A cyclic bridged biscyclopentadienyl catalyst, its preparation and use

Abstract

The application relates to the technical field of metal catalysts, in particular to a cyclic bridged metallocene catalyst and a preparation method and application thereof, wherein the cyclic bridged metallocene catalyst has a structure shown in formula I. The cyclic bridged metallocene catalyst provided by the application has high catalytic activity, good high-temperature resistance and good copolymerization activity. Compared with the prior art, the structure is convenient to modify, and when the cyclic bridged metallocene catalyst is used to catalyze the copolymerization reaction of ethylene and alpha-olefins such as 1-butene, 1-hexene and 1-octene, a polymer product with high molecular weight and high comonomer insertion rate can be obtained, which helps to enhance the competitive ability of the polyolefin polymer material technology market in China.

Description

TECHNICAL FIELD

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

[0002] Polyolefin material is the most widely used synthetic polymer material at present, which has many advantages such as high cost performance, good mechanical properties, stable thermal properties and the like, and is widely used in various fields of industrial production and daily life, and improves and enhances people's life quality.

[0003] At present, the preparation of polyolefin is mostly carried out by high-temperature solution olefin polymerization process, and a catalyst needs to be used in the polymerization process, and the catalyst used needs to have thermal stability at high temperature, high activity, high molecular weight capacity and copolymer monomer combination capacity.

[0004] Therefore, it is of great significance to develop a homogeneous metal catalyst with improved high-temperature performance for high-temperature solution olefin polymerization process.

[0005] The bridged metallocene catalyst developed by introducing bridge chain structures such as carbon bridge, silicon bridge and hetero bridge has the advantages that the rotation of the ring structure is inhibited due to the introduction of the bridge group, the stereorigidity of the catalyst is increased, and the stability of the polymer chain growth is improved. The bridged metallocene catalyst developed by Mitsui Chemicals has a dimethyl carbon bridge, and the steric hindrance and rigidity of the bridge are small, and the thermal stability is poor (CN1684968A). The bridged metallocene catalyst developed by ExxonMobil has an alkyl chain introduced on the bridge group, which can improve the solubility of the catalyst in alkanes, but the two aryl groups and the bridging carbon can be twisted, resulting in a larger fluctuation range of the included angle between the two metallocene rings and a larger steric hindrance around the metal center, which is not conducive to the insertion of copolymer monomers with large volume. In the copolymerization of ethylene and 1-octene, the mass insertion rate of octene is less than 17% (CN1138796C). Herrmann et al. (Chem. Rev., 2000, 100(4): 1347-1376.) studied various bridge group complexes and their catalytic properties. However, there are few reports on catalysts with cyclic bridged structure. The development of photovoltaics has driven the growing demand for polyolefin elastomers, and many domestic enterprises have also begun to research POE technology. The POE localization process is rapidly advancing, and the lack of catalysts with independent intellectual property rights is a problem that needs to be solved. Therefore, it is of great significance to innovatively introduce a cyclic bridged structure to develop a cyclic bridged metallocene catalyst, which is conducive to breaking the blockade of foreign patents and obtaining a catalyst system with independent intellectual property rights. SUMMARY

[0006] Therefore, the present application aims to solve the technical problem of providing a cyclic bridged metallocene catalyst and a preparation method and application thereof, which has high thermal stability.

[0007] To achieve the above object, the present application provides a cyclic bridged metallocene catalyst having the structure shown in Formula I:

[0008]

[0009] wherein M is selected from the group consisting of transition metals of the fourth subgroup;

[0010] R1 is selected from the group consisting of halogen, substituted or unsubstituted alkyl, amine group; R1 can also be an anionic ligand or a neutral ligand capable of coordinating with a lone pair of electrons;

[0011] X is selected from the group consisting of oxygen, sulfur, nitrogen, selenium, carbon;

[0012] when X is selected from the group consisting of oxygen, sulfur or selenium, R2 is absent;

[0013] when X is selected from the group consisting of nitrogen or carbon, R2 is selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, cycloalkyl, aryl, heteroaryl, silicon group;

[0014] In the present application, when X is a carbon atom, one or two R2 can be connected, when one R2 is connected, the carbon atom is CH.

[0015] R3~R 22 are independently selected from the group consisting of halogen, hydrogen, substituted or unsubstituted alkyl, alkoxy, cycloalkyl, aryl, heteroaryl, silicon group; and R3~R 22 may be the same or different;

[0016] or any two adjacent of R7-R 10 , R 11 , R 14 , R 16 , R 19 , R 20 , R 21 , R 22 , R 15 adjacent to the aryl carbon atom connected together to form a substituted or unsubstituted five- to twelve-membered cyclic structure group, that is, any adjacent substituents on the benzene ring can be connected by an alkyl chain to form a substituted or unsubstituted five- to twelve-membered cyclic structure group.

[0017] The M is the metal element of the catalyst, preferably the fourth subgroup transition metal, more preferably zirconium (Zr), hafnium (Hf) or titanium (Ti).

[0018] The R1 is selected from the group consisting of halogen, substituted or unsubstituted alkyl, amine group; preferably halogen, substituted or unsubstituted C1-C10 alkyl, amine group; more preferably halogen, substituted or unsubstituted C1-C6 alkyl, amine group.

[0019] The substituents of R1are preferably halogen, alkyl, alkoxy, silyl, aryl or heteroaryl; more preferably halogen, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 alkyl silyl, C6-C12 aryl, C2-C12 heteroaryl; further preferably halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkyl silyl, C6-C12 mono- or bi-cyclic aryl, C2-C12 mono- or bi-cyclic heteroaryl; the heteroatoms of the heteroaryl are one to three; the heteroatoms of the heteroaryl are selected from one or more of N, O, S. In some embodiments of the application, the substituents of R1are specifically one or more of F, Cl, Br, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, n-hexyl, methoxy, ethoxy, n-propoxy, i-propoxy, phenyl.

[0020] In some embodiments of the application, R1is selected from the group consisting of Cl, Br, F, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, n-hexyl, benzyl, trimethylsilylmethyl, di(trimethylsilyl)amino.

[0021] X is selected from oxygen, sulfur, nitrogen, selenium, carbon.

[0022] When X is selected from oxygen, sulfur or selenium, R2is absent.

[0023] When X is selected from nitrogen or carbon, R2is selected from hydrogen, substituted or unsubstituted alkyl, cycloalkyl, aryl, heteroaryl, silyl; preferably hydrogen, substituted or unsubstituted C1-C10 alkyl, 3-6 membered cycloalkyl, C6-C12 aryl, C2-C12 heteroaryl, silyl; further preferably hydrogen, substituted or unsubstituted C1-C8 alkyl, C6-C12 mono- or bi-cyclic aryl, C2-C12 mono- or bi-cyclic heteroaryl, silyl; the heteroatoms of the heteroaryl are one to three; the heteroatoms of the heteroaryl are selected from one or more of N, O, S.

[0024] The substituents of R2are preferably halogen, alkyl, alkoxy, aryl or heteroaryl; more preferably halogen, C1-C10 alkyl, C1-C10 alkoxy, C6-C12 aryl, C2-C12 heteroaryl; further preferably halogen, C1-C8 alkyl, C1-C8 alkoxy, C6-C12 mono- or bi-cyclic aryl, C2-C12 mono- or bi-cyclic heteroaryl; the heteroatoms of the heteroaryl are one to three; the heteroatoms of the heteroaryl are selected from one or more of N, O, S. In some embodiments of the application, the substituents of R2are specifically one or more of F, Cl, Br, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, n-hexyl, methoxy, ethoxy, n-propoxy, i-propoxy, phenyl.

[0025] In some embodiments of the application, R2is selected from the group consisting of H, Cl, Br, F, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, C5alkyl, C6alkyl, C7alkyl, C8alkyl, C9alkyl, C10alkyl, cyclopentyl, cyclohexyl, phenyl, benzyl, p-methylphenyl, p-methoxyphenyl, 3,5-di-t-butylphenyl, trimethylsilyl, triphenylsilyl.

[0026] R3to R6are independently selected from the group consisting of halogen, hydrogen, substituted or non-substituted alkyl, alkoxy, cycloalkyl, aryl, heteroaryl, silyl; preferably halogen, hydrogen, substituted or non-substituted C1-C20alkyl, C1-C20alkoxy, 3-6 membered cycloalkyl, C6-C12aryl, C2-C12heteroaryl, silyl; more preferably halogen, hydrogen, substituted or non-substituted C1-C6alkyl, C1-C6alkoxy, 5-6 membered cycloalkyl, C6-C12monocyclic or bicyclic aryl, C2-C12monocyclic or bicyclic heteroaryl, silyl; the heteroatoms of the heteroaryl are 1-3; the heteroatoms of the heteroaryl are selected from one or more of N, O, S. 22 R3to R6are independently selected from the group consisting of halogen, hydrogen, substituted or non-substituted alkyl, alkoxy, cycloalkyl, aryl, heteroaryl, silyl; preferably halogen, hydrogen, substituted or non-substituted C1-C20alkyl, C1-C20alkoxy, 3-6 membered cycloalkyl, C6-C12aryl, C2-C12heteroaryl, silyl; more preferably halogen, hydrogen, substituted or non-substituted C1-C6alkyl, C1-C6alkoxy, 5-6 membered cycloalkyl, C6-C12monocyclic or bicyclic aryl, C2-C12monocyclic or bicyclic heteroaryl, silyl; the heteroatoms of the heteroaryl are 1-3; the heteroatoms of the heteroaryl are selected from one or more of N, O, S.

[0027] R3to R6are independently selected from the group consisting of halogen, hydrogen, substituted or non-substituted alkyl, alkoxy, cycloalkyl, aryl, heteroaryl, silyl; preferably halogen, hydrogen, substituted or non-substituted C1-C20alkyl, C1-C20alkoxy, 3-6 membered cycloalkyl, C6-C12aryl, C2-C12heteroaryl, silyl; more preferably halogen, hydrogen, substituted or non-substituted C1-C6alkyl, C1-C6alkoxy, 5-6 membered cycloalkyl, C6-C12monocyclic or bicyclic aryl, C2-C12monocyclic or bicyclic heteroaryl, silyl; the heteroatoms of the heteroaryl are 1-3; the heteroatoms of the heteroaryl are selected from one or more of N, O, S. 22 R3to R6are independently selected from the group consisting of halogen, hydrogen, substituted or non-substituted alkyl, alkoxy, cycloalkyl, aryl, heteroaryl, silyl; preferably halogen, hydrogen, substituted or non-substituted C1-C20alkyl, C1-C20alkoxy, 3-6 membered cycloalkyl, C6-C12aryl, C2-C12heteroaryl, silyl; more preferably halogen, hydrogen, substituted or non-substituted C1-C6alkyl, C1-C6alkoxy, 5-6 membered cycloalkyl, C6-C12monocyclic or bicyclic aryl, C2-C12monocyclic or bicyclic heteroaryl, silyl; the heteroatoms of the heteroaryl are 1-3; the heteroatoms of the heteroaryl are selected from one or more of N, O, S. 22 R3to R6are independently selected from the group consisting of halogen, hydrogen, substituted or non-substituted alkyl, alkoxy, cycloalkyl, aryl, heteroaryl, silyl; preferably halogen, hydrogen, substituted or non-substituted C1-C20alkyl, C1-C20alkoxy, 3-6 membered cycloalkyl, C6-C12aryl, C2-C12heteroaryl, silyl; more preferably halogen, hydrogen, substituted or non-substituted C1-C6alkyl, C1-C6alkoxy, 5-6 membered cycloalkyl, C6-C12monocyclic or bicyclic aryl, C2-C12monocyclic or bicyclic heteroaryl, silyl; the heteroatoms of the heteroaryl are 1-3; the heteroatoms of the heteroaryl are selected from one or more of N, O, S.

[0028] R3to R6are independently selected from the group consisting of halogen, hydrogen, substituted or non-substituted alkyl, alkoxy, cycloalkyl, aryl, heteroaryl, silyl; preferably halogen, hydrogen, substituted or non-substituted C1-C20alkyl, C1-C20alkoxy, 3-6 membered cycloalkyl, C6-C12aryl, C2-C12heteroaryl, silyl; more preferably halogen, hydrogen, substituted or non-substituted C1-C6alkyl, C1-C6alkoxy, 5-6 membered cycloalkyl, C6-C12monocyclic or bicyclic aryl, C2-C12monocyclic or bicyclic heteroaryl, silyl; the heteroatoms of the heteroaryl are 1-3; the heteroatoms of the heteroaryl are selected from one or more of N, O, S. 22 R3to R6are independently selected from the group consisting of halogen, hydrogen, substituted or non-substituted alkyl, alkoxy, cycloalkyl, aryl, heteroaryl, silyl; preferably halogen, hydrogen, substituted or non-substituted C1-C20alkyl, C1-C20alkoxy, 3-6 membered cycloalkyl, C6-C12aryl, C2-C12heteroaryl, silyl; more preferably halogen, hydrogen, substituted or non-substituted C1-C6alkyl, C1-C6alkoxy, 5-6 membered cycloalkyl, C6-C12monocyclic or bicyclic aryl, C2-C12monocyclic or bicyclic heteroaryl, silyl; the heteroatoms of the heteroaryl are 1-3; the heteroatoms of the heteroaryl are selected from one or more of N, O, S.

[0029] R3to R6are independently selected from the group consisting of halogen, hydrogen, substituted or non-substituted alkyl, alkoxy, cycloalkyl, aryl, heteroaryl, silyl; preferably halogen, hydrogen, substituted or non-substituted C1-C20alkyl, C1-C20alkoxy, 3-6 membered cycloalkyl, C6-C12aryl, C2-C12heteroaryl, silyl; more preferably halogen, hydrogen, substituted or non-substituted C1-C6alkyl, C1-C6alkoxy, 5-6 membered cycloalkyl, C6-C12monocyclic or bicyclic aryl, C2-C12monocyclic or bicyclic heteroaryl, silyl; the heteroatoms of the heteroaryl are 1-3; the heteroatoms of the heteroaryl are selected from one or more of N, O, S. 22Any three or more of them are selected from alkyl or silyl groups, more preferably C1 to C20 alkyl or silyl groups.

[0030] Preferably, R8, R9, R 12 R 13 R 17 R 18 R 21 R 22 One or more of the components are selected from alkyl or silane groups, more preferably C1 to C20 alkyl or silane groups.

[0031] Preferably, R7~R 22 It can be hydrogen at the same time, or it can be hydrogen at different times.

[0032] Preferably, R3, R4, R5, and R6 are all hydrogen atoms, or one or two of them are not hydrogen atoms.

[0033] Or the aforementioned R7-R 10 Any two adjacent R in 11 -R 14 Any two adjacent R in 16 -R 19 Any two adjacent R in 20 R 21 R 22 R 15 Any two adjacent substituents on the benzene ring, together with the aryl carbon atom to which they are attached, form a substituted or unsubstituted five- to twelve-membered cyclic structure group. That is, adjacent substituents on any benzene ring can be connected by an alkyl chain to form a substituted or unsubstituted five- to twelve-membered cyclic structure group.

[0034] Preferably, the R7-R 10 Any two adjacent R in the equation 11 -R 14 Any two adjacent R in the equation 16 -R 19 Any two adjacent R in 15 R 20 -R 22 Any two adjacent atoms in the group, together with the aryl carbon atom to which they are attached, form a substituted or unsubstituted five- to eight-membered cyclic structure group.

[0035] More preferably, the R7-R 10 Any two adjacent R in the equation 11 -R 14 Any two adjacent R in the equation 16 -R 19 Any two adjacent R in 15 R 20 -R22 Any two adjacent atoms in the group, together with the attached aryl carbon atom, form a substituted or unsubstituted five- or six-membered cyclic structure group.

[0036] Preferably, the cyclic structural group is an aromatic group, a heteroaromatic group, or a cycloalkyl group. More preferably, it is a substituted or unsubstituted phenyl, cyclopentyl, or cyclohexyl group.

[0037] Preferably, R8 and R9, R 12 and R 13 R 17 and R 18 R 21 and R 22 Each of these groups, together with the attached aryl carbon atom, forms either a substituted or unsubstituted cyclic structural group.

[0038] The substituents of the cyclic structural group are preferably halogens, alkyl groups, alkoxy groups, aryl groups, or heteroaryl groups; more preferably halogens, C1-C10 alkyl groups, C1-C10 alkoxy groups, C6-C12 aryl groups, or C2-C12 heteroaryl groups; and even more preferably halogens, C1-C6 alkyl groups, C6-C12 monocyclic or bicyclic aryl groups, or C2-C12 monocyclic or bicyclic heteroaryl groups; the heteroaryl group has 1 to 3 heteroatoms; and the heteroatoms of the heteroaryl group are selected from one or more of N, O, and S. In some specific embodiments of the present invention, the substituents of the cyclic structural group are specifically one or more of F, Cl, Br, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, methoxy, ethoxy, n-propoxy, isopropoxy, and phenyl.

[0039] In some specific embodiments of the present invention, the cyclic structural group is a methyl-substituted cyclopentyl or cyclohexyl group.

[0040] In some specific embodiments of the present invention, the R7-R 10 Any two adjacent R in 11 -R 14 Any two adjacent R in 16 -R 19 Any two adjacent R in 15 R 20 -R 22 Any two adjacent elements in the matrix, preferably R8 and R9, R 12 and R 13 R 17 and R 18 R 21 and R 22 Each of these groups, together with the phenyl group to which it is attached, forms any of the following groups:

[0041]

[0042] Preferably, the cyclic bridged biscyclopentadienyl catalyst has any one of the following structures:

[0043]

[0044]

[0045] The application also provides a preparation method of the cyclic bridged biscyclopentadienyl catalyst, comprising the following steps:

[0046] S1) reacting a compound shown in formula a with a compound shown in formula b to obtain a compound shown in formula c;

[0047] S2) coordinating the compound shown in formula c with a metal precursor to obtain the cyclic bridged biscyclopentadienyl catalyst shown in formula I;

[0048]

[0049] wherein, M, R1, X, R2, R3~R 22 The range of R1, R2, R3~R6 is the same as above, which is not repeated here.

[0050] The step S2) is preferably as follows:

[0051] Under a nitrogen atmosphere, a lithium salt solution of a monolithium salt Lli (the compound shown in formula c) treated with an excess of n-butyllithium is reacted with MX4, and then treated with an excess of methyllithium to obtain the cyclic bridged biscyclopentadienyl catalyst shown in formula I.

[0052] wherein, X is halogen.

[0053] The step S2) is more preferably as follows:

[0054] Under a nitrogen atmosphere, 1 mole equivalent of the ligand compound shown in formula c and 4 mole equivalents of LiMe are refluxed at low temperature (preferably -35°C) in THF, preferably for 6h, and then the ligand lithium salt is added to a zirconium chloride solution at low temperature (preferably -35°C), and stirred at room temperature, preferably for 6h. After the solvent is removed by suction, the residue is washed with 5mL of anhydrous n-hexane, and then the residue is dried by suction, dissolved in a good solvent and filtered. After the solvent is removed from the good solvent filtrate, the cyclic bridged biscyclopentadienyl catalyst is obtained by washing with a poor solvent.

[0055] The good solvent is preferably one or more of dichloromethane, toluene and THF.

[0056] The poor solvent is preferably one or more of n-hexane and diethyl ether.

[0057] Optionally, the compound shown in formula a is prepared by reacting a compound shown in formula a-1 with a compound shown in formula a-2.

[0058]

[0059] Preferably, the preparation method of the compound shown in formula a is as follows:

[0060] The compound shown in formula a-2 is dissolved in an ethanol solution containing 1 equivalent of sodium ethoxide under a nitrogen atmosphere, 1.2 equivalents of the compound shown in formula a-1 is added dropwise at 50℃, after the dropwise addition is completed, the temperature is restored to room temperature and stirring is performed, preferably for 12h, the solid is filtered, washed with 20mL of cold ethanol, then recrystallized with 80mL of methanol to obtain an orange solid, and then washed once with 10mL of cold methanol, and the solid is vacuum dried to obtain the compound shown in formula a.

[0061] The equation of the reaction is as follows:

[0062]

[0063] The application also provides the use of the above bridged biscyclopentadienyl catalyst as an olefin polymerization catalyst.

[0064] The polymerization can be homopolymerization or copolymerization.

[0065] The application also provides an olefin polymerization catalyst system, which comprises at least two of a catalyst, a cocatalyst, and a boron agent.

[0066] The catalyst is the above-mentioned cyclic bridged biscyclopentadienyl catalyst.

[0067] The cocatalyst is preferably one or more of alkylaluminum, aluminoxane, and chlorinated alkylaluminum; more preferably one or more of trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, monochlorodiethylaluminum, dichloroethylaluminum, methylaluminoxane (MAO), ethylaluminoxane, isobutylaluminoxane, modified methylaluminoxane (MMAO), and the like.

[0068] The boron agent is preferably high-solubility oil boron, and more preferably one or more of tris-pentafluorophenyl boron, triphenylcarbenium tetrakis(pentafluorophenyl)borate, tri(4-octylphenyl)carbenium tetrakis(pentafluorophenyl)borate, [PhNHMe2][B(C6F5)4], [(C6H5)2NHMe][B(C6F5)4], [PhNHMe2][B(C6F5)4], [(C6H5)2NHMe][B(C6F5)4], [C6H5NHMePh][B(C6F5)4], and the like. 18 H 37 )2NHMe][B(C6F5)4], [PhNHMe2][B(C6F5)4], [(C 18 H 37 )2NHMe][B(C6F5)4], [PhNHMe2][B(C6F5)4], [(C 18 H 37 NHMePh][B(C6F5)4] and the like.

[0069] The olefin can be one or more of olefins known to those skilled in the art that can undergo olefin polymerization, preferably one or more of ethylene, propylene, 1-butene, 1-hexene, 1-octene, styrene, cyclopentene, cyclohexene, norbornene, ethylidene norbornene, 1,3-butadiene, 1,3-pentadiene, and the like.

[0070] The present application also provides a method for preparing an olefin polymer, comprising the following steps:

[0071] The one or more olefins are subjected to polymerization under the catalysis of the above-mentioned cyclic bridged metallocene catalyst or the above-mentioned catalyst system for olefin polymerization to prepare the olefin polymer.

[0072] Preferably, the temperature of the above-mentioned polymerization is 80-200°C, and the time is preferably 10-20 min. The pressure of the above-mentioned polymerization is preferably 0.1-10.0 MPa, and more preferably 0.5-9.5 MPa.

[0073] The molar ratio of aluminum atoms in the above-mentioned cocatalyst to metal atoms in the above-mentioned catalyst is preferably (5-5000):1, and more preferably (100-1500):1.

[0074] Preferably, an alkane solvent is added as a diluent during the above-mentioned polymerization, and the alkane solvent is preferably one or more of n-hexane, isooctane, ISOPAR E, cyclohexane, heptane, toluene, and the like.

[0075] The olefin can be one or more of olefins known to those skilled in the art that can undergo olefin polymerization, preferably one or more of ethylene, propylene, 1-butene, 1-hexene, 1-octene, styrene, cyclopentene, cyclohexene, norbornene, ethylidene norbornene, 1,3-butadiene, 1,3-pentadiene, and the like.

[0076] When one olefin is used for polymerization, the polymerization is homopolymerization, and the obtained olefin polymer is a homopolymer.

[0077] When multiple olefins are used for polymerization, the polymerization is copolymerization, and the obtained olefin polymer is a copolymer.

[0078] Specifically, the present application provides an ethylene and α-olefin binary copolymer, wherein the molecular weight Mw of the copolymer is 100-1000 kg·mol -1 , the molar insertion rate is 7-40 mol%, the melting point is 20-90°C, the glass transition temperature is -30--90°C, and the light transmittance is ≥91%.

[0079] The α-olefin is preferably one or more of propylene, 1-butene, 1-hexene, 1-octene, and styrene.

[0080] Specifically, the application provides an ethylene, alpha-olefin, diene terpolymer, the molecular weight Mw of the terpolymer is 100-1000 kg·mol -1 , the molar insertion rate is 9-40 mol%, the melting point is 25-95 DEG C, the glass transition temperature is -25 DEG C to -95 DEG C, and the light transmittance is greater than or equal to 91%.

[0081] The diene is preferably one or more of ethylidene norbornene, 1,3-butadiene and 1,3-pentadiene.

[0082] The experimental results show that the molecular weight of the polymer obtained by copolymerization of ethylene and 1-butene catalyzed by the cyclic bridged metallocene catalyst provided by the application is up to 38.5*10 4 g / mol, and the molar insertion rate of 1-butene is up to 36.2%; the molecular weight of the polymer obtained by copolymerization of ethylene and 1-hexene is up to 40.1*10 4 g / mol, and the molar insertion rate of 1-hexene is up to 25.1%; the molecular weight of the polymer obtained by copolymerization of ethylene and 1-octene is up to 36.1*10 4 g / mol, and the molar insertion rate of 1-octene is up to 19.0%.

[0083] Compared with the prior art, the application provides a cyclic bridged metallocene catalyst having the structure shown in formula I.

[0084] The cyclic bridged metallocene catalyst provided by the application has high catalytic activity, good high-temperature resistance and good copolymerization activity. Compared with the prior art, the structure is convenient to modify, and the copolymerization reaction of ethylene and alpha-olefins such as 1-butene, 1-hexene and 1-octene catalyzed by the catalyst can obtain a polymer product with high molecular weight and high comonomer insertion rate, which helps to enhance the competitive ability of the polyolefin polymer material technology market in China.

[0085] The application innovatively introduces a cyclic bridging structure on the bridge of the bridged biscyclopentadienyl catalyst, designs and synthesizes a new cyclic bridging bridged biscyclopentadienyl catalyst, and can conveniently regulate the electronic effect of the model metal catalyst by changing the type of introduced heteroatoms, so as to realize different catalytic performances and prepare polyolefin high molecular materials with various structures and various performances. The above cyclic bridging structure not only maintains the overall rigidity of the catalyst molecule and maintains high temperature resistance, but also controls the two substituents on the bridge on a plane, and the steric hindrance is relatively small, so that higher comonomer insertion capacity can be expected. The unlinked two aryl groups have relatively large volatility and steric hindrance, which may be not conducive to the insertion of comonomers. Although the rigidity is increased, the comonomer insertion capacity is also reduced. The rigid structure introduced in the application is linked and controlled on a plane, so that the steric position is reduced, and the thermal stability and comonomer insertion capacity are simultaneously improved.

[0086] In addition, the application adopts a large steric hindance fulvene synthesis and a small steric hindance cyclopentadiene attack strategy, so that the synthesis of the catalyst is more simple and easy, and the synthesis efficiency is improved.

[0087] The novel cyclic bridged biscyclopentadienyl catalyst provided by the application has the characteristics of cheap and easily available raw materials, simple synthesis route and high product yield. In the presence of a proper amount of a cocatalyst such as MAO, the zirconium and hafnium metal catalysts show extremely high activity, and the activity can reach 16.08*10 4 g(PE)·g(M), the prepared polyethylene has high linearity and high molecular weight, the prepared ethylene and alpha-olefin copolymer has good elasticity, controllable insertion rate and good light transmittance. BRIEF DESCRIPTION OF DRAWINGS

[0088] Figure 1 It is a polymer sample diagram obtained in embodiment 4 of the application;

[0089] Figure 2 It is a polymer sample diagram obtained in embodiment 5 of the application;

[0090] Figure 3 It is a polymer sample diagram obtained in embodiment 6 of the application;

[0091] Figure 4 It is a nuclear magnetic hydrogen spectrum diagram of the compound II-1 of the application;

[0092] Figure 5 It is a nuclear magnetic hydrogen spectrum diagram of the compound II-1 of the application;

[0093] Figure 6 It is a nuclear magnetic hydrogen spectrum diagram of the catalyst I-1 of the application. DETAILED DESCRIPTION

[0094] In order to further illustrate the present application, the cyclic bridged bis-indenyl catalyst, the preparation method and the application thereof provided by the present application are described in detail below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present application, but not for limiting the claims of the present application.

[0095] All the raw materials of the present application are not particularly limited in source, and can be purchased on the market or prepared according to the conventional methods well known to those skilled in the art.

[0096] Example 1, Preparation of Ligand Mono-lithium Salt LLi

[0097] The structural general formula of the mono-lithium salt LLi is as follows:

[0098]

[0099] The preparation process is as follows:

[0100]

[0101] 18 mmol of the compound shown in formula (II) is weighed and dissolved in 100 mL of anhydrous ether, 18 mmol of cyclopentadienyl lithium shown in formula (III) is added under the condition of nitrogen atmosphere at -35℃, and then gradually restored to room temperature, stirred for 3 h, and then the solvent is removed, followed by slushing the remaining solid with n-hexane (100 mL), filtering, washing with additional n-hexane (2 x 100 mL), and then drying under vacuum to obtain the ligand mono-lithium salt LLi.

[0102] The synthesis method of the compound shown in formula (II) is as follows:

[0103] 0.25 mol of sodium ethoxide is weighed, 190 mL of anhydrous ethanol is added at room temperature, and the sodium ethoxide is stirred until it is completely dissolved to prepare an ethanol solution of sodium ethoxide. 0.25 mol of the compound shown in formula (IV) is added to the sodium ethoxide solution, and the reaction system is heated to 50℃ and stirred until it is completely dissolved. At this temperature, 0.3 mol of fluorene shown in formula (V) is added dropwise to the reaction system, and after the dropwise addition is completed, the system is restored to room temperature and stirred for 12 h, filtered, the solid is washed with 20 mL of cold ethanol, and then recrystallized with 80 mL of methanol to obtain orange red solid, which is washed once more with 10 mL of cold methanol, and then the solid is dried under vacuum to obtain the compound shown in formula (II).

[0104] The cyclopentadienyl lithium shown in formula (III) is prepared by reacting substituted cyclopentadiene with n-butyllithium.

[0105] The following compounds are prepared according to the above method:

[0106] LLi1: R3~R 22 = hydrogen; X = O; R2 is absent;

[0107] LLi2: R3~R 22 = hydrogen; X = S; R2 is absent;

[0108] LLi3: R2 = methyl; R3~R 22 = hydrogen; X = N;

[0109] LLi4: R2 = ethyl; R3~R 22 = hydrogen; X = N;

[0110] LLi5: R2 = t-butyl; R3~R 22 = hydrogen; X = N;

[0111] LLi6: R2 = phenyl; R3~R 22 = hydrogen; X = N;

[0112] LLi7: R3~R7, R 10 , R 11 , R 14～ R 16 , R 18～ R 21 = hydrogen; R 17 , R 22 = methoxy; R8,

[0113] R9, R 12 , R 13 = t-butyl; X = O; R2 is absent;

[0114] LLi8: R3~R7, R 10 , R 11 , R 14～ R 22 = hydrogen; R8, R9, R 12 , R 13 = t-butyl; X =

[0115] O; R2 is absent;

[0116] LLi9: R2 = methyl; R3~R7, R 10 , R 11 , R 14～ R 22 = hydrogen; R8, R9, R 12 , R 13 = t

[0117] butyl; X = CMe;

[0118] LLi10: R3~R7, R 10 , R 11 , R 14～ R 22= Hydrogen; R8, R9 and the carbon atoms of the benzene ring are connected to form a five-membered ring, R 12 R 13 It connects with the carbon atom of the benzene ring to form a five-membered ring; X = O; R2 does not exist;

[0119] LLi11: R3~R7, R 10 R 11 R 14～ R 17 R 19 R 20 R 22 = Hydrogen; R8, R9, R 12 ,

[0120] R 13 R 18 R 21 = tert-butyl; X = 0; R² does not exist;

[0121] LLi12: R3~R7, R 10 R 11 R 14～ R 16 R 18 ~R 21 = Hydrogen; R8, R9, R 12 R 13 R 17 ,

[0122] R 22 = tert-butyl; X = 0; R² does not exist;

[0123] LLi13: R3~R7, R 10 ~R 11 R 14～ R 16 R 19 ~R 20 = Hydrogen; R8, R9, R 12 R 13 =Shuding

[0124] Base; R 17 R 18 The carbon atom of the benzene ring undergoes ring fusion to form a tetramethylcyclohexyl group; R 21 R 22 The carbon atom of the benzene ring undergoes ring fusion to form a tetramethylcyclohexyl group; X = O; R2 is not present;

[0125] LLi14: R3~R7, R 10 ~R 11 R 14～ R 16 R 19 ~R 20= hydrogen; R8, R9and the carbon atoms of the phenyl ring form a tetramethylcyclohexyl ring; R 12 = hydrogen; R8, R9and the carbon atoms of the phenyl ring form a tetramethylcyclohexyl ring; R 13 = hydrogen; R8, R9and the carbon atoms of the phenyl ring form a tetramethylcyclohexyl ring; R 17 = hydrogen; R8, R9and the carbon atoms of the phenyl ring form a tetramethylcyclohexyl ring; R 18 = hydrogen; R8, R9and the carbon atoms of the phenyl ring form a tetramethylcyclohexyl ring; R 21 = hydrogen; R8, R9and the carbon atoms of the phenyl ring form a tetramethylcyclohexyl ring; R 22 = hydrogen; R8, R9and the carbon atoms of the phenyl ring form a tetramethylcyclohexyl ring; X = O; R2is absent.

[0126] LLi15: R3~R7, R 10 ~R 11 , R 14～ R 16 , R 18 ~R 21 = hydrogen; R8, R9and the carbon atoms of the phenyl ring form a tetramethylcyclohexyl ring; R 12 , R 13 = hydrogen; R8, R9and the carbon atoms of the phenyl ring form a tetramethylcyclohexyl ring; R 17 , R 22 = isopropyl; X = O; R2is absent.

[0127] Figure 4 is the nuclear magnetic hydrogen spectrum of the compound of formula II-1 of the present application; in formula II-1, R7~R 22 = hydrogen; X = O.

[0128] Figure 5 is the nuclear magnetic hydrogen spectrum of the compound of LLi-1 of the present application.

[0129] Example 2, Preparation of the ring-bridged metallocene catalyst

[0130] In the following preparation process, the type of M is consistent with that in the structural formula of the catalyst.

[0131] (1) Preparation of catalysts I-1~I-16

[0132] Under nitrogen atmosphere, 3.9 mmol of the ligand monolithium salt (one of LLi1~LLi14) was weighed and added into 40 mL of ether to form a slurry, 16 mmol of LiMe was added dropwise under the condition of -35°C, and gradually restored to room temperature and stirred for 3 h, then 3.9 mmol of MCl4was weighed and added into 20 mL of ether under the condition of -35°C, the above ligand monolithium salt solution was slowly added into the MCl4solution, and restored to room temperature and stirred for 6 h, the reaction reagent was extracted and the product was extracted with n-hexane to remove LiCl. The product was recrystallized with toluene / n-hexane (volume ratio 1:16) to obtain the metal complex.

[0133] (2) Preparation of catalyst I-17

[0134] Under nitrogen atmosphere, 3.9 mmol of the ligand LLi14 was weighed into 40 mL of diethyl ether to form a slurry, and 20 mL of diethyl ether was added dropwise at -35 °C n BuLi 3.9 mmol, and stirred at room temperature for 3 h, and then 3.9 mmol of MCl4 was weighed, 20 mL of diethyl ether was added at -35 °C, and the above ligand lithium salt solution was slowly added into the MCl4 solution, and stirred at room temperature for 6 h. The reaction reagent was removed by suction, and the product was extracted with dichloromethane (toluene) to remove LiCl. The product was recrystallized with dichloromethane / n-hexane (volume ratio 1:16) to obtain the metal complex.

[0135] (3) Preparation of catalyst I-18

[0136] Under nitrogen atmosphere, the above prepared metal catalyst I-17 (3 mmol) was dissolved in toluene (50 mL) and cooled to -35 °C, and a benzyl magnesium bromide solution (6 mmol) was slowly added dropwise, and the reaction was carried out at room temperature for 3 h. The insoluble matter was removed by filtration, and the filtrate was removed by suction to obtain the target metal complex I-18.

[0137] The experimental results are as follows:

[0138] Catalyst I-1, yield: 0.73 g, yield: 35.1%, purity 95%, elemental analysis: found (calculated) C: 74.79 (74.81); H: 4.93 (4.95); O: 3.19 (3.02);

[0139] Catalyst I-2, yield: 0.72 g, yield: 33.6%, purity 94%, elemental analysis: found (calculated) C: 72.60 (72.61); H: 4.81 (4.80); S: 5.85 (5.87);

[0140] Catalyst I-3, yield: 0.68 g, yield: 32.7%, purity 96%, elemental analysis: found (calculated) C: 75.23 (75.21); H: 5.39 (5.37); N: 2.57 (2.58);

[0141] Catalyst I-4, yield: 0.75 g, yield: 34.5%, purity 95%, elemental analysis: found (calculated) C: 75.48 (75.49); H: 5.60 (5.61); N: 2.53 (2.52);

[0142] Catalyst I-5, yield: 0.73 g, yield: 32.1%, purity 94%, elemental analysis: found (calculated) C: 75.97 (75.98); H: 6.04 (6.03); N: 2.38 (2.39);

[0143] Catalyst I-6, yield: 0.79 g, 33.5% yield, 97% purity, elemental analysis: found (calculated) C: 77.43 (77.44); H: 5.19 (5.17); N: 2.31 (2.32);

[0144] Catalyst I-7, yield: 1.01 g, 31.7% yield, 95% purity, elemental analysis: found (calculated) C: 75.22 (75.23); H: 7.69 (7.68); O: 5.88 (5.89);

[0145] Catalyst I-8, yield: 1.00 g, 33.9% yield, 96% purity, elemental analysis: found (calculated) C: 78.02 (78.03); H: 7.74 (7.75); O: 2.13 (2.12);

[0146] Catalyst I-9, yield: 1.04 g, 31.8% yield, 94% purity, elemental analysis: found (calculated) C: 69.93 (69.94); H: 6.94 (6.95); O: 1.91 (1.90);

[0147] Catalyst I-10, yield: 0.90 g, 32.4% yield, 95% purity, elemental analysis: found (calculated) C: 82.78 (82.79); H: 8.23 (8.22); O: 2.24 (2.25);

[0148] Catalyst I-11, yield: 1.01 g, 33.2% yield, 94% purity, elemental analysis: found (calculated) C: 80.04 (80.04); H: 8.27 (8.27);

[0149] Catalyst I-12, yield: 0.77 g, 32.5% yield, 93% purity, elemental analysis: found (calculated) C: 76.79 (76.80); H: 5.61 (5.62); O: 2.61 (2.62);

[0150] Catalyst I-13, yield: 1.12 g, 33.1% yield, 94% purity, elemental analysis: found (calculated) C: 79.01 (79.02); H: 8.59 (8.61); O: 1.84 (1.85);

[0151] Catalyst I-14, yield: 1.10 g, 32.6% yield, 95% purity, elemental analysis: found (calculated) C: 79.00 (79.02); H: 8.60 (8.61); O: 1.83 (1.85);

[0152] Catalyst I-15, yield: 1.20 g, yield: 31.5%, purity 96%, elemental analysis: found (calculated) C: 80.08 (80.10); H: 8.88 (8.89); O: 1.63 (1.64);

[0153] Catalyst I-16, yield: 1.03 g, yield: 31.6%, purity 97%, elemental analysis: found (calculated) C: 79.17 (79.18); H: 7.96 (7.97); O: 1.91 (1.92);

[0154] Catalyst I-17, yield: 1.12 g, yield: 32.7%, purity 94%, elemental analysis: found (calculated) C: 72.73 (72.74); H: 6.90 (6.91); O: 1.82 (1.83);

[0155] Catalyst I-18, yield: 1.01 g, yield: 34.1%, purity 95%, elemental analysis: found (calculated) C: 81.56 (81.57); H: 7.55 (7.56); O: 1.61 (1.62).

[0156] Figure 6 NMR spectrum of the catalyst I-1 of the present application.

[0157] Example 3, catalytic ethylene polymerization

[0158] The polymerization reaction was carried out in a 1000 mL stainless steel autoclave, the polymerization reactor equipped with mechanical stirring was heated to 160°C, vacuumized for 2 h, and replaced with ethylene three times, the system was cooled to 65°C, and the required solvent and cocatalyst modified methylaluminoxane (MMAO) were sequentially added to the polymerization reactor under vacuum, the temperature in the reactor was increased to the required polymerization temperature of 150°C, after the temperature was constant, ethylene gas was introduced to make the polymerization pressure reach 4 MPa, and the system was balanced for 15 min to make ethylene fully dissolved to saturation (total liquid volume 600 mL). The main catalyst was transferred from the glove box to the main catalyst feeding tank under a nitrogen atmosphere, and then the main catalyst was pressed into the reaction system using a 4.5 MPa ethylene pressure difference, and the timing was started. The reaction was terminated after 15 min. The temperature was rapidly reduced to 60°C, the pressure was released, and then the reactor was opened, and the reaction mixture was poured into a mixed solution of 2M hydrochloric acid and ethanol with a volume ratio of 1:1, stirred for 30 min, and then filtered, and the polymer product was dried in a vacuum oven. The mass was weighed, the polymer molecular weight and molecular weight distribution were analyzed by high temperature GPC, and the comonomer insertion rate was analyzed by high temperature quantitative carbon spectrum, and the results are shown in Table 1.

[0159] Table 1 Catalyst I-1~I-18 catalytic ethylene polymerization data a

[0160]

[0161] aPolymerization conditions: 1 μmol of the procatalyst I-1 to I-18, MMAO-7 as cocatalyst, Al / M = 500, polymerization temperature: 150°C, polymerization pressure: 4.5 MPa, polymerization time: 15 min;bMolecular weight and molecular weight distribution were measured by GPC.

[0162] Example 4, copolymerization of ethylene with 1-butene

[0163] The polymerization was carried out in a 1000 mL stainless steel autoclave equipped with a mechanical stirrer. The polymerization reactor was heated to 160°C and vacuumed for 2 h. The reactor was cooled to 65°C and the required solvent and 1-butene (for easy calculation, the 1-butene was converted to the molar concentration relative to the n-hexane solvent in Table 2) were added into the reactor. The required amount of cocatalyst was added (the total volume of the solution was 600 mL) and the temperature of the reactor was increased to 150°C. When the temperature was constant, ethylene was introduced into the reactor to reach a pressure of 4 MPa. After 15 min of equilibration, the main catalyst was transferred from the glove box into the main catalyst feeding tank and then the main catalyst was injected into the reactor by the pressure difference of ethylene (4.5 MPa). The reaction was started and terminated after 15 min. The reactor was cooled to 60°C rapidly and then opened after depressurization. The reaction mixture was poured into a mixture of 2 M hydrochloric acid and ethanol (1:1 by volume) and stirred for 30 min. The polymer was collected by filtration and dried in a vacuum oven. The mass of the polymer was measured and the molecular weight and molecular weight distribution of the polymer were analyzed by high temperature GPC. The comonomer incorporation was analyzed by high temperature quantitative carbon spectrum. The results are shown in Table 2.

[0164] Table 2. Copolymerization data of ethylene with 1-butene catalyzed by the catalysts I-1 to I-18 a

[0165]

[0166]

[0167] aPolymerization conditions: 1 μmol of the procatalyst I-1 to I-18, MMAO-7 as cocatalyst, Al / M = 500, polymerization temperature: 150°C, polymerization pressure: 4.5 MPa, polymerization time: 15 min;bMolecular weight and molecular weight distribution were measured by GPC. 13CNMR measured, d co-catalyst is MMAO-3A, Al / M = 500; e co-catalyst is tri- (pentafluorophenyl)boron, MMAO-3A, B / M = 1.2, Al / M = 100; f co-catalyst is triphenylcarbenium tetrakis(pentafluorophenyl)borate, triisobutylaluminum, B / M = 1.2, Al / M = 100; g co-catalyst is [PhNHMe2][B(C6F5)4], tri-n-octylaluminum, B / M = 1.2, Al / M = 100; h co-catalyst is [(C18H37)2NHMe][B(C6F5)4], tri-n-octylaluminum, B / M = 1.2, Al / M = 100.

[0168] Figure 1 The polymer sample prepared in this example is shown in the figure, which shows that the obtained polymer has good transparency and uniformity, has very good light transmittance, and has high insertion rate, and is an elastomer material.

[0169] Example 5, catalyzing ethylene and 1-hexene copolymerization

[0170] The polymerization was carried out in a 1000 mL stainless steel autoclave, the polymerization reactor equipped with mechanical stirring was heated to 160°C, vacuumized for 2 h, the system was cooled to 65°C, the required solvent and the designed amount of 1-hexene (for convenience of calculation, the 1-hexene in the polymerization data in Table 3 was converted into the molar concentration relative to n-hexane solvent) were sequentially added to the polymerization reactor, the required amount of modified methylaluminoxane (MMAO) was added (the total volume of the final solution was 600 mL), the temperature in the reactor was increased to the required polymerization temperature of 150°C, after the temperature was constant, ethylene gas was introduced to make the polymerization pressure reach 4 MPa, and the system was balanced for 15 min to make ethylene fully dissolve to saturation, under the nitrogen atmosphere, the procatalyst prepared from the glove box was transferred to the procatalyst feeding tank, and then the procatalyst was pressed into the reaction system by using the pressure difference of ethylene (4.5 MPa), and the timing was started, and the reaction was terminated after 15 min. First, the temperature was rapidly decreased to 60°C, and then the pressure was released, the reactor was opened, and the reaction mixture was poured into a mixed solution of 2M hydrochloric acid and ethanol with a volume ratio of 1:1, stirred for 30 min, and then filtered, and the polymer product was dried in a vacuum oven. The mass was weighed, the polymer molecular weight and molecular weight distribution were analyzed by high temperature GPC, and the comonomer insertion rate was analyzed by high temperature quantitative carbon spectrum, and the results are shown in Table 3.

[0171] Table 3, catalysts I-1 to I-18 are the data of catalyzing ethylene and 1-hexene copolymerizationa

[0172]

[0173]

[0174] aPolymerization conditions: the amount of the main catalyst I-1 to I-18 was 1 μmol, the cocatalyst was MMAO-7, Al / M=500, the polymerization temperature was 150°C, the polymerization pressure was 4.5 MPa, and the polymerization time was 15 min;bThe molecular weight and the molecular weight distribution were measured by GPC;cThe comonomer insertion rate was measured by high temperature quantitative carbon spectrum 13 CNMR.

[0175] Figure 2 The polymer sample prepared in this example is shown in the figure, and it can be seen that the polymer has good uniformity, is semi-transparent, and has a good insertion rate.

[0176] Example 6, catalyzing ethylene and 1-octene copolymerization

[0177] The polymerization was carried out in a 1000 mL stainless steel high-pressure reactor, the polymerization reactor with mechanical stirring was heated to 160°C, vacuumized for 2 h, the system was cooled to 35°C, and then the required 1-octene (so that the concentration of 1-octene was 1.50 mol / L) and the designed amount of solvent were sequentially added to the polymerization reactor, and then the required amount of modified methylaluminoxane (MMAO) was added (the total volume of the final solution was 600 mL), the temperature in the reactor was increased to the required polymerization temperature of 150°C, and after the temperature was constant, ethylene gas was introduced to make the polymerization pressure reach 4 MPa, and the system was balanced for 15 min to make ethylene fully dissolve to saturation. Under the nitrogen atmosphere, the main catalyst prepared in the glove box was transferred to the main catalyst feeding tank, and then the main catalyst was pressed into the reaction system by using the pressure difference of ethylene (4.5 MPa), and the timing was started. After 15 min of reaction, the reaction was terminated. The temperature was rapidly decreased to 60°C, the pressure was released, and then the reactor was opened, and the reaction mixture was poured into a mixed solution of 2M hydrochloric acid and ethanol at a volume ratio of 1:1, stirred for 30 min, and then filtered, and the polymer product was dried in a vacuum oven. The mass was weighed, the molecular weight and the molecular weight distribution of the polymer were analyzed by high temperature GPC, and the comonomer insertion rate was analyzed by high temperature quantitative carbon spectrum, and the results are shown in Table 4.

[0178] Table 4 Data of catalyzing ethylene and 1-octene copolymerization by using the main catalyst I-1 to I-18

[0179]

[0180]

[0181] aPolymerization conditions: the amount of the main catalyst I-1 to I-18 was 1 μmol, the cocatalyst was MMAO-7, Al / M=500, the concentration of 1-octene was 1.50 mol / L, the polymerization pressure was 3 MPa, the polymerization temperature was 90°C, and the polymerization time was 15 min;bThe molecular weight and the molecular weight distribution were measured by GPC;cThe comonomer insertion rate was measured by high temperature quantitative carbon spectrum 13 CNMR.

[0182] Figure 3The polymer sample prepared in this example is shown in the figure. It can be seen that the polymer has good transparency, high light transmittance, good uniformity and high insertion rate.

[0183] Example 7, catalyzing ethylene and propylene to prepare propylene-based elastomer

[0184] The polymerization was carried out in a 1000 mL stainless steel autoclave. The polymerization reactor with mechanical stirring was heated to 160°C, vacuumized for 2 h, and the system was cooled to 45°C. Then, 200 g of propylene, the designed amount of solvent, and the required amount of modified methylaluminoxane (MMAO) (the total volume of the final solution was 600 mL) were sequentially added to the polymerization reactor. The temperature in the reactor was increased to 80°C, the required temperature for polymerization. After the temperature was constant, ethylene gas was introduced to make the polymerization pressure reach 2.5 MPa. After 15 min of equilibration, the ethylene was fully dissolved to saturation. Under a nitrogen atmosphere, the master catalyst prepared in the glove box was transferred to the master catalyst feeding tank, and then the master catalyst was pressed into the reaction system using the pressure difference of ethylene (3 MPa). The reaction was started and timed. After 15 min, the reaction was terminated. The temperature was rapidly decreased to 60°C, and the pressure was released. Then, the reactor was opened, and the reaction mixture was poured into a mixed solution of 2 M hydrochloric acid and ethanol with a volume ratio of 1:1. After stirring for 30 min, the polymer product was filtered and dried in a vacuum oven. The mass of the polymer product was measured, and the molecular weight and molecular weight distribution of the polymer were analyzed by high-temperature GPC. The comonomer insertion rate was analyzed by high-temperature quantitative carbon spectrum. The results are shown in Table 5.

[0185] Table 5. Data of catalyzing ethylene and propylene copolymerization by catalysts I-1 to I-6 as master catalyst

[0186]

[0187] a The amount of master catalyst I-1 to I-6 was 1 μmol, the cocatalyst was MMAO-7, Al / M = 500, the polymerization pressure was 3 MPa, the polymerization temperature was 80°C, and the polymerization time was 15 min; b The molecular weight and molecular weight distribution were measured by GPC; c The comonomer insertion rate was measured by 13 CNMR.

[0188] Example 8, catalyzing propylene / 1-butene copolymerization to prepare propylene-based elastomer

[0189] The polymerization was carried out in a 1000 mL stainless steel autoclave, the polymerization reactor equipped with mechanical stirring was heated to 160°C, vacuumized for 2 h, the system was cooled to 45°C, 200 g of propylene and 50 g of 1-butene were added into the polymerization reactor, the required amount of modified methylaluminoxane (MMAO) (the total volume of the final solution was 600 mL) was added, the temperature in the reactor was increased to the required polymerization temperature of 80°C, after the temperature was constant, the polymerization pressure was maintained at 1 MPa, and the system was balanced for 15 min. Under the nitrogen atmosphere, the master catalyst was transferred from the glove box to the master catalyst feeding tank, and then the master catalyst was pressed into the reaction system by using the nitrogen pressure difference (1.2 MPa), the reaction was started to be timed, and the reaction was terminated after 15 min. The temperature was rapidly decreased to 60°C, the pressure was released, and then the reactor was opened, the reaction mixture was poured into a mixed solution of 2M hydrochloric acid and ethanol with a volume ratio of 1:1, stirred for 30 min, and then filtered, and the polymer product was dried in a vacuum oven. The mass was weighed, the molecular weight and the molecular weight distribution of the polymer were analyzed by high temperature GPC, and the comonomer insertion rate was analyzed by high temperature quantitative carbon spectrum, and the results are shown in Table 6.

[0190] Table 6: Propylene / 1-butene copolymerization data catalyzed by catalysts I-1 to I-6 as master catalysts

[0191]

[0192]

[0193] aThe polymerization conditions: the amount of master catalyst I-1 to I-6 was 1 μmol, the cocatalyst was MMAO-7, Al / M=500, the polymerization pressure was 1 MPa, the polymerization temperature was 80°C, and the polymerization time was 15 min; bThe molecular weight and the molecular weight distribution were measured by GPC; cThe comonomer insertion rate was measured by CNMR. 13

[0194] Example 9: Preparation of propylene-based elastomer by catalyzing ethylene / propylene / 1-butene copolymerization

[0195] ​The polymerization was carried out in a 1000 mL stainless steel autoclave, the polymerization reactor equipped with mechanical stirring was heated to 160°C, vacuumized for 2 h, the system was cooled to 45°C, 200 g of propylene and 50 g of 1-butene were added into the polymerization reactor, the desired amount of modified methylaluminoxane (MMAO) (the total volume of the final solution was 600 mL) was added, the temperature in the reactor was increased to the desired polymerization temperature of 80°C, after the temperature was constant, ethylene gas was introduced to make the polymerization pressure reach 2.5 MPa, and the system was balanced for 15 min to make ethylene fully dissolved to saturation. Under the atmosphere of nitrogen, the master catalyst configured from the glove box was transferred to the master catalyst feeding tank, and then the master catalyst was pressed into the reaction system by using the pressure difference of ethylene (3 MPa), and the timing was started. The reaction was terminated after 15 min. The temperature was rapidly decreased to 60°C, and the reaction kettle was opened after depressurization, and the reaction mixture was poured into a mixed solution of 2 M hydrochloric acid and ethanol with a volume ratio of 1:1, stirred for 30 min, and then filtered. The polymer product was dried in a vacuum oven. The mass was weighed, the molecular weight and molecular weight distribution of the polymer were analyzed by high temperature GPC, and the comonomer insertion rate was analyzed by high temperature quantitative carbon spectrum, and the results are shown in Table 7.

[0196] Table 7 Catalyst I-1 ~ I-6 is the data of ethylene / propylene / 1-butene copolymerization catalyzed by the master catalysta

[0197]

[0198]

[0199] aThe amount of the master catalyst I-1 ~ I-6 was 1 μmol, the cocatalyst was MMAO-7, Al / M = 500, the polymerization pressure was 3 MPa, the polymerization temperature was 80°C, and the polymerization time was 15 min; bThe molecular weight and molecular weight distribution were measured by GPC; cThe comonomer insertion rate was measured by CNMR. 13 CNMR.

[0200] Example 10, catalyzing ethylene / propylene / 1,3-pentadiene copolymerization

[0201] The polymerization was carried out in a 1000 mL stainless steel autoclave, the polymerization reactor equipped with mechanical stirring was heated to 160℃, vacuumized for 2 h, the system was cooled to 45℃, 200 g of propylene and 50 g of 1,3-pentadiene were sequentially added into the polymerization reactor; the required amount of modified methylaluminoxane (MMAO) (the total volume of the final solution was 600 mL) was added, the temperature in the reactor was increased to the required polymerization temperature of 80℃, after the temperature was constant, ethylene gas was introduced to make the polymerization pressure reach 2.5 MPa, and the system was balanced for 15 min to make ethylene fully dissolved to saturation, under the nitrogen atmosphere, the master catalyst configured from the glove box was transferred to the master catalyst feeding tank, and then the master catalyst was pressed into the reaction system by using the pressure difference of ethylene (3 MPa), the timing was started, and the reaction was terminated after 15 min. The temperature was rapidly decreased to 60℃, the pressure was released, and then the reactor was opened, the reaction mixture was poured into a mixed solution of 2M hydrochloric acid and ethanol with a volume ratio of 1:1, stirred for 30 min, and then filtered, and the polymer product was dried in a vacuum oven. The mass was weighed, the polymer molecular weight and molecular weight distribution were analyzed by high temperature GPC, and the comonomer insertion rate was analyzed by high temperature quantitative carbon spectrum, and the results are shown in Table 8.

[0202] Table 8: Data of ethylene / propylene / 1,3-pentadiene copolymerization catalyzed by catalysts I-1~I-6 as master catalysts

[0203]

[0204]

[0205] a The polymerization conditions: the amount of master catalysts I-1~I-6 was 1 μmol, the cocatalyst was MMAO-7, Al / M=500, the polymerization pressure was 3 MPa, the polymerization temperature was 80℃, and the polymerization time was 15 min; b The molecular weight and molecular weight distribution were measured by GPC; c The comonomer insertion rate was measured by CNMR. 13

[0206] It can be known from the above examples that the ring-bridged biscyclopentadienyl catalyst developed by the application has high thermal stability, high activity and high copolymerization performance, and can maintain very high catalytic activity at 150℃. The catalyst has super-high activity in catalyzing the copolymerization of ethylene and 1-butene, 1-hexene and 1-octene, and the molecular weight and comonomer insertion rate of the polymer are also very high. The experimental results show that the molecular weight of the polymer obtained by the catalyst provided by the application in the copolymerization of ethylene and 1-butene is up to 38.5×10 4 g / mol, and the 1-butene molar insertion rate is up to 36.2%; the molecular weight of the polymer obtained by the copolymerization of ethylene and 1-hexene is up to 40.1×10 4 g / mol, and the 1-hexene molar insertion rate is up to 25.1%; the molecular weight of the polymer obtained by the copolymerization of ethylene and 1-octene is up to 36.1×10​4 g / mol, the highest 1-octene molar insertion rate was 19.0%; the molecular weight of the polymer obtained by ethylene and propylene copolymerization was up to 25.9 x 10 4 g / mol, the highest 1-octene molar insertion rate was 19.0%; the molecular weight of the polymer obtained by ethylene and propylene copolymerization was up to 25.9 x 10 4 g / mol, the highest 1-octene molar insertion rate was 19.0%; the molecular weight of the polymer obtained by ethylene and propylene copolymerization was up to 25.9 x 10 4 g / mol, the highest 1-octene molar insertion rate was 19.0%; the molecular weight of the polymer obtained by ethylene and propylene copolymerization was up to 25.9 x 10 4 g / mol, the highest 1-octene molar insertion rate was 19.0%; the molecular weight of the polymer obtained by ethylene and propylene copolymerization was up to 25.9 x 10

[0207] The above examples are only used to help understand the method of the present application and its core idea. It should be noted that for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified, and these improvements and modifications also fall within the scope of the claims of the present application.

Claims

1. A cyclic bridged bis-metallocene catalyst having the structure of Formula I: Formula I; M is selected from Zr, Hf or Ti; R1 is selected from halogen, substituted or unsubstituted C1-C10 alkyl; the substituents of R1 are independently selected from halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkylsilyl, C6-C12 mono or bi-cyclic aryl; X is selected from oxygen, sulfur, nitrogen, selenium, carbon; when X is selected from oxygen, sulfur or selenium, R2 is absent; when X is selected from nitrogen or carbon, R2 is selected from hydrogen, substituted or unsubstituted C1-C10 alkyl, 3-6 membered cycloalkyl, C6-C12 aryl, C2-C12 heteroaryl; the substituents of R2 are independently selected from halogen, C1-C10 alkyl, C1-C10 alkoxy, C6-C12 mono or bi-cyclic aryl, C2-C12 mono or bi-cyclic heteroaryl; the substituents of the cyclic structure group are selected from halogen, C1-C10 alkyl. having any one of the following structures: wherein 3. A method for preparing the cyclic bridged bis-metallocene catalyst of any one of claims 1-2, comprising the following steps: S1) reacting a compound of Formula a with a compound of Formula b to obtain a compound of Formula c; S2) coordinating the compound of Formula c with a metal precursor to obtain the cyclic bridged bis-metallocene catalyst of Formula I; Formula I; 4. A catalyst system for olefin polymerization, comprising at least two of a catalyst, a co-catalyst, and a boron agent; the catalyst is the cyclic bridged bis-metallocene catalyst of any one of claims 1-2; the co-catalyst is selected from one or more of an alkyl aluminum, an aluminoxane, and a chlorinated alkyl aluminum; comprising: polymerizing one or more olefins under the catalysis of the cyclic bridged bis-metallocene catalyst of any one of claims 1-2 or the catalyst system of any one of claims 4-5 to obtain an olefin polymer; the olefin comprises one or more of ethylene, propylene, 1-butene, 1-hexene, 1-octene, styrene, cyclopentene, cyclohexene, norbornene, ethylidene norbornene, 1,3-butadiene, 1,3-pentadiene; the polymerization reaction is carried out at a temperature of 80-200 °C and a pressure of 0.1-10 MPa.

5. The olefin polymer obtained by the method of claim 3 or 4. ​ ​ ​ ​ The R3~R 22 Independently selected from halogens, hydrogen, substituted or unsubstituted C1-C10 alkyl, C1-C10 alkoxy, 3-6 membered cycloalkyl, C6-C12 aryl, C2-C12 heteroaryl; R3to R6are independently selected from the group consisting of halogen, C1-C6alkyl, C6-C12monocyclic or bicyclic aryl, C2-C12monocyclic or bicyclic heteroaryl; and 22 R3to R6are independently selected from the group consisting of halogen, C1-C6alkyl, C6-C12monocyclic or bicyclic aryl, C2-C12monocyclic or bicyclic heteroaryl; and or any two of the R7-R 10 adjacent to each other, together with the aryl carbon atom to which they are attached, form a substituted or unsubstituted five- to six-membered cyclic structural group; 11 -R 14 adjacent to each other, together with the aryl carbon atom to which they are attached, form a substituted or unsubstituted five- to six-membered cyclic structural group; ​ 2. The annular bridged bis-metallocene catalyst of claim 1, wherein, ​ 。 ​ ​ ​ Formula a; Formula b; Formula c; ​ wherein M, R1, X, R2, R3~R 22 are as described in any one of claims 1-2. ​ ​ 5. The catalyst system for the polymerization of olefins according to claim 4, characterized in that, ​ the boron agent is selected from one or more of tris(pentafluorophenyl)boron, triphenylcarbenium tetra(pentafluorophenyl)borate, tri(4-octylphenyl)carbenium tetra(pentafluorophenyl)borate, [PhNHMe2][B(C6F5)4], [(C 18 H 37 )2NHMe][B(C6F5)4], [C 18 H 37 NHMePh][B(C6F5)4].

6. A process for the preparation of an olefin polymer, characterized by, ​ ​ ​ ​ The molecular weight Mw of the olefin polymer is 100-800 kg·mol -1 The molar insertion rate of the olefin monomer is 9-40 mol%, the melting point is 20-90℃, the glass transition temperature is -40--90℃, and the light transmittance is ≥91%.

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