Solid catalyst component for the polymerization of olefins, catalyst and preparation process and use

Abstract

This invention discloses a solid catalyst component for olefin polymerization, its preparation method, the catalyst itself, and its applications. The solid catalyst component comprises the reaction products of the following components: 1) an alkoxymagnesium compound; 2) a magnesium-containing composite solution; 3) a titanium-containing compound; and 4) an electron-donating compound. This invention also provides a catalyst comprising the above-mentioned catalyst components. The alkoxymagnesium catalyst of this invention exhibits high mechanical strength, adjustable particle size, narrow particle size distribution, high catalytic activity, and good hydrogen sensitivity. Compared with other methods, the preparation method of this invention is simple to operate, highly adjustable, and has greater application prospects.

Description

Technical Field

[0001] This invention relates to the field of olefin polymerization technology, and more specifically, to a solid catalyst component, catalyst, preparation method, and application for olefin polymerization. Background Technology

[0002] Polyolefins, as one of the world's largest industries, play a vital role in various fields of defense technology and people's lives. Ziegler-Natta catalysts are currently the most widely used catalysts in the polyolefin industry. Since their inception in the 1950s, they have undergone years of improvement by researchers and have formed a mature industrial system. They mainly consist of TiCl4 supported on MgCl2 and Lewis basic compounds. Currently, most industrial catalysts are synthesized using two main methods: one is the direct dissolution method using titanium supported on MgCl2, and the other is a chemical reaction method using magnesium ethoxylate as a precursor. The latter uses magnesium ethoxylate as a support, reacting with TiCl4 to convert magnesium ethoxylate to MgCl2 while simultaneously supporting titanium. Due to its excellent hydrogen regulation properties and particle morphology, it occupies an important position in the field of polyolefin catalysis.

[0003] However, the alkoxymagnesium catalysts currently used in slurry polyethylene plants have limitations when applied to ethylene polymerization. The hydrogen-modified properties make it difficult to control the performance of the secondary reaction products, resulting in powder products with numerous crystal points and fisheyes. Several methods for preparing alkoxymagnesium have been disclosed in the prior art. Patents such as US3644318A and CN101120025 disclose a method for preparing alkoxymagnesium catalysts using a pulverized and titanium-supported method. However, when used in ethylene polymerization, this catalyst produces a large amount of fine powder that is easily broken. CN108690152A proposes a method for preparing alkoxymagnesium microspheres by spray drying. Alkoxymagnesium solid powder is mixed with ethanol, ground in a ball mill, and then treated with a high-speed disperser for a period of time to form a gel-like dispersion. This dispersion is then spray-dried to obtain small-diameter alkoxymagnesium microspheres. However, this method has a low yield and the grinding process damages some active centers, reducing the activity of the resulting catalyst. CN102482371A proposes a pre-polymerization method, using a polyethylene film produced by pre-polymerization to encapsulate the catalyst and reduce breakage.

[0004] Currently, there are various methods for improving alkoxy magnesium catalysts, but their effects are relatively limited. In particular, the removal of alkoxy groups during the titanium chlorination process on alkoxy magnesium supports leads to a large number of micropores inside the catalyst, resulting in poor mechanical properties. Therefore, it is of great significance to develop an alkoxy magnesium catalyst with high mechanical strength and excellent particle morphology. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides an alkoxymagnesium catalyst component for olefin polymerization, its preparation method, the catalyst itself, and its applications. The alkoxymagnesium catalyst support particles obtained by this invention have excellent morphology, suitable particle size, and uniform particle distribution. The size is controllable, the catalyst exhibits high activity, high mechanical strength, and good hydrogen sensitivity, making it suitable for olefin polymerization.

[0006] One object of the present invention is to provide a solid catalyst composition for olefin polymerization, comprising the reaction product of the following components:

[0007] 1) Alkoxymagnesium compounds;

[0008] 2) Magnesium-containing composite solution;

[0009] 3) Titanium-containing compounds;

[0010] 4) Electron-donating compounds.

[0011] The alkoxymagnesium compound has the general formula Mg(OR) 4 ) n (OR 5 ) 2-n Where 0≤n≤2, R 4 and R 5 Whether they are the same or different, they are independently classified as C1 to C2. 20 The hydrocarbon group, preferably C1 to C2, is preferred. 20 The alkyl or aromatic group is more preferably derived from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, 2-ethylbutyl, 2-ethylhexyl, 4-methylsec-pentyl, 3,3,5-trimethylpentyl, 1-ethyl-2-methylpentyl, benzyl, 2-phenylethyl, or 1-phenylpropyl, more preferably from ethyl or isooctyl. Further preferably, the alkoxymagnesium compound is at least one selected from dimethoxymagnesium, diethoxymagnesium, dipropoxymagnesium, dibutoxymagnesium, ethoxypropoxymagnesium, or butoxyethoxymagnesium; most preferably, the alkoxymagnesium compound is diethoxymagnesium or dipropoxymagnesium.

[0012] The general formula of the titanium-containing compound is Ti(OR). a X b Where R is C1 to C 10 The compound contains an aliphatic or aromatic hydrocarbon group, where X is a halogen, preferably fluorine, chlorine, or bromine, a is an integer from 0 to 4, b is an integer from 0 to 4, and a + b = 3 or 4. Specifically, the titanium-containing compound can be at least one of titanium tetrachloride, titanium tetrabromide, titanium tetraethoxy, titanium monochlorotriethoxy, titanium trichloride, titanium dichlorodiethoxy, or titanium trichloromonoethoxy.

[0013] The electron-donating compound is selected from at least one of the following: alkyl esters of aliphatic monocarboxylic acids, alkyl esters of aromatic monocarboxylic acids, alkyl esters of aliphatic polycarboxylic acids, alkyl esters of aromatic polycarboxylic acids, aliphatic ethers, cyclic aliphatic ethers, and aliphatic ketones, preferably at least one of the following: alkyl esters of C1-C4 saturated aliphatic carboxylic acids, alkyl esters of C7-C8 aromatic carboxylic acids, C2-C6 aliphatic ethers, C3-C4 cyclic ethers, and C3-C6 saturated aliphatic ketones.

[0014] In a specific example, the electron donor compound is selected from at least one of methyl formate, ethyl acetate, butyl acetate, ethyl benzoate, diisobutyl phthalate, di-n-butyl phthalate, diisooctyl phthalate, 1,3-dipentyl phthalate, diethyl ether, hexyl ether, tetrahydrofuran (THF), acetone, or methyl isobutyl ketone, preferably from at least one of ethyl benzoate, di-n-butyl phthalate, diisobutyl phthalate, or 1,3-dipentyl phthalate.

[0015] The magnesium-containing composite solution is any one of the following mixtures:

[0016] Mixture 1: A mixture of magnesium halide, alcohols, silicon compounds, and solvents;

[0017] Mixture 2: A mixture of magnesium halide, organic epoxy compounds, organophosphorus compounds, alcohols, and solvents;

[0018] Mixture 3: A mixture of magnesium halide, organic epoxy compounds, organophosphorus compounds, organic acid anhydrides, and solvents;

[0019] Mixture 4: A mixture of magnesium halide solution, organic epoxy compound, organophosphorus compound and solvent.

[0020] All of the substances mentioned above can be conventional substances in this field.

[0021] The magnesium halide is selected from at least one of magnesium dihalides, complexes of magnesium dihalides with water or alcohol, and derivatives of magnesium dihalides in which one or two halogen atoms are replaced by alkyl halides. Preferably, the magnesium halide is at least one of magnesium dichloride, magnesium dibromide, magnesium diiodide, magnesium phenoxychloride, magnesium isopropoxychloride, or magnesium butoxychloride.

[0022] The alcohol compounds are selected from C1 to C2. 18 fatty alcohols, C6-C 18 At least one of the aromatic alcohols. The alcohol compound is preferably at least one of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tert-butanol, hexanol, cyclohexanol, octanol, isooctanol, benzyl alcohol, phenethyl alcohol, ethylene glycol, propylene glycol, butanediol, hexanediol, or isohexanediol.

[0023] The general formula of the silicon compound is R 1 x R 2 y Si(OR 3 ) z , where R 1 and R 2 They are C1 to C1 respectively. 10 Hydrocarbon group or halogen, preferably C1 to C2. 10 Alkyl or halogen, R 3 For C1~C 10 The hydrocarbon group, preferably C1 to C2, is preferred. 10 The alkyl or halogen, 0≤x≤2, 0≤y≤2 and 0≤z≤4, and x+y+z=4. The silicon compound is preferably at least one of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, or tetra(2-ethylhexyloxy)silane.

[0024] The organic epoxy compound is selected from at least one of the following: oxides of C2-C8 aliphatic olefins, oxides of C2-C8 aliphatic dienes, oxides of C2-C8 halogenated aliphatic olefins, oxides of C2-C8 halogenated aliphatic dienes, glycidyl ethers, and internal ethers. Preferably, the organic epoxy compound can be at least one of the following: ethylene oxide, propylene oxide, butane oxide, butadiene oxide, butadiene dioxide, epichlorohydrin, glycidyl methacrylate, methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, or diglycidyl ether.

[0025] The organophosphorus compound is selected from at least one of the following: a hydrocarbon ester of orthophosphoric acid, a hydrocarbon ester of phosphorous acid, a halohydrocarbon ester of orthophosphoric acid, and a halohydrocarbon ester of phosphorous acid. Preferably, the organophosphorus compound is at least one of the following: trimethyl orthophosphoric acid, triethyl orthophosphoric acid, tributyl orthophosphoric acid, triphenyl orthophosphoric acid, trimethyl orthophosphoric acid, triethyl orthophosphoric acid, tributyl orthophosphoric acid, or triphenyl orthophosphoric acid.

[0026] The solvent is selected from at least one of aromatic compounds and alkane compounds. The aromatic compounds are preferably benzene, toluene, xylene, monochlorobenzene, dichlorobenzene, monochlorotoluene, and their derivatives; the alkane compounds are one or a mixture of straight-chain alkanes, branched alkanes, or cycloalkanes with 3 to 20 carbon atoms, such as butane, pentane, hexane, cyclohexane, heptane, etc., as long as they facilitate the dispersion of magnesium halides and alkoxymagnesium. The above solvents can be used alone or in combination.

[0027] In the mixture 1, per mole of magnesium halide, the amount of alcohol is 0.5–20 mol, the amount of silicon compound is 0.01–10 mol, and the amount of solvent is 0.1–10 L. Preferably, the amount of alcohol is 1–10 mol, the amount of silicon compound is 0.1–3 mol, and the amount of solvent is 0.3–1 L. Specifically, the amount of alcohol can be 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 15 mol, 20 mol, etc., and the amount of silicon compound can be 0.01 mol, 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 10 mol, etc.

[0028] In the mixture 2, per mole of magnesium halide, the amount of organic epoxy compound is 0.1–10 mol, the amount of organic phosphorus compound is 0.1–10 mol, the amount of alcohol compound is 0.4–10 mol, and the amount of solvent is 0.2–10 L. Preferably, the amount of organic epoxy compound is 0.3–3 mol, the amount of organic phosphorus compound is 0.2–3 mol, the amount of alcohol compound is 1–5 mol, and the amount of solvent is 0.5–5 L. Specifically, the amount of organic epoxy compound can be 0.1 mol, 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 10 mol, etc., the amount of organic phosphorus compound can be 0.1 mol, 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 10 mol, etc., and the amount of alcohol compound can be 0.4 mol, 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 10 mol, etc.

[0029] In the mixture 3, per mole of magnesium halide, the organic epoxy compound is 0.2–10 mol, the organophosphorus compound is 0.2–10 mol, the organic anhydride is 0.03–1 mol, and the solvent volume is 0.2–10 L. Preferably, the organic epoxy compound is 0.5–5 mol, the organophosphorus compound is 0.5–5 mol, the organic anhydride is 0.07–0.5 mol, and the solvent volume is 0.5–5 L. Specifically, the amount of organic epoxy compound can be 0.2 mol, 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 10 mol, etc., the amount of organophosphorus compound can be 0.2 mol, 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 10 mol, etc., and the amount of organic anhydride can be 0.03 mol, 0.05 mol, 0.07 mol, 0.1 mol, 0.3 mol, 0.5 mol, 0.7 mol, 1 mol, etc.

[0030] In the mixture 4, per mole of magnesium halide, the organic epoxy compound is 0.1–10 mol, the organophosphorus compound is 0.1–10 mol, and the solvent volume is 0.2–10 L. Preferably, the organic epoxy compound is 0.5–5 mol, the organophosphorus compound is 0.5–5 mol, and the solvent volume is 0.5–5 L. Specifically, the amount of organic epoxy compound can be 0.1 mol, 0.2 mol, 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 10 mol, etc., and the amount of organophosphorus compound can be 0.1 mol, 0.2 mol, 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 10 mol, etc.

[0031] The magnesium-containing composite solution is a homogeneous and transparent solution formed by dissolving magnesium halide in organic components.

[0032] The magnesium-containing composite solution can be prepared using conventional methods in the art. For example, the magnesium-containing composite solution can be prepared using any of the following methods:

[0033] Method 1: Dissolve magnesium halide in an alcohol solvent system, add silicon compound to the system to react and form a homogeneous solution, and obtain mixture 1.

[0034] Method 2: Dissolve magnesium halide in a solvent system containing organic epoxy compounds, organophosphorus compounds and alcohols to form a homogeneous solution, and obtain mixture 2.

[0035] Method 3: After dissolving magnesium halide in a solvent system containing organic epoxy compounds and organic phosphorus compounds and reacting fully, organic acid anhydrides are introduced into the solution to form a homogeneous solution, resulting in mixture 3.

[0036] Method 4: Dissolve magnesium halide in a solvent system containing organic epoxy compounds and organophosphorus compounds to form a homogeneous solution, and obtain mixture 4.

[0037] The above methods for preparing magnesium-containing composite solutions are illustrative examples of the present invention, but the present invention is not limited to these methods. The substances, amounts, and parameters used in the above methods can be set with reference to existing technologies, and are not specifically limited here. For example:

[0038] In Method 1, the dissolution temperature is 100–145℃ and the reaction time is 2–4 hours; the temperature when adding the silicon compound is 40–60℃ and the reaction time is 1–3 hours.

[0039] In Method 2, the dissolution temperature is 50–80℃ and the time is 1–3 hours.

[0040] In Method 3, the dissolution temperature is 50–80℃ and the time is 1–3 hours; organic acid anhydrides are introduced at the dissolution temperature and the reaction time is 0.5–2 hours.

[0041] In Method 4, the dissolution temperature is 50–80℃ and the time is 1–3 hours.

[0042] In the solid catalyst component, based on the amount of magnesium-containing composite solution (based on magnesium atoms) per mole of alkoxymagnesium compound, the amount is 0.01–10 mol, preferably 0.1–5 mol; the amount of titanium-containing compound is 1–100 mol, preferably 3–60 mol; and the amount of electron-donating compound is 0.01–10 mol, preferably 0.1–5 mol.

[0043] Specifically, the amount of magnesium-containing composite solution can be 0.01 mol, 0.05 mol, 0.1 mol, 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 10 mol, etc., the amount of titanium-containing compound can be 1 mol, 3 mol, 5 mol, 10 mol, 20 mol, 30 mol, 40 mol, 50 mol, 60 mol, 70 mol, 80 mol, 90 mol, 100 mol, etc., and the amount of electron-donating compound can be 0.01 mol, 0.05 mol, 0.1 mol, 0.5 mol, 1 mol, 3 mol, 5 mol, 7 mol, 10 mol, etc.

[0044] A second objective of this invention is to provide a method for preparing the aforementioned solid catalyst component for olefin polymerization, which includes two methods, method M and method N, as described below.

[0045] Method M includes the following steps:

[0046] Step 1) Disperse the alkoxymagnesium compound in a magnesium-containing composite solution to form a suspension;

[0047] Step 2) The suspension obtained in Step 1) is reacted with titanium-containing compounds and / or electron-donating compounds at low temperature. During the gradual heating process, magnesium / titanium / halogen solid particles are gradually precipitated on the surface of the chlorinated alkoxy magnesium catalyst particles.

[0048] The method M further includes step 3) removing unreacted substances and solvent from the mixture obtained in step 2), washing it with an inert solvent to obtain the solid catalyst component.

[0049] In step 2) of method M of the present invention, a titanium-containing compound and / or an electron donor compound are added to the suspension at -60℃ to 0℃ and reacted for 1 to 3 hours, with the temperature raised to 75℃ to 110℃ and held at that temperature for 0.5 to 2 hours.

[0050] Method N includes the following steps:

[0051] Step 1) The alkoxymagnesium compound is reacted with the titanium-containing compound to form a suspension;

[0052] Step 2) The suspension obtained in Step 1) is reacted with a magnesium-containing composite solution and / or an electron donor compound at low temperature. During the gradual heating process, magnesium / titanium / halogen solid particles are gradually precipitated on the surface of the chlorinated alkoxy magnesium catalyst particles.

[0053] The method N further includes step 3) removing unreacted substances and solvent from the mixture obtained in step 2), washing it with an inert solvent to obtain the solid catalyst component.

[0054] In step 1) of method N of the present invention, a titanium-containing compound is added to the alkoxymagnesium compound at -60℃ to 0℃ and reacted for 1 to 3 hours, or a titanium-containing compound at -60℃ to 0℃ is added to the alkoxymagnesium compound at room temperature and reacted for 1 to 3 hours; in step 2), the heating temperature is 75℃ to 130℃ and the temperature is kept constant for 0.5 to 2 hours.

[0055] The inert solvent can be saturated aliphatic or aromatic hydrocarbons such as isobutane, hexane, heptane, cyclohexane, naphtha, raffinate, hydrogenated gasoline, kerosene, benzene, toluene, and xylene, preferably toluene, n-hexane, or cyclohexane.

[0056] According to the present invention, "aliphatic hydrocarbon group" refers to a straight-chain or branched chain hydrocarbon group composed only of carbon and hydrogen atoms. Specific examples include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, vinyl, 1-propenyl, allyl, ethynyl, 1-propynyl, 2-propynyl, butynyl, etc. "Aromatic hydrocarbon group" refers to a hydrocarbon group having a benzene ring, including aryl, aryl-substituted hydrocarbon groups, or hydrocarbon-substituted aryl groups, such as phenyl, benzyl, anthracene, and naphthyl, etc.

[0057] A third objective of this invention is to provide a catalyst for olefin polymerization, the catalyst comprising the following components:

[0058] (1) The solid catalyst components described above or the solid catalyst components prepared by the above preparation method;

[0059] (2) The general formula is AlR' p X 3-p Organoaluminum compounds, wherein R' is hydrogen or C1-C2. 20 Hydrocarbon group, where X is a halogen atom, preferably fluorine, chlorine or bromine, 0 < p ≤ 3.

[0060] In this invention, the organoaluminum compound can be at least one of Al(CH3)3, Al(CH2CH3)3, Al(i-Bu)3, AlH(CH2CH3)2, AlH(i-Bu)2, AlCl(CH2CH3)2, Al2Cl3(CH2CH3)3, or AlCl2(CH2CH3), preferably at least one of Al(CH2CH3)3 and Al(i-Bu)3.

[0061] According to the present invention, the molar ratio of the organoaluminum compound in the component to the titanium in the solid catalyst component can be (5-500):1, preferably (20-200):1, and more preferably (50-100):1.

[0062] The fourth objective of this invention is to provide the application of the above-mentioned solid catalyst components, the solid catalyst components prepared by the above-mentioned preparation method, or the above-mentioned catalysts in olefin polymerization.

[0063] The olefin polymerization according to the present invention may include homopolymerization of olefins and copolymerization with α-olefins. Specific examples of olefins include: ethylene, propylene, butene, pentene, hexene, octene, 4-methyl-1-pentene, etc.

[0064] The olefin polymerization method according to the present invention does not particularly limit the polymerization conditions of the olefins. Polymerization conditions known to those skilled in the art of olefin polymerization can be used.

[0065] Preferably, the olefin polymerization is ethylene polymerization, which can be carried out using liquid-phase polymerization or gas-phase polymerization. Liquid-phase polymerization media include inert solvents such as isobutane, hexane, heptane, cyclohexane, naphtha, raffinate, hydrogenated gasoline, kerosene, benzene, toluene, xylene, and other saturated aliphatic or aromatic hydrocarbons. Hydrogen can be used as a molecular weight regulator to adjust the molecular weight of the final polymer.

[0066] The substances and parameters not limited in this invention can be selected according to existing technology, which is a conventional technical means in this field.

[0067] The beneficial effects of this invention are:

[0068] The solid catalyst components of this invention exhibit high mechanical strength, adjustable particle size, and narrow particle size distribution. The catalyst used for olefin polymerization demonstrates high catalytic activity and good hydrogen sensitivity.

[0069] Compared with other methods, the preparation method of the present invention is simple to operate, highly adjustable, and has greater application prospects. Detailed Implementation

[0070] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0071] Furthermore, various embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention. The resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0072] Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0073] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0074] In the following examples and comparative examples, the data were obtained using the following test methods:

[0075] 1. Particle size distribution of catalyst components: determined using a Malvern laser particle size and shape analyzer.

[0076] 2. The relative weight percentage of titanium in the catalyst component was determined by spectrophotometry.

[0077] 3. Melt index of polymer (MI / 2.16Kg): determined according to ASTM D1238-99.

[0078] Preparation Example 1

[0079] 4.0 g magnesium chloride, 50 mL toluene, 3.0 mL epichlorohydrin, 9 mL tri-n-butyl phosphate and 4.4 mL ethanol were added to a reaction vessel and reacted at a constant temperature of 70 °C for 2 hours. The mixture was then cooled to room temperature to obtain magnesium-containing composite solution B1.

[0080] Preparation Example 2

[0081] 4.0 g magnesium chloride, 90 mL toluene, 8.0 mL epichlorohydrin, and 16.0 mL tri-n-butyl phosphate were added to a reaction vessel. The mixture was stirred at 450 rpm and at 60 °C for 2 hours. Then, 3 g phthalic anhydride was added, and the mixture was kept at a constant temperature for another hour before being cooled to room temperature to obtain magnesium-containing composite solution B2.

[0082] Preparation Example 3

[0083] 4.0 g magnesium chloride, 100 mL toluene, 6.0 mL epichlorohydrin and 12 mL triisobutyl phosphate were added to a reaction vessel. After reacting for 2 hours at a stirring speed of 450 rpm and a temperature of 60 °C, the mixture was cooled to room temperature to obtain magnesium-containing composite solution B3.

[0084] Preparation Example 4

[0085] 4.0 g of magnesium chloride, 30 mL of decane, and 20 mL of isooctanol were added to a reaction vessel and reacted for 3 hours at a stirring rate of 300 rpm and a temperature of 130 °C. The system was then cooled to 50 °C, and 3.5 mL of tetraethoxysilane was added, followed by stirring for another 2 hours. The system was then cooled to room temperature to obtain magnesium-containing composite solution B4.

[0086] Example 1

[0087] (1) Preparation of catalyst component 1

[0088] Magnesium-containing composite solution B1 (42 mmol based on magnesium atoms) was cooled to -10°C, and 4.0 g of magnesium diethoxy support (~8 μm) was added. 70 mL of titanium tetrachloride was slowly added dropwise, followed by 3 mL of ethyl benzoate. The temperature was gradually increased to 85°C and held at this temperature for 1 hour. Stirring was stopped, and the solution was allowed to stand. The suspension quickly separated into layers. The supernatant was removed, and the solution was washed four times with hexane. The solution was dried under high-purity nitrogen to obtain solid catalyst component 1 with good flowability.

[0089] (2) Polymerization reaction

[0090] Polymerization with low hydrogen-to-ethylene ratio: A 2L stainless steel reactor was fully purged with high-purity nitrogen, then 1L of hexane and 1.0mL of 1M triethylaluminum were added, followed by catalyst component 1 prepared by the above method. The temperature was raised to 75℃, and hydrogen was introduced to bring the pressure inside the reactor to 0.28MPa (gauge pressure). Ethylene was then introduced to bring the total pressure inside the reactor to 1.03MPa. Polymerization was carried out at 85℃ for 2 hours. The polymerization results are shown in Tables 1 and 2.

[0091] Polymerization with a high hydrogen-to-ethylene ratio: A 2L stainless steel reactor was fully purged with high-purity nitrogen, then 1L of hexane and 1.0mL of 1M triethylaluminum were added, followed by catalyst component 1 prepared by the above method. The temperature was raised to 75℃, and hydrogen was introduced to bring the pressure inside the reactor to 0.68MPa (gauge pressure). Ethylene was then introduced to bring the total pressure inside the reactor to 1.03MPa. Polymerization was carried out at 85℃ for 2 hours. The polymerization results are shown in Tables 1 and 2.

[0092] Example 2

[0093] (1) Preparation of catalyst component 2

[0094] Same as in Example 1, using a ~30μm alkoxy magnesium support, catalyst component 2 was obtained.

[0095] (2) Polymerization reaction: Same as in Example 1, but using catalyst component 2. The polymerization results are shown in Table 1 and Table 2.

[0096] Example 3

[0097] (1) Preparation of catalyst component 3

[0098] Magnesium-containing composite solution B2 (42 mmol based on magnesium atoms) was cooled to -40°C, and 4.0 g of alkoxymagnesium support (~8 μm) was added. 70 mL of titanium tetrachloride was slowly added dropwise, followed by 3 mL of ethyl benzoate. The temperature was gradually increased to 85°C and held at this temperature for 1 hour. Stirring was stopped, and the solution was allowed to stand. The suspension quickly separated into layers. The supernatant was removed, and the solution was washed repeatedly with toluene and hexane. The solution was dried under high-purity nitrogen to obtain solid catalyst component 3 with good flowability.

[0099] (2) Polymerization reaction: Same as in Example 1, using catalyst component 3. The polymerization results are shown in Table 1 and Table 2.

[0100] Example 4

[0101] (1) Preparation of catalyst component 4

[0102] Same as in Example 3, using a ~30μm alkoxy magnesium support, catalyst component 4 was obtained.

[0103] (2) Polymerization reaction: Same as in Example 1, using catalyst component 4. The polymerization results are shown in Table 1 and Table 2.

[0104] Example 5

[0105] (1) Preparation of catalyst component 5

[0106] Magnesium-containing composite solution B3 (42 mmol based on magnesium atoms) was cooled to -40°C, and 4.0 g of alkoxymagnesium support (~8 μm) was added. 70 mL of titanium tetrachloride was slowly added dropwise, followed by 3 mL of ethyl benzoate. The temperature was gradually increased to 85°C and held at this temperature for 1 hour. Stirring was stopped, and the solution was allowed to stand. The suspension quickly separated into layers. The supernatant was removed, and the solution was washed repeatedly with toluene and hexane. The solution was dried under high-purity nitrogen to obtain solid catalyst component 5 with good flowability.

[0107] (2) Polymerization reaction: Same as in Example 1, using catalyst component 5. The polymerization results are shown in Table 1 and Table 2.

[0108] Example 6

[0109] (1) Preparation of catalyst component 6

[0110] Same as in Example 5, using a ~30 μm alkoxy magnesium support, catalyst component 6 was obtained.

[0111] (2) Polymerization reaction: Same as in Example 1, using catalyst component 6. The polymerization results are shown in Table 1 and Table 2.

[0112] Example 7

[0113] (1) Preparation of catalyst component 7

[0114] 4.0 g of alkoxymagnesium support (42 mmol based on magnesium atoms) (~8 μm) was added to 200 mL of titanium tetrachloride at 0 °C, followed by 3 mL of ethyl benzoate. After reacting for 1 hour, magnesium-containing composite solution B4 was slowly added dropwise, and the mixture was kept at the same temperature for 1 hour after the addition was complete. The system was then gradually heated to 110 °C and kept at that temperature for 1 hour. Stirring was stopped, and the mixture was allowed to stand. The suspension quickly separated into layers. The supernatant was removed, and the mixture was washed repeatedly with toluene and hexane. The mixture was dried under high-purity nitrogen to obtain solid catalyst component 7 with good flowability.

[0115] (2) Polymerization reaction: Same as in Example 1, using catalyst component 7. The polymerization results are shown in Table 1 and Table 2.

[0116] Example 8

[0117] (1) Preparation of catalyst component 8

[0118] Same as in Example 7, using a ~20 μm alkoxy magnesium support, catalyst component 8 was obtained.

[0119] (2) Polymerization reaction: Same as in Example 1, using catalyst component 8. The polymerization results are shown in Table 1 and Table 2.

[0120] Example 9

[0121] (1) Preparation of catalyst component 9

[0122] Same as in Example 7, using a ~30 μm alkoxy magnesium support, catalyst component 9 was obtained.

[0123] (2) Polymerization reaction: Same as in Example 1, using catalyst component 9. The polymerization results are shown in Table 1 and Table 2.

[0124] Comparative Example 1

[0125] (1) Preparation of catalyst component D1

[0126] The magnesium-containing composite solution B1 (42 mmol based on magnesium atoms) was cooled to -10°C, and 70 mL of titanium tetrachloride was slowly added dropwise, followed by 3 mL of ethyl benzoate. The temperature was gradually increased to 85°C and held at this temperature for 1 hour. Stirring was stopped, and the solution was allowed to stand. The suspension quickly separated into layers. The supernatant was removed, and the solution was washed four times with hexane. The solution was then dried under high-purity nitrogen to obtain the free-flowing solid catalyst component D1.

[0127] (3) Polymerization reaction: Same as in Example 1, using catalyst component D1. The polymerization results are shown in Table 1 and Table 2.

[0128] Comparative Example 2

[0129] (1) Preparation of catalyst component D2

[0130] The magnesium-containing composite solution B2 (42 mmol based on magnesium atoms) was cooled to -40°C, and 70 mL of titanium tetrachloride was slowly added dropwise, followed by 3 mL of ethyl benzoate. The temperature was gradually increased to 85°C and held at this temperature for 1 hour. Stirring was stopped, and the solution was allowed to stand. The suspension quickly separated into layers. The supernatant was removed, and the solution was washed repeatedly with toluene and hexane. The solution was then dried under high-purity nitrogen to obtain the free-flowing solid catalyst component D2.

[0131] (2) Polymerization reaction: Same as in Example 1, using catalyst component D2. The polymerization results are shown in Table 1 and Table 2.

[0132] Comparative Example 3

[0133] (1) Preparation of catalyst component D3

[0134] The magnesium-containing composite solution B3 (42 mmol based on magnesium atoms) was cooled to -40°C, and 70 mL of titanium tetrachloride was slowly added dropwise, followed by 3 mL of ethyl benzoate. The temperature was gradually increased to 85°C and held at this temperature for 1 hour. Stirring was stopped, and the solution was allowed to stand. The suspension quickly separated into layers. The supernatant was removed, and the solution was washed repeatedly with toluene and hexane. The solution was dried under high-purity nitrogen to obtain solid catalyst component 3 with good flowability.

[0135] (2) Polymerization reaction: Same as in Example 1, using catalyst component D3. The polymerization results are shown in Table 1 and Table 2.

[0136] Comparative Example 4

[0137] (1) Preparation of catalyst component D4

[0138] A magnesium-containing composite solution B4 (42 mmol based on magnesium atoms) was slowly added to 200 mL of titanium tetrachloride at 0 °C, followed by the addition of 3 mL of ethyl benzoate. The mixture was kept at this temperature for 1 hour after the addition was complete. The system was then gradually heated to 110 °C and kept at this temperature for 1 hour. Stirring was stopped, and the mixture was allowed to stand. The suspension quickly separated into layers. The supernatant was removed, and the solution was washed repeatedly with toluene and hexane. The solution was then dried under high-purity nitrogen to obtain a free-flowing solid catalyst component, D4.

[0139] (2) Polymerization reaction: Same as in Example 1, using catalyst component D4. The polymerization results are shown in Table 1 and Table 2.

[0140] Comparative Example 5

[0141] (1) Preparation of catalyst component D5

[0142] 4.0 g of alkoxymagnesium support (~8 μm) was dispersed in 60 mL of toluene to form a suspension. The suspension was cooled to -15 °C, and 15 mL of titanium tetrachloride and 3 mL of ethyl benzoate were slowly added dropwise. The system was gradually heated to 80 °C and held at that temperature for 2 h. Stirring was stopped, and the suspension was allowed to stand. The suspension quickly separated into layers. The supernatant was removed, and the mixture was washed repeatedly with hexane. The mixture was dried under high-purity nitrogen to obtain a free-flowing solid catalyst component, D5.

[0143] (2) Polymerization reaction: Same as in Example 1, using catalyst component D5. The polymerization results are shown in Table 1 and Table 2.

[0144] Comparative Example 6

[0145] (1) Preparation of catalyst component D6

[0146] 4.0 g of alkoxymagnesium support (~30 μm) was dispersed in 60 mL of toluene to form a suspension. The suspension was cooled to -15 °C, and 15 mL of titanium tetrachloride and 3 mL of ethyl benzoate were slowly added dropwise. The system was gradually heated to 80 °C and held at that temperature for 2 h. Stirring was stopped, and the suspension was allowed to stand. The suspension quickly separated into layers. The supernatant was removed, and the mixture was washed several times with hexane. The mixture was dried under high-purity nitrogen to obtain solid catalyst component D6 with good flowability.

[0147] (2) Polymerization reaction: Same as in Example 1, using catalyst component D6. The polymerization results are shown in Table 1 and Table 2.

[0148] Table 1

[0149]

[0150] As shown in Table 1, the catalyst particle size is larger than that of the alkoxymagnesium support used, indicating that the reaction products of the magnesium-containing composite solution and the titanium-containing compound precipitate on the surface of the alkoxymagnesium catalyst. Compared with the comparative example, the particle size of the solid catalyst in the examples is highly correlated with the particle size of the alkoxymagnesium support used, which is beneficial for controlling the catalyst particle size distribution. In addition, the titanium content of the solid catalyst in the examples is significantly increased, indicating that the catalyst preparation method of the present invention can effectively increase the titanium content of the catalyst. Compared with the comparative example, the polymerization activity and powder melt index of each catalyst component in the examples are significantly increased at low / high hydrogen-to-ethylene ratios, indicating that the catalyst components of the present invention can effectively improve the polymerization activity and hydrogen sensitivity of the catalyst.

[0151] Table 2

[0152]

[0153] The fine powder is caused by insufficient mechanical strength of the catalyst during polymerization, resulting in breakage. The particle size of the fine powder is >200 mesh. As shown in Table 2, compared with the comparative example, the polymer prepared by this invention has higher mechanical strength, less fine powder, a more concentrated particle size distribution, and a higher packing density. In summary, the catalyst component of this invention has better overall performance.

[0154] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A solid catalyst component for olefin polymerization, comprising the reaction product of the following components: 1) Alkoxymagnesium compounds; 2) Magnesium-containing composite solution; 3) Titanium-containing compounds; 4) Electron-donating compounds.

2. The solid catalyst component according to claim 1, characterized in that... The magnesium-containing composite solution is any one of the following mixtures: Mixture 1: A mixture of magnesium halide, alcohols, silicon compounds, and solvents; Mixture 2: A mixture of magnesium halide, organic epoxy compounds, organophosphorus compounds, alcohols, and solvents; Mixture 3: A mixture of magnesium halide, organic epoxy compounds, organophosphorus compounds, organic acid anhydrides, and solvents; Mixture 4: A mixture of magnesium halide solution, organic epoxy compound, organophosphorus compound and solvent.

3. The solid catalyst component according to claim 2, characterized in that: The magnesium halide is selected from at least one of magnesium dihalides, complexes of magnesium dihalides with water or alcohol, and derivatives of magnesium dihalides in which one or two halogen atoms are replaced by alkyl halides, preferably from at least one of magnesium dichloride, magnesium dibromide, magnesium diiodide, magnesium phenoxychloride, magnesium isopropoxychloride, or magnesium butoxychloride; and / or, The alcohol compounds are selected from C1 to C2. 18 fatty alcohols, C6-C 18 At least one of the aromatic alcohols, preferably at least one selected from methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tert-butanol, hexanol, cyclohexanol, octanol, isooctanol, benzyl alcohol, phenethyl alcohol, ethylene glycol, propylene glycol, butanediol, hexanediol, or isohexanediol; and / or, The general formula of the silicon compound is R 1 x R 2 y Si(OR 3 ) z , where R 1 and R 2 They are C1 to C1 respectively. 10 hydrocarbon group or halogen, R 3 For C1~C 10 The hydrocarbon group, 0≤x≤2, 0≤y≤2 and 0≤z≤4, and x+y+z=4, is preferably selected from at least one of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, and tetra(2-ethylhexyloxy)silane; and / or, The organic epoxy compound is selected from at least one of the following: oxides of C2-C8 aliphatic olefins, oxides of C2-C8 aliphatic dienes, oxides of C2-C8 haloaliphatic olefins, oxides of C2-C8 haloaliphatic dienes, glycidyl ethers, and internal ethers; preferably from at least one of ethylene oxide, propylene oxide, epibutylene oxide, butadiene oxide, epichlorohydrin, methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, or diglycidyl ether; and / or, The organophosphorus compound is selected from at least one of the following: alkyl esters of orthophosphoric acid, alkyl esters of phosphorous acid, haloalkyl esters of orthophosphoric acid, and haloalkyl esters of phosphorous acid, preferably from at least one of trimethyl orthophosphoric acid, triethyl orthophosphoric acid, tributyl orthophosphoric acid, triphenyl orthophosphoric acid, trimethyl orthophosphoric acid, triethyl orthophosphoric acid, tributyl orthophosphoric acid, or triphenyl orthophosphoric acid; and / or, The organic acid anhydride is selected from at least one of acetic anhydride, propionic anhydride, butyric anhydride, acrylic anhydride, phthalic anhydride, butenoic anhydride, or maleic anhydride; and / or, The solvent is selected from at least one of aromatic compounds and alkane compounds.

4. The solid catalyst component according to claim 2, characterized in that... In the mixture: In the mixture 1, per mole of magnesium halide, the amount of alcohol is 0.5–20 mol, the amount of silicon compound is 0.01–10 mol, and the amount of solvent is 0.1–10 L; preferably, the amount of alcohol is 1–10 mol, the amount of silicon compound is 0.1–3 mol, and the amount of solvent is 0.3–1 L. In the mixture 2, per mole of magnesium halide, the organic epoxy compound is 0.1–10 mol, the organophosphorus compound is 0.1–10 mol, the alcohol compound is 0.4–10 mol, and the solvent volume is 0.2–10 L; preferably, the organic epoxy compound is 0.3–3 mol, the organophosphorus compound is 0.2–3 mol, the alcohol compound is 1–5 mol, and the solvent volume is 0.5–5 L. In the mixture 3, per mole of magnesium halide, the organic epoxy compound is 0.2–10 mol, the organic phosphorus compound is 0.2–10 mol, the organic acid anhydride is 0.03–1 mol, and the solvent volume is 0.2–10 L; preferably, the organic epoxy compound is 0.5–5 mol, the organic phosphorus compound is 0.5–5 mol, the organic acid anhydride is 0.07–0.5 mol, and the solvent volume is 0.5–5 L. In the mixture 4, the organic epoxy compound is 0.1-10 mol per mole of magnesium halide, the organic phosphorus compound is 0.1-10 mol per mole, and the solvent volume is 0.2-10 L; preferably, the organic epoxy compound is 0.5-5 mol per mole of magnesium halide, the organic phosphorus compound is 0.5-5 mol per mole, and the solvent volume is 0.5-5 L.

5. The solid catalyst component according to claim 1, characterized in that: The general formula of the alkoxymagnesium compound is Mg(OR) 4 ) n (OR 5 ) 2-n Where 0≤n≤2, R 4 and R 5 Whether they are the same or different, they are independently classified as C1 to C2. 20 hydrocarbon groups; and / or, The electron-donating compound is selected from at least one of the following: alkyl esters of aliphatic monocarboxylic acids, alkyl esters of aromatic monocarboxylic acids, alkyl esters of aliphatic polycarboxylic acids, alkyl esters of aromatic polycarboxylic acids, aliphatic ethers, cyclic aliphatic ethers, and aliphatic ketones; preferably from at least one of methyl formate, ethyl acetate, butyl acetate, ethyl benzoate, diisobutyl phthalate, di-n-butyl phthalate, diisooctyl phthalate, 1,3-dipentyl phthalate, diethyl ether, hexyl ether, tetrahydrofuran, acetone, or methyl isobutyl ketone; and / or, The general formula of the titanium-containing compound is Ti(OR). a X b Where R is C1 to C 10 The aliphatic or aromatic hydrocarbon group, where X is a halogen, a is an integer from 0 to 4, b is an integer from 0 to 4, and a+b=3 or 4.

6. The solid catalyst component according to claim 1, characterized in that: In the solid catalyst component, based on the amount of magnesium-containing composite solution (based on magnesium atoms) per mole of alkoxymagnesium compound, the amount is 0.01–10 mol, preferably 0.1–5 mol; the amount of titanium-containing compound is 1–100 mol, preferably 3–60 mol; and the amount of electron-donating compound is 0.01–10 mol, preferably 0.1–5 mol.

7. A method for preparing a solid catalyst component according to any one of claims 1 to 6, comprising the following two methods: Method M, step 1) dispersing an alkoxymagnesium compound in a magnesium-containing composite solution to form a suspension; step 2) reacting the suspension with a titanium-containing compound and / or an electron-donating compound at low temperature, followed by gradual heating; or, Method N, step 1) reacts an alkoxymagnesium compound with a titanium-containing compound to form a suspension; step 2) reacts the suspension with a magnesium-containing composite solution and / or an electron donor compound at low temperature, and then gradually increases the temperature.

8. The preparation method according to claim 7, characterized in that: In step 2) of method M, a titanium-containing compound and / or an electron donor compound are added to the suspension at -60℃ to 0℃ and reacted for 1 to 3 hours, with the temperature increased to 75℃ to 110℃ and held at that temperature for 0.5 to 2 hours. In step 1) of method N, a titanium-containing compound is added to the alkoxymagnesium compound at -60℃ to 0℃ and reacted for 1 to 3 hours, or a titanium-containing compound at -60℃ to 0℃ is added to the alkoxymagnesium compound at room temperature and reacted for 1 to 3 hours; in step 2), the temperature is raised to 75℃ to 130℃ and held at that temperature for 0.5 to 2 hours.

9. A catalyst for olefin polymerization, comprising: (1) The solid catalyst component according to any one of claims 1 to 6 or the solid catalyst component obtained by the preparation method according to any one of claims 7 to 8; and (2) The general formula is AlR' p X 3-p Organoaluminum compounds, where R' is hydrogen or C1~C2. 20 Hydrocarbon group, X is halogen, 0 < p ≤ 3.

10. The catalyst for olefin polymerization according to claim 9, characterized in that: The molar ratio of organoaluminum compound to titanium in the solid catalyst component is (5-500):1, preferably (20-200):

1.

11. The use of a solid catalyst component according to any one of claims 1 to 6, or a solid catalyst component obtained by the preparation method according to any one of claims 7 to 8, or a catalyst according to any one of claims 9 to 10, in olefin polymerization.

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