Olefin polymerization catalyst component, preparation method thereof, catalyst system and application

Abstract

The invention provides a preparation method of an olefin polymerization catalyst solid component, which comprises the following steps: in the presence of a first dispersant, carrying out first contact reaction on alkoxy magnesium and a hydrogen halide alcohol solution; then carrying out a second contact reaction with an alcohol compound to obtain a solution; carrying out third contact reaction on the solution and a first titanium compound in the presence of an assistant precipitation agent and a second dispersing agent, and heating to separate out solid precipitate; carrying out fourth contact reaction on the solid precipitate and an internal electron donor compound; separating to obtain a solid product and carrying out fifth contact reaction on the solid product and a second titanium compound. The catalyst solid component obtained by the method can be used for preparing an olefin polymerization catalyst with good particle morphology and high polymerization activity.

Description

Technical Field

[0001] This invention relates to a solid component of an olefin polymerization catalyst and its preparation method, as well as a catalyst system using the solid component of the olefin polymerization catalyst and its application. Background Technology

[0002] Currently, polymers and copolymers of lower α-olefins, particularly ethylene, propylene, and butene, are widely used. These polymers are relatively inexpensive to manufacture and possess many properties suitable for industrial applications. The most common form of these polymers is a highly crystalline solid. During polymerization, whether via liquid-phase, gas-phase, slurry polymerization, or any other commonly used method, the morphology of both catalyst particles and polymer particles must meet specific requirements for shape and size. The morphology of the catalyst particles plays a decisive role, and the morphological characteristics of the main catalyst support determine the morphological characteristics of the main catalyst. Therefore, the formation, preparation, and morphological characteristics of the catalyst support are crucial for producing polymer particles of the appropriate shape and size.

[0003] US patents US5082907A, US5151399A, US5229342A, US5106806A, US5146028A, US5066737A, US5124298A, and US5077357A disclose various magnesium and titanium-containing catalyst precursors, some of which are prepared using alkoxymagnesium as a starting material. These precursors lack polymerization catalytic activity and do not contain any effective electron donors, but they are precisely the precursors used as starting materials in the subsequent conversion into active pre-catalysts. The magnesium and titanium-containing pre-catalysts are formed either by the direct chlorination of the magnesium and titanium-containing precursors or by reacting the magnesium and titanium-containing precursors with tetravalent titanium halide, optionally a hydrocarbon, and optionally an electron donor. The resulting pre-catalyst solids are then separated from the reaction slurry (through processes such as filtration, precipitation, and crystallization), and these main catalysts are then reacted with a co-catalyst and a selectivity control agent to convert them into polymerization catalysts. US Patent 5034361A discloses a method for dissolving magnesium alkoxy compounds in an alkanol solvent by interacting the magnesium alkoxy compound with a certain acidic substance. This magnesium-containing catalyst precursor is then reacted with various titanium compounds to prepare magnesium- and titanium-containing catalyst precursors.

[0004] When alkoxymagnesium, such as ethoxymagnesium, is used as a starting material to form a precatalyst precursor, a cleavage agent is often required to break up the aggregated ethoxymagnesium and allow it to react with other components. As disclosed in US patents US5124298A and US5077357A, the precursor is prepared using chlorobenzene as a solvent and o-cresol, which chemically breaks up aggregated ethoxymagnesium, as a cleavage agent. A small amount of o-cresol (1-3%) remains in the precursor product, which, besides being physiologically irritating, can still become a polymerization catalyst poison if not effectively filtered out during catalyst preparation. In addition to the cleavage agents described in the aforementioned patents, including physiologically irritating phenolic compounds such as p-cresol, 3-methoxyphenol, and 4-dimethylaminophenol, many methods employ borate ester solubilizers to dissolve the alkoxymagnesium, allowing the magnesium compound reaction to occur in the liquid phase. This method is complex because it requires a precipitant to precipitate the solid product, and it is costly and inefficient due to the loss of some raw materials during the dissolution process.

[0005] Therefore, it is of great significance to find a substance or system of substances that will not irritate the catalyst preparation personnel or cause toxicity to the polymerization catalyst to promote the dissolution of magnesium alkoxy.

[0006] Furthermore, existing solutions for dissolving magnesium alkoxylates require specific methods to precipitate catalyst supports that meet the required catalyst particle morphology. The preparation process of the catalyst support necessitates the addition of specific precipitating agents to improve the particle morphology of the precipitated solid components. To this end, the inventors have previously disclosed a series of precipitating agent systems containing 1,3-diol esters, and the resulting olefin polymerization catalysts (CN102276765B, CN101993506B, CN101864009B, CN101643519B, CN103012627A, CN103012625A, CN103012626). The olefin polymerization catalysts prepared using 1,3-diol ester-containing precipitating agent systems contain small amounts of 1,3-diol ester compounds, the presence of which significantly improves the catalyst particle morphology. However, the aforementioned particle systems contain toxic substances, such as o-cresol, resulting in poor performance of the solid components of the obtained olefin polymerization catalysts. Summary of the Invention

[0007] To address the aforementioned problems in existing technologies, this invention provides a novel method for preparing the solid component of an olefin polymerization catalyst. This invention utilizes alkoxymagnesium, which is not limited by particle morphology, as the initial raw material. An alkoxymagnesium solution is prepared using a non-toxic substance system. Then, a precipitation aid is used to precipitate the solid component, which is then loaded with an optional internal electron donor. Finally, a polyolefin catalyst with good particle morphology and high polymerization activity is prepared.

[0008] The first aspect of this invention provides a method for preparing a solid component of an olefin polymerization catalyst, comprising:

[0009] (1) In the presence of a first dispersant, magnesium alkoxy and a hydrogen alcohol solution are subjected to a first contact reaction to obtain a dispersion slurry;

[0010] (2) The dispersion slurry is reacted with an alcohol compound in a second contact reaction to obtain a solution;

[0011] (3) In the presence of a precipitation aid and a second dispersant, the solution is reacted with a first titanium compound in a third contact reaction, and the solid precipitate is precipitated by heating to obtain a mixture containing the solid precipitate. Optionally, the mixture is reacted with an internal electron donor compound in a fourth contact reaction to obtain an intermediate product.

[0012] (4) The intermediate product is subjected to solid-liquid separation to obtain a solid product and then reacted with the second titanium compound in a fifth contact reaction.

[0013] According to some embodiments of the present invention, in step (1), the alkoxy magnesium has the structural formula Mg(R1O)(R2O), wherein R1 and R2 are the same or different, and each is independently a C1-C with or without substituents. 10 hydrocarbon group, with or without substituents, C6-C 20 phenyl.

[0014] According to some embodiments of the present invention, OR1 and OR2 may be the same or different, and each is independently selected from one or more of ethoxy, propoxy, butoxy and phenoxy.

[0015] According to some embodiments of the present invention, the alkoxy magnesium is selected from one or more of magnesium diethoxy, magnesium diepropoxy, magnesium diebutoxy, and magnesium diphenoxy.

[0016] According to some embodiments of the present invention, the hydrogen halide alcohol solution is an alcohol solution in which hydrogen halide is dissolved, wherein the mass concentration of hydrogen halide is 10% to 35% (wt%), preferably 20% to 30%. The hydrogen halide is selected from at least one of HCl, HBr, and HI, preferably HCl. The alcohol in the hydrogen halide alcohol solution is C1-C. 10 At least one of straight-chain and branched alcohols, preferably C2-C 10 The alcohol is a straight-chain alcohol. Preferably, the alcohol in the hydrogen halide alcohol solution is selected from one or more of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, isopentanol, hexanol, heptanol, octanol, isooctanol, nonanol, and decanol.

[0017] According to some embodiments of the present invention, the molar ratio of hydrogen halide to magnesium alkoxy in the hydrogen halide alcohol solution is 2:1-3:1, more preferably 2:1.

[0018] According to the present invention, in step (1), the order of addition of alkoxymagnesium, halohydrin solution and first dispersant is not specifically limited. Preferably, the addition order may be: first add alkoxymagnesium, then add dispersant and stir to achieve uniform dispersion, and then add halohydrin solution to carry out contact reaction.

[0019] The present invention adds a halohydrin solution to alkoxymagnesium, which can fully dissolve the alkoxymagnesium, not only significantly increasing the yield of the precipitated solid component, but also improving the morphology and overall performance of the catalyst.

[0020] According to some embodiments of the present invention, the purpose of the first contact reaction is to allow the alkoxymagnesium and halohydrin solution to react in the presence of a first dispersant to form a homogeneous slurry. The present invention does not specifically limit the conditions for carrying out the first contact reaction to form a homogeneous slurry, and these conditions can be determined according to the specific alkoxymagnesium used. Preferably, the conditions for the first contact reaction include: a temperature of 10-150°C, preferably 60-120°C; and a time of 0.1-2 hours, preferably 0.2-1 hour.

[0021] According to some embodiments of the present invention, the first dispersant and the second dispersant may be the same or different, and may be various alkane compounds, aromatic hydrocarbon compounds or mineral oils commonly used in the art that do not chemically interact with alkoxymagnesium or alcohol compounds. Specific examples may be one or more of alkanes, cycloalkanes, aromatic hydrocarbons, kerosene, petrolatum oil, and white oil, preferably one or more of hexane, heptane, octane, decane, benzene, toluene and xylene.

[0022] According to some embodiments of the present invention, the amount of the first dispersant is 0.01-50 mol, preferably 5-20 mol, relative to 1 mol of alkoxymagnesium based on elemental magnesium.

[0023] According to some embodiments of the present invention, the amount of the second dispersant is 0.01-50 mol, preferably 5-20 mol, relative to 1 mol of alkoxymagnesium based on elemental magnesium.

[0024] According to some embodiments of the present invention, in step (2), the alcohol compound is one or more of fatty alcohols, alicyclic alcohols, and aromatic alcohols; preferably C1-C1. 10 Straight-chain fatty alcohols, C3-C 10 Branched-chain fatty alcohols, C3-C 12 alicyclic alcohols, C6-C 20 aryl alcohols and C7-C20 The alcohol is selected from one or more of alkyl aryl alcohols; more preferably, the alcohol is selected from one or more of ethanol, propanol, butanol, 2-ethylhexanol, benzyl alcohol and phenethyl alcohol.

[0025] According to some embodiments of the present invention, the amount of alcohol compound (including alcohol and alcohol compound in the hydrogen halide alcohol solution) is 0.2-10 moles, more preferably 2-5 moles, relative to 1 mole of alkoxymagnesium based on magnesium element.

[0026] According to some embodiments of the present invention, the conditions for the second contact reaction include: a temperature of 10-150°C, preferably 60-140°C; and a time of 0.1-10 hours, preferably 0.5-6 hours.

[0027] According to some embodiments of the present invention, in step (3), the precipitation aid includes precipitation aid a, precipitation aid b and precipitation aid c, wherein precipitation aid a is a glycol ester compound, precipitation aid b is an alkyl ester of an aliphatic or aromatic carboxylic acid, and precipitation aid c is a titanate compound.

[0028] According to some embodiments of the present invention, relative to 1 mole of alkoxymagnesium based on elemental magnesium, the amount of the precipitation aid a is 0.005-0.1 moles, preferably 0.01-0.05 moles; the amount of the precipitation aid b is 0.01-0.5 moles, preferably 0.02-0.2 moles; and the amount of the precipitation aid c is 0.01-0.3 moles, preferably 0.02-0.08 moles.

[0029] According to some embodiments of the present invention, the precipitation aid a is a diol ester compound represented by formula (I).

[0030]

[0031] In equation (I), R1-R2 may be the same or different, and each is independently substituted or unsubstituted C1-C. 20 Straight-chain alkyl, substituted or unsubstituted C3-C 20 Branched alkyl groups, substituted or unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C7-C 20 alkylaryl, substituted or unsubstituted C7-C 20 Aryl, substituted or unsubstituted C2-C 10 olefinic or substituted or unsubstituted C 10 -C 20 Fused ring aryl group; R3-R8 may be the same or different, each independently being hydrogen, halogenated, substituted or unsubstituted C1-C20 Straight-chain alkyl, substituted or unsubstituted C3-C 20 Branched alkyl groups, substituted or unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C7-C 20 alkylaryl, substituted or unsubstituted C7-C 20 Aryl, substituted or unsubstituted C2-C 10 olefinic or substituted or unsubstituted C 10 -C 20 The fused-ring aryl group; or at least one of R3-R6 forming a ring with at least one of R7-R8; preferably, the co-precipitant a is selected from 2-ethyl-1,3-propanediol dibenzoate, 2-propyl-1,3-propanediol dibenzoate, 2-isopropyl-2-isopentyl-1,3-propanediol dibenzoate, 1,3-butanediol dimethylbenzoate, 2-methyl-1,3-butanediol di-m-chlorobenzoate, 2,3-dimethyl- One or more of the following: 1,3-butanediol dibenzoate, 1,3-pentanediol dinepentate, 2,4-pentanediol dibenzoate, 2-methyl-1,3-pentanediol cinnamic acid ester, 2,2-dimethyl-1,3-pentanediol dibenzoate, 2,4-heptanediol dibenzoate, 3,5-heptanediol dibenzoate, 4-ethyl-3,5-heptanediol dibenzoate, and 2-methyl-3,5-heptanediol dibenzoate.

[0032] According to some embodiments of the present invention, the amount of the precipitation aid a is 0.005-0.1 mol, preferably 0.01-0.05 mol, relative to 1 mol of alkoxymagnesium based on elemental magnesium.

[0033] According to some embodiments of the present invention, the precipitation aid b is a C1-C8 aliphatic carboxylic acid or a C7-C8 aliphatic carboxylic acid. 10 C1-C of aromatic carboxylic acids 10 Alkyl esters; preferably, the precipitant b is selected from one or more of ethyl benzoate, diethyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, diethyl adipate, and dibutyl adipate.

[0034] According to some embodiments of the present invention, the amount of the precipitation aid b is 0.01-0.5 mol, preferably 0.02-0.2 mol, relative to 1 mol of alkoxymagnesium (calculated as elemental magnesium).

[0035] According to some embodiments of the present invention, the precipitation aid c has the general formula Ti(OR9). n X 4-nTitanate compounds, wherein R9 is C1-C 10 Alkyl or C3-C 10 The cycloalkyl group, where X is a halogen; 1≤n≤4, where n is an integer; preferably, the precipitant c is selected from one or more of tetrabutyl titanate, tetraethyl titanate, and isopropyl titanate.

[0036] According to some embodiments of the present invention, the amount of the precipitation aid c is 0.01-0.3 mol, preferably 0.02-0.08 mol, relative to 1 mol of alkoxymagnesium based on elemental magnesium.

[0037] According to some embodiments of the present invention, the first titanium compound and the second titanium compound may be the same or different, and each independently has the general formula Ti(OR) 10 ) m X 4－m The titanium compound shown, wherein R 10 It is an alkyl group, preferably C1-C. 10 Alkyl group; X is a halogen, preferably Cl, Br or I; 0≤m≤3, where m is an integer.

[0038] According to some embodiments of the present invention, the first titanium compound and the second titanium compound are each independently selected from at least one or more of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium alkoxytrihalide, titanium dialkoxydihalide and titanium trialkoxyhalide.

[0039] According to some embodiments of the present invention, the amount of the first titanium compound is 5-35 moles, preferably 8-25 moles, relative to 1 mole of alkoxymagnesium based on magnesium element.

[0040] According to some embodiments of the present invention, the amount of the second titanium compound is 3-40 moles, preferably 5-35 moles, relative to 1 mole of alkoxymagnesium based on elemental magnesium.

[0041] According to some embodiments of the present invention, in step (3), in the presence of a precipitant, the homogeneous solution obtained in step (2) is subjected to a third contact reaction with the first titanium compound to precipitate a solid precipitate. There are no particular limitations on the resulting mixture containing the solid precipitate; the reaction can be carried out with reference to existing techniques. For example, the first titanium compound in step (3) can react alone with the homogeneous solution obtained in step (2) in the presence of the precipitant, or the first titanium compound can be mixed with a dispersant and then reacted with the homogeneous solution obtained in step (2) in the presence of the precipitant. Preferably, the first titanium compound is mixed with a dispersant and then reacted with the homogeneous solution obtained in step (2) in the presence of the precipitant. Generally, in the method for preparing the catalyst component for olefin polymerization according to the present invention, the dispersant mixed with the first titanium compound can be at least one of hexane, heptane, octane, decane, benzene, toluene, and xylene.

[0042] According to some embodiments of the present invention, the third contact reaction, in the presence of a precipitation aid, involves contacting the homogeneous solution obtained in step (2) with the first titanium compound at a temperature of -40°C to 0°C for 3-5 hours, and then raising the temperature to 50-150°C; preferably, in the presence of a precipitation aid, the homogeneous solution obtained in step (2) is contacted with the first titanium compound at a temperature of -30°C to -20°C for 3.5-4.5 hours, and then raised the temperature to 90-130°C. In step (3), the first titanium compound and the homogeneous solution obtained in step (2) can be mixed first at a temperature of -40°C to 0°C, and then the precipitant solution can be added and contacted for 3-5 hours, and then the temperature can be raised to 50-150°C to obtain a mixture containing solid precipitate; or the precipitant solution can be added to the homogeneous solution obtained in step (2) first, and then the mixture can be contacted with the first titanium compound at a temperature of -40°C to 0°C for 3-5 hours, and then the temperature can be raised to 50-150°C to obtain a mixture containing solid precipitate; preferably, the precipitant solution can be added to the homogeneous solution obtained in step (2) first, and then the mixture can be contacted with the first titanium compound at a temperature of -40°C to 0°C for 3-5 hours, and then the temperature can be raised to 50-150°C to obtain a mixture containing solid precipitate; more preferably, the precipitant solution can be added to the homogeneous solution obtained in step (2) first, and then the mixture can be contacted with the first titanium compound at a temperature of -30°C to -20°C for 3.5-4.5 hours, and then the temperature can be raised to 90-130°C to obtain a mixture containing solid precipitate.

[0043] The solid component in the mixture containing solid precipitate in step (3) is an olefin polymerization catalyst support component, which contains 0.01-1% by weight of titanium, 0.1-3.5% by weight of precipitant a, and 0.1-4.5% by weight of precipitant b, based on the total weight of the catalyst support component.

[0044] According to some embodiments of the present invention, the conditions for the third contact reaction include: a temperature of -40°C to 0°C; and a time of 3-5 hours.

[0045] According to some embodiments of the present invention, the temperature is raised to 50-150°C.

[0046] According to some embodiments of the present invention, generally, depending on the needs of practical applications, particularly for catalyst solid components used in propylene polymerization, at least one internal electron donor compound is added during the preparation of the catalyst solid component in order to obtain a high isotactic propylene polymer. Preferably, the internal electron donor compound is selected from one or more of phthalate internal electron donor compounds, glycol ester compounds, 1,3-diether compounds, succinate compounds, and cyanobutyl succinate compounds. More preferably, the internal electron donor compound is selected from one or more of diisobutyl phthalate, di-n-butyl phthalate, 9,9-di(methoxymethyl)fluorene, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 3,5-heptanediol dibenzoate, 2,4-pentanediol dibenzoate, diethyl 2,3-diisopropylsuccinate, and diethyl 2-cyano-2,3-diisopropylsuccinate.

[0047] According to some embodiments of the present invention, the conditions for the fourth contact reaction include: a temperature of 20-120°C, preferably 70-110°C; and a reaction time of 0.5-6 hours, preferably 1-4 hours.

[0048] According to some embodiments of the present invention, the amount of the internal electron donor compound is 0.01-3 moles, preferably 0.02-0.3 moles, relative to 1 mole of alkoxymagnesium (calculated as magnesium element).

[0049] According to some embodiments of the present invention, the weight ratio of the total internal electron donor compound content to the co-precipitant a in the solid component of the olefin polymerization catalyst is 2-8:1, preferably 3-5:1.

[0050] It should be noted that, in this invention, the internal electron donor compound can only be added after the solid precipitates in step (3). This is mainly because adding it before the solid precipitates in step (3) will, on the one hand, affect the precipitation effect of the solid in step (3), that is, affect the particle morphology of the catalyst solid component, and ultimately affect the overall performance of the catalyst; on the other hand, studies have shown that adding the internal electron donor compound before the solid precipitates will also affect the utilization efficiency of the internal electron donor compound. Specifically, even if a large amount of internal electron donor compound is added, it is difficult to obtain a large amount of internal electron donor compound in the final catalyst solid component, thereby affecting the performance of the final prepared resin.

[0051] According to some embodiments of the present invention, the form in which the titanium compound is used in steps (3) and (4) is not particularly limited. For example, the second titanium compound in step (4) can react alone with the solid product after solid-liquid separation of the intermediate product obtained in step (3), or the second titanium compound can be mixed with a dispersant and reacted with the separated solid product. The types of dispersants have been described in detail above and will not be repeated here.

[0052] According to some embodiments of the present invention, the conditions for the fifth contact reaction include: a temperature of 50-150°C, preferably 80-120°C; and a reaction time of 1-6 hours, preferably 2.5-4.5 hours.

[0053] A second aspect of the present invention provides an olefin polymerization catalyst component obtained according to the preparation method described above.

[0054] A third aspect of the present invention provides a catalyst system comprising:

[0055] A. An olefin polymerization catalyst component prepared according to the method of the first aspect above or an olefin polymerization catalyst component according to the second aspect above;

[0056] B. Alkyl aluminum compounds;

[0057] C. Optionally, external electron-donating compounds.

[0058] According to some embodiments of the present invention, in the above-described olefin polymerization catalyst, the alkylaluminum compound can be any alkylaluminum compound commonly used in the field of olefin polymerization that can be used as a co-catalyst for Ziegler-Natta type catalysts. Preferably, the alkylaluminum compound can be a compound represented by formula (III).

[0059] AlR' n' X' 3-n' (III)

[0060] In formula (III), R' is hydrogen, an alkyl group having 1-20 carbon atoms, or an aryl group having 6-20 carbon atoms, X' is a halogen, and n' is an integer from 1 to 3. Specific examples of the alkylaluminum compound may be at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum hydrogen, diisobutylaluminum hydrogen, diethylaluminum chloride, diisobutylaluminum chloride, sesquiethylaluminum chloride, and diethylaluminum chloride.

[0061] According to some embodiments of the present invention, the amount of the alkylaluminum compound can be a conventional amount in the art. Generally, the molar ratio of aluminum in the alkylaluminum compound to titanium in the catalyst is 5-5000:1. Preferably, the molar ratio of aluminum in the alkylaluminum compound to titanium in the catalyst is 20-1000:1. More preferably, the molar ratio of aluminum in the alkylaluminum compound to titanium in the catalyst is 50-500:1.

[0062] Since only the precipitant used in the preparation process of the olefin polymerization catalyst components has been improved in the olefin polymerization catalyst of the present invention, the type and content of the external electron donor compound in the olefin polymerization catalyst of the present invention are not particularly limited. In a preferred embodiment, the molar ratio of aluminum in the alkylaluminum compound to the external electron donor compound is 0.1-500:1, preferably 1-300:1, and more preferably 3-100:1.

[0063] According to some embodiments of the present invention, in the above-described olefin polymerization catalyst, the external electron donor component may be an organosilicon compound represented by formula (VI).

[0064] R 1 " m” R 2 " n” Si(OR 3 ”) 4-m”-n” (VI)

[0065] In equation (VI), R 1 "and R 2 "Same or different, respectively, one of the following: halogen, hydrogen atom, alkyl group with 1-20 carbon atoms, cycloalkyl group with 3-20 carbon atoms, aryl group with 6-20 carbon atoms, and haloalkyl group with 1-20 carbon atoms; R" 3"m" represents one of the following: alkyl groups with 1-20 carbon atoms, cycloalkyl groups with 3-20 carbon atoms, aryl groups with 6-20 carbon atoms, and haloalkyl groups with 1-20 carbon atoms; m" and n" are integers from 0 to 3, and m" + n" < 4. Specific examples of the organosilicon compounds include trimethylmethoxysilane, trimethylethoxysilane, trimethylphenoxytriethylmethoxysilane, triethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, ethylisopropyldimethoxysilane, propylisopropyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, isopropylisobutyldimethoxysilane, and di-tert-butyldimethoxysilane. Alkane, tert-butylmethyldimethoxysilane, tert-butylethyldimethoxysilane, tert-butylpropyldimethoxysilane, tert-butylisopropyldimethoxysilane, tert-butyl, tert-butylbutyldimethoxysilane, tert-butylisobutyldimethoxysilane, tert-butyl(sec-butyl)dimethoxysilane, tert-butylpentyldimethoxysilane, tert-butylnonyldimethoxysilane, tert-butylhexyldimethoxysilane, tert-butylheptyldimethoxysilane, tert-butyloctyldimethoxysilane, tert-butyldecyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylethyldimethoxysilane, cyclohexylpropyldimethoxysilane, cyclohexylisobutyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexyl-tert-butyl Dimethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylethyldimethoxysilane, cyclopentylpropyldimethoxysilane, cyclopentyltert-butyldimethoxysilane, dicyclopentyldimethoxysilane, cyclopentylcyclohexyldimethoxysilane, bis(2-methylcyclopentyl)dimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, isopropyltrimethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane, tert-butyltrimethoxysilane, sec-butyltrimethoxysilane, pentyltrimethoxysilane These include silanes such as isopentyltrimethoxysilane, cyclopentyltrimethoxysilane, cyclohexyltrimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, vinyltrimethoxysilane, cyclohexylmethyldimethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, 2-ethylpiperidinyl-2-tert-butyldimethoxysilane, (1,1,1-trifluoro-2-propyl)-2-ethylpiperidinyldimethoxysilane, and (1,1,1-trifluoro-2-propyl)-methyldimethoxysilane. These organosilicon compounds can be used individually or in combination of two or more.More preferably, compound C, as an external electron donor, contains at least one of dicyclopentyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, cyclohexylmethyldimethoxysilane, methyl tert-butyldimethoxysilane, and tetramethoxysilane.

[0066] The fourth aspect of the present invention provides the above-described olefin polymerization catalyst components, a method for preparing the above-described olefin polymerization catalyst components, and the application of the above-described olefin polymerization catalyst system in olefin polymerization.

[0067] According to some embodiments of the present invention, the olefin is an olefin represented by the general formula CH2=CHR, wherein R is selected from hydrogen or a C1-C6 alkyl group. The olefin polymerization method of the present invention can be used for homopolymerization of olefins, and can also be used for copolymerization of multiple olefins. At least one of the olefins is an olefin represented by the general formula CH2=CHR, wherein R is hydrogen or an alkyl group having 1-6 carbon atoms. Specific examples of the olefin represented by the general formula CH2=CHR include: ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Preferably, the α-olefin CH2=CHR is one or more selected from ethylene, propylene, 1-butene, 4-methyl-1-pentene, and 1-hexene. More preferably, the olefin represented by the general formula CH2=CHR is propylene.

[0068] According to the method for applying the solid catalyst component in olefin polymerization of the present invention, the components of the olefin polymerization catalyst, namely the solid catalyst component, the organoaluminum compound as a co-catalyst, and the compound as an external electron donor, can be contacted before contacting the olefin monomer, which is referred to in the industry as "pre-contact" or "pre-complexation"; alternatively, the solid catalyst component, the organoaluminum compound, and the external electron donor compound can be added separately to the olefin monomer before the polymerization reaction, i.e., "pre-contact" is not performed. Preferably, the reaction of the components of the olefin polymerization catalyst is carried out using the "pre-contact" method. The "pre-contact" time is 0.1-30 min, preferably 1-10 min; the "pre-contact" temperature is -20 to 80°C, preferably 10-50°C.

[0069] The olefin polymerization catalyst is first polymerized to a certain extent in the presence of a small amount of olefin monomer to obtain a prepolymerization catalyst, and then the prepolymerization catalyst is further reacted with olefin monomer to obtain olefin polymer.

[0070] This technology, known in the industry as the "prepolymerization" process, helps to improve catalyst polymerization activity and polymer packing density. According to the olefin polymerization method of the present invention, the olefin polymerization catalyst may or may not employ the "prepolymerization" process, but the "prepolymerization" process is preferred. The "prepolymerization" ratio is 5-1000 gPP / gCat, preferably 10-500 gPP / gCat; the "prepolymerization" temperature is -20 to 80°C, preferably 10-50°C.

[0071] According to the olefin polymerization method of the present invention, the olefin polymerization conditions can be conventional conditions in the art. The amount of catalyst used can be the amount of various catalysts in the prior art.

[0072] The beneficial effects of this invention are:

[0073] (1) This invention utilizes alkoxy magnesium, which is not limited by particle morphology, as the initial raw material. It can use a non-toxic substance system to complete the conversion of alkoxy magnesium into olefin polymerization catalyst precursor and complete the preparation of the olefin polymerization catalyst precursor (solution).

[0074] (2) After the alkoxy magnesium solution is dissolved, a specific precipitation aid system is added to precipitate the solid component, thus completing the preparation of the olefin polymerization catalyst support.

[0075] (3) The olefin polymerization catalyst component prepared by the method of the present invention has a high yield and good particle morphology.

[0076] (4) The final polyolefin catalyst obtained has good particle morphology and high polymerization activity. Detailed Implementation

[0077] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not limited to the scope of application of the present invention.

[0078] The testing method and equipment used in this invention are as follows:

[0079] 1. Catalyst support yield: Catalyst support yield % = Mass of obtained catalyst support / Mass of magnesium chloride corresponding to the number of moles of alkoxy magnesium used × 100%.

[0080] 2. Titanium content in the catalyst support: measured using a 721 spectrophotometer.

[0081] 3. Catalyst support particle size distribution: measured according to the Malvern 2000 hexane dispersant laser diffraction method.

[0082] 4. The content of the precipitant in the catalyst support component of olefin polymerization was determined using a Waters 600E liquid chromatograph or an Agilent 7890 gas chromatograph.

[0083] 5. Determination of polymer melt index (MI): Determined according to GB / T3682-2000.

[0084] 6. Polymer isotacticity (%) was determined by heptane extraction: 2 g of dry polymer sample was placed in an extractor and extracted with boiling heptane for 6 hours. The residue was dried to constant weight. The ratio of the polymer weight (g) to 2 (g) is the isotacticity.

[0085] 7. Activity Calculation: Catalyst Activity = (Mass of prepared polyolefin, kg) / (Mass of solid catalyst component, gCat)

[0086] 8. Bulk density determination: The prepared polymer powder is dropped freely from a height of 10 cm into a 100 mL container through a funnel. The weight of the polymer powder in the container is Mg. The bulk density of the polymer is M / 100 g / cm³. 3 .

[0087] 9. span=(D(90)-D(10)) / D(50).

[0088]

Example 1

[0089] 1. Preparation of catalyst component A1:

[0090] In a reactor that has undergone repeated high-purity nitrogen replacement, 5.7 g (0.05 mol) of magnesium diethoxy, 40 mL (0.375 mol) of toluene, and 12 mL of ethanol solution of hydrogen chloride (30% wt) were added sequentially. The mixture was stirred at 200 rpm and reacted at 80 °C for 30 min. Then, 15 mL (0.26 mol) of 2-ethylhexanol was added, and the temperature was raised to 110 °C. The reaction was carried out for 1 hour to obtain an alcoholic solution of magnesium compounds. Then, 1.0 mL (3.73 mmol) of diisobutyl phthalate, 1.0 mL (2.93 mmol) of tetrabutyl titanate, and 0.5 mL (1.8 mmol) of 3,5-heptanediol dibenzoate were added, and the mixture was stirred for 60 min and cooled to room temperature.

[0091] The homogeneous solution prepared above was added to a reactor containing 60 mL (0.55 mol) titanium tetrachloride and 40 mL (0.375 mol) toluene at -20 °C, which had been fully purged with nitrogen. The mixture was stirred to ensure full contact at low temperature. After 5 hours, the temperature was raised to 110 °C. During the heating process, a solid precipitate was formed. 2.7 g (10 mmol) of diisobutyl phthalate was added, and the reaction was carried out for 1 hour. After the reaction was completed, the liquid was filtered out. Then, 96 mL of toluene and 24 mL of titanium tetrachloride were added, and the mixture was contacted at 110 °C for 0.5 hours. This operation was repeated once more. The mixture was washed five times with 120 mL (0.92 mol) of hexane and dried to obtain titanium-containing solid catalyst component A1.

[0092] The analysis results of titanium content, precipitant a content, electron donor content, and particle size distribution of catalyst solid component A1 are shown in Table 1.

[0093] 2. Catalyst-assisted polymerization:

[0094] Polymerization evaluation: In a 5L high-pressure reactor, after complete displacement of the gaseous phase with propylene, 5 mL of triethylaluminum in hexane (concentration of triethylaluminum: 0.5 mmol / mL), 1 mL of cyclohexylmethyldimethoxysilane (CHMMS) in hexane (concentration of CHMMS: 0.1 mmol / mL), 10 mL of anhydrous hexane, and 10 mg of solid catalyst component were added at room temperature. The high-pressure reactor was closed, and 0.18 mol of hydrogen and 1.15 kg of liquid propylene were introduced; the temperature was raised to 70°C with stirring. The polymerization reaction was carried out at 70°C for a certain period of time. After the reaction was completed, stirring was stopped, unpolymerized propylene monomers were removed, the polymer was collected, vacuum dried, weighed, and the catalyst activity was calculated.

[0095] The polymerization activity of the catalyst system containing solid catalyst component A1 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0096]

Example 2

[0097] 1. Preparation of catalyst component A2:

[0098] The preparation method of catalyst solid component A2 is the same as that of A1 in Example 1, except that 2.7g of diisobutyl phthalate is replaced with 2.7g of di-n-butyl phthalate.

[0099] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component A2 and catalyst support component are shown in Table 1.

[0100] 2. Catalyst-assisted polymerization:

[0101] Polymerization was carried out using catalyst component A2 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing catalyst solid component A2 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0102]

Example 3

[0103] 1. Preparation of catalyst component A3:

[0104] The preparation method of catalyst solid component A3 is the same as that of A1 in Example 1, except that 2.7g of diisobutyl phthalate is replaced with 3.6g of diisobutyl phthalate.

[0105] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component A3 are shown in Table 1.

[0106] 2. Catalyst-assisted polymerization:

[0107] Polymerization was carried out using catalyst component A3 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing solid catalyst component A3 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0108]

Example 4

[0109] 1. Preparation of catalyst component A4:

[0110] The preparation method of catalyst solid component A4 is the same as that of A1 in Example 1, except that 2.7g of diisobutyl phthalate is replaced with 3.6g of di-n-butyl phthalate.

[0111] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component A4 are shown in Table 1.

[0112] 2. Catalyst-assisted polymerization:

[0113] Polymerization was carried out using catalyst component A4 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing catalyst solid component A4 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0114]

Example 5

[0115] 1. Preparation of catalyst component A5:

[0116] The preparation method of catalyst solid component A5 is the same as that of A1 in Example 1, except that 2.7g of diisobutyl phthalate is replaced with 4.6g of 2-isopropyl-2-isopentyl-1,3-dimethoxypropane.

[0117] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst support components in catalyst group A5 are shown in Table 1.

[0118] 2. Catalyst-assisted polymerization:

[0119] Polymerization was carried out using catalyst component A5 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing catalyst solid component A5 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0120]

Example 6

[0121] 1. Preparation of catalyst component A6:

[0122] The preparation method of catalyst solid component A6 is the same as that of A1 in Example 1, except that 2.7g of diisobutyl phthalate is replaced with 4.6g of 9,9-di(methoxymethyl)fluorene.

[0123] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component A6 and catalyst support component are shown in Table 1.

[0124] 2. Catalyst-assisted polymerization:

[0125] Polymerization was carried out using catalyst component A6 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing catalyst solid component A6 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0126]

Example 7

[0127] 1. Preparation of catalyst component A7:

[0128] The preparation method of catalyst solid component A7 is the same as that of A1 in Example 1, except that 2.7g of diisobutyl phthalate is replaced with 3.1g of 3,5-heptanediol dibenzoate.

[0129] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component A7 are shown in Table 1.

[0130] 2. Catalyst-assisted polymerization:

[0131] Polymerization was carried out using catalyst component A7 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing solid catalyst component A7 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0132]

Example 8

[0133] 1. Preparation of catalyst component A8:

[0134] The preparation method of catalyst solid component A8 is the same as that of A1 in Example 1, except that 2.7g of diisobutyl phthalate is replaced with 3.1g of 2,4-pentanediol dibenzoate.

[0135] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component A8 are shown in Table 1.

[0136] 2. Catalyst-assisted polymerization:

[0137] Polymerization was carried out using catalyst component A8 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing catalyst solid component A8 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0138]

Example 9

[0139] 1. Preparation of catalyst component A9:

[0140] The preparation method of catalyst solid component A9 is the same as that of A1 in Example 1, except that 2.7 g of diisobutyl phthalate is replaced with 5 mmol of diethyl 2,3-diisopropylsuccinate.

[0141] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component A9 are shown in Table 1.

[0142] 2. Catalyst-assisted polymerization:

[0143] Polymerization was carried out using catalyst component A9 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing catalyst solid component A9 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0144]

Example 10

[0145] 1. Preparation of catalyst component A10:

[0146] The preparation method of catalyst solid component A10 is the same as that of A1 in Example 1, except that 2.7g of diisobutyl phthalate is replaced with 4g of diethyl 2-cyano-2,3-diisopropylsuccinate.

[0147] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component A10 are shown in Table 1.

[0148] 2. Catalyst-assisted polymerization:

[0149] Polymerization was carried out using catalyst component A10 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing solid catalyst component A10 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0150]

Example 11

[0151] 1. Preparation of catalyst component A11:

[0152] The preparation method of catalyst solid component A11 is the same as that of A1 in Example 1, except that 12 mL of hydrogen chloride ethanol solution (30% wt) is replaced with 18 mL of hydrogen chloride ethanol solution (20% wt), and 15 mL (0.26 mol) of 2-ethylhexanol is replaced with 10 mL (0.017 mol) of 2-ethylhexanol.

[0153] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component A11 are shown in Table 1.

[0154] 2. Catalyst-assisted polymerization:

[0155] Polymerization was carried out using catalyst component A11 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing solid catalyst component A11 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0156]

Example 12

[0157] 1. Preparation of catalyst component A12:

[0158] Catalyst solid component A12 was prepared according to Example 1, except that the reaction time in step 1 was adjusted from 30 min to 1 hour.

[0159] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component A12 are shown in Table 1.

[0160] 2. Catalyst-assisted polymerization:

[0161] Polymerization was carried out using catalyst component A12 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing solid catalyst component A12 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0162] Comparative Example 1

[0163] 1. Preparation of catalyst component D1:

[0164] The preparation method of catalyst solid component A2 is the same as that of A1 in Example 1, except that 12 mL of hydrogen chloride ethanol solution (30% wt) is replaced with 5 mL of hydrogen chloride ethanol solution (30% wt); and 15 mL (0.26 mol) of 2-ethylhexanol is replaced with 22 mL (0.26 mol) of 2-ethylhexanol.

[0165] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component D1 are shown in Table 1.

[0166] 2. Catalyst-assisted polymerization:

[0167] Polymerization was carried out using catalyst component D1 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing catalyst solid component D1 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0168] Comparative Example 2

[0169] 1. Preparation of catalyst component D2:

[0170] Same as Example 1, except that no hydrogen chloride was dissolved in the added ethanol solution.

[0171] The results of titanium content, co-precipitant a content, electron donor content, and particle size distribution of catalyst component D2 and catalyst support component are shown in Table 1.

[0172] 2. Catalyst-assisted polymerization:

[0173] Polymerization was carried out using catalyst component D2 according to the polymerization method of Example 1. The polymerization activity of the catalyst system containing solid catalyst component D2 in propylene polymerization and the performance parameters of the polymer are shown in Table 2.

[0174] Table 1. Catalyst support results

[0175]

[0176]

[0177] Table 2. Comparison of propylene polymerization properties

[0178]

[0179] As can be seen from the data in Tables 1 and 2, the catalyst prepared by this invention exhibits excellent performance in terms of composition, particle morphology, and polymerization properties.

[0180] In Comparative Example 1, only 5 ml of hydrogen chloride ethanol solution was added, resulting in insufficient dissolution of alkoxymagnesium, which significantly reduced the yield of the precipitated solid component and affected the overall performance of the catalyst. In Comparative Example 2, the ethanol added in step 1 did not dissolve the hydrogen chloride, causing the reaction process to be unable to proceed smoothly and preventing the preparation of the solution. As a result, the alkoxymagnesium could not dissolve properly, making subsequent catalyst preparation impossible.

[0181] The above description is merely a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, based on the technical teachings provided by the present invention and as common knowledge in the field, other equivalent modifications and improvements can be made, and these should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a solid component of an olefin polymerization catalyst, comprising: (1) In the presence of a first dispersant, magnesium alkoxy and a hydrogen alcohol solution are subjected to a first contact reaction to obtain a dispersion slurry; (2) The dispersion slurry is reacted with an alcohol compound in a second contact reaction to obtain a solution; (3) In the presence of a precipitation aid and a second dispersant, the solution is reacted with a first titanium compound in a third contact reaction, and the solid precipitate is precipitated by heating to obtain a mixture containing the solid precipitate; optionally, the mixture is reacted with an internal electron donor compound in a fourth contact reaction to obtain an intermediate product; (4) The intermediate product is subjected to solid-liquid separation to obtain a solid product and then reacted with the second titanium compound in a fifth contact reaction.

2. According to the preparation method of claim 1, in step (1), the alkoxy magnesium has the structural formula Mg(R1O)(R2O), wherein, R1 and R2 may be the same or different, and each is independently a C1-C with or without substituents. 10 hydrocarbon group, with or without substituents, C6-C 20 phenyl; Preferably, the alkoxymagnesium is selected from one or more of magnesium diethoxy, magnesium dipropoxy, magnesium dibutoxy, and magnesium diphenoxy.

3. The preparation method according to claim 1 or 2, wherein, The hydrogen halide alcohol solution is an alcohol solution in which hydrogen halide is dissolved, wherein the mass concentration of hydrogen halide is 10% to 35%, preferably 20% to 30%. Preferably, the hydrogen halide is selected from at least one of HCl, HBr, and HI, with HCl being the most preferred; Preferably, the alcohol in the hydrogen halide alcohol solution is C1-C. 10 At least one of straight-chain and branched-chain alcohols, preferably C2-C 10 At least one of the straight-chain alcohols, more preferably, the alcohol in the hydrogen halide alcohol solution is selected from one or more of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, isopentanol, hexanol, heptanol, octanol, isooctanol, nonanol, and decanol; Preferably, the molar ratio of hydrogen halide to magnesium alkoxy in the hydrogen halide alcohol solution is 2:1-3:1, more preferably 2:

1.

4. The preparation method according to any one of claims 1-3, wherein, The alcohol compound is one or more of fatty alcohols, alicyclic alcohols, and aromatic alcohols; preferably C1-C1. 10 Straight-chain fatty alcohols, C3-C 10 Branched-chain fatty alcohols, C3-C 12 alicyclic alcohols, C6-C 20 aryl alcohols and C7-C 20 The alcohol is selected from one or more of alkyl aryl alcohols; more preferably, the alcohol is selected from one or more of ethanol, propanol, butanol, 2-ethylhexanol, benzyl alcohol, and phenethyl alcohol. Preferably, relative to 1 mole of alkoxymagnesium (calculated as elemental magnesium), the amount of alcohol compound (including alcohols and alcohol compounds in the hydrogen halide alcohol solution) is 0.2-10 moles, more preferably 2-5 moles.

5. The preparation method according to any one of claims 1-4, wherein, The precipitation aid includes precipitation aid a, precipitation aid b, and precipitation aid c, wherein precipitation aid a is a glycol ester compound, precipitation aid b is an alkyl ester of an aliphatic or aromatic carboxylic acid, and precipitation aid c is a titanate compound. Preferably, the precipitation aid a is a diol ester compound represented by formula (I). In equation (I), R1-R2 may be the same or different, and each is independently substituted or unsubstituted C1-C. 20 Straight-chain alkyl, substituted or unsubstituted C3-C 20 Branched alkyl groups, substituted or unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C7-C 20 alkylaryl, substituted or unsubstituted C7-C 20 Aryl, substituted or unsubstituted C2-C 10 olefinic or substituted or unsubstituted C 10 -C 20 Fused ring aryl group; R3-R8 may be the same or different, each independently being hydrogen, halogenated, substituted or unsubstituted C1-C 20 Straight-chain alkyl, substituted or unsubstituted C3-C 20 Branched alkyl groups, substituted or unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C7-C 20 alkylaryl, substituted or unsubstituted C7-C 20 Aryl, substituted or unsubstituted C2-C 10 olefinic or substituted or unsubstituted C 10 -C 20 The fused-ring aryl group; or at least one of R3-R6 forming a ring with at least one of R7-R8; preferably, the co-precipitant a is selected from 2-ethyl-1,3-propanediol dibenzoate, 2-propyl-1,3-propanediol dibenzoate, 2-isopropyl-2-isopentyl-1,3-propanediol dibenzoate, 1,3-butanediol dimethylbenzoate, 2-methyl-1,3-butanediol di-m-chlorobenzoate, 2,3-dimethyl One or more of the following: 1,3-butanediol dibenzoate, 1,3-pentanediol dinepentyl ester, 2,4-pentanediol dibenzoate, 2-methyl-1,3-pentanediol cinnamate, 2,2-dimethyl-1,3-pentanediol dibenzoate, 2,4-heptanediol dibenzoate, 3,5-heptanediol dibenzoate, 4-ethyl-3,5-heptanediol dibenzoate, and 2-methyl-3,5-heptanediol dibenzoate; Preferably, the precipitation aid b is a C1-C8 aliphatic carboxylic acid or a C7-C8 aliphatic carboxylic acid. 10 C1-C of aromatic carboxylic acids 10 Alkyl esters; preferably, the precipitant b is selected from one or more of ethyl benzoate, diethyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, diethyl adipate, and dibutyl adipate; Preferably, the precipitation aid c has the general formula Ti(OR9). n X 4-n Titanate compounds, wherein R9 is C1-C 10 Alkyl or C3-C 10 The cycloalkyl group, where X is a halogen; 1≤n≤4, where n is an integer; preferably, the precipitant c is selected from one or more of tetrabutyl titanate, tetraethyl titanate and isopropyl titanate. Preferably, relative to 1 mole of magnesium alkoxy, the amount of the precipitation aid a is 0.005-0.1 moles, more preferably 0.01-0.05 moles; the amount of the precipitation aid b is 0.01-0.5 moles, more preferably 0.02-0.2 moles; and the amount of the precipitation aid c is 0.01-0.3 moles, more preferably 0.02-0.08 moles.

6. The preparation method according to any one of claims 1-5, wherein, The first titanium compound and the second titanium compound may be the same or different, and each independently has the general formula Ti(OR) 10 ) m X 4－m The titanium compound shown, wherein R 10 It is an alkyl group, preferably C1-C. 10 Alkyl group; X is a halogen, preferably Cl, Br or I; 0≤m≤3, m is an integer; Preferably, the first titanium compound and the second titanium compound are each independently selected from one or more of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium alkoxytrihalide, titanium dialkoxydihalide, and titanium trialkoxyhalide; Preferably, the amount of the first titanium compound is 5-35 moles, more preferably 8-25 moles, relative to 1 mole of magnesium-based alkoxymagnesium. Preferably, the amount of the second titanium compound is 3-40 moles, more preferably 5-35 moles, relative to 1 mole of alkoxymagnesium based on elemental magnesium.

7. The preparation method according to any one of claims 1-6, wherein, The first dispersant and the second dispersant may be the same or different, and each is independently selected from one or more of alkane compounds, aromatic hydrocarbon compounds or mineral oil, preferably one or more of alkanes, cycloalkanes, aromatic hydrocarbons, kerosene, petrolatum oil, and white oil, and more preferably one or more of hexane, heptane, octane, decane, benzene, toluene and xylene; Preferably, the amount of the first dispersant is 0.01-50 mol relative to 1 mol of alkoxymagnesium based on elemental magnesium, more preferably 5-20 mol. Preferably, the amount of the second dispersant is 0.01-50 mol relative to 1 mol of alkoxymagnesium (calculated as elemental magnesium), more preferably 5-20 mol.

8. The preparation method according to any one of claims 1-7, wherein, The internal electron donor compound is selected from one or more of phthalate internal electron donor compounds, glycol ester compounds, 1,3-diether compounds, succinate compounds, and cyanobutyl succinate compounds; preferably, the internal electron donor compound is selected from one or more of diisobutyl phthalate, di-n-butyl phthalate, 9,9-di(methoxymethyl)fluorene, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 3,5-heptanediol dibenzoate, 2,4-pentanediol dibenzoate, diethyl 2,3-diisopropylsuccinate, and diethyl 2-cyano-2,3-diisopropylsuccinate.

9. The preparation method according to any one of claims 1-8, wherein, The conditions for the first contact reaction include: a temperature of 10-150℃, preferably 60-120℃; and a time of 0.1-2 hours, preferably 0.2-1 hour. And / or, the conditions for the second contact reaction include: a temperature of 10-150°C, preferably 60-140°C; and a time of 0.1-10 hours, preferably 0.5-6 hours; And / or, the conditions for the third contact reaction include: a temperature of -40°C to 0°C; and a time of 3-5 hours; And / or, the conditions for the fourth contact reaction include: a temperature of 20-120°C, preferably 70-110°C; and a reaction time of 0.5-6 hours, preferably 1-4 hours. And / or, the conditions for the fifth contact reaction include: a temperature of 50-150°C, preferably 80-120°C; and a reaction time of 1-6 hours, preferably 2.5-4.5 hours.

10. The olefin polymerization catalyst component obtained by the preparation method according to any one of claims 1-9.

11. A catalyst system comprising (1) The olefin polymerization catalyst component obtained by the preparation method according to any one of claims 1-9 or the olefin polymerization catalyst component according to claim 10; (2) Alkyl aluminum compounds; (3)Optionally, external electron-donating compounds.

12. The application of the olefin polymerization catalyst component obtained by the preparation method of any one of claims 1-9, the olefin polymerization catalyst component of claim 10, or the catalyst system of claim 11 in olefin polymerization.

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