CN112724291B

CN112724291B - Ethylene homopolymerization method and ethylene homopolymer

Info

Publication number: CN112724291B
Application number: CN202011173887.6A
Authority: CN
Inventors: 韩书亮; 宋文波; 王路生; 李昊坤; 金钊; 方园园
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2019-10-28
Filing date: 2020-10-28
Publication date: 2021-12-31
Anticipated expiration: 2040-10-28
Also published as: CN112724291A

Abstract

The invention discloses a homopolymerization method of ethylene, which comprises the steps of carrying out homopolymerization reaction on the ethylene in the presence of a catalyst; the catalyst comprises a biphenol metal complex shown as a formula I; in the formula I, R₁、R₁＇、R₂、R₂' same or different, each independently selected from hydrogen and substituted or unsubstituted C₁‑C₂₀A hydrocarbon group of (a); r₃‑R₇、R₃＇‑R₇' same or different, each independently selected from hydrogen and substituted or unsubstituted C₁‑C₂₀A hydrocarbon group of (a); r₈And R₉Same or different, each independently selected from hydrogen or substituted or unsubstituted C₁‑C₂₀A hydrocarbon group of (a); m and M', which are identical or different, are selected from group IV metals; x is halogen;

Description

Ethylene homopolymerization method and ethylene homopolymer

Technical Field

The invention relates to an ethylene homopolymerization method and an ethylene homopolymer prepared by the method, belonging to the field of olefin polymerization.

Background

The polyolefin material has the characteristics of relatively low density, good chemical resistance, water resistance, good mechanical strength, electrical insulation and the like, can be used for films, pipes, plates, various molded products, wires, cables and the like, has wide application in the aspects of daily sundry products such as agriculture, packaging, automobiles, electric appliances and the like, provides convenience for human clothes, eating and housing, and plays a great role in strategic items such as national defense, energy, aerospace and the like.

Coordination polymerization represented by a Ziegler-Natta catalyst has promoted rapid development of the polyolefin industry and has gradually matured. Nowadays, metal catalysts for solution polymerization have been the focus of research in the field of coordination polymerization, and transition metal catalysts based on phenol ligands belong to one of them. Such catalysts have good olefin catalytic activity, for example: the 2, 6-diisopropylphenol titanium catalyst successfully realizes homopolymerization of ethylene to obtain linear polyethylene (Nomura K, Naga N, Miki M, et al, Macromolecules 1998,31,7588-7597), and a copolymer with high alpha-olefin content can also be obtained by copolymerization of ethylene and alpha-olefin to obtain a thermoplastic elastomer. However, the catalyst has strict requirements on ligand substituents, wherein the steric hindrance effect of the 2-and 6-position substituents is greater than that of diisopropyl group, and the cyclopentadienyl group can ensure high activity only by having a methyl substituent.

Meanwhile, based on the research result of active enzyme catalysis, people gradually develop a catalyst with synergistic effect. It has been found that when using a zirconium-bis metal catalyst, the polymerization activity of ethylene and the molecular weight of the resulting polymer are comparable to those of a zirconium-mono metal catalyst, but the ethyl grafting rate in the polymer chain is much higher, up to 12%, whereas the ethyl grafting rate of the polymer obtained by using a zirconium-mono metal catalyst to catalyze ethylene is only 1.1%. Meanwhile, when using a bis-zirconium metal catalyst, the ethyl grafting yield (12%) of the polymer obtained with the bis-boron co-catalyst is also higher than the ethyl grafting yield (2.7%) of the polymer obtained with the mono-boron co-catalyst (Li, H.; Marks, T.J.Proc.Natl.Acad.Sci.2006,103, 15295).

CN201010204671.1 discloses ethylene homopolymerization and ethylene copolymerization with hexene, octene and other monomers of a dual titanium metal catalyst, but the polymerization activity under normal pressure is only 10⁴g·mol^-1(Ti)·h^-1The molecular weight of the copolymer is about 30 ten thousand, and the molecular weight distribution is more than 2.

Disclosure of Invention

The invention aims to provide a method for homopolymerizing ethylene, aiming at overcoming the defects of the prior art, the used catalyst comprises a main catalyst of a biphenol metal complex and a cocatalyst, the molecular weight of the prepared ethylene can be higher than 20 ten thousand, and the dispersity is in a range of 1.5-20.

According to one aspect of the present invention, there is provided a process for homopolymerizing ethylene, comprising homopolymerizing ethylene in the presence of a catalyst; the catalyst comprises a biphenol metal complex shown as a formula I;

in the formula I, R₁、R₁＇、R₂、R₂' same or different, each independently selected from hydrogen and substituted or unsubstituted C₁-C₂₀A hydrocarbon group of (a); r₃-R₇、R₃＇-R₇' same or different, each independently selected from hydrogen and substituted or unsubstituted C₁-C₂₀A hydrocarbon group of (a); r₈And R₉Same or different, each independently selected from hydrogen and substituted or unsubstituted C₁-C₂₀A hydrocarbon group of (a); m and M', which are identical or different, are selected from group IV metals; x is halogen.

According to a preferred embodiment of the invention, in formula I, R₁、R₁＇、R₂、R₂Identical or different, each independently selected from hydrogen, substituted or unsubstituted C₁-C₂₀Straight or branched alkyl and substituted or unsubstituted C₁-C₂₀Is preferably selected from hydrogen and substituted or unsubstituted C₁-C₁₀More preferably selected from hydrogen and substituted or unsubstituted C₁-C₆Linear or branched alkyl of (a); r₃-R₇、R₃＇-R₇' same or different, each independently selected from hydrogen and substituted or unsubstituted C₁-C₂₀Is preferably selected from hydrogen and substituted or unsubstituted C₁-C₁₀More preferably selected from hydrogen and substituted or unsubstituted C₁-C₆Linear or branched alkyl of (a); r₈And R₉Same or different, each independently selected from hydrogen and substituted or unsubstituted C₁-C₂₀Is preferably selected from hydrogen and substituted or unsubstituted C₁-C₁₀More preferably selected from hydrogen and substituted or unsubstituted C₁-C₆Linear or branched alkyl of (a); m and M', which are identical or different, are chosen from titanium, zirconium and hafnium, preferably titanium; x is selected from fluorine, chlorine, bromine and iodine, preferably chlorine.

According to the invention, said substitution means R₁-R₇、R₁＇-R₇＇、R₈And R₉The hydrocarbon group in (1), preferably alkyl group, aryl group, may be optionally substituted with hetero atom at the carbon atom on the main chain, and the hydrogen atom bonded to the carbon atom may be optionally substituted with hetero atom, alkyl group or alkoxy group; the hetero atom includes an oxygen atom, a nitrogen atom, a boron atom, a sulfur atom, a phosphorus atom, a silicon atom, a germanium atom, a tin atom, a halogen atom and the like.

According to some embodiments of the invention, the metal bis-phenol complex is selected from at least one of the complexes represented by formula I below:

bisphenol metal complex 1: r₁＝R₂＝R₁＇＝R₂＇＝Me，R₃＝R₄＝R₅＝R₆＝R₇＝R₃＇＝R₄＇＝R₅＇＝R₆＇＝R₇＇＝R₈＝R₉＝H，M＝M＇＝Ti，X＝Cl；

Bisphenol metal complex 2: r₁＝R₂＝R₁＇＝R₂＇＝Et，R₃＝R₄＝R₅＝R₆＝R₇＝R₃＇＝R₄＇＝R₅＇＝R₆＇＝R₇＇＝R₈＝R₉＝H，M＝M＇＝Ti，X＝Cl；

Bisphenol metal complex 3: r₁＝R₂＝R₁＇＝R₂＇＝iPr，R₃＝R₄＝R₅＝R₆＝R₇＝R₃＇＝R₄＇＝R₅＇＝R₆＇＝R₇＇＝R₈＝R₉＝H，M＝M＇＝Ti，X＝Cl；

Bisphenol metal complex 4: r₁＝R₂＝R₁＇＝R₂＇＝tBu，R₃＝R₄＝R₅＝R₆＝R₇＝R₃＇＝R₄＇＝R₅＇＝R₆＇＝R₇＇＝R₈＝R₉＝H，M＝M＇＝Ti，X＝Cl；

Bisphenol metal complex 5: r₁＝R₂＝R₁＇＝R₂＇＝Me，R₃＝R₄＝R₅＝R₆＝R₇＝R₃＇＝R₄＇＝R₅＇＝R₆＇＝R₇＇＝Me，R₈＝R₉＝H，M＝M＇＝Ti，X＝Cl；

Bis-phenol metal complex 6: r₁＝R₂＝R₁＇＝R₂＇＝Et，R₃＝R₄＝R₅＝R₆＝R₇＝R₃＇＝R₄＇＝R₅＇＝R₆＇＝R₇＇＝Me，R₈＝R₉＝H，M＝M＇＝Ti，X＝Cl；

Bisphenol metal complex 7: r₁＝R₂＝R₁＇＝R₂＇＝iPr，R₃＝R₄＝R₅＝R₆＝R₇＝R₃＇＝R₄＇＝R₅＇＝R₆＇＝R₇＇＝Me，R₈＝R₉＝H，M＝M＇＝Ti，X＝Cl；

Bisphenol metal complex 8: r₁＝R₂＝R₁＇＝R₂＇＝tBu，R₃＝R₄＝R₅＝R₆＝R₇＝R₃＇＝R₄＇＝R₅＇＝R₆＇＝R₇＇＝Me，R₈＝R₉＝H，M＝M＇＝Ti，X＝Cl。

According to another aspect of the present invention, there is provided a method for preparing the above-mentioned biphenol metal complex, comprising the steps of:

1) reacting a biphenol compound shown in a formula II with a metal compound shown in a formula III to obtain a compound shown in a formula IV;

2) reacting a compound shown in a formula IV with a metal complex shown in a formula V to obtain a biphenol metal complex shown in a formula I;

in formulae II and IV, R₁、R₁＇、R₂、R₂＇、R₈And R₉Have the same definitions as in formula I;

in the formula III, M₁Selected from group IA metals, preferably lithium, sodium or potassium, R is hydrogen or C₁-C₁₀Linear or branched alkyl of (a);

in formula V, R3-R7 have the same meanings as in formula I.

According to a preferred embodiment of the present invention, the preparation method comprises: reacting a biphenol compound shown in a formula II with a metal compound shown in a formula III in an organic solvent to obtain a compound shown in a formula IV, and then reacting with a metal complex shown in a formula V in the organic solvent to obtain a biphenol metal complex shown in a formula I.

According to some embodiments of the invention, the organic solvent is selected from tetrahydrofuran, diethyl ether, 1, 4-dioxane and dichloromethane.

According to a preferred embodiment of the present invention, the bisphenol compound is at least one selected from the group consisting of bisphenol compounds represented by the following formula II:

bisphenol compound 1: r₁＝R₂＝R₁＇＝R₂＇＝Me，R₈＝R₉＝H；

Bisphenol compound 2: r₁＝R₂＝R₁＇＝R₂＇＝Et，R₈＝R₉＝H；

Bisphenol compound 3: r₁＝R₂＝R₁＇＝R₂＇＝iPr，R₈＝R₉＝H；

Bisphenol compound 4: r₁＝R₂＝R₁＇＝R₂＇＝tBu，R₈＝R₉＝H。

According to a preferred embodiment of the present invention, the metal compound represented by formula III is selected from at least one of KH, NaH, MeLi, EtLi, PrLi, and BuLi.

According to a preferred embodiment of the invention, the compound of formula IV is selected from at least one of the following compounds:

compound 1: r₁＝R₂＝R₁＇＝R₂＇＝Me，R₈＝R₉＝H，M₁＝Li；

Compound 2: r₁＝R₂＝R₁＇＝R₂＇＝Et，R₈＝R₉＝H，M₁＝Li；

Compound 3: r₁＝R₂＝R₁＇＝R₂＇＝iPr，R₈＝R₉＝H，M₁＝Li；

Compound 4: r₁＝R₂＝R₁＇＝R₂＇＝tBu，R₈＝R₉＝H，M₁＝Li；

Compound 5: r₁＝R₂＝R₁＇＝R₂＇＝Me，R₈＝R₉＝H，M₁＝Na；

Compound 6: r₁＝R₂＝R₁＇＝R₂＇＝Et，R₈＝R₉＝H，M₁＝Na；

Compound 7: r₁＝R₂＝R₁＇＝R₂＇＝iPr，R₈＝R₉＝H，M₁＝Na；

Compound 8: r₁＝R₂＝R₁＇＝R₂＇＝tBu，R₈＝R₉＝H，M₁＝Na；

Compound 9: r₁＝R₂＝R₁＇＝R₂＇＝Me，R₈＝R₉＝H，M₁＝K；

Compound 10: r₁＝R₂＝R₁＇＝R₂＇＝Et，R₈＝R₉＝H，M₁＝K；

Compound 11: r₁＝R₂＝R₁＇＝R₂＇＝iPr，R₈＝R₉＝H，M₁＝K；

Compound 12: r₁＝R₂＝R₁＇＝R₂＇＝tBu，R₈＝R₉＝H，M₁＝K。

According to a preferred embodiment of the present invention, the metal complex is at least one selected from the group consisting of metal complexes represented by the following formula V:

metal complex 1: r₃＝R₄＝R₅＝R₆＝R₇＝H，M＝Ti，X＝Cl；

Metal complex 2: r₃＝R₄＝R₅＝R₆＝R₇＝Me，M＝Ti，X＝Cl。

According to a preferred embodiment of the present invention, the molar ratio of the bisphenol compound represented by formula II to the compound represented by formula III is 1: (1-20), such as 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5, 1:10, 1:10.5, 1:11, 1:11.5, 1:12, 1:12.5, 1:13, 1:13.5, 1:14, 1:14.5, 1:15, 1:15.5, 1:16, 1:16.5, 1:17, 1:17.5, 1:18, 1:18.5, 1:19, 1:19.5, 1:20 and any value in between them, preferably 1: (2-10), preferably 1: (4-8).

According to a preferred embodiment of the present invention, the reaction temperature of the reaction of the biphenol compound represented by the formula II with the compound represented by the formula III is-78 ℃ to 60 ℃, for example-60 ℃, -50 ℃, -40 ℃, -30 ℃, -20 ℃, -10 ℃, 0 ℃,10 ℃, 20 ℃, 30 ℃ and any value therebetween, preferably-10 ℃ to 40 ℃.

According to a preferred embodiment of the present invention, the reaction time of the reaction of the biphenol compound represented by formula II with the compound represented by formula III is 1 to 10 hours, such as 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 and any value therebetween, preferably 1.5 to 3 hours.

According to a preferred embodiment of the invention, the molar ratio of the compound of formula IV to the metal compound of formula V is 1: (1.8-2.4), e.g. 1:1.9, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4 and any value in between, preferably 1:2. wherein the number of moles of the compound represented by formula IV is determined as the number of moles of the biphenol compound.

According to a preferred embodiment of the invention the reaction temperature of the reaction of the compound of formula IV with the metal compound of formula V is in the range of-78 ℃ to 60 ℃, such as-60 ℃, -50 ℃, -40 ℃, -30 ℃, -20 ℃, -10 ℃, 0 ℃,10 ℃, 20 ℃, 30 ℃ and any value in between, preferably in the range of-10 ℃ to 40 ℃.

According to a preferred embodiment of the invention, the reaction time of the reaction of the compound of formula IV with the metal compound of formula V is 6 to 24 hours, such as 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 and any value in between, preferably 6 to 19 hours.

According to some embodiments of the invention, the catalyst further comprises a cocatalyst.

In some embodiments, the cocatalyst comprises an alkylaluminum compound and an organoboron compound. The alkyl aluminum compound comprises an alkyl aluminum or an alkyl aluminum halide; and/or the organoboron compound is selected from an aryl boron and/or a borate.

According to a preferred embodiment of the invention, the molar ratio of the procatalyst, the organoboron compound and the alkylaluminum compound is 1: (1-10): (100-2000), preferably 1: (2-8): (200-1000).

Specific examples of the alkylaluminum or alkylaluminum halide include, but are not limited to: trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, trioctylaluminum, diethylaluminum monohydrogen, diisobutylaluminum monohydrogen, diethylaluminum monochloride, diisobutylaluminum monochloride, ethylaluminum sesquichloride and ethylaluminum dichloride. Preferably trimethylaluminum, triethylaluminum or triisobutylaluminum.

According to a preferred embodiment of the invention, the organoboron compound is selected from an aryl boron and/or a borate. The arylborole is preferably a substituted or unsubstituted phenylborone, more preferably tris (pentafluorophenyl) boron. The borate is preferably N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate and/or triphenylmethyl tetrakis (pentafluorophenyl) borate.

In some embodiments, the cocatalyst comprises an aluminoxane. The molar ratio of the main catalyst to the aluminoxane is 1: (200- & lt5000- & gt), preferably 1: (2000-3000).

According to a preferred embodiment of the present invention, the aluminoxane has the general formula:

in the formula VI, R is selected from C₁-C₁₂Preferably methyl or isobutyl;among them, the aluminoxane is preferably Methylaluminoxane (MAO) and modified methylaluminoxane, and more preferably methylaluminoxane.

According to some embodiments of the invention, the temperature of the homopolymerization is from-30 to 150 ℃, preferably from 50 to 110 ℃; and/or the homopolymerization pressure is 0.1-10MPa, preferably 0.5-4 MPa; and/or the time of homopolymerization is 10-60 minutes.

The homopolymerization reaction of the present invention may be carried out in an inert solvent. The solvent used may be an aromatic hydrocarbon or an alkane, such as benzene, toluene, hexane, heptane and mixtures thereof.

According to a further aspect of the present invention, there is provided an ethylene homopolymer prepared according to the above process. The polymers prepared by the process according to the invention have molecular weights of more than 20 ten thousand and dispersions in the range from 1.5 to 20.

Detailed Description

The present invention is further illustrated by the following examples, which are not to be construed as limiting the invention in any way.

In the following examples, the evaluation and testing methods involved are as follows:

1. nuclear magnetic hydrogen and carbon spectra were measured on a Bruker-300 nmr using deuterated chloroform as solvent at 110 ℃.

2. High resolution mass spectra were determined on a Bruker ESI-Q/TOF MS mass spectrometer with acetonitrile dispersion solvent.

3. Polymerization Activity: the polymer obtained by polymerization was dried and weighed, and the catalyst activity was obtained by dividing the amount of the catalyst added at the time of polymerization.

4. Molecular weight and molecular weight distribution PDI (PDI ═ Mw/Mn) of the polymer: measured at 150 ℃ using PL-GPC220 and 1,2, 4-trichlorobenzene as a solvent (standard: PS, flow rate: 1.0mL/min, column: 3 XPlgel 10um M1 XED-B300X 7.5 nm).

5. The melting point of the polymer was measured using Differential Scanning Calorimetry (DSC): 10mg of the sample was placed in a crucible and measured on an METTLER DSC1 differential scanning calorimeter. Heating from-70 ℃ to 200 ℃ at a heating rate of 10 ℃/min in a nitrogen atmosphere, preserving heat for l min, cooling to-70 ℃ at 10 ℃/min, preserving heat for 3min, then heating to 200 ℃ at 10 ℃/min, and recording second heating scanning data.

Example 1

Preparation of bisphenol Metal Complex 7

Bisphenol compound 3(2.24mmol) was dissolved in ether solvent, pure KH solid (8.96mmol) was added to the solution at-78 deg.C and reacted for 1 hour, and the reaction was returned to room temperature and continued for 2 hours. Thereafter, the solution was transferred to a dichloromethane solution of metal complex 2(4.48mmol) at-78 ℃ through a double-horn needle and reacted at that temperature for 1 hour, and then the system was gradually returned to room temperature and reacted for another 12 hours. After the reaction was complete, the solvent was removed using a vacuum line, the residue was washed with dichloromethane and filtered through celite, the filtrate was dried and the crude product was recrystallized from dichloromethane/n-hexane to give an orange product (yield 90%).¹H NMR(CDCl₃,400MHz):δ＝7.45(dd,J＝7.6,2.0Hz,2H,aryl-H),7.25(s,4H,aryl-H),7.14-7.21(m,4H,aryl-H),3.13(m,4H,CH),2.18(s,30H,CH₃),1.80(s,6H,CH₃),1.03(d,J＝6.8Hz,24H,CH₃).¹³C NMR(CDCl₃,100MHz):δ＝159.1,146.9,138.9,133.5,132.8,130.6,130.4,130.0,124.5,122.9,34.3,33.9,26.3,24.3,13.1.ESI-MS for C₅₉H₇₂Cl₄O₃Ti₂：M＝1064.34.

Example 2

Preparation of bisphenol Metal Complex 7

Bisphenol compound 3(2.24mmol) was dissolved in ether solvent, pure KH solid (2.24mmol) was added to the solution at-78 deg.C and reacted for 1 hour, and the reaction was returned to room temperature and continued for 8 hours. Thereafter, the solution was transferred to a dichloromethane solution of metal complex 2(4.00mmol) at-78 ℃ through a double-horn needle and reacted at that temperature for 1 hour, and then the system was gradually returned to room temperature and reacted for another 18 hours. After the reaction was complete, the solvent was removed using a vacuum line, the residue was washed with dichloromethane and filtered through celite, the filtrate was dried and the crude product was recrystallized from dichloromethane/n-hexane to give an orange product (yield 61%).

Example 3

Preparation of bisphenol Metal Complex 7

Bisphenol compound 3(2.24mmol) was dissolved in ether solvent, pure KH solid (22.4mmol) was added to the solution at 40 ℃ and the reaction was allowed to proceed for 1 hour, then returned to room temperature and continued for 0.5 hour. After this time, the solution was transferred via a double-pointed needle at 40 ℃ into a solution of metal complex 2(4.93mmol) in dichloromethane and reacted at this temperature for 6 hours, after the reaction was complete, the solvent was removed using a vacuum line, the residue was washed with dichloromethane and filtered through celite, the filtrate was drained and the crude product was recrystallized from dichloromethane/n-hexane to give an orange product (73% yield).

Example 4

Preparation of bisphenol Metal Complex 4

Bisphenol compound 4(2.00mmol) was dissolved in tetrahydrofuran solvent, and pure NaH solid (12.00mmol) was added to the solution at-10 ℃ to react for 1 hour, and the reaction was allowed to return to room temperature and continued for 1 hour. Thereafter, the solution was transferred to a tetrahydrofuran solution of metal complex 1(4.00mmol) at-10 ℃ through a double-horn needle and reacted at that temperature for half an hour, and then the system was gradually returned to room temperature and reacted for another 8 hours. After the reaction was complete, the solvent was removed using a vacuum line, the residue was washed with dichloromethane and filtered through celite, the filtrate was dried and the crude product was recrystallized from dichloromethane/n-hexane to give an orange product (92% yield). The characterization data are as follows: ESI-MS for C₅₁H₅₆Cl₄O₃Ti₂:M/Z＝954.21.

Example 5

Preparation of bisphenol Metal Complex 4

Bisphenol compound 4(2.00mmol) was dissolved in methylene chloride solvent, and 1.0mol/L BuLi solution (2.00mmol) was added to the solution at-10 ℃ to react for 1 hour, and the reaction was returned to room temperature and continued for 4 hours. Thereafter, the solution was transferred to a dichloromethane solution of metal complex 1(4.00mmol) through a double-horn needle at-10 ℃ and reacted at that temperature for half an hour, and then the system was gradually returned to room temperature and reacted for another 15 hours. After the reaction was complete, the solvent was removed using a vacuum line, the residue was washed with dichloromethane and filtered through celite, the filtrate was dried and the crude product was recrystallized from dichloromethane/n-hexane to give an orange product (84% yield).

Example 6

A500 mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, and then 10mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 150mL of n-hexane subjected to anhydrous oxygen-free treatment and 1mL (5. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 were sequentially added. Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 20 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 2.8g of polymer, and its polymerization activity is 8.4X 10⁵g·mol^-1(Ti)·h^-1。

Melting point 133.5 ℃ by DSC; GPC measured M of polyethylene_wIs 1.9X 10⁵，M_w/M_nIs 4.82.

Example 7

A500 mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, and then 5mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 150mL of n-hexane subjected to anhydrous oxygen-free treatment and 1mL (5. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 were sequentially added. Introducing ethylene under 0.5MPa under mechanical stirring, reacting at 20 deg.C for 20min under the pressure, adding ethanol to terminate the reaction to obtain 2.0g of polymer with polymerization activity of 6.0 × 10⁵g·mol^-1(Ti)·h^-1。

Melting point by DSC is 131.9 ℃; GPC measured M of polyethylene_wIs 2.1 × 10⁵，M_w/M_nWas 6.02.

Example 8

A500 mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, and then 5mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 150mL of n-hexane subjected to anhydrous oxygen-free treatment and 1mL (5. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 were sequentially added. In thatIntroducing ethylene under the condition of mechanical stirring and pressure of 0.1MPa, making reaction at 20 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 2.79g of polymer, and its polymerization activity is 1.7X 10⁶g·mol^-1(Ti)·h^-1。

Melting point by DSC is 132.7 ℃; GPC measured M of polyethylene_wIs 1.8X 10⁵，M_w/M_nIt was 7.87.

Example 9

A500 mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, and then 5mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 150mL of n-hexane subjected to anhydrous oxygen-free treatment and 1mL (5.0. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 were sequentially added. Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 80 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 3.1g of polymer, and its polymerization activity is 9.3X 10⁵g·mol^-1(Ti)·h^-1。

Melting point was 131.4 ℃ by DSC; GPC measured M of polyethylene_wIs 2.2X 10⁵，M_w/M_nIs 5.17.

Example 10

A500 mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, and then 5mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 150mL of n-hexane subjected to anhydrous oxygen-free treatment and 1mL (5.0. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 were sequentially added. Ethylene was passed under mechanical stirring at a pressure of 1.0MPa and reacted at 0 ℃ for 20min under this pressure, after which ethanol was added to terminate the reaction to give 3.6g of a polymer, the polymerization activity of which was determined by calculation to be 1.1X 10⁶g·mol^-1(Ti)·h^-1。

Melting point by DSC is 134.2 ℃; GPC measured M of polyethylene_wIs 8.0X 10⁴，M_w/M_nIs 3.95.

Example 11

Heating and drying the obtained product 500A mL polymerization vessel was evacuated twice with nitrogen, evacuated again, and charged with ethylene gas, followed by addition of 5mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 150mL of anhydrous and oxygen-free treated n-hexane, and 1mL (5.0. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 in this order. Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 20 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 2.9g of polymer, and its polymerization activity is 8.7X 10⁵g·mol^-1(Ti)·h^-1。

Melting point 131.0 ℃ by DSC; GPC measured M of polyethylene_wIs 2.1 × 10⁵，M_w/M_nWas 10.1.

Example 12

A500 mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, and then 2.5mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 150mL of n-hexane subjected to anhydrous oxygen-free treatment and 1mL (5.0. mu. mol/mL) of a toluene solution containing biphenol metal complex 7 were sequentially added. Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 20 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 2.6g of polymer, and its polymerization activity is 7.8X 10⁵g·mol^-1(Ti)·h^-1。

Melting point 133.2 ℃ by DSC; GPC measured M of polyethylene_wIs 2.3X 10⁵，M_w/M_nWas 8.08.

Example 13

The 500mL polymerization kettle which is heated and dried is vacuumized and introduced with nitrogen twice, vacuumized and introduced with ethylene gas, and then sequentially added with 5mL (1mmol/mL) of toluene solution of Modified Methylaluminoxane (MMAO), 150mL of n-hexane which is subjected to anhydrous and anaerobic treatment and 1mL (5.0 mu mol/mL) of toluene solution containing the biphenol metal complex 7. Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 20 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 3.3g of polymer, and its polymerization activity is 9.9X 10⁵g·mol^-1(Ti)·h^-1。

Melting point by DSC is 132.5 ℃; GPC measured M of polyethylene_wIs 1.7X 10⁵，M_w/M_nIt was 6.81.

Example 14

A500 mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, and then 5mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 150mL of n-hexane subjected to anhydrous oxygen-free treatment and 2mL (5. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 were sequentially added. Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 20 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 6.8g of polymer, and its polymerization activity is 1.02X 10⁶g·mol^-1(Ti)·h^-1。

Melting point by DSC is 132.4 ℃; GPC measured M of polyethylene_wIs 2.5 multiplied by 10⁵，M_w/M_nIt was 9.03.

Example 15

A500 mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, and then 5mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 150mL of n-hexane subjected to anhydrous oxygen-free treatment and 1mL (2.5. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 were sequentially added. Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 20 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 1.81g of polymer, and its polymerization activity is 1.09X 10⁶g·mol^-1(Ti)·h^-1。

Melting point by DSC is 135.3 ℃; GPC measured M of polyethylene_wIs 2.5 multiplied by 10⁵，M_w/M_nIt was 7.84.

Example 16

The 500mL polymerization kettle which is heated and dried is vacuumized and introduced with nitrogen twice, vacuumized and introduced with ethylene gas, and then sequentially added with 5mL (2mmol/mL) of toluene solution of Methylaluminoxane (MAO), 150mL of n-hexane which is subjected to anhydrous and oxygen-free treatment and 1mL of toluene solution containing biphenol metal complex 7 (the mixture is obtained by the steps of5.0. mu. mol/mL). Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 20 deg.C for 30min, then adding ethyl alcohol to stop reaction to obtain 3.5g of polymer, and its polymerization activity is 7.0X 10⁵g·mol^-1(Ti)·h^-1。

Melting point by DSC is 131.2 ℃; GPC measured M of polyethylene_wIs 2.6X 10⁵，M_w/M_nIt was 6.99.

Example 17

A500 mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, and then 5mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 150mL of n-hexane subjected to anhydrous oxygen-free treatment and 1.0mL (5.0. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 were sequentially added. Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 20 deg.C for 10min, then adding ethyl alcohol to stop reaction to obtain 1.94g of polymer, and its polymerization activity is 1.16X 10⁶g·mol^-1(Ti)·h^-1。

Melting point by DSC is 132.6 ℃; GPC measured M of polyethylene_wIs 1.9X 10⁵，M_w/M_nIt was 4.79.

Example 18

A500 mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, evacuated again and purged with ethylene, and then 5mL (2mmol/mL) of a toluene solution of Methylaluminoxane (MAO), 100mL of toluene subjected to anhydrous oxygen-free treatment and 1.0mL (5.0. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 were sequentially added. Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 20 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 3.7g of polymer, and its polymerization activity is 1.11X 10⁶g·mol^-1(Ti)·h^-1。

Melting point by DSC is 131.9 ℃; GPC measured M of polyethylene_wIs 2.0X 10⁵，M_w/M_nWas 6.69.

Example 19

Will pass throughThe 500mL polymerization vessel heated and dried was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, then 2mL (0.5mmol/mL) of an n-hexane solution of triisobutylaluminum, 150mL of an n-hexane solution subjected to anhydrous oxygen-free treatment and 1mL (2.5. mu. mol/mL) of a toluene solution containing the biphenol metal complex 7 were sequentially added, and a boron-containing reagent [ Ph ] was further added₃C][B(C₆F₅)₄]2mL (5. mu. mol/mL). Introducing ethylene under the condition of mechanical stirring and pressure of 1.0MPa, making reaction at 80 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 5.1g of polymer, and its polymerization activity is 3.06X 10⁶g·mol^-1(Ti)·h^-1。

Melting point 133.3 ℃ by DSC; GPC measured M of polyethylene_wIs 1.8X 10⁵，M_w/M_nWas 6.84.

Example 20

The 500mL polymerization reactor after heating and drying was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, then 2mL (0.5mmol/mL) of an n-hexane solution of triisobutylaluminum, 150mL of an n-hexane solution subjected to anhydrous oxygen-free treatment and 1mL (2.5. mu. mol/mL) of a toluene solution containing a biphenol metal complex 7 were sequentially added, and a boron-containing reagent [ Ph ] was further added₃C][B(C₆F₅)₄]2mL (5. mu. mol/mL). Introducing ethylene under 0.5MPa and reacting at 40 deg.C for 20min under mechanical stirring, adding ethanol to terminate the reaction to obtain 2.6g of polymer with polymerization activity of 1.56 × 10⁶g·mol^-1(Ti)·h^-1。

Melting point 130.6 ℃ by DSC; GPC measured M of polyethylene_wIs 2.0X 10⁵，M_w/M_nIt was 7.05.

Example 21

The 500mL polymerization reactor after heating and drying was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, then 2mL (0.5mmol/mL) of an n-hexane solution of triisobutylaluminum, 150mL of an n-hexane solution subjected to anhydrous oxygen-free treatment and 1mL (2.5. mu. mol/mL) of a toluene solution containing a biphenol metal complex 7 were sequentially added, and a boron-containing reagent [ Ph ] was further added₃C][B(C₆F₅)₄]2mL (5. mu. mol/mL). Ethylene was passed under mechanical stirring at a pressure of 0.1MPa and reacted at 0 ℃ for 20min under this pressure, after which ethanol was added to terminate the reaction to give 1.15g of a polymer whose polymerization activity was determined by calculation to be 6.90X 10⁵g·mol^-1(Ti)·h^-1。

Melting point by DSC is 131.5 ℃; GPC measured M of polyethylene_wIs 1.7X 10⁵，M_w/M_nIt was 8.97.

Example 22

The 500mL polymerization reactor after heating and drying was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, then 5mL (0.5mmol/mL) of an n-hexane solution of triisobutylaluminum, 150mL of an n-hexane solution subjected to anhydrous oxygen-free treatment and 1mL (2.5. mu. mol/mL) of a toluene solution containing a biphenol metal complex 7 were sequentially added, and a boron-containing reagent [ Ph ] was further added₃C][B(C₆F₅)₄]4mL (5. mu. mol/mL). Introducing ethylene under the condition of mechanical stirring and pressure of 0.5MPa, making reaction at 80 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 3.4g of polymer, and its polymerization activity is 2.04X 10⁶g·mol^-1(Ti)·h^-1。

Melting point 130.3 ℃ by DSC; GPC measured M of polyethylene_wIs 1.5X 10⁵，M_w/M_nIs 4.10.

Example 23

The 500mL polymerization reactor after heating and drying was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, then 1.5mL (0.5mmol/mL) of an n-hexane solution of triisobutylaluminum, 150mL of an n-hexane solution subjected to anhydrous oxygen-free treatment and 1mL (2.5. mu. mol/mL) of a toluene solution containing a biphenol metal complex 7 were sequentially added, and a boron-containing reagent [ Ph ] was further added₃C][B(C₆F₅)₄]8mL (5. mu. mol/mL). Introducing ethylene under the condition of mechanical stirring and pressure of 0.5MPa, making reaction at 80 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 2.3g of polymer, and its polymerization activity is 1.38X 10⁶g·mol^-1(Ti)·h^-1。

Melting point by DSC is 134.1 ℃; GPC measured M of polyethylene_wIs 1.9X 10⁵，M_w/M_nIs 5.93.

Example 24

The 500mL polymerization reactor after heating and drying was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, and then 4mL (0.5mmol/mL) of an n-hexane solution of triisobutylaluminum, 150mL of an n-hexane solution subjected to anhydrous oxygen-free treatment and 2mL (2.5. mu. mol/mL) of a toluene solution containing a biphenol metal complex 7 were sequentially added, followed by addition of a boron-containing reagent [ Ph₃C][B(C₆F₅)₄]4mL (5. mu. mol/mL). Introducing ethylene under the condition of mechanical stirring and pressure of 0.5MPa, making reaction at 80 deg.C for 20min, then adding ethyl alcohol to stop reaction to obtain 5.9g of polymer, and its polymerization activity is 1.77X 10⁶g·mol^-1(Ti)·h^-1。

Melting point by DSC is 134.3 ℃; GPC measured M of polyethylene_wIs 2.0X 10⁵，M_w/M_nIt was 7.94.

Example 25

The 500mL polymerization reactor after heating and drying was evacuated twice and purged with nitrogen, further evacuated and purged with ethylene, then 2mL (0.5mmol/mL) of a toluene solution of triisobutylaluminum, 150mL of toluene subjected to anhydrous oxygen-free treatment and 1mL (2.5. mu. mol/mL) of a toluene solution containing biphenol metal complex 7 were sequentially added, and a boron-containing reagent [ Ph ] was further added₃C][B(C₆F₅)₄]2mL (5. mu. mol/mL). Introducing ethylene under the condition of mechanical stirring and pressure of 0.5MPa, making reaction at 80 deg.C for 40min, then adding ethyl alcohol to stop reaction to obtain 6.3g of polymer, and its polymerization activity is 1.89X 10⁶g·mol^-1(Ti)·h^-1。

Melting point 131.0 ℃ by DSC; GPC measured M of polyethylene_wIs 1.9X 10⁵，M_w/M_nIs 5.54.

Example 26

Vacuumizing the 500mL polymerization kettle after being heated and dried for twice by introducing nitrogen, and vacuumizing the polymerization kettleEthylene gas was introduced, and then 2mL (0.5mmol/mL) of a toluene solution of triisobutylaluminum, 150mL of n-heptane subjected to anhydrous oxygen-free treatment and 1mL (2.5. mu. mol/mL) of a toluene solution containing biphenol metal complex 7 were added in this order, followed by addition of a boron-containing reagent [ Ph₃C][B(C₆F₅)₄]2mL (5. mu. mol/mL). Introducing ethylene under the condition of mechanical stirring and pressure of 0.5MPa, making reaction at 80 deg.C for 10min, then adding ethyl alcohol to stop reaction to obtain 2.6g of polymer, and its polymerization activity is 3.12X 10⁶g·mol^-1(Ti)·h^-1。

Melting point 133.0 ℃ by DSC; GPC measured M of polyethylene_wIs 1.6X 10⁵，M_w/M_nIs 4.99.

TABLE 1 amounts of raw materials and reaction conditions in examples 6-26

In Table 1, A represents triisobutylaluminum, B represents triethylaluminum, and C represents [ Ph ]₃C][B(C₆F₅)₄]D represents [ PhNMe₂][B(C₆F₅)₄]。

TABLE 2 results of the reactions of examples 6 to 26

Any numerical value mentioned in this specification, if there is only a two unit interval between any lowest value and any highest value, includes all values from the lowest value to the highest value incremented by one unit at a time. For example, if it is stated that the amount of a component, or a value of a process variable such as temperature, pressure, time, etc., is 50 to 90, it is meant in this specification that values of 51 to 89, 52 to 88 … …, and 69 to 71, and 70 to 71, etc., are specifically enumerated. For non-integer values, units of 0.1, 0.01, 0.001, or 0.0001 may be considered as appropriate. These are only some specifically named examples. In a similar manner, all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be disclosed in this application.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.

Claims

1. A process for the homopolymerization of ethylene, which comprises homopolymerizing ethylene in the presence of a catalyst; the catalyst comprises a biphenol metal complex shown as a formula I as a main catalyst;

2. The process for homopolymerization of ethylene as claimed in claim 1, wherein R in formula I₁、R₁＇、R₂、R₂Identical or different, each independently selected from hydrogen, substituted or unsubstituted C₁-C₂₀Straight or branched alkyl and substituted or unsubstituted C₆-C₂₀Aryl of (a); r₃-R₇、R₃＇-R₇' same or different, each independently selected from hydrogen and substituted or unsubstituted C₁-C₂₀Linear or branched alkyl of (a); r₈And R₉Same or different, each independently selected from hydrogen and substituted or unsubstituted C₁-C₂₀Linear or branched alkyl of (a); m and M', which are identical or different, are selected from titanium, zirconium and hafnium; x is selected from fluorine, chlorine, bromine and iodine.

3. The process for homopolymerization of ethylene as claimed in claim 2, wherein R in formula I₁、R₁＇、R₂、R₂' same or different, each independently selected from hydrogen and substituted or unsubstituted C₁-C₁₀Linear or branched alkyl.

4. The process for homopolymerization of ethylene as claimed in claim 2, wherein R is₃-R₇、R₃＇-R₇' same or different, each independently selected from hydrogen and substituted or unsubstituted C₁-C₁₀Linear or branched alkyl.

5. The process for homopolymerization of ethylene as claimed in claim 2, wherein R is₈And R₉Same or different, each independently selected from hydrogen and substituted or unsubstituted C₁-C₁₀Linear or branched alkyl.

6. The process for homopolymerization of ethylene according to claim 2, wherein M and M' are titanium; x is chlorine.

7. The method for homopolymerizing ethylene according to any one of claims 1 to 6, wherein the metal biphenol complex represented by the formula I is prepared by a method comprising the steps of:

in the formula III, M₁Selected from group IA metals, R is hydrogen or C₁-C₁₀Linear or branched alkyl of (a);

in the formula V, R₃-R₇Have the same definitions as in formula I.

8. Process for the homopolymerization of ethylene according to claim 7, wherein M is M in formula III₁Is lithium, sodium or potassium.

9. The method for homopolymerizing ethylene according to any one of claims 1 to 6, wherein the catalyst further comprises a cocatalyst comprising an alkylaluminum compound and an organoboron compound.

10. A process for the homopolymerization of ethylene according to claim 9, wherein the organoboron compound is selected from arylboron and/or a borate.

11. The method of claim 9, wherein the molar ratio of the main catalyst, the organoboron compound, and the alkyl aluminum compound is 1: (1-10): (100-2000).

12. Process for the homopolymerization of ethylene according to any one of claims 1 to 6, wherein said catalyst further comprises a cocatalyst comprising an aluminoxane.

13. The method of claim 12, wherein the molar ratio of the procatalyst to the aluminoxane is from 1: (200-5000).

14. The method of claim 13, wherein the molar ratio of the procatalyst to the aluminoxane is from 1: (2000-3000).

15. The process for the homopolymerization of ethylene according to any one of claims 1 to 6, wherein the homopolymerization is carried out at a temperature of-30 to 150 ℃; and/or the pressure of the homopolymerization is 0.1-10 MPa; and/or the time of homopolymerization is 10-60 minutes.

16. The process for the homopolymerization of ethylene according to claim 15, wherein the temperature of the homopolymerization is 50 to 110 ℃; and/or the pressure of the homopolymerization is 0.5-4 MPa.

17. Homopolymerization process of ethylene according to any of claims 1-6, characterized in that the homopolymerization is carried out in an inert solvent, which is an aromatic hydrocarbon or an alkane.

18. The method of claim 17, wherein the inert solvent comprises benzene, toluene, hexane, heptane, and mixtures thereof.

19. An ethylene homopolymer prepared according to the method of any one of claims 1-18, comprising a biphenol metal complex represented by formula I;