CN1405191A - Catalyst component for ethylene polymerization or copolymerization, and catalyst and use thereof - Google Patents

Abstract

A kind of catalyzer component of ethylene polymerization or copolymerization is put forward, whose valid component titanium trichloride is got by reverting titanium tetrachloride adopting organic magnesium compound on the spot, contains not only not hopeless outgrowth, but also one sort of the got ougrowth is MgCl2 which is one of valid components of catalyzer and may used on the spot, the other sort is alkylhalide which operates advance function with catalyzer component on the contrary and also may be used on the spot, and that catalyzer component is simple to prepare and easy to operate, therefore reaction outcome of catalyzer component and organic aluminium promotor is the same with copolymerization of ethylene and senior a-alkene, in favor of decreasing production of ethane extractable rsidues and volatile oil.

Description

Catalyst component for ethylene polymerization or copolymerization, catalyst and application thereof

Technical Field

The present invention relates to a catalyst component suitable for ethylene polymerization or copolymerization, its preparation method and catalyst containing said catalyst component, and the application of said catalyst in the polymerization or copolymerization of olefin, specially in the gas-phase polymerization of ethylene, and can be used for producing homopolymer and copolymer of ethylene.

Background

It is well known that the production of ethylene homopolymers and copolymers by gas phase fluidized bed processes is one of the most important polyethylene production techniques, and the selection of a suitable catalyst is critical to the production technique. U.S. Pat. No. 4,4293673, U.S. Pat. No. 4,4302565, U.S. Pat. No. 5,4302566, U.S. Pat. No. 4303771 disclose a catalyst comprising titanium trichloride/magnesium dichloride/tetrahydrofuran as an effective component supported on a silica gel support; chinese patent CN1268520A discloses a catalyst which takes titanium trichloride/magnesium dichloride/tetrahydrofuran/cyclic chlorohydrocarbon as an effective component and is loaded on a silica gel carrier; chinese patent CN1291617A discloses a catalyst supported on a silica gel carrier, which contains titanium trichloride/magnesium dichloride/tetrahydrofuran/halohydrin as an effective component. These catalysts are suitable for the production of polyethylene resins in a gas phase fluidized bed apparatus, and are particularly suitable for the production of linear low density polyethylene resins.

The titanium trichloride used in the above catalyst system is usually produced by reducing titanium tetrachloride with metallic aluminum, and the titanium trichloride is actually a mixed crystal of titanium trichloride and aluminum trichloride (TiCl)₃·1/3AlCl₃). Although the catalyst prepared by the titanium trichloride has higher polymerization activity, two obvious defects still exist. One is that because the aluminum trichloride is mixed in the effective composition of the catalyst, the load capacity of the carrier silica gel is limited due to the limitation of the specific surface area of the carrier silica gel, and the existence of the aluminum trichloride is not beneficial to the improvement of the load capacity of the effective composition of the catalyst, so that the improvement of the activity of the catalyst is limited; secondly, due to the mixed crystals (TiCl) in the catalyst system₃·1/3AlCl₃) Due to the existence ofCopolymerization of ethylene with higher α -olefins such as hexene, octene promotes the production of resins with undesirably high levels of hexane extractables and tackifying resins (as set forth in chinese patent CN 1085915A), thereby affecting the stability of gas phase fluidized bed production and the increase in production load.

In order to overcome the above disadvantages, chinese patent CN1085915A discloses a process for preparing trichlorinated titanium by in situ reduction of titanium tetrachloride using magnesium powder in tetrahydrofuranA process for the preparation of titanium and catalysts formed therefrom, wherein the reduction is carried out during the preparation of the catalyst, with MgCl being produced as a by-product₂Is also one of the active components of the catalyst, can be used in situ and by supplementing it with a certain amount of MgCl₂The final Mg/Ti molar ratio was adjusted to the desired value. The resulting catalyst overcomes the disadvantages of the above catalysts because the titanium trichloride produced does not contain aluminum trichloride, an undesirable by-product. However, the reaction of reducing titanium tetrachloride in situ by using magnesium powder is a solid-liquid reaction, the reaction uniformity is poor, the control is difficult,and the operation is difficult, meanwhile, after the reaction is finished, the unreacted magnesium powder must be removed by a filter device, otherwise, the performance of the final catalyst is affected, because magnesium is an active metal, if the filtered magnesium powder is not reused, the inactivation treatment must be carried out on the filtered magnesium powder, so that a lot of inconvenience is brought to the industrial production, and the continuous industrial production is not facilitated.

Disclosure of Invention

Thus, the present inventors have, through trial and error, provided an improved catalyst component in which the effective component of titanium trichloride was obtained by reducing titanium tetrachloride in situ with an organomagnesium compound, not only free of undesirable by-products, but also one of the by-products obtained was MgCl₂The catalyst component of the present invention is suitable for copolymerization of ethylene and high-grade α -olefin, and this is favorable to reducing hexane extractables and volatile oil.

The invention provides a catalyst component suitable for ethylene polymerization or copolymerization, which comprises a reaction product of a titanium-containing active component and at least one halide improver, wherein the titanium-containing active component is supported on a carrier material;

the titanium-containing active component is prepared by reacting titanium-containing active component in an electron donor solvent without an active hydrogen group,by MgR₂Or MgRX and titanium tetrachloride are contacted and reacted to reduce the titanium tetrachloride into titanium trichloride, and then MgX is added₂Obtained after reaction;

the halide improver is represented by the following general formula F-R¹[R² _bX_(3-b)]A class of compounds of (a), wherein:

f is an oxygen-containing functional group which can chemically react with an organoaluminum compound, a titanium compound or a hydroxyl group, R is¹Is a divalent C₁～C₆An aliphatic or aromatic group of (a), which is bonded to the oxygen atom in the functional group F; r²Is hydrogen, C₁～C₆Alkyl, cycloalkyl or aryl or halogen substituted C₁～C₆Alkyl, cycloalkylaryl, b is 0, 1 or 2, X is F, Cl or Br;

in the titanium-containing catalyst component according to the invention, the proportions of the components are, per mole of titanium compound: 0.5 to 50 mol, preferably 1.5 to 5 mol, of a magnesium compound, 0.5 to 50 mol, preferably 1 to 10 mol, of an electron donor, and 0.5 to 50 mol, preferably 1 to 10 mol, of a halide modifier.

The Electron Donor (ED) used above which does not contain an active hydrogen group is preferably as follows: alkyl esters of aliphatic or aromatic carboxylic acids, aliphatic ethers, cyclic ethers, and aliphatic ketones. Among these electron donors, C is preferred₁～C₄Alkyl esters of saturated aliphatic carboxylic acids, C₇～C₈Alkyl esters of aromatic carboxylic acids, C₂～C₆Aliphatic ethers, C₃～C₄Cyclic ether, C₃～C₆A saturated aliphatic ketone. Most preferred of these electron donors are methyl formate, ethyl acetate, butyl acetate, diethyl ether, hexyl ether, Tetrahydrofuran (THF), acetone, and methyl isobutyl ketone. The electron donor can be used alone or in combination of several kinds.

It should be noted that when the organic magnesium compound is used to reduce titanium tetrachloride, the invention generates a byproduct of alkyl chloride, for example, tetrahydrofuran is used as an electron donor solvent, and quantitative dibutyl magnesium and titanium tetrachloride undergo the following chemical reduction reaction:

it was indicated in CN1085915A that the chloroalkanes formed in this process are undesirable by-products which must be separated from the titanium trichloride product prior to use. In the catalyst component of the present invention, the inventors have surprisingly found through repeated experiments that chlorobutane, which is a by-product generated by the above reaction, has no adverse effect on the catalyst, but rather has a certain promotion effect on the activity of the catalyst. Since the boiling point of chlorobutane is 107.8 ℃ which is far higher than the boiling points of tetrahydrofuran (66 ℃) and isopentane (27.9 ℃), the by-products do not need to be removed and remain in the catalyst, which is beneficial to the exertion of the activity of the catalyst.

It is worth noting that the reduction of titanium tetrachloride in the catalyst component of the present invention using organomagnesium compounds can exhibit the following advantages: firstly, a titanium trichloride component is prepared in situ, and the titanium trichloride does not contain undesirable aluminum trichloride, so that the loading capacity of the effective components of the catalyst on a silica gel carrier is improved, and the activity of the catalyst is correspondingly improved; secondly, the catalyst does not contain mixed crystals (TiCl)₃·1/3AlCl₃) Thirdly, the reaction of organic magnesium and titanium tetrachloride is rapid and quantitative, the quality of the prepared catalyst is ensured, the process is simple and easy to operate, the by-product chloroalkane does not need to be removed, the existence of the chloroalkane is favorable for the exertion of the activity of thecatalyst, and simultaneously, the by-product MgCl is used as another by-product₂It can also be used in situ.

Wherein the organomagnesium compound can be alkyl magnesium such as MgR₂Or magnesium chloroalkylates such as MgRX, where the R group is C₂～C₁₀The alkyl, cycloalkyl or aryl group of (1) is, for example, diethylmagnesium, dipropylmagnesium, dibutylmagnesium, dipentylgagnesium, dihexylmagnesium, dioctylmagnesium, butylmagnesium chloride, hexylmagnesium chloride, octylmagnesium chloride. Preferably dibutyl magnesium or dioctyl magnesium.

Wherein the general formula MgX₂In the magnesium compound, X is selected from Cl, Br, IOr mixtures thereof. Specifically, magnesium dichloride, magnesium dibromide and magnesium diiodide can be used, and magnesium dichloride is preferred.

The halide improver has a general formula of F-R¹[R² _bX_(3-b)]A class of compounds of (a), wherein:

f is a compound which can react with the hydroxyl groups of the organic aluminium compound, titanium compound or silica gelFunctional groups such as aldehyde groups, acyl groups, hydroxyl groups, amino groups, or ester groups, etc.; r¹Is a divalent C₁～C₆An aliphatic group or an aromatic group bonded to the oxygen atom in the functional group F; r²Is hydrogen, unsubstituted or halogen-substituted C₁～C₆Alkyl radical, C₃～C₆Cycloalkyl or C₆～C₁₀An aromatic group, b is 0, 1 or 2, and X is F, Cl or Br.

When F is a hydroxyl group, the modifier is a halohydrin, and a specific compound is 2, 2, 2-trichloroethanol (Cl)₃CCH₂OH), 2-dichloroethanol (Cl)₂CHCH₂OH), 2-chloroethanol (ClCH)₂CH₂OH), 1-dimethyl-2, 2, 2-trichloroethanol (Cl)₃CC(CH₃)₂OH), 4-chlorobutanol (ClCH)₂CH₂CH₂CH₂OH), p-chlorophenol, m-chlorophenol, o-chlorophenol, 2-chlorocyclohexanol, and the like. 2, 2, 2-Trichloroethanol (Cl) is preferred₃CCH₂OH), 2-dichloroethanol (Cl)₂CHCH₂OH), 2-chloroethanol (ClCH)₂CH₂OH) or 1, 1-dimethyl-2, 2, 2-trichloroethanol (Cl)₃CC(CH₃)₂OH)。

When F is acyl, the improver is a halogenated acyl halide, and specific compounds are trichloroacetyl chloride, dichloroacetyl chloride, chloroacetyl chloride, o-chlorobenzoyl chloride, 2-chlorocyclohexyl carbonyl chloride and the like. Trichloroacetyl chloride, dichloroacetyl chloride or chloroacetyl chloride is preferred.

The preparation method of the catalyst component generally loads an active component on a silica gel carrier by an impregnation method, titanium tetrachloride and stoichiometric organic magnesium react in an electron donor solvent to produce titanium trichloride and magnesium dichloride, and the titanium trichloride and the magnesium dichloride and the electron donor form a soluble complex, then a certain amount of magnesium dichloride is added into the solution, and the molar ratio of Mg/Ti is increased to a required value to obtain the desired catalyst component. Then the solution is immersed in a suitable porous carrier material, and the catalyst effective composition is loaded on the carrier by means of evaporating solvent or spray drying, etc. to obtain the ideal solid catalyst component, which together with the cocatalyst of alkyl aluminium forms the olefin polymerization catalyst.

The porous carrier material can adopt spherical or spheroidal silica gel, the average particle size of the silica gel is 10-100 μm, and the preferred is: 20-80 μm, preferably: 30-60 μm;the specific surface area is 50-1000 m²The ratio of the total amount of the components is preferably: 100 to 800m²The optimal ratio is: 200 to 800m²(ii)/g; the pore volume is 1.0-6.0 ml/g, preferably: 2.0-5.0 ml/g; the average diameter of pores is 5-45 nm, preferablyComprises the following steps: 10 to 35 nm. The dehydrated silica gel is the best, the content of the surface hydroxyl can be adjusted by controlling the thermal activation condition of the silica gel,

in the above-mentioned process of thermally activating the silica gel, an organoaluminum compound such as AlEt may be further added₃MAO or organomagnesium compounds such as butyl magnesium.

Preferred embodiments may include the following reaction steps:

(1) activating the silica gel carrier by a conventional method, and dehydrating for 4 hours at 600 ℃ under a preferable condition;

(2) adding the thermally activated silica gel into a lower alkane solvent, adding an alkyl aluminum compound, reacting for a period of time, evaporating the solvent, and drying to obtain solid powder;

(3) dissolving titanium tetrachloride compound and organic magnesium compound in electron donor, reacting for a period of time, and adding a certain amount of MgX₂Dissolving to prepare a mother liquor, wherein MgX is₂The time and the sequence of adding the compound into the electron donor compound are not strictly limited as long as the final Mg/Ti molar ratio is ensured to reach the required value;

(4) adding the activated carrier obtained in the step (2) into the mother liquor, reacting for a certain time, drying, removing excessive solvent, namely electron donor, and generally controlling the residual content to be 10-21 wt%;

(5) suspending the solid matter obtained in the step (4) in a lower alkane solvent, reducing the solid matter by using one or more alkyl aluminum compounds, and drying the solid matter to obtain the final catalyst component.

Wherein the lower alkane solvent in the step (2) and the step (5) is C₃～C₉Alkanes, preferably C₅And C₆Alkanes such as isopentane, pentane, hexane, and the like;

wherein the alkyl aluminum compound used in step (2) and step (5) is preferably of the formula AlR_m′X_3-mWherein R' are the same or different C_1-8Alkyl, X is halogen, and m is an integer of 1 to 3. The preferred alkylaluminum compound is AlEt₃、Al(n-C₆H₁₃)₃、AlEt₂Cl, and the like.

It is specifically noted that the halide improver of the present invention may be incorporated into the catalyst component in any effective manner. For example, any of the following methods can be selected to give a good promoting effect: i) introduction in the silica gel treatment step (2), ii) introduction in the step (3) in which the catalyst complex is supported on silica gel, iii) introduction in the catalyst reduction step (5), and the like.

The invention also relates to a catalyst for ethylene polymerization or copolymerization, which is a reaction product of the catalyst component and an alkyl aluminum compound, wherein the alkyl aluminum compound used has the general formula AlR₃In which R' are identical or different C_1-8One or two of the alkyl groups may be substituted by chlorine, and one or more alkyl aluminum groups may be used in combination, with AlEt being preferred₃、Al(iso-Bu)₃、Al(n-C₆H₁₃)₃、Al(n-C₈H₁₇)₃、AlEt₂Cl, and the like.

The catalyst of the present invention is suitable for homopolymerization of ethylene or copolymerization of ethylene and other α -olefin, and the α -olefin may be one of propylene, butene, pentene, hexene, octene and 4-methylpentene-1.

Detailed Description

The catalyst of the present invention will be further described with reference to the following examples, but it should be understood that the catalyst of the present invention is not limited to the following examples.

The related physical property parameter testing method comprises the following steps: specific surface area, pore volume, pore average diameter: mercury intrusion melt flow index MI-GB3682-83(2.16kg) melt flow index FI-GB3682-83(21.6kg) MFR FI/MI apparent density BD-ASTM-D-1895Example 1Preparation of the catalyst component

(1) Approximately 12g of spherical silica gel (SMR) was weighed^#49-4039, produced by Grace, USA, with an average particle size of 55 μm and a specific surface area of 717m²/g, pore volume 4.6ml/g, pore mean diameter 25.7nm) was activated at 600 ℃ for 4 hours.

(2) Under the protection of nitrogen, in a reaction flask with a stirrer, isopentane as a solvent (100ml), 10g of thermally activated silica gel and 6.1ml of AlEt obtained in the step (1) were added₃The hexane solution (1mmol/ml) reacts for half an hour at the temperature of 20-30 ℃, and then 1.1ml of Cl is slowly dropped₃CCH₂OH, reacting for half an hour after the addition is finished, and blowing and drying the mixture into flowing powder by using high-purity nitrogen.

(3) In another reaction flask with stirrer, 1.42g MgCl was added₂And 0.64ml TiCl₄And 140ml of tetrahydrofuran, heating, refluxing and stirring for 1 hour, and then dropwise adding 2.8ml of MgBu₂The solution (1mmol/ml heptane solution) was refluxed for 4 hours to obtain a catalyst mother liquor.

(4) And (3) mixing the silica gel treated in the step (2) with the mother liquor prepared in the step (3), refluxing and stirring for 1 hour, and then blowing and drying by using high-purity nitrogen to obtain the flowing light yellow solid powder, wherein the content of tetrahydrofuran is 14.0 wt%.

(5) Using isopentane as solvent and AlEt at room temperature₂Cl and Al (n-C)₆H₁₃)₃Pre-reducing the reaction product obtained in the step (4) to control AlEt₂Cl/THF molar ratio 0.45, Al (n-C)₆H₁₃)₃THF 0.20, hexane 100ml, 7.0ml of AlEt were added dropwise first₂A solution of Cl in hexane (2.21mmol) was reacted for half an hour after the addition was completed. 4.5ml of Al (n-C) are then added dropwise₆H₁₃)₃The reaction is carried out for half an hour, and then high-purity nitrogen is used for blowing and drying to obtain a yellowish solid powdery catalyst component. The catalyst comprises the following components: and Ti% is 1.28 wt%. Evaluation of catalyst:

slurry homopolymerization of ethylene: slurry evaluation was performed in a 2L stainless steel reactor using 50mg of catalyst, H₂/C₂H₄1ml AlEt 0.28/0.75MPa₃The hexane solution (1mmol/ml), 1L hexane, 85 ℃ reaction for 2 hours. The results of the polymerization evaluation are shown in Table I.Example 2Preparation of the catalyst component

The procedure was as in example 1 except for the following differences. The difference is as follows:

(1) in step (5), Al (C)₆H₁₂)₃After 30 minutes of reaction, 1.1ml of Cl was added dropwise₃CCH₂OH, reacting for 30 minutes again and drying;

(2) the THF% in the masterbatch was 17.4 wt%;

(3) the Ti% in the catalyst was 1.37 wt%.

Catalyst slurry polymerization was evaluated as in example 1, and the polymerization results are shown in Table 1.Example 3Preparation of the catalyst component

The procedure was as in example 1 except for the following differences.

(1) Using 6.1ml MgBu₂Solution (1mmol/ml heptane solution) instead of 6.1ml AlEt₃Solution (1mmol/ml hexane solution) treatment of thermally activated SiO₂。

(2) The THF% in the masterbatch was 18.9 wt%;

(3)1.1ml Cl₃CCH₂al (C) OH in catalyst Pre-activation step₆H₁₂)₃Adding the mixture to react for 30 minutes, then dripping the mixture, reacting for 30 minutes again and drying;

(4) the catalyst had a Ti% of 1.40%.

Catalyst slurry polymerization was evaluated as in example 1, and the polymerization results are shown in Table 1.Example 4Preparation of the catalyst component

(1) About 12g of spherical silica gel (SYLOPOL948, produced by Grace, USA, with an average particle size of 50 μm and a specific surface area of 295m²G, pore volume 1.7ml/g, pore mean diameter 23.3nm) was activated at 600 ℃ for 4 hours.

(2) Under the protection of nitrogen, in a reaction flask with a stirrer, isopentane as a solvent (100ml), 10g of thermally activated silica gel and 6.1ml of AlEt obtained in the step (1) were added₃The hexane solution (1mmol/ml) is reacted at 20-30 ℃ for half an hour, and then dried into flowing powder by purging with high-purity nitrogen.

(3) In another reaction flask with stirrer, 0.93g MgCl was added₂And 0.4ml TiCl₄And 100ml of tetrahydrofuran, heating, refluxing and stirring for 1 hour, and then dropwise adding 1.8ml of MgBu₂The solution (1mmol/ml heptane solution) was refluxed for 4 hours to obtain a catalyst mother liquor.

(4) And (3) mixing the silica gel treated in the step (2) with the mother liquor prepared in the step (3), refluxing and stirring for 1 hour, and then blowing and drying by using high-purity nitrogen to obtain the flowing light yellow solid powder, wherein the tetrahydrofuran content is 13.3 wt%.

(5) Using isopentane as solvent and AlEt at room temperature₂Cl and Al (n-C)₆H₁₃)₃Pre-reducing the reaction product obtained in the step (4) to control AlEt₂Cl/THF molar ratio 0.45, Al (n-C)₆H₁₃)₃THF 0.20, hexane 100ml, 5.3ml of AlEt were first added dropwise₂A solution of Cl in hexane (2.21mmol) was reacted for half an hour after the addition was completed. 3.5ml of Al (n-C) are added dropwise₆H₁₃)₃In hexane (1.5mmol), reacted for half an hour, and then 0.71ml of Cl was added dropwise₃CCH₂OH, reacting for half an hour, and blowing and drying by using high-purity nitrogen to obtain a yellowish solid powdery catalyst groupAnd (4) dividing. The catalyst comprises the following components: and Ti% is 1.22 wt%. Evaluation of catalyst:

slurry homopolymerization of ethylene: slurry evaluation was performed in a 2L stainless steel reactor using 50mg of catalyst, H₂/C₂H₄1ml AlEt 0.28/0.75MPa₃The hexane solution (1mmol/ml), 1L hexane, 85 ℃ reaction for 2 hours. The polymerization results are shown in Table 1.Comparative example 1Preparation of the catalyst component

The procedure was as in example 1 except for the following differences. The difference is as follows:

(1) with commercial grade 1.16gAA TiCl₃And 1.74g MgCl₂Preparation of catalyst mother liquor, notWith 2.8 mmole MgBu₂Reduction of 0.64ml TiCl₄Preparation of TiCl₃Then 1.42g of MgCl was added₂The method of (1) preparing a catalyst mother liquor;

(2) the THF% in the masterbatch was 17.7 wt%;

(3) the Ti% in the catalyst is 1.14 wt%;

catalyst slurry polymerization was evaluated as in example 1, and the polymerization results are shown in Table 1.Comparative example 2Preparation of the catalyst component

The procedure was as in example 4 except for the following differences. The difference is as follows:

(1) with commercial grade 0.73gAA TiCl₃And 1.1g MgCl₂Preparation of catalyst mother liquor instead of using 1.8 mmole MgBu₂Reduction of 0.4ml TiCl₄Preparation of TiCl₃Then, 0.93g of MgCl was added thereto₂The method of (1) preparing a catalyst mother liquor;

(2) THF% in the masterbatch was 14.2 wt%;

(3) the Ti% in the catalyst is 0.9 wt%;

catalyst slurry polymerization was evaluated as in example 1, and the polymerization results are shown in Table 1.

TABLE 1 polymerization evaluation results

Examples	Ti％	Activity (gPE/gCat)
			Example 1	1.28	5770
Example 2	1.37	5349
			Example 3	1.40	4609
Example 4	1.22	3049
			Comparative example 1	1.14	4955
Comparative example 2	0.90	1800

Example 5

Catalyst preparation and slurry evaluation were the same as in example 2. In the polymerization evaluation, chlorobutane was added, and the influence of chlorobutane and the amount thereof on the polymerization of the catalyst and the polyethylene resin was examined. The results are shown in Table 2. TABLE 2 influence of added chlorobutane on catalyst activity and polyethylene resin Performance

Chlorinated n-butane- Titanium (mol/mol)	Activity of (gPE/gCat)	BD (g/cm3)	MI (g/10min)	FI (g/10min)	MFR
						0	5349	0.34	0.39	11.3	29.1
10	5979	0.35	0.50	14.1	28.3
						50	5563	0.34	0.31	9.53	30.7
100	4988	0.32	0.30	8.27	27.6

Note: total pressure: 1.03 MPa; polymerization temperature: 85 ℃; reaction time: 2 h; hexane: 1.0L; alkyl aluminum: 0.1 mmol; n-butyl chloride was prepared as a 1mmol/ml hexane solution.

Compared with the comparative example 1, the comparison between the examples 1-2 and the comparative example 1 shows that the catalyst provided by the invention has obviously improved titanium content and activity; as can be seen from example 5, the addition of a small amount of chlorobutane is advantageous for improving the catalyst activity, and even if chlorobutane is introduced in a large amount, no significant adverse effect on the catalyst and the polymer is observed, demonstrating the use of MgBu₂Reduction of TiCl₄Preparation of TiCl₃The small amount of the byproduct chlorobutane does not need to be removed, and the existence of the chlorobutane is beneficial to the exertion of the activity of the catalyst.

Claims (13)

1. A catalyst component suitable for the polymerization or copolymerization of ethylene comprising the reaction product of a titanium-containing active component and at least one halide modifier on a support material;

the titanium-containing active component is prepared by MgR in an electron donor solvent without active hydrogen group₂Or MgRX and titanium tetrachloride are contacted and reacted to reduce the titanium tetrachloride into titanium trichloride, and then MgX is added₂The reaction product is obtained after the reaction, and the reaction solution is obtained,

the halide improver is represented by the following general formula F-R¹[R² _bX_(3-b)]A class of compounds of (a), wherein:

f is an oxygen-containing functional group which can chemically react with an organoaluminum compound, a titanium compound or a hydroxyl group, R is¹Is a divalent C₁～C₆An aliphatic or aromatic group of (a), which is bonded to the oxygen atom in the functional group F; r²Is hydrogen, C₁～C₆Alkyl, cycloalkyl or aryl or halogen substituted C₁～C₆Alkyl, cycloalkylaryl, b is 0, 1 or 2, and X is F, Cl or Br.

2. The catalyst component according to claim 1, characterized in that the proportions between the components are such that, per mole of titanium: 0.5-50% of magnesium, 0.5-50% of electron donor and 0.5-50% of halide improver.

3. The catalyst component of claim 1 wherein F in the halide modifier is one of an aldehyde group, an acyl group, and a hydroxyl group.

4. The catalyst component of claim 1 wherein the halide modifier is selected from one or more of the following halohydrins: 2, 2, 2-trichloroethanol, 2, 2-dichloroethanol, 2-chloroethanol, 1-dimethyl-2, 2, 2-trichloroethanol, 4-chlorobutanol, p-chlorophenol, m-chlorophenol, o-chlorophenol and 2-chlorocyclohexanol.

5. Catalyst set according to claim 1Characterized in that MgR is₂Or in MgRX, R is C₂～C₁₀And X is chlorine, bromine or iodine.

6. The catalyst component of claim 1 wherein the MgR is₂Is dibutyl magnesium or dioctyl magnesium.

7. The catalyst component of claim 1 wherein the MgX is₂Is magnesium dichloride, magnesium dibromide or magnesium diiodide.

8. The catalyst component of claim 1 wherein the electron donor compound is selected from the group consisting of C₁～C₄Alkyl esters of saturated fatty carboxylic acids, C₇～C₈Alkyl esters of aromatic carboxylic acids, C₂～C₆Fatty ethers, C₃～C₄Cyclic ether, C₃～C₆One or a mixture of saturated aliphatic ketones.

9. The catalyst component according to claim 1 wherein the carrier material has an average particle size of 10 to 100 μm and a specific surface area of 50 to 1000m²Silica gel with a pore volume of 1.0 to 6.0ml/g and an average pore diameter of 5 to 45 nm.

10. A process for the preparation of the catalyst component according to any one of claims 1 to 9, comprising the steps of:

(1) the carrier is activated in a conventional manner,

(2) adding the activated carrier into a lower alkane solvent, adding an alkyl aluminum compound, reacting for a period of time, and removing the solvent to obtain solid powder;

(3) in the electron donor, MgR is added₂Or MgRX and titanium tetrachloride are contacted and reacted to reduce the titanium tetrachloride into titanium trichloride, and then MgX is added₂After the reaction, mother liquor is prepared, and the final titanium/magnesium ratio is 0.5-50;

(4) adding the activated carrier obtained in the step (2) into the mother liquor obtained in the step (3), reacting for a certain time, removing excessive electron donor, and controlling the content of the residual electron donor to be 10-21 wt%;

(5) suspending the solid matter obtained in the step (4) in a lower alkane solvent, reducing by using one or more alkyl aluminum compounds, and drying to obtain a catalyst component;

the halide improver can be introduced in the step (2) or the step (3) or the step (5) respectively or simultaneously;

wherein the lower alkane solvent in the step (2) and the step (5) is C₃～C₉An alkane;

wherein the alkyl aluminum compound used in step (2) and step (5) is of the general formula AlR_m′X_3-mWherein R' are the same or different C_1-8Alkyl, X is halogen, and m is an integer of 1 to 3.

11. A catalyst suitable for the polymerization or copolymerization of ethylene comprising the reaction product of:

(1) the catalyst component according to any one of claims 1 to 9;

(2) an organoaluminum component; the ratio of aluminum/titanium between component (1) and component (2) is 5-200.

12. The catalyst according to claim 11, characterized in that the component (2) is an organoaluminum selected from AlEt₃、Al(iso-Bu)₃、Al(n-C₆H₁₃)₃、Al(n-C₈H₁₇)₃、AlEt₂One or a mixture of Cl.

13. Use of a catalyst according to claim 11 or 12 in the gas phase or slurry polymerization or copolymerization of ethylene.