Single-site catalysts, processes for their preparation and use

Abstract

The application discloses a single-center catalyst and a preparation method and application thereof. The catalyst system introduces a large steric hindrance aniline on a highly rigid 2-phenyl quinoline skeleton, thereby providing better protection for the active center of the catalytic system, enhancing the high-temperature resistance and activity of the catalytic olefin polymerization, and the polymerization activity at 150 DEG C can be more than 1*10 7 6 g / (mol.h). The synthetic route adopted in the application is simple and easy to operate, and a ligand with a high yield can be obtained through one-step reaction, that is, the yield of the ligand synthesized from 2-phenyl-8-amino quinoline raw material is more than 75%, which is favorable for improving the production efficiency and yield of the product.

Description

TECHNICAL FIELD

[0001] The present application relates to a single-site catalyst and its preparation method and application. BACKGROUND

[0002] Polyolefin elastomer (POE) is an elastomer polymerized from ethylene and α-olefin under the action of homogeneous metal catalyst, which has wide application and can be used as rubber, thermoplastic elastomer, plastic impact modifier and toughening agent, and has been well applied in the toughening modification of various plastics.

[0003] At the earliest, polyolefin elastomer was first synthesized by using high-temperature solution Insite process and using constrained geometry metallocene catalyst (CGC). The catalyst is a complex of monocyclopentadiene and transition metal of group IV by coordination bond, in which one cyclopentadiene or its derivative in the structure of bridged metallocene catalyst is replaced by amino group and silane group is used as bridge. SUMMARY

[0004] In order to further enrich the selection range of catalysts for polyolefin elastomer, develop a catalyst which can maintain good catalytic activity and selectivity under high temperature conditions, and make the present application.

[0005] As an aspect of the present application, it relates to a single-site catalyst, which is a bidentate amino quinoline single-site catalyst (cat-a) as shown in formula (I):

[0006]

[0007] wherein M is zirconium or hafnium; R1 is selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl, fluorine or trifluoromethyl; and R2 is selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl or phenyl.

[0008] In specific embodiments, the activity of the single-site catalyst is not less than 1×10 7 g / (mol·h) when catalyzing the polymerization of olefin under the condition of not less than 150℃.

[0009] As another aspect of the present application, it relates to a method for preparing the single-site catalyst, which produces the bidentate amino quinoline single-site catalyst with 2-phenyl-8-amino quinoline as the mother body.

[0010] Specifically, the method comprises the following steps:

[0011] S1, in a benzene solvent, sequentially adding 2-phenyl-8-aminoquinoline, bromobenzene with substituent on benzene ring, tris(dibenzylidene)acetone palladium, 2,2'-bis(diphenylphosphine)-1,1'-binaphthalene and sodium tert-butoxide, warming to reflux, and chromatographically separating to obtain ligand L;

[0012] S2, after the ligand L in S1 is deprotonated with a strong base, adding a metal salt to prepare a bidentate aminoquinoline single-site catalyst.

[0013] In specific embodiments, in S1, the benzene solvent is selected from benzene, toluene or xylene.

[0014] In specific embodiments, in S1, the temperature is increased to the boiling point of the benzene solvent and then refluxed.

[0015] In specific embodiments, in S1, the ligand L is shown in formula (II):

[0016]

[0017] wherein R1 is selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl, fluorine or trifluoromethyl; and R2 is selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl or phenyl.

[0018] In specific embodiments, in S2, the metal salt is a chlorine-containing metal salt.

[0019] Further, the chlorine-containing metal salt is selected from zirconium tetrachloride or hafnium tetrachloride.

[0020] As another aspect of the present application, it relates to the use of the above-mentioned single-site catalyst in catalyzing the polymerization of olefins, and the single-site catalyst is used to catalyze the copolymerization reaction between ethylene and α-olefin.

[0021] In specific embodiments, the α-olefin is selected from butene, hexene or octene.

[0022] The bidentate catalytic system of the present application can catalyze the copolymerization of ethylene and α-olefin at high temperature (≥ 150℃) with high activity.

[0023] The bidentate catalytic system of the present application introduces a large steric hindrance aniline on the highly rigid 2-phenylquinoline skeleton, which can provide better protection for the active center of the catalytic system, enhance the high-temperature resistance and activity of the catalytic system for olefin polymerization, and the polymerization activity at 150℃ can exceed 1×10 7 g / (mol·h).

[0024] The synthetic route adopted in the present application is simple and easy to operate, and a ligand with high yield can be obtained in one step, that is, the yield of the ligand synthesized from 2-phenyl-8-aminoquinoline raw material is more than 75%, which is beneficial to improve the production efficiency and yield of the product.

[0025] Other features and advantages of the present application will be set forth in the following specification, and in part will be apparent from the specification, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and attained by the structure particularly pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a synthetic route diagram of the ligand L;

[0027] Figure 2 is a synthetic route diagram of the bidentate aminoquinoline mononuclear catalyst (cat-a). DETAILED DESCRIPTION

[0028] The production of polyolefin elastomers requires the use of a high-temperature solution polymerization process, and a higher polymerization temperature is beneficial to reduce the viscosity of the reaction system and ensure better heat transfer and mass transfer in the reactor. However, when a high-temperature solution polymerization process is used to prepare polyolefin elastomers, higher requirements are placed on the catalyst.

[0029] The inventors found that the metallocene catalyst of Chinese patent 90107395.4 has excellent polymerization activity and copolymerization ability, but the synthesis steps are complex and the yield is low. In comparison, the synthesis steps of the non-metallocene mononuclear catalyst are more concise.

[0030] The inventors also refer to the two-dentate 2-methyl-8-aminoquinoline mononuclear catalyst reported by Philip P. Fontaine (Organometallics 2012, 31, 6244-6251; Organometallics 2015, 34, 1354-1363) and found that the catalyst still has good activity and copolymerization ability when catalyzing the copolymerization of ethylene and octene at 140℃. However, the inventors found through further experimental exploration that the activity of this type of catalyst is lower when polymerized at a higher temperature (> 140℃), and the results are not as expected.

[0031] In view of the fact that the prior art cannot meet the inventors' expectations, the inventors have made further research and development to make the present application.

[0032] In one aspect, the present application designs a bidentate aminoquinoline single-site catalyst (cat-a), which takes highly rigid 2-phenyl-aminoquinoline as a skeleton, introduces a large steric hindrance aniline to provide better protection for the active center of the catalytic system, and can effectively enhance the high-temperature resistance and activity of the catalytic olefin polymerization.

[0033] In still another aspect, the present application provides a preparation method of the bidentate aminoquinoline single-site catalyst. The inventors can obtain a ligand L with a yield of more than 75% through one-step reaction, which can effectively improve the conversion rate and production efficiency of the product; in addition, the process conditions in step two are also simple and easy to operate.

[0034] In still another aspect, the catalyst of the present application can be used for catalyzing the reaction of polyolefin elastomer, and the polymerization activity of the catalyst can be more than 1×10 7 g / (mol·h) under the reaction condition of 150℃.

[0035] The present application is further described below in combination with specific examples, and the protection scope of the present application is not limited by the following examples. The materials mainly involved in the examples are all conventional commercially available products.

[0036] When designing the present application, the inventors further optimize the intermediate ligand L for producing the bidentate aminoquinoline single-site catalyst based on the prior art, refer to the attached Figure 1 , and make Preparation Examples 1-4.

[0037] Synthesis of ligand L1 in Preparation Example 1

[0038] Take 100ml of a flask, and sequentially add 20mmol of 2-phenyl-8-aminoquinoline, 0.8mmol of tris(dibenzylideneacetone)dipalladium, 1.6mmol of 2,2'-bis(diphenylphosphino)-1,1'-binaphthalene and 35mmol of sodium tert-butoxide, and then take 20mmol of 2,6-diisopropylbromobenzene and add 50ml of toluene. The temperature is raised to 110℃, and refluxed for 12 hours, then stop heating, load on silica gel, prepare eluent (petroleum ether: ethyl acetate = 9:1), and column chromatography to obtain the target product: ligand L1. The detection parameters of the obtained product are as follows:

[0039] 1 H-NMR: 8.33-8.36 (s, 2H), 8.21-8.23 (m, 4H), 7.75-7.76 (m, 4H), 6.85 (m, 1H), 6.63-6.65 (m, 2H), 4.12 (s, 1H), 3.12 (m, 2H), 1.33-1.35 (m, 12H); Calcd.(%) for C 27 H 28N2: C: 85.22, H: 7.42, N: 7.36; found: C: 85.25, H: 7.44, N: 7.31.

[0040] Synthesis of Ligand L2 of Preparation Example 2

[0041] The difference from Preparation Example 1 is that 2,6-diisopropylbromobenzene is replaced by 2,6-difluorobromobenzene. The obtained product is detected for the following parameters:

[0042] 1 H-NMR: 7.99 (s, 2H), 7.68 (s, 1H), 7.28-7.39 (m, 6H), 6.55-6.73 (m, 4H), 4.16 (s, 1H); Calcd. (%) for C 21 H 14 F2N2: C: 75.89, H: 4.25, N: 8.43; found: C: 75.65, H: 4.34, N: 8.31.

[0043] Synthesis of Ligand L3 of Preparation Example 3

[0044] The difference from Preparation Example 1 is that 2,6-diisopropylbromobenzene is replaced by 2,6-diisopropyl-4-methyl-bromobenzene. The obtained product is detected for the following parameters:

[0045] 1 H-NMR: 8.13-8.16 (s, 2H), 8.01-8.03 (m, 4H), 7.65-7.67 (m, 4H), 6.63-6.65 (m, 2H), 4.12 (s, 1H), 3.12 (m, 2H), 2.35 (s, 3H), 1.33-1.35 (m, 12H); Calcd. (%) for C 28 H 30 N2: C: 85.24, H: 7.66, N: 7.10; found: C: 85.35, H: 7.74, N: 6.91.

[0046] Synthesis of Ligand L4 of Preparation Example 4

[0047] The difference from Preparation Example 1 is that 2,6-diisopropylbromobenzene is replaced by 2,6-dimethylbromobenzene. The obtained product is detected for the following parameters:

[0048] 1 H-NMR: 8.01 (s, 2H), 7.67 (s, 1H), 7.28-7.39 (m, 6H), 6.45-6.74 (m, 4H), 4.17 (s, 1H), 2.38 (s, 6H); Calcd. (%) for C 23 H20 N2: C: 85.15, H: 6.21, N: 8.63; found: C: 85.25, H: 6.23, N: 8.52.

[0049] In order to clearly express the ligand L prepared in Preparation Examples 1-4, the structure thereof is described as follows, see Table 1, and the yield thereof is given:

[0050] Ligand L:

[0051]

[0052] Table 1: Ligand L structure and yield information table

[0053] Ligand [R1] [R2] Yield / % L1 Isopropyl Hydrogen 83％ L2 Fluoro Hydrogen 81％ L3 Isopropyl Methyl 79％ L4 Methyl Hydrogen 82％

[0054] From the data recorded in the above table, we can conclude that this kind of ligand is prepared by coupling reaction, easy to synthesize, high yield.

[0055] Taking the ligand L prepared in Preparation Examples 1-4 above as an example, the bidentate amino quinoline monometallic catalyst (cat-a) described in the present application is further prepared, see the following Figure 2 , the following Examples 1-8 are given.

[0056] Synthesis of catalyst cat-1a of Example 1

[0057] A 50ml Schlenk flask was used, ligand L1(2mmol) prepared in Preparation Example 1 was weighed and dissolved with 10mL of toluene, 1.6M n-butyllithium solution(2.2mmol) was slowly added dropwise under nitrogen protection at a temperature of-20℃, and the reaction was carried out for 6h. The toluene was pumped dry in vacuum, and the unreacted n-butyllithium was washed with n-hexane, and the supernatant was poured out to obtain yellow precipitate of lithium salt.

[0058] Another 100ml flask was used, the above lithium salt and toluene were sequentially added and dissolved by shaking, and then HfCl4(2.5mmol) was added to the system, the temperature was raised to 110℃ and refluxed for 12h. After the solution was cooled to room temperature, it was filtered, concentrated to 1mL, n-hexane was added, a suspension was prepared, and then frozen overnight, filtered, and brown yellow crystals were obtained. The obtained product was detected for the following parameters:

[0059] 1 H-NMR: 8.10-8.13(s, 2H), 8.03-8.05(m, 5H), 7.35-7.36(m, 4H), 6.65-6.67(m, 2H), 3.08(m, 2H), 1.31-1.33(m, 12H); Calcd.(%) for C 27 H 27Cl3HfN2: C: 49.57, H: 4.31, N: 4.13; found: C: 49.61, H: 4.27, N: 4.11.

[0060] Synthesis of catalyst cat-2a of example 2

[0061] The difference with example 1 is that the ligand L2 in preparation 2 is used instead of the ligand L1 in preparation 1. The resulting product is characterized by:

[0062] 1 H-NMR: 7.73-7.86 (m, 3H), 7.27-7.32 (m, 6H), 6.62-6.70 (m, 3H), 3.13 (m, 2H), 2.42 (s, 3H), 1.33-1.34 (m, 12H); Calcd. (%) for C 21 H 13 Cl3F2HfN2: C: 40.93, H: 2.13, N: 4.55; found: C: 40.91, H: 2.24, N: 4.61.

[0063] Synthesis of catalyst cat-3a of example 3

[0064] The difference with example 1 is that the ligand L3 in preparation 3 is used instead of the ligand L1 in preparation 1. The resulting product is characterized by:

[0065] 1 H-NMR: 7.73-7.86 (m, 3H), 7.27-7.32 (m, 6H), 6.62-6.70 (m, 3H), 3.13 (m, 2H), 2.42 (s, 3H), 1.33-1.34 (m, 12H); Calcd. (%) for C 28 H 29 Cl3HfN2: C: 49.57, H: 4.31, N: 4.13; found: C: 49.61, H: 4.27, N: 4.11.

[0066] Synthesis of catalyst cat-4a of example 4

[0067] The difference with example 1 is that the ligand L4 in preparation 4 is used instead of the ligand L1 in preparation 1. The resulting product is characterized by:

[0068] 1 H-NMR: 7.73-7.86 (m, 3H), 7.27-7.32 (m, 6H), 6.62-6.70 (m, 3H), 3.13 (m, 2H), 2.42 (s, 3H), 1.33-1.34 (m, 12H); Calcd. (%) for C 23 H 19Cl3HfN2: C: 45.42, H: 3.15, N: 4.61; found: C: 45.55, H: 3.21, N: 4.68.

[0069] Synthesis of catalyst cat-5a of example 5

[0070] The difference with example 1 is that ZrCl4is used instead of HfCl4. The obtained product is characterized by:

[0071] 1 H-NMR: 8.15-8.17 (s, 2H), 8.09-8.11 (m, 5H), 7.39-7.41 (m, 4H), 6.68-6.71 (m, 2H), 3.12 (m, 2H), 1.34-1.35 (m, 12H); Calcd. (%) for C 27 H 27 Cl3N2Zr: C: 56.19, H: 4.72, N: 4.85; found: C: 56.22, H: 4.74, N: 4.81.

[0072] Synthesis of catalyst cat-6a of example 6

[0073] The difference with example 5 is that the ligand L2in preparation 2 is used instead of the ligand L1in preparation 1. The obtained product is characterized by:

[0074] 1 H-NMR: 7.76-7.89 (m, 3H), 7.30-7.41 (m, 6H), 6.53-6.77 (m, 4H); Calcd. (%) for C 21 H 13 Cl3F2N2Zr: C: 47.69, H: 2.48, N: 5.30; found: C: 47.72, H: 2.54, N: 5.41.

[0075] Synthesis of catalyst cat-7a of example 7

[0076] The difference with example 5 is that the ligand L3in preparation 3 is used instead of the ligand L1in preparation 1. The obtained product is characterized by:

[0077] 1 H-NMR: 7.71-7.85 (m, 3H), 7.25-7.31 (m, 6H), 6.63-6.71 (m, 3H), 3.15 (m, 2H), 2.41 (s, 3H), 1.31-1.32 (m, 12H); Calcd. (%) for C 28 H 29Cl3N2Zr: C: 56.89, H: 4.94, N: 4.74; found: C: 56.72, H: 4.84, N: 4.81.

[0078] Synthesis of catalyst cat-8a of Example 8

[0079] The difference from Example 5 is that the ligand L4 in Preparation Example 4 is used instead of the ligand L1 in Preparation Example 1. The detection parameters of the obtained product are as follows:

[0080] 1 H-NMR: 7.78-7.88 (m, 3H), 7.32-7.38 (m, 6H), 6.41-6.68 (m, 4H), 2.41 (s, 6H); Calcd. (%) for C 23 H 19 Cl3N2Zr: C: 53.02, H: 3.68, N: 5.38; found: C: 53.11, H: 3.74, N: 5.45.

[0081] In order to clearly express the bidentate aminoquinoline monometallic catalyst cat-a prepared in Examples 1-8, the structure thereof is described as follows, see Table 2 for details, and the yield thereof is given:

[0082] Catalyst cat-a:

[0083]

[0084] Table 2: Catalyst structure information and yield table

[0085] Catalyst M [R1] [R2] Yield / % Cat-1a Hf Isopropyl Hydrogen 71％ Cat-2a Hf Fluoro Hydrogen 73％ Cat-3a Hf Isopropyl Methyl 72％ Cat-4a Hf Methyl Hydrogen 76％ Cat-5a Zr Isopropyl Hydrogen 75％ Cat-6a Zr Fluoro Hydrogen 69％ Cat-7a Zr Isopropyl Methyl 67％ Cat-8a Zr Methyl Hydrogen 65％

[0086] Through the experimental data recorded in the above table, the synthesis route of such catalysts is simple, the yield is high, and the production cost of the catalysts can be effectively reduced.

[0087] The inventors applied the above Examples 1-8 to the reaction of catalyzing olefin polymerization, and obtained the following Application Examples 1-11.

[0088] Application Example 1

[0089] The present application example provides a method for catalyzing ethylene and octene copolymerization by using the catalyst cat-1a prepared in Example 1, which specifically comprises the following steps:

[0090] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-octene, and 1000 μmol methylaluminoxane (Hf:Al = 1:500) were added into a reaction kettle, and the temperature was raised to 150°C. 2 μmol of the catalyst cat-1a was dissolved in 10 mL of toluene and then was pressurized into the reaction kettle with ethylene. The pressure of ethylene was adjusted to 2 MPa, and the copolymerization of ethylene and 1-octene was carried out at 150°C for 30 min. After the reaction was stopped, the polymerization was terminated with 5% hydrochloric acid ethanol solution. After stirring for 0.5 h, the product was filtered, washed with ethanol three times, and dried at 70°C under vacuum for 12 h to obtain an ethylene-octene copolymer.

[0091] The catalytic activity of cat-1a in this application example was 7.1 x 10 7 g / (mol Hf·h), and the weight average molecular weight of the prepared ethylene-octene copolymer was 225 kg / mol, the molecular weight distribution index was 2.1, the glass transition temperature was -55°C, and the melting temperature was 61°C.

[0092] Application Example 2

[0093] This application example provides a method for catalyzing the copolymerization of ethylene and octene with the catalyst cat-2a prepared in Example 2, which specifically comprises the following steps:

[0094] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-octene, and 1000 μmol methylaluminoxane (Hf:Al = 1:500) were added into a reaction kettle, and the temperature was raised to 150°C. 2 μmol of the catalyst cat-1a was dissolved in 10 mL of toluene and then was pressurized into the reaction kettle with ethylene. The pressure of ethylene was adjusted to 2 MPa, and the copolymerization of ethylene and 1-octene was carried out at 150°C for 30 min. After the reaction was stopped, the polymerization was terminated with 5% hydrochloric acid ethanol solution. After stirring for 0.5 h, the product was filtered, washed with ethanol three times, and dried at 70°C under vacuum for 12 h to obtain an ethylene-octene copolymer.

[0095] The catalytic activity of cat-2a in this application example was 1.5 x 10 7 g / (mol Hf·h), and the weight average molecular weight of the prepared ethylene-octene copolymer was 161 kg / mol, the molecular weight distribution index was 2.3, the glass transition temperature was -45°C, and the melting temperature was 85°C.

[0096] Application Example 3

[0097] This application example provides a method for catalyzing the copolymerization of ethylene and octene with the catalyst cat-3a prepared in Example 3, which specifically comprises the following steps:

[0098] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-octene, and 1000 μmol methylaluminoxane (Hf:Al = 1:500) were added into a reaction kettle, and the temperature was raised to 150 ℃. 2 μmol of the catalyst cat-1a was dissolved in 10 mL of toluene, and then the reaction kettle was pressurized with ethylene. The pressure of ethylene was adjusted to 2 MPa, and the copolymerization of ethylene and 1-octene was carried out at 150 ℃ for 30 min. After the reaction was stopped, the polymerization was terminated with 5% hydrochloric acid ethanol solution. After stirring for 0.5 h, the product was filtered, washed with ethanol three times, and dried at 70 ℃ under vacuum for 12 h to obtain an ethylene-octene copolymer.

[0099] The catalytic activity of cat-3a in this example was 6.2 x 10 7 g / (mol Hf·h), and the weight average molecular weight of the prepared ethylene-octene copolymer was 195 kg / mol, the molecular weight distribution index was 2.3, the glass transition temperature was -47 ℃, and the melting temperature was 75 ℃.

[0100] Application Example 4

[0101] This application example provides a method for catalyzing the copolymerization of ethylene and octene by the catalyst cat-4a prepared in Example 4, which specifically comprises the following steps:

[0102] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-octene, and 1000 μmol methylaluminoxane (Hf:Al = 1:500) were added into a reaction kettle, and the temperature was raised to 150 ℃. 2 μmol of the catalyst cat-1a was dissolved in 10 mL of toluene, and then the reaction kettle was pressurized with ethylene. The pressure of ethylene was adjusted to 2 MPa, and the copolymerization of ethylene and 1-octene was carried out at 150 ℃ for 30 min. After the reaction was stopped, the polymerization was terminated with 5% hydrochloric acid ethanol solution. After stirring for 0.5 h, the product was filtered, washed with ethanol three times, and dried at 70 ℃ under vacuum for 12 h to obtain an ethylene-octene copolymer.

[0103] The catalytic activity of cat-4a in this application example was 4.6 x 10 7 g / (mol Hf·h), and the weight average molecular weight of the prepared ethylene-octene copolymer was 171 kg / mol, the molecular weight distribution index was 2.5, the glass transition temperature was -45 ℃, and the melting temperature was 80 ℃.

[0104] Application Example 5

[0105] This application example provides a method for catalyzing the copolymerization of ethylene and octene by the catalyst cat-5a prepared in Example 5, which specifically comprises the following steps:

[0106] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-octene, and 1000 μmol methylaluminoxane (Zr:Al = 1:500) were added into a reaction kettle, which was heated to 150 ℃, 2 μmol of catalyst cat-1a was dissolved in 10 mL of toluene and then was pressurized into the reaction kettle with ethylene, the pressure of ethylene was adjusted to 2 MPa, and the copolymerization of ethylene and 1-octene was carried out at 150 ℃ for 30 min. After the reaction was stopped, the polymerization was terminated with 5% hydrochloric acid ethanol solution, and after stirring for 0.5 h, the product was filtered, washed with ethanol for three times, and vacuum dried at 70 ℃ for 12 h to obtain an ethylene-octene copolymer.

[0107] The catalytic activity of cat-5a in this application example was 6.5 x 10 7 g / (mol Zr·h), the weight average molecular weight of the prepared ethylene-octene copolymer was 151 kg / mol, the molecular weight distribution index was 2.3, the glass transition temperature was -44 ℃, and the melting temperature was 73 ℃.

[0108] Application Example 6

[0109] This application example provides a method for catalyzing the copolymerization of ethylene and octene by using the catalyst cat-6a prepared in Example 6, which specifically comprises the following steps:

[0110] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-octene, and 1000 μmol methylaluminoxane (Zr:Al = 1:500) were added into a reaction kettle, which was heated to 150 ℃, 2 μmol of catalyst cat-1a was dissolved in 10 mL of toluene and then was pressurized into the reaction kettle with ethylene, the pressure of ethylene was adjusted to 2 MPa, and the copolymerization of ethylene and 1-octene was carried out at 150 ℃ for 30 min. After the reaction was stopped, the polymerization was terminated with 5% hydrochloric acid ethanol solution, and after stirring for 0.5 h, the product was filtered, washed with ethanol for three times, and vacuum dried at 70 ℃ for 12 h to obtain an ethylene-octene copolymer.

[0111] The catalytic activity of cat-6a in this application example was 1.3 x 10 7 g / (mol Zr·h), the weight average molecular weight of the prepared ethylene-octene copolymer was 144 kg / mol, the molecular weight distribution index was 2.3, the glass transition temperature was -41 ℃, and the melting temperature was 77 ℃.

[0112] Application Example 7

[0113] This application example provides a method for catalyzing the copolymerization of ethylene and octene by using the catalyst cat-7a prepared in Example 7, which specifically comprises the following steps:

[0114] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-octene, and 1000 μmol methylaluminoxane (Zr:Al = 1:500) were added into a reaction kettle, and the temperature was raised to 150°C. 2 μmol of the catalyst cat-1a was dissolved in 10 mL of toluene and then was pressurized into the reaction kettle with ethylene. The pressure of ethylene was adjusted to 2 MPa, and the copolymerization of ethylene and 1-octene was carried out at 150°C for 30 min. After the reaction was stopped, the polymerization was terminated with 5% hydrochloric acid ethanol solution. After stirring for 0.5 h, the product was filtered, washed with ethanol three times, and dried at 70°C under vacuum for 12 h to obtain an ethylene-octene copolymer.

[0115] The catalytic activity of cat-7a in this application example was 4.4 x 10 7 g / (mol Zr·h), and the weight average molecular weight of the prepared ethylene-octene copolymer was 144 kg / mol, the molecular weight distribution index was 2.1, the glass transition temperature was -50°C, and the melting temperature was 68°C.

[0116] Application Example 8

[0117] This application example provides a method for catalyzing the copolymerization of ethylene and octene by the catalyst cat-8a prepared in Example 8, which specifically comprises the following steps:

[0118] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-octene, and 1000 μmol methylaluminoxane (Zr:Al = 1:500) were added into a reaction kettle, and the temperature was raised to 150°C. 2 μmol of the catalyst cat-1a was dissolved in 10 mL of toluene and then was pressurized into the reaction kettle with ethylene. The pressure of ethylene was adjusted to 2 MPa, and the copolymerization of ethylene and 1-octene was carried out at 150°C for 30 min. After the reaction was stopped, the polymerization was terminated with 5% hydrochloric acid ethanol solution. After stirring for 0.5 h, the product was filtered, washed with ethanol three times, and dried at 70°C under vacuum for 12 h to obtain an ethylene-octene copolymer.

[0119] The catalytic activity of cat-8a in this application example was 3.2 x 10 7 g / (mol Zr·h), and the weight average molecular weight of the prepared ethylene-octene copolymer was 143 kg / mol, the molecular weight distribution index was 2.4, the glass transition temperature was -44°C, and the melting temperature was 76°C.

[0120] Application Example 9

[0121] This application example provides a method for catalyzing the copolymerization of ethylene and hexene by the catalyst cat-1a prepared in Example 1, which specifically comprises the following steps:

[0122] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-hexene, and 1000 μmol methylaluminoxane (Hf:Al = 1:500) were added into a reaction kettle, and the temperature was raised to 150°C. After 2 μmol of the catalyst cat-1a was dissolved in 10 mL of toluene, the reaction kettle was pressurized with ethylene. The pressure of ethylene was adjusted to 2 MPa, and the copolymerization of ethylene and 1-hexene was carried out at 150°C for 30 min. After the reaction was terminated, the polymerization was terminated with 5% hydrochloric acid ethanol solution. After stirring for 0.5 h, the product was filtered, washed with ethanol three times, and dried at 70°C under vacuum for 12 h to obtain an ethylene-hexene copolymer.

[0123] The catalytic activity of cat-1a in this application example was 6.5 x 10 7 g / (mol Hf·h). The weight average molecular weight of the prepared ethylene-hexene copolymer was 138 kg / mol, the molecular weight distribution index was 2.3, the glass transition temperature was -41°C, and the melting temperature was 86°C.

[0124] Application Example 10

[0125] This application example provides a method for catalyzing the copolymerization of ethylene and butene by using the catalyst cat-1a prepared in Example 1, which specifically comprises the following steps:

[0126] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-butene, and 1000 μmol methylaluminoxane (Hf:Al = 1:500) were added into a reaction kettle, and the temperature was raised to 150°C. After 2 μmol of the catalyst cat-1a was dissolved in 10 mL of toluene, the reaction kettle was pressurized with ethylene. The pressure of ethylene was adjusted to 2 MPa, and the copolymerization of ethylene and 1-butene was carried out at 150°C for 30 min. After the reaction was terminated, the polymerization was terminated with 5% hydrochloric acid ethanol solution. After stirring for 0.5 h, the product was filtered, washed with ethanol three times, and dried at 70°C under vacuum for 12 h to obtain an ethylene-butene copolymer.

[0127] The catalytic activity of cat-1a in this application example was 6.9 x 10 7 g / (mol Hf·h). The weight average molecular weight of the prepared ethylene-butene copolymer was 141 kg / mol, the molecular weight distribution index was 2.4, the glass transition temperature was -40°C, and the melting temperature was 95°C.

[0128] Application Example 11

[0129] This application example provides a method for catalyzing the copolymerization of ethylene and octene by using the catalyst cat-1a prepared in Example 1, which specifically comprises the following steps:

[0130] Under the condition of no water and no oxygen, 1000 mL of toluene, 300 mL of 1-octene, and 1000 μmol methylaluminoxane (Hf:Al = 1:500) were added into a reaction kettle, and the temperature was raised to 170 ℃. After 2 μmol of the catalyst cat-1a was dissolved in 10 mL of toluene, the solution was pressurized into the reaction kettle with ethylene, and the ethylene pressure was adjusted to 2 MPa. The copolymerization of ethylene and 1-octene was carried out at 150 ℃ for 30 min. After the reaction was stopped, the polymerization was terminated with 5% hydrochloric acid ethanol solution. After stirring for 0.5 h, the product was filtered, washed with ethanol three times, and dried at 70 ℃ under vacuum for 12 h to obtain an ethylene-octene copolymer.

[0131] The catalytic activity of cat-1a in this application example was 7.0 x 10 7 g / (mol Hf·h), and the weight average molecular weight of the prepared ethylene-octene copolymer was 228 kg / mol, the molecular weight distribution index was 2.2, the glass transition temperature was -54 ℃, and the melting temperature was 60 ℃.

[0132] As can be seen from Examples 1-8 and Application Examples 1-11, the yield of the catalyst prepared in Examples 1-8 is not less than 65%, and the catalyst still has relatively high catalytic activity under high-temperature reaction conditions of 150 ℃. For example, the yield of the catalyst prepared in Example 1 and corresponding Application Example 1 is as high as 71%, and the catalytic activity is as high as 7.1 x 10 7 g / (mol Hf·h) at 150 ℃.

[0133] In addition, as can be seen from Application Example 1 and Application Examples 9-11, the bidentate amino quinoline single-site catalyst prepared by the application still has relatively high catalytic activity under the condition of 150 ℃ when catalyzing the copolymerization of ethylene and α-olefin, and the catalytic activity is not less than 6.5 x 10 7 g / (mol·h). Even under the condition of 170 ℃, the catalytic activity can be as high as 7.0 x 10 7 g / (mol·h). Therefore, it can be inferred that the bidentate amino quinoline single-site catalyst prepared by the application has strong high-temperature resistance, and the high-temperature resistance of the catalyst is not less than 170 ℃.

[0134] Application Comparative Example 1

[0135] The bidentate 2-methyl-8-amino quinoline single-site catalyst reported by Philip P. Fontaine (Organometallics 2012, 31, 6244-6251; Organometallics 2015, 34, 1354-1363) is used as a comparative example.

[0136] By comparison between the two, we find that: the bidentate 2-methyl-8-amino quinoline single center catalyst is applied to the olefin polymerization reaction, and the catalyst in the prior art is lower than the catalyst in the application in the polymerization temperature.

[0137] In summary, by using the bidentate catalytic system of the application, not only the high-temperature resistance and activity of the catalytic olefin polymerization can be enhanced, but also the ethylene and alpha-olefin copolymerization with high activity at high temperature (≥ 150℃) can be realized, and the polymerization activity of the catalyst at 150℃ can be more than 1 x 10 7 g / (mol·h). In addition, the synthetic route adopted in the application is simple and easy to operate, and a ligand with high yield can be obtained by one-step reaction, that is, the yield of the ligand synthesized from 2-phenyl-8-amino quinoline raw material is more than 75%; and the bidentate amino quinoline single center catalyst (cat-a) prepared from the intermediate ligand L has a yield of not less than 65%. Based on this, when it is quantitatively produced in industry, the production cost can be effectively saved.

[0138] The above is only a preferred embodiment of the application, and does not limit the protection scope of the application. Any modification or application of the above embodiment is within the protection scope of the technical scheme.

[0139] Although the specific embodiments of the application have been described in detail, those skilled in the art will understand that various modifications and substitutions can be made to those details based on all the teachings disclosed herein, and these changes are within the protection scope of the application. The entire scope of the application is given by the appended claims and any equivalents thereof.

Claims

1. Single-site catalyst characterised in that, The single-center catalyst is a bidentate amino quinoline single-center catalyst, as shown in formula (I): （Ⅰ）； In the formula, M is zirconium or hafnium; R1 is selected from methyl, isopropyl or fluorine; and R2 is selected from hydrogen or methyl.

2. A process for the preparation of the single-site catalyst according to claim 1, characterized in that, The method produces the bidentate amino quinoline single-center catalyst from 2-phenyl-8-amino quinoline as a parent.

3. The process for the preparation of a single-site catalyst according to claim 2, characterized in that, The method comprises the following steps: S1, in a benzene solvent, 2-phenyl-8-amino quinoline, bromobenzene with a substituent on the benzene ring, tris(dibenzylidene) palladium acetone, 2,2'-bis(diphenylphosphine)-1,1'-binaphthalene and sodium tert-butoxide are sequentially added, and the temperature is raised to reflux, and the ligand L is separated by chromatography; S2, after the ligand L in S1 is deprotonated with a strong base, a metal salt is added to prepare a bidentate amino quinoline single-center catalyst.

4. The process for the preparation of a single-site catalyst according to claim 3, characterized in that, In S1, the benzene solvent is selected from benzene, toluene or xylene.

5. The process for the preparation of a single-site catalyst according to claim 3, characterized in that, In S1, the temperature is raised to the boiling point of the benzene solvent and then refluxed.

6. The process for the preparation of a single-site catalyst according to claim 3, characterized in that, In S1, the ligand L is shown in formula (II): （Ⅱ）； In the formula, R1 is selected from methyl, isopropyl or fluorine; and R2 is selected from hydrogen or methyl.

7. The process for the preparation of a single-site catalyst according to claim 3, characterized in that, In S2, the metal salt is a chlorine-containing metal salt.

8. The process for the preparation of a single-site catalyst according to claim 7, characterized in that, The chlorine-containing metal salt is selected from zirconium tetrachloride or hafnium tetrachloride.

9. Use of a single-site catalyst as claimed in claim 1 or a single-site catalyst prepared by the process of any one of claims 2 to 8 in the catalysis of the polymerisation of olefins, characterised in that, The single-center catalyst is used to catalyze the copolymerization reaction between ethylene and α-olefin.

10. Use of the single-site catalyst according to claim 9 for catalysing the polymerisation of olefins, characterised in that, The α-olefin is selected from butene, hexene or octene.

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