A metallocene compound, a preparation method and a metallocene catalyst and applications thereof

Abstract

The application relates to the chemical technology field and discloses a metallocene compound, a preparation method and a metallocene catalyst and application thereof. The metallocene compound provided by the application comprises a fluorenyl ligand, a metallocene ligand, a bridging structure and a metal part in a chemical structure. By introducing an adsorption group with a micropore effect into the fluorenyl ligand, the metallocene compound can exhibit strong saturated adsorption capacity when interacting with cocatalysts such as organic boron and organic aluminum, the cocatalyst concentration around the metal center can be improved, the activity and thermal stability of the catalyst can be significantly enhanced, the metallocene compound can catalyze alpha-olefin polymerization with high activity, the amount of the cocatalyst is reduced, and the production cost of polyolefin is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical industry, in particular to a metallocene compound, a preparation method, a metallocene catalyst and application thereof. BACKGROUND

[0002] Polyolefin is a kind of high molecular material polymerized by olefin monomer, which is widely used in various fields of industrial production and daily life. The iteration and upgrading of polyolefin technology cannot be separated from the development of polyolefin catalyst. At present, the olefin polymerization catalysts industrialized mainly include Ziegler-Natta type catalyst and metallocene catalyst. Among them, the metallocene catalyst refers to a catalytic system composed of a transition metal element (such as Ti, Zr, Hf) complex as a main catalyst and an alkyl aluminum oxide (such as methyl aluminum oxide, abbreviated as MAO) or an organic boride (such as B(C6F5)3) as a cocatalyst, and the ligand of the transition metal element contains at least one metallocene (Cp - ) or its derivative.

[0003] The metallocene catalyst has excellent advantages in the development of polyolefin new materials due to its high polymerization activity, excellent copolymerization performance, and the characteristics of accurately controlling the structure, molecular weight and distribution of the polymer. However, a large amount of modified methylaluminoxane (abbreviated as MMAO) is needed in the production of high-end polyolefin catalyzed by metallocene as a decontaminant and a cocatalyst for the reaction system, which not only has high cost but also limits the supply of high-end polyolefin products due to the serious global shortage of MMAO. Therefore, it is urgent to develop a new type of metallocene catalyst with high catalytic activity to reduce the production cost of polyolefin. SUMMARY

[0004] The present application provides a metallocene compound and a preparation method thereof, which aims to improve the catalytic activity of the metallocene catalyst to a certain extent and reduce the production cost of polyolefin.

[0005] In a first aspect, the present application provides a metallocene compound, which includes a fluorene-based ligand, a metallocene ligand, a bridging structure and a metal part in its chemical structure; the metallocene compound has a structure shown in formula (I):

[0006]

[0007] wherein A1, A2, A3, A4 are each independently selected from H or an adsorption group, and at least one of A1-A4 is selected from an adsorption group, and the adsorption group is a bulky group that can adsorb organic boron or organic aluminum;

[0008] R1, R2, R3, R4, R5, R6 are each independently selected from H, halogen, a substituted or unsubstituted G group, and the G group includes C1-C40 alkyl, C3-C 40 cycloalkyl, C2-C 40 heterocycloalkyl, C6-C 60 aryl, C4-C 60 heteroaryl, C7-C 60 aralkyl, C6-C 60 heteroaralkyl;

[0009] L is selected from C, Si, Ge, or Sn;

[0010] M is selected from Ti, Zr, or Hf;

[0011] X is selected from halogen, a substituted or unsubstituted Y group, the Y group comprising any of C1-C 30 alkyl, C3-C 30 cycloalkyl, C2-C 30 heterocycloalkyl, C2-C 20 unsaturated hydrocarbon group, C6-C 30 aryl, C4-C 30 heteroaryl, C5-C 30 aralkyl, C5-C 30 heteroaralkyl;

[0012] the halogen is at least one of F, Cl, Br, I.

[0013] The metallocene compound provided in the present application, by introducing an adsorption group having a micropore effect in a fluorenyl ligand, enables the metallocene compound of the present application to exhibit strong saturated adsorption capacity when interacting with a cocatalyst such as an organic boron, an organic aluminum, etc., can improve the cocatalyst concentration around the metal center, significantly enhances the activity and thermal stability of the catalyst, thereby can catalyze the polymerization of an α-olefin with high activity, at the same time also reduces the amount of the cocatalyst, reduces the production cost of the polyolefin.

[0014] In an alternative embodiment, the adsorption group is selected from adamantyl or a derivative of adamantyl, the derivative of adamantyl comprising a Q group and at least one adamantyl, the Q group sharing a carbon atom with the adamantyl or the Q group being connected to the adamantyl through a covalent bond; the Q group is selected from a heteroatom, a T group, a halogen-substituted T group, or a T group comprising a heteroatom, the T group comprising any of C1-C 20 alkyl, C2-C 20 cycloalkyl, C4-C 30 aryl, C5-C 30at least one of O, N, P, S, Si, Ge. In some embodiments, the adamantyl derivative is connected to the fluorenyl group through an adamantyl group or a Q group, and the adamantyl derivative is selected from any one of C1-C5 alkyl-substituted adamantyl, C2-C5 heterocycloalkyl-substituted adamantyl, a spirocyclic group formed by C2-C5 heterocycloalkyl and adamantyl, adamantyl-substituted amine group, adamantyl-substituted alkyl group, and adamantyl-substituted phosphine group. It should be noted that the adamantane molecule has a high degree of spatial symmetry and structural rigidity. The introduction of the adamantyl group or its derivative into the metallocene compound can increase the structural rigidity and specific surface area of the metallocene compound, which is conducive to the formation of a stable void structure, thereby producing a microporous effect.

[0015] The present application finds that the adamantyl group or its derivative has good adaptability in the metallocene compound skeleton. On the one hand, the adamantyl group or its derivative is a bulky group that can limit the stereochemical structure of the metallocene compound. The introduction of the adamantyl group or its derivative into the fluorenyl ligand of the metallocene compound can better regulate the steric effect of the metal active center, so that the metallocene catalyst has higher catalytic activity. On the other hand, the adamantyl group or its derivative has a microporous effect, so that the organic boron and / or organic aluminum can diffuse into the microporous inner surface of the metallocene compound to reach adsorption equilibrium. Therefore, the metallocene compound can exhibit strong saturated adsorption capacity for the organic boron and / or organic aluminum, thereby increasing the cocatalyst concentration around the metal center, enhancing the thermal stability of the catalyst, and further catalyzing the polymerization of α-olefins with high activity. At the same time, the amount of cocatalyst is also reduced, thereby reducing the production cost of polyolefins.

[0016] In an alternative embodiment, the G group includes any one of C1-C 10 alkyl, C3-C 10 cycloalkyl, C2-C6 heterocycloalkyl, C6-C 15 aryl, C4-C 15 heteroaryl, C7-C 15 aralkyl, C6-C 15 heteroaralkyl.

[0017] In an alternative embodiment, the substituent in the substituted G group is selected from any one of halogen, C1-C5 alkyl, C1-C5 alkoxy, and C1-C5 haloalkyl.

[0018] In some embodiments, the substituted or unsubstituted G group includes any one of methyl, ethyl, propyl, t-butyl, cyclohexyl, phenyl, methylphenyl, methoxyphenyl, fluorophenyl, trifluoromethylphenyl, t-butylphenyl, and biphenyl.

[0019] In one alternative embodiment, the Y group includes C1-C5 alkyl groups, C3-C5 alkyl groups, and C4-C5 alkyl groups. 10 Cycloalkyl, C2-C6 heterocycloalkyl, C2-C 10 unsaturated hydrocarbon groups, C6-C 15 aryl, C4-C 15 heteroaryl, C7-C 15 Aryl groups, C6-C 15 Any one of the heteroaryl groups.

[0020] In one alternative embodiment, the substituent in the substituted Y group is selected from any one of halogen, C1-C5 alkyl, C1-C5 alkoxy, and C1-C5 haloalkyl.

[0021] In one alternative embodiment, the substituted or unsubstituted Y group includes either methyl or benzyl.

[0022] In one alternative embodiment, the fluorene ligand is selected from any of the following structures:

[0023]

[0024]

[0025] In one alternative implementation, the cyclohexene ligand is selected from any of the following structures:

[0026]

[0027] In one alternative implementation, the bridging structure is selected from any of the following structures:

[0028]

[0029]

[0030] In one alternative embodiment, the metallocene compound is selected from any of the following structures:

[0031]

[0032]

[0033]

[0034] In a second aspect, this application provides a method for preparing the metallocene compound described in the first aspect, comprising the following steps:

[0035]

[0036] 1) Compound i is reacted with the first dehydrogenating agent in the first organic solvent at a reaction temperature of T1 and a reaction time of t1; then compound ii is added and the reaction continues at a reaction temperature of T2 and a reaction time of t2 to obtain compound iii;

[0037] 2) In the second organic solvent, compound iii is allowed to react fully with the second dehydrogenating agent at a reaction temperature of T3 and a reaction time of t3; then, metal M salt or metal M organic compound is added to continue the reaction at a reaction temperature of T4 and a reaction time of t4 to obtain the metallocene compound shown in Formula I.

[0038] The preparation method of this application has a short synthetic route and is simple to operate. The target compound can be obtained in just two steps, which can meet the needs of large-scale production.

[0039] In one alternative embodiment, the first organic solvent and the second organic solvent are each independently selected from at least one of toluene, xylene, pentane, cyclopentane, n-hexane, cyclohexane, n-heptane, methylcyclohexane, octane, isooctane, and tetrahydrofuran.

[0040] In one optional embodiment, the first dehydrogenating agent and the second dehydrogenating agent are each independently selected from at least one of alkyllithium, phenyllithium, sodium hydride, potassium hydride, lithium hydride, tetramethylethylenediamine, bis(trimethylsilylamino)lithium, bis(trimethylsilylamino)sodium, diisopropylaminolithium, and potassium carbonate.

[0041] In one alternative embodiment, the molar ratio of compound i to the first dehydrogenating agent is 1:1.0-1.5.

[0042] In one alternative embodiment, the molar ratio of compound i to compound ii is 1:1.0-1.5.

[0043] In one optional implementation, T1 is -78°C to 100°C, and t1 is 0.5h to 36h.

[0044] In one alternative implementation, T2 is -78°C to 50°C, and t2 is 0.5h to 36h.

[0045] In one alternative embodiment, the molar ratio of compound iii to the second dehydrogenating agent is 1:2.0-3.0.

[0046] In one alternative embodiment, the molar ratio of compound iii to the metal M salt or metal M organocompound is 1:1.0-1.5.

[0047] In one alternative implementation, T3 is -78°C to 100°C, and t3 is 0.5h to 36h.

[0048] In one alternative implementation, T4 is -78°C to 50°C, and t4 is 0.5h to 36h.

[0049] The above process conditions can ensure the smooth progress of the reaction, while also suppressing the generation of by-products and guaranteeing the yield of the target compound.

[0050] Thirdly, this application also provides a metallocene catalyst, comprising a main catalyst and a co-catalyst, wherein the co-catalyst comprises organoaluminum and / or organoboron; the main catalyst is the metallocene compound described in the first aspect or a metallocene compound prepared by the preparation method described in the second aspect.

[0051] In one alternative embodiment, the molar ratio of Al in the organoaluminum to M in the metallocene compound is 2-600.

[0052] Further optionally, the molar ratio of Al in the organoaluminum to M in the metallocene compound is 10-100.

[0053] In one alternative embodiment, the molar ratio of element B in the organoboron to element M in the metallocene compound is 0-80.

[0054] Further optionally, the molar ratio of element B in the organoboron to element M in the metallocene compound is 0-20.

[0055] In one optional embodiment, the organoaluminum is selected from at least one of aluminum oxanes, alkylaluminum, and alkylaluminum chloride. Specifically, the aluminum oxane includes at least one of methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, n-propylaluminoxane, isopropylaluminoxane, n-butylaluminoxane, isobutylaluminoxane, neopentylaluminoxane, n-hexylaluminoxane, and n-octylaluminoxane; the modified methylaluminoxane includes at least one of ethylaluminum-modified methylaluminoxane, butylaluminum-modified methylaluminoxane, and octylaluminum-modified methylaluminoxane; and the alkylaluminum includes trimethylaluminum, triethylaluminum, and tri-n-ethylaluminum. The alkyl aluminum chloride comprises at least one of the following: propyl aluminum, triisopropyl aluminum, tri-n-butyl aluminum, triisobutyl aluminum, tri-n-hexyl aluminum, triisohexyl aluminum, tri-n-octyl aluminum, and triisooctyl aluminum; the alkyl aluminum chloride comprises at least one of the following: dichloromethyl aluminum, dichloroethyl aluminum, dichlorodimethyl aluminum, dichlorodiethyl aluminum, dichlorodi-n-butyl aluminum, dichlorodiisobutyl aluminum, dichlorodi-n-butyl aluminum, dichloroisobutyl aluminum, sesqui-n-butyl aluminum chloride, sesquiethyl aluminum chloride, sesquimethyl aluminum chloride, and sesquiisobutyl aluminum chloride.

[0056] In one optional embodiment, the organoboron is selected from at least one of tris(pentafluorophenyl)boron, triphenylmethyltetra(pentafluorophenyl)borate, triphenylmethyltetra(pentafluorophenyl)borate, triphenylmethyltetra(pentafluorophenyl)borate, tetra(pentafluorophenyl)borate-methyl di-(octadecyl)ammonium, N,N-bisoctadecylmethylaminotetra(pentafluorophenyl)borate, N,N-dimethylphenylammonium tetra(pentafluorophenyl)borate, bisoctadecylmethyltert-ammonium tetra(pentafluorophenyl)borate, and dihydrogenated tallow methyltert-ammonium tetra(pentafluorophenyl)borate.

[0057] Fourthly, this application provides the application of the metallocene catalyst described in the third aspect in the production of polyolefins.

[0058] Fifthly, this application also provides a method for preparing an ethylene / α-olefin copolymer, comprising the following steps:

[0059] In the presence of the metallocene catalyst described in the fourth aspect, ethylene and α-olefins undergo a polymerization reaction in an organic solvent to prepare an ethylene / α-olefin copolymer.

[0060] In one optional embodiment, the polymerization reaction temperature is 40℃-260℃, and the polymerization reaction gauge pressure is 0.1MPa-60MPa.

[0061] Alternatively, the polymerization temperature is 80℃-230℃, and the polymerization gauge pressure is 1MPa-10MPa.

[0062] In one alternative embodiment, the amount of the metallocene catalyst added, expressed as the molar concentration of element M in the organic solvent, is 0.01 μmol / L to 7 μmol / L.

[0063] In one alternative embodiment, the α-olefin is selected from at least one of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, cyclopentene, cyclohexene, norbornene, phenylnorbornene, and styrene.

[0064] In one optional embodiment, the organic solvent is selected from at least one of aromatic and alkane organic solvents, such as C8 isoalkanes, isohexanes, 2-methyl-2-propanol, methylcyclohexane, toluene, etc.

[0065] Additional aspects and advantages of the embodiments of this application will be described and shown in part in the following description, or illustrated by practice of the embodiments of this application. Detailed Implementation

[0066] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion.

[0068] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0069] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0070] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0071] The present application will be further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in this application. All materials and reagents used in the following embodiments were purchased from commercial sources, wherein:

[0072] Toluene: AR, aladdin;

[0073] n-Butyllithium: AR, Innochem;

[0074] Compounds i-1 to i10: AR, Innochem;

[0075] Compounds ii-1 to ii10: AR, Innochem;

[0076] ZrCl4: Tokyo Chemical Industry Co., Ltd.;

[0077] HfCl4: Tokyo Chemical Industry Co., Ltd.;

[0078] ZrMe4: Tokyo Chemical Industry Co., Ltd.;

[0079] ZrBn4: Tokyo Chemical Industry Co., Ltd.;

[0080] Methylaluminoxane (MAO): Albemarle;

[0081] Modified methylaluminoxane (MMAO): Albemarle;

[0082] Trimethylaluminum (Me3Al): AR, Aladdin;

[0083] Dichloroethylaluminum: AR, Aladdin;

[0084] Triphenylmethyltetra(pentafluorophenyl)borate: AR, Aladdin;

[0085] Ethylene: 99.9%, Beijing Yanshan Petrochemical Company;

[0086] 1-Hexene: 98%, Beijing Yanshan Petrochemical Company;

[0087] 1-Octenene: 98%, Beijing Yanshan Petrochemical Company;

[0088] Cyclohexene: 98%, Beijing Yanshan Petrochemical Company;

[0089] Phenylon norbornene: 98%, Beijing Yanshan Petrochemical Company;

[0090] Styrene: 98%, Beijing Yanshan Petrochemical Company;

[0091] Isopar E: ExxonMobil.

[0092] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0093] The compounds in the following examples were characterized using a nuclear magnetic resonance spectrometer (Brucker ARX-400).

[0094] In the following examples and comparative examples, calculations were performed according to the following formula:

[0095] Polymerization 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.

[0097] The method for calculating the comonomer insertion rate is referenced in (Macromolecules 1999, 32, 3817). In all the following examples and comparative examples, the chemical reactions involved were carried out after nitrogen purging. Examples 1-10 below were used to prepare different metallocene compounds:

[0098] Example 1

[0099]

[0100] 1) Add 5g of compound i-1 and 4.36ml of n-butyllithium in n-hexane solution (2.5M) to ultra-dry toluene at a molar ratio of 1:1.2. React at -78℃ for 3h, then add 3.46g of compound ii-1 to continue the reaction, ensuring that the molar ratio of compound i-1 to compound ii-1 is 1:1.1. At the same time, control the reaction temperature at 25℃ and the reaction time at 5h. After the reaction is completed, add ethanol to the reaction solution, stir to obtain a suspension, filter, wash and dry to obtain intermediate iii-1.

[0101] 2) Add 3g of intermediate iii-1 and 1.6ml of n-butyllithium in n-hexane (2.5M) to ultra-dry toluene at a molar ratio of 1:2.2. After reacting at -78℃ for 24h, slowly raise the temperature to 25℃ and add 0.5g of tetramethylzirconium to continue the reaction, ensuring that the molar ratio of intermediate iii-1 to tetramethylzirconium is 1:1. Control the reaction temperature at 25℃ and the reaction time at 24h. After the reaction is completed, filter, concentrate, slurry, and dry the reaction solution to obtain the metallocene compound P7.

[0102] P7 NMR data: 1 H NMR(500MHz,Chloroform)δ7.84(s,2H),7.68(s,2H),7.32(d,J=36.5Hz,6H),6.85(s,4H),3.86(s,8H),3.79(s,6H),2.83(s,4H ),2.71(s,4H),2.23(d,J=17.2Hz,6H),2.04(d,J=19.0Hz,4H),1.80(s,4H),1.65(d,J=5.0Hz,12H),0.81(s,4H),-0.25(s,6H).

[0103] Example 2

[0104]

[0105] 1) Add 5g of compound i-2 and 4.36ml of n-butyllithium in n-hexane solution (2.5M) to ultra-dry toluene at a molar ratio of 1:1.2. React at -78℃ for 3h, then add 3.64g of compound ii-2 to continue the reaction, ensuring that the molar ratio of compound i-2 to compound ii-2 is 1:1.1. At the same time, control the reaction temperature at 25℃ and the reaction time at 5h. After the reaction is completed, add ethanol to the reaction solution, stir to obtain a suspension, filter, wash and dry to obtain intermediate iii-2.

[0106] 2) Add 3g of a 2.5M solution of intermediate iii-2 and 3ml of n-butyllithium in hexane to ultra-dry toluene at a molar ratio of 1:2.2. After reacting at -78℃ for 24h, slowly raise the temperature to 25℃ and add 0.51g of tetramethylzirconium to continue the reaction, ensuring that the molar ratio of intermediate iii-2 to tetramethylzirconium is 1:1. Control the reaction temperature at 25℃ and the reaction time for 24h. After the reaction is completed, filter, concentrate, slurry, and dry the reaction solution to obtain the metallocene compound P8.

[0107] P8 NMR data: 1H NMR(500MHz,Chloroform)δ7.88(s,2H),7.70(s,2H),7.33(s,2H),7.28(s,4H),7.23(d,J =10.0Hz,6H),6.15(s,1H),5.90(s,1H),4.33(s,1H),3.86(s,8H),2.85(s,4H),2.71(s,4H ),2.65(s,1H),2.25(s,4H),2.20(s,2H),2.02(d,J=19.0Hz,4H),1.81(d,J=3.2Hz,6H),1. 60(s,1H),1.50(s,2H),1.37(s,2H),1.20(s,2H),1.12(s,1H),0.81(s,4H),-0.25(s,6H).

[0108] Example 3

[0109]

[0110] 1) Add 5g of compound i-3 and 4.36ml of n-butyllithium in n-hexane solution (2.5M) to ultra-dry toluene at a molar ratio of 1:1.2. React at -78℃ for 3h, then add 2.28g of compound ii-3 to continue the reaction, ensuring that the molar ratio of compound i-3 to compound ii-3 is 1:1.1. At the same time, control the reaction temperature at 25℃ and the reaction time at 5h. After the reaction is completed, add ethanol to the reaction solution, stir to obtain a suspension, filter, wash and dry to obtain intermediate iii-3.

[0111] 2) Add 3g of a 2.5M solution of intermediate iii-3 and 3.55ml of n-butyllithium in hexane to ultra-dry toluene at a molar ratio of 1:2.2. After reacting at -78℃ for 24h, slowly raise the temperature to 25℃ and add 0.61g of tetramethylzirconium to continue the reaction, ensuring that the molar ratio of intermediate iii-3 to tetramethylzirconium is 1:1. Control the reaction temperature at 25℃ and the reaction time at 24h. After the reaction is completed, filter, concentrate, slurry, and dry the reaction solution to obtain metallocene compound P9.

[0112] P9 NMR data: 1H NMR(500MHz,Chloroform)δ7.94(d,2H),7.67(d,2H),7.36(d,2H),6.28-6.21(m,2H),5.81(d,2H),5.50(s,2H),3.86(s,8H),2.77-2.69(m,4H),2.2 7-2.17(m,8H),2.15(s,2H),2.06(d,J=19.0Hz,4H),1.83(d,J=15.3Hz,6H ),1.49-1.33(m,2H),0.95(s,4H),0.65(s,6H),0.25(s,4H),-0.2(m,6H).

[0113] Example 4

[0114]

[0115] 1) Add 5g of compound i-4 and 4.36ml of n-butyllithium in n-hexane (2.5M) to ultra-dry toluene at a molar ratio of 1:1.2. React at -78℃ for 3h, then add 1.9g of compound ii-4 to continue the reaction, ensuring that the molar ratio of compound i-4 to compound ii-4 is 1:1.1. At the same time, control the reaction temperature at 25℃ and the reaction time at 5h. After the reaction is completed, add ethanol to the reaction solution, stir to obtain a suspension, filter, wash and dry to obtain intermediate iii-4.

[0116] 2) Add 3g of a 2.5M solution of intermediate iii-4 and 3.56ml of n-butyllithium in hexane to ultra-dry toluene at a molar ratio of 1:2.2. After reacting at -78℃ for 24h, slowly raise the temperature to 25℃ and add 1.85g of tetrabenzylzirconium to continue the reaction, ensuring that the molar ratio of intermediate iii-4 to tetrabenzylzirconium is 1:1. Control the reaction temperature at 25℃ and the reaction time at 24h. After the reaction is complete, filter, concentrate, slurry, and dry the reaction solution to obtain the metallocene compound P22.

[0117] P22 NMR data: 1H NMR(500MHz,Chloroform)δ7.91(d,2H),7.68(d,2H),7.41(d,2H),7.23(d,J=5.0Hz,8H),7.19(s,1H),4.28(s,1H),3.86(s,8H),2.88(d,4H) ,2.76-2.72(m,3H),2.65(s,4H),2.28-2.20(m,6H),1.85(d,4H),1.65 (d,J=5.0Hz,12H),1.59-1.31(m,8H),1.06(s,3H),0.84-0.79(m,8H).

[0118] Example 5

[0119]

[0120] 1) Add 5g of compound i-5 and 4.15ml of n-butyllithium in n-hexane solution (2.5M) to ultra-dry toluene at a molar ratio of 1:1.2. React at -78℃ for 3h, then add 4.27g of compound ii-5 to continue the reaction, ensuring that the molar ratio of compound i-5 to compound ii-5 is 1:1.1. At the same time, control the reaction temperature at 25℃ and the reaction time at 5h. After the reaction is completed, add ethanol to the reaction solution, stir to obtain a suspension, filter, wash and dry to obtain intermediate iii-5.

[0121] 2) Add 3g of a 2.5M solution of intermediate iii-5 and 2.66ml of n-butyllithium in n-hexane to ultra-dry toluene at a molar ratio of 1:2.2. After reacting at -78℃ for 24h, slowly raise the temperature to 25℃ and add 0.97g of hafnium tetrachloride to continue the reaction, ensuring that the molar ratio of intermediate iii-5 to hafnium tetrachloride is 1:1. Control the reaction temperature at 25℃ and the reaction time at 24h. After the reaction is completed, filter, concentrate, slurry, and dry the reaction solution to obtain the metallocene compound P35.

[0122] P35 NMR data: 1 H NMR(500MHz,Chloroform)δ8.69(s,2H),7.95(s,2H),7.75(s,4H),7.59-7.32(m,17H),6.39(s,1H),5.96(s,1H),4.81(s,2H),3.86(d,J=5 0.0Hz,8H),3.49(s,1H),2.28(s,4H),2.17(d,J=3.0Hz,4H),2.15-1.98(m,12H),1.81(d,J=1.0Hz,4H),1.66(d,J=5.0Hz,4H),1.05(s,2H).

[0123] Example 6

[0124]

[0125] 1) Add 5g of compound i-6 and 4.87ml of n-butyllithium in n-hexane solution (2.5M) to ultra-dry toluene at a molar ratio of 1:1.2. React at -78℃ for 3h, then add 1.18g of compound ii-6 to continue the reaction, ensuring that the molar ratio of compound i-6 to compound ii-6 is 1:1.1. At the same time, control the reaction temperature at 25℃ and the reaction time at 5h. After the reaction is completed, add ethanol to the reaction solution, stir to obtain a suspension, filter, wash and dry to obtain intermediate iii-6;

[0126] 2) Add 3g of a 2.5M solution of intermediate iii-6 and 4.41ml of n-butyllithium in hexane at a molar ratio of 1:2.2 to ultra-dry toluene. After reacting at -78℃ for 24h, slowly raise the temperature to 25℃ and add 1.6g of hafnium tetrachloride to continue the reaction, ensuring that the molar ratio of intermediate iii-6 to hafnium tetrachloride is 1:1. Control the reaction temperature at 25℃ and the reaction time at 24h. After the reaction is complete, filter, concentrate, slurry, and dry the reaction solution to obtain the metallocene compound P40.

[0127] P40 NMR data: 1 H NMR(500MHz,Chloroform)δ8.11(s,2H),7.37(s,2H),6.84(d,2H),6.33(d,1H),6.16-5.95(m ,2H),3.31(t,1H),3.02(s,2H),2.18(s,14H),2.16–2.11(m,6H),1.71(t,14H),1.01(s,6H).

[0128] Example 7

[0129]

[0130] 1) Add 5g of compound i-7 and 2.25ml of n-butyllithium in n-hexane (2.5M) to ultra-dry toluene at a molar ratio of 1:1.2. React at -78℃ for 3h, then add 5.37g of compound ii-7 to continue the reaction, ensuring that the molar ratio of compound i-7 to compound ii-7 is 1:1.1. At the same time, control the reaction temperature at 25℃ and the reaction time at 5h. After the reaction is completed, add ethanol to the reaction solution, stir to obtain a suspension, filter, wash and dry to obtain intermediate iii-7.

[0131] 2) Add 3g of a 2.5M solution of intermediate iii-7 and 3.07ml of n-butyllithium in hexane to ultra-dry toluene at a molar ratio of 1:2.2. After reacting at -78℃ for 24h, slowly raise the temperature to 25℃ and add 0.81g of zirconium tetrachloride to continue the reaction, ensuring that the molar ratio of intermediate iii-7 to zirconium tetrachloride is 1:1. Control the reaction temperature at 25℃ and the reaction time at 24h. After the reaction is completed, filter, concentrate, slurry, and dry the reaction solution to obtain metallocene compound P49.

[0132] P49 NMR data: 1 H NMR(500MHz,Chloroform)δ8.64(s,2H),7.92(s,2H),7.34(d,J=13.7Hz,6H),7.16(s,4H),6.29(s,2H),5.39(s,2H),4.16(s,2H),3.69( s,2H),3.29(s,2H),2.75(s,2H),2.00(d,J=15.0Hz,12H),1.81(s,2H),1.72(s,12H),1.60(s,2H),1.33(s,18H),1.16(d,J=40.0Hz,4H).

[0133] Example 8

[0134]

[0135] 1) Add 5g of compound i-8 and 3.13ml of n-butyllithium in n-hexane solution (2.5M) to ultra-dry toluene at a molar ratio of 1:1.2. React at -78℃ for 3h, then add 3.21g of compound ii-8 to continue the reaction, ensuring that the molar ratio of compound i-8 to compound ii-8 is 1:1.1. Control the reaction temperature at 25℃ and the reaction time for 5h. After the reaction is completed, add ethanol to the reaction solution, stir to obtain a suspension, filter, wash and dry to obtain intermediate iii-8.

[0136] 2) Add 3g of a 2.5M solution of intermediate iii-8 and 2.17ml of n-butyllithium in n-hexane to ultra-dry toluene at a molar ratio of 1:2.2. After reacting at -78℃ for 24h, slowly raise the temperature to 25℃ and add 0.58g of zirconium tetrachloride to continue the reaction, ensuring that the molar ratio of intermediate iii-8 to zirconium tetrachloride is 1:1. Control the reaction temperature at 25℃ and the reaction time at 24h. After the reaction is completed, filter, concentrate, slurry, and dry the reaction solution to obtain the metallocene compound P54.

[0137] P54 NMR data: 1H NMR(500MHz,Chloroform)δ7.50(s,4H),6.58(d,J=23.0Hz,4H),6.00(s,4H),3.5 5(s,4H),1.99(s,12H),1.65-1.85(m,48H),1.59–1.38(m,8H),1.15-1.31(m,4H).

[0138] Example 9

[0139]

[0140] 1) Add 5g of compound i-9 and 5.52ml of n-butyllithium in n-hexane (2.5M) to ultra-dry toluene at a molar ratio of 1:1.2. React at -78℃ for 3h, then add 2.91g of compound ii-9 to continue the reaction, ensuring that the molar ratio of compound i-9 to compound ii-9 is 1:1.1. At the same time, control the reaction temperature at 25℃ and the reaction time at 5h. After the reaction is completed, add ethanol to the reaction solution, stir to obtain a suspension, filter, wash and dry to obtain intermediate iii-9.

[0141] 2) Add 3g of a 2.5M solution of intermediate iii-9 and 3.97ml of n-butyllithium in n-hexane to ultra-dry toluene at a molar ratio of 1:2.2. After reacting at -78℃ for 24h, slowly raise the temperature to 25℃ and add 1.04g of zirconium tetrachloride to continue the reaction, ensuring that the molar ratio of intermediate iii-9 to zirconium tetrachloride is 1:1. Control the reaction temperature at 25℃ and the reaction time at 24h. After the reaction is completed, filter, concentrate, slurry, and dry the reaction solution to obtain the metallocene compound P62.

[0142] P62 NMR data: 1 H NMR(500MHz,Chloroform)δ8.10(s,2H),8.01(s,2H),7.93(s,2H),7.65(s,2H),7.49(s,2H),7.40(s,2H),7.33( t,J=15.0Hz,10H),6.38(s,2H),6.31(s,2H),5.71(s,2H),4.45(s,2H),2.00(s,6H),1.70(s,12H),1.61(s,12H).

[0143] Example 10

[0144]

[0145] 1) Add 5g of compound i-10 and 5.14ml of n-butyllithium in n-hexane solution (2.5M) to ultra-dry toluene at a molar ratio of 1:1.2. React at -78℃ for 3h, then add 2.74g of compound ii-10 to continue the reaction, ensuring that the molar ratio of compound i-10 to compound ii-10 is 1:1.1. At the same time, control the reaction temperature at 25℃ and the reaction time at 5h. After the reaction is completed, add ethanol to the reaction solution, stir to obtain a suspension, filter, wash and dry to obtain intermediate iii-10.

[0146] 2) Add 3g of a 2.5M solution of intermediate iii-10 and 3.78ml of n-butyllithium in n-hexane to ultra-dry toluene at a molar ratio of 1:2.2. After reacting at -78℃ for 24h, slowly raise the temperature to 25℃ and add 0.99g of zirconium tetrachloride to continue the reaction, ensuring that the molar ratio of intermediate iii-10 to zirconium tetrachloride is 1:1. Control the reaction temperature at 25℃ and the reaction time at 24h. After the reaction is completed, filter, concentrate, slurry, and dry the reaction solution to obtain the metallocene compound P97.

[0147] P97 NMR data: 1 H NMR(500MHz,Chloroform)δ8.06(d,J=3.1Hz,1H),7.97(d,J=70.3Hz,2H),7.84(s,1H),7.39-7.29(m,2H),7.24(t,1H),5.95(d,2H) ,5.65(d,2H),2.74(s,2H),2.01-1.97(m,4H),1.71(t,12H),1.62(d,12H),1.55(s,2H),1.43-1.39(m,2H),0.94(d,J=5.0Hz,20H).

[0148] Example 11

[0149] A method for preparing an ethylene / hexene copolymer includes the following steps:

[0150] 1 μmol of the metallocene compound P7 prepared in Example 1, 80 mL of 1-hexene, and MMAO were added to 200 mL of Isopar E solvent at a molar ratio of Al / M = 50. The temperature was raised to 140 °C, and 4 MPa of ethylene gas was introduced. The polymerization reaction was carried out for 5 min. After the reaction was completed, the ethylene was vented, the reaction solution was discharged into ethanol, the precipitate was collected, and the ethylene / hexene copolymer was obtained by drying.

[0151] Example 12

[0152] The ethylene / hexene copolymer was prepared according to the method provided in Example 11, except that the metallocene compound P8 obtained in Example 2 was used instead of the metallocene compound P7.

[0153] Example 13

[0154] The ethylene / hexene copolymer was prepared according to the method provided in Example 11, except that the metallocene compound P9 obtained in Example 3 was used instead of the metallocene compound P7.

[0155] Example 14

[0156] The ethylene / hexene copolymer was prepared according to the method provided in Example 11, except that the metallocene compound P22 obtained in Example 4 was used instead of the metallocene compound P7.

[0157] Example 15

[0158] The ethylene / hexene copolymer was prepared according to the method provided in Example 11, except that the metallocene compound P35 obtained in Example 5 was used instead of the metallocene compound P7.

[0159] Example 16

[0160] The ethylene / hexene copolymer was prepared according to the method provided in Example 11, except that the metallocene compound P40 obtained in Example 6 was used instead of the metallocene compound P7.

[0161] Example 17

[0162] The ethylene / hexene copolymer was prepared according to the method provided in Example 11, except that the metallocene compound P49 obtained in Example 7 was used instead of the metallocene compound P7.

[0163] Example 18

[0164] The ethylene / hexene copolymer was prepared according to the method provided in Example 11, except that the metallocene compound P54 obtained in Example 8 was used instead of the metallocene compound P7.

[0165] Example 19

[0166] The ethylene / hexene copolymer was prepared according to the method provided in Example 11, except that the metallocene compound P62 obtained in Example 9 was used instead of the metallocene compound P7.

[0167] Example 20

[0168] The ethylene / hexene copolymer was prepared according to the method provided in Example 11, except that the metallocene compound P97 obtained in Example 10 was used instead of the metallocene compound P7.

[0169] Example 21

[0170] A method for preparing an ethylene / octene copolymer includes the following steps:

[0171] 1 μmol of the metallocene compound P62 prepared in Example 9, 50 mL of 1-octene, and MMAO were added to 200 mL of Isopar E solvent at a molar ratio of Al / M = 20 and triphenylmethyltetra(pentafluorophenyl)borate at a molar ratio of B / M = 0.5. The temperature was raised to 140 °C, and 4 MPa of ethylene gas was introduced. The polymerization reaction was carried out for 5 min. After the reaction was completed, the ethylene was vented, the reaction solution was discharged into ethanol, the precipitate was collected, and dried to obtain the ethylene / octene copolymer.

[0172] Example 22

[0173] A method for preparing an ethylene / cyclohexene copolymer includes the following steps:

[0174] 1 μmol of metallocene compound P62 prepared in Example 9, 90 mL of cyclohexene, and MAO were added to 200 mL of Isopar E solvent at a molar ratio of Al / M = 40. The temperature was raised to 200 °C, and 4 MPa of ethylene gas was introduced. The polymerization reaction was carried out for 5 min. After the reaction was completed, the ethylene was vented, the reaction solution was discharged into ethanol, the precipitate was collected, and the ethylene / cyclohexene copolymer was obtained by drying.

[0175] Example 23

[0176] A method for preparing an ethylene / phenyl norbornene copolymer includes the following steps:

[0177] 1 μmol of metallocene compound P62 prepared in Example 9, 90 mL of phenylnorbornene, and dichloroethylaluminum were added to 200 mL of Isopar E solvent at a molar ratio of Al / M = 20 and triphenylmethyltetra(pentafluorophenyl)borate at a molar ratio of B / M = 1. The temperature was raised to 90 °C, and 4 MPa of ethylene gas was introduced. The polymerization reaction was carried out for 5 min. After the reaction was completed, the ethylene was vented, the reaction solution was discharged into ethanol, the precipitate was collected, and dried to obtain the ethylene / phenylnorbornene copolymer.

[0178] Example 24

[0179] A method for preparing an ethylene / styrene copolymer includes the following steps:

[0180] 1 μmol of metallocene compound P62 prepared in Example 9, 90 mL of styrene, and triisobutylaluminum were added to 200 mL of Isopar E solvent at a molar ratio of Al / M = 10, and triphenylmethyltetra(pentafluorophenyl)borate was added at a molar ratio of B / M = 2. The temperature was raised to 170 °C, and 4 MPa of ethylene gas was introduced. The polymerization reaction was carried out for 5 min. After the reaction was completed, the ethylene was vented, the reaction solution was discharged into ethanol, the precipitate was collected, and dried to obtain the ethylene / styrene copolymer.

[0181] Comparative Example 1

[0182] The ethylene / hexene copolymer was prepared according to the method provided in Example 19, except that a compound as shown in Formula II-1 was used instead of the metallocene compound P62.

[0183]

[0184] Comparative Example 2

[0185] The ethylene / hexene copolymer was prepared according to the method provided in Example 19, except that the Al / M molar ratio was 1000 and compound II-1 was used instead of metallocene compound P62.

[0186] Comparative Example 3

[0187] The ethylene / octene copolymer was prepared according to the method provided in Example 21, except that compound II-1 was used instead of metallocene compound P62.

[0188] Comparative Example 4

[0189] The ethylene / styrene copolymer was prepared according to the method provided in Example 24, except that compound II-1 was used instead of metallocene compound P62.

[0190] Comparative Example 5

[0191] The ethylene / styrene copolymer was prepared according to the method provided in Example 24, except that the B / M molar ratio was 200 and compound II-1 was used instead of metallocene compound P62.

[0192] Test case

[0193] The amount of cocatalyst used in Examples 11-24 and Comparative Examples 1-5 and the performance of the prepared polyolefins were tested, and the results are shown in Table 1 below.

[0194] Table 1

[0195]

[0196] As shown in Table 1, the polymers prepared in Examples 11-24 exhibited high polymerization activity and comonomer insertion rates, indicating that the metallocene catalyst of this application has good catalytic activity and good copolymerization performance for the polymerization of α-olefins. Compared with Examples 19, 21, and 24, respectively, the polymerization effects of Comparative Examples 1, 3, and 4 were poor, further demonstrating that the introduction of adamantyl groups into the metallocene catalyst can significantly improve the catalytic activity of the metallocene catalyst.

[0197] In order to obtain a catalytic effect that is basically equivalent to that of Example 19, a larger amount of co-catalyst is required when using compound II-1 as the main catalyst in Comparative Example 2. However, even with the addition of a large amount of co-catalyst, Comparative Example 5 still cannot achieve the catalytic effect of Example 24 when using compound II-1 as the main catalyst. This shows that the metallocene catalyst of this application can reduce the amount of co-catalyst, which can not only reduce the production cost of polyolefins, but more importantly, avoid the impact on the quality of polyolefins due to excessive co-catalyst residue, and expand the application scenarios of the product.

[0198] The above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A metallocene compound, comprising a fluorenyl ligand, a cyclopentadiene ligand, a bridging structure, and a metallic moiety in its chemical structure; characterized in that, The metallocene compound has the structure shown in formula (I): Wherein, A1, A2, A3, and A4 are each independently selected from H or adsorption groups, and at least one of A1-A4 is selected from an adsorption group, wherein the adsorption group is a bulky group capable of adsorbing organoboron or organoaluminum. R1, R2, R3, R4, R5, and R6 are each independently selected from H, halogens, substituted or unsubstituted G groups, wherein the G groups include C1-C... 40 Alkyl, C3-C 40 cycloalkyl, C2-C 40 Heterocyclic alkyl, C6-C 60 aryl, C4-C 60 heteroaryl, C7-C 60 Aryl groups, C6-C 60 Any one of the heteroaryl alkyl groups; L is selected from C, Si, Ge, or Sn; M is selected from Ti, Zr, or Hf; X is selected from halogens, substituted or unsubstituted Y groups, wherein the Y group comprises C1-C 30 Alkyl, C3-C 30 cycloalkyl, C2-C 30 Heterocyclic alkyl, C2-C 20 Unsaturated hydrocarbon groups, C6-C 30 aryl, C4-C 30 heteroaryl, C5-C 30 Aryl groups, C5-C 30 Any one of the heteroaryl alkyl groups; The halogen is at least one of F, Cl, Br, and I; The adsorption group is selected from adamantyl or a derivative of adamantyl, wherein the adamantyl derivative includes a Q group and at least one adamantyl group, wherein the Q group shares a carbon atom with the adamantyl group or the Q group is covalently linked to the adamantyl group; the Q group is selected from heteroatoms, T groups, halogen-substituted T groups, or T groups containing heteroatoms, wherein the T group includes C1-C... 20 Alkyl, C2-C 20 cycloalkyl, C4-C 30 aryl, C5-C 30 At least one of the aryl alkyl groups, wherein the heteroatom is selected from at least one of O, N, P, S, Si, and Ge.

2. The metallocene compound according to claim 1, characterized in that, The G group includes C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C2-C6 heterocycloalkyl, C6-C 15 aryl, C4-C 15 heteroaryl, C7-C 15 Aryl groups, C6-C 15 Any one of the heteroaryl alkyl groups; And / or, the substituents in the substituted G group are selected from any one of halogens, C1-C5 alkyl groups, C1-C5 alkoxy groups, and C1-C5 haloalkyl groups; And / or, the Y group includes C1-C5 alkyl groups, C3-C5 alkyl groups, and C5-C6 alkyl groups. 10 Cycloalkyl, C2-C6 heterocycloalkyl, C2-C 10 Unsaturated hydrocarbon groups, C6-C 15 aryl, C4-C 15 heteroaryl, C7-C 15 Aryl groups, C6-C 15 Any one of the heteroaryl alkyl groups; And / or, the substituents in the substituted Y group are selected from any one of halogens, C1-C5 alkyl groups, C1-C5 alkoxy groups, and C1-C5 haloalkyl groups.

3. The metallocene compound according to claim 2, characterized in that, The adamantyl derivative is linked to a fluorenyl group via an adamantyl or Q group, and the adamantyl derivative is selected from any one of C1-C5 alkyl-substituted adamantyl, C2-C5 heterocyclic alkyl-substituted adamantyl, a spirocyclic group formed by C2-C5 heterocyclic alkyl and adamantyl, an amino group substituted by adamantyl, an alkyl group substituted by adamantyl, and a phosphin group substituted by adamantyl. And / or, the substituted or unsubstituted G group includes any one of methyl, ethyl, propyl, tert-butyl, cyclohexyl, phenyl, methylphenyl, methoxyphenyl, fluorophenyl, trifluoromethylphenyl, tert-butylphenyl, and biphenyl; And / or, the substituted or unsubstituted Y group includes any one of methyl or benzyl.

4. The metallocene compound according to any one of claims 1-3, characterized in that, The fluorene ligand is selected from any of the following structures: And / or, the locene ligand is selected from any of the following structures: And / or, the bridging structure is selected from any of the following structures: 。 5. The metallocene compound according to claim 4, characterized in that, The metallocene compound is selected from any of the following structures: 。 6. The method for preparing the metallocene compound according to any one of claims 1-5, characterized in that, Includes the following steps: 1) Compound i is reacted with the first dehydrogenating agent in the first organic solvent at a reaction temperature of T1 and a reaction time of t1; then compound ii is added and the reaction continues at a reaction temperature of T2 and a reaction time of t2 to obtain compound iii; 2) In the second organic solvent, compound iii is allowed to react fully with the second dehydrogenating agent at a reaction temperature of T3 and a reaction time of t3; then, metal M salt or metal M organic compound is added to continue the reaction at a reaction temperature of T4 and a reaction time of t4 to obtain the metallocene compound shown in Formula I.

7. The method for preparing the metallocene compound according to claim 6, characterized in that, The first organic solvent and the second organic solvent are each independently selected from at least one of toluene, xylene, pentane, cyclopentane, n-hexane, cyclohexane, n-heptane, methylcyclohexane, octane, isooctane, and tetrahydrofuran; And / or, the first dehydrogenating agent and the second dehydrogenating agent are each independently selected from at least one of alkyl lithium, phenyl lithium, sodium hydride, potassium hydride, lithium hydride, tetramethylethylenediamine, bis(trimethylsilylamino)lithium, bis(trimethylsilylamino)sodium, diisopropylaminolithium, and potassium carbonate; And / or, the molar ratio of compound i to the first dehydrogenating agent is 1:1.0-1.5; And / or, the molar ratio of compound i to compound ii is 1:1.0-1.5; And / or, T1 is -78°C to 100°C, and t1 is 0.5h to 36h; And / or, the T2 is -78°C to 50°C, and the t2 is 0.5h to 36h; And / or, the molar ratio of compound iii to the second dehydrogenating agent is 1:2.0-3.0; And / or, the molar ratio of compound iii to the metal M salt or metal M organocompound is 1:1.0-1.5; And / or, the T3 is -78°C to 100°C, and the t3 is 0.5h to 36h; And / or, the T4 is -78°C to 50°C, and the t4 is 0.5h to 36h.

8. A metallocene catalyst, comprising a main catalyst and a co-catalyst, wherein the co-catalyst comprises organoaluminum and / or organoboron; characterized in that, The main catalyst is a metallocene compound as described in any one of claims 1-5 or a metallocene compound prepared by the preparation method described in claim 6 or 7.

9. The metallocene catalyst according to claim 8, characterized in that, The molar ratio of Al in the organoaluminum compound to M in the metallocene compound is 2-600.

10. The metallocene catalyst according to claim 9, characterized in that, The molar ratio of Al in the organoaluminum compound to M in the metallocene compound is 10-100.

11. The metallocene catalyst according to claim 8, characterized in that, The molar ratio of element B in the organoboron to element M in the metallocene compound is 0-80.

12. The metallocene catalyst according to claim 11, characterized in that, The molar ratio of element B in the organoboron to element M in the metallocene compound is 0-20.

13. The metallocene catalyst according to any one of claims 8-10, characterized in that, The organoaluminum is selected from at least one of aluminum oxanes, alkylaluminum, and alkylaluminum chlorides; the aluminum oxane includes at least one of methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, n-propylaluminoxane, isopropylaluminoxane, n-butylaluminoxane, isobutylaluminoxane, neopentylaluminoxane, n-hexylaluminoxane, and n-octylaluminoxane; the alkylaluminum includes at least one of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, triisohexylaluminum, tri-n-octylaluminum, and triisooctylaluminum; the alkylaluminum chloride includes at least one of dichloromethylaluminum, dichloroethylaluminum, dichlorodimethylaluminum, dichlorodi-n-butylaluminum, dichlorodiisobutylaluminum, dichlorodi-n-butylaluminum, dichloroisobutylaluminum, sesqui-n-butylaluminum chloride, sesquiethylaluminum chloride, sesquimethylaluminum chloride, and sesquiisobutylaluminum chloride.

14. The metallocene catalyst according to claim 8, 11, or 12, characterized in that, The organoboron is selected from at least one of tris(pentafluorophenyl)boron, triphenylmethyltetra(pentafluorophenyl)borate, triphenylmethyltetra(pentafluorophenyl)borate, triphenylmethyltetra(pentafluorophenyl)borate, tetra(pentafluorophenyl)borate-methyl di-(octadecyl)ammonium, N,N-bisoctadecylmethylaminotetra(pentafluorophenyl)borate, N,N-dimethylphenylammonium tetra(pentafluorophenyl)borate, bisoctadecylmethyltert-ammonium tetra(pentafluorophenyl)borate, and dihydrogenated tallow methyltert-ammonium tetra(pentafluorophenyl)borate.

15. The use of the metallocene catalyst according to any one of claims 8-14 in the production of polyolefins.

16. A method for preparing an ethylene / α-olefin copolymer, characterized in that, Includes the following steps: In the presence of the metallocene catalyst according to any one of claims 8-14, ethylene and α-olefins are polymerized in an organic solvent to prepare an ethylene / α-olefin copolymer.

17. The method for preparing the ethylene / α-olefin copolymer according to claim 16, characterized in that, The polymerization reaction temperature is 40℃-260℃.

18. The method for preparing the ethylene / α-olefin copolymer according to claim 17, characterized in that, The polymerization reaction temperature is 80℃-230℃.

19. The method for preparing the ethylene / α-olefin copolymer according to claim 16, characterized in that, The gauge pressure for the polymerization reaction is 0.1 MPa-60 MPa.

20. The method for preparing the ethylene / α-olefin copolymer according to claim 19, characterized in that, The gauge pressure for the polymerization reaction is 1 MPa-10 MPa.

21. The method for preparing the ethylene / α-olefin copolymer according to claim 16, characterized in that, The amount of the metallocene catalyst added, based on the molar concentration of element M in the organic solvent, is 0.01 μmol / L to 7 μmol / L.

22. The method for preparing the ethylene / α-olefin copolymer according to any one of claims 16-21, characterized in that, The α-olefin is selected from at least one of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, cyclopentene, cyclohexene, norbornene, phenylnorbornene, and styrene.

23. The method for preparing the ethylene / α-olefin copolymer according to any one of claims 16-21, characterized in that, The organic solvent is selected from at least one of aromatic and alkane organic solvents.

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