Metal catalyst, catalyst composition and application thereof

Abstract

The present invention provides a metal catalyst, a catalyst composition, and applications thereof. The metal catalyst has a structure as shown in Formula I. Through the structural design of the ligand, the metal catalyst has excellent heat resistance and catalytic activity, especially good high-temperature catalytic performance, can catalytically prepare olefin polymers with high molecular weight and narrow molecular weight distribution, and significantly improves the insertion rate of α-olefin monomers in olefin copolymers. In addition, the metal catalyst is easy to structurally expand and has broad industrial application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of olefin polymerization catalysis, and in particular relates to a metal catalyst, a catalyst composition and applications thereof. Background Art

[0002] In the field of olefin polymerization, catalysts play a crucial role. Their performance directly affects many key parameters of the polymer products, such as microstructure, molecular weight, and stereoselectivity, and thus directly determines their performance. The discovery and use of metallocene catalysts began in the early 1950s, but development was slow and they have not received sufficient attention. The discovery of methylaluminoxane (MAO) in 1980 significantly improved the performance of metallocenes, which attracted widespread attention and also initiated researchers' pursuit of single-core catalysts. Metallocene catalysts can catalyze the preparation of various types of polyolefin products with high activity, including ethylene-propylene copolymers, ethylene and α-olefin copolymers, and polypropylene with different stereoregularities. However, metallocene catalysts are generally difficult to synthesize, with low yields and high costs. Therefore, various catalyst systems that do not contain metallocene have attracted widespread research interest, and a variety of catalytic systems with excellent performance have continuously emerged.

[0003] In recent years, the pyridylamine hafnium catalyst developed by Dow has attracted attention in the industry for its excellent catalytic activity and heat resistance. The typical structure of the pyridylamine hafnium catalyst is Where X is a monovalent ligand group, and R is a methyl, phenyl, tert-butyl, or a simple substituted group. This catalyst can catalyze the polymerization of ethylene to produce linear polyethylene and propylene to produce highly isotactic polypropylene. It also exhibits excellent catalytic copolymerization performance, catalyzing the copolymerization of ethylene and α-olefins to produce polyolefin elastomers (POE). In combination with the FI-Zr catalyst developed by Mitsui, with the aid of a chain shuttling agent, it can produce olefin multi-block copolymers (OBCs), which have been successfully commercialized. Furthermore, the pyridylamine-based hafnium catalyst exhibits good functional group tolerance and has been used to catalyze the copolymerization of ethylene or propylene with various monomers bearing functional groups.

[0004] Although pyridylamine-based hafnium catalysts have achieved commercial success, their performance still has room for further improvement. For example, they have poor heat resistance, significantly insufficient performance under high temperature conditions, low molecular weight of the polymers obtained by catalytic polymerization, wide molecular weight distribution, and reduced insertion rate of the copolymers. To this end, academia and industry have been exploring new catalyst design ideas and optimizing their structures, including focusing on their skeleton structures, aromatic amine groups, naphthalene rings, and reduced Schiff base groups, especially the first two. However, the improvement in catalytic performance is not obvious enough, and the structure of the catalyst is still relatively simple and lacks scalability. In addition, the industry has also proposed a bimetallic core catalyst based on pyridylamine ligands. Although the heat resistance is improved compared to the mononuclear catalyst, the catalyst is not easy to purify, the molecular weight of the polymer obtained by catalysis is low, the molecular weight distribution is wide, and the insertion rate of α-olefin in ethylene and α-olefin copolymers is still low.

[0005] Based on this, developing catalysts with high high-temperature catalytic activity that can catalyze the production of polyolefins with large molecular weight and narrow molecular weight distribution, while increasing the insertion rate of α-olefins in the copolymer products, is an urgent problem to be solved in this field. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a metal catalyst, a catalyst composition and its application. Through the design of the ligand molecular structure, the metal catalyst has excellent heat resistance and catalytic activity, especially high catalytic activity under high temperature conditions, and can catalyze the production of polyolefins with large molecular weight and narrow molecular weight distribution, and significantly improve the α-olefin insertion rate in olefin copolymers.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a metal catalyst having a structure as shown in Formula I:

[0009]

[0010] In formula I, the structure of Ar is -* represents the connection site of the group; the dotted arc represents the conjugated double bond in the five-membered ring, that is, the structure of Ar is

[0011] D1, D2, and D3 are each independently selected from O, S, N, and NR A1 or CR A2 Any one of the following, not all of which are CR A2 .

[0012] D4 is selected from N or CR A3 Any one of .

[0013] RA1 、R A2 、R A3 , R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 、R 11 Each is independently selected from any one of hydrogen, halogen, substituted or unsubstituted C1-C30 straight or branched alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, C1-C30 alkylsilyl and C1-C30 alkoxysilyl.

[0014] R A2 、R A3 Any two adjacent groups among R1, R2, R3, R4, R5, R6, R7, R8, and R9 are not connected or are connected to form a ring through a chemical bond.

[0015] In the present invention, "R A2 、R A3 , R1, R2, R3, R4, R5, R6, R7, R8, and R9 are each independently not connected to the adjacent ring structure" means that the aforementioned groups are only connected to the C atom through a single bond; "R A2 、R A3 The term "any two adjacent groups among R1, R2, R3, R4, R5, R6, R7, R8, and R9 are connected to form a ring through a chemical bond" means that any two adjacent groups among the aforementioned groups are connected through a chemical bond to form a fused ring structure. When the same description is mentioned below, they all have the same meaning and will not be repeated one by one.

[0016] In formula I, X1 and X2 are each independently selected from any one of halogen, C1-C30 linear or branched alkyl, C6-C30 aryl, C7-C30 arylalkyl, C1-C30 alkylamino, and C6-C30 arylamino.

[0017] In formula I, M is selected from any one of Group IVB metals.

[0018] The substituted substituents are each independently selected from at least one of halogen, unsubstituted or R'-substituted C1-C10 straight or branched alkyl, unsubstituted or R'-substituted C1-C10 alkoxy, and unsubstituted or R'-substituted C2-C10 alkenyl; R' is each independently selected from at least one of halogen and C6-C12 aryl.

[0019] In the present invention, the "substituted or unsubstituted" group may be substituted with one or more substituents. When there are multiple substituents (at least two), they may be the same or different. The same expressions used below have the same meaning. Unless otherwise specified, the selection range of the substituents is as shown above and will not be repeated here.

[0020] The molecular structure of the metal catalyst provided by the present invention is shown in Formula I. A heteroaryl group Ar with a specific structure is introduced on the amino group and the pyridine bridging carbon atom. Through the structural design of the pyridylamine ligand, especially the introduction of the heteroaryl group Ar at a specific site, the metal catalyst inherits the advantages of traditional pyridylamine-based hafnium catalysts while having significantly improved heat resistance and excellent catalytic activity, especially good high-temperature catalytic performance. It can catalytically prepare polyolefins with high molecular weight and narrow molecular weight distribution, and effectively improve the insertion rate of α-olefins in olefin copolymers. In addition, the metal catalyst has good modifiability, is easy to expand and improve the structure, and has broad industrial application prospects.

[0021] 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.

[0022] In the present invention, the halogen includes fluorine, chlorine, bromine and iodine.

[0023] In the present invention, the C1-C30 straight chain or branched chain alkyl group can be a straight chain or branched chain alkyl group of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C20, C22, C24, C25, C26, C28, etc., preferably a C1-C20 straight chain or branched chain alkyl group, further preferably a C1-C10 straight chain or branched chain alkyl group, 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.

[0024] In the present invention, the C1-C30 alkoxy group can be a straight chain or branched chain alkoxy group of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C20, C22, C24, C25, C26, C28, etc., preferably a C1-C20 alkoxy group, and more preferably a C1-C10 alkoxy group. Specific examples are monovalent groups formed by the above-mentioned straight chain or branched chain alkyl groups connected to O.

[0025] In the present invention, the C3-C30 cycloalkyl group can be a cycloalkyl group of C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C20, C22, C24, C25, C26 or C28, including a monocyclic alkyl group or a polycyclic alkyl group, preferably a C3-C20 cycloalkyl group, further preferably a C3-C10 cycloalkyl group, illustratively including but not limited to: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl and the like.

[0026] In the present invention, the C6-C30 aromatic groups can be aromatic groups such as C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, and C6-C20 aromatic groups are further preferred, including monocyclic aromatic groups and condensed-ring aromatic groups, illustratively including but not limited to phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthrenyl, etc.

[0027] In the present invention, the C3-C30 heteroaryl group can be a heteroaryl group of C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, preferably a C3-C20 heteroaryl group, wherein the heteroatom can be N, O, S, etc.; including monocyclic heteroaryl groups or condensed-ring heteroaryl groups, illustratively including but not limited to: pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, furyl, thienyl, pyrrolyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothiophenyl, indolyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, N-phenylcarbazolyl, etc.

[0028] In the present invention, the C1-C30 alkylsilyl groups can all be alkylsilyl groups of C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C20, C22, C24, C25, C26, C28, etc., which are monovalent groups in which at least one hydrogen in -SiH3 is replaced by the above-mentioned straight-chain or branched alkyl groups.

[0029] In the present invention, the C1-C30 alkoxysilyl groups can all be alkoxysilyl groups of C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C20, C22, C24, C25, C26, C28, etc., which are monovalent groups in which at least one hydrogen in -SiH3 is replaced by the above-mentioned alkoxy group.

[0030] In the present invention, the C7-C30 arylalkyl group can be an arylalkyl group of C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C20, C22, C24, C25, C26, C28, etc. Specific examples are monovalent groups formed by connecting the above aryl groups to straight-chain or branched alkyl groups, a typical example of which is benzyl (phenylmethyl).

[0031] In the present invention, the C1-C30 alkylamino group can be an alkylamino group of C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C20, C22, C24, C25, C26, C28, etc., which is a monovalent group obtained by replacing at least one hydrogen in -NH2 with the above-mentioned straight-chain or branched alkyl group.

[0032] 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, and is a monovalent group in which at least one hydrogen in -NH2 is replaced by the above aryl group.

[0033] 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, or 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.

[0034] In the present invention, the C1-C10 alkoxy groups can be straight-chain or branched alkoxy groups of C1, C2, C3, C4, C5, C6, C7, C8, C9, or C10, and specific examples include monovalent groups formed by connecting the above straight-chain or branched alkyl groups to O.

[0035] In the present invention, the C2-C10 alkenyl groups can be straight-chain or branched alkenyl groups of C2, C3, C4, C5, C6, C7, C8, C9, or C10, containing at least one C=C, illustratively including but not limited to: vinyl, propenyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, butadienyl, pentadienyl, etc.

[0036] In the present invention, the C6-C12 aryl groups may be C6, C9, C10, C12, etc., illustratively including but not limited to phenyl, biphenyl, naphthyl, etc.

[0037] Preferably, any two adjacent groups among R1, R2, R3, R4, R5, R6, R7, R8, and R9 are not connected or are connected by a chemical bond to form a ring Cy1; the ring Cy1 is selected from substituted or unsubstituted C3-C20 (such as C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17 or C18, etc.), alicyclic, substituted or unsubstituted C6-C20 (such as C6, C9, C10, C12, C14 , C16, C18, etc.) aromatic ring, substituted or unsubstituted C3-C20 (for example, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17 or C18, etc.) heteroaromatic ring, further preferably any one of substituted or unsubstituted C3-C8 alicyclic ring, substituted or unsubstituted C6-C10 aromatic ring, substituted or unsubstituted C3-C8 heteroaromatic ring; the heteroatoms in the heteroaromatic ring include at least one of O, S or N.

[0038] Preferably, any two adjacent groups among R1, R2, R3, R4, R5, R6, R7, R8, and R9 are not connected or are connected by a chemical bond to form a benzene ring.

[0039] Preferably, the metal catalyst has a structure as shown in Formula II:

[0040]

[0041] In formula II, Ar, R1, R2, R3, R4, R5, R 10 、R 11 , X1, X2, and M have the same defined ranges as in Formula I.

[0042] Preferably, R1 and R5 are each independently selected from any one of C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) linear or branched alkyl groups, more preferably C1-C6 linear or branched alkyl groups, and even more preferably isopropyl.

[0043] As a preferred technical solution of the present invention, the R 11 Any one selected from hydrogen or a simple less hindered group, such as hydrogen, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight chain or branched alkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C16, C18, etc.) aryl, more preferably hydrogen, methyl, ethyl, n-propyl, n-butyl, tert-butyl, phenyl, further preferably hydrogen.

[0044] As a preferred technical solution of the present invention, the R2, R4, R10 Each is independently selected from any one of hydrogen, halogen, substituted or unsubstituted C1-C10 (for example, C2, C3, C4, C5, C6, C7, C8 or C9, etc.) straight chain or branched alkyl, substituted or unsubstituted C1-C10 (for example, C2, C3, C4, C5, C6, C7, C8 or C9, etc.) alkoxy, substituted or unsubstituted C6-C20 (for example, C6, C9, C10, C12, C14, C16 or C18, etc.) aryl.

[0045] Preferably, the R2, R4, R 10 and R 11 For hydrogen.

[0046] Preferably, the metal catalyst has a structure as shown in Formula III:

[0047]

[0048] wherein Ar, R3, X1, X2, and M have the same defined ranges as in formula I.

[0049] Preferably, R3 is selected from any one of hydrogen, halogen, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) linear or branched alkyl, and C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkoxy, more preferably any one of hydrogen, halogen, C1-C6 linear or branched alkyl, and C1-C6 alkoxy, even more preferably hydrogen, fluorine, chlorine, methyl or methoxy.

[0050] Preferably, in Ar, 1-3 (e.g., 1, 2, or 3) of D1, D2, D3, and D4 are O, S, N, NR A1 , the rest are CR A2 or CR A3 , R A2 、R A3 Any two adjacent groups are not connected or are connected to form a ring by a chemical bond; thereby, Ar is any one of the following substituted or unsubstituted groups: pyrrolyl, furyl, thienyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyrazolyl, imidazolyl, indolyl, benzothienyl, benzofuranyl, triazolyl, etc.

[0051] Preferably, the structure of Ar is -* represents the attachment site of the group;

[0052] D1 is selected from O, S or NR A1 Any of the following;

[0053] R A1Any one selected from hydrogen, halogen, substituted or unsubstituted C1-C30 straight or branched alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, C1-C30 alkylsilyl, C1-C30 alkoxysilyl, further preferably hydrogen, substituted or unsubstituted C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight or branched alkyl, substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C14, C16, C18, etc.) aryl, further preferably hydrogen, C1-C6 straight or branched alkyl, phenyl, biphenyl, naphthyl.

[0054] R A Each is independently selected from any one of halogen, substituted or unsubstituted C1-C30 straight or branched alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, C1-C30 alkylsilyl, and C1-C30 alkoxysilyl; any two adjacent R A They are not connected or connected to form a ring through chemical bonds.

[0055] The substituted substituents are each independently selected from at least one of halogen, unsubstituted or R'-substituted C1-C10 straight or branched alkyl, unsubstituted or R'-substituted alkoxy, and unsubstituted or R'-substituted C2-C10 alkenyl; R' is each independently selected from at least one of halogen and C6-C12 aryl.

[0056] n represents a substituent R A The number of R is selected from an integer of 0-4, for example, 0, 1, 2, 3 or 4; when n≥2, multiple (at least 2) R A are the same or different groups.

[0057] Preferably, the R Aeach independently selected from halogen, substituted or unsubstituted C1-C10 (e.g. C2, C3, C4, C5, C6, C7, C8, C9, etc.) linear or branched alkyl, substituted or unsubstituted C1-C10 (e.g. C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkoxy, substituted or unsubstituted C3-C10 (e.g. C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, substituted or unsubstituted C6-C20 (e.g. C6, C9, C10, Any one of a C12, C14, C15, C16 or C18 (e.g., C12, C14, C15, C16 or C18) aryl group, a substituted or unsubstituted C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16 or C18) heteroaryl group, a C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkylsilyl group, or a C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkoxysilyl group;

[0058] Preferably, any two adjacent R A are not connected or are connected by chemical bonds to form a ring Cy2; the ring Cy2 is selected from a substituted or unsubstituted C3-C20 (e.g., C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17 or C18, etc.) alicyclic ring, a substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C14, C16, C18, etc.) aromatic ring, a substituted or unsubstituted C any one of a C3-C20 (e.g., C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17 or C18, etc.) heteroaromatic ring, further preferably any one of a substituted or unsubstituted C3-C8 alicyclic ring, a substituted or unsubstituted C6-C10 aromatic ring, or a substituted or unsubstituted C3-C8 heteroaromatic ring; the heteroatoms in the heteroaromatic ring include at least one of O, S or N.

[0059] Further preferably, any two adjacent R A They are not connected or connected to form benzene rings through chemical bonds.

[0060] Preferably, Ar is selected from any one of the following groups:

[0061]

[0062] Among them, R A4 、R A5 、R A6Each is independently selected from any one of hydrogen, halogen, substituted or unsubstituted C1-C30 straight or branched alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, C1-C30 alkylsilyl, C1-C30 alkoxysilyl, and more preferably hydrogen, halogen, substituted or unsubstituted C1-C30 straight or branched alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, C1-C30 alkylsilyl, and C1-C30 alkoxysilyl. Any one of unsubstituted C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight chain or branched alkyl, substituted or unsubstituted C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkoxy, substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C14, C16, C18, etc.) aryl.

[0063] Preferably, R A4 、R A5 、R A6 The substituents substituted in the above-mentioned are each independently selected from halogen, unsubstituted or R'-substituted C1-C10 (e.g. C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight or branched alkyl, unsubstituted or R'-substituted C1-C10 (e.g. C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkoxy, unsubstituted or R'-substituted C2-C10 (e.g. C3, C4, C5, C6, C7, C8, C9, etc.) R' is independently selected from at least one of halogen, C6-C12 (such as C6, C9, C10, C12, etc.) aryl; further preferably, the substituted substituents are independently selected from any one of halogen (fluorine, chlorine, bromine, iodine), unsubstituted or halogenated C1-C6 straight or branched alkyl, unsubstituted or halogenated C1-C6 alkoxy, unsubstituted or halogenated C2-C6 alkenyl, and di(phenyl)alkenyl.

[0064] Further preferably, the Ar is selected from any one of the following groups:

[0065]

[0066] Wherein, -* represents the attachment site of the group.

[0067] R A1Each is independently selected from any one of hydrogen, substituted or unsubstituted C1-C10 (for example, C2, C3, C4, C5, C6, C7, C8, C9, etc.) linear or branched alkyl, substituted or unsubstituted C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18, etc.) aryl, more preferably any one of hydrogen, C1-C6 linear or branched alkyl, phenyl, biphenyl, naphthyl, further preferably hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, isobutyl or phenyl.

[0068] R A4 、R A5 Each is independently selected from any one of hydrogen, halogen, substituted or unsubstituted C1-C10 (for example, C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight chain or branched alkyl, substituted or unsubstituted C1-C10 (for example, C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkoxy, and substituted or unsubstituted C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18, etc.) aryl.

[0069] Preferably, R A4 、R A5 The substituents substituted in the above-mentioned are each independently selected from halogen, unsubstituted or R'-substituted C1-C10 (e.g. C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight or branched alkyl, unsubstituted or R'-substituted C1-C10 (e.g. C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkoxy, unsubstituted or R'-substituted C2-C10 (e.g. C3, C4, C5, C6, C7, C8, C9, etc.) R' is independently selected from at least one of halogen, C6-C12 (such as C6, C9, C10, C12, etc.) aryl; further preferably, the substituted substituents are independently selected from any one of halogen (fluorine, chlorine, bromine, iodine), unsubstituted or halogenated C1-C6 straight or branched alkyl, unsubstituted or halogenated C1-C6 alkoxy, unsubstituted or halogenated C2-C6 alkenyl, and di(phenyl)alkenyl.

[0070] More preferably, R A4 、R A5 Each is independently selected from hydrogen, halogen, unsubstituted or halogenated C1-C6 (e.g. C2, C3, C4, C5, C6, etc.) straight or branched alkyl, unsubstituted or halogenated C1-C6 (e.g. C2, C3, C4, C5, C6, etc.) alkoxy, phenyl, Any one of; Ph represents a phenyl group, -* represents the attachment site of the group.

[0071] Preferably, the M is selected from any one of titanium, zirconium and hafnium, more preferably hafnium.

[0072] Preferably, the metal catalyst has any one of the following structures:

[0073]

[0074]

[0075] Preferably, X1 and X2 are each independently selected from any one of halogen (fluorine, chlorine, bromine, iodine), C1-C10 (for example, C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight chain or branched alkyl, benzyl, C1-C10 (for example, C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkylamino, C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18, etc.) arylamino, and more preferably any one of halogen, methyl, benzyl, and dimethylamino.

[0076] In a second aspect, the present invention provides a method for preparing the metal catalyst according to the first aspect, the preparation method comprising the following steps:

[0077] (1) A heterocyclic metal compound represented by formula A reacts with a pyridine imine Schiff base compound represented by formula B to obtain a pyridine amine ligand represented by formula C. The reaction formula is as follows:

[0078]

[0079] Among them, Ar, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 、R 11 , X1, X2 and M have the same defined ranges as in Formula I;

[0080] Y is selected from any one of Li or Mg-Hal, and Hal is selected from any one of halogens;

[0081] (2) After the pyridylamine ligand undergoes a first reaction with a hydrogen abstraction reagent, it undergoes a second reaction with a metal M source to obtain the metal catalyst having a structure as shown in Formula I.

[0082] Preferably, the preparation method of the heterocyclic metal compound comprises: reacting a heterocyclic compound having a structure represented by Formula AS with a lithium reagent or metallic magnesium to obtain the heterocyclic metal compound having a structure represented by Formula A, and the reaction formula is as follows:

[0083]

[0084] Wherein, Y2 is selected from any one of hydrogen or halogen, more preferably hydrogen or bromine.

[0085] As a preferred technical solution of the present invention, the heterocyclic metal compound of the structure shown in Formula A can be a lithium salt obtained by reacting a heterocyclic compound of the structure shown in Formula AS with a lithium reagent (e.g., metallic lithium, alkyl lithium, lithium amide) (Y in Formula A is Li); or, the heterocyclic metal compound of the structure shown in Formula A can be a Grignard reagent obtained by reacting a heterocyclic compound of the structure shown in Formula AS with metallic magnesium (Y in Formula A is Mg-Hal, Hal is a halogen).

[0086] Preferably, the preparation method of the heterocyclic metal compound comprises: performing a halogen-lithium exchange reaction on a heterocyclic compound having a structure represented by Formula AS and a lithium reagent to obtain the heterocyclic metal compound having a structure represented by Formula A.

[0087] Preferably, the temperature of the halogen-lithium exchange reaction is <0°C, for example, it can be -90°C, -85°C, -80°C, -78°C, -75°C, -70°C, -60°C, -50°C, -40°C, -30°C, -25°C, -10°C, -5°C or -2°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.

[0088] Preferably, the alkyl lithium includes any one of n-butyl lithium, methyl lithium, and tert-butyl lithium, or a combination of at least two thereof.

[0089] Preferably, the lithium amide includes lithium bis(trimethylsilyl)amide.

[0090] In addition, the Ar (five-membered ring) contains halogen, that is, R A2 、R A3 、R A4 、R A5 、R A6 and R A When at least one of the halogens is halogen, preferably bromine, after the heterocyclic metal compound represented by formula A in step (1) reacts with the pyridine imine Schiff base compound represented by formula B, bromine is retained and can be used for coupling reaction with other organic compounds to achieve further derivatization of the ligand. The organic compound is any one of an organoboron compound, an organotin compound, an organomagnesium compound, an organozinc compound, an organoaluminum compound, an organosilicon compound, an organothalium compound, and a double bond-containing compound, preferably an organoboron compound or an organozinc compound.

[0091] In the present invention, the pyridine imine Schiff base compound of the structure represented by Formula B can be prepared by referring to the methods disclosed in the prior art. As a preferred technical solution of the present invention, it can be prepared by referring to the multi-step reaction disclosed in CN100381475C. Specifically, the pyridine compound of the structure represented by Formula B-1 and the aromatic amine compound of the structure represented by Formula B-2 are subjected to a Schiff base condensation reaction under acidic conditions, and then subjected to a Suzuki coupling reaction with an aromatic boronic acid compound of the structure represented by Formula B-3. The reaction formula is as follows:

[0092]

[0093] As another preferred technical solution of the present invention, the pyridine imine Schiff base compound of the structure shown in Formula B can be obtained by subjecting the compound of the structure shown in Formula B-S2 and the aromatic amine compound of the structure shown in Formula B-2 to a Schiff base condensation reaction under acidic conditions, and the reaction formula is as follows:

[0094]

[0095] Preferably, the compound represented by the structure of formula B-S2 can be purchased or obtained by Suzuki coupling reaction, as shown in the following reaction formula:

[0096]

[0097] Wherein, Hal2 is selected from any one of the halogens, for example, it can be Br.

[0098] Preferably, the temperature of the reaction in step (1) is ≤50°C, for example, it can be -90°C, -85°C, -80°C, -78°C, -75°C, -70°C, -60°C, -50°C, -40°C, -30°C, -25°C, -10°C, -5°C, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 38°C, 40°C, 45°C or 48°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range; further preferably, -10°C to room temperature.

[0099] Preferably, the reaction time of step (1) is 0.5-24 h, for example, it can be 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 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 range.

[0100] Preferably, the hydrogen abstraction reagent includes any one or a combination of at least two of potassium hydride, sodium hydride, lithium bistrimethylsilylamide, sodium bistrimethylsilylamide, lithium diisopropylamide, and C1-C6 (e.g., C2, C3, C4, C5, etc.) alkyl lithium, and further preferably any one or a combination of at least two of sodium hydride, potassium hydride, and C1-C6 alkyl lithium.

[0101] Preferably, the temperature of the first reaction in step (2) is ≤25°C, for example, it can be -80°C, -78°C, -75°C, -70°C, -60°C, -50°C, -40°C, -30°C, -25°C, -10°C, -5°C, 0°C, 5°C, 10°C, 15°C, 20°C or 22°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; room temperature is further preferred.

[0102] Preferably, the time of the first reaction in step (2) is 0.1-12 h, for example, it can be 0.5 h, 0.8 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 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.

[0103] Preferably, the metal M source includes a metal M salt, such as any one of Group IVB metal halides, amino compounds, alkyl compounds, alkylamino compounds, aryl compounds, benzyl compounds, or a combination of at least two thereof.

[0104] Preferably, the metal M source illustratively includes but is not limited to: titanium tetrachloride, zirconium tetrachloride, hafnium tetrachloride, bis(dimethylamino)titanium dichloride, bis(diethylamino)zirconium dichloride, tetrakis(dimethylamino)hafnium.

[0105] Illustratively, the method of the second reaction includes: the hydrogen abstraction product of the pyridineamine ligand directly reacts with a metal M source to obtain the heterocyclic metal compound with the structure shown in Formula A; or, the hydrogen abstraction product of the pyridineamine ligand reacts with a halide of a Group IVB metal and then undergoes an alkylation reaction to obtain the heterocyclic metal compound with the structure shown in Formula A.

[0106] Preferably, the temperature of the second reaction in step (2) is 50-150°C, for example, it can be 55°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 145°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 100-145°C is further preferred.

[0107] Preferably, the time of the second reaction in step (2) is 1-12 h, for example, it can be 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 8 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 enumerates the specific point values ​​included in the range, and 2-6 h is further preferred.

[0108] Preferably, the alkylating agent used in the alkylation reaction includes at least one of an alkyl Grignard reagent and an alkyl aluminum, more preferably an alkyl Grignard reagent, and more preferably methylmagnesium bromide (MeMgBr).

[0109] Preferably, the temperature of the alkylation reaction is ≤50°C, for example, it can be -10°C, -5°C, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 38°C, 40°C, 45°C or 48°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and room temperature is further preferred.

[0110] Preferably, the alkylation reaction time is 0.1-24 h, for example, 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 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 values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range.

[0111] In a third aspect, the present invention provides a catalyst composition, comprising a main catalyst and a co-catalyst, wherein the main catalyst comprises at least one of the metal catalysts described in the first aspect.

[0112] Preferably, the co-catalyst includes any one of an alkyl aluminum compound, an organic aluminum oxy compound, and a boron salt, or a combination of at least two thereof.

[0113] Preferably, the alkyl aluminum compound includes any one of trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tri-n-hexylaluminum, and trioctylaluminum, or a combination of at least two thereof.

[0114] Preferably, the organic aluminum oxy-compound includes any one of methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, and alkylaluminum-modified methylaluminoxane, or a combination of at least two thereof.

[0115] Preferably, the boron salt includes any one or a combination of at least two of tris(pentafluorophenyl)boron, triphenylcarbonium tetrakis(pentafluorophenyl)boron, tetrakis(pentafluorophenyl)boric acid-methyldi-(octadecyl)ammonium salt, and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate.

[0116] As a preferred technical solution of the present invention, the co-catalyst includes a boron salt, and an alkyl aluminum compound can be used as an impurity scavenger.

[0117] Preferably, the molar ratio of the metal Al in the co-catalyst to the metal M in the main catalyst is (10-5000):1, for example, it can be 20:1, 50:1, 80:1, 100:1, 200:1, 300:1, 500:1, 600:1, 800:1, 1000:1, 1500:1, 2000:1, 2500:1, 3000:1, 3500:1, 4000:1, 4500:1 or 4800:1, further preferably (30-1000):1, and even more preferably (40-100):1.

[0118] Preferably, the molar ratio of the B element in the co-catalyst to the metal M in the main catalyst is (1-2):1, for example, it can be 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1 or 1.9:1, and more preferably (1-1.5):1.

[0119] In a fourth aspect, the present invention provides use of the metal catalyst as described in the first aspect and the catalyst composition as described in the third aspect in catalyzing olefin polymerization.

[0120] Preferably, the olefin polymerization includes olefin homopolymerization or ethylene / α-olefin copolymerization.

[0121] Wherein, the olefin homopolymerization includes homopolymerization of any one of ethylene and α-olefins, and the α-olefin includes propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, C10-C30 (such as C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C22, C23, C24, C25, C26, C28, etc.) linear α-olefins, C10-C30 (such as C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C22, C23, C24, C25, C26, C28, etc.) branched α-olefins, and any one or a combination of at least two of the aforementioned α-olefins with double bonds or functional groups containing nitrogen, oxygen, boron, aluminum, phosphorus, or halogen.

[0122] In a fifth aspect, 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;

[0123] The catalyst includes at least one of the metal catalyst described in the first aspect and the catalyst composition described in the third aspect.

[0124] Preferably, the olefin monomer comprises ethylene and / or α-olefin.

[0125] Preferably, the α-olefin includes any one or a combination of at least two of propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, C10-C30 (e.g., C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C22, C23, C24, C25, C26, C28, etc.) linear α-olefins, and C10-C30 (e.g., C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C22, C23, C24, C25, C26, C28, etc.) branched α-olefins.

[0126] Preferably, the α-olefin further comprises any one or a combination of at least two of the aforementioned α-olefins having a double bond, or a functional group containing nitrogen, oxygen, boron, aluminum, phosphorus, or halogen.

[0127] Preferably, the polymerization reaction is carried out in the presence of an organic solvent.

[0128] Preferably, the organic solvent includes any one or a combination of at least two of an alkane solvent, a halogenated alkane solvent, a cycloalkane solvent, and an aromatic solvent, and more preferably any one or a combination of at least two of Isopar E, n-hexane, heptane, toluene, and xylene.

[0129] Preferably, the temperature of the polymerization reaction is 0-200°C, for example, it can be 5°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C or 190°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 100-160°C is further preferred.

[0130] Preferably, the polymerization reaction pressure is 0.1-10 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, 4.5 MPa, 5 MPa, 5.5 MPa, 6 MPa, 7 MPa, 8 MPa or 9 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, and 0.5-5 MPa is further preferred.

[0131] As a preferred technical solution of the present invention, the metal catalyst is used to catalyze the homopolymerization reaction of olefin monomers, has excellent catalytic activity and thermal stability, and the obtained olefin homopolymer has a high molecular weight, a narrow molecular weight distribution, and exhibits the characteristics of high linearity and a high melting point.

[0132] Preferably, the metal catalyst (catalyst composition) of the present invention is used to catalyze the preparation of polyethylene at a high temperature (≥110° C.), so that the molecular weight of the polyethylene is high and the weight average molecular weight (M w ) can be 18.4×10 4 g / mol, and the molecular weight distribution is narrow, the molecular weight distribution index (PDI) ≤ 2.6; catalytic activity ≥ 10 7 g / mol·h, especially the catalytic activity at 130℃≥10 7 g / mol·h.

[0133] As another preferred technical solution of the present invention, the metal catalyst is used to catalyze the copolymerization reaction of ethylene and α-olefin, has excellent catalytic activity and thermal stability, and the copolymerization product has a high α-olefin insertion rate and has the properties of a polyolefin elastomer.

[0134] Preferably, the metal catalyst of the present invention is used to catalyze the preparation of ethylene-octene copolymer at high temperature (e.g., 130° C.), and the obtained ethylene-octene copolymer has a high molecular weight and a weight average molecular weight (M w )≥4.2×10 4 g / mol,M w It can be 4.2×10 4 -5.3×10 4 g / mol, narrow molecular weight distribution, PDI ≤ 2.7, insertion rate of 1-octene monomer ≥ 32.5wt%, can be 32.5-53.9wt%. Catalytic activity > 1.7×10 7 g / mol·h.

[0135] Compared with the prior art, the present invention has the following beneficial effects:

[0136] (1) The metal catalyst provided by the present invention has a structure as shown in Formula I, and a heteroaryl group Ar with a specific structure is introduced on the amino group and the pyridine bridge carbon atom. Through the structural design of the ligand, the metal catalyst has excellent heat resistance and catalytic activity, especially good high-temperature catalytic performance, and can catalytically prepare olefin polymers with high molecular weight and narrow molecular weight distribution, and significantly improve the insertion rate of α-olefin monomers in olefin copolymers; in addition, the metal catalyst is easy to expand its structure and has broad industrial application prospects.

[0137] (2) The metal catalyst provided by the present invention is used to catalyze ethylene homopolymerization, has excellent high-temperature catalytic performance, and can produce polyethylene with high molecular weight and narrow molecular weight distribution. The metal catalyst is used to catalyze ethylene-octene copolymerization, has excellent catalytic performance and high catalytic activity, and can produce ethylene-octene copolymers with high molecular weight, narrow molecular weight distribution, high octene insertion rate, and excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0138] Figure 1 The H NMR spectrum of the ligand L1 provided in Preparation Example 2;

[0139] Figure 2 The H NMR spectrum of the ligand L5 provided in Preparation Example 6;

[0140] Figure 3 This is the H-NMR spectrum of the metal catalyst Cat 1 provided in Example 1;

[0141] Figure 4 This is the H-NMR spectrum of the metal catalyst Cat 2 provided in Example 2;

[0142] Figure 5 This is the H-NMR spectrum of the metal catalyst Cat 5 provided in Example 5. DETAILED DESCRIPTION

[0143] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0144] In the following specific embodiments of the present invention, the materials, reagents, etc. used can all be conventional commercially available raw materials obtained from commercial channels.

[0145] In a specific embodiment, the metal catalyst is a Hf (hafnium) catalyst, which can be prepared by the following synthetic route:

[0146]

[0147] (1) Synthesizing naphthyl-containing pyridine imine Schiff base compounds according to known routes;

[0148] (2) A heterocyclic metal compound (lithium salt or Grignard reagent) is added to a solution of a pyridine imine Schiff base compound (the solvent may be an ether solvent, such as tetrahydrofuran and / or diethyl ether) and monitored by thin layer chromatography (TLC). Generally, the pyridine imine Schiff base compound can be completely converted by overnight reaction; sometimes, additional heterocyclic metal compound is required, and finally the pyridine imine Schiff base compound can be completely converted. In this step, the target ligand can be obtained without column chromatography.

[0149] (3) The obtained ligand is dissolved in a solvent (e.g., toluene), hydrogen is abstracted with n-butyllithium n-BuLi, and then mixed with HfX4 (X represents a halogen, e.g., HfCl4), refluxed in the solvent, and then treated with a Grignard reagent to obtain the target metal catalyst.

[0150] The specific preparation method of the metal catalyst of the present invention will be described in detail below with multiple preparation examples and examples, but the preparation method of the present invention is not limited to these preparation examples and examples.

[0151] In the preparation examples and embodiments of the present invention, nuclear magnetic resonance spectroscopy ( 1 The product structure was characterized and confirmed by H NMR. The deuterated solvent used was one of deuterated benzene (benzene-d6), deuterated dimethyl sulfoxide (DMSO-d6), and deuterated chloroform (CDCl3).

[0152] Preparation Example 1: Synthesis of Pyridineimine Schiff Base 6-(1-naphthyl)-2-((2,6-diisopropylphenyl)imino)pyridine (Compound A)

[0153]

[0154] 23.3 g (100 mmol) of compound 1 and 26.56 g (150 mmol) of compound 2 were dissolved in 100 mL of dry toluene. 20 mg of p-toluenesulfonic acid (PTSA) was added to the solution, and the mixture was heated to 90°C and reacted for 10 h to form a gray solution. The solution was returned to room temperature, the toluene was concentrated, and 50 mL of anhydrous ethanol was added and stirred for 2 h to form a slurry. The solid was filtered to obtain 36 g with a yield of 90%.

[0155] Structural characterization: 1 H NMR (500MHz, benzene-d6): δ8.63(s,1H),8.36(dd,J=7.7,1.2Hz,1H),8.30–8.22(m,1H),7.76–7.64(m,2H),7.58(d d,J=7.2,1.3Hz,1H),7.32–7.23(m,4H),7.22–7.07(m,4H),3.22(hept,J=6.9Hz,2H),1.18(d,J=6.9Hz,12H).

[0156] Preparation Example 2: Synthesis of 2-(N-(2,6-diisopropylphenylamino)-2-benzofuranylmethyl)-6-(1-naphthyl)-pyridine (ligand L1)

[0157]

[0158] Under nitrogen, 0.6 g (5.08 mmol) of benzofuran was dissolved in 20 mL of dry, anhydrous tetrahydrofuran (THF). The system was then cooled to -78°C, and 3.2 mL (5.08 mmol) of n-butyllithium (n-BuLi) was added dropwise at this temperature. After the addition was complete, the solution exhibited a bright yellow color and was maintained at this temperature for 10 minutes with continuous stirring. The system was then gradually warmed to room temperature and stirred for 30 minutes. The system was cooled again to -78°C. At this point, another 20 mL dry, anhydrous THF solution containing 1.99 g (5.08 mmol) of Compound A was slowly added dropwise to the previous benzofuran lithium salt solution at low temperature. During the addition, the color of the reaction solution darkened significantly. The system was then warmed to room temperature again and stirred overnight. The reaction progress was monitored by TLC. After completion, the reaction was quenched by the addition of 20 mL of water, followed by three extractions with 40 mL of ethyl acetate (EA). The organic phases were combined, dried over anhydrous sodium sulfate, and then concentrated. Purification was performed by silica gel column chromatography (petroleum ether PE:EA=50:1) to obtain 1.3 g of product L1 with a yield of 50%.

[0159] The H NMR spectrum of ligand L1 is shown in Figure 1 As shown, 1 H NMR (500MHz, DMSO-d6): δ8.07–7.95(m,4H),7.70–7.56(m,5H),7.53–7.45(m,2H) ),7.27(td,J=8.2,7.7,1.5Hz,1H),7.24–7.18(m,1H),7.12(ddd,J=8.3,6.8,1. 4Hz,1H),7.04–6.93(m,3H),6.88(s,1H),5.50(d,J=10.5Hz,1H),5.17(d,J=10. 5Hz, 1H), 3.25 (hept, J = 6.8Hz, 2H), 0.99 (d, J = 6.7Hz, 6H), 0.95 (d, J = 6.7Hz, 6H).

[0160] Preparation Example 3: Synthesis of 2-(N-(2,6-diisopropylphenylamino)-2-benzothienylmethyl)-6-(1-naphthyl)-pyridine (ligand L2)

[0161]

[0162] Under nitrogen, 0.7 g (5.22 mmol) of benzothiophene was dissolved in 20 mL of dry, anhydrous tetrahydrofuran. The system was cooled to -78°C, and 3.3 mL (5.22 mmol) of n-butyllithium was added dropwise at this temperature. Upon completion of the addition, the solution turned yellow and was maintained at this temperature for 10 minutes with continuous stirring. The system was then warmed to room temperature and stirred for 30 minutes. The system was then cooled again to -78°C. Another solution containing 2.05 g (5.22 mmol) of Compound A in 20 mL of dry, anhydrous THF was then slowly added dropwise to the previous solution of the benzothiophene lithium salt at low temperature. The color of the reaction solution gradually darkened as the addition proceeded. The system was then warmed to room temperature again and stirred overnight. TLC (PE:EA = 5:1) indicated the reaction was complete. The reaction was quenched by the addition of 20 mL of water, followed by three extractions with 40 mL of EA. The organic phases were combined and dried over anhydrous sodium sulfate, and the solvent was concentrated. Finally, the product was purified by silica gel column chromatography (PE:EA=50:1) to obtain 1.18 g of product with a yield of 43%.

[0163] 1 H NMR (400MHz, benzene-d6): δ8.33(d,J=8.3Hz,1H),7.69-7.60(m,3H),7.50(d,J=8.0Hz,1H),7.44(d,J=7.9Hz,1H),7.29(dd,J=8.3,7.1Hz,1H),7.24- 6.99(m,10H),6.83(dd,J=7.5,1.3Hz,1H),5.72(d,J=9.7Hz,1H),5.38(d,J=9.9Hz,1H),3.53(sept,J=6.8Hz,2H),1.07(dd,J=8.0,6.8Hz,12H).

[0164] Preparation Example 4: Synthesis of 2-(N-(2,6-diisopropylphenylamino)-3-benzothienylmethyl)-6-(1-naphthyl)-pyridine (ligand L3)

[0165]

[0166] 0.97g (4.55mmol) of 3-bromobenzothiophene was dissolved in 20mL of ether and placed in a 100mL reaction bottle in a glove box. At -78°C, 2mL (2.4M, 4.77mmol) of n-butyllithium was slowly added dropwise and the temperature was maintained for 1h. 1.5g (3.82mmol) of compound A was dissolved in ether and added dropwise to the above lithium salt solution. The temperature was slowly raised to -50°C for 0.5h, then raised to -20°C for 0.5h, and finally reacted at room temperature for 12h. The reaction progress was monitored by TLC to ensure that compound A was completely reacted. Water was added to quench the reaction, the aqueous phase was separated, the organic phase was extracted with ethyl acetate, dried and concentrated. The product was separated by column chromatography using petroleum ether and ethyl acetate (PE:EA=100:1) as eluents to obtain 1.1g of ligand L3 in a yield of 55%.

[0167] 1 H NMR (500MHz, CDCl3): δ7.95–7.81(m,3H),7.75–7.71(m,2H),7.64(dd,J=8.6,1.1Hz,1H ),7.52(q,J=3.7Hz,2H),7.47–7.38(m,3H),7.31(ddd,J=14.7,6.8,1.1Hz,2H),7.21(dd d,J=8.1,7.0,1.1Hz,1H),7.11(ddd,J=8.4,6.7,1.4Hz,1H),7.04(s,3H),5.53(d,J=9.1 Hz, 1H), 4.61 (d, J = 9.2Hz, 1H), 3.00 (sept, J = 6.9Hz, 2H), 0.97 (dd, J = 27.5, 6.8Hz, 12H).

[0168] Preparation Example 5: Synthesis of 2-(N-(2,6-diisopropylphenylamino)-3-bromo-2-thienylmethyl)-6-(1-naphthyl)-pyridine (ligand L4)

[0169]

[0170] In a 100 mL reaction flask, 1.1 g (4.54 mmol) of 2,3-dibromothiophene was weighed and dissolved in 20 mL of diethyl ether. At -78°C, 1.9 mL (2.4 M, 4.54 mmol) of n-butyllithium was added dropwise, maintaining the temperature for 1 hour. 1.5 g (3.82 mmol) of Compound A was dissolved in diethyl ether and added dropwise to the lithium salt. The temperature was then gradually increased to -50°C for 0.5 hour, then to -20°C for 0.5 hour, and finally to room temperature for 12 hours. The reaction was monitored using a TLC plate to ensure no residual starting material. The reaction was quenched with water, and the organic phase was extracted with ethyl acetate, dried, and concentrated. The product was isolated by column chromatography using petroleum ether and ethyl acetate (PE:EA = 100:1) as the eluent to obtain 31.2 g of the target product L4 in a 56% yield.

[0171] 1 H NMR (500MHz, CDCl3): δ8.14-8.09(m,1H),7.96-7.89(m,2H),7.72(t,J=7.7Hz,1H),7.65(dd,J= 7.0,1.3Hz,1H),7.58(dd,J=8.1,7.1Hz,1H),7.53-7.46(m,2H),7.41(ddd,J=8.3,6.7,1.4Hz,1 H),7.34(dd,J=7.7,1.0Hz,1H),7.27-7.25(m,1H),7.06-6.98(m,3H),6.93(d,J=5.3Hz,1H),5. 57(s,1H),5.07(s,1H),3.12(hept,J=6.8Hz,2H),1.10(d,J=6.9Hz,6H),0.94(d,J=6.7Hz,6H).

[0172] Preparation Example 6: Synthesis of 2-(N-(2,6-diisopropylphenylamino)-3-bromo-2-benzothienylmethyl)-6-(1-naphthyl)-pyridine (ligand L5)

[0173]

[0174] 0.64 g (3 mmol) of 3-bromobenzothiophene was dissolved in 20 mL of dry anhydrous tetrahydrofuran under nitrogen atmosphere, and the mixture was cooled to -78 ° C. At this temperature, 3 mL (3 mmol) of tetrahydrofuran solution of lithium bis(trimethylsilyl)amide LiHMDS was added dropwise. After the addition was completed, a yellow solution was formed and stirred at this temperature for 10 min, then heated to room temperature and stirred for 30 min. After cooling to -78 ° C, another 20 mL of dry anhydrous tetrahydrofuran was taken to dissolve the mixture. 1.18 g (3 mmol) of compound A was dissolved and added dropwise to a solution of 3-bromobenzothiophene lithium salt at low temperature. The reaction solution turned dark in color and then was heated to room temperature and stirred overnight. The reaction progress was monitored by TLC (PE:EA=5:1). After completion of the reaction, 20 mL of water was added to quench the reaction. The mixture was extracted with EA (40 mL×3 times). The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was concentrated. The mixture was purified by silica gel column chromatography (PE:EA=50:1) to obtain 0.7 g of ligand L5 in a yield of 38.48%.

[0175] The H NMR spectrum of ligand L5 is shown in Figure 2 As shown, 1 H NMR (500MHz, benzene-d6): δ8.24 (d, J = 8.5 Hz, 1H), 7.72 (d, J = 8.0 Hz, 1H), 7.67-7. 63(m,2H),7.61(dd,J=7.1,1.2Hz,1H),7.40-7.22(m,4H),7.13-7.02(m,7H) ,6.95(ddd,J=8.2,7.1,1.2Hz,1H),5.95(d,J=9.0Hz,1H),5.57(d,J=9.0Hz, 1H), 3.43 (sept, J=6.8Hz, 2H), 1.10 (d, J=6.8Hz, 6H), 1.04 (d, J=6.8Hz, 6H).

[0176] Preparation Example 7: Synthesis of 2-(N-(2,6-diisopropylphenylamino)-3-(2-methoxyphenyl)-2-thienylmethyl)-6-(1-naphthyl)-pyridine (ligand L6)

[0177]

[0178] Under nitrogen, 2-methoxyphenylboronic acid (0.15 g, 0.98 mmol), ligand L4 (0.5 g, 0.89 mmol), potassium carbonate (0.24 g, 2 eq.), and tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (0.05 g, 0.05 eq.) were weighed into a 250 mL reaction flask. 50 mL of toluene, 20 mL of ethanol, and 10 mL of water were added. The reaction was incubated at 85°C for 12 h. The reaction was monitored by TLC, concentrated, and separated with ethyl acetate. The organic phase was dried, concentrated, and separated by column chromatography (PE:EA = 50:1) to obtain 140 mg of ligand L6 in a 27% yield.

[0179] 1 H NMR (500MHz, CDCl3): δ8.08(d,J=8.6Hz,1H),7.94-7.87(m,2H),7.61(dd,J=7.1,1.4Hz,1H),7.56( dd,J=8.1,7.1Hz,1H),7.49(ddd,J=8.1,6.7,1.2Hz,1H),7.45-7.36(m,2H),7.34-7.29(m,2H),7.1 8(ddd,J=8.9,6.7,2.5Hz,1H),7.01-6.90(m,4H),6.78-6.66(m,4H),5.34(d,J=9.8Hz,1H),4.65(d ,J=9.8Hz,1H),3.56(s,3H),3.09(sept,J=6.8Hz,2H),1.00(d,J=6.8Hz,6H),0.82(d,J=6.8Hz,6H).

[0180] Preparation Example 8: Synthesis of 2-(N-(2,6-diisopropylphenylamino)-3-phenyl-5-methyl-2-thienylmethyl)-6-(1-naphthyl)-pyridine (ligand L7)

[0181]

[0182] Under a nitrogen atmosphere, phenylboronic acid (6.8 g, 55.76 mmol), 2-methyl-4-bromothiophene (9 g, 50.83 mmol), potassium carbonate (7 g, 2 eq.), and tetrakis(triphenylphosphine)palladium (2.93 g, 0.05 eq.) were weighed into a 500 mL reaction flask. 150 mL of toluene, 60 mL of ethanol, and 30 mL of water were added. The reaction was incubated at 85°C for 12 h. The reaction was monitored by TLC, concentrated, and extracted with ethyl acetate. The organic phase was dried, concentrated, and separated by column chromatography (PE:EA = 50:1) to afford 2-methyl-4-bromothiophene (6.6 g, 75% yield).

[0183] 1H NMR (500MHz, CDCl3): δ7.54-7.45(m,2H),7.39-7.25(m,2H),7.22-7.15(m,1H),7.11(d,J=1.5Hz,1H),6.98(s,1H),2.45(s,3H).

[0184] Ligand L7 was prepared by the same method as that for synthesizing ligand L2, except that 2-methyl-4-phenylthiophene was used in an equal molar amount to replace benzothiophene. The yield of ligand L7 was 42%.

[0185] 1 H NMR (500MHz, CDCl3): δ8.20(d,J=8.5Hz,1H),7.96–7.89(m,2H),7.68(dd,J=7.0,1.3Hz,1H),7 .58(td,J=7.9,4.4Hz,2H),7.52(ddd,J=8.2,6.7,1.3Hz,1H),7.48–7.37(m,3H),7.20(dd,J=5 .0,1.9Hz,2H),7.02–6.88(m,6H),6.60(d,J=1.3Hz,1H),5.39(d,J=9.1Hz,1H),4.65(d,J=9.1 Hz,1H),3.24–3.07(m,2H),2.50(d,J=1.1Hz,3H),0.93(d,J=6.8Hz,6H),0.85(d,J=6.7Hz,6H).

[0186] Example 1

[0187] Metal catalyst Cat 1, structure: The preparation method is as follows:

[0188]

[0189] Under nitrogen protection, 0.6g (1.17mmol) of ligand L1 was dissolved in toluene solvent. At 0°C, 0.77mL (1.23mmol, 1.05eq.) of n-butyllithium was added thereto and the reaction was carried out for 2h. After the solvent was drained, it was washed several times with n-hexane and then drained again. The treated product was mixed with 0.394g (1.23mol) of hafnium tetrachloride and reacted at 120°C for 5.5h. After the reaction was completed, it was cooled to room temperature, 3.3 equivalents of MeMgBr were added thereto, and the reaction was allowed to proceed overnight at room temperature. The volatiles were drained and the product was extracted with toluene. The filtrate was drained and washed several times with n-hexane to obtain 0.4g of the target product with a yield of 47.5%.

[0190] The nuclear magnetic hydrogen spectrum of metal catalyst Cat 1 is as follows Figure 3As shown, 1 H NMR (500MHz, benzene-d6): δ8.57(d,J=7.6Hz,1H),8.20–8.06(m,1H),7.81(d,J=7.6Hz,1H),7.75–7.65(m,1H),7.44(d,J=8.0Hz,1H),7.31 –7.26(m,3H),7.23–7.18(m,2H),7.17(d,J=1.6Hz,1H),7.12(dd,J=7.4,2.1Hz,1H),7.03(td,J=7.5,1.0Hz,1H),6.95(ddd,J=8.4,7 .2,1.4Hz,1H),6.81(t,J=7.9Hz,1H),6.53(d,J=7.6Hz,1H),6.04(s,1H),5.98(d,J=0.9Hz,1H),4.04(sept,J=6.8Hz,1H),3.28(sep t,J=6.8Hz,1H),1.41(d,J=6.8Hz,3H),1.35(d,J=6.8Hz,3H),1.16(d,J=6.8Hz,3H),1.09(s,3H),0.69(s,3H),0.51(d,J=6.7Hz,3H).

[0191] Example 2

[0192] Metal catalyst Cat 2, structure: The preparation method thereof differs from that of Example 1 only in that the ligand L1 is replaced by an equivalent amount of L2, and the other materials, amounts and processes are the same as those of Example 1, to obtain the metal catalyst Cat 2.

[0193]

[0194] The nuclear magnetic hydrogen spectrum of the metal catalyst Cat 2 is as follows Figure 4 As shown, 1H NMR (500MHz, benzene-d6): δ8.56(d,J=7.7Hz,1H), 8.19(d,J=7.6Hz,1H), 7.81(d,J=7.7Hz,1H), 7.75–7.68(m,1H), 7.49(d,J=8.0Hz,1H),7.39(dd,J=8.0,4.9Hz,3H),7.31–7.27(m,4H),6.99(dt,J=12.4,5.6Hz,2H),6.86(t, J=7.8Hz,1H),6.67(s,1H),6.56(d,J=7.8Hz,1H),6.28(s,1H),4.27(sept,J=6.9Hz,1H),3.25(sept,J=6.8H z,1H),1.41(dd,J=10.0,6.8Hz,6H),1.16(d,J=6.7Hz,3H),1.09(s,3H),0.68(s,3H),0.52(d,J=6.7Hz,3H).

[0195] Example 3

[0196] Metal catalyst Cat 3, structure is The preparation method thereof differs from that of Example 1 only in that the ligand L1 is replaced by an equivalent amount of L3, and the other materials, amounts and processes are the same as those of Example 1, to obtain the metal catalyst Cat 3.

[0197]

[0198] 1 H NMR (500MHz, benzene-d6): δ7.61(dd,J=7.1,1.2Hz,1H),7.48–7.43(m,3H),7.37(dd,J =7.6Hz,1H),7.23(d,J=8.1Hz,2H),7.14–6.98(m,3H),6.93–6.82(m,3H),6.80– 6.65(m,4H),4.23(sept,J=6.7Hz,1H),3.93(sept,J=6.8Hz,1H),1.81(d,J=6.6 Hz,3H),1.67(t,J=7.0Hz,6H),0.97(s,3H),0.33(d,J=6.8Hz,3H),-2.75(s,3H).

[0199] Example 4

[0200] Metal catalyst Cat 4, structure is The preparation method thereof differs from that of Example 1 only in that the ligand L1 is replaced by an equivalent amount of L4, and the other materials, amounts and processes are the same as those of Example 1, to obtain the metal catalyst Cat 4.

[0201]

[0202] 1 H NMR (500MHz, benzene-d6): δ8.60(d,J=7.8,1H),8.13(d,J=7.8,1H),7.90-7.87(m,2H),7.76(d,J=7.5Hz,1H),7.72 –7.68(m,1H),7.68–7.65(d,J=8.1Hz,1H),7.57-7.45(m,2H),7.43-7.40(m,2H),7.16-7.00(m,1H),6.9(t,J =7.8Hz,1H),6.6(d,J=7.8Hz,1H),6.35(s,1H),3.85(sept,J=6.9Hz,1H),3.10(sept,J=6.9Hz,1H),1.35(d, J=6.9Hz,3H),1.33(d,J=6.8Hz,3H),1.17(d,J=6.8Hz,3H),1.11(s,3H),0.80(s,3H),0.54(d,J=6.8Hz,3H).

[0203] Example 5

[0204] Metal catalyst Cat 5, structure is The preparation method thereof differs from that of Example 1 only in that the ligand L1 is replaced by an equimolar amount of L5, and the other materials, amounts and processes are the same as those of Example 1, to obtain the metal catalyst Cat 5.

[0205]

[0206] The nuclear magnetic hydrogen spectrum of metal catalyst Cat 5 is as follows Figure 5 As shown, 1H NMR (500MHz, benzene-d6): δ8.56(d,J=7.7Hz,1H),8.20(d,J=7.9Hz,1H),7.81(d,J=7.6Hz,1H),7 .72(d,J=7.5Hz,1H),7.66(d,J=8.1Hz,1H),7.51(d,J=7.9Hz,1H),7.29(br,3H),7.04–6.8 0(m,6H),6.66(d,J=13.9Hz,1H),6.29(s,1H),4.22(br,1H),3.32(br,1H),1.55(d,J=6.7H z,3H),1.39(d,J=7.1Hz,3H),1.18(d,J=6.9Hz,3H),1.09(s,3H),0.70(s,3H),0.47(s,3H).

[0207] Example 6

[0208] Metal catalyst Cat 6, structure The preparation method thereof differs from that of Example 1 only in that the ligand L1 is replaced by an equivalent amount of L6, and the other materials, amounts and processes are the same as those of Example 1, to obtain the metal catalyst Cat 6.

[0209]

[0210] 1 H NMR (500MHz, benzene-d6): δ8.48(d,J=7.8,1H),8.00(d,J=7.8,1H),7.86-7.74(m,3H),7.72–7.60(m,2H) ),7.55–7.45(m,2H),7.43-7.40(m,3H),7.28–7.02(m,3H),6.96-6.90(m,2H),6.68(d,J=7.8Hz,1H ),6.40(s,1H),3.88(s,3H),3.63(sept,J=6.8Hz,1H),3.08(sept,J=6.8Hz,1H),1.40(d,J=6.9Hz, 3H),1.39(d,J=6.8Hz,3H),1.13(d,J=6.8Hz,3H),1.12(s,3H),0.65(s,3H),0.60(d,J=6.8Hz,3H).

[0211] Example 7

[0212] Metal catalyst Cat 7, structure is The preparation method thereof differs from that of Example 1 only in that the ligand L1 is replaced by an equivalent amount of L7, and the other materials, amounts and processes are the same as those of Example 1, to obtain the metal catalyst Cat 7.

[0213]

[0214] 1 H NMR (500MHz, benzene-d6): δ8.62(d,J=7.8,1H),8.20(d,J=7.8,1H),7.66-7.60(m,5H),7.55(d, J=7.8Hz,2H),7.48-7.46(m,2H),7.32(d,J=7.8Hz,2H),7.30–6.99(m,5H),6.30(s,1H),3. 64(sept,J=6.8Hz,1H),3.44(sept,J=6.8Hz,1H),2.58(s,2H),1.30(d,J=6.9Hz,3H),1.2 6(d,J=6.8Hz,3H),1.25(d,J=6.8Hz,3H),1.20(s,3H),0.48(s,3H),0.38(d,J=6.8Hz,3H).

[0215] The application of the metal catalyst of the present invention in catalyzing olefin polymerization will be described in detail below with reference to a number of application examples, but the application of the metal catalyst of the present invention is not limited to these application examples.

[0216] In the following specific embodiments of the present invention, the main testing methods for polymers are as follows:

[0217] (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 determined by high temperature gel permeation chromatography (GPC) on a PL-GPC 220 gel permeation chromatography instrument at 150°C using 1,2,4-trichlorobenzene as the mobile phase.

[0218] (2) Comonomer insertion rate: measured by high-temperature H-NMR spectroscopy 1 The H NMR measurements were performed on a Bruker AV400 NMR spectrometer at 125°C and 400 MHz using deuterated 1,1,2,2-tetrachloroethane as the solvent.

[0219] (3) Melting temperature of polymer (T m):Measured on a TA company Q2000 differential scanning calorimeter (DSC) instrument, the scanning temperature range is 40-170 ° C, the heating and cooling rate is 10 ° C / min, and the second heating temperature is taken as the melting point T m .

[0220] (4) Catalytic activity: calculated according to the following formula: Catalytic activity = polymer mass / (molar amount of metal catalyst × polymerization time).

[0221] Application Example 1

[0222] The present invention provides an application of the metal catalyst Cat 1 in ethylene homopolymerization, specifically, a method for preparing polyethylene, as follows:

[0223] Ethylene homopolymerization was catalyzed using 2 μmol of metal catalyst Cat 1, 1.2 equivalents of the boron salt triphenylcarbonium tetrakis(pentafluorophenyl)boron (CPh3) (B(C6F5)4) as an activator, and 50 equivalents of triisobutylaluminum (TIBA) as an impurity scavenger. First, in a glove box, TIBA was mixed with 100 mL of Isopar E solvent and placed in a glass reactor. The glove box was then removed and connected to an ethylene line. Catalyst Cat 1 and the boron salt were dissolved in toluene and mixed separately. The mixture was then added to the reactor under an ethylene atmosphere. The ethylene pressure was set to 8 bar and the temperature was set to 110°C. The reaction was allowed to proceed with magnetic stirring for 5 minutes. After the reaction, the reaction mixture was poured into 200 mL of ethanol for precipitation, filtered, and dried to yield 3.74 g of polymer. The molecular weight, molecular weight distribution, melting point, and catalytic activity of the polymer are shown in Table 1.

[0224] Application Example 2-6

[0225] The present invention provides an application of a metal catalyst in ethylene homopolymerization, specifically, a method for preparing polyethylene, which differs from Application Example 1 in that the metal catalyst (main catalyst) and the polymerization temperature are shown in Table 1; the materials and parameters not shown in Table 1 are the same as those in Application Example 1; and the molecular weight, molecular weight distribution, melting point, and catalytic activity of the polymer are shown in Table 1.

[0226] Comparative Example 1-2: The only difference from Application Example 1 is that the main catalyst is the catalyst CatiPr

[0227]

[0228] Table 1

[0229]

[0230] Application Example 7

[0231] The present invention provides an application of the metal catalyst Cat 1 in the copolymerization of ethylene and 1-octene, specifically providing a method for preparing an ethylene-octene copolymer, as follows:

[0232] 2μmol of metal catalyst Cat 1 was used to catalyze the copolymerization of ethylene and 1-octene, 1.2 equivalents of boron salt (CPh3) (B(C6F5)4) as an activator, and 100 equivalents of triisobutylaluminum TIBA as an impurity scavenger. TIBA, 100mL of solvent Isopar E, and 3mL of 1-octene were mixed in a glove box and placed in a glass reactor. The glove box was removed and an ethylene line was connected. Catalyst Cat 1 and boron salt were dissolved and mixed in toluene, added to the reactor under an ethylene atmosphere, the ethylene pressure was set to 8 bar, the temperature was set to 130°C, and the reaction was carried out under magnetic stirring for 5 minutes. After the reaction, the reaction mixture was poured into 200mL of ethanol for precipitation, filtered, and dried to obtain 4.12g of polymer, the test data of which are shown in Table 2.

[0233] Application Examples 8-13

[0234] The present invention provides an application of a metal catalyst in the copolymerization of ethylene and 1-octene. Specifically, a method for preparing an ethylene-octene copolymer is provided. The method differs from Application Example 7 in that the metal catalyst (main catalyst) is shown in Table 2; the materials and parameters not shown in Table 2 are the same as those in Application Example 7; and the test data of the polymerization product are shown in Table 2.

[0235] Comparative Example 3: The only difference from Application Example 7 is that the main catalyst is the catalyst CatiPr produced by Dow Chemical Company.

[0236] Table 2

[0237]

[0238] The data in Tables 1 and 2 indicate that the non-metallocene catalysts provided by the present invention exhibit excellent thermal stability and, in the catalytic polymerization of ethylene and copolymerization of ethylene with 1-octene, can produce olefin polymers with high molecular weights, narrow molecular weight distributions, and high comonomer insertion rates. In particular, under high-temperature reaction conditions, the catalytic activity, molecular weight, molecular weight distribution, and insertion rate of the metal catalysts provided by the present invention are significantly superior to those of existing hafnium pyridylamine catalysts. Furthermore, the heterocycles in the metal catalysts of the present invention exhibit excellent modifiability, facilitating further improvements in the catalyst structure and demonstrating excellent application value.

[0239] The applicant states that while the above-described embodiments illustrate the metal catalyst, catalyst composition, and their applications, the present invention is not limited to the aforementioned process steps, nor does it necessarily rely on the aforementioned process steps for implementation. Persons skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for the raw materials used, addition of auxiliary components, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A metal catalyst, characterized in that The metal catalyst has a structure as shown in Formula III: wherein M is selected from any one of Group IVB metals; R3 is selected from any one of hydrogen, halogen, C1-C10 straight or branched alkyl, and C1-C10 alkoxy; Ar is selected from any one of the following groups: Wherein, -* represents the attachment site of the group; R A4 、R A5 Each is independently selected from hydrogen, halogen, unsubstituted or halogenated C1-C6 straight or branched alkyl, unsubstituted or halogenated C1-C6 alkoxy, phenyl, Any of the following; X1 and X2 are each independently selected from any one of halogen, methyl, benzyl, and dimethylamino.

2. The metal catalyst according to claim 1, characterized in that The M is selected from any one of titanium, zirconium and hafnium.

3. The metal catalyst according to claim 2, characterized in that The M is hafnium.

4. The metal catalyst according to claim 1, characterized in that The metal catalyst has any one of the following structures:

5. A method for preparing a metal catalyst according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: (1) A heterocyclic metal compound represented by formula A reacts with a pyridine imine Schiff base compound represented by formula B to obtain a pyridine amine ligand represented by formula C. The reaction formula is as follows: wherein Ar, R3 and M have the same defined ranges as in formula III; R1 and R5 are all isopropyl, R2, R4, R6, R7, R 10 、R 11 All are hydrogen, and R8 and R9 are connected by chemical bonds to form a benzene ring; Y is selected from any one of Li or Mg-Hal, and Hal is selected from any one of halogens; (2) After the pyridylamine ligand undergoes a first reaction with a hydrogen abstraction reagent, it undergoes a second reaction with a metal M source to obtain the metal catalyst having a structure as shown in Formula III.

6. The preparation method according to claim 5, characterized in that The preparation method of the heterocyclic metal compound comprises: reacting a heterocyclic compound having a structure represented by formula AS with a lithium reagent or metal magnesium to obtain the heterocyclic metal compound having a structure represented by formula A, and the reaction formula is as follows: Wherein, Y2 is selected from any one of hydrogen or halogen.

7. The preparation method according to claim 5, characterized in that The hydrogen abstraction reagent includes any one of potassium hydride, sodium hydride, lithium hydride, lithium bis(trimethylsilylamide), sodium bis(trimethylsilylamide), lithium diisopropylamide, and C1-C6 alkyl lithium, or a combination of at least two thereof.

8. A catalyst composition, characterized in that The catalyst composition comprises a main catalyst and a co-catalyst, wherein the main catalyst comprises at least one of the metal catalysts according to any one of claims 1 to 4.

9. The catalyst composition according to claim 8, characterized in that The co-catalyst includes any one of an alkyl aluminum compound, an organic aluminum oxide compound, and a boron salt, or a combination of at least two of them.

10. The catalyst composition according to claim 9, characterized in that The alkyl aluminum compound includes any one of trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tri-n-hexylaluminum, and trioctylaluminum, or a combination of at least two thereof.

11. The catalyst composition according to claim 9, characterized in that The organic aluminum oxy-compound includes any one of methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, and alkylaluminum-modified methylaluminoxane, or a combination of at least two thereof.

12. The catalyst composition according to claim 9, characterized in that The boron salt includes any one or a combination of at least two of tris(pentafluorophenyl)boron, triphenylcarbonium tetra(pentafluorophenyl)boron, tetra(pentafluorophenyl)boric acid-methyldi-(octadecyl)ammonium salt, and N,N-dimethylanilinium tetra(pentafluorophenyl)borate.

13. The catalyst composition according to claim 9, characterized in that The molar ratio of the metal Al in the co-catalyst to the metal M in the main catalyst is (10-5000):

1.

14. The catalyst composition according to claim 13, characterized in that The molar ratio of the metal Al in the co-catalyst to the metal M in the main catalyst is (50-1000):

1.

15. The catalyst composition according to claim 9, characterized in that The molar ratio of the B element in the co-catalyst to the metal M in the main catalyst is (1-2):

1.

16. Use of the metal catalyst according to any one of claims 1 to 4 or the catalyst composition according to any one of claims 8 to 15 in catalyzing olefin polymerization.

17. The use according to claim 16, characterized in that The olefin polymerization includes olefin homopolymerization or ethylene / α-olefin copolymerization.

18. A method for preparing polyolefin, characterized in that: The preparation method comprises: carrying out polymerization reaction of olefin monomers in the presence of a catalyst to obtain the polyolefin; The catalyst comprises at least one of the metal catalyst according to any one of claims 1 to 4 and the catalyst composition according to any one of claims 8 to 15.

19. The preparation method according to claim 18, characterized in that The olefin monomers include ethylene and / or α-olefins.

20. The preparation method according to claim 18, characterized in that The polymerization reaction is carried out in the presence of an organic solvent.

21. The preparation method according to claim 18, characterized in that The polymerization reaction temperature is 0-200°C.

22. The preparation method according to claim 21, characterized in that The polymerization temperature is 100-160°C.

23. The preparation method according to claim 18, characterized in that The polymerization reaction pressure is 0.1-10 MPa.

24. The preparation method according to claim 23, characterized in that The polymerization reaction pressure is 0.5-5 MPa.

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