A nitrogen-oxygen chelated transition metal complex catalyst, a preparation method and application thereof

Abstract

The application discloses a nitrogen-oxygen chelated transition metal complex catalyst and a preparation method and application thereof, and belongs to the field of olefin polymerization catalysts. The nitrogen-oxygen chelated transition metal complex catalyst has a structure of formula (I), M is selected from group IVB transition metal atoms, Y is selected from silicon, carbon, phosphorus and other atoms, an oxygen-containing functional group is additionally introduced into a ligand of the catalyst to be coordinated with a central atom titanium, and a chelated transition metal complex is formed. In olefin polymerization, Ti active center cations are coordinated with oxygen to be stable, the deactivation of the active center can be effectively slowed down, and the active maintenance time can reach more than 1 hour. The catalyst can be used in the copolymerization reaction of ethylene and C8 or above alpha-olefins.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of olefin polymerization catalysts, in particular to a nitrogen-oxygen chelated transition metal complex catalyst and its preparation method and application. BACKGROUND

[0002] Polyolefin elastomer (Poly-Olefin Elastomer, POE for short) is a kind of main chain saturated thermoplastic elastomer polymerized by ethylene and α-olefin or cyclic olefin, which has low density, narrow molecular weight distribution, excellent elasticity, wear resistance, mechanical properties and processing properties, and is usually prepared by solution polymerization process using single-site catalyst. POE is widely used in automotive toughening materials, photovoltaic cells, shoe materials and medical fields. In order to make these polyolefin materials have excellent performance, the research and development of the structure of the polymerization catalyst required to prepare these materials is crucial, while the research on the catalyst system for producing POE is relatively lagging behind.

[0003] Metallocene catalyst is the most widely used catalyst for producing POE. In the early 1990s, the industrial application of metallocene catalyst laid the foundation for the development of polyolefin elastomer. The constrained geometry metallocene catalyst structure is shown in formula 1, which connects a monocyclopentadienyl (Cp) to another ligand through a bridge group and simultaneously coordinates with the metal center, limiting the relative rotation of the metal center and the metallocene ring, which is a bridged monocyclopentadienyl metal structure. In 1993, Dow Chemical developed POE products based on high-temperature solution polymerization process using constrained geometry metallocene catalyst (CGC). It has the advantages of single active center, excellent copolymerization ability and simple synthesis route, and is very mature in application.

[0004]

[0005] When used alone, the CGC catalyst does not have catalytic activity for olefin polymerization. The CGC catalyst needs to be activated by an assistant (methylaluminoxane MAO, organoborane or borate) to convert into a cationic alkyl titanium active center, which then catalyzes the coordination insertion of olefin to catalyze the polymerization of olefin. Among them, the cationic alkyl titanium active center has strong Lewis acidity, which is easy to combine with weakly basic organoborane in the polymerization system or to occur dimerization reaction between active centers, resulting in catalyst deactivation. Generally, the activity of CGC catalyst activated by the assistant in high-temperature solution polymerization reaction can be maintained for less than 10 minutes.

[0006] The catalyst of patent publication No. CN116284514A utilizes alkyl metal compounds and organic ammonium borate to pre-activate the CGC catalyst. After activation, the ammonium cation is converted into an organic amine, which coordinates with the Ti active center cation, stabilizes the catalyst, and makes the activated catalyst be stored for up to 40 days at room temperature in an inert atmosphere. However, in high-temperature reactions, the coordination of amine and Ti is easy to dissociate to regenerate unstable low-coordination number active centers. Therefore, the stability of the catalyst in the high-temperature polymerization process has not been significantly improved.

[0007] The reaction mechanism is as follows:

[0008] SUMMARY

[0009] The purpose of the present application is to overcome the steps of the prior art, and provide a nitrogen-oxygen chelated transition metal complex catalyst and its preparation method and application. The catalyst is based on the CGC catalyst, and an oxygen-containing functional group is additionally introduced into the ligand to coordinate with the central atom titanium to form a chelated transition metal complex. In olefin polymerization, the Ti active center cation coordinates with oxygen to stabilize, which can effectively slow down the deactivation of the active center, and the activity maintenance time can reach more than 1 hour. It can be used for high-temperature solution copolymerization of ethylene and C8 or more alpha-olefins.

[0010] The present application provides a nitrogen-oxygen chelated transition metal complex, which has the following formula (I) structure:

[0011]

[0012] Among them:

[0013] R 1 ,R 2 ,R 3 ,R 4 selected from hydrogen, C1-C 18 alkyl or aryl, wherein R 1 ,R 2 ,R 3 ,R 4 The groups can be the same or different from each other, and adjacent groups can also be bonded to each other or form a ring;

[0014] R 5 selected from hydrogen, C1-C 18 alkyl or aryl, C1-C 18 alkyl or aryl substituted silicon group, C1-C 18 alkyl or aryl substituted phosphine group;

[0015] R 6 ,R 7 selected from hydrogen, C1-C18 alkyl or aryl groups, which can be the same or different, and which can be bonded to each other or form a ring;

[0016] R is selected from the group consisting of hydrogen, C1-C 18 alkyl or aryl groups, the number of which is determined by the valence of Y, which can be the same or different, and which can be bonded to each other or form a ring;

[0017] M is selected from the group consisting of transition metal atoms of Group IVB;

[0018] X 1 ,X 2 is selected from the group consisting of halogen atoms, hydrogen atoms, C1-C5 hydrocarbon groups and alkoxy groups, carboxylate groups, aliphatic amine groups, aromatic amine groups, aliphatic phosphine groups, aromatic phosphine groups, alkylthio groups, borane groups, borate groups, alkylaluminum groups, silane-substituted C1-C5 hydrocarbon groups, and the like.

[0019] Y is selected from the group consisting of silicon, carbon, phosphorus, and the like;

[0020] n = 0, 1, 2, 3, 4, 5.

[0021] To achieve the above object, the present application further provides a preparation method of a transition metal complex with nitrogen-oxygen chelation, which comprises the following steps:

[0022] Step 1: 1, w-aminyl alcohol is reacted with a halogenated hydrocarbon, a halogenated silane or a halogenated phosphine (R 5 in the presence of a base to obtain an intermediate shown in formula (II);

[0023]

[0024] Step 2: the intermediate shown in formula (II) is reacted with a chloride containing a metallocycle and a bridged heteroatom in an inert gas atmosphere to generate a ligand shown in formula (III);

[0025]

[0026] Step 3: the ligand shown in formula (III) is mixed with an organic lithium reagent at low temperature in an inert gas atmosphere, and then the reaction is carried out at room temperature to prepare an organic lithium intermediate shown in formula (IV);

[0027]

[0028] Step 4: the organic lithium intermediate shown in formula (IV) is reacted with a tetrahydrofuran complex MX 1 myTHF reaction to form a nitrogen-oxygen chelated transition metal complex catalyst represented by formula (I), M represents a transition metal atom of Group IVB, X 1 selected from halogen atoms, m = 3, 4 (the specific number is determined according to the valence state of the metal), y = 0, 1, 2 (the specific number is determined according to the coordination number of the metal);

[0029]

[0030] Preferably, the inert gas atmosphere in the above steps is selected from high-purity nitrogen, high-purity argon, etc.

[0031] Preferably, in step 1, the halogenated hydrocarbon is selected from C1-C 18 chlorinated, brominated or iodinated alkanes or arenes, the halogenated silane is selected from chlorosilanes, C1-C 18 alkyl or aryl substituted chlorosilanes, and the halogenated phosphine is selected from chlorophosphines, C1-C 18 alkyl or aryl substituted chlorophosphines.

[0032] Preferably, in step 1, the base is selected from sodium carbonate, potassium carbonate, potassium phosphate, potassium tert-butoxide, n-butyllithium or triethylamine, and the molar ratio of 1, w-aminyl alcohol, halogenated hydrocarbon / halogenated silane / halogenated phosphine, base is 1:1:2-1:1:4.

[0033] Preferably, in step 2, the molar ratio of the intermediate represented by formula (II) to the chloride containing a metallocycle and a bridging heteroatom is 2:1-1:2;

[0034] Preferably, in step 2, the intermediate represented by formula (II) and the chloride containing a metallocycle and a bridging heteroatom are selected from the following structures:

[0035]

[0036] wherein, R 1 , R 2 , R 3 , R 4 is selected from hydrogen, C1-C 18 alkyl or aryl, wherein R 1 , R 2 , R 3 , R 4 groups can be the same or different from each other, and adjacent groups can also bond to each other or form a ring; R is selected from hydrogen, C1-C 18 alkyl or aryl, the number is determined by the valence state of Y, and can be the same or different from each other, and adjacent groups can also bond to each other or form a ring; Y is selected from silicon, carbon, phosphorus and the like.

[0037] Preferably, in step 3, the organolithium reagent is selected from methyllithium, n-butyllithium, tert-butyllithium;

[0038] Preferably, in step 3, the molar ratio of the ligand of formula (III) to the organic lithium reagent is 1:2 to 1:4.

[0039] Preferably, in step 3, the temperature of the low temperature is -78°C to 0°C.

[0040] Preferably, in step 4, the molar ratio of the organic lithium of formula (IV) to the tetrahydrofuran complex of the Group IVB metal halide is 1.1:1 to 1:1.

[0041] The reaction scheme of the preparation method of the catalyst is shown as follows:

[0042]

[0043] Further, the nitric oxide chelated transition metal complex of the present application is selected from one of the following structures:

[0044]

[0045] In each of the structural formulae, i Pr represents isopropyl, and Ph represents phenyl.

[0046] Further, the nitric oxide chelated transition metal complex catalyst is preferably one of the following structures:

[0047]

[0048] The present application also provides the use of the above-mentioned nitric oxide chelated transition metal complex as a catalyst in olefin polymerization.

[0049] Further, the use is to catalyze the polymerization of olefins by using the above-mentioned transition metal complex as a main catalyst, and in the presence of methylaluminoxane and borane as cocatalysts.

[0050] Further, the polymerized olefin monomers are one or more of ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, etc.

[0051] Further, the olefin polymerization is the copolymerization of ethylene and α-olefin.

[0052] Further, the polymerization is carried out in the presence of methylaluminoxane and borane in n-hexane solvent, the molar ratio of methylaluminoxane to the central metal of the main catalyst is 100-1000:1, the molar ratio of borane to the central metal of the main catalyst is 2-8:1, the polymerization temperature is 115-135°C, and the polymerization pressure is 3-4 MPa.

[0053] Compared with the prior art, the oxygen atom and the group connected therewith are introduced into the catalyst, so that the catalyst is chelated with the ligand. The Ti active center cation is coordinated with oxygen to stabilize and prolong the active maintenance time of the catalyst. Meanwhile, the coordination of the oxygen atom with the central metal makes the central metal away from the position of the large group aggregation, so that the olefin insertion space around the central metal is larger, the catalyst is more easily activated, and the copolymerization insertion rate is larger. DETAILED DESCRIPTION

[0054] In order to better understand the technical solutions of the present application, the following specific examples are further described below to illustrate the content of the present application, but the content of the present application is not limited to the following examples. Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0055] The following examples provide those of ordinary skill in the art with a conception how to make and use the present application. The examples are merely exemplary and are not intended to limit the scope of the disclosure. Although efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), some errors and deviations should be accounted for. Unless indicated otherwise, temperature is in °C or at ambient temperature, and pressure is at or near atmospheric pressure.

[0056] The preparation method described in the present embodiment for the disclosed compounds is one of many methods, and there are many other methods for preparing the disclosed compounds, which are not limited by the present application. Therefore, those skilled in the art to which the present disclosure pertains can easily modify the described methods or use different methods to prepare one or more of the disclosed compounds. The following methods are merely exemplary, and the temperature, catalyst, concentration, reactant composition, and other process conditions can be changed, and for the desired compounds, those skilled in the art to which the present disclosure pertains can easily select appropriate reactants and conditions for preparation.

[0057] The present embodiment specifically adopts the following typical but not limited preparation process to implement the preparation method of the nitrogen-oxygen chelated transition metal complex in the inventive content part:

[0058] Step 1: Under the protection of inert gas, 1, w-aminyl alcohol, potassium carbonate are mixed in dichloromethane solvent in a Schlenk reaction bottle, and then C1-C 18 The halide of the alkane or aralkane, the halide of the silane or arylsilane, or the halide of the phosphane or arylphosphane is heated to 40°C, and stirring is continued for 2 hours. After the reaction is completed, water is added, and the aqueous phase and the organic phase are separated. The aqueous phase is extracted with dichloromethane for 3 times, and the organic phase is rotary evaporated to dryness. The water pump is used for vacuum distillation to obtain the substance shown in formula (II). 1, w-aminyl alcohol, potassium carbonate, C1-C 18The molar ratio of the alkane or arene halide, silane or silarene halide or phosphane or phospharene halide is 1:2-5:1, preferably 1, w-aminol, potassium carbonate, C1-C 18 The molar ratio of the alkane or arene halide, silane or silarene halide or phosphane or phospharene halide is 1:2:1.

[0059] Step 2: Under inert gas protection, the formula (II) substance is dissolved in n-hexane in a Schlenk reaction bottle, then the metallocycle and bridged heteroatom-containing chloride is slowly added dropwise at 0℃, after the dropwise addition is completed, stirring is continued for 12-24 hours, after the reaction is completed, filtration is performed, the solid is washed with n-hexane, and the obtained liquid is dried to obtain a bridged ligand containing a metallocycle, a bridged heteroatom and an oxygen atom shown in formula (III). The molar ratio of the formula (II) substance to the metallocycle and bridged heteroatom-containing chloride is 1:1-3.

[0060] Step 3: Under inert gas protection, the bridged ligand containing a metallocycle, a bridged heteroatom and an oxygen atom shown in formula (III) is added in a Schlenk reaction bottle, then n-butyllithium n-hexane solution is slowly added dropwise at -78℃, the temperature is restored to room temperature, stirring is continued for 12-24 hours, vacuum drying is performed, the solid is vacuum dried to obtain a lithium salt of the ligand shown in formula (IV).

[0061] Step 4: Under inert gas protection, a Schlenk reaction bottle is added with a tetrahydrofuran complex MX n of a metal halide (M represents a group IVB transition metal atom, X is selected from a halogen atom, n=0, 1, 2…, y=0, 1, 2…), a tetrahydrofuran solution of the lithium salt of the ligand shown in formula (IV) is slowly added dropwise at -78℃, stirring is continued for 30 minutes, then lead dichloride is added, stirring is continued for 2-4 hours, the product is filtered, vacuum dried, washed with n-hexane, recrystallized at -20℃ to obtain a nitrogen-oxygen chelated transition metal complex shown in formula (I).

[0062] The preparation method of the nitrogen-oxygen chelated transition metal complex catalyst provided by the application is carried out under inert gas protection throughout the whole reaction process, and the inert gas is one of nitrogen and argon.

[0063] The technical solutions of the application will be further described below through specific examples.

[0064] Example 1

[0065] Synthesis of the ligand L1

[0066]

[0067] Into a dry 100 mL Schlenk flask, 2-amino-2-methyl-1-propanol (7.12 g, 80 mmol), potassium carbonate (0.69 g, 5 mmol) were added into dichloromethane solvent (300 ml) and then trimethylsilylchloride (8.72 g, 80 mmol) was added dropwise slowly. The reaction mixture was stirred at 40 °C for 2 h. After the reaction was completed, water (200 ml) was added. The aqueous and organic phases were separated. The aqueous phase was extracted with dichloromethane three times. The organic phase was dried and distilled under reduced pressure with a water pump to obtain 2-amino-2-methyl-1-trimethylsilyl ether (8.35 g, 52 mmol) with a yield of 65%.

[0068] Into a dry 100 mL Schlenk flask, 2-amino-2-methyl-1-trimethylsilyl ether (3.22 g, 20 mmol) was added into n-hexane solvent (200 ml). Tetramethylcyclopentadiene chlorosilane (2.15 g, 10 mmol) was added dropwise slowly at 0 °C. The reaction mixture was stirred at room temperature for 12-24 h. After the reaction was completed, the solid was filtered and dried. The obtained liquid was distilled under reduced pressure with a water pump to obtain ligand L1 (4.81 g, 14 mmol) with a yield of 70%.

[0069] NMR of hydrogen: 1 H NMR (300 MHz, CDC13) δ 3.95 (s, 2H), 2.63 (s, 1H), 2.11 (s, 6H), 1.76 (s, 6H), 1.20 (s, 6H), 0.22 (s, 9H), 0.08 (s, 6H).

[0070] NMR of carbon: 13 C NMR (101 MHz, CDC13) δ 135.5, 127.5, 82.7, 56.7, 41.3, 27.5, 20.6, 11.1, 3.7, 2.2.

[0071] Example 2

[0072] Synthesis of ligand L2

[0073]

[0074] Into a dry 100 mL Schlenk flask, 2-amino-2-methyl-1-propanol (0.712 g, 8 mmol), potassium carbonate (2.208 g, 16 mmol) were added in dichloromethane solvent (300 ml) mixture, then triphenylsilylchloride (2.360 g, 8 mmol) was added dropwise slowly, the temperature was raised to 40 °C, and stirring was continued for 2 h. After completion of the reaction, water (200 ml) was added, and the mixture was extracted. The aqueous and organic layers were separated, and the aqueous layer was extracted with dichloromethane three times. The organic layer was dried under vacuum, and the solvent was removed by distillation under reduced pressure to obtain 2-amino-2-methyl-1-triphenylsilyl ether crude product. The crude product was separated by column chromatography to obtain 2-amino-2-methyl-1-triphenylsilyl ether (1.743 g, 5 mmol) with a yield of 62.5%.

[0075] Into a dry 100 mL Schlenk flask, 2-amino-2-methyl-1-triphenylsilyl ether (0.696 g, 2 mmol) was added in n-hexane solvent (30 ml), and tetramethylcyclopentadiene chlorosilane (0.215 g, 1 mmol) was added dropwise slowly at 0 °C. The temperature was raised to room temperature, and stirring was continued for 12-24 h. After completion of the reaction, the mixture was filtered, and the solid was washed with n-hexane. The obtained liquid was dried under vacuum to obtain ligand L2 (0.842 g, 1.6 mmol) with a yield of 80%.

[0076] Nuclear magnetic resonance hydrogen spectrum: 1 H NMR (300 MHz, CDC13) δ 7.45-7.35 (m, 15H), 3.91 (s, 2H), 2.67 (s, 1H), 2.14 (s, 6H), 1.76 (s, 6H), 1.21 (s, 6H), 0.06 (s, 6H).

[0077] Example 3

[0078] Synthesis of ligand L3

[0079]

[0080] Into a dry 250 mL Schlenk flask, diphenylphosphine chloride (1.105 g, 5 mmol) was added in dichloromethane solvent (50 ml), and triethylamine (1 M, 5 mL) was added. The mixture was stirred at room temperature for 30 min, and 2-amino-2-methyl-1-propanol (0.445 g, 5 mmol) was added at 0 °C. The temperature was raised to room temperature, and stirring was continued for 24 h. After completion of the reaction, the mixture was filtered, and the filtrate was dried under vacuum. The crude product was separated by column chromatography to obtain 2-amino-2-methyl-1-diphenylphosphine methyl ether (1.1201 g, 4.1 mmol) with a yield of 82%.

[0081] Into a dry 100 mL Schlenk flask, 2-amino-2-methyl-1 -diphenylphosphinyl ether (0.273 g, 1 mmol) was added, n-hexane solvent (30 ml) was added, tetramethylcyclopentadiene chlorosilane (0.215 g, 1 mmol) was slowly added dropwise at 0 °C, and the reaction was continued to stir for 12-24 hours. After the reaction was completed, the solid was filtered and washed with n-hexane, and the obtained liquid was dried to obtain ligand L3 (0.317 g, 0.7 mmol) with a yield of 70%.

[0082] Nuclear magnetic resonance hydrogen spectrum: 1 H NMR (300 MHz, CDC13) δ 7.44 (t, J = 8.0 Hz, 6H), 7.18 (d, J = 8.0 Hz, 4H), 3.9 (s, 1H), 3.65 (s, 2H), 2.62 (s, 1H), 2.14 (s, 6H), 1.77 (s, 6H), 1.25 (s, 6H), 0.07 (s, 6H).

[0083] Example 4

[0084] Synthesis of catalyst CAT1

[0085]

[0086] Into a dry 500 mL Schlenk flask, ligand L1 (3.06 g, 9 mmol) was added, and then n-butyllithium n-hexane solution (2.4 M, 18 mmol) was slowly added dropwise at -78 °C. The reaction was continued to stir for 12-24 hours. After the reaction was completed, the solid was filtered and washed with n-hexane three times, and the solid was dried to obtain lithium salt of ligand L1 (2.373 g, 6.7 mmol) with a yield of 74%.

[0087] Into a dry 100 mL Schlenk flask, titanium trichloride tetrahydrofuran complex TiCl3-3THF (1.480 g, 4 mmol) was added, and then tetrahydrofuran solvent 100 mL was added. Lithium salt of ligand L1 (1.416 g, 4 mmol) in tetrahydrofuran (0.5 M, 4 mmol) was slowly added dropwise at -78 °C. The reaction was continued to stir for 30 min, and then lead dichloride (0.556 g, 2 mmol) was added. The reaction was continued to stir for 2 hours. The obtained mixture was filtered, and the filtrate was dried in vacuum and washed with n-hexane until the filtrate was bright yellow. The filtrate was dried by removing a large amount of n-hexane solvent, and the concentrated bright yellow solution was freeze recrystallized. Catalyst CAT1 (1.414 g, 3.1 mmol) was obtained by filtration with a yield of 76%.

[0088] Nuclear magnetic resonance hydrogen spectrum: 1H NMR (300 MHz, C6D6) δ 3.95 (s, 2H), 2.14 (s, 6H), 1.75 (s, 6H), 1.24 (s, 6H), 0.23 (s, 9H), 0.06 (s, 6H).

[0089] Example 5

[0090] Synthesis of catalyst CAT2

[0091]

[0092] Under nitrogen protection, a dry 500 mL Schlenk reaction flask was charged with ligand L2 (2.63 g, 5 mmol), then a n-butyllithium solution in n-hexane (2.4 M, 10 mmol) was slowly added dropwise at -78 °C, recovered to room temperature, continued to stir for 12-24 hours, filtered, washed with n-hexane for three times, the solid was pumped dry, to obtain the lithium salt of ligand L2 (2.061 g, 3.8 mmol), the yield was 76%.

[0093] Under nitrogen protection, a dry 250 mL Schlenk reaction flask was charged with titanium trichloride tetrahydrofuran complex TiCl3·3THF (0.740 g, 2 mmol), then 50 mL of tetrahydrofuran solvent was added, a tetrahydrofuran solution (0.5 M, 2 mmol) of the lithium salt of ligand L2 (1.08 g, 2 mmol) was slowly added dropwise at -78 °C, continued to stir for 30 min, lead dichloride (0.556 g, 2 mmol) was added, continued to stir for two hours, the resulting mixture was filtered, the filtrate was dried in vacuum, washed with n-hexane until the filtrate was bright yellow, the filtrate was pumped to remove a large amount of n-hexane solvent, the concentrated bright yellow solution was frozen and recrystallized, filtered to obtain catalyst CAT2 (1.0293 g, 1.6 mmol), the yield was 80%.

[0094] Nuclear magnetic resonance hydrogen spectrum: 1 H NMR (300 MHz, C6D6) δ 3.95 (s, 2H), 2.14 (s, 6H), 1.75 (s, 6H), 1.24 (s, 6H), 0.23 (s, 9H), 0.06 (s, 6H).

[0095] Example 6

[0096] Synthesis of catalyst CAT3

[0097]

[0098] Into a dry 250 mL Schlenk reaction flask under nitrogen protection, ligand L3 (2.260 g, 5 mmol) was added, then n-butyllithium solution in n-hexane (2.4 M, 10 mmol) was slowly added dropwise at -78 °C, recovered to room temperature, continued to stir for 12-24 hours, filtered, washed with n-hexane for three times, the solid was dried, to obtain the lithium salt of ligand L3 (1.819 g, 3.9 mmol), the yield was 78%.

[0099] Into a dry 250 mL Schlenk reaction flask under nitrogen protection, ZrCl4·2THF (0.754 g, 2 mmol) was added, then THF solvent 50 mL was added, then the lithium salt of ligand L3 (0.932 g, 2 mmol) solution in THF (0.5 M, 2 mmol) was slowly added dropwise at -78 °C, continued to stir for 2 hours, the resulting mixture was filtered, the filtrate was dried under vacuum, washed with n-hexane until the filtrate was bright yellow, the filtrate was dried with a large amount of n-hexane solvent, the concentrated bright yellow solution was frozen and recrystallized, filtered to obtain the catalyst CAT3 (0.980 g, 1.6 mmol), the yield was 80%.

[0100] Nuclear magnetic resonance hydrogen spectrum: 1 H NMR (300 MHz, CDC13) δ 7.46 (t, J = 8.0 Hz, 6H), 7.14 (d, J = 8.0 Hz, 4H), 3.7 (s, 1H), 3.66 (s, 2H), 2.15 (s, 6H), 1.81 (s, 6H), 1.21 (s, 6H), 0.09 (s, 6H).

[0101] The present application provides an olefin polymerization method, which is catalyzed by the above-mentioned nitrogen-oxygen chelated transition metal complex catalyst. Preferably, the above-mentioned nitrogen-oxygen chelated transition metal complex catalyst acts as a main catalyst, and catalyzes the olefin polymerization reaction under the joint action of methylaluminoxane and borane as cocatalysts.

[0102] The nitrogen-oxygen chelated transition metal complex catalyst of the present application can be used to catalyze the polymerization of at least one of the following olefin monomers: ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, and 1-dodecene.

[0103] Example 7

[0104] Catalyst CAT1 catalyzing the copolymerization of ethylene and 1-octene

[0105] The copolymerization of ethylene with 1-octene was carried out in a 100 mL polymerization reactor equipped with a cooling reflux device and magnetic stirring. 35 mL of n-hexane, 1.33 mL of MAO (1.5 M), a toluene solution of borane (8 μmol / mL, 1 mL), 9 mL of 1-octene and a toluene solution of catalyst CAT1 (0.0009 g, 2 μmol, 1 mL) were sequentially added into a dry 100 mL polymerization reactor, and the polymerization was started by introducing 35 bar of ethylene monomer. The stirring rate and the ethylene pressure were kept constant during the whole polymerization, and the polymerization temperature was maintained at 115°C by the cooling device. After 10 min, the reaction was neutralized with a 5 wt% hydrochloric acid acidified industrial alcohol solution, the polymer precipitate was obtained and washed several times, and vacuum dried to constant weight. 1.41 g of polymer was obtained, with a polymerization activity of 4.23 x 10 6 (g-mol -1 -h -1 ), an octene conversion of 25%, Mw (weight average molecular weight of the polymer) = 2.01 x 10 5 g / mol, Mw / Mn (molecular weight distribution index of the polymer) = 1.67, and octene insertion rate (determined and calculated by carbon nuclear magnetic resonance) = 15.0%.

[0106] Comparative Example 1

[0107] Catalyst CGC catalyzes the copolymerization of ethylene with 1-octene

[0108] The copolymerization of ethylene with 1-octene was carried out in a 100 mL polymerization reactor equipped with a cooling reflux device and magnetic stirring. 35 mL of n-hexane, 1.33 mL of MAO (1.5 M), a toluene solution of borane (8 μmol / mL, 1 mL), 9 mL of 1-octene and a toluene solution of catalyst CGC (0.0007 g, 2 μmol, 1 mL) were sequentially added into a dry 100 mL polymerization reactor, and the polymerization was started by introducing 35 bar of ethylene monomer. The stirring rate and the ethylene pressure were kept constant during the whole polymerization, and the polymerization temperature was maintained at 115°C by the cooling device. After 10 min, the reaction was neutralized with a 5 wt% hydrochloric acid acidified industrial alcohol solution, the polymer precipitate was obtained and washed several times, and vacuum dried to constant weight. 1.30 g of polymer was obtained, with a polymerization activity of 3.90 x 10 6 (g-mol -1 -h -1 ), an octene conversion of 21%, Mw (weight average molecular weight of the polymer) = 1.74 x 10 5 g / mol, Mw / Mn (molecular weight distribution index of the polymer) = 1.56, and octene insertion rate (determined and calculated by carbon nuclear magnetic resonance) = 14.5%.

[0109] Comparative Example 2

[0110] Catalyst CGC catalyzes copolymerization of ethylene with 1-octene

[0111] The copolymerization of ethylene with 1-octene was carried out in a 100 mL polymerization reactor equipped with a cooling reflux device and magnetic stirring. 35 mL of n-hexane, 1.33 mL of MAO (1.5 M), a toluene solution of borane (8 μmol / mL, 1 mL), 9 mL of 1-octene and a toluene solution of catalyst CGC (0.0007 g, 2 μmol, 1 mL) were sequentially added into the dry 100 mL polymerization reactor, and 35 bar of ethylene monomer was introduced to start the polymerization. The stirring rate and the ethylene pressure were kept constant during the whole polymerization, and the polymerization temperature was maintained at 115°C by the cooling device. After 30 min, the reaction solution was neutralized with a 5 wt% hydrochloric acid-acidified industrial alcohol solution, the polymer was precipitated and washed several times, and dried to constant weight under vacuum. 2.20 g of polymer was obtained, with a polymerization activity of 2.20 x 10 6 (g·mol -1 ·h -1 ), an octene conversion of 20%, Mw (weight average molecular weight of the polymer) = 1.88 x 10 5 g / mol, Mw / Mn (molecular weight distribution index of the polymer) = 1.72, and an octene insertion rate (determined and calculated by carbon nuclear magnetic resonance spectroscopy) = 14.3%.

[0112] Example 8

[0113] Catalyst CAT2 catalyzes copolymerization of ethylene with 1-octene

[0114] The copolymerization of ethylene with 1-octene was carried out in a 100 mL polymerization reactor equipped with a cooling reflux device and magnetic stirring. 35 mL of n-hexane, 1.33 mL of MAO (1.5 M), a toluene solution of borane (8 μmol / mL, 1 mL), 9 mL of 1-octene and a toluene solution of catalyst CAT2 (0.0013 g, 2 μmol, 1 mL) were sequentially added into the dry 100 mL polymerization reactor, and 35 bar of ethylene monomer was introduced to start the polymerization. The stirring rate and the ethylene pressure were kept constant during the whole polymerization, and the polymerization temperature was maintained at 115°C by the cooling device. After 30 min, the reaction solution was neutralized with a 5 wt% hydrochloric acid-acidified industrial alcohol solution, the polymer was precipitated and washed several times, and dried to constant weight under vacuum. 4.79 g of polymer was obtained, with a polymerization activity of 4.79 x 10 6 (g·mol -1 ·h -1 ), an octene conversion of 31%, Mw (weight average molecular weight of the polymer) = 1.89 x 10 5g / mol, Mw / Mn (polymer molecular weight distribution index) = 1.55, octene insertion rate (determined and calculated by carbon nuclear magnetic resonance spectroscopy) = 17%.

[0115] Example 9

[0116] Catalysis of ethylene copolymerization with 1-octene by catalyst CAT3

[0117] The copolymerization of ethylene with 1-octene was carried out in a 100 mL polymerization reactor equipped with a cooling reflux device and magnetic stirring. 35 mL of n-hexane, 1.33 mL of MAO (1.5 M), a toluene solution of borane (8 μmol / mL, 1 mL), 9 mL of 1-octene and a toluene solution of catalyst CAT2 (0.0011 g, 2 μmol, 1 mL) were sequentially added into the dry 100 mL polymerization reactor, and 35 bar of ethylene monomer was introduced, and the polymerization reaction was started. During the whole polymerization process, the stirring rate and the ethylene pressure were kept constant, and the polymerization temperature was maintained at 115°C by the cooling device. After 30 min, the reaction solution was neutralized with a 5 wt% hydrochloric acid acidified industrial alcohol solution, the polymer was precipitated and washed several times, and vacuum dried to constant weight. 4.61 g of polymer was obtained, and the polymerization activity was 4.61 x 10 6 (g·mol -1 ·h -1 ), the octene conversion was 30%, Mw (weight average molecular weight of the polymer) = 1.44 x 10 5 g / mol, Mw / Mn (polymer molecular weight distribution index) = 1.79, octene insertion rate (determined and calculated by carbon nuclear magnetic resonance spectroscopy) = 16.2%.

[0118] Example 10

[0119] Catalysis of ethylene copolymerization with 1-heptene by catalyst CAT3

[0120] The copolymerization of ethylene with 1-heptene was carried out in a 100 mL polymerization reactor equipped with a cooling reflux device and magnetic stirring. 35 mL of n-hexane, 1.33 mL of MAO (1.5 M), a toluene solution of borane (8 μmol / mL, 1 mL), 3 mL of 1-heptene and a toluene solution of catalyst CAT3 (0.0011 g, 2 μmol, 1 mL) were sequentially added into the dry 100 mL polymerization reactor, and 35 bar of ethylene monomer was introduced, and the polymerization reaction was started. During the whole polymerization process, the stirring rate and the ethylene pressure were kept constant, and the polymerization temperature was maintained at 115°C by the cooling device. After 30 min, the reaction solution was neutralized with a 5 wt% hydrochloric acid acidified industrial alcohol solution, the polymer was precipitated and washed several times, and vacuum dried to constant weight. 4.74 g of polymer was obtained, and the polymerization activity was 4.74 x 10 6 (g·mol-1 ·h -1 ), the conversion of heptene was 32%, Mw (weight average molecular weight of the polymer) = 1.21 x 10 5 g / mol, Mw / Mn (molecular weight distribution index of the polymer) = 1.81, the heptene insertion rate (determined and calculated by carbon nuclear magnetic resonance spectroscopy) = 16.8%.

[0121] Example 11

[0122] Catalyst CAT3 catalyzing copolymerization of ethylene with 1-nonene

[0123] The copolymerization of ethylene with 1-nonene was carried out in a 100 mL polymerization reactor equipped with a cooling reflux device and magnetic stirring. In a dry 100 mL polymerization reactor, 35 mL of n-hexane, 1.33 mL of MAO (1.5 M), a toluene solution of borane (8 μmol / mL, 1 mL), 4 mL of 1-nonene and a toluene solution of catalyst CAT3 (0.0011 g, 2 μmol, 1 mL) were sequentially added, and 35 bar of ethylene monomer was introduced to start the polymerization. During the entire polymerization process, the stirring rate and the ethylene pressure remained unchanged, and the polymerization temperature was maintained at 115°C by the cooling device. After 30 min, the reaction solution was neutralized with a 5 wt% hydrochloric acid acidified industrial alcohol solution, the polymer was precipitated and washed several times, and vacuum dried to constant weight. 4.82 g of polymer was obtained, and the polymerization activity was 4.82 x 10 6 (g·mol -1 ·h -1 ), the conversion of nonene was 31%, Mw (weight average molecular weight of the polymer) = 1.46 x 10 5 g / mol, Mw / Mn (molecular weight distribution index of the polymer) = 1.65, the nonene insertion rate (determined and calculated by carbon nuclear magnetic resonance spectroscopy) = 17.5%.

[0124] Example 12

[0125] Catalyst CAT3 catalyzing copolymerization of ethylene with 1-decene

[0126] The copolymerization reaction of ethylene and 1-decene was carried out in a 100 mL polymerization reactor equipped with a cooling reflux device and magnetic stirring. 35 mL of n-hexane, 1.33 mL of MAO (1.5 M), a toluene solution of borane (8 μmol / mL, 1 mL), 3 mL of 1-decene and a dichloromethane solution of the catalyst CAT3 (0.0011 g, 2 μmol, 1 mL) were sequentially added into a dry 100 mL polymerization reactor, and 35 bar of ethylene monomer was introduced to start the polymerization reaction. During the whole polymerization process, the stirring rate and the ethylene pressure were kept constant, and the polymerization temperature was maintained at 115°C by the cooling device. After 30 min, the reaction solution was neutralized with a 5 wt% hydrochloric acid solution in industrial alcohol, the polymer was precipitated and washed several times, and then vacuum dried to constant weight. 4.99 g of polymer was obtained, and the polymerization activity was 4.99×10 6 (g·mol -1 ·h -1 ), the conversion rate of decene was 32%, Mw (the weight average molecular weight of the polymer) = 1.90×10 5 g / mol, Mw / Mn (the molecular weight distribution index of the polymer) = 1.79, and the decene insertion rate (determined by carbon nuclear magnetic resonance spectroscopy and calculated) = 18%.

[0127] As can be seen from the above examples, the nitrogen-oxygen chelated transition metal complex provided by the application can initiate coordination polymerization under the joint action of methylaluminoxane and borane. The complex as a catalyst can catalyze the copolymerization reaction of ethylene and 1-octene and long-chain α-olefins, and can obtain a polymer product with high molecular weight, high comonomer insertion rate and narrow molecular weight distribution with high activity.

[0128] The experimental results show that the polymer obtained by the copolymerization of ethylene and 1-octene catalyzed by the nitrogen-oxygen chelated transition metal complex catalyst provided by the application has a molecular weight of up to 2.01×10 5 g / mol, a 1-octene molar insertion rate of up to 17%, a molecular weight distribution of up to 1.55, an activity maintenance time of up to 30 min, and a polymerization activity of up to 4.79×10 6 (g·mol -1 ·h -1 ); the polymer obtained by the copolymerization of ethylene and 1-heptene has a molecular weight of up to 1.21×10 5 g / mol, a 1-heptene molar insertion rate of up to 16.8%, a molecular weight distribution of up to 1.81, an activity maintenance time of up to 30 min, and a polymerization activity of up to 4.74×10 6 (g·mol -1 ·h -1 ); the polymer obtained by the copolymerization of ethylene and 1-nonene has a molecular weight of up to 1.46×10 5The molecular weight of the polymer obtained from the copolymerization of ethylene and 1-nonene is up to 1.90×10 g / mol, the highest 1-nonene molar insertion rate is 17.5%, the minimum molecular weight distribution is 1.65, the active time can reach 30 min, and the polymerization activity can reach 4.82×10 6 (g·mol -1 ·h -1 ); The molecular weight of the polymer obtained from the copolymerization of ethylene and 1-nonene is up to 1.90×10 g / mol, the highest 1-nonene molar insertion rate is 17.5%, the minimum molecular weight distribution is 1.65, the active time can reach 30 min, and the polymerization activity can reach 4.82×10 5 (g·mol 6 ·h -1 ·h -1 ).

[0129] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can also be made, which should be considered as the protection scope of the present application.

Claims

1. A nitrogen-oxygen chelate transition metal complex catalyst, characterized in that, The transition metal complex catalyst is selected from one of the following structures: Among them, in each structural formula i Pr represents isopropyl, and Ph represents phenyl.

2. A method for preparing the nitrogen-oxygen chelate transition metal complex catalyst according to claim 1, characterized in that, Includes the following steps: Step 1: 1,w-amino alcohol The intermediate shown in formula (II) is obtained by reacting with halosilanes or halophosphines in the presence of a base. Step 2: Under an inert gas atmosphere, the intermediate shown in formula (II) reacts with a chloride containing cyclopentadienyl rings and bridging heteroatoms. The reaction produces the ligand shown in formula (Ⅲ); Step 3: Under an inert gas atmosphere, the ligand shown in formula (Ⅲ) is mixed with an organolithium reagent at low temperature, and then the mixture is heated to room temperature to prepare the organolithium intermediate shown in formula (IV). Step 4: Under an inert gas atmosphere, the organolithium intermediate shown in formula (Ⅳ) forms a tetrahydrofuran complex MX with a group IV B metal halide. 1 m The ·yTHF reaction produces a nitrogen-oxygen chelate transition metal complex catalyst as shown in formula (I), M, X 1 Y, R, R 1 R 2 R 3 R 4 R 5 R 6 R 7 For the corresponding groups in claim 1, n = 1, m = 3, 4, y = 1, 2; 3. The method for preparing the nitrogen-oxygen chelate transition metal complex catalyst according to claim 2, characterized in that, In step 1, the alkali is selected from sodium carbonate, potassium carbonate, potassium phosphate, potassium tert-butoxide, n-butyllithium or triethylamine, and the molar ratio of 1,w-amino alcohol, halosilane / halophosphine to alkali is 1:1:2 to 1:1:

4.

4. The method for preparing the nitrogen-oxygen chelate transition metal complex catalyst according to claim 2, characterized in that, In step 2, the molar ratio of the intermediate of formula (II) to the chloride containing cyclopentadienyl rings and bridging heteroatoms is 2:1 to 1:

2.

5. The method for preparing the nitrogen-oxygen chelate transition metal complex catalyst according to claim 2, characterized in that, In step 3, the organolithium reagent is selected from one or more of methyllithium, n-butyllithium or tert-butyllithium; the molar ratio of the ligand shown in formula (III) to the organolithium reagent is 1:2 to 1:4; the low temperature is -78℃ to 0℃.

6. The method for preparing the nitrogen-oxygen chelate transition metal complex catalyst according to claim 2, characterized in that, In step 4, the molar ratio of the organolithium intermediate shown in formula (IV) to the tetrahydrofuran complex of group IVB metal halides is 1.1:1 to 1:

1.

7. The application of the nitrogen-oxygen chelate transition metal complex catalyst of claim 1 as a catalyst in olefin polymerization.

8. The application according to claim 7, characterized in that, The olefin is selected from at least one of the group consisting of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, and 1-dodecene.

9. The application according to claim 7, characterized in that, The olefin polymerization is a copolymerization reaction of ethylene and α-olefin.

Images