A metal catalyst, its preparation method and use

Abstract

The application provides a metal catalyst, a preparation method and application thereof, and the metal catalyst has a structure as shown in formula I, is a metal complex containing a nitrogen heterocyclic carbine skeleton, and through design of a molecular structure, the metal catalyst has excellent high-temperature resistance and catalytic activity, can realize micro-control of a polymer structure, and can be used for catalytic preparation of an olefin polymer with ultrahigh molecular weight, narrow molecular weight distribution, high glass transition temperature, high high-temperature resistance, low melt index, low terminal double bond content, excellent mechanical properties and excellent processing yellowing resistance, and is especially suitable for high-temperature solution polymerization and has a wide industrial application prospect.

Description

Technical Field

[0001] This invention belongs to the field of olefin polymerization technology, specifically relating to a metal catalyst, its preparation method, and its application. Background Technology

[0002] Polyolefin materials, as a new type of polymer material developed in the last century, are diverse in type and closely related to people's lives, becoming an indispensable material in human social development. With the continuous development of society, traditional polyolefin materials can no longer meet people's needs, forcing polyolefin materials to develop towards functionalization and high-end applications. Polyolefin elastomers, as a high-end polyolefin material, are favored for their narrow molecular weight distribution, high elasticity, and good mechanical properties, and are widely used in various fields.

[0003] The discovery and industrialization of polyolefin catalysts have driven the rapid development of polyolefin materials. Driven by market demand for novel polyolefin materials, new polyolefin catalysts have become a focus of attention. Currently, industrialized catalysts mainly include Ziegler-Natta type catalysts and Phillips type catalysts. Different types of catalysts have their own advantages and disadvantages, and are used in combination with different polymerization processes to produce different grades of polyolefin products. However, most catalysts cannot be used for the catalytic production of polyolefin elastomers, especially supported catalysts, which cannot meet the requirements for catalytic production of polyolefin elastomers.

[0004] For example, the FI catalyst reported in the literature (Chem. Lett. 1999, 10, 1065; "AFamily of Zirconium Complexes Having Two Phenoxy-Imine Chelate Ligands for Olefin Polymerization", Shigekazu Matsui et al., J. Am. Chem. Soc., 2001, 123, 6847) has a typical structure as follows: This type of catalyst exhibits good catalytic performance for the homopolymerization of ethylene under low temperature conditions, but its activity is very low or even deactivated under high temperature conditions; moreover, its selectivity for comonomers is poor, making it difficult to meet the requirements for the preparation of olefin copolymers.

[0005] For example, EP416815A2 discloses a catalyst with a typical structure as follows: It can be used to produce EPDM rubber; however, this type of catalyst has poor high-temperature resistance. When the polymerization temperature is >120℃, the molecular weight of the polymer decreases, and the tensile strength of the polymer is low, resulting in insufficient mechanical properties.

[0006] Therefore, in catalyst research, how to improve catalytic activity and obtain polyolefin materials with high molecular weight, narrow molecular weight distribution, and good mechanical and processing properties has become the core and focus of catalyst research, and also a key factor in achieving industrialization. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a metal catalyst, its preparation method, and its application. Through molecular structure design, the metal catalyst possesses excellent high-temperature resistance and catalytic activity, enabling microscopic control of polymer structure. It can catalyze the preparation of olefin polymers with ultra-high molecular weight, narrow molecular weight distribution, high glass transition temperature, high temperature resistance, low melt index, low terminal double bond content, and excellent mechanical properties and processing resistance to yellowing, thus having broad industrial application prospects.

[0008] To achieve this objective, the present invention adopts the following technical solution:

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

[0010]

[0011] In Formula I, the two R1s are the same group, selected from any one of hydrogen, halogen, substituted or unsubstituted C1-C20 straight-chain or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 alkylamino, substituted or unsubstituted C2-C20 heterocyclic alkyl, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C6-C20 aryloxy, substituted or unsubstituted C3-C20 heteroaryl, and C6-C20 arylamino.

[0012] The substituents described in R1 are each independently selected from at least one of halogens, C1-C10 straight-chain or branched alkyl groups, and phenyl groups.

[0013] In Formula I, R2, R3, R4, R5, R6, and R7 are each independently selected from any one of C1-C6 straight-chain or branched alkyl groups.

[0014] In Formula I, X1 and X2 are each independently selected from any one of halogen, C1-C20 straight-chain or branched alkyl, C6-C20 aryl, C7-C20 arylalkyl, C1-C20 alkylamino, and C6-C20 arylamino.

[0015] In Formula I, M is selected from any metal in Group IVB.

[0016] The molecular structure of the metal catalyst provided by this invention is shown in Formula I. It is a metal complex containing a nitrogen-containing carbene framework. The cyclopentadienyl ring in the molecular structure is connected to the nitrogen-containing carbene. The electronic effect of the carbene affects the π bond formed between the cyclopentadienyl ring and the metal center, making the cyclopentadienyl ring less prone to electron slip at high temperatures and the structure more stable. By changing the position of the substituents, the magnitude of steric hindrance, and the strength of the electron-donating ability in the ligand framework structure, the microscopic control of the polymer structure can be achieved. This allows for the preparation of olefin polymers with ultra-high molecular weight, narrow molecular weight distribution, high glass transition temperature, good high-temperature resistance, low melt index, and low terminal double bond content. It also gives the olefin polymers a higher stress yield point, improves the mechanical properties and processing resistance to yellowing of the olefin polymers, broadens the application fields of olefin polymers, and has broad industrial application prospects.

[0017] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0018] In this invention, the halogens include fluorine, chlorine, bromine, and iodine.

[0019] In this invention, the C1-C20 straight-chain or branched alkyl groups can be straight-chain or branched alkyl groups of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, etc., preferably C1-C10 straight-chain or branched alkyl groups, 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.

[0020] The C3-C20 cycloalkyl groups can all be cycloalkyl groups of C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, etc., including monocycloalkyl or polycycloalkyl groups, preferably C3-C10 cycloalkyl groups, and exemplary examples include but are not limited to: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, etc.

[0021] The C1-C20 alkoxy groups can all be straight-chain or branched alkoxy groups of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, etc., preferably C1-C10 alkoxy groups. A specific example is a monovalent group formed by connecting the above-mentioned straight-chain or branched alkyl groups to O.

[0022] The C1-C20 alkylamino groups can all be alkylamino groups of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, etc., and are monovalent groups obtained by substituting at least one hydrogen atom in -NH2 with the above-mentioned straight-chain or branched alkyl groups.

[0023] The C2-C20 heterocyclic alkyl groups can all be heterocyclic alkyl groups of C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, etc., wherein the heteroatom can be N, O, S, P, B, Si or Se, preferably N, O or S; a specific example is a monovalent group formed by replacing at least one ring C atom in the above-mentioned cycloalkyl group with a heteroatom, including but not limited to: epoxy group, oxetane, tetrahydrofuranyl, tetrahydrothiophenyl, tetrahydropyrroleyl, morpholinyl, piperazineyl, piperidinyl, oxetanehexyl, dioxanecyclohexyl, etc.

[0024] The C6-C20 aryl groups can all be aryl groups of C6, C9, C10, C12, C14, C16, C18, etc., including monocyclic aryl or fused-ring aryl groups, and exemplary of which include but are not limited to: phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, etc.

[0025] The C6-C20 aryloxy groups can all be aryloxy groups of C6, C9, C10, C12, C14, C16, C18, etc., and a specific example is the monovalent group formed by the above-mentioned aryl group and O.

[0026] The C3-C20 heteroaryl groups can all be heteroaryl groups of C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, etc., wherein the heteroatom can be N, O, S, P, B, Si or Se, preferably N, O or S; including monocyclic heteroaryl or fused-ring heteroaryl groups, exemplary including but not limited to: pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, furanyl, thiopheneyl, pyrroleyl, quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothiopheneyl, indolyl, dibenzofuranyl, dibenzothiopheneyl, carbazoleyl, N-phenylcarbazoleyl, etc.

[0027] The C6-C20 arylamino groups can all be arylamino groups of C6, C9, C10, C12, C14, C16, C18, etc., and are monovalent groups obtained by substituting at least one hydrogen in -NH2 with the above-mentioned aryl group.

[0028] The C7-C20 aryl alkyl groups can all be aryl alkyl groups such as C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, and C18. Specific examples are monovalent groups formed by attaching the above-mentioned aryl group to a straight-chain or branched alkyl group, with a typical example being benzyl (phenylmethyl).

[0029] Preferably, R1 is selected from hydrogen, halogen, substituted or unsubstituted C1-C8 (e.g., C2, C3, C4, C5, C6, C7, etc.) straight-chain or branched alkyl groups, substituted or unsubstituted C3-C6 (e.g., C3, C4, C5, C6, etc.) cycloalkyl groups, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkoxy groups, C2-C6 (e.g., C3, C4, C5, C6, etc.) heterocyclic alkyl groups, and C1-C10 (e.g., C2, C3, C4, C5, C6, etc.) chain alkyl groups. Any one of the following: alkylamino (C7, C8, C9, etc.), substituted or unsubstituted C6-C12 (e.g., C6, C9, C10, C12, etc.) aryl, substituted or unsubstituted C6-C12 (e.g., C6, C9, C10, C12, etc.) aryloxy, substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C14, C16, C18, etc.) heteroaryl, and C6-C20 (e.g., C6, C9, C10, C12, C14, C16, C18, etc.) arylamino.

[0030] Preferably, the substituents in R1 are each independently selected from at least one of halogens, C1-C6 (e.g., C2, C3, C4, C5, etc.) straight-chain or branched alkyl groups, and phenyl groups, and more preferably at least one of methyl, ethyl, isopropyl, n-propyl, and phenyl groups.

[0031] Preferably, R1 is selected from any one of hydrogen, fluorine, chlorine, methyl, tert-butyl, isopropyl, diphenylmethyl, tetrahydropyrrolyl, carbazole, trimethylphenyl, dimethylamino, methoxy, isopropylphenyl, pyridyl, and diphenylamino.

[0032] Preferably, R2, R3, R4, R5, R6, and R7 are each independently selected from any one of C1-C4 (e.g., C1, C2, C3, C4, etc.) straight-chain or branched alkyl groups, and more preferably ethyl.

[0033] Preferably, X1 and X2 are each independently selected from halogen, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight-chain or branched alkyl, benzyl, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkylamino, C6-C20 (e.g., C6, C9, C10, C12, C14, C16, C18, etc.) arylamino, and more preferably methyl, chloro, dimethylamino, benzyl.

[0034] Preferably, M is selected from Ti, Zr, or Hf.

[0035] Preferably, the metal catalyst is selected from any one or a combination of at least two of the following compounds:

[0036]

[0037]

[0038] In this context, Me represents methyl and Bn represents benzyl.

[0039] In a second aspect, the present invention provides a method for preparing a metal catalyst as described in the first aspect, the method comprising the following steps:

[0040] (1) The amino-containing compound with the structure shown in Formula II reacts with the silane compound with the structure shown in Formula III to give intermediate A with the structure shown in Formula IV. The reaction formula is as follows:

[0041]

[0042] (2) The intermediate A reacts with the fluorenone compound of formula V in the presence of a catalyst, a reducing agent and a basic compound to obtain the intermediate B of formula VI, as shown in the following reaction formula:

[0043]

[0044] (3) The intermediate B, triethyl orthoformate, bis(trimethylsilyl)aminopotassium and acidic compound are mixed and reacted to obtain intermediate C with the structure shown in formula VII. The reaction formula is as follows:

[0045]

[0046] (4) After the intermediate C is pre-reacted with the dehydrogenation reagent, it is then reacted with the metal M salt to obtain the metal catalyst with the structure shown in Formula I.

[0047] Among them, R1, R2, R3, R4, R5, R6, R7, X1, X2, and M have the same limited range as Equation I; Hal is selected from any of the halogens.

[0048] Preferably, the Hal is selected from Cl or Br, and more preferably Cl.

[0049] Preferably, the molar ratio of the amino-containing compound to the silane compound is 1:(0.2-1), for example, it can be 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9 or 1:0.95, and more preferably 1:(0.8-1).

[0050] Preferably, the reaction in step (1) is carried out in the presence of a solvent.

[0051] Preferably, the solvent in step (1) includes an alcohol solvent, and more preferably methanol.

[0052] Preferably, based on the total mass of the amino-containing compound and the silane compound as 100%, the mass of the solvent in step (1) is 50-2000%, for example, it can be 80%, 100%, 200%, 300%, 400%, 500%, 600%, 800%, 1000%, 1200%, 1500% or 1800%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 100-500% is further preferred.

[0053] Preferably, the reaction temperature in step (1) is from -30°C to 50°C, for example, it can be -25°C, -20°C, -15°C, -10°C, -5°C, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C or 45°C, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 0-50°C is further preferred.

[0054] Preferably, the reaction time in step (1) is 0.2-16h, for example, it can be 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h, 2.8h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h or 15h, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 0.5-3h is further preferred.

[0055] Preferably, the fluorenone compound can be any one or a combination of at least two of 2,7-di-tert-butylfluorenone, 2,7-ditetrahydropyrrolidone, 2,7-dicarbazolefluorenone, 2,7-difluorofluorenone, 2,7-dimethoxyfluorenone, and 2,7-bis((2,4,6)-trimethylphenyl)fluorenone.

[0056] Preferably, the catalyst in step (2) comprises isopropyl titanate; and / or, the reducing agent comprises sodium borohydride; and / or, the basic compound comprises sodium hydroxide.

[0057] Preferably, the molar ratio of the fluorenone compound, isopropyl titanate, intermediate A, sodium borohydride, and sodium hydroxide in step (2) is (0.3-1):(0.5-2):(0.5-2):(1-10):(3-10); wherein, "0.3-1" can be 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1, etc.; and "0.5-2" can each independently be 0.6, 0.7, 0.8, 0.9, 1, etc. 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8 or 1.9, etc.; "1-10" can be 2, 3, 4, 5, 6, 7, 8 or 9, etc.; "3-10" can be 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9 or 9.5, etc.; further preferred is (0.5-1):(0.5-2):(0.5-1):(1-5):(3-5).

[0058] Preferably, the reaction in step (2) is carried out in the presence of a solvent.

[0059] Preferably, the solvent in step (2) includes an alcohol solvent, and more preferably methanol.

[0060] Preferably, based on the total mass of the fluorenone compound, isopropyl titanate, intermediate A, sodium borohydride, and sodium hydroxide as 100%, the mass of the solvent in step (2) is 100-2000%, for example, 150%, 200%, 300%, 400%, 500%, 600%, 800%, 1000%, 1200%, 1500%, or 1800%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 300-1000% is further preferred.

[0061] Preferably, the reaction temperature in step (2) is 10-100℃, for example, it can be 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 70℃, 80℃ or 90℃, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 10-50℃ is further preferred.

[0062] Preferably, the reaction time in step (2) is 0.2-16h, for example, it can be 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h, 2.8h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h or 15h, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 0.5-6h is further preferred.

[0063] Preferably, the acidic compound in step (3) includes hydrochloric acid.

[0064] Preferably, the molar ratio of intermediate B, triethyl orthoformate, hydrochloric acid, and bis(trimethylsilyl)aminopotassium is 1:(2-50):(1-10):(2-20), wherein "2-50" can be 3, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 42, 45, or 48, etc.; "1-10" can be... The values ​​are 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, or 9.5, etc.; "2-20" can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19, etc.; a further preferred value is 1:(10-30):(2-5):(5-10).

[0065] Preferably, the reaction in step (3) is carried out in the presence of a solvent.

[0066] Preferably, the solvent comprises dioxane.

[0067] Preferably, based on the total mass of intermediate B, triethyl orthoformate, hydrochloric acid, and bis(trimethylsilyl)aminopotassium as 100%, the mass of the solvent in step (3) is 200-3000%, for example, it can be 300%, 400%, 500%, 600%, 800%, 1000%, 1200%, 1500%, 1800%, 2000%, 2200%, 2500%, or 2800%, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 300-1000% is further preferred.

[0068] Preferably, the reaction temperature in step (3) is 0-80℃, for example, it can be 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃ or 70℃, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 10-50℃ is further preferred.

[0069] Preferably, the reaction time in step (3) is 0.2-16h, for example, it can be 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h, 2.8h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h or 15h, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 0.5-8h is further preferred.

[0070] Preferably, the dehydrogenation reagent in step (4) includes any one or a combination of at least two of sodium metal, potassium metal, methyl magnesium bromide, sodium hydride, potassium hydride, lithium hydride, C1-C6 (e.g., C1, C2, C3, C4, C5, C6) alkyl lithium, diisopropylamino lithium, and bistrimethylsilylamino lithium. More preferably, it includes any one or a combination of at least two of sodium metal, potassium metal, sodium hydride, potassium hydride, and C1-C6 alkyl lithium. Even more preferably, it includes any one or a combination of at least two of methyl lithium, n-butyl lithium, sodium metal, n-hexyl lithium, and potassium metal.

[0071] Preferably, the molar ratio of intermediate C to dehydrogenating agent is 1:(2-12), for example, it can be 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11 or 1:11.5, and more preferably 1:(4-10).

[0072] Preferably, the molar ratio of intermediate C to metal M salt is 1:(1-2), for example, it can be 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8 or 1:1.9, and more preferably 1:(1-1.5).

[0073] Preferably, the metal M salt is selected from any one or a combination of at least two of Group IVB metal halides, alkyl metal compounds, amino metal compounds, aryl metal compounds, and metal halides with ether coordination. More preferably, it is a combination of any one or at least two of Group IVB metal halides, alkyl metal compounds, amino metal compounds, and aryl metal compounds. More preferably, it is a combination of any one or at least two of Group IVB metal chlorides.

[0074] Preferably, the pre-reaction and reaction in step (4) are carried out in the presence of an organic solvent; that is, the organic solvent required for the pre-reaction is added first to carry out the pre-reaction, and then the organic solvent required for the reaction is added to carry out the reaction.

[0075] Preferably, the organic solvents for the pre-reaction and the reaction each independently include any one or a combination of at least two of tetrahydrofuran, 2-methyltetrahydrofuran, diethyl ether, methyl tert-butyl ether, cyclopentane, n-pentane, n-hexane, n-heptane, methylcyclohexane, benzene, toluene, and xylene. More preferably, the organic solvents include any one or a combination of at least two of tetrahydrofuran, diethyl ether, methyl tert-butyl ether, toluene, and n-hexane. The organic solvents added in the two reactions (the organic solvent required for the pre-reaction and the organic solvent required for the reaction) can be the same or different.

[0076] Preferably, based on the total mass of the intermediate C, the dehydrogenating agent, and the metal M salt as 100%, the total mass of the organic solvent required for the pre-reaction and reaction in step (4) is 50-1000%, for example, it can be 80%, 100%, 200%, 300%, 400%, 500%, 600%, 800%, or 900%, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 100-500% is further preferred.

[0077] Preferably, the mass ratio of the organic solvent required for the pre-reaction to the organic solvent required for the reaction is 1:(0.8-1.1), for example, it can be 1:0.82, 1:0.85, 1:0.88, 1:0.9, 1:0.92, 1:0.95, 1:0.98, 1:1, 1:1.02, 1:1.05 or 1:1.08, etc.

[0078] Preferably, the temperature of the pre-reaction in step (4) is -80℃ to 35℃, for example, it can be -75℃, -70℃, -60℃, -50℃, -45℃, -40℃, -30℃, -20℃, -10℃, -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, 25℃ or 30℃, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and it is further preferred to be -40℃ to 35℃.

[0079] Preferably, the pre-reaction time in step (4) is 0.1-24h, for example, it can be 0.5h, 0.8h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h or 22h, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 0.2-6h is further preferred.

[0080] Preferably, the reaction temperature in step (4) is from -80°C to 35°C, for example, it can be -75°C, -70°C, -60°C, -50°C, -45°C, -40°C, -30°C, -20°C, -10°C, -5°C, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C or 30°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but it is further preferred to be from -40°C to 35°C.

[0081] Preferably, the reaction time in step (4) is 1-24h, for example, it can be 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h or 22h, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 2-6h is further preferred.

[0082] Thirdly, the present invention provides an olefin polymerization catalyst, the olefin polymerization catalyst comprising the metal catalyst as described in the first aspect.

[0083] Preferably, the metal catalyst is used as the main catalyst, and the olefin polymerization catalyst also includes a co-catalyst.

[0084] Preferably, the cocatalyst comprises a boron-containing compound and / or an organoaluminum oxide compound.

[0085] Preferably, the boron-containing compound includes any one or a combination of at least two of tri(pentafluorophenyl)boron, triphenylcarbium tetra(pentafluorophenyl)borate, and tetra(pentafluorophenyl)boronic acid-methyl di-(octadecyl)ammonium salt.

[0086] Preferably, the molar ratio of M in the metal catalyst to B in the boron-containing compound is 1:(1-20), for example, it can be 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.5, 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, 1:17, 1:18 or 1:19, etc., and more preferably 1:(1-2).

[0087] Preferably, the organoaluminum oxide compound includes modified alkylaluminoxane (MMAO).

[0088] Preferably, the molar ratio of M in the metal catalyst to Al in the modified aluminum oxide is 1:(1-30), for example, it can be 1:2, 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, 1:19, 1:20, 1:22, 1:25 or 1:28, etc., and more preferably 1:(5-20).

[0089] Fourthly, the present invention provides the application of the metal catalyst as described in the first aspect and the olefin polymerization catalyst as described in the third aspect in olefin polymerization.

[0090] Preferably, the method for olefin polymerization includes olefin solution polymerization.

[0091] Preferably, the olefin comprises any one or a combination of at least two of ethylene, propylene, styrene, 1-butene, 1-hexene, 1-octene, norbornene, and tetracyclododecene.

[0092] Preferably, the olefin polymerization includes olefin homopolymerization, such as ethylene homopolymerization, propylene homopolymerization, etc.

[0093] Fifthly, the present invention provides a method for preparing a polyolefin, the method comprising: polymerizing an olefin monomer in the presence of a catalyst to obtain the polyolefin; the catalyst comprising a metal catalyst as described in the first aspect and / or an olefin polymerization catalyst as described in the third aspect.

[0094] Preferably, the preparation method includes: placing a catalyst solution in a reaction apparatus, and then introducing an olefin monomer to carry out a polymerization reaction to obtain the polyolefin.

[0095] Preferably, the solvent of the catalyst solution includes any one or a combination of at least two of the following: alkane solvents, haloalkane solvents, cycloalkane solvents, and aromatic solvents.

[0096] Preferably, the solvent of the catalyst solution includes any one or a combination of at least two of toluene, hexane, heptane, Isopar E, methylcyclohexane, and dichloromethane.

[0097] Preferably, the mass concentration of the metal catalyst in the catalyst solution is 0.1-100 ppm, for example, it can be 0.2 ppm, 0.5 ppm, 0.8 ppm, 1 ppm, 2 ppm, 3 ppm, 4 ppm, 5 ppm, 6 ppm, 7 ppm, 8 ppm, 9 ppm, 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm or 90 ppm, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 1-5 ppm is further preferred.

[0098] Preferably, the feed rate of the olefin monomer is controlled by the reaction pressure.

[0099] Preferably, the pressure of the polymerization reaction is 0.1-5 MPa, for example, it can be 0.2 MPa, 0.5 MPa, 0.8 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa or 4.5 MPa, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 1-5 MPa is further preferred.

[0100] Preferably, the feed mass flow rate of the olefin monomer is 1000-5000 g / min, for example, it can be 1200 g / min, 1500 g / min, 1800 g / min, 2000 g / min, 2200 g / min, 2500 g / min, 2800 g / min, 3000 g / min, 3200 g / min, 3500 g / min, 4000 g / min or 4500 g / min, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 1000-3000 g / min is further preferred.

[0101] Preferably, the polymerization reaction temperature is from -20°C to 220°C, for example, it can be -15°C, -10°C, -5°C, 0°C, 10°C, 20°C, 50°C, 80°C, 100°C, 120°C, 150°C, 180°C, 200°C or 210°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 40-200°C is further preferred.

[0102] As a preferred embodiment of the present invention, the metal catalyst is used to catalyze the homopolymerization of ethylene, and its activity in high-temperature polymerization at 200°C is ≥0.78×10⁻⁶. 7 g / mol, which can be 0.78 × 10 7 -11.7×10 7 g / mol.

[0103] As a preferred embodiment of the present invention, the metal catalyst is used to catalyze the homopolymerization of ethylene, resulting in polyethylene with a weight-average molecular weight of 580,000-1,120,000, a narrow molecular weight distribution, and a melting point T. m The temperature is 134-137℃.

[0104] As a preferred embodiment of the present invention, the metal catalyst is used to catalyze the copolymerization of ethylene and octene, and its activity is ≥7×10⁻⁶. 7 g / mol, which can be 7.02 × 10 7 -21.9×10 7 g / mol.

[0105] As a preferred embodiment of the present invention, the metal catalyst is used to catalyze the copolymerization of ethylene and octene, resulting in an ethylene-octene copolymer with a weight-average molecular weight of 10300-364000, a narrow molecular weight distribution, and T... m The temperature range is 55-73℃, the octene monomer insertion rate is ≥20.1wt%, which can reach 40-58.3wt%, and the melt index is as low as 0.3-8.7g / 10min.

[0106] Compared with the prior art, the present invention has the following beneficial effects:

[0107] (1) The metal catalyst provided by the present invention has the structure shown in Formula I. It is a metal complex containing a nitrogen-containing carbene skeleton. Through the design of the molecular structure, the metal catalyst has excellent high temperature resistance and catalytic activity. It can achieve micro-control of polymer structure and catalyze the preparation of olefin polymers with ultra-high molecular weight, narrow molecular weight distribution, high glass transition temperature, high temperature resistance, low melt index, low terminal double bond content, better mechanical properties and processing resistance to yellowing. It is especially suitable for high temperature solution polymerization and has broad industrial application prospects.

[0108] (2) The metal catalyst provided by this invention is used for catalyzing the homopolymerization of ethylene and exhibits excellent catalytic performance with an activity ≥0.72×10⁻⁶. 7 The desired molecular weight (g / mol) yields high-molecular-weight polyethylene with good thermal stability, suitable for high-temperature solution polymerization. The metal catalyst exhibits excellent catalytic performance and high catalytic activity (≥7×10⁻⁶) in the catalytic polymerization of ethylene-octene. 7 g / mol yields ethylene-octene copolymers with high molecular weight, excellent thermal stability, high octene insertion rate, low melt index, low terminal double bond content, and excellent mechanical properties. Detailed Implementation

[0109] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0110] Unless otherwise specified, the experimental methods used in the following specific embodiments of the present invention are conventional methods in the art.

[0111] In the following specific embodiments of the present invention, the materials and reagents used can all be obtained commercially. The main raw material source information is as follows. Unless otherwise specified, other raw materials are all common commercially available raw materials.

[0112] 2,7-Dicarbazolium fluorenone, 2,7-Dimethoxyfluorenone, Ultra-dry dichloromethane, Ultra-dry tetrahydrofuran (THF): AR, Innochem;

[0113] 2,7-Difluorofluorenone, 2-hydroxy-3,5-di-tert-butylbenzylamine, 2-hydroxy-3,5-diisobutylphenol, benzophenone, dimethyl-tert-butylchlorosilane, toluene, ultra-dry n-hexane, ethyl acetate, triphenylcarbium tetra(pentafluorophenyl)borate, tri(pentafluorophenyl)boron, Isopar E, titanium tetrachloride, zirconium tetrachloride, tetradimethylamine titanium, tetradimethylamine zirconium tetrachloride, hafnium tetrachloride, tetrabenzylhafnium: AR, Aladdin;

[0114] n-Butyllithium in hexane solution (2.5M), methyllithium (1.6M), methylmagnesium bromide (2.2M): AR, Aladdin;

[0115] Triethyl orthoformate: AR, Merck;

[0116] Diethyl ether: AR, Comio;

[0117] Petroleum ether: 60-90℃, Chinese medicine;

[0118] Deuterated chloroform: AR, Acros;

[0119] Industrial ethanol: 95%, Beijing Chemical Reagent Company;

[0120] Silica gel: AR, 200-300 mesh, Shanghai Wusi Chemical Reagent Company.

[0121] In specific embodiments of the present invention, the main testing methods employed are as follows:

[0122] (1) The structures of the intermediates and target compounds obtained in the examples were characterized by nuclear magnetic resonance (NMR, Brucker ARX-400).

[0123] (2) The molecular weight of the polymer (weight-average molecular weight M) w ), molecular weight distribution (M w / M n The results were obtained by gel permeation chromatography (GPC), specifically by using a PL-GPC220 at 150℃, with three PLgel 10μm MIXED-B separation columns connected in series, and 1,2,4,-trichlorobenzene as the solvent.

[0124] (3) Melting point T of the polymer m Both the glass transition temperature and the glass transition temperature were measured using the conventional differential scanning calorimetry (DSC) (2000) method.

[0125] (4) The polymerization activity is calculated according to the following formula: Polymer activity = polymer mass / (metal content of metal catalyst × polymerization time); the polymer terminal double bond is calculated according to the iodometric method.

[0126] (5) The comonomer insertion rate was obtained by carbon NMR spectroscopy, specifically using high temperature... 13 The results were obtained by C NMR analysis using 1,1,2,2,-tetrachloroethane as a solvent at 120 °C using a Brucker DMX at 100 MHz.

[0127] (6) Mechanical properties: Tensile modulus (MPa, 100%, tangent) and elongation at break (%) were tested according to the method in standard ISO 178; tear strength was tested according to the method in standard GB / T 10808-2006.

[0128] The technical solution of the present invention is described below with reference to specific embodiments.

[0129] Preparation Example 1: Preparation of Intermediate A1

[0130]

[0131] Et represents ethyl.

[0132] Under a nitrogen atmosphere, triethylsilanediamine (17.4 g, 100 mmol) and triethylsilane chloride (15 g, 100 mmol) were added and mixed in 60 g of methanol. The mixture was reacted at 20 °C for 2 h. The methanol was removed under reduced pressure, and the mixture was extracted with 100 mL each of water and ethyl acetate. The ethyl acetate was removed under reduced pressure, and the mixture was subjected to column chromatography (eluting with petroleum ether and ethyl acetate in a 1:1 v / v ratio) to give intermediate A1, 27.4 g, in 95% yield.

[0133] 1 H NMR (400MHz, CDCl3): δ8.61(s,2H,NH2),2.94(m,2H),2.32(t,1H,CH),1.35(s,1H,NH),0.96(s,18H,Et3Si),0.69(m,12H,SiEt3).

[0134] Example 1

[0135] A metal catalyst S1, with the following structure: The preparation method is as follows:

[0136]

[0137]

[0138] (1) Under a nitrogen atmosphere, 2,7-ditetrahydropyrrolidone (31.8 g, 100 mmol) was dissolved in 100 mL of methanol, and isopropyl titanate (28.4 g, 100 mmol) was added. The mixture was stirred at room temperature for 1 h, and intermediate A1 (46 g, 160 mmol) was added. The reaction mixture was stirred at room temperature for 30 min. Sodium borohydride (30.4 g, 800 mmol) was added to the reaction system, and the mixture was stirred for 2 h. 150 mL of 10% sodium hydroxide aqueous solution was added, followed by 300 mL of ethyl acetate. The mixture was extracted and separated. Ethyl acetate was removed under reduced pressure, and column chromatography (eluent: petroleum ether and ethyl acetate in a volume ratio of 4:1) was performed to give intermediate B1, 51.4 g, in 87% yield.

[0139] 1 H NMR (400MHz, CDCl3): δ7.71(d,2H),6.86(s,2H),6.76(dd,2H),5.06(s,1H),4.16(s,1H),3.32(t,8H,C H),2.58(m,2H),2.04(dd,8H),1.51(s,1H),1.35(s,1H,NH),0.96(s,18H,Et3Si),0.69(m,12H,SiEt3).

[0140] (2) Under a nitrogen atmosphere, intermediate B1 (59.1 g, 100 mmol) was weighed and added to triethyl orthoformate (328 g, 2200 mmol). The mixture was added to 1000 mL of dioxane, 4 M HCl was added, and the mixture was stirred at room temperature for 5 h. The solvent was removed under vacuum, and 500 mL of diethyl ether was added for washing. 1000 mL of THF was added, and potassium bis(trimethylsilyl)amino (60 g, 300 mmol) was added. The mixture was reacted at room temperature for 2 h, and the solvent was removed under vacuum. 200 mL of n-hexane was added, and the mixture was crystallized at -30 °C to obtain intermediate C1 49.7 g, with a yield of 89.7%.

[0141] 1 H NMR (400MHz, CDCl3): δ7.72(d,2H),6.83(s,2H),6.76(dd,2H),5.03(s,1H),3.29(t,8H,C H),2.51(m,2H),2.04(dd,8H),1.38(s,1H,NH),0.96(s,18H,Et3Si),0.69(m,12H,SiEt3).

[0142] (3) Under a nitrogen atmosphere, intermediate C1 (6 g, 10 mmol) was added to 30 mL of anhydrous THF. 4.4 mL of n-butyllithium was added at -20 °C, and the reaction was allowed to proceed for 20 min. Then, titanium tetrachloride (2.3 g, 12 mmol) was added, and the reaction was allowed to proceed for 3 h at room temperature. The solvent was removed under vacuum, 50 mL of toluene was added, and the mixture was filtered. The filtrate was concentrated to 5 mL, and crystallized at -30 °C for 10 h. The crystals were then rapidly filtered, and the solid was dried under vacuum to obtain 4.02 g of the target product S1, with a yield of 56%.

[0143] 1 H NMR (400MHz, CDCl3): δ7.74(d,2H),6.83(s,2H),6.76(dd,2H),3.29(t,8H,CH),2.5 3(m,2H),2.04(dd,8H),1.38(s,1H,NH),0.94(s,18H,Et3Si),0.67(m,12H,SiEt3).

[0144] Example 2

[0145] A metal catalyst S2, with the following structure: The preparation method is as follows:

[0146]

[0147] (1) The difference from Example 1 is that 2,7-ditetrahydropyrrolidone was replaced with an equimolar amount of 2,7-dicarbazol fluorenone (100 mmol) to obtain 67.3 g of intermediate B2 with a yield of 86%.

[0148] 1 H NMR (400MHz, CDCl3): δ8.55(dd,2H),8.19(dd,2H),8.04(dd,22H),7.94(m, 2H),7.71(d,2H),7.58(m,2H),7.50(m,4H),7.16(m,4H),6.86(s,2H),6.76( dd,2H),5.06(s,1H),4.16(s,1H),3.32(t,8H,CH),2.58(m,2H),2.04(dd,8 H),1.51(s,1H),1.35(s,1H,NH),0.96(s,18H,Et3Si),0.69(m,12H,SiEt3).

[0149] (2) The difference from Example 1 is that intermediate B1 was replaced with an equimolar amount of intermediate B2 (78.3g, 100mmol) to obtain 58g of intermediate C2 with a yield of 73%.

[0150] 1 H NMR (400MHz, CDCl3): δ8.54(dd,2H),8.19(dd,2H),8.04(dd,22H),7.95(m,2H),7.71(d,2H),7.58(m,2H),7.50(m,4H),7.16(m,4H),6.8 6(s,2H),6.76(dd,2H),5.06(s,1H),3.32(t,8H,CH),2.48(m,2H),2.04(dd,8H),1.51(s,1H),0.95(s,18H,Et3Si),0.66(m,12H,SiEt3).

[0151] (3) The difference from Example 1 is that intermediate C1 was replaced with an equimolar amount of intermediate C2 (7.94 g, 10 mmol), and titanium tetrachloride was replaced with an equimolar amount of zirconium tetrachloride, to obtain 5 g of target product S2 with a yield of 55%.

[0152] 1H NMR (400MHz, CDCl3): δ8.54(dd,2H),8.19(dd,2H),8.04(dd,22H),7.94(m,2H),7.71(d,2H),7.58(m,2H),7.51(m,4H),7.16(m,4H ),6.86(s,2H),6.76(dd,2H),3.29(t,8H,CH),2.58(m,2H),2.03(dd,8H),1.51(s,1H),0.97(s,18H,Et3Si),0.69(m,12H,SiEt3).

[0153] Example 3

[0154] A metal catalyst S3, with the following structure: The preparation method is as follows:

[0155]

[0156] (1) The difference from Example 1 is that 2,7-ditetrahydropyrrolidone was replaced with an equimolar amount of 2,7-di-tert-butylfluorenone (100 mmol) to obtain 44.07 g of intermediate B3 with a yield of 78%.

[0157] 1 H NMR (400MHz, CDCl3): δ7.89(dd,2H),7.58(d,2H),7.44(dd,2H),5.06(s,1H),3.32(m,2H,C H),2.59(m,1H),2.04(s,2H),1.35(s,18H),1.05(m,6H),0.97(s,18H,Et3Si),0.69(m,6H).

[0158] (2) The difference from Example 1 is that intermediate B1 was replaced with an equimolar amount of intermediate B3 (100 mmol) to obtain 52.5 g of intermediate C3 with a yield of 91%.

[0159] 1 H NMR (400MHz, CDCl3): δ7.89(dd,2H),7.59(d,2H),7.44(dd,2H),5.06(s,1H),3.67(m,2H),3.33(m,2H ,CH),2.58(m,1H),2.04(s,2H),1.35(s,18H),1.05(m,6H),0.96(s,18H,Et3Si),0.69(m,6H,SiEt3).

[0160] (3) The difference from Example 1 is that intermediate C1 was replaced with an equimolar amount of intermediate C3, titanium tetrachloride was replaced with an equimolar amount of zirconium tetrachloride, and n-butyllithium was replaced with an equimolar amount of methyllithium, resulting in 2.99 g of target product S3 with a yield of 43%.

[0161] 1 H NMR (400MHz, CDCl3): δ7.89(dd,2H),7.60(d,2H),7.45(dd,2H),3.32(m,2H,CH),2.59(m,1H),2.04(s, 2H),1.35(s,18H),1.05(m,6H),0.96(s,18H,Et3Si),0.69(m,6H,SiEt3),-1.16(s,3H),-1.24(s,3H).

[0162] Example 4

[0163] A metal catalyst S4, with the following structure: The preparation method is as follows:

[0164]

[0165] (1) The difference from Example 1 is that 2,7-ditetrahydropyrrolidone was replaced with an equimolar amount of 2,7-difluorofluorenone (21.6 g, 100 mmol) to obtain 67.3 g of intermediate B4 with a yield of 86%.

[0166] 1 H NMR (400MHz, CDCl3): δ7.85(dd,2H),7.28(dd,2H),7.04(t,2H),5.03(s,1H),3.32( m,2H,CH),2.58(m,1H),2.04(s,2H),1.05(m,6H),0.96(s,18H,Et3Si),0.69(m,6H).

[0167] (2) The difference from Example 1 is that intermediate B1 was replaced with an equimolar amount of intermediate B4 (100 mmol) to obtain 39 g of intermediate C4 with a yield of 78%.

[0168] 1 H NMR (400MHz, CDCl3): δ7.97(dd,2H),7.59(dd,2H),7.14(t,2H),5.02(s,1H),3.35(m ,2H,CH),2.58(m,1H),2.04(s,2H),1.05(m,6H),0.96(s,18H,Et3Si),0.69(m,12H).

[0169] (3) The difference from Example 1 is that intermediate C1 was replaced with an equimolar amount of intermediate C4, and titanium tetrachloride was replaced with an equimolar amount of hafnium tetrachloride (10 mmol), resulting in 4.63 g of target product S4 with a yield of 62%.

[0170] 1 H NMR (400MHz, CDCl3): δ7.86(dd,2H),7.29(dd,2H),7.04(t,2H),3.32(m,2H,C H),2.57(m,1H),2.02(s,2H),1.03(m,6H),0.96(s,18H,Et3Si),0.69(m,6H).

[0171] Example 5

[0172] A metal catalyst S5, with the following structure: The preparation method is as follows:

[0173]

[0174] (1) The difference from Example 1 is that 2,7-ditetrahydropyrrolidone was replaced with an equimolar amount of 2,7-di((2,4,6)-trimethylphenyl)fluorenone (41.6 g, 100 mmol) to obtain 62.6 g of intermediate B5 with a yield of 91%.

[0175] 1 H NMR (400MHz, CDCl3): δ7.93(dd,2H),7.78(dd,2H),7.63(t,2H),6.97(d,4H),5.03(s,1H),3.03(s ,12H),2.98(m,2H,CH),2.58(m,1H),2.04(s,2H),1.05(m,6H),0.96(s,18H,Et3Si),0.69(m,6H).

[0176] (2) The difference from Example 1 is that intermediate B1 was replaced with an equimolar amount of intermediate B5 (68.8 g, 100 mmol) to obtain 59.5 g of intermediate C5, with a yield of 85%.

[0177] 1H NMR (400MHz, CDCl3): δ7.91(dd,2H),7.80(dd,2H),7.63(t,2H),6.98(d,4H),5.05(s,1H),3.02(s ,12H),2.78(m,2H,CH),2.58(m,1H),2.03(s,2H),1.05(m,6H),0.96(s,18H,Et3Si),0.69(m,6H).

[0178] (3) The difference from Example 1 is that intermediate C1 was replaced with an equimolar amount of intermediate C5, and titanium tetrachloride was replaced with an equimolar amount of tetra(dimethylamine)zirconium (2.67 g, 10 mmol), to obtain 47.4 g of target product S5 with a yield of 54%.

[0179] 1 H NMR (400MHz, CDCl3): δ7.95(dd,2H),7.78(dd,2H),7.63(t,2H),6.97(d,4H), 3.04(s,12H), 2.98(m,2H,CH),2.59(m,1H),2.48(s,12H),1.05(m,6H),0.96(s,18H,Et3Si),0.68(m,6H).

[0180] Example 6

[0181] A metal catalyst S6, with the following structure: The preparation method is as follows:

[0182]

[0183]

[0184] (1) The difference from Example 1 is that 2,7-ditetrahydropyrrolidone was replaced with an equimolar amount of 2,7-dimethoxyfluorenone (100 mmol) to obtain 44 g of intermediate B6 with a yield of 86%.

[0185] 1 H NMR (400MHz, CDCl3): δ7.75(dd,2H),7.08(dd,2H),6.89(t,2H),5.03(s,1H),3.83(s,6H), 3.32(m,2H,CH),2.58(m,1H),2.04(s,2H),1.05(m,6H),0.96(s,18H,Et3Si),0.69(m,6H).

[0186] (2) The difference from Example 1 is that intermediate B1 was replaced with an equimolar amount of intermediate B6 (100 mmol) to obtain 46.1 g of intermediate C6 with a yield of 88%.

[0187] 1 H NMR (400MHz, CDCl3): δ7.77(dd,2H),7.09(dd,2H),6.88(t,2H),5.05(s,1H),3.86(s,6H), 3.32(m,2H,CH),2.58(m,1H),2.05(s,2H),1.05(m,6H),0.98(s,18H,Et3Si),0.68(m,6H).

[0188] (3) The difference from Example 1 is that intermediate C1 was replaced with an equimolar amount of intermediate C6, and titanium tetrachloride was replaced with tetrabenzylhafnium (8.15 g, 15 mmol), resulting in 6 g of target product S6 with a yield of 68%.

[0189] 1 H NMR (400MHz, CDCl3): δ7.77(dd,2H),7.33(m,4H),7.08(dd,2H),6.89(t,2H),6.68(d,4H), 3.83(s,6H),3.32(m,2H,CH),2.61(s,4H),1.05(m,6H),0.96(s,18H,Et3Si),0.69(m,6H).

[0190] Application Example 1

[0191] The application of the metal catalyst S1 provided by this invention in the homopolymerization of ethylene, specifically, provides a method for preparing polyethylene, as follows:

[0192] A 1L polymerization reactor was continuously dried at 120℃ for 6 hours. While still hot, it was evacuated and purged three times with N2 gas. After cooling to room temperature, the reactor was purged three times with ethylene. 500mL of Isopar-E solvent was added, along with a trace amount of MMAO, to achieve a molar ratio of Al in MMAO to Ti in the metal catalyst S1 of MMAO (10:1). Then, 12mL of a toluene solution of borate (0.1μmol / mL) was added to achieve a B:Ti ratio of 1:2. At room temperature, 10mL of a toluene solution of the main catalyst S1 (0.5μmol / mL) was added, and the ethylene pressure was adjusted to 4MPa and maintained constant. The reaction was vigorously stirred at 25℃ for 10 minutes. After the reaction was complete, the reactor was cooled to room temperature and the pressure was released. The reaction solution was neutralized with an ethanol solution acidified with 5% hydrochloric acid to obtain a polymer precipitate. The precipitate was washed several times with ethanol and water, dried under vacuum to constant weight, and the obtained polyethylene was weighed, totaling 1.2g.

[0193] Polymerization activity: 7.2 × 10⁻⁶ 6 g·mol -1 (Ti)·h -1 The weight-average molecular weight M of the polymer w = 580000 g / mol, molecular weight distribution M w / M n =2.1, melting point T m =136℃.

[0194] Application Example 2-9

[0195] The application of the metal catalyst provided by this invention in the homopolymerization of ethylene specifically provides a method for preparing polyethylene. The difference between this method and Application Example 1 lies in the different metal catalyst (main catalyst) and / or polymerization reaction temperature, as shown in Table 1. Materials and parameters not shown in Table 1 are the same as in Application Example 1. The mass of the polymer (polyethylene) and M are tested and calculated. w M w / M n T m and polymerization activity (10) 7 g·mol -1 (M)·h -1 M represents the type of metal in the metal catalyst, specifically Ti, Zr, and Hf, as shown in Table 1.

[0196] Comparative Example 1

[0197] A method for preparing polyethylene differs from Application Example 1 in that the catalyst is a commercially available ZN catalyst, specifically the CS-1-A catalyst from Liaoning Xiangyang Chemical Group; polymerization is carried out using the same process as in Application Example 1, and the product is tested, with the specific results shown in Table 1.

[0198] Table 1

[0199]

[0200] As shown in Table 1, the metal catalyst provided by this invention, as the main catalyst for olefin polymerization, combined with the co-catalyst, exhibits high ethylene homopolymerization activity, high polymer molecular weight, and high thermal stability, making it suitable for high-temperature solution polymerization.

[0201] Application Example 10

[0202] The application of the metal catalyst S1 provided by this invention in the copolymerization of ethylene and 1-octene, specifically, provides a method for preparing ethylene-octene copolymer, as follows:

[0203] A 2L polymerization reactor was continuously dried at 120℃ for 6 hours. While still hot, it was evacuated and purged three times with N2 gas. After cooling to room temperature, the reactor was purged three times with ethylene. 533 mL of Isopar-E, 347 mL / 250 g of 1-octene, and a trace amount of MMAO were added to make the Al:Ti ratio in the metal catalyst S1 10:1. Then, 12 mL of a toluene solution of borate (0.1 μmol / mL) was added to make the B:Ti ratio 1:2. The temperature was raised to 200℃, and 10 mL of a toluene solution of the main catalyst S1 (0.1 μmol / mL) was added. The ethylene pressure was adjusted to 4 MPa and kept constant. The reaction was stirred vigorously for 10 min. After the reaction was complete, the reactor was cooled to room temperature and the pressure was released. The reaction solution was neutralized with an ethanol solution acidified with 5% hydrochloric acid to obtain a polymer precipitate. The precipitate was washed several times with ethanol and water, dried under vacuum to constant weight, and 12.2 g of copolymer was weighed.

[0204] Polymerization activity: 7.32 × 10⁻⁶ 7 g·mol -1 (Ti)·h -1 M of the copolymer w =180000 g / mol, molecular weight distribution M w / M n =3.1, melting point T m =55℃, 1-octene content (comonomer insertion rate) is 58.3wt%.

[0205] Application Examples 11-15

[0206] The application of the metal catalyst provided by this invention in the copolymerization of ethylene and 1-octene specifically provides a method for preparing ethylene-octene copolymers. The difference between this method and Application Example 10 lies in the different metal catalyst (main catalyst), as shown in Table 2. Materials and parameters not shown in Table 2 are the same as in Application Example 10. The mass of the copolymer and M are tested and calculated. w M w / M n T m Comonomer insertion rate (1-octene content), polymerization activity (10) 7 g·mol -1 (M)·h -1 M represents the type of metal in the metal catalyst, specifically Ti, Zr, and Hf, as shown in Table 2.

[0207] Comparative Example 2

[0208] The method for preparing an ethylene-octene copolymer differs from Application Example 10 in that the catalyst is a commercially available ZN catalyst, specifically the CS-1-A catalyst from Liaoning Xiangyang Chemical Group. The polymerization is carried out using the same process as in Application Example 10, and the product is tested. The specific results are shown in Table 2.

[0209] Table 2

[0210]

[0211]

[0212] According to the data in Table 2, the metal catalyst provided by this invention, as the main catalyst for olefin polymerization, combined with the co-catalyst, exhibits high ethylene-1-octene copolymerization activity, high polymer molecular weight, high thermal stability, and high octene insertion rate, making it suitable for high-temperature solution polymerization.

[0213] The ethylene-octene copolymers prepared in corresponding use cases 10-15 and Comparative Example 2 were tested for melt index, terminal double bond content, and mechanical properties. The test results are shown in Table 3.

[0214] Table 3

[0215]

[0216] According to the test results in Tables 2 and 3, the metal catalyst provided by this invention is used to catalyze the copolymerization of ethylene and octene. The resulting ethylene-octene copolymer has a higher molecular weight, a narrower molecular weight distribution, a higher octene insertion rate, better high-temperature resistance, a lower melt index, a lower content of terminal double bonds, and higher tensile modulus, elongation at break, and tear strength, thus significantly improving mechanical properties.

[0217] The applicant declares that the present invention is illustrated by the above embodiments to demonstrate the metal catalyst, its preparation method, and its application. However, the present invention is not limited to the above embodiments, i.e., it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials in the product of the present invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A metal catalyst, characterized in that, The metal catalyst has the structure shown in Formula I: Equation I; Wherein, R1 is selected from any one of hydrogen, halogen, substituted or unsubstituted C1-C20 straight-chain or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 alkylamino, substituted or unsubstituted C2-C20 heterocycloalkyl, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C6-C20 aryloxy, substituted or unsubstituted C3-C20 heteroaryl, and C6-C20 arylamino; The substituents described in R1 are each independently selected from at least one of halogens, C1-C10 straight-chain or branched alkyl groups, and phenyl groups; R2, R3, R4, R5, R6, and R7 are each independently selected from any one of C1-C6 straight-chain or branched alkyl groups; X1 and X2 are each independently selected from any one of halogen, C1-C20 straight-chain or branched alkyl, C6-C20 aryl, C7-C20 arylalkyl, C1-C20 alkylamino, and C6-C20 arylamino. M is selected from any one of Ti, Zr, or Hf.

2. The metal catalyst according to claim 1, characterized in that, R1 is selected from any one of hydrogen, halogen, substituted or unsubstituted C1-C8 straight-chain or branched alkyl, substituted or unsubstituted C3-C6 cycloalkyl, C1-C10 alkoxy, C2-C6 heterocyclic alkyl, C1-C10 alkylamino, substituted or unsubstituted C6-C12 aryl, substituted or unsubstituted C6-C12 aryloxy, substituted or unsubstituted C6-C20 heteroaryl, and C6-C20 arylamino.

3. The metal catalyst according to claim 1, characterized in that, The substituents described in R1 are each independently selected from at least one of halogens, C1-C6 straight-chain or branched alkyl groups, and phenyl groups.

4. The metal catalyst according to claim 1, characterized in that, R1 is selected from any one of hydrogen, fluorine, chlorine, methyl, tert-butyl, isopropyl, diphenylmethyl, tetrahydropyrrolyl, carbazole, trimethylphenyl, dimethylamino, methoxy, isopropylphenyl, pyridyl, and diphenylamino.

5. The metal catalyst according to claim 1, characterized in that, R2, R3, R4, R5, R6, and R7 are each independently selected from any one of C1-C4 straight-chain or branched alkyl groups.

6. The metal catalyst according to claim 5, characterized in that, R2, R3, R4, R5, R6, and R7 are each independently selected from ethyl groups.

7. The metal catalyst according to claim 1, characterized in that, X1 and X2 are each independently selected from any one of halogen, C1-C10 straight-chain or branched alkyl, benzyl, C1-C10 alkylamino, and C6-C20 arylamino.

8. The metal catalyst according to claim 7, characterized in that, X1 and X2 are each independently selected from any one of methyl, chlorine, dimethylamino, and benzyl.

9. The metal catalyst according to claim 1, characterized in that, The metal catalyst is selected from any one or a combination of at least two of the following compounds: 、 、 、 、 、 ； In this context, Me represents methyl and Bn represents benzyl.

10. A method for preparing a metal catalyst according to any one of claims 1-9, characterized in that, The preparation method includes the following steps: (1) The amino-containing compound with the structure shown in Formula II reacts with the silane compound with the structure shown in Formula III to obtain intermediate A with the structure shown in Formula IV. The reaction formula is as follows: ； (2) The intermediate A reacts with the fluorenone compound of formula V in the presence of a catalyst, a reducing agent and a basic compound to obtain the intermediate B of formula VI, as shown in the following reaction formula: ； (3) The intermediate B, triethyl orthoformate, bis(trimethylsilyl)aminopotassium and acidic compound are mixed and reacted to obtain intermediate C with the structure shown in formula VII. The reaction formula is as follows: ； (4) The intermediate C is pre-reacted with the dehydrogenation reagent and then reacted with the metal M salt to obtain the metal catalyst with the structure shown in Formula I. Among them, R1, R2, R3, R4, R5, R6, R7, X1, X2, and M have the same limited range as Equation I; Hal is selected from any of the halogens.

11. The preparation method according to claim 10, characterized in that, The molar ratio of the amino-containing compound to the silane compound is 1:(0.2-1).

12. The preparation method according to claim 11, characterized in that, The molar ratio of the amino-containing compound to the silane compound is 1:(0.8-1).

13. The preparation method according to claim 10, characterized in that, The reaction temperature in step (1) is from -30°C to 50°C.

14. The preparation method according to claim 13, characterized in that, The reaction temperature in step (1) is 0-50℃.

15. The preparation method according to claim 10, characterized in that, The reaction time in step (1) is 0.2-16 h.

16. The preparation method according to claim 15, characterized in that, The reaction time in step (1) is 0.5-3 hours.

17. The preparation method according to claim 10, characterized in that, The catalyst in step (2) is selected from isopropyl titanate; and / or the reducing agent is selected from sodium borohydride; and / or the basic compound is selected from sodium hydroxide.

18. The preparation method according to claim 17, characterized in that, The molar ratio of the fluorenone compound, isopropyl titanate, intermediate A, sodium borohydride, and sodium hydroxide in step (2) is (0.3-1):(0.5-2):(0.5-2):(1-10):(3-10).

19. The preparation method according to claim 18, characterized in that, The molar ratio of the fluorenone compound, isopropyl titanate, intermediate A, sodium borohydride and sodium hydroxide in step (2) is (0.5-1):(0.5-2):(0.5-1):(1-5):(3-5).

20. The preparation method according to claim 10, characterized in that, The reaction temperature in step (2) is 10-100℃.

21. The preparation method according to claim 20, characterized in that, The reaction temperature in step (2) is 10-50℃.

22. The preparation method according to claim 10, characterized in that, The reaction time in step (2) is 0.2-16 h.

23. The preparation method according to claim 22, characterized in that, The reaction time in step (2) is 0.5-6 hours.

24. The preparation method according to claim 10, characterized in that, The acidic compound in step (3) is selected from hydrochloric acid.

25. The preparation method according to claim 24, characterized in that, The molar ratio of intermediate B, triethyl orthoformate, hydrochloric acid, and bis(trimethylsilyl)aminopotassium is 1:(2-50):(1-10):(2-20).

26. The preparation method according to claim 25, characterized in that, The molar ratio of intermediate B, triethyl orthoformate, hydrochloric acid, and bis(trimethylsilyl)aminopotassium is 1:(10-30):(2-5):(5-10).

27. The preparation method according to claim 10, characterized in that, The reaction temperature in step (3) is 0-80℃.

28. The preparation method according to claim 27, characterized in that, The reaction temperature in step (3) is 10-50℃.

29. The preparation method according to claim 10, characterized in that, The reaction time in step (3) is 0.2-16 h.

30. The preparation method according to claim 29, characterized in that, The reaction time in step (3) is 0.5-8 hours.

31. The preparation method according to claim 10, characterized in that, The dehydrogenation reagent in step (4) is selected from any one or a combination of at least two of sodium, potassium, methyl magnesium bromide, sodium hydride, potassium hydride, lithium hydride, C1-C6 alkyl lithium, diisopropylamino lithium, and bistrimethylsilylamino lithium.

32. The preparation method according to claim 31, characterized in that, The dehydrogenation reagent in step (4) is selected from any one or a combination of at least two of sodium, potassium, sodium hydride, potassium hydride, and C1-C6 alkyllithium.

33. The preparation method according to claim 10, characterized in that, The molar ratio of intermediate C to the dehydrogenating agent is 1:(2-12).

34. The preparation method according to claim 33, characterized in that, The molar ratio of intermediate C to the dehydrogenation reagent is 1:(4-10).

35. The preparation method according to claim 10, characterized in that, The molar ratio of intermediate C to metal M salt is 1:(1-2).

36. The preparation method according to claim 35, characterized in that, The molar ratio of intermediate C to metal M salt is 1:(1-1.5).

37. The preparation method according to claim 10, characterized in that, The temperature of the pre-reaction in step (4) is from -80°C to 35°C.

38. The preparation method according to claim 37, characterized in that, The temperature of the pre-reaction in step (4) is from -40°C to 35°C.

39. The preparation method according to claim 10, characterized in that, The pre-reaction time in step (4) is 0.1-24 h.

40. The preparation method according to claim 39, characterized in that, The pre-reaction time in step (4) is 0.2-6 hours.

41. The preparation method according to claim 10, characterized in that, The reaction temperature in step (4) is from -80°C to 35°C.

42. The preparation method according to claim 41, characterized in that, The reaction temperature in step (4) is from -40°C to 35°C.

43. The preparation method according to claim 10, characterized in that, The reaction time in step (4) is 1-24 h.

44. The preparation method according to claim 43, characterized in that, The reaction time in step (4) is 2-6 h.

45. An olefin polymerization catalyst, characterized in that, The olefin polymerization catalyst includes the metal catalyst as described in any one of claims 1-9.

46. ​​The olefin polymerization catalyst according to claim 45, characterized in that, The olefin polymerization catalyst also includes a co-catalyst.

47. The olefin polymerization catalyst according to claim 46, characterized in that, The cocatalyst is selected from boron-containing compounds and / or organoaluminum oxide compounds.

48. The olefin polymerization catalyst according to claim 47, characterized in that, The boron-containing compound is selected from any one or a combination of at least two of tri(pentafluorophenyl)boron, triphenylcarbium tetra(pentafluorophenyl)borate, and tetra(pentafluorophenyl)boronic acid-methyl di-(octadecyl)ammonium salt.

49. The olefin polymerization catalyst according to claim 47, characterized in that, The molar ratio of M in the metal catalyst to B in the boron-containing compound is 1:(1-20).

50. The olefin polymerization catalyst according to claim 49, characterized in that, The molar ratio of M in the metal catalyst to B in the boron-containing compound is 1:(1-2).

51. The olefin polymerization catalyst according to claim 47, characterized in that, The organoaluminum oxide compound is selected from modified alkylaluminoxanes.

52. The olefin polymerization catalyst according to claim 47, characterized in that, The molar ratio of M in the metal catalyst to Al in the organoaluminum oxide is 1:(1-30).

53. The olefin polymerization catalyst according to claim 52, characterized in that, The molar ratio of M in the metal catalyst to Al in the organoaluminum oxide is 1:(5-20).

54. The use of a metal catalyst as described in any one of claims 1-9, or an olefin polymerization catalyst as described in any one of claims 45-53, in olefin polymerization.

55. The application according to claim 54, characterized in that, The method for olefin polymerization is olefin solution polymerization.

56. The application according to claim 54, characterized in that, The olefin is selected from any one or a combination of at least two of ethylene, propylene, styrene, 1-butene, 1-hexene, 1-octene, norbornene, and tetracyclododecene.

57. The application according to claim 54, characterized in that, The olefin polymerization is olefin homopolymerization.

58. A method for preparing a polyolefin, characterized in that, The preparation method includes: polymerizing olefin monomers in the presence of a catalyst to obtain the polyolefin; The catalyst includes the metal catalyst as described in any one of claims 1-9 and / or the olefin polymerization catalyst as described in any one of claims 45-53.

59. The preparation method according to claim 58, characterized in that, The preparation method is as follows: a catalyst solution is placed in a reaction apparatus, and then an olefin monomer is introduced to carry out a polymerization reaction to obtain the polyolefin.

60. The preparation method according to claim 59, characterized in that, The solvent of the catalyst solution is selected from any one or a combination of at least two of the following: alkane solvents, haloalkane solvents, cycloalkane solvents, and aromatic solvents.

61. The preparation method according to claim 59, characterized in that, The mass concentration of the metal catalyst in the catalyst solution is 0.1-100 ppm.

62. The preparation method according to claim 61, characterized in that, The mass concentration of the metal catalyst in the catalyst solution is 1-5 ppm.

63. The preparation method according to claim 58, characterized in that, The polymerization reaction is carried out at a pressure of 0.1-5 MPa.

64. The preparation method according to claim 63, characterized in that, The polymerization reaction is carried out at a pressure of 1-5 MPa.

65. The preparation method according to claim 58, characterized in that, The polymerization reaction is carried out at temperatures ranging from -20°C to 220°C.

66. The preparation method according to claim 65, characterized in that, The polymerization reaction is carried out at a temperature of 40-200℃.

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