Catalyst carrier for olefin polymerization and preparation method thereof

Abstract

The invention discloses a catalyst carrier for olefin polymerization, which is obtained by contact reaction of metal magnesium powder, mixed alcohol, an initiator and an aluminum-containing compound, and the molar ratio of the mixed alcohol to the metal magnesium powder is 2-40; the molar ratio of the initiator to the metal magnesium powder is 0.001-2, and the molar ratio of the aluminum-containing compound to the metal magnesium powder is 0.01-0.1; in percentage by weight, the content of halogenated alkoxy in the catalyst carrier for olefin polymerization is 0.5-30%, and the content of aluminum element is 0.001-10%. The invention also discloses a preparation method of the catalyst carrier for olefin polymerization. The catalyst carrier for olefin polymerization provided by the invention has excellent form and larger specific surface area, and the internal structure of generated alkoxy magnesium particles is more compact, so that the formed carrier particles are not easy to break, the bulk density of a polymer is improved, and the requirement of high activity of a catalyst loaded by the alkoxy magnesium carrier is met.

Description

Technical Field

[0001] This invention belongs to the field of catalyst support technology, and relates to catalyst supports for olefin polymerization. This invention also relates to a method for preparing the above-mentioned catalyst supports for olefin polymerization. Background Technology As is well known, with the development of the economy, the demand for polyolefin materials is increasing. Highly efficient polyolefin catalysts for producing polyolefin materials are widely used in the field of polyolefin catalysts due to their well-controllable particle morphology and microstructure. Ziegler-Natta catalysts used in the polyolefin industry are most commonly prepared with MgCl2 as the support. These mainly include MgCl2-supported catalysts prepared using MgCl2 as the magnesium source and alkoxymagnesium-supported catalysts, which are synthesized in situ using alkoxymagnesium as the magnesium source via chemical conversion to form MgCl2. Among these, alkoxymagnesium-supported catalysts are favored in the polyolefin industry due to their high activity, good hydrogen sensitivity, excellent particle morphology, and superior copolymerization performance.

[0002] Many patent documents use magnesium alkoxy as a support for high-performance catalysts. Catalysts prepared with magnesium alkoxy support exhibit significantly higher activity, good hydrogen sensitivity, and excellent copolymerization properties. In recent years, various methods for preparing magnesium alkoxy have been reported in published technical literature, mainly falling into the following categories: One method, as disclosed in Japanese Patent Application Publication Nos. 03-74341 and 04-368391, involves reacting metallic magnesium with alcohol in the presence of iodine to obtain spherical or ellipsoidal magnesium diethoxy. However, this method is difficult to control at a suitable reaction rate, inevitably resulting in unevenly distributed large particles or fine powder, and generally low bulk density. Another method, as disclosed in Japanese Patent Application Publication Nos. 6-8733, involves spray drying a magnesium diethoxy alcohol solution to prepare spherical particles, followed by decarboxylation treatment. This process is cumbersome and expensive, and the resulting product is difficult to completely decarboxylate, making it difficult to meet downstream application quality requirements. Finally, another method involves reacting metallic magnesium with alcohol to obtain magnesium alkoxy, followed by mechanical grinding to control particle size. This also results in uneven particle size, severely affecting usability.

[0003] There is a significant replication phenomenon among the morphologies of the support, catalyst, and polypropylene particles. The performance of the support directly determines the performance of polypropylene; therefore, it is essential to prepare alkoxymagnesium supports with uniform morphology and excellent performance. The specific surface area and pore volume of the support are important physical properties affecting the performance of supported catalysts. Catalyst activity is related to specific surface area and pore volume. Catalysts prepared from alkoxymagnesium supports exhibit a honeycomb structure with abundant porosity and a large specific surface area, which helps to improve catalyst activity.

[0004] Currently, alkoxymagnesium is usually prepared by reacting alcohols and magnesium powder in the presence of an initiator. Ethanol is generally used as the alcohol, and halogen-containing substances are typically chosen as initiators, with elemental iodine and carbon tetrachloride compounds being the most common. In order to obtain alkoxy magnesium carriers with better performance, researchers have conducted extensive research on the direct synthesis of magnesium alcohol compounds. Patents such as US5556820, US005965478A, US2001012908, WO2005044873, WO2009084799, US2009181845, and US2009186755 mainly focus on three aspects: (1) the influence of the physical properties of each reactant on the properties of the product, such as the morphology of metallic magnesium, flake, sphere or ribbon; the type and water content of alcohol; the type of initiator, elemental iodine, carbon tetrachloride, mercuric chloride and other novel initiators; (2) the influence of the amount of reactants on the performance of the product, such as the halogen-magnesium ratio, the alcohol-magnesium ratio, etc.; (3) the influence of process parameters on the performance of the product, such as reaction temperature, reaction time, feeding method, feeding sequence and feeding time, etc.

[0005] Existing technologies reveal that when only magnesium, alcohol, and initiator participate in the reaction, the resulting alkoxymagnesium flakes are large and loosely packed, making the formed support particles prone to breakage and resulting in a low bulk density. Based on existing technologies, the internal pore structure of the support particles needs improvement to meet the high activity requirements of catalysts supported on alkoxymagnesium. Therefore, there is still room for technological improvement in the production process of alkoxymagnesium particles. Summary of the Invention

[0006] The first objective of this invention is to provide a catalyst support for olefin polymerization that has excellent morphology and a large specific surface area, resulting in a more compact internal structure of the generated alkoxymagnesium particles. Consequently, the formed support particles are less prone to breakage, increasing the bulk density of the polymer and achieving the requirement of high catalyst activity supported on alkoxymagnesium.

[0007] A second objective of this invention is to provide a method for preparing a catalyst support for olefin polymerization.

[0008] The technical solution adopted in this invention is a catalyst support for olefin polymerization, which is obtained by contact reaction of magnesium powder, mixed alcohol, initiator and aluminum-containing compound, wherein the molar ratio of mixed alcohol to magnesium powder is 2~40:1; the molar ratio of initiator to magnesium powder is 0.001~2:1; and the molar ratio of aluminum-containing compound to magnesium powder is 0.01~0.1:1. By weight percentage, the catalyst support used for olefin polymerization contains 0.5-30% haloalkoxy groups and 0.001-10% aluminum.

[0009] The invention is further characterized in that, Mixed alcohols include haloalcohols and other alcohols, and the water content in the mixed alcohols is less than 200 ppm; By weight percentage, the content of haloalcohols in the mixed alcohols is 0-35%, and the content of other alcohols is 65-100%. Haloalcohols are those with the general formula R 1 Compounds of OH, wherein R 1 C1~C 20 The halogenated hydrocarbon group is a straight-chain, branched-chain, or cyclic chain hydrocarbon. The halogen atom and the hydroxyl group on the halogenated alcohol are located on different saturated carbon atoms. The halogen atom is chlorine or bromine. Other alcohols are those with the general formula R. 2 Compounds of OH, in which R is a general formula 2 It is C1 to C 20 Alkyl groups that are straight-chain, branched, or cyclic.

[0010] Halogenated alcohols include 2-chloroethanol, 3-chloropropanol, 4-chlorobutanol, 5-chloropentanol, 6-chlorohexanol, 2,2-dichloroethanol, 2,3-dichloropropanol, 3,4-dichlorobutanol, 4,5-dichloropentanol, 5,6-dichlorohexanol, 2,2,2-trichloroethanol, 2,2,2-trichloropropanol, 2,2,2-trichlorobutanol, 2,2,2-trichloropentanol, 2,2,2-trichlorohexanol, 3,3,3-trichlorobutanol, 3,3,3-trichloropentanol, 3,3,3-trichlorohexanol, trichlorotert-butanol, 2-chlorocyclohexanol, and 2-bromoethanol. The following are any one or more of the following in any ratio: 3-bromopropanol, 4-bromobutanol, 5-bromopentanol, 6-bromohexanol, 2,2-dibromoethanol, 2,3-dibromopropanol, 3,4-dibromobutanol, 4,5-dibromopentanol, 5,6-dibromohexanol, 2,2,2-tribromoethanol, 2,2,2-tribromopropanol, 2,2,2-tribromobutanol, 2,2,2-tribromopentanol, 2,2,2-tribromohexanol, 3,3,3-tribromobutanol, 3,3,3-tribromopentanol, 3,3,3-tribromohexanol, tribromotert-butanol, or 2-bromocyclohexanol.

[0011] Other alcohols include any one or more of the following in any ratio: methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, isopropanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 2-nonanol, 2-decanol, 2-ethylbutanol, 2-ethylhexanol, 4-methyl-2-pentanol, 3,3,5-trimethylpentanol, or 4-methyl-3-heptanol.

[0012] The initiator is any one or two of the following: halogen elements or halogen-containing compounds, mixed in any ratio. The halogen element is chlorine, bromine, or iodine; the halogen-containing compound is a halogen-containing metal compound, specifically MgCl2, MgBr2, MgI2, Mg(OEt)Cl, Mg(OEt)I, CaCl2, CaBr2, CaI2, NaCl, or KBr. The above halogen elements or halogen-containing compounds can be used alone or in combination of two or more in any ratio.

[0013] Magnesium powder is a compound that does not form magnesium hydroxide or magnesium acid on its surface.

[0014] Aluminum-containing compounds are combinations of aluminum halides and alkyl aluminum halides in any ratio; Aluminum halides have the general formula AlX3, where X is fluorine, chlorine, bromine or iodine; Alkyl aluminum halides are dialkyl aluminum halides or monoalkyl dialkyl aluminum halides; the general formula for alkyl aluminum halides is AlR. 3 2X or AlR 3 X2, where R 3 It consists of C1 to C10 hydrocarbon groups, which are saturated straight or branched chains.

[0015] Aluminum halides include any one or more of aluminum trifluoride, aluminum trichloride, aluminum tribromide, and aluminum triiodide in any ratio; Alkyl aluminum halides include any one or more of methyl aluminum difluoride, ethyl aluminum difluoride, propyl aluminum difluoride, butyl aluminum difluoride, methyl aluminum dichloride, ethyl aluminum dichloride, propyl aluminum dichloride, butyl aluminum dichloride, pentyl aluminum dichloride, hexyl aluminum dichloride, dimethyl aluminum dichloride, diethyl aluminum dichloride, dipropyl aluminum dichloride, methyl aluminum dibromide, ethyl aluminum dibromide, propyl aluminum dibromide, butyl aluminum dibromide, methyl aluminum diiodide, ethyl aluminum diiodide, propyl aluminum diiodide, or butyl aluminum diiodide, mixed in any proportion.

[0016] The second technical solution adopted in this invention is a method for preparing a catalyst support for olefin polymerization, the specific steps of which are as follows: S1. Under the protection of inert gases such as helium, argon or nitrogen, dissolve the initiator in a mixture of 20-30% other alcohols and haloalcohols, mix evenly, and obtain the first treatment solution. S2. Add the aluminum-containing compound to the first treatment solution, then heat to 30~90℃, and then add the magnesium powder and the remaining other alcohols in 3~5 portions, maintaining the reflux temperature for 1~10 hours until no more gas is produced; then wash and dry to obtain the catalyst support for olefin polymerization. By weight percentage, the content of haloalkoxy groups in the catalyst support for olefin polymerization is 0.5~30% and the content of aluminum element is 0.001~10%.

[0017] The second technical solution of the present invention is further characterized in that, S2 is washed with a mixture of alcohols, ethanol, or an inert organic solvent, wherein the inert organic solvent is hexane or toluene; the water content of the ethanol is less than 200 ppm.

[0018] The beneficial effects of this invention are: (1) The method for preparing the catalyst support for olefin polymerization provided by the present invention overcomes some shortcomings of the prior art by introducing aluminum-containing compounds, and obtains alkoxy magnesium particles with good particle morphology, an average particle size of 10-80 μm, a narrow particle size distribution, and a bulk density greater than 0.3 g·cm³. -1 Specific surface area 60~200m² 2 ·g -1 The catalyst activity is greater than 40 kg PP / g Cat; the polymer bulk density is greater than 0.5 g·cm³. -3 It is particularly suitable as a catalyst support for gas-phase olefin polymerization, such as propylene polymerization. Its comprehensive performance is superior to existing technologies and it has a promising application prospect. (2) The alkoxy magnesium support particles prepared by the present invention have excellent particle morphology and high specific surface area; the catalyst prepared by the alkoxy magnesium support of the present invention improves the bulk density of the polymer while maintaining high activity, and makes the polymer have good particle morphology. Attached Figure Description

[0019] Figure 1 This is a scanning electron microscope image of the catalyst support prepared in Example 1 of the present invention; Figure 2 This is a scanning electron microscope image of the catalyst support prepared in Comparative Example 1 of the present invention. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] The catalyst support for olefin polymerization is obtained by contact reaction of magnesium powder, mixed alcohol, initiator and aluminum-containing compound. The molar ratio of mixed alcohol to magnesium powder is 2~40:1; the molar ratio of initiator to magnesium powder is 0.001~2:1; and the molar ratio of aluminum-containing compound to magnesium powder is 0.01~0.1:1. By weight percentage, the catalyst support used for olefin polymerization contains 0.5-30% haloalkoxy groups, 0.001-10% aluminum, and the remainder is alkylmagnesium oxy groups.

[0022] The mixed alcohols include haloalcohols and other alcohols, and the water content in the mixed alcohols is less than 200 ppm, preferably less than 100 ppm; By weight percentage, the content of haloalcohols in the mixed alcohols is 0-35%, and the content of other alcohols is 65-100%. Haloalcohols are those with the general formula R 1 Compounds of OH, wherein R 1 C1~C 20 The haloalkane group is preferably C1 to C6. The haloalkane group is a straight-chain, branched-chain, or cyclic chain hydrocarbon. The halogen atom and the hydroxyl group on the haloalcohol are located on different saturated carbon atoms. The halogen atom is chlorine or bromine. Other alcohols are those with the general formula R. 2 Compounds of OH, in which R is a general formula 2 It is C1 to C 20 Alkyl groups that are straight-chain, branched, or cyclic.

[0023] Halogenated alcohols include 2-chloroethanol, 3-chloropropanol, 4-chlorobutanol, 5-chloropentanol, 6-chlorohexanol, 2,2-dichloroethanol, 2,3-dichloropropanol, 3,4-dichlorobutanol, 4,5-dichloropentanol, 5,6-dichlorohexanol, 2,2,2-trichloroethanol, 2,2,2-trichloropropanol, 2,2,2-trichlorobutanol, 2,2,2-trichloropentanol, 2,2,2-trichlorohexanol, 3,3,3-trichlorobutanol, 3,3,3-trichloropentanol, 3,3,3-trichlorohexanol, trichlorotert-butanol, 2-chlorocyclohexanol, and 2-bromoethanol. The following are any one or more of the following in any ratio: 3-bromopropanol, 4-bromobutanol, 5-bromopentanol, 6-bromohexanol, 2,2-dibromoethanol, 2,3-dibromopropanol, 3,4-dibromobutanol, 4,5-dibromopentanol, 5,6-dibromohexanol, 2,2,2-tribromoethanol, 2,2,2-tribromopropanol, 2,2,2-tribromobutanol, 2,2,2-tribromopentanol, 2,2,2-tribromohexanol, 3,3,3-tribromobutanol, 3,3,3-tribromopentanol, 3,3,3-tribromohexanol, tribromotert-butanol, or 2-bromocyclohexanol.

[0024] The preferred haloalcohols are 2,2,2-trichloroethanol or trichlorotert-butanol.

[0025] Other alcohols include any one or more of the following in any ratio: methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, isopropanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 2-nonanol, 2-decanol, 2-ethylbutanol, 2-ethylhexanol, 4-methyl-2-pentanol, 3,3,5-trimethylpentanol, or 4-methyl-3-heptanol.

[0026] Ethanol is preferred among the other alcohols.

[0027] The initiator is any one or two of the following: halogen elements or halogen-containing compounds, mixed in any ratio. The halogen elements are chlorine, bromine, or iodine; the halogen-containing compounds are halogen-containing metal compounds, specifically MgCl2, MgBr2, MgI2, Mg(OEt)Cl, Mg(OEt)I, CaCl2, CaBr2, CaI2, NaCl, and KBr. The above halogen elements or halogen-containing compounds can be used alone or in combination of two or more in any ratio, with the effect being better when two are used in combination.

[0028] The preferred halogen element is iodine, and the preferred halogen-containing compound is MgCl2.

[0029] The magnesium powder is a compound on which no magnesium hydroxide or magnesium acid is formed. Spherical passivated magnesium powder is preferred, with an average particle size of 50-300 μm.

[0030] In this invention, there are no strict restrictions on the shape of the magnesium powder particles used, but an average particle size of 50-300 μm is required, preferably 50-200 μm, in order to control the average particle size of the generated alkoxymagnesium particles to be 10-80 μm. This also ensures relatively uniform reactivity and a well-developed, uniform particle morphology. No particular limitations are placed on the morphology and particle size of these compounds; they can be arbitrary.

[0031] Aluminum-containing compounds are combinations of aluminum halides and alkyl aluminum halides in any ratio; the general formula for aluminum halides is AlX3, where X is fluorine, chlorine, bromine, or iodine; the general formula for alkyl aluminum halides is dialkyl aluminum halides or monoalkyl dialkyl aluminum halides; the general formula for alkyl aluminum halides is AlR. 3 2X or AlR 3 X2, where R 3 It consists of C1 to C10 hydrocarbon groups, which are saturated straight or branched chains.

[0032] Aluminum halides include any one or more of aluminum trifluoride, aluminum trichloride, aluminum tribromide, and aluminum triiodide in any proportion; aluminum trichloride is preferred among the aluminum halides.

[0033] Alkyl aluminum halides include any one or more of methyl aluminum difluoride, ethyl aluminum difluoride, propyl aluminum difluoride, butyl aluminum difluoride, methyl aluminum dichloride, ethyl aluminum dichloride, propyl aluminum dichloride, butyl aluminum dichloride, pentyl aluminum dichloride, hexyl aluminum dichloride, dimethyl aluminum dichloride, diethyl aluminum dichloride, dipropyl aluminum dichloride, methyl aluminum dibromide, ethyl aluminum dibromide, propyl aluminum dibromide, butyl aluminum dibromide, methyl aluminum diiodide, ethyl aluminum diiodide, propyl aluminum diiodide, or butyl aluminum diiodide, mixed in any proportion. Methyl aluminum dichloride is preferred among the alkyl aluminum halides.

[0034] The specific steps of the above-mentioned method for preparing the catalyst support for olefin polymerization are as follows: S1. Under the protection of inert gases such as helium, argon or nitrogen, dissolve the initiator in a mixture of 20-30% other alcohols and haloalcohols, mix evenly, and obtain the first treatment solution. S2. Add the aluminum-containing compound to the first treatment solution, then heat to 30-90℃, and add the magnesium powder and the remaining alcohols in 3-5 portions. Maintain the reflux temperature and react for 1-10 hours, preferably 2-10 hours, until no more gas is produced. Then wash and dry to obtain the catalyst support for olefin polymerization. Specifically, wash with a mixed alcohol, ethanol or an inert organic solvent. The inert organic solvent is hexane or toluene. The water content of the ethanol is less than 200 ppm.

[0035] All operations in the above manufacturing process are carried out under the protection of an inert gas, such as helium, argon, or nitrogen. This invention, through the synergistic effects of aluminum-containing compounds, mixed alcohols containing haloalcohols, feeding methods, material ratios, and reaction temperatures, reveals that the crystal phase structure of the alkoxymagnesium support is altered, resulting in abundant porosity and a large specific surface area, which helps improve catalyst activity. Simultaneously, the internal structure of the alkoxymagnesium particles becomes more compact, which is beneficial for increasing the bulk density of the alkoxymagnesium support. The preparation process of the alkoxymagnesium support is simple and yields high products. The resulting alkoxymagnesium support has a narrow particle size distribution and high bulk density. When the prepared catalyst is used for propylene polymerization, it exhibits high catalytic activity and bulk density.

[0036] Example 1 In this embodiment, the reactor was fully purged with high-purity nitrogen. Under nitrogen protection, 0.40 g of iodine, 0.05 g of MgCl2, 10 mL of anhydrous ethanol, and 5 mL of 2,2,2-trichloroethanol were added sequentially. After stirring and dissolving, 0.5 g of aluminum trichloride and 0.3 g of methylaluminum dichloride were added. The temperature was raised to 70°C, and 1.0 g of 100-200 mesh magnesium powder and 10 mL of anhydrous ethanol were added. The reaction was continued at 70°C. After 20 minutes, another 1.0 g of 100-200 mesh magnesium powder and 10 mL of anhydrous ethanol were added, for a total of 4.0 g of magnesium powder and 40 mL of anhydrous ethanol in four additions. After the addition was complete, the reaction was maintained under reflux for 3 hours. The mixture was then washed twice with hexane, 80 mL each time. After washing, the mixture was dried to obtain a grayish-white, free-flowing solid powder, which is the alkoxymagnesium support. The scanning electron microscope image of the prepared catalyst support is shown below. Figure 1 As shown.

[0037] Example 2 The ingredients added at the beginning of Example 1, "0.5 g aluminum trichloride and 0.3 g methyl aluminum dichloride", were adjusted to "0.7 g aluminum trichloride and 0.5 g methyl aluminum dichloride"; "heated to 70°C" was adjusted to "heated to 90°C"; and other conditions were the same as in Example 1, to prepare the alkoxy magnesium support.

[0038] Example 3 In Example 1, “0.05 g MgCl2” was changed to “0.10 g MgCl2”; “5 mL 2,2,2-trichloroethanol” was changed to “10 mL 2,2,2-trichloroethanol”; and “heated to 70°C” was changed to “heated to 30°C”. Other conditions were the same as in Example 1, and an alkoxy magnesium support was prepared.

[0039] Example 4 The ingredients in Example 1, "0.40 g iodine, 0.05 g MgCl2", were adjusted to "0.80 g iodine, 0.10 g MgCl2"; the ingredients in Example 1, "0.5 g aluminum trichloride and 0.3 g methyl aluminum dichloride" were adjusted to "0.5 g aluminum trifluoride and 0.3 g butyl aluminum diiodide"; the mixture was washed twice with ethanol, and other conditions were the same as in Example 1, to prepare the alkoxy magnesium support.

[0040] Example 5 The "10 ml anhydrous ethanol" added at the beginning of Example 1 was adjusted to "30 ml anhydrous ethanol"; the "100-200 mesh magnesium powder" was adjusted to "80-150 mesh magnesium powder"; the "0.5 g aluminum trichloride and 0.3 g methyl aluminum dichloride" were adjusted to "0.5 g aluminum triiodide and 0.3 g propyl aluminum dibromide"; the mixture was washed twice with toluene, and other conditions were the same as in Example 1, to prepare the alkoxy magnesium support.

[0041] Example 6 The "0.40 g iodine" added at the beginning of Example 1 was adjusted to "0.40 g bromine"; "0.5 g aluminum trichloride and 0.3 g methyl aluminum dichloride" were adjusted to "0.5 g aluminum tribromide and 0.3 g ethyl aluminum dichloride"; "heated to 70°C" was adjusted to "heated to 60°C"; the mixture was washed twice with a mixed alcohol, and other conditions were the same as in Example 1, to prepare the alkoxy magnesium support.

[0042] Example 7 The "5 ml 2,2,2-trichloroethanol" added at the beginning of Example 1 was adjusted to "5 ml trichlorotert-butanol"; the "0.5 g aluminum trichloride and 0.3 g methyl aluminum dichloride" were adjusted to "0.7 g aluminum trichloride and 0.5 g methyl aluminum dichloride", and other conditions were the same as in Example 1, to prepare the alkoxy magnesium support.

[0043] Example 8 The "5 ml of 2,2,2-trichloroethanol" added at the beginning of Example 1 was adjusted to "5 ml of 2,3-dichloropropanol"; the "0.5 g of aluminum trichloride and 0.3 g of methyl aluminum dichloride" was adjusted to "0.3 g of aluminum trichloride and 0.2 g of methyl aluminum dichloride", and other conditions were the same as in Example 1, to prepare the alkoxy magnesium support.

[0044] Comparative Example 1 In this comparative example, the reactor was fully purged with high-purity nitrogen. Under nitrogen protection, 0.40 g of iodine and 10 mL of anhydrous ethanol were added sequentially. After stirring and dissolving, the temperature was raised to 70 °C. Then, 1.0 g of 100-200 mesh magnesium powder and 10 mL of anhydrous ethanol were added, and the reaction was maintained under reflux. 1.0 g of 100-200 mesh magnesium powder and 10 mL of anhydrous ethanol were added again every 20 minutes, for a total of 4.0 g of magnesium powder and 40 mL of anhydrous ethanol added in four separate additions. After all additions were completed, the reaction was maintained under reflux for 3 hours. The mixture was then washed twice with 80 mL of hexane each time. After washing, the mixture was dried to obtain a grayish-white, free-flowing solid powder, thus preparing the alkoxy magnesium support. The scanning electron microscope image of the prepared catalyst support is shown below. Figure 2 As shown.

[0045] Comparative Example 2 In this comparative example, the reactor was fully purged with high-purity nitrogen. Under nitrogen protection, 0.40 g of iodine, 0.05 g of MgCl2, 10 mL of anhydrous ethanol, and 5 mL of isopropanol were added sequentially. After stirring and dissolving, the mixture was heated, and 1.0 g of 100-200 mesh magnesium powder and 10 mL of anhydrous ethanol were added. The reaction was maintained under reflux. After 20 minutes, 1.0 g of 100-200 mesh magnesium powder and 10 mL of anhydrous ethanol were added again. A total of 4.0 g of magnesium powder and 50 mL of anhydrous ethanol were added in 4 batches. After the addition was complete, the reaction was maintained under reflux for 3 hours. The mixture was then washed twice with hexane, with 80 mL of hexane used each time. After washing, the mixture was dried to obtain a grayish-white free-flowing solid powder, thus preparing the alkoxy magnesium support.

[0046] Comparative Example 3 In this comparative example, the reactor was fully purged with high-purity nitrogen. Under nitrogen protection, 0.40 g of iodine, 0.05 g of MgCl2, 10 mL of anhydrous ethanol, and 5 mL of trichloroethanol were added sequentially. After stirring and dissolving, the temperature was raised, and 4.0 g of 100-200 mesh magnesium powder and 40 mL of anhydrous ethanol were added at once. The reaction was maintained under reflux for a total of 4.0 g of magnesium powder and 50 mL of anhydrous ethanol. After the addition was complete, the reaction was maintained under reflux for 3 hours. The mixture was then washed twice with hexane, with 80 mL of hexane used each time. After washing, the mixture was dried to obtain a grayish-white free-flowing solid powder, thus preparing the alkoxy magnesium support.

[0047] The performance of the catalyst supports (alkoxymagnesium supports) prepared in Examples 1-8 and Comparative Examples 1-3 were tested respectively, and the test results are shown in Table 1.

[0048] (a) Testing methods: (1) Determination of polymer bulk density: Refer to GB / T1636-1989 standard; (2) Testing of scanning electron microscope images of the carrier: Philips XL20, magnification 2000; (3) Particle size and distribution of support and catalyst: Mastersize 2000 particle size analyzer, n-hexane as dispersant, measurement range 0.02~2000μm, span=(D90-D10) / D50; (4) Halogenated alkoxy group content: determined by gas chromatography (external standard method); (5) The aluminum content was determined by ICP-AES inductively coupled plasma atomic emission spectrometry.

[0049] Table 1. Comparison of test data for magnesium alkoxy particles in Examples 1-8 and Comparative Examples 1-3

[0050] The catalyst supports prepared in Examples 1-8 and Comparative Examples 1-3 were experimentally verified, as follows: The alkoxymagnesium particles prepared in the embodiments and comparative examples of this invention can be used as catalyst components for the synthesis of olefin polymerization: In a reactor that has been repeatedly purged with high-purity nitrogen, 50 mL of titanium tetrachloride is added, the temperature is lowered to 0°C, 5 g of alkoxymagnesium particles obtained in the examples are added, and then the temperature is slowly raised to 30°C. 1.5 mL of DIBP (diisobutyl phthalate) is added, the temperature is further raised to 110°C and the reaction is maintained for 2 hours. The liquid is then filtered clean, and 50 mL of titanium tetrachloride is added again, the temperature is raised to 110°C and the reaction is maintained for 2 hours. The liquid is then filtered clean, and the process is repeated once more. The resulting solid is washed three times with 100 mL of hexane at 50°C, and finally dried to obtain solid catalyst powder. The test results of the catalyst are shown in Table 2 below.

[0051] Propylene polymerization: After the reactor was fully purged with high-purity nitrogen, 1.5 mmol of triethylaluminum and 0.1 mmol of cyclohexylmethyldimethoxysilane were added, followed by 10 mg of the above catalyst. 2.5 L of liquid propylene and 1 L of hydrogen (under standard conditions) were added with stirring. The temperature was raised to 70 °C and the reaction was maintained for 1 hour. The polymer test results are shown in Table 2 below.

[0052] Table 2 Comparison of catalyst and polymer test data in Examples 1-8 and Comparative Examples 1-3

[0053] From Table 1, Table 2, Figure 1 and Figure 2It can be seen that, compared with comparative examples 1-3, the alkoxymagnesium carrier particles prepared in Examples 1-8 have better morphology, narrower particle size distribution, and higher bulk density and specific surface area, with the bulk density being greater than 0.3 g·cm³. -1 Due to its abundant porous structure, the prepared alkoxymagnesium support has a small average pore size. Furthermore, the catalyst prepared using this alkoxymagnesium support exhibits high activity and high packing density, making it suitable for polypropylene production.

Claims

1. A catalyst support for olefin polymerization, characterized in that, It is obtained by contact reaction of magnesium powder, mixed alcohol, initiator and aluminum-containing compound, wherein the molar ratio of mixed alcohol to magnesium powder is 2~40:1; the molar ratio of initiator to magnesium powder is 0.001~2:1; and the molar ratio of aluminum-containing compound to magnesium powder is 0.01~0.1:

1. The catalyst support for olefin polymerization contains 0.5-30% haloalkoxy groups and 0.001-10% aluminum by weight percentage.

2. The catalyst support for olefin polymerization according to claim 1, characterized in that, The mixed alcohols include haloalcohols and other alcohols, and the water content in the mixed alcohols is less than 200 ppm; By weight percentage, the mixed alcohols contain 0-35% haloalcohols and 65-100% other alcohols; The haloalcohol is of the general formula R. 1 Compounds of OH, wherein R 1 C1~C 20 The haloalkane group is a straight-chain, branched-chain, or cyclic chain hydrocarbon, wherein the halogen atom and the hydroxyl group on the haloalcohol are located on different saturated carbon atoms, and the halogen atom is chlorine or bromine; The other alcohols are those with the general formula R. 2 Compounds of OH, in which R is a general formula 2 It is C1 to C 20 Alkyl groups that are straight-chain, branched, or cyclic.

3. The catalyst support for olefin polymerization according to claim 2, characterized in that, The haloalcohols include 2-chloroethanol, 3-chloropropanol, 4-chlorobutanol, 5-chloropentanol, 6-chlorohexanol, 2,2-dichloroethanol, 2,3-dichloropropanol, 3,4-dichlorobutanol, 4,5-dichloropentanol, 5,6-dichlorohexanol, 2,2,2-trichloroethanol, 2,2,2-trichloropropanol, 2,2,2-trichlorobutanol, 2,2,2-trichloropentanol, 2,2,2-trichlorohexanol, 3,3,3-trichlorobutanol, 3,3,3-trichloropentanol, 3,3,3-trichlorohexanol, trichlorotert-butanol, 2-chlorocyclohexanol, and 2-bromoethanol. The alcohol, 3-bromopropanol, 4-bromobutanol, 5-bromopentanol, 6-bromohexanol, 2,2-dibromoethanol, 2,3-dibromopropanol, 3,4-dibromobutanol, 4,5-dibromopentanol, 5,6-dibromohexanol, 2,2,2-tribromoethanol, 2,2,2-tribromopropanol, 2,2,2-tribromobutanol, 2,2,2-tribromopentanol, 2,2,2-tribromohexanol, 3,3,3-tribromobutanol, 3,3,3-tribromopentanol, 3,3,3-tribromohexanol, tribromotert-butanol or 2-bromocyclohexanol, in any combination of one or more of these in any ratio.

4. The catalyst support for olefin polymerization according to claim 3, characterized in that, The other alcohols include any one or more of the following in any ratio: methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, isopropanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 2-nonanol, 2-decanol, 2-ethylbutanol, 2-ethylhexanol, 4-methyl-2-pentanol, 3,3,5-trimethylpentanol, or 4-methyl-3-heptanol.

5. The catalyst support for olefin polymerization according to claim 1, characterized in that, The initiator is any one or two of halogen elements or halogen-containing compounds in any ratio. The halogen element is chlorine, bromine, or iodine. The halogen-containing compound is a halogen-containing metal compound, specifically MgCl2, MgBr2, MgI2, Mg(OEt)Cl, Mg(OEt)I, CaCl2, CaBr2, CaI2, NaCl, or KBr. The above halogen elements or halogen-containing compounds can be used alone or in combination of two or more in any ratio.

6. The catalyst support for olefin polymerization according to claim 1, characterized in that, The magnesium powder is a compound in which no magnesium hydroxide or magnesium acid is formed on the surface.

7. The catalyst support for olefin polymerization according to claim 1, characterized in that, The aluminum-containing compound is a combination of aluminum halide and alkyl aluminum halide in any ratio; The aluminum halide has the general formula AlX3, where X is fluorine, chlorine, bromine or iodine; The alkyl aluminum halide is a dialkyl aluminum halide or a monoalkyl dialkyl aluminum halide; the general formula of the alkyl aluminum halide is AlR. 3 2X or AlR 3 X2, where R 3 It consists of C1 to C10 hydrocarbon groups, which are saturated straight or branched chains.

8. The catalyst support for olefin polymerization according to claim 7, characterized in that, The aluminum halide includes any one or more of aluminum trifluoride, aluminum trichloride, aluminum tribromide, and aluminum triiodide, mixed in any ratio; The alkyl aluminum halides include any one or more of methyl aluminum difluoride, ethyl aluminum difluoride, propyl aluminum difluoride, butyl aluminum difluoride, methyl aluminum dichloride, ethyl aluminum dichloride, propyl aluminum dichloride, butyl aluminum dichloride, pentyl aluminum dichloride, hexyl aluminum dichloride, dimethyl aluminum dichloride, diethyl aluminum dichloride, dipropyl aluminum dichloride, methyl aluminum dibromide, ethyl aluminum dibromide, propyl aluminum dibromide, butyl aluminum dibromide, methyl aluminum diiodide, ethyl aluminum diiodide, propyl aluminum diiodide, or butyl aluminum diiodide, mixed in any proportion.

9. A method for preparing a catalyst support for olefin polymerization, characterized in that, The specific steps are as follows: S1. Under the protection of inert gases such as helium, argon or nitrogen, dissolve the initiator in a mixture of 20-30% other alcohols and haloalcohols, mix evenly, and obtain the first treatment solution. S2. Add the aluminum-containing compound to the first treatment solution, then heat to 30~90℃, and then add the magnesium powder and the remaining other alcohols in 3~5 portions, maintaining the reflux temperature for 1~10 hours until no more gas is produced; then wash and dry to obtain a catalyst support for olefin polymerization. By weight percentage, the content of haloalkoxy groups in the catalyst support for olefin polymerization is 0.5~30% and the content of aluminum element is 0.001~10%.

10. The method for preparing a catalyst support for olefin polymerization according to claim 9, characterized in that, In step S2, washing is performed using a mixed alcohol, ethanol, or an inert organic solvent, wherein the inert organic solvent is hexane or toluene; and the ethanol has a water content of less than 200 ppm.

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