A bimetallic catalyst based on acylhydrazone pyrene skeleton, its preparation method and use

Abstract

The application discloses an olefin polymerization catalyst, which has an acylhydrazone pyrene skeleton structure. By introducing the acylhydrazone pyrene skeleton, the catalyst has improved catalytic activity, and by adjusting the structure and central metal of the catalyst, the spatial and electronic effects of the catalyst are changed, so that the catalyst can be used for preparing polyolefin products with excellent anti-yellowing performance, high glass transition temperature, high stereoregularity and ultrahigh molecular weight. The catalyst based on the acylhydrazone pyrene skeleton has wide application prospects and improves the competitiveness of a polyolefin product technology market in China.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalysts, in particular to a bimetallic catalyst based on acylhydrazone pyrene skeleton, its preparation method and use. BACKGROUND

[0002] Polyolefin materials are one of the pillars of modern polymer material industry. Many excellent polyolefin products have good performance, and the products have unique properties in tear strength, impact strength, thermal adhesion strength, tensile strength, toughness and other aspects, and have unique applications in all aspects of people's life. Polyolefin catalysts play a crucial role in olefin polymerization, so it is particularly important to accelerate the research of polyolefin catalysts.

[0003] In 1989, Dow Chemical Company reported a class of catalysts with limited geometry in patent EP0416815B1, which had a high comonomer insertion rate, but low activity at high temperature. The catalyst cannot well catalyze the reaction at high temperature, and has poor thermal stability.

[0004] Patent CN116444579A proposes to introduce an anthracene skeleton into the structure of salicylaldehyde imine catalyst (as shown in the following formula), which has simple preparation, high activity and high temperature resistance, but low insertion rate and low molecular weight of the polymer, which cannot meet the needs of industry.

[0005]

[0006] Patent CN116284510A reports a structure in which cyclopentadiene and the nitrogen of hydrazine are connected through a carbon atom (as shown in the following formula), which greatly improves the molecular weight of the polymer, but also has the problem of poor insertion rate, which cannot meet the production needs.

[0007]

[0008] In view of the above problems existing in the prior art, the metal catalyst needs to be further regulated by controlling the type of catalyst center metal, ligand structure and the like, so as to improve the performance of the catalyst. SUMMARY

[0009] In order to solve the above technical problems, the present application proposes an olefin polymerization bimetallic catalyst (metal complex) based on acylhydrazone pyrene skeleton, its preparation method and use.

[0010] The catalyst structure combines acylhydrazone groups and pyrene, the complex structure is more stable, compared with the traditional diimine structure, the change of bond length makes the catalyst obtain better space structure, improves the stability and catalytic activity of the catalyst structure, in addition, the structure has certain space flexibility, and by introducing different substituents, the steric effect and the strength of the power supply of the ligand are modified, so that the performance of the catalyst is regulated, and the polyolefin product with excellent anti-yellowing performance, high glass transition temperature, high isotacticity and ultrahigh molecular weight is prepared, and has wide application prospect.

[0011] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0012] A bimetallic catalyst based on acylhydrazone pyrene skeleton, the structure is shown as formula I:

[0013]

[0014] Among them,

[0015] R1 is each independently selected from C1-C24 alkyl;

[0016] R2 and R3 are each independently selected from C1-C24 alkyl, C6-C30 aryl, C3-C18 cycloalkyl, C5-C10 cycloalkenyl, wherein the C6-C30 aryl is optionally substituted with C1-C6 alkyl or C1-C6 alkoxy; R2 and R3 can be the same or different, preferably the two are the same;

[0017] M is selected from IVB metal elements;

[0018] X is independently selected from halogen, C1-C16 alkylamino or C5-C16 arylalkyl.

[0019] According to the bimetallic catalyst, in the bimetallic catalyst shown as formula I, R1 is each independently selected from C1-C16 alkyl, preferably C1-C12 alkyl, more preferably C1-C8 alkyl, for example, R1 is each independently selected from methyl, ethyl, isopropyl, n-butyl, t-butyl or 3-pentyl.

[0020] In the bimetallic catalyst according to the present application, R2 and R3 in the bimetallic catalyst of formula I are each independently selected from C1-C16 alkyl, C6-C20 aryl, C5-C10 cycloalkenyl or C3-C12 cycloalkyl, wherein the C6-C20 aryl is optionally substituted with C1-C6 alkyl or C1-C6 alkoxy; preferably, R2 and R3 in the bimetallic catalyst of formula I are each independently selected from C1-C10 alkyl, C6-C16 aryl, C5-C8 cycloalkenyl or C3-C8 cycloalkyl, wherein the C6-C16 aryl is optionally substituted with C1-C6 alkyl or C1-C6 alkoxy; more preferably, R2 and R3 in the bimetallic catalyst of formula I are each independently selected from C1-C6 alkyl, C6-C14 aryl, C5-C7 cycloalkenyl or C3-C6 cycloalkyl, wherein the C6-C14 aryl is optionally substituted with C1-C6 alkyl or C1-C6 alkoxy; for example, R2 and R3 are each independently selected from phenyl, p-methylphenyl, cyclopropyl, cyclohexyl, cyclooctyl, cyclopentadienyl, anthracenyl, n-pentyl or p-methoxyphenyl.

[0021] In the bimetallic catalyst according to the present application, M in the bimetallic catalyst of formula I is selected from titanium, zirconium or hafnium.

[0022] In the bimetallic catalyst according to the present application, X in the bimetallic catalyst of formula I is independently selected from halogen, C1-C10 alkyl, C1-C10 alkylamino or C5-C10 arylalkyl, preferably, X is independently selected from halogen, C1-C8 alkyl, C1-C8 alkylamino or C5-C8 arylalkyl, more preferably, X is independently selected from halogen, C1-C6 alkyl, C1-C6 alkylamino or C5-C7 arylalkyl, for example, X is independently selected from methyl, chlorine, bromine, fluorine, dimethylamino, benzyl or (methylethyl)amino.

[0023] In the bimetallic catalyst according to the present application, the structure of the bimetallic catalyst of formula I is as follows:

[0024]

[0025] wherein X and M are as defined above.

[0026] The technical scheme of the preparation method of the bimetallic catalyst based on the acylhydrazone pyrene skeleton according to the present application is as follows:

[0027] The preparation method of a bimetallic catalyst based on an acylhydrazone pyrene skeleton comprises:

[0028] In the presence of a hydrogen abstraction reagent, a complex reaction is carried out between a ligand compound of formula II and a metal salt MX4.

[0029]

[0030] wherein

[0031] each R1is independently selected from C1-C24alkyl;

[0032] each R2, R3is independently selected from C1-C24alkyl, C6-C30aryl, C3-C18cycloalkyl, C5-C10cycloalkenyl, wherein the C6-C30aryl is optionally substituted with C1-C6alkyl or C1-C6alkoxy; R2, R3may be the same or different, preferably both are the same;

[0033] in the metal salt MX4, M is selected from IVB metal elements; X is independently selected from halogen, C1-C16alkylamino or C5-C16arylalkyl.

[0034] According to the method for preparing the bimetallic catalyst, in the ligand compound shown in formula II, each R1is independently selected from C1-C16alkyl, preferably C1-C12alkyl, more preferably C1-C8alkyl, for example, each R1is independently selected from methyl, ethyl, isopropyl, n-butyl, t-butyl or 3-pentyl.

[0035] According to the method for preparing the bimetallic catalyst, in the ligand compound shown in formula II, each R2, R3is independently selected from C1-C16alkyl, C6-C20aryl, C5-C10cycloalkenyl or C3-C12cycloalkyl, wherein the C6-C20aryl is optionally substituted with C1-C6alkyl or C1-C6alkoxy; preferably, each R2, R3in the ligand compound shown in formula II is independently selected from C1-C10alkyl, C6-C16aryl, C5-C8cycloalkenyl or C3-C8cycloalkyl, wherein the C6-C16aryl is optionally substituted with C1-C6alkyl or C1-C6alkoxy; more preferably, each R2, R3in the ligand compound shown in formula II is independently selected from C1-C6alkyl, C6-C14aryl, C5-C7cycloalkenyl or C3-C6cycloalkyl, wherein the C6-C14aryl is optionally substituted with C1-C6alkyl or C1-C6alkoxy; for example, each R2, R3is independently selected from phenyl, p-methylphenyl, cyclopropyl, cyclohexyl, cyclooctyl, cyclopentadienyl, anthracenyl, n-pentyl or p-methoxyphenyl.

[0036] According to the method for preparing the bimetallic catalyst, in the metal salt MX4, M is selected from titanium, zirconium or hafnium.

[0037] The preparation method of the bimetallic catalyst according to the present application, wherein X in the metal salt MX4 is independently selected from halogen, C1-C10 alkyl, C1-C10 alkylamino or C5-C10 arylalkyl, preferably X is independently selected from halogen, C1-C8 alkyl, C1-C8 alkylamino or C5-C8 arylalkyl, more preferably X is independently selected from halogen, C1-C6 alkyl, C1-C6 alkylamino or C5-C7 arylalkyl, for example, X is independently selected from methyl, chlorine, bromine, fluorine, dimethylamino, benzyl or (methylethyl)amino.

[0038] The preparation method of the bimetallic catalyst according to the present application, wherein the metal salt MX4 is selected from titanium tetrachloride, zirconium tetrachloride, hafnium tetrachloride, hafnium tetrabenzyl, zirconium tetra(methylethyl)amino, titanium tetrabromide, zirconium tetrabromide or hafnium tetrabromide.

[0039] The preparation method of the bimetallic catalyst according to the present application, wherein the molar ratio of the ligand compound of formula II to the metal salt MX4 is 1:(2-5), and the molar ratio of the ligand compound of formula II to the hydrogen abstraction reagent is 1:(4-8).

[0040] The preparation method of the bimetallic catalyst according to the present application, wherein the hydrogen abstraction reagent is one or more of alkyl lithium, phenyl lithium, potassium carbonate, sodium hydride, sodium, Grignard reagent, preferably n-butyllithium, methyllithium and / or n-hexyllithium.

[0041] The preparation method of the bimetallic catalyst according to the present application, wherein the temperature of the complexation reaction is 20-60°C, and the time is 1-4 hours.

[0042] The preparation method of the bimetallic catalyst according to the present application, wherein the ligand compound of formula II is prepared by the following reaction formula:

[0043]

[0044] wherein R1, R2 and R3 are as defined above.

[0045] The preparation method of the bimetallic catalyst according to the present application, wherein the preparation step of the ligand compound of formula II comprises:

[0046] 1) reacting diacetylene ketone and compound A in an organic solvent to form compound B;

[0047] 2) adding sodium nitrite to compound C under strong acid conditions to form a diazonium salt of compound C, adding aqueous urea to neutralize excess nitrous acid, adding a solvent after concentration, and reacting the diazonium salt of compound C with compound B in the solvent to form compound D.

[0048] The preparation method of the bimetallic catalyst according to the present application, wherein, in the preparation step of the ligand compound shown in formula II,

[0049] In step 1), the reaction conditions are: reaction temperature 60-110℃, reaction time 1-5h;

[0050] In step 2), the reaction conditions are: reaction temperature 0-60℃, reaction time 2-12h.

[0051] The preparation method of the bimetallic catalyst according to the present application, wherein, in the preparation step of the ligand compound shown in formula II,

[0052] In step 1), the compound A is selected from one or more of aniline, cyclohexylamine, cyclopropylamine, 4-methylaniline, 4-methoxyaniline, 3,4,5-trimethylaniline, 3,4,5-trimethoxyaniline, 3,4,5-trichloroaniline, 4-methylcyclohexylamine, 3,4,5-trimethylcyclohexylamine, 3,4,5-trimethoxycyclohexylamine, tetrahydrothiopyran-4-amine, 9-aminoanthracene, cyclooctylamine, n-pentylamine, cyclopentadiene-1-amine, and the organic solvent is one or more of benzene, toluene, methanol, ethanol;

[0053] In step 2), the strong acid is concentrated hydrochloric acid, and the reaction solvent is one or more of water, ethanol, methanol, ethyl acetate, tetrahydrofuran.

[0054] The preparation method of the bimetallic catalyst according to the present application, wherein, in the preparation step of the ligand compound shown in formula II,

[0055] In step 1), the molar ratio of diacetylene ketone and compound A is 1:(1-1.5);

[0056] In step 2), the molar ratio of compound C, strong acid, sodium nitrite, compound B is 1:(2-5):(2-6):(2-4).

[0057] The present application further provides a preparation method of polyolefin, which comprises: polymerizing olefin or α-olefin in a solvent in the presence of the bimetallic catalyst and cocatalyst according to the present application to prepare a polyolefin product.

[0058] The preparation method of polyolefin according to the present application, wherein the concentration of the bimetallic catalyst in the solvent is 0.1-10μmol / L, preferably 2-5μmol / L.

[0059] The preparation method of polyolefin according to the present application, wherein the solvent used in the polymerization reaction is selected from one or more of alkanes, cycloalkanes, aromatic hydrocarbons, preferably toluene, heptane, hexane, Isopar E, cyclohexane.

[0060] According to the polyolefin preparation method, the temperature of the polymerization reaction is 10-300 DEG C, preferably 80-250 DEG C; the polymerization reaction pressure is 0.1-20 MPa, preferably 1-8 MPa.

[0061] According to the polyolefin preparation method, the cocatalyst is alkyl aluminum and borate.

[0062] According to the polyolefin preparation method, the alkyl aluminum is selected from C1-C 10 Aluminum alkyl or modified aluminum alkyl, preferably methyl aluminum alkyl, tert-butyl aluminum alkyl or tert-butyl modified methyl aluminum alkyl, wherein the molar ratio of metal Al in the alkyl aluminum to metal M in the bimetallic catalyst of formula I is Al / M = (10-200):1, preferably (40-180):1.

[0063] According to the polyolefin preparation method, the borate is selected from one or more of N,N-dimethylphenylammonium tetrakis(pentafluorophenyl)borate, tri(pentafluorophenyl)borate, triphenylmethyl tetrakis(pentafluorophenyl)borate, preferably tri(pentafluorophenyl)borate, wherein the molar ratio of element B in the borate to metal M in the bimetallic catalyst of formula I is B / M = (0-30):1, preferably (0-20):1.

[0064] The application also provides the use of the bimetallic catalyst in the preparation of polyolefin.

[0065] Advantages

[0066] Compared with the prior art, the technical scheme of the application has the beneficial effects that:

[0067] The catalyst structure combines acylhydrazone groups and pyrene, and the complex structure is more stable; compared with the traditional diimine structure, the change in bond length enables the catalyst to obtain a better spatial structure, thereby improving the stability of the catalyst structure; in addition, the structure has a certain spatial flexibility, and different substituents are introduced to modify the steric hindrance effect and the strength of the power supply capacity of the ligand, so as to realize the regulation of the performance of the catalyst.

[0068] The bimetallic catalyst of the application is used for catalyzing olefin polymerization, and polyolefin products with excellent polymerization activity, anti-yellowing performance, high glass transition temperature, high degree of polymerization, ultrahigh molecular weight, and wide application prospects are prepared. DETAILED DESCRIPTION

[0069] The application will be further described below through specific examples, and the examples of the application are only used to illustrate the application and do not limit the scope of the application.

[0070] The sources of the main materials and reagents used in the following examples are as follows: Diacetylene: AR, Aladdin

[0071] Aniline: AR, Innochem

[0072] Cyclopropylamine: AR, Aladdin 4-Methoxyaniline: AR, Aladdin

[0073] 9-Aminoanthracene: AR, Innochem

[0074] 2,7-Di-tert-butyl-4,9-diaminopyrene: AR, Innochem 2,7-Dimethyl-4,9-diaminopyrene: AR, Innochem 2,7-Diethyl-4,9-diaminopyrene: AR, Innochem 2,7-Di-n-butyl-4,9-diaminopyrene: AR, Innochem Benzene: AR, Aladdin

[0075] Toluene: AR, Aladdin

[0076] Methanol: AR, Aladdin

[0077] Tetrahydrofuran: AR, Innochem

[0078] Ethyl acetate: AR, Aldrich

[0079] Petroleum ether: AR, Aldrich

[0080] Anhydrous sodium sulfate: AR, Innochem

[0081] Silica gel: AR, Aladdin

[0082] Hydrochloric acid: AR, Aldrich

[0083] Sodium nitrite: AR, Innochem

[0084] Anhydrous sodium acetate: AR, Innochem

[0085] Urea: AR, Innochem

[0086] Methyllithium: AR, Innochem

[0087] n-Butyllithium: AR, Innochem TiCl4: Tokyo Chemical Industry Co., Ltd. ZrCl4: Tokyo Chemical Industry Co., Ltd. HfCl4: Tokyo Chemical Industry Co., Ltd. Tris(pentafluorophenyl)borate: AR, Aladdin

[0088] Phenoxyimine zirconium: AR, Aladdin

[0089] Isopar E: ExxonMobil

[0090] tert-Butylaluminoxane (MAO): Albemarle

[0091] Ethylene: 99.9%, Beijing Yanshan Petrochemical Company

[0092] 1-Hexene: 98%, Beijing Yanshan Petrochemical Company

[0093] Unless otherwise specified, all other raw materials and reagents were purchased through commercial channels.

[0094] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0095] The polymerization activity of the polymers described in the following examples was calculated according to the following formula: Polymer activity = polymer mass / (metal content in catalyst * polymerization time);

[0096] The weight-average molecular weight (Mw) of the polymer was obtained by testing with a PL-GPC220 at 160°C using three PLgel 10μm MIXED-B separation columns in series, with 1,2,4-trichlorobenzene as the solvent.

[0097] The method for calculating the comonomer insertion rate is referenced in (Macromolecules 1999, 32, 3817);

[0098] The melting point and glass transition temperature of the polymer were measured using conventional DSC methods.

[0099] The terminal double bonds of the polymer were calculated using iodometric titration.

[0100] The polymer isotacticity was obtained by NMR calculation.

[0101] high temperature 13 The C NMR was obtained using 1,1,2,2,-tetrachloroethane as solvent and measured at 120 °C using a Brucker DMX at 100 MHz.

[0102] In all the following examples and comparative examples, the chemical reactions involved were carried out after nitrogen purging.

[0103] Example 1: Preparation of metal complex E1

[0104] The ligand and metal complex E1 were prepared according to the following combined route:

[0105]

[0106] (1) Diacetylene ketone (84 g, 1 mol) and compound A1 (93.1 g, 1 mol) were dissolved in solvent benzene (500 mL), magnetic stirring was turned on, the reactants were completely dissolved in the solvent benzene, the temperature was set to 60 °C, and the reaction was allowed to proceed for 5 h. After the reaction was completed, washing, ethyl acetate extraction, drying, filtration, and concentration under reduced pressure were performed to obtain compound B1 crude product, which was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 20:1 (v / v)) to obtain compound B1 (109.86 g, 62%).

[0107] The nuclear magnetic resonance data of compound B1 are as follows: 1 H NMR (CDCl3, 500 MHz, TMS) δ 7.58 (s, 2H), 7.30 (s, 2H), 7.07 (s, 2H), 3.71 (s, 2H), 2.25 (s, 3H).

[0108] (2) Compound C1 (69.3 g, 0.2 mol) and concentrated hydrochloric acid (33.4 mL, 0.4 mol) were added to water, stirring was performed, and an ice bath at 0 °C was used. Sodium nitrite (27.6 g, 0.4 mol) was continuously added to the reaction bottle, stirring was performed for 30 min, the reaction bath temperature was kept below 10 °C, anhydrous sodium acetate was added to adjust the pH to about 6, a few drops of urea aqueous solution were added to neutralize the excess nitrous acid, the reaction mixture was filtered, and the reaction mixture was washed with water to obtain an aqueous solution of diazonium salt. Compound B1 (70.88 g, 0.4 mol) was added to the diazonium salt solution, stirring was performed at 20 °C, and the reaction was allowed to proceed for 2 h. Washing with water, ethyl acetate extraction, drying, filtration, and concentration under reduced pressure were performed to obtain compound D1 crude product, which was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 12:1 (v / v)) to obtain compound D1 (160 g, 66%).

[0109] The nuclear magnetic resonance data of compound D1 are as follows: 1 H NMR (CDCl3, 500 MHz, TMS) δ 10.12 (s, 2H), 7.60 (s, 4H), 7.24 (s, 4H), 7.06 (s, 2H), 7.0 (s, 2H), 5.36 (s, 2H), 5.28 (s, 2H), 5.17 (s, 2H), 4.05 (s, 2H), 2.42 (s, 6H), 1.31 (s, 18H).

[0110] (3) Anhydrous and anaerobic operation was carried out in a glove box, compound D1 (10 g, 0.014 mol) was placed in a reaction bottle, toluene (100 mL) was added and stirred to dissolve, 1.6 M methyl lithium (35 mL, 0.056 mol) was slowly added dropwise, stirred at room temperature for 1 h, TiCl4(5.31 g, 0.028 mol) was added, the reaction was carried out for 3 h, after the reaction was completed, filtration was carried out, the filtrate was dried, n-hexane was added for washing, filtration was carried out to obtain a solid product, which was recorded as metal complex E1.

[0111]

[0112] Preparation of metal complex E2 according to example 2

[0113] The ligand and metal complex E2 were prepared according to the following synthetic route:

[0114]

[0115] (1) Diacetylene (100 g, 1.19 mol) and compound A2 (101.91 g, 1.79 mol) were dissolved in solvent benzene (650 mL), magnetic stirring was turned on to make the reactants completely dissolved in the solvent benzene, the temperature was set to 80 °C, the reaction was carried out for 3 h, after the reaction was completed, washing was carried out, extraction was carried out with ethyl acetate, drying was carried out, filtration was carried out, and concentration was carried out under reduced pressure to obtain a crude product of compound B2, which was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 15: 1 (v / v)) to obtain compound B2 (84.7 g, 50.42%).

[0116] The nuclear magnetic resonance data of compound B2 are as follows: 1 H NMR (CDCl3, 500 MHz, TMS) δ 8.45 (s, 1H), 3.66 (s, 2H), 2.69 (s, 1H), 2.25 (s, 3H), 0.82 (s, 2H), 0.57 (s, 2H).

[0117] (2) To water, add compound C2 (80 g, 0.3 mol) and concentrated hydrochloric acid (75 mL, 0.9 mol), stir, continue to add sodium nitrite (62.1 g, 0.9 mol) to the reaction bottle under ice bath conditions, stir for 70 min, keep the reaction bath temperature below 10°C, add anhydrous sodium acetate to adjust the pH to about 6, add a few drops of urea aqueous solution to neutralize the excess nitrous acid, filter the reaction mixture, wash the reaction mixture with distilled water, obtain the filtrate, add ethanol after concentration, add compound B2 (105.88 g, 0.72 mol) to the obtained diazonium salt solution, set the temperature to 35°C, stir, react for 5 h, wash with distilled water, extract with ethyl acetate, dry, filter, and concentrate under reduced pressure to obtain compound D2 crude product, purify by silica gel column chromatography (petroleum ether: ethyl acetate = 32:1 (v / v)) to obtain compound D2 (68 g, 40%).

[0118] The nuclear magnetic resonance data of compound D2 are as follows: 1 H NMR (CDCI3, 500 MHz, TMS) δ 7.0 (s, 2H), 6.27 (s, 2H), 5.53 (s, 2H), 5.40 (s, 2H), 5.32 (s, 2H), 4.04 (s, 2H), 2.75 (s, 2H), 2.42 (s, 6H), 2.36 (s, 6H), 0.57 (s, 4H), 0.33 (s, 4H).

[0119] (3) In the glove box, perform anhydrous and anaerobic operation, place compound D2 (15 g, 0.026 mol) in a reaction bottle, add benzene (100 mL) and stir to dissolve, slowly drop 1.6 M n-hexyllithium (89.37 mL, 0.143 mol), set the temperature to 50°C, add ZrCl4 (18.51 g, 0.078 mol), react for 1 h, after the reaction is completed, filter, dry the filtrate, wash with n-hexane, and filter to obtain a solid product, which is denoted as metal complex E2.

[0120]

[0121] Preparation of metal complex E3 according to Example 3

[0122] The ligand and metal complex E3 are prepared according to the following combined route:

[0123]

[0124] (1) Compound A3 (515.95 g, 2.67 mol) and diacetylene ketone (150 g, 1.78 mol) were dissolved in solvent methanol (1300 mL), and magnetic stirring was started to completely dissolve the reactants in methanol. The temperature was set to 105°C, and the reaction was performed for 1 h. After the reaction was completed, washing, ethyl acetate extraction, drying, filtration, and concentration under reduced pressure were performed to obtain crude compound B3. Purification by silica gel column chromatography (petroleum ether: ethyl acetate = 55:1 (v / v)) was performed to obtain compound B3 (282.87 g, 57.3%).

[0125] The NMR data of compound B3 are as follows: 1 H NMR (CDCl3, 500 MHz, TMS) δ 8.39 (s, 1H), 8.22 (s, 2H), 8.09 (s, 2H), 7.56 (d, J = 10.0 Hz, 4H), 7.23 (s, 1H), 3.71 (s, 2H), 2.25 (s, 3H).

[0126] (2) Compound C3 (100 g, 0.34 mol) and concentrated hydrochloric acid (127.5 mL, 1.53 mol) were added to water, and stirring was performed. Sodium nitrite (140.76 g, 2.04 mol) was further added to the reaction bottle under ice bath conditions, and stirring was performed for 30 min while maintaining the reaction bath temperature below 10°C. Anhydrous sodium acetate was added to adjust the pH to about 6, and the presence of excess sodium nitrite was detected using starch iodide paper. A few drops of aqueous urea were added to destroy the excess nitrous acid. The reaction mixture was filtered, washed with distilled water, and concentrated to obtain a filtrate. Tetrahydrofuran (200 mL) was added to the filtrate, and compound B3 (357.74 g, 1.29 mol) was added thereto. The reaction was performed at a temperature of 55°C for 4 h. Washing with water, ethyl acetate extraction, drying, filtration, and concentration under reduced pressure were performed to obtain crude compound D3. Purification by silica gel column chromatography (petroleum ether: ethyl acetate = 45:1 (v / v)) was performed to obtain compound D3 (173.4 g, 58.82%).

[0127] The NMR data of compound D3 are as follows: 1 H NMR (CDCl3, 500 MHz, TMS) δ 8.82 (s, 2H), 8.13-7.77 (m, 10H), 7.49 (d, J = 5.0 Hz, 8H), 7.0 (s, 2H), 5.72-5.38 (m, 6H), 4.19 (s, 2H), 2.72 (s, 4H), 2.42 (s, 6H), 1.18 (s, 6H).

[0128] (3) Anhydrous and anaerobic operation was carried out in a glove box, compound D3 (15 g, 0.017 mol) was placed in a reaction bottle, toluene (100 mL) was added and stirred to dissolve, 60% sodium hydride (5.54 g, 0.136 mol) was slowly added dropwise, stirred at room temperature for 1 h, HfCl4(27.23 g, 0.085 mol) was added, the reaction was carried out for 2 h, after the reaction was completed, filtration was carried out, the filtrate was dried, n-hexane was added for washing, filtration was carried out to obtain a solid product, which was recorded as metal complex E3.

[0129]

[0130] Example 4 Preparation of metal complex E4

[0131] The ligand and metal complex E4 were prepared according to the following combined route:

[0132]

[0133] (1) Diacetylene (126.1 g, 1.5 mol) and compound A4 (156.89 g, 1.8 mol) were dissolved in solvent toluene (350 mL), stirring was started, the reactants were completely dissolved, the temperature was set to 110°C, the reaction was carried out for 1 h, after the reaction was completed, washing was carried out, extraction was carried out with ethyl acetate, drying was carried out, filtration was carried out, and concentration was carried out under reduced pressure to obtain crude compound B4, which was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 9:1 (v / v)) to obtain compound B4 (148.21 g, 53.3%).

[0134] The nuclear magnetic resonance data of compound B4 are as follows: 1 H NMR (CDCI3, 500 MHz, TMS) δ 5.36 (s, 1H), 3.63 (s, 2H), 2.99 (s, 2H), 2.23 (s, 3H), 1.45-1.11 (m, 8H), 0.88 (s, 3H).

[0135] (2) To water, add compound C4 (39.81 g, 0.125 mol) and concentrated hydrochloric acid (41.67 mL, 0.5 mol), stir, continue to add sodium nitrite (34.5 g, 0.5 mol) under ice bath condition, stir for 60 min, keep the reaction bath temperature below 10 °C, add anhydrous sodium acetate to adjust the pH to about 6, add a few drops of urea aqueous solution to neutralize the excess nitrous acid, filter the reaction mixture, wash the reaction mixture with distilled water, obtain the filtrate, add ethanol after concentration, add compound B4 (92.63 g, 0.5 mol) to the obtained diazonium salt solution, set the temperature to 42 °C, stir, react for 5 h, wash with distilled water, extract with ethyl acetate, dry, filter, concentrate under reduced pressure to obtain compound D4 crude product, purify by silica gel column chromatography (petroleum ether: ethyl acetate = 25:1 (v / v)) to obtain compound D4 (60.4 g, 56%).

[0136] The nuclear magnetic resonance data of compound D4 are as follows: 1 H NMR (CDCI3, 500 MHz, TMS) δ 6.95 (s, 2H), 6.48 (s, 2H), 5.44 (s, 2H), 5.22 (d, J = 22.4 Hz, 4H), 4.00 (s, 2H), 3.18 (s, 4H), 2.86 (s, 2H), 2.41 (s, 6H), 1.49 (s, 4H), 1.41-1.10 (m, 20H), 0.89 (s, 6H).

[0137] (3) In the glove box, perform anhydrous and anaerobic operation, place compound D4 (43.14 g, 0.05 mol) in a reaction bottle, add benzene (100 mL) and stir to dissolve, slowly drop potassium carbonate (55.2 g, 0.4 mol), set the temperature to 60 °C, add tetrabenzyl hafnium (67.88 g, 0.125 mol), react for 1 h, after the reaction is completed, filter, dry the filtrate, wash with n-hexane, filter to obtain solid product, mark as metal complex E4.

[0138]

[0139] Example 5 Preparation of metal complex E5

[0140] The ligand and metal complex E5 are prepared according to the following combined route:

[0141]

[0142] (1) Diacetylene ketone (168.14 g, 2 mol) and compound A5 (246.3 g, 2 mol) were dissolved in solvent ethanol (500 mL), magnetic stirring was turned on, the reactants were completely dissolved in the solvent ethanol, the temperature was set to 80 °C, and the reaction was allowed to proceed for 3 h. After the reaction was completed, washing, ethyl acetate extraction, drying, filtration, and concentration under reduced pressure were performed to obtain compound B5 crude product, which was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 25:1 (v / v)) to obtain compound B5 (217.59 g, 52.5%).

[0143] The nuclear magnetic resonance data of compound B5 are as follows: 1 H NMR (CDCl3, 500MHz, TMS) δ 7.45 (s, 2H), 7.23 (s, 1H), 6.86 (s, 2H), 3.79 (s, 3H), 3.71 (s, 2H), 2.25 (s, 3H).

[0144] (2) Compound C5 (242.56 g, 0.7 mol) and concentrated hydrochloric acid (175 mL, 2.1 mol) were added to water, stirring was performed, and an ice bath was set to 0 °C. Sodium nitrite (193.2 g, 2.8 mol) was continuously added to the reaction bottle, stirring was performed for 30 min, the reaction bath temperature was kept below 10 °C, anhydrous sodium acetate was added to adjust the pH to about 6, a few drops of urea aqueous solution were added to neutralize the excess nitrous acid, the reaction mixture was filtered, and the reaction mixture was washed with water to obtain an aqueous solution of diazonium salt. Compound B5 (507.71 g, 2.45 mol) was added to the diazonium salt solution, stirring was performed at 35 °C, and the reaction was allowed to proceed for 2.5 h. Washing with water, ethyl acetate extraction, drying, filtration, and concentration under reduced pressure were performed to obtain compound D5 crude product, which was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 20:1 (v / v)) to obtain compound D5 (234.88 g, 42.86%).

[0145] The nuclear magnetic resonance data of compound D5 are as follows: 1 H NMR (CDCl3, 500MHz, TMS) 1H NMR (500MHz, Chloroform) δ 8.60 (s, 2H), 7.70 (s, 4H), 6.96 (s, 4H), 6.51 (s, 2H), 5.52 (s, 2H), 5.28 (d, J = 5.5 Hz, 4H), 4.09 (s, 2H), 3.79 (s, 6H), 2.64 (s, 4H), 2.42 (s, 6H), 1.56 (s, 4H), 1.33 (s, 4H), 0.89 (s, 6H).

[0146] (3) Anhydrous and anaerobic operation was carried out in a glove box, compound D5 (15.66 g, 0.02 mol) was placed in a reaction bottle, toluene (50 mL) was added and stirred to dissolve, 2.0 M phenyllithium (50 mL, 0.10 mol) was slowly added dropwise, stirred at room temperature for 1 h, ZrBr4(24.65 g, 0.06 mol) was added, the reaction was carried out for 3 h, after the reaction was completed, filtration was carried out, the filtrate was dried by suction, washed with n-hexane, and the solid product was obtained by filtration, which was marked as metal complex E5.

[0147]

[0148] Example 6 Preparation of metal complex E6

[0149] The ligand and metal complex E6 were prepared according to the following synthetic route:

[0150]

[0151] (1) Diacetylene (100.88 g, 1.2 mol) and compound A6 (192.87 g, 1.8 mol) were dissolved in solvent benzene (250 mL), stirring was started, and the reaction was carried out for 4 h at 60°C, after the reaction was completed, washing was carried out, extraction was carried out with ethyl acetate, drying was carried out, filtration was carried out, and the crude product of compound B6 was obtained by concentration under reduced pressure, which was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 13: 1 (v / v)) to obtain compound B6 (152.98 g, 66.67%).

[0152] The nuclear magnetic resonance data of compound B6 are as follows: 1 H NMR (CDCl3, 500 MHz, TMS) δ 7.45 (s, 2H), 7.10 (s, 2H), 6.75 (s, 1H), 3.71 (s, 2H), 2.32 (s, 3H), 2.25 (s, 3H).

[0153] (2) To water, add compound C6 (112.27 g, 0.3 mol) and concentrated hydrochloric acid (91.67 mL, 1.1 mol), stir, continue to add sodium nitrite (62.1 g, 0.9 mol) under ice bath condition, stir for 30 min, keep the reaction bath temperature below 10 °C, add anhydrous sodium acetate to adjust the pH to about 6, add a few drops of urea aqueous solution to neutralize the excess nitrous acid, filter the reaction mixture, wash the reaction mixture with distilled water, obtain the filtrate, concentrate, add ethanol, add compound B6 (133.86 g, 0.7 mol) to the obtained diazonium salt solution, set the temperature to 38 °C, stir, react for 6.5 h, wash with distilled water, extract with ethyl acetate, dry, filter, concentrate under reduced pressure to obtain compound D6 crude product, purify by silica gel column chromatography (petroleum ether: ethyl acetate = 25:1 (v / v)) to obtain compound D6 (121.52 g, 52%).

[0154] The nuclear magnetic resonance data of compound D6 are as follows: 1 H NMR (CDCI3, 500 MHz, TMS) δ 9.08 (s, 2H), 7.54 (s, 4H), 7.15 (s, 4H), 6.35 (s, 2H), 5.54 (s, 2H), 5.29 (s, 2H), 5.24 (s, 2H), 3.83 (s, 2H), 2.41 (s, 6H), 2.31 (s, 6H), 2.10 (s, 2H), 1.60 (s, 5H), 1.55 (s, 3H), 0.76 (s, 6H).

[0155] (3) In the glove box, perform anhydrous and anaerobic operation, place compound D6 (38.95 g, 0.05 mol) in a reaction bottle, add benzene (80 mL) and stir to dissolve, slowly add metallic sodium (4.6 g, 0.2 mol), set the temperature to 55 °C, add titanium tetrabromide (73.49 g, 0.2 mol), react for 2 h, after the reaction is completed, filter, dry the filtrate, wash with n-hexane, filter to obtain solid product, marked as metal complex E6.

[0156]

[0157] Example 7 Preparation of metal complex E7

[0158] The ligand and metal complex E7 are prepared according to the following combined route:

[0159]

[0160] (1) Compound A7 (126.55 g, 1.56 mol) and diacetylene ketone (100.89 g, 1.2 mol) were dissolved in toluene (250 mL) and stirred until the reactants were completely dissolved. The temperature was set to 85°C and the reaction was allowed to proceed for 1 hour. After the reaction was completed, the product was washed with distilled water, extracted with ethyl acetate, dried, filtered, and concentrated under reduced pressure to obtain a crude compound B7. The compound B7 was purified by column chromatography on silica gel (petroleum ether: ethyl acetate = 14:1 (v / v)) to obtain 129.84 g (65.5%) of compound B7.

[0161] The NMR data of compound B7 are as follows: 1 H NMR (CDCl3, 500 MHz, TMS) δ 7.95 (s, 1H), 6.09 (s, 1H), 5.43 (s, 1H), 5.03 (s, 1H), 3.66 (s, 2H), 3.22 (s, 2H), 2.25 (s, 3H).

[0162] (2) Compound C7 (69.3 g, 0.2 mol) and concentrated hydrochloric acid (36.67 mL, 0.44 mol) were added to distilled water and stirred. Sodium nitrite (30.36 g, 0.44 mol) was added under ice bath conditions and stirred for 35 minutes while maintaining the reaction bath temperature below 10°C. Anhydrous sodium acetate was added to adjust the pH to about 6, and a few drops of an aqueous urea solution were added to neutralize the excess nitrous acid. The reaction mixture was filtered and washed with distilled water to obtain a filtrate. After concentration, ethyl acetate was added to the resulting diazonium salt solution. Compound B7 (72.68 g, 0.44 mol) was added while setting the temperature to 40°C, and the mixture was stirred for 7 hours. The reaction mixture was washed with distilled water, extracted with ethyl acetate, dried, filtered, and concentrated under reduced pressure to obtain a crude compound D7. The compound D7 was purified by column chromatography on silica gel (petroleum ether: ethyl acetate = 28:1 (v / v)) to obtain 92.95 g (61%) of compound D7.

[0163] The NMR data of compound D7 are as follows: 1 H NMR (CDCl3, 500 MHz, TMS) δ 8.77 (s, 2H), 6.85 (s, 2H), 6.03 (s, 2H), 5.40 (s, 2H), 5.33 (s, 2H), 5.31 (t, J = 2.0 Hz, 1H), 5.29 (t, J = 2.0 Hz, 1H), 5.22 (s, 2H), 4.97 (s, 2H), 3.90 (s, 2H), 3.00 (s, 4H), 2.41 (s, 6H), 1.30 (s, 18H).

[0164] (3) Anhydrous and anaerobic operation was carried out in a glove box, compound D7 (34.94 g, 0.05 mol) was placed in a reaction bottle, benzene (100 mL) was added and stirred, dissolved, 1.6 M methyl lithium (125 mL, 0.2 mol) was slowly added dropwise, the temperature was set to 60°C, and tetra (methyl ethyl amino) zirconium (32.36 g, 0.1 mol) was added, the reaction was carried out for 1.5 h, after the reaction was completed, filtration was carried out, the filtrate was dried by suction, n-hexane was added for washing, and filtration was carried out to obtain a solid product, which was recorded as metal complex E7.

[0165]

[0166] Preparation of metal complex E8 in Comparative Example 1

[0167] The catalyst E8 shown in the following formula was prepared by the method of Example 2 of patent CN114316101A.

[0168]

[0169] Preparation of metal complex E9 in Comparative Example 2

[0170] The catalyst E9 shown in the following formula was prepared by the method of Example 2 of patent CN116284510A.

[0171]

[0172] Preparation of polyolefin

[0173] The metal complexes prepared by Example 1-Example 7, Comparative Example 1-Comparative Example 2 and commercially available phenoxyimine zirconium (as Comparative Example 3) were used as the main catalyst, and the ethylene / 1-hexene copolymerization reaction was carried out according to the following method and the raw materials, parameters, etc. shown in Table 1 to prepare the corresponding polyolefin products:

[0174] The high-pressure reactor with ampoule containing the main catalyst was set to a temperature of 150°C, dried for 3 hours, vacuumized and gradually cooled to 25°C. 350 mL of Isopar E, 100 mL of 1-hexene, t-butylaluminoxane and tri (pentafluorophenyl) borate were sequentially added, wherein the molar ratio of t-butylaluminoxane to the metal element of the main catalyst was recorded as Al / M, and the molar ratio of the B element in tri (pentafluorophenyl) borate to the metal element M in the main catalyst was recorded as B / M. The addition amounts of t-butylaluminoxane and tri (pentafluorophenyl) borate are shown in Table 1 below. The temperature was raised to 80-250°C, 1-8 MPa of ethylene monomer was introduced, the ampoule was broken, and the polymerization reaction was carried out. During the entire polymerization, the stirring speed, polymerization temperature and ethylene pressure remained unchanged. The reaction time was 5 minutes, after the reaction was completed, the gas in the reactor was exhausted, the reaction liquid was neutralized, the polymer precipitate was washed several times, and the polyolefin product was obtained after drying.

[0175] Reaction conditions of each example and comparative example in Table 1

[0176]

[0177] Performance test of test example polyolefin

[0178] The polyolefin products prepared in each example and comparative example were subjected to the performance tests in Table 2 below, and the results were as follows:

[0179] Table 2 Performance test results

[0180]

[0181]

[0182] The above example and comparative example data show that the catalysts described in the present application have excellent catalytic performance, and when applied to the copolymerization of olefin / 1-hexene, they still maintain high catalytic activity at high temperature. The polyolefin products prepared by the catalysts of the present application have excellent yellowing resistance, high glass transition temperature, high isotacticity and ultrahigh molecular weight.

[0183] The above is only the preferred embodiment of the present application, and it should be noted that for those skilled in the art, without departing from the method of the present application, several improvements and supplements can also be made, which should also be considered as the protection scope of the present application.

Claims

1. A double metal catalyst based on acylhydrazone pyrene skeleton, having a structure as shown in formula I: wherein, each R1 is independently selected from C1-C24 alkyl; each R2 and R3 is independently selected from C1-C24 alkyl, C6-C30 aryl, C3-C18 cycloalkyl, C5-C10 cycloalkenyl, wherein the C6-C30 aryl is optionally substituted with C1-C6 alkyl or C1-C6 alkoxy; R2 and R3 can be the same or different; M is selected from IVB metal elements; X is independently selected from halogen, C1-C16 alkylamino or C5-C16 arylalkyl. 2.The double metal catalyst according to claim 1, wherein, each R1 in the double metal catalyst of formula I is independently selected from C1-C16 alkyl; each R2 and R3 in the double metal catalyst of formula I is independently selected from C1-C16 alkyl, C6-C20 aryl, C5-C10 cycloalkenyl or C3-C12 cycloalkyl, wherein the C6-C20 aryl is optionally substituted with C1-C6 alkyl or C1-C6 alkoxy.

3. The bimetallic catalyst of claim 1 or 2, wherein, R2 and R3 are the same. 4.The double metal catalyst according to claim 1 or 2, wherein, each R1 in the double metal catalyst of formula I is independently selected from C1-C12 alkyl; each R2 and R3 in the double metal catalyst of formula I is independently selected from C1-C10 alkyl, C6-C16 aryl, C5-C8 cycloalkenyl or C3-C8 cycloalkyl, wherein the C6-C16 aryl is optionally substituted with C1-C6 alkyl or C1-C6 alkoxy. 5.The double metal catalyst according to claim 1 or 2, wherein, M in the double metal catalyst of formula I is selected from titanium, zirconium or hafnium; X in the double metal catalyst of formula I is independently selected from halogen, C1-C10 alkyl, C1-C10 alkylamino or C5-C10 arylalkyl. 6.The double metal catalyst according to claim 5, wherein, X in the double metal catalyst of formula I is independently selected from halogen, C1-C8 alkyl, C1-C8 alkylamino or C5-C8 arylalkyl.

7. The bimetallic catalyst of claim 1 or 2, wherein, The double metal catalyst of formula I has a structure as shown below: wherein, X and M are as defined in claim 1. 8.A method for preparing a double metal catalyst based on acylhydrazone pyrene skeleton, comprising: complexing a ligand compound of formula II with a metal salt MX4 in the presence of a hydrogen abstractor; wherein, R1, R2, R3, M and X are as defined in claim 1.

9. The method of making a bimetallic catalyst according to claim 8, wherein, The metal salt MX4 is selected from titanium tetrachloride, zirconium tetrachloride, hafnium tetrachloride, hafnium tetrabenzyl, zirconium tetra(methylethyl)amido, titanium tetrabromide, zirconium tetrabromide or hafnium tetrabromide. 10.The method for preparing a double metal catalyst according to claim 8 or 9, wherein, the molar ratio of the ligand compound of formula II to the metal salt MX4 is 1:(2-5); the molar ratio of the ligand compound of formula II to the hydrogen abstractor is 1:(4-8); the hydrogen abstractor is one or more of alkyl lithium, phenyl lithium, potassium carbonate, sodium hydride, sodium, Grignard reagent; the complexing reaction is carried out at a temperature of 20-60℃ for 1-4 hours. 11.The method for preparing a double metal catalyst according to claim 10, wherein, The hydrogen-removing reagent is n-butyllithium, methyllithium and / or n-hexyllithium.

12. The method of making a bimetallic catalyst according to claim 8 or 9, wherein, The ligand compound shown in formula II is prepared by the following reaction formula: wherein R1, R2 and R3 are as defined in claim 1.

13. The method of making a bimetallic catalyst according to claim 12, wherein, The preparation steps of the ligand compound shown in formula II include: 1) reacting diacetylene ketone and compound A in an organic solvent to generate compound B; 2) adding sodium nitrite to compound C under strong acid conditions to generate diazonium salt of compound C, adding aqueous urea to neutralize excess nitrous acid, adding a solvent after concentration, and reacting diazonium salt of compound C with compound B in the solvent to generate compound D.

14. The method of making a bimetallic catalyst according to claim 13, wherein, In the preparation steps of the ligand compound shown in formula II, in step 1), the reaction conditions are: reaction temperature 60-110℃, reaction time 1-5h; in step 1), the compound A is selected from one or more of aniline, cyclohexylamine, cyclopropylamine, 4-methylaniline, 4-methoxyaniline, 3,4,5-trimethylaniline, 3,4,5-trimethoxyaniline, 3,4,5-trichloroaniline, 4-methylcyclohexylamine, 3,4,5-trimethylcyclohexylamine, 3,4,5-trimethoxycyclohexylamine, tetrahydrothiopyran-4-amine, 9-aminoanthracene, cyclooctylamine, n-pentylamine, and cyclopentadiene-1-amine, and the organic solvent is one or more of benzene, toluene, methanol, and ethanol; in step 1), the molar ratio of diacetylene ketone to compound A is 1:(1-1.5).

15. The method of making a bimetallic catalyst according to claim 13 or 14, wherein, In the preparation steps of the ligand compound shown in formula II, in step 2), the reaction conditions are: reaction temperature 0-60℃, reaction time 2-12h; in step 2), the strong acid is concentrated hydrochloric acid, and the reaction solvent is one or more of water, ethanol, methanol, ethyl acetate, and tetrahydrofuran; in step 2), the molar ratio of compound C, strong acid, sodium nitrite, and compound B is 1:(2-5):(2-6):(2-4).

16. A process for the preparation of a polyolefin, said process comprising: An olefin or α-olefin is subjected to a polymerization reaction in the presence of a bimetallic catalyst and a co-catalyst according to any one of claims 1-7 in a solvent to prepare a polyolefin product.

17. The method for preparing a polyolefin according to claim 16, wherein, the concentration of the bimetallic catalyst in the solvent is 0.1-10 μmol / L; the solvent used in the polymerization reaction is selected from one or more of an alkane, a cycloalkane, and an aromatic hydrocarbon; the temperature of the polymerization reaction is 10-300℃, and the polymerization reaction pressure is 0.1-20 MPa.

18. The method for preparing a polyolefin according to claim 17, wherein, the concentration of the bimetallic catalyst in the solvent is 2-5 μmol / L; the solvent used in the polymerization reaction is selected from one or more of toluene, heptane, hexane, Isopar E, and cyclohexane; the temperature of the polymerization reaction is 80-250℃, and the polymerization reaction pressure is 1-8 MPa.

19. The process for the preparation of polyolefins according to any one of claims 16-18, wherein, the co-catalyst is an alkylaluminum and a borate salt; said alkyl aluminum is selected from the group consisting of C1-C 10 alkyl aluminum, wherein the molar ratio of metal Al in said alkyl aluminum to metal M in the bimetallic catalyst of formula I is (10-200): 1; The borate salt is selected from one or more of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, tri(pentafluorophenyl)borate, trityl tetrakis(pentafluorophenyl)borate, wherein the molar ratio of element B in the borate salt to metal M in the bimetallic catalyst of Formula I is B / M is (0-30):

1.

20. The method of producing a polyolefin according to claim 19, wherein, The alkyl aluminum is selected from methylaluminoxane, t-butylaluminoxane, or t-butyl-modified methylaluminoxane, wherein the molar ratio of metal Al in the alkyl aluminum to metal M in the bimetallic catalyst of Formula I is Al / M is (40-180):

1. The borate salt is selected from tri(pentafluorophenyl)borate, wherein the molar ratio of element B in the borate salt to metal M in the bimetallic catalyst of Formula I is B / M is (0-20):

1.

21. Use of the bimetallic catalyst according to any one of claims 1-7 in the production of a polyolefin.

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