CN117903343A

CN117903343A - Composite catalyst component, olefin polymerization catalyst, and preparation and application thereof

Info

Publication number: CN117903343A
Application number: CN202211249626.7A
Authority: CN
Inventors: 寇鹏; 李秉毅; 马永华; 梁迎迎; 刘照贺
Original assignee: Sinopec Beijing Chemical Research Institute Co ltd; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Chemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2022-10-12
Filing date: 2022-10-12
Publication date: 2024-04-19

Abstract

The invention relates to the field of olefin polymerization catalysts, and provides a composite catalyst component, an olefin polymerization catalyst, a preparation method and application thereof. The composite catalyst component contains superfine inorganic oxide and a main catalytic component obtained by reacting components including diphenyl silane compounds, electron donor compounds, magnesium halides and titanium halides, and can be used for olefin polymerization after the composite catalyst component is mixed with an organic aluminum compound. The polymer prepared by the catalyst has higher melt index and low oligomer content.

Description

Composite catalyst component, olefin polymerization catalyst, and preparation and application thereof

Technical Field

The invention belongs to the field of olefin polymerization catalysts, and particularly relates to a composite catalyst component for olefin polymerization, an olefin polymerization catalyst, a preparation method and application thereof.

Background

In the homopolymerization of ethylene or the copolymerization of ethylene with alpha-olefins, the performance of the catalyst affects the performance of the polymer. The catalyst can produce some oligomers while catalyzing ethylene polymerization, the oligomers change stress conditions among polyethylene molecules, the usability and processability of the product are affected, and the yield strength, the elongation, the rigidity and the like of the product are affected. The amount of oligomer is generally measured by the amount of hexane extract, and therefore, the amount of hexane extract is also an important index for measuring the performance of the catalyst.

Chinese patent CN102432713a provides a titanium-containing solid catalyst component for ethylene polymerization and a preparation method thereof, which is obtained by the following three consecutive synthetic steps: 1) Preparing a magnesium-containing solid by reacting metallic magnesium with an alcohol in the presence of a halogen or a halogen-containing compound; 2) Treating the magnesium-containing solid with an organometallic compound or a mixture of an organometallic compound and an electron donor compound to obtain a magnesium-containing catalyst support; 3) The catalyst component is obtained by treating the magnesium-containing catalyst support with a transition metal titanium compound in the presence of an inert organic solvent and then with an alkoxy silicon compound. Has the characteristics of simple process, convenient operation, low investment on industrial equipment, easy control of product quality and the like. High catalytic activity, strong copolymerization capability, high polymer bulk density, less subdivision and the like, and is suitable for slurry polymerization or gas phase polymerization of ethylene. However, the catalyst generates more fine powder in industrial application, which is unfavorable for the operation of the device.

Chinese patent CN1493599a discloses an improved catalyst for ethylene polymerization by adding alkyl silicate in the preparation of mother liquor of the catalyst main body catalytic component to improve catalyst activity and reduce oligomer content in the polymer, but the catalyst activity is not high enough.

Chinese patent CN112812205A discloses a catalyst component for olefin polymerization, its catalyst and its preparation method and application, and is specially applicable to gas-phase fluidized bed process. The catalyst component comprises a catalyst component 1 and a catalyst component 2; wherein catalyst component 1 comprises: 1) A superfine inorganic oxide support, and 2) a reaction and coordination product of magnesium halide, titanium halide, an electron donor compound, and a nitrogen-oxygen-containing heterocyclic compound; the catalyst component 2 is a heterocyclic compound containing an S atom. The catalyst comprises the reaction product of: (A) the catalyst component of the present invention; and (B) an organoaluminum compound of the formula AlR _dX_3-d. The catalyst of the invention has high activity in the field of gas phase polymerization, and the obtained polymer has higher bulk density and more importantly, has good copolymerization performance, and provides a foundation for improving the production stability of a gas phase fluidized bed and developing new products.

Therefore, there is a need to develop a catalyst for olefin polymerization having higher activity and melt index and low oligomer content in the polymer.

Disclosure of Invention

In view of the above-mentioned shortcomings in the prior art, the present invention provides a composite catalyst component for olefin polymerization and an olefin polymerization catalyst containing the same. The composite catalyst component contains superfine inorganic oxide and main catalytic component, and is used for olefin polymerization after the catalyst component and the organic aluminum compound are activated.

The invention aims at providing a composite catalyst component which comprises an ultrafine inorganic oxide and a main catalytic component, wherein the ultrafine inorganic oxide is at least one of silicon oxide and aluminum oxide, and the main catalytic component is a product obtained by reacting components comprising a diphenyl silane compound, an electron donor compound, magnesium halide and titanium halide.

According to an embodiment of the present invention, the diphenylsilane compound has a general formula (R ¹O)(R²O)SiPh₂, wherein R ¹、R² is independently selected from H, C to C5 alkyl, C2 to C4 alkenyl, C2 to C4 alkynyl, C3 to C8 cycloalkyl or C6 to C10 aryl, preferably H, C to C6 alkyl, C3 to C8 cycloalkyl or C6 to C10 aryl, more preferably the diphenylsilane compound is selected from at least one of dihydroxydiphenylsilane, dimethoxydiphenylsilane and diethoxydiphenylsilane.

According to an embodiment of the present invention, the electron donor compound is selected from at least one of esters, ethers and ketones, preferably from at least one of alkyl esters of C1 to C4 saturated aliphatic carboxylic acids, alkyl esters of C7 to C8 aromatic carboxylic acids, C2 to C6 aliphatic ethers, C3 to C4 cyclic ethers, C3 to C6 saturated aliphatic ketones, more preferably 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, diethyl ether, propyl ether, hexyl ether, tetrahydrofuran, acetone and methyl isobutyl ketone, most preferably from at least one of methyl formate, ethyl acetate, butyl acetate, diethyl ether, hexyl ether, tetrahydrofuran, acetone and methyl isobutyl ketone, particularly preferably tetrahydrofuran;

According to an embodiment of the present invention, the ultrafine inorganic oxide may be selected conventionally according to the prior art in the field, for example, may be selected from at least one of silicon oxide and aluminum oxide commonly used in the field, preferably, the ultrafine inorganic oxide is selected from at least one of aluminum oxide and silicon dioxide, more preferably, from silicon dioxide, and the ultrafine inorganic oxide may be in a solid form or a dispersion form; the particle size of the ultrafine inorganic oxide is 0.01 to 10. Mu.m, preferably 0.01 to 5. Mu.m, more preferably 0.01 to 2. Mu.m, most preferably 0.01 to 1. Mu.m; the ultrafine inorganic oxide is preferably silica having a particle diameter of 0.01 to 1. Mu.m.

According to an embodiment of the present invention, the magnesium halide is at least one selected from the group consisting of magnesium chloride, magnesium bromide, and magnesium iodide; the titanium halide is at least one selected from titanium trichloride, titanium tetrachloride, titanium tribromide and titanium tetrabromide, preferably at least one selected from titanium trichloride and titanium tetrachloride.

According to an embodiment of the present invention, the content of the ultrafine inorganic oxide in the composite catalyst component is 5 to 50wt%, for example, may be 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50wt%, or a value or a range of values between any two of the above values, based on 100wt% of the total weight of the composite catalyst component, preferably, the content of the ultrafine inorganic oxide is 10 to 40wt%, more preferably, 15 to 30wt%; the titanium content of the composite catalyst component is 0.1 to 6wt%, for example, may be 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6%, or a value or range of values between any two of the above; preferably, the titanium content is 0.5 to 3.5wt%;

The diphenylsilane compound may be, for example, 0.01 to 15mol, 0.1, 0.5, 1,2,5, 9, 10, 12 or 15mol, or a value or a range of values between any two of the above, preferably 0.1 to 15mol, more preferably 0.1 to 5mol, per mol of titanium halide; the electron donor compound is 1 to 600mol, for example, 1,10, 15, 20, 50, 100, 150, 200, 220, 250, 270, 300, 350, 400, 450, 500, 550 or 600mol, or a value or a range of values between any two of the above values, preferably, the electron donor compound is 20 to 300mol, more preferably, 100 to 250mol; the magnesium halide may be 0.1 to 15mol, for example, 0.1, 0.5, 1,2,5, 9, 10, 12 or 15mol, or a value or a range of values between any two of the above, and preferably, the magnesium halide is 1 to 12mol, and more preferably, 2 to 8mol.

The second object of the present invention is to provide a method for preparing the above composite catalyst component, comprising: the main catalytic component is obtained by reacting the components comprising diphenyl silane compounds, electron donor compounds, magnesium halide and titanium halide, and then the main catalytic component is loaded on superfine inorganic oxide, thus obtaining the composite catalyst component. Preferably, the preparation method specifically comprises the following steps:

step (1) stirring components comprising the diphenyl silane compound, the electron donor compound, the magnesium halide and the titanium halide for reaction to obtain a main catalytic component mother solution;

step (2) adding the superfine inorganic oxide into the main catalytic component mother liquor obtained in the step (1), and mixing to obtain slurry;

and (3) spray-drying the slurry obtained in the step (2) to obtain the composite catalyst component.

Specifically:

the reaction conditions in the step (1) can be selected conventionally according to the prior art in the field, and the reaction temperature is preferably 50-80 ℃ and the reaction time is 2-5 h;

The superfine inorganic oxide added in the step (2) contains almost no physical and chemical adsorption water when in use, and can be subjected to activation treatment before use; the superfine inorganic oxide is added in an amount such that a slurry suitable for spray drying is formed after mixing with the mother liquor, preferably the superfine inorganic oxide is contained in the slurry in an amount of 0.5 to 50wt%, preferably 2 to 30wt%;

The spray drying conditions in step (3) include: the inlet temperature is 80-240 ℃, preferably 120-200 ℃; the outlet temperature is 60 to 130 ℃, preferably 90 to 110 ℃.

It is a further object of the present invention to provide an olefin polymerization catalyst comprising:

component (A): the above composite catalyst component or a composite catalyst component obtained by the above production method;

Component (B): an organoaluminum compound.

Wherein the organic aluminum compound has a general formula of A1R _nX_3-n, wherein R is hydrogen or C1-C20 alkyl, X is halogen, preferably chlorine, bromine and iodine; n is more than 0 and less than or equal to 3; preferably, the organic aluminum compound is at least one selected from triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum and diethylaluminum chloride;

The molar ratio of aluminum in the component (B) to titanium in the component (A) is (5-500): 1, preferably (10 to 200): 1.

In order to make the solid catalyst component obtained after spray-drying suitable for producing an ethylene polymer, it is necessary that the organoaluminum compound as an activator component thereof reduces titanium atoms in the catalyst component to a state allowing ethylene to be efficiently polymerized. Generally, the above catalyst component is reacted with an activator component in a hydrocarbon solvent to obtain a catalyst capable of conducting olefin polymerization; the polymerization of olefins may also be further initiated by reacting the above catalyst component with an activator component in a hydrocarbon solvent during the polymerization process. Wherein the hydrocarbon solvent includes, but is not limited to: isopentane, hexane, heptane, toluene, xylene, naphtha, mineral oil.

The fourth object of the present invention is to provide a process for producing the above olefin polymerization catalyst, comprising: mixing the organic aluminum compound and the composite catalyst component to obtain the olefin polymerization catalyst.

It is a fifth object of the present invention to provide an olefin polymerization catalyst as described above or an olefin polymerization catalyst obtained by the above-described production method, which is useful for olefin polymerization, in particular, olefin homo-polymerization or copolymerization.

The catalyst of the invention is suitable for homo-polymerization of various kinds of ethylene or copolymerization of ethylene and alpha-olefin, wherein the alpha-olefin can be selected from one of propylene, butene, pentene, hexene, octene and 4-methylpentene-1. The polymerization process can adopt a gas phase method, a slurry method and a solution method, and is more suitable for gas phase fluidized bed polymerization. The conditions for the polymerization of the olefin may be conventionally selected according to the prior art and will not be described in detail herein.

The catalyst for olefin polymerization is prepared by taking superfine inorganic oxide as a carrier, mixing mother liquor prepared by reacting an electron donor compound, magnesium halide, diphenyl silane compound and titanium halide with the carrier, preparing a catalyst component by adopting a spray forming mode, adding an organic aluminum compound to obtain the olefin polymerization catalyst with high activity, and preparing a polymer with higher melt index by adopting the catalyst, wherein a hexane extract is low and an oligomer content is low. The diphenyl silane compound adopted by the invention is phenyl silane compound containing hydroxyl or alkoxy, wherein the hydroxyl or alkoxy has a strong electron donating effect, so that the polymerization efficiency of the active center of the catalyst can be effectively improved after the silicon atom is coordinated with the active center; in addition, the phenyl of the diphenyl silane compound provides an electronic effect, and simultaneously, the hydrogen sensitivity of polymerization can be improved and the catalytic efficiency can be improved due to the space effect.

Detailed Description

The present invention is described in detail below with reference to specific embodiments, and it should be noted that the following embodiments are only for further description of the present invention and should not be construed as limiting the scope of the present invention, and some insubstantial modifications and adjustments of the present invention by those skilled in the art from the present disclosure are still within the scope of the present invention.

The test instruments and test conditions used in the examples are as follows:

1. Catalyst activity: expressed as weight of resin obtained per gram of catalyst;

2. polymer Melt Index (MI): 6932 melt index meter, CEAST company, italy;

3. Hexane extractables content in polymer powder (wt%): and extracting the dried polymer powder by using hexane, specifically leaching the polymer by using hexane for 4 hours, wherein the weight difference between the polymer powder before and after extraction accounts for the weight of the polymer powder before extraction, namely the hexane extractable content in the polymer powder.

4. Determination of titanium content in the catalyst component: the catalyst sample was dissolved with 1M sulfuric acid, the solution was measured using a spectrophotometer, and the titanium content was calculated using a working curve.

5. The superfine inorganic oxide content is obtained by calculating the mass ratio of the fed amount to the produced catalyst.

The raw materials used in the examples were all commercial products.

Example 1

(1) Preparation of the catalyst component

To a 250mL three-necked flask purged with nitrogen, 1.5gTiCl ₄, 4.0g of anhydrous MgCl ₂, 1.4g of dihydroxydiphenylsilane and 100mL of tetrahydrofuran were successively added, and the mixture was stirred and heated to 65℃to perform a constant temperature reaction for 3 hours and then cooled to 35℃to obtain a mother liquor.

6G of silica gel (Cabot Corporation TS-610 with the particle size of 0.02-0.1 mu m) is added into a 250mL three-necked flask which is blown off by nitrogen, the cooled mother solution is added, the temperature is kept at 35 ℃, the mixture is stirred for 1 hour, and then the mother solution obtained by mixing the silica gel is subjected to spray drying by a spray dryer under the spray conditions: the catalyst component was obtained at an inlet temperature of 195℃and an outlet temperature of 110℃with a titanium content of 2.33% by weight and a silica content of 24% by weight.

(2) Slurry polymerization of ethylene

Adding 1L of hexane into a 2L polymerization kettle blown and discharged by nitrogen, simultaneously adding 2mL of 1M triethylaluminum/hexane and 0.01g of the catalyst component obtained in the step (1), heating to 75 ℃, adding 0.18Mpa of hydrogen, adding 0.75Mpa of ethylene after hydrogenation, heating to 85 ℃, reacting for 2 hours, and cooling and discharging. The polymerization results are shown in Table 1.

Example 2

(1) Preparation of the catalyst component

As in example 1.

(2) Slurry polymerization of ethylene

The procedure of example 1 was repeated except that 0.05g of the catalyst component obtained in step (1) was added, the temperature was raised to 75℃and 0.68MPa of hydrogen was added, and after the completion of the hydrogenation, 0.35MPa of ethylene was added, and the polymerization results were shown in Table 1.

Example 3

(1) Preparation of the catalyst component

The difference from example 1 is that: the amount of dihydroxydiphenyl silane used was 2.8g, and the titanium content of the resulting catalyst component was 2.42% by weight and the silica content was 22% by weight.

(2) Slurry polymerization of ethylene

The polymerization results are shown in Table 1, as in example 1.

Example 4

(1) Preparation of the catalyst component

Same as in example 3.

(2) Slurry polymerization of ethylene

The polymerization results are shown in Table 1 as in example 2.

Example 5

(1) Preparation of the catalyst component

The same as in example 1 except that the dihydroxydiphenyl silane was used in an amount of 0.7g, the titanium content of the resulting catalyst component was 2.28% by weight and the silica content was 23% by weight.

(2) Slurry polymerization of ethylene

The polymerization results are shown in Table 1, as in example 1.

Example 6

(1) Preparation of the catalyst component

Same as in example 5.

(2) Slurry polymerization of ethylene

The polymerization results are shown in Table 1 as in example 2.

Example 7

(1) Preparation of the catalyst component

The same as in example 1 except that dihydroxydiphenylsilane was replaced with diethoxydiphenylsilane in an amount of 0.9g, the titanium content of the resulting catalyst component was 2.31% by weight and the silica content was 23% by weight.

(2) Slurry polymerization of ethylene

The polymerization results are shown in Table 1, as in example 1.

Example 8

(1) Preparation of the catalyst component

Same as in example 7.

(2) Slurry polymerization of ethylene

The polymerization results are shown in Table 1 as in example 2.

Example 9

(1) Preparation of the catalyst component

The same as in example 1 except that the dihydroxydiphenylsilane was replaced with diphenyldimethoxydiphenylsilane in an amount of 0.8g, the titanium content of the obtained catalyst component was 2.35% by weight and the silica content was 24% by weight.

(2) Slurry polymerization of ethylene

The polymerization results are shown in Table 1, as in example 1.

Example 10

(1) Preparation of the catalyst component

Same as in example 9.

(2) Slurry polymerization of ethylene

The polymerization results are shown in Table 1 as in example 2.

Comparative example 1

(1) Preparation of the catalyst component

To a 250mL three-necked flask purged with nitrogen, 1.5g TiC1 ₄, 4.0g anhydrous MgCl ₂ and 100mL tetrahydrofuran were successively added, and the mixture was stirred and heated to 65℃to perform a constant temperature reaction for 3 hours, and then cooled to 35℃to obtain a mother liquor.

6G of silica gel (Cabot Corporation TS-610 with the particle size of 0.02-0.1 μm) is added into a 250mL three-necked flask which is blown off by nitrogen, the cooled mother solution is added, the temperature is kept at 35 ℃, the mixture is stirred for 1 hour, and the mother solution obtained after the silica gel is mixed is sprayed and dried by a spray dryer under the spraying condition: the catalyst component was obtained at an inlet temperature of 195℃and an outlet temperature of 110℃with a titanium content of 2.2% by weight and a silica content of 25% by weight.

(2) Slurry polymerization of ethylene

1L of hexane is added into a 2L polymerization kettle blown off by nitrogen, 2mL of 1M triethylaluminum/hexane and 0.01g of catalyst are added, the temperature is raised to 75 ℃, 0.18Mpa of hydrogen is added, 0.75Mpa of ethylene is added after the hydrogenation is finished, the temperature is raised to 85 ℃, and the temperature is reduced and the material is discharged after the reaction is carried out for 2 hours. The polymerization results are shown in Table 1.

Comparative example 2

(1) Preparation of the catalyst component

As in comparative example 1.

(2) Slurry polymerization of ethylene

The difference is that 0.05g of catalyst was added, hydrogen gas was added at 0.68MPa after the completion of hydrogenation at 75℃and ethylene was added at 0.35MPa, and the polymerization results are shown in Table 1.

TABLE 1 catalyst Performance obtained in examples and comparative examples

From the polymerization data in Table 1, the catalyst in the examples of the present invention has higher activity and better hydrogen sensitivity under the same polymerization conditions; the resulting polymer has a higher melt index and a lower hexane extractables content.

The foregoing description of embodiments of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described.

Claims

1. The composite catalyst component comprises an ultrafine inorganic oxide and a main catalytic component, wherein the ultrafine inorganic oxide is at least one of silicon oxide and aluminum oxide, and the main catalytic component is a product obtained by reacting components comprising a diphenyl silane compound, an electron donor compound, magnesium halide and titanium halide.

2. The composite catalyst component according to claim 1, wherein,

The general formula of the diphenylsilane compound is (R ¹O)(R²O)SiPh₂, wherein R ¹、R² is independently selected from H, C-C5 alkyl, C2-C4 alkenyl, C2-C4 alkynyl, C3-C8 cycloalkyl or C6-C10 aryl, preferably H, C-C5 alkyl, C3-C8 cycloalkyl or C6-C10 aryl, and/or,

The electron donor compound is at least one of esters, ethers and ketones, preferably at least one of alkyl esters of C1-C4 saturated aliphatic carboxylic acids, alkyl esters of C7-C8 aromatic carboxylic acids, C2-C6 aliphatic ethers, C3-C4 cyclic ethers and C3-C6 saturated aliphatic ketones, more preferably 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, diethyl ether, propyl ether, hexyl ether, tetrahydrofuran, acetone and methyl isobutyl ketone; and/or the number of the groups of groups,

The superfine inorganic oxide is at least one of alumina and silicon dioxide, preferably silicon dioxide; and/or the number of the groups of groups,

The particle size of the superfine inorganic oxide is 0.01-10 mu m, preferably 0.01-5 mu m; and/or the number of the groups of groups,

The magnesium halide is at least one selected from magnesium chloride, magnesium bromide and magnesium iodide; and/or the number of the groups of groups,

The titanium halide is at least one selected from titanium trichloride, titanium tetrachloride, titanium tribromide and titanium tetrabromide, preferably at least one selected from titanium trichloride and titanium tetrachloride.

3. The composite catalyst component according to claim 2, wherein,

The diphenyl silane compound is at least one selected from dihydroxydiphenyl silane, dimethoxy diphenyl silane and diethoxy diphenyl silane; and/or the number of the groups of groups,

The electron donor compound is at least one selected from methyl formate, ethyl acetate, butyl acetate, diethyl ether, hexyl ether, tetrahydrofuran, acetone and methyl isobutyl ketone, and preferably tetrahydrofuran; and/or the number of the groups of groups,

The particle size of the superfine inorganic oxide is 0.01-2 mu m.

4. The composite catalyst according to claim 1, wherein,

The content of the ultrafine inorganic oxide in the composite catalyst component is 5 to 50wt%, preferably 10 to 40wt%, more preferably 15 to 30wt%, based on 100wt% of the total weight of the composite catalyst component; and/or the number of the groups of groups,

The titanium content of the composite catalyst component is 0.1 to 6wt%, preferably 0.5 to 3.5wt%, based on 100wt% of the total weight of the composite catalyst component; and/or the number of the groups of groups,

The diphenylsilane compound is present in an amount of 0.01 to 15mol, preferably 0.1 to 15mol, more preferably 0.1 to 5mol, per mol of titanium halide; the electron donor compound is 1 to 600mol, preferably 20 to 300mol, more preferably 100 to 250mol; the magnesium halide is 0.1 to 15mol, preferably 1 to 12mol, more preferably 2 to 8mol.

5. A method of preparing the composite catalyst component according to any one of claims 1 to 4, comprising: the main catalytic component is obtained by reacting the components comprising diphenyl silane compounds, electron donor compounds, magnesium halide and titanium halide, and then the main catalytic component is loaded on superfine inorganic oxide, thus obtaining the composite catalyst component.

6. The preparation method according to claim 5, wherein the preparation method specifically comprises:

7. The method according to claim 6, wherein,

The reaction conditions in the step (1) are as follows: the reaction temperature is 50-80 ℃ and the reaction time is 2-5 h; and/or the number of the groups of groups,

The content of the superfine inorganic oxide in the slurry liquid in the step (2) is 0.5-50 wt%, preferably 2-30 wt%; and/or the number of the groups of groups,

8. An olefin polymerization catalyst comprising:

Component A: a composite catalyst component according to any one of claims 1 to 4 or a composite catalyst component obtained by the production process according to any one of claims 5 to 7;

Component B: an organoaluminum compound.

9. The olefin polymerization catalyst according to claim 8, wherein,

The general formula of the organic aluminum compound is A1R _nX_3-n, wherein R is C1-C20 alkyl, X is halogen, and n is more than 0 and less than or equal to 3; preferably, the organic aluminum compound is at least one selected from triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum and diethylaluminum chloride; and/or the number of the groups of groups,

The molar ratio of aluminum in the component B to titanium in the component A is (5-500): 1, preferably (10 to 200): 1.

10. A method of preparing the olefin polymerization catalyst of claim 8 or 9, comprising: and mixing the organic aluminum compound and the composite catalyst component to obtain the olefin polymerization catalyst.

11. Use of the olefin polymerization catalyst according to claim 8 or 9 or the olefin polymerization catalyst obtained by the production process according to claim 10 in olefin polymerization.