Preparation of anthracene skeleton single-metallocene bimetallic catalyst and application thereof in synthesis of high-performance polyolefin

Abstract

The application reports a preparation of a single-metallocene double-metal catalyst based on anthracene skeleton and application of the catalyst in olefin polymerization. The anthracene skeleton is introduced into the structure of salicylaldehyde imine catalyst, the high-temperature resistance of the catalyst is improved, and by designing different ligand skeleton configurations and central metals, the space effect and electronic effect of the metal catalyst under the micro-morphology can be changed, so as to control the polymerization process of the catalyst to prepare polyolefin materials with various structures and different properties. The new single-metallocene double-metal catalyst based on anthracene skeleton reported in the application has the characteristics of simple preparation, high activity, high temperature resistance and excellent copolymerization performance, and is suitable for homogeneous high-temperature solution polymerization to prepare polyolefin elastomers and cycloolefin copolymers. Therefore, the single-metallocene double-metal catalyst based on anthracene skeleton reported in the application has original innovation, and can enhance the competitiveness of China in participating in the international high-end polyolefin polymer material technology market.

Description

TECHNICAL FIELD

[0001] The present application relates to a single-metallocene bimetallic catalyst based on anthracene skeleton and its application in olefin polymerization. BACKGROUND

[0002] Polyolefins are one of the pillars of the modern polymer industry, with hundreds of millions of tons of polyolefin products produced globally each year. Many of these polyolefin materials are excellent, and each polymer has its unique physical and chemical properties, which can be applied in different scenarios, greatly enriching people's daily life. Olefins can be polymerized into polymers with different structures and properties under the catalysis of different catalysts, so the research on metal catalysts is crucial in the polymerization industry. Currently, the industrialized polyethylene catalysts include Ziegler-Natta catalysts (DE Pat 889229 (1953); IT Pat 545332 (1956) and IT Pat 536899 (1955)), Phillips catalysts (Belg. Pat. 530617 (1955)) and metallocene catalysts (W. Kaminsky, Metalorganic Catalysts for Synthesis and Polymerization, Berlin: Springer, 1999), as well as the transition metal complex catalysts for efficient ethylene homopolymerization and copolymerization developed in recent years. High-temperature-resistant catalysts are the key to the preparation of polyolefin elastomer POE by high-temperature solution polymerization. The most important one is the constrained geometry catalyst reported by Dow Chemical (EP0416815A2). Nomura's group and Kim's group reported aryloxy monometallic titanium complex catalysts for ethylene polymerization and ethylene and various olefin copolymerization, respectively (J Mol Catal A Chem 2000, 152, 249-252; Macromolecules 2009, 42, 6932-6943). The catalysts have extremely high activity for ethylene and octene copolymerization, and are resistant to high temperature, suitable for high-temperature solution polymerization process. Bimetallic catalysts can improve the catalytic performance of the catalysts through synergistic catalytic effect (Organometallics 2020, 39, 3268-3274).

[0003] The application reports a preparation of an anthracene skeleton monometallic bimetallic catalyst and application thereof in olefin polymerization. The anthracene skeleton is introduced into the structure of the FI catalyst to improve the high-temperature resistance of the catalyst, and by designing different ligand skeleton configurations and central metals, the spatial effect and electronic effect of the metal catalyst under the micro-morphology can be changed to regulate the polymerization process of the catalyst to prepare polyolefin materials with various structures and different properties. The new anthracene skeleton monometallic bimetallic catalyst reported in the application has the characteristics of simple preparation, high activity, high temperature resistance and excellent copolymerization performance, and is suitable for homogeneous high-temperature solution polymerization to prepare polyolefin elastomers and cyclic olefin copolymers. The prepared polyolefin elastomers have higher molecular weight, and the cyclic olefin copolymers have higher comonomer insertion rate. Therefore, the anthracene skeleton monometallic bimetallic catalyst reported in the application has original innovation, and can enhance the competitiveness of China in participating in the international high-end polyolefin high polymer material technology market. SUMMARY

[0004] The application aims to provide a preparation of an anthracene skeleton monometallic bimetallic catalyst and application thereof in olefin polymerization.

[0005] The application provides an anthracene skeleton bimetallic catalyst shown in formula (I):

[0006]

[0007] wherein M is selected from titanium, zirconium and hafnium; X is selected from methyl, chlorine and dimethylamine group; and Cp' is selected from cyclopentadiene, pentamethylcyclopentadienyl, indenyl and fluorenyl.

[0008] The application provides a preparation method of the anthracene skeleton monometallic bimetallic catalyst, comprising the following steps:

[0009] Under a nitrogen atmosphere, 1,5-diamino-anthracene (0.416 g, 2.00 mmol) is mixed with salicylaldehyde (0.488 g, 4.00 mmol), 20 mg of p-toluenesulfonic acid is added into a 500 mL single-neck flask, 200 mL of toluene is added, and the reaction is refluxed for 12-24 hours; the solvent is removed by rotary evaporation under reduced pressure, and dichloromethane is added to completely dissolve it, and then it is placed in an environment at-20 DEG C for recrystallization; after crystallization, the precipitate is filtered and purified to obtain an organic ligand; the organic ligand is dissolved in anhydrous solvent, Cp*TiMe3 (0.55 g, 2.40 mmol) is added, and the reaction is carried out for 24 hours; the solvent is removed under reduced pressure, and then n-hexane is used for washing to obtain the anthracene skeleton monometallic bimetallic catalyst.

[0010] In the preparation method, the anhydrous solvent is selected from benzene, toluene and xylene; and the poor solvent is selected from n-hexane, n-pentane, n-heptane and cyclohexane.

[0011] The application also provides the application of the anthracene skeleton-based single-metallocene bimetallic catalyst shown in the above formula (I) in catalyzing the polymerization of olefins.

[0012] In the above application, the olefin is one or more of ethylene, propylene, styrene, 1-butene, 1-hexene, 1-octene, norbornene, cyclohexene, and tetracyclododecene.

[0013] The above catalyst is additionally added with a cocatalyst, which is one or more of triphenylphosphine boron, triphenylcarbenium tetrakis(pentafluorophenyl)borate, aluminoxane, alkylaluminum, and chlorinated alkylaluminum. The aluminoxane is methylaluminoxane, ethylaluminoxane, or isobutylaluminoxane; the alkylaluminum is trimethylaluminum, triethylaluminum, triisobutylaluminum, or tri-n-hexylaluminum; and the chlorinated alkylaluminum is monochlorodiethylaluminum, sesqui-monochlorodiethylaluminum, or ethylaluminum dichloride.

[0014] In the above polymerization, the polymerization temperature is 0-180°C, the polymerization pressure is 0.1-5.0 MPa, and the polymerization solvent is one or more of toluene, hexane, and heptane.

[0015] The application provides the preparation of an anthracene skeleton-based single-metallocene bimetallic catalyst and the application of the catalyst in catalyzing the polymerization of olefins. The anthracene skeleton-based single-metallocene bimetallic catalyst reported in the application has the characteristics of simple preparation, high activity, high temperature resistance, and good copolymerization performance, and is suitable for the high-temperature solution polymerization of olefins to prepare polyolefin elastomers and cycloolefin copolymers. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the hydrogen nuclear magnetic spectrum of the catalyst Ti2.

[0017] Figure 2 It is the carbon nuclear magnetic spectrum of the catalyst Ti2. DETAILED DESCRIPTION

[0018] The application is further illustrated by the examples, but the application is not limited thereto. The examples of the application can enable a person skilled in the art to have a more comprehensive understanding of the application.

[0019] In the following examples, the experimental methods used are conventional methods unless otherwise specified.

[0020] The application is described below by specific examples.

[0021] Example 1, preparation of the catalyst Ti2

[0022] The 1,5-diamino-anthracene (0.416 g, 2.00 mmol) was mixed with salicylaldehyde (0.488 g, 4.00 mmol) under nitrogen atmosphere, 20 mg of p-toluene sulfonic acid was added, 500 mL of a single neck flask was used, 200 mL of toluene was added, the reaction was refluxed for 12-24 hours. The solvent was removed by rotary evaporation under reduced pressure and dichloromethane was added to dissolve completely, it was recrystallized by keeping in -20 °C environment, after crystallization the precipitate was filtered and purified to get the organic ligand (0.501 g, 1.16 mmol, 58%). The organic ligand (0.42 g, 1.00 mmol) was dissolved in dry solvent, Cp*TiMe3(0.55 g, 2.40 mmol) was added and the reaction was carried out for 24 hours, the solvent was removed under reduced pressure and then washed with n-hexane to get the anthracene backbone bimetallic catalyst Ti2(0.405 g, 0.482 mmol, yield 83.1%). 1 H NMR (400 MHz, CDC13) δ 9.13 (s, 2H), 8.94 (s, 2H), 8.44 (dd, J = 7.8, 1.4 Hz, 2H), 7.91 (d, J = 8.6 Hz, 2H), 7.48 - 7.37 (m, 4H), 7.14 (t, J = 7.5 Hz, 1H), 6.97 (d, J = 6.9 Hz, 1H), 6.92 (d, J = 8.0 Hz, 1H), 1.90 (s, 30H), 0.52 (s, 12H). 13 C NMR (100 MHz, C6D6) δ 164.99 (s), 156.60 (s), 150.35 (s), 132.92 (s), 132.19 (s), 129.19 (s), 128.48 (s), 128.38 (s), 127.79 (s), 126.65 (s), 126.36 (s), 125.58 (s), 123.25 (s), 122.82 (s), 121.79 (s), 121.40 (s), 111.52 (s), 56.36 (s), 11.79 (s). Anal. Calcd for C 52 H 60 N2O2Ti2: C, 74.28; H, 7.19; N, 3.33. Found: C, 74.53; H, 7.10; N, 3.18.

[0023] Example 2, Ti2 catalyzed ethylene polymerization

[0024] A 250 mL polymerization flask with magnetic stirrer was continuously dried at 25°C for 6 hours, vacuumed while hot and replaced with N2 three times. 0.84 mg (1 μmol) Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. Then vacuumed again and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, maintained at 5 atm of ethylene pressure at 25°C, and the reaction was stirred vigorously for 2 min. The reaction was neutralized with 5% hydrochloric acid acidified ethanol solution, and the polymer precipitate was washed with ethanol and water several times, vacuum dried to constant weight, and weighed. Polymerization activity: 1.6 x 10 7 g-mol -1 (Ti)-h -1 . Polymer Polymer M w = 27 kg-mol -1 , M w / M n = 1.7.

[0025] Example 3, Ti2 catalyzed ethylene polymerization

[0026] A 250 mL polymerization flask with magnetic stirrer was continuously dried at 50°C for 6 hours, vacuumed while hot and replaced with N2 three times. 0.84 mg (1 μmol) Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. Then vacuumed again and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, maintained at 5 atm of ethylene pressure at 50°C, and the reaction was stirred vigorously for 2 min. The reaction was neutralized with 5% hydrochloric acid acidified ethanol solution, and the polymer precipitate was washed with ethanol and water several times, vacuum dried to constant weight, and weighed. Polymerization activity: 1.7 x 10 7 g-mol -1 (Ti)-h -1 . Polymer Polymer M w = 30 kg-mol -1 , M w / M n = 1.7.

[0027] Example 4, Ti2 catalyzed ethylene polymerization

[0028] A 250 mL polymerization flask with magnetic stirrer was continuously dried at 80°C for 6 hours, vacuumed while hot and replaced with N2 three times. 0.84 mg (1 μmol) Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. Then vacuumed again and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, and the reaction was carried out at 80°C under 5 atm of ethylene pressure with vigorous stirring for 2 min. The reaction was neutralized with 5% hydrochloric acid in ethanol solution, and the polymer precipitate was obtained. The polymer was washed with ethanol and water several times, and dried to constant weight in vacuum. Polymerization activity: 1.7 x 10 7 g·mol -1 (Ti)·h -1 . Polymer Polymer M w = 41 kg·mol -1 , M w / M n = 1.9.

[0029] Example 5, Ti2 catalyzed ethylene polymerization

[0030] A 250 mL polymerization flask with magnetic stirrer was continuously dried at 100°C for 6 hours, vacuumed while hot and replaced with N2 three times. 0.84 mg (1 μmol) Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. Then vacuumed again and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, and the reaction was carried out at 100°C under 5 atm of ethylene pressure with vigorous stirring for 2 min. The reaction was neutralized with 5% hydrochloric acid in ethanol solution, and the polymer precipitate was obtained. The polymer was washed with ethanol and water several times, and dried to constant weight in vacuum. Polymerization activity: 2.3 x 10 7 g·mol -1 (Ti)·h -1 . Polymer Polymer M w = 50 kg·mol -1 , M w / M n = 1.7.

[0031] Example 6, Ti2 catalyzed ethylene polymerization

[0032] A 250 mL polymerization flask equipped with a magnetic stirrer was continuously dried at 120 °C for 6 h, vacuumed while hot and replaced with N2 three times. 0.84 mg (1 μmol) of Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. Then vacuumed again and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, maintained at 5 atm of ethylene pressure at 120 °C, and the reaction was stirred vigorously for 2 min. The reaction was neutralized with 5% hydrochloric acid in ethanol solution, and the polymer precipitate was washed with ethanol and water several times, vacuum dried to constant weight, and weighed. Polymerization activity: 2.0 x 10 7 g-mol -1 (Ti) - h -1 . Polymer M w = 54 kg-mol -1 , M w / M n = 1.8.

[0033] Example 7, Ti2 catalyzed copolymerization of ethylene and 1-octene

[0034] A 250 mL polymerization flask equipped with a magnetic stirrer was continuously dried at 50 °C for 6 h, vacuumed while hot and replaced with N2 three times. 0.84 mg (1 μmol) of Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. Then vacuumed again and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, 10 mmol of 1-octene was added at 50 °C, maintained at 5 atm of ethylene pressure, and the reaction was stirred vigorously for 2 min. The reaction was neutralized with 5% hydrochloric acid in ethanol solution, and the polymer precipitate was washed with ethanol and water several times, vacuum dried to constant weight, and weighed. Polymerization activity: 2.0 x 10 7 g-mol -1 (Ti) - h -1 . Polymer M w = 65 kg-mol -1 , M w / M n = 1.8, 1-octene insertion 19 mol%.

[0035] Example 8, Ti2 catalyzed copolymerization of ethylene and 1-octene

[0036] A 250 mL polymerization flask with magnetic stirrer was continuously dried at 50 °C for 6 h, vacuumed while hot and replaced with N2 three times. 0.84 mg (1 μmol) of Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. The flask was then vacuumed and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, 25 mmol of 1-octene was added at 50 °C, and the reaction was stirred vigorously for 2 min under 5 atm of ethylene pressure. The reaction was neutralized with 5% HCl acidified ethanol solution, and the polymer precipitate was washed with ethanol and water several times, oven dried to constant weight, and weighed. Polymerization activity: 2.2 x 10 7 g-mol -1 (Ti)-h -1 . Polymer M w = 70 kg-mol -1 , M w / M n = 1.9, 1-octene insertion rate 22 mol%.

[0037] Example 9, Ti2 catalyzed copolymerization of ethylene and 1-octene

[0038] A 250 mL polymerization flask with magnetic stirrer was continuously dried at 50 °C for 6 h, vacuumed while hot and replaced with N2 three times. 0.84 mg (1 μmol) of Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. The flask was then vacuumed and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, 50 mmol of 1-octene was added at 50 °C, and the reaction was stirred vigorously for 2 min under 5 atm of ethylene pressure. The reaction was neutralized with 5% HCl acidified ethanol solution, and the polymer precipitate was washed with ethanol and water several times, oven dried to constant weight, and weighed. Polymerization activity: 1.8 x 10 7 g-mol -1 (Ti)-h -1 . Polymer M w = 72 kg-mol -1 , M w / M n = 2.4, 1-octene insertion rate 25 mol%.

[0039] Example 10, Ti2 catalyzed copolymerization of ethylene and 1-octene

[0040] A 250 mL polymerization flask equipped with a magnetic stirrer was continuously dried at 50°C for 6 hours, vacuumed while hot and replaced with N2 three times. 0.84 mg (1 μmol) of Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. Then vacuumed again and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, 100 mmol of 1-octene was added at 50°C, maintained 5 atm of ethylene pressure, and the reaction was stirred vigorously for 2 min. The reaction was neutralized with 5% hydrochloric acid in ethanol solution to obtain polymer precipitate, washed with ethanol and water several times, vacuum dried to constant weight, and weighed. Polymerization activity: 2.4 x 10 7 g·mol -1 (Ti)·h -1 . Polymer M w = 76 kg·mol -1 , M w / M n = 1.9, 1-octene insertion rate 21 mol%.

[0041] Example 11, Ti2-catalyzed copolymerization of ethylene and 1-octene

[0042] A 250 mL polymerization flask equipped with a magnetic stirrer was continuously dried at 100°C for 6 hours, vacuumed while hot and replaced with N2 three times. 0.84 mg (1 μmol) of Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. Then vacuumed again and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, 25 mmol of 1-octene was added at 100°C, maintained 5 atm of ethylene pressure, and the reaction was stirred vigorously for 2 min. The reaction was neutralized with 5% hydrochloric acid in ethanol solution to obtain polymer precipitate, washed with ethanol and water several times, vacuum dried to constant weight, and weighed. Polymerization activity: 2.4 x 10 7 g·mol -1 (Ti)·h -1 . Polymer M w = 76 kg·mol -1 , M w / M n = 1.9, 1-octene insertion rate 21 mol%.

[0043] Example 12, Ti2-catalyzed copolymerization of ethylene and 1-octene

[0044] A 250 mL polymerization flask equipped with a magnetic stirrer was continuously dried at 120 °C for 6 hours. While still hot, a vacuum was applied and the mixture was purged three times with N2 gas. 0.84 mg (1 μmol) Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. The mixture was then purged again and purged three times with ethylene. 50 mL of toluene was injected using a syringe, and 25 mmol of 1-octene was added at 120 °C. The ethylene pressure was maintained at 5 atm, and the reaction was vigorously stirred for 2 min. The reaction solution was neutralized with 5% hydrochloric acid-acidified ethanol solution to obtain a polymer precipitate. The precipitate was washed several times with ethanol and water, vacuum dried to constant weight, and weighed. Polymerization activity: 2.2 × 10⁻⁶ 7 g·mol -1 (Ti)·h -1 Polymer M w =80kg·mol -1 M w / M n =2.2, 1-octene insertion rate 23 mol%.

[0045] Example 13: Ti2-catalyzed copolymerization of ethylene and norbornene

[0046] A 250 mL polymerization flask equipped with a magnetic stirrer was continuously dried at 120 °C for 6 hours. While still hot, a vacuum was applied and the mixture was purged three times with N2 gas. 0.84 mg (1 μmol) Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. The mixture was then purged again and purged three times with ethylene. 50 mL of toluene was injected using a syringe, and 100 mmol of norbornene was added at 120 °C. The reaction mixture was stirred vigorously for 2 min while maintaining an ethylene pressure of 5 atm. The reaction solution was neutralized with ethanol acidified with 5% hydrochloric acid to obtain a polymer precipitate. The precipitate was washed several times with ethanol and water, dried under vacuum to constant weight, and weighed. Polymerization activity: 5.3 × 10⁻⁶ 6 g·mol -1 (Ti)·h -1 Polymer M w =53kg·mol -1 M w / M n =1.5, norbornene insertion rate 39 mol%.

[0047] Example 14: Ti2-catalyzed copolymerization of ethylene and norbornene

[0048] A 250 mL polymerization flask equipped with a magnetic stir bar was continuously dried at 120 °C for 6 h, evacuated while hot and replaced with N2 three times. 0.84 mg (1 μmol) of Ti2 was added, followed by [Ph3C][B(C6F5)4], B / M = 1.2. The flask was then evacuated and replaced with ethylene three times. 50 mL of toluene was injected with a syringe, 200 mmol of norbornene was added at 120 °C, 5 atm of ethylene pressure was maintained and the reaction was stirred vigorously for 2 min. The reaction was neutralized with 5% HCl in ethanol solution to precipitate the polymer, which was washed with ethanol, water several times and dried to constant weight under vacuum. Polymerization activity: 4.3 x 10 6 g·mol -1 (Ti)·h -1 . Polymer M w = 92 kg·mol -1 , M w / M n = 1.3, norbornene insertion 40 mol%.

Claims

1. A class of anthracene-based monocyclic bimetallic catalysts, the structure of which is shown in formula (I): in, M is selected from titanium, zirconium, and hafnium; X is selected from methyl; and Cp' is selected from cyclopentadienyl and pentamethylcyclopentadienyl.

2. The preparation method of the anthracene-based monocyclic bimetallic catalyst according to claim 1 comprises the following steps: under a nitrogen atmosphere, 0.416 g of 2.00 mmol of 1,5-diamino-anthracene, 0.488 g of 4.00 mmol of salicylaldehyde, and 20 mg of p-toluenesulfonic acid are mixed and added to a 500 mL single-necked flask. 200 mL of toluene is added, and the mixture is refluxed for 12-24 hours. The solvent is removed by rotary evaporation under reduced pressure, and dichloromethane is added to completely dissolve the solvent. The mixture is then recrystallized at -20°C. After crystallization, the precipitate is filtered and purified to obtain an organic ligand. The organic ligand is dissolved in an anhydrous solvent, and 0.55 g of 2.40 mmol of Cp*TiMe3 is added. The mixture is reacted for 24 hours, the solvent is removed under reduced pressure, and the mixture is washed with n-hexane to obtain the anthracene-based monocyclic bimetallic catalyst.

3. The preparation method according to claim 2, characterized in that: The anhydrous solvent is selected from benzene, toluene, and xylene.

4. A method for carrying out an olefin polymerization reaction, characterized in that: The catalyst for the reaction is the anthracene-based monocyclic bimetallic catalyst as described in claim 1, and the olefin is one or more of ethylene, propylene, 1-butene, 1-hexene, 1-octene, and norbornene.

5. The method according to claim 4, characterized in that: The catalyst is further provided with a co-catalyst, which is one or more of tris(pentafluorophenylboron), triphenylcarbazide tetra(pentafluorophenyl)borate, aluminoxane, alkylaluminum and alkylaluminum chloride.

6. The method according to claim 5, 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.

7. The method according to claim 4, characterized in that: The polymerization temperature is 0-180℃, the polymerization pressure is 0.1-5.0MPa, and the polymerization solvent is one or more of toluene, hexane, and heptane.

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