Binuclear metal catalyst and application thereof, and preparation method of cycloolefin copolymer

Abstract

The invention provides a binuclear metal catalyst and application thereof, and a preparation method of a cycloolefin copolymer, the binuclear metal catalyst has a structure as shown in formula I, the binuclear metal catalyst contains two metal centers, through the design of a molecular structure, the three-dimensional effect and the electronic effect of the two center metals of the catalyst can be regulated, and the performance of the catalyst is improved. Therefore, the synergistic catalytic effect of the double metal centers is achieved. The binuclear metal catalyst has excellent catalytic activity and thermal stability, is especially suitable for catalyzing copolymerization of ethylene and cycloolefin, and is high in catalytic activity, so that the prepared cycloolefin copolymer has the characteristics of high cycloolefin insertion rate, high molecular weight and high glass transition temperature, and meanwhile, the molecular weight distribution is proper; and the processing performance is excellent.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts and olefin polymerization, and specifically relates to a binuclear metal catalyst and application thereof, and a method for preparing a cycloolefin copolymer. Background Art

[0002] Cyclic Olefin Copolymer (COC) has excellent heat resistance, chemical corrosion resistance, high strength, high rigidity, excellent UV-Vis transparency and extremely low hygroscopicity, and has broad application prospects in the fields of optical lenses, medical packaging materials, etc.

[0003] At present, the main polymerization method of cycloolefin copolymer is the chain addition copolymerization of ethylene or α-olefin and norbornene cycloolefin monomers. The polymerization reaction can be carried out in different systems such as metallocene catalysts and non-metallocene catalysts. Metallocene catalysts have been a research hotspot in metal organic chemistry, catalysis, polymer chemistry and materials science in recent decades. The characteristics of metallocene catalysts are that the molecular weight distribution and chemical composition distribution of the obtained polymers are relatively uniform, and the molecular structure and molecular weight of the polymers can be highly controlled by adjusting the catalyst structure. Catalyzed by metallocene catalysts, olefin copolymers with a high comonomer content can be obtained, which has very obvious advantages for the preparation of cycloolefin copolymers.

[0004] CN115677879A discloses a method for preparing cycloolefin copolymers using a metallocene catalyst, wherein the main catalyst has the structure of D is a bridging group containing C or Si, Q is a metal center, at least one of R5, R6, R7, and R8 is a silicon-containing substituent, and / or R a , R b At least one of the groups is a silicon-containing group. The catalyst can be used to prepare a low molecular weight cycloolefin copolymer without the additional introduction of molecular weight regulators such as hydrogen and propylene. CN102702433A discloses a method for preparing an ethylene-norbornene copolymer, wherein the main catalyst used is a semi-metallocene catalyst, and the molecular structure contains P, O or S atoms, so that the catalyst has good activity. After the action of a co-catalyst, a salt ion active center is formed to catalyze the copolymerization of ethylene and norbornene to obtain a cycloolefin copolymer with a higher molecular weight. However, the performance of the existing metallocene / semi-metallocene catalysts in cycloolefin copolymerization is still very insufficient, mainly manifested in low catalytic activity and low insertion rate of cycloolefins in the copolymer.

[0005] Compared with mononuclear metallocene catalysts, dinuclear metallocene catalysts have unique catalytic properties. For example, the synthesis and application of dinuclear metallocene catalysts are reported in the literature ("Multinuclear Olefin Polymerization Catalysts", Chem. Rev., 2011, 111, 2450-2485), but the catalyst has serious chain transfer reactions, resulting in low molecular weight of the polymer. CN114031703A discloses a method for preparing ethylene and norbornene copolymers using a dinuclear catalyst, but its polymerization activity is not high, and the molecular weight of the prepared copolymer is low.

[0006] Since the existing metallocene catalysts have low polymerization activity in the catalytic preparation of COC and low cyclic olefin insertion rate, the production cost of COC is high, which restricts its further market expansion. Therefore, the development of more economical and effective catalysts is the key to allowing COC to play a greater role in more occasions. Summary of the invention

[0007] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a binuclear metal catalyst and its application, and a method for preparing a cycloolefin copolymer. Through the design of the molecular structure, the binuclear metal catalyst has excellent catalytic activity and thermal stability. It is used to catalyze the copolymerization of cycloolefins and can prepare cycloolefin copolymers with high molecular weight, high glass transition temperature and high cycloolefin insertion rate.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a binuclear metal catalyst having a structure as shown in Formula I:

[0010]

[0011] In formula I, R is selected from any one of C1-C6 straight chain or branched chain alkyl groups.

[0012] In formula I, X1 and X2 are each independently selected from any one of halogen, C1-C10 straight or branched alkyl, C6-C20 aryl, C7-C20 arylalkyl, C1-C20 alkylamino, and C6-C30 arylamino.

[0013] In formula I, M is selected from any one of the Group IVB metals.

[0014] The binuclear metal catalyst provided by the present invention is shown in Formula I, wherein it contains two metal centers, has two ligands of cyclopentadienyl and fluorenyl, and is connected to a bridging silicon group through a biphenyl structure, and can regulate the stereo effect and electronic effect of the two central metals of the catalyst, thereby achieving a synergistic catalytic effect of the bimetallic center. Based on the design of the molecular structure, the binuclear metal catalyst has high catalytic activity and excellent thermal stability. When catalyzing the copolymerization of ethylene and cycloolefins, it can maintain high activity and high insertion rate of cycloolefins, and can also make the copolymer have a high molecular weight and an appropriate molecular weight distribution, thereby obtaining a cycloolefin copolymer with a high glass transition temperature and excellent processing performance.

[0015] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0016] In the present invention, the halogen includes fluorine, chlorine, bromine and iodine.

[0017] In the present invention, the C1-C6 straight chain or branched alkyl group can be a straight chain or branched alkyl group of C1, C2, C3, C4, C5, or C6, illustratively including but not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-methylbutyl, n-pentyl, isopentyl, neopentyl, n-hexyl, neohexyl, and the like.

[0018] In the present invention, the C1-C10 straight chain or branched alkyl group can be a straight chain or branched alkyl group of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, illustratively including but not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-methylbutyl, n-pentyl, isopentyl, neopentyl, n-hexyl, neohexyl, 2-ethylhexyl, n-octyl, n-heptyl, n-nonyl, n-decyl, etc.

[0019] In the present invention, the C6-C20 aromatic groups can be aromatic groups of C6, C9, C10, C12, C14, C16, C18, C20, etc., including monocyclic aromatic groups and condensed-ring aromatic groups, illustratively including but not limited to: phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthrenyl, fluorenyl, indenyl, etc.

[0020] In the present invention, the C7-C20 aryl alkyl group can be an aryl alkyl group of C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, etc., and a specific example is a monovalent group formed by connecting the above aryl groups to a straight-chain or branched alkyl group, and a typical example is benzyl (phenylmethyl).

[0021] In the present invention, the C1-C20 alkylamino group can be an alkylamino group of C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, etc., which is a monovalent group in which at least one hydrogen in -NH2 is replaced by the above-mentioned straight-chain or branched alkyl group.

[0022] In the present invention, the C6-C30 arylamino group can be an arylamino group of C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, which is a monovalent group in which at least one hydrogen in -NH2 is replaced by the above aryl group.

[0023] Preferably, R is selected from any one of C1-C4 straight or branched alkyl groups, more preferably any one of methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, and more preferably methyl.

[0024] Preferably, X1 and X2 are each independently selected from any one of halogen, C1-C6 straight or branched alkyl, benzyl, and C2-C10 alkylamino, and more preferably any one of chlorine, methyl, tert-butyl, benzyl, and dimethylamino.

[0025] Preferably, the M is selected from any one of titanium, zirconium and hafnium, and zirconium is more preferred.

[0026] Preferably, the binuclear metal catalyst comprises any one or a combination of at least two of the following compounds:

[0027]

[0028] In another aspect, the present invention provides a method for preparing the metal catalyst as described in the first aspect, the preparation method comprising the following steps:

[0029] (1) a halogenated fluorene of the structure represented by formula A is subjected to a first reaction with magnesium in an anhydrous solvent to obtain a halogenated magnesium compound, and the halogenated magnesium compound is subjected to a second reaction with a silane compound of the structure represented by formula B in an anhydrous solvent to obtain a first intermediate of the structure represented by formula C;

[0030] (2) reacting the first intermediate with a biphenyl compound of formula D to obtain a second intermediate of formula E;

[0031] (3) the second intermediate reacts with cyclopentadiene to obtain a ligand having a structure shown in formula F;

[0032] (4) the ligand reacts with a metal M source to obtain a binuclear metal catalyst having a structure shown in formula I;

[0033] The reaction formula is as follows:

[0034]

[0035] Wherein, R, X1, X2, and M have the same definitions as in the first aspect; Hal1, Hal2, Hal3, Hal4, and Hal5 represent halogens, each independently selected from any one of F, Cl, Br, or I.

[0036] Preferably, the Hal1 is Br, and the Hal2, Hal3 and Hal4 are all Cl.

[0037] Preferably, the first reaction in step (1) is carried out in an inert atmosphere, and the inert atmosphere is preferably a nitrogen atmosphere and / or an argon atmosphere.

[0038] Preferably, the temperature of the first reaction in step (1) is 50-120°C, for example, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or 115°C, and specific values ​​between the above values. Due to space limitations and for simplicity, the present invention no longer exhaustively lists the specific values ​​included in the range, and further preferably, the reflux temperature. The reflux temperature is about the boiling point of the anhydrous solvent in step (1).

[0039] Preferably, the time of the first reaction in step (1) is 1-12 h, for example, it can be 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h or 11 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0040] Preferably, the temperature of the second reaction in step (1) is 50-120°C, for example, it can be 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or 115°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and the reflux temperature is further preferred.

[0041] Preferably, the time of the second reaction in step (1) is 1-24 h, for example, it can be 2 h, 4 h, 5 h, 6 h, 8 h, 10 h, 12 h, 14 h, 15 h, 16 h, 18 h, 20 h or 22 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the range, and the reflux temperature is further preferred.

[0042] Preferably, step (1) further comprises a post-treatment step after the second reaction is completed, and the post-treatment step comprises solvent removal, redissolution, filtration and recrystallization.

[0043] Preferably, Hal5 is Br, that is, the biphenyl compound is 4,4'-dibromobiphenyl.

[0044] Preferably, the reaction method of step (2) comprises: firstly subjecting the biphenyl compound of the structure shown in formula D to a first reaction with sodium in an anhydrous solvent, and then subjecting the obtained product to a second reaction with the first intermediate in an anhydrous solvent to obtain the second intermediate.

[0045] Preferably, the first reaction in step (2) is carried out in an inert atmosphere, and the inert atmosphere is preferably a nitrogen atmosphere and / or an argon atmosphere.

[0046] Preferably, the temperature of the first reaction in step (2) is 50-120°C, for example, it can be 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or 115°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the range, and the reflux temperature is further preferred.

[0047] Preferably, the time of the first reaction in step (2) is 1-12 h, for example, it can be 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h or 11 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0048] Preferably, the temperature of the second reaction in step (2) is 50-120°C, for example, it can be 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or 115°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and the reflux temperature is further preferred.

[0049] Preferably, the time of the second reaction in step (2) is 1-24 h, for example, it can be 2 h, 4 h, 5 h, 6 h, 8 h, 10 h, 12 h, 14 h, 15 h, 16 h, 18 h, 20 h or 22 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0050] Preferably, step (2) further comprises a post-treatment step after completion of the second reaction, and the post-treatment comprises solvent removal, redissolution, filtration and recrystallization.

[0051] Preferably, the reaction method in step (3) comprises: performing a first reaction on the cyclopentadiene and butyl lithium in an anhydrous solvent, and performing a second reaction on the obtained product and the second intermediate to obtain a ligand with a structure shown in formula F.

[0052] Preferably, the butyl lithium includes n-butyl lithium and / or tert-butyl lithium, and n-butyl lithium is further preferred.

[0053] Preferably, the temperature of the first reaction and the second reaction in step (3) is independently 15-40°C, for example, 18°C, 20°C, 22°C, 25°C, 28°C, 30°C, 32°C, 35°C or 38°C, as well as specific values ​​between the above-mentioned points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the said range, and room temperature / normal temperature is further preferred.

[0054] Preferably, the time for the first reaction and the second reaction in step (3) is independently 1-24 h, for example, 2 h, 4 h, 5 h, 6 h, 8 h, 10 h, 12 h, 14 h, 15 h, 16 h, 18 h, 20 h or 22 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0055] Preferably, step (3) further comprises a post-treatment step after completion of the second reaction, wherein the post-treatment step comprises solvent removal, redissolution, filtration and recrystallization.

[0056] Preferably, the reaction method of step (4) comprises: performing a first reaction between the ligand and an organic lithium reagent in an anhydrous solvent to obtain a lithium salt solution of the ligand; and performing a second reaction between the lithium salt solution of the ligand and a metal M source to obtain the binuclear metal catalyst.

[0057] Preferably, the organic lithium reagent includes n-butyl lithium and / or tert-butyl lithium, and n-butyl lithium is more preferred.

[0058] Preferably, the metal M source comprises a metal M salt, such as any one or a combination of at least two of a halide of a Group IVB metal, an amide of a Group IVB metal, an alkyl compound of a Group IVB metal, an alkylamide of a Group IVB metal, an aryl compound of a Group IVB metal, or a benzyl compound of a Group IVB metal.

[0059] Preferably, the metal M source includes titanium tetrachloride, zirconium tetrachloride or hafnium tetrachloride.

[0060] Preferably, the temperature of the first reaction and the second reaction in step (4) is independently 15-40°C, for example, 18°C, 20°C, 22°C, 25°C, 28°C, 30°C, 32°C, 35°C or 38°C, as well as specific values ​​between the above-mentioned points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the said range, and room temperature / normal temperature is further preferred.

[0061] Preferably, the time for the first reaction and the second reaction in step (4) is independently 1-24 h, for example, 2 h, 4 h, 5 h, 6 h, 8 h, 10 h, 12 h, 14 h, 15 h, 16 h, 18 h, 20 h or 22 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0062] Preferably, step (4) further comprises a post-treatment step after completion of the second reaction, wherein the post-treatment step comprises solvent removal, redissolution, filtration and recrystallization.

[0063] Preferably, the anhydrous solvents in the preparation method independently include any one of benzene, toluene, xylene, tetrahydrofuran, diethyl ether, and dichloromethane, or a combination of at least two thereof.

[0064] It should be noted that obtaining the binuclear metal catalyst represented by formula I in the present invention is not limited to the synthesis method and raw materials used in the present invention. Those skilled in the art can also select other methods or routes to obtain the binuclear metal catalyst proposed in the present invention.

[0065] In a second aspect, the present invention provides a catalyst composition, which comprises the binuclear metal catalyst as described in the first aspect and a co-catalyst.

[0066] Preferably, the co-catalyst comprises any one of an organoaluminum oxy compound, an alkyl aluminum compound, and an organoboron compound, or a combination of at least two of them, and more preferably a combination of an organoaluminum oxy compound or an alkyl aluminum compound and an organoboron compound.

[0067] Preferably, the molar ratio of the binuclear metal catalyst to the co-catalyst is 1:(1-1000), for example, it can be 1:2, 1:5, 1:10, 1:20, 1:40, 1:50, 1:80, 1:100, 1:150, 1:200, 1:250, 1:300, 1:350, 1:400, 1:450, 1:500, 1:550, 1:600, 1:650, 1:700, 1:750, 1:800, 1:850, 1:900 or 1:950, etc.

[0068] Preferably, the organic aluminum oxide compound includes any one of methylaluminoxane (MAO), modified methylaluminoxane (MMAO), ethylaluminoxane, and isobutylaluminoxane, or a combination of at least two thereof.

[0069] Preferably, the molar ratio of the organic aluminum oxide compound to the binuclear metal catalyst in the co-catalyst is (50-2000):1, for example, it can be 60:1, 80:1, 100:1, 150:1, 200:1, 250:1, 300:1, 350:1, 400:1, 450:1, 500:1, 550:1, 600:1, 650:1, 700:1 or 750:1, 800:1, 900:1, 1000:1, 1200:1, 1400:1, 1500:1, 1600:1 or 1800:1, etc.

[0070] Preferably, the alkyl aluminum compound includes any one of trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tri-n-hexylaluminum, and diethylaluminum monochloride, or a combination of at least two thereof.

[0071] Preferably, the molar ratio of the alkyl aluminum compound to the binuclear metal catalyst in the co-catalyst is (5-1000):1, for example, it can be 8:1, 10:1, 20:1, 40:1, 50:1, 60:1, 80:1, 100:1, 150:1, 200:1, 250:1, 300:1, 350:1, 400:1, 450:1, 500:1, 550:1, 600:1, 650:1, 700:1, 750:1, 800:1, 850:1, 900:1 or 950:1, etc.

[0072] Preferably, the organic boron compound includes any one of triphenylborane, tri(pentafluorophenyl)borane, triperfluorobiphenylborane, triphenylmethyltetrakis(pentafluorophenyl)borate, and tert-butyltriphenylmethyltetrakis(pentafluorophenyl)borate, or a combination of at least two thereof.

[0073] Preferably, the molar ratio of the organic boron compound to the binuclear metal catalyst in the co-catalyst is (2-20):1, for example, it can be 2.5:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1 or 19:1, etc.

[0074] In a third aspect, the present invention provides a use of the binuclear metal catalyst as described in the first aspect and the catalyst composition as described in the second aspect in olefin polymerization.

[0075] Preferably, the olefin includes any one of ethylene, α-olefin, cycloolefin, or a combination of at least two thereof.

[0076] Preferably, the polymerization comprises homopolymerization or copolymerization.

[0077] Further preferably, the olefin polymerization is copolymerization of a cycloolefin and a second olefin monomer, and the second olefin monomer includes any one of ethylene and α-olefin or a combination of at least two of them.

[0078] In a fourth aspect, the present invention provides a method for preparing a cycloolefin copolymer, the preparation method comprising: subjecting a cycloolefin and a second olefin monomer to a polymerization reaction in the presence of a catalyst to obtain the cycloolefin copolymer; the catalyst comprising any one of the binuclear metal catalyst described in the first aspect and the catalyst composition described in the second aspect.

[0079] Preferably, the cyclic olefin includes any one of norbornene, vinyl norbornene, 5-ethylidene-2-norbornene (ethylidene norbornene), dicyclopentadiene, and tetracyclododecene, or a combination of at least two thereof.

[0080] Preferably, the second olefin monomer includes any one of ethylene and α-olefin or a combination of at least two of them, and ethylene is more preferred.

[0081] Preferably, the α-olefin includes C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C11, C12, C14, C15, C16, C18, etc.) α-olefins, illustratively including but not limited to: any one of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene, or a combination of at least two thereof.

[0082] Preferably, the polymerization reaction is carried out in the presence of a solvent, that is, the polymerization reaction adopts a solution polymerization method.

[0083] Preferably, the solvent includes any one of aliphatic hydrocarbon solvents, halogenated aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, aromatic hydrocarbon solvents, and halogenated aromatic hydrocarbon solvents, or a combination of at least two thereof.

[0084] Preferably, the aliphatic hydrocarbon solvent includes any one of n-hexane, n-heptane, and isoparaffins, or a combination of at least two of them.

[0085] Preferably, the alicyclic hydrocarbon solvent includes any one of cyclohexane, cyclooctane, and decalin, or a combination of at least two of them.

[0086] Preferably, the aromatic hydrocarbon solvent includes toluene and / or xylene.

[0087] Preferably, the polymerization reaction is carried out optionally in the presence of a chain transfer agent.

[0088] Preferably, the chain transfer agent comprises hydrogen.

[0089] Preferably, the polymerization reaction temperature is 80-160°C, for example, it can be 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C or 155°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0090] Preferably, the polymerization reaction pressure is 0.2-2.0 MPa, for example, it can be 0.3 MPa, 0.5 MPa, 0.8 MPa, 1 MPa, 1.2 MPa, 1.4 MPa, 1.5 MPa, 1.6 MPa or 1.8 MPa, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0091] Preferably, the polymerization reaction time is 1-30 min, for example, it can be 2 min, 5 min, 8 min, 10 min, 12 min, 15 min, 16 min, 18 min, 20 min, 22 min, 25 min or 28 min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0092] Preferably, after the polymerization reaction is completed, a post-treatment step is further included, and the post-treatment includes precipitation, washing and drying.

[0093] Preferably, the precipitation solvent used for the precipitation is an acid-alcohol solution, and the acid-alcohol solution includes a combination of ethanol and hydrochloric acid.

[0094] Preferably, the mass percentage of ethanol in the acid-alcohol solution is 95-99.99%, for example, it can be 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, 99.8% or 99.9%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0095] As a preferred technical solution of the present invention, the binuclear metal catalyst is used to catalyze the preparation of cycloolefin copolymers, and its catalytic activity is high, which can be 0.8×10 7 -4×10 7g / (mol Cat·h) and has excellent thermal stability. The obtained cycloolefin copolymer has high molecular weight, high glass transition temperature, high cycloolefin insertion rate, suitable molecular weight distribution and excellent processability.

[0096] Preferably, the weight average molecular weight (M w )≥5×10 4 g / mol, for example, 5.2×10 4 g / mol, 5.5×10 4 g / mol, 5.8×10 4 g / mol, 6×10 4 g / mol, 6.2×10 4 g / mol, 6.5×10 4 g / mol, 6.8×10 4 g / mol, 7×10 4 g / mol, 7.5×10 4 g / mol, 8×10 4 g / mol, 8.5×10 4 g / mol, 9×10 4 g / mol, 9.5×10 4 g / mol, 10×10 4 g / mol, 10.5×10 4 g / mol, 11×10 4 g / mol or 12×10 4 g / mol, etc., as well as specific point values ​​between the above point values, limited by the length of the article and for the sake of simplicity, the present invention will no longer exhaustively list the specific point values ​​included in the range, and further preferably 5.2×10 4 -11×10 4 g / mol.

[0097] Preferably, the molecular weight distribution (PDI, M w / M n ) is 3-8, for example, it can be 3.5, 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 5.8, 6, 6.2, 6.5, 6.8, 7, 7.2, 7.5 or 7.8, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the said range, and 4-7 is further preferred.

[0098] Preferably, the molar insertion rate of cycloolefin in the cycloolefin copolymer is ≥50%, for example, it can be 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80% or 85%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0099] Preferably, the glass transition temperature (T g )≥140°C, for example, it can be 142°C, 145°C, 148°C, 150°C, 152°C, 155°C, 158°C, 160°C, 162°C, 165°C, 168°C, 170°C, 172°C, 175°C, 178°C, 180°C, 185°C, 190°C or 195°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the said range, and 145-192°C is further preferred.

[0100] Compared with the prior art, the present invention has the following beneficial effects:

[0101] The binuclear metal catalyst provided by the present invention contains two metal centers. Through the design of the molecular structure, the stereo effect and electronic effect of the two central metals of the catalyst can be regulated, thereby realizing the synergistic catalytic effect of the binuclear metal center. The binuclear metal catalyst has excellent catalytic activity and thermal stability, is particularly suitable for catalyzing the copolymerization reaction of ethylene and cycloolefins, has high catalytic activity, and makes the prepared cycloolefin copolymer have the characteristics of high cycloolefin insertion rate, high molecular weight and high glass transition temperature, and has suitable molecular weight distribution and excellent processing performance. DETAILED DESCRIPTION

[0102] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0103] In one embodiment, the binuclear metal catalyst of the structure shown in Formula I can be prepared by the following exemplary preparation method. Of course, those skilled in the art can also obtain the binuclear metal catalyst by other methods. The exemplary preparation method comprises the following steps:

[0104] (1) In an inert atmosphere, 9-bromofluorene is added dropwise to an anhydrous solvent containing magnesium chips, the mixture is heated to reflux temperature and stirred for reaction for 1-12 hours, cooled and allowed to stand, the supernatant is taken and added dropwise to an anhydrous solvent containing an appropriate amount of trichloroalkylsilane, and the mixture is heated to reflux temperature and stirred for reaction for 1-24 hours. The solvent is then removed in vacuo, an appropriate amount of anhydrous toluene is added, and the mixture is stirred at room temperature for 1-5 hours. The solid portion is removed by filtration through a diatomaceous earth plug, and the filtrate is recrystallized with anhydrous n-hexane to obtain a first intermediate of the structure shown in Formula C.

[0105] (2) In an inert atmosphere, 4,4'-dibromobiphenyl is added dropwise to an anhydrous solvent containing sodium crumbs, the mixture is heated to reflux temperature and stirred for reaction for 1-12 hours, after cooling and standing, the supernatant is taken and added dropwise to an anhydrous solvent containing an appropriate amount of the first intermediate, and the mixture is heated to reflux temperature and stirred for reaction for 1-24 hours. After the solvent is removed in vacuo, an appropriate amount of anhydrous toluene is added and stirred at room temperature for 1-5 hours. The solid portion is removed by filtration through a diatomaceous earth plug, and the filtrate is recrystallized with anhydrous n-hexane to obtain a second intermediate of the structure shown in Formula E;

[0106] (3) In an inert atmosphere, cyclopentadiene is dissolved in an anhydrous solvent, an appropriate amount of n-butyl lithium is added under low temperature, the temperature is gradually raised to room temperature and stirred for reaction for 1-24 hours, then the temperature is lowered to low temperature, an appropriate amount of the second intermediate is added dropwise, and the temperature is gradually raised to room temperature and stirred for reaction for 1-24 hours after the addition is completed. After the solvent is removed in vacuo, an appropriate amount of anhydrous toluene is added and stirred at room temperature for 1-5 hours. The solid part is removed by filtration through a diatomaceous earth plug, and the filtrate is recrystallized with anhydrous n-hexane to obtain a ligand with the structure shown in Formula F;

[0107] (4) In an inert atmosphere, the ligand is dispersed in an anhydrous solvent, and an appropriate amount of n-butyl lithium is added under low temperature conditions, and the temperature is gradually raised to room temperature and stirred for 1-24 hours to obtain a ligand lithium salt solution. An appropriate amount of metal M source is dispersed in an anhydrous solvent at low temperature, and the temperature is gradually raised to room temperature and stirred for 0.5-2 hours to obtain a solution or suspension of the metal M source. The ligand lithium salt solution is then cooled to a low temperature, and a solution or suspension of an appropriate metal M source is added dropwise, and the temperature is gradually raised to room temperature. The reaction is stirred at room temperature for 1-24 hours. After the solvent is removed in vacuo, an appropriate amount of anhydrous toluene is added, and the reaction is stirred at room temperature for 1-5 hours. The solid portion is removed by filtration through a diatomaceous earth plug, and the filtrate is recrystallized with anhydrous n-hexane to obtain a binuclear metal catalyst with the structure shown in Formula I; the reaction formula is as follows:

[0108]

[0109] Wherein, R, X1, X2, and M have the same definitions as in Formula I.

[0110] In a preferred embodiment, the inert atmosphere in steps (1) to (4) is a nitrogen atmosphere.

[0111] In a preferred embodiment, the anhydrous solvents in steps (1) to (4) each independently include any one of benzene, toluene, xylene, tetrahydrofuran, diethyl ether, and dichloromethane, or a combination of at least two thereof.

[0112] In a preferred embodiment, the temperature of the low temperature conditions in steps (3)-(4) is less than 0°C, for example, it can be -10°C, -20°C, -30°C, -40°C, -50°C, -60°C, -70°C, -80°C, -90°C, -100°C or -110°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range, and further preferably -30°C to -100°C.

[0113] In a preferred embodiment, the metal M source includes titanium tetrachloride, zirconium tetrachloride or hafnium tetrachloride.

[0114] The binuclear metal catalyst and its preparation method of the present invention will be described in detail below with multiple examples, but the binuclear metal catalyst of the present invention is not limited to these examples.

[0115] In the embodiments of the present invention, the raw materials used are all conventional raw materials in the art, and the purity specifications used are analytically pure or chemically pure, as follows:

[0116]

[0117]

[0118] Example 1

[0119] Binuclear metal catalyst A1, structure The preparation method comprises the following steps:

[0120] (1) Under a nitrogen atmosphere, 9-bromofluorene (0.1 mol) was added dropwise to anhydrous THF (250 mL) containing magnesium chips (0.5 mol), the reaction mixture was heated to reflux temperature and stirred for 4 h, cooled and allowed to stand, the supernatant was taken and added dropwise to anhydrous THF (250 mL) containing trichloromethylsilane (0.11 mol), and the reaction mixture was heated to reflux temperature and stirred for 20 h. After the solvent was removed in vacuo, 500 mL of anhydrous toluene was added, and then stirred at room temperature for 2 h. The solid portion was removed by filtration through diatomaceous earth. The filtrate was recrystallized with anhydrous n-hexane to obtain the first intermediate (CH3Si(Flu)Cl2, ).

[0121] Structural characterization: 1H-NMR (400MHz, CDCl3), δ: 0.75(s,3H),6.36(s,1H),7.3(td,2H),7.5(td,2H),7.6(dd,2H)7.7(dd,2H).

[0122] (2) Under nitrogen atmosphere, 4,4'-dibromobiphenyl (0.03 mol) was added dropwise to anhydrous THF (200 mL) containing sodium crumbs (0.15 mol), the reaction mixture was heated to reflux temperature and stirred for 8 h, cooled and allowed to stand, the supernatant was taken and added dropwise to anhydrous THF (200 mL) containing the first intermediate (0.06 mol), and the reaction mixture was heated to reflux temperature and stirred for 24 h. After the solvent was removed in vacuo, 400 mL of anhydrous toluene was added, and then stirred at room temperature for 5 h. The solid portion was removed by filtration through diatomaceous earth. The filtrate was recrystallized with anhydrous n-hexane to obtain the second intermediate (C 40 H 32 Si2Cl2, ).

[0123] Structural characterization: 1 H-NMR (400MHz, CDCl3), δ: 0.71(s,6H),6.7(s,2H),7.4(td,4H),7.5(td,4H),7.5(d,4H),7.6(d,4H),7.6(dd,4H)7.7(dd,4H).

[0124] (3) Under nitrogen atmosphere, cyclopentadiene (0.06 mol) was dissolved in THF (150 mL), 0.066 mol of n-butyl lithium was added at ≤-40°C, the temperature was gradually raised to room temperature and the reaction was stirred for 12 h, then the temperature was lowered to ≤40°C, and 150 mL of THF containing 0.03 mol of the second intermediate was added dropwise. After the addition was completed, the temperature was gradually raised to room temperature and the reaction was stirred for 24 h. After the solvent was removed in vacuo, 300 mL of anhydrous toluene was added and the reaction was stirred at room temperature for 2 h. The solid portion was removed by filtration through a diatomaceous earth plug. The filtrate was recrystallized from anhydrous n-hexane to obtain the ligand (C 50 H 42 Si2, ).

[0125] Structural characterization: 1 H-NMR (400MHz, CDCl3), δ: 0.61(s,6H),2.9(td,2H),6.1(m,4H),6.2(s,2H),7.0(td,4H),7.3(d,8H),7.6(dd,8H)7.7(dd,8H).

[0126] (4) Under nitrogen atmosphere, the ligand (0.02 mol) was dispersed in anhydrous THF (100 mL), and 0.022 mol of n-butyl lithium was added at ≤-40°C, and the temperature was gradually raised to room temperature and stirred for 24 hours to obtain a ligand lithium salt solution. 0.044 mol of ZrCl4 was dispersed in anhydrous THF (100 mL) at ≤-40°C, and the temperature was gradually raised to room temperature and stirred for 2 hours. The ligand lithium salt solution was then cooled to ≤-40°C, and the ZrCl4 solution was added dropwise, and the temperature was gradually raised to room temperature. The mixture was stirred at room temperature for 24 hours. After the solvent was removed in vacuo, 200 mL of anhydrous toluene was added, and the mixture was stirred at room temperature for 5 hours. The solid portion was removed by filtration through diatomaceous earth. The filtrate was recrystallized from anhydrous n-hexane to obtain the target compound A1.

[0127] Structural characterization: 1 H-NMR (400MHz, CDCl3), δ: 0.63(s,6H),6.3(dd,4H),7.0(dd,4H),7.3(dd,4H),7.4(dd,8H),7.5(dd,8H),7.6(dd,4H).

[0128] Example 2

[0129] Binuclear metal catalyst A2, structure The preparation method is similar to A1, the only difference is that ZrCl4 in step (4) is replaced by HfCl4.

[0130] The application of the binuclear metal catalyst of the present invention in the catalytic preparation of cycloolefin copolymers will be described in detail below with multiple application examples, but the application of the binuclear metal catalyst of the present invention is not limited to these application examples.

[0131] In the following specific embodiments of the present invention, the main testing methods for cycloolefin copolymers are as follows:

[0132] (1) Molecular weight (weight average molecular weight M w , number average molecular weight M n ), molecular weight distribution index (PDI, M w / M n ) was obtained by high temperature gel permeation chromatography (GPC) test, the instrument was Polymer Char GPC-IR, the chromatographic column was Agilent PL1110-6400, 1,2,4-trichlorobenzene was used as the eluent, the elution was carried out at 160°C with a flow rate of 1.00mL / min, and the instrument calibration standard was narrow distribution polystyrene.

[0133] (2) Molar insertion rate of cycloolefins: measured by carbon nuclear magnetic resonance spectroscopy 13C NMR test was performed using a Bruker Ascend III 400 MHz instrument. 100 mg of sample was weighed into the NMR tube, 0.6 mL of deuterated o-dichlorobenzene was added, and the sample was fully dissolved in a heating mantle at 140 °C. The solution was tested after it became clear and transparent, and the test temperature was 120 °C.

[0134] (3) Glass transition temperature (T g ): The temperature range of the scanning was 30-230°C, and the heating and cooling rates were both 15 K / min, T g The second heating stage shall prevail.

[0135] (4) Catalytic activity: Calculated by the formula: Catalytic activity = mass of cycloolefin copolymer / (molar amount of binuclear metal catalyst × polymerization time).

[0136] In the application examples of the present invention, the raw materials for which the preparation methods are not provided are all commercially available chemicals, as follows:

[0137]

[0138]

[0139] The following application example is the application of the binuclear metal catalyst provided by the present invention in ethylene-norbornene copolymerization, specifically a method for preparing a cycloolefin copolymer.

[0140] Application Example 1

[0141] A method for preparing a cycloolefin copolymer is as follows:

[0142] In a 2L autoclave reactor, 0.5mol of refined norbornene, 1L of refined toluene and 0.016g of hydrogen were added in sequence. Under the conditions of solution temperature of 130°C and stirring at 500rpm, 1.0mmol of TIBA, 5μmol of binuclear metal catalyst A1 and 20μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. During the polymerization process, ethylene partial pressure was controlled to be 0.8MPa by adding ethylene in a supplementary metered manner.

[0143] After 3 min of reaction, the reaction was stopped, the reaction solution was poured into an acid alcohol (1 wt% concentrated hydrochloric acid + 99 wt% ethanol) for precipitation and then filtered. The filter cake was washed with ethanol and dried at 80°C to constant weight to obtain 7.4 g of cycloolefin copolymer. The molecular weight, molecular weight distribution, T g The catalytic activities of the catalysts are shown in Table 2.

[0144] Application Example 2

[0145] A method for preparing a cycloolefin copolymer is as follows:

[0146] In a 2L autoclave reactor, 0.5mol of refined norbornene, 1L of refined toluene and 0.016g of hydrogen were added in sequence. At a solution temperature of 150°C and stirring at 500rpm, 1.0mmol of TIBA, 5μmol of binuclear metal catalyst A1 and 50μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. During the polymerization process, ethylene was added by supplementary metering to control the ethylene partial pressure to 1.4MPa.

[0147] After 10 min of reaction, the reaction was stopped, the reaction solution was poured into an acid alcohol (1 wt% concentrated hydrochloric acid + 99 wt% ethanol) for precipitation and then filtered. The filter cake was washed with ethanol and dried at 80°C to constant weight to obtain 18.8 g of cycloolefin copolymer. The molecular weight, molecular weight distribution, T g The catalytic activities of the catalysts are shown in Table 2.

[0148] Application Example 3

[0149] A method for preparing a cycloolefin copolymer is as follows:

[0150] In a 2L autoclave reactor, 0.5mol of refined norbornene, 1L of refined toluene and 0.016g of hydrogen were added in sequence. Under the conditions of solution temperature of 80°C and stirring at 500rpm, 5.0mmol of MMAO and 5μmol of binuclear metal catalyst A1 were added in sequence. Ethylene was added by supplementary metering during the polymerization process, and the ethylene partial pressure was 0.8MPa.

[0151] After 15 min of reaction, the reaction was stopped, the reaction solution was poured into an acid alcohol (1 wt% concentrated hydrochloric acid + 99 wt% ethanol) for precipitation and then filtered. The filter cake was washed with ethanol and dried at 80°C to constant weight to obtain 11.1 g of cycloolefin copolymer. The molecular weight, molecular weight distribution, T g The catalytic activities of the catalysts are shown in Table 2.

[0152] Application Example 4

[0153] A method for preparing a cycloolefin copolymer is as follows:

[0154] In a 2L autoclave reactor, 0.5mol of refined norbornene and 1L of refined toluene were added in sequence. Under the conditions of solution temperature of 130°C and stirring at 500rpm, 1.0mmol of TIBA, 5μmol of binuclear metal catalyst A1 and 50μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. During the polymerization process, ethylene partial pressure was controlled to be 0.6MPa by adding ethylene in a supplementary metered manner.

[0155] After 20 min of reaction, the reaction was stopped, the reaction solution was poured into an acid alcohol (1 wt% concentrated hydrochloric acid + 99 wt% ethanol) for precipitation and then filtered. The filter cake was washed with ethanol and dried at 80°C to constant weight to obtain 28.1 g of cycloolefin copolymer. The molecular weight, molecular weight distribution, T g The catalytic activities of the catalysts are shown in Table 2.

[0156] Application Example 5

[0157] A method for preparing a cycloolefin copolymer is as follows:

[0158] In a 2L autoclave reactor, 0.5mol of refined norbornene and 1L of refined toluene were added in sequence. Under the conditions of solution temperature of 130°C and stirring at 500rpm, 1.0mmol of TIBA, 5μmol of binuclear metal catalyst A2 and 20μmol of triphenylmethyltetrakis(pentafluorophenyl)borate were added in sequence. During the polymerization process, ethylene partial pressure was controlled to be 0.8MPa by adding ethylene in a supplementary metered manner.

[0159] After 10 min of reaction, the reaction was stopped, the reaction solution was poured into an acid alcohol (1 wt% concentrated hydrochloric acid + 99 wt% ethanol) for precipitation and then filtered. The filter cake was washed with ethanol and dried at 80°C to constant weight to obtain 8.3 g of cycloolefin copolymer. The molecular weight, molecular weight distribution, T g The catalytic activities of the catalysts are shown in Table 2.

[0160] Comparative Example 1

[0161] A method for preparing a cycloolefin copolymer is as follows:

[0162] In a 2L autoclave reactor, 0.5 mol of purified norbornene, 1L of purified toluene and 0.016 g of hydrogen were added in sequence. The solution temperature was 130°C and stirred at 500 rpm. Then 1.0 mmol of TIBA, 5 μmol of i PrCpFluZrCl2 and 20 μmol triphenylmethyltetrakis(pentafluorophenyl)borate; ethylene was added by supplementary metering during the polymerization process, and the ethylene partial pressure was 0.8 MPa.

[0163] After 10 min of reaction, the reaction was stopped, the reaction solution was poured into an acid alcohol (1 wt% concentrated hydrochloric acid + 99 wt% ethanol) for precipitation and then filtered. The filter cake was washed with ethanol and dried at 80°C to constant weight to obtain 4.8 g of cycloolefin copolymer. The molecular weight, molecular weight distribution, T g The catalytic activities of the catalysts are shown in Table 2.

[0164] Comparative Example 2

[0165] A method for preparing a cycloolefin copolymer is as follows:

[0166] In a 2L autoclave reactor, 0.5 mol of refined norbornene, 1L of refined toluene and 0.016 g of hydrogen were added in sequence. The solution temperature was 130°C and stirred at 500 rpm. Then, 1.0 mmol of TIBA, 5 μmol of catalyst μ-C 12 H8((SiPh(Ind)2)ZrCl2)2 and 20 μmol triphenylmethyltetrakis(pentafluorophenyl)borate; ethylene was added by additional metering during the polymerization process, and the ethylene partial pressure was 0.8 MPa.

[0167] After 10 min of reaction, the reaction was stopped, the reaction solution was poured into an acid alcohol (1 wt% concentrated hydrochloric acid + 99 wt% ethanol) for precipitation and then filtered. The filter cake was washed with ethanol and dried at 80°C to constant weight to obtain 1.8 g of cycloolefin copolymer. The molecular weight, molecular weight distribution, T g The catalytic activities of the catalysts are shown in Table 2.

[0168] The process parameters of Application Examples 1-6 and Comparative Examples 1-2 are summarized in Table 1:

[0169] Table 1

[0170]

[0171]

[0172] Table 2

[0173]

[0174] According to the data in Table 1, the binuclear metal catalyst provided by the present invention has excellent catalytic activity and thermal stability, is an economical and effective catalyst, is suitable for catalyzing the copolymerization of ethylene and cycloolefins, has high activity, and the catalytic activity is ≥0.89×10 7 g / (mol Cat·h), good hydrogen adjustment sensitivity, and the molecular weight of the obtained cycloolefin copolymer is high, M w ≥5.3×10 4 g / mol, the cyclic olefin insertion rate is high, and its molar insertion rate is ≥52.9mol%, and the glass transition temperature of the copolymer is high, T g ≥147.8℃, wide molecular weight distribution, PDI is 4.9-6.3, which is more conducive to processing.

[0175] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the binuclear metal catalyst and its application, and the preparation method of the cycloolefin copolymer of the present invention, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A binuclear metal catalyst, characterized in that: The binuclear metal catalyst has a structure as shown in Formula I: Wherein, R is selected from any one of C1-C6 straight chain or branched chain alkyl; X1 and X2 are each independently selected from any one of halogen, C1-C10 straight or branched alkyl, C6-C20 aryl, C7-C20 arylalkyl, C1-C20 alkylamino, and C6-C30 arylamino; M is selected from any one of Group IVB metals.

2. The binuclear metal catalyst according to claim 1, characterized in that The R is selected from any one of methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl and isobutyl; Preferably, X1 and X2 are each independently selected from any one of halogen, C1-C6 straight or branched alkyl, benzyl, C2-C10 alkylamino, and more preferably any one of chlorine, methyl, tert-butyl, benzyl, and dimethylamino; Preferably, the M is selected from any one of titanium, zirconium and hafnium, and zirconium is more preferred.

3. The binuclear metal catalyst according to claim 1, characterized in that The binuclear metal catalyst comprises any one or a combination of at least two of the following compounds:

4. A catalyst composition, characterized in that The catalyst composition comprises the binuclear metal catalyst as described in any one of claims 1 to 3 and a co-catalyst.

5. The catalyst composition according to claim 4, characterized in that The co-catalyst comprises any one or a combination of at least two of an organic aluminum oxide compound, an alkyl aluminum compound, and an organic boron compound; Preferably, the molar ratio of the binuclear metal catalyst to the co-catalyst is 1:(1-1000).

6. The catalyst composition according to claim 5, characterized in that The organoaluminum oxide compound includes any one of methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, and isobutylaluminoxane, or a combination of at least two thereof; Preferably, the molar ratio of the organoaluminum oxide compound to the binuclear metal catalyst in the co-catalyst is (50-2000):1; Preferably, the alkyl aluminum compound includes any one of trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tri-n-hexyl aluminum, and diethyl aluminum monochloride, or a combination of at least two thereof; Preferably, the molar ratio of the alkyl aluminum compound to the binuclear metal catalyst in the co-catalyst is (5-1000):

1.

7. The catalyst composition according to claim 5, characterized in that The organic boron compound includes any one of triphenylborane, tri(pentafluorophenyl)borane, triperfluorobiphenylborane, triphenylmethyltetrakis(pentafluorophenyl)borate, and tert-butyltriphenylmethyltetrakis(pentafluorophenyl)borate, or a combination of at least two thereof; Preferably, the molar ratio of the organic boron compound to the binuclear metal catalyst in the co-catalyst is (2-20):

1.

8. Use of the binuclear metal catalyst according to any one of claims 1 to 3 or the catalyst composition according to any one of claims 5 to 7 in olefin polymerization; Preferably, the olefin includes any one of ethylene, α-olefin, cycloolefin, or a combination of at least two thereof.

9. A method for preparing a cycloolefin copolymer, characterized in that: The preparation method comprises: a cycloolefin and a second olefin monomer are polymerized in the presence of a catalyst to obtain the cycloolefin copolymer; the catalyst comprises any one of the binuclear metal catalysts as described in any one of claims 1 to 3 and the catalyst composition as described in any one of claims 5 to 7.

10. The preparation method according to claim 9, characterized in that: The cyclic olefin includes any one or a combination of at least two of norbornene, vinyl norbornene, 5-ethylidene-2-norbornene, dicyclopentadiene, and tetracyclododecene; Preferably, the second olefin monomer comprises any one of ethylene and α-olefin or a combination of at least two thereof; Preferably, the polymerization reaction is carried out in the presence of a solvent; Preferably, the polymerization reaction temperature is 80-160°C; Preferably, the polymerization reaction pressure is 0.2-2.0 MPa; Preferably, the polymerization reaction time is 1-30 min.

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