Novel vanadium-based catalytic system containing activating agent and olefin polymerization method

Abstract

The invention provides a novel vanadium-based catalytic system containing an activator and an olefin polymerization method, and belongs to the technical field of vanadium-based catalytic systems. The activating agent contained in the vanadium-based catalytic system provided by the invention is halogenated phenyl ethyl acetate substituted by at least two halogen atoms, and at least one halogen atom is substituted on a phenyl position or a benzyl position. When the vanadium-based catalytic system provided by the invention is applied to ethylene propylene rubber synthesis through olefin polymerization, the use amount of the main catalyst and the cocatalyst can be reduced while the activity of ethylene propylene rubber synthesis copolymerization reaction is improved, the residual amount of the catalyst in the product (dry glue) is reduced, the production cost is reduced, and the post-treatment of the product is easier.

Description

Technical Field

[0001] The present invention relates to the technical field of vanadium-based catalyst systems, and particularly to a novel vanadium-based catalyst system containing an activator and a method for olefin polymerization. Background Art

[0002] Ethylene-propylene rubber is a synthetic rubber with ethylene and propylene as the main monomers. Its types can be mainly divided into two categories according to the composition of the comonomer: binary ethylene-propylene rubber and ternary ethylene-propylene rubber. Ethylene-propylene rubber is one of the synthetic rubber varieties that have developed rapidly since the 1980s. It is used in automotive parts, waterproof building materials, oil additives, and polymer modifiers, etc., and the annual global consumption of ethylene-propylene rubber is increasing. In order to improve the quality and output of products, the most important method is to improve the catalyst system for ethylene-propylene rubber production. Although the catalyst systems applied in ethylene-propylene rubber production have now developed from a single Ziegler-Natta catalyst system to a pattern where Ziegler-Natta catalyst systems, metallocene catalyst systems, and non-metallocene catalyst systems coexist, the Ziegler-Natta vanadium-based catalyst system (hereinafter referred to as the vanadium-based catalyst system) still accounts for a significant proportion in the production of ethylene-propylene rubber. Common vanadium-based catalysts in this system include vanadium oxychloride (VOCl3), vanadium tetrachloride (VCl4), vanadium acetylacetonate (V(acac)3), etc. The cocatalyst usually selects alkyl aluminum chloride. However, vanadium-based catalysts have obvious disadvantages such as low activity and easy deactivation. If the method of increasing the dosage of vanadium-based catalyst is used to make up for the deficiency of the vanadium-based catalyst system in terms of activity, it will lead to an increase in the vanadium content in the product and make the post-treatment of rubber difficult, so its application will be affected. And because the dosage of vanadium-based catalyst is increased, the cost for storing vanadium-based catalyst will also increase significantly.

[0003] Many studies have found that adding an activator to the vanadium-based catalyst system can reactivate the deactivated vanadium centers, thereby prolonging the life of the vanadium-based catalyst and increasing the activity of the vanadium-based catalyst. Therefore, forming a new vanadium-based catalyst system by adding a suitable activator is one of the important methods to reduce production costs and increase polymerization activity. USP4181790 discloses that a vanadium-based catalyst with 2,3,4,4-tetrachlorobutyrate as an activator has a relatively high polymerization yield, but the vanadium compound activated by it is very sensitive to air and water, and the actual application conditions are harsh; Japanese Patent 1973-71492 discloses that a vanadium-based catalyst with anthraquinone oxide as an activator has high activity, but poor compatibility; CN85108910 discloses that a catalyst activity system with trichlorofluoromethane and silicon tetrachloride as activators has relatively high activity, but because silicon tetrachloride is corrosive and may cause pollution to the product. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a novel vanadium-based catalytic system containing an activator and an olefin polymerization method. The vanadium-based catalytic system provided by the present invention can reduce the dosage of the main catalyst and the cocatalyst while improving the activity of the olefin polymerization to synthesize ethylene-propylene rubber copolymerization reaction, reduce the production cost, and make the post-treatment of the product easier.

[0005] To achieve the above object, the present invention provides the following technical solutions: A novel vanadium-based catalytic system containing an activator, wherein the activator is ethyl halophenylacetate with at least two halogen atoms substituted, and at least one halogen atom is substituted at the phenyl position or the benzyl position.

[0006] Preferably, the activator is selected from at least one of ethyl 2,4-dichlorophenylacetate, ethyl 3,4-dichlorophenylacetate, ethyl 2,3-difluorophenylacetate, ethyl 2,6-difluorophenylacetate, ethyl 3-fluoro-4-chlorophenylacetate, ethyl 2-fluoro-2-(2-fluorophenyl)acetate, ethyl 2-fluoro-2-(2-chlorophenyl)acetate, ethyl 2-fluoro-2-(2-bromophenyl)acetate, ethyl 2-chloro-2-(2-fluorophenyl)acetate, ethyl 2-chloro-2-(2-chlorophenyl)acetate, ethyl 2-chloro-2-(2-bromophenyl)acetate, ethyl 2-chloro-2-(4-chlorophenyl)acetate, ethyl 2-fluoro-2-(3,4-dibromophenyl)acetate, ethyl 2,2-difluoro-2-(3-chlorophenyl)acetate, ethyl 2-chlorophenylacetate-β-chloroethyl ester, ethyl 2-fluorophenylacetate-β-chloroethyl ester, ethyl 2-chloro-2-(2-chlorophenyl)acetate-β-chloroethyl ester.

[0007] Preferably, the vanadium-based catalytic system further includes a vanadium-based main catalyst; the general formula of the vanadium-based main catalyst is VO(OR)nClm, wherein the valence state of vanadium is +5, OR is an alkoxy group, n is 1, 2, or 3, m is 0, 1, or 2, and m + n = 3.

[0008] More preferably, the alkoxy group in the structure of the vanadium-based main catalyst is at least one of methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, n-pentyloxy, n-hexyloxy, cyclohexyloxy.

[0009] Preferably, the vanadium-based catalytic system further includes a cocatalyst; the cocatalyst is an organoaluminum compound.

[0010] More preferably, the molar ratio of aluminum atoms in the cocatalyst to vanadium in the vanadium-based main catalyst is (1 - 100):1; the molar ratio of the activator to vanadium in the vanadium-based main catalyst is (5 - 80):1.

[0011] The present invention also provides a method for olefin polymerization, in which ethylene, propylene and a molecular weight regulator are subjected to copolymerization under the vanadium-based catalyst system described in the above technical solution; or, ethylene, propylene, diene and a molecular weight regulator are subjected to copolymerization under the vanadium-based catalyst system described in the above technical solution.

[0012] Preferably, the molecular weight regulator is hydrogen.

[0013] Preferably, the diene is one of ethylidene norbornene, dicyclopentadiene and 1,4-hexadiene.

[0014] Preferably, the copolymerization temperature is 0-75°C; the copolymerization time is 10-180 min; the copolymerization pressure is 0.1-1.0 MPa.

[0015] Beneficial technical effects: The activator contained in the vanadium-based catalyst system provided by the present invention is ethyl halophenylacetate with at least two halogen atoms substituted, wherein at least one halogen atom is substituted at the phenyl position or the benzyl position. Applying the vanadium-based catalyst system provided by the present invention to the olefin polymerization reaction can improve the activity of the ethylene-propylene rubber copolymerization reaction while reducing the usage amounts of the main catalyst and the cocatalyst, reducing the catalyst residue in the product (dry rubber), reducing the production cost, and making the post-treatment of the product easier. Detailed embodiments

[0016] The present invention provides a novel vanadium-based catalyst system containing an activator, and the activator is ethyl halophenylacetate with at least two halogen atoms substituted, wherein at least one halogen atom is substituted at the phenyl position or the benzyl position.

[0017] In the present invention, the activator is selected from at least one of ethyl 2,4-dichlorophenylacetate, ethyl 3,4-dichlorophenylacetate, ethyl 2,3-difluorophenylacetate, ethyl 2,6-difluorophenylacetate, ethyl 3-fluoro-4-chlorophenylacetate, ethyl 2-fluoro-2-(2-fluorophenyl)acetate, ethyl 2-fluoro-2-(2-chlorophenyl)acetate, ethyl 2-fluoro-2-(2-bromophenyl)acetate, ethyl 2-chloro-2-(2-fluorophenyl)acetate, ethyl 2-chloro-2-(2-chlorophenyl)acetate, ethyl 2-chloro-2-(2-bromophenyl)acetate, ethyl 2-chloro-2-(4-chlorophenyl)acetate, ethyl 2-fluoro-2-(3,4-dibromophenyl)acetate, ethyl 2,2-difluoro-2-(3-chlorophenyl)acetate, ethyl 2-chlorophenylacetate-β-chloroethanol ester, ethyl 2-fluorophenylacetate-β-chloroethanol ester, and ethyl 2-chloro-2-(2-chlorophenyl)acetate-β-chloroethanol ester.

[0018] In the present invention, the vanadium-based catalyst system further includes a vanadium-based main catalyst; the general formula of the vanadium-based main catalyst is VO(OR)nClm, where the valence of vanadium is +5, OR is an alkoxy group, n is 1, 2, or 3, m is 0, 1, or 2, and m + n = 3.

[0019] In the present invention, the alkoxy group in the structure of the vanadium-based main catalyst is preferably at least one of methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, n-pentyloxy, n-hexyloxy, and cyclohexyloxy.

[0020] In the present invention, the vanadium-based catalyst system further includes a cocatalyst; the cocatalyst is an organoaluminum compound, preferably an alkylaluminum chloride, more preferably at least one of dimethylaluminum chloride, diethylaluminum chloride, di-n-butylaluminum chloride, diisobutylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, n-butylaluminum dichloride, isobutylaluminum dichloride, sesquimethylaluminum chloride, sesquietylaluminum chloride, sesqui-n-butylaluminum chloride, and sesquiisobutylaluminum chloride, and most preferably sesquietylaluminum chloride.

[0021] In the present invention, the molar ratio of aluminum atoms in the cocatalyst to vanadium in the vanadium-based main catalyst is preferably (1 to 100):1, more preferably (20 to 60):1; the molar ratio of the activator to vanadium in the vanadium-based main catalyst is preferably (5 to 80):1, more preferably (5 to 20):1, and most preferably (5 to 10):1.

[0022] The present invention also provides a method for olefin polymerization, in which ethylene, propylene, and a molecular weight regulator are subjected to a copolymerization reaction under the vanadium-based catalyst system described in the above technical solution; or, ethylene, propylene, a diene, and a molecular weight regulator are subjected to a copolymerization reaction under the vanadium-based catalyst system described in the above technical solution.

[0023] In the present invention, the molecular weight regulator is preferably hydrogen; the molar ratio of hydrogen in the mixture of ethylene, propylene, and hydrogen is preferably 1% to 3%.

[0024] In the present invention, in the ethylene / propylene mixture, the molar ratio of propylene to ethylene is preferably (1 to 5):1.

[0025] In the present invention, the diene is preferably one of ethylidene norbornene (ENB), dicyclopentadiene, and 1,4-hexadiene.

[0026] In the present invention, the copolymerization reaction further includes using a polymerization solvent, and the polymerization solvent is preferably an aliphatic alkane or a cycloalkane, more preferably cyclohexane, and most preferably hexane.

[0027] In the present invention, the copolymerization reaction further includes using a terminator, and the terminator is preferably ethanol or methanol.

[0028] In the present invention, the copolymerization reaction temperature is preferably 0 to 75 °C; the copolymerization reaction time is preferably 10 to 180 min; and the copolymerization reaction pressure is preferably 0.1 to 1.0 MPa.

[0029] In the present invention, when ethylene, propylene and a molecular weight regulator are copolymerized under the vanadium-based catalyst system described in the above technical solution, the specific operation of the copolymerization reaction is as follows:

[0030] The reactor is treated to be anhydrous and anaerobic, and then a solvent equivalent to 40 to 70% of the reactor volume is added to the reactor. Then, the raw material gas is introduced into the reaction kettle. In the present invention, the raw material gas is prepared according to a molar ratio of ethylene:propylene:hydrogen = 1:(4 to 5):(0.01 to 0.03). Then, a vanadium-based main catalyst, a co-catalyst and an activator are added. The addition amount of the vanadium-based main catalyst is 0.02 to 0.1 mmol / 100 mL of solvent, the addition amount of the co-catalyst is 0.02 to 10 mmol / 100 mL of solvent, and the addition amount of the activator is 0.02 to 8 mmol / 100 mL of solvent. During the reaction process, the polymerization reaction pressure is controlled to be constant at 0.1 to 1.0 MPa through the raw material gas adding valve. After polymerization for 30 to 120 minutes, ethanol is added to terminate the reaction.

[0031] In the present invention, the reactor used for the polymerization reaction is a jacketed reactor, and the function of the jacket is to introduce a cooling medium to control the reaction temperature.

[0032] In the present invention, when ethylene, propylene, diene and a molecular weight regulator are copolymerized under the vanadium-based catalyst system described in the above technical solution, the specific operation of the copolymerization reaction is as follows:

[0033] The reactor is treated to be anhydrous and anaerobic, and then a solvent equivalent to 40 to 70% of the reactor volume is added to the reactor. Then, the raw material gas is introduced into the reaction kettle. In the present invention, the raw material gas is prepared according to a molar ratio of ethylene:propylene:hydrogen = 1:(4 to 5):(0.01 to 0.03). Then, a vanadium-based main catalyst, a co-catalyst and an activator are added to synthesize binary ethylene-propylene rubber, or a vanadium-based main catalyst, a co-catalyst, an activator and a diene are added to synthesize ternary ethylene-propylene rubber. The addition amount of the vanadium-based main catalyst is 0.02 to 0.1 mmol / 100 mL of solvent, the addition amount of the co-catalyst is 0.02 to 10 mmol / 100 mL of solvent, the addition amount of the activator is 0.02 to 8 mmol / 100 mL of solvent, and in the synthesis reaction of ternary ethylene-propylene rubber, the addition amount of the diene is 2 to 8 mL / 100 mL of solvent. During the reaction process, the polymerization reaction pressure is controlled to be constant at 0.1 to 1.0 MPa through the raw material gas adding valve. After polymerization for 30 to 120 minutes, ethanol is added to terminate the reaction.

[0034] In the present invention, the reactor used in the polymerization reaction is a jacketed reactor, and the function of the jacket is to allow the introduction of a cooling medium to control the reaction temperature.

[0035] To better understand the present invention, the content of the present invention will be further illustrated below in conjunction with embodiments, but the content of the present invention is not limited to the following embodiments.

[0036] The activity of the catalyst is calculated according to the mass of dry rubber produced per mole of the vanadium-based main catalyst, with the unit being the yield of dry rubber (unit: g) / the amount of substance of the vanadium-based main catalyst (unit: mol) (expressed as g polymer.(mol -1 of V)).

[0037] According to SH / T 1751-2005, a Fourier transform infrared spectrometer (FTIR) is used to determine the ethylene monomer and propylene monomer contents of the ethylene-propylene rubber.

[0038] According to GB / T 21864-2008, high-performance size exclusion chromatography (HPSEC) is used to determine the average molecular weight and molecular weight distribution of the copolymer.

[0039] Example 1

[0040] The polymerization reaction is carried out in a 2 L stainless steel jacketed polymerization kettle. First, the polymerization kettle is treated under anhydrous and anaerobic conditions for 1 hour. Secondly, 1 L of dry hexane (water content ≤ 10 ppm) is added thereto. Then, a raw material gas prepared according to a molar ratio of ethylene:propylene:hydrogen of 1:4.5:0.015 is introduced. Next, 0.3 mmol of the vanadium-based main catalyst vanadium dichloroethoxyoxide (VO(OEt)Cl2, VX), 6 mmol of the cocatalyst sesquiethylaluminum chloride (AQ), and 1.5 mmol of the activator ethyl 2-fluoro-2-(3,4-dibromophenyl)acetate (FDBPAE) are added. The polymerization reaction is carried out at room temperature. During the reaction process, the polymerization reaction pressure is controlled to be constant at 0.5 MPa through the raw material gas addition valve. The polymerization reaction time is 30 minutes. After the polymerization is completed, the rubber solution is discharged from the polymerization kettle, terminated with ethanol, and then a large amount of ethanol is used to precipitate the ethylene-propylene copolymer. The precipitated ethylene-propylene copolymer is dried in a vacuum oven to obtain 48.26 g of dry rubber.

[0041] It is calculated that the catalyst activity in this example is 1.61×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber is about 110,000, the relative molecular weight distribution is 2.4, the ethylene content is 55.0%, and the propylene content is 45.0%.

[0042] Compared with Comparative Example 1, the catalytic activity of the catalyst system increased by 53.3%.

[0043] Example 2

[0044] Same as Example 1, except that the addition amount of AQ was changed to 12 mmol, and 73.01 g of dry rubber was obtained.

[0045] The catalytic activity of the catalyst in this example was calculated to be 2.43×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 140,000, the relative molecular weight distribution was 2.7, the ethylene content was 53.6%, and the propylene content was 46.4%.

[0046] Compared with Comparative Example 2, the catalytic activity of the catalyst system increased by 24.6%.

[0047] Example 3

[0048] Same as Example 1, except that the addition amount of AQ was changed to 18 mmol, and 71.43 g of dry rubber was obtained.

[0049] The catalytic activity of the catalyst in this example was calculated to be 2.38×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 170,000, the relative molecular weight distribution was 3.1, the ethylene content was 50.2%, and the propylene content was 49.8%.

[0050] Compared with Comparative Example 3, the catalytic activity of the catalyst system increased by 25.3%.

[0051] Example 4

[0052] Same as Example 1, except that the addition amount of AQ was changed to 24 mmol, and 69.89 g of dry rubber was obtained.

[0053] The catalytic activity of the catalyst in this example was calculated to be 2.33×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 120,000, the relative molecular weight distribution was 2.8, the ethylene content was 51.6%, and the propylene content was 48.4%.

[0054] Compared with Comparative Example 4, the catalytic activity of the catalyst system increased by 26.6%.

[0055] Example 5

[0056] Same as Example 1, except that the vanadium-based main catalyst and the activator are changed. 0.3 mmol of the vanadium-based main catalyst diethoxyoxovanadium chloride VO(OEt)2Cl (abbreviated as VY) is added, and 1.5 mmol of the activator ethyl 2,2-difluoro-2-(3-chlorophenyl)acetate (DFCPAE) is added. 63.57 g of dry gum is obtained.

[0057] It is calculated that the catalyst activity in this example is 2.12×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry gum is about 160,000, the relative molecular weight distribution is 2.7, the ethylene content is 53.8%, and the propylene content is 46.2%.

[0058] Compared with Comparative Example 5, the catalytic activity of the catalyst system is increased by 31.7%.

[0059] Example 6

[0060] Same as Example 3, except that the alkylaluminum halide cocatalyst and the activator are changed. 18 mmol of diethylaluminum chloride (DEAC) is added, and 1.5 mmol of the activator β-chloroethyl 2-chlorophenylacetate (CPCAE) is added. 65.68 g of dry gum is obtained.

[0061] It is calculated that the catalyst activity in this example is 2.19×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry gum is about 150,000, the relative molecular weight distribution is 2.8, the ethylene content is 53.9%, and the propylene content is 46.1%.

[0062] Compared with Comparative Example 6, the catalytic activity of the catalyst system is increased by 23.0%.

[0063] Comparative Example 1

[0064] Same as Example 1, except that the activator is replaced with ethyl trichloroacetate (ETCA), 31.62 g of dry gum is obtained, and it is calculated that the catalyst activity in this example is 1.05×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry gum is about 140,000, the relative molecular weight distribution is 2.9, the ethylene content is 55.9%, and the propylene content is 44.1%.

[0065] Comparative Example 2

[0066] Same as Example 2, except that the activator was replaced with ethyl trichloroacetate (ETCA), 58.52 g of dry rubber was obtained, and the catalyst activity in this example was calculated to be 1.95×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 120,000, the relative molecular weight distribution was 2.7, the ethylene content was 53.6%, and the propylene content was 46.4%.

[0067] Comparative Example 3

[0068] Same as Example 3, except that the activator was replaced with ethyl trichloroacetate (ETCA), 56.86 g of dry rubber was obtained, and the catalyst activity in this example was calculated to be 1.90×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 140,000, the relative molecular weight distribution was 2.8, the ethylene content was 50.6%, and the propylene content was 49.4%.

[0069] Comparative Example 4

[0070] Same as Example 4, except that the activator was replaced with ethyl trichloroacetate (ETCA), 55.25 g of dry rubber was obtained, and the catalyst activity in this example was calculated to be 1.84×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 130,000, the relative molecular weight distribution was 2.8, the ethylene content was 51.6%, and the propylene content was 48.4%.

[0071] Comparative Example 5

[0072] Same as Example 5, except that the activator was replaced with ethyl trichloroacetate (ETCA), 48.34 g of dry rubber was obtained, and the catalyst activity in this example was calculated to be 1.61×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 130,000, the relative molecular weight distribution was 2.7, the ethylene content was 53.8%, and the propylene content was 46.2%.

[0073] Comparative Example 6

[0074] Same as Example 6, except that the activator was replaced with ethyl trichloroacetate (ETCA), 53.38 g of dry rubber was obtained, and the catalyst activity in this example was calculated to be 1.78×10 5 g polymer.(mol -1of V). The weight-average relative molecular weight of the obtained dry rubber is about 130,000, the relative molecular weight distribution is 2.9, the ethylene content is 53.1%, and the propylene content is 46.9%.

[0075] The relevant parameters such as the yield, catalytic activity, weight-average molecular weight, molecular weight distribution, ethylene content, and propylene content in Examples 1-6 and Comparative Examples 1-6 are shown in Table 1.

[0076] Table 1

[0077]

[0078]

[0079] Example 7

[0080] The polymerization reaction was carried out in a 2 L stainless steel jacketed polymerization kettle. First, the polymerization kettle was treated under anhydrous and anaerobic conditions for 1 hour. Secondly, 1 L of dry hexane (water content ≤ 10 ppm) was added thereto. Then, a raw material gas prepared according to a molar ratio of ethylene, propylene, and hydrogen of 1:4.5:0.015 was introduced. Next, 0.3 mmol of a vanadium-based main catalyst vanadyl dichloroethoxide (VO(OEt)Cl2, VX), 6 mmol of a co-catalyst sesquiethylaluminum chloride (AQ), and 1.5 mmol of an activator ethyl 2-fluoro-2-(3,4-dibromophenyl)acetate (FDBPAE) were added. Finally, 35 mL of ENB was added. The polymerization reaction was carried out at room temperature. During the reaction process, the polymerization reaction pressure was controlled to be constant at 0.5 MPa through the raw material gas addition valve. The polymerization reaction time was 30 minutes. After the polymerization was completed, the glue solution was discharged from the bottom pipe of the polymerization kettle. After termination with ethanol, the ethylene-propylene terpolymer was precipitated with a large amount of ethanol. The precipitated ethylene-propylene terpolymer was dried in a vacuum oven to obtain 65.87 g of dry rubber.

[0081] It was calculated that the catalytic activity of the catalyst in this example was 2.20×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber is about 320,000, the relative molecular weight distribution is 4.7, the ethylene content is 38.0%, the propylene content is 54.9%, and the ENB content is 7.1%.

[0082] Compared with Comparative Example 7, the catalytic activity of the catalyst system was increased by 21.5%.

[0083] Example 8

[0084] Same as Example 7, the difference is that the addition amount of AQ was changed to 12 mmol, and 68.71 g of dry rubber was obtained.

[0085] It was calculated that the catalytic activity of the catalyst in this example was 2.29×105 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber is about 370,000, the relative molecular weight distribution is 4.1, the ethylene content is 35.6%, the propylene content is 57.4%, and the ENB content is 7.0%.

[0086] Compared with Comparative Example 8, the catalytic activity of the catalyst system is increased by 44.9%.

[0087] Example 9

[0088] Same as Example 7, except that the addition amount of AQ is changed to 18 mmol, and 64.02 g of dry rubber is obtained.

[0089] It is calculated that the catalyst activity in this example is 2.13×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber is about 370,000, the relative molecular weight distribution is 4.6, the ethylene content is 45.7%, the propylene content is 46.7%, and the ENB content is 7.6%.

[0090] Compared with Comparative Example 9, the catalytic activity of the catalyst system is increased by 43.0%.

[0091] Example 10

[0092] Same as Example 7, except that the addition amount of AQ is changed to 24 mmol, and 56.23 g of dry rubber is obtained.

[0093] It is calculated that the catalyst activity in this example is 1.87×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber is about 360,000, the relative molecular weight distribution is 4.2, the ethylene content is 51.7%, the propylene content is 39.4%, and the ENB content is 8.9%.

[0094] Compared with Comparative Example 10, the catalytic activity of the catalyst system is increased by 46.1%.

[0095] Example 11

[0096] Same as Example 7, except that the vanadium-based main catalyst and the activator are changed. 0.3 mmol of vanadium-based main catalyst diethoxyoxovanadium chloride VO(OEt)2Cl (abbreviation: VY) is added, and 1.5 mmol of activator ethyl 2,2-difluoro-2-(3-chlorophenyl)acetate (DFCPAE) is added. 61.11 g of dry rubber is obtained.

[0097] It is calculated that the catalyst activity in this example is 2.04×105 g polymer.(mol -1 of V). The weight-average relative molecular weight of the resulting dry rubber is about 360,000, the relative molecular weight distribution is 5.1, the ethylene content is 52.6%, the propylene content is 38.6%, and the ENB content is 8.8%.

[0098] Compared with Comparative Example 11, the catalytic activity of the catalyst system increased by 30.8%.

[0099] Example 12

[0100] Same as Example 9, except that the alkyl aluminum halide cocatalyst and the activator were changed. 18 mmol of diethylaluminum chloride (DEAC) was added, and 1.5 mmol of the activator ethyl 2-chloro-2-(2-bromophenyl)acetate (CBPAE) was added to obtain 52.55 g of dry rubber.

[0101] The catalytic activity of the catalyst in this example was calculated to be 1.75×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the resulting dry rubber is about 350,000, the relative molecular weight distribution is 5.4, the ethylene content is 53.9%, the propylene content is 37.4%, and the ENB content is 8.7%.

[0102] Compared with Comparative Example 12, the catalytic activity of the catalyst system increased by 36.7%.

[0103] Comparative Example 7

[0104] Same as Example 7, except that the activator was replaced with ethyl trichloroacetate (ETCA) to obtain 54.35 g of dry rubber. The catalytic activity of the catalyst in this example was calculated to be 1.81×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the resulting dry rubber is about 340,000, the relative molecular weight distribution is 5.1, the ethylene content is 51.9%, the propylene content is 40.7%, and the ENB content is 7.4%.

[0105] Comparative Example 8

[0106] Same as Example 8, except that the activator was replaced with ethyl trichloroacetate (ETCA) to obtain 47.52 g of dry rubber. The catalytic activity of the catalyst in this example was calculated to be 1.58×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the resulting dry rubber is about 360,000, the relative molecular weight distribution is 5.4, the ethylene content is 48.8%, the propylene content is 43%, and the ENB content is 8.2%.

[0107] Comparative Example 9

[0108] Same as Example 9, except that the activator was replaced with ethyl trichloroacetate (ETCA), and 44.61 g of dry rubber was obtained. The catalyst activity in this example was calculated to be 1.49×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 360,000, the relative molecular weight distribution was 5.2, the ethylene content was 50.6%, the propylene content was 39.8%, and the ENB content was 9.6%.

[0109] Comparative Example 10

[0110] Same as Example 10, except that the activator was replaced with ethyl trichloroacetate (ETCA), and 20.07 g of dry rubber was obtained. The catalyst activity in this example was calculated to be 0.67×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 350,000, the relative molecular weight distribution was 5.1, the ethylene content was 53.1%, the propylene content was 36.3%, and the ENB content was 10.6%.

[0111] Comparative Example 11

[0112] Same as Example 11, except that the activator was replaced with ethyl trichloroacetate (ETCA), and 19.76 g of dry rubber was obtained. The catalyst activity in this example was calculated to be 0.66×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 420,000, the relative molecular weight distribution was 4.8, the ethylene content was 54.1%, the propylene content was 35.7%, and the ENB content was 10.2%.

[0113] Comparative Example 12

[0114] Same as Example 12, except that the activator was replaced with ethyl trichloroacetate (ETCA), and 51.32 g of dry rubber was obtained. The catalyst activity in this example was calculated to be 1.71×10 5 g polymer.(mol -1 of V). The weight-average relative molecular weight of the obtained dry rubber was about 360,000, the relative molecular weight distribution was 5.2, the ethylene content was 53.1%, the propylene content was 37.6%, and the ENB content was 9.3%.

[0115] The relevant parameters such as production, catalytic activity, weight-average molecular weight, molecular weight distribution, ethylene content, and propylene content in Examples 7-12 and Comparative Examples 7-12 are shown in Table 2.

[0116] Table 2

[0117]

[0118]

[0119] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A novel vanadium-based catalytic system containing an activator, characterized in that, The activator is ethyl halophenylacetate with at least two halogen atoms substituted, wherein at least one halogen atom is substituted at the phenyl position or the benzyl position.

2. The vanadium-based catalyst system according to claim 1, characterized in that, The activator is selected from at least one of ethyl 2,4-dichlorophenylacetate, ethyl 3,4-dichlorophenylacetate, ethyl 2,3-difluorophenylacetate, ethyl 2,6-difluorophenylacetate, ethyl 3-fluoro-4-chlorophenylacetate, ethyl 2-fluoro-2-(2-fluorophenyl)acetate, ethyl 2-fluoro-2-(2-chlorophenyl)acetate, ethyl 2-fluoro-2-(2-bromophenyl)acetate, ethyl 2-chloro-2-(2-fluorophenyl)acetate, ethyl 2-chloro-2-(2-chlorophenyl)acetate, ethyl 2-chloro-2-(2-bromophenyl)acetate, ethyl 2-chloro-2-(4-chlorophenyl)acetate, ethyl 2-fluoro-2-(3,4-dibromophenyl)acetate, ethyl 2,2-difluoro-2-(3-chlorophenyl)acetate, β-chloroethyl 2-chlorophenylacetate, β-chloroethyl 2-fluorophenylacetate, β-chloroethyl 2-chloro-2-(2-chlorophenyl)acetate.

3. The vanadium-based catalyst system according to claim 1, characterized in that, The vanadium-based catalyst system further includes a vanadium-based main catalyst; the general formula of the vanadium-based main catalyst is VO(OR)nClm, wherein the valence state of vanadium is +5, OR is an alkoxy group, n is 1, 2, or 3, m is 0, 1, or 2, and m + n = 3.

4. The vanadium-based catalyst system according to claim 3, wherein The alkoxy group in the structure of the vanadium-based main catalyst is at least one of methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, n-pentyloxy, n-hexyloxy, cyclohexyloxy.

5. The vanadium-based catalyst system according to claim 1, characterized in that, The vanadium-based catalyst system further includes a cocatalyst; the cocatalyst is an organoaluminum compound.

6. The vanadium-based catalyst system according to claim 5, wherein, The molar ratio of aluminum atoms in the cocatalyst to vanadium in the vanadium-based main catalyst is (1 - 100):1; the molar ratio of the activator to vanadium in the vanadium-based main catalyst is (5 - 80):

1.

7. A process for olefin polymerization, characterized in that, Ethylene, propylene, and a molecular weight regulator are subjected to copolymerization under the vanadium-based catalyst system described in claim 1; or, ethylene, propylene, a diene, and a molecular weight regulator are subjected to copolymerization under the vanadium-based catalyst system described in claim 1.

8. The method according to claim 7, wherein The molecular weight regulator is hydrogen.

9. The method according to claim 7, wherein The diene is one of ethylidene norbornene, dicyclopentadiene, and 1,4-hexadiene.

10. The method according to claim 7, wherein The copolymerization temperature is 0 - 75 °C; the copolymerization time is 10 - 180 min; the copolymerization pressure is 0.1 - 1.0 MPa.

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