阅读说明：本技术 固体钛/镁催化剂及其制备方法、烯烃聚合用催化剂及其应用、聚丙烯聚合物 (Solid titanium/magnesium catalyst, preparation method thereof, catalyst for olefin polymerization, application of catalyst, and polypropylene polymer ) 是由 郭正阳 雷世龙 王迎 刘萃莲 唐璐 于 2019-10-28 设计创作，主要内容包括：本发明涉及烯烃聚合领域,公开了一种固体钛/镁催化剂的制备方法,包括：(1)将镁化合物溶解在包含有机环醚化合物、有机醇化合物、有机环氧化合物、有机磷化合物和惰性稀释剂的混合溶剂中,经搅拌形成均匀溶液,进行第一反应；(2)在第一温度下,将钛化合物滴入步骤(1)得到的产物中,或者将步骤(1)得到的产物滴入钛化合物得到溶液I,将溶液I与电子给体化合物进行混合,并在升温条件下进行第二反应过滤得到滤饼；(3)将所述滤饼用钛化合物和惰性溶剂活化、洗涤。本发明所述固体钛/镁催化剂制备成本低,组分简单、颗粒形貌优异、催化活性高且粒径可调,可聚合得到等规指数高且球形度高的聚合物。(The invention relates to the field of olefin polymerization, and discloses a preparation method of a solid titanium/magnesium catalyst, which comprises the following steps: (1) dissolving a magnesium compound in a mixed solvent containing an organic cyclic ether compound, an organic alcohol compound, an organic epoxy compound, an organic phosphorus compound and an inert diluent, stirring to form a uniform solution, and carrying out a first reaction; (2) at a first temperature, dropping a titanium compound into the product obtained in the step (1), or dropping the product obtained in the step (1) into the titanium compound to obtain a solution I, mixing the solution I with an electron donor compound, and carrying out a second reaction and filtration under the condition of temperature rise to obtain a filter cake; (3) and activating and washing the filter cake by using a titanium compound and an inert solvent. The solid titanium/magnesium catalyst disclosed by the invention is low in preparation cost, simple in components, excellent in particle morphology, high in catalytic activity and adjustable in particle size, and can be polymerized to obtain a polymer with high isotactic index and high sphericity.)

1. A method for preparing a solid titanium/magnesium catalyst, wherein the method comprises the steps of:

(1) dissolving a magnesium compound in a mixed solvent containing an organic cyclic ether compound, an organic alcohol compound, an organic epoxy compound, an organic phosphorus compound and an inert diluent, stirring to form a uniform solution, and carrying out a first reaction;

(2) at a first temperature, dropping a titanium compound into the product obtained in the step (1), or dropping the product obtained in the step (1) into the titanium compound to obtain a solution I, mixing the solution I with an electron donor compound, carrying out a second reaction at a temperature rise condition, and filtering to obtain a filter cake;

(3) and activating and washing the filter cake by using a titanium compound and an inert solvent to obtain the solid titanium/magnesium catalyst.

2. The production process according to claim 1, wherein in the step (1), the organic cyclic ether compound is contained in an amount of 1 to 20 moles, preferably 2 to 10 moles, per mole of the magnesium compound; 0.5 to 20 moles, preferably 2 to 10 moles of the organic alcohol compound; 0.005 to 15 mol, preferably 0.06 to 10 mol of an organic epoxy compound; 0.005 to 15 mol, preferably 0.06 to 10 mol of an organophosphorus compound; 0.005 to 15 moles, preferably 0.06 to 10 moles of an electron donor compound;

preferably, the molar ratio of the organic cyclic ether compound to the organic epoxy compound is 0.1 to 1, preferably 0.2 to 0.8.

3. The production method according to claim 1 or 2, wherein, in the step (1), the magnesium compound is at least one selected from the group consisting of magnesium halide, alkyl magnesium halide and magnesium haloalcoholate;

preferably, the organic cyclic ether compound is a cyclic ether having 3 to 6 carbon atoms in the ring or a derivative thereof; preferably tetrahydrofuran and/or 2-methyltetrahydrofuran; more preferably tetrahydrofuran;

preferably, the organic alcohol compound is a monohydric alcohol and/or a polyhydric alcohol having 1 to 12 carbon atoms, preferably a monohydric alcohol and/or a polyhydric alcohol having 2 to 12 carbon atoms;

preferably, the organic epoxy compound is selected from at least one of oxides including aliphatic olefins, diolefins, halogenated aliphatic olefins and diolefins having 2 to 8 carbon atoms, preferably at least one of ethylene oxide, propylene oxide, butylene oxide, butadiene double oxide and epichlorohydrin;

preferably, the organophosphorus compound is selected from hydrocarbyl phosphates and/or halohydrocarbyl phosphates;

more preferably, the phosphoric acid is orthophosphoric acid and/or phosphorous acid;

more preferably, the organophosphorus compound is at least one of trimethyl orthophosphate, triethyl orthophosphate, tributyl orthophosphate, triphenyl orthophosphate, trimethyl phosphite, triethyl phosphite, tributyl phosphite and benzyl phosphite;

in the step (1), the first reaction condition includes: the reaction temperature is 90-120 ℃, and the reaction time is 0.5-4 h; preferably, the reaction temperature is 100-110 ℃, and the reaction time is 1-2 h.

4. The production process according to any one of claims 1 to 3, wherein in the step (2), the electron donor compound comprises at least one of alkyl esters of aliphatic and aromatic monocarboxylic acids, alkyl esters of aliphatic and aromatic polycarboxylic acids, aliphatic ethers, cycloaliphatic ethers, and aliphatic ketones;

preferably, the electron donor comprises C₁-C₄Alkyl esters of saturated fatty carboxylic acids, C₇-C₈Alkyl esters of aromatic carboxylic acids, C₂-C₆Fatty ethers, C₃-C₄Cyclic ether, C₃-C₆Saturation ofAt least one of fatty ketones;

more preferably, the electron donor is selected from at least one of methyl formate, ethyl acetate, butyl acetate, diisobutyl phthalate, di-n-butyl phthalate, diisooctyl phthalate, diethyl ether, hexyl ether, tetrahydrofuran, acetone and methyl isobutyl ketone; further preferably diisobutylphthalate and/or di-n-butylphthalate;

preferably, the inert diluent is selected from at least one of hexane, heptane, octane, decane, benzene, toluene and xylene;

preferably, the titanium compound is titanium tetrachloride;

preferably, in step (2), the first temperature is from-30 ℃ to 60 ℃, preferably from 0 ℃ to 30 ℃;

the temperature rise conditions include: heating to a second temperature at a heating rate of 0.5-2 ℃/min from the first temperature, and keeping the temperature for 0.5-3 h; preferably, the second temperature is 75-100 ℃.

5. The production method according to any one of claims 1 to 4, wherein in the step (3), the inert solvent is at least one of an aliphatic hydrocarbon, an alicyclic hydrocarbon and an aromatic hydrocarbon; preferably, the aliphatic hydrocarbon is at least one of pentane, hexane, heptane, octane and decane, the alicyclic hydrocarbon is cyclohexane and/or methylcyclohexane, and the aromatic hydrocarbon is at least one of toluene, benzene, xylene and ethylbenzene;

preferably, the activating conditions include: the activation temperature is 90-120 ℃, and the activation time is 0.5-4 h; preferably, the activation temperature is 100-;

more preferably, in step (3), said activation is performed at least twice.

6. A solid titanium/magnesium catalyst obtained by the method for producing a solid titanium/magnesium catalyst according to any one of claims 1 to 5;

preferably, the solid titanium/magnesium catalyst comprises, by mass, 1 to 10% of titanium, 10 to 20% of magnesium, 40 to 70% of chlorine, 5 to 25% of an electron donor compound, and 0 to 10% of an inert diluent.

7. A catalyst for the polymerization of olefins, wherein the catalyst comprises component a, component B and optionally component C;

component a, the solid titanium/magnesium catalyst of claim 6;

component B, an organoaluminum compound;

component C and an organic silicon compound.

8. The olefin polymerization catalyst according to claim 7, wherein the components A and B are used in such an amount that the molar ratio of aluminum/titanium in the catalyst is from 5 to 5000, preferably from 20 to 500;

the molar ratio of the organoaluminum compound to the organosilicon compound is from 0.1 to 300, preferably from 1 to 100.

9. The catalyst for olefin polymerization according to claim 7 or 8, wherein the organoaluminum compound has a general formula of AlR_nX_3-nWherein R is hydrogen and/or a hydrocarbon group having 1 to 20 carbon atoms, preferably an alkyl group, an aralkyl group or an aryl group; x is halogen, preferably chlorine and bromine; n is 0<n is an integer of 3 or less;

preferably, the organic aluminum compound is at least one of trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, trioctyl aluminum, diethyl aluminum monohydrogen, diisobutyl aluminum monohydrogen, diethyl aluminum monochloride, diisobutyl aluminum monochloride, ethyl aluminum sesquichloride and diisoethyl aluminum, preferably triethyl aluminum and/or triisobutyl aluminum;

the organosilicon compound has a general formula of R'_mSi(OR₁)_4-mWherein m is an integer of 0 to 3, R' and R₁Is at least one of alkyl cycloalkyl, aryl, halogenated alkyl, halogen and hydrogen atom, R' and R₁May be the same or different;

preferably, the organosilicon compound is at least one of trimethylmethoxysilane, trimethylethoxysilane, trimethylphenoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methylcyclohexyldiethoxysilane, methylcyclohexyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane and vinyltrimethoxysilane.

10. Use of the catalyst for olefin polymerization according to any one of claims 7 to 9, wherein the olefin is at least one of ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-pentene;

the polymerization is at least one of slurry polymerization, bulk polymerization, and gas phase polymerization.

11. A polypropylene polymer produced by the catalyst for olefin polymerization according to any one of claims 7 to 9;

preferably, the polypropylene polymer has a sphericity of at least 0.90 and an isotactic index of at least 96 wt%.

Technical Field

The invention relates to the field of olefin polymerization, in particular to a solid titanium/magnesium catalyst and a preparation method thereof, a catalyst for olefin polymerization and application thereof, and a polypropylene polymer.

Background

In the prior art, methods for preparing olefin polymerization solid catalyst components are divided into two types, one is a supported catalyst, namely, a titanium-containing active component is supported on a carrier with a certain shape, the main raw material used by the carrier is generally magnesium chloride or silica gel, and the shape is mostly spherical, such as methods disclosed in US4399054, EP0065700A1 and the like; the other is a granular catalyst, which is prepared by preparing magnesium chloride powder into a uniform solution, and crystallizing to precipitate and load titanium-containing active components, such as methods disclosed in CN85100997A and CN1042156A, but the method has the disadvantages that the addition amount of titanium compounds used for crystallization is large, the generated titanium-containing waste liquid is large, and the subsequent treatment is inconvenient.

In recent years, there are patent documents disclosing the preparation of spherical catalysts by a chemical reaction method.

CN1374971A discloses a solid complex titanium catalyst for homo-polymerization and co-polymerization of α -olefin, obtained by: (i) preparing a magnesium compound solution by dissolving a magnesium compound and a compound of group IIIA of the periodic table in a mixed solvent of a cyclic ether, one or more alcohols, a phosphorus compound, and an organosilane; (ii) reacting the magnesium solution with a transition metal compound, a silicon compound, or a mixture thereof to precipitate solid particles; and (iii) reacting the precipitated solid particles with a titanium compound and an electron donor. The catalyst particles are spherical, the surface is smooth, the particle shape is better, but the activity of the catalyst component is not high, and the polymer bulk density and isotacticity are lower.

CN101663333A discloses a method for obtaining spherical catalyst component by dissolving magnesium chloride in alcohol and tetrahydrofuran and then precipitating out titanium tetrachloride, which comprises the following steps: dissolving magnesium chloride in an oxygen-containing solvent to form a uniform solution, wherein the oxygen-containing solvent is a mixed solvent consisting of cyclic ether and at least one alcohol; the magnesium chloride solution is in contact reaction with a titanium compound to separate out magnesium chloride particles; and (3) carrying an electron donor on the particles, and activating and washing to obtain the solid catalyst component. The method can obtain spherical particles with the particle size of less than 100 microns, has smooth surface morphology and good particle shape, but has low activity when used for olefin polymerization, and the obtained polymer has low bulk density and isotacticity and does not have industrial application value.

CN1258684A provides a catalyst for propylene polymerization or copolymerization, wherein the active component of the catalyst is a homogeneous solution formed by dissolving magnesium halide in organic epoxy compound, organic phosphorus compound and inert diluent, the solution is mixed with titanium tetrahalide or its derivatives, solid is precipitated in the presence of precipitation assistant, the solid is washed by the same inert solvent as the magnesium halide solution, which replaces dichloroethane solvent with high toxicity, and the problem that azeotrope formed by two solvents is not easy to separate in the solvent recovery process is avoided, the process flow is shortened, the recovery rate of the solvent is improved, and the production cost of the catalyst is reduced. However, the catalyst has a spherical-like particle shape, the sphericity is low, and when the particle size of the catalyst is large (more than 30 microns), the particle shape is changed into a strip shape or a rod shape, so that the application of the catalyst is influenced.

Disclosure of Invention

The invention aims to overcome the problems of poor particle morphology and low catalytic activity of a catalyst for olefin polymerization in the prior art, and provides a solid titanium/magnesium catalyst and a preparation method thereof, a catalyst for olefin polymerization and application thereof. The provided solid titanium/magnesium catalyst and the olefin polymer catalyst containing the solid titanium/magnesium catalyst have the advantages of simple catalyst components, excellent particle morphology, high catalytic activity and adjustable particle size, and in the preparation process, less titanium compound is added, less titanium-containing waste liquid is generated, and the cost is lower.

The present invention provides in a first aspect a process for the preparation of a solid titanium/magnesium catalyst, wherein the process comprises the steps of:

(1) dissolving a magnesium compound in a mixed solvent containing an organic cyclic ether compound, an organic alcohol compound, an organic epoxy compound, an organic phosphorus compound and an inert diluent, stirring to form a uniform solution, and carrying out a first reaction;

(2) at a first temperature, dropping a titanium compound into the product obtained in the step (1), or dropping the product obtained in the step (1) into the titanium compound to obtain a solution I, mixing the solution I with an electron donor compound, carrying out a second reaction at a temperature rise condition, and filtering to obtain a filter cake;

(3) and activating and washing the filter cake by using a titanium compound and an inert solvent to obtain the solid titanium/magnesium catalyst.

In a second aspect, the present invention provides a solid titanium/magnesium catalyst obtained by the preparation method of the present invention.

The third aspect of the present invention provides a catalyst for olefin polymerization, wherein the catalyst comprises component a, component B and optionally component C;

component a, the solid titanium/magnesium catalyst of the present invention;

component B, an organoaluminum compound;

component C and an organic silicon compound.

In a fourth aspect, the present invention provides a catalyst for olefin polymerization, which is used in olefin polymerization.

The fifth aspect of the present invention provides a polypropylene polymer prepared from the catalyst for olefin polymerization according to the present invention.

Through the technical scheme, the solid titanium/magnesium catalyst, the preparation method thereof and the olefin polymerization catalyst provided by the invention have the following beneficial technical effects:

(1) the solid titanium/magnesium catalyst provided by the invention has the advantages of simple catalyst component, high catalytic activity, adjustable particle size and the like, and in the preparation process, less titanium compound is added, less titanium-containing waste liquid is generated, and the cost is lower.

(2) When the catalyst component containing the solid titanium/magnesium catalyst provided by the invention is used for olefin polymerization, a polymer with excellent polymer isotactic index and sphericity can be prepared, and the catalyst can be suitable for olefin polymerization under different process conditions such as slurry polymerization, bulk polymerization and gas phase polymerization.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The first aspect of the present invention provides a method for preparing a solid titanium/magnesium catalyst, wherein the method comprises the following steps:

(1) dissolving a magnesium compound in a mixed solvent containing an organic cyclic ether compound, an organic alcohol compound, an organic epoxy compound, an organic phosphorus compound and an inert diluent, stirring to form a uniform solution, and carrying out a first reaction;

(2) at a first temperature, dropping a titanium compound into the product obtained in the step (1), or dropping the titanium compound into the product obtained in the step (1) to obtain a solution I, mixing the solution I with an electron donor compound, carrying out a second reaction at a temperature rise condition, and filtering to obtain a filter cake;

(3) and activating and washing the filter cake by using a titanium compound and an inert solvent to obtain the solid catalyst.

In the invention, the mixed solvent containing the organic epoxy compound is adopted to dissolve the magnesium compound, so that the solubility of the magnesium compound can be obviously improved, meanwhile, the use amounts of the organic phosphorus compound and the titanium compound are obviously reduced, the generation of titanium waste liquid in the preparation process is obviously reduced, and the cost is reduced.

According to the invention, by adopting the preparation method disclosed by the invention, the electron donor compound is contacted with the solution I containing the titanium compound and the magnesium compound, and the prepared solid titanium/magnesium catalyst has excellent particle size controllability and excellent olefin catalytic activity. When the catalyst prepared by the invention is used for olefin polymerization, an olefin polymer with more excellent polymer sphericity and isotacticity can be prepared.

According to the present invention, in the step (1), the organic cyclic ether compound is present in an amount of 1 to 20 moles, preferably 2 to 10 moles, per mole of the magnesium compound; 0.5 to 20 moles, preferably 2 to 10 moles of the organic alcohol compound; 0.005 to 15 mol, preferably 0.06 to 10 mol of an organic epoxy compound; 0.005 to 15 mol, preferably 0.06 to 10 mol of an organophosphorus compound; the electron donor compound is used in an amount of 0.005 to 15 mol, preferably 0.06 to 10 mol.

According to the present invention, the molar ratio of the organic cyclic ether compound to the organic epoxy compound is 0.1 to 1.

In the present invention, the inventors have studied and found that when the molar ratio of the organic cyclic ether compound to the organic epoxy compound is within the range defined in the present invention, the obtained solid titanium/magnesium catalyst can obtain more excellent catalytic activity, and the polymer obtained by the catalysis thereof has more excellent isotacticity and sphericity.

Further, in the present invention, the molar ratio of the organic cyclic ether compound to the organic epoxy compound is preferably 0.2 to 0.8.

According to the present invention, in the step (1), the magnesium compound is at least one selected from the group consisting of magnesium halide, alkyl magnesium halide and magnesium haloalcoholate.

According to the present invention, the organic cyclic ether compound is a cyclic ether having 3 to 6 carbon atoms in the ring or a derivative thereof; preferably tetrahydrofuran and/or 2-methyltetrahydrofuran; more preferably tetrahydrofuran.

According to the present invention, the organic alcohol compound is a monohydric alcohol and/or a polyhydric alcohol having 1 to 12 carbon atoms, preferably a monohydric alcohol and/or a polyhydric alcohol having 2 to 12 carbon atoms.

According to the invention, the organic epoxy compound is selected from at least one of oxides including aliphatic olefins, diolefins, halogenated aliphatic olefins and diolefins with the number of carbon atoms of 2-8; preferably at least one of ethylene oxide, propylene oxide, butylene oxide, butadiene double oxide and epichlorohydrin.

According to the invention, the organophosphorus compound is selected from hydrocarbyl phosphates and/or halohydrocarbyl phosphates; preferably, the phosphoric acid is orthophosphoric acid and/or phosphorous acid; preferably, the organophosphorus compound is at least one of trimethyl orthophosphate, triethyl orthophosphate, tributyl orthophosphate, triphenyl orthophosphate, trimethyl phosphite, triethyl phosphite, tributyl phosphite and benzyl phosphite.

According to the present invention, in step (1), the first reaction conditions include: the reaction temperature is 90-120 ℃, and the reaction time is 0.5-4 h; preferably, the reaction temperature is 100-110 ℃, and the reaction time is 1-2 h.

According to the present invention, in the step (2), the electron donor compound includes at least one of alkyl esters of aliphatic and aromatic monocarboxylic acids, alkyl esters of aliphatic and aromatic polycarboxylic acids, aliphatic ethers, cycloaliphatic ethers, and aliphatic ketones.

According to the invention, the electron donor comprises C₁-C₄Alkyl esters of saturated fatty carboxylic acids, C₇-C₈Alkyl esters of aromatic carboxylic acids, C₂-C₆Fatty ethers, C₃-C₄Cyclic ether, C₃-C₆At least one saturated aliphatic ketone.

Preferably, the electron donor is selected from at least one of methyl formate, ethyl acetate, butyl acetate, diisobutyl phthalate, di-n-butyl phthalate, diisooctyl phthalate, diethyl ether, hexyl ether, tetrahydrofuran, acetone and methyl isobutyl ketone; further preferred is diisobutyl phthalate and/or di-n-butyl phthalate.

According to the present invention, the inert diluent is selected from at least one of hexane, heptane, octane, decane, benzene, toluene and xylene.

According to the invention, the titanium compound is titanium tetrachloride.

According to the invention, in step (2), the first temperature is from-30 ℃ to 60 ℃, preferably from 0 ℃ to 30 ℃.

According to the present invention, the temperature raising condition includes: heating to a second temperature at a heating rate of 0.5-2 ℃/min from the first temperature, and keeping the temperature for 0.5-3 h; preferably, the second temperature is 75-100 ℃.

According to the invention, in the step (3), the inert solvent is at least one of aliphatic hydrocarbon, alicyclic hydrocarbon and aromatic hydrocarbon; preferably, the aliphatic hydrocarbon is at least one of pentane, hexane, heptane, octane and decane, the alicyclic hydrocarbon is cyclohexane and/or methylcyclohexane, and the aromatic hydrocarbon is at least one of toluene, benzene, xylene and ethylbenzene.

According to the invention, in step (3), the activating conditions include: the activation temperature is 90-120 ℃, and the activation time is 0.5-4 h.

Preferably, the activation temperature is 100-110 ℃, and the activation time is 1-3 h.

More preferably, in step (3), said activation is performed at least twice.

In a second aspect, the present invention provides a solid titanium/magnesium catalyst obtained by the preparation method of the present invention.

According to the invention, the solid titanium/magnesium catalyst comprises, by mass, 1-10% of titanium, 10-20% of magnesium, 40-70% of chlorine, 5-25% of an electron donor compound, and 0-10% of an inert diluent.

The third aspect of the present invention provides a catalyst for olefin polymerization, wherein the catalyst comprises component a, component B and optionally component C;

component a, the solid titanium/magnesium catalyst of the present invention;

component B, an organoaluminum compound;

component C and an organic silicon compound.

According to the invention, said component A and component B are used in such an amount that the molar ratio aluminum/titanium in the catalyst is between 5 and 5000, preferably between 20 and 500.

The molar ratio of the organoaluminum compound to the organosilicon compound is from 0.1 to 300, preferably from 1 to 100.

According to the inventionThe general formula of the organic aluminum compound is AlR_nX_3-nWherein R is hydrogen and/or a hydrocarbon group having 1 to 20 carbon atoms, preferably an alkyl group, an aralkyl group or an aryl group; x is halogen, preferably chlorine and bromine; n is 0<n is an integer of 3 or less.

Preferably, the organic aluminum compound is at least one of trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, trioctyl aluminum, diethyl aluminum monohydrogen, diisobutyl aluminum monohydrogen, diethyl aluminum monochloride, diisobutyl aluminum monochloride, ethyl aluminum sesquichloride and diisoethyl aluminum, and is preferably triethyl aluminum and/or triisobutyl aluminum.

According to the invention, the organosilicon compound has the general formula R'_mSi(OR₁)_4-mWherein m is an integer of 0 to 3, R' and R₁Is at least one of alkyl cycloalkyl, aryl, halogenated alkyl, halogen and hydrogen atom, R' and R₁May be the same or different.

Preferably, the organosilicon compound is at least one of trimethylmethoxysilane, trimethylethoxysilane, trimethylphenoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methylcyclohexyldiethoxysilane, methylcyclohexyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane and vinyltrimethoxysilane.

In a fourth aspect, the present invention provides a use of the catalyst for olefin polymerization according to the present invention in olefin polymerization, wherein the olefin is at least one of ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-pentene.

According to the present invention, the polymerization is at least one of slurry polymerization, bulk polymerization and gas phase polymerization.

The fifth aspect of the present invention provides a polypropylene polymer prepared from the catalyst for olefin polymerization according to the present invention.

According to the invention, the polypropylene polymer has a sphericity of at least 0.90 and an isotactic index of at least 96 wt%.

The present invention will be described in detail below by way of examples, but the present invention is not limited thereto. In the following examples:

polymer isotactic index: testing according to GB2412-80 standard;

measuring the sphericity data of the polymer by using a CAMSIZER powder tester;

the catalyst particle size distribution was determined using a Mastersizer 2000 instrument (Malvern, uk);

the catalytic activity of the catalyst is characterized by adopting the method in the test example, and the mass ratio of the polymer obtained by polymerization to the added catalyst is the activity of the catalyst.

The raw materials used in the examples and comparative examples are all commercially available products.

Example 1

(1) Sequentially adding 4.8 g (0.05mol) of anhydrous magnesium chloride, 176 ml (1.66mol) of toluene, 3.0 ml (0.037mol) of tetrahydrofuran, 9.2 ml (0.1mol) of butanol, 5.0 ml (0.064mol) of epoxy chloropropane and 5.0 ml (0.018mol) of tributyl phosphate into a reaction kettle repeatedly replaced by high-purity nitrogen, and reacting for 1 hour at the temperature of 103 ℃; wherein the molar ratio of tetrahydrofuran to epichlorohydrin is 0.58;

(2) cooling to 10 ℃, dropwise adding 5 ml of titanium tetrachloride, adding 2.1 ml of di-n-butyl phthalate (DNBP), gradually heating to 93 ℃, keeping the temperature for one hour, and filtering out mother liquor;

(3) keeping the temperature of 48 ml of titanium tetrachloride and 72 ml of toluene at 110 ℃ for 1.5 hours, filtering, adding 48 ml of titanium tetrachloride and 72 ml of toluene, and keeping the temperature at 110 ℃ for 1.0 hour; then washed 5 times with hexane and the remaining solid product was dried under vacuum to give solid titanium/magnesium catalyst A1.

Example 2

A solid titanium/magnesium catalyst was prepared according to the method of example 1, except that: in step (1), tetrahydrofuran was added in an amount of 1 ml. The molar ratio of tetrahydrofuran to epichlorohydrin was 0.19. A solid titanium/magnesium catalyst A2 was obtained.

Example 3

A solid titanium/magnesium catalyst was prepared according to the method of example 1, except that: in the step (1), the amount of butanol added was 12 ml. A solid titanium/magnesium catalyst A3 was obtained.

Example 4

A solid titanium/magnesium catalyst was prepared according to the method of example 1, except that: in the step (2), the amount of titanium tetrachloride added was 8.0 ml. A solid titanium/magnesium catalyst A4 was obtained.

Example 5

A solid titanium/magnesium catalyst was prepared according to the method of example 1, except that: in step (1), the amount of toluene added was 150 ml. A solid titanium/magnesium catalyst A5 was obtained.

Example 6

A solid titanium/magnesium catalyst was prepared according to the method of example 1, except that: and (2) cooling to 10 ℃, dropwise adding 5 ml of titanium tetrachloride, adding 1.0 ml of di-n-butyl phthalate (DNBP), gradually heating, adding 1.0 ml of di-n-butyl phthalate (DNBP) when heating to 80 ℃, continuing to 93 ℃, keeping the temperature for one hour, and filtering out a mother liquor. A solid titanium/magnesium catalyst A6 was obtained.

Example 7

A catalyst component was prepared in the same manner as in example 1, except that: the molar ratio between tetrahydrofuran and epichlorohydrin was 1.95. A solid titanium/magnesium catalyst A7 was obtained.

Comparative example 1

A solid titanium/magnesium catalyst was prepared according to the method of example 1, except that: in the step (1), epichlorohydrin and tributyl phosphate are not added. The magnesium chloride does not dissolve and a solid titanium/magnesium catalyst cannot be produced.

Comparative example 2

A solid titanium/magnesium catalyst was prepared according to the method of example 1, except that: in the step (1), tetrahydrofuran and butanol are not added. The magnesium chloride does not dissolve and a solid titanium/magnesium catalyst cannot be produced.

Comparative example 3

A solid titanium/magnesium catalyst was prepared according to the method of example 1, except that: in the step (1), epichlorohydrin is not added, the amount of tetrahydrofuran is 9.6 ml, and the reaction time is 2 hours; in the step (2), the mother liquor was filtered off, and then washed with toluene 2 times. A solid titanium/magnesium catalyst D3 was obtained.

Comparative example 4

A solid titanium/magnesium catalyst was prepared with reference to the procedure of CN1258684A, except that:

(1): tetrahydrofuran and butanol are not added, the dosage of toluene is 70 ml, the dosage of epichlorohydrin is 4.0 ml, the dosage of tributyl phosphate is 12.5 ml, the reaction time is 1.5 hours under the condition that the reaction temperature is 62 ℃, 1.4 g of precipitation assistant phthalic anhydride is added at 55 ℃, and 40 ml of toluene is added after the constant temperature is 0.5 hour;

(2): cooling to-28 ℃, dropwise adding 56 ml of titanium tetrachloride, heating to 85 ℃ within 5 hours, adding 1.1 ml of di-n-butyl phthalate at 80 ℃, keeping the temperature at 85 ℃ for 1 hour, filtering out a mother solution, and washing twice with toluene;

(3) then, 72 ml of toluene and 48 ml of titanium tetrachloride were added, and the temperature was maintained at 110 ℃ for 0.5 hour, and the treatment was repeated twice more after filtration, followed by washing 3 times with hexane and vacuum-drying of the remaining solid product to obtain a solid titanium/magnesium catalyst component D4.

Comparative example 5

A solid titanium/magnesium catalyst was prepared with reference to the procedure of CN1258684A, except that:

(1): tetrahydrofuran and butanol are not added, the dosage of the toluene is 150 ml, the dosage of the epichlorohydrin is 4.0 ml, the dosage of the tributyl phosphate is 12.5 ml, the reaction is carried out for 1.5 hours under the condition that the temperature is 62 ℃, 1.4 g of the precipitation aid phthalic anhydride is added at 55 ℃, and the constant temperature is kept for 0.5 hour;

(2): cooling to-28 ℃, dropwise adding 56 ml of titanium tetrachloride, heating to 85 ℃ within 5 hours, adding 1.1 ml of di-n-butyl phthalate at 80 ℃, keeping the temperature at 85 ℃ for 1 hour, filtering out a mother solution, and washing twice with toluene;

(3): then, 72 ml of toluene and 48 ml of titanium tetrachloride were added, and the temperature was maintained at 110 ℃ for 0.5 hour, and the treatment was repeated twice more after filtration, followed by washing 3 times with hexane and vacuum-drying of the remaining solid product to obtain a solid titanium/magnesium catalyst component D5.

Test example

The solid titanium/magnesium catalysts provided in the examples and comparative examples of the present invention were used to catalyze polymerization reactions to produce polypropylene according to the polymerization methods described below.

After a 5-liter stainless steel reactor was sufficiently purged with nitrogen, 5 ml of a triethylaluminum hexane solution having a concentration of 0.5 mol/l and 1 ml of a methylcyclohexyldimethoxysilane (CMMS) hexane solution having a concentration of 1 mol/l and 10 mg of a catalyst were added, then 10 ml of hexane was added to flush the feed line, 1 liter (in a normal state) of hydrogen and 2 liters of purified propylene were added, and the temperature was raised to 70 ℃ to a hydrogen partial pressure of 0.2MPa, at which temperature polymerization was carried out for 1 hour. After the reaction is finished, the reaction kettle is cooled and stirred, reaction products are discharged, white polymers are obtained after drying, and the isotacticity index and the sphericity of the polymers are tested, and the results are shown in table 1.

TABLE 1

As can be seen from the data in Table 1, the solid titanium/magnesium catalyst prepared by the method of the present invention has excellent catalytic activity and adjustable average particle size, the olefin polymer prepared from the catalyst has improved isotacticity and sphericity, and the amount of titanium compound added dropwise when preparing the catalyst is significantly reduced.

In comparative examples 1 and 2, the magnesium chloride was not dissolved and a solid titanium/magnesium catalyst could not be obtained, as compared with examples 1 to 6 of the present invention, while in comparative example 3, the amount of the titanium compound added was small when preparing the solid titanium/magnesium catalyst and the sphericity of the polymer obtained when the catalyst obtained therefrom was used for the catalytic polymerization of olefin, the catalyst activity and the isotacticity of the polymer were low and there was no industrial application value. Meanwhile, the catalytic activity of the catalysts obtained in comparative examples 4 and 5 and the isotacticity of the polymer obtained by catalytic polymerization satisfy practical conditions, but the amount of titanium used in the preparation process is large and the sphericity of the polymer obtained is not too high.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.