Catalyst component for ethylene polymerization based on alkoxymagnesium support, preparation method and application thereof

Abstract

The present invention provides a catalyst component for ethylene polymerization or copolymerization based on an alkoxymagnesium support, a preparation method, and its application. The catalyst component is a solid material containing titanium, magnesium, and aluminum. It is prepared by first activating the alkoxymagnesium support with an organoaluminum compound and then adding a titanium compound to the support for titanium loading. The catalyst component is suitable for various ethylene polymerization or copolymerization processes and exhibits high activity, good hydrogen regulation, high bulk density, and low fines content.

Description

Technical Field

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

[0002] Since the successful development of high-efficiency polyethylene catalysts in the 1970s, the Ziegler-Natta catalyst system has dominated the polyethylene industry. The core of polyethylene catalyst research is to control the polymerization activity of the catalyst, the particle morphology and size distribution of the polymer produced by the catalyst, the catalyst's sensitivity to hydrogen regulation, and the catalyst's copolymerization performance, based on the matching of different production process conditions.

[0003] ZN catalysts used in ethylene slurry polymerization processes are generally controlled by dissolution and precipitation to ensure high catalyst activity and particle size distribution. For example, the catalysts for ethylene polymerization or copolymerization disclosed in Chinese Patent Publication Nos. CN1229092A, CN 02120861A, and CN1752114A are prepared by dissolving a magnesium halide in an organic epoxy compound and an organic phosphine compound, adding an electron donor activator to form a uniform solution, and then reacting the solution with at least one precipitation aid and a transition metal titanium halide and its derivatives. These catalysts exhibit high activity in ethylene slurry polymerization, but poor control over the catalyst morphology results in a high fines content in the resulting polyethylene powder, seriously affecting the long-term stable operation of the reactor.

[0004] In actual applications, the inventors found that the catalyst with alkoxymagnesium as the carrier has relatively regular catalyst particles that are not easy to break, and shows very good hydrogen adjustment sensitivity during polymerization. The polymer melt index increases rapidly with the increase of hydrogenation amount, but the catalyst activity and polymer bulk density decrease significantly.

[0005] Therefore, further research is needed to develop more suitable ethylene polymerization or copolymerization catalyst components and their preparation methods. Summary of the Invention

[0006] In order to solve the above problems, the purpose of the present invention is to provide a catalyst component for ethylene polymerization or copolymerization based on an alkoxymagnesium support, which catalyst component for ethylene polymerization not only has high activity, high bulk density, uniform particle size distribution, but also has good hydrogen regulation performance and low fine powder content.

[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 adopts the method of pre-treating an alkoxy magnesium carrier by first adding an organic aluminum compound, and then performing titanium loading, washing, drying, etc., so as to finally obtain a catalyst with excellent comprehensive performance, ensuring that the catalyst can maintain higher activity and bulk density even under high hydrogen concentration. The prepared catalyst is used for ethylene polymerization or copolymerization and has the characteristics of high activity, good hydrogen adjustment, high bulk density, and low fine powder content.

[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 alkoxymagnesium support, which is a solid material containing titanium, magnesium and aluminum. The alkoxymagnesium support is first activated by an organic aluminum compound and then a titanium compound is added to carry out titanium loading treatment.

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

[0012] 1) dispersing the alkoxy magnesium support in an inert solvent and adding at least one organoaluminum compound for activation treatment;

[0013] 2) then carrying out titanium loading treatment with a titanium compound;

[0014] 3) Finally, the product is filtered, washed and dried.

[0015] Wherein, in step 1), the general formula of the magnesium alkoxide 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, a+b=2.

[0016] 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.

[0017] The general formula of the organoaluminum compound is Al(OR 3 ) c R 4 d X 1e , where R 3 、R 4 is hydrogen, a hydrocarbon group having 1 to 20 carbon atoms; X 1 is a halogen, c, d, e are integers, 0≤c≤3, 0≤d≤3, 0≤e≤3, c+d+e=3.

[0018] The organoaluminum compound is selected from at least one of alkylaluminum, alkylaluminum halide, alkoxyaluminum halide, and alkoxyaluminum, preferably alkylaluminum halide, alkoxyaluminum halide, and alkoxyaluminum, and more preferably alkoxyaluminum.

[0019] Wherein, the alkyl aluminum compound is triethylaluminum, tributylaluminum, triisobutylaluminum, tri-n-hexylaluminum or tri-n-octylaluminum; the alkyl aluminum halide compound is diethylaluminum monochloride, monoethylaluminum dichloride or sesquiethylaluminum; the alkoxyaluminum halide is diethoxyaluminum chloride or ethoxyaluminum dichloride; the alkoxyaluminum is aluminum triethoxide, aluminum tri-n-propoxide, aluminum triisopropoxide, aluminum tri-n-butoxide, aluminum triisobutoxide or aluminum tri-tert-butoxide.

[0020] 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.

[0021] The inert solvent can be an aromatic hydrocarbon compound, an alkane compound, or a mixture thereof in any proportion that is liquid at room temperature. The aromatic hydrocarbon compound can be benzene, toluene, xylene, ethylbenzene, propylbenzene, trimethylbenzene, or chlorobenzene. The alkane compound can be hexane, heptane, decane, or cyclohexane. 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 10 to 150° C. The reaction time is also arbitrary, as long as the alkoxymagnesium support and the organoaluminum compound react completely.

[0023] In step 2), the general formula of the titanium compound is TiX 2 m (OR 5 ) 4-m , where R 5 C1~C 20 The hydrocarbon group, X 2 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.

[0024] 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 or tri-n-butoxy titanium chloride; and the alkoxy titanium is tetraethoxy titanium, tetrapropoxy titanium or tetrabutoxy titanium.

[0025] The amount of the titanium 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.

[0026] In step 2), the titanium compound may be added as a pure substance or as a dilute solution with an inert diluent. The reaction temperature is arbitrary, preferably 50 to 150°C.

[0027] The titanium compound can be added for any time, preferably not more than 10 hours. After the addition is completed, the reaction temperature can be appropriately increased to make the reaction more complete. The reaction temperature is optional, preferably 50-150°C.

[0028] In step 3), the filtration, washing, and drying steps employed can be performed using post-processing procedures commonly employed in the art. These steps can optionally be repeated multiple times to remove free chemical substances. The temperature for these operations is arbitrary, preferably 20° C. to 80° C. The duration of these operations is also arbitrary. The solid component finally separated is vacuum-dried or dried with nitrogen to obtain the catalyst component.

[0029] The present invention also provides a method for preparing a catalyst component for ethylene polymerization or copolymerization based on an alkoxymagnesium support, which comprises the following steps:

[0030] 1) dispersing the alkoxy magnesium support in an inert solvent and adding at least one organoaluminum compound for activation treatment;

[0031] 2) then carrying out titanium loading treatment with a titanium compound;

[0032] 3) Finally, the product is filtered, washed and dried.

[0033] Wherein, in step 1), the general formula of the magnesium alkoxide 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, a+b=2.

[0034] 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.

[0035] The general formula of the organoaluminum compound is Al(OR 3 ) c R 4 d X 1 e , where R 3 、R 4 is hydrogen, a hydrocarbon group having 1 to 20 carbon atoms; X 1 is a halogen, c, d, e are integers, 0≤c≤3, 0≤d≤3, 0≤e≤3, c+d+e=3.

[0036] The organoaluminum compound is selected from at least one of alkylaluminum, alkylaluminum halide, alkoxyaluminum halide, and alkoxyaluminum, preferably alkylaluminum halide, alkoxyaluminum halide, and alkoxyaluminum, and more preferably alkoxyaluminum.

[0037] Wherein, the alkyl aluminum compound is triethylaluminum, tributylaluminum, triisobutylaluminum, tri-n-hexylaluminum or tri-n-octylaluminum; the alkyl aluminum halide compound is diethylaluminum monochloride, ethylaluminum dichloride or ethylaluminum sesquichloride; the alkoxyaluminum halide is diethoxyaluminum chloride or ethoxyaluminum dichloride; the alkoxyaluminum is aluminum triethoxide, aluminum tri-n-propoxide, aluminum triisopropoxide, aluminum tri-n-butoxide, aluminum triisobutoxide or aluminum tri-tert-butoxide.

[0038] 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.

[0039] The inert solvent can be an aromatic hydrocarbon compound, an alkane compound, or a mixture thereof in any proportion that is liquid at room temperature. The aromatic hydrocarbon compound can be benzene, toluene, xylene, ethylbenzene, propylbenzene, trimethylbenzene, or chlorobenzene. The alkane compound can be hexane, heptane, decane, or cyclohexane. The aromatic hydrocarbon compound and the alkane compound can be used alone or in combination.

[0040] The reaction temperature in step 1) can be any, preferably 10 to 150° C. The reaction time is also arbitrary, as long as the alkoxymagnesium support and the organoaluminum compound react completely.

[0041] In step 2), the general formula of the titanium compound is TiX 2m (OR 5 ) 4-m , where R 5 C1~C 20 The hydrocarbon group, X 2 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.

[0042] 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 or tri-n-butoxy titanium chloride; and the alkoxy titanium is tetraethoxy titanium, tetrapropoxy titanium or tetrabutoxy titanium.

[0043] The amount of the titanium 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.

[0044] In step 2), the titanium compound may be added as a pure substance or as a dilute solution with an inert diluent. The reaction temperature is arbitrary, preferably 50 to 150°C.

[0045] The titanium compound can be added for any time, preferably not more than 10 hours. After the addition is completed, the reaction temperature can be appropriately increased to make the reaction more complete. The reaction temperature is optional, preferably 50-150°C.

[0046] In step 3), the filtration, washing, and drying steps employed can be performed using post-processing procedures commonly employed in the art. These steps can optionally be repeated multiple times to remove free chemical substances. The temperature for these operations is arbitrary, preferably 20° C. to 80° C. The duration of these operations is also arbitrary. The solid component finally separated is vacuum dried or dried with nitrogen to obtain the catalyst component.

[0047] The present invention provides application of the catalyst in catalyzing ethylene polymerization or copolymerization.

[0048] In the preparation of existing polyethylene catalysts, the main purpose of using organic aluminum compounds to treat the catalyst components is to interact with the titanium compounds in the catalyst components to adjust the valence state of titanium in the active center of the catalyst from Ti 4+ Restore to Ti 3+ Or lower valence state, play the role of pre-activation to improve the polymerization performance of the catalyst, but the effect on the structure and composition of the catalyst components is small. In this state, since the polymerization active center is transformed into Ti3+ Or lower valence state, the active center becomes very sensitive and easily deactivated by the storage environment or impurities during the polymerization process. Therefore, after the catalyst component is treated with an organoaluminum compound, it needs to be stored at low temperature or pre-polymerized for better application.

[0049] Based on this, the present invention uses an organoaluminum compound to treat the alkoxy magnesium support before loading the titanium active center. When the organoaluminum compound treats the alkoxy magnesium support, the alkyl, alkoxy, halogen and other functional groups in the organoaluminum compound fully exchange with the alkoxy groups in the support. After the exchange reaction, the high active sites on the surface of the support are fully eliminated, and the activation treatment forms an aluminum-containing porous catalyst support (see reaction for details).

[0050]

[0051] 1,2). The aluminum-containing porous catalyst carrier is then treated with titanium compounds to carry out titanium treatment (see reactions 3,4 for details). The heterogeneous reaction becomes more uniform and milder, the distribution of the polymerization active centers becomes more uniform, and the main valence state of the titanium in the catalyst active center is still Ti 4+ The catalyst thus obtained has the characteristics of high activity, high bulk density, uniform particle size distribution, good hydrogen regulation performance and low fine powder content when used in ethylene polymerization.

[0052] Furthermore, the catalyst components of the present invention can be combined with alkyl aluminum compounds and alkyl aluminum halide compounds to form a catalyst for ethylene polymerization or copolymerization.

[0053] The present invention provides a catalyst for ethylene polymerization or copolymerization, which comprises the following components or the reaction product of the following components:

[0054] a) the aforementioned catalyst components;

[0055] b) a general formula of AlR 6 n X 3 3-n 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.

[0056] The alkyl aluminum compounds and alkyl aluminum halide compounds have been widely recognized and used as components of olefin catalysts. The general formula is AlR 6 n X 3 3-n 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 n is an integer from 1 to 3. Specifically, trialkylaluminum compounds, alkylaluminum halides, and mixtures thereof in any proportion are preferred, preferably triethylaluminum, triisobutylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, and more preferably triethylaluminum or triisobutylaluminum.

[0057] The optional ethylene comonomers are those having the general formula CH2=CHR 7 Alkenes, where R 7 C1~C 12 Alkyl groups such as linear olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene; branched olefins such as 3-methyl-1-butene or 4-methyl-1-pentene; and dienes such as butadiene, vinylcyclopentene, or vinylcyclohexene. These olefins may be used alone or in combination.

[0058] The catalyst components of the present invention can be used in currently known ethylene polymerization and / or copolymerization processes, including kettle slurry processes, loop slurry processes, and gas-phase fluidized bed processes. Polymerization conditions can be selected from those commonly used in the art. Therefore, polymerization is generally carried out at a temperature of 30 to 180° C., preferably 50 to 120° C. In any polymerization process employed, the catalyst components can be precontacted with an alkylaluminum compound or an alkylaluminum halide compound prior to introduction into the polymerization reactor. This precontacting step can be carried out in the absence of a polymerizable olefin.

[0059] The present invention discloses an alkoxymagnesium-based catalyst component for ethylene polymerization or copolymerization, a preparation method, and an application thereof. The catalyst component for ethylene polymerization not only has high activity, high bulk density, and uniform particle size distribution, but also has good hydrogen regulation performance and low fine powder content.

[0060] The present invention uniquely adopts the method of first contacting the organoaluminum compound with the alkoxy magnesium support for activation treatment, and then adding the titanium compound to carry out the titanium loading reaction. At this time, the main valence state of titanium is still tetravalent, which ensures the stability of the catalyst properties and excellent comprehensive performance. 氢气 :P 乙烯 =0.48MPa:0.25MPa), has the characteristics of high MI, high bulk density, and high activity. The prepared catalyst is used for ethylene polymerization or copolymerization, and has the characteristics of high activity, good hydrogen adjustment, high bulk density, and low fine powder content. It is particularly suitable for the production of bimodal polyethylene on the device. DETAILED DESCRIPTION

[0061] The present invention is further described below with reference to examples, which are conducive to a better understanding of the present invention and its advantages and effects. However, the examples are only used to illustrate the present invention and are not intended to limit the present invention.

[0062] Characterization

[0063] 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.

[0064] Polymer particle size distribution

[0065] ASTM E1187

[0066] Melt index measurement

[0067] ASTM D1238

[0068] Bulk density of polymer

[0069] DIN53194

[0070] The operations for preparing the catalyst components in the examples were all carried out in an airtight state.

[0071] Example 1

[0072] 1. Preparation of catalyst components:

[0073] To a 500ml, nitrogen-purged, stirred, five-necked flask, add 20g of diethoxymagnesium and 200ml of dehydrated and deoxygenated decane. Cool to 0°C and slowly add 43.7ml of a 2mol / L diethylaluminum chloride hexane solution dropwise. After the addition is complete, raise the temperature to 100°C at a constant rate and hold for 1 hour. Cool to 0°C and slowly add 48ml of titanium tetrachloride dropwise. After the addition is complete, raise the temperature to 100°C at a constant rate and hold for 1 hour. Allow to settle, filter, and wash the solid four times with 200ml of hexane at 60°C. Vacuum dry to yield 28.7g of solid. Catalyst composition is shown in Table 1.

[0074] 2. Aggregation

[0075] After fully purging the atmosphere with nitrogen, a 2L stainless steel reactor was charged with 1L of n-hexane, 5mL of a 0.5mol / L triethylaluminum hexane solution, and 80mg of a catalyst hexane solution. The reactor was heated to 70°C, and hydrogen was introduced to a pressure of 0.28MPa. Ethylene was then introduced to a total pressure of 0.73MPa. Polymerization was continued at 80°C for 2 hours. After the reaction was complete, the reactor was cooled, stirring was stopped, and the reaction product was discharged. The polymerization results are shown in Table 2.

[0076] Example 2

[0077] 1. Preparation of catalyst components: Same as Example 1, except that the diethylaluminum monochloride hexane solution was replaced with ethylaluminum sesquichloride solution. The catalyst composition is shown in Table 1.

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

[0079] 3. Specific Surface Area: Wash the support treated with diethylaluminum monochloride with hexane and drain. Measure the specific surface area of ​​the final catalyst. See Table 3 for the specific surface area test results.

[0080] Example 3

[0081] 1. Preparation of catalyst components: Same as Example 1, except that the diethylaluminum chloride hexane solution was replaced with diethoxyaluminum chloride solution. The catalyst composition is shown in Table 1.

[0082] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0083] Example 4

[0084] 1. Preparation of catalyst components: Same as Example 1, except that the amount of diethylaluminum monochloride hexane solution added was changed to 21.9 ml. The catalyst composition is shown in Table 1.

[0085] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0086] Example 5

[0087] 1. Preparation of catalyst components: Same as Example 2, except that the amount of sesquiethylaluminum hexane added was changed to 21.9 ml. The catalyst composition is shown in Table 1.

[0088] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0089] Example 6

[0090] 1. Preparation of catalyst components: Same as Example 3, except that the amount of diethoxyaluminum chloride hexane solution added was changed to 21.9 ml. The catalyst composition is shown in Table 1.

[0091] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0092] Example 7

[0093] 1. Preparation of catalyst components: Same as Example 1, except that the diethylaluminum monochloride hexane solution was replaced with aluminum triethanolate hexane solution. The catalyst composition is shown in Table 1.

[0094] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0095] 3. Specific Surface Area: The support treated with aluminum triethoxide was washed with hexane and dried. The final catalyst was then tested for specific surface area. The specific surface area test results are shown in Table 3.

[0096] Example 8

[0097] 1. Preparation of Catalyst Components: Same as in Example 1, except that the diethylaluminum chloride hexane solution was replaced with a mixed solution of diethylaluminum chloride hexane solution (21.9 ml) and 2 mol / L aluminum triethanolate hexane solution (21.9 ml). 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 9

[0100] 1. Preparation of catalyst components: Same as Example 1. Catalyst composition is shown in Table 1.

[0101] 2. Aggregation:

[0102] After fully purging the atmosphere with nitrogen, a 2L stainless steel reactor was charged with 1L of n-hexane, 5mL of a 0.5mol / L triethylaluminum hexane solution, and 80mg of a catalyst hexane solution. The reactor was heated to 70°C, and hydrogen was introduced to a pressure of 0.48MPa. Ethylene was then introduced to a total pressure of 0.73MPa. Polymerization was continued at 80°C for 2 hours. After the reaction was complete, the reactor was cooled, stirring was stopped, and the reaction product was discharged. The polymerization results are shown in Table 2.

[0103] Example 10

[0104] 1. Preparation of catalyst components: Same as Example 3. Catalyst composition is shown in Table 1.

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

[0106] Example 11

[0107] 1. Preparation of catalyst components: Same as Example 7. Catalyst composition is shown in Table 1.

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

[0109] Example 12

[0110] 1. Preparation of catalyst components: Same as Example 11. Catalyst composition is shown in Table 1.

[0111] 2. Polymerization: Same as Example 8. The polymerization results are shown in Table 2.

[0112] Comparative Example 1

[0113] 1. Preparation of catalyst components:

[0114] To a 500ml, nitrogen-purged, stirred, five-necked flask, 4g of diethoxymagnesium and 23.8g of tetrabutoxytitanium (Ti / Mg = 2) were added. The temperature was then raised to 110°C and held constant for 3 hours. The temperature was then lowered to 50°C, and 100ml of dehydrated and deoxygenated n-hexane was added. The mixture was stirred for 10 minutes. Over 2 hours, 100ml of a 2mol / L diethylaluminum monochloride hexane solution was added dropwise. After the addition was complete, the temperature was raised uniformly to 60°C. During the heating process, a solid precipitated. The precipitate was filtered and washed twice with 100ml of hexane to obtain a solid. After filtration, the precipitate was washed four times with 60ml of hexane. After vacuum drying, 15g of solid was obtained. The catalyst composition is shown in Table 1.

[0115] The polymerization method was the same as in Example 1. The polymerization results are shown in Table 2.

[0116] Comparative Example 2

[0117] 1. Preparation of catalyst components:

[0118] To a 500ml, nitrogen-purged, stirred, five-necked flask, add 10g of a diethoxymagnesium support with an average particle size of 11μm and 100ml of toluene. Cool the mixture to 0°C and slowly add 100ml of titanium tetrachloride dropwise with stirring over 2 hours. Raise the temperature to 100°C and maintain it for 1 hour. Allow the suspension to settle, allowing it to separate into layers. The liquid is filtered clean and the resulting solid is washed four times with 100ml of hexane at 60°C. Vacuum dry the mixture to yield 12g of solid. See Table 1 for the catalyst composition.

[0119] The polymerization method was the same as in Example 1. The polymerization results are shown in Table 2.

[0120] Comparative Example 3

[0121] 1. Preparation of catalyst components:

[0122] In a 500ml, nitrogen-purged, stirred, five-necked flask, add 28ml of decane, 4.76g of ground magnesium chloride, and 16.3g of isooctyl alcohol dropwise. The mixture is then heated to 130°C and held at this temperature for 3 hours. The temperature is then lowered to 50°C, and 3.1g of dehydrated and deoxygenated tetraethoxysilane is added, followed by stirring for 2 hours. The temperature is then lowered to 30°C. The above magnesium chloride alcohol solution is slowly added dropwise to 200ml of TiCl₄ solution over 2 hours. The temperature is then raised to 110°C and held at this temperature for 2 hours. The solid is then separated and the resulting solid is washed twice with 100ml of decane at 110°C and four times with 100ml of hexane at 60°C. After vacuum drying, 6.4g of solid is obtained. The catalyst composition is shown in Table 1.

[0123] The polymerization method was the same as in Example 1. The polymerization results are shown in Table 2.

[0124] Comparative Example 4

[0125] 1. Preparation of Catalyst Components: Same as Comparative Example 2, except that after washing four times with hexane at 60°C, 100 ml of decane was added, the temperature was lowered to 0°C, and 21.9 ml of a 2 mol / L diethylaluminum monochloride hexane solution was slowly added dropwise. After addition, the temperature was uniformly raised to 100°C and held at this temperature for 1 hour. The mixture was allowed to settle, filtered, and dried under vacuum to obtain 13.8 g of a solid.

[0126] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0127] Comparative Example 5

[0128] 1. Preparation of Catalyst Components: Same as Comparative Example 3, except that after washing four times with hexane at 60°C, 100 ml of decane was added, the temperature was lowered to 0°C, and 12.5 ml of a 2 mol / L diethylaluminum monochloride hexane solution was slowly added dropwise. After addition, the temperature was uniformly raised to 100°C and held at this temperature for 1 hour. The mixture was allowed to settle, filtered, and dried under vacuum to obtain 6.7 g of a solid.

[0129] 2. Polymerization: Same as Example 1. The polymerization results are shown in Table 2.

[0130] Comparative Example 6

[0131] 1. Preparation of catalyst components: same as Comparative Example 1.

[0132] 2. Polymerization: Same as Example 8. The polymerization results are shown in Table 2.

[0133] Comparative Example 7

[0134] 3. Preparation of catalyst components: same as Comparative Example 2.

[0135] 4. Polymerization: Same as Example 8. The polymerization results are shown in Table 2.

[0136] Comparative Example 8

[0137] 1. Preparation of catalyst components: same as Comparative Example 3.

[0138] 2. Polymerization: Same as Example 8. The polymerization results are shown in Table 2.

[0139] Table 1 Catalyst composition and particle size distribution

[0140]

[0141] It can be seen from Table 1 that in the solid catalyst component prepared by the present invention, the titanium main body is still +4 valence, and the catalyst particles are concentratedly distributed.

[0142] As can be seen from Table 2, the solid catalyst component prepared by the present invention has the characteristics of high activity and high bulk density in conventional polymerization, and has high activity and high bulk density in conventional polymerization under high hydrogenation polymerization conditions (P 氢气 :P 乙烯=0.48MPa:0.25MPa), it has the characteristics of high MI, high bulk density, high activity, and less polymer fine powder.

[0143]

[0144] As can be seen from Table 2, the solid catalyst component prepared by the present invention has the characteristics of high activity and high bulk density in conventional polymerization, and has high activity and high bulk density in conventional polymerization under high hydrogenation polymerization conditions (P 氢气 :P 乙烯 =0.48MPa:0.25MPa), it has the characteristics of high MI, high bulk density, high activity, and less polymer fine powder.

[0145] Table 3 Comparison of specific surface area performance of support, support after organoaluminum treatment and final catalyst

[0146]

[0147] As can be seen from Table 3, the specific surface areas of the ethoxy magnesium support, the ethoxy magnesium support after organoaluminum treatment, and the final catalyst were tested. After the treatment with organoaluminum compounds, the specific surface area of ​​the ethoxy magnesium support increased from 7.396 m 2 / g increases to 22~30m 2 / g, the specific surface area increases and the pore size increases at the same time, and an aluminum-containing porous carrier structure is initially formed.

[0148] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

[0149] The terms used herein are intended only to illustrate specific embodiments and are not intended to limit the present invention. Unless otherwise defined, all terms used herein (including technical and scientific terms) are the same as those understood by those skilled in the art to which the present invention pertains. It should also be understood that, unless otherwise clearly defined herein, terms commonly 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 in an idealized or overly formalized manner.

Claims

1. A catalyst component for ethylene polymerization or copolymerization based on an alkoxymagnesium support, which is a solid material containing titanium, magnesium and aluminum, and is prepared by the following method: 1) dispersing an alkoxy magnesium support in an inert solvent and adding at least one organoaluminum compound for activation treatment; the amount of each reactant is calculated per mole of magnesium, and the organoaluminum compound is 0.1 to 20 moles; the general formula of the alkoxy magnesium 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, a+b=2; the organoaluminum compound is selected from at least one of alkylaluminum, alkylaluminum halide, alkoxyaluminum halide, and alkoxyaluminum; 2) Then, the titanium compound is treated with titanium; the general formula of the titanium compound is TiX 2 m (OR 5 ) 4-m , where R 5 C1~C 20 The hydrocarbon group, X 2 is a halogen, and m is an integer from 0 to 4; 3) Finally, the product is filtered, washed and dried.

2. The catalyst component for ethylene polymerization or copolymerization according to claim 1, characterized in that The amount of each reactant used is calculated per mole of magnesium, and the organic aluminum compound is 0.1 to 5 moles.

3. The catalyst component for ethylene polymerization or copolymerization according to claim 1, characterized in that The amount of each reactant used is calculated per mole of magnesium, and the titanium compound is 0.1 to 20 moles.

4. The catalyst component for ethylene polymerization or copolymerization according to claim 3, characterized in that The amount of each reactant used is calculated per mole of magnesium, and the titanium compound is 0.1 to 5 moles.

5. The catalyst component for ethylene polymerization or copolymerization according to any one of claims 1 to 4, characterized in that The alkoxymagnesium is selected from dimethoxymagnesium, diethoxymagnesium, di-n-propoxymagnesium, diisopropoxymagnesium, di-n-butoxymagnesium, diisobutoxymagnesium, methoxyethoxymagnesium, methoxypropoxymagnesium, ethoxy-n-propoxymagnesium, ethoxyisopropoxymagnesium, ethoxy-n-butoxymagnesium, and ethoxyisobutoxymagnesium.

6. The catalyst component for ethylene polymerization or copolymerization according to claim 5, characterized in that The alkoxymagnesium is selected from diethoxymagnesium, di-n-propoxymagnesium, diisopropoxymagnesium, and di-n-butoxymagnesium.

7. The catalyst component for ethylene polymerization or copolymerization according to claim 6, characterized in that The alkoxy magnesium is diethoxy magnesium.

8. The catalyst component for ethylene polymerization or copolymerization according to claim 1, characterized in that The organoaluminum compound is selected from at least one of alkylaluminum halides, alkoxyaluminum halides, and alkoxyaluminum.

9. The catalyst component for ethylene polymerization or copolymerization according to claim 8, characterized in that The organoaluminum compound is an aluminum alkoxide.

10. The catalyst component for ethylene polymerization or copolymerization according to claim 1, characterized in that The alkyl aluminum compound is triethylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum or tri-n-octylaluminum; the alkyl aluminum halide compound is diethylaluminum monochloride, ethylaluminum dichloride or ethylaluminum sesquichloride; the alkoxyaluminum halide is diethoxyaluminum chloride or ethoxyaluminum dichloride; the alkoxyaluminum is aluminum triethoxide, aluminum tri-n-propoxide, aluminum triisopropoxide, aluminum tri-n-butoxide, aluminum triisobutoxide or aluminum tri-tert-butoxide.

11. The catalyst component for ethylene polymerization or copolymerization according to claim 1, characterized in that: The titanium compounds include titanium halides, titanium alkoxide halides and titanium alkoxides.

12. The catalyst component for ethylene polymerization or copolymerization according to claim 11, characterized in that: The titanium compound is titanium halide or alkoxy titanium halide.

13. The catalyst component for ethylene polymerization or copolymerization according to claim 12, characterized in that: The titanium compound is titanium halide.

14. The catalyst component for ethylene polymerization or copolymerization according to claim 11, characterized in that: The titanium halide is titanium tetrachloride, titanium tetrabromide or titanium tetraiodide, the alkoxy titanium halide is methoxytitanium trichloride, ethoxytitanium trichloride, propoxytitanium trichloride, n-butoxytitanium trichloride, dimethoxytitanium dichloride, diethoxytitanium dichloride, dipropoxytitanium dichloride, di-n-butoxytitanium dichloride, trimethoxytitanium chloride, triethoxytitanium chloride, tripropoxytitanium chloride or tri-n-butoxytitanium chloride, and the alkoxy titanium is tetraethoxytitanium, tetrapropoxytitanium or tetrabutoxytitanium.

15. The method for preparing a catalyst component for ethylene polymerization or copolymerization according to any one of claims 1 to 14, characterized in that: It includes the following steps: 1) dispersing the alkoxy magnesium support in an inert solvent and adding at least one organoaluminum compound for activation treatment; 2) then treated with titanium compound for titanium loading; 3) Finally, the product is filtered, washed and dried.

16. The method for preparing a catalyst component for ethylene polymerization or copolymerization according to claim 15, characterized in that: The reaction temperature in step 1) is 10-150°C; the reaction temperature in step 2) is 50-150°C.

17. 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 14; b) a general formula of AlR 6 n X 3 3-n An organoaluminum compound, 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.

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