CN117946299A - Catalyst component for preparing polyethylene, and preparation method and application thereof - Google Patents

Abstract

The invention belongs to the technical field of olefin polymerization catalysts, and discloses a catalyst component for preparing polyethylene, which comprises, by weight, 1-10% of titanium, 10-20% of magnesium, 0.01-1% of phosphorus, 1-10% of alkoxy, 0.01-5% of aluminum, 40-70% of halogen and 0.1-10% of inert solvent. The catalyst component of the invention has higher activity, the prepared polymer has higher molecular weight and the bulk density of the polymer is obviously higher.

Description

A catalyst component for polyethylene preparation and its preparation method and application

Technical Field

The invention belongs to the technical field of olefin polymerization catalysts, and in particular relates to a catalyst component for polyethylene preparation, a preparation method and an application thereof.

Background technique

Ultra-high molecular weight polyethylene is a thermoplastic material with excellent performance, and has outstanding characteristics such as wear resistance, self-lubrication, high impact strength, and corrosion resistance. It has been widely studied and applied in the fields of military industry, national defense, textiles, chemical machinery, etc. In recent years, the application of ultra-high molecular weight polyethylene in lithium battery membranes and medical filter materials has developed rapidly. The catalyst used to prepare ultra-high molecular weight polyethylene is generally a Z-N catalyst, and the particle size of the catalyst is relatively small, and the uniformity of the catalyst particle size is required to be high.

Generally, the polymerization of olefins, especially the polymerization of ethylene or the copolymerization of ethylene and α-olefins, mostly uses Z-N catalyst components with magnesium, titanium, halogen and electron donor as basic components. The catalyst used for ultra-high molecular weight polyethylene generally uses a granular Z-N catalyst to facilitate the particle size control of the catalyst.

One of them is to dissolve the magnesium compound into a uniform solution, and then react it with a titanium compound to precipitate magnesium chloride particles while loading titanium chloride and electron donors, such as disclosed in patent documents CN85100997, CN1112373C, CN1229092A, CN1958620, etc. This method generally dissolves the magnesium compound in a polar solvent, and the dissolved solution is contacted with titanium tetrachloride to precipitate catalyst component particles containing titanium magnesium and electron donors.

For example, in patent document CN85100997, magnesium halide is dissolved in organic epoxy compound and organic phosphorus compound to form a uniform solution, and then reacted with at least one precipitation aid and transition metal titanium halide and its derivatives to prepare. Because organic epoxy compound and organic phosphorus compound without active hydrogen are used as solvents, they dissolve magnesium chloride slowly, and the reaction with titanium tetrachloride is easy to control, so the precipitated particles have better particle shape, which is spherical, and the prepared polymer has better particle shape and higher bulk density, but the activity is very low when used for ethylene polymerization.

For example, in patent document CN1112373C, magnesium chloride is dissolved in isooctyl alcohol with decane as dispersant, and then silane is added as precipitation agent, and the catalyst component particles are prepared by reaction with titanium tetrachloride. The solvent used in this system is isooctyl alcohol, the raw materials are simple, the catalyst component has high activity during ethylene polymerization, and the hydrogen regulation performance is good, but this catalyst component preparation method uses more titanium tetrachloride, and the particle shape of the catalyst component is not very regular.

For example, patent document CN1229092A discloses a catalyst for ethylene polymerization or copolymerization, which is prepared by dissolving magnesium halide in organic epoxy compound and organic phosphorus compound, adding a low-carbon alcohol as an electron donor activator to form a uniform solution, and then reacting with at least one acid anhydride precipitation aid and transition metal titanium halide and its derivatives. The catalyst shows high activity when used for ethylene slurry polymerization, but the particle morphology and particle size distribution of the catalyst component prepared by this method still need to be improved.

For example, in patent document CN1958620, a catalyst is prepared by dissolving magnesium halide in an organic epoxy compound, an organic phosphorus compound and a low-carbon alcohol to form a uniform solution, and then reacting with at least one silane compound and a transition metal titanium halide and its derivatives. The catalyst has high activity when used in slurry polymerization of ethylene, but the particle morphology and particle size distribution of the catalyst component prepared by this method still need to be improved.

Summary of the invention

In view of the above situation, the purpose of the present invention is to provide a catalyst component for the preparation of polyethylene and a preparation method and application thereof. The catalyst component has high activity and the prepared polyethylene has high molecular weight and high bulk density.

The first aspect of the present invention provides a catalyst component for the preparation of polyethylene, which contains titanium, magnesium, alkoxy, phosphorus, aluminum, halogen and an inert solvent. By weight, the titanium content is 1-10%, the magnesium content is 10-20%, the phosphorus content is 0.01-1%, the alkoxy content is 1-10%, the aluminum content is 0.01-5%, the halogen content is 40-70%, and the inert solvent content is 0.1-10%.

The second aspect of the present invention provides a method for preparing the catalyst component for preparing polyethylene, which is method one or method two:

Method 1 comprises the following steps:

a. mixing a magnesium compound, an organic epoxy compound, an organic phosphorus compound, an organic alcohol compound and an optional diluent, stirring and reacting to obtain a uniform solution;

b. Cooling the uniform solution obtained in step a to -30°C to 5°C, adding a titanium compound dropwise for reaction, then adding an organic aluminum compound for contact, heating to precipitate solid particles, washing with an inert solvent, and drying to obtain the catalyst component;

Method 2 comprises the following steps:

(1) mixing a magnesium compound, an organic epoxy compound, an organic phosphorus compound, an organic alcohol compound and an optional diluent, stirring and reacting to obtain a uniform solution;

(2) cooling the homogeneous solution obtained in step (1) to -30°C to 5°C, adding a titanium compound dropwise for reaction, heating to precipitate solid particles, and washing with an inert solvent;

(3) The washed solid particles are mixed with an organoaluminum compound and an inert solvent to prepare a slurry catalyst component.

The third aspect of the present invention provides the use of the above-mentioned catalyst component and the catalyst component obtained by the above-mentioned preparation method in the preparation of polyethylene, in the presence of the catalyst, ethylene and optional α-olefins are polymerized to obtain polyethylene; the catalyst contains the catalyst component and an organic aluminum co-catalyst.

The catalyst component of the invention has high activity when used for ethylene polymerization, and the prepared polyethylene has high molecular weight and high bulk density.

Other features and advantages of the present invention will be described in detail in the following detailed description.

Detailed ways

The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

According to the first aspect of the present invention, the present invention provides a catalyst component for the preparation of polyethylene, which catalyst component contains titanium, magnesium, alkoxy, phosphorus, aluminum, halogen and an inert solvent, and the content of titanium is 1-10% by weight, the content of magnesium is 10-20%, the content of phosphorus is 0.01-1%, the content of alkoxy is 1-10%, the content of aluminum is 0.01-5%, the content of halogen is 40-70%, and the content of inert solvent is 0.1-10%.

Preferably, in the catalyst component, by weight, the titanium content is 2-7%, the magnesium content is 12-20%, the phosphorus content is 0.1-0.8%, the alkoxy content is 2-8%, the aluminum content is 0.1-3.5%, the halogen content is 45-60%, and the inert solvent content is 0.5-8%.

According to the second aspect of the present invention, the present invention provides a method for preparing the catalyst component for preparing polyethylene, which is method one or method two:

Method 1 comprises the following steps:

a. mixing a magnesium compound, an organic epoxy compound, an organic phosphorus compound, an organic alcohol compound and an optional diluent, stirring and reacting to obtain a uniform solution;

b. Cooling the uniform solution obtained in step a to -30°C to 5°C, adding a titanium compound dropwise for reaction, then adding an organic aluminum compound for contact, heating to precipitate solid particles, washing with an inert solvent, and drying to obtain the catalyst component;

Method 2 comprises the following steps:

(1) mixing a magnesium compound, an organic epoxy compound, an organic phosphorus compound, an organic alcohol compound and an optional diluent, stirring and reacting to obtain a uniform solution;

(2) cooling the homogeneous solution obtained in step (1) to -30°C to 5°C, adding a titanium compound dropwise for reaction, heating to precipitate solid particles, and washing with an inert solvent;

(3) The washed solid particles are mixed with an organoaluminum compound and an inert solvent to prepare a slurry catalyst component.

According to the present invention, the general formula of the organoaluminum compound is _{AlRnX3 -n} , wherein R is selected from hydrogen, _C1 - _C20 hydrocarbon group, preferably hydrogen, _C1 - _C20 alkyl group, _C7 - _C20 aralkyl group, _C6 - _C20 aryl group; X is halogen, preferably selected from chlorine and bromine; n is a number of 0＜n≤3.

Specifically, the organic aluminum compound can be selected from at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum monohydrogen, diisobutylaluminum monohydrogen, diethylaluminum monochloride, diisobutylaluminum monochloride, sesquiethylaluminum chloride, and ethylaluminum dichloride.

In the present invention, the magnesium compound may be any of the existing magnesium compounds that can be used as olefin polymerization catalysts. For example, the magnesium compound may be magnesium dihalide or a derivative of magnesium dihalide in which a halogen atom in the molecular formula is replaced by a hydrocarbon group or a halohydrocarbonoxy group.

According to the present invention, the organic epoxy compound can be selected from aliphatic olefins, dienes, halogenated aliphatic olefins, oxides, glycidyl ethers or internal ethers of dienes having 2 to 8 carbon atoms. Specifically, it can be at least one of ethylene oxide, propylene oxide, butylene oxide, butadiene oxide, butadiene dioxide, epichlorohydrin, methyl glycidyl ether and diglycidyl ether.

In the present invention, the organophosphorus compound can be selected from alkyl or halogenated alkyl esters of orthophosphoric acid, alkyl or halogenated alkyl esters of phosphorous acid, and specifically can be selected from trimethyl orthophosphate, triethyl orthophosphate, tributyl orthophosphate, triphenyl orthophosphate, trimethyl phosphite, triethyl phosphite, tributyl phosphite, and benzyl phosphite.

According to the present invention, the organic alcohol compound can be selected from linear alcohols or isomeric alcohols having carbon atoms of 1 to 8. For example, it can be selected from at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-octanol and isooctyl alcohol.

In the present invention, the diluent may be benzene, toluene, xylene, chlorobenzene or a derivative thereof, and may be selectively added or not added when preparing a uniform solution.

According to the present invention, the inert solvent can be selected from C ₅ -C ₁₅ alkanes or C ₆ -C ₈ aromatic hydrocarbons, preferably at least one of hexane, heptane and toluene. When washing, toluene can be used for washing first, and then hexane can be used for washing.

In the present invention, the titanium compound can be a conventional choice in the art. For example, the general formula of the titanium compound is Ti(OR') _a X' _b , wherein R' is a C ₁ -C ₁₄ aliphatic hydrocarbon group or an aromatic hydrocarbon group, X' is a halogen atom, a is an integer of 0-2, b is an integer of 0-4, and a+b=3 or 4.

Specifically, the titanium compound can be at least one of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium tetrabutoxide, titanium tetraethoxide, titanium trichloride, titanium trichloride, titanium trichloride, titanium trichloride, titanium trichloride, titanium trichloride, titanium tetra ...

According to the present invention, in method 1 and method 2, the conditions for stirring the reaction and the conditions for heating to precipitate solid particles are the same. Specifically, the conditions for stirring the reaction include: stirring speed 350-500rpm, reaction temperature 50-60°C, reaction time 0.5-1.5h. The conditions for heating to precipitate solid particles include: heating temperature of 60-110°C, constant temperature 0.5-2h.

In the method 1 of the present invention, per mole of magnesium compound, the amount of the organic epoxy compound is 0.01-10 moles, preferably 0.02-4 moles; the amount of the organic phosphorus compound is 0.01-10 moles, preferably 0.02-4 moles; the amount of the organic alcohol compound is 0.01-15 moles, preferably 0.05-10 moles; the amount of the diluent is 0.2-5L; the amount of the organic aluminum compound is 0.05-0.8 moles, preferably 0.1-0.5 moles; the amount of the titanium compound is 0.2-30 moles, preferably 1-20 moles.

In the second method of the present invention, per mole of magnesium compound, the amount of the organic epoxy compound is 0.01-10 moles, preferably 0.02-4 moles; the amount of the organic phosphorus compound is 0.01-10 moles, preferably 0.02-4 moles; the amount of the organic alcohol compound is 0.01-15 moles, preferably 0.05-10 moles; the amount of the diluent is 0.2-5L; the amount of the organic aluminum compound is 0.005-0.2 moles, preferably 0.01-0.1 moles; the amount of the inert solvent is 0.2-5L; the amount of the titanium compound is 0.2-30 moles, preferably 1-20 moles.

According to the third aspect of the present invention, the present invention provides the use of the above-mentioned catalyst component and the catalyst component obtained by the above-mentioned preparation method in the preparation of polyethylene, in the presence of the catalyst, ethylene and optional α-olefins are polymerized to obtain polyethylene; the catalyst contains the catalyst component and an organic aluminum co-catalyst.

According to the present invention, the α-olefin may be a C ₃ -C ₁₀ α-olefin, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and the like.

In the present invention, the organic aluminum co-catalyst can be conventionally selected according to the prior art, such as an aluminum alkyl compound or an aluminum alkoxide compound, specifically triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, and methylaluminoxane.

According to the present invention, the polymerization reaction can be carried out in an inert solvent containing a polymerization monomer, in a liquid phase monomer, or in a gas phase under the protection of an inert gas. The conditions of the polymerization reaction include: a reaction temperature of 50-90°C, preferably 50-75°C; a reaction pressure of 0.01-5MPa, preferably 0.02-2MPa; a reaction time of 0.5-4h, preferably 1-3h. In addition, during the polymerization reaction, the types and amounts of the inert gas and solvent are well known to those skilled in the art and will not be repeated here.

The substances and parameters not limited in the present invention can be selected according to the existing technology and belong to the conventional technical means in this field.

The present invention will be further described below with reference to the following examples, but is not limited to these examples.

Determination of data in the following examples and comparative examples:

The apparent bulk density (BD) of the polymer is measured according to ASTM D1895-96.

The contents of titanium, magnesium, aluminum and halogen in the catalyst are determined by chemical analysis, the contents of alkoxy and inert solvent are determined by gas chromatography, and the content of phosphorus is determined by X-ray energy spectrum analysis.

The molecular weight (Mv) of the polymer was determined by the viscosity method.

Example 1

Preparation of catalyst component: 4.8 g of magnesium chloride, 55 ml of toluene, 3.0 ml of epichlorohydrin, 3.6 ml of tributyl phosphate, and 7.6 ml of ethanol were added to a reactor, stirred at 450 rpm and 55°C for 1 hour, cooled to -10°C, 40 ml of titanium tetrachloride was added dropwise, and then 22 ml of 1M diethylaluminum monochloride was added dropwise, the temperature was raised to 80°C within 4 hours, kept constant for 1.0 hour, washed twice with 120 ml of toluene at 60°C, washed 4 times with hexane, and dried to obtain the catalyst component. The composition of the catalyst component is shown in Table 1.

Ethylene polymerization: A 2-liter polymerization kettle was filled with nitrogen and evacuated alternately three times, 1 liter of n-hexane, 2 mmol of triethylaluminum and 5 mg of catalyst components were added, the temperature was raised to 60°C, ethylene was added to maintain the kettle pressure at 0.7 MPa, and the reaction was carried out at 60°C for 2 hours. The catalyst activity was calculated, and the bulk density and molecular weight of the polymer were determined, as shown in Table 2.

Example 2

Preparation of catalyst component: 4.8 g of magnesium chloride, 55 ml of toluene, 3.0 ml of epichlorohydrin, 3.6 ml of tributyl phosphate, and 7.6 ml of ethanol were added to a reactor, stirred at 450 rpm and 55°C for 1 hour, cooled to -10°C, 40 ml of titanium tetrachloride was added dropwise, and then 15 ml of 1M triethylaluminum was added dropwise, heated to 80°C within 4 hours, kept at this temperature for 1.0 hour, washed twice with 120 ml of toluene at 60°C, washed 4 times with hexane, and dried to obtain the catalyst component. The composition of the catalyst component is shown in Table 1.

Ethylene polymerization: A 2-liter polymerization kettle was filled with nitrogen and evacuated alternately three times, 1 liter of n-hexane, 2 mmol of triethylaluminum and 5 mg of catalyst components were added, the temperature was raised to 60°C, ethylene was added to maintain the kettle pressure at 0.7 MPa, and the reaction was carried out at 60°C for 2 hours. The catalyst activity was calculated, and the bulk density and molecular weight of the polymer were determined, as shown in Table 2.

Example 3

Preparation of catalyst component: 4.8 g of magnesium chloride, 55 ml of toluene, 3.0 ml of epichlorohydrin, 3.6 ml of tributyl phosphate, and 7.6 ml of ethanol were added to a reactor, stirred at 450 rpm and 55°C for 1 hour, cooled to -10°C, 40 ml of titanium tetrachloride was added dropwise, heated to 80°C within 4 hours, kept constant for 1.0 hour, washed twice with 120 ml of toluene at 60°C, washed 4 times with hexane, and 1.0 ml of 1M triethylaluminum and 100 ml of hexane were added to prepare a slurry catalyst component. The composition of the catalyst component after drying is shown in Table 1.

Ethylene polymerization: A 2-liter polymerization kettle was filled with nitrogen and evacuated alternately three times, 1 liter of n-hexane, 2 mmol of triethylaluminum and 0.1 ml of slurry catalyst component were added, the temperature was raised to 60°C, ethylene was added to maintain the kettle pressure at 0.7 MPa, and the reaction was carried out at 60°C for 2 hours. The catalyst activity was calculated, and the bulk density and molecular weight of the polymer were determined, as shown in Table 2.

Comparative Example 1

Preparation of catalyst component: 4.8 g of magnesium chloride, 55 ml of toluene, 3.0 ml of epichlorohydrin, 3.6 ml of tributyl phosphate, and 7.6 ml of ethanol were added to a reactor, stirred at 450 rpm and 55°C for 1 hour, cooled to -10°C, 40 ml of titanium tetrachloride was added dropwise, heated to 80°C within 4 hours, kept at this temperature for 1.0 hour, washed twice with 120 ml of toluene at 60°C, washed 4 times with hexane, and dried to obtain the catalyst component. The composition of the catalyst component is shown in Table 1.

Ethylene polymerization: A 2-liter polymerization kettle was filled with nitrogen and evacuated alternately three times, 1 liter of n-hexane, 2 mmol of triethylaluminum and 5 mg of catalyst components were added, the temperature was raised to 60°C, ethylene was added to maintain the kettle pressure at 0.7 MPa, and the reaction was carried out at 60°C for 2 hours. The catalyst activity was calculated, and the bulk density and molecular weight of the polymer were determined, as shown in Table 2.

Comparative Example 2

Preparation of catalyst component: 4.8 g of magnesium chloride, 55 ml of toluene, 3.0 ml of epichlorohydrin, 3.6 ml of tributyl phosphate, and 7.6 ml of ethanol were added to a reactor, stirred at 450 rpm and 55°C for 1 hour, cooled to -10°C, 40 ml of titanium tetrachloride was added dropwise, heated to 80°C within 4 hours, kept at this temperature for 1.0 hour, washed twice with 120 ml of toluene at 60°C, washed 4 times with hexane, and 100 ml of hexane was added to prepare a slurry catalyst component. The composition of the catalyst component after drying is shown in Table 1.

Ethylene polymerization: A 2-liter polymerization kettle was filled with nitrogen and evacuated alternately three times, 1 liter of n-hexane, 2 mmol of triethylaluminum and 0.1 ml of slurry catalyst component were added, the temperature was raised to 60°C, ethylene was added to maintain the kettle pressure at 0.7 MPa, and the reaction was carried out at 60°C for 2 hours. The catalyst activity was calculated, and the bulk density and molecular weight of the polymer were determined, as shown in Table 2.

Table 1

Table 2

It can be seen from Table 1 that the catalyst component of the present invention has a higher activity, the molecular weight of the prepared polymer is higher, and the bulk density of the polymer is significantly higher.

The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims (12)

1. Catalyst component for the preparation of polyethylene, characterized in that it comprises titanium, magnesium, alkoxy groups, phosphorus, aluminium, halogen and inert solvents, the content of titanium being 1-10%, the content of magnesium being 10-20%, the content of phosphorus being 0.01-1%, the content of alkoxy groups being 1-10%, the content of aluminium being 0.01-5%, the content of halogen being 40-70% and the content of inert solvents being 0.1-10% by weight.

2. The catalyst component for the production of polyethylene according to claim 1, wherein the titanium is contained in an amount of 2 to 7% by weight, the magnesium is contained in an amount of 12 to 20% by weight, the phosphorus is contained in an amount of 0.1 to 0.8% by weight, the alkoxy group is contained in an amount of 2 to 8% by weight, the aluminum is contained in an amount of 0.1 to 3.5% by weight, the halogen is contained in an amount of 45 to 60% by weight, and the inert solvent is contained in an amount of 0.5 to 8% by weight.

3. The process for preparing a catalyst component for polyethylene production according to claim 1 or 2, characterized in that the preparation process is a process one or a process two:

A method one, comprising the steps of:

a. mixing a magnesium compound, an organic epoxy compound, an organic phosphorus compound, an organic alcohol compound and an optional diluent, and stirring for reaction to obtain a uniform solution;

b. cooling the uniform solution obtained in the step a to-30 ℃ to 5 ℃, dropwise adding a titanium compound for reaction, then adding an organic aluminum compound for contact, heating to separate out solid particles, washing with an inert solvent, and drying to obtain the catalyst component;

the second method comprises the following steps:

(1) Mixing a magnesium compound, an organic epoxy compound, an organic phosphorus compound, an organic alcohol compound and an optional diluent, and stirring for reaction to obtain a uniform solution;

(2) Cooling the uniform solution obtained in the step (1) to-30 ℃ to 5 ℃, dropwise adding a titanium compound for reaction, heating to separate out solid particles, and washing with an inert solvent;

(3) Mixing the washed solid particles with an organic aluminum compound and an inert solvent to prepare a slurry catalyst component.

4. A process for the preparation of a catalyst component for the preparation of polyethylene according to claim 3, wherein the organoaluminum compound has the general formula AlR _nX_3-n, wherein R is selected from hydrogen, C ₁-C₂₀ hydrocarbyl, preferably from hydrogen, C ₁-C₂₀ alkyl, C ₇-C₂₀ aralkyl, C ₆-C₂₀ aryl; x is halogen, preferably selected from chlorine and bromine; n is a number of 0 < n.ltoreq.3;

preferably, the organoaluminum compound is at least one selected from trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum monohydride, diisobutylaluminum monohydride, diethylaluminum monochloride, diisobutylaluminum monochloride, sesquiethylaluminum chloride, ethylaluminum dichloride.

5. The method for producing a catalyst component for polyethylene production according to claim 3, wherein the magnesium compound is magnesium dihalide or a derivative in which one halogen atom in the formula of magnesium dihalide is substituted with a hydrocarbon group or a halogen hydrocarbyloxy group;

the organic epoxy compound is selected from aliphatic olefin, diene, halogenated aliphatic olefin, oxide of diene, glycidyl ether or internal ether with 2-8 carbon atoms; preferably at least one of ethylene oxide, propylene oxide, butylene oxide, butadiene double oxide, epichlorohydrin, methyl glycidyl ether and diglycidyl ether.

6. The method for preparing a catalyst component for polyethylene production according to claim 3, wherein the organic phosphorus compound is selected from the group consisting of hydrocarbyl or halocarbyl esters of orthophosphoric acid, hydrocarbyl or halocarbyl esters of phosphorous acid; preferably trimethyl orthophosphate, triethyl orthophosphate, tributyl orthophosphate, triphenyl orthophosphate, trimethyl phosphite, triethyl phosphite, tributyl phosphite, benzyl phosphite;

The organic alcohol compound is selected from straight-chain alcohol or isomeric alcohol with carbon number of 1-8; preferably at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-octanol and isooctanol.

7. The method for preparing a catalyst component for polyethylene production according to claim 3, wherein the diluent is benzene, toluene, xylene, chlorobenzene or a derivative thereof; the inert solvent is selected from C ₅-C₁₅ alkane or C ₆-C₈ arene, preferably at least one of hexane, heptane and toluene.

8. The method for producing a catalyst component for polyethylene production according to claim 3, wherein the titanium compound has a general formula of Ti (OR ') _aX'_b, wherein R ' is an aliphatic hydrocarbon group OR an aromatic hydrocarbon group of C ₁-C₁₄, X ' is a halogen atom, a is an integer of 0 to 2, b is an integer of 0 to 4, a+b=3 OR 4; the titanium compound is preferably at least one of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium tetrabutoxide, titanium tetraethoxide, titanium monochlorotriethoxide, titanium dichlorodiethoxide, titanium monochloroethoxide and titanium trichloride, more preferably titanium tetrachloride, titanium monochloroethoxide or titanium trichloride.

9. The method for producing a catalyst component for polyethylene production according to claim 3, wherein in the first and second methods, the condition of stirring reaction comprises: stirring speed is 350-500rpm, reaction temperature is 50-60 ℃, and reaction time is 0.5-1.5h; the temperature of the heating is 60-110 ℃.

10. A process for the preparation of a catalyst component for the preparation of polyethylene according to claim 3, wherein in process one, the organic epoxy compound is used in an amount of 0.01 to 10 moles, preferably 0.02 to 4 moles, per mole of magnesium compound; 0.01 to 10 moles, preferably 0.02 to 4 moles of the organic phosphorus compound; the organic alcohol compound is used in an amount of 0.01 to 15 moles, preferably 0.05 to 10 moles; the dosage of the diluent is 0.2-5L; the organoaluminum compound is used in an amount of 0.05 to 0.8 mol, preferably 0.1 to 0.5 mol; the titanium compound is used in an amount of 0.2 to 30 moles, preferably 1 to 20 moles.

11. A process for the preparation of a catalyst component for the preparation of polyethylene according to claim 3, wherein in process two, the organic epoxy compound is used in an amount of 0.01 to 10 moles, preferably 0.02 to 4 moles, per mole of magnesium compound; 0.01 to 10 moles, preferably 0.02 to 4 moles of the organic phosphorus compound; the organic alcohol compound is used in an amount of 0.01 to 15 moles, preferably 0.05 to 10 moles; the dosage of the diluent is 0.2-5L; the organoaluminum compound is used in an amount of 0.005 to 0.2 mol, preferably 0.01 to 0.1 mol; the dosage of the inert solvent is 0.2-5L; the titanium compound is used in an amount of 0.2 to 30 moles, preferably 1 to 20 moles.

12. Use of the catalyst component according to claim 1 or 2, the catalyst component produced by the production process according to any one of claims 3 to 11 in the production of polyethylene, characterized in that ethylene and optionally alpha-olefins are polymerized in the presence of a catalyst to give polyethylene; the catalyst contains the catalyst component and an organoaluminum cocatalyst.