (0.5 - 5):

1.

8. The method according to any one of claims 1-7, wherein the metallocene catalyst is selected from zirconocene dichloride, bis(cyclopentadienyl)dimethylhafnium, bis(indenyl)dimethylzirconium, rac-ethylenebis(indenyl)zirconium dichloride, rac-dimethylsilylene bis(2-methylindenyl)zirconium dichloride, dimethylsilylene bis(indenyl)zirconium dichloride, diphenylmethylene(cyclopentadienyl)(fluorenyl)zirconium dichloride, dimethylsilylene(tetramethylcyclopentadienyl)(tert-butylamido)dimethyltitanium, bis(indenyl)zirconium dichloride, silyl(N-tert-butylamido)(tetramethylcyclopentadienyl)titanium dichloride, bis[2-(3',5'-di-tert-butylphenyl)indenyl]zirconium dichloride, bis(2-methyl-4,5-benzoindenyl)zirconium dichloride, bis(cyclopentadienyl)diphenoxyzirconium, dimethylsilylene bis(indenyl)zirconium dichloride, diphenylmethylene(cyclopentadienyl)(fluorenyl)zirconium dichloride, diphenylmethylene(cyclopentadienyl)(2-dimethylamino-fluorenyl)zirconium dichloride, dimethylsilylene(tetramethylcyclopentadienyl)(tert-butylamido)dimethyltitanium, dimethylsilylene(3-pyrrolylindenyl)(tert-butylamido)dimethyltitanium, rac-dimethylsilylene bis(2-methylindenyl)zirconium dichloride, and dimethylsilylene(fluorenyl)(tert-butylamido)dimethyltitanium.

9. The method according to any one of claims 1-7, wherein the post-metallocene catalyst is selected from imine-amine type catalysts, ketoimine type catalysts, amidine type catalysts, diimine palladium nickel type catalysts, and phenoxyimine type catalysts.

10. The method according to any one of claims 1-7, wherein the metal compound is selected from zirconium tetrachloride, hafnium tetrachloride, titanium tetrachloride, dimethylzirconium dichloride, dimethylhafnium dichloride, dimethyltitanium dichloride, nickel dichloride, and nickel dibromide.

11. The method according to any one of claims 1-7, wherein the time for coordinating the metal compound constituting the olefin polymerization catalyst to the ligand is 3-60 hours.

12. The method according to any one of claims 1-7, wherein the molar ratio of the metal compound to the ligand is (0.2-10):

1.

13. The method according to claim 12, wherein the molar ratio of the metal compound to the ligand is (0.5-5):

1.

14. A COF-supported olefin polymerization catalyst prepared by the method according to any one of claims 1-13.

15. The COF-supported olefin polymerization catalyst according to claim 14, having a polymerization activity of 1.0×10 6 -1.0×10 8 g polymer / g catalyst·bar·h.

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