Catalyst component based on alkoxy magnesium carrier for ethylene polymerization or copolymerization, preparation method and application thereof

Abstract

The present invention provides a catalyst component for ethylene polymerization or copolymerization based on an alkoxy magnesium carrier, a preparation method and an application thereof. The catalyst component is a solid containing titanium, magnesium and aluminum, and is prepared by firstly subjecting the alkoxy magnesium carrier to a titanium compound for titanium loading reaction, then loading at least one organic alcohol compound for surface modification reaction, and finally adding an organic aluminum compound for activation treatment. The catalyst component of the present invention is suitable for various ethylene polymerizations or copolymerizations, and has the characteristics of high activity, good hydrogen adjustment, large polymer molecular weight distribution Mw / Mn, high bulk density and low fine powder content.

Description

Technical Field

[0001] The invention relates to a catalyst component for polyolefin based on an alkoxy magnesium carrier, in particular to a catalyst component for ethylene polymerization or copolymerization based on an alkoxy magnesium carrier, a preparation method and application of the catalyst component in catalyzing ethylene polymerization or copolymerization. Background Art

[0002] The molecular weight and molecular weight distribution of polyethylene have an important influence on the rheological properties of its melt and the mechanical properties of the product. A wide molecular weight distribution can make the polyethylene melt have good fluidity at high shear rates, which is very important for blow molding and extrusion processes.

[0003] At present, there are three main ways to regulate the molecular weight and distribution of polyethylene: first, adding a post-reactor or melt blending the resin. This method not only increases the cost, but also makes it difficult to achieve completely uniform blending of the resin, which affects the resin performance; second, through multi-stage reactor segmented polymerization, uniform mixing can be implemented in the reactor, and the operation adjustment flexibility is large, but there are problems of affecting efficiency and high cost; third, using bimetallic or multi-metallic active component catalysts in a single reactor, taking advantage of their respective different polymerization behaviors, directly producing bimodal wide distribution polyethylene in a single reactor. Theoretically, this method is the best, but in practice, it is the most difficult to achieve coordination and unification of multiple polymerization behaviors.

[0004] The polymerization is carried out using a bimetallic or multi-metallic active component catalyst to achieve the purpose of broadening the molecular weight distribution of the polymer. For example, WO9526369 discloses a method for preparing a synthetic polyethylene catalyst with a wide molecular weight distribution, wherein the method uses magnesium chloride to load bimetallic compounds Ti(OBu)Cl3 and Cp2ZrCl2 to prepare a bimetallic composite catalyst; EP0324586 discloses a method for preparing a synthetic polyethylene catalyst with a wide molecular weight distribution, wherein the catalyst uses SiO2 doped with organic zinc as a carrier, and then the carrier is reacted with VOCl3 / TiCl4 to obtain a bimetallic composite catalyst.

[0005] The inventors have found in practical applications that the catalyst using alkoxymagnesium as a carrier has relatively regular catalyst particles that are not easily broken, exhibits very good hydrogen adjustment sensitivity during polymerization, and the polymer melt index increases rapidly with the increase in the amount of hydrogenation. However, the molecular weight distribution of the catalyst is relatively narrow, and a multi-step polymerization process is required to obtain polyethylene with a wide molecular weight distribution. The production cost is high and it is not able to meet the requirements of actual production. Summary of the invention

[0006] In order to solve the above problems, the purpose of the present invention is to provide a catalyst component based on an alkoxymagnesium carrier for ethylene polymerization or copolymerization, which catalyst component for ethylene polymerization not only has the advantages of high activity, good hydrogen adjustment, high bulk density and low fine powder content, but also has a large molecular weight distribution Mw / Mn of the ethylene polymer.

[0007] Another object of the present invention is to provide a method for preparing the catalyst component.

[0008] Another object of the present invention is to provide use of the catalyst component in catalyzing ethylene polymerization or copolymerization.

[0009] In the synthesis of ethylene polymerization or copolymerization catalyst components, the present invention firstly carries out titanium loading reaction on an alkoxy magnesium carrier and a titanium compound, then further loads at least one organic alcohol compound on the carrier for surface modification, and finally adds an organic aluminum compound for activation treatment, so as to finally obtain a catalyst with excellent comprehensive performance, ensure that the catalyst maintains high activity, high hydrogen regulation, high bulk density and low fine powder content when used for ethylene polymerization or copolymerization, and at the same time, the molecular weight distribution of the prepared polymer is relatively large.

[0010] In order to achieve the purpose of the present invention, the present invention provides a catalyst component for ethylene polymerization or copolymerization based on an alkoxy magnesium carrier, which is a solid containing titanium, magnesium and aluminum. The alkoxy magnesium carrier is first subjected to a titanium loading reaction with a titanium compound, and then at least one organic alcohol compound is loaded thereon for a surface modification reaction, and finally an organic aluminum compound is added for activation treatment.

[0011] Specifically, the catalyst component is prepared by the following steps:

[0012] 1) firstly reacting an alkoxy magnesium support with a titanium compound to carry out a titanium loading reaction;

[0013] 2) loading at least one organic alcohol compound for surface modification reaction;

[0014] 3) then adding an organoaluminum compound for activation treatment;

[0015] 4) Finally, the product is filtered, washed and dried.

[0016] Wherein, in step 1), the general formula of the alkoxy magnesium carrier is Mg(OR 1 ) a (OR 2 ) b , where R 1 , R 2 C1~C 10 A hydrocarbon group, a and b are integers and satisfy 0≤a≤2, 0≤b≤2, and a+b=2.

[0017] The alkoxymagnesium can be selected from dimethoxymagnesium, diethoxymagnesium, dipropoxymagnesium, diisopropoxymagnesium, dibutoxymagnesium, diisobutoxymagnesium, methoxyethoxymagnesium, methoxypropoxymagnesium, ethoxypropoxymagnesium, ethoxyisopropoxymagnesium, ethoxybutoxymagnesium, ethoxyisobutoxymagnesium, preferably diethoxymagnesium, dipropoxymagnesium, diisopropoxymagnesium, dibutoxymagnesium, and most preferably diethoxymagnesium.

[0018] The general formula of the titanium compound is TiX 1 m (OR 3 ) 4-m , where R 3 C1~C 20 The hydrocarbon group, X 1 is a halogen, and m is an integer of 0 to 4. Preferably, the titanium compound includes titanium halide, alkoxy titanium halide and alkoxy titanium, more preferably titanium halide or alkoxy titanium halide; most preferably titanium halide.

[0019] The titanium halide is titanium tetrachloride, titanium tetrabromide or titanium tetraiodide, preferably titanium tetrachloride, the alkoxy titanium halide is 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, tripropoxy titanium chloride or tri-n-butoxy titanium chloride, and the alkoxy titanium is tetraethoxy titanium, tetrapropoxy titanium or tetrabutoxy titanium.

[0020] The titanium compound is present in an amount of 0.1 to 100 moles, preferably 0.1 to 20 moles, and most preferably 0.1 to 5 moles per mole of magnesium.

[0021] The inert solvent used for the dispersion carrier can be an aromatic hydrocarbon compound, an alkane compound or a mixture of any proportion thereof which is liquid at room temperature. The aromatic hydrocarbon compound is benzene, toluene, xylene, ethylbenzene, propylbenzene, trimethylbenzene or chlorobenzene, etc. The alkane compound is hexane, heptane, decane or cyclohexane, etc. The aromatic hydrocarbon compound and the alkane compound can be used alone or in combination.

[0022] The reaction temperature in step 1) can be any, preferably -20 to 150° C. The reaction time is also any, as long as the alkoxy magnesium support and the titanium compound react completely.

[0023] In step 2), the general formula of the organic alcohol compound is R 4 (OH) n , where R 4 C1~C 20A hydrocarbon group, n is an integer of 1 to 3; preferably, the organic alcohol compound is selected from at least one straight-chain alcohol, isomeric alcohol, and aromatic alcohol, preferably a straight-chain alcohol and an isomeric alcohol, and more preferably a straight-chain alcohol of 1 to 10 carbon atoms.

[0024] The straight-chain alcohol is methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, ethylene glycol, propylene glycol, and glycerol, preferably ethanol, n-propanol, n-butanol, ethylene glycol, propylene glycol, and glycerol; the isomeric alcohol is isopropanol, isobutanol, isopentanol, isohexanol, isoheptanol, isooctyl alcohol, isononanol, and isodecanol; the aromatic alcohol is phenol, benzyl alcohol, phenylethyl alcohol, and phenylpropanol.

[0025] In step 2), the organic alcohol compound can be added as a pure substance or as a dilute solution with an inert diluent. The time for adding the organic alcohol compound is arbitrary, preferably not more than 10 hours. After the addition is completed, the reaction temperature can be appropriately increased to make the reaction more complete, and the reaction temperature is arbitrary, preferably -20 to 50°C.

[0026] The organic alcohol compound is present in an amount of 0.01 to 10 moles, preferably 0.01 to 5 moles, and most preferably 0.01 to 0.5 moles per mole of magnesium.

[0027] In step 3), the general formula of the organoaluminum compound is AlR 5 c X 2 d , where R 5 is hydrogen, a hydrocarbon group having 1 to 20 carbon atoms; X 2 is a halogen, c and d are integers, 0≤c≤3, 0≤d≤3, c+d=3.

[0028] Preferably, the organoaluminum compound is selected from at least one alkylaluminum, alkylaluminum halide, more preferably alkylaluminum, the alkylaluminum compound is triethylaluminum, tributylaluminum, triisobutylaluminum, tri-n-hexylaluminum or tri-n-octylaluminum; the alkylaluminum halide compound is diethylaluminum monochloride, monoethylaluminum dichloride or sesquiethylaluminum.

[0029] The amount of the organoaluminum compound is 0.1 to 100 moles, preferably 0.1 to 20 moles, and most preferably 0.1 to 5 moles per mole of magnesium.

[0030] In step 4), the filtering, washing and drying can be carried out by the post-treatment steps commonly used in the art, and the above steps can be selectively repeated multiple times to remove free chemical substances. The temperature of the above operation is arbitrary, preferably 20 to 80° C. The time of the above operation is arbitrary.

[0031] The solid component finally separated is dried by vacuum or nitrogen blowing to obtain the catalyst component.

[0032] The present invention also provides a method for preparing a catalyst component for ethylene polymerization or copolymerization based on an alkoxymagnesium carrier, which comprises the following steps:

[0033] 1) firstly reacting an alkoxy magnesium support with a titanium compound to carry out a titanium loading reaction;

[0034] 2) loading at least one organic alcohol compound for surface modification reaction;

[0035] 3) Then an organic aluminum compound is added to perform activation treatment.

[0036] Preferably, the method may further include: 4) finally filtering, washing and drying.

[0037] Wherein, in step 1), the general formula of the alkoxy magnesium carrier is Mg(OR 1 ) a (OR 2 ) b , where R 1 , R 2 C1~C 10 A hydrocarbon group, a and b are integers and satisfy 0≤a≤2, 0≤b≤2, and a+b=2.

[0038] The alkoxymagnesium can be selected from dimethoxymagnesium, diethoxymagnesium, dipropoxymagnesium, diisopropoxymagnesium, dibutoxymagnesium, diisobutoxymagnesium, methoxyethoxymagnesium, methoxypropoxymagnesium, ethoxypropoxymagnesium, ethoxyisopropoxymagnesium, ethoxybutoxymagnesium, ethoxyisobutoxymagnesium, preferably diethoxymagnesium, dipropoxymagnesium, diisopropoxymagnesium, dibutoxymagnesium, and most preferably diethoxymagnesium.

[0039] The general formula of the titanium compound is TiX 1 m (OR 3 ) 4-m , where R 3 C1~C 20 The hydrocarbon group, X 1 is a halogen, and m is an integer of 0 to 4. Preferably, the titanium compound includes titanium halide, alkoxy titanium halide and alkoxy titanium, more preferably titanium halide or alkoxy titanium halide; most preferably titanium halide.

[0040] The titanium halide is titanium tetrachloride, titanium tetrabromide or titanium tetraiodide, preferably titanium tetrachloride, the alkoxy titanium halide is 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, tripropoxy titanium chloride or tri-n-butoxy titanium chloride, and the alkoxy titanium is tetraethoxy titanium, tetrapropoxy titanium or tetrabutoxy titanium.

[0041] The titanium compound is present in an amount of 0.1 to 100 moles, preferably 0.1 to 20 moles, and most preferably 0.1 to 5 moles per mole of magnesium.

[0042] The inert solvent used for the dispersion carrier can be an aromatic hydrocarbon compound, an alkane compound or a mixture of any proportion thereof which is liquid at room temperature. The aromatic hydrocarbon compound is benzene, toluene, xylene, ethylbenzene, propylbenzene, trimethylbenzene or chlorobenzene, etc. The alkane compound is hexane, heptane, decane or cyclohexane, etc. The aromatic hydrocarbon compound and the alkane compound can be used alone or in combination.

[0043] The reaction temperature in step 1) can be any, preferably -20 to 150° C. The reaction time is also any, as long as the alkoxy magnesium support and the titanium compound react completely.

[0044] In step 2), the general formula of the organic alcohol compound is R 4 (OH) n , where R 4 C1~C 20 A hydrocarbon group, n is an integer of 1 to 3; preferably, the organic alcohol compound is selected from at least one straight-chain alcohol, isomeric alcohol, and aromatic alcohol, preferably a straight-chain alcohol and an isomeric alcohol, and more preferably a straight-chain alcohol of 1 to 10 carbon atoms.

[0045] The straight-chain alcohol is methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, ethylene glycol, propylene glycol, and glycerol, preferably ethanol, n-propanol, n-butanol, ethylene glycol, propylene glycol, and glycerol; the isomeric alcohol is isopropanol, isobutanol, isopentanol, isohexanol, isoheptanol, isooctyl alcohol, isononanol, and isodecanol; the aromatic alcohol is phenol, benzyl alcohol, phenylethyl alcohol, and phenylpropanol.

[0046] In step 2), the organic alcohol compound may be added as a pure substance or prepared into a dilute solution with an inert diluent.

[0047] The time for adding the organic alcohol compound is arbitrary, preferably not more than 10 hours. After the addition is completed, the reaction temperature can be appropriately increased to make the reaction more complete, and the reaction temperature is arbitrary, preferably -20 to 50°C.

[0048] The organic alcohol compound is present in an amount of 0.01 to 10 moles, preferably 0.01 to 5 moles, and most preferably 0.01 to 0.5 moles per mole of magnesium.

[0049] In step 3), the general formula of the organoaluminum compound is AlR 5 c X 2 d , where R 5 is hydrogen, a hydrocarbon group having 1 to 20 carbon atoms; X 2 is a halogen, c and d are integers, 0≤c≤3, 0≤d≤3, c+d=3.

[0050] Preferably, the organoaluminum compound is selected from at least one alkylaluminum, alkylaluminum halide, more preferably alkylaluminum, the alkylaluminum compound is triethylaluminum, tributylaluminum, triisobutylaluminum, tri-n-hexylaluminum or tri-n-octylaluminum; the alkylaluminum halide compound is diethylaluminum monochloride, monoethylaluminum dichloride or sesquiethylaluminum.

[0051] The amount of the organoaluminum compound is 0.1 to 100 moles, preferably 0.1 to 20 moles, and most preferably 0.1 to 5 moles per mole of magnesium.

[0052] In step 4), the filtering, washing and drying can be carried out by the post-treatment steps commonly used in the art, and the above steps can be selectively repeated multiple times to remove free chemical substances. The temperature of the above operation is arbitrary, preferably 20 to 80° C. The time of the above operation is arbitrary. The solid component finally separated is vacuum dried or dried with nitrogen, which is the catalyst component.

[0053] Furthermore, the catalyst component of the present invention can be combined with an alkyl aluminum compound or an alkyl aluminum halide compound to form a catalyst for ethylene polymerization or copolymerization.

[0054] The present invention provides a catalyst for ethylene polymerization or copolymerization based on an alkoxy magnesium carrier, which comprises the following components or the reaction product of the following components:

[0055] a) the aforementioned catalyst components;

[0056] b) a general formula of AlR 6 p X 3 3-p Alkyl aluminum compounds, alkyl aluminum halide compounds, wherein R 6is hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, X 3 is a halogen, and p is an integer of 1 to 3.

[0057] The alkyl aluminum compounds and alkyl aluminum halide compounds have been widely recognized and applied as components of olefin catalysts. The general formula is AlR 6 p X 3 3-p Alkyl aluminum compounds, alkyl aluminum halide compounds, wherein R 6 is hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, X 3 is a halogen, and n is an integer of 1 to 3. Specifically, it is preferably: a trialkylaluminum compound, an alkylaluminum halide, and a mixture thereof in any proportion, further preferably triethylaluminum, triisobutylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, and more preferably triethylaluminum or triisobutylaluminum.

[0058] The present invention further provides the use of the catalyst component and the catalyst in catalyzing ethylene polymerization or copolymerization.

[0059] The optional ethylene copolymer monomers of the present invention are those having the general formula CH2=CHR 7 An alkene, wherein R 7 It 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 olefins: 3-methyl-1-butene or 4-methyl-1-pentene; and dienes: butadiene, vinylcyclopentene or vinylcyclohexene. These olefins can be used alone or in combination.

[0060] The catalyst component of the present invention can be used in currently known ethylene polymerization and / or copolymerization processes, including kettle slurry process, loop slurry process, gas phase fluidized bed process, and the polymerization conditions can be selected from the conditions commonly used in the art. Therefore, the polymerization is generally carried out at 30 to 180° C., preferably 50 to 120° C. In any polymerization method used, before the catalyst component is introduced into the polymerization reactor, the catalyst component can be pre-contacted with an alkyl aluminum compound or an alkyl aluminum halide compound. The pre-contact step can be carried out in the absence of a polymerizable olefin.

[0061] At present, alkoxy magnesium has been widely used as a carrier in the preparation of polyethylene catalysts. The polyethylene catalyst prepared with alkoxy magnesium carrier has the advantages of high activity, good hydrogen adjustment, high bulk density, and low subdivision content. However, the molecular weight distribution of the prepared polyethylene is narrow. In the actual production process, it is necessary to adjust the polymerization process conditions through "double reactors" or "three reactors" and a variety of different polymerization conditions to achieve the purpose of producing wide molecular weight polyethylene.

[0062] Based on this, after years of research and exploration, the researchers of the present invention have creatively adopted the method of first contacting the alkoxy magnesium carrier with the titanium compound for titanium loading reaction to generate magnesium chloride and halogenated alkoxy titanium (taking the ethoxy magnesium carrier as an example, the catalyst will contain TiCl3OEt active components, see the first step reaction); then the organic alcohol compound is loaded for surface modification treatment, at this time, the organic alcohol is exchanged with the halogen in the titanium compound on the catalyst surface, and another alkoxy-substituted titanium compound is obtained (taking the organic alcohol as butanol as an example, TiCl3OBu active components will be produced, see the second step reaction). Due to the presence of different alkoxy titanium active components (TiCl3OEt and TiCl3OBu), after alkyl aluminum activation, the molecular weight of the polyethylene generated by polymerization is different, thereby widening the molecular weight distribution. The present invention adjusts the type and amount of organic alcohol added, adjusts the type and ratio of alkoxy titanium in the catalyst component, so that the catalyst can obtain polyethylene with a widened molecular weight distribution during polymerization while maintaining the high hydrogen adjustment performance unchanged, and the molecular weight distribution width can be adjusted within a certain range.

[0063] First step reaction: Second step reaction:

[0064] The catalyst component based on an alkoxy magnesium carrier of the present invention contains a plurality of alkoxy titanium active center components, is used for ethylene polymerization or copolymerization, has the characteristics of high activity, good hydrogen adjustment, large polymer molecular weight distribution Mw / Mn, high bulk density, and low fine powder content, can be well adapted to the existing polymerization process, and can obtain a catalyst with excellent comprehensive performance, ensuring that the catalyst maintains high activity, high bulk density, and low fine powder content when used for ethylene polymerization or copolymerization, while the prepared polymer has a large molecular weight distribution. DETAILED DESCRIPTION

[0065] 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.

[0066] Characterization

[0067] Composition of the catalyst The metal elements in the catalyst were determined by spectrophotometry, the halogen was determined by silver nitrate titration, and the alkoxy was determined by gas chromatography.

[0068] Particle size distribution of polymer

[0069] ASTM E1187

[0070] Melt Index Measurement

[0071] ASTM D1238

[0072] Bulk density of polymer

[0073] DIN53194

[0074] The operations for preparing the catalyst components in the examples were all carried out in an air-tight state.

[0075] Example 1

[0076] 1. Preparation of catalyst components:

[0077] In a 500ml 5-necked flask with nitrogen fully replaced and stirred, add 20g of diethoxymagnesium and 200ml of dehydrated and deoxygenated toluene, cool to 0℃, slowly drop 48.0ml of titanium tetrachloride, raise the temperature to 100℃ at a uniform rate after dropping, and keep the temperature constant for 1h. Separate the solid and liquid, and wash the solid with 200ml of hexane at 60℃ for 5 times.

[0078] After the last hexane washing, add 200 ml of hexane, cool to 0°C, slowly drop 0.65 g of n-butanol, and keep constant temperature at 0°C for 1 hour; continue to add 14 ml of 2 mol / L triethylaluminum hexane solution at 0°C, then uniformly heat to 100°C, and keep constant temperature at 100°C for 30 minutes. Solid-liquid separation, solid washed with hexane at 60°C until the titanium content in the hexane washing liquid is ≤50ppm. After vacuum drying, 32.1 g of solid was obtained. Catalyst composition is shown in Table 1.

[0079] 2. Aggregation

[0080] After nitrogen was fully replaced in a 2L stainless steel reactor, 1L of n-hexane was added, 5ml of 0.5mol / L triethylaluminum hexane solution and 80mg of catalyst hexane solution were added, the temperature was raised to 70°C, hydrogen was introduced to make the pressure in the reactor reach 0.28MPa, and ethylene was introduced to make the total pressure in the reactor reach 0.73MPa, and polymerization was carried out at 80°C for 2 hours. After the reaction was completed, the reactor was cooled and stirring was stopped to discharge the reaction product. The polymerization results are shown in Table 2.

[0081] Example 2

[0082] 1. Preparation of catalyst components: Same as Example 1, except that the amount of n-butanol added is 1.3 g. The catalyst composition is shown in Table 1.

[0083] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0084] Example 3

[0085] 1. Preparation of catalyst components: Same as Example 1, except that the amount of n-butanol added is 2.6 g. The catalyst composition is shown in Table 1.

[0086] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0087] Example 4

[0088] 1. Preparation of catalyst components: Same as Example 3, except that n-butanol is replaced by isooctyl alcohol, and the amount of isooctyl alcohol added is 1.14 g. The catalyst composition is shown in Table 1.

[0089] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0090] Example 5

[0091] 1. Preparation of catalyst components: Same as Example 3, except that the amount of isooctyl alcohol added is 2.28 g. The catalyst composition is shown in Table 1.

[0092] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0093] Example 6

[0094] 1. Preparation of catalyst components: Same as Example 1, except that the triethylaluminum hexane solution is replaced with diethylaluminum monochloride hexane solution. The catalyst composition is shown in Table 1.

[0095] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0096] Example 7

[0097] 1. Preparation of catalyst components: Same as Example 1, except that the isothermal temperature of diethoxymagnesium and titanium tetrachloride is adjusted to 85° C. The catalyst composition is shown in Table 1.

[0098] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0099] Example 8

[0100] 1. Preparation of catalyst components: same as in Example 1.

[0101] 2. Aggregation:

[0102] After nitrogen was fully replaced in a 2L stainless steel reactor, 1L of n-hexane was added, 5ml of 0.5mol / L triethylaluminum hexane solution and 80mg of catalyst hexane solution were added, the temperature was raised to 70°C, hydrogen was introduced to make the pressure in the reactor reach 0.48MPa, and ethylene was introduced to make the total pressure in the reactor reach 0.73MPa, and polymerization was carried out at 80°C for 2 hours. After the reaction was completed, the reactor was cooled and stirring was stopped to discharge the reaction product. The polymerization results are shown in Table 2.

[0103] Example 9

[0104] 1. Preparation of catalyst components: same as Example 2.

[0105] 2. Polymerization: Same as Example 8. The polymerization results are shown in Table 2.

[0106] Example 10

[0107] 1. Preparation of catalyst components: same as Example 3.

[0108] 2. Polymerization: Same as Example 8. The polymerization results are shown in Table 2.

[0109] Comparative Example 1

[0110] 1. Preparation of catalyst components:

[0111] In a 500ml 5-necked flask with nitrogen fully replaced and stirred, add 4g of diethoxymagnesium and 23.8g of tetrabutoxytitanium (Ti / Mg=2), then heat to 110℃ and keep constant for 3 hours, cool to 50℃, add 100ml of n-hexane treated with dehydration and deoxygenation, and stir for 10min; add 100ml of 2mol / L monochlorodiethylaluminum hexane solution dropwise within 2h, and heat to 60℃ at a uniform rate after dripping. Solids gradually precipitate during the heating process, filter, and wash twice with 100ml of hexane to obtain a solid precipitate. After filtering, wash four times with 60ml of hexane. After vacuum drying, 15g of solids are obtained. The catalyst composition is shown in Table 1.

[0112] The polymerization method was the same as in Example 1. The polymerization results are shown in Table 2.

[0113] Comparative Example 2

[0114] 1. Preparation of catalyst components:

[0115] In a 500ml 5-necked flask with nitrogen fully replaced and stirred, add 20g of diethoxymagnesium and 200ml of dehydrated and deoxygenated toluene, cool to 0℃, slowly drop 48.0ml of titanium tetrachloride, and raise the temperature to 100℃ at a uniform rate after dropping, and keep the temperature constant for 1h. Separate the solid and liquid, wash the solid with hexane at 60℃ until the titanium content in the hexane washing liquid is ≤50ppm. After vacuum drying, 24.7g of solid is obtained. The catalyst composition is shown in Table 1.

[0116] The polymerization method was the same as in Example 1. The polymerization results are shown in Table 2.

[0117] Comparative Example 3

[0118] 1. Preparation of catalyst components:

[0119] In a 500ml 5-necked flask with stirring and fully replaced with nitrogen, add 28ml decane, 4.76g ground magnesium chloride, and drop 16.3g isooctyl alcohol, then heat to 130℃ and keep constant temperature for 3 hours; cool to 50℃, add 3.1g tetraethoxysilane treated with dehydration and deoxygenation, stir for 2 hours; cool to 30℃. Slowly drop 200ml TiCl4 solution into the above magnesium chloride alcohol solution for 2 hours; heat to 110 degrees after dripping, and keep constant temperature for 2 hours; separate solid and liquid, wash the obtained solid with 100ml decane at 110℃ twice, and wash with 100ml hexane at 60℃ 4 times. After vacuum drying, 6.4g solid is obtained. Catalyst composition is shown in Table 1.

[0120] The polymerization method was the same as in Example 1. The polymerization results are shown in Table 2.

[0121] Comparative Example 4

[0122] 1. Preparation of catalyst components: same as Comparative Example 1.

[0123] 2. Polymerization: Same as Example 8. The polymerization results are shown in Table 2.

[0124] Comparative Example 5

[0125] 1. Preparation of catalyst components: same as Comparative Example 2.

[0126] 2. Polymerization: Same as Example 8. The polymerization results are shown in Table 2.

[0127] Comparative Example 6

[0128] 1. Preparation of catalyst components: same as Comparative Example 3.

[0129] 2. Polymerization: Same as Example 8. The polymerization results are shown in Table 2.

[0130] Table 1 Catalyst composition and particle size distribution

[0131]

[0132] It can be seen from Table 1 and Table 2 that the solid catalyst component prepared by the present invention contains a variety of alkoxytitanium active center components and is used for ethylene polymerization or copolymerization, and has the characteristics of high activity, good hydrogen adjustment, large polymer molecular weight distribution Mw / Mn, high bulk density and low fine powder content.

[0133] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

[0134] The terms used herein are only for illustration of specific embodiments and are not intended to limit the present invention. Unless otherwise defined, all terms (including technical terms and scientific terms) used herein are the same as those understood by those of ordinary skill in the art to which the present invention belongs. It should also be made clear that, except for clear definitions herein, terms such as those generally defined in dictionaries should be interpreted as having a consistent meaning in the context of this specification and the related art, and should not be interpreted as idealized or overly formalized.

[0135]

Claims

1. A catalyst component for ethylene polymerization or copolymerization based on an alkoxymagnesium carrier, which is a solid containing titanium, magnesium and aluminum, characterized in that: The method comprises firstly subjecting an alkoxy magnesium carrier to titanium loading reaction with a titanium compound, then loading at least one organic alcohol compound thereon for surface modification reaction, and finally adding an organic aluminum compound for activation treatment.

2. The catalyst component for ethylene polymerization or copolymerization according to claim 1, characterized in that The catalyst component is prepared by the following steps: 1) firstly reacting an alkoxy magnesium support with a titanium compound to carry out a titanium loading reaction; 2) loading at least one organic alcohol compound for surface modification reaction; 3) then adding an organoaluminum compound for activation treatment; 4) Finally, the product is filtered, washed and dried.

3. The catalyst component for ethylene polymerization or copolymerization according to claim 1 or 2, characterized in that The amount of each reactant used is per mole of magnesium: the titanium compound is 0.1 to 100 moles, preferably 0.1 to 20 moles, and most preferably 0.1 to 5 moles; the organic alcohol compound is 0.01 to 10 moles, preferably 0.01 to 5 moles, and most preferably 0.01 to 0.5 moles; the organic aluminum compound is 0.1 to 100 moles, preferably 0.1 to 20 moles, and most preferably 0.1 to 5 moles.

4. The catalyst component for ethylene polymerization or copolymerization according to any one of claims 1 to 3, characterized in that: The general formula of the organic alcohol compound is R 4 (OH) n , where R 4 is a C1-C20 hydrocarbon group, and n is an integer of 1-3; preferably, the organic alcohol compound is selected from at least one straight-chain alcohol, isomeric alcohol, and aromatic alcohol, preferably a straight-chain alcohol or isomeric alcohol, and more preferably a straight-chain alcohol of 1 to 10 carbon atoms.

5. The catalyst component for ethylene polymerization or copolymerization according to any one of claims 1 to 4, characterized in that: The general formula of the magnesium alkoxide is Mg(OR 1 ) a (OR 2 ) b , where R 1 , R 2 are respectively C1-C10 hydrocarbon groups, a and b are integers and satisfy 0≤a≤2, 0≤b≤2, and a+b=2; the alkoxy magnesium is selected from dimethoxy magnesium, diethoxy magnesium, dipropoxy magnesium, diisopropoxy magnesium, dibutoxy magnesium, diisobutoxy magnesium, methoxyethoxy magnesium, methoxypropoxy magnesium, ethoxypropoxy magnesium, ethoxyisopropoxy magnesium, ethoxybutoxy magnesium, and ethoxyisobutoxy magnesium, preferably diethoxy magnesium, dipropoxy magnesium, diisopropoxy magnesium, and dibutoxy magnesium, and most preferably diethoxy magnesium.

6. The catalyst component for ethylene polymerization or copolymerization according to any one of claims 1 to 5, characterized in that: The general formula of the titanium compound is TiX 1 m (OR 3 ) 4-m , where R 3 is a C1-C20 hydrocarbon group, X 1 is a halogen, and m is an integer of 0 to 4; preferably, the titanium compound includes titanium halide, alkoxy titanium halide and alkoxy titanium, more preferably titanium halide or alkoxy titanium halide; most preferably titanium halide; wherein the titanium halide is titanium tetrachloride, titanium tetrabromide or titanium tetraiodide, the alkoxy titanium halide is 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, tripropoxy titanium chloride or tri-n-butoxy titanium chloride, and the alkoxy titanium is tetraethoxy titanium, tetrapropoxy titanium or tetrabutoxy titanium.

7. The catalyst component for ethylene polymerization or copolymerization according to any one of claims 1 to 6, characterized in that: The general formula of the organoaluminum compound is AlR 5 c X 2 d , where R 5 is hydrogen, a hydrocarbon group having 1 to 20 carbon atoms; X 2 is a halogen, c and d are integers, 0≤c≤3, 0≤d≤3, c+d=3; the organoaluminum compound is selected from at least one alkylaluminum and alkylaluminum halide, preferably an alkylaluminum; the alkylaluminum compound is triethylaluminum, tributylaluminum, triisobutylaluminum, tri-n-hexylaluminum or tri-n-octylaluminum; the alkylaluminum halide compound is diethylaluminum monochloride, monoethylaluminum dichloride or sesquiethylaluminum.

8. A method for preparing a catalyst component for ethylene polymerization or copolymerization according to any one of claims 1 to 7, characterized in that: It includes the following steps: 1) firstly reacting an alkoxy magnesium support with a titanium compound to carry out a titanium loading reaction; 2) loading at least one organic alcohol compound for surface modification reaction; 3) Then an organic aluminum compound is added to perform activation treatment.

9. The method for preparing a catalyst component for ethylene polymerization or copolymerization according to claim 8, characterized in that: The reaction temperature in step 1) is -20 to 150°C; the reaction temperature in step 2) is -20 to 50°C; the reaction temperature in step 3) is -20 to 150°C.

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

11. The catalyst component for ethylene polymerization or copolymerization according to any one of claims 1 to 7 and use of the catalyst according to claim 10 in catalyzing ethylene polymerization or copolymerization.

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