Mono-metallocene chromium metal complex as well as preparation method and application thereof

Abstract

The invention relates to the field of olefin polymerization organic metal catalysts, and discloses a mono-chromcene metal complex as well as a preparation method and application thereof. The structural formula of the mono-chromcene metal complex is as shown in formula (I), R1-R5 are independently selected from hydrogen and substituted or unsubstituted C1-C20 alkyl, or R1-R5 are optionally mutually cyclized; r1 is selected from substituted or unsubstituted C6-C20 aryl groups; x is selected from halogen or C1-C10 alkyl. The olefin polymerization catalyst prepared from the mono-chromcene metal complex has higher polymerization activity under similar polymerization conditions, and the molecular weight distribution of the obtained polymer is narrower.

Description

Technical Field

[0001] This invention relates to the field of organometallic catalysts for olefin polymerization, specifically to a monochromium chromium metal complex, its preparation method, and its application. Background Technology

[0002] Polyolefin resins have excellent environmental compatibility compared to other resin materials, and are therefore widely used in industry and daily life. Polyethylene resin is an important polyolefin resin. Industrially used polyethylene catalysts include Ziegler-Natta type catalysts (see, for example, DE Pat 889229 (1953); IT Pat 545332 (1956) and IT Pat 536899 (1955); Chem. Rev., 2000, 100, 1169 and related literature in this issue), Phillips type catalysts (for example, Belg. Pat. 530617 (1955); Chem. Rev. 1996, 96, 3327), metallocene catalysts (for example, W. Kaminsky, Metalorganic Catalysts for Synthesis and Polymerization, Berlin: Springer, 1999), and post-transition metal complex ethylene oligomerization / polymerization catalysts that have developed rapidly in recent years. In 2006, the Gibson group of British scientists discovered that group IV phenol-phosphine zirconium complexes have good catalytic ability for olefin polymerization. With the activation of co-catalysts such as methylaluminoxane (MAO), they can effectively carry out ethylene or propylene polymerization reactions (Inorg. Chem, 2006, 45, 511-513, Organometallics 2008, 27, 235-245).

[0003] However, all of the above catalysts have the problem of not being able to maintain high catalytic activity and high polymerization performance at high temperatures. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems existing in the prior art and provide a monochromium-based metal complex. Catalysts for olefin polymerization prepared using this monochromium-based metal complex have high polymerization activity at high temperatures.

[0005] To achieve the above objectives, the present invention provides a monochromium chromium metal complex, the structural formula of which is shown in formula (I):

[0006]

[0007] R1-R5 are each independently selected from hydrogen and substituted or unsubstituted C1-C20 hydrocarbon groups, or R1-R5 are optionally cyclic to each other; R 1Selected from substituted or unsubstituted C6-C20 aryl groups; X is selected from halogens or C1-C10 hydrocarbon groups.

[0008] Preferably, the structural formula of the monochromium chromium metal complex is shown in formula (II):

[0009]

[0010] R11-R15 are each independently selected from hydrogen, halogen, hydroxyl, and substituted or unsubstituted C1-C20 hydrocarbon groups.

[0011] Preferably, R1-R5 are selected from hydrogen and substituted or unsubstituted C1-C10 hydrocarbon groups.

[0012] Preferably, X is selected from halogens or C1-C8 hydrocarbon groups.

[0013] Preferably, R11-R15 are each independently selected from hydrogen, halogen, hydroxyl, substituted or unsubstituted C1-C10 alkyl and substituted or unsubstituted C6-C15 aryl.

[0014] Preferably, the substituent is selected from halogen, hydroxyl, C1-C6 alkyl, halogenated C1-C6 alkyl, C1-C6 alkoxy or halogenated C1-C6 alkoxy.

[0015] Preferably, the C1-C6 alkyl group is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, isohexyl or 3,3-dimethylbutyl.

[0016] Preferably, the C1-C6 alkoxy group is selected from methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, n-pentoxy, isopentoxy, n-hexyloxy, isohexyloxy, or 3,3-dimethylbutoxy.

[0017] Preferably, the halogen is selected from fluorine, chlorine, bromine or iodine.

[0018] Preferably, the monochromium chromium metal complex is selected from the group consisting of the following complexes:

[0019] Complex 1: The complex shown in formula (II), wherein R1-R5 are H, R 11 -R 15 H is H, and X is Cl;

[0020] Complex 2: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 -R 15 H is H, and X is Cl;

[0021] Complex 3: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 -R15 H is H, and X is Cl;

[0022] Complex 4: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 -R 15 H is H, and X is Cl;

[0023] Complex 5: The complex shown in formula (II), wherein R1 is tert-butyl, R2-R5 are H, and R 11 -R 15 H is H, and X is Cl;

[0024] Complex 6: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl;

[0025] Complex 7: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 12 R 14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group.

[0026] Complex 8: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl;

[0027] Complex 9: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group.

[0028] Complex 10: The complex shown in formula (II), wherein R1-R5 are H, R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group.

[0029] Complex 11: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 12 R 14 and R15 For H, R 13 X is a methoxy group, and Cl is a methyl group.

[0030] Complex 12: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl;

[0031] Complex 13: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group.

[0032] Complex 14: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl;

[0033] Complex 15: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group.

[0034] Complex 16: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group.

[0035] Complex 17: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group.

[0036] Complex 18: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R13 X is -CF3, and C is Cl;

[0037] Complex 19: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group.

[0038] Complex 20: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl;

[0039] Complex 21: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group.

[0040] Complex 22: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group.

[0041] Complex 23: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group.

[0042] Complex 24: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl;

[0043] Complex 25: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 12 R 14 and R15 For H, R 13 X is a methyl group, and Cl is a methyl group.

[0044] Complex 26: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl;

[0045] Complex 27: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group.

[0046] Complex 28: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group.

[0047] Complex 29: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group.

[0048] Complex 30: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 -R 15 H is H, and X is Br;

[0049] Complex 31: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and Br is Br.

[0050] Complex 32: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is methyl, and Br is Br.

[0051] Complex 33: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and Br is Br.

[0052] Complex 34: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is methyl, and Br is Br.

[0053] Complex 35: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Br is a methyl methoxy group.

[0054] Complex 36: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Br is a methyl methoxy group.

[0055] Complex 37: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 -R 15 Let H be the integer part of the hexagram and I be the integer part of the hexagram.

[0056] Complex 38: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 -CF3, X is I;

[0057] Complex 39: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is methyl, and I is methyl.

[0058] Complex 40: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15For H, R 12 and R 14 -CF3, X is I;

[0059] Complex 41: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is methyl, and I is methyl.

[0060] Complex 42: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 12 R 13 R 14 and R 15 For H, R 11 It is a methoxy group, and X is I;

[0061] Complex 43: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 It is a methoxy group, and X is I.

[0062] A second aspect of the present invention provides a method for preparing the above-mentioned monochromium chromium metal complex, the method comprising the following steps:

[0063] (1) The compound shown in formula (III) is reacted with the compound shown in formula (IV) to generate a ligand;

[0064] (2) The ligand is reacted with a chromium compound and a lithium compound, wherein the lithium compound comprises a substituted or unsubstituted cyclopentadienyl group, a substituted or unsubstituted indene group, or a substituted or unsubstituted fluorenyl group.

[0065]

[0066] Among them, R 1 The definition is the same as described above.

[0067] Preferably, the chromium compound is selected from one or more of CrCl3(THF)3, CrCl3(H2O), CrCl3(H2O)6, CrCl3, CrBr3(H2O)6, CrBr3 and CrI3.

[0068] Preferably, the lithium compound is selected from one or more of cyclopentadienyllithium, pentamethylcyclopentadienyllithium, methyl-cyclopentadienyllithium, n-butyl-cyclopentadienyllithium, tert-butyl-cyclopentadienyllithium, indenelithium, fluorenyllithium, butyl-indenelithium, 1-methyl-indenelithium, 2-methyl-indenelithium, and 1-phenyl-indenelithium.

[0069] A third aspect of the present invention provides the application of the above-mentioned monochromium chromium metal complex in olefin polymerization.

[0070] A fourth aspect of the present invention provides a catalyst composition for olefin polymerization, the catalyst composition for olefin polymerization comprising a monochromium chromium metal complex, chlorinated hydrocarbon silicon, an organoaluminum compound and a silica gel support, wherein the monochromium chromium metal complex is the aforementioned monochromium chromium metal complex.

[0071] Preferably, based on each gram of silica gel carrier, the amount of chlorinated hydrocarbon silicon is 0.01-3 mmol, the amount of organoaluminum compound is 0.01-30 mmol, and the amount of metallic chromium in the monochromium metal complex is 1-1000 μmol.

[0072] Preferably, the general formula of the chlorinated hydrocarbon-based silicon is as follows: Cl n Si(R 16 ) 4-n ;where R 16 It is a C1-20 hydrocarbon group, and n is selected from 1 to 4 and n is an integer.

[0073] Preferably, the organoaluminum compound is selected from alkylaluminoxanes, alkylaluminum compounds, or alkylaluminum chloride compounds; wherein the general formula of alkylaluminoxanes is:

[0074]

[0075] Where R is a C1-12 hydrocarbon group, and a is selected from 4 to 30 and a is an integer.

[0076] The fifth aspect of this invention provides a method for preparing a catalyst for olefin polymerization, the method comprising the following steps:

[0077] A1: Under an inert atmosphere, the dispersant S1, the silica gel support and chlorinated hydrocarbon silicon in the above-mentioned catalyst composition for olefin polymerization are reacted at 0-120°C for 3-24 hours;

[0078] A2: Under an inert atmosphere, the intermediate material obtained in step A1, the dispersant S2, and the organoaluminum compound in the above-mentioned catalyst composition for olefin polymerization are reacted at 30-120°C for 3-24 hours.

[0079] A3: Under an inert atmosphere, the intermediate material obtained in step A2, the dispersant S3, and the monochromocene metal complex in the above-mentioned catalyst composition for olefin polymerization are reacted at 0-120°C for 0.5-24 h.

[0080] The dispersant S1, dispersant S2 and dispersant S3 are each independently selected from one or more of toluene, benzene, xylene, hexane, heptane and cyclohexane.

[0081] The sixth aspect of the present invention provides a catalyst for olefin polymerization prepared by the above method, wherein, based on the total weight of the catalyst for olefin polymerization, the aluminum content is 1-15 wt% and the chromium content is 0.05-10 wt%.

[0082] A seventh aspect of the present invention provides a method for olefin polymerization, comprising carrying out an olefin polymerization reaction in the presence of the catalyst described above for olefin polymerization.

[0083] Preferably, during the polymerization reaction, the concentration of the catalyst used for olefin polymerization is 1×10⁻⁶. -8 mol / L~1×10 -3 mol / L, preferably 1×10 -8 mol / L~1×10 -5 mol / L.

[0084] Preferably, the polymerization temperature is -78℃ to 150℃, more preferably 0℃ to 90℃; the polymerization pressure is 0.01 to 10MPa, more preferably 0.01 to 2MPa.

[0085] Compared with the prior art, the present invention has the following advantages:

[0086] (1) The method for synthesizing monochromium metal complexes described in this invention is simple, has a high yield, and low cost;

[0087] (2) The catalyst for olefin polymerization described in this invention can catalyze ethylene polymerization or copolymerization with high activity and maintain high polymerization activity even at higher polymerization temperatures;

[0088] (3) The catalyst particles for olefin polymerization described in this invention have good particle morphology, adjustable particle size, and high packing density, and can be applied to slurry polymerization and gas-phase polymerization processes. Detailed Implementation

[0089] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0090] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0091] In one aspect, this invention provides a monochromium chromium metal complex, the structural formula of which is shown in formula (I):

[0092]

[0093] R1-R5 are each independently selected from hydrogen and substituted or unsubstituted C1-C20 hydrocarbon groups, or R1-R5 are optionally cyclic to each other; R 1 Selected from substituted or unsubstituted C6-C20 aryl groups; X is selected from halogens or C1-C10 hydrocarbon groups.

[0094] In a preferred embodiment, the structural formula of the monochromium chromium metal complex is shown in formula (II):

[0095]

[0096] Among them, R 11 -R 15 Each is independently selected from hydrogen, halogen, hydroxyl, and substituted or unsubstituted C1-C20 hydrocarbon groups.

[0097] In a preferred embodiment, R1-R5 are selected from hydrogen and substituted or unsubstituted C1-C10 hydrocarbon groups.

[0098] In this invention, in formulas (I) and (II), the ring structure connected to Cr is a cyclopentadienyl ring structure, such as cyclopentadienyl, pentamethylcyclopentadienyl, methyl-cyclopentadienyl, n-butyl-cyclopentadienyl, tert-butyl-cyclopentadienyl, indole, fluorenyl, butyl-indole, 1-methyl-indole, 2-methyl-indole, or 1-phenyl-indole, etc.

[0099] In a preferred embodiment, R 11 -R 15 Each is independently selected from hydrogen, halogen, hydroxyl, substituted or unsubstituted C1-C10 alkyl and substituted or unsubstituted C6-C15 aryl.

[0100] In a preferred embodiment, X is selected from halogens or C1-C8 hydrocarbon groups.

[0101] According to some embodiments of the present invention, X is selected from chlorine, bromine or iodine.

[0102] In this invention, "substituted or unsubstituted" means containing a substituent, which can be selected from halogens, hydroxyl groups, C1-C6 alkyl groups, halogenated C1-C6 alkyl groups, C1-C6 alkoxy groups, or halogenated C1-C6 alkoxy groups.

[0103] In this invention, the alkyl group (such as C1-C6 alkyl or C1-C10 alkyl) may be selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, isohexyl or 3,3-dimethylbutyl.

[0104] In this invention, the alkoxy group (such as C1-C6 alkoxy) may be selected from methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, n-pentoxy, isopentoxy, n-hexyloxy, isohexyloxy, or 3,3-dimethylbutoxy.

[0105] In this invention, the aryl group (such as C6-C15 aryl) can be selected from phenyl, 4-methylphenyl, 4-ethylphenyl, dimethylphenyl and vinylphenyl.

[0106] In this invention, the halogen is selected from fluorine, chlorine, bromine or iodine.

[0107] In a further preferred embodiment, the monochromium chromium metal complex is selected from the group consisting of the following complexes:

[0108] Complex 1: The complex shown in formula (II), wherein R1-R5 are H, R 11 -R 15 H is H, and X is Cl;

[0109] Complex 2: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 -R 15 H is H, and X is Cl;

[0110] Complex 3: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 -R 15 H is H, and X is Cl;

[0111] Complex 4: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 -R 15 H is H, and X is Cl;

[0112] Complex 5: The complex shown in formula (II), wherein R1 is tert-butyl, R2-R5 are H, and R 11 -R 15 H is H, and X is Cl;

[0113] Complex 6: The complex shown in formula (II), wherein R1-R5 are H, R11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl;

[0114] Complex 7: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 12 R 14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group.

[0115] Complex 8: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl;

[0116] Complex 9: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group.

[0117] Complex 10: The complex shown in formula (II), wherein R1-R5 are H, R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group.

[0118] Complex 11: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group.

[0119] Complex 12: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl;

[0120] Complex 13: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group.

[0121] Complex 14: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl;

[0122] Complex 15: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group.

[0123] Complex 16: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group.

[0124] Complex 17: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group.

[0125] Complex 18: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl;

[0126] Complex 19: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group.

[0127] Complex 20: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 13 and R 15For H, R 12 and R 14 X is -CF3, and C is Cl;

[0128] Complex 21: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group.

[0129] Complex 22: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group.

[0130] Complex 23: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group.

[0131] Complex 24: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl;

[0132] Complex 25: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group.

[0133] Complex 26: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl;

[0134] Complex 27: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 13 and R15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group.

[0135] Complex 28: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group.

[0136] Complex 29: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group.

[0137] Complex 30: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 -R 15 H is H, and X is Br;

[0138] Complex 31: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and Br is Br.

[0139] Complex 32: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is methyl, and Br is Br.

[0140] Complex 33: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and Br is Br.

[0141] Complex 34: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is methyl, and Br is Br.

[0142] Complex 35: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Br is a methyl methoxy group.

[0143] Complex 36: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Br is a methyl methoxy group.

[0144] Complex 37: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 -R 15 Let H be the integer part of the hexagram and I be the integer part of the hexagram.

[0145] Complex 38: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 -CF3, X is I;

[0146] Complex 39: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is methyl, and I is methyl.

[0147] Complex 40: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 -CF3, X is I;

[0148] Complex 41: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is methyl, and I is methyl.

[0149] Complex 42: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 12 R 13 R 14and R 15 For H, R 11 It is a methoxy group, and X is I;

[0150] Complex 43: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 It is a methoxy group, and X is I.

[0151] A second aspect of the present invention provides a method for preparing the above-mentioned monochromium chromium metal complex, the method comprising the following steps:

[0152] (1) The compound shown in formula (III) is reacted with the compound shown in formula (IV) to generate a ligand as shown in formula (V);

[0153] (2) The ligand is reacted with a chromium compound and a lithium compound, wherein the lithium compound comprises a substituted or unsubstituted cyclopentadienyl group, a substituted or unsubstituted indene group, or a substituted or unsubstituted fluorenyl group.

[0154]

[0155] Among them, R 1 The definition is the same as described above.

[0156] In the method described in this invention, the chromium compound is selected from one or more of CrCl3(THF)3, CrCl3(H2O), CrCl3(H2O)6, CrCl3, CrBr3(H2O)6, CrBr3 and CrI3.

[0157] In this invention, "THF" stands for "tetrahydrofuran".

[0158] In the method described in this invention, the lithium compound is selected from one or more of cyclopentadienyllithium, pentamethylcyclopentadienyllithium, methyl-cyclopentadienyllithium, n-butyl-cyclopentadienyllithium, tert-butyl-cyclopentadienyllithium, indenelithium, fluorenyllithium, butyl-indenelithium, 1-methyl-indenelithium, 2-methyl-indenelithium, and 1-phenyl-indenelithium.

[0159] In the method described in this invention, the reaction process of step (1) is shown in the following reaction formula.

[0160]

[0161] Among them, R 1 The definition is the same as described above.

[0162] In a preferred embodiment, the reaction process of step (1) is as shown in the following reaction formula.

[0163]

[0164] Among them, R 11 -R 15 The definition is the same as described above.

[0165] In the method described in this invention, the reaction process of step (2) is shown in the following reaction formula.

[0166]

[0167] Among them, R 1 The definitions of R1-R5 and X are the same as those described above.

[0168] In a preferred embodiment, the reaction process of step (2) is as shown in the following reaction formula.

[0169]

[0170] Among them, R 11 -R 15 The definitions of R1-R5 and X are the same as those described above.

[0171] In a preferred embodiment, the reaction in step (1) is carried out in the presence of a solvent; in a specific embodiment, the solvent may be diethyl ether or tetrahydrofuran.

[0172] In a preferred embodiment, the reaction in step (2) is carried out in the presence of a reaction solvent; in a specific embodiment, the reaction solvent may be tetrahydrofuran.

[0173] In one specific embodiment, the preparation process of step (1) includes: dissolving the compound shown in formula (III) in anhydrous diethyl ether under a protective gas atmosphere (such as nitrogen), adding n-BuLi (n-butyllithium) solution dropwise at room temperature and stirring for 4 h, then adding tetrahydrofuran to react; subsequently, adding the compound shown in formula (IV) dropwise at 0 °C and stirring at room temperature. Quenching with NH4Cl aqueous solution, extracting the organic phase with ethyl acetate, drying the obtained organic phase with anhydrous sodium sulfate, recrystallizing with dichloromethane / hexane, adding methanol and 5 mL of concentrated hydrochloric acid to react, monitoring the reaction by TLC, removing the organic solvent, dissolving the product in ethyl acetate, then adding NaHCO3 aqueous solution for neutralization, extracting the organic phase, drying with anhydrous MgSO4, filtering, concentrating, and column chromatography (using dichloromethane as solvent) to obtain the ligand shown in formula (V).

[0174] In one specific embodiment, the preparation process of step (2) includes: in a protective gas atmosphere (such as nitrogen) at 0°C, dissolving the chromium compound and the lithium compound in tetrahydrofuran respectively, then slowly adding the lithium compound tetrahydrofuran solution to the chromium metal compound tetrahydrofuran solution, reacting overnight at room temperature to obtain a blue solution; in a protective gas atmosphere (such as nitrogen), dissolving the ligand obtained in step (1) in a reaction solvent (such as tetrahydrofuran), adding an excess of a hydrogen-removing agent (such as sodium hydride), reacting at room temperature, filtering to remove the hydrogen-removing agent, adding the blue solution, reacting overnight at room temperature, drying the solvent, adding dichloromethane to dissolve and filter, removing the filter cake, concentrating the filtrate, adding heptane for recrystallization to obtain the monocerocene chromium metal complex described in this invention.

[0175] A third aspect of the present invention provides the application of the above-mentioned monochromium chromium metal complex in olefin polymerization.

[0176] In a preferred embodiment, the olefin is selected from ethylene or α-olefin.

[0177] In a more preferred embodiment, the α-olefin is selected from propylene, butene, pentene, hexene, octene, or 4-methyl-1-pentene.

[0178] A fourth aspect of the present invention provides a catalyst composition for olefin polymerization, the catalyst composition comprising a monochromium chromium metal complex, chlorinated hydrocarbon silicon, an organoaluminum compound, and a silica gel support;

[0179] The monochromium-based metal complex is the aforementioned monochromium-based metal complex.

[0180] In a preferred embodiment, based on each gram of silica gel carrier, the amount of chlorinated hydrocarbon silicon is 0.01-3 mmol, the amount of organoaluminum compound is 0.01-30 mmol, and the amount of metallic chromium in the monochromocene metal complex is 1-1000 μmol. Specifically, the amount of chlorinated hydrocarbon silicon can be 0.01 mmol, 0.05 mmol, 0.1 mmol, 0.5 mmol, 1 mmol, 2 mmol, or 3 mmol; the amount of organoaluminum compound can be 0.01 mmol, 1 mmol, 5 mmol, 10 mmol, 15 mmol, 20 mmol, 25 mmol, or 30 mmol; and the amount of metallic chromium in the monochromocene metal complex can be 1 μmol, 100 μmol, 200 μmol, 300 μmol, 400 μmol, 500 μmol, 600 μmol, 700 μmol, 800 μmol, 900 μmol, or 1000 μmol.

[0181] In this invention, the general formula of the chlorinated hydrocarbon-based silicon is as follows: Cl n Si(R 16 )4-n ;where R 16 It is a C1-20 hydrocarbon group, and n is selected from 1 to 4 and n is an integer.

[0182] In a preferred embodiment, the chlorinated hydrocarbon silicon is selected from trimethylchlorosilane, triethylchlorosilane, triisopropylchlorosilane, dimethylethylchlorosilane, diethylpropylchlorosilane, dipropylmethylchlorosilane, dichlorodimethylsilane, dichlorodiethylsilane, dichlorodiphenylsilane, dichloromethyl-n-propylsilane, dichloromethylphenylsilane, trichloromethylsilane, trichloroethylsilane, phenyltrichlorosilane, and silicon tetrachloride, preferably trimethylchlorosilane, triethylchlorosilane, dichlorodiethylsilane, dichlorodiphenylsilane, trichloromethylsilane, trichloroethylsilane, or silicon tetrachloride.

[0183] In this invention, the organoaluminum compound is selected from alkylaluminoxanes, alkylaluminum compounds, or alkylaluminum chloride compounds; wherein the general formula of alkylaluminoxanes is:

[0184]

[0185] Where R is a C1-12 hydrocarbon group, and a is selected from 4 to 30 and a is an integer.

[0186] In a preferred embodiment, R in alkylaluminoxane is methyl, and a is selected from 10-30 and a is an integer.

[0187] In a specific embodiment, the alkylaluminoxane is methylaluminoxane (MAO) or modified methylaluminoxane (MMAO).

[0188] In a preferred embodiment, the alkylaluminum compound is selected from trialkylaluminum, such as trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, or tri-n-octylaluminum.

[0189] In a preferred embodiment, the alkylaluminum chloride compound is selected from diethylaluminum chloride, ethylaluminum dichloride, or ethylaluminum sesquichloride.

[0190] The fifth aspect of this invention provides a method for preparing a catalyst for olefin polymerization, the method comprising the following steps:

[0191] A1: Under an inert atmosphere, the dispersant S1, the silica gel support and chlorinated hydrocarbon silicon in the above-mentioned catalyst composition for olefin polymerization are reacted at 0-120°C for 3-24 hours;

[0192] A2: Under an inert atmosphere, the intermediate material obtained in step A1, the dispersant S2, and the organoaluminum compound in the above-mentioned catalyst composition for olefin polymerization are reacted at 30-120°C for 3-24 hours.

[0193] A3: Under an inert atmosphere, the intermediate material obtained in step A2, the dispersant S3, and the monochromocene metal complex in the above-mentioned catalyst composition for olefin polymerization are reacted at 0-120°C for 0.5-24 h.

[0194] The dispersant S1, dispersant S2 and dispersant S3 are each independently selected from one or more of toluene, benzene, xylene, hexane, heptane and cyclohexane.

[0195] In a preferred embodiment, the reaction temperature is 20-100°C in step A1; 30-100°C in step A2; and 20-100°C in step A3.

[0196] In a specific embodiment, step A1 includes: under nitrogen protection, adding the silica gel support in the above-mentioned catalyst composition for olefin polymerization into a reactor, then adding dispersant S1 to disperse it into a suspension, then adding chlorinated hydrocarbon silicon in the above-mentioned catalyst composition for olefin polymerization, heating to 20-100°C, stirring and reacting for 3-24 hours, then washing several times with dispersant S1 and vacuum drying.

[0197] In a specific embodiment, step A2 includes: under nitrogen protection, adding the intermediate material obtained in step A1 into the reactor, then adding dispersant S2 to disperse it into a suspension, then adding the organoaluminum compound from the above-mentioned catalyst composition for olefin polymerization, heating to 30-100°C, stirring and reacting for 3-24 hours, then washing several times with dispersant S2 and vacuum drying.

[0198] In a specific embodiment, step A3 includes: under nitrogen protection, adding the intermediate material obtained in step A2 to dispersant S3 to form a slurry, then slowly adding the aqueous solution of the monochromium metal complex in the above-mentioned olefin polymerization catalyst composition to the above-mentioned slurry, reacting at 20-100°C for 0.5-24 hours to obtain the above-mentioned olefin polymerization catalyst slurry, or removing the solvent from the obtained olefin polymerization catalyst slurry and washing and drying it.

[0199] The sixth aspect of the present invention provides a catalyst for olefin polymerization prepared by the above-described method, wherein, based on the total weight of the catalyst for olefin polymerization, the aluminum content is 1-15 wt% and the chromium content is 0.05-10 wt%; specifically, the aluminum content can be 1 wt%, 5 wt%, 10 wt%, 10.5 wt%, 11 wt%, or 15 wt%; and the chromium content can be 0.05 wt%, 0.1 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 2 wt%, 4 wt%, 6 wt%, 8 wt%, or 10 wt%.

[0200] A seventh aspect of the present invention provides a method for olefin polymerization, comprising carrying out an olefin polymerization reaction in the presence of the catalyst described above for olefin polymerization.

[0201] In this invention, the olefin polymerization process can be gas-phase polymerization or slurry polymerization; in the gas-phase polymerization process, alkyl aluminum can also be added as a co-catalyst for olefin polymerization; in the slurry polymerization process, the addition of alkyl aluminum can remove impurities in the system and improve the polymerization activity to a certain extent, without the need to add expensive MAO as a co-catalyst.

[0202] In a preferred embodiment, during the olefin polymerization process, the concentration of the catalyst used for olefin polymerization is 1 × 10⁻⁶. -8 mol / L~1×10 -3 mol / L, preferably 1×10 -8 mol / L~1×10 -5 mol / L.

[0203] In a preferred embodiment, the polymerization temperature is -78°C to 150°C, more preferably 0°C to 90°C; the polymerization pressure is 0.01 to 10 MPa, more preferably 0.01 to 2 MPa.

[0204] In this invention, "polymerization pressure" refers to the ethylene pressure in the polymerization system, expressed as absolute pressure.

[0205] According to some embodiments of the present invention, the polymerization reaction is carried out by olefin monomers in a solvent, the solvent being independently selected from one or more of alkanes, aromatic hydrocarbons and halogenated hydrocarbons.

[0206] According to some specific embodiments of the present invention, the polymerization solvent is independently selected from one or more of hexane, pentane, heptane, benzene, toluene, dichloromethane, chloroform and dichloroethane, more preferably from one or more of hexane, toluene and heptane.

[0207] In this invention, alkyl refers to straight-chain alkyl, branched alkyl, or cycloalkyl, including but not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, n-decyl, cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-ethylcyclohexyl, 4-n-propylcyclohexyl, and 4-n-butylcyclohexyl.

[0208] Examples of aryl groups in this invention include, but are not limited to, phenyl, 4-methylphenyl, 4-ethylphenyl, dimethylphenyl, and vinylphenyl.

[0209] The following examples further illustrate the monochromium chromium metal complex, its preparation method, and its applications according to the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0210] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0211] The analytical characterization instruments and test methods used in the following examples and comparative examples are as follows:

[0212] (1) Nuclear magnetic resonance spectrometer: Bruker DMX 300 (300MHz), with tetramethylsilicon (TMS) as internal standard;

[0213] (2) ICP (Inductively Coupled Plasma Emission Spectrometry) characterization: quantitative determination of the weight percentage of metals in catalysts used for olefin polymerization; the instrument used was a P1000 ICP-AES plasma emission spectrometer manufactured by PE Corporation, USA.

[0214] (3) Characterization of polymer molecular weight and molecular weight distribution: Molecular weight and its distribution were determined by gel permeation chromatography (GPC) using a Waters Alliance GPCV 2000 instrument. The polymer samples were dissolved in 1,2,4-trichlorobenzene at 150℃, with a sample concentration of 1 mg / mL and a solvent flow rate of 1.0 mL / min. Each sample was measured twice.

[0215] (4) Activity measurement method: The polymer was washed with hydrochloric acid ethanol solution, vacuum dried, and the weight of the polymer was obtained; the polymerization activity was calculated as: polymer weight (g) / chromium (mol) × 60 / polymerization time (min).

[0216] Example 1

[0217] Complex 2: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 -R 15 H is H, and X is Cl;

[0218] In a nitrogen atmosphere, the compound shown in formula (III) (11.23 g, 30 mmol, S type) was dissolved in anhydrous diethyl ether (150 mL). A 2.7 M, 33.3 mL, 90 mmol solution of n-butyllithium was added dropwise at room temperature. The mixture was stirred at room temperature for 4 h, then tetrahydrofuran (150 mL) was added to obtain a black solution containing a precipitate. Stirring continued for 1 h. Diphenylphosphine chloride (PPh₂Cl) (90 mmol, 16.7 mL) was added at 0 °C. After stirring at room temperature for 1 h, N₂O₃ was added. Quenching with 5 mL of H4Cl aqueous solution; extracting the organic phase with ethyl acetate, drying the obtained organic phase with anhydrous sodium sulfate, recrystallizing with dichloromethane / hexane, adding methanol (100 mL) and 5 mL of concentrated hydrochloric acid, refluxing for 16 h, and monitoring the reaction by TLC until completion; removing the organic solvent, dissolving the product in ethyl acetate, neutralizing with NaHCO3 aqueous solution, extracting the organic phase, drying with anhydrous MgSO4, filtering, concentrating, and column chromatography (using dichloromethane as solvent) to obtain ligand L1 in 67% yield; 1 H NMR (400MHz, CDCl3): δ = 5.41 (s, 2H), 7.13-7.15 (m, 2H), 7.24-7.29 (m, 4H), 7.38-7.45 (m, 22H), 7.62-7.64 (m, 2H). 31 P NMR (162MHz, CDCl3): δ=-17.19(s); High-resolution mass spectrometry test: theoretical value: 654.19; measured value: 655.20;

[0219] In a nitrogen atmosphere, CrCl3(THF)3 (0.75 g, 2.00 mmol) was dissolved in 20 mL of tetrahydrofuran at 0 °C, and pentamethylcyclopentadienyllithium (0.284 g, 2 mmol) was dissolved in 10 mL of tetrahydrofuran and slowly added dropwise. The reaction was carried out overnight at room temperature to obtain blue solution B.

[0220] Under a nitrogen atmosphere, ligand L1 (0.654 g, 1 mmol) was dissolved in tetrahydrofuran, and excess NaH (0.072 g, 3 mmol) was added. The mixture was stirred at room temperature for 10 h, and the NaH was removed by filtration. The above blue solution B was added dropwise, and the reaction was carried out overnight at room temperature. The solvent was dried under vacuum, and dichloromethane (40 mL) was added to dissolve the compound. The filter cake was removed by filtration, the filtrate was concentrated, and heptane was added for recrystallization to obtain complex 2. Elemental analysis showed that C... 64 H 60 Cl2Cr2O2P2: Theoretical values: C, 70.01; H, 5.51; Test values: C, 70.23; H, 5.67;

[0221] Catalyst M1 for the preparation of olefin polymerization:

[0222] A1: Under nitrogen protection, 10g of dry silica gel support was added to a glass reactor, followed by 150ml of dry hexane to disperse it into a suspension. Then, 1ml of SiCl2(n-Bu)2 was added, stirred and heated to 30℃, reacted for 4h and then dried under vacuum.

[0223] A2: Under nitrogen protection, take 5g of the intermediate material obtained in step A1 and add it to a glass reactor. Then add 60ml of dry toluene and disperse it into a suspension. Then add 18ml of 10wt% MAO (methylaluminoxane) toluene solution, heat to 50℃, stir and react for 4h. Then wash three times with 50ml of toluene, then wash with hexane and vacuum dry.

[0224] A3: Under nitrogen protection, 2g of the intermediate material obtained in step A2 was added to a glass reactor, and then 30ml of dry toluene was added to prepare a slurry. 0.22g (0.2mmol) of complex 2 was dissolved in 20ml of toluene, and then the toluene solution of complex 2 was added dropwise to the reactor. The reaction was carried out at 30℃ for 30min, and then washed with 30ml of toluene and dried under vacuum. ICP characterization showed that the Cr content in catalyst M1 for olefin polymerization was 0.66wt% and the Al content was 10.36wt%.

[0225] The 1L stainless steel high-pressure polymerization reactor was purged three times each with nitrogen and ethylene. Then, 500ml of hexane was added, followed by 2ml of 1mol / L triethylaluminum (TEA) hexane solution, and then 30mg of olefin polymerization catalyst M1 was added. The temperature was raised to 80℃, the polymerization pressure was increased to 1MPa and maintained for 1h. After the polymerization reaction was completed, the temperature was lowered, the polyethylene granules were collected, weighed and the polymerization activity was tested. The weight-average molecular weight, molecular weight distribution and polymerization activity test data of the obtained polymer are shown in Table 1.

[0226] Example 2

[0227] Complex 14: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl;

[0228] In a nitrogen atmosphere, the compound shown in formula (III) (3.74 g, 10 mmol, type R) was dissolved in anhydrous diethyl ether (120 mL). A solution of n-butyllithium (2.7 M, 11.1 mL, 30 mmol) was added dropwise at room temperature and stirred for 4 h. Then, tetrahydrofuran (120 mL) was added to obtain a black solution containing a precipitate. Stirring continued for 1 h. Bis(3,5-bis(trifluoromethyl)phenyl)chlorophosphine (30 mmol, 14.78 g) was added at 0 °C, and the mixture was stirred at room temperature for 1 h. Then, N2O2 was added. Quenching with 5 mL of H4Cl aqueous solution, the organic phase was extracted with ethyl acetate, dried with anhydrous sodium sulfate, recrystallized with dichloromethane / hexane, and then methanol (100 mL) and 5 mL of concentrated hydrochloric acid were added. The mixture was refluxed for 16 h, and the reaction was monitored by TLC until completion. The organic solvent was removed, the product was dissolved in ethyl acetate, neutralized with NaHCO3 aqueous solution, the organic phase was extracted, dried with anhydrous MgSO4, filtered, concentrated, and column chromatography (with dichloromethane as solvent) was performed to obtain ligand L2 in 40% yield. 1 H NMR(400MHz,DMSO)δ9.10(s,2H),8.17(s,2H),8.13(s,2H),8.08(dd,J=13.3,6.5Hz,8 H),7.81(d,J=7.6Hz,2H),7.56(d,J=8.4Hz,2H),7.27(dd,4H),6.90(d,J=8.2Hz,2H); 31 P NMR (162MHz, DMSO): δ=-8.37(s); High-resolution mass spectrometry test: Theoretical calculated value: 1198.09; Test value: 1198.95.

[0229] Blue solution B was prepared according to the method described in Example 1;

[0230] Under a nitrogen atmosphere, ligand L2 (1.20 g, 1 mmol) was dissolved in tetrahydrofuran, and excess NaH (0.072 g, 3 mmol) was added. The mixture was stirred at room temperature for 10 h, and the NaH was removed by filtration. Then, the above blue solution B was added dropwise, and the reaction was carried out overnight at room temperature. The solvent was dried under vacuum, and dichloromethane (40 mL) was added to dissolve the compound. The filter cake was removed by filtration, the filtrate was concentrated, and heptane was added for recrystallization to obtain complex 14 with a yield of 70%. Elemental analysis showed that C... 72 H 52 Cl2Cr2F 24 O2P2: Theoretical values: C, 52.67; H, 3.19; Test values: C, 52.43; H, 3.27;

[0231] Catalyst M2 for the preparation of olefin polymerization:

[0232] The process was carried out in accordance with Example 1, except that in step A1, SiCl4 was used to replace SiCl2(n-Bu)2 in equal molar amounts, and in step A3, complex 14 was used to replace complex 2 in equal molar amounts. According to ICP characterization, the Cr content in catalyst M2 for olefin polymerization was 0.68 wt%, and the Al content was 10.54 wt%.

[0233] The 1L stainless steel high-pressure polymerization reactor was purged three times each with nitrogen and ethylene. Then, 500ml of hexane was added, followed by 2ml of 1mol / L triethylaluminum (TEA) hexane solution, and then 35mg of olefin polymerization catalyst M2 was added. The temperature was raised to 80℃, the polymerization pressure was increased to 1MPa and maintained for 1h. After the polymerization reaction was completed, the temperature was lowered, the polyethylene granules were collected, weighed and the polymerization activity was tested. The weight-average molecular weight, molecular weight distribution and polymerization activity test data of the obtained polymer are shown in Table 1.

[0234] Example 3

[0235] Complex 15: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group.

[0236] In a nitrogen atmosphere, the compound shown in formula (III) (3.74 g, 10 mmol, R type) was dissolved in anhydrous diethyl ether (120 mL). A solution of n-butyllithium (2.5 M, 12 mL, 30 mmol) was added dropwise at room temperature and stirred for 4 h. Then, tetrahydrofuran (120 mL) was added to obtain a black solution containing a precipitate. Stirring continued for 1 h. Bis(3,5-dimethylphenyl)chlorophosphine (30 mmol, 8.30 g) was added at 0 °C, and the mixture was stirred at room temperature for 1 h. Then, NH4+ was added... Quenching with 4Cl aqueous solution (5 mL), the organic phase was extracted with ethyl acetate, dried with anhydrous sodium sulfate, recrystallized with dichloromethane / hexane, methanol (100 mL) and 5 mL concentrated hydrochloric acid were added, and the reaction was refluxed for 16 h. The reaction was monitored by TLC until completion. The organic solvent was removed, the product was dissolved in ethyl acetate, neutralized with NaHCO3 aqueous solution, the organic phase was extracted, dried with anhydrous MgSO4, filtered, concentrated, and column chromatography (dichloromethane as solvent) was performed to obtain ligand L3 in 58% yield. 1 H NMR (400MHz, CDCl3) δ: 2.28 (s, 24H), 5.43 (s, 2H), 6.96-7.05 (m, 12H), 7.17 (m, 2H), 7.24-7.29 (m, 4H), 7.43 (d, 2H), 7.65 (m, 2H). 31P NMR (162MHz, CDCl3) δ=-15.4(s); High-resolution mass spectrometry test: theoretical calculated value: 766.31; measured value: 767.32;

[0237] Blue solution B was prepared according to the method described in Example 1;

[0238] Under a nitrogen atmosphere, ligand L3 (0.77 g, 1 mmol) was dissolved in tetrahydrofuran, and excess NaH (0.072 g, 3 mmol) was added. The mixture was stirred at room temperature for 10 h, and the NaH was removed by filtration. Then, the above blue solution B was added dropwise, and the reaction was carried out overnight at room temperature. The solvent was dried under vacuum, and dichloromethane (40 mL) was added to dissolve the solution. The filter cake was removed by filtration, the filtrate was concentrated, and heptane was added for recrystallization to obtain complex 15 with a yield of 70%. Elemental analysis showed that C... 72 H 76 Cl2Cr2O2P2: Theoretical values: C, 71.46; H, 6.33; Test values: C, 71.42; H, 6.47;

[0239] Catalyst M3 for the preparation of olefin polymerization:

[0240] The process was carried out in accordance with Example 1, except that in step A2, 13 mL of 2M diethylaluminum chloride was used to replace 18 mL of 10 wt% MAO, and in step A3, the same molar amount of complex 15 was used to replace complex 2. According to ICP characterization, the Cr content in catalyst M3 for olefin polymerization was 0.66 wt%, and the Al content was 10.37 wt%.

[0241] The 1L stainless steel high-pressure polymerization reactor was purged three times each with nitrogen and ethylene. Then, 500ml of hexane was added, followed by 2ml of 1mol / L triethylaluminum (TEA) hexane solution, and then 32mg of olefin polymerization catalyst M3 was added. The temperature was raised to 80℃, the polymerization pressure was increased to 1MPa and maintained for 1h. After the polymerization reaction was completed, the temperature was lowered, the polyethylene granules were collected, weighed and the polymerization activity was tested. The weight-average molecular weight, molecular weight distribution and polymerization activity test data of the obtained polymer are shown in Table 1.

[0242] Example 4

[0243] Complex 17: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group.

[0244] Under a nitrogen atmosphere, the compound shown in formula (III) (3.74 g, 10 mmol, S type) was dissolved in anhydrous diethyl ether (120 mL). A hexane solution of n-butyllithium (2.7 M, 11.1 mL, 30 mmol) was added dropwise at room temperature and stirred for 4 h. Then, tetrahydrofuran (120 mL) was added to obtain a black solution containing a precipitate. Stirring continued for 1 h. Di(4-methoxy)phosphine chloride (30 mmol, 8.42 g) was added at 0 °C. After stirring at room temperature for 1 h, NH4Cl aqueous solution was added. The solution was quenched (5 mL), the organic phase was extracted with ethyl acetate, dried with anhydrous sodium sulfate, recrystallized with dichloromethane / hexane, and then methanol (100 mL) and 5 mL concentrated hydrochloric acid were added. The mixture was refluxed for 16 h. After the reaction was completed by TLC, the organic solvent was removed, the compound was dissolved in ethyl acetate, neutralized with NaHCO3 aqueous solution, the organic phase was extracted, dried with anhydrous MgSO4, filtered, concentrated, and column chromatography (dichloromethane as solvent) was performed to obtain ligand L4 in 56% yield; elemental analysis showed C 48 H 40 O6P2: Theoretical values: C, 74.41; H, 5.20; Test values: C, 74.32; H, 5.38;

[0245] Blue solution B was prepared according to the method described in Example 1;

[0246] Under a nitrogen atmosphere, ligand L4 (0.77 g, 1 mmol) was dissolved in tetrahydrofuran, and excess NaH (0.072 g, 3 mmol) was added. The mixture was stirred at room temperature for 10 h, and the NaH was removed by filtration. Then, the above blue solution B was added dropwise, and the reaction was carried out overnight at room temperature. The solvent was dried under vacuum, and dichloromethane (40 mL) was added to dissolve the compound. The filter cake was removed by filtration, the filtrate was concentrated, and heptane was added for recrystallization to obtain complex 17 with a yield of 72%. Elemental analysis showed that C... 68 H 68 Cl2Cr2O6P2: Theoretical values: C, 67.05; H, 5.63; Test values: C, 67.32; H, 5.77;

[0247] Catalyst M4 for the preparation of olefin polymerization:

[0248] The process was carried out in accordance with Example 1, except that in step A1, an equimolar amount of CH3SiCl3 was used to replace SiCl2(n-Bu)2, and in step A3, an equal molar amount of complex 17 was used to replace complex 2. According to ICP characterization, the Cr content in catalyst M4 for olefin polymerization was 0.68 wt%, and the Al content was 10.68 wt%.

[0249] The 1L stainless steel high-pressure polymerization reactor was purged three times each with nitrogen and ethylene. Then, 500ml of hexane was added, followed by 2ml of 1mol / L triethylaluminum (TEA) hexane solution, and then 38mg of olefin polymerization catalyst M4 was added. The temperature was raised to 80℃, the polymerization pressure was increased to 1MPa and maintained for 1h. After the polymerization reaction was completed, the temperature was lowered, the polyethylene granules were collected, weighed and the polymerization activity was tested. The weight-average molecular weight, molecular weight distribution and polymerization activity test data of the obtained polymer are shown in Table 1.

[0250] Example 5

[0251] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 6 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 500mL of hexane was injected into the polymerization reactor, followed by triethylaluminum (2mL, 2mmol), 25mL norbornene, and 38mg of olefin polymerization catalyst M2. The temperature was raised to 60℃, and the polymerization pressure was increased to 1MPa and maintained for 1 hour. After the polymerization reaction was completed, the temperature was lowered, the polymer particles were collected, weighed, and the polymerization activity was tested. The weight-average molecular weight, molecular weight distribution, and polymerization activity data of the obtained polymer are shown in Table 1.

[0252] Comparative Example 1

[0253] Catalyst S1 for the preparation of olefin polymerization:

[0254] The process was carried out in accordance with Example 1, except that in step A3, 0.4 mmol of the comparative complex 1* (the structure of which is shown below, and the synthesis process is referenced in Organometallics 2013, 32, 4805-4812) was used instead of 0.2 mmol of complex 2. ICP characterization showed that the Cr content in catalyst S1 for olefin polymerization was 0.54 wt% and the Al content was 10.43 wt%.

[0255] The 1L stainless steel high-pressure polymerization reactor was purged three times each with nitrogen and ethylene. Then, 500ml of hexane was added, followed by 2ml of 1mol / L triethylaluminum (TEA) hexane solution, and then 30mg of olefin polymerization catalyst S1 was added. The temperature was raised to 80℃, the polymerization pressure was increased to 1MPa and maintained for 1h. After the polymerization reaction was completed, the temperature was lowered, the polyethylene granules were collected, weighed and the polymerization activity was tested. The weight-average molecular weight, molecular weight distribution and polymerization activity test data of the obtained polymer are shown in Table 1.

[0256] Comparative complex 1*

[0257] Table 1

[0258] serial number coordination compounds Polymerization activity (g / molcat.h) <![CDATA[M w ×10 -4 ]]> <![CDATA[M w / M n ]]> Example 1 Complex 2 <![CDATA[8.32×10 5 ]]> 10.37 4.2 Example 2 Complex 14 <![CDATA[9.12×10 5 ]]> 12.17 4.3 Example 3 Complex 15 <![CDATA[7.14×10 5 ]]> 11.30 4.2 Example 4 Complex 17 <![CDATA[6.27×10 5 ]]> 12.43 4.4 Example 5 Complex 14 <![CDATA[7.33×10 5 ]]> 20.31 3.1 Comparative Example 1 Comparative complex 1* <![CDATA[1.33×10 5 ]]> 6.31 4.5

[0259] As can be seen from the results in Table 1, the catalyst for olefin polymerization prepared using the monochromium metal complex of the present invention has higher polymerization activity under similar polymerization conditions, the molecular weight of the obtained polymer is significantly higher than that of the polymer obtained in the comparative example, and the molecular weight distribution of the obtained polymer is narrower.

[0260] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A monochromium-based metal complex, characterized in that, Its structural formula is shown in equation (I): R1-R5 are each independently selected from hydrogen and substituted or unsubstituted C1-C20 hydrocarbon groups, or R1-R5 are optionally cyclic to each other; R 1 Selected from substituted or unsubstituted C6-C20 aryl groups; X is selected from halogens or C1-C10 hydrocarbon groups.

2. The monochromium-based chromium metal complex according to claim 1, characterized in that, Its structural formula is shown in formula (II): Among them, R 11 -R 15 Each is independently selected from hydrogen, halogen, hydroxyl, and substituted or unsubstituted C1-C20 hydrocarbon groups; Preferably, R1-R5 are selected from hydrogen and substituted or unsubstituted C1-C10 hydrocarbon groups; Preferably, X is selected from halogens or C1-C8 hydrocarbon groups.

3. The monochromium-based chromium metal complex according to claim 2, characterized in that, R 11 -R 15 Each is independently selected from hydrogen, halogen, hydroxyl, substituted or unsubstituted C1-C10 alkyl and substituted or unsubstituted C6-C15 aryl; Preferably, the substituent is selected from halogen, hydroxyl, C1-C6 alkyl, halogenated C1-C6 alkyl, C1-C6 alkoxy or halogenated C1-C6 alkoxy; Preferably, the C1-C6 alkyl group is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, isohexyl or 3,3-dimethylbutyl; Preferably, the C1-C6 alkoxy group is selected from methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, n-pentoxy, isopentoxy, n-hexyloxy, isohexyloxy, or 3,3-dimethylbutoxy. Preferably, the halogen is selected from fluorine, chlorine, bromine or iodine.

4. The monochromium-based metal complex according to claim 2 or 3, characterized in that, It is selected from the group consisting of the following coordination compounds: Complex 1: The complex shown in formula (II), wherein R1-R5 are H, R 11 -R 15 H is H, and X is Cl; Complex 2: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 -R 15 H is H, and X is Cl; Complex 3: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 -R 15 H is H, and X is Cl; Complex 4: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 -R 15 H is H, and X is Cl; Complex 5: The complex shown in formula (II), wherein R1 is tert-butyl, R2-R5 are H, and R 11 -R 15 H is H, and X is Cl; Complex 6: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl; Complex 7: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 12 R 14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group. Complex 8: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl; Complex 9: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group. Complex 10: The complex shown in formula (II), wherein R1-R5 are H, R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group. Complex 11: The complex shown in formula (II), wherein R1-R5 are H, R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group. Complex 12: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl; Complex 13: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group. Complex 14: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl; Complex 15: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group. Complex 16: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group. Complex 17: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group. Complex 18: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl; Complex 19: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group. Complex 20: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl; Complex 21: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group. Complex 22: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group. Complex 23: The complex shown in formula (II), wherein R1 is methyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group. Complex 24: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and C is Cl; Complex 25: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methyl group, and Cl is a methyl group. Complex 26: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and C is Cl; Complex 27: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 13 and R 15 For H, R 12 and R 14 X is a methyl group, and Cl is a methyl group. Complex 28: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Cl is a methyl group. Complex 29: The complex shown in formula (II), wherein R1 is n-butyl, R2-R5 are H, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Cl is a methyl group. Complex 30: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 -R 15 H is H, and X is Br; Complex 31: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is -CF3, and Br is Br. Complex 32: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is methyl, and Br is Br. Complex 33: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is -CF3, and Br is Br. Complex 34: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is methyl, and Br is Br. Complex 35: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 12 R 13 R 14 and R 15 For H, R 11 X is a methoxy group, and Br is a methyl methoxy group. Complex 36: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is a methoxy group, and Br is a methyl methoxy group. Complex 37: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 -R 15 Let H be the integer part of the hexagram and I be the integer part of the hexagram. Complex 38: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 -CF3, X is I; Complex 39: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 X is methyl, and I is methyl. Complex 40: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 -CF3, X is I; Complex 41: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 13 and R 15 For H, R 12 and R 14 X is methyl, and I is methyl. Complex 42: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 12 R 13 R 14 and R 15 For H, R 11 It is a methoxy group, and X is I; Complex 43: The complex shown in formula (II), wherein R1-R5 are methyl groups, and R 11 R 12 R 14 and R 15 For H, R 13 It is a methoxy group, and X is I.

5. A method for preparing the monochromocene metal complex according to any one of claims 1-4, characterized in that, The method includes the following steps: (1) The compound shown in formula (III) is reacted with the compound shown in formula (IV) to generate a ligand; (2) The ligand is reacted with a chromium compound and a lithium compound, wherein the lithium compound comprises a substituted or unsubstituted cyclopentadienyl group, a substituted or unsubstituted indene group, or a substituted or unsubstituted fluorenyl group. Among them, R 1 The definition is the same as that in claim 1.

6. The method according to claim 5, characterized in that, The chromium compound is selected from one or more of CrCl3(THF)3, CrCl3(H2O), CrCl3(H2O)6, CrCl3, CrBr3(H2O)6, CrBr3 and CrI3; Preferably, the lithium compound is selected from one or more of cyclopentadienyllithium, pentamethylcyclopentadienyllithium, methyl-cyclopentadienyllithium, n-butyl-cyclopentadienyllithium, tert-butyl-cyclopentadienyllithium, indenelithium, fluorenyllithium, butyl-indenelithium, 1-methyl-indenelithium, 2-methyl-indenelithium, and 1-phenyl-indenelithium.

7. The application of the monochromocene metal complex according to any one of claims 1-4 in olefin polymerization.

8. A catalyst composition for olefin polymerization, characterized in that, The catalyst composition for olefin polymerization includes a monochromium-ceramic metal complex, chlorinated hydrocarbon silicon, an organoaluminum compound, and a silica gel support. The monochromium metal complex is the monochromium metal complex according to any one of claims 1-4.

9. The catalyst composition for olefin polymerization according to claim 8, characterized in that, Based on each gram of silica gel carrier, the amount of chlorinated hydrocarbon silicon used is 0.01-3 mmol, the amount of organoaluminum compound used is 0.01-30 mmol, and the amount of metallic chromium in monochromium metal complex is 1-1000 μmol.

10. A catalyst composition for olefin polymerization according to claim 8 or 9, characterized in that, The general formula of the chlorinated hydrocarbon-based silicon is as follows: Cl n Si(R 16 ) 4-n ;where R 16 It is a C1-20 hydrocarbon group, and n is selected from 1 to 4 and n is an integer; Preferably, the organoaluminum compound is selected from alkylaluminoxanes, alkylaluminum compounds, or alkylaluminum chloride compounds; The general formula for alkylaluminoxanes is: Where R is a C1-12 hydrocarbon group, and a is selected from 4 to 30 and a is an integer.

11. A method for preparing a catalyst for olefin polymerization, characterized in that, The method includes the following steps: A1: Under an inert atmosphere, the dispersant S1, the silica gel support and chlorinated hydrocarbon silicon in the catalyst composition for olefin polymerization according to any one of claims 8-10 are reacted at 0-120°C for 3-24 hours; A2: Under an inert atmosphere, the intermediate material obtained in step A1, the dispersant S2, and the organoaluminum compound in the catalyst composition for olefin polymerization according to any one of claims 8-10 are reacted at 30-120°C for 3-24 hours. A3: Under an inert atmosphere, the intermediate material obtained in step A2, the dispersant S3, and the monochromocene metal complex in the catalyst composition for olefin polymerization according to any one of claims 8-10 are reacted at 0-120°C for 0.5-24 h. The dispersant S1, dispersant S2 and dispersant S3 are each independently selected from one or more of toluene, benzene, xylene, hexane, heptane and cyclohexane.

12. A catalyst for olefin polymerization prepared by the method of claim 11, characterized in that, Based on the total weight of the catalyst used for olefin polymerization, the aluminum content is 1-15 wt% and the chromium content is 0.05-10 wt%.

13. A method for olefin polymerization, characterized in that, Includes carrying out an olefin polymerization reaction in the presence of the catalyst for olefin polymerization as described in claim 12; Preferably, during the polymerization reaction, the concentration of the catalyst used for olefin polymerization is 1×10⁻⁶. -8 mol / L~1×10 - 3 mol / L, preferably 1×10 -8 mol / L~1×10 -5 mol / L; Preferably, the polymerization temperature is -78℃ to 150℃, more preferably 0℃ to 90℃; the polymerization pressure is 0.01 to 10MPa, more preferably 0.01 to 2MPa.

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