A metal catalyst comprising a 9,9-dimethyloxyxanthene bridge and a preparation method and application thereof

Abstract

The application discloses a metal catalyst containing 9,9-dimethyloxyxanthene bridge and a preparation method and application thereof. The metal catalyst has a general structure shown in formula I, wherein 9,9-dimethyloxyxanthene is connected with heteroatoms N and O through a benzene ring. The metal catalyst can be used as an olefin polymerization catalyst and has good performance in a process of obtaining polyolefin through a high-temperature solution method, has good high-temperature resistance and catalytic performance, and can obtain a polymer with LCB / 1000C greater than or equal to 0.05 in the polymerization process of ethylene and octene. Formula I.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a metal catalyst containing 9,9-dimethyloxanthracene bridging, its preparation method, and its uses. Background Technology

[0002] Polyolefin products are one of the pillar industries of modern polymer materials industry. The development, innovation and upgrading of polyolefin products are inseparable from the development of polyolefin catalysts. By regulating the catalysts, the performance of polymers can be adjusted to meet various application needs.

[0003] There are currently many types of polyethylene products on the market, but their flowability or processing performance usually have certain problems. These problems are often addressed by blending different products, but this method usually results in the loss of other physical properties of the polymer.

[0004] CN117924349A discloses a xanthracene-bridged aryloxytridentate ligand-metal complex, its preparation method, and a method for olefin polymerization. In the olefin polymerization method, the xanthracene-bridged aryloxytridentate ligand-metal complex is used as the main catalyst, and one or more of a metallic aluminum activator and optional borate auxiliaries are used as co-catalysts to carry out homopolymerization or copolymerization reactions to prepare polymeric olefins. The catalyst provided by this patent has excellent heat resistance and can be simultaneously applied to catalyze ethylene / α-olefin copolymerization and ethylene / cycloolefin copolymerization, exhibiting high high-temperature catalytic activity and comonomer insertion rate. However, this patent still has the drawback of poor rheological processing properties of the prepared polyolefins.

[0005] Therefore, it is still necessary to develop a new catalyst to improve the rheological properties of polyolefin products by introducing long branches into polymer molecules, making them more suitable for applications such as injection molding, polymer extrusion / processing, and film production. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the defect of poor rheological processing properties of polyolefins prepared by existing catalysts, and to provide a metal catalyst containing 9,9-dimethyloxanthracene bridging, which introduces long branches while ensuring good high temperature resistance and catalytic performance, and obtains a polymer with an LCB / 1000C greater than or equal to 0.05.

[0007] Another object of the present invention is to provide a method for preparing such a metal catalyst.

[0008] Another object of the present invention is to provide the application of such metal catalysts in the preparation of polyolefins.

[0009] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0010] In a first aspect, the present invention provides a metal catalyst comprising 9,9-dimethyloxanthracene bridging, having the general structure of Formula I:

[0011] Formula I

[0012] R1 and R2 are each independently selected from hydrogen or C1~C10 alkyl groups, such as methyl, ethyl, propyl, butyl, isopropyl, pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, etc. The alkyl group can be straight-chain or branched alkyl group, and R1 and R2 may be the same or different.

[0013] M is selected from Group IVB metallic elements;

[0014] X is selected from halogens, C1-C20 alkyl groups, C6-C20 aryl groups, C6-C16 aralkyl groups, and C1-C20 alkylamino groups. Examples of halogens include F, Cl, Br, and I; examples of C1-C20 alkyl groups include methyl, ethyl, propyl, butyl, isopropyl, pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, pentadecyl, octadecyl, and eicosyl groups; examples of C6-C20 aryl groups include phenyl and xxx groups; examples of C6-C16 aralkyl groups include benzyl and ethylphenyl groups; and examples of C1-C20 alkylamino groups include dimethylamino groups. X is preferably chlorine, bromine, methyl, benzyl, or dimethylamino.

[0015] In one alternative embodiment, the metal catalyst satisfies at least one of A to D:

[0016] A. R1 is selected from methyl, ethyl, propyl or tert-butyl;

[0017] B. R2 is selected from methyl, ethyl, isopropyl, or tert-butyl;

[0018] C. M is selected from zirconium, titanium, or hafnium;

[0019] D. X is selected from chlorine, bromine, benzyl, dimethylamino or ethylmethylamino.

[0020] In one alternative embodiment, the metal catalyst represented by Formula I is selected from chemical substances represented by any of the following structural formulas:

[0021]

[0022] A second aspect of the present invention provides a method for preparing a metal catalyst comprising 9,9-dimethyloxanthracene bridging, comprising the following steps:

[0023] (1) Boric acid is added to compound A to give compound B;

[0024] (2) Compound C undergoes nucleophilic substitution to yield compound D;

[0025] (3) Compound B undergoes a coupling reaction with compound D to obtain compound E;

[0026] (4) The compound E undergoes a complexation reaction with the metal salt MX to obtain a metal catalyst of formula I containing 9,9-dimethyloxanthracene bridges;

[0027] Compound A has the following structural formula:

[0028] Formula II

[0029] The compound B has the following structural formula:

[0030] Formula III

[0031] Compound C has the following structural formula:

[0032] Formula IV

[0033] The compound D has the following structural formula:

[0034] Formula V

[0035] The compound E has the following structural formula:

[0036] Style VI

[0037] R1 and R2 are each independently selected from hydrogen or C1~C10 alkyl groups, and R1 and R2 may be the same or different;

[0038] M is selected from Group IVB metallic elements;

[0039] X is selected from halogens, C1~C20 alkyl groups, C6~C20 aryl groups, C6~C16 aralkyl groups, and C1~C20 alkylamino groups, preferably from chlorine, bromine, methyl, benzyl, or dimethylamino.

[0040] In one optional embodiment, the preparation method satisfies at least one of A to J:

[0041] A. In step (1), the reaction temperature is -20~10℃, for example -20℃, -15℃, -10℃, -5℃, 0℃, 1℃, 5℃, 10℃, etc.

[0042] B. In step (1), lithiation is first performed. The lithiation material includes at least one of n-butyllithium, methyllithium, and hexyllithium. The lithiation reaction time is 0.5~2h, for example, 0.5h, 1h, 1.5h, 2h, etc.

[0043] C. In step (1), after the compound A is lithiated, it reacts with triisopropyl borate to obtain compound B. The reaction time is 1-2 hours, for example, 1 hour, 1.5 hours, 2 hours, etc.

[0044] D. In step (1), the molar ratio of compound A to the lithium substance is 1:(2~4), for example, 1:3, etc.

[0045] E. In step (1), the molar ratio of compound A to triisopropyl borate is 1:(2~4), for example 1:3, etc.

[0046] F. In step (1), the reaction is carried out under a protective atmosphere, such as an inert atmosphere or a nitrogen atmosphere.

[0047] G. In step (2), the reaction temperature is -40~10℃, for example -40℃, -30℃, -20℃, -10℃, 0℃, 10℃, etc., and the reaction time is 1h~3h, for example 1h, 2h, 3h, etc.

[0048] H. In step (2), compound C and the haloalkane undergo nucleophilic substitution, and their molar ratio is 1:(2~3), for example, 1:2.5, etc.

[0049] I. In step (3), the molar ratio of compound B to compound D is 1:(2~4), for example 1:3, etc.

[0050] J. In step (3), the reaction requires an alkaline substance to provide alkaline conditions; the alkaline substance includes at least one of sodium hydroxide, potassium hydroxide, potassium carbonate and sodium carbonate solution; the reaction is preferably carried out under the catalysis of tetra(triphenylphosphine)palladium.

[0051] In one alternative implementation, step (4) satisfies at least one of A to E:

[0052] A. The reaction temperature is 40℃~80℃, for example 50℃, 60℃, 70℃, etc., and the time is 1h~5h, for example 2h, 3h, 4h, etc.

[0053] B. The metal salt MX is selected from zirconium tetrachloride, titanium tetrachloride, hafnium tetrachloride, tetrabenzyl hafnium, tetra(dimethylamino)zirconium, tetra(ethylmethylamino)hafnium, titanium tetrabromide, zirconium tetrabromide, or hafnium tetrabromide;

[0054] C. The molar ratio of the compound D to the metal salt MX is 1:(1~2), for example, 1:1.5, etc.

[0055] D. Before the complexation in step (4), the step of adding a dehydrogenating agent is also included;

[0056] The dehydrogenation reagent is at least one of alkyllithium, phenyllithium, potassium carbonate, sodium carbonate, potassium carbonate, and sodium hydride.

[0057] Preferably, the dehydrogenating agent is at least one selected from n-butyllithium, methyllithium, and n-hexyllithium;

[0058] E. The molar ratio of the compound D to the dehydrogenating agent is 1:(2~4), for example, 1:3, etc.

[0059] In one optional embodiment, in step (1), the reaction solvent is tetrahydrofuran, and the amount used is 5 to 20 times the mass of compound A, for example, 10, 12, 15, 18 times, etc.

[0060] In one optional embodiment, in step (2), the reaction solvent is N,N-dimethylformamide, and the amount used is 5 to 20 times the mass of compound C, for example, 10, 12, 15, 18 times, etc.

[0061] In one optional embodiment, in step (3), the reaction solvent is tetrahydrofuran, and the amount of solvent used is 5 to 15 times the mass of compound B, for example, 10, 12, 15 times, etc.; step (3) is carried out in a nitrogen atmosphere.

[0062] In an optional embodiment, step (4) further includes the step of adding a solvent, which may be one or more of tetrahydrofuran, acetonitrile, toluene, and n-hexane, but is not limited thereto; the amount of solvent used is 1 to 10 times the mass of compound E, for example 2, 3, 5, 6, 8 times, etc.; step (4) is carried out in a glove box.

[0063] In a third aspect, the present invention provides a catalyst for preparing polyolefins, comprising the above-described metal catalyst containing 9,9-dimethyloxanthracene bridging or the metal catalyst containing 9,9-dimethyloxanthracene bridging prepared by the above-described preparation method.

[0064] In an optional embodiment, the catalyst further includes a co-catalyst, which is at least one of alkylaluminum and borates; preferably, the co-catalyst satisfies at least one of A to D:

[0065] A. The alkylaluminum is selected from C1~C10 alkylaluminoxanes or alkyl-modified aluminumoxanes;

[0066] Preferably, the alkylaluminum is methylaluminoxane, ethylaluminoxane, or tert-butylaluminoxane;

[0067] B. The borate is selected from at least one or more of N,N-dimethylphenylamine tetra(pentafluorophenyl)borate, tripentafluorophenyl borate, and triphenylmethyltetra(pentafluorophenyl) borate;

[0068] Preferably, the borate is trifluorophenyl borate;

[0069] C. Based on the metal element Al in the alkyl aluminum and the metal element M in the metal catalyst, the molar ratio of the alkyl aluminum to the metal catalyst is (5-400):1, for example 10:1, 50:1, 100:1, 150:1, 200:1, 250:1, 300:1, 350:1, 400:1, etc.

[0070] D. Based on element B in the borate and metal element M in the metal catalyst, the molar ratio of the borate to the metal catalyst is (0-25):1, for example, 1:1, 5:1, 10:1, 15:1, 20:1, 25:1, etc.

[0071] In a fourth aspect, the present invention provides a method for preparing a polyolefin, comprising: polymerizing an olefin under the action of the catalyst used for preparing the polyolefin.

[0072] In one optional embodiment, the preparation method satisfies at least one of A to B:

[0073] A. The olefin is selected from at least one of ethylene, propylene, 1-butene, 1-hexene, 1-heptene, 1-octene, styrene, and norbornene;

[0074] B. The polymerization reaction is carried out at a temperature of 50~300℃ and a pressure of 0.1~20MPa.

[0075] Preferably, the polymerization reaction is carried out at a temperature of 80~250℃ and a pressure of 1~8MPa.

[0076] In one optional embodiment, the polymerization reaction further includes the step of adding a solvent, which may be at least one of alkanes, cycloalkanes and aromatics, preferably Isopar E, toluene, n-heptane and cyclohexane.

[0077] The polymerization reaction is particularly suitable for the polymerization of ethylene and α-olefins.

[0078] Unless otherwise specified, all preparation methods described above in this invention are carried out under normal pressure. For processes not specifically described, reference can be made to existing technologies. The key to this invention lies in the innovation of the catalyst and its preparation method.

[0079] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0080] 1) The present invention provides a metal catalyst comprising 9,9-dimethyloxanthracene bridging, which has the structure shown in Formula I. The 9,9-dimethyloxanthracene is connected to heteroatoms N and O via a benzene ring, exhibiting a particularly wide dihedral angle. The electronic effects of nitrogen and oxygen in the molecular structure enhance the metal coordination ability. Simultaneously, by changing the substituents, the steric hindrance effect and electron-donating ability of the ligands can be adjusted, thereby achieving the regulation of the polymerization performance of the metal catalyst.

[0081] 2) When the metal catalyst of this invention is used to catalyze olefin polymerization, it exhibits good performance in the high-temperature solution process for obtaining polyolefins under high-temperature conditions. It demonstrates good high-temperature resistance and catalytic performance, and in the polymerization of ethylene and octene, it yields polymers with an LCB / 1000C ratio greater than or equal to 0.05. Here, LCB / 1000C represents the long-branch content; a higher value indicates more long branches and better processing performance. Detailed Implementation

[0082] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0083] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0084] The main sources of the main materials and reagents used in the following examples are as follows:

[0085] Tetrahydrofuran: AR, Innochem; n-Butyllithium: AR, Innochem; Hexyllithium: AR, Innochem; Triisopropyl borate: AR, Innochem; N,N-Dimethylformamide: AR, Innochem; Toluene: AR, Aladdin; n-Hexane: AR, Innochem; Potassium hydroxide: AR, Innochem; Sodium hydroxide: AR, Innochem; Potassium carbonate: AR, Innochem; Sodium carbonate: AR, Innochem; Tetra(triphenylphosphine)palladium; TiCl4: Tokyo Chemical Industry Co., Ltd.; ZrCl4: Tokyo Chemical Industry Co., Ltd.; HfCl4: Tokyo Chemical Industry Co., Ltd.; ZrBn4: Tokyo Chemical Industry Co., Ltd.; Tris(pentafluorophenyl)boron: AR, Aladdin; Phenoxyimide zirconium: AR, Aladdin; Isopar E: ExxonMobil Corporation; tert-butylaluminoxane (MAO): Albemarle; Ethylene: 99.9%, Beijing Yanshan Petrochemical Company; 1-Hexene: 98%, Beijing Yanshan Petrochemical Company; 4,5-Dibromo-2,7-ditert-butyl-9,9-dimethyloxanthracene: AR, Aladdin; 4,5-Dibromo-2,7-dimethyl-9,9-dimethyloxanthracene: AR, Aladdin; 4,5-Dibromo-9,9-dimethyloxanthracene: AR, Aladdin; 4,5-Dibromo-2,7-diethyl-9,9-dimethyloxanthracene: AR, Aladdin; 2-Amino-5-bromophenol: AR, Innochem.

[0086] Unless otherwise specified, all other raw materials and reagents were obtained through commercially available channels.

[0087] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0088] The metal catalysts in the following examples were synthesized according to the following synthetic route:

[0089]

[0090] Example 1

[0091] This embodiment provides a metal catalyst F1 containing 9,9-dimethyloxanthracene bridges, with the following structural formula:

[0092]

[0093] The preparation method, synthetic route, and steps of the above-mentioned metal catalyst are as follows:

[0094]

[0095] (1) Compound A1 (39.6 g, 0.1 mol) was dissolved in 200 mL of tetrahydrofuran under nitrogen protection at -20 °C. After stirring, 1.6 M methyllithium (125 mL, 0.2 mol) was added for 30 min, followed by the addition of triisopropyl borate (37.61 g, 0.2 mol). The reaction was stirred for 1 h and then stopped. The mixture was quenched with water. The reaction solution was concentrated, and the crude product was extracted with ethyl acetate, washed, dried, filtered, and concentrated under reduced pressure to obtain crude compound B1. The crude compound B1 was recrystallized from methanol to obtain compound B1 (24.45 g, 75%).

[0096] The NMR data of compound B1 are as follows: 1H NMR (500 MHz, Chloroform) δ6.97 (dd, 2H), 6.74 (t, 2H), 2.29 (s, 6H), 1.68 (d, , 6H), 1.45 (d, 4H).

[0097] (2) Compound C1 (18.8 g, 0.1 mol) was dissolved in 100 mL of N,N-dimethylformamide, sodium hydroxide (8 g, 0.2 mol) was added, the temperature was set to -40 ℃, iodomethane (28.39 g, 0.2 mol) was added, the temperature was maintained, and the reaction was monitored by TLC. The reaction was stopped after the starting material spot disappeared after 3 h. The reaction solution was extracted with ethyl acetate, washed, dried and filtered, and concentrated under reduced pressure to obtain crude compound D1. The crude compound D1 was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 20:1 (v / v)) to obtain compound D1 (15.13 g, 70%).

[0098] The NMR data of compound D1 are as follows: 1H NMR (500 MHz, Chloroform) δ 6.97 (d, 1H), 6.80 (dd, 1H), 6.45 (d, 1H), 5.79 (s, 1H), 3.00 (s, 6H).

[0099] (3) Compound B1 (10 g, 0.03 mol) and compound D1 (12.96 g, 0.06 mol) were dissolved in 50 mL of tetrahydrofuran and 10 mL of water. The mixture was stirred and nitrogen protection was required for the reaction. Tetra(triphenylphosphine)palladium (1.73 g, 0.0015 mol) and sodium hydroxide (2.4 g, 0.06 mol) were added. The reaction temperature was 70 °C. The reaction was monitored by TLC. The reaction was stopped after 1 h when the starting material spot disappeared. The reaction solution was concentrated, extracted with ethyl acetate, washed, dried and filtered, and concentrated under reduced pressure to obtain crude compound E1. The crude compound E1 was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 35:1 (v / v)) to obtain compound E1 (9.46 g, 62%).

[0100] The NMR data for compound E1 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.64 (d, 2H), 7.01 – 6.92 (m, 4H), 6.90 (d, 2H), 6.78 – 6.71 (m, 2H), 5.60 (s, 2H), 3.00 (s, 12H), 2.31 (s, 6H), 1.69 (s, 6H).

[0101] (4) Anhydrous and oxygen-free operation was carried out in a glove box. Compound E1 (8 g, 0.016 mol) was placed in a reaction flask, toluene (30 mL) was added and stirred to dissolve. 1.6 M methyl lithium (20 mL, 0.032 mol) was slowly added dropwise. The mixture was stirred at room temperature for 10 min. Zirconium tetrachloride (3.73 g, 0.016 mol) was added. The temperature was set at 40℃ and the reaction was carried out for 1 h. After the reaction was completed, the mixture was filtered, the filtrate was dried under vacuum, and hexane was added to wash the product. The solid product was obtained by filtration and was recorded as metal complex F1 (6.21 g, 58%).

[0102] The NMR data for compound F1 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.38 (d, 2H), 6.89 – 6.55 (m, 4H), 6.43 (d, 2H), 6.38 – 6.27 (m, 2H), 3.00 (s, 12H), 2.31 (s, 6H), 1.69 (s, 6H).

[0103] Example 2

[0104] This embodiment provides a metal catalyst F2 containing 9,9-dimethyloxanthracene bridges, with the following structural formula:

[0105]

[0106] The preparation method, synthetic route, and steps of the above-mentioned metal catalyst are as follows:

[0107]

[0108] (1) Compound A2 (48.03 g, 0.1 mol) was dissolved in 400 mL of tetrahydrofuran under nitrogen protection at -10 °C. After stirring, 2.5 M butyllithium (120 mL, 0.3 mol) was added for 30 min, followed by the addition of triisopropyl borate (56.42 g, 0.3 mol). The reaction was stopped after stirring for 60 min and quenched with water. The reaction solution was concentrated, and the crude product was extracted with ethyl acetate, washed, dried, filtered, and concentrated under reduced pressure to obtain crude compound B2. The crude compound B2 was recrystallized from methanol to obtain compound B2 (34.04 g, 83%).

[0109] The NMR data for compound B2 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.31 (dt, 2H), 7.02 – 6.23 (m, 2H), 1.69 (s, 6H), 1.51 (s, 4H), 1.30 (d, 18H).

[0110] (2) Compound C2 (18.8 g, 0.1 mol) was dissolved in 200 mL of N,N-dimethylformamide, and sodium carbonate (31.8 g, 0.3 mol) was added. The temperature was set to -25 ℃, and 2-iodo-2-methylpropane (55.2 g, 0.3 mol) was added. The temperature was maintained, and the reaction was monitored by TLC. The reaction was stopped after 2 h when the starting material spot disappeared. The reaction solution was extracted with ethyl acetate, washed, dried, filtered, and concentrated under reduced pressure to obtain crude compound D2. The crude compound D2 was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 15:1 (v / v)) to obtain compound D2 (16.51 g, 55%).

[0111] The NMR data for compound D2 are as follows: 1H NMR (500 MHz, Chloroform) δ 8.45 – 6.84 (m, 1H), 8.45 – 6.60 (m, 2H), 6.45 (d, 1H), 5.98 (s, 1H), 1.35 (s, 17H).

[0112] (3) Compound B2 (20 g, 0.05 mol) and compound D2 (45.03 g, 0.15 mol) were dissolved in 200 mL of tetrahydrofuran and 60 mL of water. The mixture was stirred and nitrogen protection was required for the reaction. Tetra(triphenylphosphine)palladium (2.89 g, 0.0025 mol) and sodium carbonate (15.9 g, 0.15 mol) were added. The reaction temperature was 60 °C. The reaction was monitored by TLC. The reaction was stopped after the starting material spot disappeared after 3 h. The reaction solution was concentrated, extracted with ethyl acetate, washed, dried and filtered, and concentrated under reduced pressure to obtain crude compound E2. The crude compound E2 was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 25:1 (v / v)) to obtain compound E2 (28.92 g, 76%).

[0113] The NMR data for compound E2 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.62 (d, 2H), 7.01 – 6.92 (m, 4H), 6.82 (d, 2H), 6.78 – 6.71 (m, 2H), 5.60 (s, 2H), 3.00 (s, 36H), 2.28 (s, 18H), 1.69 (s, 6H).

[0114] (4) Anhydrous and oxygen-free operation was carried out in a glove box. Compound E2 (10 g, 0.013 mol) was placed in a reaction flask, acetonitrile (60 mL) was added and stirred to dissolve. 2.5 M butyllithium (15.6 mL, 0.039 mol) was slowly added dropwise. The mixture was stirred at room temperature for 20 min. Tetrabenzylhafnium (10.32 g, 0.019 mol) was added. The temperature was set at 60 °C and the reaction was carried out for 3 h. After the reaction was completed, the mixture was filtered, the filtrate was dried, and hexane was added to wash the product. The solid product was obtained by filtration and was recorded as metal complex F2 (8.01 g, 55%).

[0115] The NMR data for compound F2 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.60 (d, 2H), 7.56 – 7.09 (m, 10H), 7.01 – 6.88 (m, 4H), 6.82 (d, 2H), 6.78 – 6.71 (m, 2H), 5.16 (s, 4H), 2.87 (s, 36H), 2.31 (s, 18H), 1.69 (s, 6H).

[0116] Example 3

[0117] This embodiment provides a metal catalyst F3 comprising 9,9-dimethyloxanthracene bridging, with the following structural formula:

[0118]

[0119] The preparation method, synthetic route, and steps of the above-mentioned metal catalyst are as follows:

[0120]

[0121] (1) Compound A3 (36.8 g, 0.1 mol) was dissolved in 600 mL of tetrahydrofuran under nitrogen protection at 10 °C. After stirring, 1.6 M hexyllithium (250 mL, 0.4 mol) was added for 2 h, followed by the addition of triisopropyl borate (75.23 g, 0.4 mol). The reaction was stopped after stirring for 2 h and quenched with water. The reaction solution was concentrated, and the crude product was extracted with ethyl acetate, washed, dried, filtered, and concentrated under reduced pressure to obtain crude compound B3. The crude compound B3 was recrystallized from methanol to obtain compound B3 (22.94 g, 77%).

[0122] The NMR data of compound B3 are as follows: 1H NMR (500 MHz, Chloroform) δ 6.97 (dd, 2H), 6.74 (t, 2H), 6.68 (t, 2H), 2.29 (s, 6H), 1.45 (d, 4H).

[0123] (2) Compound C3 (18.8 g, 0.1 mol) was dissolved in 380 mL of N,N-dimethylformamide, potassium hydroxide (16.8 g, 0.3 mol) was added, the temperature was set at 10 ℃, iodomethane (35.49 g, 0.25 mol) was added, the temperature was maintained at low temperature, and the reaction was monitored by TLC. The reaction was stopped after the starting material spot disappeared after 1 h. The reaction solution was extracted with ethyl acetate, washed, dried and filtered, and concentrated under reduced pressure to obtain crude compound D3. The crude compound D3 was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 20:1 (v / v)) to obtain compound D3 (11.88 g, 55%).

[0124] The NMR data of compound D3 are as follows: 1H NMR (500 MHz, Chloroform) δ 6.97 (s, 1H), 6.80 (s, 1H), 6.45 (s, 1H), 5.79 (s, 1H), 3.00 (s, 1H).

[0125] (3) Compound B3 (10 g, 0.03 mol) and compound D3 (25.93 g, 0.12 mol) were dissolved in 150 mL of tetrahydrofuran and 60 mL of water. The mixture was stirred and nitrogen protection was required for the reaction. Tetra(triphenylphosphine)palladium (1.73 g, 0.0025 mol) and potassium hydroxide (6.72 g, 0.12 mol) were added. The reaction temperature was 40 °C. The reaction was monitored by TLC. The reaction was stopped after the starting material spot disappeared after 5 h. The reaction solution was concentrated, extracted with ethyl acetate, washed, dried and filtered, and concentrated under reduced pressure to obtain crude compound E3. The crude compound E3 was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 30:1 (v / v)) to obtain compound E3 (9.52 g, 66%).

[0126] The NMR data for compound E3 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.85 (s, 2H), 7.30 (s, 2H), 7.22 (s, 2H), 6.97 (d, 4H), 6.75 (s, 2H), 5.60 (s, 2H), 3.00 (s, 12H), 1.69 (s, 6H).

[0127] (4) Anhydrous and oxygen-free operation was carried out in a glove box. Compound E3 (8 g, 0.017 mol) was placed in a reaction flask, tetrahydrofuran (80 mL) was added and stirred to dissolve. 1.6 M hexyllithium (42.5 mL, 0.068 mol) was slowly added dropwise. The mixture was stirred at room temperature for 30 min. Titanium tetrabromide (12.49 g, 0.034 mol) was added. The temperature was set at 80 °C and the reaction was carried out for 5 h. After the reaction was completed, the mixture was filtered, the filtrate was dried, and hexane was added to wash the product. The solid product was obtained by filtration and was recorded as metal complex F3 (7.00 g, 60%).

[0128] The NMR data of compound F3 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.77 (s, 2H), 7.30 (s, 2H), 7.10 (s, 2H), 6.99 (d, 4H), 6.75 (s, 2H), 2.73 (s, 12H), 1.48 (s, 6H).

[0129] Example 4

[0130] This embodiment provides a metal catalyst F4 containing 9,9-dimethyloxanthracene bridges, with the following structural formula:

[0131]

[0132] The preparation method, synthetic route, and steps of the above-mentioned metal catalyst are as follows:

[0133]

[0134] (1) Compound A4 (48.03 g, 0.1 mol) was dissolved in 500 mL of tetrahydrofuran under nitrogen protection at 10 °C. After stirring, 1.6 M hexyllithium (156 mL, 0.25 mol) was added for 1 h, followed by the addition of triisopropyl borate (47.03 g, 0.25 mol). The reaction was stirred for 1.5 h and then stopped. The mixture was quenched with water. The reaction solution was concentrated, and the crude product was extracted with ethyl acetate, washed, dried, filtered, and concentrated under reduced pressure to obtain crude compound B4. The crude compound B4 was recrystallized from methanol to obtain compound B4 (28.71 g, 70%).

[0135] The NMR data for compound B4 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.31 (dt, 2H), 7.02 – 6.23 (m, 2H), 1.69 (s, 6H), 1.51 (s, 4H), 1.30 (d, 18H).

[0136] (2) Compound C4 (18.8 g, 0.1 mol) was dissolved in 200 mL of N,N-dimethylformamide, potassium carbonate (41.46 g, 0.3 mol) was added, the temperature was set to 0 ℃, iodoethane (38.99 g, 0.25 mol) was added, the temperature was maintained at low temperature, and the reaction was monitored by TLC. The reaction was stopped after the starting material spot disappeared after 2.5 h. The reaction solution was extracted with ethyl acetate, washed, dried and filtered, and concentrated under reduced pressure to obtain crude compound D4. The crude compound D4 was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 25:1 (v / v)) to obtain compound D4 (13.43 g, 55%).

[0137] The NMR data of compound D4 are as follows: 1H NMR (500 MHz, Chloroform) δ 6.97 (s, 1H), 6.80 (s, 1H), 6.45 (s, 1H), 5.91 (s, 1H), 3.41 (s, 4H), 1.13 (s, 6H).

[0138] (3) Compound B4 (16.40 g, 0.04 mol) and compound D4 (24.41 g, 0.10 mol) were dissolved in 100 mL of tetrahydrofuran and 30 mL of water. The mixture was stirred and nitrogen protection was required for the reaction. Tetra(triphenylphosphine)palladium (4.62 g, 0.004 mol) and potassium carbonate (22.11 g, 0.16 mol) were added. The reaction temperature was 80 °C. The reaction was monitored by TLC. The reaction was stopped after 1.5 h when the starting material spot disappeared. The reaction solution was concentrated, extracted with ethyl acetate, washed, dried and filtered, and concentrated under reduced pressure to obtain crude compound E4. The crude compound E4 was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 30:1 (v / v)) to obtain compound E4 (14.54 g, 56%).

[0139] The NMR data for compound E4 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.78 (d, J = 2.9 Hz, 2H), 7.04 (d, J = 2.9 Hz, 2H), 6.98 (d, J = 3.1 Hz, 1H), 6.95 (t, J = 2.7 Hz, 3H), 6.75 (d, J = 2.6 Hz, 1H), 6.73 (d, J = 2.6 Hz, 1H), 5.86 (s, 2H), 3.41 (q, J = 12.6 Hz, 8H), 1.69 (s, 6H), 1.32 (s, 18H), 1.13 (t, J = 12.6 Hz, 12H).

[0140] (4) Anhydrous and oxygen-free operation was carried out in a glove box. Compound E4 (11.03 g, 0.017 mol) was placed in a reaction flask, tetrahydrofuran (20 mL) was added and stirred to dissolve. 1.6 M hexyllithium (42.5 mL, 0.068 mol) was slowly added dropwise. The mixture was stirred at room temperature for 10 min. Titanium tetrabromide (12.49 g, 0.034 mol) was added. The temperature was set at 80 °C and the reaction was carried out for 4 h. After the reaction was completed, the mixture was filtered, the filtrate was dried, and hexane was added to wash the product. The solid product was obtained by filtration and was named metal complex F4 (8.57 g, 61%).

[0141] The NMR data for compound F4 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.78 (d, J = 2.9 Hz, 2H), 7.11 (d, J = 2.9 Hz, 2H), 6.98 (d, J = 3.1 Hz, 1H), 6.88 (t, J = 2.7 Hz, 3H), 6.75 (d, J = 2.6 Hz, 1H), 5.85 (d, J = 2.6 Hz, 1H), 3.33 (q, J = 12.6 Hz, 8H), 1.69 (s, 6H), 1.52 (t, J = 12.6 Hz, 12H), 1.32 (s, 18H), 1.11 (t, J = 12.6 Hz, 12H) .

[0142] Example 5

[0143] This embodiment provides a metal catalyst F5 containing 9,9-dimethyloxanthracene bridges, with the following structural formula:

[0144]

[0145] The preparation method, synthetic route, and steps of the above-mentioned metal catalyst are as follows:

[0146]

[0147] (1) Compound A5 (42.42 g, 0.1 mol) was dissolved in 250 mL of tetrahydrofuran under nitrogen protection at 0 °C. After stirring, 1.6 M butyllithium (187.5 mL, 0.3 mol) was added for 1 h, followed by the addition of triisopropyl borate (47.03 g, 0.25 mol). The reaction was stirred for 1 h and then stopped. The mixture was quenched with water. The reaction solution was concentrated, and the crude product was extracted with ethyl acetate, washed, dried, filtered, and concentrated under reduced pressure to obtain crude compound B5. The crude compound B5 was recrystallized from methanol to obtain compound B5 (24.07 g, 68%).

[0148] The NMR data of compound B5 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.22 (s, 2H), 6.78 (s, 2H), 3.51 (s, 4H), 2.72 (s, 4H), 1.69 (s, 6H), 1.18 (s, 6H).

[0149] (2) Compound C5 (18.8 g, 0.1 mol) was dissolved in 250 mL of N,N-dimethylformamide, sodium carbonate (31.8 g, 0.3 mol) was added, the temperature was set to -10 ℃, 2-iodopropane (38.99 g, 0.3 mol) was added, the temperature was maintained, and the reaction was monitored by TLC. The reaction was stopped after the starting material spot disappeared after 3 h. The reaction solution was extracted with ethyl acetate, washed, dried and filtered, and concentrated under reduced pressure to obtain crude compound D5. The crude compound D5 was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 25:1 (v / v)) to obtain compound D5 (13.06 g, 48%).

[0150] The NMR data of compound D5 are as follows: 1H NMR (500 MHz, Chloroform) δ 6.97 (s, 1H), 6.80 (s, 1H), 6.45 (s, 1H), 5.91 (s, 1H), 3.67 (s, 2H), 1.19 (s, 12H).

[0151] (3) Compound B5 (17.70 g, 0.05 mol) and compound D5 (40.83 g, 0.15 mol) were dissolved in 180 mL of tetrahydrofuran and 60 mL of water. The mixture was stirred and nitrogen protection was required for the reaction. Tetra(triphenylphosphine)palladium (5.78 g, 0.005 mol) and sodium hydroxide (8 g, 0.20 mol) were added. The reaction temperature was 50 °C. The reaction was monitored by TLC. The reaction was stopped after 3.5 h when the starting material spot disappeared. The reaction solution was concentrated, extracted with ethyl acetate, washed, dried and filtered, and concentrated under reduced pressure to obtain crude compound E5. The crude compound E5 was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 25:1 (v / v)) to obtain compound E5 (15.57 g, 48%).

[0152] The NMR data for compound E5 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.68 (s, 2H), 7.03 – 6.89 (m, 6H), 6.75 (s, 2H), 5.17 (s, 2H), 3.80 (s, 4H), 2.72 (s, 4H), 1.69 (s, 6H), 1.19 (d, J = 5.0 Hz, 30H).

[0153] (4) Anhydrous and oxygen-free operation was carried out in a glove box. Compound E5 (12.98 g, 0.02 mol) was placed in a reaction flask, tetrahydrofuran (20 mL) was added and stirred to dissolve. 1.6 M butyllithium (37.5 mL, 0.06 mol) was slowly added dropwise. The mixture was stirred at room temperature for 10 min. Tetrabis(ethylmethylamino)hafnium (12.33 g, 0.03 mol) was added. The temperature was set at 70 °C and the reaction was carried out for 3 h. After the reaction was completed, the mixture was filtered, the filtrate was dried, and hexane was added to wash the mixture. The solid product was obtained by filtration and was recorded as metal complex F5 (12.62 g, 67%).

[0154] The NMR data for compound F5 are as follows: ¹H NMR (500 MHz, Chloroform) δ 7.95 (s, 2H), 7.55 – 6.99 (m, 6H), 6.75 (s, 2H), 3.69 (s, 4H), 2.72 (s, 4H), 1.88 (s, 6H), 1.69 (s, 6H), 1.57 (s, 6H), 1.33 (s, 4H), 1.19 (d, J = 5.0 Hz, 30H).

[0155] Comparative Example 1

[0156] This comparative example provides a catalyst F6 with the following structural formula, and the preparation method is as described in Example 1 of CN116444579A.

[0157]

[0158] Comparative Example 2

[0159] This comparative example provides a method for preparing polyolefins using commercially available phenoxyimide zirconium as a catalyst.

[0160] Application Example 1

[0161] This application example provides a method for preparing a polyolefin, including the following steps:

[0162] Using the examples and comparative examples as the main catalysts, and tert-butylaluminoxane and tris(pentafluorophenyl)boron salt as co-catalysts, 1 μmol of the main catalyst was loaded into an ampoule in a high-pressure reactor. The reactor was set at 150°C and dried for 6 hours. Vacuum was then applied and the set temperature was gradually lowered to 25°C. 350 mL of Isopar E, 100 mL of 1-hexene, tert-butylaluminoxane, and tris(pentafluorophenyl)boron salt were added sequentially. The temperature was raised to 80-250°C, and ethylene monomer at 1-8 MPa was introduced. The ampoule was then broken, and the polymerization reaction was initiated. During the polymerization reaction, the stirring rate, polymerization set temperature, and ethylene pressure remained constant. The reaction time was 5 minutes. After the reaction, the gas in the reactor was vented, the reaction liquid was neutralized, and a polymer precipitate was obtained. After washing several times and drying, the polyolefin product was obtained. The molar ratio of tert-butylaluminoxane to the main catalyst metal element is denoted as Al / M, and the molar ratio of B element in tris(pentafluorophenyl)boron salt to the main catalyst metal element M is denoted as B / M. The polymerization reaction temperature, ethylene pressure, Al / M, and B / M corresponding to the metal catalysts used in the preparation of polyolefins in each embodiment are shown in Table 1.

[0163] Table 1 Reaction conditions for each embodiment and comparative example

[0164]

[0165] Test case

[0166] This test example provides the performance of polyolefins prepared using the examples and comparative examples as catalysts, as detailed below:

[0167] (1) Copolymerization activity: Calculated according to the following formula:

[0168]

[0169] The units for polymer mass are g, the units for metal content in catalyst are mol, and the units for polymerization reaction time are h.

[0170] (2) Weight average molecular weight Mw of polymer: The molecular weight was obtained by testing PL-GPC220 at 160℃ using three PLgel 10 µm MIXED-B separation columns in series, with 1,2,4-trichlorobenzene as solvent.

[0171] (3) Molecular weight distribution of polymer: The molecular weight distribution was obtained by testing with PL-GPC220 at 150℃, using a series of Plgel 10µm MIXED-B separation columns, with 1,2,4-trichlorobenzene as solvent.

[0172] (4) fLCB / 1000C: The result was obtained by testing with PL-GPC220 at 150℃, using a series of Plgel 10µm MIXED-B separation columns, with 1,2,4-trichlorobenzene as the solvent.

[0173] Table 2 Performance Test Results

[0174]

[0175] The catalyst provided by this invention is applied to olefin polymerization and does not fail under high polymerization temperature conditions. The catalyst is a high-temperature resistant catalyst, which reduces the energy consumption of the olefin polymerization process. It has the characteristics of high molecular weight and narrow molecular weight distribution. In the polymerization process of ethylene and octene, a polymer with an LCB / 1000C greater than or equal to 0.05 is obtained, which greatly improves the flowability or processing performance of the product and broadens its application range.

[0176] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A metal catalyst comprising 9,9-dimethyloxanthracene bridging, characterized in that, It has the general formula structure of Equation I: Formula I R1 and R2 are each independently selected from hydrogen or C1~C10 alkyl groups; M is selected from zirconium, titanium, or hafnium; X is selected from chlorine, bromine, benzyl, dimethylamino, or ethylmethylamino.

2. The metal catalyst according to claim 1, characterized in that, Satisfy at least one of a~b: a. R1 is selected from methyl, ethyl, propyl or tert-butyl; b. R2 is selected from methyl, ethyl, isopropyl or tert-butyl.

3. The metal catalyst according to claim 1, characterized in that, The metal catalyst represented by Formula I is selected from chemical substances represented by any of the following structural formulas: 。 4. A method for preparing a metal catalyst comprising 9,9-dimethyloxanthracene bridging, characterized in that, Includes the following steps: (1) Compound A is reacted with boric acid to obtain compound B; (2) Compound C undergoes nucleophilic substitution to yield compound D; (3) Compound B and compound D undergo a coupling reaction to obtain compound E; (4) The compound E undergoes a complexation reaction with a metal salt to obtain a metal catalyst of formula I containing 9,9-dimethyloxanthracene bridges; Formula I Compound A has the following structural formula: Formula II The compound B has the following structural formula: Formula III The compound C has the following structural formula: Formula IV The compound D has the following structural formula: Formula V The compound E has the following structural formula: Formula VI R1 and R2 are each independently selected from hydrogen or C1~C10 alkyl groups; M is selected from zirconium, titanium, or hafnium; X is selected from chlorine, bromine, benzyl, dimethylamino, or ethylmethylamino.

5. The preparation method according to claim 4, characterized in that, Satisfy at least one of A to G: A. In step (1), the reaction temperature is -20~10℃; B. In step (1), lithiation is first performed. The lithiation material includes at least one of n-butyllithium, methyllithium, and hexyllithium. The lithiation reaction time is 0.5~2h. C. In step (1), the reaction is carried out under a protective atmosphere; D. In step (2), the reaction temperature is -40~10℃; E. In step (2), compound C and the haloalkane undergo nucleophilic substitution, and their molar ratio is 1:(2~3); F. In step (3), the molar ratio of compound B to compound D is 1:(2~4); G. In step (3), the reaction requires an alkaline substance to provide alkaline conditions; the alkaline substance includes at least one of sodium hydroxide, potassium hydroxide, potassium carbonate and sodium carbonate solution.

6. The preparation method according to claim 5, characterized in that, In step (1), compound A is lithiated and then reacted with triisopropyl borate to obtain compound B; and / or The molar ratio of compound A to the lithium material is 1:(2~4).

7. The preparation method according to claim 6, characterized in that, The molar ratio of compound A to triisopropyl borate is 1:(2~4).

8. The preparation method according to claim 5, characterized in that, In step (3), the reaction is carried out under conditions catalyzed by tetra(triphenylphosphine)palladium.

9. The preparation method according to claim 4, characterized in that, Step (4) satisfies at least one of A to D: A. The reaction temperature is 40℃~80℃, and the time is 1h~5h; B. The metal salt is selected from zirconium tetrachloride, titanium tetrachloride, hafnium tetrachloride, tetrabenzylhafnium, tetra(dimethylamino)zirconium, tetra(ethylmethylamino)hafnium, titanium tetrabromide, zirconium tetrabromide, or hafnium tetrabromide; C. The molar ratio of the compound D to the metal salt is 1:(1~2); D. Before the complexation in step (4), the step of adding a dehydrogenating agent is also included; The dehydrogenating agent is at least one selected from alkyllithium, phenyllithium, potassium carbonate, sodium carbonate, potassium carbonate, and sodium hydride.

10. The preparation method according to claim 9, characterized in that, The dehydrogen-removing agent is at least one of n-butyllithium, methyllithium, and n-hexyllithium.

11. The preparation method according to claim 9, characterized in that, The molar ratio of compound D to the dehydrogenating agent is 1:(2~4).

12. A catalyst for preparing polyolefins, characterized in that, The metal catalyst comprising 9,9-dimethyloxanthracene bridging as described in any one of claims 1 to 3, or the metal catalyst comprising 9,9-dimethyloxanthracene bridging prepared by the preparation method described in any one of claims 4 to 11.

13. The catalyst for preparing polyolefins according to claim 12, characterized in that, The catalyst further includes a co-catalyst, which is at least one of alkylaluminum and borate; and / or The co-catalyst satisfies at least one of A to D: A. The alkylaluminum is selected from C1~C10 alkylaluminoxanes or alkyl-modified aluminumoxanes; B. The borate is selected from at least one or more of N,N-dimethylphenylamine tetra(pentafluorophenyl)borate, tripentafluorophenyl borate, and triphenylmethyltetra(pentafluorophenyl) borate; C. Based on the metal element Al in the alkyl aluminum and the metal element M in the metal catalyst, the molar ratio of the alkyl aluminum to the metal catalyst is (5-400):

1. D. Based on element B in the borate and metal element M in the metal catalyst, the molar ratio of the borate to the metal catalyst is (0-25):

1.

14. A method for preparing a polyolefin, characterized in that, include: The olefins are polymerized in the presence of the catalyst described in claim 12 or 13.

15. The preparation method according to claim 14, characterized in that, The preparation method satisfies at least one of A to B: A. The olefin is selected from at least one of ethylene, propylene, 1-butene, 1-hexene, 1-heptene, 1-octene, styrene, and norbornene; B. The polymerization reaction is carried out at a temperature of 50~300℃ and a pressure of 0.1~20MPa.

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