Raw material composition of solid titanium catalyst component, solid titanium catalyst component, catalyst and preparation method and application of catalyst

Abstract

The invention discloses a raw material composition of a solid titanium catalyst component, the solid titanium catalyst component, a catalyst as well as a preparation method and application of the catalyst. The raw material composition comprises magnesium halide, a solvent, a compound shown in a formula (I), an inorganic oxide carrier filler and a titanium-containing compound. The solid titanium catalyst component is prepared from the raw material composition. When the catalyst containing the solid titanium catalyst component disclosed by the invention is used for catalyzing polymerization of ethylene and alpha-olefin, the catalyst has relatively low fine powder content of powder, relatively high powder stacking density, equivalent melt index and catalyst activity and relatively low resin density. Wherein the compound shown in the formula (I) has the following structure: # imgabs 0 #; in the formula (I), R1, R2, R3, R4 and R5 are respectively and independently selected from hydrogen, C1-C15 straight-chain alkyl or branched-chain alkyl, naphthenic base, aryl, alkaryl or aralkyl, and R1, R2, R3, R4 and R5 are respectively and independently selected from hydrogen, C1-C15 straight-chain alkyl or branched-chain alkyl, naphthenic base, aryl, alkaryl or aralkyl; and n represents an integer of 0-10.

Description

Technical Field

[0001] The present invention relates to the technical field of alpha-olefin polymerization, and more particularly to a raw material composition of a solid titanium catalyst component, a solid titanium catalyst component, a catalyst for olefin polymerization reaction, and their preparation methods and applications. Background Art

[0002] As is known to all, the efficient Ziegler-Natta catalyst for olefin polymerization consists of two parts: a main catalyst and a co-catalyst. The main catalyst is composed of a transition metal compound located in the fourth to eighth main group in the periodic table, and the co-catalyst is a metal organic compound located in the first to third main group in the periodic table. Generally, the main catalyst can be divided into two parts: an inert carrier and an active component supported by it. The preparation of the main catalyst is generally prepared by reacting a titanium halide with a magnesium halide with a lattice defect or by loading the reactant on an inert carrier. Among them, the magnesium compound is preferably a magnesium halide with a lattice defect, and the magnesium halide with a lattice defect can be generated from a magnesium compound, or can be obtained by reacting an electron donor such as an alcohol, ether, ester with a magnesium halide, and then removing part of the electron donor such as the alcohol, ether, ester, etc.

[0003] In the polymerization of ethylene or the copolymerization of ethylene and α-olefins, the performance of the catalyst affects the performance of the polymer. It is desirable to have high catalyst activity and good hydrogen adjustment performance at the same time. In particular, high catalyst activity under the condition of high hydrogen / olefin ratio is conducive to the production of resins with higher melt index, especially conducive to the production of resin grades with higher melt index and higher density. It is also desirable to have high catalyst activity and good copolymerization performance at the same time, which is conducive to the production of resin grades with lower density. In addition, good copolymerization performance reduces the amount of comonomer added when producing resin grades with the same density, thereby improving the fluidity of the resin powder and making the production stable under higher loads. It is desirable to have lower catalyst particle content and lower electron donor or solvent content. When the electron donor or solvent content is high, a higher amount of co-catalyst alkyl aluminum will be used during polymerization, which not only increases the cost, but also increases the residual aluminum content in the resin, increases the resin ash content, and increases the haze when producing films.

[0004] During the polymerization process, polymer particles mainly come from particles in the catalyst, active particles in the catalyst, and fragmentation of the catalyst during the polymerization process. Polymer particles are not conducive to the polymerization process because they may cause equipment failure, impaired operability, and reduced efficiency. Therefore, it is desirable to minimize polymer particles during olefin polymerization. One factor in reducing such polymer particles is by eliminating or reducing the catalyst particles that generate polymer particles. It is also desirable to have a higher bulk density of the polymer powder during the polymerization process. A suitably high bulk density of the polymer powder can make the polymerization reactor control more stable.

[0005] In the prior art, CN1958620A, CN102295717A and CN103772536A adopt the method of precipitation and sedimentation in the solution, respectively introducing siloxane electron donors, ortho-alkoxy substituted benzoate / carboxylate (or diether) composite electron donors, and benzoate electron donors to improve the hydrogen adjustment sensitivity of the catalyst. For example, CN102807638A adopts the method of impregnation loading, and introduces a composite long carbon chain monoester / short carbon chain monoester electron donor into the spherical carrier of magnesium chloride-alcohol adduct formed by high-speed stirring and low-temperature condensation to improve the activity of the catalyst. For example, CN1103406A adopts the method of external electron donors, and introduces diethers, especially 1,3-diether electron donors, into the polymerization kettle at the same time as the catalyst to obtain polyethylene products with narrower molecular weight distribution. For example, EP0219998B1 adopts a method of precipitation and sedimentation in a solution. After obtaining a particle suspension, an appropriate amount of water as an electron donor is introduced to improve the particle size and distribution of the obtained polyethylene powder and reduce the fine powder content. For example, CN1726230A, CN1798774A and CN101050248A adopt an impregnation loading method, and introduce alcohols, ketones, amines, amides, nitrile, alkoxysilane, aliphatic ethers and aliphatic carboxylates and other electron donors into a spherical carrier of magnesium chloride-alcohol adduct formed by high-speed stirring and low-temperature condensation to improve the copolymerization performance of the catalyst. For example, WO2021115929A1 adopts a spherical carrier of magnesium chloride-alcohol adduct formed by high-speed stirring and low-temperature condensation in a titanium compound impregnation treatment, and a guanidine compound is added as an internal electron donor after washing to obtain a spherical catalyst. The catalyst shows the ability to uniformly distribute comonomers in the preparation of ethylene copolymers. In the process of preparing the spherical carrier of magnesium chloride-alcohol adduct by high-speed stirring and low-temperature condensation molding, other liquid organic compounds must be used, which increases the consumption of reagents and complicates the subsequent liquid-solid separation steps. For example, Czaja reported in Polymer (Polymer, 2000, 41, 7899-7904) that the copolymerization of ethylene and 1-octene was catalyzed by vanadium-based catalyst MgCl2(THF)2 / VCl4 / Et2AlCl, and the insertion amount of 1-octene in the copolymer was 0.47%. Under the same polymerization conditions, the insertion rate of 1-octene in the copolymer obtained by using titanium-based catalyst was 0.39%. Boisson reported in ACS Catalysis (ACSCatal.2020, 10, 7216-7229) that the amount of co-catalyst triethylaluminum can not only regulate the kinetics of copolymerization, but also has a non-negligible effect on the distribution of comonomers in the polymer chain. As proposed in US8546499B2, the type of alkyl aluminum can adjust the distribution of comonomers in the polymer chain. It is worth noting that although the insertion of comonomers can be adjusted by the type of alkyl aluminum and the ratio to the catalyst, it can only be regulated within a limited range.CN101885793A and CN101885795A respectively use composite electron donors containing organic mercaptan and organic silicon amine to improve the copolymerization performance of the catalyst, but the synthesis steps of the catalyst are relatively complicated, and the organic mercaptan and organic silicon amine used have an unpleasant odor and are relatively expensive. For example, CN104211844A discloses a gas phase fluidized bed LLDPE catalyst and its preparation method and application. The catalyst uses porous silica gel and anhydrous magnesium chloride as carriers, a titanium-containing transition metal loaded on the porous silica gel and magnesium chloride composite carrier as an active component, an electron donor compound as a modifier, and the loaded components account for the overall mass percentage of the catalyst as follows: Ti: 1.00-5.00%, Cl: 15.20-32.35%, Mg: 1.35-6.52%, electron donor: 0.10-5.78%, and the rest is silica gel. The preparation method of the catalyst comprises the following steps: reacting an alkane solvent, anhydrous magnesium chloride and an organic alcohol at a certain temperature for a certain time to obtain a homogeneous reactant A; adding an electron donor compound to the reactant A solution to obtain a reactant B, wherein the electron donor compound is silane, ester, ether, amine, ketone or a mixture of different electron donors; adding silica gel (preliminarily activated at 200°C in a Maboi furnace under nitrogen protection for 2 hours and then activated at 600°C for 4 hours) to the reactant B to obtain a reactant C; slowly cooling the reactant C to -5°C, slowly dropping a titanium tetrachloride compound, reacting at this temperature for a certain time, then slowly heating and reacting at a certain temperature at a constant temperature, after the reaction is completed, removing the upper layer of liquid by suction filtration to obtain a reactant D, heating the reactant D with toluene and then washing the reactant D with n-hexane, and finally drying the reactant with high-purity nitrogen to obtain a solid powder catalyst. The purpose is to provide a catalyst component for preparing LLDPE by a gas phase fluidized bed method, so that the catalyst system has high activity, high copolymerizability, hydrogen sensitivity, and the polyethylene product obtained has good morphology, uniform particles, and high bulk density; in addition, by adding different electron donors in the catalyst preparation, polyethylene resins with adjustable molecular weight and molecular weight distribution are produced, thereby improving the performance of the product, improving the processability of the resin, and broadening the application field of the product. However, the titanium loading process in the catalyst synthesis step requires a large amount of titanium tetrachloride, and also requires a large amount of toluene and hexane hot washing. The recovery of toluene, hexane, and titanium tetrachloride is complicated, the catalyst production process has high energy and material consumption, and will pollute the environment.

[0006] Spray drying is an effective method for preparing high-efficiency Ziegler-Natta catalysts for olefin polymerization. The method uses gas to spray dissolved liquid or suspended liquid through a specially designed nozzle into a hot inert gas drying chamber for drying, and the dispersed mist droplets are dried into powder or granular products. Once the droplets come into contact with the dry carrier gas, evaporation occurs on the saturated vapor film that is quickly established on the surface of the droplets. During evaporation, the size distribution of the droplets changes, and different products show different characteristics. During the evaporation process, the droplets are prone to expansion, collapse, breakage or splitting, resulting in porous and irregular shapes, which is related to the characteristics of the droplets formed in the spray process. The structural modification of the particles can be affected by changes in the composition, volume and size of the droplets. By adjusting the conditions of the spray drying process, large, small or aggregated particles can be obtained.

[0007] For example, US4421674 discloses a process for preparing spherical MgCl2 carrier-type polyolefin catalyst by spray drying: 1) Preparation of spray mother liquor: Dissolve MgCl2 in ethanol to make the solution concentration 100-300g MgCl2 / liter solution, and the water content in the solution does not exceed 5%; 2) Preparation of spherical MgCl2 carrier by spray drying: The inert gas used in the drying process and spraying is N2, and its purity is greater than 99%. The inlet temperature of the spray dryer is set between 180 and 280°C, and the spray mother liquor and gas N2 delivery amount are controlled to make the instrument outlet temperature lower than the inlet temperature by more than 40°C and stabilized between 130 and 210°C. The obtained solid product is collected to obtain spherical MgCl2 particles, and the alcohol content of the spherical MgCl2 carrier is between 12% and 25wt%. 3) Titanium-carrying process: The spherical MgCl2 obtained in the process of 2) is contacted with gaseous or liquid titanium halides under certain conditions until the titanium content on the spherical carrier reaches 0.7-12%. The method prepares the carrier and the catalyst in steps. The solvent used in preparing the carrier is an alcohol containing active hydrogen, such as ethanol, so that the titanium loading process needs to be distributed, and a large amount of gaseous or liquid titanium halide is required when loading titanium. The excess titanium halide is recovered and refined, and the preparation process is long and complicated; at the same time, the catalyst loaded by the spherical MgCl2 carrier particles is easy to break when used directly. For example, CN1668654A discloses a spray-dried polymerization catalyst and a polymerization method using the polymerization catalyst. The catalyst includes a spray-dried composition of an inert porous filler and a reaction product of the following substances: a mixture or reaction product of a magnesium halide, a solvent, an electron donor compound, and a transition metal compound. The catalyst contains an alcohol compound as an electron donor and uses a spherical inert porous filler with an average particle size of 1μm to 12μm. The method is to reduce the content of particles in the polymer by reducing small catalyst particles in the catalyst. For example, CN1993391A discloses a strongly spray-dried Ziegler-Natta catalyst composition, which includes an inert porous filler, a magnesium halide, a solvent or diluent, a Lewis base electron donor compound, a mixture of transition metal compounds or a reaction product, wherein the amount of the magnesium halide compound present in the solvent or diluent is at least 90% of the saturated concentration, and the electron donor compound used is an alcohol or tetrahydrofuran. The catalyst particles obtained by spray drying have an average diameter (D50) of 10 to 70 μm, wherein at least 5% of the particles have an internal void volume substantially or completely surrounded by a single surface layer (shell), wherein the layer is characterized in that the particles with a particle diameter greater than 30 μm have an average shell thickness / particle diameter (thickness ratio) determined by SEM technology greater than 0.2. The catalyst reduces polymer particles by reducing catalyst breakage or catalyst fragments that are still large after breakage. For example, CN1085915A discloses a method for preparing a Ziegler-Natta catalyst system.In tetrahydrofuran, titanium tetrachloride is reduced by magnesium metal to obtain a tetrahydrofuran solution of TiCl3, and then magnesium chloride is dissolved in tetrahydrofuran. The two solutions are fully mixed, unreacted magnesium and undissolved magnesium chloride are filtered out, and the filtered solution is fully mixed with silica gel, and then spray-dried to obtain dispersed particles of the catalyst. The catalyst has a high titanium content and high activity, and can reduce hexane extractables by multiples when catalyzing the polymerization of ethylene and α-olefins. However, when the yield is high in the preparation of the catalyst, its D. 10 Smaller, keep larger D 10 It is necessary to reduce the total yield of the catalyst, which will produce more catalyst particles, which not only increases the production cost, but also produces more waste residue. For example, CN104761665A discloses a spray-dried Ziegler-Natta catalyst composition, which includes inorganic oxide particles, magnesium halide, electron donor compound, silane coupling agent, titanium halide, and the electron donor compound is selected from one of alcohol or ether, or a mixture thereof; the silane coupling agent improves the surface properties of the silica carrier, and the catalyst has the characteristics of high activity, good hydrogen adjustment sensitivity, and low fine powder content. For example, CN100368440C discloses a spray-dried polymerization catalyst and a polymerization method using the polymerization catalyst, wherein the catalyst comprises a spray-dried composition of an inert porous filler and a reaction product of the following substances: a mixture or reaction product of a magnesium halide, a solvent, an electron donor compound, and a transition metal compound, wherein the electron donor compound improves the solubility of the magnesium halide in the electron donor solvent so that the solubility does not decrease in any temperature interval up to the boiling point of the electron donor solvent, and the electron donor compound used herein does not include a solvent, even when such a solvent has electron donor characteristics. Exemplary electron donor compounds include alcohols, thiols, weakly contributing amines, and phosphines. The catalyst contains an improved activity; a spherical inert porous filler with an average particle size of 1 μm to 12 μm is used to reduce small catalyst particles in the catalyst, thereby reducing the content of microparticles in the polymer, but the hydrogen regulation performance is not improved.

[0008] The above-mentioned various Ziegler-Natta type olefin polymerization catalysts have been improved in one or some aspects of performance parameters such as catalyst activity, hydrogen adjustment sensitivity, copolymerization performance, bulk density of polymerization powder, melt index and melt flow ratio, fine powder content, copolymerization unit distribution, etc., but are still not ideal. In order to better meet the needs of industrial production and obtain polyolefin products with better performance and lower density, it is necessary to develop a catalyst with better catalyst copolymerization performance and good comprehensive performance. Summary of the invention

[0009] In order to solve the problems in the prior art, the present invention proposes a raw material composition of a solid titanium catalyst component, a solid titanium catalyst component, a catalyst for olefin polymerization reaction, and a preparation method and application thereof. The solid titanium catalyst component of the present invention dissolves a magnesium halide and a titanium-containing compound in a solvent, and adds a certain proportion of at least one compound of formula (I) and an inorganic oxide carrier filler to form a suspension. The obtained suspension is spray-dried and molded to obtain a spherical solid titanium catalyst component. When the catalyst containing the solid titanium catalyst component of the present invention is used to catalyze the polymerization of ethylene and α-olefins, it has the characteristics of high activity, less fine powder content in the obtained polyethylene powder, high bulk density, and low polyethylene resin density.

[0010] One of the purposes of the present invention is to provide a raw material composition of a solid titanium catalyst component, wherein the raw material composition of the catalyst component comprises a magnesium halide, a compound represented by formula (I), an inorganic oxide carrier filler, a titanium-containing compound, and a solvent:

[0011] Wherein, the compound represented by the formula (I) has the following structure:

[0012]

[0013] In formula (I), R1, R2, R3, R4 and R5 are each independently selected from hydrogen, a C1-C15 straight-chain alkyl or branched alkyl, a cycloalkyl, an aryl, an alkaryl or an aralkyl group; and n is an integer from 0 to 10.

[0014] In the present invention, the added compound of formula (I) can inhibit the expansion, collapse, breakage or splitting of droplets during the evaporation process of spray drying, thereby reducing the generation of porous and irregularly shaped catalyst component particles, thereby reducing the polymer fine powder content caused by excessive polymer particles during the polymerization process, and can reduce the density of the polymer; at the same time, the compound of formula (I) is beneficial to reducing the solvent content in the catalyst component particles.

[0015] In the raw material composition of the solid titanium catalyst component of the present invention, preferably,

[0016] In the compound of formula (I), R1, R2, R3, R4, and R5 are each independently selected from hydrogen, C1-C10 straight-chain alkyl or branched alkyl, aryl or aralkyl. Specifically, the compound of formula (I) can be selected from aminomethanol, aminoethanol, 3-aminopropanol, 4-aminobutanol, 3-amino-2,2-dimethyl-1-propanol, 10-amino-1-n-decanol, methylaminomethanol, methylaminoethanol, 3-methylamino-1-propanol, 2-methylamino-1-propanol, 1-methylamino-2-propanol, 4-methylamino-1-butanol, 4-benzylamino-1-butanol, 6-methylamino-1-hexanol, 6-ethylamino-1-hexanol, 10-ethylamino-1-decanol, isopropylaminoethanol, 3-isopropylamino-1-propanol, 4- At least one of isopropylamino-1-butanol, 6-isopropylamino-1-hexanol, dimethylaminomethanol, dimethylaminoethanol, diisopropylaminoethanol, 3-dimethylamino-1-propanol, 2-dimethylamino-1-propanol, 1-dimethylamino-2-propanol, 4-dimethylamino-1-butanol, 4-diisopropylamino-1-butanol, 6-dimethylamino-1-hexanol, 6-diethylamino-1-hexanol, N-methyl-N-ethylethanolamine, methyl-N-isopropylethanolamine, N-methyl-N-ethylpropanolamine, N-methyl-N-ethylbutanolamine, N-methyl-N-isopropylhexanolamine, 2-(N-benzyl-N-methylamino)ethanol, 2-(N-methyl-N-butylamino)ethanol, and 2-dimethylamino-2-phenyl-n-butanol.

[0017] Most preferably, the compound represented by formula (I) is at least one selected from diisopropylaminoethanol, 3-dimethylamino-1-propanol, and 4-dimethylamino-1-butanol.

[0018] In the raw material composition of the solid titanium catalyst component of the present invention, preferably,

[0019] The magnesium halide is selected from at least one of magnesium dichloride, magnesium dibromide or magnesium diiodide, and is more preferably magnesium dichloride.

[0020] In the raw material composition of the solid titanium catalyst component of the present invention, preferably,

[0021] The titanium-containing compound is at least one of a titanium halide, a product of aluminum reduction of a titanium halide, and a product of magnesium reduction of a titanium halide. The general formula of the product of aluminum reduction of a titanium halide is TiXm·n'AlXp, wherein 0<n'≤1, 0<m≤3, 0<p≤3, and X is bromine or chlorine; the general formula of the product of magnesium reduction of a titanium halide is TiXm'·qMgXr, wherein 0<q≤1, 0<m'≤3, 0<r≤2, and X is bromine or chlorine. Further preferably, the product of aluminum reduction of a titanium halide is TiCl3·1 / 3AlCl3; the product of magnesium reduction of a titanium halide is TiCl3·1 / 2MgCl2. The titanium halide is selected from at least one of titanium tribromide, titanium tetrabromide, titanium trichloride or titanium tetrachloride. The titanium-containing compound here can also be other compounds, such as titanium-containing compounds of titanium tetrachloride reduced by iron or zinc.

[0022] In the raw material composition of the solid titanium catalyst component of the present invention, preferably,

[0023] The solvent is selected from solvents capable of dissolving magnesium halide and titanium-containing compounds. Preferably, the solvent is selected from at least one of methyl formate, ethyl formate, isopropyl formate, n-propyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, ethyl ether, propyl ether, hexyl ether, tetrahydrofuran, methyltetrahydrofuran, acetone and methyl isobutyl ketone. More preferably, the solvent is selected from at least one of tetrahydrofuran and methyltetrahydrofuran.

[0024] In the raw material composition of the solid titanium catalyst component of the present invention, preferably, the inorganic oxide carrier filler is silicon oxide and / or aluminum oxide.

[0025] The particle size of the inorganic oxide carrier filler is 0.01 to 10 microns; preferably, the particle size of the inorganic oxide carrier filler is 0.01 to 5 microns.

[0026] More preferably, the particle size of the inorganic oxide carrier filler is 0.1 to 1 micron.

[0027] More preferably, the inorganic oxide carrier filler is silicon dioxide.

[0028] The silicon oxide or aluminum oxide used in the present invention is an inert carrier. The use of the inert carrier in spray drying helps to control the shape and composition of the catalyst particles, and the generated catalyst particles have good shape, high strength and are not easy to break.

[0029] As a preferred embodiment, no matter which inorganic oxide support filler (filler) is selected, it should be dry, that is, free of absorbed moisture. The filler is dried by heating for a period of time at a temperature below the sintering or melting point of the filler material (however, some fillers, such as fumed silica, naturally have a low residual moisture content due to their specific manufacturing methods); generally, a temperature of at least 100°C is used for drying, and lower temperatures can be used when extended drying times are acceptable or when the filler has a low melting or sintering temperature; the inorganic filler material is usually dried at a temperature of 200 to 800°C; at the same time, the filler material can be treated with one or more Lewis acids (e.g., trialkylaluminum compounds or organosilanes) in an optional amount of 1 to 10 wt% to remove polar impurities including water or hydroxyl groups.

[0030] In the raw material composition of the solid titanium catalyst component of the present invention, preferably, the raw material composition of the solid titanium catalyst component comprises magnesium halide, solvent, compound represented by formula (I), inorganic oxide carrier filler, and titanium-containing compound. The magnesium halide, titanium-containing compound, solvent, inorganic oxide carrier filler, and at least one compound represented by formula (I) are contacted to form a suspension; the obtained suspension is spray-dried to obtain a solid titanium catalyst component.

[0031] Preferably, in the raw material composition of the solid titanium catalyst component,

[0032] The molar ratio of magnesium halide to titanium-containing compound is 1 to 20, preferably 2 to 10;

[0033] The molar ratio of the compound represented by formula (I) to the titanium-containing compound is 0.01 to 10, preferably 0.1 to 5;

[0034] The weight ratio of the inorganic oxide carrier filler to the magnesium halide is 0.1 to 10, preferably 0.5 to 2;

[0035] The molar ratio of the solvent to the magnesium halide is 10 to 120, preferably 20 to 60;

[0036] The molar amount of the magnesium halide is calculated based on magnesium, and the molar amount of the titanium-containing compound is calculated based on titanium.

[0037] The second object of the present invention is to provide a solid titanium catalyst component prepared from a raw material composition comprising the solid titanium catalyst component described in one of the objects of the present invention.

[0038] Preferably, in the solid titanium catalyst component, based on 100 wt % of the solid titanium catalyst component,

[0039] The magnesium content is 4 to 10 wt%, more preferably, the magnesium content is 4 to 8 wt%;

[0040] The titanium content is 1 to 5 wt%; more preferably, the titanium content is 1 to 3 wt%;

[0041] The halogen content is 14 to 30 wt%;

[0042] The content of the compound represented by formula (I) is 1 to 8 wt%; for example, the content of the compound represented by formula (I) may be 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, etc.;

[0043] The content of the inorganic oxide carrier filler is 25 to 45 wt%;

[0044] The solvent content is 20-33%.

[0045] The contents of the remaining components vary depending on the reaction raw materials, as long as the total amount of all components is 100%.

[0046] The third object of the present invention is to provide a method for preparing the solid titanium catalyst component described in the second object of the present invention, comprising the following steps:

[0047] Step S1, preparation of mother liquor: contacting a solvent, a magnesium halide, a titanium-containing compound and a compound represented by formula (I) under a protective atmosphere to prepare a mother liquor;

[0048] Step S2, carrier blending: under a protective atmosphere, during or after step S1, an inorganic oxide carrier filler is added for blending to obtain a slurry suspension;

[0049] Step S3, spray molding: spray-drying the slurry suspension obtained in step S2 to obtain particles of the solid titanium catalyst component.

[0050] According to the present invention, the reaction product of the magnesium halide, the titanium-containing compound, the solvent and the compound shown in formula (I) is loaded on the inorganic oxide carrier filler to form particles of the solid titanium catalyst component. The inorganic oxide carrier filler can be added at any time during the preparation of the mother liquor. For example, the magnesium halide, the titanium-containing compound, the inorganic oxide carrier filler and the compound shown in formula (I) are mixed and reacted in the solvent to obtain a slurry liquid material, and the obtained slurry liquid is spray-dried. As a preferred embodiment, the carrier blending is: the prepared mother liquor is mixed with the inorganic oxide carrier filler to obtain a slurry suspension.

[0051] In the present invention, the amount of solvent added is preferably such that the magnesium halide and the titanium-containing compound can be fully dissolved and the magnesium halide, the titanium-containing compound, the solvent, the inorganic oxide carrier filler and at least one compound represented by formula (I) can be contacted to form a relatively stable suspension. The amount of solvent added can be according to the commonly used amount in the art.

[0052] In the method for preparing the solid titanium catalyst component of the present invention, preferably,

[0053] In step S1, the contact temperature is room temperature to 85°C, and the contact time is not less than 0.1 hour;

[0054] In step S3, the inlet temperature of the spray drying is 100-240°C, and the outlet temperature of the spray drying is 60-130°C;

[0055] The particles of the solid titanium catalyst component obtained by the present invention are spherical solid particles;

[0056] More preferably, in step S3, the inlet temperature of the spray drying is 120-160°C, and the outlet temperature of the spray drying is 90-115°C.

[0057] The above method can be used to prepare particles of solid titanium catalyst component having a substantially spherical morphology and an average diameter of 2 to 100 μm, preferably 18 to 30 μm. As particles having a substantially spherical morphology, it means that the ratio between the small axis and the large axis is ≥ 0.67, and preferably ≥ 0.77. Particles of this morphology have better use effect.

[0058] A fourth object of the present invention is to provide a catalyst for olefin polymerization, wherein the catalyst is prepared from a raw material comprising the following components:

[0059] Component (A): the solid titanium catalyst component described in the second object of the present invention and / or the solid titanium catalyst component prepared by the method described in the third object of the present invention;

[0060] Component (B): general formula A1R' b X' 3-b An organoaluminum compound, wherein R' is hydrogen or a C1-C20 hydrocarbon group, 0<b≤3, and X' is a halogen.

[0061] In the catalyst for olefin polymerization described in the present invention, preferably,

[0062] General formula A1R' b X' 3-b In which 1<b≤3, X' is chlorine, bromine or iodine;

[0063] More preferably,

[0064] The organoaluminum compound is selected from at least one of trimethylaluminum, triethylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, diisobutylaluminum chloride, ethylaluminum sesquichloride (a mixture of diethylaluminum dichloride and diethylaluminum monochloride) and dimethylaluminum chloride.

[0065] In the catalyst for olefin polymerization described in the present invention, preferably,

[0066] The molar ratio of aluminum contained in the component (B) to titanium contained in the component (A) is (1 to 1000):1, preferably (5 to 200):1.

[0067] In order to make the obtained solid titanium catalyst component suitable for the production of ethylene polymers, the solid titanium catalyst component must be activated by an activator component organoaluminum compound. Preferably, the solid titanium catalyst component obtained by the present invention is reacted with an activator component organoaluminum compound in a hydrocarbon solvent to obtain a catalyst; or the solid titanium catalyst component obtained by the present invention is reacted with an activator component organoaluminum compound during the polymerization process to initiate olefin polymerization.

[0068] The fifth object of the present invention is to provide the use of the catalyst described in the fourth object of the present invention in olefin polymerization, preferably in ethylene homopolymerization or in the polymerization of ethylene and one or more α-olefins; more preferably in the polymerization of ethylene and one or more α-olefins to obtain a polyethylene resin with lower density;

[0069] Preferably,

[0070] The temperature of the olefin polymerization reaction is 20 to 120°C, more preferably 65 to 90°C.

[0071] The polymerization process for olefin polymerization can be carried out according to available techniques, for example, using a gas phase process, a slurry process and a solution process.

[0072] The endpoints and any values ​​of the scope disclosed in the present invention are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, the endpoint values ​​of each scope, the endpoint values ​​of each scope and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be regarded as specifically disclosed in this article.

[0073] Compared with the prior art, the present invention has the following advantages:

[0074] The solid titanium catalyst component prepared by the present invention has less microparticles, which is beneficial to reducing polymer microparticles in the olefin polymerization process.

[0075] The catalyst of the present invention, when used for olefin polymerization, has high catalyst activity, low density of the obtained ethylene and α-olefin copolymer (in the prior art, it is very difficult to reduce the resin density using a Ziegler-Natta catalyst), high polymer powder bulk density, and low fine powder content in the polymer powder. DETAILED DESCRIPTION

[0076] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0077] It should also be noted that the various specific technical features described in the following specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0078] In addition, the various embodiments of the present invention may be arbitrarily combined as long as they do not violate the concept of the present invention. The technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0079] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0080] Test method:

[0081] 1. Activity: expressed as the weight of resin obtained per gram of catalyst in two hours;

[0082] 2. Polymer melt index (MI): determined according to ASTM D1238-99, load 2.16 kg, 190°C;

[0083] 3. Polymer apparent bulk density (BD): tested in accordance with ASTM D1895-69.

[0084] 4. The sieving analysis value is based on: refer to ASTM D-1921 standard.

[0085] 5. Catalyst particle size: measured by MASTERSIZER2000 particle size analyzer, termed D 10 , D 50 , D 90 It means that the special percentage distribution of the standard logarithmic particle size distribution, such as the catalyst particle size with D 50 The median particle size is 24 μm; D10 7μm means that 10% of the particles have a diameter less than 7μm. 90 45 μm means that 90% of the particles are smaller than 45 μm.

[0086] 6. Titanium, magnesium and chlorine content: measured by Spectrumlab 752s UV-visible spectrophotometer; the content of the compound of formula (I) in the solid titanium catalyst component was measured by liquid nuclear magnetic resonance. 1 H-NMR calculations.

[0087] 7. Polyethylene resin density: refer to ASTM D1505-2010 standard.

[0088] 8. THF content: measured using Agilent Technologies 7890A GC System.

[0089] Example 1

[0090] (1) Preparation of solid titanium catalyst component

[0091] In a 250ml four-necked flask equipped with a temperature controller, a stirrer, a reflux condenser, and purged and protected by nitrogen, 100ml of tetrahydrofuran (THF), 4.0g of magnesium chloride, 0.91ml of TiCl4, and 0.42ml of diisopropylethanolamine were added successively under stirring, and the temperature was raised to 68°C under stirring, and the reaction was carried out under constant temperature reflux for 3 hours to obtain a mother liquor. During this process, the nitrogen atmosphere (<5ppmH2O) was maintained;

[0092] 5.7 g of silica gel (Cabot Corporation TS-610, particle size 0.1-1 μm) was added to a 250 ml four-necked flask equipped with a temperature controller, a stirrer, a reflux condenser, and protected by nitrogen. The mother liquor was added under stirring, and the mixture was refluxed and stirred at 68°C for 2 hours to completely disperse the silica gel in the mother liquor to obtain a slurry suspension. The mixture was kept in a nitrogen atmosphere (<5 ppm H2O) during the process.

[0093] In a closed-loop airflow spray dryer (such as Mini Spray Dryer B-290), nitrogen with a carrier gas inlet temperature of 145°C was introduced into the spray dryer, the obtained slurry suspension at 43°C was added to the circulating dryer, the slurry suspension feed rate and the spray gas (N2) flow rate at room temperature were adjusted to about 27 mL / min and 350 L / h respectively, and the carrier gas (N2) flow rate was adjusted to make the outlet temperature 98°C to obtain a solid catalyst component. The obtained catalyst component has a desired particle size D 50= about 20 to 23 microns. The parameters of the catalyst components obtained are shown in Table 1.

[0094] (2) Ethylene slurry polymerization

[0095] A 2-liter polymerization kettle that had been purged with nitrogen first and then hydrogen was added with 1 liter of hexane, 2 ml of 1M triethylaluminum hexane solution, 40 ml of 1-hexene and 15 mg of the solid titanium catalyst component obtained in Example (1) were added, the temperature was raised to 85°C, hydrogen was added to 0.28 MPa, and after the hydrogenation was completed, ethylene was added to 1.03 MPa, and the reaction was carried out at a constant temperature and pressure of 85°C and 1.03 MPa for 2 hours, then the reaction was stopped, the temperature was lowered and the material was discharged. The polymerization results are shown in Table 2.

[0096] Example 2

[0097] (1) Preparation of solid titanium catalyst component

[0098] In a 250ml four-necked flask equipped with a temperature controller, a stirrer, a reflux condenser, and purged and protected by nitrogen, 100ml of tetrahydrofuran (THF) and 0.104g of magnesium powder (average particle size 80-100 microns) were added successively under stirring, and then 0.91ml of TiCl4 was slowly added over 0.5 hours, heated to 50°C, stirred at constant temperature for 4 hours, and then 3.59g of magnesium chloride was added, the temperature was raised to 68°C and stirred at constant temperature for 2 hours, and then 0.42ml of diisopropylethanolamine was added, and the reaction was refluxed at 68°C for 1 hour to obtain a mother liquor of tetrahydrofuran, magnesium chloride, magnesium-reduced titanium halide and dimethylethanolamine. During this process, the mixture was kept in a nitrogen atmosphere (<5ppmH2O);

[0099] 5.7 g of silica gel (Cabot Corporation TS-610, particle size 0.1-1 μm) was added to a 250 ml four-necked flask equipped with a temperature controller, a stirrer, a reflux condenser, and protected by nitrogen. The mother liquor was added under stirring, and the mixture was refluxed and stirred at 68°C for 2 hours to completely disperse the silica gel in the mother liquor to obtain a slurry suspension. The mixture was kept in a nitrogen atmosphere (<5 ppm H2O) during the process.

[0100] In a closed-loop airflow spray dryer (such as Mini Spray Dryer B-290), nitrogen with a carrier gas inlet temperature of 145°C was introduced into the spray dryer, the obtained slurry suspension at 43°C was added to the circulating dryer, the slurry suspension feed rate and the spray gas (N2) flow rate at room temperature were adjusted to about 24 mL / min and 330 L / h, respectively, and the carrier gas (N2) flow rate was adjusted to make the outlet temperature 102°C to obtain a solid catalyst component. The obtained catalyst component has a desired particle size D 50= about 20 to 23 microns. The parameters of the catalyst components obtained are shown in Table 1.

[0101] (2) Ethylene slurry polymerization

[0102] A 2-liter polymerization kettle that had been purged with nitrogen first and then hydrogen was added with 1 liter of hexane, 2 ml of 1M triethylaluminum hexane solution, 40 ml of 1-hexene and 15 mg of the solid titanium catalyst component obtained in Example (1) were added, the temperature was raised to 85°C, hydrogen was added to 0.28 MPa, and after the hydrogenation was completed, ethylene was added to 1.03 MPa, and the reaction was carried out at a constant temperature and pressure of 85°C and 1.03 MPa for 2 hours, then the reaction was stopped, the temperature was lowered and the material was discharged. The polymerization results are shown in Table 2.

[0103] Example 3

[0104] (1) Preparation of solid titanium catalyst component

[0105] In a 250ml four-necked flask equipped with a temperature controller, a stirrer, a reflux condenser, and purged and protected by nitrogen, 100ml of tetrahydrofuran (THF), 4g of magnesium chloride, 1.64g of TiCl3·1 / 3AlCl3, and 0.42ml of diisopropylethanolamine were added successively under stirring, and the temperature was raised to 68°C under stirring, and the reaction was carried out under constant temperature reflux for 3 hours at this temperature to obtain a mother liquor. During this process, the nitrogen atmosphere (<5ppmH2O) was maintained;

[0106] 5.7 g of silica gel (Cabot Corporation TS-610, particle size 0.1-1 μm) was added to a 250 ml four-necked flask equipped with a temperature controller, a stirrer, a reflux condenser, and protected by nitrogen. The mother liquor was added under stirring, and the mixture was refluxed and stirred at 68°C for 2 hours to completely disperse the silica gel in the mother liquor to obtain a slurry suspension. The mixture was kept in a nitrogen atmosphere (<5 ppm H2O) during the process.

[0107] In a closed-loop airflow spray dryer (such as Mini Spray Dryer B-290), nitrogen with a carrier gas inlet temperature of 145°C was introduced into the spray dryer, the obtained slurry suspension at 43°C was added to the circulating dryer, the slurry suspension feed rate and the spray gas (N2) flow rate at room temperature were adjusted to about 23 mL / min and 330 L / h respectively, and the carrier gas (N2) flow rate was adjusted to make the outlet temperature 103°C to obtain a solid catalyst component. The obtained catalyst component has a desired particle size D 50 = about 20 to 23 microns. The parameters of the catalyst components obtained are shown in Table 1.

[0108] (2) Ethylene slurry polymerization

[0109] A 2-liter polymerization kettle that had been purged with nitrogen first and then hydrogen was added with 1 liter of hexane, 2 ml of 1M triethylaluminum hexane solution, 40 ml of 1-hexene and 15 mg of the solid titanium catalyst component obtained in Example (1) were added, the temperature was raised to 85°C, hydrogen was added to 0.28 MPa, and after the hydrogenation was completed, ethylene was added to 1.03 MPa, and the reaction was carried out at a constant temperature and pressure of 85°C and 1.03 MPa for 2 hours, then the reaction was stopped, the temperature was lowered and the material was discharged. The polymerization results are shown in Table 2.

[0110] Example 4

[0111] Compared with Example 1, the only difference is that in the preparation of the solid titanium catalyst component in step (1), the amount of diisopropylethanolamine added is changed from 0.42 ml to 0.63 ml. The rest is the same as Example 1.

[0112] Example 5

[0113] Compared with Example 2, the only difference is that in the preparation of the solid titanium catalyst component in step (2), the amount of diisopropylethanolamine added is changed from 0.42 ml to 0.63 ml. The rest is the same as Example 2.

[0114] Example 6

[0115] Compared with Example 2, the only difference is that in the preparation of the solid titanium catalyst component in step (1), the amount of diisopropylethanolamine added is changed from 0.42 ml to 1.26 ml. The rest is the same as Example 2.

[0116] Example 7

[0117] Compared with Example 1, the only difference is that in the preparation of the solid titanium catalyst component in step (1), the amount of diisopropylethanolamine added is changed from 0.42 ml to 0.56 ml of 4-dimethylamino-1-butanol. The rest is the same as Example 1.

[0118] Example 8

[0119] Compared with Example 2, the only difference is that in the preparation of the solid titanium catalyst component in step (1), the amount of diisopropylethanolamine added is changed from 0.42 ml to 0.28 ml of 4-dimethylamino-1-butanol. The rest is the same as Example 2.

[0120] Example 9

[0121] Compared with Example 3, the only difference is that in the preparation of the solid titanium catalyst component in step (1), 1.64 g of TiCl3·1 / 3AlCl3 is changed to 0.82 g. The rest is the same as Example 3.

[0122] Example 10

[0123] Compared with Example 3, the only difference is that in the preparation of the solid titanium catalyst component in step (1), 1.64 g of TiCl3·1 / 3AlCl3 is changed to 3.28 g. The rest is the same as Example 3.

[0124] Embodiment 11

[0125] Compared with Example 3, the only difference is that in the preparation of the solid titanium catalyst component in step (1), 4 grams of magnesium chloride is changed to 5.3 grams, and the rest is the same as Example 3.

[0126] Example 12

[0127] Compared with Example 3, the only difference is that in the preparation of the solid titanium catalyst component in step (1), 4 grams of magnesium chloride is changed to 2.4 grams. The rest is the same as Example 3.

[0128] Comparative Example 1

[0129] Compared with Example 1, the only difference is that 0.42 ml of diisopropylethanolamine is not added in the preparation of the solid titanium catalyst component in step (1). The rest is the same as Example 1.

[0130] Comparative Example 2

[0131] Compared with Example 2, the only difference is that 0.42 ml of diisopropylethanolamine is not added in the preparation of the solid titanium catalyst component in step (1). The rest is the same as Example 2.

[0132] Comparative Example 3

[0133] Compared with Example 3, the only difference is that 0.42 ml of diisopropylethanolamine is not added in the preparation of the solid titanium catalyst component in step (1). The rest is the same as Example 3.

[0134] The solid titanium catalyst component parameters of the embodiments and comparative examples are shown in Table 1 below:

[0135] Table 1 Solid titanium catalyst component parameters

[0136]

[0137] As shown in Table 1, the addition of the compound of formula (I) of the present invention can effectively reduce the content of tetrahydrofuran in the catalyst component particles. 10 becomes larger and the microparticles decrease.

[0138] The properties of the polymers obtained in the examples and comparative examples are shown in Table 2 below:

[0139] Table 2 Polymer properties

[0140]

[0141] As shown in Table 2, compared with the comparative example, when the catalyst prepared by the present invention is used to catalyze ethylene polymerization, the obtained polyethylene powder has less fine powder content of 105 microns and below, higher powder bulk density, comparable melt index and catalyst activity, and the obtained resin density is low. It shows that the catalyst of the present invention has obvious advantages in catalyzing the copolymerization of ethylene and 1-hexene: while maintaining the appropriate comprehensive performance of the catalyst, the density of the polyethylene resin can be significantly reduced, the copolymerization performance of the catalyst is improved, and the practicability of the catalyst is enhanced.

[0142] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0143] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of a conflict, the definition in this specification shall prevail.

[0144] In the context of the present specification, any matters or items not mentioned are directly applicable to those known in the art without any changes except those explicitly stated.

Claims

1. A raw material composition of a solid titanium catalyst component, comprising a magnesium halide, a compound represented by formula (I), an inorganic oxide carrier filler, a titanium-containing compound, and a solvent: in, The compound represented by formula (I) has the following structure: In formula (I), R1, R2, R3, R4 and R5 are each independently selected from hydrogen, a C1-C15 straight-chain alkyl or branched alkyl, a cycloalkyl, an aryl, an alkaryl or an aralkyl group; and n is an integer from 0 to 10.

2. The raw material composition of the solid titanium catalyst component according to claim 1, characterized in that: In formula (I), R1, R2, R3, R4, and R5 are each independently selected from hydrogen, C1-C10 straight-chain alkyl or branched alkyl, aryl or aralkyl. Preferably, the compound represented by formula (I) is selected from aminomethanol, aminoethanol, 3-aminopropanol, 4-aminobutanol, 3-amino-2,2-dimethyl-1-propanol, 10-amino-1-n-decanol, methylaminomethanol, methylaminoethanol, 3-methylamino-1-propanol, 2-methylamino-1-propanol, 1-methylamino-2-propanol, 4-methylamino-1-butanol, 4-benzylamino-1-butanol, 6-methylamino-1-hexanol, 6-ethylamino-1-hexanol, 10-ethylamino-1-decanol, isopropylaminoethanol, 3-isopropylamino-1-propanol, 4-isopropylamino The invention further comprises at least one of 1-(2-methyl-1-butylamino)ethanol, 2-(4-methyl-1-butylamino)ethanol, 3-(4-dimethylamino)-1-propanol, 2-(4-dimethylamino)-1-propanol, 1-(4-dimethylamino)-2-propanol, 4-(4-dimethylamino)-1-butanol, 4-diisopropylamino-1-butanol, 6-dimethylamino-1-hexanol, 6-diethylamino-1-hexanol, N-methyl-N-ethylethanolamine, methyl-N-isopropylethanolamine, N-methyl-N-ethylpropanolamine, N-methyl-N-ethylbutanolamine, N-methyl-N-isopropylhexanolamine, 2-(N-benzyl-N-methylamino)ethanol, 2-(N-methyl-N-butylamino)ethanol and 2-dimethylamino-2-phenyl-n-butanol.

3. The raw material composition of the solid titanium catalyst component according to claim 1, characterized in that: The magnesium halide is selected from at least one of magnesium dichloride, magnesium dibromide and magnesium diiodide; and / or, The titanium-containing compound is at least one of titanium halide, a product of aluminum reduction of titanium halide, and a product of magnesium reduction of titanium halide. Preferably, the general formula of the product of aluminum reduction of titanium halide is TiXm·n'AlXp, wherein 0<n'≤1, 0<m≤3, 0<p≤3, and X is bromine or chlorine; the general formula of the product of magnesium reduction of titanium halide is TiXm'·qMgXr, wherein 0<q≤1, 0<m'≤3, 0<r≤2, and X is bromine or chlorine; and / or, The inorganic oxide carrier filler is silicon oxide and / or aluminum oxide. Preferably, the particle size of the inorganic oxide carrier filler is 0.01 to 10 microns, more preferably 0.01 to 5 microns; and / or, The solvent is selected from solvents capable of dissolving magnesium halide and titanium-containing compounds. Preferably, the solvent is selected from at least one of methyl formate, ethyl formate, isopropyl formate, n-propyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, ethyl ether, propyl ether, hexyl ether, tetrahydrofuran, methyltetrahydrofuran, acetone, and methyl isobutyl ketone.

4. The raw material composition of the solid titanium catalyst component according to claim 3, characterized in that: The titanium halide is selected from at least one of titanium tribromide, titanium tetrabromide, titanium trichloride and titanium tetrachloride; and / or, The product of the aluminum reduction of titanium halide is TiCl3·1 / 3AlCl3; and / or, The product of magnesium reduction of titanium halide is TiCl3·1 / 2MgCl2; and / or, The inorganic oxide carrier filler is silicon dioxide.

5. The raw material composition of the solid titanium catalyst component according to claim 1, characterized in that: The molar ratio of magnesium halide to titanium-containing compound is 1 to 20; preferably 2 to 10; and / or, The molar ratio of the compound represented by formula (I) to the titanium-containing compound is 0.01 to 10, preferably 0.1 to 5; and / or, The weight ratio of the inorganic oxide support filler to the magnesium halide is 0.1 to 10; preferably 0.5 to 2; and / or, The molar ratio of the solvent to the magnesium halide is 10 to 120, preferably 20 to 60, The molar amount of the magnesium halide is calculated based on magnesium, and the molar amount of the titanium-containing compound is calculated based on titanium.

6. A solid titanium catalyst component prepared from a raw material composition comprising the solid titanium catalyst component according to any one of claims 1 to 5.

7. The solid titanium catalyst component according to claim 6, characterized in that: Based on 100wt% of the solid titanium catalyst component, the magnesium content is 4-10wt%, the titanium content is 1-5wt%, the halogen content is 14-30wt%, the compound content represented by formula (I) is 1-8wt%, the inorganic oxide carrier filler content is 25-45wt%, and the solvent content is 20-33wt%.

8. A method for preparing the solid titanium catalyst component according to claim 6 or 7, comprising the following steps: Step S1, preparing a mother solution: contacting a solvent, a magnesium halide, a titanium-containing compound and a compound represented by formula (I) under a protective atmosphere to prepare a mother solution; Step S2, carrier blending: under a protective atmosphere, during or after step S1, an inorganic oxide carrier filler is added for blending to obtain a slurry suspension; Step S3, spray molding: spray-drying the slurry suspension obtained in step S2 to obtain particles of the solid titanium catalyst component.

9. The method for preparing a solid titanium catalyst component according to claim 8, characterized in that: In step S1, the contact temperature is room temperature to 85° C., and the contact time is not less than 0.1 hour; and / or, In step S3, the inlet temperature of the spray drying is 100-240° C., and the outlet temperature of the spray drying is 60-130° C.; and / or, The particles of the solid titanium catalyst component are spherical solid particles; Preferably, in step S3, the inlet temperature of the spray drying is 120-160°C, and the outlet temperature of the spray drying is 90-115°C.

10. A catalyst for olefin polymerization, prepared from a raw material comprising the following components: Component (A): the solid titanium catalyst component according to claim 6 or 7 or the solid titanium catalyst component prepared by the method according to claim 8 or 9; Component (B): general formula A1R' b X' 3-b An organoaluminum compound, wherein R' is hydrogen or a C1-C20 hydrocarbon group, 0<b≤3, and X' is a halogen.

11. The catalyst for olefin polymerization according to claim 10, characterized in that: General formula A1R' b X' 3-b In which 1<b≤3, X' is chlorine, bromine or iodine; Preferably, the organoaluminum compound is selected from at least one of trimethylaluminum, triethylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, diisobutylaluminum chloride, ethylaluminum sesquichloride and dimethylaluminum chloride.

12. The catalyst for olefin polymerization according to claim 10, characterized in that: The molar ratio of aluminum contained in the component (B) to titanium contained in the component (A) is (1 to 1000):1, preferably (5 to 200):

1.

13. Use of the catalyst according to claim 11 or 12 in olefin polymerization, preferably in ethylene homopolymerization or polymerization of ethylene with one or more α-olefins; More preferably, the temperature of the olefin polymerization reaction is 20 to 120°C, and further preferably 65 to 90°C.

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