Preparation method of vanadium catalyst composition for ethylene propylene rubber
By using chlorovanadium compounds and dialkyl magnesium compounds to form a new vanadium catalyst composition during the polymerization process, the problem of complex preparation of traditional supported catalysts was solved, and efficient EPDM copolymerization reaction and improved catalyst stability were achieved.
Patent Information
- Application Number
- CN202510656908.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-21
- Publication Date
- 2025-09-19
AI Technical Summary
The preparation process of traditional supported catalysts is complicated, not suitable for existing industrial production equipment, and has low practicality.
A novel vanadium catalyst composition is formed by using a chlorovanadium compound and a dialkyl magnesium compound in a polymerization process, and an in-situ polymerization reaction is performed to improve the electron cloud density of the active center of the vanadium catalyst.
The copolymerization activity and propylene insertion rate are improved, the stability of the vanadium catalyst is enhanced, the preparation process is simplified, and the catalyst is suitable for existing industrial production equipment.
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Figure CN120665223A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of catalysts, and in particular to a method for preparing a vanadium catalyst composition for ethylene propylene rubber. Background Art
[0002] Ethylene propylene diene monomer (EPDM) rubber is a copolymer rubber based on ethylene and propylene. It can be specifically divided into EPDM (ethylene propylene diene monomer) and EPDM (ethylene propylene diene monomer) rubber. Compared to other rubber types, EPDM rubber offers the following advantages: 1. It contains no double bonds in its main chain, is fully saturated, and is resistant to ozone, aging, chemicals, and high temperatures; 2. It has a low specific gravity; 3. It has excellent insulating properties; and 4. It can be highly oil-filled. EPDM rubber is one of the most promising rubber types. Since its commercial production, its application areas have continued to expand, and it is widely used in automotive parts, building materials, wire and cable, heat-resistant hoses, advanced sealing materials, lubricant additives, and polyolefin modification.
[0003] The production of EPDM rubber (EPDM) both domestically and internationally mostly uses vanadium compounds as the main catalyst, with organoaluminum compounds and activating promoters as co-catalysts. Supported catalysts were first developed by the Belgian company Solvay in the late 1960s. The use of supported Ziegler-Natta catalysts in EPDM copolymerization is an extension and development of the application of supported polyolefin catalysts in synthetic rubber. (Liu Dahua, Handbook of Synthetic Rubber Industry (First Edition) [M]. Beijing: Chemical Industry Press, 1991, pp. 581-631.) As a highly efficient support for Ziegler-Natta catalysts, the use of MgCl₂ can improve catalytic activity by several orders of magnitude compared to traditional vanadium catalysts. This is due to three factors. First, MgCl₂, prepared using a specific method, has a large specific surface area, allowing the main catalyst to be well dispersed on its surface, even to the point of monomolecular dispersion. All vanadium supported on the support surface is potentially active, significantly increasing the number of active sites, thereby reducing the amount of transition metal required and increasing its utilization. Second, the main catalyst adsorbed on the MgCl₂ surface is reduced by alkyl aluminum, and through chloride bridge interactions, the active sites are firmly complexed with the MgCl₂, resulting in excellent stability. Third, the presence of MgCl2 changes the electronic properties of active vanadium, increasing the growth rate of the polymerization chain. The electropositive magnesium atom is connected to the vanadium atom through a dichloro bridge, which can improve the polarity of the VC bond in the chain growth center, thereby accelerating the insertion rate of the monomer. Therefore, it can be considered that MgCl2 not only acts as a carrier in the catalyst, but also as an effective component of the catalyst to participate in the composition and polymerization reaction of the active center (Li Sanxi. "Ethylene / α-olefin copolymerization of chemically efficient carrier titanium catalyst" Petrochemical Engineering, 30 (4), 2001; Huang Baotong, Shen Zhiquan et al. Progress in olefin and diene coordination polymerization [M], Beijing: Science Press, 1998, 25-26, 1-27.). The supported catalyst is composed of a main catalyst supported on a solid inorganic compound or an organic polymer compound to form a carrier complex, which is then mixed with alkyl aluminum. The main methods used are impregnation and grinding. The preparation process is complicated, and the polymerization method mostly adopts gas phase polymerization. It is not suitable for the solution polymerization device currently used in domestic ethylene propylene rubber production and has low practicality. Summary of the Invention
[0004] The present invention provides a method for preparing a vanadium catalyst composition for ethylene propylene rubber. The method comprises forming a new vanadium catalyst composition from a chlorovanadium compound and a dialkyl magnesium compound during a polymerization process, and carrying out an in-situ polymerization reaction, thereby improving the electron cloud density of the active center of the vanadium catalyst, and enhancing the copolymerization activity and the insertion rate of the comonomer propylene. The method overcomes the shortcomings of a traditional supported catalyst, such as a complex preparation process, unsuitability for existing industrial production equipment, and low practicality.
[0005] In order to achieve the above object, the technical solution of the present invention is: a method for preparing a vanadium catalyst composition for EPDM, which is produced by polymerization reaction of a chlorovanadium compound and a dialkyl magnesium compound.
[0006] Furthermore, the preparation method comprises the following steps:
[0007] (1) adding a vanadium chloride compound into a polymerization reactor;
[0008] (2) Adding an alkane solution containing a dialkyl magnesium compound into a polymerization kettle, mixing the mixture uniformly to carry out a polymerization reaction, and obtaining a vanadium catalyst composition after the reaction.
[0009] Furthermore, the chlorovanadium compound is selected from VOCl3, VCl4, VCl3 or VO(OR)Cl2, wherein R is an alkyl group containing 4-8 carbon atoms.
[0010] Furthermore, the structural formula of the dialkyl magnesium compound is RMgR', wherein R, R' are the same or different alkyl groups containing 4-8 carbon atoms; the alkane is selected from one or more mixtures of C6-C8 alkanes and cycloalkanes.
[0011] Furthermore, the ratio of the molar number of vanadium in the chlorovanadium compound to the molar number of the dialkylmagnesium compound is 1:(1 to 100).
[0012] Furthermore, in the step (1), the polymerization reaction temperature is 20 to 70° C., and the reaction time is 1 to 60 min.
[0013] Furthermore, the dialkyl magnesium compound is selected from one of dibutyl magnesium, dihexyl magnesium, butylhexyl magnesium or butyloctyl magnesium, and the alkane is selected from one of n-hexane, cyclohexane, n-heptane or hydrogenated gasoline.
[0014] Furthermore, the molar concentration of the dialkyl magnesium compound in the alkane solution containing the dialkyl magnesium compound is 0.1 to 1.0 mol / L.
[0015] The technical solution of the present invention is to use the vanadium catalyst composition prepared by the preparation method in the preparation of EPDM rubber or EPDM rubber.
[0016] The beneficial effects of the present invention are as follows: the present invention directly reacts a chlorovanadium compound and a dialkylmagnesium compound in a polymerization reactor to generate a vanadium catalyst composition. The vanadium catalyst composition is reduced by alkylaluminum and interacts with the dialkylmagnesium via a chloro bridge, thereby reducing the electron cloud density of the vanadium metal active center and enhancing the stability of the vanadium catalyst. Compared with the traditional Ziegler-Natta supported vanadium catalyst, the complex metal active center loading process is avoided. At the same time, the dialkylmagnesium can directly interact with the vanadium metal active center during the copolymerization of ethylene and propylene, thereby improving the polarity of the VC bond of the chain growth center, accelerating the insertion rate of the monomer, and enhancing the reaction activity. In addition, the dialkylmagnesium also serves as an effective component of the vanadium catalyst system, enhancing the ability of ethylene and propylene to randomly copolymerize. Under the same polymerization conditions, the propylene insertion rate is high, and the formation of gel in the EPDM rubber during the polymerization process can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 1 is the GPC spectrum of ethylene propylene rubber obtained in Example 1, Example 8 and Comparative Example 2 of the present invention;
[0018] Figure 2 It is the infrared spectra of ethylene propylene rubber obtained in Example 8 of the present invention and Comparative Example 2. DETAILED DESCRIPTION
[0019] In order to further understand the present invention, the preparation method and application of the polymer supported vanadium catalyst provided by the present invention are described below with reference to the examples. The protection scope of the present invention is not limited by the following examples.
[0020] Unless otherwise specified, all raw materials involved in the present invention were purchased from the market.
[0021] Example 1
[0022] A method for preparing a vanadium catalyst composition for EPDM comprises the following steps: adding 100 mL of hexane to a 0.5 L polymerization kettle after nitrogen displacement, starting stirring, injecting 1 mL of a n-hexane solution containing 0.1 mol / L dibutyl magnesium, extracting 0.1 mL of a hexane solution containing 0.1 mmol VOCl3, setting the reaction temperature at 20°C and the reaction time for 1 minute, and obtaining a suspension solution, i.e., the vanadium catalyst composition, after completion of the reaction.
[0023] To the above suspension, 4.0 mmol of triethylaluminum trichloride (Al2(C2H5)3Cl3), 0.6 mmol of ethyl trichloroacetate (ETCA), and 200 mL of hexane were added. A mixed gas of ethylene and propylene in a molar ratio of 1:2 was introduced, and the polymerization pressure was controlled at 0.4 MPa with stirring. The reaction was carried out at 20°C for 30 minutes. After the polymerization was completed, 5 mL of a 5% by mass hydrochloric acid-ethanol solution was added to the polymer product, which was then washed with ethanol and dried under vacuum to obtain EPDM rubber. Specific test data are shown in Table 1.
[0024] Example 2
[0025] A method for preparing a vanadium catalyst composition for EPDM comprises the following steps: adding 100 mL of hexane to a 0.5 L polymerization kettle after nitrogen replacement, starting stirring, injecting 5 mL of an n-heptane solution containing 0.1 mol / L of dibutyl magnesium, extracting 0.1 mL of a hexane solution containing 0.1 mmol of VOCl3, setting the reaction temperature at 30°C and the reaction time for 2 minutes, and obtaining a suspension solution, i.e., the vanadium catalyst composition, after completion of the reaction.
[0026] To the above suspension, 2.0 mmol of triethylaluminum trichloride (Al2(C2H5)3Cl3), 0.5 mmol of ethyl trichloroacetate (ETCA), and 200 mL of hexane were added. A mixture of ethylene and propylene in a molar ratio of 1:2 was introduced, and the polymerization pressure was controlled at 0.4 MPa with stirring. The reaction was carried out at 30°C for 30 minutes. After the polymerization was completed, 5 mL of a 5% by mass hydrochloric acid-ethanol solution was added to the polymer product, which was then washed with ethanol and dried under vacuum to obtain EPDM rubber. Specific test data are shown in Table 1.
[0027] Example 3
[0028] A method for preparing a vanadium catalyst composition for EPDM comprises the following steps: adding 100 mL of hexane to a 0.5 L polymerization kettle after nitrogen replacement, starting stirring, injecting 1 mL of a hexane solution containing 1.0 mol / L of butyloctyl magnesium, extracting 0.1 mL of a hexane solution containing 0.1 mmol of VOCl3, setting the reaction temperature to 40°C and the reaction time to 10 minutes, and obtaining a suspension solution, namely the vanadium catalyst composition, after the reaction is completed.
[0029] To the above suspension, 3.0 mmol of triethylaluminum trichloride (Al2(C2H5)3Cl3), 0.8 mmol of ethyl trichloroacetate (ETCA), and 200 mL of hexane were added. A mixture of ethylene and propylene in a molar ratio of 1:2 was introduced, and the polymerization pressure was maintained at 0.4 MPa with stirring. The reaction was carried out at 40°C for 30 minutes. After the polymerization was completed, 5 mL of a 5% by mass hydrochloric acid-ethanol solution was added to the polymer product, which was then washed with ethanol and dried under vacuum to obtain EPDM rubber. Specific test data are shown in Table 1.
[0030] Examples 4 to 6
[0031] A method for preparing a vanadium catalyst composition for EPDM comprises the following steps: adding 100 mL of hexane to a 0.5 L polymerization kettle after nitrogen replacement, starting stirring, injecting 6 mL of a cyclohexane solution containing 0.5 mol / L of dihexylmagnesium, extracting 0.1 mL of a hexane solution containing 0.1 mmol of a vanadium complex, setting the reaction temperature to 60° C. and the reaction time to 30 minutes. After completion of the reaction, a suspension solution, namely the vanadium catalyst composition, is obtained.
[0032] To the above suspension, 4.0 mmol of triethylaluminum trichloride (Al2(C2H5)3Cl3), 0.6 mmol of ethyl trichloroacetate (ETCA), and 300 mL of hexane were added. A mixed gas of ethylene and propylene in a molar ratio of 1:2 was introduced, and the polymerization pressure was controlled at 0.4 MPa with stirring. The reaction was carried out at 60°C for 30 minutes. After the polymerization was completed, 5 mL of a 5% by mass hydrochloric acid-ethanol solution was added to the polymer product, which was then washed with ethanol and dried under vacuum to obtain EPDM rubber. Specific test data are shown in Table 1.
[0033] The vanadium complexes used in Examples 4 to 6 are: fatty alcohol vanadium complex VOCl3·3NOOH (NOOH is the abbreviation of n-octanol compound), amine vanadium complex VOCl3·TOA (TOA is the abbreviation of trioctylamine), and phosphate vanadium complex VOCl3·3TBP (TBP is the abbreviation of tributyl phosphate) as VOCl3 electron donor complex compounds.
[0034] Example 7
[0035] A method for preparing a vanadium catalyst composition for EPDM comprises the following steps: adding 100 mL of hexane to a 0.5 L polymerization kettle after nitrogen displacement, starting stirring, injecting 60 mL of a hexane solution containing 0.1 mol / L of butylhexylmagnesium, extracting 0.1 mL of a hexane solution containing 0.1 mmol of VOCl3, setting the reaction temperature to 70°C and the reaction time to 60 minutes, and obtaining a suspension solution, namely the vanadium catalyst composition, after completion of the reaction.
[0036] To the above suspension, 4.0 mmol of triethylaluminum trichloride (Al2(C2H5)3Cl3), 0.6 mmol of ethyl trichloroacetate (ETCA), and 200 mL of hexane were added. A mixture of ethylene and propylene in a molar ratio of 1:2 was introduced, and the polymerization pressure was maintained at 0.4 MPa with stirring. The reaction was carried out at 60°C for 30 minutes. After the polymerization was completed, 5 mL of a 5% by mass hydrochloric acid-ethanol solution was added to the polymer product, which was then washed with ethanol and dried under vacuum to obtain EPDM rubber. Specific test data are shown in Table 1.
[0037] Comparative Example 1
[0038] Install the polymerization reactor, keep it airtight, and replace the nitrogen atmosphere. Add 0.1 mmol of VOCl3 catalyst, 4.0 mmol of triethylaluminum trichloride (Al2(C2H5)3Cl3), 0.6 mmol of ethyl trichloroacetate (ETCA), and 300 mL of hexane in that order. A mixture of ethylene and propylene in a molar ratio of 1:2 was introduced, and the polymerization pressure was maintained at 0.4 MPa. Stir and react at 20°C for 30 minutes. After the polymerization is complete, add 5 mL of a 5% by mass hydrochloric acid-ethanol solution to the polymer product, wash with ethanol, and then dry under vacuum to obtain EPDM rubber. Specific test data are shown in Table 1.
[0039] The glass transition temperature of the obtained polymer was analyzed by differential scanning calorimetry (DSC); 13 The bound propylene content (C3 wt %) of the obtained polymer was analyzed by C-NMR spectroscopy; the number average molecular weight and molecular weight distribution of the obtained polymer were analyzed by GPC.
[0040] Table 1 Comparison of polymer properties obtained using different vanadium catalysts in Examples 1 to 7 and Comparative Example 1
[0041]
[0042]
[0043] Example 8
[0044] A method for preparing a vanadium catalyst composition for ethylene propylene rubber: the preparation method is the same as that in Example 2, and a suspension solution of the vanadium catalyst composition is obtained.
[0045] To the above suspension solution, 4.0 mmol of diethylaluminum monochloride (Al(C2H5)2Cl), 0.5 mmol of ethyl trichloroacetate (ETCA), 2 mL of ENB, and 300 mL of hexane were added; a mixed gas of ethylene and propylene with a molar ratio of 1:2 was introduced, the polymerization pressure was controlled at 0.4 MPa, and the mixture was stirred and reacted at 20°C for 30 minutes. After the polymerization was completed, 5 mL of a 5% by mass hydrochloric acid-ethanol solution was added to the polymer product, and the product was washed with ethanol and then dried under vacuum to obtain EPDM rubber. Specific test data are shown in Table 2, and the infrared spectrum is shown in Figure 2. Figure 2 shown.
[0046] Comparative Example 2
[0047] Install the reactor used for polymerization, keep it airtight, and replace the nitrogen. Add 0.1mmol VOCl3, 4.0mmol diethylaluminum monochloride (Al(C2H5)2Cl), 0.5mmol ethyl trichloroacetate (ETCA), 2mL ENB, and 300mL hexane in sequence. Pass a mixed gas with a molar ratio of ethylene to propylene of 1:2, control the polymerization pressure at 0.4MPa, stir, and react at 20°C for 30min. After the polymerization is completed, add 5ml of a 5% by weight hydrochloric acid-ethanol solution to the polymer product, wash with ethanol, and then dry under vacuum to obtain EPDM rubber. Specific test data are shown in Table 2, and the infrared spectrum is shown in Figure 2. Figure 2 As shown by Figure 2 It can be seen that compared with Comparative Example 2, the double bond binding rate of the EPDM rubber prepared in Example 8 is higher.
[0048] Table 2 Comparison of polymer properties obtained using different vanadium catalysts in Example 8 and Comparative Example 2
[0049]
[0050] Test method for xylene insoluble matter content: dissolve EPDM rubber (0.1 g / 30 mL) in xylene at 125°C, filter the insoluble matter, dry it, and weigh it to calculate its mass percentage in the sample.
[0051] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.
Claims
1. A method for preparing a vanadium catalyst composition for EPDM, characterized in that: It is produced by the polymerization reaction of vanadium chloride compounds and dialkyl magnesium compounds.
2. The preparation method according to claim 1, characterized in that The following steps are involved: (1) adding a vanadium chloride compound into a polymerization reactor; (2) Adding an alkane solution containing a dialkyl magnesium compound into a polymerization kettle, mixing the mixture uniformly to carry out a polymerization reaction, and obtaining a vanadium catalyst composition after the reaction.
3. The preparation method according to claim 2, wherein: The chlorovanadium compound is selected from VOCl3, VCl4, VCl3 or VO(OR)Cl2, wherein R is an alkyl group containing 4 to 8 carbon atoms.
4. The preparation method according to claim 2, wherein: The structural formula of the dialkyl magnesium compound is RMgR', wherein R and R' are the same or different alkyl groups containing 4 to 8 carbon atoms; the alkane is selected from one or a mixture of C6 to C8 alkanes and cycloalkanes.
5. The preparation method according to claim 2, wherein: The ratio of the mole number of vanadium in the chlorovanadium compound to the mole number of the dialkyl magnesium compound is 1:(1-100).
6. The preparation method according to claim 2, wherein: In the step (1), the polymerization reaction temperature is 20-70° C., and the reaction time is 1-60 min.
7. The preparation method according to claim 2, characterized in that: The dialkyl magnesium compound is selected from one of dibutyl magnesium, dihexyl magnesium, butylhexyl magnesium or butyloctyl magnesium, and the alkane is selected from one of n-hexane, cyclohexane, n-heptane or hydrogenated gasoline.
8. The preparation method according to claim 2, wherein: The molar concentration of the dialkyl magnesium compound in the alkane solution containing the dialkyl magnesium compound is 0.1 to 1.0 mol / L.
9. Use of the vanadium catalyst composition prepared by the preparation method according to any one of claims 1 to 7 in the preparation of EPDM rubber or EPDM rubber.