A catalyst component for the polymerization of olefins, process for its preparation, catalyst and use thereof

Abstract

The application belongs to the technical field of olefin polymerization, and discloses a catalyst component for olefin polymerization, a preparation method, a catalyst and application thereof. The catalyst component comprises a reaction product of a magnesium halide alcohol compound, a carbonate compound and a titanium compound; wherein the general formula of the magnesium halide alcohol compound is MgX2·m(ROH), X is halogen; ROH is a C1-C 12 aliphatic alcohol, a C7-C 12 aromatic alcohol, a substituted alcohol derived from a C1-C 12 aliphatic alcohol or a substituted alcohol derived from a C7-C 12 aromatic alcohol; the carbonate compound comprises at least one of the compounds shown in formula I; wherein R1-R6 are independently C1-C8 hydrocarbyl, C1-C8 halogenated hydrocarbyl, H or halogen; the catalyst has higher activity, polymer powder bulk density and better hydrogen sensitivity during high hydrogen polymerization.

Description

Technical Field

[0001] This invention relates to the field of olefin polymerization technology, and more specifically, to a catalyst component for olefin polymerization, its preparation method, the catalyst, and its application. Background Technology

[0002] Since its invention in the 1930s, polyethylene has been widely used in industry, agriculture, packaging and daily consumption due to its abundant raw materials and excellent product performance.

[0003] Catalyst research has always played a crucial role in the synthesis and production of polyethylene. Currently, there are numerous studies and reports on catalyst performance improvement, mainly focusing on the following aspects: catalyst efficiency, particle morphology control, copolymerization capability, molecular weight, and molecular weight distribution. In particular, for the production of polyolefin resins, the "metamorphic phenomenon" (the phenomenon where catalyst particles replicate their morphology to the polyolefin powder particles they produce through polymerization) during polymerization makes good catalyst particle morphology beneficial to improving resin production efficiency. Therefore, a large number of patents involve the control of catalyst particle shape.

[0004] For example, CN201510531912.6 describes how introducing organic acid anhydrides / acetic acid esters / aromatic esters as complex electron donors into an N-type polyolefin catalyst preparation system can produce spherical / ellipsoidal magnesium / titanium-containing solid particles; CN202011136155.X relates to the preparation of an alkoxy magnesium support and related catalysts.

[0005] Improving the morphology of catalyst particles can correspondingly increase the bulk density of polymer powder, thereby improving the production load of the unit. Summary of the Invention

[0006] The purpose of this invention is to provide a catalyst component for olefin polymerization, its preparation method, catalyst, and application. The catalyst of this invention has good overall performance, especially because its good particle morphology results in a high packing density of the polymer.

[0007] To achieve the above objectives, a first aspect of the present invention provides a catalyst component for olefin polymerization, the catalyst component comprising reaction products of magnesium halide alkoxides, carbonate compounds, and titanium compounds;

[0008] The general formula of the magnesium halide alkoxide is MgX2·m(ROH), where X is a halogen and ROH is C1-C2. 12 fatty alcohols, C7-C 12 Aromatic alcohols, composed of C1 to C2 12 Alcohols derived from fatty alcohols or substituted alcohols from C7 to C812 Substituted alcohols derived from aromatic alcohols;

[0009] The carbonate compounds comprise at least one of the compounds shown in Formula I; wherein R1-R6 are each independently a C1-C8 hydrocarbon group, a C1-C8 halohydrocarbon group, H, or a halogen;

[0010]

[0011] A second aspect of the present invention provides a method for preparing the above-mentioned catalyst component, wherein the magnesium halide alkoxide is reacted with the carbonate compound in the presence of an inert solvent, and then reacted with the titanium compound to obtain the catalyst component.

[0012] A third aspect of the present invention provides a catalyst for olefin polymerization, the catalyst comprising the following components:

[0013] Component A: The catalyst components mentioned above;

[0014] Component B: Organoaluminum compound; its general formula is AlR n X 3-n In the formula, R is a hydrocarbon group with 1 to 20 carbon atoms; X is a halogen, preferably chlorine or bromine; n is an integer 0 < n ≤ 3;

[0015] Preferably, the molar ratio of aluminum in component B to titanium in component A is 1 to 1000:1, more preferably 5 to 500:1.

[0016] A fourth aspect of the present invention provides the application of the above-described catalyst component or the above-described catalyst in an olefin polymerization reaction.

[0017] Compared with existing technologies, the present invention has the following obvious advantages:

[0018] (1) First, the carbonate compounds of the present invention are simple and readily available, and have low toxicity and are environmentally friendly. Second, when the carbonate compounds of the present invention are used as catalyst components, they can significantly improve the overall performance of existing polyethylene catalysts. During high-hydrogen polymerization, the catalyst has higher activity and polymer powder packing density, as well as better hydrogen regulation sensitivity.

[0019] (2) The raw materials used in the catalyst of the present invention are relatively environmentally friendly, and the catalyst preparation process is simple.

[0020] Other features and advantages of the present invention will be described in detail in the following detailed description section. Detailed Implementation

[0021] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0022] A first aspect of the present invention provides a catalyst component for olefin polymerization, the catalyst component comprising reaction products of magnesium halide alkoxides, carbonate compounds, and titanium compounds;

[0023] The general formula of the magnesium halide alkoxide is MgX2·m(ROH), where X is a halogen and ROH is C1-C2. 12 fatty alcohols, C7-C 12 Aromatic alcohols, composed of C1 to C2 12 Alcohols derived from fatty alcohols or substituted alcohols from C7 to C8 12 Substituted alcohols derived from aromatic alcohols;

[0024] The carbonate compounds comprise at least one of the compounds shown in Formula I; wherein R1-R6 are each independently a C1-C8 hydrocarbon group, a C1-C8 halohydrocarbon group, H, or a halogen;

[0025]

[0026] In this invention, the inventors, through extensive experimental research during the development of polyethylene catalysts, surprisingly discovered that specific carbonate compounds, as shown in Formula I, can significantly improve the overall performance of specific titanium-magnesium polyolefin catalysts when used as components. During high-hydrogen polymerization, this catalyst exhibits high activity and high polymer powder packing density, while its hydrogen sensitivity is significantly enhanced. Based on this discovery, this invention provides a catalyst component for olefin homopolymerization or copolymerization.

[0027] According to the present invention, preferably, the magnesium halide in the magnesium halide alkoxide is at least one of magnesium dichloride, magnesium dibromide and magnesium diiodide, and preferably magnesium dichloride;

[0028] The alcohol in the magnesium halide alcohol is selected from at least one of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, 2-ethylhexanol, n-octanol, dodecanol, benzyl alcohol, phenethyl alcohol, and the haloalcohols of the above alcohols; wherein the haloalcohols of the above alcohols are haloalcohols of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, 2-ethylhexanol, n-octanol, dodecanol, benzyl alcohol, and phenethyl alcohol.

[0029] Preferably, it is at least one of ethanol, isopropanol, butanol, 2-ethylhexanol, benzyl alcohol, phenethyl alcohol, and haloalcohols of the above alcohols; wherein the haloalcohols of the above alcohols are haloalcohols of ethanol, isopropanol, butanol, 2-ethylhexanol, benzyl alcohol, and phenethyl alcohol.

[0030] According to the present invention, preferably, m is 0.1 to 10 moles per mole of magnesium halide, more preferably 1 to 5 moles per mole of magnesium halide.

[0031] In this invention, the magnesium halide alcohols are preferably spherical and / or near-spherical. The magnesium halide alcohols can be obtained commercially or through conventional preparation methods in the art. For example, spherical magnesium halide alcohols can be prepared by spray drying, spray cooling, high-pressure extrusion, high-speed stirring or a rotating bed under high gravity, and mesh forming. Specifically, refer to the magnesium chloride alcohol preparation methods disclosed in US4421674 (spray drying), US6020279 (spray cooling), CN200010009216.2 (high-speed stirring preparation), CN1463990A (emulsification cooling), CN200310053152.X (rotating bed under high gravity), and CN201510708527.4 (mesh forming), which will not be detailed here.

[0032] According to the present invention, preferably, the carbonate compound includes at least one of the following: iodomethyl isopropyl carbonate, methyl carbonate, dimethyl carbonate, di(trichloromethyl) carbonate, dimethyl chlorocarbonate, ethyl methyl carbonate, diethyl carbonate, diisopropyl carbonate, 1-chloroethylethyl carbonate, isopropyl chloromethyl carbonate, and 1-chloroethyl isopropyl carbonate; preferably at least one of the following halogenated carbonates; more preferably di(trichloromethyl) carbonate.

[0033] According to the present invention, preferably, the titanium compound has the general formula TiX. n (OR) 4-n Where: X is a halogen, and R is a C1 to C2 halogen. 14 Aliphatic hydrocarbon groups or C6~C 14 Aromatic hydrocarbon group, where n is an integer from 0 to 4;

[0034] The titanium compound is preferably at least one of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium tetraethoxy, titanium tetrabutoxy, titanium monochlorotriethoxy, titanium dichlorodiethoxy, and titanium trichloromonethoxy; more preferably at least one of titanium tetrachloride, titanium tetraethoxy, and titanium tetrabutoxy.

[0035] According to the present invention, preferably, the carbonate compound is 0.001 to 10 moles per mole of magnesium halide alkoxide, more preferably 0.002 to 1 mole; and the titanium compound is 0.2 to 100 moles per mole, more preferably 1.0 to 20 moles per mole of magnesium halide alkoxide.

[0036] A second aspect of the present invention provides a method for preparing the above-mentioned catalyst component, wherein the magnesium halide alkoxide is reacted with the carbonate compound in the presence of an inert solvent, and then reacted with the titanium compound to obtain the catalyst component.

[0037] In this invention, preferably, the magnesium halide alkoxide is reacted with the carbonate compound in the presence of an inert solvent and a protective gas, and then reacted with the titanium compound to obtain the catalyst component.

[0038] In this invention, the preferred reaction with the titanium compound is as follows: (1) adding the titanium compound, maintaining the temperature at -40°C to 40°C for 0.5-10h, then raising the temperature to 40-150°C and reacting for 0.1-10h, and collecting the solid by solid-liquid separation; (2) reacting the solid with the titanium compound at 60-130°C for 0.1-5h; (3) repeating step (2) multiple times, preferably 2-4 times.

[0039] In this invention, preferably, the inert solvent is a liquid hydrocarbon, which preferably includes at least one of halogenated aromatic hydrocarbons, non-halogenated aromatic hydrocarbons, halogenated aliphatic hydrocarbons, and non-halogenated aliphatic hydrocarbons; more preferably, it includes at least one of benzene and its homologues, chlorobenzene, dichlorobenzene, hexane, heptane, decane, kerosene, dichloromethane, dichloroethane, chloroform, and cyclohexane.

[0040] In this invention, the preparation of spherical magnesium halide alcohols is carried out first. The preparation method can refer to existing public technologies. It should be noted that the focus of this invention is on the application of specific carbonate compounds. Therefore, regardless of which existing method is used, the above-mentioned carbonate compounds are one of the essential components.

[0041] Since the main purpose of this invention is to verify the effectiveness of specific carbonate compounds as catalyst components in the preparation of polyolefin catalysts from magnesium halide alcohols, the specific preparation method of the magnesium halide alcohols used is not particularly limited here, and its specific preparation can be referred to existing technologies.

[0042] Specifically, readily available magnesium halide alkoxides can be used. Generally, they are first suspended in an inert solvent, then the carbonate compound is added, and after a period of reaction, they are brought into contact with the titanium compound for further reaction. Specifically, the reaction product of the magnesium halide alkoxide and carbonate compound with the titanium compound can be carried out in the same manner as in existing technologies. For example, the titanium compound can be dropwise added to a system containing the reaction product of the magnesium halide alkoxide and carbonate compound suspended at a low temperature (the temperature of the system can be -40°C to 40°C, preferably -35°C to 30°C). The resulting mixture is then heated to 40-150°C, preferably to 60-130°C, and maintained at this temperature for 0.1-10 hours. Solid-liquid separation is then performed to remove the liquid. Next, a possible inert solvent and titanium compound are added to the resulting solid, and the mixture is heated to 40-150°C, preferably to 60-130°C, and maintained at this temperature for 0.1-5 hours. Solid-liquid separation is then performed to remove the liquid. This operation can be performed once or multiple times, preferably 2-4 times. Finally, the mixture is washed with an inert solvent to obtain the main catalyst component.

[0043] Generally, other known conventional electron donors may be added before or after contact with titanium compounds to further improve the relevant catalyst components. For the sake of clarity, the synthesis system is simplified as much as possible in this invention.

[0044] The above preparation method is an example description of the catalyst components of the present invention. In actual feeding, the carbonate compounds of the present invention can also be added after the titanium compounds. In addition, the above components are only the basic components of the present invention. In actual synthesis, it is not limited to these basic components. If necessary, other electron donors and promoters can also be added at the same time. These will not be pointed out one by one in the present invention.

[0045] After the above steps, component A of the catalyst of the present invention is obtained, which can be used in the form of a solid or a suspension.

[0046] A third aspect of the present invention provides a catalyst for olefin polymerization, the catalyst comprising the following components:

[0047] Component A: The catalyst components mentioned above;

[0048] Component B: Organoaluminum compound; its general formula is AlR n X 3-n In the formula, R is a hydrocarbon group with 1 to 20 carbon atoms; X is a halogen, preferably chlorine or bromine; n is an integer 0 < n ≤ 3;

[0049] Preferably, the molar ratio of aluminum in component B to titanium in component A is 1 to 1000:1, more preferably 5 to 500:1.

[0050] According to the present invention, preferably, the organoaluminum compound is at least one selected from trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum hydrogen, diisobutylaluminum hydrogen, diethylaluminum chloride, diisobutylaluminum chloride, sesquiethylaluminum chloride, and diethylaluminum chloride; preferably triethylaluminum and / or triisobutylaluminum.

[0051] In this invention, R is a hydrocarbon group having 1 to 20 carbon atoms, wherein the hydrocarbon group can be alkyl, aralkyl, aryl, etc.

[0052] In this invention, trimethylaluminum, triethylaluminum, triisobutylaluminum, and trioctylaluminum belong to trialkylaluminum; diethylaluminum monohydrogen and diisobutylaluminum monohydrogen belong to alkylaluminum hydrogenates; and diethylaluminum monochloro, diisobutylaluminum monochloro, sesquiethylaluminum chloride, and diethylaluminum dichlorochloride belong to alkylaluminum chlorides.

[0053] The A and B components (organoaluminum compounds) of the catalyst of this invention can be directly applied to the polymerization system, or they can be pre-complexed and then applied to the polymerization system.

[0054] A fourth aspect of the present invention provides the use of the above-described catalyst component or the above-described catalyst in olefin polymerization reactions.

[0055] The catalyst component or catalyst of the present invention can be used for homopolymerization of ethylene, and can also be used for copolymerization of ethylene and α-olefins. The comonomer can be propylene, butene, pentene, hexene, octene, or 4-methyl-1-pentene.

[0056] Polymerization can be performed in either the liquid phase or the gas phase. In liquid phase polymerization, inert solvents such as propane, hexane, heptane, cyclohexane, isobutane, isopentane, naphtha, raffinate, hydrogenated gasoline, kerosene, benzene, toluene, and xylene, or saturated aliphatic or aromatic hydrocarbons, can be used as the reaction medium. Prepolymerization can be performed before polymerization. Polymerization can be carried out in batch, semi-continuous, or continuous processes.

[0057] The polymerization temperature is room temperature to 150°C, preferably 50°C to 100°C. Hydrogen is used as a molecular weight regulator to adjust the polymer's molecular weight.

[0058] The following embodiments are examples of the present invention in more detail, but the present invention is not limited to these embodiments.

[0059] In the following embodiments and comparative examples:

[0060] The magnesium halide ethanolate used was magnesium chloride ethanolate, with a molar ratio of ethanol to magnesium chloride of 2.6. This magnesium halide ethanolate consisted of white spherical particles with a particle size D. 50 It is 6 micrometers;

[0061] Determination of polymer melt index (MI): According to ASTM D1238-99, the test was conducted at 190°C with a load of 2.16 kg.

[0062] Polymer bulk density was determined using the test method for apparent density, volume factor and pourability of plastics (ASTM D1895).

[0063] (I) Preparation of catalyst components

[0064] Preparation of spherical catalyst components:

[0065] Example 1:

[0066] In a 300 mL glass reaction flask under nitrogen protection, 40 mL of hexane and 12.0 g of spherical magnesium halide alcohols were added sequentially, followed by stirring with 4.0 mL of dimethyl carbonate. The mixture was stirred at 25 °C for 30 minutes, cooled to -20 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, then slowly heated to 80 °C and maintained for 30 minutes. The liquid was then filtered off. Next, 40 mL of toluene and 40 mL of titanium tetrachloride were added, the temperature was raised to 110 °C, and maintained at 110 °C for 30 minutes before filtering off the liquid. Then, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, the temperature was raised to 110 °C, and maintained at 110 °C for 30 minutes before filtering off the liquid. Finally, the mixture was washed multiple times with hexane and dried under vacuum to obtain the spherical catalyst component C1.

[0067] Comparative Example 1:

[0068] In a 300 mL glass reaction flask under nitrogen protection, 40 mL of hexane and 12.0 g of spherical magnesium halide alcohols were added sequentially, followed by stirring with 4.0 mL of ethyl benzoate. The mixture was stirred at 25 °C for 30 minutes, cooled to -20 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, then slowly heated to 80 °C and maintained for 30 minutes. The liquid was then filtered off. Next, 40 mL of toluene and 40 mL of titanium tetrachloride were added, the temperature was raised to 110 °C, and maintained at 110 °C for 30 minutes before filtering off the liquid. Then, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, the temperature was raised to 110 °C, and maintained at 110 °C for 30 minutes before filtering off the liquid. Finally, the mixture was washed multiple times with hexane and dried under vacuum to obtain the spherical catalyst component B1.

[0069] Example 2:

[0070] In a 300 mL glass reaction flask under nitrogen protection, 40 mL of hexane and 12.0 g of spherical magnesium halide alcohols were added sequentially, followed by stirring with 4.0 mL of diethyl carbonate. The mixture was stirred at 25 °C for 30 minutes, cooled to -20 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, then slowly heated to 80 °C and maintained for 30 minutes. The liquid was then filtered off. Next, 40 mL of toluene and 40 mL of titanium tetrachloride were added, the temperature was raised to 110 °C, and maintained at 110 °C for 30 minutes before filtering off the liquid. Then, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, the temperature was raised to 110 °C, and maintained at 110 °C for 30 minutes before filtering off the liquid. Finally, the mixture was washed multiple times with hexane and dried under vacuum to obtain the spherical catalyst component C2.

[0071] Comparative Example 2:

[0072] In a 300 mL glass reaction flask under nitrogen protection, 40 mL of hexane and 12.0 g of spherical magnesium halide alkoxide were added sequentially, and the mixture was stirred at 25 °C for 30 minutes. The mixture was then cooled to -20 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, then slowly heated to 80 °C and maintained for 30 minutes. The liquid was then filtered off. Next, 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Then, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Finally, the mixture was washed repeatedly with hexane and dried under vacuum to obtain the spherical catalyst component B2.

[0073] Example 3:

[0074] In a 300 mL glass reaction flask under nitrogen protection, 40 mL of hexane and 12.0 g of spherical magnesium halide alcohols were added sequentially. 4.0 g of di(trichloromethyl) carbonate was then added with stirring, and the mixture was stirred at 25 °C for 30 minutes. The mixture was cooled to -20 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, then slowly heated to 80 °C and maintained for 30 minutes. The liquid was then filtered off. Next, 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Then, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Finally, the mixture was washed multiple times with hexane and dried under vacuum to obtain the spherical catalyst component C3.

[0075] Example 4:

[0076] In a 300 mL glass reaction flask under nitrogen protection, 40 mL of hexane and 12.0 g of spherical magnesium halide alcohols were added sequentially. 0.2 g of bis(trichloromethyl) carbonate was added with stirring, and the mixture was stirred at 25 °C for 30 minutes. The mixture was then cooled to -20 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, then slowly heated to 80 °C and maintained for 30 minutes. The liquid was then filtered off. Next, 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Then, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Finally, the mixture was washed repeatedly with hexane and dried under vacuum to obtain the spherical catalyst component C4.

[0077] Example 5:

[0078] In a 300 mL glass reaction flask under nitrogen protection, 60 mL of hexane and 12.0 g of spherical magnesium halide alcohols were added sequentially. 0.5 g of bis(trichloromethyl) carbonate was added with stirring, and the mixture was stirred at 25 °C for 30 minutes. The mixture was then cooled to -30 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, then slowly heated to 80 °C and maintained for 30 minutes. The liquid was then filtered off. 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Next, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Finally, the mixture was washed repeatedly with hexane and dried under vacuum to obtain the spherical catalyst component C5.

[0079] Example 6:

[0080] In a 300 mL glass reaction flask under nitrogen protection, 60 mL of toluene and 12.0 g of spherical magnesium halide alcohols were added sequentially. 1.0 g of bis(trichloromethyl) carbonate was then added with stirring, and the mixture was stirred at 25 °C for 30 minutes. The mixture was then cooled to -30 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, then slowly heated to 80 °C and maintained for 30 minutes. The liquid was then filtered off. Next, 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Then, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Finally, the mixture was washed multiple times with hexane and dried under vacuum to obtain the spherical catalyst component C6.

[0081] Example 7:

[0082] In a 300 mL glass reaction flask under nitrogen protection, 60 mL of toluene and 12.0 g of spherical magnesium halide alcohols were added sequentially. 2.0 g of bis(trichloromethyl) carbonate was then added with stirring, and the mixture was stirred at 25 °C for 30 minutes. The mixture was cooled to -10 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, then slowly heated to 80 °C and maintained for 30 minutes. The liquid was then filtered off. Next, 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Then, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Finally, the mixture was washed multiple times with hexane and dried under vacuum to obtain the spherical catalyst component C7.

[0083] Example 8:

[0084] In a 300 mL glass reaction flask under nitrogen protection, 60 mL of hexane and 12.0 g of spherical magnesium halide alcohols were added sequentially. Then, 3.0 g of bis(trichloromethyl) carbonate was added with stirring, and the mixture was stirred at 25 °C for 30 minutes. The mixture was cooled to 0 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, then slowly heated to 80 °C and maintained for 30 minutes. The liquid was then filtered off. Next, 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Then, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was heated to 110 °C and maintained for 30 minutes before filtering off the liquid. Finally, the mixture was washed repeatedly with hexane and dried under vacuum to obtain the spherical catalyst component C8.

[0085] Comparative Example 3:

[0086] In a 300 mL glass reaction flask under nitrogen protection, 40 mL of hexane and 12.0 g of spherical magnesium halide alcohols were added sequentially. The mixture was cooled to -20 °C, and 2.0 mL of tetraethyl orthosilicate was added. The mixture was maintained for 30 minutes, and then 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at a constant temperature for 1 hour. Then, the temperature was slowly increased to 80 °C and maintained for 30 minutes. The liquid was filtered off. 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the temperature was increased to 110 °C. The mixture was maintained at 110 °C for 30 minutes, and then the liquid was filtered off. Next, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the temperature was increased to 110 °C. The mixture was maintained at 110 °C for 30 minutes, and then the liquid was filtered off. Finally, the mixture was washed multiple times with hexane and dried under vacuum to obtain the spherical catalyst component B3.

[0087] Comparative Example 4:

[0088] In a 300 mL glass reaction flask under nitrogen protection, 40 mL of hexane and 12.0 g of spherical magnesium halide alcohols were added sequentially. The mixture was cooled to -20 °C, and 20 mL of titanium tetrachloride was added dropwise. The mixture was kept at this temperature for 1 hour, and then 2.0 mL of tetraethyl orthosilicate was added and maintained for 30 minutes. The temperature was then slowly increased to 80 °C and maintained for 30 minutes, after which the liquid was filtered off. Next, 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the temperature was increased to 110 °C and maintained for 30 minutes before filtering off the liquid. Then, another 40 mL of toluene and 40 mL of titanium tetrachloride were added, and the temperature was increased to 110 °C and maintained for 30 minutes before filtering off the liquid. Finally, the mixture was washed repeatedly with hexane and dried under vacuum to obtain the spherical catalyst component B4.

[0089] Comparative Example 5

[0090] In a reactor that has undergone repeated purging with high-purity nitrogen, 4.0 g of anhydrous magnesium chloride, 50 ml of toluene, 2.0 ml of epichlorohydrin, and 3.0 ml of tributyl phosphate were added sequentially. The mixture was heated to 50 °C with stirring and maintained for 15 minutes. Then, 6.0 ml of ethanol was added and the mixture was maintained for 15 minutes. The temperature was then lowered to -5 °C, and a mixture of 30 ml of titanium tetrachloride and 30 ml of heptane was added dropwise. Finally, 2 ml of diethyl ether was added, and the system was gradually heated to 80 °C and held at that temperature for 2 hours. Stirring was stopped, the mixture was allowed to stand, and the supernatant was removed. After washing with hexane multiple times, the mixture was dried to obtain solid catalyst component B5.

[0091] (II) Ethylene Polymerization

[0092] A 2-liter stainless steel reactor was fully purged with H2, then 1000 mL of hexane, 1.0 mL of a 1 mol / L triethylaluminum hexane solution, and a measured amount (containing approximately 0.04 mmol of titanium) of the prepared catalyst component were added. The reactor was heated to 70°C and hydrogen was added at 0.58 MPa (gauge pressure). Ethylene was then introduced to bring the pressure inside the reactor to 0.73 MPa (gauge pressure), and polymerization was carried out at 85°C for 2 hours. The experimental results are shown in the table below:

[0093] Table 1: Experimental Results

[0094]

[0095] As can be seen from the data in the table above, the addition of specific carbonate compounds in this invention enables the catalyst to have higher activity and polymer powder bulk density during high-hydrogen polymerization, while the melt index of the resulting polymer powder is significantly improved.

[0096] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A catalyst component for olefin polymerization, characterized in that, The catalyst composition includes reaction products of magnesium halide alkoxides, carbonate compounds, and titanium compounds; The general formula of the magnesium halide alkoxide is MgX2·m(ROH), where X is a halogen and ROH is C1-C2. 12 fatty alcohols, C7-C 12 Aromatic alcohols, composed of C1 to C2 12 Alcohols derived from fatty alcohols or substituted alcohols from C7 to C8 12 Substituted alcohols derived from aromatic alcohols; The carbonate compound is bis(trichloromethyl) carbonate.

2. The catalyst component according to claim 1, wherein, The magnesium halide in the magnesium halide alkoxide is at least one of magnesium dichloride, magnesium dibromide and magnesium diiodide; The alcohol in the magnesium halide alcohol is selected from at least one of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, 2-ethylhexanol, n-octanol, dodecanol, benzyl alcohol, phenethyl alcohol, and haloalcohols of the above alcohols.

3. The catalyst component according to claim 2, wherein, The magnesium halide in the magnesium halide alkoxide is magnesium dichloride; The alcohol in the magnesium halide alcohol is at least one of ethanol, isopropanol, butanol, 2-ethylhexanol, benzyl alcohol, phenethyl alcohol, and haloalcohols of the above alcohols.

4. The catalyst component according to claim 1, wherein, In the magnesium halide alcohol, m is 0.1 to 10 moles per mole of magnesium halide.

5. The catalyst component according to claim 4, wherein, In the magnesium halide alkoxide, m is 1 to 5 moles per mole of magnesium halide.

6. The catalyst component according to claim 1, wherein, The general formula of the titanium compound is TiX. n (OR) 4-n Where: X is a halogen, and R is a C1 to C2 halogen. 14 Aliphatic hydrocarbon groups or C6~C 14 Aromatic hydrocarbon group, where n is an integer from 0 to 4.

7. The catalyst component according to claim 6, wherein, The titanium compound is at least one selected from titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium tetraethoxy, titanium tetrabutoxy, titanium monochlorotriethoxy, titanium dichlorodiethoxy, and titanium trichloromonoethoxy.

8. The catalyst component according to claim 7, wherein, The titanium compound is at least one of titanium tetrachloride, titanium tetraethoxy, and titanium tetrabutoxy.

9. The catalyst component according to claim 1, wherein, The carbonate compound is 0.001 to 10 moles per mole of magnesium halide alcohol; the titanium compound is 0.2 to 100 moles per mole of magnesium halide alcohol.

10. The catalyst component according to claim 9, wherein, The carbonate compound is 0.002 to 1 mole per mole of magnesium halide alcohol; the titanium compound is 1.0 to 20 moles per mole of magnesium halide alcohol.

11. A method for preparing the catalyst component according to any one of claims 1-10, characterized in that, In the presence of an inert solvent, the magnesium halide alkoxide is reacted with the carbonate compound, and then with the titanium compound to obtain the catalyst component.

12. A catalyst for olefin polymerization, characterized in that, The catalyst comprises the following components: Component A: The catalyst component according to any one of claims 1 to 10; Component B: Organoaluminum compound; its general formula is AlR n X 3-n In the formula, R is a hydrocarbon group with 1 to 20 carbon atoms; X is a halogen; and n is an integer 0 < n ≤ 3.

13. The catalyst according to claim 12, wherein, X is chlorine or bromine.

14. The catalyst according to claim 12 or 13, wherein, The molar ratio of aluminum in component B to titanium in component A is 1 to 1000:

1.

15. The catalyst according to claim 14, wherein, The molar ratio of aluminum in component B to titanium in component A is 5 to 500:

1.

16. The catalyst according to claim 12, wherein, The organoaluminum compound is at least one selected from trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum hydrogen, diisobutylaluminum hydrogen, diethylaluminum chloride, diisobutylaluminum chloride, sesquiethylaluminum chloride, and diethylaluminum chloride.

17. The catalyst according to claim 16, wherein, The organoaluminum compound is triethylaluminum and / or triisobutylaluminum.

18. The use of a catalyst component according to any one of claims 1-10 or a catalyst according to any one of claims 12-17 in an olefin polymerization reaction.

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