CNN-tridentate coordination titanium-zirconium-hafnium metal catalyst and high-melting-point polyolefin block copolymer prepared from same

Abstract

The CNN-tridentate coordination titanium zirconium hafnium metal catalyst reported by the invention has the advantages of simple synthesis, easily available raw materials and high product yield. In the presence of a cocatalyst, the catalyst shows excellent activity (1.95 * 10 < 7 > g (PE). Mol <-1 > (M). H <-1 >), can be used for preparing high-molecular-weight polyolefin (the molecular weight Mw of a polymer reaches 134 * 10 < 4 > g. Mol <-1 >), also shows excellent high-temperature resistance, is suitable for high-temperature solution polymerization, and can be used for preparing high-performance polyolefin. In addition, the catalyst can also be used as a hard segment catalyst to be combined with a pyridine amine hafnium catalyst developed by Dow chemistry to prepare a high-melting-point (Tm = 130.0 DEG C) polyolefin multi-block copolymer OBC through chain shuttling polymerization under the action of a chain shuttling agent (such as diethyl zinc and the like). Therefore, the invention has original innovation, and provides a new direction for the development of the field of polyolefin materials.

Description

Technical Field

[0001] The present invention relates to the preparation of metal catalysts for olefin coordination polymerization and their applications in the field of olefin polymerization. Background Art

[0002] As the cornerstone of modern industry, polyolefin materials are widely used in packaging, automotive, electronics, medical, and new energy fields due to their light weight, corrosion resistance, easy processing, and low cost. Polyethylene (PE), polypropylene (PP), etc. are the core members of the polyolefin family. In recent years, with the upgrading of market demand for high-performance materials, olefin block copolymers (OBCs) have gradually become the focus of research. By precisely regulating the chemical composition and sequence distribution of polymer segments, these materials achieve a dynamic balance between the rigidity and elasticity of thermoplastic elastomers, showing unique potential in high-end applications. However, their synthesis highly depends on the innovation of catalytic systems. In particular, the development of metal catalysts with high activity, high selectivity, and high temperature resistance has become the core challenge for promoting technological breakthroughs.

[0003] Early polyolefin polymerization mainly relied on Ziegler-Natta catalysts. Although these heterogeneous catalysts could achieve efficient polymerization of ethylene and propylene, the resulting products had a wide molecular weight distribution and uncontrollable chain structures, making it difficult to meet the requirements of high-performance materials. In the 1990s, the breakthrough of metallocene catalysts significantly improved the controllability of the polymerization process. Their single active center property allows for precise regulation of the stereoregularity and molecular weight distribution of polymers through ligand design. Nevertheless, metallocene catalysts still suffer from the disadvantages of a large amount of cocatalyst (methylaluminoxane) usage and a wide patent coverage. To overcome the limitations of metallocene catalysts, non-metallocene transition metal catalysts have become a research hotspot (Chem. Rev. 1998, 98, 2587 - 2598). Among them, metal catalysts with pyridylamine, imine, and quinoline groups have attracted much attention due to their adjustable electronic effects and steric hindrance characteristics. For example, the pyridylamine hafnium catalyst developed by Dow Chemical showed high activity (>10 7 g(polymer)·mol -1 ·h -1) with α-olefin selectivity (>30 mol%) (Angew. Chem. Int. Ed. 2006, 45, 3278 - 3283). Meanwhile, this catalyst can also prepare OBCs through Chain Shuttling Polymerization (CSP). This technology uses two types of catalysts (such as soft-segment catalysts with high α-olefin insertion rates and hard-segment catalysts with low α-olefin insertion rates) to achieve dynamic shuttling of chain segments during polymerization, thereby generating multi-block structures (Science. 2006, 312, 714 - 719). For example, Dow Chemical's Infuse TM technology uses a pyridylamine hafnium catalyst with strong comonomer insertion ability and a bisphenol oxazoline zirconium FI catalyst with weak comonomer insertion ability, and successfully prepares a multi-block copolymer with alternating hard and soft segments under the condition of diethylzinc as a chain shuttling agent. However, this technology has extremely high requirements for catalyst matching. The two catalysts need to not interfere with each other, have large differences in monomer selectivity, and the chain shuttling agent needs to match both catalysts simultaneously.

[0004] In the present invention, a series of quinoline-based CNN-tridentate coordinated titanium-zirconium-hafnium metal catalysts were synthesized in high yield. These catalysts showed high catalytic activity (1.95×10 7 g(PE)·mol -1 ·h -1 ) in ethylene homopolymerization and were able to obtain ultra-high molecular weight polymers (the weight-average molecular weight of the polymer reached 134×10 4 g·mol -1 ). In the copolymerization of ethylene and α-olefins, these catalysts also showed excellent activity and had very low α-olefins (<1 mol%). Therefore, the catalysts reported in the present invention can also be used as hard-segment catalysts in combination with the pyridylamine hafnium catalyst developed by Dow Chemical to prepare (ethylene / 1-octene) multi-block copolymer OBCs. The melting point of the prepared (ethylene / 1-octene) multi-block copolymer OBC can reach up to 130 °C, which is much higher than the melting point of the OBC produced by Dow (Science. 2006, 312, 714 - 719), greatly expanding the application temperature range of OBCs. Therefore, the present invention has original innovation and provides a new direction for the development of the polyolefin material field. Summary of the Invention

[0005] The object of the present invention is to provide the synthesis of a CNN-tridentate coordinated titanium-zirconium-hafnium metal catalyst and its application in preparing high-density polyethylene (HDPE) and polyolefin block copolymers (OBC).

[0006] The present invention provides a CNN-tridentate coordinated titanium-zirconium-hafnium metal catalyst represented by formula (I):

[0007]

[0008] Among them, M is selected from titanium, zirconium, and hafnium; R 1 is selected from methyl, ethyl, hydrogen, isopropyl, chlorine, and fluorine; R 2 is selected from methyl, ethyl, hydrogen, isopropyl, chlorine, and fluorine; R 3 is selected from methyl, methoxy, hydrogen, tert-butyl, R 4 is selected from a straight-chain alkyl group having 1 to 6 carbon atoms, phenyl, benzyl, or cumyl.

[0009] Preferably, the metal compound of the present invention is selected from any one of the following metal catalysts:

[0010]

[0011] The present invention provides a method for preparing the above-mentioned CNN-tridentate coordination titanium-zirconium-hafnium metal catalyst, comprising the following steps:

[0012] Under a nitrogen atmosphere, the metal salt MCl 4 is dissolved in 20 - 80 mL of an anhydrous solvent, 4.0 - 5.0 molar equivalents of methylmagnesium bromide are added, and the reaction is carried out at a low temperature for 2 - 6 hours under nitrogen protection. Then, 1 molar equivalent of a ligand is added and the reaction is carried out for 2 - 12 hours; after the reaction is completed, the solvent is removed under reduced pressure and extracted with a good solvent to obtain the CNN-tridentate coordination titanium-zirconium-hafnium metal catalyst described in claim 1.

[0013] In the above preparation method, the anhydrous solvent is selected from one or more of toluene, n-hexane, xylene, and benzene; the good solvent is selected from one or more of n-hexane, toluene, pentane, heptane, and cyclohexane.

[0014] In the above preparation method, the metal salt MCl 4 is selected from any one of TiCl 4 , ZrCl 4 , and HfCl 4 .

[0015] The present invention also provides an application of the above-mentioned CNN-tridentate coordination titanium-zirconium-hafnium metal catalyst in the catalytic polymerization of olefins.

[0016] In the above application, the olefin monomer is one or more of ethylene, propylene, 1-butene, styrene, 1-hexene, norbornene, and 1-octene.

[0017] The CNN-tridentate coordinated titanium-zirconium-hafnium metal catalyst needs to be used in combination with a cocatalyst, and the cocatalyst is one or more of tris(pentafluorophenyl)borane, trityl tetrakis(pentafluorophenyl)borate, aluminoxane, alkylaluminum, and alkylaluminum chloride; the aluminoxane is methylaluminoxane, ethylaluminoxane, or isobutylaluminoxane; the alkylaluminum is trimethylaluminum, triethylaluminum, triisobutylaluminum, or tri-n-hexylaluminum; the alkylaluminum chloride is diethylaluminum monochloride, sesqui-diethylaluminum monochloride, or diethylaluminum dichloride.

[0018] In the above polymerization reaction, the polymerization temperature is 0-200 °C, the polymerization pressure is 0.1-5 MPa, and the polymerization solvent is one or more of n-hexane, heptane, pentane, and toluene.

[0019] The CNN-tridentate coordinated titanium-zirconium-hafnium metal catalyst is combined with the catalyst shown in formula (ΙI),

[0020]

[0021] Under the action of a chain shuttling agent, chain shuttling polymerization can be achieved to prepare a high melting point polyolefin block copolymer; the chain shuttling agent is one or more of diethylzinc, dimethylzinc, triisobutylaluminum, trimethylaluminum, triethylaluminum, and tri-n-hexylaluminum.

[0022] The present invention provides the preparation of a CNN-tridentate coordinated titanium-zirconium-hafnium metal catalyst based on a quinoline skeleton, and the application of this catalyst in olefin polymerization. The CNN-tridentate coordinated titanium-zirconium-hafnium metal catalyst with a quinoline skeleton reported in the present invention has the advantages of simple synthesis, easy availability of raw materials, and high product yield. It shows high catalytic activity in ethylene homopolymerization (the highest activity can reach 1.95×10 7 g(PE)·mol -1 ·h -1 ), high polymer molecular weight (the polymer weight average molecular weight reaches 134×10 4 g·mol -1 ), and is especially suitable for high-temperature solution polymerization to prepare high-quality and high-performance polyolefin materials. It shows the characteristic of extremely low 1-octene insertion rate in the copolymerization of ethylene and 1-octene. When preparing (ethylene / 1-octene) multiblock copolymers in combination with the pyridineamine-based hafnium catalyst developed by Dow Chemical, this type of catalyst has the advantages of high matching, narrow polymer molecular weight distribution (weight average molecular weight / number average molecular weight ≈ 2.0), and relatively high polymer melting point (130 °C). By adjusting the content of the hard and soft segments, an elastomer material with excellent properties can be obtained. The metal catalyst provided by the present invention has original innovation and can promote the development of China's high-end polyolefin chemical industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the 1H NMR spectrum of catalyst C1.

[0024] Figure 2 1H NMR spectrum of catalyst C2.

[0025] Figure 3 FT-IR spectrum of high-density polyethylene (HDPE) with 1-octene insertion rate < 1 mol%.

[0026] Figure 4 GPC chart of (ethylene / 1-octene) multiblock copolymer with a molecular weight distribution of 2.0.

[0027] Figure 5 DSC chart of (ethylene / 1-octene) multiblock copolymer with a melting point of 130 °C.

[0028] Figure 6 Crystal diagram of catalyst C1. Detailed implementation mode

[0029] The present invention will be further illustrated by examples, but the present invention is not limited thereto. The examples of the present invention can enable those skilled in the art to understand the present invention more comprehensively.

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

[0031] The CNN-tridentate ligands C1-L and C4-L of the present invention are shown in (III), and the corresponding synthesis methods are given in Examples 1 and 4. 8-Phenyl-2-quinolinecarboxaldehyde and 8-(2,6-dimethylphenyl)-2-quinolinecarboxaldehyde are synthesized according to the reference method (Macromolecules, 2024, 57: 3604-3613). The pyridylamine hafnium catalyst, Ar-Hf catalyst (2,6- i Pr 2 -phenyl-N-(2- i Pr-phenyl)[6-(naphthalenyl)-2-pyridyl]HfMe 2 ) is synthesized according to the reference method (Angew. Chem. Int. Ed. 2006, 45, 3278-3283).

[0032]

[0033] The present invention will be described below with specific examples.

[0034] Example 1. Preparation of ligand C1-L and catalyst C1

[0035] C1-L: 8-Phenyl-2-quinolinecarboxaldehyde (2.33 g, 10 mmol) and 2,6-diisopropylaniline (1.77 g, 10 mmol) were added. After dissolving in 200 mL of toluene, 30 mg of p-toluenesulfonic acid was added. A water separator and a reflux condenser were installed on the round-bottom flask, and the reaction was carried out overnight at 130 °C. After the reaction was completed, the reaction system was cooled to room temperature, and the solvent was removed by rotary evaporation under vacuum to obtain a green oily substance. It was purified by column chromatography with the eluent: (ethyl acetate: petroleum ether = 1:10) to obtain a yellow powder. After adding a small amount of ethanol and recrystallizing, 3.01 g of yellow particles C1-L were obtained, and the yield was 76.7%. 1 H NMR (400 MHz, CDCl 3 ): δ 8.46–8.38 (m, 2H), 8.33 (d, J = 8.5 Hz, 1H), 7.89 (dd, J = 8.1, 1.4 Hz, 1H), 7.83 (dd, J = 10.7, 4.2 Hz, 3H), 7.72–7.64 (m, 1H), 7.43 (dt, J = 26.7, 7.2 Hz, 3H), 7.21–7.09 (m, 3H), 3.00 (hept, J = 6.9 Hz, 2H), 1.18 (d, J = 6.9 Hz, 12H) ppm. Anal. Calcd for C 28 H 28 N 2 : C, 85.67; H, 7.19; N, 7.14. Found: C, 85.63; H, 7.21; N, 7.13.

[0036] C1: Hafnium chloride 4 (0.80 g, 2.5 mmol) was weighed and 30 mL of anhydrous toluene was added. At -40 °C, 4 mL of methylmagnesium bromide (3 M in Et 2 O) was added under nitrogen. The reaction was carried out at -40 °C for 3 h. After adding the ligand C1-L (0.79 g, 2 mmol), the gas in the Schlenk flask was replaced with a nitrogen atmosphere, and then 20 mL of anhydrous toluene was added to dissolve. At this time, the solution turned into a yellow clear liquid. And at -40 °C, this solution was introduced into the metal suspension with two needles. After reacting at -40 °C in the dark for 4 h, it was slowly warmed to room temperature and then continued to react in the dark for 10 h. At this time, the solution turned into a black suspension. The black suspension was pumped into a cold trap to obtain a black solid. After adding 30 mL of toluene, it was ultrasonicated and allowed to stand. The lower layer was a black powder and the upper layer was a red-brown clear liquid. After single-needle filtration, a red clear liquid was obtained. After drying the toluene in the clear liquid, 5 mL of n-hexane was added for recrystallization to obtain 0.838 g of orange-red crystals C1, and the yield was 68%. 1 HNMR (400 MHz, C 6 D 6): δ 8.54 (dd, J = 7.1, 1.3 Hz, 1H), 7.96 (dd, J = 7.1, 1.7 Hz, 1H), 7.64 (d, J = 7.8 Hz, 1H), 7.53 (d, J = 8.5 Hz, 1H), 7.45 (td, J = 7.2, 0.9 Hz, 1H), 7.35 (dd, J = 7.6, 6.1 Hz, 1H), 7.29–7.19 (m, 5H), 6.68 (d, J = 8.5 Hz, 1H), 5.20 (q, J = 6.9 Hz, 1H), 3.97 (hept, J = 6.8 Hz, 1H), 3.66 (hept, J = 6.9 Hz, 1H), 1.61 (d, J = 6.9 Hz, 3H), 1.37 (d, 6.9 Hz, 3H), 1.33 (d, J = 6.9 Hz, 3H), 1.16 (d, J = 6.8 Hz, 3H), 1.10 (d, J = 6.8 Hz, 3H), 0.65 (s, 3H), 0.00 (s, 3H) ppm. 13 C NMR (100 MHz, C 6 D 6 ): δ 204.40, 170.39, 147.94, 146.61, 143.29, 143.05, 141.96, 140.85, 140.03, 136.09, 131.06, 129.95, 129.50, 127.96, 127.67, 127.23, 126.61, 126.44, 124.82, 124.45, 118.82, 71.47, 63.46, 60.46, 28.32, 27.89, 26.12, 25.97, 25.53, 24.70, 23.55 ppm. Anal. Calcd for C 31 H 36 N 2 Hf: C, 60.53; H, 5.90; N, 4.55. Found: C, 60.54; H, 5.92; N, 4.52.

[0037] Example 2. Preparation of Catalyst C2

[0038] Weigh ZrCl 4 (0.58 g, 2.5 mmol), and add 30 mL of anhydrous toluene. Cool the Schlenk flask to -40 °C (ice acetonitrile bath), and add 4 mL of methylmagnesium bromide (3 M in Et 2O), React at -40 °C for 3 h. At this time, the solution becomes a light gray suspension. Take another dried Schlenk flask, add ligand C1-L (0.79 g, 2 mmol), displace the gas in the Schlenk flask with nitrogen, add 20 mL of anhydrous toluene to dissolve it. At this time, the solution color becomes a yellow clear liquid. And at -40 °C, double-needle introduce this solution into the metal suspension, react in the dark at -40 °C for 4 h, then slowly raise the temperature to room temperature and continue to react in the dark for 10 h. At this time, the solution becomes a black suspension. The black suspension is pumped through a cold trap to obtain a black solid. Add 30 mL of toluene, then ultrasonicate and let it stand. The lower layer is black powder and the upper layer is a reddish-brown clear liquid. After single-needle filtration, a red clear liquid is obtained. After drying the toluene in the clear liquid, add 5 mL of n-hexane for recrystallization to obtain yellow crystals C2: 0.676 g, with a yield of 64%. 1 H NMR(400MHz C 6 D 6 ): δ 8.55 (d, J = 7.2 Hz, 1H), 7.95 (dd, J = 7.2, 1.6 Hz, 1H), 7.58–7.50 (m, 2H), 7.36 (m, 2H), 7.30–7.20 (m, 5H), 6.71 (d, J = 8.5 Hz, 1H), 5.12 (q, J = 6.9 Hz, 1H), 3.94 (hept, J = 6.9 Hz, 1H), 3.64 (hept, J = 6.8 Hz, 1H), 1.58 (d, J = 6.9 Hz, 3H), 1.34 (d, J = 6.9 Hz, 3H), 1.32 (d, J = 6.9 Hz, 3H), 1.14 (d, J = 6.8 Hz, 3H), 1.14 (d, J = 6.8 Hz, 3H), 0.76 (s, 3H), 0.23 (s, 3H) ppm. 13 C NMR(100MHz,C 6 D 6 ): δ 190.07, 170.07, 148.10, 146.79, 142.14, 141.80, 141.57, 140.35, 139.87, 134.70, 130.93, 129.68, 129.42, 128.18, 127.94, 127.24, 126.83, 126.31, 124.95, 124.52, 118.58, 71.59, 49.77, 49.72, 28.40, 27.92, 26.05, 25.97, 25.52, 24.66, 22.68 ppm. Anal. Calcd for C 31 H 36 N 2Zr: C, 70.54; H, 6.87; N, 5.31. Found: C, 70.52; H, 6.82; N, 5.34.

[0039] Example 3. Preparation of Catalyst C3

[0040] Weigh TiCl 4 (0.47 g, 2.5 mmol), and add 30 mL of anhydrous toluene. Cool the Schlenk flask to -40 °C (ice-acetonitrile bath), and add 4 mL of methylmagnesium bromide (3 M in Et 2 O) under nitrogen. React at -40 °C for 3 h, and the solution becomes a light gray suspension at this time. Take another dried Schlenk flask, add ligand C1-L (0.79 g, 2 mmol), displace the gas in the Schlenk flask with nitrogen, add 20 mL of anhydrous toluene to dissolve it, and the solution turns yellow and clear at this time. Then, at -40 °C, introduce this solution into the metal suspension through a double needle. After reacting in the dark at -40 °C for 4 h, slowly raise the temperature to room temperature and continue to react in the dark for 10 h. The solution becomes a black suspension at this time. The black suspension is pumped through a cold trap to obtain a black solid. Add 30 mL of toluene, sonicate and let it stand. The lower layer is black powder, and the upper layer is a reddish-brown clear liquid. After single-needle filtration, a red clear liquid is obtained. After drying the toluene in the clear liquid, add 5 mL of n-hexane for recrystallization to obtain 0.66 g of yellow crystal C3, with a yield of 87%. 1 H NMR (400 MHz, C 6 D 6 ): δ 7.38 (d, J = 8.5 Hz, 1H), 7.31–7.11 (m, 6H), 7.18–7.03 (m, 3H), 7.11–6.86 (m, 1H), 6.79 (d, J = 7.4 Hz, 1H), 6.54 (d, J = 8.5 Hz, 1H), 4.57 (q, J = 6.9 Hz, 1H), 4.24 (hept, J = 6.8 Hz 1H), 3.58 (hept, J = 6.9 Hz1H), 2.53 (d, J = 6.0 Hz, 1H), 1.48 (s, 3H), 1.46 (d, J = 6.0 Hz, 1H), 1.42 (d, J = 6.8 Hz, 3H), 1.39 (t, J = 6.5 Hz, 6H), 1.38 (d, J = 6.8 Hz, 3H), 1.28 (d, J = 6.9 Hz, 3H), -0.14 (s, 3H), -0.20 (s, 3H) ppm. 13 C NMR (100 MHz, C 6 D 6): δ 171.82, 148.50, 146.14, 145.74, 143.36, 142.46, 139.83, 139.38, 137.04, 135.06, 133.21, 133.14, 128.67, 126.68, 126.66, 126.02, 126.45 125.93, 124.84, 124.71, 118.84, 73.97, 60.51, 59.99, 48.31, 28.58, 27.97, 26.07, 25.59, 25.57, 25.42, 24.83, 22.16 ppm. Anal. Calcd for C 33 H 40 N 2 Ti: C, 61.62; H, 6.27; N, 4.36. Found: C, 61.64; H, 6.29; N, 4.33.

[0041] Example 4: Preparation of Ligand C4-L and Catalyst C4

[0042] C4-L: Add 8-phenyl-2-(2,6-diisopropylaniline)quinoline (C1-L) (3.93 g, 10 mmol). After evacuating and filling with gas three times, add 30 mL of anhydrous ether. Take another Schlenk flask, place a magnetic stir bar in it, and add 2-isopropylphenyllithium (1.26 g, 10 mmol) dissolved in 20 mL of anhydrous ether in the glove box. Slowly introduce it into the ether solution of ligand L1 under an ice-water bath. After slowly warming to room temperature, react overnight. After the reaction is completed, quench with aqueous ammonium chloride solution. Separate the reaction solution, retain the organic phase, dry it, and then remove the solvent by rotary evaporation under vacuum to obtain a yellow oil. Add ethanol for recrystallization to obtain 3.79 g of orange-yellow powder C4-L, with a yield of 74%. 1 H NMR (400 MHz, CDCl 3): δ 7.94 (d, J = 8.5 Hz, 1H), 7.71–7.65 (m, 2H), 7.70–7.66 (m, 2H), 7.48 (dd, J = 8.1, 7.2 Hz, 1H), 7.38 (d, J = 7.5 Hz, 1H), 7.35–7.30 (m, 2H), 7.28–7.22 (m, 1H), 7.17–7.13 (m, 3H), 7.11–7.07 (m, 1H), 6.93–6.86 (m, 3H), 5.38 (s, 1H), 4.95 (s, 1H), 3.15 (hept, J = 6.7 Hz, 1H), 2.85 (hept, J = 6.8 Hz, 2H), 0.96 (d, J = 6.8 Hz, 3H), 0.79 (d, J = 6.8 Hz, 6H), 0.71 (dd, J = 6.8, 3.7 Hz, 9H) ppm. Anal. Calcd for C 37 H 40 N 2 : C, 86.67; H, 7.86; N, 5.46. Found: C, 86.63; H, 7.85; N, 5.48.

[0043] C4: Add ligand C4-L (1.03 g, 2 mmol), add 30 mL of anhydrous and anaerobic toluene, and dissolve it. The solution becomes a yellow clear liquid at this time. Slowly add 0.78 mL of n-butyllithium (2.7 M in Hex) dropwise at room temperature and react at room temperature for 2 h. The solution becomes a black suspension at this time. After the reaction is completed, take the pressure-resistant bottle into the glove box and add HfCl 4 (0.80 g, 2.5 mmol) in the glove box. After taking it out of the glove box, reflux at 110 °C for 2 h. The system becomes a yellow suspension at this time. After the reaction is completed, cool the pressure-resistant bottle to room temperature, and then slowly add 4 mL of methylmagnesium bromide (3 M in Et 2 O) at room temperature and stir overnight at room temperature. The system becomes a black suspension again at this time. Cool it to a cold trap to obtain a black solid. Add 30 mL of toluene, sonicate and let it stand. The lower layer is black powder and the upper layer is a red-brown clear liquid. After single-needle filtration, a red clear liquid is obtained. After drying the toluene in the clear liquid, add 2 mL of n-hexane for recrystallization to obtain 0.65 g of yellow crystals with a yield of 45%. 1 H NMR (400 MHz C 6 D 6): δ 8.58 (dd, J = 7.0, 1.2 Hz, 1H), 8.00 (dd, J = 7.3, 1.6 Hz, 1H), 7.73 (d, J = 7.8 Hz, 1H), 7.45 (td, J = 7.2, 1.1 Hz, 1H), 7.38 (d, J = 8.5 Hz, 2H), 7.24–7.17 (m, 5H), 7.09 (dd, J = 7.6, 1.8 Hz, 1H), 6.96 (dd, J = 7.9, 1.2 Hz, 1H), 6.83 (td, J = 8.2, 1.3 Hz, 1H), 6.76 (d, J = 8.4 Hz, 1H), 6.70 (s, 1H), 6.59–6.45 (m, 1H), 3.82 (hept, J = 6.8 Hz, 1H), 3.63 (hept, J = 6.8 Hz, 1H), 3.06 (hept, J = 6.8 Hz, 1H), 1.50 (d, J = 6.9 Hz, 3H), 1.47 (d, J = 6.9 Hz, 3H), 1.38 (d, J = 6.8 Hz, 3H), 1.17 (d, J = 7.0 Hz, 3H), 0.73 (s, 3H), 0.61 (d, J = 6.7 Hz, 3H), 0.22 (s, 3H), 0.20 (s, 3H) ppm. 13 C NMR (100 MHz, C 6 D 6 ): δ 204.23, 169.89, 147.82, 147.80, 146.35, 143.86, 143.05, 141.93, 140.79, 139.90, 139.09, 136.30, 130.95, 130.91, 129.96, 129.65, 128.18, 127.94, 127.49, 127.42, 126.98, 126.78, 126.49, 125.73, 124.82, 124.52, 119.89, 75.49, 63.77, 61.55, 28.57, 28.53, 28.44, 27.24, 25.79, 25.43, 24.79, 24.23, 22.74 ppm. Anal. Calcd for C 39 H 44 N 2 Hf: C, 65.12; H, 6.17; N, 3.89. Found: C, 65.09; H, 6.15; N, 3.93.

[0044] Example 5. Preparation of Catalyst C5

[0045] Ligand C4-L (1.03 g, 2 mmol) was added to 30 mL of anhydrous and anaerobic toluene and dissolved. At this time, the solution became a yellow clear liquid. 0.78 mL of n-butyllithium (2.7 M in Hex) was slowly added dropwise at room temperature, and the reaction was carried out at room temperature for 2 h. At this time, the solution became a black suspension. After the reaction was completed, the pressure-resistant bottle was taken into the glove box, and ZrCl 4 (0.58 g, 2.5 mmol) was added in the glove box. After taking out of the glove box, it was refluxed at 110 °C for 2 h. At this time, the system became a yellow suspension. After the reaction was completed, the pressure-resistant bottle was cooled to room temperature, and then 4 mL of methylmagnesium bromide (3 M in Et 2 O) was slowly added at room temperature, and the mixture was stirred overnight at room temperature. At this time, the system became a black suspension again. The black solid was obtained by cold trap. After adding 30 mL of toluene, it was ultrasonicated and allowed to stand. The lower layer was black powder and the upper layer was a red-brown clear liquid. After single-needle filtration, a red clear liquid was obtained. After the toluene in the clear liquid was dried by suction, 2 mL of n-hexane was added for recrystallization to obtain 0.60 g of yellow crystal C5 with a yield of 48%. 1 1H NMR (400 MHz, C 6 D 6 ): δ 8.65–8.60 (m, 1H), 8.02 (dd, J = 7.1, 1.6 Hz, 1H), 7.65–7.60 (m, 1H), 7.40–7.35 (m, 3H), 7.23–7.18 (m, 5H), 7.08 (dd, J = 7.4, 1.9 Hz, 1H), 6.99–6.93 (m, 1H), 6.88–6.82 (m, 1H), 6.81 (d, J = 8.4 Hz, 1H), 6.61 (s, 1H), 6.56–6.46 (m, 1H), 3.80 (hept, J = 6.8 Hz, 1H), 3.60 (hept, J = 6.8 Hz, 1H), 3.07 (m, 1H), 1.50 (d, J = 6.9 Hz, 3H), 1.46 (d, J = 6.9 Hz, 3H), 1.37 (d, J = 6.8 Hz, 3H), 1.19 (d, J = 6.9 Hz, 3H), 0.87 (s, 3H), 0.63 (d, J = 6.7 Hz, 3H), 0.40 (s, 3H), 0.23 (d, J = 6.7 Hz, 3H) ppm. 13 13C NMR (100 MHz, C 6 D 6): δ 190.12, 169.53, 147.99, 147.67, 146.43, 142.83, 142.10, 141.32, 140.31, 139.75, 138.31, 134.89, 130.93, 130.90, 129.86, 129.38, 128.18, 127.94, 127.63, 127.47, 126.83, 126.77, 126.68, 125.68, 124.83, 124.69, 119.79, 75.41, 50.98, 50.21, 28.62, 28.55, 28.52, 27.19, 25.83, 25.41, 24.75, 24.12, 22.77 ppm. Anal. Calcd for C 39 H 44 N 2 Zr: C, 74.12; H, 7.02; N, 4.43. Found: C, 74.09; H, 7.04; N, 4.45.

[0046] Example 6, Polymerization of Ethylene Catalyzed by C1

[0047] A 100 mL steel reactor equipped with a magnetic stir bar was used for the polymerization reaction. 50 mL of toluene was injected with a syringe, and the reactor contents were heated to 80 °C. The reactor was saturated with 2 MPa of ethylene. 2 μmol of catalyst C1, 100 μmol of methylaluminoxane, and 2.2 μmol of triphenylcarbenium tetrakis(pentafluorophenyl)borate were added in a glove box, dissolved in toluene, transferred to a catalyst storage tube by syringe, and then pressured into the reactor with nitrogen (over 2 MPa). During the polymerization, the reaction pressure was maintained at 2 MPa by continuously introducing ethylene gas. After reaching the set reaction time of 2 min, 2 mL of ethanol was pressured into the reactor under nitrogen (over 2 MPa). After the reactor was cooled and vented, the contents of the reactor were poured into a large amount of ethanol, and the polymer precipitated. The polymer was filtered, washed with a small amount of ethanol, and finally dried under vacuum overnight and weighed. Polymerization activity: 13200 kg·mol -1 (M)·h -1 , Polymer M w = 592 kg·mol -1 , M w / M n = 2.4.

[0048] Example 7, Polymerization of Ethylene Catalyzed by C1

[0049] The polymerization reaction process and reaction conditions were the same as in Example 6, and the polymerization temperature was 120 °C. Polymerization activity: 8000 kg·mol -1 (M)·h -1 . Polymer Mw = 261 kg·mol -1 , M w / M n = 2.5.

[0050] Example 8, C1-catalyzed ethylene polymerization

[0051] The polymerization reaction process and reaction conditions are the same as those in Example 6, and the polymerization temperature is 160 °C. Polymerization activity: 7500 kg·mol -1 (M)·h -1 . Polymer M w = 241 kg·mol -1 , M w / M n = 2.5.

[0052] Example 9, C1-catalyzed ethylene polymerization

[0053] The polymerization reaction process and reaction conditions are the same as those in Example 6, and the polymerization temperature is 180 °C. Polymerization activity: 7400 kg·mol -1 (M)·h -1 . Polymer M w = 200 kg·mol -1 , M w / M n = 2.7.

[0054] Example 10, C1-catalyzed ethylene polymerization

[0055] A 350 mL glass reactor equipped with a magnetic stir bar is used for the polymerization reaction. In the glove box, 2 μmol of catalyst C1, 2.2 μmol of tris(pentafluorophenyl)borate, and methylaluminoxane are weighed. The glass reaction kettle is connected to the polymerization pipeline. After the temperature rises to 80 °C, 50 mL of toluene is added to it. During the polymerization process, ethylene gas is continuously introduced to ensure that the reaction pressure is 5 atm. After reacting for 2 min, 30 mL of ethanol is added to the reactor under a nitrogen atmosphere. After cooling, the reaction solution is poured into a large amount of ethanol for precipitation, and the final polymer is obtained after filtration and drying. Polymerization activity: 6500 kg·mol -1 (M)·h -1 , polymer M w = 530 kg·mol -1 , M w / M n = 2.2.

[0056] Example 11, C1-catalyzed ethylene polymerization

[0057] A 100 mL steel reactor equipped with a magnetic stir bar was used for the polymerization reaction. 50 mL of toluene was injected with a syringe. The reactor contents were heated to 80 °C and saturated with 2 MPa of ethylene. 2 μmol of catalyst C1 and 1000 μmol of methylaluminoxane were added in a glove box, dissolved in toluene, transferred to a catalyst storage tube by syringe, and pressured into the reactor with nitrogen (over 2 MPa). During the polymerization, the reaction pressure was maintained at 2 MPa by continuously introducing ethylene gas. After reaching the set reaction time of 2 min, 2 mL of ethanol was pressured into the reactor under nitrogen (over 2 MPa). After the reactor was cooled, the gas was discharged. The contents of the reactor were poured into a large amount of ethanol, and the polymer precipitated. The polymer was filtered, washed with a small amount of ethanol, and finally dried under vacuum overnight and weighed. Polymerization activity: 2030 kg·mol -1 (M)·h -1 , polymer M w = 350 kg·mol -1 , M w / M n = 2.4

[0058] Example 12, Ethylene Polymerization Catalyzed by C2

[0059] The polymerization reaction process and reaction conditions were the same as in Example 6, and the catalyst used was C2. Polymerization activity: 11500 kg·mol -1 (M)·h -1 . Polymer M w = 1130 kg·mol -1 , M w / M n = 2.5

[0060] Example 13, Ethylene Polymerization Catalyzed by C3

[0061] The polymerization reaction process and reaction conditions were the same as in Example 6, and the catalyst used was C3. Polymerization activity: 10500 kg·mol -1 (M)·h -1 . Polymer M w = 1320 kg·mol -1 , M w / M n = 2.5

[0062] Example 14, Ethylene Polymerization Catalyzed by C4

[0063] The polymerization reaction process and reaction conditions were the same as in Example 6, and the catalyst used was C4. Polymerization activity: 13350 kg·mol -1 (M)·h -1 . Polymer M w = 1060 kg·mol -1 , Mw / M n = 2.9.

[0064] Example 15, C5-catalyzed ethylene polymerization

[0065] The polymerization reaction process and reaction conditions are the same as in Example 6, and the catalyst used is C5. Polymerization activity: 11850 kg·mol -1 (M)·h -1 . Polymer M w = 1160 kg·mol -1 , M w / M n = 2.6.

[0066] Example 16, C1-catalyzed ethylene / 1-octene copolymerization

[0067] A 100 mL steel reactor equipped with a magnetic stirrer was used for the polymerization reaction. 25.6 mL of toluene and 24.4 mL of 1-octene were added thereto by syringe injection. The reactor contents were heated to 80 °C and saturated with 2 MPa of ethylene. 2 μmol of catalyst C1, 100 μmol of methylaluminoxane, and 2.2 μmol of triphenylcarbenium tetrakis(pentafluorophenyl)borate were added in a glove box, dissolved in toluene, transferred to a catalyst storage tube by syringe, and pressured into the reactor with nitrogen (over 2 MPa). During the polymerization, the reaction pressure was maintained at 2 MPa by continuously introducing ethylene gas. After reaching the set reaction time of 2 min, 2 mL of ethanol was pressured into the reactor under nitrogen (over 2 MPa). After the reactor was cooled and vented, the substances in the reactor were poured into a large amount of ethanol, and the polymer precipitated. The polymer was filtered, washed with a small amount of ethanol, and finally dried under vacuum overnight and weighed. Polymerization activity: 8520 kg·mol -1 (M)·h -1 , polymer M w = 524 kg·mol -1 , M w / M n = 2.3, and the content of 1-octene in the copolymer < 0.1 mol%.

[0068] Example 17, C1-catalyzed ethylene / 1-octene copolymerization

[0069] The polymerization reaction process and reaction conditions are the same as in Example 16, and the toluene used is 34.4 mL and the 1-octene is 15.6 mL. Polymerization activity: 10070 kg·mol -1 (M)·h -1 . Polymer M w = 530 kg·mol -1 , M w / M n= 2.3, the content of 1-octene in the copolymer is 0.12 mol%.

[0070] Example 18, C1-catalyzed ethylene / 1-octene copolymerization

[0071] The polymerization reaction process and reaction conditions are the same as those in Example 16. The toluene used is 42.2 mL, and the 1-octene is 7.8 mL. Polymerization activity: 12150 kg·mol -1 (M)·h -1 . Polymer M w = 568 kg·mol -1 , M w / M n = 2.1, the content of 1-octene in the copolymer is 0.30 mol%.

[0072] Example 19, C1-catalyzed ethylene / 1-octene copolymerization

[0073] The polymerization reaction process and reaction conditions are the same as those in Example 16, and the polymerization pressure is 1 MPa. Polymerization activity: 7550 kg·mol -1 (M)·h -1 . Polymer M w = 520 kg·mol -1 , M w / M n = 2.3, the content of 1-octene in the copolymer is 0.11 mol%.

[0074] Example 20, C1-catalyzed ethylene / 1-octene copolymerization

[0075] The polymerization reaction process and reaction conditions are the same as in Example 16, and the polymerization pressure is 3 MPa. Polymerization activity: 12300 kg·mol -1 (M)·h -1 . Polymer M w = 570 kg·mol -1 , M w / M n = 2.3, the content of 1-octene in the copolymer is <0.1 mol%.

[0076] Example 21, C2-catalyzed ethylene / 1-octene copolymerization

[0077] The polymerization reaction process and reaction conditions are the same as those in Example 16, and the catalyst used is C2. Polymerization activity: 8630 kg·mol -1 (M)·h -1 , polymer M w = 580 kg·mol -1 , M w / M n= 2.2, the content of 1-octene in the copolymer is 0.16 mol%.

[0078] Example 22, C3-catalyzed ethylene / 1-octene copolymerization

[0079] The polymerization reaction process and reaction conditions are the same as those in Example 16, and the catalyst used is C3. Polymerization activity: 8520 kg·mol -1 (M)·h -1 . Polymer M w = 458 kg·mol -1 , M w / M n = 2.3, the content of 1-octene in the copolymer is 0.16 mol%.

[0080] Example 23, C4-catalyzed ethylene / 1-octene copolymerization

[0081] The polymerization reaction process and reaction conditions are the same as those in Example 16, and the catalyst used is C4. Polymerization activity: 5480 kg·mol -1 (M)·h -1 . Polymer M w = 620 kg·mol -1 , M w / M n = 1.9, the content of 1-octene in the copolymer is 0.10 mol%.

[0082] Example 24, C5-catalyzed ethylene / 1-octene copolymerization

[0083] The polymerization reaction process and reaction conditions are the same as those in Example 16, and the catalyst used is C5. Polymerization activity: 5670 kg·mol -1 (M)·h -1 . Polymer M w = 622 kg·mol -1 , M w / M n = 2.3, the content of 1-octene in the copolymer is 0.14 mol%.

[0084] Example 25, Preparation of (ethylene / 1-octene) multiblock copolymer by chain shuttling polymerization of C4 and Ar-Hf

[0085] A 100 mL steel reactor equipped with a magnetic stir bar was used for the polymerization reaction. 34.4 mL of toluene and 15.6 mL of 1-octene were added thereto by syringe injection. 240 μmol of diethylzinc dissolved in toluene was added to the reaction kettle. The reactor contents were heated to 100 °C and saturated with 2 MPa of ethylene. 10.0 μmol of catalyst C4, 2.0 μmol of Ar-Hf, 100 μmol of methylaluminoxane, and 24.0 μmol of triphenylcarbenium tetrakis(pentafluorophenyl)borate were added in the glove box, dissolved in toluene, transferred to the catalyst storage tube by syringe, and pressured into the reactor with nitrogen (over 2 MPa). During the polymerization process, the reaction pressure was maintained at 2 MPa by continuously introducing ethylene gas. After reaching the set reaction time of 10 min, 2 mL of ethanol was pressured into the reactor under nitrogen (over 2 MPa). After the reactor was cooled, the gas was discharged. The contents of the reactor were poured into a large amount of ethanol, and the polymer precipitated. The polymer was filtered, washed with a small amount of ethanol, and finally dried under vacuum overnight and weighed. Polymerization activity: 4850 kg·mol -1 (M)·h -1 , polymer M w = 174 kg·mol -1 , M w / M n = 2.0, T m = 129.0 °C. The content of 1-octene in the copolymer was 19.7 mol%.

[0086] Example 26. Preparation of (ethylene / 1-octene) multiblock copolymer by chain shuttling polymerization of C1 and Ar-Hf

[0087] The polymerization reaction process and reaction conditions were the same as in Example 25, and the catalyst used was C1. Polymerization activity: 4730 kg·mol -1 (M)·h -1 , polymer M w = 17.7 kg·mol -1 , M w / M n = 2.0, T m = 129.3 °C. The content of 1-octene in the copolymer was 19.9 mol%.

[0088] Example 27. Preparation of (ethylene / 1-octene) multiblock copolymer by chain shuttling polymerization of C2 and Ar-Hf

[0089] The polymerization reaction process and reaction conditions were the same as in Example 25, and the catalyst used was C2. Polymerization activity: 4930 kg·mol -1 (M)·h -1 , polymer M w = 18.7 kg·mol -1 , Mw / M n = 2.0, T m = 129.4 °C. The content of 1-octene in the copolymer is 19.1 mol%.

[0090] Example 28. Preparation of (ethylene / 1-octene) multiblock copolymer by chain shuttling polymerization of C3 and Ar-Hf

[0091] The polymerization reaction process and reaction conditions are the same as those in Example 25, and the catalyst used is C3. Polymerization activity: 4650 kg·mol -1 (M)·h -1 , polymer M w = 18.1 kg·mol -1 , M w / M n = 2.0, T m = 129.6 °C. The content of 1-octene in the copolymer is 19.1 mol%.

[0092] Example 29. Preparation of (ethylene / 1-octene) multiblock copolymer by chain shuttling polymerization of C5 and Ar-Hf

[0093] The polymerization reaction process and reaction conditions are the same as those in Example 25, and the catalyst used is C5. Polymerization activity: 5100 kg·mol -1 (M)·h -1 , polymer M w = 15.6 kg·mol -1 , M w / M n = 2.0, T m = 129.2 °C. The content of 1-octene in the copolymer is 17.9 mol%.

[0094] Example 30. Preparation of (ethylene / 1-octene) multiblock copolymer by chain shuttling polymerization of C4 and Ar-Hf

[0095] The polymerization reaction process and reaction conditions are the same as those in Example 25, and the chain shuttling agent used is dimethylzinc. Polymerization activity: 4060 kg·mol -1 (M)·h -1 , polymer M w = 13.6 kg·mol -1 , M w / M n = 2.1, T m = 129.3 °C. The content of 1-octene in the copolymer is 19.9 mol%.

[0096] Example 31. Preparation of (ethylene / 1-octene) multiblock copolymer by chain shuttling polymerization of C4 and Ar-Hf

[0097] The polymerization process and reaction conditions were the same as in Example 25, and the chain shuttling agent used was triisobutylaluminum. Polymerization activity: 4960 kg·mol -1 (M)·h -1 , and the polymer M w = 13.8 kg·mol -1 , M w / M n = 2.0, T m = 129.4 °C. The content of 1-octene in the copolymer was 20.7 mol%.

[0098] Example 32. Preparation of (ethylene / 1-octene) multiblock copolymer by chain shuttling polymerization of C4 and Ar-Hf

[0099] The polymerization process and reaction conditions were the same as in Example 25, and 5.0 μmol of C4 and 2.0 μmol of Ar-Hf were used as catalysts. Polymerization activity: 5060 kg·mol -1 (M)·h -1 , and the polymer M w = 12.8 kg·mol -1 , M w / M n = 2.0, T m = 129.3 °C. The content of 1-octene in the copolymer was 22.3 mol%.

[0100] Example 33. Preparation of (ethylene / 1-octene) multiblock copolymer by chain shuttling polymerization of C4 and Ar-Hf

[0101] The polymerization process and reaction conditions were the same as in Example 25, and 120 μmol of diethylzinc was used. Polymerization activity: 4630 kg·mol -1 (M)·h -1 , and the polymer M w = 38.4 kg·mol -1 , M w / M n = 2.0, T m = 129.5 °C. The content of 1-octene in the copolymer was 19.7 mol%.

[0102] Example 34. Preparation of (ethylene / 1-octene) multiblock copolymer by chain shuttling polymerization of C4 and Ar-Hf

[0103] The polymerization process and reaction conditions were the same as in Example 25, and 60 μmol of diethylzinc was used. Polymerization activity: 4150 kg·mol -1 (M)·h -1 , and the polymer M w = 193 kg·mol-1 , M w / M n = 1.9, T m = 130.0 °C. The content of 1-octene in the copolymer is 19.3 mol%.

Claims

1. A type of CNN-tridentate coordinated titanium-zirconium-hafnium metal catalyst, whose structure is shown in formula (I): in, M is selected from titanium, zirconium, and hafnium; R 1 is selected from methyl, ethyl, hydrogen, isopropyl, chlorine, fluorine; R 2 is selected from methyl, ethyl, hydrogen, isopropyl, chlorine, fluorine; R 3 is selected from methyl, methoxy, hydrogen, tert-butyl, R 4 Selected from C1-C6 straight chain alkyl or phenyl or isopropylphenyl.

2. The preparation method of the CNN-tridentate titanium zirconium hafnium metal catalyst according to claim 1 comprises the following steps: under a nitrogen atmosphere, dissolving the metal salt MCl4 in 20-80 mL of anhydrous solvent, adding 4.0-5.0 molar equivalents of methylmagnesium bromide, reacting at low temperature for 2-6 hours under nitrogen protection, and then adding 1 molar equivalent of ligand to react for 2-12 hours; after the reaction is completed, removing the solvent under reduced pressure, and extracting with a good solvent to obtain the CNN-tridentate titanium zirconium hafnium metal catalyst according to claim 1.

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

4. The preparation method according to claim 2, characterized in that: The metal salt MCl4 is selected from any one of TiCl4, ZrCl4, and HfCl4.

5. A method for preparing polyolefin by olefin polymerization, characterized in that: The catalyst used is the CNN-tridentate coordinated titanium zirconium hafnium metal catalyst 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, norbornene and 1-octene.

7. The method according to claim 5, characterized in that: The CNN-tridentate titanium zirconium hafnium metal catalyst needs to be coordinated with a co-catalyst for catalysis, and the co-catalyst is one or more of trispentafluorophenyl boron, triphenylcarbonium tetrakis(pentafluorophenyl)borate, aluminoxane, alkylaluminum and alkylaluminum chloride.

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

9. The method according to claim 5, characterized in that: The polymerization temperature is 0-200° C., the polymerization pressure is 0.1-5 MPa, and the polymerization solvent is one or more of n-hexane, n-heptane, n-pentane, and toluene.

10. The method according to claim 5, characterized in that: The CNN-tridentate titanium zirconium hafnium metal catalyst is matched with the catalyst shown in formula (II), Under the action of a chain shuttling agent, continuous shuttling polymerization can be achieved to prepare a high melting point polyolefin block copolymer; wherein the chain shuttling agent is one or more of diethyl zinc, dimethyl zinc, triisobutyl aluminum, trimethyl aluminum, triethyl aluminum and tri-n-hexyl aluminum.

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