Preparation method of pyridylamino binuclear metal titanium zirconium hafnium catalyst and application of catalyst in olefin polymerization

Abstract

According to the invention, rigid anthracene is introduced as a framework of bridged binuclear metal, a pyridylamino binuclear metal titanium-zirconium-hafnium catalyst is constructed, and the molecular weight of the obtained polymer can be effectively improved through the synergistic effect between the binuclear metal and the steric hindrance and electronic effect on the catalyst structure; the polyolefin elastomer (POE), the isotatic polypropylene (iPP) and the propenyl elastomer (PBE) are efficiently synthesized. The pyridylamino binuclear metal titanium-zirconium-hafnium catalyst has the advantages that synthesis is simple, raw materials are easy to obtain, and the product yield is high. In copolymerization of ethylene and alpha-olefin, the catalyst shows excellent activity (5.75 * 10 < 7 > g (POE). Mol <-1 > (M). H <-1 >) and alpha-olefin selectivity (the insertion rate reaches 16.2 mol%), and the polyolefin elastomer POE with excellent performance is prepared. In propylene polymerization, the regularity of the polypropylene chain segment can be effectively regulated and controlled by adjusting the steric hindrance and the electronic effect of the catalyst, and the regularity gt is prepared with high activity (3.84 * 10 < 7 > g (PP). Mol <-1 > (M). H <-1 >); and the polypropylene material with high stereoregularity is prepared from 80 mmmm% of polypropylene with high stereoregularity. In copolymerization of ethylene and propylene, an elastomer material which takes propylene as a main material, can regulate and control the ethylene content to be 5-50 wt% and has unique characteristics of a propylene-ethylene semi-crystalline copolymer is prepared. In addition, the pyridylamino binuclear metal titanium-zirconium-hafnium catalyst also shows excellent high-temperature resistance (higher than 160 DEG C), is suitable for high-temperature solution polymerization, and can be used for preparing high-performance polyolefin elastomers. Therefore, the invention has original innovation, and provides a new direction for the development of the field of polyolefin materials.

Description

Technical Field

[0001] This invention relates to the preparation of metal catalysts for olefin coordination polymerization and their application in the field of olefin polymerization. Background Technology

[0002] In recent years, the production capacity and application range of polyolefin materials have continued to grow. With the continuous development of society, the demand for high-performance polyolefins is constantly increasing. Among them, polyolefin elastomers (POE) are random copolymers formed by copolymerizing ethylene with 1-octene, 1-hexene, or 1-butene. When the content of higher α-olefins in the copolymer is high (usually exceeding 20 wt%), it is a semi-crystalline, low-modulus polymer with excellent mechanical and elastic properties, and has attracted much attention in the automotive industry and photovoltaic film field.

[0003] Propylene-based elastomers (PBE) are a novel type of ethylene / α-olefin copolymer product, primarily composed of propylene and secondarily of ethylene. They possess unique characteristics of a propylene-ethylene semi-crystalline copolymer, with polypropylene crystalline segments as the hard segments and randomly arranged ethylene and propylene segments as the soft segments. This is achieved by ExxonMobil Chemicals using its special discrete metallocene catalyst technology, Exxpol. TM This polymer, obtained through solution polymerization, allows for strict control of its properties. Unlike ethylene / octene copolymers (POE) and ethylene-propylene rubber (EPR), this polymer is a low-ethylene thermoplastic elastomer. It can be used as a toughening modifier for olefin polymers or directly in the production of finished products. As a modifier, depending on the amount added, it can improve the properties of polymers, giving them high elasticity, high transparency, high puncture resistance, good high and low temperature performance, and mechanical properties. It is widely used in the production of plastic products and has a very broad application prospect. It should be noted that POE and PBE can share production lines and can be flexibly adjusted according to market demand. In some downstream applications, PBE has a similar application structure to POE and POP, so the low-priced PBE has an advantage in competing with POE.

[0004] Generally, polyolefin elastomers are synthesized via solution polymerization, a technique that allows for more efficient product synthesis and better control over the polymer's microstructure, resulting in materials with superior performance. Solution polymerization is best performed at high temperatures (typically above 120°C) to prevent polymer precipitation during polymerization. Furthermore, high-temperature solution polymerization reduces viscosity, increases product yield, and thus lowers costs. However, these limitations pose significant challenges to catalysts used in olefin polymerization, as the activity of polyolefin catalysts and the molecular weight (Mws) of the resulting polymer typically decrease with increasing polymerization temperature. Therefore, developing homogeneous metal catalysts with superior catalytic performance at high temperatures is essential.

[0005] To address this, researchers worldwide have designed and synthesized metallocene and constrained geometry (CGC) catalysts, which were successfully used in the commercial production of polyolefin elastomers (POE) starting in the early 1990s (Chem. Rev. 1998, 98, 2587-2598). Subsequent development of bridging metallocene catalysts has also been applied to the preparation of propylene-based elastomers (Polym Eng Sci. 2023, 1-10). In addition, many non-metallocene transition metal catalysts have gradually been developed. Among them, pyridine-amine metal catalysts were initially screened by Dow Chemical using high-throughput methods (Angew. Chem. Int. Ed. 2006, 45, 3278-3283). The resulting metal catalysts exhibited high activity in the polymerization of ethylene and α-olefins and could control the α-olefin content, and could achieve highly isomeric polypropylene in propylene polymerization. However, these pyridine-amine metal catalysts performed poorly in high-temperature resistance and the preparation of ultra-high molecular weight polymers.

[0006] Subsequently, Marks et al. introduced a naphthyl framework to construct a pyridineamine-based binuclear hafnium metal catalyst. The binuclear synergistic effect effectively improved the polymer molecular weight and monomer insertion rate (ACS Catal. 2015, 5, 5272-5282). In propylene polymerization, steric hindrance and intramolecular intermetallic chain transfer can cause 2,1-insertion of monomers, leading to regiodefects and reducing the stereoregularity of the polymer. Although the bispyridineamine ligand can provide good copolymerization performance for the metal catalyst, it does not significantly improve the catalyst's high-temperature resistance; the optimal polymerization performance is at 80℃ (Macromolecules 2018, 51, 2401-2410). Liu et al. prepared a binuclear pyridineamine-based metal catalyst that maintained high activity and high α-olefin insertion rate under high-temperature conditions. In propylene polymerization, the binuclear synergistic effect effectively improved the polymer molecular weight, producing catalysts with molecular weights greater than 10. 6 g mol -1 Ultra-high molecular weight random polypropylene (Polym.Chem.2024,15,4141).

[0007] In this invention, rigid anthracene is introduced as a bridging binuclear metal framework to construct a pyridine-amine-based binuclear metal titanium-zirconium-hafnium catalyst. Through the synergistic effect of the binuclear metals and the steric hindrance and electronic effects of the catalyst structure, the molecular weight of the resulting polymer can be effectively increased, leading to the efficient synthesis of polyolefin elastomers (POE), high isotactic polypropylene (iPP), and propylene-based elastomers (PBE). The pyridine-amine-based binuclear metal titanium-zirconium-hafnium catalyst reported in this invention has the advantages of simple synthesis, readily available raw materials, and high product yield. In the copolymerization of ethylene and α-olefins, the catalyst exhibits excellent activity (5.75 × 10⁻⁶). 7 g(POE)·mol -1(M)·h -1 High molecular weight polyolefin elastomer POE (polymer molecular weight Mw up to 925 kg·mol⁻¹) was prepared by selectively processing α-olefins (insertion rate up to 16.2 mol%). -1 In propylene polymerization, the regularity of polypropylene segments can be effectively controlled by adjusting the steric hindrance and electronic effects of the catalyst, achieving high activity (3.83 × 10⁻⁶). 7 g(PP)·mol -1 (M)·h -1 Prepare polypropylene materials with high stereoregularity (>80 mm). Prepare propylene-based elastomer materials with propylene as the main component and adjustable ethylene content (5 wt%–20 wt%) through propylene-ethylene copolymerization.

[0008] Furthermore, the pyridine-amine-based binuclear metal titanium-zirconium-hafnium catalyst reported in this invention also exhibits excellent high-temperature resistance (greater than 160°C), making it suitable for high-temperature solution polymerization and capable of preparing high-performance polyolefin elastomers. Compared to similar pyridine-amine-based mononuclear metal catalysts, such as the Ar-Hf1 catalyst (2,6- i Pr2-phenyl-N-(2- i Pr-phenyl)[6-(naphthalenyl)-2-pyridyl]HfMe2 (Angew. Chem. Int. Ed. 2006, 45, 3278-3283) and Me-Hf1 catalyst (2,6- i The pyridine-amine-based binuclear titanium-zirconium-hafnium catalyst reported in this invention (Pr2-phenyl-N-methyl[6-(naphthalenyl)-2-pyridyl]HfMe2)(Polym. Chem. 2024, 15, 4141) exhibits superior catalytic performance. Therefore, this invention is original and innovative, providing a new direction for the development of polyolefin materials. Summary of the Invention

[0009] The purpose of this invention is to provide a method for preparing a pyridine-amine-based binuclear titanium-zirconium-hafnium catalyst and its application in olefin polymerization to prepare polyolefin elastomers (POE), isotactic polypropylene (iPP), and propylene-based elastomers (PBE).

[0010] This invention provides a pyridineamine-based binuclear metallic titanium-zirconium-hafnium catalyst of formula (I):

[0011]

[0012] Where M is selected from titanium, zirconium, and hafnium; R 1 -R 4 R 1’ -R 4’Each is independently selected from hydrogen, C1-C 20 Alkyl, C1-C 20 Alkoxy, C6-C 20 Aryl, C6-C 20 Aryl alkyl groups, or phenyl groups, form a ring of 4-20 carbon atoms with surrounding substituents by any two adjacent carbon atoms; R 1’ -R 4’ respectively with R 1 -R 4 Same or different; R 5 R 5’ Each is independently selected from C1-C6 straight-chain alkyl, tert-butyl, phenyl, benzyl, or isopropylphenyl.

[0013] Preferably, the pyridineamine-based binuclear metallic titanium-zirconium-hafnium catalyst of the present invention is selected from any one of the metal catalysts shown in (II):

[0014]

[0015] This invention provides a method for preparing the above-mentioned pyridineamine-based binuclear metallic titanium-zirconium-hafnium catalyst, comprising the following steps:

[0016] Under a nitrogen atmosphere, the metal salt was dissolved in 10-80 mL of anhydrous solvent, and 4.0-5.0 molar equivalents of methyl magnesium bromide were added. The reaction was carried out at -40°C to -20°C for 2-6 hours. Then, 0.5 molar equivalents of pyridineamine ligand were added, and the reaction was carried out at -40°C to -20°C for 2-6 hours. The reaction was then brought to room temperature for 2-12 hours. After the reaction was completed, the solvent was removed under reduced pressure, and the product was extracted with a good solvent to obtain the target pyridineamine binuclear titanium zirconium hafnium catalyst.

[0017] In the above preparation method, the anhydrous solvent is selected from toluene, n-hexane, xylene, and benzene; the good solvent is selected from n-hexane, toluene, pentane, heptane, and cyclohexane.

[0018] In the above preparation method, the metal salt is selected from one of TiCl4, ZrCl4, and HfCl4.

[0019] This invention also provides the application of the above-mentioned pyridine-amine binuclear titanium-zirconium-hafnium catalyst in the catalytic polymerization of olefins.

[0020] In the above applications, the olefin monomer is one or more of ethylene, propylene, 1-butene, styrene, 1-hexene, 1-octene, and 1-decene.

[0021] In the above polymerization reaction, the pyridineamine-based binuclear titanium-zirconium-hafnium catalyst requires a co-catalyst for catalysis. The co-catalyst is one or more of tripentafluorophenylboron, triphenylcarbium tetra(pentafluorophenyl)borate, aluminoxane, alkylaluminum, and alkylaluminum chloride. The aluminoxane is methylaluminoxane, ethylaluminoxane, or isobutylaluminoxane; the alkylaluminum is trimethylaluminum, triethylaluminum, triisobutylaluminum, or tri-n-hexylaluminum; and the alkylaluminum chloride is diethylaluminum chloride, sesqui-diethylaluminum chloride, or ethylaluminum dichloride.

[0022] In the above polymerization reaction, the polymerization temperature is 0-200℃, the polymerization pressure is 0.1-5MPa, the molar ratio of the catalyst to the co-catalyst is 1:(1-5000), the reaction time is 0.1-48h, and the solvent used for polymerization is one or more of n-hexane, n-heptane, n-pentane, and toluene.

[0023] This invention provides the preparation of a pyridine-amine-based binuclear titanium-zirconium-hafnium catalyst, and its application in catalyzing the polymerization of olefins to prepare polyolefin elastomers (POE), isotactic polypropylene (iPP), and propylene-based elastomers (PBE). The pyridine-amine-based binuclear titanium-zirconium-hafnium catalyst reported in this invention has the advantages of simple synthesis, readily available raw materials, and high product yield. It exhibits high catalytic activity in the copolymerization of ethylene and α-olefins (the highest activity reaching 5.75 × 10⁻⁶). 7 ·mol -1 ·h -1 ) and better copolymerization performance (1-octene insertion rate can reach 16.2 mol%); in propylene polymerization, the regularity of polypropylene segments can be effectively controlled by regulating the steric hindrance of different substituents, with high activity (3.84 × 10 7 g(PP)·mol -1 (M)·h -1 This invention relates to the preparation of high stereoregularity polypropylene materials with a regularity >80 mm. In the copolymerization of propylene and ethylene, propylene-based elastomer materials with adjustable ethylene content (5 wt%–20 wt%) are prepared. Especially in high-temperature solution polymerization, the catalyst maintains excellent polymerization performance, enabling the preparation of high-quality, high-performance polyolefin materials. The pyridine-amine-based binuclear titanium-zirconium-hafnium catalyst provided by this invention is original and innovative, and can promote the development of my country's high-end polyolefin chemical industry. Attached Figure Description

[0024] Figure 1 This is the 1H NMR spectrum of catalyst C2.

[0025] Figure 2 The image shows the carbon NMR spectrum of a polyolefin elastomer with a 1-octene insertion rate of 6.5 mol%.

[0026] Figure 3The image shows the carbon NMR spectrum of a polyolefin elastomer with a 1-octene insertion rate of 16.2 mol%.

[0027] Figure 4 The carbon NMR spectrum of polypropylene with a regularity of 82 mm is shown.

[0028] Figure 5 The image shows the DSC diagram of a propylene-based elastomer with an ethylene content of 10 wt%. Detailed Implementation

[0029] The present invention is further illustrated by examples, but is not limited thereto. These examples will enable those skilled in the art to gain a more comprehensive understanding of the invention.

[0030] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0031] In this invention, the pyridine amino ligands C1-L, C2-L, and C4-L are shown in (III), and the corresponding synthetic methods are given in Examples 1, 2, and 3. The mononuclear metal catalyst used for the control experiments is shown in (IV), the Ar-Hf1 catalyst (2,6- i Pr2-phenyl-N-(2- i Pr-phenyl)[6-(naphthalenyl)-2-pyridyl]HfMe2 (Angew. Chem. Int. Ed. 2006, 45, 3278-3283) and Me-Hf1 catalyst (2,6- i Pr2-phenyl-N-methyl[6-(naphthalenyl)-2-pyridyl]HfMe2)(Polym.Chem.2024,15,4141) was synthesized according to the method described in the literature.

[0032]

[0033] The present invention is described below with reference to specific embodiments.

[0034] Example 1: Preparation of Catalyst C1

[0035] Weigh out 1,8-diborane anthracene (4 g / 10 mmol), 4-bromo-2,6-dimethylaniline (6.00 g / 30 mmol), anhydrous sodium carbonate (5.3 g / 50 mmol), and tetraphenylphosphine palladium (1 g, 0.95 mmol, 5.0 mol%), introduce tetrahydrofuran and deoxygenated water, and reflux the mixture at 80 °C for 48 h. After the reaction is complete, evaporate the tetrahydrofuran solution to dryness, extract with dichloromethane and water, dry the organic phase with anhydrous magnesium sulfate, filter, evaporate the solvent to dryness, and obtain a blackish-yellow oily substance. Add a small amount of methanol and sonicate to obtain a suspension, filter, wash with a small amount of methanol, and filter again to obtain 2.78 g of yellowish-green powder 1,8-bis(2,6-dimethylaniline)anthracene, yield 67%.

[0036] 1,8-bis(2,6-dimethylaniline)anthracene (1.25 g / 3 mmol) and 6-naphthyl-2-pyridinaldehyde (1.53 g / 6.6 mmol) were weighed into a round-bottom flask, 20 mL of anhydrous ethanol was added, and 2 mg of p-toluenesulfonic acid was added as a catalyst. The mixture was refluxed under a nitrogen atmosphere for 12 hours to obtain a yellow suspension. The suspension was filtered and washed with a small amount of ice-cold ethanol to obtain 2.13 g of yellow-green ligand powder Cl-L, with a yield of 84%. 1 H NMR (400MHz, CDCl3) δ9.00(s,1H),8.60(d,J=8.5Hz,2H),8.65(s,2H),8.48(s,1H),8.16(d,J=7.3Hz,2H),8.03(d,J=8.2Hz,4H),7.97–7.92(m,4H ),7.89–7.86(m,4H),7.82–7.78(m,4H),7.75(d,J=7.7Hz,2H),7.65(d,J =7.1Hz,2H),7.55–7.45(m,4H),7.24(d,J=7.4Hz,2H),2.30(s,12H)ppm. 13 C NMR (100MHz, CDCl3) δ157.73,157.60,156.13,145.83,139.13,136.30,134.95,134.70,133.63,132.91,132.72,132.21,130.39,129.52, 129.03,128.86,128.84,128.76,128.39,126.79,126.76,126.58,126.24,126.11,125.55,123.77,123.54,122.32,18.72ppm.Anal.Calcd for C 62 H 46N4:C,87.91;H,5.47;N,6.61.Found:C,87.95;H,5.44;N,6.59.HRMS Calcd.for[M+H + 848.0860, Found: 848.0859.

[0037] Hafnium tetrachloride (0.352 g, 1.1 mmol) was weighed and added to 10 mL of anhydrous toluene. The mixture was then slowly added to 1.6 mL / 4.8 mmol methyl magnesium bromide solution (3 M) at -40 °C (acetonitrile-liquid nitrogen cold bath), and stirred for 2 hours. Then, ligand C1-L (0.423 g / 0.5 mmol) was added, and the reaction was continued at -40 °C in the dark for 2 hours, followed by a 5-hour reaction at room temperature. After the reaction was complete, the solvent was removed, and the product was extracted with toluene and filtered to obtain 0.89 g of the product, with a yield of 69%. 1 H NMR (400MHz, CDCl3): δ9.56 (s, 1H), 8.98 (d, J = 8.5Hz, 2H), 8.60 (s, 2H), 8.44 (s, 1H), 8 .26(d,J=7.3Hz,2H),8.12(d,J=8.2Hz,4H),7.99–7.96(m,4H),7.91–7.88(m,4H),7.8 0–7.76(m,4H),7.73(d,J=7.7Hz,2H),7.65(d,J=7.1Hz,2H),7.55–7.45(m,4H),7.35( m,2H),7.21(d,J=7.4Hz,2H),4.9(q,2H),2.30(s,12H),0.86(s,6H),0.80(s,6H)ppm. 13 C NMR (100MHz, CDCl3): δ151.21,143.45,142.93,142.72,140.85,138.49,137.62,135.96,135.38,133.63,130.42,130.26,129.38,129.08,129. 03,128.92,128.15,127.63,127.59,127.45,126.79,126.58,126.42,1 26.11,125.30,123.54,120.87,57.94,21.96,18.58,18.14.Anal.Calcd for C 68 H 62 Hf2N4:C,63.20;H,4.84;N,4.34.Found:C,63.28;H,4.76;N,4.44.

[0038] Example 2: Preparation of catalyst C2

[0039] Weigh out 1,8-diborane anthracene (4 g / 10 mmol), 4-bromo-2,6-diisopropylaniline (7.68 g / 30 mmol), anhydrous sodium carbonate (5.3 g / 50 mmol), and tetraphenylphosphine palladium (1 g, 0.95 mmol, 5.0 mol%), introduce tetrahydrofuran and deoxygenated water, and reflux the mixture at 80 °C for 48 h. After the reaction is complete, evaporate the tetrahydrofuran solution to dryness, extract with dichloromethane and water, dry the organic phase with anhydrous magnesium sulfate, filter, evaporate the solvent to dryness, and obtain a blackish-yellow oily substance. Add a small amount of methanol and sonicate to obtain a suspension, filter, wash with a small amount of methanol, and obtain 2.9 g of yellowish-green powder 1,8-bis(2,6-diisopropylaniline)anthracene, yield 54%.

[0040] 1,8-bis(2,6-diisopropylanilino)anthracene (1.58 g / 3 mmol) and 6-naphthyl-2-pyridinaldehyde (1.53 g / 6.6 mmol) were weighed into a round-bottom flask, 20 mL of anhydrous ethanol was added, and 2 mg of p-toluenesulfonic acid was added as a catalyst. The mixture was refluxed under a nitrogen atmosphere for 12 hours to obtain a yellow suspension. The suspension was filtered and washed with a small amount of ice-cold ethanol to obtain 2.35 g of yellow-green ligand powder C2-L, with a yield of 82%. 1 H NMR (400MHz, CDCl3): δ9.26(s,1H),8.54(s,1H),8.41(s,2H),8.26(d,J=7.6Hz,2H)8.11(d,J=8.4Hz,2H),8.00(d,J=8.4Hz,2H),7.88( t,J=8.2,7.8Hz,4H),7.68-7.60(m,4H),7.54–7.48(m,7H),7.47–7.36(m,7H),7.21(s,2H),2.98(hetp,4H),1.02(d,J=8.6Hz,24H)ppm. 13 C NMR (100MHz, CDCl3): δ163.17,159.09,154.71,147.83,141.40,138.12,137.32,137.04,136.44,134.20,132.25,131.29,130.31,129.31,128 .56,127.89,127.42,127.21,126.71,126.64,126.52,126.14,125.72,125.54,125.49,125.07,124.13,119.66,28.13,23.58ppm.Anal.Calcd for C 70 H 62N4:C,87.64;H,6.51;N,5.84.Found:C,87.57;H,6.53;N,5.79.HRMS Calcd.for[M+H + ]960.3018,found960.3020.

[0041] Hafnium tetrachloride (0.352 g, 1.1 mmol) was weighed and added to 10 mL of anhydrous toluene. The mixture was then slowly added to 1.6 mL / 4.8 mmol methyl magnesium bromide solution (3 M) at -40 °C (acetonitrile-liquid nitrogen cold bath), and stirred for 2 hours. Then, ligand C2-L (0.480 g / 0.5 mmol) was added, and the reaction was carried out at -40 °C in the dark for 2 hours. The reaction was then continued at room temperature for 5 hours. After the reaction was complete, the solvent was removed, and the product was extracted with toluene and filtered to obtain 0.884 g of the product, with a yield of 63%. 1 H NMR (400MHz, C6D6): δ9.89(s,1H),8.60(d,J=8.5Hz,2H),8.47(s,2H),8.50(s,1H),8.20(d,J=8.4Hz,2 H),8.16(d,J=8.5Hz,2H),7.99(d,J=8.1Hz,2H),7.91(d,J=8.2Hz,2H),7.82–7.78(m,4H),7.72–7.68(m ,4H),7.58–7.50(t,J=8.1Hz,J=8.2Hz,4H),7.56–7.52(m,4H),4.9(q,2H),4.35(hetp,2H),3.12(hetp, 2H),1.56(d,J=7.7Hz,12H)1.54(d,J=8.4Hz,6H),1.35(d,J=7.4Hz,12H),0.85(s,6H),0.67(s,6H)ppm. 13 C NMR (100MHz, C6D6): δ147.81,145.77,143.45,142.72,140.32,139.22,136 .41,136.36,134.89,133.95,131.37,130.78,129.70,129.49,129.05,128 .87,127.57,127.24,126.80,126.66,125.92,125.73,125.57,125.52,124 .97,123.65,121.65,57.48,29.48,23.43,19.98,17.42,17.37.Anal.Calcd for C 76 H 78Hf2N4:C,65.00;H,5.60;N,3.99. Found:C,64.84;H 5.76;N,5.62.

[0042] Example 3: Preparation of catalyst C3

[0043] Zirconium tetrachloride (0.256 g, 1.1 mmol) was weighed and added to 10 mL of dry toluene. The mixture was then slowly added to 1.6 mL / 4.8 mmol methyl magnesium bromide solution (3 M) at -40 °C (acetonitrile-liquid nitrogen bath), and stirred for 2 hours. Then, ligand C2-L (0.480 g / 0.5 mmol) was added, and the mixture was stirred in the dark at -40 °C for 2 hours. The reaction was then continued at room temperature for 5 hours. After the reaction was complete, the solvent was removed, and the mixture was extracted with toluene. The extract was filtered to give 0.651 g of the product, with a yield of 53%. 1 H NMR (400MHz, C6D6): δ9.82(s,1H),8.57(d,J=8.5Hz,2H),8.47(s,2H),8.40(s,1H),8.16(d,J=7.4H z,2H),8.11(d,J=8.6Hz,2H),7.88(d,J=7.4Hz,2H),7.84(d,J=6.2Hz,2H),7.83–7.79(m,4H),7.70 –7.68(m,4H),7.64–7.58(m,4H),7.58–7.54(m,4H),4.75(q,2H),4.33(hetp,2H),3.10(hetp,2H), 1.53(d,J=8.7Hz,12H)1.54(d,J=7.4Hz,6H),1.32(d,J=7.2Hz,12H),0.88(s,6H),0.67(s,6H)ppm. 13 C NMR (100MHz, C6D6): δ147.59,145.90,143.20,142.28,140.13,138.32,13 6.45,136.41,134.89,133.95,131.37,130.78,129.68,129.22,129.11,12 8.87,127.57,127.24,126.80,126.66,125.92,125.73,125.50,125.48,1 25.21,123.65,121.66,57.45,29.48,23.43,19.64,18.58ppm.Anal.Calcd for C 76 H 78 Zr2N4:C,74.22;H,6.39;N,4.56.Found:C,74.01;H,6.48;N,4.68.

[0044] Example 4: Preparation of Catalyst C4

[0045] Weigh the corresponding C2-L ligand (0.96 g / 1 mmol) into a flask, purge with nitrogen three times under vacuum, add 20 mL of anhydrous diethyl ether, and slowly add 3 equivalents of tert-butyllithium (3 mL / 1 M in Hex) under a nitrogen atmosphere. Stir at room temperature for 2 hours. Quench with 1 M NH4Cl aqueous solution, extract with ethyl acetate, remove the upper organic layer, dry, and remove the solvent under low pressure to give 0.84 g of yellow solid product C4-L, yield 78%. 1 HNMR (400MHz, CDCl3): δ9.21 (s, 1H), 8.91 (d, J = 7.4Hz, 2H), 8.22 (s, 1H), 8.03–7.98 (m, 2H ),7.88–7.83(m,4H),7.82–7.78(m,4H),7.75–7.69(m,4H),7.65–7.59(m,4H),7.51–7.47( m,4H),7.32(d,J=8.0Hz,2H),7.24(d,J=8.0Hz,2H),7.21(dd,J=8.3,1.3Hz,2H),7.02(d,J =9.1Hz,2H),4.98–4.92(m,2H),2.98(hetp,4H),1.02(d,J=8.6Hz,24H),1.07(s,18H)ppm. 13 C NMR (100MHz, CDCl3): δ159.24,155.40,140.52,139.28,137.97,136.94,134.88,134.69,133.63,132.58,131.91,130.66,129.51,129.03,128 .86,128.76,128.39,126.79,126.56,126.27,126.11,125.65,124.29, 123.54,123.26,122.14,70.10,35.14,30.48,26.77,23.48.Anal.Calcd for C78H82N4:C,87.11;H,7.69;N,5.21.Found:C,87.54;H,7.46;N,5.41.HRMS Calcd.for[M + H + ]1076.5500,found1076.5549.

[0046] Hafnium tetrachloride (0.352 g, 1.1 mmol) was weighed and added to 10 mL of dry toluene. The mixture was then slowly added to 1.6 mL / 4.8 mmol methyl magnesium bromide solution (3 M) at -40 °C (acetonitrile-liquid nitrogen bath), and stirred for 2 hours. Then, ligand C2-L (0.308 g / 0.5 mmol) was added, and the mixture was stirred in the dark at -40 °C for two hours. After returning to room temperature, the reaction was continued for 5 hours. After the reaction was complete, the solvent was removed, and the mixture was extracted with toluene. The extract was filtered to give 0.863 g of the product, with a yield of 58%. 1 H NMR (400MHz, C6D6): δ9.33(s,1H),8.82–8.77(m,2H),8.52–8.40(m,2H),8.37(s,1H),7.88–7.84 (m,4H),7.82(d,J=8.0Hz,2H),7.72–7.64(m,4H),7.52–7.44(m,4H),7.41–7.38(m,2H),7.25(dd, J=7.7Hz,2H),4.27(t,J=1.4Hz,2H),3.56(hetp,2H),3.22(hetp,2H),1.53(d,J=8.7Hz,12H)1.44 (d,J=7.4Hz,6H),1.32(d,J=7.2Hz,12H),1.07(s,9H),1.05(s,9H),0.83(s,6H),0.68(s,6H)ppm. 13 C NMR (100MHz, C6D6): δ149.58,144.36,142.36,141.31,139.81,139.70,139.26,139.01,138. 81,137.86,137.20,136.44,136.36,134.98,134.96,133.98,131.70,130.81,129.49,129.05 ,128.90,128.87,128.20,127.67,126.81,126.68,126.66,125.92,125.43,125.36,124.66, 124.19,123.65,121.65,71.99,41.29,29.54,25.92,23.47,17.49,17.47,17.44.Anal.Calcd for C 82 H 90 Hf2N4:C,66.16;H,6.09;N,3.76.Found:C,66.02;H,6.19;N,3.80.

[0047] Example 5: C1-catalyzed propylene polymerization

[0048] A 350 mL glass reactor equipped with a magnetic induction chamber was used for the polymerization reaction. 2 μmol of catalyst C1, 2.2 μmol of triphenylcarbontetra(pentafluorophenyl)borate, and 100 μmol of methylaluminoxane were weighed in a glove box. The glass reactor was connected to the polymerization line. Once the temperature reached 80 °C, 50 mL of toluene was added. Propylene gas was continuously introduced during polymerization to maintain a reaction pressure of 5 atm. After reacting for 2 minutes, 30 mL of ethanol was added to the reactor under a nitrogen atmosphere. After cooling, the reaction solution was poured into a large amount of ethanol to settle, filtered, and dried to obtain the final polymer. Polymerization activity: 29424 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =625kg·mol -1 , M w / M n =2.1, 80mmmm%.

[0049] Example 6: C1-catalyzed propylene polymerization

[0050] The polymerization process and conditions were the same as in Example 5, with a polymerization temperature of 120°C. Polymerization activity: 38304 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =584 kg·mol -1 , M w / M n =2.2, 80mmmm%.

[0051] Example 7: C1-catalyzed propylene polymerization

[0052] A 100 mL steel reactor equipped with a magnetic inductor was used for the polymerization reaction. 50 mL of toluene was injected using a syringe, and the reactor contents were heated to 160 °C. The reactor was saturated with propylene gas at 1 MPa. In a glove box, 2 μmol of catalyst C1, 100 μmol of methylaluminoxane, and 2.2 μmol of triphenylcarbontetra(pentafluorophenyl)borate were added, dissolved in toluene, and transferred to a catalyst storage tube using a syringe. Nitrogen gas (above 1 MPa) was introduced into the reactor, and the reaction pressure was maintained at 1 MPa by continuously introducing propylene gas during polymerization. After the set reaction time of 2 minutes, 2 mL of ethanol was introduced into the reactor under nitrogen gas (above 1 MPa). The reactor was cooled and vented. The contents of the reactor were poured into a large amount of ethanol, causing polymer precipitation. The polymer was obtained by filtration, washed with a small amount of ethanol, and finally vacuum dried overnight and weighed. Polymerization activity: 38400 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w = 443 kg·mol -1 , Mw / M n =2.4, 78mmmm%.

[0053] Example 8: C1-catalyzed propylene polymerization

[0054] The polymerization process and conditions were the same as in Example 7, with a polymerization temperature of 180°C. Polymerization activity: 30700 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =384 kg·mol -1 , M w / M n =2.4, 78mmmm%.

[0055] Example 9: C1-catalyzed propylene polymerization

[0056] A 350 mL glass reactor equipped with a magnetic induction chamber was used for the polymerization reaction. 2 μmol of catalyst C1, 2.2 μmol of trifluorophenylborone, and 100 μmol of methylaluminoxane were weighed in a glove box. The glass reactor was connected to the polymerization pipeline. Once the temperature reached 120 °C, 50 mL of toluene was added. Propylene gas was continuously introduced during polymerization to maintain a reaction pressure of 5 atm. After reacting for 2 minutes, 30 mL of ethanol was added to the reactor under a nitrogen atmosphere. After cooling, the reaction solution was poured into a large amount of ethanol to settle, filtered, and dried to obtain the final polymer. Polymerization activity: 8840 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =241 kg·mol -1 , M w / M n =1.9, 80mmmm%.

[0057] Example 10: C1-catalyzed propylene polymerization

[0058] A 350 mL glass reactor equipped with a magnetic induction chamber was used for the polymerization reaction. 2 μmol of catalyst C1 and 1000 μmol of methylaluminoxane were weighed in a glove box. The glass reactor was connected to the polymerization pipeline. Once the temperature reached 120 °C, 50 mL of toluene was added. Propylene gas was continuously introduced during polymerization to maintain a reaction pressure of 5 atm. After reacting for 2 minutes, 30 mL of ethanol was added to the reactor under a nitrogen atmosphere. After cooling, the reaction solution was poured into a large amount of ethanol to settle, filtered, and dried to obtain the final polymer. Polymerization activity: 739 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =190kg·mol -1 , M w / Mn =2.6, 81mmmm%.

[0059] Example 11: C2-catalyzed propylene polymerization

[0060] The polymerization process and reaction conditions were the same as in Example 8, and the catalyst used was C2. Polymerization activity: 17850 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =365kg·mol -1 , M w / M n =2.0, 88mmmm%.

[0061] Example 12: C3-catalyzed propylene polymerization

[0062] The polymerization process and reaction conditions were the same as in Example 8, and the catalyst used was C3. Polymerization activity: 14522 kg·mol⁻¹ -1 (Zr)·h -1 Polymer M w =334 kg·mol -1 , M w / M n =2.1, 85mmmm%.

[0063] Example 13: C4-catalyzed propylene polymerization

[0064] The polymerization process and reaction conditions were the same as in Example 8, and the catalyst used was C4. Polymerization activity: 13214 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =1010 kg·mol -1 , M w / M n =2.1, 90mmmm%.

[0065] Example 14: Me-Hf1-catalyzed propylene polymerization

[0066] The polymerization process and reaction conditions were the same as in Example 8, and the catalyst used was Me-Hf1. Polymerization activity: 22450 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =170kg·mol -1 , M w / M n =2.1, 75mmmm%.

[0067] Example 15: Ar-Hf1-catalyzed propylene polymerization

[0068] The polymerization process and reaction conditions were the same as in Example 8, and the catalyst used was Ar-Hf1. Polymerization activity: 28750 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =520kg·mol -1 , M w / M n =1.9, 95mmmm%.

[0069] Example 16: C2-catalyzed copolymerization of ethylene / 1-octene

[0070] A 350 mL glass reactor equipped with a magnetic induction valve was used for the polymerization reaction. 2 μmol of catalyst C2, 2.2 μmol of triphenylcarbontetra(pentafluorophenyl)borate, and 100 μmol of methylaluminoxane were weighed in a glove box. The glass reactor was then connected to the polymerization line. Once the temperature reached 120 °C, 26.6 mL of toluene and 23.4 mL of 1-octene were added. Ethylene gas was continuously introduced during polymerization to maintain a reaction pressure of 5 atm. After reacting for 2 minutes, 30 mL of ethanol was added to the reactor under a nitrogen atmosphere. After cooling, the reaction solution was poured into a large volume of ethanol to settle, filtered, and dried to obtain the final polymer. Polymerization activity: 46800 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =1710 kg·mol -1 , M w / M n =2.2, the copolymer contains 16.2 mol% 1-octene.

[0071] Example 17: C2-catalyzed copolymerization of ethylene / 1-octene

[0072] The polymerization process and reaction conditions were the same as in Example 16, using 34.4 mL of toluene and 15.6 mL of 1-octene. Polymerization activity: 40200 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =824 kg·mol -1 , M w / M n =2.3, the copolymer contains 13.5 mol% 1-octene.

[0073] Example 18: C2-catalyzed copolymerization of ethylene / 1-octene

[0074] The polymerization process and reaction conditions were the same as in Example 16, using 42.2 mL of toluene and 7.8 mL of 1-octene. Polymerization activity: 37500 kg·mol⁻¹ -1 (Hf)·h-1 Polymer M w =794 kg·mol -1 , M w / M n =2.2, the copolymer contains 9.8 mol% 1-octene.

[0075] Example 19: C2-catalyzed copolymerization of ethylene / 1-octene

[0076] A 100 mL steel reactor equipped with a magnetic inductor was used for the polymerization reaction. A mixture of 26.6 mL toluene and 23.4 mL 1-octene (total 50 mL) was injected using a syringe. The reactor contents were heated to 120 °C, and the reactor was saturated with ethylene at 1 MPa. In a glove box, 2 μmol of catalyst C2, 100 μmol of methylaluminoxane, and 2.2 μmol of triphenylcarbontetra(pentafluorophenyl)borate were added, dissolved in toluene, and transferred to a catalyst storage tube via a syringe. Nitrogen gas (above 1 MPa) was then pressurized into the reactor. During polymerization, the reaction pressure was maintained at 1 MPa by continuously introducing ethylene gas. After the set reaction time of 2 minutes, 2 mL of ethanol was pressurized into the reactor under nitrogen (above 1 MPa). After the reactor cooled and the atmosphere was vented, the contents were poured into a large volume of ethanol, causing polymer precipitation. The polymer was obtained by filtration, washed with a small amount of ethanol, and finally vacuum dried overnight and weighed. Polymerization activity: 48750 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w = 492 kg·mol -1 , M w / M n =2.1, the content of 1-octene in the copolymer is 12.8 mol%.

[0077] Example 20: C2-catalyzed copolymerization of ethylene / 1-octene

[0078] The polymerization process and conditions were the same as in Example 19, with a polymerization pressure of 2 MPa. Polymerization activity: 55200 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =541 kg·mol -1 , M w / M n =2.1, the copolymer contains 6.5 mol% 1-octene.

[0079] Example 21: C2-catalyzed copolymerization of ethylene / 1-octene

[0080] The polymerization process and conditions were the same as in Example 19, with a polymerization pressure of 3 MPa. Polymerization activity: 57500 kg·mol⁻¹ -1(Hf)·h -1 Polymer M w =568kg·mol -1 , M w / M n =2.0, the copolymer contains 4.8 mol% 1-octene.

[0081] Example 22: C2-catalyzed copolymerization of ethylene / 1-octene

[0082] The polymerization process and reaction conditions were the same as in Example 19, with the selected temperature being 140℃. Polymerization activity: 33250 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w = 492 kg·mol -1 , M w / M n =2.1, the copolymer contains 13.8 mol% 1-octene.

[0083] Example 23: C2-catalyzed copolymerization of ethylene / 1-octene

[0084] The polymerization process and reaction conditions were the same as in Example 19, with the selected temperature being 160℃. Polymerization activity: 22450 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w = 431 kg·mol -1 , M w / M n =2.3, the copolymer contains 14.2 mol% 1-octene.

[0085] Example 24: C1-catalyzed copolymerization of ethylene / 1-octene

[0086] The polymerization process and reaction conditions were the same as in Example 19, and the catalyst used was C1. Polymerization activity: 33450 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =824 kg·mol -1 , M w / M n =2.1, the copolymer contains 11.5 mol% 1-octene.

[0087] Example 25: C3-catalyzed copolymerization of ethylene / 1-octene

[0088] The polymerization process and reaction conditions were the same as in Example 19, and the catalyst used was C3. Polymerization activity: 35400 kg·mol⁻¹ -1 (Hf)·h -1 Polymer Mw =876 kg·mol -1 , M w / M n =2.3, the copolymer contains 14.8 mol% 1-octene.

[0089] Example 26: C4-catalyzed copolymerization of ethylene / 1-octene

[0090] The polymerization process and reaction conditions were the same as in Example 19, and the catalyst used was C4. Polymerization activity: 29800 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =925kg·mol -1 , M w / M n =2.2, the content of 1-octene in the copolymer is 5.6 mol%.

[0091] Example 27: C2-catalyzed copolymerization of ethylene / 1-hexene

[0092] A 350 mL glass reactor equipped with a magnetic induction valve was used for the polymerization reaction. 2 μmol of catalyst C2, 2.2 μmol of triphenylcarbontetra(pentafluorophenyl)borate, and 100 μmol of methylaluminoxane were weighed in a glove box. The glass reactor was then connected to the polymerization line. Once the temperature reached 120 °C, 31.6 mL of toluene and 18.4 mL of 1-hexene were added. Ethylene gas was continuously introduced during polymerization to maintain a reaction pressure of 5 atm. After 2 minutes of reaction, 30 mL of ethanol was added to the reactor under a nitrogen atmosphere. After cooling, the reaction solution was poured into a large volume of ethanol to settle, filtered, and dried to obtain the final polymer. Polymerization activity: 22500 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =773 kg·mol -1 , M w / M n =2.0, the content of 1-hexene in the copolymer is 17.6 mol%.

[0093] Example 28: Me-Hf1-catalyzed copolymerization of ethylene / 1-hexene

[0094] The polymerization process and reaction conditions were the same as in Example 27, and the catalyst used was Me-Hf1. Polymerization activity: 32130 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =180kg·mol -1 , M w / M n=2.2, the content of 1-hexene in the copolymer is 12.5 mol%.

[0095] Example 29: Ar-Hf1-catalyzed copolymerization of ethylene / 1-hexene

[0096] The polymerization process and reaction conditions were the same as in Example 27, and the catalyst used was Ar-Hf1. Polymerization activity: 39800 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =284 kg·mol -1 , M w / M n =2.7, the content of 1-hexene in the copolymer is 22.4 mol%.

[0097] Example 30: C2-catalyzed ethylene / propylene copolymerization

[0098] A 1000 mL steel reactor equipped with a stirrer was used for the polymerization reaction. 220 mL of toluene was injected using a syringe, and the reactor contents were heated to 120°C. After saturating the reactor with 0.65 MPa propylene, 0.8 MPa ethylene was introduced, with a monomer ratio of 4:1. In a glove box, 2 μmol of catalyst C2, 100 μmol of methylaluminoxane, and 2.2 μmol of triphenylcarbontetra(pentafluorophenyl)borate were added, dissolved in toluene, and transferred to a catalyst storage tube using a syringe. Nitrogen gas (above 1 MPa) was then pressurized into the reactor. During polymerization, the reaction pressure was maintained at 0.8 MPa by continuously introducing ethylene gas. After the set reaction time of 2 minutes, 2 mL of ethanol was injected into the reactor under nitrogen (above 1 MPa). After the reactor cooled and the atmosphere was vented, the contents were poured into a large amount of ethanol, causing polymer precipitation. The polymer was filtered, washed with a small amount of ethanol, and finally vacuum-dried overnight before weighing. Polymerization activity: 17890 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =598kg·mol -1 , M w / M n =2.2, ethylene content in the copolymer is 7.5wt%.

[0099] Example 31: C2-catalyzed ethylene / propylene copolymerization

[0100] The polymerization process and reaction conditions were the same as in Example 30, using C2 catalyst and a monomer mixing ratio of 3:1. Polymerization activity: 16350 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =598kg·mol -1 , Mw / M n =2.2, the copolymer contains 18.6 wt% ethylene.

[0101] Example 32: C1-catalyzed ethylene / propylene copolymerization

[0102] The polymerization process and reaction conditions were the same as in Example 30, and the catalyst used was C1. Polymerization activity: 14400 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =398kg·mol -1 , M w / M n =2.2, the copolymer contains 14.3 wt% ethylene.

[0103] Example 33: C3-catalyzed ethylene / propylene copolymerization

[0104] The polymerization process and reaction conditions were the same as in Example 30, and the catalyst used was C3. Polymerization activity: 12350 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =348kg·mol -1 , M w / M n =2.2, the copolymer contains 16.5 wt% ethylene.

[0105] Example 34: C4-catalyzed ethylene / propylene copolymerization

[0106] The polymerization process and reaction conditions were the same as in Example 30, and the catalyst used was C4. Polymerization activity: 11250 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =882 kg·mol -1 , M w / M n =2.2, the copolymer contains 22.9 wt% ethylene.

[0107] Example 35: Me-Hf1-catalyzed ethylene / propylene copolymerization

[0108] The polymerization process and reaction conditions were the same as in Example 30, and the catalyst used was Me-Hf1. Polymerization activity: 22520 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =225kg·mol -1 , M w / M n =2.2, the copolymer contains 10.5 wt% ethylene.

[0109] Example 36: Ar-Hf1-catalyzed ethylene / propylene copolymerization

[0110] The polymerization process and reaction conditions were the same as in Example 30, and the catalyst used was Ar-Hf. Polymerization activity: 16350 kg·mol⁻¹ -1 (Hf)·h -1 Polymer M w =341 kg·mol -1 , M w / M n =2.2, the copolymer contains 13.5 wt% ethylene.

Claims

1. A class of pyridineamine-based binuclear metallic titanium-zirconium-hafnium catalysts, the structure of which is shown in formula (I): in, M is selected from titanium, zirconium, and hafnium; R 1 -R 4 R 1’ -R 4’ Each is independently selected from hydrogen, C1-C 20 Alkyl, C1-C 20 Alkoxy, C6-C 20 Aryl, C6-C 20 Aryl alkyl groups, or phenyl groups, form a ring of 4-20 carbon atoms with surrounding substituents by any two adjacent carbon atoms; R 1’ -R 4’ respectively with R 1 -R 4 Same or different; R 5 R 5’ Each is independently selected from C1-C6 straight-chain alkyl, tert-butyl, phenyl, benzyl, or isopropylphenyl.

2. The preparation method of the pyridineamine-based binuclear metallic titanium-zirconium-hafnium catalyst according to claim 1 comprises the following steps: under a nitrogen atmosphere, dissolving a metal salt in 10-80 mL of anhydrous solvent, adding 4.0-5.0 molar equivalents of methyl magnesium bromide, reacting at -40°C to -20°C for 2-6 hours, then adding 0.5 molar equivalents of pyridineamine ligand, reacting at -40°C to -20°C for 2-6 hours, and then raising the temperature to room temperature for 2-12 hours; after the reaction is completed, removing the solvent under reduced pressure, extracting with a good solvent, and obtaining the pyridineamine-based binuclear metallic titanium-zirconium-hafnium catalyst according to claim 1.

3. The preparation method according to claim 2, characterized in that: The anhydrous solvent is selected from toluene, n-hexane, xylene, and benzene; the good solvent is selected from n-hexane, toluene, pentane, heptane, and cyclohexane.

4. The preparation method according to claim 2, characterized in that: The metal salt is selected from one of TiCl4, ZrCl4, and HfCl4.

5. A method for olefin polymerization, characterized in that: The catalyst used is the pyridineamine-based binuclear metal titanium-zirconium-hafnium catalyst as described in claim 1.

6. The method according to claim 5, characterized in that: The olefin monomer is one or more of ethylene, propylene, 1-butene, styrene, 1-hexene, 1-octene, and 1-decene.

7. The method according to claim 5, characterized in that: The pyridineamine-based binuclear titanium zirconium hafnium catalyst requires the use of a co-catalyst for catalysis. The co-catalyst is one or more of tripentafluorophenylboron, triphenylcarbium tetra(pentafluorophenyl)borate, aluminoxane, alkylaluminum, and alkylaluminum chloride.

8. The method according to claim 7, characterized in that: The aluminum oxane is methylaluminoxane, ethylaluminoxane, or isobutylaluminoxane; the alkylaluminum is trimethylaluminum, triethylaluminum, triisobutylaluminum, or tri-n-hexylaluminum; and the alkylaluminum chloride is diethylaluminum chloride, sesqui-diethylaluminum chloride, or ethylaluminum dichloride.

9. The method according to claim 5, characterized in that: The polymerization temperature is 0-200℃, the polymerization pressure is 0.1-5MPa, the molar ratio of the catalyst to the co-catalyst is 1:(1-5000), the reaction time is 0.1-48h, and the solvent used for polymerization is one or more of n-hexane, n-heptane, n-pentane, and toluene.

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