CN1461756A - Nonmetallocene polyolefine catalyst and its preparation method - Google Patents

Abstract

A polyolefin catalyst having the following structural expression: in formulas [I] and [II], R ¹ is selected from C ₁ to C ₁₂ alkyl groups; R ² and R ³ are respectively selected from hydrogen, C ₁ to C 12 C ₁₂ alkyl, C ₁ -C ₆ alkoxy or nitro; M is selected from group IVB metal elements; X is selected from halogen, and n is an integer of 1-3. The above-mentioned compounds are loaded on the carrier of magnesium chloride, which can be prepared as a supported catalyst. It is especially suitable for the homopolymerization and copolymerization of ethylene and α-olefin, and has a high polymerization activity. The molecular weight of the prepared polymer is High, wide molecular weight distribution.

Description

Non-metallocene polyolefin catalyst and preparation method thereof

technical field

The invention relates to a non-metallocene polyolefin catalyst and a preparation method thereof. Specifically, it is a non-metallocene catalyst containing a β-diketone structure in a ligand and a preparation method thereof.

Background technique

Following the typical transition metal compounds with cyclopentadiene and its derivatives as ligands, that is, metallocene catalysts, another type of non-metallocene compounds containing oxygen, nitrogen and other coordinated heteroatom ligands in the conjugated system The application of polyolefins, especially polyethylene catalysts, has attracted more and more attention and attention.

The non-metallocene compound that contains oxygen atom in the ligand, as the titanium compound with β-diketone and derivative as ligand usually can only be used for styrene polymerization, as CN1158859A discloses a kind of titanium chloride with β-diketone Catalyst system for the synthesis of syndiotactic polystyrene as the main catalyst. The preferred main catalyst of this patent is a titanium halide with a β-diketone derivative as a ligand, and the ligand is acetylacetone or dibenzoylmethane, the number of which is 1 to 4, and the preferred catalyst is Titanium trichloride acetylacetonate and titanium trichloride dibenzoylmethane. The catalyst can prepare polystyrene with high syndiotacticity and high heat resistance temperature.

Recently, while studying metallocene and non-metallocene catalysts, people are also studying the above-mentioned catalysts as active components loaded on different inorganic compound supports to make supported catalysts. For example, USP5,869,417 discloses a method for preparing a supported catalyst with a metallocene as an active component and a molecular sieve as a carrier. The carrier used in this patent is a macroporous molecular sieve with a pore size of 7 to 15 Å, such as faujasite , SAPO-37, etc., the catalyst prepared by supporting metallocene on the above-mentioned molecular sieve carrier can be used for the polymerization of ethylene, propylene or styrene.

The article that K.Soga etc. publishes in J.Polym.Sci., Polym.Chem.Ed.35,291-311 discusses the polymerization performance of the catalyst prepared by loading cyclopentadiene titanium trichloride on the magnesium chloride carrier , the catalyst can be used in combination with triisobutylaluminum cocatalyst to prepare polypropylene, and has high polymerization activity.

Contents of the invention

The object of the present invention is to provide a non-metallocene polyolefin catalyst and a supported catalyst prepared by using the catalyst as an active component.

Another object of the present invention is to provide a preparation method of the catalyst.

We have found that a non-metallocene compound having a β-diketone structure in the ligand can be prepared by reacting an alkali metal salt of an acyl naphthol compound with a transition metal halide, which can be used as a catalyst for olefin polymerization. A polyethylene catalyst with higher activity can be prepared by loading the compound as an active component on an inorganic chloride carrier.

When the supported catalyst prepared by the invention is used for ethylene homopolymerization or copolymerization, it has high polymerization activity. If the reaction is carried out at 0.7MPa and 70°C, the polymerization activity reaches 7.88×10 ⁶ g PE/mole Ti·hour, and the obtained polymer has a high molecular weight and a wide molecular weight distribution.

Detailed ways

The non-metallocene polyolefin catalyst provided by the present invention has the following structural expression:

In formulas [I] and [II], R ¹ is selected from C ₁ -C ₁₂ alkyl; R ² and R ³ are respectively selected from hydrogen, C ₁ -C ₁₂ alkyl, C ₁ -C ₆ alkoxy group or nitro group; M is selected from group IVB metal elements; X is selected from halogen, and n is an integer of 1 to 3.

In the above expression, R ² is a substituent on a benzene ring with a β-diketone structure, R ² is preferably hydrogen, C ₁ to C ₄ alkoxy or nitro, more preferably methoxy or ethoxy, The substituting position can be 3 or 4, preferably 4 substitutions. R ³ is a substituent of a free benzene ring. R ³ is preferably hydrogen, C ₁ -C ₄ alkoxy or nitro, more preferably nitro, and its substituent position can be any position on the benzene ring, preferably 8.

The R ¹ is a substituent on a carbonyl group, preferably a C ₁ -C ₄ alkyl group, more preferably a methyl group or an ethyl group.

M is preferably titanium or zirconium and X is preferably chlorine.

More preferred formula [I] and [II] compound have: (alpha-acetyl naphthol)-titanium trichloride, (4-methoxy group-alpha-acetyl naphthol)-titanium trichloride, (4 -Nitro-α-acetylnaphthol)-titanium trichloride, (8-methoxy-α-acetylnaphthol)-titanium trichloride, (8-nitro-α-acetylnaphthol) - Titanium trichloride, bis(α-acetylnaphthol)-titanium dichloride, bis(4-methoxy-α-acetylnaphthol)-titanium dichloride, bis(4-nitro-α -acetylnaphthol)-titanium dichloride, bis(8-methoxy-α-acetylnaphthol)-titanium dichloride, bis(8-nitro-α-acetylnaphthol)-dichloro Titanium chloride, (β-acetylnaphthol)-titanium trichloride, (4-methoxy-β-acetylnaphthol)-titanium trichloride, (4-nitro-β-acetylnaphthol) -Titanium trichloride, (8-methoxy-β-acetylnaphthol)-titanium trichloride, (8-nitro-β-acetylnaphthol)-titanium trichloride, di(β-acetyl Nylnaphthol)-titanium dichloride, bis(4-methoxy-β-acetylnaphthol)-titanium dichloride, bis(4-nitro-β-acetylnaphthol)-titanium dichloride , bis(8-methoxy-β-acetylnaphthol)-titanium dichloride, bis(8-nitro-β-acetylnaphthol)-titanium dichloride.

The preparation method of the compound of formula [I] or [II] comprises in the presence of an organic solvent, making MX ₄ react with an alkali metal salt of an acyl naphthol compound according to a molar ratio of 1: 1 to 2, and removing the solvent, MX ₄ in the formula M Metal elements selected from Group IVB, preferably titanium or zirconium, X is halogen, preferably chlorine, and the acyl naphthol compound is α-acyl naphthol or 3-acyl naphthol.

The preparation method of the alkali metal salt of the acyl naphthol compound is as follows: reacting the acyl naphthol compound and an equimolar amount of the alkali metal compound in the presence of an organic solvent to form a salt of the acyl naphthol compound. The alkali metal compound used is selected from alkali metals, alkali metal hydrides, alkyls or amides, and the alkyl group in the alkylate is a C ₁ -C ₂₄ alkyl group, such as butyl, more preferably alkali metal The compound is sodium, potassium, butyl lithium, sodium hydride, potassium hydride, sodium amide or potassium amide.

The reaction temperature for preparing the alkali metal salt of the acyl naphthol compound is -30-40°C, preferably -15-10°C. The reaction time is 0.5 to 24 hours, preferably 2 to 5 hours.

The reaction temperature of MX ₄ and the alkali metal salt of acyl naphthol compound is -30-40°C, preferably -15-10°C, and the reaction time is 0.5-24 hours, preferably 5-10 hours. After the reaction is completed and the solvent is removed, the solid is dried to obtain the compound of formula [I] or [II].

The organic solvent used in the above reaction is selected from halogenated alkanes containing 1 to 5 carbon atoms, preferably chlorinated alkanes containing 1 to 3 carbon atoms, such as methylene chloride or ethylene dichloride.

The supported catalyst provided by the invention comprises an inorganic chloride carrier and a non-metallocene active component having the expression of formula [I] or formula [II] loaded on the carrier, and the content of the IVB group metal in the catalyst is 0.1 ~ 10% by weight, preferably 0.5 to 5.0% by weight.

The preparation method of supported catalyst comprises dissolving inorganic chloride in tetrahydrofuran to form an adduct solution, and then fully contacting with the non-metallocene active component of formula [I] or formula [II] in the presence of a polar organic medium, Then add a non-polar organic solvent, and dry after the precipitation is fully separated.

When preparing the inorganic chloride adduct, the amount of tetrahydrofuran added is 10-250 times, preferably 20-50 times, the weight of the inorganic chloride.

During the reaction, the polar organic medium is selected from toluene, C ₁ -C ₅ halogenated alkanes, and tetrahydrofuran. The preferred halogenated alkanes have 1 to 3 carbon atoms, and the number of halogen atoms is 1 to 3. Among them, the chlorinated alkanes Most preferably, the preferred chlorinated alkanes are methylene chloride, chloroform, ethylene dichloride, and carbon tetrachloride. The amount of the polar organic medium used is 5-200 times, preferably 10-20 times, the weight of the non-metallocene active component.

In the method for preparing the supported catalyst, after the reactants are fully mixed and contacted, the catalyst is prepared by the co-precipitation method. The non-polar solvent used for coprecipitation is C ₅ ~ C ₂₀ alkanes, preferably C ₅ ~ C ₈ alkanes, such as hexane, octane, heptane, and the amount of non-polar solvent is the same as that of the polar solvent. The volume ratio is 3-50:1.

In the above preparation process, the molar ratio of the inorganic chloride to the non-metallocene is 5-500:1, preferably 5-50:1, and the temperature for the full contact reaction of the two solutions should be controlled at 10-70°C, preferably 10°C. ~30°C, the contact time is 0.5-72 hours, preferably 0.5-10.0 hours, and it is best to use stirring to fully contact the two solutions.

Co-precipitation can be carried out under the same conditions as the reaction temperature, preferably 10-30°C, and the standing time after adding the non-polar solvent is 0.5-72 hours, preferably 0.5-12 hours. After the precipitate is completely precipitated, the separated solid is dried. The preferred drying temperature is 30-50° C. and the drying time is 3-6 hours, so that a supported catalyst with good fluidity can be obtained.

The inorganic chloride carrier used for preparing the supported catalyst is preferably magnesium chloride, its water content should be less than 1.0% by weight, the average particle size is 30-40 microns, and the specific surface area is 10-20 m2/ ^g .

The catalyst provided by the invention is suitable for the polymerization reaction of α-olefin, such as the polymerization reaction of ethylene or styrene. The prepared supported catalyst is especially suitable for homopolymerization of ethylene or copolymerization of ethylene and alpha-olefin. Aluminoxane or alkylaluminum cocatalyst needs to be added during polymerization, and the polymerization temperature is 10-100°C, preferably 30-80°C. Preferred comonomers for copolymerization are C ₃ -C ₁₅ alpha-olefins, such as butene, pentene, hexene or styrene.

或

The cocatalyst aluminoxane can be linear or cyclic, and has the following repeating units:

or

In the formula, R" is an alkyl group of C ₁ to C ₈ , preferably methyl, ethyl or isobutyl, and n is 5 to 40. Particularly preferred cocatalysts are methylalumoxane, ethylalumoxane or isobutyl Butylaluminoxane.

The cocatalyst aluminum alkyl is selected from triethylaluminum, triisobutylaluminum, trihexylaluminum or their mixtures.

During the polymerization reaction, the molar ratio of aluminum in the cocatalyst to the metal in the main catalyst, ie the Al/M ratio, is 25-2000, preferably 800-1500.

The present invention will be described in detail below by examples, but the present invention is not limited thereto.

Instance 1

(1) Preparation of (α-acetylnaphthol)-titanium trichloride

元素分析实测(计算)值：C 42.59重％(42.46重％)，H 3.23重％(2.67重％)，Ti 14.23重％(14.11重％)。Take 1.86 grams of α-acetylnaphthol (Shanghai Reagent Factory), dissolve it in 50 milliliters of dichloromethane, add 0.24 grams of sodium hydride at -10°C for 2 hours, then slowly drop the reaction solution into 10 milliliters containing In the dichloromethane of 1.90 grams of TiCl , make the molar ratio _{of TiCl 4 and} α-acetyl naphthol sodium be 1:1. Stir the reaction at room temperature for 8 hours. After the reaction is completed, the reaction solution is concentrated to 15 milliliters, the precipitated solid is filtered, and washed 3 times with hexane to obtain (α-acetylnaphthol)-titanium trichloride. Its structural formula is as follows:

Elemental analysis measured (calculated) values: C 42.59 wt% (42.46 wt%), H 3.23 wt% (2.67 wt%), Ti 14.23 wt% (14.11 wt%).

During the elemental analysis test, the carbon and hydrogen elements are measured by chromatographic separation-thermal conductivity detection method, and the titanium content is measured by plasma emission spectrometry (ICP), the same below.

(2) preparation of supported catalyst

Take 1.2 grams of dry magnesium chloride (produced by Jinzhou Aluminum Plant) with a water content of less than 1.0% by weight and put it into a reaction flask, add 30 milliliters of dry tetrahydrofuran, and react at 55° C. for 1 hour to form an adduct solution. Slowly drip 5 ml of toluene solution containing 0.48 g of (α-acetylnaphthol)-titanium trichloride into the reaction flask, stir and react at 20°C for 1 hour, stop stirring, add 100 ml of hexane solution, and let it stand at room temperature. The precipitate was left for 2 hours, filtered, and the solid was dried at 20°C for 6 hours to obtain 1.59 g of deep red catalyst A. ICP method records that the titanium content of catalyst A is 1.75% by weight, and the magnesium content is 12.6% by weight

Example 2

(1) Prepare two (alpha-acetyl naphthol)-titanium dichlorides according to the method of Example 1. The difference is that the addition of α-acetyl naphthol is 3.72 grams, adding sodium hydride is 0.48 grams, making the molar ratio of TiCl ₄ and α-acetyl naphthol sodium be 1: 2, and the reaction temperature is 0°C. Obtain the structural formula of two (alpha-acetyl naphthol)-titanium dichlorides as follows,

Elemental analysis measured (calculated) values: C 59.24 wt% (58.91 wt%), H 3.90 wt% (3.71 wt%), Ti 10.06 wt% (9.79 wt%).

(2) preparation of supported catalyst

Prepare supported catalyst by the method for example 1, difference is that 10 milliliters are dissolved with the toluene solution of 0.68 gram two (alpha-acetyl naphthol)-titanium dichlorides and the tetrahydrofuran solution of magnesium chloride reaction, obtain 1.6 grams deep red catalyst B . Catalyst B has a titanium content of 1.55% by weight and a magnesium content of 14.4% by weight.

Example 3

(1) Prepare the active component (β-acetyl naphthol)-titanium trichloride according to the method of Example 1. The difference is that 1.86 grams of β-acetylnaphthol (Shanghai Reagent Factory) was added for reaction, and the molar ratio of _TiCl to β-acetylnaphthol sodium was 1:1. Obtain the structural formula of (β-acetyl naphthol)-titanium trichloride as follows,

Elemental analysis measured (calculated) values: C 58.82 wt% (58.91 wt%), H 3.80 wt% (3.71 wt%), Ti 10.17 wt% (9.79 wt%).

(2) preparation of supported catalyst

Prepare supported catalyst by the method for example 1, difference is that 10 milliliters are dissolved with the toluene solution of 0.68 gram (β-acetyl naphthol)-titanium trichloride and the tetrahydrofuran solution of magnesium chloride reaction, obtain 1.42 gram dark red catalyst C. Catalyst C had a titanium content of 1.83% by weight and a magnesium content of 11.8% by weight.

Example 4

(1) Prepare the active component bis(β-acetylnaphthol)-titanium dichloride according to the method of Example 1. The difference is that the add-on of β-acetyl naphthol is 3.72 grams, and adding sodium hydride is _0.48 grams, so that the mol ratio of TiCl and sodium β-acetyl naphthol is 1:2. Obtain the structural formula of two (beta-acetyl naphthol)-titanium dichlorides as follows,

Elemental analysis measured (calculated) values: C 42.30 wt% (42.46 wt%), H 3.08 wt% (2.67 wt%), Ti 14.15 wt% (14.11 wt%).

(2) preparation of supported catalyst

Prepare supported catalyst by the method for example 1 step (2), difference is that 5 milliliters are dissolved with 0.48 gram two (beta-acetyl naphthol)-titanium dichloride toluene solution and the THF solution reaction of magnesium chloride, obtain 1.5 grams Crimson Catalyst D. Catalyst D has a titanium content of 1.49% by weight and a magnesium content of 13.7% by weight.

Example 5

(1) Prepare (4-methoxy-α-acetyl naphthol)-titanium trichloride according to the method of Example 1. The difference is to react with 4-methoxyl-alpha-acetylnaphthol and titanium tetrachloride to obtain the structural formula of (4-methoxyl-alpha-acetylnaphthol)-titanium trichloride as follows,

Elemental analysis measured (calculated) values: C 43.09 wt% (42.63 wt%), H 3.26 wt% (3.13 wt%).

(2) preparation of supported catalyst

Prepare supported catalyst by the method for example 1, difference is that 5 milliliters are dissolved with 0.68 gram (4-methoxy group-alpha-acetyl naphthol)-titanium trichloride toluene solution and the tetrahydrofuran solution reaction of magnesium chloride, obtain 1.5 grams Crimson Catalyst E. Catalyst E has a titanium content of 1.58% by weight and a magnesium content of 13.8% by weight

Example 6

(1) Prepare bis(4-methoxy-α-acetylnaphthol)-titanium dichloride according to the method of Example 1. The difference is that 4-methoxyl-α-acetylnaphthol is used to react with titanium tetrachloride, so that the molar ratio of TiCl4 to ₄ -methoxyl-α-acetylnaphthol sodium is 1:2. The active component bis(4-methoxy-α-acetylnaphthol)-titanium dichloride structural formula is as follows,

Elemental analysis measured (calculated) values: C 57.13 wt% (57.64 wt%), H 4.31 wt% (4.10 wt%).

(2) preparation of supported catalyst

Prepare supported catalyst by the method for example 1, difference is that 5 milliliters are dissolved in the toluene solution of 1.0 gram two (4-methoxyl-alpha-acetyl naphthol)-titanium dichloride reacts with the tetrahydrofuran solution of magnesium chloride, obtains 1.7 g of Crimson Catalyst F. Catalyst F had a titanium content of 1.63% by weight and a magnesium content of 12.8% by weight.

Example 7

(1) Prepare (8-nitro-α-acetyl naphthol)-titanium trichloride according to the method of Example 1. The difference is to react with 8-nitro-alpha-acetyl naphthol to obtain the structural formula of the active component (8-nitro-alpha-acetyl naphthol)-titanium trichloride as follows,

Elemental analysis measured (calculated) values: C 37.13 wt% (37.51 wt%), H 2.21 wt% (2.10 wt%).

(2) preparation of supported catalyst

Prepare supported catalyst by the method for example 1, difference is that 5 milliliters are dissolved with the toluene solution of 0.8 gram (8-nitro-alpha-acetyl naphthol)-titanium trichloride and the tetrahydrofuran solution reaction of magnesium chloride, obtain 1.7 grams Crimson Catalyst G. Catalyst G had a titanium content of 1.53% by weight and a magnesium content of 14.1% by weight.

Example 8

(1) Prepare bis(8-nitro-α-acetyl naphthol)-titanium dichloride according to the method of Example 1. The difference is to react with 8-nitro-α-acetyl naphthol, so that the molar ratio of TiCl ₄ and 8-nitro-α-acetyl naphthol is 1:2. The structural formula of the active component two (8-nitro-alpha-acetyl naphthol)-titanium dichloride is as follows,

Elemental analysis measured (calculated) values: C 50.13 wt% (49.81 wt%), H 3.01 wt% (2.79 wt%).

(2) preparation of supported catalyst

Prepare supported catalyst by the method for example 1, difference is that 5 milliliters are dissolved with 1.0 gram two (8-nitro-alpha-acetyl naphthol)-titanium dichloride toluene solution and the tetrahydrofuran solution reaction of magnesium chloride, obtain 1.6 grams Crimson Catalyst H. Catalyst H had a titanium content of 1.43% by weight and a magnesium content of 14.9% by weight.

Instances 9-16

The following examples use the catalyst of the invention for high pressure ethylene homopolymerization.

In a 1 liter stainless steel autoclave, feed ethylene, and keep its pressure at 0.7MPa, add 90 milliliters of methylalumoxane (MAO) toluene solution (produced by Albemarle Company) containing 10% by weight of aluminum, and then add the hexane of the catalyst Alkanes solution 300 ml, the Al/Ti molar ratio was 500:1. Polymerization at 70°C for 0.5 hours, and the reaction was terminated with HCl. Catalyst activity is shown in Table 1.

Instances 17-20

The following examples use the catalysts of this invention for high pressure ethylene copolymerization.

Carry out high-pressure ethylene copolymerization with the catalyst of the present invention according to the method of Example 9, and add a certain amount of comonomer during polymerization. The catalyst activity and comonomer amount used in each example are shown in Table 1.

Example 21

Carry out high-pressure ethylene homopolymerization reaction with catalyst A according to the method of example 9, different is the hexane solution (produced by Albemarle company) of the modified methylalumoxane (MMAO) that contains aluminum 10 weight % instead of methylalumoxane ( MAO), the catalyst activity is shown in Table 1.

Example 22

Carry out high-pressure ethylene homopolymerization reaction with catalyst A according to the method of example 9, except that methylaluminoxane (MAO) is replaced by a hexane solution of triisobutylaluminum containing 10% by weight of aluminum. The catalyst activity is shown in Table 1.

Example 23

Carry out high-pressure ethylene homopolymerization reaction with catalyst A according to the method of Example 9, except that the hexane solution of triethylaluminum containing 10% by weight of aluminum is used instead of methylaluminoxane (MAO). The catalyst activity is shown in Table 1.

Table 1 example Catalyst number comonomer Catalytic activity×10 ^-5 , g polyethylene/mole titanium·hour M _W ×10 ^-4 M _W /Mn 9 A - 7.88 79.8 4.25 10 B - 4.05 87.7 3.66 11 C - 6.53 83.3 4.21 12 D. - 5.68 70.9 4.55 13 E. - 3.05 90.1 3.55 14 f - 2.13 93.6 3.81 15 G - 8.21 71.2 4.33 16 h - 6.07 71.3 4.7 17 A 10 ml hexene 8.13 70.2 4.52 18 B 10 ml hexene 4.89 76.5 4.63 19 C 10 ml hexene 6.83 72.5 4.72 20 D. 10 ml hexene 6.23 61.9 4.91 twenty one A - 6.78 79.0 5.61 twenty two A - 5.64 85.3 5.14 twenty three A - 1.60 47.9 8.64

Claims (11)

1. A non-metallocene polyolefin catalyst has the following structural expression: In formulas [I] and [II], R ¹ is selected from C ₁ -C ₁₂ alkyl; R ² and R ³ are respectively selected from hydrogen, C ₁ -C ₁₂ alkyl, C ₁ -C ₆ alkoxy group or nitro group; M is selected from group IVB metal elements; X is selected from halogen, and n is an integer of 1 to 3. 2. The catalyst according to claim 1, characterized in that said R ¹ is selected from C ₁ -C ₄ alkyl, R ² and R ³ are respectively selected from hydrogen, C ₁ -C ₄ alkoxy or Nitro, M is selected from titanium or zirconium, X is chlorine. 3. The catalyst according to claim 2, characterized in that said R ¹ is methyl or ethyl, R ² is methoxy or ethoxy, R ³ is nitro, M is titanium, X is chlorine . 4. A supported catalyst, comprising an inorganic chloride carrier and a non-metallocene compound of formula [I] or [II] supported on the carrier, the content of Group IVB metals in the catalyst is 0.1-10 Heavy%. 5. The catalyst according to claim 4, characterized in that said inorganic chloride is magnesium chloride, and the content of Group IVB metals in the catalyst is 0.5-5.0% by weight. 6. A method for preparing the catalyst as claimed in claim 1, comprising reacting MX ₄ and the alkali metal salt of acyl naphthol compound in a molar ratio of 1: 1 to 2 in the presence of an organic solvent, removing the solvent, and MX ₄ has the formula M is selected from group IVB metal elements, and X is a halogen. 7. The method according to claim 6, wherein the organic solvent is selected from halogenated alkanes containing 1 to 5 carbon atoms, the alkali metal salt of the acyl naphthol compound is sodium acyl naphthol, and the reaction temperature is - 30-40°C. 8. The method according to claim 7, characterized in that said organic solvent is a chlorinated alkane containing 1 to 3 carbon atoms. 9. A method for preparing the catalyst as claimed in claim 4, comprising dissolving the inorganic chloride in tetrahydrofuran to form an adduct solution, and then reacting with the non-metallocene compound of formula [I] or [II] in the presence of a polar organic medium The compound is fully contacted, and then a non-polar organic solvent is added, and the precipitate is fully separated and then dried. 10. The method according to claim 9, characterized in that the polar organic medium is toluene, tetrahydrofuran, C ₁ -C ₅ halogenated alkanes, and the non-polar organic solvent is selected from C ₅ -C ₂₀ alkanes, The molar ratio of inorganic chloride to non-metallocene is 5-500:1. 11. The method according to claim 9, characterized in that the contact temperature is 10-70°C, and the time for adding a non-polar organic solvent for precipitation is 0.5-72 hours.