Preparation method and application of nn-bidentate coordination metal catalyst based on quinoline skeleton

Abstract

In the present application, a series of new quinoline-amine ligands were directly synthesized by p-TsOH catalyzed amine-aldehyde condensation between 2-formaldehyde-quinoline and various anilines. Next, the quinoline-amine metal catalysts were obtained by one-pot reaction of the obtained ligands with MMe4(M = Ti, Zr or Hf) synthesized in situ, which has high yield and great economic benefits. The NN-bidentate titanium zirconium hafnium metal catalysts obtained were used in the synthesis of polyolefin elastomers, and it was found that by changing the substituents on the structure of the catalyst, the molecular weight and alpha-olefin insertion rate of the obtained polymer can be effectively improved. The NN-bidentate titanium zirconium hafnium metal catalysts reported in the present application have the advantages of simple synthesis, easy to obtain raw materials and high product yield. In the presence of a cocatalyst, the catalyst exhibits excellent activity (3.56×10 8 g(POE)·mol ‑1 (Hf)·h ‑1 ), alpha-olefin selectivity (insertion rate up to 36.6mol%), and preparation of high molecular weight polyolefin elastomer POE (polymer molecular weight Mw up to 1150kg·mol ‑1 ). In addition, the NN-bidentate titanium zirconium hafnium metal catalysts reported in the present application also exhibit excellent high temperature resistance (greater than 160℃), which is suitable for high temperature solution polymerization and can prepare high performance polyolefin elastomer. Therefore, the present application has originality and innovation, and provides a new direction for the development of polyolefin material field.

Description

TECHNICAL FIELD

[0001] The present invention relates to the preparation of olefin coordination polymerization metal catalysts and their use in the field of olefin polymerization. BACKGROUND

[0002] In recent years, the production capacity and application of polyolefin materials have been rising. Polyethylene (PE), polypropylene (PP), and ethylene / alpha-olefin copolymers, etc. polyolefin materials are widely used in daily necessities, military products, from toys, sports equipment to automobiles, aircraft, rockets, etc. various fields due to their light weight, high mechanical strength, impact resistance, good processability and other advantages. With the continuous development of society, the application range of polyolefin materials continues to expand. However, in this development process, a single polyolefin material cannot meet the diversified needs. Therefore, high-performance polyolefin materials such as ultrahigh molecular weight polyethylene, polyolefin elastomer, etc. have emerged. Among them, polyolefin elastomer (POE) is a kind of ethylene-based random copolymer with high alpha-olefin content (usually more than 20 wt. %), which is copolymerized by ethylene and 1-octene, 1-hexene or 1-butene. It is a kind of high-performance polyolefin with excellent mechanical and elastic properties, which has attracted much attention in the automotive industry and photovoltaic field. Generally speaking, polyolefin elastomer is synthesized by solution polymerization technology, which can more efficiently synthesize the product and better control the polymer microstructure, thereby obtaining a material with more excellent performance. Solution polymerization is best carried out at high temperature (usually more than 120℃) to prevent the polymer from precipitating during polymerization. In addition, high-temperature solution polymerization can reduce viscosity, increase product yield, and thus reduce cost. However, these limitations pose great challenges to the catalysts used in catalytic olefin polymerization, because as the polymerization temperature increases, the activity of the polyolefin catalyst for catalyzing olefin polymerization and the molecular weight (Mws) of the generated polymer are usually reduced. Therefore, it is very necessary to develop a homogeneous metal catalyst with better catalytic performance at high temperature.

[0003] To this end, metallocene and constrained geometry catalysts (CGC) were designed and synthesized by researchers worldwide and successfully used in the commercial production of POE in the early 1990s (Chem. Rev. 1998, 98, 2587-2598). In addition, a number of non-metallocene transition metal catalysts have also gradually developed. Among them, the imine-amine type metal catalyst was first discovered by Dow Chemical (Organometallics 2007, 26, 3896-3899), and the imine ligand can be easily obtained from the market, and the resulting metal catalyst has high activity and can achieve the regulation of α-olefin content. However, this kind of imine-amine metal catalyst performs poorly in terms of high temperature resistance. Subsequently, the imine-based complex designed by introducing a six-membered ring into the ligand structure has better thermal stability, but the ligand itself is prone to isomerization under the induction of acid, which brings inconvenience to synthesis (Organometallics 2011, 30, 1695-1709). Kloin et al. successfully improved the high temperature resistance of the catalyst by introducing a quinoline structure into the catalyst skeleton

[0004] (Organometallics 2012, 31, 6244-6251), and a series of polyolefin catalysts with different catalytic properties were obtained by changing the substituents on the catalyst structure. Although the amine-quinoline ligand can provide the metal catalyst with good high temperature resistance and copolymerization performance, its one cannot ignore the disadvantage is that the expensive Pd catalyst is used in the synthesis of the ligand to catalyze the coupling reaction, which makes it have an undeniable disadvantage in large-scale production.

[0005] In the present application, a series of new quinoline-amine ligands are directly synthesized by p-TsOH-catalyzed amine aldehyde condensation between 2-formaldehyde-quinoline and various anilines. Next, the quinoline-amine metal catalyst is obtained by one-pot reaction of the obtained ligand with MMe4(M = Ti, Zr or Hf) synthesized in situ, which has high yield and is very economical. The NN-bidentate titanium, zirconium and hafnium metal catalyst obtained is used in the synthesis of polyolefin elastomers, and it is found that by changing the substituents on the catalyst structure, the molecular weight and α-olefin insertion rate of the obtained polymer can be effectively improved. The NN-bidentate titanium, zirconium and hafnium metal catalyst reported in the present application has the advantages of simple synthesis, easy availability of raw materials and high product yield. In the presence of a cocatalyst, the catalyst exhibits excellent activity (3.56×10 8 g (POE)·mol -1 (Hf)·h -1 ), α-olefin selectivity (insertion rate of 36.6 mol%), and preparation of high molecular weight polyolefin elastomer POE (polymer molecular weight Mw of 1150 kg·mol -1). In addition, the NN-bidentate titanium zirconium hafnium metal catalyst reported in the present application also exhibits excellent high temperature resistance (greater than 160℃), which is suitable for high temperature solution polymerization and can be used to prepare high performance polyolefin elastomers. As a comparison, the NN-bidentate titanium zirconium hafnium metal catalyst reported in the present application exhibits better catalytic effect than the constrained geometry catalyst CGC ((tert-butylamido)(tetramethyl-η 5 -cyclopentadienyl)-1,2-ethanediylhafnium dichloride) (Eur. Patent EP416815, 1991), NN-Hf catalyst (((2,6-Diisopropylphenyl)(quinolin-8-yl)amino)hafniumtrimethyl) (Organometallics 2012, 31, 6244-6251). Therefore, the present application has original innovation and provides a new direction for the development of polyolefin materials field. SUMMARY

[0006] The purpose of the present application is to provide a synthesis of NN-bidentate titanium zirconium hafnium metal catalyst and its application in the preparation of polyolefin elastomers.

[0007] The present application provides a NN-bidentate titanium zirconium hafnium metal catalyst represented by formula (I):

[0008]

[0009] wherein M is selected from titanium, zirconium, hafnium; R 1 selected from methyl, ethyl, hydrogen, isopropyl, chlorine, fluorine; R 2 selected from methyl, ethyl, hydrogen, isopropyl, chlorine, fluorine; R 3 selected from methyl, methoxy, hydrogen, tert-butyl, R 4 selected from C1-C6 linear alkyl or phenyl or benzyl or isopropylphenyl.

[0010] Preferably, the metal compound of the present application is selected from any one of the metal catalysts represented by formula (II):

[0011]

[0012] The present application provides a preparation method of the above-mentioned NN-bidentate titanium zirconium hafnium metal catalyst, comprising the following steps:

[0013] The metal salt is dissolved in 20-80 mL of anhydrous solvent under a nitrogen atmosphere, 4.0-5.0 molar equivalents of methyl magnesium bromide are added, and the reaction is carried out at low temperature under nitrogen protection for 2 hours, then 1 molar equivalent of quinoline imine is added and the reaction is carried out for 5 hours; after the reaction is completed, the solvent is removed under reduced pressure, and the product is extracted with a good solvent to obtain the NN-bidentate titanium zirconium hafnium metal catalyst.

[0014] In the above preparation method, the anhydrous solvent is selected from toluene, n-hexane, xylene and benzene; and the good solvent is selected from n-hexane, toluene, pentane, heptane and cyclohexane.

[0015] In the above preparation method, the metal salt MCl4 is selected from one of TiCl4, ZrCl4 and HfCl4.

[0016] The application further provides the application of the above-mentioned NN-bidentate titanium zirconium hafnium metal catalyst in catalyzing olefin polymerization.

[0017] In the above application, the olefin monomer is one or more of ethylene, propylene, 1-butene, styrene, 1-hexene, norbornene and 1-octene.

[0018] The NN-bidentate titanium zirconium hafnium metal catalyst needs to be combined with a cocatalyst for catalysis, and the cocatalyst is one or more of trifluorophenyl boron, triphenyl carbonium tetrakis (pentafluorophenyl) borate, aluminoxane, alkyl aluminum and chlorinated alkyl aluminum. The aluminoxane is methyl aluminoxane, ethyl aluminoxane or isobutyl aluminoxane; the alkyl aluminum is trimethyl aluminum, triethyl aluminum, triisobutyl aluminum or tri-n-hexyl aluminum; and the chlorinated alkyl aluminum is monochlorodiethyl aluminum, sesqui-monochlorodiethyl aluminum or diethyl aluminum chloride.

[0019] In the above polymerization reaction, the polymerization temperature is 0-200℃, the polymerization pressure is 0.1-5 MPa, and the polymerization solvent is one or more of n-hexane, heptane, pentane and toluene.

[0020] The application provides the preparation of an NN-bidentate titanium zirconium hafnium metal catalyst based on a quinoline skeleton and the application of the catalyst in catalyzing olefin polymerization. The NN-bidentate titanium zirconium hafnium metal catalyst based on a quinoline skeleton reported in the application has the advantages of simple synthesis, easy availability of raw materials, high product yield, high catalytic activity (the highest activity can reach 3.56×10 8 g (PE) · mol -1 (Hf) · h -1 ), good copolymerization performance (the 1-octene insertion rate can reach 36.6 mol%) and the like, and is especially suitable for high-temperature solution polymerization for preparing high-quality and high-performance polyolefin materials. The metal catalyst provided in the application has original innovation and can promote the development of high-end polyolefin chemical industry in China. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 This is the 1H NMR spectrum of catalyst C1.

[0022] Figure 2 This is the 1H NMR spectrum of catalyst C2.

[0023] Figure 3 This is the 1H NMR spectrum of catalyst C3.

[0024] Figure 4 This is the 1H NMR spectrum of catalyst C4.

[0025] Figure 5 The POE carbon NMR spectrum of a polyolefin elastomer with a 1-octene insertion rate of 10.9%.

[0026] Figure 6 The image shows the carbon NMR spectrum of a polyolefin elastomer with a 1-octene insertion rate of 30.6%.

[0027] Figure 7 The image shows the carbon NMR spectrum of a polyolefin elastomer with a 1-octene insertion rate of 32.6%.

[0028] Figure 8 The image shows the carbon NMR spectrum of a polyolefin elastomer with a 1-octene insertion rate of 36.6%.

[0029] Figure 9 This is a crystal diagram of catalyst C3.

[0030] Figure 10 This is a crystal diagram of catalyst C4. Detailed Implementation

[0031] 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.

[0032] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0033] In this invention, the NN-bidactile ligands 2–(2,6–Me2–C6H3–N=CH)–quinoline, 2–(2,4,6–Me3–C6H2–N=CH)–quinoline, and 2–(2,6– i Pr2–C6H3–N=CH)–quinoline and 2–(2,6–Cl2–C6H3–N=CH)–quinoline were synthesized according to the literature method (Dalton Transactions 2017, 46, 15520-15534). As shown in (III), the defined geometry catalyst CGC((tert-butylamido)(tetramethyl-η) was used for the control experiment. 5-NN-Hf catalyst ((2,6-Diisopropylphenyl)(quinolin-8-yl)amino)hafnium trimethyl, refer to literature method (Eur. Patent EP416815, 1991; Organometallics 2012, 31, 6244-6251.) synthesis.

[0034]

[0035] The present application is described in the following with specific examples.

[0036] Example 1, preparation of catalyst C1

[0037] Hafnium tetrachloride (0.352 g, 1.1 mmol) was weighed, 10 mL of anhydrous toluene was added, 1.6 mL / 4.8 mmol of methyl magnesium bromide solution (3M) was slowly added at -40°C (acetonitrile-liquid nitrogen bath), and stirred for 2 hours. Then ligand 2-(2,6-Me2-C6H3-N=CH)-quinoline (0.26 g / 1 mmol) was added, and the reaction was carried out at -40°C for 2 hours in the dark, and then continued at room temperature for 5 hours. After the reaction was completed, the solvent was removed, toluene was added for extraction, and filtration was performed to obtain the product 0.44 g with a yield of 75%. 1 H NMR (400 MHz, C6D6): δ 8.47 (d, J = 8.6 Hz, 1H), 7.37 (d, J = 8.6 Hz, 1H), 7.30-7.24 (m, 2H), 7.21 (d, J = 7.5 Hz, 1H), 7.09-7.04 (m, 2H), 6.61 (d, J = 8.6 Hz, 1H), 4.94 (q, J = 6.8 Hz, 1H), 2.66 (s, 3H), 2.35 (s, 3H), 1.18 (d, J = 6.8 Hz, 3H), 0.61 (s, 9H) ppm. 13 C NMR (400 MHz, C6D6): δ 170.07, 148.30, 145.32, 138.79, 136.93, 135.60, 130.16, 129.42, 129.11, 127.08, 126.96, 125.08, 119.34, 70.45, 59.32, 24.17, 20.53, 18.86 ppm. Anal. Calcd for C 22 H 28HfN2: C, 53.85; H, 5.89; N, 5.46. Found: C, 53.64; H, 5.71; N, 5.52.

[0038] Example 2, preparation of catalyst C2

[0039] HfCl4(0.256 g, 1.1 mmol) was weighed into 10 mL of dry toluene and 1.6 mL / 4.8 mmol of a methylmagnesium bromide solution (3 M) was slowly added at -40°C (acetonitrile-liquid nitrogen bath) and stirred for 2 hours. The ligand 2-(2,4,6-Me3-C6H2-N=CH)-quinoline (0.27 g / 1 mmol) was then added and stirred for two hours at -40°C in the dark. After returning to room temperature, the reaction was continued for 5 hours. After the reaction was completed, the solvent was removed, toluene was added for extraction, filtered, and the product was obtained as 0.42 g with a yield of 85%. 1 H NMR (400 MHz, C6D6): δ 8.49 (d, J = 8.6 Hz, 1H), 7.37 (d, J = 8.6 Hz, 1H), 7.31-7.24 (m, 2H), 7.07 (t, J = 7.5 Hz, 1H), 7.00 (d, J = 17.2 Hz, 2H), 6.62 (d, J = 8.6 Hz, 1H), 4.96 (q, J = 6.8 Hz, 1H), 2.65 (s, 3H), 2.36 (s, 3H), 2.23 (s, 3H), 1.22 (d, J = 6.8 Hz, 3H), 0.63 (s, 9H) ppm. 13 C NMR (400 MHz, C6D6): δ 170.12, 145.35, 145.11, 138.71, 136.60, 135.30, 134.03, 130.28, 130.12, 129.91, 127.17, 126.94, 119.36, 70.55, 59.07, 24.13, 21.06, 20.47, 18.80 ppm. Anal. Calcd for C 23 H 30 HfN2: C, 53.85; H, 5.89; N, 5.46. Found: C, 53.64; H, 5.71; N, 5.52.

[0040] Example 3, preparation of catalyst C3

[0041] HfCl4(0.256 g, 1.1 mmol) was weighed into 10 mL of dry toluene and 1.6 mL / 4.8 mmol of a methylmagnesium bromide solution (3 M) was slowly added at -40°C (acetonitrile-liquid nitrogen bath) and stirred for 2 hours. The ligand 2-(2,4,6-Me3-C6H2-N=CH)-quinoline (0.27 g / 1 mmol) was then added and stirred for two hours at -40°C in the dark. After returning to room temperature, the reaction was continued for 5 hours. After the reaction was completed, the solvent was removed, toluene was added for extraction, filtered, and the product was obtained as 0.42 g with a yield of 85%. iPr2-C6H3-N=CH)-quinoline (0.32 g / 1 mmol), stirring for 2 hours at -40 °C in the dark, and continuing the reaction for 5 hours at room temperature. After the end of the reaction, the solvent was removed, toluene was added for extraction, filtered, and the product was obtained as 0.45 g with a yield of 88%. 1 H NMR (400 MHz, C6D6): δ 8.52 (dd, J = 8.6, 0.6 Hz, 1H), 7.40 (d, J = 8.5 Hz, 1H), 7.35 - 7.17 (m, 5H), 7.09 (ddd, J = 8.0, 7.0, 0.9 Hz, 1H), 6.65 (d, J = 8.6 Hz, 1H), 5.10 (q, J = 6.9 Hz, 1H), 4.10 (hept, J = 6.8 Hz, 1H), 3.55 (hept, J = 6.9 Hz, 1H), 1.58 (d, J = 6.8 Hz, 3H), 1.37 (d, J = 6.8 Hz, 3H), 1.30 (d, J = 6.8 Hz, 6H), 1.21 (d, J = 6.9 Hz, 3H), 0.62 (s, 9H) ppm. 13 C NMR (400 MHz, C6D6) δ 169.61, 147.52, 146.43, 145.36, 143.52, 138.77, 130.12, 127.36, 127.03, 126.35, 124.98, 124.50, 119.55, 71.43, 28.38, 27.87, 26.20, 26.11, 25.31, 25.02, 23.56 ppm. Anal. Calcd for C 26 H 36 HfN2: C, 56.26; H, 6.54; N, 5.05. Found: C, 56.27; H, 6.44; N, 5.15.

[0042] Example 4, Preparation of Catalyst C4

[0043] HfCI4(0.352 g, 1.1 mmol) was weighed, 10 mL of dry toluene was added, and 1.6 mL / 4.8 mmol of methyl magnesium bromide solution (3 M) was slowly added at -40 °C (acetonitrile-liquid nitrogen bath) and stirred for 2 hours. Then the ligand 2-(2,6-Cl2-C6H3-N=CH)-quinoline (0.30 g / 1 mmol) was added, stirred for two hours at -40 °C in the dark, and continued to react for 5 hours at room temperature. After the end of the reaction, the solvent was removed, toluene was added for extraction, filtered, and the product was obtained as 0.46 g with a yield of 77%. 1H NMR (400 MHz, C6D6): δ 8.53 (d, J = 8.7 Hz, 1H), 7.33 (d, J = 8.6 Hz, 1H), 7.28 - 7.18 (m, 4H), 7.05 (t, J = 7.9 Hz, 1H), 6.61 (d, J = 8.6 Hz, 1H), 6.49 (s, 1H), 5.47 (q, J = 6.9 Hz, 1H), 1.27 (d, J = 6.9 Hz, 3H), 0.73 (s, 9H) ppm. 13 C NMR (400 MHz, C6D6): δ 169.92, 147.93, 145.28, 139.23, 130.27, 128.86, 127.02, 126.83, 125.62, 119.50, 69.48, 61.40, 24.12, 1.42 ppm. Anal. Calcd for C 20 H 22 Cl2HfN2: C, 44.50; H, 4.11; Cl, 13.13; N, 5.19. Found: C, 44.38; H, 4.09; N, 5.21.

[0044] Example 5, Preparation of Catalyst C5

[0045] The quinoline imine ligand (1.90 g, 6.00 mmol) was weighed out and 30 mL of anhydrous and oxygen-free toluene was added. At low temperature (acetonitrile-liquid nitrogen bath), trimethylaluminum (2 M in Et20) was slowly added (3 mL, 6 mmol). The reaction was allowed to recover to room temperature for 3 h. After the reaction was completed, 20 mL of an aqueous NH4CI solution (1 M) was added to quench the reaction. The organic phase was collected and washed with saturated brine once more. The solvent was removed by rotary evaporation. The ligand 2-(2,6-iPr-C6H3-N-CH-Me)-quinoline was purified by column chromatography (petroleum ether: ethyl acetate = 10: 1). To the solution of the ligand 2-(2,6-iPr-C6H3-N-CH-Me)-quinoline (1.43 g, 4.30 mmol, 8 mL hexane) was added Ti(NMe2)4(1.07 g, 4.70 mmol) under nitrogen using a syringe. The reaction mixture was stirred at 65 °C for 24 h to obtain a yellow suspension. The suspension was filtered at room temperature. The residue was washed with 2 mL of hexane and dried under reduced pressure to obtain a yellow powder (1.84 g, 3.60 mmol, 83% yield). To the solution of the yellow powder (1.53 g, 3.00 mmol) obtained in the previous step in 50 mL of toluene was slowly added Me2SiCI2(2.15 g, 16.7 mmol) using a syringe at 0 °C. The reaction mixture was stirred at room temperature overnight. The solvent was removed from the reaction mixture under reduced pressure. The residue was washed with 20 mL of hexane to obtain a red powder (1.28 g, 2.64 mmol, 88% yield). To the red powder (0.63 g, 1.30 mmol) suspended in 50 mL of toluene was added 2 mL (6.0 mmol) of a 3 M MeMeBr solution in diethyl ether at -40 °C to obtain a black suspension. The reaction mixture was stirred at room temperature for 3 h. The solvent was removed from the reaction mixture under reduced pressure. To the residue was added 80 mL of hexane. After stirring at room temperature for 5 min, the suspension was filtered. The filtrate was concentrated and filtered to obtain a yellow powder product (0.47 g, 1.10 mmol, 80% yield). 1HNMR (400 MHz, C6D6): δ 8.49 (dd, J = 8.6, 0.6 Hz, 1H), 7.36 (d, J = 8.5 Hz, 1H), 7.35 - 7.16 (m, 5H), 7.05 (ddd, J = 8.0, 7.0, 0.9 Hz, 1H), 6.55 (d, J = 8.6 Hz, 1H), 5.04 (q, J = 6.9 Hz, 1H), 4.04 (hept, J = 6.8 Hz, 1H), 3.51 (hept, J = 6.9 Hz, 1H), 1.56 (d, J = 6.8 Hz, 3H), 1.31 (d, J = 6.8 Hz, 3H), 1.25 (d, J = 6.8 Hz, 6H), 1.17 (d, J = 6.9 Hz, 3H), 0.55 (s, 9H) ppm. 13 C NMR (400 MHz, C6D6): δ 168.61, 146.51, 144.42, 143.36, 142.12, 138.01, 131.10, 126.11, 125.53, 124.15, 123.98, 123.51, 119.50, 71.03, 28.18, 27.57, 26.21, 26.01, 25.31, 25.02, 23.56 ppm. Anal. Calcd for C 26 H 36 TiN2: C, 73.57; H, 8.55; N, 6.60 Found: C, 73.27; H, 8.44; N, 6.15.

[0046] Example 6, Preparation of Catalyst C6

[0047] Zirconium tetrachloride (0.256 g, 1.1 mmol) was weighed, 10 mL of dry toluene was added, and 1.6 mL / 4.8 mmol of methyl magnesium bromide solution (3M) was slowly added at -40°C (acetonitrile-liquid nitrogen bath) and stirred for 2 hours. Then ligand 2-(2,6-iPr-C6H3-N=CH)-quinoline (0.30 g / 1 mmol) was added, and stirring was continued for two hours at -40°C in the dark, and the reaction was continued for 5 hours after the temperature was returned to room temperature. After the reaction was completed, the solvent was removed, toluene was added for extraction, and filtration was performed to obtain the product 0.34 g with a yield of 72%. 1H NMR (400 MHz, C6D6) δ 8.48 (d, J = 8.7 Hz, 1H), 7.40 (d, J = 8.6 Hz, 1H), 7.33 - 7.27 (m, 2H), 7.24 (m, 2H), 7.19 (dd, J = 6.9, 2.6 Hz, 1H), 7.10 (t, J = 7.1 Hz, 1H), 6.67 (d, J = 8.6 Hz, 1H), 5.04 (q, J = 6.9 Hz, 1H), 4.11 (hept, J = 6.8 Hz, 1H), 3.53 (hept, J = 6.9 Hz, 1H), 1.56 (d, J = 6.9 Hz, 3H), 1.34 (d, J = 6.8 Hz, 3H), 1.29 (dd, J = 6.8, 1.4 Hz, 6H), 1.23 (d, J = 6.9 Hz, 3H), 0.84 (s, 9H) ppm. 13 C NMR (400 MHz, C6D6): δ 168.51, 146.52, 145.01, 144.30, 142.33, 137.54, 129.55, 128.65, 126.11, 125.37, 133.55, 123.55, 118.26, 72.53, 29.44, 28.87, 27.56, 26.41, 25.66, 25.02, 23.06 ppm. Anal. Calcd for C 20 H 22 HZrN2: C, 66.75; H, 7.76; N, 5.99. Found: C, 66.55; H, 7.52; N, 5.76.

[0048] Example 7, C1 catalyzed ethylene polymerization

[0049] A 350 mL glass reactor equipped with a magnetic stirrer was used for the polymerization. In a glove box, 2 μmol of catalyst C1, 2.2 μmol of triphenylcarbenium tetrakis(pentafluorophenyl)borate and 100 μmol of methylaluminoxane were weighed. The glass reactor was attached to the polymerization line and 50 mL of toluene was added to it. The temperature was raised to 80 °C and ethylene gas was continuously fed to maintain the pressure at 5 atm. After 2 min of reaction, 30 mL of ethanol was added to the reactor under nitrogen atmosphere. After cooling, the reaction solution was poured into a large amount of ethanol to precipitate, and the final polymer was obtained by filtration and drying. Polymerization activity: 41,000 kg-mol -1 (Hf)·h -1 , polymer Mw = 273 kg-mol -1 , Mw / Mn = 2.0.

[0050] Example 8, C1 catalyzed ethylene polymerization

[0051] The polymerization process and reaction conditions were the same as in Example 7, and the polymerization temperature was 120°C. Polymerization activity: 62300 kg-mol -1 (Hf) - h -1 . Polymer Mw = 261 kg-mol -1 , Mw / Mn = 2.2.

[0052] Example 9, ethylene polymerization catalyzed by C1

[0053] A 100 mL steel reactor equipped with a magnetic stirrer was used for the polymerization, 50 mL of toluene was injected with a syringe, and the reactor contents were heated to 160°C, and the reactor was saturated with 1 MPa of ethylene. In a glove box, 2 μmol of catalyst C1, 100 μmol of methylaluminoxane, and 2.2 μmol of triphenylcarbenium tetrakis(pentafluorophenyl)borate were added, dissolved in toluene, and transferred to a catalyst storage tube with a syringe, and were pressurized into the reactor with nitrogen (over 1 MPa). During the polymerization, the reaction pressure was maintained at 1 MPa by continuously introducing ethylene gas. After the set reaction time of 2 min was reached, 2 mL of ethanol was pressurized into the reactor with nitrogen (over 1 MPa), the reactor was cooled, and the reactor was vented, and the contents of the reactor were poured into a large amount of ethanol, and the polymer was precipitated, and was filtered, washed with a small amount of ethanol, and finally dried in a vacuum overnight, and was weighed. Polymerization activity: 142000 kg-mol -1 (Hf) - h -1 . Polymer Mw = 338 kg-mol -1 , Mw / Mn = 2.2.

[0054] Example 10, ethylene polymerization catalyzed by C1

[0055] The polymerization process and reaction conditions were the same as in Example 9, and the polymerization temperature was 180°C. Polymerization activity: 110900 kg-mol -1 (Hf) - h -1 . Polymer Mw = 335 kg-mol -1 , Mw / Mn = 2.0.

[0056] Example 11, ethylene polymerization catalyzed by C1

[0057] A 350 mL glass reactor equipped with a magnetic stirrer was used for the polymerization. In a glove box, 2 μmol of catalyst C1, 2.2 μmol of triphenylphosphonium salt and methylaluminoxane were weighed. The glass reactor was attached to the polymerization line and 50 mL of toluene was added to it. The temperature was raised to 120 °C and ethylene gas was continuously fed to maintain the reaction pressure at 5 atm. After 2 min of reaction, 30 mL of ethanol was added to the reactor under nitrogen atmosphere. After cooling, the reaction solution was poured into a large amount of ethanol to precipitate, and the final polymer was obtained by filtration and drying. Polymerization activity: 10010 kg-mol -1 (Hf) - h -1 , Polymer Mw = 232 kg-mol -1 , Mw / Mn = 1.9.

[0058] Example 12, ethylene polymerization catalyzed by C1

[0059] A 350 mL glass reactor equipped with a magnetic stirrer was used for the polymerization. In a glove box, 2 μmol of catalyst C1, 1000 μmol of methylaluminoxane were weighed. The glass reactor was attached to the polymerization line and 50 mL of toluene was added to it. The temperature was raised to 120 °C and ethylene gas was continuously fed to maintain the reaction pressure at 5 atm. After 2 min of reaction, 30 mL of ethanol was added to the reactor under nitrogen atmosphere. After cooling, the reaction solution was poured into a large amount of ethanol to precipitate, and the final polymer was obtained by filtration and drying. Polymerization activity: 203 kg-mol -1 (Hf) - h -1 , Polymer Mw = 130 kg-mol -1 , Mw / Mn = 2.2.

[0060] Example 13, ethylene polymerization catalyzed by C2

[0061] The polymerization was carried out under the same conditions as in Example 8, using C2 as catalyst. Polymerization activity: 72500 kg-mol -1 (Hf) - h -1 , Polymer Mw = 280 kg-mol -1 , Mw / Mn = 2.0.

[0062] Example 14, ethylene polymerization catalyzed by C3

[0063] The polymerization was carried out under the same conditions as in Example 8, using C3 as catalyst. Polymerization activity: 85100 kg-mol -1 (Hf) - h -1 , Polymer Mw = 485 kg-mol -1 , Mw / Mn = 2.1.

[0064] Example 15, ethylene polymerization catalyzed by C4

[0065] The polymerization was carried out under the same conditions as in Example 8, using catalyst C4. Polymerization activity: 10520 kg-mol -1 (Hf) - h -1 . Polymer Mw = 101 kg-mol -1 , Mw / Mn = 2.1.

[0066] Example 16, ethylene polymerization with catalyst C5

[0067] The polymerization was carried out under the same conditions as in Example 8, using catalyst C5. Polymerization activity: 21000 kg-mol -1 (Ti) - h -1 . Polymer Mw = 180 kg-mol -1 , Mw / Mn = 2.2.

[0068] Example 17, ethylene polymerization with catalyst C6

[0069] The polymerization was carried out under the same conditions as in Example 8, using catalyst C6. Polymerization activity: 53000 kg-mol -1 (Zr) - h -1 . Polymer Mw = 250 kg-mol -1 , Mw / Mn = 2.0.

[0070] Example 18, ethylene / 1-octene copolymerization with catalyst C3

[0071] A 350 mL glass reactor equipped with a magnetic stirrer was used for the polymerization. In a glove box, 2 μmol of catalyst C3, 2.2 μmol of triphenylcarbenium tetrakis(pentafluorophenyl)borate and 100 μmol of methylaluminoxane were weighed. The glass reactor was then connected to the polymerization line and, after the temperature had risen to 120°C, 26.6 mL of toluene and 23.4 mL of 1-octene were added, and ethylene gas was continuously fed to maintain a reaction pressure of 5 atm. After 2 min, 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 and the final polymer was obtained by filtration and drying. Polymerization activity: 78150 kg-mol -1 (Hf) - h -1 . Polymer Mw = 168 kg-mol -1 , Mw / Mn = 2.4, content of 1-octene in the copolymer 36.6 mol%.

[0072] Example 19, ethylene / 1-octene copolymerization with catalyst C3

[0073] The polymerization was carried out under the same conditions as in Example 18, using 34.4 mL of toluene and 15.6 mL of 1-octene. Polymerization activity: 74 250 kg-mol -1 (Hf) - h -1 The polymer Mw= 155 kg-mol -1 Mw / Mn = 2.3, the content of 1-octene in the copolymer being 33.7 mol %.

[0074] Example 20, C3-catalyzed ethylene / 1-octene copolymerization

[0075] The polymerization was carried out under the same conditions as in Example 18, using 42.2 mL of toluene and 7.8 mL of 1-octene. Polymerization activity: 59 700 kg-mol -1 (Hf) - h -1 The polymer Mw= 145 kg-mol -1 Mw / Mn = 2.2, the content of 1-octene in the copolymer being 16.6 mol %.

[0076] Example 21, C3-catalyzed ethylene / 1-octene copolymerization

[0077] A 100 mL steel reactor equipped with a magnetic stirrer was used for the polymerization. A mixture of 26.6 mL of toluene and 23.4 mL of 1-octene (total 50 mL) was injected with a syringe, the reactor contents were heated to 120°C and the reactor was saturated with 1 MPa of ethylene. In a glove box, 2 μmol of catalyst C3, 100 μmol of methylaluminoxane, 2.2 μmol of triphenylcarbenium tetrakis(pentafluorophenyl)borate were dissolved in toluene and transferred to a catalyst storage tube with a syringe, then they were pressurized into the reactor with nitrogen (over 1 MPa). During the polymerization, the reaction pressure was maintained at 1 MPa by continuously feeding in ethylene gas. After the set reaction time of 2 min, 2 mL of ethanol was pressurized into the reactor with nitrogen (over 1 MPa), the reactor was cooled and vented, the contents of the reactor were poured into a large amount of ethanol, the polymer precipitated, was filtered, washed with a small amount of ethanol and finally dried in a vacuum overnight. Polymerization activity: 126 000 kg-mol -1 (Hf) - h -1 The polymer Mw= 630 kg-mol -1 Mw / Mn = 2.1, the content of 1-octene in the copolymer being 29.8 mol %.

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

[0079] The polymerization was carried out under the same conditions as in Example 21, the polymerization pressure being 2 MPa. Polymerization activity: 201 000 kg-mol -1 (Hf) - h-1 Polymer Mw = 690 kg-mol -1 Mw / Mn = 2.1, content of 1-octene in the copolymer 19.0 mol %.

[0080] Example 23, C3 catalyzed ethylene / 1-octene copolymerization

[0081] The polymerization was carried out under the same conditions as in Example 21, the polymerization pressure being 3 MPa. Polymerization activity: 356000 kg-mol -1 (Hf) - h -1 Polymer Mw = 1150 kg-mol -1 Mw / Mn = 2.0, content of 1-octene in the copolymer 11.5 mol %.

[0082] Example 24, C3 catalyzed ethylene / 1-octene copolymerization

[0083] The polymerization was carried out under the same conditions as in Example 22, the temperature selected being 140°C. Polymerization activity: 265500 kg-mol -1 (Hf) - h -1 Polymer Mw = 600 kg-mol -1 Mw / Mn = 2.2, content of 1-octene in the copolymer 22.0 mol %.

[0084] Example 25, C3 catalyzed ethylene / 1-octene copolymerization

[0085] The polymerization was carried out under the same conditions as in Example 22, the temperature selected being 160°C. Polymerization activity: 224500 kg-mol -1 (Hf) - h -1 Polymer Mw = 350 kg-mol -1 Mw / Mn = 2.3, content of 1-octene in the copolymer 21.3 mol %.

[0086] Example 26, C1 catalyzed ethylene / 1-octene copolymerization

[0087] The polymerization was carried out under the same conditions as in Example 18, the catalyst used being C1. Polymerization activity: 81400 kg-mol -1 (Hf) - h -1 Polymer Mw = 368 kg-mol -1 Mw / Mn = 2.1, content of 1-octene in the copolymer 32.6 mol %.

[0088] Example 27, C2 catalyzed ethylene / 1-octene copolymerization

[0089] The polymerization was carried out under the same conditions as in Example 18, using catalyst C2. Polymerization activity: 96400 kg-mol -1 (Hf) - h -1 . Polymer Mw = 365 kg-mol -1 Mw / Mn = 2.4, content of 1-octene in the copolymer 31.4 mol %.

[0090] Example 28, copolymerization of ethylene / 1-octene catalyzed by C4

[0091] The polymerization was carried out under the same conditions as in Example 18, using catalyst C4. Polymerization activity: 15050 kg-mol -1 (Hf) - h -1 . Polymer Mw = 282 kg-mol -1 Mw / Mn = 2.3, content of 1-octene in the copolymer 15.5 mol %.

[0092] Example 29, copolymerization of ethylene / 1-octene catalyzed by C5

[0093] The polymerization was carried out under the same conditions as in Example 18, using catalyst C5. Polymerization activity: 43800 kg-mol -1 (Hf) - h -1 . Polymer Mw = 250 kg-mol -1 Mw / Mn = 2.3, content of 1-octene in the copolymer 12.5 mol %.

[0094] Example 30, copolymerization of ethylene / 1-octene catalyzed by C6

[0095] The polymerization was carried out under the same conditions as in Example 18, using catalyst C6. Polymerization activity: 87450 kg-mol -1 (Hf) - h -1 . Polymer Mw = 450 kg-mol -1 Mw / Mn = 2.4, content of 1-octene in the copolymer 35.0 mol %.

[0096] Example 31, copolymerization of ethylene / 1-hexene catalyzed by C3

[0097] A 350 mL glass reactor equipped with a magnet was used for the polymerization. In a glove box, 2 μmol of catalyst C3, 2.2 μmol of triphenylcarbenium tetrakis(pentafluorophenyl)borate and 100 μmol of methylaluminoxane were weighed. The glass reactor was then attached to the polymerization line and 31.6 mL of toluene and 18.4 mL of 1-hexene were added to it. The temperature was raised to 120°C and ethylene gas was continuously fed to maintain the pressure at 5 atm. After 2 min of reaction, 30 mL of ethanol was added to the reactor under nitrogen atmosphere. After cooling, the reaction solution was poured into a large amount of ethanol and precipitated, filtered and dried to obtain the final polymer. Polymerization activity: 105100 kg-mol -1 (Hf) - h -1 Polymer Mw = 400 kg-mol -1 Mw / Mn = 1.8, content of 1-hexene in the copolymer 39.0 mol%.

[0098] Example 32, CGC catalyzed ethylene / 1-octene copolymerization

[0099] The polymerization was carried out under the same conditions as in Example 23 using CGC as the catalyst. Polymerization activity: 54520 kg-mol -1 (Hf) - h -1 Polymer Mw = 180 kg-mol -1 Mw / Mn = 3.2, content of 1-hexene in the copolymer 38 mol%.

[0100] Example 33, NN-Hf catalyzed ethylene / 1-octene copolymerization

[0101] The polymerization was carried out under the same conditions as in Example 23 using NN-Hf as the catalyst. Polymerization activity: 42130 kg-mol -1 (Hf) - h -1 Polymer Mw = 590 kg-mol -1 Mw / Mn = 2.7, content of 1-hexene in the copolymer 9.2 mol%.

Claims

1. A class of NN-bidentate coordination titanium zirconium hafnium metal catalysts, the structure of which is shown in formula (I): wherein M is selected from titanium, zirconium, hafnium; R 1 selected from methyl, ethyl, hydrogen, isopropyl, chloro, fluoro; R 2 selected from methyl, ethyl, hydrogen, isopropyl, chloro, fluoro; R 3 selected from methyl, methoxy, hydrogen, t-butyl, R 4 selected from C1-C6 linear alkyl.

2. The preparation method of the NN-bidentate coordination titanium zirconium hafnium metal catalysts of claim 1, comprising the following steps: dissolving the metal salt in 20-80 mL of anhydrous solvent under a nitrogen atmosphere, adding 4.0-5.0 molar equivalents of methyl magnesium bromide, reacting at low temperature under nitrogen protection for 2 hours, and then adding 1 molar equivalent of quinoline imine for 5 hours; after the reaction is completed, the solvent is removed under reduced pressure, extracted with a good solvent, and the NN-bidentate coordination titanium zirconium hafnium metal catalysts of claim 1 are obtained.

3. The method of claim 2, wherein: 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 method of claim 2, wherein: The metal salt MCl4 is selected from one of TiCl4, ZrCl4, and HfCl4.

5. A process for the polymerization of olefins, characterized in that: The catalyst used is the NN-bidentate coordination titanium zirconium hafnium metal catalyst of claim 1.

6. The method of claim 5, wherein: The olefin monomer is one or more of ethylene, propylene, 1-butene, styrene, 1-hexene, norbornene, and 1-octene.

7. The method of claim 5, wherein: The NN-bidentate coordination titanium zirconium hafnium metal catalyst needs to be catalyzed with a cocatalyst, which is one or more of triphenylphosphine boron, triphenylcarbenium tetrakis(pentafluorophenyl)borate, aluminoxane, alkyl aluminum, and chlorinated alkyl aluminum.

8. The method of claim 7, wherein: The aluminoxane is methyl aluminoxane, ethyl aluminoxane, or isobutyl aluminoxane; the alkyl aluminum is trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, or tri-n-hexyl aluminum; the chlorinated alkyl aluminum is monochlorodiethyl aluminum, hemi-monochlorodiethyl aluminum, or dichloroethyl aluminum.

9. The method of claim 5, wherein: The polymerization temperature is 0-200°C, the polymerization pressure is 0.1-5 MPa, and the solvent used for polymerization is one or more of n-hexane, n-heptane, n-pentane, and toluene.

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