A bimetallic center heterogeneous catalyst composition, and methods of making and using the same

Abstract

The application provides a bimetallic center heterogeneous catalyst composition, which comprises a main catalyst, a cocatalyst, a titanium compound and a magnesium compound; wherein the titanium compound has a general formula of Ti(X N (OR a ) 4‑N , R a is a C1-C 20 linear or branched hydrocarbon group, X" is halogen, and N=1-4; the magnesium compound is a precursor selected from alcoholates of magnesium dihalides; the cocatalyst is a Lewis acid; and the main catalyst is a metallocene complex having a structure shown in formula I. The metallocene complex with a specific structure is loaded on a magnesium alcohol carrier containing Ti active centers, so that two metal active centers can be simultaneously provided in a single kettle, and the application has high activity, less fine powder, high regular particle packing density, and a wider polypropylene molecular weight distribution compared with a silica gel loaded metallocene catalyst.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of polyolefin catalyst technology, in particular to a metallocene heterogeneous catalyst composition, a preparation method thereof and its application in ethylene-propylene copolymerization. BACKGROUND

[0002] In the field of metallocene complex catalysts, in addition to the classic bridged substituted cyclopentadiene (substituted-Cyclopentadienyl, Cp'), bridged substituted indene (substituted-Indenyl, Ind'), bridged substituted fluorenyl (substituted fluorenyl, Flu'), and the huge number of metallocene complexes formed by mutual combination between Cp' / Ind' / Flu' (Metallocenes: Synthesis, Reactivity, Applications, A. Togni and R. L. Halterman Eds, Wiley, 1998), in recent years, a certain number of metallocene complexes have introduced, for example, nitrogen, phosphorus, oxygen, sulfur, and other heteroatoms in the cyclopentadienyl ring (Cp) or in the saturated or unsaturated ring adjacent to the Cp ring. The metallocene complex containing heteroatom ring or having special activity for olefin polymerization or special regioselectivity or stereoselectivity (C. De Rosa, F. Auriema, A. Di Capua, L. Resconi, S. Guidotti, I. Camurati, I. E. Nifant'ev, I. P. Laishevets, J. Am. Chem. Soc. 2004, 12, 17040).

[0003] For example, Canadian Patent Document CA 2204803 describes phosphorus heteroatom containing metallocene complexes and their excellent activity and molecular weight distribution in the catalysis of ethylene polymerization, as well as superior high temperature catalytic activity. Group IV element metallocene complex catalyst systems related thereto can catalyze the polymerization of ethylene at high temperatures to produce high molecular weight polyethylene. WO 9822486 and EP 9706297 describe a class of metallocene complexes containing oxygen and / or sulfur and / or nitrogen in a five-membered side ring adjacent to Cp, which when combined with methylaluminoxane (MAO) have very high activity in the polymerization of propylene. WO 0144318 describes metallocene complexes containing sulfur π-ligands and their process for the catalytic copolymerization of ethylene / propylene, but the resulting ethylene / propylene copolymers have a low molecular weight and are not of practical use. WO 03045964 describes a process for the preparation of a class of dimethylsilicon-bridged substituted thia-pentalene and substituted indene zirconocene metallocene complexes and their process for the catalytic copolymerization of ethylene / propylene. Using the process described in WO 03045964, the zirconocene metallocene complexes have very high activity in the polymerization and the resulting ethylene / propylene copolymers have a high molecular weight and the ethylene content of the copolymers is between 4 and 13 percent by weight, and the material properties are intermediate between RCP and TPE. US 6683150 discloses a class of bridged indenoindole derivatives as ligands for Group IV transition metallocene complex catalysts that catalyze the polymerization of propylene over a wide temperature range to produce high molecular weight polypropylene. WO 03089485 provides a class of nitrogen-containing π-ligand Group IV transition metallocene complexes in combination with methylaluminoxane (MAO) to form a catalytic system characterized by the use of very low aluminum / metal ratios and high activity, and when combined with a suitable support, can produce high molecular weight linear low density polyethylene (mLLDPE). WO 9924446 describes a class of nitrogen heteroatom-containing π-ligands in combination with Group IV transition metals to form metallocene complexes. These metallocene complexes are not only simple to synthesize and have high yields, but when activated with methylaluminoxane (MAO) or modified methylaluminoxane (MMAO) are excellent olefin polymerization catalysts that can produce high molecular weight polyethylene and polypropylene, respectively.

[0004] In polymerization production application, metallocene catalysts as homogeneous catalysts, the polymer product morphology produced is poor, and the polymerization kettle and device are prone to be blocked during polymerization and product conveying, which is poor in adaptability to industrial device, causing difficulty in industrial use, so it is needed to be loaded on solid catalyst for application. Silica gel is a widely used carrier because it has high specific surface area, good fluidity, suitable bulk density, suitable average particle size and particle size distribution, and suitable mechanical strength. However, its disadvantage is that the activity is not ideal because in the loading process, the metal catalyst ligand can react with the hydroxyl group on the carrier, causing the ligand to fall off, resulting in part of the catalyst losing activity, and the catalyst can also react with other parts of the carrier. In addition, the existing metallocene catalysts described above are single active center catalysts, which can generate narrow molecular weight distribution high molecular weight polypropylene through propylene homopolymerization, but it is difficult to produce polypropylene with a wide molecular weight distribution in a single kettle. Only using a silica gel carrier only provides a loading effect and cannot introduce additional active centers, so it is a technical problem to be solved at present to improve the polymer product morphology and the polymerization activity while realizing single-kettle production of polypropylene with a wide molecular weight distribution. SUMMARY

[0005] The purpose of the present application is to solve the problem in the prior art that metallocene catalysts cannot realize single-kettle production of polypropylene with a wide molecular weight distribution while improving the polymer product morphology and the polymerization activity, thereby providing a bimetallic center heterogeneous catalyst composition and a preparation method and application thereof.

[0006] To achieve the above purpose, the present application provides a bimetallic center heterogeneous catalyst composition, comprising a main catalyst, a cocatalyst, a titanium compound and a magnesium compound; wherein the general formula of the titanium compound is Ti(X") N (OR a ) 4-N , R a is a C1-C 20 linear or branched hydrocarbon group, X" is halogen (F, Cl, Br or I), N = 1-4; the precursor of the magnesium compound is selected from alcoholates of magnesium dihalides, preferably MgCl2·mR b OH, m is 0.1-6, R b is a C1-C 20 linear or branched hydrocarbon group; the cocatalyst is a Lewis acid; the main catalyst is a metallocene complex, and the metallocene complex has the structure shown in Formula I,

[0007]

[0008] wherein M is a transition metal selected from any one of the elements in Group IIIB, Group IVB, Group VB and Group VIB of the periodic table of elements;

[0009] n is 1, 2, 3 or 4, each X is the same or different and is independently selected from the group consisting of hydrogen, a halogen radical, an unsubstituted or Rm-substituted C1-C 20 an unsubstituted or Rm-substituted C3-C 20 cycloalkyl radical, an unsubstituted or Rm-substituted C6-C 30 aryl radical, a C1-C 20 straight-chain or branched alkoxy radical, a C1-C 20 straight-chain or branched mercapto radical, a C1-C 20 straight-chain or branched carboxyl radical, a C2-C 20 straight-chain or branched imino radical, a C2-C 20 straight-chain or branched phosphino radical, -OR°O- or -OSO2CF3, R° is a divalent radical selected from the group consisting of C2-C 40 unsubstituted or Rm-substituted C6-C 30 arylene radical (in the -OR°O- structure, the two oxygen atoms can each be in any position of the radical, but preferably the positions of the two oxygen atoms are in the combination of adjacent (α, β-position) and interjacent (α, γ-position) positions of the radical); the product of n and the charge number of X is equal to the charge number of the central metal atom M minus two;

[0010] Q is a divalent radical selected from the group consisting of =C(R')2, =Si(R')2, =Ge(R')2, =NR', =PR' and =BR', wherein each R' is independently selected from the group consisting of an unsubstituted or Rm-substituted C1-C 20 straight-chain or branched alkyl radical, a C3-C 20

[0011] cycloalkyl radical, an unsubstituted or Rm-substituted C6-C 30 aryl radical, a benzyl radical and a trimethylsilyl radical;

[0012] A is a π-ligand having the structure shown in Formula II:

[0013]

[0014] E is a divalent radical of an element of Group 15 or 16 of the Periodic Table of the Elements selected from the group consisting of an oxygen radical, a sulfur radical, a selenium radical, =NR" and =PR", wherein R" is selected from the group consisting of an unsubstituted or Rm-substituted C1-C 20 straight-chain or branched alkyl radical, an unsubstituted or Rm-substituted C6-C 30 aryl radical and a benzyl radical;

[0015] ​L is a divalent radical selected from any one of the structures shown in Formula III, Formula IV, Formula V, Formula VI, Formula VII, and Formula VIII, wherein i is 2:

[0016]

[0017] Z is a π-ligand, Z is the same as A, or is selected from any one of the structures shown in Formula IX, Formula X, Formula XI, Formula XII, and Formula XIII;

[0018]

[0019] wherein R 1 and each R 12 is independently selected from any one of hydrogen, C4-C6heteroaryl, C1-C 20 straight or branched chain alkyl, C3-C 20 cycloalkyl, C6-C 30 aryl, unsubstituted or Rm-substituted;

[0020] R 2 , R 3 , each R 6 , each R 7 , and each R 13 is independently selected from any one of hydrogen, halogen, C1-C 20 straight or branched chain alkyl, C3-C 20 cycloalkyl, C6-C 30 aryl, unsubstituted or Rm-substituted;

[0021] R 4 is selected from any one of hydrogen, C1-C 20 straight or branched chain alkyl, trifluoromethyl, phenyl, p-t-butylphenyl, p-trimethylsilylphenyl, p-trifluoromethylphenyl, 3,5-dichloro-4-trimethylsilylphenyl, or 2-naphthyl;

[0022] each R 5 is independently selected from any one of hydrogen, fluorine, or methyl;

[0023] each R 8 is independently selected from any one of C1-C 20 straight or branched chain alkyl, phenyl, unsubstituted or Rm-substituted;

[0024] R 9 and R 9’ are independently selected from any one of hydrogen, C6-C 15 aryl, C3-C 10heteroaryl; said Rn is selected from at least one of cyano, nitro, halogen, methyl, ethyl, isopropyl, methoxy, tert-butyl, trifluoromethoxy, trifluoromethyl and trimethylsilyl;

[0025] each R 10 and R 10’ are each independently selected from hydrogen, halogen, unsubstituted or Rm-substituted C1-C 20 linear or branched alkyl or unsubstituted or Rm-substituted C6-C 30 aryl;

[0026] each R 11 and R 11’ are each independently selected from hydrogen, halogen, ester, alkoxy, thiol, amine or phosphine;

[0027] Rm in the above is selected from at least one of halogen group, elements of the thirteenth to seventeenth groups of the periodic table, C1-C 10 linear or branched alkyl, C6-C 10 aryl.

[0028] The symbol * in each of the above structural formulae, whether attached to a chemical bond, atom or free radical, indicates that this point can form a chemical single bond with a like chemical bond, atom, free radical; and all symbols * hereinafter have the same meaning.

[0029] In the above, examples of unsubstituted or Rm-substituted C1-C 20 linear or branched alkyl are, for example, methyl, trifluoromethyl, ethyl, 1,1,1-trifluoroethyl, perfluoroethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, n-heptyl, n-octyl, n-dodecyl, n-octadecyl, trimethylsilyl, triethylsilyl, triphenylsilyl, vinyl, propenyl, allyl, etc., but are not limited thereto. Examples of C3-C 20 cycloalkyl are, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, 1-adamantyl, etc., but are not limited thereto. Examples of unsubstituted or Rm-substituted C6-C 30Examples of aryl groups include: phenyl, 1-naphthyl, 2-naphthyl, 1-anthrayl, 2-anthrayl, 9-anthrayl, 1-phenanthyl, 2-phenanthyl, 3-phenanthyl, 4-phenanthyl, 9-phenanthyl, 2-methylphenyl, 2,6-dimethylphenyl, 2-fluoro-3-methylphenyl, 2-fluoro-4-methylphenyl, 2,6-difluoro-3-methylphenyl, 2,6-difluoro-4-methylphenyl, 2-chloro-3-methylphenyl, 2-chloro-4-methylphenyl 2,6-Dichloro-3-methylphenyl, 2,6-Dichloro-4-methylphenyl, 2-ethylphenyl, 2,6-Diethylphenyl, 2-isopropylphenyl, 2,6-diisopropylphenyl, 3-methylphenyl, 3,5-dimethylphenyl, 3-fluoro-4-methylphenyl, 3,5-difluoro-4-methylphenyl, 3,5-difluoro-4-ethylphenyl, 3,5-difluoro-4-isopropylphenyl, 3,5-difluoro-4-tert-butyl Phenyl, 3,5-difluoro-4-trimethylsilylphenyl, 3-trifluoromethylphenyl, 3,5-bistrifluoromethylphenyl, 4-methylphenyl, 4-trifluoromethylphenyl, 4-ethylphenyl, 4-isopropylphenyl, 4-tert-butylphenyl, 4-trimethylsilylphenyl, benzyl, p-methylbenzyl, p-fluorobenzyl, p-chlorobenzyl, p-ethylbenzyl, p-isopropylbenzyl, p-tert-butylbenzyl, etc., p-trifluoromethylbenzyl, p-trimethylsilylbenzyl, 3, 5-Difluorobenzyl, 3,4,5-trifluorobenzyl, 3,5-bistrimethylbenzyl, 3,5-bistrifluoromethylbenzyl, phenethyl, p-methylphenethyl, p-fluorophenethyl, p-chlorophenethyl, p-isopropylphenethyl, p-tert-butylphenethyl, p-trimethylsilylphenethyl, 2,6-difluorophenethyl, 3,5-difluorophenethyl, 3,4,5-trifluorophenethyl, perfluorophenethyl, 1-naphthylmethyl, di-naphthylmethyl, etc., but not limited to these.

[0030] Optionally, in Formula I, the monovalent anion π-ligand of A is formed by the π-ligand shown in Formula II and the nucleophile LR. n It is prepared by an exchange reaction, and the reaction formula is as follows:

[0031]

[0032] Among them, R n It is a C1-C6 straight-chain alkyl or C6-C 12 aryl, the nucleophile LR n LiR is an organolithium reagent n .

[0033] Optionally, E is selected from any one of oxygen free radicals, sulfur free radicals, and NR″, and R″ is selected from any one of 1-naphthyl, 2-naphthyl, 2-anthrayl, 1-phenanthyl, 2-phenanthyl, and 5-phenanthyl; preferably, E is selected from any one of oxygen free radicals, sulfur free radicals, and NPh.

[0034] R1 selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl, benzyl, 2-furyl, or 2- thienyl; R 2 , R 3 are each independently selected from hydrogen or fluorine; R 4 selected from hydrogen, methyl, isopropyl, or tert-butyl; preferably, R 1 , R 2 , R 3 and R 4 are each selected from hydrogen.

[0035] Optionally, each X is independently selected from any one of H, a halogen group, a C1-C5 straight chain alkyl group, a C1-C5 straight chain alkoxy group, and a C1-C5 straight chain carboxyl group; preferably, in formula I, each X is independently selected from any one of H, CI, methyl, methoxy, and EtCOO-;

[0036] M is selected from any one of zirconium, titanium, yttrium, hafnium, vanadium, and chromium;

[0037] Q is selected from any one of =C(R')2, =Si(R')2, =Ge(R')2, =NR', =PR', and =BR', each R' is independently selected from any one of methyl, ethyl, isopropyl, benzyl, and phenyl; preferably, Q is selected from any one of =C(Me)2, =Si(Me)2, =NPh, and =PPh.

[0038] Optionally, each R 5 and R 7 are each selected from hydrogen;

[0039] each R 8 is independently selected from a C1-C5 straight chain or branched alkyl group, preferably, each R 8 is selected from methyl, ethyl, isopropyl, tert-butyl, n-butyl, or n-butyl;

[0040] each R 9 and R 9’ is independently selected from hydrogen, phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, furyl, thienyl, quinolyl, imidazolyl, pyrimidinyl, or a phenyl group substituted with Rn, Rn is selected from at least one of cyano, nitro, halogen, methyl, ethyl, isopropyl, tert-butyl, methoxy, tert-butyl, trifluoromethoxy, trifluoromethyl, and trimethylsilyl; each R 10 and R 10’ is independently selected from hydrogen, fluorine, chlorine, methyl, ethyl, or phenyl; each R 11 and R 11’ is independently selected from hydrogen, fluorine, or chlorine; each R 12are each independently selected from hydrogen, methyl, ethyl, isopropyl or benzyl; each R 13 are each independently selected from hydrogen, fluorine or chlorine; preferably, R 9 is selected from furanyl, imidazolyl, phenyl or Rn-substituted phenyl, Rn being selected from at least one of cyano, nitro, F, Cl, tert-butyl, methoxy, trifluoromethoxy and trifluoromethyl; R 9’ , R 10 , R 10’ , R 11 , R 11’ and R 13 are each selected from H;

[0041] each R 12 is independently selected from hydrogen, methyl or ethyl.

[0042] Optionally, the titanium compound is TiCl4;

[0043] The alcoholate of the magnesium dihalide is MgCl2.mR b OH, m being from 0.1 to 6, R b being a C1-C 20 linear or branched hydrocarbon radical;

[0044] The Lewis acid is selected from poly-methylaluminoxane, modified poly-methylaluminoxane or organoboron reagents having simultaneously in solution equilibrium states of chain, cyclic and clathrate structures.

[0045] In particular, the Lewis acid is a class of Lewis acidic species which are volumetrically swollen, electronically delocalized and coordinatively poor. Representative of this class of species are poly-methylaluminoxane (PMAO) and modified poly-methylaluminoxane (MMAO) having simultaneously in solution equilibrium states of chain, cyclic and clathrate structures.

[0046]

[0047] There are a number of examples of anionic species which are volumetrically swollen, electronically delocalized and coordinatively poor, such as; [B(C6H5)4] - , [(CH3)B(C6F5)3] - , [B(C6F5)4] - , [B(2,6-(CH3)2-C6H3)4] - , [B(2,4,6-(CH3)3-C6H2)4] - , [B(2,3,5,6-(CH3)4-C6H)4] - , [B(2,6-(CF3)2-C6H3)4] - , [B(2,4,6-(CF3)3-C6H2)4] -[B(2,3,5,6-(CF3)4-C6H)4] - [B(3,5-(CH3)2-C6H3)4] - [B(3,4,5-(CH3)3-C6H2)4] - [B(3,5-(CF3)2-C6H3)4] - [B(3,4,5-(CF3)3-C6H2)4] - [B(2,6-(CF3)2-C6F3)4] - [B(2,4,6-(CF3)3-C6F2)4] - [B(2,3,5,6-(CF3)4-C6F)4] - [B(3,5-(CF3)2-C6F3)4] - [B(3,4,5-(CF3)3-C6F2)4] - [Al(C6H5)4] - [(CH3)Al(C6F5)3] - [Al(C6F5)4] - [Al(2,6-(CH3)2-C6H3)4] - [Al(2,4,6-(CH3)3-C6H2)4] - [Al(2,3,5,6-(CH3)4-C6H)4] - [Al(3,5-(CH3)2-C6H3)4] - [Al(3,4,5-(CH3)3-C6H2)4] - [Al(2,6-(CH3)2-C6F3)4] - [Al(2,4,6-(CH3)3-C6F2)4] - [Al(2,3,5,6-(CH3)4-C6F)4] - [Al(3,5-(CH3)2-C6F3)4] - [Al(3,4,5-(CH3)3-C6F2)4] - [Al(2,6-(CF3)2-C6H3)4] - [Al(2,4,6-(CF3)3-C6H2)4] - [Al(2,3,5,6-(CF3)4-C6H)4] - [Al(3,5-(CF3)2-C6H3)4] - [Al(3,4,5-(CF3)3-C6H2)4]- [Al(2,6-(CF3)2-C6F3)4] - [Al(2,4,6-(CF3)3-C6F2)4] - [Al(2,3,5,6-(CF3)4-C6F)4] - [Al(3,5-(CF3)2-C6F3)4] - [Al(3,4,5-(CF3)3-C6F2)4] - {t-Bu-CH=C[B(C6F5)2]2(CH3)} - {Ph-CH=C[B(C6F5)2]2(CH3)} - {(C6F5)-CH=C[B(C6F5)2]2(CH3)} - {t-Bu-CH=C[Al(C6F5)2]2(CH3)} - {Ph-CH=C[Al(C6F5)2]2(CH3)} - {(C6F5)-CH=C[Al(C6F5)2]2(CH3)} - [1,1’-C 12 F8-2,2’=B(C6F5)2] - [1,1’-C 12 F8-2,2’=Al(C6F5)2] - [FB(1-C6F4-2-C6F5)3] - [(CH3)B(1-C6F4-2-C6F5)3] - [(C6F5)B(1-C6F4-2-C6F5)3] - [(C6F5)Al(1-C6F4-2-C6F5)3] - [FAl(1-C6F4-2-C6F5)3]-,[(CH3)Al(1-C6F4-2-C6F5)3]-,] - [HB(1-C6F4-2-C6F5)3] - [HAl(1-C6F4-2-C6F5)3] - [(CH3)B(2-C 10 F7)3] - [(CH3)Al(2-C 10 F7)3] - [(CH3)B(p-C6F4SiMe3)3] - [B(p-C6F4SiMe3)4] -[(CH3)B(p-C6F4Si(n-Bu)3)3] - [B(p-C6F4Si(n-Bu)3)4] - [(CH3)B(p-C6F4Si(i-Bu)3)3] - [B(p-C6F4Si(i-Bu)3)4] - [(CH3)B(p-C6F4Si(t-Bu)3)3] - [B(p-C6F4Si(t-Bu)3)4] - [(C6F5)3B-C6F4-B(C6F5)2] - [C6F4-1,2-(B(C6F5)3)2] - [C6F4-1,2-(Al(C6F5)3)2] - [(C6F4)-1,2-(B(C6F5)2)2-1’,2’-(C6F4)] - [(C6F4)-1,2-(Al(C6F5)2)2-1’,2’-(C6F4)] - [(C6F5)3B-CN-B(C6F5)3] - [(C6F5)3Al-CN-Al(C6F5)3] - [((C6F5)3BNC)4Ni] - [((C6F5)3AlNC)4Ni] - [(1,1’-C 12 F8)2-2,2’-B] - [(1,1’-C 12 F8)2-2,2’-Al] - [B(O-C6F5)4] - [Al(O-C6F5)4] - [(C6F5)3Al-C6F4-Al(C6F5)2] - [(CH3)Al(p-C6F4SiMe3)3] - [Al(p-C6F4SiMe3)4] - [(CH3)Al(p-C6F4Si(n-Bu)3)3] - [Al(p-C6F4Si(n-Bu)3)4] - [(CH3)Al(p-C6F4Si(i-Bu)3)3] - [Al(p-C6F4Si(i-Bu)3)4] -,[(CH3)Al(p-C6F4Si(t-Bu)3)3] - [Al(p-C6F4Si(t-Bu)3)4] - [C5(C6H5)5] - [C5(2,6-(CH3)2-C6H3)5] - [C5(2,4,6-(CH3)3-C6H2)5] - [C5(3,5-(CH3)2-C6H3)5] - [C5(3,4,5-(CH3)3-C6H2)5] - [C5(2,6-(CF3)2-C6H3)5] - [C5(2,4,6-(CF3)3-C6H2)5] - [C5(3,5-(CF3)2-C6H3)5] - [C5(3,4,5-(CF3)3-C6H2)5] - [C5(2,6-(CH3)2-C6F3)5] - [C5(2,4,6-(CH3)3-C6F2)5] - [C5(3,5-(CH3)2-C6F3)5] - [C5(3,4,5-(CH3)3-C6F2)5] - [C5(2,6-(CF3)2-C6F3)5] - ,[C5(2,4,6-(CF3)3-C6F2)5] - ,[C5(3,5-(CF3)2-C6F3)5] - ,[C5(3,4,5-(CF3)3-C6F2)5] - [C5(C6F5)5] - ,[Li(Ta(OC6F5)4(2-OC6F5)2)2] - [Nb(OC6F5)6] - [PF6] - [AsF6] - [SbF6] - [BF4] - [ClO4] - Carborea anions, such as: [C₂B₉H₂] 12 ] - ,[CB 11 H 12 ] - However, it is not limited to this.

[0048] The present application also provides a preparation method of the above-mentioned bimetallic center heterogeneous catalyst composition, comprising the following steps:

[0049] (1) reacting a titanium compound with a magnesium compound precursor at 80-135°C, and after the reaction, separating to obtain a magnesium-titanium adduct;

[0050] (2) mixing the magnesium-titanium adduct with a main catalyst and a cocatalyst to obtain the bimetallic center heterogeneous catalyst composition.

[0051] Optionally, the preparation method further comprises the step of mixing an organoaluminum compound with the magnesium-titanium adduct, the main catalyst and the cocatalyst, preferably, the organoaluminum compound is mixed with the magnesium-titanium adduct, and then sequentially mixed with the cocatalyst and the main catalyst.

[0052] Optionally, the preparation method further comprises the step of mixing a siloxane compound with the magnesium-titanium adduct, the main catalyst and the cocatalyst; preferably, the siloxane compound is mixed with the magnesium-titanium adduct, and then sequentially mixed with the cocatalyst and the main catalyst.

[0053] Optionally, the preparation method further comprises the step of mixing a siloxane compound, an organoaluminum compound with the magnesium-titanium adduct, the main catalyst and the cocatalyst; preferably, the organoaluminum compound and the siloxane compound are mixed with the magnesium-titanium adduct, and then sequentially mixed with the cocatalyst and the main catalyst.

[0054] The content of each component in the bimetallic center heterogeneous catalyst composition provided by the present application can be adjusted according to actual needs, for example, the molar ratio of Ti in the titanium compound to M in the metallocene complex is set to 10-100; the molar ratio of Mg in the magnesium compound to M in the metallocene complex (I) is set to 100-1000; and the molar ratio of Lewis acid to M in the metallocene complex is set to ≥300.

[0055] Optionally, specifically, in step (1), alcohol R b OH and magnesium dihalide are mixed in an inert organic solvent (preferably an inert hydrocarbon such as hexane which is not miscible with the magnesium-titanium adduct), the obtained emulsion is rapidly quenched, and the magnesium-titanium adduct is solidified in the form of spherical particles, and the solidified adduct can be directly reacted with the titanium compound at 80-135°C;

[0056] or, alcohol R bThe emulsion obtained by mixing OH and magnesium dihalide in an inert organic solvent is subjected to a preliminary dealcoholation under thermal control (80-130°C) to obtain a precursor of the magnesium compound having a molar number of alcohol generally lower than 3 (preferably between 0.1 and 2.5) which is suspended in a cold titanium compound (generally -25-0°C) and then heated to 80-130°C to react with the titanium compound;

[0057] After the reaction (generally for 0.5-2h), the product is filtered, washed with liquid titanium compound and inert organic solvent, and dried to obtain the magnesium-titanium adduct.

[0058] Alternatively, the process for preparing the metallocene complex comprises the steps of:

[0059]

[0060] The compound of formula XIV is reacted with a compound of formula XV to obtain the compound of formula I;

[0061] wherein T is selected from monodentate or bidentate ligands, each T being the same or different;

[0062] LG is a leaving group, each LG being the same or different, said LG being selected from hydrogen, alkali elements or organic radicals of the heavier elements of Group XIV;

[0063] x is 0, 1, 2 or 3.

[0064] Alternatively, the monodentate ligand comprises ethers ROR, thioethers RSR, tertiary amines N(R)3, tertiary phosphines P(R)3, cyclic ethers, cyclic thioethers, ketones, Rm-substituted cyclic ketones, Rm-substituted pyridines, Rm-substituted pyrroles, Rm-substituted piperidines, esters, lactones, amides and lactams, wherein R is selected from linear or branched hydrocarbon radicals of 1 to 20 carbon atoms, alkyl radicals containing heteroatoms of the elements of Groups 13 to 17 of the Periodic Table of the Elements, cycloalkyl radicals of 3 to 20 carbon atoms, unsubstituted or Rm-substituted aryl radicals of 6 to 20 carbon atoms, wherein Rm is as defined above. 20 20 30

[0065] Alternatively, the bidentate ligand comprises ortho-bisethers, α,ω-bisethers, ortho-bisamines, α,ω-bisamines, ortho-bisthiethers, α,ω-bisthiethers, ortho-bisphosphines and α,ω-bisphosphines, etc.

[0066] Alternatively, the alkali elements comprise lithium, sodium and potassium, etc.; the organic radicals of the heavier elements of Group XIV comprise Si(R)3, Ge(R)3, Sn(R)3, Pd(R)3, ZnR, BaR, MgR and CaR, wherein each R is independently selected from linear or branched hydrocarbon radicals of 1 to 20 carbon atoms, alkyl radicals containing heteroatoms of the elements of Groups 13 to 17 of the Periodic Table of the Elements, cycloalkyl radicals of 3 to 20 carbon atoms, unsubstituted or Rm-substituted aryl radicals of 6 to 20 carbon atoms, wherein Rm is as defined above. 20 ​​​Straight-chain or branched hydrocarbon groups, containing halogens or heteroatoms of elements from groups 13 to 17 of the periodic table, C1-C 20 Straight-chain or branched alkyl groups, C3-C 20 cycloalkyl, unsubstituted or Rm-substituted C6-C 30 Aryl groups, etc., where Rm is defined as described above.

[0067] Optionally, the metallocene complex is prepared using a C5-C reaction medium. 15 Saturated alkanes, C5-C 15 At least one of the cycloalkanes; preferably, the reaction medium is hexane, heptane, octane, toluene, or xylene.

[0068] Optionally, the reaction temperature between compound XIV and compound XV is -100℃ to +300℃; preferably, the reaction temperature is -75℃ to +250℃; more preferably, the reaction temperature is -50℃ to +150℃.

[0069] The present invention also provides the application of the above-described bimetallic heterogeneous catalyst composition in olefin polymerization, preferably, the olefin being CH2=CHR. 14 R 14 It is hydrogen or C1-C 12 A straight-chain or branched hydrocarbon group; more preferably, the olefin is selected from at least one of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-nonene, 1-decene, 3-methyl-1-butene and 4-methyl-1-pentene, butadiene, hexadiene, vinylcyclopentene and vinylcyclohexene.

[0070] Compared with the prior art, the present invention has the following advantages:

[0071] Because single-reactor processes are simpler and less expensive, the production of polypropylene with a wide molecular weight distribution using a single reactor has been a key focus in the industry. The key to this technology lies in the catalyst system having at least two active sites, and the resulting polymers from propylene polymerization exhibiting significant differences in molecular weight, thus yielding polypropylene products with a wide molecular weight distribution. Using binuclear catalysts or mixtures of two metallocene catalysts is costly and cannot meet the needs of large-scale industrial production. Furthermore, existing methods reported in the literature that utilize a mixture of metallocene and Ziegler-Natta catalysts lack control over the morphology of the polypropylene produced by the metallocene catalyst, resulting in a mixture of polypropylene particles from the Ziegler-Natta catalyst and polypropylene powder from the metallocene catalyst, which is not conducive to industrial implementation.

[0072] The present application loads the metallocene complex with specific structure on the magnesium alcohol carrier containing Ti active center, can have two metal active centers in a single kettle at the same time, the catalyst composition is high in activity, the polymer prepared by using the catalyst composition has less fine powder, regular particle, high bulk density, and compared with the silica gel loaded metallocene catalyst, the polypropylene has wider molecular weight distribution, the polymer product morphology is improved, the polymerization activity is improved, and the single kettle production of wide molecular weight distribution is realized. DETAILED DESCRIPTION

[0073] The following detailed description of the embodiments of the present application is given on the premise of the technical solutions of the present application, and detailed implementation methods and processes are given, but the protection scope of the present application is not limited to the following embodiments. The experimental methods not specified in the following embodiments are usually performed according to conventional conditions.

[0074] The following detailed description of the embodiments of the present application is given on the premise of the technical solutions of the present application, and detailed implementation methods and processes are given, but the protection scope of the present application is not limited to the following embodiments. The experimental methods not specified in the following embodiments are usually performed according to conventional conditions.

[0075] The experimental steps or conditions not specified in the embodiments can be performed according to the conventional experimental steps described in the literature in the art or the operation or conditions. The reagents or instruments not specified by the manufacturer are conventional reagent products that can be obtained by purchase.

[0076] The operations for preparing the catalyst in the examples are all performed under the protection of high-purity nitrogen, and the specific implementation is as follows.

[0077] The analysis of the ligand and complex is performed by nuclear magnetic resonance and mass spectrometer.

[0078] Nuclear magnetic resonance: AV400, Germany BRUKER.

[0079] Mass spectrometer: 5973N, Agilent, USA.

[0080] GPC analyzer of Germany NICE company: Waters 2000, USA Waters company

[0081] Example 1

[0082] (1) Synthesis of metallocene complex Cat-1:

[0083]

[0084] In the above reaction formula, M is Zr, and the specific synthesis steps are shown in Example 1 of Chinese patent document CN105985368A.

[0085] (2) Preparation of catalyst composition CTM-1:

[0086] In a 500ml flask with 5 ports, stirred and replaced with nitrogen, 10g MgCl2-2.5C2H5OH microspheres and 150ml titanium tetrachloride were added to prepare a suspension at -10°C, then maintained at -10°C for 1 hour, slowly warmed (the warming rate was stable) to 110°C for 1 hour, then the liquid was filtered clean, the liquid was filtered off, the obtained solid was washed with 120ml titanium tetrachloride at 110°C for 3 times. The obtained solid was washed with 150ml hexane at 60°C for 4 times, the liquid was filtered off and dried to obtain the Mg-Ti adduct.

[0087] The metallocene complex Cat-1 was dissolved in toluene to prepare a solution with a concentration of 10mM. 100mg of the above Mg-Ti adduct was added to a 50ml flask containing 20ml hexane, 5000μmol of MAO (methylaluminoxane) solution was added, 1ml of Cat-1 toluene solution (10mM) was added after stirring for 5 minutes, and the solution was stirred at room temperature for 30 minutes to obtain the catalyst composition solution CTM-1.

[0088] (3) Polymerization:

[0089] After the 5L reactor was vacuumed and replaced with nitrogen for 3 times, 400μmol of triisobutylaluminum and 1000g of propylene were added to the reactor; the catalyst composition solution prepared in step (2) was pressurized into the reactor with high-pressure nitrogen; the temperature was raised to 70°C, and the polymerization reaction was carried out for 1 hour. The polymerization data is shown in Table 2.

[0090] Examples 2-33

[0091] (1) Synthesis of metallocene complexes Cat-2-Cat-33: The steps were the same as in Example 1, and the raw materials were replaced with ligand raw materials with corresponding substituents. The substituents of the catalyst complexes are shown in Table 1.

[0092] (2) Preparation of catalyst compositions CTM-2-CTM-33: The same as in Example 1, except that Cat-1 was replaced by Cat-2-Cat-33, respectively.

[0093] (3) Polymerization: The polymerization conditions were the same as in Example 1, and the polymerization performance is shown in Table 2.

[0094] Examples 34-37

[0095] (1) The metallocene complexes were Cat-1-Cat4.

[0096] (2) Preparation of catalyst compositions CTM-34-CTM-37:

[0097] A suspension was prepared by adding 10 g of MgCl2-2.5C2H5OH microspheres and 150 mL of titanium tetrachloride into a 500 mL 5-neck flask with stirring, which was then maintained at -15°C for 1 hour, slowly warmed to 110°C for 1 hour, and then filtered clean. The obtained solid was washed with 120 mL of titanium tetrachloride at 125°C for 3 times, and then washed with 150 mL of hexane at 60°C for 4 times. To the obtained Mg-Ti adduct, 100 mL of hexane and 3 mL of 1.6 M AlEt3 were added, and stirred at room temperature for 30 minutes. The liquid was filtered off and dried to obtain a heterogeneous catalyst component.

[0098] The metallocene complexes Cat-1 to Cat-4 were dissolved in toluene to prepare a solution with a concentration of 10 mM, respectively. 60 mg of the above heterogeneous catalyst component was added to a 50 mL flask containing 20 mL of hexane, and 5000 μmol of MAO (methylaluminoxane) solution was added. After stirring for 5 minutes, 1 mL of the above prepared toluene solution (10 mM) of Cat-1 to Cat-4 was added, respectively, and stirred at room temperature for 30 minutes to obtain catalyst compositions CTM-34 to CTM-37, respectively.

[0099] (3) Polymerization: The polymerization conditions were the same as in Example 1, and the polymerization properties are shown in Table 2.

[0100] Examples 38 to 41

[0101] (1) The metallocene complexes were Cat-1 to Cat-4.

[0102] (2) Preparation of catalyst compositions CTM-38 to CTM-41:

[0103] A suspension was prepared by adding 10 g of MgCl2-2.5C2H5OH microspheres and 150 mL of titanium tetrachloride into a 500 mL 5-neck flask with stirring, which was then maintained at -15°C for 1 hour, slowly warmed to 110°C for 1 hour, and then filtered clean. The obtained solid was washed with 120 mL of titanium tetrachloride at 125°C for 3 times. The obtained solid was washed with 150 mL of hexane at 60°C for 4 times. To the obtained Mg-Ti adduct, 100 mL of hexane, 3 mL of 1.6 M AlEt3, and 0.5 mL of methylcyclohexyldimethoxysilane were added, and stirred at room temperature for 30 minutes. The liquid was filtered off and dried to obtain a heterogeneous catalyst component.

[0104] The metallocene complexes Cat-1 to Cat-4 were dissolved in toluene to prepare a solution having a concentration of 10 mM. 60 mg of the above heterogeneous catalyst component was added to a 50 mL flask containing 20 mL of hexane, and 5000 μmol of a MAO (methylaluminoxane) solution was added. After stirring for five minutes, 1 mL of the above prepared Cat-1 to Cat-4 toluene solution (10 mM) was added, and stirring was performed at room temperature for 30 minutes to obtain catalyst compositions CTM-38 to 41, respectively.

[0105] (3) Polymerization: The polymerization conditions were the same as in Example 1, and the polymerization properties are shown in Table 2.

[0106] Comparative Examples 1 to 4

[0107] (1) The metallocene complexes were Cat-1 to Cat-4, respectively.

[0108] (2) Activation of the silica gel support S0:

[0109] The Grace 955 silica gel was vacuumed at 450°C for 3 hours, and then naturally cooled to room temperature under inert gas protection.

[0110] (3) Preparation of catalyst compositions D1 to D4:

[0111] The metallocene complexes Cat-1 to Cat-4 were dissolved in toluene to prepare a solution having a concentration of 10 mM. 100 mg of the Grace-955 silica gel support activated in step (2) was added to a 50 mL flask containing 20 mL of hexane, and 5000 μmol of a MAO (methylaluminoxane) solution was added. After stirring for five minutes, 1 mL of the above prepared Cat-1 to Cat-4 toluene solution (10 mM) was added, and stirring was performed at room temperature for 30 minutes to obtain catalyst compositions D1 to D4.

[0112] (4) Polymerization: The polymerization conditions were the same as in Example 1, and the polymerization properties are shown in Table 2.

[0113] Comparative Example 5

[0114] (1) The metallocene complex was Cat-1.

[0115] (2) Preparation of catalyst composition D5:

[0116] The metallocene complex Cat-1 was dissolved in toluene to prepare a solution having a concentration of 10 mM. 1 mL of the Cat-1 toluene solution was added to 5000 μmol of a MAO (methylaluminoxane) solution, and stirring was performed at room temperature for 30 minutes to obtain catalyst composition D5.

[0117] (3) Polymerization: The polymerization conditions were the same as in Example 1, and the polymerization properties are shown in Table 2.

[0118] Comparative Example 6

[0119] (1) The metallocene complex used was Et(Ind)2ZrCl2.

[0120] (2) Preparation of catalyst composition D6:

[0121] Et(Ind)2ZrCl2was dissolved in toluene to make a 10 mM solution. 100 mg of Mg-Ti adduct prepared in Example 1 was added to a 50 mL flask containing 20 mL of hexane, 5000 μmol of MAO solution was added, and after stirring for five minutes, 1 mL of Et(Ind)2ZrCl2toluene solution (10 mM) was added. The mixture was stirred at room temperature for 30 minutes to obtain catalyst composition solution D6.

[0122] (3) Polymerization: The polymerization conditions were the same as in Example 1, and the polymerization properties are shown in Table 2.

[0123] Comparative Example 7

[0124] (1) The metallocene complex used was Cat-1.

[0125] (2) Preparation of catalyst composition D7:

[0126] After 100 g of anhydrous magnesium chloride was ground in a small vacuum ball mill at room temperature for 1 hour, it was contacted with 800 mL of TiCl4at 100°C for 2 hours, and washed with 500 mL of toluene and 1 L of hexane at 60°C for 3 times, respectively, and dried to obtain a Mg-Ti adduct. The metallocene complex Cat-1 was dissolved in toluene to make a 10 mM solution. 100 mg of the Mg-Ti adduct was added to a 50 mL flask containing 20 mL of hexane, 5000 μmol of MAO solution was added, and after stirring for five minutes, 1 mL of Cat-1 toluene solution (10 mM) was added. The mixture was stirred at room temperature for 30 minutes to obtain catalyst composition solution D7.

[0127] (3) Polymerization: The polymerization conditions were the same as in Example 1, and the polymerization properties are shown in Table 2.

[0128] Table 1

[0129] Complex Z A E L M X Q [R 1 ]]> [R 2 ]]> [R 3 ]]> [R 4 ]]> <![CDATA[R 5 ]]> [R 6 ]]> [R 7 ]]> [R 8 ]]> [R 9 ]]> [R 9’ ]]> [R 10 ]]> [R 10’ ]]> [R 11 ]]> [R 11’ ]]> [R 12 ]]> [R 13 ]]> Cat-1 X II NPh V Zr Cl [SiMe2] H H H H — H — — Ph H H H — — Me H Cat-2 X II NPh V Zr Cl SiMe2 H H H H — H — — m-OMePh H H H — — Me H Cat-3 X II NPh V Zr Cl [SiMe2] H H H H — H — — m-ClPh H H H — — Me H Cat-4 X II NPh V Zr Cl [SiMe2] H H H H — H — — p- t BuPh]]> H H H — — Me H Cat-5 X II NPh V Zr Cl [CMe2] H H H H — H — — [C4H3O-] H H H — — Me H Cat-6 X II NPh V Zr Cl [CMe2] H H H H — H — — [C3H3N2-] H H H — — Me H Cat-7 X II NPh V Zr Cl [CMe2] H H H H — H — — m-CF3Ph H H H — — Me H Cat-8 IX II NPh V Zr Cl SiMe2 H H H H — H — Me — — — — — — Me — Cat-9 XI II NPh V Zr Cl [SiMe2] H H H H — H — — — — H — H — H H Cat-10 XII II NPh V Zr Cl SiMe2 H H H H — H — — — — H H H H H H Cat-11 XIII II NPh V Zr Cl [SiMe2] H H H H — H — — — — H H H H H H Cat-12 XI II NPh III Zr Cl SiMe2 H H H H H — — — — — H — H — H H Cat-13 XI II NPh IV Zr Cl SiMe2 H H H H H — — — — — H — H — H H Cat-14 XI II NPh VI Zr Cl SiMe2 H H H H — H H — — — H — H — H H Cat-15 XI II NPh VII Zr Cl SiMe2 H H H H — H H — — — H — H — H H Cat-16 XI II NPh VIII Zr Cl [SiMe2] H H H H — H H — — — H — H — H H Cat-17 IX II NPh V Ti Cl SiMe2 H H H H — H — Me — — — — — — Me — Cat-18 IX II NPh V Ti Cl [CMe2] H H H H — H — Bu — — — — — — Me — Cat-19 IX II NPh V Hf Cl [SiMe2] H H H H — H — Me — — — — — — Me — Cat-20 IX II NPh V Y Cl SiMe2 H H H H — H — Me — — — — — — Me — Cat-21 IX II NPh V V Cl SiMe2 H H H H — H — Me — — — — — — Me — Cat-22 IX II NPh V Cr Cl SiMe2 H H H H — H — Me — — — — — — Me — Cat-23 X II NPh V Zr OMe SiMe2 H H H H — H — — m-FPh H H H — — Me H Cat-24 X II NPh V Zr Me SiMe2 H H H H — H — — [p-CF3OPh] H H H — — Me H Cat-25 X II NPh V Zr OCOEt SiMe2 H H H H — H — — m-CF3Ph H H H — — Me H Cat-26 X II NPh V Ti Cl NPh H H H H — H — — m-NO2Ph H H H — — Et H Cat-27 X II NPh VII Ti Cl PPh H H H H — H H — m-NCPh H H H — — Me H Cat-28 X II PPh VII Ti Cl SiMe2 H Me H H — H H — p-FPh H H H — — Me H Cat-29 X II O V Ti Cl SiMe2 H H H H — H — — o-ClPh H H H — — Me H Cat-30 X II S V Ti Cl SiMe2 H H H H — H — — 3,5-(CF3)2Ph H H H — — Me H Cat-31 X II NPh V Zr H SiMe2 H H H H — H — — Ph H H H — — Me H Cat-32 II II NPh V Zr Cl SiMe2 H H H H — H — Me — — — — — — Me — Cat-33 II II NPh V Zr Cl [CMe2] H H H H — H — Me — — — — — — Me —

[0130] Table 2

[0131]

[0132]

[0133] Note: M w / M nThe ratio of weight average molecular weight to number average molecular weight, used to represent the relative molecular mass distribution of the polymer.

[0134] From the experimental data in Table 2 above, it can be seen that the catalyst composition in Comparative Example 5 does not contain magnesium compound and titanium compound, and the final polymer prepared has poor flowability, is lumped, and the bulk density cannot be measured; the catalyst composition prepared in Comparative Example 6 uses ethyldiindenyl zirconium dichloride as the main catalyst, and the activity of the obtained catalyst composition is low; the catalyst composition prepared in Comparative Example 7 uses a ball milling method to prepare the Mg-Ti adduct, and the activity of the obtained catalyst composition is lower, the fine powder content is high, and the bulk density is lower; the magnesium compound and the titanium compound in the catalyst composition of the present application cooperate with each other, which can improve the polymer morphology and increase the bulk density. As can be seen from Comparative Examples 1-4 and Examples 1-4, the magnesium compound and the titanium compound in the catalyst composition of the present application combine with other components, and the components cooperate with each other, which can significantly improve the activity of the catalyst composition, reduce the fine powder content, and broaden the molecular weight distribution. The catalyst compositions in Examples 34-37 contain triethylaluminum, and the catalyst compositions in Examples 38-41 contain triethylaluminum and organosilane. Compared with Examples 1-4, the catalyst composition added with organoaluminum compound and / or organosilane has higher catalytic activity, increases the bulk density of the prepared polymer, reduces the fine powder content, improves the polymer morphology (the polymer morphology can be reflected from the bulk density and the fine powder content, the high bulk density indicates that the particle morphology is more regular, and the low fine powder content indicates that the particle is less complete and broken), and broadens the molecular weight distribution.

[0135] Of course, the present application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications should all belong to the protection scope of the present application.

Claims

1. A bimetallic center heterogeneous catalyst composition characterized in that, comprising a procatalyst, a cocatalyst, a titanium compound and a magnesium compound; wherein the titanium compound has a general formula of Ti(X") N (OR a ) 4-N , R a is a C1-C 20 linear or branched hydrocarbon group, X" is halogen, N=1-4; the magnesium compound is a precursor selected from alcoholates of magnesium dihalides; the cocatalyst is a Lewis acid; the procatalyst is a metallocene complex having a structure shown in Formula I, I wherein M is a transition metal selected from any one of the group IIIB, group IVB, group VB and group VIB elements in the periodic table; n is 1, 2, 3 or 4, each X is the same or different and is independently selected from the group consisting of H, a halogen radical, unsubstituted or Rm-substituted C1-C 20 straight-chain or branched hydrocarbon radicals, unsubstituted or Rm-substituted C3-C 20 cycloalkyl radicals, unsubstituted or Rm-substituted C6-C 30 aryl radicals, C1-C 20 straight-chain or branched alkoxy radicals, C1-C 20 straight-chain or branched mercapto radicals, C1-C 20 straight-chain or branched carboxyl radicals, C2-C 20 straight-chain or branched imino radicals, C2-C 20 straight-chain or branched phosphino radicals, -OR°O- or -OSO2CF3, R° is a divalent radical selected from the group consisting of C2-C 40 alkylene radicals, unsubstituted or Rm-substituted C6-C 30 arylene radicals; the product of n and the charge number of X equals the charge number of the central metal atom M minus two; Q is a divalent radical selected from any one of =C(R')2, =Si(R')2, =Ge(R')2, =NR', =PR', and =BR', wherein each R' is independently selected from any one of unsubstituted or Rm-substituted C1-C 20 linear or branched hydrocarbyl, C3-C 20 cycloalkyl, unsubstituted or Rm-substituted C6-C 30 aryl, and trimethylsilyl; A is a π-ligand having the structure shown in formula II: II E is a divalent radical of a Group 15 or 16 element of the Periodic Table selected from any one of the group consisting of oxygen radicals, sulfur radicals, selenium radicals, =NR" and =PR" wherein R" is selected from any one of the group consisting of unsubstituted or Rm-substituted C1-C 20 straight-chain or branched hydrocarbon radicals, unsubstituted or Rm-substituted C6-C 30 aryl radicals and benzyl radicals; L is a divalent radical selected from any one of the structures shown in formula III, formula V, formula VI, formula VII and formula VIII, wherein i is 2: III V VI VII VIII Z is a π-ligand, Z is the same as A, or is selected from any one of the structures shown in formula IX, formula X, formula XI, formula XII and formula XIII; IX X XI XII XIII wherein R 1 and each R 12 is independently selected from any of hydrogen, C4-C6heteroaryl, C1-C 20 linear or branched alkyl, C3-C 20 cycloalkyl, C6-C 30 aryl, unsubstituted or Rm-substituted; R 2 , each R 3 , each R 6 , each R 7 , and each R 13 is independently selected from any of hydrogen, halogen, unsubstituted or Rm-substituted C1-C 20 linear or branched alkyl, unsubstituted or Rm-substituted C3-C 20 cycloalkyl, unsubstituted or Rm-substituted C6-C 30 aryl; R 4 Selected from hydrogen, unsubstituted or Rm-substituted C1-C 20 Straight-chain or branched hydrocarbon groups, trifluoromethyl, phenyl, p-tert-butylphenyl, p-trimethylsilylphenyl, p-trifluoromethylphenyl, 3,5-dichloro-4-trimethylsilylphenyl or 2-naphthyl; Each R 5 Each is independently selected from hydrogen, fluorine, or methyl; each R 8 are independently selected from the group consisting of unsubstituted or Rm-substituted C1-C 20 linear or branched hydrocarbyl or phenyl; R 9 and R 9’ are each independently selected from the group consisting of unsubstituted or Rn-substituted C6-C 15 aryl, C3-C 10 heteroaryl; said Rn is selected from at least one of cyano, nitro, halogen, methyl, ethyl, isopropyl, methoxy, tert-butyl, trifluoromethoxy, trifluoromethyl and trimethylsilyl; each R 10 and R 10’ is independently selected from the group consisting of hydrogen, halogen, unsubstituted or Rm-substituted C1-C 20 linear or branched hydrocarbyl or unsubstituted or Rm-substituted C6-C 30 aryl; each R 11 and R 11’ is independently selected from hydrogen, halogen, ester, alkoxy, thiol, amine, or phosphine; Rm is selected from at least one of a halogen group, a C1-C 10 linear or branched hydrocarbon group, a C6-C 10 aryl group; The method for preparing the bimetallic center heterogeneous catalyst composition comprises the following steps: (1) reacting a titanium compound with a precursor of a magnesium compound at -25-135°C, and after the reaction is completed, separating to obtain a magnesium-titanium adduct; (2) mixing the magnesium-titanium adduct with a main catalyst and a cocatalyst to obtain the bimetallic center heterogeneous catalyst composition.

2. The bimetallic center heterogeneous catalyst composition of claim 1, wherein, E is selected from any one of an oxygen radical, a sulfur radical, =PR" and =NR", said R" is selected from any one of C1-C 10 any one of a straight chain alkyl, a phenyl, a benzyl, a 1-naphthyl, a 2-naphthyl, a 2-anthryl, a 1-phenanthryl, a 2-phenanthryl and a 5-phenanthryl; R 1 is selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl, benzyl, 2-furyl or 2-thienyl; R 2 , R 3 are each independently selected from hydrogen, methyl, ethyl or fluorine; R 4 is selected from hydrogen, methyl, trifluoromethyl, isopropyl, tert-butyl, phenyl, p-tert-butylphenyl, p-trimethylsilylphenyl, p-trifluoromethylphenyl, 3,5-dichloro-4-trimethylsilylphenyl or 2-naphthyl.

3. The bimetallic center heterogeneous catalyst composition of claim 1, wherein, Each X is independently selected from any one of H, a halogen group, a C1-C5 straight chain alkyl group, a C1-C5 straight chain alkoxy group and a C1-C5 straight chain carboxyl group; M is selected from any one of zirconium, titanium, yttrium, hafnium, vanadium and chromium; Q is selected from any one of =C(R')2, =Si(R')2, =Ge(R')2, =NR', =PR' and =BR', and R' is selected from any one of methyl, ethyl, isopropyl and phenyl.

4. The bimetallic center heterogeneous catalyst composition of claim 1, wherein, each R 5 is independently selected from hydrogen, fluoro or methyl; each R 7 is independently selected from hydrogen, fluoro or methyl; Each R 8 Alkyl or phenyl groups, each independently selected from C1-C5 straight-chain or branched groups; each R 9 and R 9’ are each independently selected from phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, furanyl, thienyl, quinolinyl, imidazolyl, pyrimidinyl, or Rn-substituted phenyl, Rn being selected from at least one of cyano, nitro, halogen, methyl, ethyl, isopropyl, methoxy, t-butyl, trifluoromethoxy, trifluoromethyl, and trimethylsilyl; each R 10 and R 10’ are each independently selected from hydrogen, fluorine, chlorine, methyl, ethyl, or phenyl; each R 11 and R 11’ are each independently selected from hydrogen, fluorine, chlorine, ester, alkoxy, thiol, amine, or phosphine; each R 12 is independently selected from hydrogen, methyl, ethyl, isopropyl, t-butyl, phenyl, benzyl, 2-furanyl, or 2-thienyl; each R 13 is independently selected from hydrogen, fluorine, or chlorine.

5. The bimetallic center heterogeneous catalyst composition of claim 1, wherein, The titanium compound is TiCl4; and / or said magnesium dihalide alcoholate is MgCl2.mR b OH, m is 0.1-6, R b is a C1-C 20 straight-chain or branched hydrocarbon radical; and / or The Lewis acid is selected from polymethylaluminoxane, modified polymethylaluminoxane or an organic boron reagent.

6. The bimetallic center heterogeneous catalyst composition of claim 1, wherein, The bimetallic center heterogeneous catalyst composition further comprises an organoaluminum compound having the general formula Al(R c ) n X( 3-n ) of at least one of the organoaluminum compounds, R c is a C1-C 20 linear or branched hydrocarbon group, X is a halogen, and n = 0, 1, 2, 3, or 4.

7. The bimetallic center heterogeneous catalyst composition of claim 1, wherein, The dual metal center heterogeneous catalyst composition further comprises a siloxane compound of the general formula (R d ) m Si(OR e ) 4-m d and R e are each independently selected from a C1-C 18 branched or straight chain hydrocarbon group, a Group VA or VIA atom of the Periodic Table of the Elements; m = 0, 1, 2, 3, or 4.​ 8. The bimetallic center heterogeneous catalyst composition of claim 1, wherein, The method for preparing the bimetallic center heterogeneous catalyst composition further comprises the step of mixing an organic aluminum compound with the magnesium-titanium adduct, the main catalyst and the cocatalyst; and / or It further comprises the step of mixing a siloxane compound with the magnesium-titanium adduct, the main catalyst and the cocatalyst.

9. The bimetallic, heterogeneous catalyst composition of claim 2, wherein, The E is selected from any one of an oxygen radical, a sulfur radical, =PPh and =NPh.

10. The bimetallic heterogeneous catalyst composition of claim 3, wherein, Each X is independently selected from any one of H, Cl, methyl, methoxy and EtCOO-.

11. The bimetallic, heterogeneous catalyst composition of claim 3, wherein, Q is selected from any one of =C(Me)2, =Si(Me)2, =NPh and =PPh.

12. The bimetallic center heterogeneous catalyst composition of claim 4, wherein, Each R 8 Each of the following is independently selected from methyl, ethyl, isopropyl, n-butyl, tert-butyl, or phenyl.

13. Use of the bimetallic center heterogeneous catalyst composition according to any one of claims 1-12 in the polymerization of olefins.

14. Use according to claim 13, characterized in that, The olefin is CH2=CHR 14 R 14 is hydrogen or a C1-C 12 linear or branched hydrocarbon group.

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