Dialkoxy magnesium carrier type solid catalyst component for ethylene polymerization or copolymerization, preparation method and application thereof

Abstract

The present invention provides a dialkoxy magnesium carrier type solid catalyst component for ethylene polymerization or copolymerization, a preparation method and application thereof, wherein the solid catalyst component uses a dialkoxy magnesium compound as a carrier, a dibasic acid ester compound and a phthalate compound as an internal electron donor, and a halogenated alkane compound as a promoter added to the prepared catalyst component. The present invention uses a halogenated alkane compound as a promoter added to the solid catalyst component, and the promoter can modify the catalyst component used for ethylene polymerization, so that the catalyst has high activity and good hydrogen regulation performance.

Description

Technical Field

[0001] The present invention relates to a catalyst component for polyolefins, in particular to a dialkoxy magnesium carrier type solid catalyst component for ethylene polymerization or copolymerization, a preparation method and application in catalyzing ethylene polymerization or copolymerization, belonging to the field of polyolefin catalysts. Background Art

[0002] Since the successful development of high-efficiency polyethylene catalysts in the 1970s, catalyst systems containing Ti / Mg complexes have occupied a dominant position in the industrial production of polyethylene. The core of polyethylene catalyst research is to determine the polymerization activity of the catalyst, the particle morphology and particle size distribution of the polymer generated by the catalyst, the hydrogen adjustment sensitivity of the catalyst, the copolymerization performance of the catalyst, etc. based on matching different process production conditions. In many polyethylene production processes, especially slurry polymerization processes and gas phase polymerization processes, in addition to requiring the catalyst to have a fairly high activity, it is very important to control the particle size and particle size distribution of the polymer generated by the catalyst. In particular, the polymer fines generated during the polymerization process are one of the most direct causes of reactor agglomeration and pipeline blockage. Controlling the particle morphology and particle size distribution of the catalyst is the most effective way to reduce the fine powder content in the polymer.

[0003] In the prior art, a catalyst containing a Ti / Mg complex can be obtained by dissolving a magnesium compound in certain solvents and adding a precipitant, a chlorinating agent, etc. For example, in patent CN85105150, magnesium chloride is dissolved in tetraethoxy titanium, and a catalyst component is precipitated by dripping an alkyl aluminum containing halogen, thereby obtaining a solid catalyst component. The catalyst activity is relatively high, but the polymer particle size distribution obtained by the catalyst for ethylene polymerization is wide, and the fine powder content is very high, which is not conducive to long-term stable operation on an industrial device. Patent CN95118622.1 selects to dissolve ethoxy magnesium in tetraalkoxy titanium, and obtains a catalyst component by dripping an alkyl aluminum containing halogen. The activity of the catalyst is relatively high, but the polymer particle size distribution width obtained by the catalyst obtained by this method for ethylene polymerization is relatively large, and the hydrogen adjustment sensitivity of the catalyst is relatively poor, which is not conducive to the production of polyethylene with a wide molecular weight distribution.

[0004] Halogenated alkanes were first used as promoters in vanadium catalyst systems. Union Carbide Corporation of the United States and others found that when vanadium olefin polymerization catalysts containing halogenated hydrocarbon promoters were used in ethylene gas phase polymerization, linear low-density polyethylene with a wide relative molecular mass distribution could be obtained. In the ethylene polymerization process, the effective combination of appropriate halogenated hydrocarbon promoters and catalysts can increase the activity of the catalyst and improve the properties of the polymer. However, there have been no reports on the use of halogenated hydrocarbon promoters in ZN catalyst ethoxymagnesium systems. Summary of the invention

[0005] The object of the present invention is to provide a dialkoxymagnesium carrier type solid catalyst component for ethylene polymerization or copolymerization, which, by adding a promoter, not only has the characteristics of high activity, high bulk density, and uniform particle size distribution, but also has good hydrogen regulation performance and low fine powder content.

[0006] Another object of the present invention is to provide a method for preparing the catalyst component.

[0007] Another object of the present invention is to provide the use of halogenated alkane compounds as promoters in dialkoxy magnesium support type solid catalyst components for ethylene polymerization or copolymerization.

[0008] The inventors found in the research process that when a dibasic acid ester compound or a phthalate ester compound is used as an internal electron donor to prepare a carrier-type solid catalyst, and a halogenated alkane compound is used as a promoter to add to a polyethylene catalyst, it can coordinate with the active center Ti atom of the catalyst and improve the polymerization activity by changing the electron cloud density of the Ti atom, while improving the hydrogen adjustment sensitivity. The halogenated alkane compound changes the electronegativity of titanium by coordinating with the active center titanium atom of the catalyst, thereby improving the catalytic activity. Usually, the titanium in the magnesium compound carrier-type catalyst is mostly in the form of Ti. 4+ exists in the form of Ti 4+ After the reaction with alkyl aluminum before olefin polymerization, it will be reduced by alkyl aluminum to generate low-valent Ti 3+ and Ti 2 + Some researchers have used the method of quantum mechanical density function to theoretically calculate the effect of the oxidation state of titanium in the supported catalyst on the olefin polymerization activity. The calculation results show that the Ti-containing 4+ [TiCl 2 CH 3 ] + The activation energy barrier of the catalyst is the lowest. The activation energy barriers of titanium in various valence states are in the following order: Ti 4+ <Ti 3+ <Ti 2+ High Spin <Ti 2+ Low spin. Therefore, it can be considered that Ti 4+ The system has the highest activity, followed by Ti 3+ and Ti 2+ The halogenated alkane in the catalyst can over-reduced Ti by alkyl aluminum. 2+ Oxidized to Ti 3 + , thus improving the catalyst activity. The addition of halogenated alkanes can reduce the formation of ethane, thereby controlling the relative molecular weight of polyethylene and widening its distribution. The widening of the relative molecular weight distribution is conducive to improving the processing properties of polyethylene.

[0009] In order to achieve the purpose of the present invention, the present invention provides a dialkoxymagnesium carrier-type solid catalyst component for ethylene polymerization or copolymerization, which is prepared by using a dialkoxymagnesium compound as a carrier, a dibasic acid ester compound or a phthalate ester compound as an internal electron donor, and a halogenated alkane compound as a promoter.

[0010] Specifically, the raw material components used in the dialkoxy magnesium support type solid catalyst component of the present invention include:

[0011] Component (1): a dialkoxy magnesium compound, wherein the dialkoxy magnesium compound is selected from dimethoxy magnesium, diethoxy magnesium, dipropoxy magnesium, dibutoxy magnesium, ethoxymethoxy magnesium, ethoxypropoxy magnesium or butoxyethoxy magnesium, which can be used alone or in combination;

[0012] Component (2): a titanium compound of the general formula TiX2n(OR3)4-n, wherein R3 is an aliphatic hydrocarbon group or an aromatic hydrocarbon group having 1 to 14 carbon atoms, and X 2 is halogen, n is 0, 1, 2, 3 or 4;

[0013] Component (3): dibasic acid ester compounds, phthalic acid ester compounds, and mixtures thereof in any proportion;

[0014] Wherein, the dibasic acid ester compound is a compound having the general formula (1):

[0015]

[0016] Where: A represents C 1 ~C 18 Alkylene, cycloalkylene, substituted alkylene; R 1 and R 2 The radicals may be the same or different and represent hydrogen or a straight-chain or branched alkyl radical having 1 to 20 carbon atoms, a cycloalkyl radical having 3 to 20 carbon atoms, an aryl radical having 6 to 20 carbon atoms, an alkaryl radical having 7 to 20 carbon atoms and an aralkyl radical.

[0017] Component (4): having the general formula RCHaX b A halogenated alkane compound, wherein R is C 1 ~C 20 A linear or branched alkyl group, X is a halogen, 0≤a≤3, 0≤b≤3, a+b=3.

[0018] The dialkoxy magnesium support type solid catalyst component of the present invention is prepared by the following method:

[0019] 1) firstly mixing component (2) or component (2) and an inert diluent with component (1) to prepare a suspension A;

[0020] 2) the suspension A reacts with component (3); and selectively reacts with component (2) again to obtain suspension B;

[0021] 3) contacting component (4) with the suspension B to obtain suspension C;

[0022] 4) The suspension C is filtered to remove the liquid and dried to obtain a solid powder, which is a solid catalyst component.

[0023] The preparation step preferably uses:

[0024] 1) firstly mixing component (2) or a mixture of component (2) and an inert solvent with component (1) in any order at a temperature in the range of -30°C to 110°C or multiple times to prepare a suspension A, more preferably at a temperature in the range of -20°C to 50°C;

[0025] 2) subsequently contacting component (3) with the suspension A at -20°C to 50°C one or more times, maintaining at 0°C to 130°C for 30 minutes to 4 hours, filtering and selectively washing with an inert solvent for 3 to 6 times, more preferably at 70°C to 120°C;

[0026] 3) selectively contacting with component (2) or a mixture of component (2) and an inert solvent again at 0°C to 130°C for one or more times, each time for 30 minutes to 4 hours; and then washing with an inert solvent for 3 to 6 times to obtain a suspension B, wherein the contact temperature is more preferably 70°C to 120°C;

[0027] 4) Finally, component (4) is contacted with the suspension B to react to obtain a modified suspension C, the reaction temperature is 10°C to 60°C, and the time is 20min to 4hr; the liquid is filtered off and dried to obtain a solid powder, which is a solid catalyst component.

[0028] In step 4), preferably, the component (4) halogenated alkane compound is slowly added dropwise to the suspension B at 10-30° C., with a dropping speed of 0.1-0.5 ml / min, and the suspension is contacted with the component B for 2-4 hours.

[0029] The liquid removed in step 4) is filtered out by sedimentation pressure filtration.

[0030] Wherein, per mole of component (1), component (2) is 0.05 to 50 moles, preferably 0.1 to 10 moles; component (3) dibasic acid ester compound or phthalate ester compound or a mixture thereof in any proportion is 0.001 to 10 moles, preferably 0.01 to 1 mole, more preferably 0.02 to 0.6 moles; component (4) is 0.001 to 10 moles, preferably 0.01 to 5 moles, more preferably 0.03 to 2 moles.

[0031] The raw material component (1) used in the solid catalyst component is a dialkoxymagnesium compound; the dialkoxymagnesium compound is selected from dimethoxymagnesium, diethoxymagnesium, dipropoxymagnesium, dibutoxymagnesium, ethoxymethoxymagnesium, ethoxypropoxymagnesium or butoxyethoxymagnesium, which can be used alone or in combination. Diethoxymagnesium is preferred.

[0032] The titanium compound used as the raw material component (2) preferably includes titanium halides, alkyl titanium halides and alkoxy titanium, wherein the titanium halides are such as titanium tetrachloride, titanium tetrabromide and titanium tetraiodide; the alkyl titanium halides are such as methoxy titanium trichloride, ethoxy titanium trichloride, propoxy titanium trichloride, n-butoxy titanium trichloride, dimethoxy titanium dichloride, diethoxy titanium dichloride, dipropoxy titanium dichloride, di-n-butoxy titanium dichloride, trimethoxy titanium chloride, triethoxy titanium chloride, tripropoxy titanium chloride or tri-n-butoxy titanium chloride; the alkoxy titanium is such as tetraethoxy titanium, tetrapropoxy titanium and tetrabutoxy titanium. These titanium compounds can be used in combination of one or more. Among them, alkyl titanium halides and alkoxy titanium are preferably used. More preferably, titanium tetrachloride, tetraethoxy titanium, tetrabutoxy titanium and mixtures thereof in any proportion are used.

[0033] Specific examples of the dibasic acid ester compounds that can be advantageously used as the raw material component (3) include: dimethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, dimethyl pimelate, dimethyl suberate, dimethyl azelaate, dimethyl sebacate, diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl pimelate, diethyl suberate, diethyl azelaate, diethyl sebacate, diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl pimelate, diethyl suberate, diethyl azelaate, diethyl sebacate, diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl pimelate, diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl pimelate, diethyl glutarate, diethyl azelaate, diethyl sebacate, diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl pimelate, diethyl glutarate ... Dipropyl ester, dipropyl succinate, dipropyl glutarate, dipropyl adipate, dipropyl pimelate, dipropyl suberate, dipropyl azelaate, dipropyl sebacate, dibutyl malonate, dibutyl succinate, dibutyl glutarate, Dibutyl adipate, dibutyl pimelate, dibutyl suberate, dibutyl azelate, dibutyl sebacate, dipyl malonate, dipyl succinate, dipyl glutarate, dipyl adipate, dipyl pimelate, dipyl suberate Esters, dipentyl azelate, dipentyl sebacate, dihexyl malonate, dihexyl succinate, dihexyl glutarate, dihexyl adipate, dihexyl pimelate, dihexyl suberate, dihexyl azelate, dihexyl sebacate, diheptyl malonate, diheptyl succinate, diheptyl glutarate, diheptyl adipate, diheptyl pimelate, diheptyl suberate, diheptyl azelate, diheptyl sebacate, dioctyl malonate, dioctyl succinate, dioctyl glutarate , dioctyl adipate, dioctyl pimelate, dioctyl suberate, dioctyl azelaic acid, dioctyl sebacate, dinonyl malonate, dinonyl succinate, dinonyl glutarate, dinonyl adipate, dinonyl pimelate, dinonyl suberate, dinonyl azelaic acid, dinonyl sebacate, didecyl malonate, didecyl succinate, didecyl glutarate, didecyl adipate, didecyl pimelate, didecyl suberate, didecyl azelaic acid, didecyl sebacate, etc. Preferably, diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl pimelate, diethyl suberate, diethyl azelaic acid, diethyl sebacate, more preferably diethyl succinate, diethyl glutarate, diethyl adipate, etc. More preferred are diethyl succinate, diethyl glutarate, diethyl adipate, and diethyl pimelate, and more preferred are diethyl succinate and diethyl glutarate.

[0034] Specific examples of phthalate compounds that can be advantageously used as the raw material component (3) include: dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, ethyl methyl phthalate, methyl isopropyl phthalate, methyl n-propyl phthalate, ethyl n-butyl phthalate, ethyl isobutyl phthalate, di-n-pentyl phthalate, diisopentyl phthalate, dihexyl phthalate, di-n-heptyl phthalate, di-n-octyl phthalate, diisooctyl phthalate, (2,2-dimethylhexyl) phthalate, (2-ethylhexyl) phthalate, di-n-nonyl phthalate Ester, diisodecyl phthalate, (2,2-dimethylheptyl) phthalate, n-butyl phthalate isohexyl ester, n-butyl phthalate (2-ethylhexyl) ester, n-pentyl phthalate n-hexyl ester, n-pentyl phthalate isononyl ester, isoamyl phthalate n-decyl phthalate, n-pentyl phthalate isohexyl ester, isoamyl phthalate isohexyl ester, n-hexyl phthalate (2-methylhexyl ester), n-hexyl phthalate (2-ethylhexyl ester), n-hexyl phthalate (isononyl ester), n-hexyl phthalate (n-decyl ester), n-heptyl phthalate (2-ethylhexyl ester), n-heptyl phthalate (isononyl ester), n-heptyl phthalate neononyl ester and 2-ethylhexyl phthalate (isononyl ester), etc. Preferred are dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, and diisobutyl phthalate, and more preferred are di-n-butyl phthalate and diisobutyl phthalate.

[0035] The halogenated alkane compound of the raw material component (4) is used as a promoter. Specific examples of the halogenated alkane compounds that can be advantageously used include: ethyl chloride, ethylene dichloride, trichloroethane, chloropropane, dichloropropane, trichloropropane, chlorobutane, dichlorobutane, trichlorobutane, chloropentane, dichloropentane, trichloropentane, hexyl chloride, dichlorohexane, trichlorohexane, chloroheptane, dichloroheptane, trichloroheptane, chlorooctane, dichlorooctane, trichlorooctane, chlorononane, dichlorononane, trichlorononane, chlorodecane, dichlorodecane, trichlorodecane, ethyl bromide, dibromoethane, tribromoethane, bromopropane, dibromopropane, tribromopropane, bromobutane, dibromobutane, tribromobutane, bromopentane, dibromopentane, tribromopentane, bromohexane, dibromohexane, tribromohexane, bromoheptane, dibromoheptane, tribromoheptane, bromooctane, dibromooctane, tribromooctane, bromononane, dibromononane, tribromononane, bromodecane, dibromodecane, tribromodecane, iodoethane, diiodoethane, triiodoethane, iodopropane, diiodopropane, triiodopropane, iodobutane, diiodobutane, triiodobutane, iodopentane, diiodopentane, triiodopentane, iodohexane, diiodohexane, triiodohexane, iodoheptane, diiodoheptane, triiodoheptane, iodooctane, diiodooctane, triiodooctane, iodononane, diiodononane, triiodononane, iododecane, diiododecane, triiododecane, etc. Preferred are chlorobutane, dichlorobutane, chloropentane and bromobutane.

[0036] The method for preparing the catalyst component for ethylene polymerization or copolymerization of the present invention comprises the following steps:

[0037] 1) firstly mixing component (2) or component (2) and an inert diluent with component (1) to prepare a suspension A;

[0038] 2) the suspension A reacts with component (3); and selectively reacts with component (2) again to obtain suspension B;

[0039] 3) contacting component (4) with the suspension B to obtain suspension C;

[0040] 4) The suspension C is filtered to remove the liquid and dried to obtain a solid powder, which is a solid catalyst component.

[0041] The preparation steps of the method preferably adopt:

[0042] 1) firstly mixing component (2) or a mixture of component (2) and an inert solvent with component (1) in any order at a temperature in the range of -30°C to 110°C or multiple times to prepare a suspension A, more preferably at a temperature in the range of -20°C to 50°C;

[0043] 2) subsequently contacting component (3) with the suspension A at -20°C to 50°C one or more times, maintaining at 0°C to 130°C for 30 minutes to 4 hours, filtering and selectively washing with an inert solvent for 3 to 6 times, more preferably at 70°C to 120°C;

[0044] 3) selectively contacting with component (2) or a mixture of component (2) and an inert solvent again at 0°C to 130°C for one or more times, each time for 30 minutes to 4 hours; and then washing with an inert solvent for 3 to 6 times to obtain a suspension B, more preferably at 70°C to 120°C;

[0045] 4) Finally, component (4) is contacted with the suspension B to react to obtain a modified suspension C, the reaction temperature is 10°C to 60°C, and the reaction time is 20min to 4hr; the liquid is filtered off and dried to obtain a solid powder, which is a solid catalyst component. More preferably, component (4) halogenated alkane compound is slowly added dropwise to suspension B at 10 to 30°C, the dropping speed is 0.1 to 0.5ml / min, and the reaction is carried out with component B for 2hr to 4hr.

[0046] The catalyst component of the present invention and an organic aluminum compound can form a catalyst for ethylene polymerization or copolymerization.

[0047] The present invention provides an olefin polymerization catalyst, characterized in that it comprises the following components or the reaction product of the following components:

[0048] a) the catalyst solid component;

[0049] b) at least one of the general formula AlR n X (3-n) An organoaluminum compound, wherein R is hydrogen or a hydrocarbon group having 1 to 20 carbon atoms; X is a halogen, and n is an integer of 0≤n≤3.

[0050] The organoaluminum compound has been widely recognized and applied as a component of olefin catalyst. Its general formula is AlR n X (3-n) An organoaluminum compound, wherein R is hydrogen or a hydrocarbon group having 1 to 20 carbon atoms; X is a halogen, and n is an integer of 0≤n≤3, preferably triethylaluminum, triisobutylaluminum, diethylaluminum monochloride, tri-n-hexylaluminum, and more preferably triethylaluminum; and the ratio between the catalyst component and the organoaluminum compound is 1:5 to 100 in terms of the molar ratio of titanium to aluminum.

[0051] The catalyst component of the present invention is used in the preparation of ethylene polymerization or copolymerization, and the ethylene comonomer that can be selected in the copolymerization is a monomer having the general formula CH 2 =CHR olefins, wherein R is a C1-C12 alkyl group, such as straight-chain olefins: propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene; branched-chain olefins such as 3-methyl-1-butene and 4-methyl-1-pentene; dienes such as butadiene, vinylcyclopentene and vinylcyclohexene. These olefins can be used alone or in combination.

[0052] The promoter of the present invention is used in the catalyst component for ethylene polymerization or copolymerization, and the promoter is of the general formula RCHaX b A halogenated alkane compound, wherein R is C 1 ~C 20 A linear or branched alkyl group, X is a halogen, 0≤a≤3, 0≤b≤3, a+b=3.

[0053] In the long-term research and application of polyethylene ZN catalysts, people gradually realized that simply pursuing high catalyst activity can no longer meet the polymerization process innovation and the market's high-level requirements for polyethylene product performance. High value-added resins have higher requirements for the particle morphology, particle size distribution, bulk density and hydrogen adjustment sensitivity of ZN catalysts, and the present invention adds halogenated alkane compounds to the ZN catalyst system to effectively improve the above-mentioned properties of the catalyst.

[0054] The olefin polymerization catalyst of the present invention is obtained by adding a halogenated alkane compound as a promoter to a polyethylene catalyst. While maintaining the ethylene polymerization catalyst with a magnesium compound as a carrier, high hydrogen regulation performance, and high bulk density, the activity of the polymer is significantly improved. At the same time, the addition of the halogenated alkane compound can reduce the formation of ethane, thereby controlling the relative molecular mass of polyethylene and widening its distribution. It is beneficial to improve the processing performance of polyethylene. DETAILED DESCRIPTION

[0055] The present invention is further described below with examples, which is conducive to a better understanding of the present invention and its advantages and effects, but the examples are only used to illustrate the present invention rather than to limit the present invention.

[0056] Example 1

[0057] 1. Preparation of catalyst components:

[0058] In a 500ml 5-necked flask with nitrogen fully replaced and stirred, add 20g of diethoxymagnesium and 120ml of hexane to prepare a suspension, then maintain at -15°C and drop 200ml of titanium tetrachloride, slowly heat the system to 80°C after the dropwise addition, add 2g of diethyl succinate, then continue to heat to 85°C and keep the temperature constant for 2 hours; let it stand for sedimentation, the suspension is layered, the liquid is filtered clean, the liquid is filtered off, the solid obtained is washed with 100mL of hexane at 60°C twice and at room temperature twice to obtain a hexane suspension, slowly drop 10ml of chlorobutane at 30°C, the drop rate is 0.5ml / min, and then stir at a constant temperature for 2 hours. After vacuum drying, a solid catalyst component is obtained.

[0059] 2. Aggregation:

[0060] Add 300mg-400mg of catalyst to an ampoule, add 50ml of hexane to disperse for polymerization test. After nitrogen is fully replaced in a 2L stainless steel reactor, add 1L of n-hexane, 2mL of 0.5mol / L triethylaluminum hexane solution and 2ml of catalyst hexane solution, heat to 70 degrees, introduce hydrogen to make the pressure in the reactor reach 0.48MPa, then introduce ethylene to make the total pressure in the reactor reach 0.73MPa, and polymerize at 80℃ for 2 hours. After the reaction is completed, cool the reactor and stop stirring to discharge the reaction product.

[0061] Example 2

[0062] 1. Preparation of catalyst components: Same as Example 1, except that di-n-butyl phthalate is used instead of diethyl succinate.

[0063] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0064] Example 3

[0065] 1. Preparation of catalyst components: Same as Example 1, except that diethyl adipate is used instead of diethyl succinate.

[0066] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0067] Example 4

[0068] 1. Preparation of catalyst components: Same as Example 1, except that diethyl adipate and di-n-butyl phthalate are used instead of diethyl succinate, wherein 1 g of diethyl adipate and 1 g of di-n-butyl phthalate are used.

[0069] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0070] Example 5

[0071] 1. Preparation of catalyst components: Same as Example 1, except that diethyl adipate and diethyl succinate are used instead of diethyl succinate, wherein 1 g of diethyl adipate and 1 g of diethyl succinate are used.

[0072] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0073] Example 6

[0074] 1. Preparation of catalyst components: Same as Example 1, except that dichlorobutane is used instead of chlorobutane.

[0075] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0076] Example 7

[0077] 1. Preparation of catalyst components: Same as Example 1, except that chloropentane is used instead of chlorobutane.

[0078] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0079] Example 8

[0080] 1. Preparation of catalyst components: Same as Example 1, except that dichlorobutane and chlorobutane are used instead of chlorobutane, wherein 5 ml of dichlorobutane and 5 ml of chlorobutane are used.

[0081] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0082] Example 9

[0083] 1. Preparation of catalyst components: Same as Example 1, except that chloropentane and chlorobutane are used instead of chlorobutane, wherein chloropentane is 5 ml and chlorobutane is 5 ml.

[0084] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0085] Example 10

[0086] 1. Preparation of catalyst components: Same as Example 1, except that 10 ml of chlorobutane is replaced by 5 ml of chlorobutane.

[0087] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0088] Embodiment 11

[0089] 1. Preparation of catalyst components: Same as Example 1, except that 10 ml of chlorobutane is replaced by 15 ml of chlorobutane.

[0090] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0091] Example 12

[0092] 1. Preparation of catalyst components: Same as Example 1, except that 10 ml of chlorobutane was stirred at a constant temperature for 1 hour instead of 10 ml of chlorobutane was stirred at a constant temperature for 30 minutes.

[0093] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0094] Embodiment 13

[0095] 1. Preparation of catalyst components: Same as Example 1, except that 10 ml of chlorobutane was stirred at a constant temperature for 1 hour instead of 10 ml of chlorobutane was stirred at a constant temperature for 2 hours.

[0096] Comparative Example 1

[0097] 1. Preparation of catalyst components:

[0098] In a 500ml 5-necked flask with nitrogen fully replaced and stirred, add 20g of diethoxymagnesium and 120ml of hexane to prepare a suspension, then maintain the temperature at -15°C and add 200ml of titanium tetrachloride dropwise. After the addition is completed, slowly heat the system to 85°C and keep the temperature constant for 2 hours; let it stand for sedimentation, the suspension is stratified, the liquid is filtered clean, the liquid is filtered off, and the obtained solid is washed twice with 100mL of hexane at 60°C and twice at room temperature.

[0099] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0100] Comparative Example 2

[0101] 1. Preparation of catalyst components:

[0102] In a 500ml 5-necked flask with nitrogen fully replaced and stirred, 20g of diethoxymagnesium and 120ml of hexane were added to prepare a suspension, and then 200ml of titanium tetrachloride was added dropwise at -15°C. After the addition was completed, the system was slowly heated to 80°C, 2g of diethyl succinate was added, and then the temperature was continued to be raised to 85°C and kept constant for 2 hours; the suspension was allowed to stand for sedimentation, and the suspension was separated into layers. The liquid was filtered clean and the liquid was filtered off. The obtained solid was washed twice with 100mL of hexane at 60°C and twice at room temperature.

[0103] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0104] Comparative Example 3

[0105] 1. Preparation of catalyst components:

[0106] In a 500ml 5-necked flask with nitrogen fully replaced and stirred, add 20g of diethoxymagnesium and 120ml of hexane to prepare a suspension, then maintain the temperature at -15°C and drop 200ml of titanium tetrachloride. After the dropwise addition is completed, slowly heat the system to 85°C and keep the temperature constant for 2 hours; let it stand for sedimentation, the suspension is layered, the liquid is filtered clean, the liquid is filtered off, and the obtained solid is washed twice with 100mL of hexane at 60°C and twice at room temperature. Add 10ml of chlorobutane at room temperature, and then stir at a constant temperature for 1 hour. After vacuum drying, a solid catalyst component is obtained.

[0107] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0108] Comparative Example 4

[0109] 1. Preparation of catalyst components: Same as Comparative Example 2, except that di-n-butyl phthalate is used instead of diethyl succinate.

[0110] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 1.

[0111] It can be seen from Table 1 that the polyethylene catalyst after adding the promoter has higher activity, bulk density and better hydrogen regulation performance than the one without the promoter for ethylene polymerization. The polymerization activity of the polyethylene catalyst containing halogenated alkane is basically higher than that of the reference catalyst, and the MI of the obtained polymer is higher than that of the polymer obtained by the reference catalyst. This is mainly because the chlorinated alkane can coordinate with the active center Ti atom of the catalyst and improve the polymerization activity by changing the electron cloud density of the Ti atom. The increase in steric hindrance makes the smaller H 2 It is easier to insert into the active center than ethylene, which reduces the relative molecular weight of the polymer and increases the MI of the polymer, thereby improving the processing properties of polyethylene.

[0112] The scope of the present invention is not limited by the specific embodiments described, which are only used as single examples to illustrate various aspects of the present invention, and functionally equivalent methods and components are also included within the scope of the present invention. In fact, in addition to the contents described herein, those skilled in the art can easily grasp various improvements to the present invention with reference to the above description. The improvements also fall within the scope of the appended claims.

[0113]

Claims

1. A dialkoxymagnesium supported solid catalyst component for ethylene polymerization or copolymerization, characterized in that: The invention adopts a dialkoxy magnesium compound as a carrier, a dibasic acid ester compound and a phthalic acid ester compound as an internal electron donor, and a halogenated alkane compound as a promoter.

2. The solid catalyst component according to claim 1, characterized in that The raw material components used for the solid catalyst component include: Component (1): a dialkoxymagnesium compound; Component (2): general formula TiX 2 n (OR 3 ) 4-n Titanium compounds, where R 3 is an aliphatic hydrocarbon group or an aromatic hydrocarbon group having 1 to 14 carbon atoms, and X 2 is halogen, n is 0, 1, 2, 3 or 4; Component (3): dibasic acid ester compounds, phthalic acid ester compounds, and mixtures thereof in any proportion; Wherein, the dibasic acid ester compound is a compound having the general formula (1): Among them: A represents C1~C 18 R1 and R2 may be the same or different and represent hydrogen or a straight-chain or branched alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or an aralkyl group; Component (4): having the general formula RCHaX b Halogenated alkane compounds, where R is C1~C 20 A linear or branched alkyl group, X is a halogen, 0≤a≤3, 0≤b≤3, a+b=3.

3. The solid catalyst component according to claim 1 or 2, characterized in that The solid catalyst component is prepared by the following method: 1) firstly mixing component (2) or component (2) and an inert diluent with component (1) to prepare a suspension A; 2) the suspension A reacts with component (3); and selectively reacts with component (2) again to obtain suspension B; 3) contacting component (4) with the suspension B to obtain suspension C; 4) The suspension C is filtered to remove liquid and dried to obtain a solid catalyst component.

4. The solid catalyst component according to claim 2 or 3, characterized in that Based on each mole of component (1), component (2) is 0.05 to 50 moles, preferably 0.1 to 10 moles; component (3) dibasic acid ester compound or phthalate ester compound or a mixture thereof in any proportion is 0.001 to 10 moles, preferably 0.01 to 1 mole, more preferably 0.02 to 0.6 moles; component (4) is 0.001 to 10 moles, preferably 0.01 to 5 moles, more preferably 0.03 to 2 moles.

5. The solid catalyst component according to any one of claims 1 to 4, characterized in that Component (4) is a halogenated alkane compound selected from the group consisting of ethyl chloride, ethylene dichloride, trichloroethane, chloropropane, dichloropropane, trichloropropane, chlorobutane, dichlorobutane, trichlorobutane, chloropentane, dichloropentane, trichloropentane, hexyl chloride, dichlorohexane, trichlorohexane, chloroheptane, dichloroheptane, trichloroheptane, chlorooctane, dichlorooctane, trichlorooctane, chlorononane, dichlorononane, trichlorononane, chlorodecane, dichlorodecane, trichlorodecane, ethyl bromide, dibromoethane, tribromoethane, bromopropane, dibromopropane, tribromopropane, bromobutane, dibromobutane, tribromobutane, bromopentane, dibromopentane, tribromopentane, bromohexane, dibromohexane , tribromohexane, bromoheptane, dibromoheptane, tribromoheptane, bromooctane, dibromooctane, tribromooctane, bromononane, dibromononane, tribromononane, bromodecane, dibromodecane, tribromodecane, iodoethane, diiodoethane, triiodoethane, iodopropane, diiodopropane, triiodopropane, iodobutane, diiodobutane, triiodobutane, iodopentane, diiodopentane, triiodopentane, iodohexane, diiodohexane, triiodohexane, iodoheptane, diiodoheptane, triiodoheptane, iodooctane, diiodooctane, triiodooctane, iodononane, diiodononane, triiodononane, iododecane, diiododecane, triiododecane; preferably chlorobutane, dichlorobutane, chloropentane, bromobutane.

6. The solid catalyst component according to any one of claims 1 to 5, characterized in that The solid catalyst component is prepared by the following method: 1) firstly mixing component (2) or a mixture of component (2) and an inert solvent with component (1) in any order at a temperature in the range of -20°C to 110°C or mixing multiple times to prepare a suspension A; 2) subsequently contacting component (3) with the suspension A at -20°C to 110°C once or multiple times, maintaining at 0°C to 130°C for 30 minutes to 4 hours, filtering, and selectively washing with an inert solvent for 3 to 6 times; 3) selectively contacting with component (2) or a mixture of component (2) and an inert solvent again at 0°C to 130°C for one or more times, each time for 30 minutes to 4 hours; and then washing with an inert solvent for 3 to 6 times to obtain a suspension B; 4) Finally, component (4) is contacted with the suspension B to react to obtain a modified suspension C, the reaction temperature is 10°C to 60°C, and the time is 20min to 4hr; the liquid is filtered off and dried to obtain a solid catalyst component.

7. A method for preparing the solid catalyst component according to any one of claims 1 to 6, characterized in that: The steps include: 1) firstly mixing component (2) or component (2) and an inert diluent with component (1) to prepare a suspension A; 2) the suspension A reacts with component (3); and selectively reacts with component (2) again to obtain suspension B; 3) contacting component (4) with the suspension B to obtain suspension C; 4) The suspension C is filtered to remove liquid and dried to obtain a solid catalyst component.

8. An olefin polymerization catalyst, characterized in that: Comprising the following components or the reaction products of the following components: a) a solid catalyst component according to any one of claims 1 to 6; b) at least one of the general formula AlR n X (3-n) An organoaluminum compound, wherein R is hydrogen or a hydrocarbon group having 1 to 20 carbon atoms; X is a halogen, and n is an integer of 0≤n≤3.

9. The olefin polymerization catalyst according to claim 1, characterized in that: The organoaluminum compound is triethylaluminum, triisobutylaluminum, diethylaluminum monochloride, tri-n-hexylaluminum, preferably triethylaluminum: the ratio between the catalyst component and the alkylaluminum compound is 1:5-100 in terms of the molar ratio of titanium to aluminum.

10. Use of a promoter in a catalyst component for ethylene polymerization or copolymerization, characterized in that: The accelerator is of the general formula RCHaX b A halogenated alkane compound, wherein R is a C1-C20 linear or branched alkyl group, X is a halogen, 0≤a≤3, 0≤b≤3, a+b=3.

Images