Anthracene-bridged metallocene complex catalyst, its preparation method and application in catalyzing olefin polymerization

Abstract

The application discloses an anthracene-bridged metallocene complex catalyst and a preparation method and application of the catalyst in catalyzing an olefin polymerization reaction. The catalyst has the following formula structure expression. The synthesis method of the anthracene-bridged metallocene complex catalyst is simple, and the synthesis efficiency is high; the anthracene-bridged metallocene complex catalyst can be used for catalyzing copolymerization of ethylene and alpha-olefin or cyclic olefin monomers, and has the performances of high catalytic activity, adjustable molecular weight distribution in a wide range and high temperature resistance.

Description

Technical Field

[0001] This invention relates to a complex catalyst for olefin polymerization, and more particularly to an anthracene-bridged metallocene complex catalyst, its preparation method, and its application in catalyzing olefin polymerization reactions. Background Technology

[0002] Polyolefin materials possess excellent comprehensive properties, readily available monomer sources, low density, and low processing temperature, making them indispensable materials for human life. In olefin polymerization, the catalyst determines the polymerization behavior, polymer particle morphology, structure, and properties. Currently, industrially available polyethylene catalysts include Ziegler-Natta type catalysts, Phillips type catalysts, and metallocene catalysts, as well as high-efficiency transition metal complex-type ethylene homopolymer and copolymer catalysts developed in recent years.

[0003] Polymers synthesized using metallocene catalysts generally exhibit narrow molecular weight distributions, which is beneficial for improving polymer performance but also leads to poorer processability. Solutions include combining two different metallocenes into a complex catalytic system or using a binuclear metallocene catalyst, leveraging the difference in the two active sites to appropriately broaden the polymer's molecular weight distribution. For example, Chinese patent CN113087825A provides an anthracene framework bimetallic catalyst for catalyzing the homopolymerization of ethylene and the copolymerization of ethylene with α-olefins or cycloolefins, exhibiting high activity and high-temperature resistance.

[0004] Modifying the structure of the bridging chain in a binuclear metallocene catalyst is an effective method to alter the molecular weight distribution and microstructure of the polymer. Studies have shown that the length of the bridging group is closely related to the polymer molecular weight and polymerization activity. When the bridging group has more than 5 atoms, the activity is improved compared to a mononuclear metallocene catalyst (J. Organomet. Chem., 2003, 667:53). The introduction of heteroatoms is beneficial to improving the catalytic activity of the metal center; however, excessive heteroatoms can poison and deactivate the metal center. By rationally designing the bridging group and the structure of the single-active-center metallocene catalyst, the two active centers can have suitable spacing, coordination space, and electron distribution, effectively leveraging the synergistic catalytic effect of the two active centers (Chemical Reviews, 2011, 111(3):2450-2485.), thus obtaining an excellent catalyst with high catalytic activity, tunable molecular weight distribution, and high-temperature resistance. A heterometallic catalyst was constructed by bridging a geometrically restricted titanium catalyst and an ethylene oligomeric chromium catalyst to catalyze the polymerization of ethylene, yielding a highly branched polyethylene product (J. Am. Chem. Soc. 2014, 136, 10460-10469). A dinuclear metallocene catalyst bridged by methylenebenzene, biphenyl, and thiophene groups weakens the conjugation between the benzene ring and the cyclopentadienyl ring, resulting in higher polymerization activity than a mononuclear catalyst, but with a longer synthetic route and higher cost (Euro Polym Jnl, 41(2005): 1519-1524).

[0005] In summary, existing bridging bimetallic catalysts currently face significant challenges, including difficulties in catalyst structure modification, unsuitable metal center distances, complex synthesis processes, and low synthesis efficiency. Therefore, it is necessary to develop novel binuclear metallocene catalysts that combine high catalytic activity, tunable molecular weight distribution over a wide range, and high-temperature resistance. Summary of the Invention

[0006] To address the above technical problems, this invention proposes an anthracene-bridged metallocene complex catalyst, its preparation method, and its application in catalyzing olefin polymerization. The anthracene-bridged metallocene complex catalyst has a simple synthesis method and high synthesis efficiency; it can be used to catalyze the copolymerization of ethylene and α-olefin or cycloolefin monomers, exhibiting high catalytic activity, a wide tunable molecular weight distribution, and high temperature resistance.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] Based on the first aspect of the present invention, an anthracene-bridged aspheronite metal complex catalyst is provided, having the following structural expression of Formula I:

[0009]

[0010] in:

[0011] M is selected from Group IV metals, preferably titanium, zirconium, or hafnium;

[0012] Cp is selected from substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl groups;

[0013] Y is selected from elements of Groups VA-VIA, preferably N, O or S;

[0014] R1 is selected from C1-C6 alkyl, C1-C6 alkoxy and any substituted or unsubstituted C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 aryloxy, preferably C1-C6 alkyl, C6-C14 alkylaryl, C6-C14 haloaryl;

[0015] R2, R3, R4, and R5 may be the same as or different from each other, and each is independently selected from hydrogen, halogen, or the following groups: C1-C6 alkyl and any substituted or unsubstituted C1-C6 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 aryloxy, and C4-C9 silyl.

[0016] X is selected from halogens, C1-C20 alkyl groups, C7-C20 substituted or unsubstituted benzyl groups, and C2-C20 alkylamino groups.

[0017] In some preferred embodiments, Cp is selected from cyclopentadienyl, methylcyclopentadienyl, ethylcyclopentadienyl, propylcyclopentadienyl, n-butylcyclopentadienyl, n-octylcyclopentadienyl, tert-butylcyclopentadienyl, trimethylsilylcyclopentadienyl, 1-tert-butyl-2-trimethylsilylcyclopentadienyl, 1,3-bis(trimethylsilyl)cyclopentadienyl, 1,2-dimethylcyclopentadienyl, 1,3-dimethylcyclopentadienyl, 1,2-diethylcyclopentadienyl, and 1,2-diethylcyclopentadienyl. Cyclopentadienyl, 1,2-diphenylcyclopentadienyl, cyclohexylcyclopentadienyl, 2,2′-biphenylcyclopentadienyl, diphenylcyclopentadienyl, indene, tetrahydroindene, 2-methylindene, 1,3-dimethylindene, 4,7-dimethylindene, benzo[a]indene, 2-methylbenzo[a]indene, 3-methylindene, 3-benzylindene, 3-phenylindene, 2-methyl-4-phenylindene, fluorenyl, octahydrofluorenyl, 2,7-di-tert-butylfluorenyl.

[0018] Based on a second aspect of the present invention, a method for preparing anthracene-bridged metallocene complex catalysts as described above is also provided, comprising the following steps:

[0019] Under an anhydrous, oxygen-free, and inert atmosphere, compound II is dissolved in an ultra-dry organic solvent to obtain its solution or suspension; an alkyl metal reagent is added at low temperature, followed by the addition of metal salt MX4 or its ether complex to obtain compound III;

[0020] The compound of formula IV was mixed with an alkyl metal reagent and then added to the reaction solution of compound III. After the reaction, the anthracene-bridged metallocene complex catalyst was obtained.

[0021]

[0022] The definitions of R1, R2, R3, R4, R5, Cp, M, X, and Y are the same as those in the previous text.

[0023] In some preferred embodiments, the alkyl metal reagent is one or more of methyllithium, n-butyllithium, n-hexyllithium, and diisopropylaminolithium.

[0024] After the reaction described in this invention is completed, post-processing and purification processes such as recrystallization and silica gel column chromatography are also included, without specific limitations.

[0025] The source of the compound of formula II is not limited in this invention; it can be obtained through commercial customization or prepared according to existing known methods. The following is merely one feasible example of a method for preparing the compound of formula II provided by this invention:

[0026]

[0027] The definitions of R2, R3, R4, R5, and Cp are the same as the definition of Cp in any one of claims 1 and 2;

[0028] (1) Dissolve compound V in an organic reagent, add an alkyl metal reagent to react, and filter after the reaction to obtain its lithium salt or sodium salt, i.e., compound VI. Preferably, the reaction conditions are: reaction temperature -80℃ to 25℃, reaction time 1-8h.

[0029] (2) Dissolve compound VII in an organic reagent and add compound VI to react and generate compound II. Preferably, the reaction conditions are: reaction temperature -20℃ to 45℃, reaction time 1-8h.

[0030] Further, in step (1), the alkyl metal reagent is one or more of methyl lithium, n-butyl lithium, n-hexyl lithium, and diisopropylamino lithium;

[0031] Preferably, the molar ratio of compound V to the alkyl metal reagent is 1:(1 to 1.5);

[0032] Preferably, compound V is selected from one or more of cyclopentadiene, 2-methylcyclopentadiene, indene, 2-methylindene, 4,7-dimethylindene, fluorene, and 2,7-di-tert-butylfluorene.

[0033] In step (1), the organic reagent is one or more of diethyl ether, tetrahydrofuran, methyl tert-butyl ether, and butyl ether;

[0034] In step (2), the organic reagent is one or more of acetonitrile, tetrahydrofuran, N,N-dimethylformamide, and toluene;

[0035] In step (2), the molar ratio of compound VII to compound VI is 1:(2-2.5);

[0036] Preferably, compound VII is selected from one or more of 1,5-dibromoanthracene, 1,5-dibromo-2,6-dimethoxyanthracene, and 1,5-dibromo-2,3,5,6-tetramethylanthracene.

[0037] Based on a third aspect of the present invention, a catalyst composition is also provided, comprising the anthracene-bridged aspheronite metal complex catalyst and the co-catalyst described above;

[0038] The cocatalyst is selected from at least one of alkylaluminum, aluminoxane, modified aluminoxane, or a mixture of at least one of them with boron salt;

[0039] Preferably, the alkylaluminum is one or more selected from trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum;

[0040] Preferably, the aluminoxane is one or more selected from methylaluminoxane, ethylaluminoxane, and isobutylaluminoxane;

[0041] Preferably, the boron salt is one or more of triphenylcarbazo(pentafluorophenyl)borate, N,N-dimethylphenylammonium tetra(pentafluorophenyl)borate, and tetra(pentafluorophenyl)borate-methyl di-(octadecyl)ammonium salt.

[0042] In some preferred embodiments, the molar ratio of the co-catalyst to the anthracene-bridged metallocene complex catalyst, based on the molar ratio of metal Al to metal M, is (10-6000):1, preferably (200-2000):1;

[0043] Preferably, the amount of boron salt, in terms of the molar amount of element B, is 0-4 times that of metal M in the anthracene-bridged aspheronite metal complex catalyst.

[0044] Based on a fourth aspect of the present invention, an olefin polymerization method is also provided, comprising: polymerizing ethylene and α-olefin in the presence of the catalyst composition described above;

[0045] Preferably, the α-olefin is one or more of propylene, 1-butene, 1-hexene, 1-octene, norbornene, alkyl-substituted norbornene, alkoxy-substituted norbornene, vinyl-substituted norbornene, ester-substituted norbornene, phenyl-substituted norbornene, phenoxy-substituted norbornene, and amino-substituted norbornene.

[0046] In some preferred embodiments, the polymerization reaction temperature is 70-200℃, the pressure is 0.3-8MPa, and the reaction time is 0.5-200min.

[0047] The beneficial effects of this invention are:

[0048] A dual-active-center metallocene complex (having the structure of Formula I) is provided, in which two mono-metallocene complexes are bridged by anthracene, resulting in suitable spacing, coordination space, and electron distribution between the two metal active centers, effectively leveraging the synergistic catalytic effect of the dual active centers. Compared to the relatively narrow molecular weight distribution of polymerization products catalyzed by mono-active-center metallocene complexes, the catalytic composition of this invention maintains high catalytic activity and thermal stability while enabling the adjustment of the molecular weight distribution of cycloolefin polymerization products over a wider range, thereby improving the polymer's processability. Detailed Implementation

[0049] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0050] Unless otherwise specified, the raw materials used in the following embodiments of the present invention can be purchased commercially.

[0051]

Example 1

[0052]

[0053] (1) Under N2 atmosphere, 1,5-dibromoanthracene (3.36 g, 10 mmol) was dissolved in 100 mL of anhydrous THF in a 200 mL Schlenk flask and placed in an ice-water bath; 10 mL of cyclopentadienyl sodium (2.0 mol / L tetrahydrofuran solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then the reaction was carried out at room temperature for 3 h. The solvent was removed under vacuum to obtain intermediate II-1 2.06 g, with a yield of 85%.

[0054] 1 H NMR(400MHz, CDCl3)δ8.45(d,J=2.9Hz,2H),7.99–7.85(m,2H),7.51–7.08(m,4H),6.77(dt,J=12.4,1 .8Hz,2H),6.27(dd,J=21.9,12.4Hz,2H),5.71(dt,J=21.7,13.9Hz,2H),3.31(dd,J=13.9,2.0Hz,4H).

[0055] (2) Under N2 atmosphere, in a 200 mL Schlenk flask, intermediate II-1 (2.06 g, 8.5 mmol) was dissolved in 100 mL of anhydrous diethyl ether and placed in an ice-water bath; 10.63 mL of n-butyllithium (1.6 mol / L hexane solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then reacted at room temperature for 3 h to obtain intermediate III-1 lithium salt solution; titanium tetrachloride (3.22 g, 17.00 mmol) was added to the above solution, and the mixture was slowly heated to room temperature and stirred for 12 h. The red suspension was dried under vacuum, and the residue was washed with toluene (30 mL × 3). The filtrate was collected, and the solvent was removed under vacuum to obtain intermediate III-1 with a yield of 75%.

[0056] 1 H NMR (400MHz, C6D6) δ8.69(d,J=2.5Hz,2H),7.86(ddd,J=7.6,2.3,1.2Hz,2H),7.37(t,J=7.8H z,2H),7.32(dd,J=7.8,1.3Hz,2H),6.47–6.39(m,4H),6.39–6.33(m,2H),4.12–4.05(m,2H).

[0057] (3) Under N2 atmosphere, 2,6-diisopropylphenol (2.27 g, 12.75 mmol) was dissolved in 100 mL toluene in a 200 mL Schlenk flask. Intermediate III-1 (3.89 g, 6.37 mmol) was added to the solution. After heating to 90 °C and reacting for 12 h, the orange-yellow suspension was filtered, the filtrate was collected, concentrated, and a small amount of n-hexane was added. The mixture was then placed at -18 °C to precipitate, yielding an orange-yellow solid powder, which was the complex Cat.1, with a yield of 69%.

[0058] 1 H NMR (400MHz, C6D6): δ9.13(d,J=2.3Hz,2H),8.08(ddd,J=7.8,2.3,1.2Hz,2H),7.72(dd,J=7.8,1.2Hz,2H),7.67–7.61(m,4H),7.57(t, J=7.8Hz,2H),7.43(dd,J=7.4,1.6Hz,2H),7.15–7.09(m,4H),7.06–6.99(m,2H),3.24–3.12(m,4H),1.22(tdd,J=6.1,2.9,1.4Hz,24H).

[0059]

Example 2

[0060]

[0061] (1) Under N2 atmosphere, 1,5-dibromoanthracene (3.36 g, 10 mmol) was dissolved in 100 mL of anhydrous THF in a 200 mL Schlenk flask and placed in an ice-water bath; 10 mL of cyclopentadienyl sodium (2.0 mol / L tetrahydrofuran solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then the reaction was carried out at room temperature for 3 h. The solvent was removed under vacuum to obtain intermediate II-2 2.06 g, with a yield of 85%.

[0062] (2) Under N2 atmosphere, in a 200 mL Schlenk flask, intermediate II-2 (2.06 g, 8.5 mmol) was dissolved in 100 mL of anhydrous diethyl ether and placed in an ice-water bath; 10.63 mL of n-butyllithium (1.6 mol / L hexane solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then reacted at room temperature for 3 h to obtain intermediate III-2 lithium salt solution; titanium tetrachloride (3.22 g, 17.00 mmol) was added to the above solution, and the mixture was slowly heated to room temperature and stirred for 12 h. The red suspension was dried under vacuum, and the residue was washed with toluene (30 mL × 3). The filtrate was collected, and the solvent was removed under vacuum to obtain intermediate III-2 with a yield of 75%.

[0063] (3) Under N2 atmosphere, 2,6-dichlorophenol (2.08 g, 12.75 mmol) was dissolved in 100 mL toluene in a 200 mL Schlenk flask. Intermediate III-2 (3.89 g, 6.37 mmol) was added to the solution. After heating to 90 °C and reacting for 12 h, the orange-yellow suspension was filtered, the filtrate was collected, concentrated, and a small amount of n-hexane was added. The mixture was then placed at -18 °C to precipitate, yielding an orange-yellow solid powder, which was the complex Cat.2, with a yield of 66%.

[0064] 1H NMR (400MHz, C6D6): δ9.16(d,J=2.3Hz,2H),8.11–8.04(m,2H),7.72(dd,J=7.8,1.2Hz,2H),7.67–7.61(m,4 H),7.57(t,J=7.8Hz,2H),7.43(dd,J=7.4,1.6Hz,2H),7.29–7.23(m,4H),7.04(ddd,J=8.2,7.4,0.7Hz,2H).

[0065] [Example 3] Preparation of complex Cat.3

[0066]

[0067] (1) Under N2 atmosphere, 1,5-dibromoanthracene (3.36 g, 10 mmol) was dissolved in 100 mL of anhydrous THF in a 200 mL Schlenk flask and placed in an ice-water bath; 10 mL of cyclopentadienyl sodium (2.0 mol / L tetrahydrofuran solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then the reaction was carried out at room temperature for 3 h. The solvent was removed under vacuum to obtain intermediate II-3 2.06 g, with a yield of 85%.

[0068] (2) Under N2 atmosphere, in a 200 mL Schlenk flask, intermediate II-3 (2.06 g, 8.5 mmol) was dissolved in 100 mL of anhydrous diethyl ether and placed in an ice-water bath; 10.63 mL of n-butyllithium (1.6 mol / L hexane solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then reacted at room temperature for 3 h to obtain intermediate III-3 lithium salt solution; titanium tetrachloride (3.22 g, 17.00 mmol) was added to the above solution, and the mixture was slowly heated to room temperature and stirred for 12 h. The red suspension was dried under vacuum, and the residue was washed with toluene (30 mL × 3). The filtrate was collected, and the solvent was removed under vacuum to obtain intermediate III-3 with a yield of 75%.

[0069] (3) Under N2 atmosphere, 2,4,6-trifluorophenol (1.89 g, 12.75 mmol) was dissolved in 100 mL toluene in a 200 mL Schlenk flask. Its intermediate III-3 (3.89 g, 6.37 mmol) was added to the solution. After heating to 90 °C and reacting for 12 h, the orange-yellow suspension was filtered, the filtrate was collected, concentrated, and a small amount of n-hexane was added. The mixture was then placed at -18 °C to precipitate, yielding an orange-yellow solid powder, which is the complex Cat.3, with a yield of 66%.

[0070] 1H NMR (400MHz, C6D6): δ9.12(d,J=2.4Hz,2H),8.11–8.04(m,2H),7.72(dd,J=7.8,1.2Hz,2H),7.67– 7.61(m,4H),7.57(t,J=7.8Hz,2H),7.43(dd,J=7.4,1.6Hz,2H),6.60(ddt,J=8.1,6.8,1.6Hz,4H).

[0071] [Example 4] Preparation of complex Cat.4

[0072]

[0073] (1) Under N2 atmosphere, 1,5-dibromoanthracene (3.36 g, 10 mmol) was dissolved in 100 mL of anhydrous THF in a 200 mL Schlenk flask and placed in an ice-water bath; 10 mL of cyclopentadienyl sodium (2.0 mol / L tetrahydrofuran solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then the reaction was carried out at room temperature for 3 h. The solvent was removed under vacuum to obtain intermediate II-4 2.06 g, with a yield of 85%.

[0074] (2) Under N2 atmosphere, in a 200 mL Schlenk flask, intermediate II-4 (2.06 g, 8.5 mmol) was dissolved in 100 mL of anhydrous diethyl ether and placed in an ice-water bath; 10.63 mL of n-butyllithium (1.6 mol / L hexane solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then reacted at room temperature for 3 h to obtain intermediate III-4 lithium salt solution; titanium tetrachloride (3.22 g, 17.00 mmol) was added to the above solution, and the mixture was slowly heated to room temperature and stirred for 12 h. The red suspension was dried under vacuum, and the residue was washed with toluene (30 mL × 3). The filtrate was collected, and the solvent was removed under vacuum to obtain intermediate III-4 with a yield of 75%.

[0075] (3) Under N2 atmosphere, 2,2,4,4-tetramethylpentane-3-imine (1.80 g, 12.75 mmol) was dissolved in 100 mL toluene in a 200 mL Schlenk flask. Its intermediate III-4 (3.89 g, 6.37 mmol) was added to the solution. After heating to 90 °C and reacting for 12 h, the purple-red suspension was filtered, the filtrate was collected, concentrated, and a small amount of n-hexane was added. The mixture was then placed at -18 °C to precipitate, yielding a purple-red needle-like solid, which was the complex Cat.4, with a yield of 69%.

[0076] 1 H NMR (400MHz, C6D6): δ8.69(d,J=2.2Hz,2H),7.86(ddd,J=7.8,2.3,1.4Hz,2H),7.38(t,J=7.8Hz,2H),7.32( dd,J=8.0,1.3Hz,2H),6.47–6.40(m,4H),6.38(d,J=9.1Hz,2H),4.07(t,J=6.7Hz,2H),1.23–1.18(m,36H).

[0077] [Example 5] Preparation of complex Cat.5

[0078]

[0079] (1) Under N2 atmosphere, 1,5-dibromoanthracene (3.36 g, 10 mmol) was dissolved in 100 mL of anhydrous THF in a 200 mL Schlenk flask and placed in an ice-water bath; 10 mL of cyclopentadienyl sodium (2.0 mol / L tetrahydrofuran solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then the reaction was carried out at room temperature for 3 h. The solvent was removed under vacuum to obtain intermediate II-5 2.06 g, with a yield of 85%.

[0080] (2) Under N2 atmosphere, in a 200 mL Schlenk flask, intermediate II-5 (2.06 g, 8.5 mmol) was dissolved in 100 mL of anhydrous diethyl ether and placed in an ice-water bath; 10.63 mL of n-butyllithium (1.6 mol / L hexane solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then reacted at room temperature for 3 h to obtain intermediate III-5 lithium salt solution; titanium tetrachloride (3.22 g, 17.00 mmol) was added to the above solution, and the mixture was slowly heated to room temperature and stirred for 12 h. The red suspension was dried under vacuum, and the residue was washed with toluene (30 mL × 3). The filtrate was collected, and the solvent was removed under vacuum to obtain intermediate III-5 with a yield of 75%.

[0081] (3) Under N2 atmosphere, 3,3-dimethylbutane-2-imine (1.26 g, 12.75 mmol) was dissolved in 100 mL toluene in a 200 mL Schlenk flask. Its intermediate III-5 (3.89 g, 6.37 mmol) was added to the solution. After heating to 90 °C and reacting for 12 h, the purple-red suspension was filtered, the filtrate was collected, concentrated, and a small amount of n-hexane was added. The mixture was then placed at -18 °C to precipitate, yielding a purple-red needle-like solid, which was the complex Cat.5, with a yield of 64%.

[0082] 1 H NMR (400MHz, C6D6): δ9.13(d,J=2.3Hz,2H),8.08(ddd,J=7.9,2.4,1.3Hz,2 H),7.75–7.65(m,6H),7.61–7.52(m,4H),2.08(s,6H),1.22–1.18(m,16H).

[0083] [Example 6] Preparation of complex Cat.6

[0084]

[0085] (1) Under N2 atmosphere, 1,5-dibromoanthracene (3.36 g, 10 mmol) was dissolved in 100 mL of anhydrous THF in a 200 mL Schlenk flask and placed in an ice-water bath; 10 mL of cyclopentadienyl sodium (2.0 mol / L tetrahydrofuran solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then the reaction was carried out at room temperature for 3 h. The solvent was removed under vacuum to obtain intermediate II-6 2.06 g, with a yield of 85%.

[0086] (2) Under N2 atmosphere, in a 200 mL Schlenk flask, intermediate II-6 (2.06 g, 8.5 mmol) was dissolved in 100 mL of anhydrous diethyl ether and placed in an ice-water bath; 10.63 mL of n-butyllithium (1.6 mol / L hexane solution) was added dropwise to the above reaction solution at 0 °C (the solution gradually changed from colorless to dark red), and then reacted at room temperature for 3 h to obtain intermediate III-6 lithium salt solution; titanium tetrachloride (3.22 g, 17.00 mmol) was added to the above solution, and the mixture was slowly heated to room temperature and stirred for 12 h. The red suspension was dried under vacuum, and the residue was washed with toluene (30 mL × 3). The filtrate was collected, and the solvent was removed under vacuum to obtain intermediate III-6 with a yield of 75%.

[0087] (3) Under N2 atmosphere, 2,6-diisopropylthiophenol (2.48 g, 12.75 mmol) was dissolved in 100 mL of toluene in a 200 mL Schlenk flask. Its intermediate III-6 (3.89 g, 6.37 mmol) was added to the solution. After heating to 90 °C and reacting for 12 h, the orange-yellow suspension was filtered, the filtrate was collected, concentrated, and a small amount of n-hexane was added. The mixture was then placed at -18 °C to precipitate, yielding an orange-yellow solid powder, which is the complex Cat.6, with a yield of 65%.

[0088] 1 H NMR (400MHz, C6D6): δ9.12(d,J=2.5Hz,2H),8.08(ddd,J=7.8,2.3,1.2Hz,2H),7.92(t,J=1.5Hz,2H),7.71(dd,J=7.8,1.2Hz,2H),7.67 –7.58(m,4H),7.57(t,J=7.8Hz,2H),7.20–7.15(m,4H),7.15–7.08(m,2H),3.12–3.00(m,4H),1.29(dddd,J=5.9,3.7,1.9,0.9Hz,24H).

[0089] Comparative Example 1

[0090] Prepare a complex Cat.7 (structure as follows) with reference to the scheme in patent WO2004044018A2.

[0091]

[0092] Comparative Example 2

[0093] The complex Cat.8 (structure shown below) was prepared with reference to the literature "acromolecules, 1998, 31, 7588–7597".

[0094]

[0095] The following comparative application examples and application examples prepare ethylene copolymers using different complex catalysts, and the main test methods involved are:

[0096] Polymer molecular weight (M) w ) and molecular weight distribution (PDI, M w / M n The determination was performed by high-temperature gel permeation chromatography (PL-GPC220) with 1,2,4-trichlorobenzene as the mobile phase and polystyrene as the standard at 150℃. The standard concentration was 0.1 mg / mL, the solvent flow rate was 1.0 mL / min, and the standard parameters were K = 59.1, α = 0.69. The sample parameters were K = 14.1, α = 0.70.

[0097] Melting point of polymer (T) m ) and glass transition temperature (T g The determination was performed using a differential scanning calorimeter (METTLER, DSC-1). The procedure was as follows: 5.0-7.0 mg of polymer sample was taken, heated to 250 °C at a rate of 30 °C / min and held for 5 min to eliminate thermal history, then cooled to 0 °C at a rate of 10 °C / min and held for 3 min, and then heated to 250 °C again. The crystallization peak temperature was obtained using the cooling curve, and the melting point or glass transition temperature of the polymer was calculated from the curve of the second heating process.

[0098] The comonomer insertion rate of ethylene copolymers is obtained through 13 ¹³C NMR (Bruker ADVANCE Ⅲ 400M) determination. The polymer was dissolved in deuterated 1,2-o-dichlorobenzene at 130℃, with a concentration of approximately 100 mg / mL. Instrument parameters: pulse angle 30 degrees, full decoupling, pulse delay time 3 s, sample scans exceeding 3000. The obtained high-temperature... 13 After assigning the peaks in the C NMR spectrum, the sequence distribution of the copolymer and the comonomer insertion rate were obtained.

[0099]

Application Example 1

[0100] A 1L high-pressure reactor was continuously dried at 120℃ for 2 hours. Vacuum was then applied and the temperature gradually lowered to 25℃. Maintaining a slight positive pressure inside the reactor and a stirring speed of 500 rpm, 500 mL of Isopar E, 125 mL of 1-octene, and 0.91 mL of triisobutylaluminum (1.1 mol / L hexane solution) were added sequentially. The reaction temperature was then raised to 150℃, and the pressure inside the reactor (polymerization reaction pressure) was maintained at 1.0 MPa using ethylene gas. After the reaction system stabilized, 5.0 mL of the complex Cat.1 solution (0.001 mol / L hexane solution) and 1.0 mL of triphenylcarbazone (pentafluorophenyl)borate (0.006 mol / L) were injected into the reaction system using ethylene gas to initiate the polymerization reaction. After the polymerization reaction is completed, the ethylene gas supply is stopped, the reactor is cooled to 100°C, the unreacted ethylene is released, and the reaction liquid is discharged into 500 mL of ethanol. The polymerization product is washed three times with ethanol and then dried in a vacuum oven at 50°C to constant weight to obtain the ethylene copolymer.

[0101] [Application Example 2-6, Comparison with Application Example 1]

[0102] The ethylene copolymer was prepared according to the method in Application Example 1, with the only difference being that the reaction conditions were adjusted according to Table 1.

[0103] Table 1. Application Examples 1-6. Comparison of reaction conditions in Application Example 1

[0104]

[0105]

Application Example 7

[0106] A 250 mL stainless steel reactor equipped with a magnetic stirrer was dried at 130 °C for more than 2 hours. While still hot, a vacuum was drawn to below 3.0 mbar. Then, N2 was introduced and the reactor was purged three times with a vacuum-N2 system, followed by three purgings with a vacuum-ethylene gas system. Maintaining a slight positive pressure inside the reactor and a stirring speed of 500 rpm, 100 mL of a 2 mol / L norbornene / toluene solution and a certain amount of MAO (1.5 mol / L toluene solution) were added sequentially. The reaction temperature was then raised to 150 °C. The pressure inside the reactor (polymerization reaction pressure) was maintained at 0.4 MPa using ethylene gas. After the reaction system stabilized, 5.0 mL of the complex Cat.4 (0.001 mol / L toluene solution) was forced into the reaction system using ethylene gas to initiate the polymerization reaction. After the polymerization reaction is completed, the ethylene gas supply is stopped, the reactor is cooled to 100°C, the unreacted ethylene is released, and the reaction liquid is discharged into 500 mL of ethanol. The polymerization product is washed three times with ethanol and then dried in a vacuum oven at 50°C to constant weight to obtain the ethylene copolymer.

[0107] [Application Example 8-11, Comparison with Application Example 2]

[0108] The ethylene copolymer was prepared according to the method in Application Example 7, with the only difference being that the reaction conditions were adjusted according to Table 2.

[0109] Table 2, Application Examples 7-11, Comparison of Reaction Conditions in Application Example 2

[0110]

[0111] The characterization results of the ethylene copolymers obtained from the above application examples and comparative application examples are shown in Table 3:

[0112] Table 3. Results Characterization

[0113]

[0114] The results in Table 3 show that the dual-active-center metallocene complexes of the present invention have excellent high-temperature stability; they have good copolymerization ability for sterically hindered comonomers such as norbornene; and the molecular weight distribution of cyclic olefin copolymers can be adjusted over a wide range without significantly reducing catalytic activity.

[0115] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. An anthracene-bridged metallocene complex catalyst, characterized in that, It has the following structure expression: Formula I in: M is selected from titanium, zirconium, or hafnium; Cp is selected from cyclopentadienyl, methylcyclopentadienyl, ethylcyclopentadienyl, propylcyclopentadienyl, n-butylcyclopentadienyl, n-octylcyclopentadienyl, tert-butylcyclopentadienyl, trimethylsilylcyclopentadienyl, 1-tert-butyl-2-trimethylsilylcyclopentadienyl, 1,3-bis(trimethylsilyl)cyclopentadienyl, 1,2-dimethylcyclopentadienyl, 1,3-dimethylcyclopentadienyl, and 1,2-diethylcyclopentadienyl. 1,2-Diphenylcyclopentadienyl, cyclohexylcyclopentadienyl, 2,2′-biphenylcyclopentadienyl, diphenylcyclopentadienyl, indene, tetrahydroindene, 2-methylindene, 1,3-dimethylindene, 4,7-dimethylindene, benzo[a]indene, 2-methylbenzo[a]indene, 3-methylindene, 3-benzylindene, 3-phenylindene, 2-methyl-4-phenylindene, fluorenyl, octahydrofluorenyl, 2,7-di-tert-butylfluorenyl; Y is selected from O or S; R1 is selected from C1-C6 alkyl, C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 alkylaryl, and C6-C14 haloaryl. R2, R3, R4, and R5 may be the same as or different from each other, and each is independently selected from hydrogen, halogen, or the following groups: C1-C6 alkyl and C1-C6 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 aryloxy, and C4-C9 silyl. X is selected from halogens, C1-C20 alkyl groups, benzyl groups, and C2-C20 alkylamino groups.

2. The anthracene-bridged metallocene complex catalyst according to claim 1, characterized in that, R1 is selected from C1-C6 alkyl, C6-C14 alkylaryl, and C6-C14 haloaryl.

3. A method for preparing an anthracene-bridged metallocene complex catalyst as described in any one of claims 1-2, characterized in that, Includes the following steps: Under an anhydrous, oxygen-free, and inert atmosphere, compound II is dissolved in an ultra-dry organic solvent to obtain its solution or suspension; an alkyl metal reagent is added at low temperature, followed by the addition of metal salt MX4 or its ether complex to obtain compound III; The compound of formula IV was mixed with an alkyl metal reagent and then added to the reaction solution of compound III. After the reaction, the anthracene-bridged metallocene complex catalyst was obtained. Formula II Formula III Formula IV The definitions of R1, R2, R3, R4, R5, Cp, M, X, and Y are the same as those in any one of claims 1-2.

4. The method for preparing the anthracene-bridged metallocene complex catalyst according to claim 3, characterized in that, The alkyl metal reagent is one or more of methyllithium, n-butyllithium, n-hexyllithium, and diisopropylaminolithium.

5. A catalyst composition, characterized in that, Includes the anthracene-bridged aspheronite metal complex catalyst and co-catalyst as described in any one of claims 1-2; The cocatalyst is selected from at least one of alkylaluminum, aluminoxane, modified aluminoxane, or a mixture of at least one of them with a boron salt.

6. The catalyst composition according to claim 5, characterized in that, The alkylaluminum is one or more of trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum.

7. The catalyst composition according to claim 5, characterized in that, The aluminoxane is one or more of methylaluminoxane, ethylaluminoxane, and isobutylaluminoxane.

8. The catalyst composition according to claim 5, characterized in that, The boron salt is one or more of triphenylcarbazo(pentafluorophenyl)borate, N,N-dimethylphenylammonium tetra(pentafluorophenyl)borate, and tetra(pentafluorophenyl)borate-methyldi-(octadecyl)ammonium salt.

9. The catalyst composition according to any one of claims 5-8, characterized in that, The molar ratio of the co-catalyst to the anthracene-bridged aspheronite metal complex catalyst, based on the molar ratio of metal Al to metal M, is (10-6000):

1.

10. The catalyst composition according to claim 9, characterized in that, The molar ratio of the co-catalyst to the anthracene-bridged aspheronite metal complex catalyst, based on the molar ratio of metal Al to metal M, is (200-2000):

1.

11. The catalyst composition according to claim 9, characterized in that, The amount of boron salt used, in terms of the molar amount of element B, is 0-4 times that of metal M in the anthracene-bridged aspheronite metal complex catalyst.

12. A method for olefin polymerization, characterized in that, In the presence of the catalyst composition according to any one of claims 5-11, ethylene and α-olefins are subjected to a polymerization reaction.

13. The olefin polymerization method according to claim 12, characterized in that, The α-olefin is one or more of propylene, 1-butene, 1-hexene, 1-octene, norbornene, alkyl-substituted norbornene, alkoxy-substituted norbornene, vinyl-substituted norbornene, ester-substituted norbornene, phenyl-substituted norbornene, phenoxy-substituted norbornene, and amino-substituted norbornene.

14. The olefin polymerization method according to claim 12, characterized in that, The polymerization reaction temperature is 70-200℃, the pressure is 0.3-8MPa, and the reaction time is 0.5-200min.

Images