CN114516930B

CN114516930B - Ethylene polymerization process and ethylene polymers made therefrom

Info

Publication number: CN114516930B
Application number: CN202011314968.3A
Authority: CN
Inventors: 高念; 陈建军; 李洪泊; 徐林; 吴宁; 郝建国
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: 2020-11-20
Filing date: 2020-11-20
Publication date: 2023-04-11
Anticipated expiration: 2040-11-20
Also published as: CN114516930A

Abstract

The invention discloses an ethylene polymerization method and an ethylene copolymer prepared by the method, and the method comprises the step of contacting ethylene and conjugated diene in the presence of a polymerization catalyst, wherein the polymerization catalyst comprises a component A and a component B, the component A is selected from metal compounds shown in a formula 1, and the component B is an organic aluminum compound and/or an organic boron compound. According to the ethylene polymerization method of the present invention, an ethylene copolymer having a higher content of a conjugated diene structural unit can be prepared with a higher catalytic activity, and the polymer main chain of the prepared ethylene copolymer contains no or substantially no unsaturated bond, and the molecular weight distribution of the prepared ethylene copolymer is narrow.

Description

Ethylene polymerization process and ethylene polymers made therefrom

Technical Field

The present invention relates to a method for polymerizing ethylene and an ethylene polymer prepared therefrom, and more particularly, to a method for polymerizing ethylene and conjugated diene and an ethylene polymer prepared therefrom.

Background

Ethylene is widely used in the plastics industry as a monomer which is used in large quantities and is readily available. Conjugated dienes, particularly butadiene and isoprene, are the most important monomers for the synthesis of rubber. Butadiene, a by-product of the petroleum route to ethylene, was once at a price similar to ethylene. Recently, the price of butadiene has increased dramatically due to the decrease in the production of butadiene resulting from the change in the ethylene production route. In contrast, the price of ethylene is reduced. Therefore, the use of ethylene as a raw material for the production of rubber for tires is attractive, and the raw material cost can be greatly saved.

However, copolymerization is difficult due to the difference in polymerization mechanism between the conjugated diene and the α -olefin, which results in difficulty in increasing the content of the structural unit derived from the conjugated diene in the copolymer to be prepared and the molecular weight of the copolymer, and results in low activity of the catalyst, low production efficiency, and difficulty in meeting the requirements of mass production. Meanwhile, from the viewpoint of application, it is also required to reduce the content of unsaturated bonds in the main chain of the polymer to improve physical properties such as weather resistance, heat resistance and ozone resistance of the copolymer.

Therefore, the copolymerization of ethylene and conjugated diene by using the same catalytic system is a very challenging subject, the realization of the copolymerization of ethylene and conjugated diene has been the direction of the academic and industrial efforts, and the development of a polymerization method suitable for the copolymerization of ethylene and conjugated diene has important significance.

Disclosure of Invention

The invention aims to provide an ethylene polymerization method, which can obtain higher catalytic activity when polymerizing ethylene and conjugated diene, can improve the content and molecular weight of structural units derived from the conjugated diene in the prepared ethylene copolymer, and simultaneously has low content of unsaturated bonds on the main chain of the prepared ethylene copolymer.

According to a first aspect of the present invention, there is provided an ethylene polymerization process comprising contacting ethylene with a conjugated diene in the presence of a polymerization catalyst comprising component A and component B,

the component A is selected from metal compounds shown in a formula 1,

in formula 1, M is a metal atom selected from groups IB, IIIB, IVB, VB, VIB, VIIB and VIII,

X ₁ and X ₂ Identical or different, each independently a halogen atom,

rb is a divalent group of a group IIIA element, a divalent group of a group IVA element, a divalent group of a group VA element or a divalent group of a group VIA element,

L ₁ and L ₂ The same or different, each independently selected from the group represented by formula 2 to formula 8, and L ₁ And L ₂ Is not the formula 6, the formula 7 or the formula 8 at the same time,

R ₁ 、R ₂ 、R ₃ 、R ₄ 、R ₅ 、R ₆ 、R ₇ 、R ₈ and R ₉ The same or different, each independently is a hydrogen atom, C ₁ -C ₂₀ Alkyl or C ₆ -C ₂₀ Aryl of (a);

the component B is an organic aluminum compound and/or an organic boron compound.

According to a second aspect of the present invention there is provided an ethylene copolymer produced by the process of the first aspect of the present invention.

According to the ethylene polymerization method, the ethylene copolymer with higher conjugated diene structural unit content and higher molecular weight can be prepared with higher catalytic activity, the polymer main chain of the prepared ethylene copolymer does not contain or basically does not contain unsaturated bonds, and the prepared ethylene has narrow molecular weight distribution. The ethylene polymerization process according to the present invention has a wide application prospect.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and these ranges or values should be understood to encompass values close to these ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

According to a first aspect of the present invention, there is provided an ethylene polymerization process comprising contacting ethylene with a conjugated diene in the presence of a polymerization catalyst comprising component a and component B.

The component A is selected from metal compounds shown in a formula 1,

in formula 1, M is a metal atom selected from groups IB, IIIB, IVB, VB, VIB, VIIB, and VIII, preferably a metal element selected from group IVB, and may be, for example, a titanium atom, a zirconium atom, or a hafnium atom, more preferably a zirconium atom.

In formula 1, X ₁ And X ₂ The same or different, each independently a halogen atom. Preferably, in formula 1, X ₁ And X ₂ Are all chlorine atoms.

In formula 1, rb is a divalent group of a group IIIA element, a divalent group of a group IVA element, a divalent group of a group VA element, or a divalent group of a group VIA element. Preferably, rb is a divalent group of a group IVA element. More preferably, rb is a divalent group represented by formula 14,

in the formula 14, R ¹ And R ² Identical or different, each independently is C ₁ -C ₁₀ Alkyl group of (1). C ₁ -C ₁₀ The alkyl group of (A) includes C ₁ -C ₁₀ Straight chain alkyl group of (1), C ₃ -C ₁₀ Branched alkyl of (2) and C ₃ -C ₁₀ Cycloalkyl of which hasSpecific examples may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl and its various isomers, hexyl and its various isomers, heptyl and its various isomers, octyl and its various isomers, nonyl and its various isomers, and decyl and its various isomers. Preferably, in formula 14, R ¹ And R ² Each independently is C ₁ -C ₆ The alkyl group of (1). More preferably, in formula 14, R ¹ And R ² Is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl. Further preferably, in formula 14, R ¹ And R ² Is methyl.

In the formula 1, L ₁ And L ₂ The same or different, each independently selected from the group represented by formula 2 to formula 8, and L ₁ And L ₂ Is not simultaneously formula 6, formula 7 or formula 8,

R ₁ 、R ₂ 、R ₃ 、R ₄ 、R ₅ 、R ₆ 、R ₇ 、R ₈ and R ₉ The same or different, each independently is a hydrogen atom, C ₁ -C ₂₀ Alkyl or C ₆ -C ₂₀ Aryl group of (1).

In the present invention, C ₁ -C ₂₀ The alkyl group of (A) includes C ₁ -C ₂₀ Straight chain alkyl of (1), C ₃ -C ₂₀ Branched alkyl and C ₃ -C ₂₀ Specific examples thereof may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl and its various isomers, hexyl and its various isomers, heptyl and its various isomers, octyl and its various isomers, nonyl and its various isomers, and mixtures thereof,Decyl and its various isomers, undecyl and its various isomers, dodecyl and its various isomers, tridecyl and its various isomers, tetradecyl and its various isomers, pentadecyl and its various isomers, hexadecyl and its various isomers, heptadecyl and its various isomers, octadecyl and its various isomers, nonadecyl and its various isomers, and eicosyl and its various isomers.

In the present invention, C ₆ -C ₂₀ Specific examples of the aryl group of (a) may include, but are not limited to: phenyl, tolyl, ethylphenyl, propylphenyl (in which propyl may be n-propyl or isopropyl), butylbenzene (in which butyl may be n-butyl, sec-butyl, isobutyl or tert-butyl), naphthyl, anthryl or phenanthryl.

Preferably, R ₁ 、R ₂ 、R ₃ 、R ₄ 、R ₅ 、R ₆ 、R ₇ 、R ₈ And R ₉ Each independently is a hydrogen atom, C ₁ -C ₁₀ Alkyl or C ₆ -C ₂₀ Aryl group of (2). More preferably, R ₁ 、R ₂ 、R ₃ 、R ₄ 、R ₅ 、R ₆ 、R ₇ 、R ₈ And R ₉ Each independently is a hydrogen atom, C ₁ -C ₅ Alkyl or C ₆ -C ₂₀ Aryl group of (1). Further preferably, R ₁ 、R ₂ 、R ₃ 、R ₄ 、R ₅ 、R ₆ 、R ₇ 、R ₈ And R ₉ Each independently a hydrogen atom, a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a phenyl group, an anthryl group or a phenanthryl group.

For the group of formula 2, in a preferred embodiment, R ₁ 、R ₂ 、R ₃ 、R ₄ And R ₅ Preferably both are hydrogen atoms.

For the group of formula 3, in a preferred embodiment, R ₂ And R ₄ Identical or different, preferably each independently of the others, is C ₁ -C ₂₀ More preferably each independently is C ₁ -C ₁₀ Alkyl of (a) furtherEach of the steps is preferably independently C ₁ -C ₅ Even more preferably each independently is C ₁ -C ₄ Particularly preferably each independently of the other is a hydrogen atom, methyl, ethyl, n-propyl or isopropyl, R ₁ 、R ₃ And R ₅ Is a hydrogen atom.

For the group of formula 4, in a preferred embodiment, R ₁ And R ₄ Preferably C ₁ -C ₂₀ More preferably C ₁ -C ₁₀ Further preferably C ₁ -C ₅ More preferably methyl, ethyl, n-propyl or isopropyl, R ₂ Preferably C ₆ -C ₂₀ More preferably C ₆ -C ₁₅ Further preferably phenyl, anthryl or phenanthryl, R ₃ Is hydrogen.

According to the process of the invention, in formula 1, L ₁ And L ₂ Preferably each independently selected from the group represented by formula 2 to formula 5. According to the process of the invention, in formula 1, L ₁ And L ₂ Preferably the same group, more preferably the same group and is a group represented by formula 2, a group represented by formula 3, a group represented by formula 4 or a group represented by formula 5.

According to the process of the present invention, in a preferred embodiment, the component A is selected from metal compounds represented by formula 9 to formula 13,

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according to this preferred embodiment, in a more preferred example, the component a is a metal compound represented by formula 13. According to this preferred embodiment, the method according to the invention allows to obtain a significantly improved catalytic activity and thus an improved production efficiency. Meanwhile, the polymer main chain of the ethylene polymer prepared according to this more preferred embodiment is substantially free of unsaturated groups.

According to this preferred embodiment, in another more preferred example, the component a is a metal compound represented by formula 11 or formula 12. According to the preferred embodiment, the polymerization catalyst has more balanced catalytic performance, not only can obtain higher catalytic activity, but also can obtain higher conjugated diene combining capacity, and the prepared ethylene copolymer has higher conjugated diene structural unit content, higher molecular weight and narrow molecular weight distribution, and the polymer main chain of the prepared ethylene copolymer does not contain unsaturated groups basically.

According to the preferred embodiment, in a further preferred example, the component a is a metal compound represented by formula 9 or formula 10. According to the preferred embodiment, a higher conjugated diene binding ability can be obtained, and the content of groups having double bonds in the side chain formed by 1, 2-polymerization of the conjugated diene is higher.

The metal compounds of component A can be obtained commercially according to the process of the present invention or can be prepared by conventional methods.

According to the process of the present invention, the component B is an organoaluminum compound and/or an organoboron compound.

The organoaluminum compound may be an aluminoxane and/or a hydrocarbylaluminum.

In one embodiment, the organoaluminum compound aluminoxane is preferably Methylaluminoxane (MAO).

In another embodiment, the organoaluminum compound is a compound represented by formula 15,

in the formula 15, R ³ 、R ⁴ And R ⁵ Are the same or different and are each independently selected from C ₁ -C ₁₀ Alkyl of (C) ₁ -C ₁₀ Alkoxy group of (1), C ₆ -C ₂₀ Aryl of, C ₇ -C ₁₅ Alkyl of (2)Aryl radical, C ₇ -C ₁₅ Aralkyl and hydrogen atom of (2), and R ³ 、R ⁴ And R ⁵ Not simultaneously hydrogen atoms.

C ₁ -C ₁₀ Is alkyl including C ₁ -C ₁₀ Straight chain alkyl group of (1), C ₃ -C ₁₀ Branched alkyl of (2) and C ₃ -C ₁₀ Specific examples thereof may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl and its various isomers, hexyl and its various isomers, heptyl and its various isomers, octyl and its various isomers, nonyl and its various isomers, decyl and its various isomers, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

Said C is ₁ -C ₁₀ Specific examples of the alkoxy group of (a) may include, but are not limited to: methoxy, ethoxy, propoxy and butoxy.

Said C is ₆ -C ₂₀ Specific examples of the aryl group of (a) may include, but are not limited to: phenyl, tolyl, ethylphenyl, propylphenyl (in which propyl may be n-propyl or isopropyl), butylbenzene (in which butyl may be n-butyl, sec-butyl, isobutyl or tert-butyl), naphthyl, anthryl or phenanthryl.

The alkaryl group means an aryl group having an alkyl substituent, and specific examples of the alkaryl group may include, but are not limited to: tolyl, ethylphenyl, dimethylphenyl, and diethylphenyl.

The aralkyl group means an alkyl group having an aryl substituent, and specific examples of the aralkyl group may include, but are not limited to: benzyl, phenethyl, 1-phenylpropyl, 2-phenylpropyl and 3-phenylpropyl.

Specific examples of the alkyl aluminum compound may include, but are not limited to: diethylaluminum hydride, di-n-propylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, p-tolylethylaluminum hydride, p-tolyl-n-propylaluminum hydride, p-tolylisopropylaluminum hydride, benzylethylaluminum hydride, benzyl-n-propylaluminum hydride, benzylisopropylaluminum hydride, ethylaluminum dihydride, butylaluminum dihydride, isobutylaluminum dihydride, octylaluminum dihydride, pentylaluminum dihydride, diethylaluminum ethoxide, dipropylaluminum ethoxide, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldiphenylaluminum, ethyldi-p-tolylaluminum, ethyldibenzylaluminum, diethylbenzylaluminum, and diethylbenzylaluminum.

In a preferred embodiment, in formula 15, R ³ 、R ⁴ And R ⁵ Is methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl. More preferably, in formula 15, R ³ 、R ⁴ And R ⁵ Are all isobutyl.

According to the production method of the present invention, the organoaluminum compound is preferably methylaluminoxane and/or triisobutylaluminum.

The organoboron compound is preferably an organoborate. The organic borate is an ionic compound consisting of borate anions and cations.

Specific examples of the borate anion may include, but are not limited to: tetraphenyl borate, tetrakis (mono-fluorophenyl) borate, tetrakis (difluorophenyl) borate, tetrakis (trifluorophenyl) borate, tetrakis (tetrafluorophenyl) borate, tetrakis (pentafluorophenyl) borate, tetrakis (tetrafluoromethylphenyl) borate, tetrakis (tolyl) borate, tetraxylyl borate, (triphenyl-pentafluorophenyl) borate, [ tris (pentafluorophenyl) phenyl ] borate, and undecahydro-7, 8-dicarbaundecaborate.

Specific examples of the cation may include, but are not limited to: carbonium cations, oxonium cations, ammonium cations, phosphine cations, cycloheptatrienyl cations, and ferrocenium cations containing transition metals. Wherein the carbonium cation comprises a trisubstituted carbonium cation, such as triphenylcarbonium cation and tris (substituted phenyl) carbonium cation. More specific examples of the tri (substituted phenyl) carbonium cation include a tri (tolyl) carbonium cation. Specific examples of ammonium cations may include, but are not limited to: trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, and tributylammonium cation; n, N-dialkylanilinium cations, such as N, N-dimethylanilinium cation, N-diethylanilinium cation and N, N-2,4, 6-pentamethylanilinium cation; and dialkylammonium cations such as diisopropylammonium cation and dicyclohexylammonium cation. Specific examples of phosphine cations may include, but are not limited to: triaryl cations such as triphenylphosphine cation, tri (tolyl) phosphine cation and tri (xylyl) phosphine cation.

According to the process of the present invention, the organoboron compound is preferably trityl-tetrakis (pentafluorophenyl) borate. The organoboron compound is preferably used in combination with the aluminum hydrocarbyl.

According to the process of the invention, the molar ratio of said component a to said component B may be 1:0.1 to 5000, preferably 1:1-3000, more preferably 1:1 to 1000, more preferably 1:10-1000, more preferably 1:100-800. When the component B is an organoaluminum compound and an organoboron compound, the molar ratio of the organoaluminum compound to the organoboron compound can be from 0.1 to 1000:1, preferably 1 to 500:1, more preferably 10 to 300:1, more preferably 40 to 100:1.

according to the process of the present invention, said component A is used in an amount of 0.1 to 100. Mu. Mol, preferably 1 to 80. Mu. Mol, more preferably 5 to 60. Mu. Mol, still more preferably 6 to 30. Mu. Mol, relative to 1mol of the conjugated diene.

According to the method of the present invention, in a preferred embodiment, the component a is a metal compound represented by formula 9 to formula 13, and the component B is an aluminoxane, preferably methylaluminoxane. According to this preferred embodiment, the ethylene copolymer produced has not only a high content of conjugated diene structural units but also a high content of 1, 2-polymerized vinyl structural units, while the content of unsaturated double bonds in the main chain of the copolymer is low. According to this preferred embodiment, the ethylene copolymer produced has good crosslinking properties, and the crosslinked product is good in weather resistance, heat resistance and ozone resistance. According to this preferred embodiment, said component A is preferably used in an amount of 6.5 to 20. Mu. Mol, more preferably 7 to 15. Mu. Mol, relative to 1mol of conjugated diene.

According to the process of the present invention, the contacting of ethylene with conjugated diolefin may be carried out at a temperature of from-50 ℃ to 150 ℃, preferably at a temperature of from 10 ℃ to 120 ℃, more preferably at a temperature of from 30 ℃ to 90 ℃, even more preferably at a temperature of from 40 ℃ to 70 ℃. In the contact polymerization of ethylene and a conjugated diene according to the process of the present invention, the pressure of ethylene may be in the range of 0 to 100MPa, preferably 2 to 50MPa, more preferably 3 to 30MPa, further preferably 5 to 10MPa, the pressure being expressed as gauge pressure (G).

According to the process of the invention, the contacting is carried out in the presence of a molecular weight regulator. The molecular weight regulator may be of conventional choice, preferably hydrogen. The ethylene copolymer prepared by the method has higher molecular weight. Generally, according to the process of the present invention, the olefin polymer produced may have a number average molecular weight (unit is g/mol) of 10,000 or more, preferably 12,000 to 500,000, more preferably 14,000 to 400,000, further preferably 16,000 to 350,000, still further preferably 20,000 to 320,000.

The process according to the invention can be carried out by solution polymerization. In solution polymerization, solvents that may be employed include C ₆ -C ₁₂ Aromatic hydrocarbon solvent, C ₆ -C ₁₂ Halogenated aromatic hydrocarbon of (1), C ₅ -C ₁₀ Linear alkane of (1) and C ₅ -C ₁₀ Cycloalkanes of (a) such as: one or more of toluene, chlorobenzene, dichlorobenzene, n-hexane and cyclohexane.

According to the process of the present invention, the conjugated diene refers to a compound having a conjugated double bond in its molecular structure. Specific examples of the conjugated diene may include, but are not limited to, butadiene and/or isoprene.

The ethylene copolymer prepared by the method has higher conjugated diene structure unit content, the main chain of the prepared ethylene copolymer does not contain or basically does not contain unsaturated bonds, and the prepared ethylene copolymer has narrow molecular weight distribution and high molecular weight.

The present invention will be described in detail with reference to examples, but the scope of the present invention is not limited thereto.

In the following examples and comparative examples, the molecular weight and molecular weight distribution index (M) of the polymer _w /M _n ) The measurement was carried out by 1260 Infinity II high temperature gel permeation chromatograph manufactured by Agilent corporation using 2 columns (300X 7.5 mm) of MIXD-B and 1 column (50X 7.5 mm) of Guard. The mobile phase is trichlorobenzene, and the flow rate is 1mL/min; the concentration of the sample solution is 0.1mg/mL, and the sample injection amount is 200 mu L; the test temperature is 150 ℃; monodispersed polystyrene was used as a standard.

In the following examples and comparative examples, the microstructure of the polymer was measured using a 400MHz NMR spectrometer commercially available from Bruke, using deuterated o-dichlorobenzene as a solvent and Tetramethylsilicon (TMS) as an internal standard. Wherein "conjugated diene structural unit" means a structural unit formed of a conjugated diene, "1, 2-polymerization" means that the conjugated diene is polymerized in a 1, 2-addition manner, "1, 4-polymerization" means that the conjugated diene is polymerized in a 1, 4-addition manner, "1, 3-polymerization" means that the conjugated diene is polymerized in a 1, 3-addition manner; "vinyl" refers to a structural unit of a conjugated diene formed by 1, 2-polymerization and having a side-chain double bond (in the case of butadiene, vinyl is

"cyclopropane ring" means a structural unit in which a conjugated diene is polymerized in 1, 2-form and which has a cyclopropane ring (in the case of butadiene, the cyclopropane ring is->

"Cyclopentane ring" means a structural unit (in terms of butadiene) in which a conjugated diene is formed in a 1, 2-polymerization manner and which has a cyclopentane ringFor example, the cyclopentane ring is->

The following examples and comparative examples relate to the following metal compounds.

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Preparation examples 1 to 5 were used for preparing metal compounds 1 to 5.

Preparation example 1

Synthesis of Metal Compound 1

0.94g (2 mmol) of bis (2, 5-dimethylcyclopentylthiophene) -dimethylsilyl and 50mL of diethyl ether are placed in a reaction flask and 2.5mL (4 mmol) of a 1.6M solution of butyllithium in hexane are added dropwise at-78 ℃. After stirring at room temperature (25 ℃ C.) for 6 hours, the temperature was reduced to-40 ℃ C and 0.466g (2 mmol) of zirconium tetrachloride was slowly added. Stir overnight. Filter and wash the solid with ether. The product was recrystallized from dichloromethane. Yield: 45% by weight.

H ¹ -NMR(CDCl ₃ ,400MHz)：δppm 6.75(q,4H)，2.51(d,12H)，1.82(s,6H)。

Preparation example 2

Synthesis of Metal Compound 4

The same synthesis method as that of the metal compound 1 is adopted, except that the bis (2, 5-dimethylcyclopentylthiophene) -dimethyl silicon is replaced by 2mmol of bis (cyclopentylthiophene) -dimethyl silicon. Yield: 57% by weight.

H ¹ -NMR(CDCl ₃ ,400MHz)：δppm 7.15(d,4H)，7.10(d,4H)，1.80(s,6H)。

Preparation example 3

Synthesis of Metal Compound 5.

1.02g (2 mmol) of bis (2, 5-dimethyl-3-phenyl-6-hydro-cyclopenta [2,3-b ] thiophene-6) -dimethylsilyl-ene and 50mL of diethyl ether are introduced into a reaction flask and 2.5mL (4 mmol) of 1.6M butyllithium hexane solution are added dropwise at-78 ℃. After stirring at room temperature (25 ℃ C.) for 6 hours, 0.466g (2 mmol) of zirconium tetrachloride was slowly added. Stir overnight. Filter and wash the solid with ether. And (4) draining the filtrate to obtain a target product. Yield: 45% by weight.

H ¹ -NMR(CD ₂ Cl ₂ ,400MHz)：δppm 7.2-7.6(m,10H)，6.60(s，2H)，2.58(s，6H)，2.3(s，6H)，1.05(s，6H)。

Preparation example 4

Synthesis of Metal Compound 2

The same synthesis as for metal compound 5 was used, except that 2mmol of bis (2, 5-dimethyl-3-phenyl-6-hydro-cyclopenta [2,3-b ] thiophen-6) -dimethylsilyl group was used instead of bis (2, 5-dimethyl-3-phenyl-6-hydro-cyclopenta [2,3-b ] thiophen-6) -dimethylsilyl group. Yield: 56% by weight.

H ¹ -NMR(CDCl ₃ ,400MHz)：δppm 7.15-8.90.(m,18H)，6.62(s，2H)，1.15-2.95(m，14H)，1.08(s，6H)，0.92(t,6H)。

Preparation example 5

Synthesis of Metal Compound 3

The same synthesis as for metal compound 5 was used, except that 2mmol of bis (2, 5-dimethyl-3-phenyl-6-hydro-cyclopenta [2,3-b ] thiophene-6) -dimethylsilyl was used instead of bis (2, 5-dimethyl-3-phenyl-6-hydro-cyclopenta [2,3-b ] thiophene-6) -dimethylsilyl. Yield: 61 wt%.

H ¹ -NMR(CDCl ₃ ,400MHz)：δppm 7.10-8.85(m,18H)，6.60(s，2H)，1.85-2.80(m，10H)，1.10(s，6H)，0.85(s，6H)。

Examples 1-12 are intended to illustrate the ethylene polymerization process according to the invention.

Example 1

A500 mL stainless steel reactor was sufficiently purged with nitrogen and then purged with hydrogen, and 120g of toluene, 8mL of methylaluminoxane (10% by weight toluene solution), 25.0g of butadiene and 0.44kg/cm of butadiene were added ² G hydrogen. At 60 ℃ with 7.8kg/cm ² G ethylene saturates the liquid and gas phases. Then 5. Mu. Mol of metal compound 1 dissolved in toluene in advance are addedAnd (3) starting polymerization. Ethylene gas was continuously supplied so that the total pressure was maintained at 7.8kg/cm ² G. After 15 minutes of polymerization, the reaction was terminated by adding a small amount of methanol. The product was precipitated by pouring into a large amount of ethanol with hydrochloric acid (HCl concentration 2% by weight), the solid was separated by filtration, and the separated solid was washed with ethanol. The washed solid was dried in a vacuum oven until the weight was no longer reduced to give an ethylene copolymer according to the present invention. The specific experimental conditions are listed in table 1 and the results of the property parameter tests of the prepared ethylene copolymers are listed in table 2.

Example 2

An ethylene copolymer was prepared in the same manner as in example 1, except that methylaluminoxane was not used, but 2.5mL of a triisobutylaluminum in n-hexane solution (concentration of triisobutylaluminum is 1M) was used, and 0.03mmol of trityl-tetrakis (pentafluorophenyl) borate was dissolved in toluene together with the metal compound 1 and added to the polymerization reactor. Specific experimental conditions are listed in table 1 and the results of the property parameter tests of the prepared ethylene copolymers are listed in table 2.

Comparative example 1

An ethylene copolymer was prepared in the same manner as in example 2, except that the metal compound 1 was replaced with the comparative metal compound 1. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Comparative example 2

An ethylene copolymer was prepared in the same manner as in example 1, except that the metal compound 1 was replaced with the comparative metal compound 1. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Example 3

An ethylene copolymer was prepared in the same manner as in example 1, except that: metal compound 1 was replaced by metal compound 2 and the properties of the ethylene copolymer prepared are given in Table 2.

Example 4

An ethylene copolymer was prepared in the same manner as in example 3, except that methylaluminoxane was not used, but 2.5mL of a triisobutylaluminum in n-hexane solution (the concentration of triisobutylaluminum was 1M) was used, and 0.03mmol of trityl-tetrakis (pentafluorophenyl) borate was dissolved in toluene together with the metal compound 2 and added to the polymerization reactor. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Comparative example 3

An ethylene copolymer was produced in the same manner as in example 3, except that the metal compound 2 was replaced with the comparative metal compound 2. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Example 5

A500 mL stainless steel autoclave was fully purged with nitrogen and then purged with hydrogen, and 120g of toluene, 7.5mL of MAO (10 wt% in toluene), 35g of butadiene were added to the autoclave, followed by addition of 0.44kg/cm ² G hydrogen gas, 7.8kg/cm at 60 DEG C ² G ethylene saturates the liquid and gas phases. Thereafter, 5. Mu. Mol of the metal compound 2 dissolved in toluene in advance was added to start the polymerization. Ethylene gas was continuously supplied so that the total pressure was maintained at 7.8kg/cm ² G. After 15 minutes of polymerization, the reaction was terminated by adding a small amount of methanol. The product is poured into a large amount of ethanol (2% by weight, hydrochloric acid in HCl) with hydrochloric acid, precipitated, filtered to separate the copolymer, and washed with ethanol. Drying in a vacuum oven until the weight is no longer reduced gives the ethylene copolymers according to the invention. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Comparative example 4

An ethylene copolymer was prepared in the same manner as in example 5 except that the metal compound 2 was replaced with the comparative metal compound 2. The specific experimental conditions are listed in table 1 and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Example 6

An ethylene copolymer was produced in the same manner as in example 1, except that the metal compound 1 was replaced with a metal compound 3. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Example 7

An ethylene copolymer was prepared in the same manner as in example 6, except that methylaluminoxane was not used, but 2.5mL of a triisobutylaluminum in n-hexane solution (the concentration of triisobutylaluminum was 1M) was used, and 0.03mmol of trityl-tetrakis (pentafluorophenyl) borate was dissolved in toluene together with the metal compound 3 and added to the polymerization reactor. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Comparative example 5

An ethylene copolymer was prepared in the same manner as in example 6, except that the metal compound 3 was replaced with the comparative metal compound 3. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Comparative example 6

An ethylene copolymer was prepared in the same manner as in example 6, except that the metal compound 3 was replaced with the comparative metal compound 3. The specific experimental conditions are listed in table 1 and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Example 8

An ethylene copolymer was prepared in the same manner as in example 1, except that the metal compound 1 was replaced with a metal compound 4. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Example 9

An ethylene copolymer was prepared in the same manner as in example 8, except that methylaluminoxane was not used, but 2.5mL of a triisobutylaluminum in n-hexane solution (the concentration of triisobutylaluminum was 1M) was used, and 0.03mmol of trityl-tetrakis (pentafluorophenyl) borate was dissolved in toluene together with the metal compound 4 and added to the polymerization reactor. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Comparative example 7

An ethylene copolymer was produced in the same manner as in example 8 except that the metal compound 4 was replaced with the comparative metal compound 4. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Example 10

An ethylene copolymer was produced in the same manner as in example 1, except that the metal compound 1 was replaced with a metal compound 4. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Comparative example 8

An ethylene copolymer was produced in the same manner as in example 9 except that the metal compound 4 was replaced with the comparative metal compound 6. Specific experimental conditions are listed in table 1, and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Comparative example 9

An ethylene copolymer was produced in the same manner as in example 9 except that the metal compound 4 was replaced with the comparative metal compound 7. The specific experimental conditions are listed in table 1 and the results of the property parameter tests of the ethylene copolymers prepared are listed in table 2.

Example 11

An ethylene copolymer was prepared in the same manner as in example 1, except that the amount of butadiene was changed and the metal compound 1 was replaced with the metal compound 5, and the results of the property parameter tests of the prepared ethylene copolymer are shown in Table 2.

Comparative example 10

An ethylene copolymer was produced in the same manner as in example 11, except that the metal compound 5 was replaced with the comparative metal compound 5, and the results of the property parameter tests of the produced ethylene copolymer were as listed in Table 2.

Example 12

Comparative example 11

An ethylene copolymer was prepared in the same manner as in example 12 except that the metal compound 5 was replaced with the comparative metal compound 5, and the results of the property parameter tests of the ethylene copolymer obtained were as shown in Table 2.

Comparative example 12

An ethylene copolymer was prepared in the same manner as in example 4, except that the metal compound 2 was replaced with the comparative metal compound 2, and the results of the property parameter tests of the ethylene copolymer prepared were as listed in Table 2.

Comparative example 13

An ethylene copolymer was prepared in the same manner as in example 9 except that the metal compound 4 was replaced with the comparative metal compound 4, and the results of the property parameter tests of the ethylene copolymer obtained were as shown in Table 2.

TABLE 1

Table 2 shows the property parameters of the ethylene copolymers prepared in examples 1 to 12 and comparative examples 1 to 13.

The results of Table 2 confirm that the process according to the present invention can produce an ethylene copolymer having a higher content of conjugated diene structural units with a higher catalytic activity, and that the polymer main chain of the produced ethylene copolymer is free or substantially free of unsaturated bonds, while the molecular weight distribution of the produced ethylene copolymer is narrow.

It can also be seen from the results of tables 1 and 2 that when the metal compounds 1 to 4 are used in combination with aluminoxane, the ethylene copolymer prepared not only has an increased molecular weight and a narrow molecular weight distribution index, but also has an increased content of conjugated diene structural units.

Test examples 1 to 2

The ethylene copolymers prepared in examples 3 and 6 were blended on a roll mill with carbon black, peroxide and a vulcanization aid according to the formulations shown in Table 3, respectively. The vulcanization characteristics of the blend were tested at 160 ℃ using an MDR vulcameter from alpha technologies for a 20 minute time period to evaluate the vulcanization rate. The test results are listed in table 4.

Testing of comparative examples 1-2

The ethylene copolymers prepared in comparative examples 3 and 6 were respectively tested for vulcanization characteristics in the same manner as in test examples 1-2, and the test results are shown in Table 4.

TABLE 3

TABLE 4

Numbering	Test example 1	Comparative test example 1	Test example 2	Comparative test example 2
					t _c 10(min)	0.5	1.1	0.7	0.9
t _c 90(min)	8.5	13.2	8.6	12.1
					MH(dNm)	92.3	45.1	90.5	56.8
ML(dNm)	0.5	0.6	0.5	0.7

As can be seen from the results of the vulcanization characteristics test in Table 4, the ethylene copolymers prepared in examples 3 and 6 undergo a faster torque rise upon vulcanization, have a faster vulcanization rate and a higher degree of vulcanization.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A process for polymerizing ethylene, which is a process for polymerizing ethylene and a conjugated diene, comprising contacting ethylene and a conjugated diene in the presence of a polymerization catalyst comprising a component A and a component B, said contacting being carried out in the presence of a molecular weight modifier, said ethylene copolymer having a number average molecular weight of 10,000 or more,

the component A is selected from metal compounds shown in formulas 9 to 12,

the component B is methylaluminoxane.

2. The method of claim 1, wherein the molar ratio of component a to component B is 1:0.1-5000.

3. The process of claim 1, wherein the conjugated diene is butadiene and/or isoprene.

4. A process according to any one of claims 1 to 3, wherein the contacting is carried out at a temperature of from-50 ℃ to 150 ℃, the ethylene pressure being from 0 to 100MPa, the pressure being in gauge.

5. A process according to any one of claims 1 to 3, wherein said component a is used in an amount of 0.1 to 100 μmol with respect to 1mol of conjugated diene.

6. The process of any of claims 1-3, wherein the ethylene copolymer has a number average molecular weight of 12,000 to 500,000.

7. The process of any of claims 1-3, wherein the ethylene copolymer has a number average molecular weight of 14,000 to 400,000.

8. The process of any of claims 1-3, wherein the ethylene copolymer has a number average molecular weight of from 16,000 to 350,000.

9. The process of any of claims 1-3, wherein the ethylene copolymer has a number average molecular weight of 20,000 to 320,000.

10. An ethylene copolymer prepared by the process of any one of claims 1-9.

11. A process for polymerizing ethylene, which is a process for polymerizing ethylene and a conjugated diene, comprising contacting ethylene and a conjugated diene in the presence of a polymerization catalyst comprising a component A and a component B,

the component A is selected from metal compounds shown in a formula 13,

12. The method according to claim 11, wherein the organoaluminum compound is aluminoxane and/or a compound represented by formula 15,

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in the formula 15, R ³ 、R ⁴ And R ⁵ Are the same or different and are each independently selected from C ₁ -C ₁₀ Alkyl of (C) ₁ -C ₁₀ Alkoxy group of (1), C ₆ -C ₂₀ Aryl of (C) ₇ -C ₁₅ Alkylaryl of, C ₇ -C ₁₅ Aralkyl and hydrogen atom of (2), and R ³ 、R ⁴ And R ⁵ Not simultaneously hydrogen atoms.

13. The process according to claim 11, wherein the organoaluminum compound is methylaluminoxane and/or triisobutylaluminum.

14. The method of claim 11, wherein the organoboron compound is an organoborate.

15. The method of claim 11, wherein the organoboron compound is trityl-tetrakis (pentafluorophenyl) borate.

16. The method of any one of claims 11-15, wherein the molar ratio of component a to component B is 1:0.1-5000.

17. A process as claimed in any one of claims 11 to 15 wherein component B is an organoaluminum compound and an organoboron compound, the molar ratio of the organoaluminum compound to the organoboron compound being from 0.1 to 1000:1.

18. the process of any one of claims 11-15, wherein the conjugated diene is butadiene and/or isoprene.

19. The process of any one of claims 11-15, wherein the contacting is carried out at a temperature of-50 ℃ to 150 ℃, the ethylene pressure being 0-100MPa, the pressure being in gauge.

20. The process according to any one of claims 11 to 15, wherein said component a is used in an amount of 0.1 to 100 μmol with respect to 1mol of conjugated diene.

21. The process of any one of claims 11-15, wherein the contacting is carried out in the presence of a molecular weight regulator, and the ethylene copolymer has a number average molecular weight of 10,000 or more.

22. The process of claim 20, wherein the ethylene copolymer has a number average molecular weight of 12,000 to 500,000.

23. The process of claim 21, wherein the ethylene copolymer has a number average molecular weight of 14,000 to 400,000.

24. The process of claim 22, wherein the ethylene copolymer has a number average molecular weight of 16,000 to 350,000.

25. The process of claim 23, wherein the ethylene copolymer has a number average molecular weight of 20,000 to 320,000.