CN114426605A

CN114426605A - Catalyst component for olefin polymerization and preparation method and application thereof

Info

Publication number: CN114426605A
Application number: CN202011072544.0A
Authority: CN
Inventors: 李秉毅; 赖菁菁; 高榕; 苟清强; 郭子芳; 寇鹏; 马永华; 纪卫民
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2020-10-09
Filing date: 2020-10-09
Publication date: 2022-05-03
Anticipated expiration: 2040-10-09
Also published as: CN114426605B

Abstract

The invention discloses a catalyst component for olefin polymerization, which comprises magnesium, titanium, a reaction product of an electron donor compound and a branched olefin polymer and an inorganic oxide carrier, wherein an alkenyl chain segment containing a branched chain structure in the branched olefin polymer accounts for 25-35 mol% of the total chain segment content. The invention also provides a preparation method of the catalyst component and a catalyst containing the catalyst component. When the catalyst is used for olefin polymerization, the polymerization activity is high, the particle size distribution of the obtained catalyst is narrow, the particle size is easier to regulate and control, the stability is better, and simultaneously, the polymer produced by the catalyst has higher bulk density. In addition, the catalyst has the advantages of extremely little breakage and low fine powder content, and is very favorable for long-period stable operation of a gas-phase fluidized bed, especially in gas-phase polymerization.

Description

Catalyst component for olefin polymerization and preparation method and application thereof

Technical Field

The invention belongs to the field of olefin polymerization, and particularly relates to a catalyst component for olefin polymerization, a preparation method thereof, a catalyst containing the catalyst component and application thereof.

Background

In the polymerization of ethylene or the copolymerization of ethylene with alpha-olefins, the properties of the catalyst influence the properties of the polymer. Generally, during polymerization, the polymer particles will replicate the morphology of the catalyst particles, i.e., the catalyst particle size and size distribution will determine the particle size and size distribution of the final polymer powder. The particle size and particle size distribution of the polymer powder directly influence the powder transport and the operational stability of the production plant.

Industrial Applicability tests have shown that the improved catalyst in slurry polymerization suffers little fragmentation during polymerization. Also in the gas phase fluidized bed reactor, the catalyst obtained by the improvement of Chinese patent CN201810985177.X is subjected to industrial production tests, and the breakage in a gas phase device is little. However, a certain amount of polymer fines still generated, which still adversely affects the long-term stable operation of the apparatus. It can be seen that the fine powder, which affects the stable operation of the apparatus, is mainly brought about by the ultrafine catalyst particles. The catalyst used in the existing gas phase process is mainly formed by spray drying, and because the catalyst is limited by the characteristics of the spray drying process, the forming process of the catalyst is mainly controlled by the shearing force of a gas phase and a liquid phase, and the average particle size and the particle size distribution of particles are almost in a fixed range.

CN100368440 discloses a spray-dried polymerization catalyst and a polymerization process using the same, the catalyst comprising a spray-dried composition of an inert porous filler and the reaction product of: magnesium halide, solvent, electron donor compound, transition metal compound mixture or reaction product. The filler is substantially spherical and has an average particle size of 1um to 12 um. However, the catalyst activity is not high enough and the amount of oligomers in the polymer is large.

CN1493599 discloses an improved catalyst for ethylene polymerization, which is prepared by adding alkyl silicate in the mother liquor preparation of the active components of the catalyst, so as to improve the activity of the catalyst and reduce the oligomer content in the polymer. However, the particle size distribution of the catalyst is not improved at all, and the fine particles are still more.

CN100408603C discloses a catalyst for ethylene polymerization prepared by spray drying process, which has better activity, but the polymer fine powder content is still higher after it is used in gas phase process.

Chinese patent CN 110862472 a discloses a catalyst for ethylene polymerization prepared by spray drying process, and the firmness of the catalyst particles is increased by adding alternating copolymer, so some effects are obtained, but because the polymerization degree of the alternating copolymer selected is limited, and is limited by its own molecular structure (the relative polarity is strong, and it is easy to absorb with other components or even coordinate reaction), its molecular conformation in the mother liquor is not ideal, and it can not well regulate and control the physical parameters of the mother liquor, and there is no obvious effect on controlling the particle size distribution of the catalyst particles.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a catalyst component for olefin polymerization and a preparation method thereof, and further provides a catalyst containing the catalyst component and application thereof. The catalyst of the present invention has high activity, and when the catalyst is used in olefin polymerization, especially gas phase polymerization, the catalyst has small crushing degree, low fine powder content and excellent comprehensive performance.

The first aspect of the present invention provides a catalyst component for olefin polymerization, which comprises a reaction product of a magnesium compound, a titanium compound, an electron donor compound and a branched olefin polymer, wherein an alkenyl segment having a branched structure accounts for 20 to 40 mol%, preferably 25 to 35 mol%, of the total segment content, and an inorganic oxide carrier.

According to some embodiments of the invention, the methyl branches in the branched olefin polymer constitute from 60 to 85 mol%, preferably from 65 to 80 mol%, of the total branch content. For example, 65 mol%, 68 mol%, 70 mol%, 75 mol%, 78 mol%, 80 mol% and any value therebetween.

According to some embodiments of the invention, the branched olefin polymer has a number average molecular weight of 30000 to 200000, preferably 80000 to 180000. In some embodiments, the branched olefin polymer has a number average molecular weight of 100000, 120000, or 150000.

According to some embodiments of the invention, the branched olefin polymer has a molecular weight distribution, Mw/Mn, of from 1.5 to 2.7, preferably from 1.5 to 2.5.

According to some embodiments of the invention, the branched olefin polymer has a crystallinity of ≦ 1%, preferably 0.

According to some embodiments of the invention, the branched olefin polymer is a branched polyethylene.

According to some embodiments of the present invention, the branched olefin polymer is a product of an olefin polymerization reaction carried out in the presence of a polymerization catalyst comprising, as a procatalyst, a complex of the formula (I):

in the formula (1), X is halogen; r₁-R₈Can be the same or different and are each independently selected from hydrogen atom, halogen, C₁-C₂₀A hydrocarbon group, a heterocyclic compound group or an organic group containing an oxygen, nitrogen, boron, sulfur, phosphorus, silicon, germanium or tin atom; and R is₁And R₂、R₅And R₆Optionally forming a ring with each other.

According to some preferred embodiments of the invention, X is selected from chlorine or bromine.

According to some preferred embodiments of the invention, R¹-R⁸May be the same or different and are each independently selected from methyl, ethyl or isopropyl, and R is²And R⁵Each independently selected from hydrogen, methyl, vinyl or bromo, and R¹And R²、R⁵And R⁶Optionally forming a ring with each other.

According to some embodiments of the invention, the complex is selected from a complex of the structure of formula II or formula III;

wherein X is chlorine or bromine; r³、R⁴、R⁷-R¹¹Can be the same or different and are each independently selected from hydrogen atom, halogen, C₁－C₂₀A hydrocarbon group, a heterocyclic compound group.

According to some embodiments of the invention, the complex is selected from at least one of the following compounds:

1) a complex of formula (II) wherein R³＝R⁷＝R⁹＝H,R⁴＝R⁸＝Me,X＝Br；

2) A complex of formula (II) wherein R³＝R⁷＝R⁴＝R⁸＝Me,R⁹＝H,X＝Br；

3) A complex of formula (II) wherein R³＝R⁷＝R⁹＝H,R⁴＝R⁸＝iPr,X＝Br；

4) A complex of formula (II) wherein R³＝R⁷＝R⁹＝H,R⁴＝R⁸＝CHPh₂,X＝Br；

5) A complex of formula (II) wherein R³＝R⁷＝H,R⁴＝R⁸＝R⁹＝CHPh₂,X＝Br；

6) A complex of formula (II) wherein R³＝R⁷＝R⁴＝R⁸＝R⁹＝CHPh₂,X＝Br；

7) A complex of formula (III) wherein R¹¹＝Ph,R¹⁰＝H,X＝Br；

8) A complex of formula (III) wherein R¹¹＝Ph,R¹⁰＝Cl,X＝Br；

9) A complex of formula (III) wherein R¹¹＝Ph,R¹⁰＝CH₃,X＝Br；

10) A complex of formula (III) wherein R¹¹＝Ph,R¹⁰＝iPr,X＝Br；

11) A complex of formula (II) wherein R³＝R⁷＝R⁹＝H,R⁴＝R⁸＝Me,X＝Cl；

12) A complex of formula (II) wherein R³＝R⁷＝R⁴＝R⁸＝Me,R⁹＝H,X＝Cl；

13) A complex of formula (II) wherein R³＝R⁷＝R⁹＝H,R⁴＝R⁸＝iPr,X＝Cl；

14) A complex of formula (II) wherein R³＝R⁷＝R⁹＝H,R⁴＝R⁸＝CHPh₂,X＝Cl；

15) A complex of formula (II) wherein R³＝R⁷＝H,R⁴＝R⁸＝R⁹＝CHPh₂,X＝Cl；

16) A complex of formula (II) wherein R³＝R⁷＝R⁴＝R⁸＝R⁹＝CHPh₂,X＝Cl；

17) A complex of formula (III) wherein R¹¹＝Ph,R¹⁰＝H,X＝Cl；

18) A complex of formula (III) wherein R¹¹＝Ph,R¹⁰＝Cl,X＝Cl；

19) A complex of formula (III) wherein R¹¹＝Ph,R¹⁰＝CH₃X ═ Cl; and

20) a complex of formula (III) wherein R¹¹＝Ph,R¹⁰＝iPr,X＝Cl。

According to a preferred embodiment of the present invention, the polymerization catalyst further comprises a co-catalyst selected from at least one of alkylaluminoxanes, alkylaluminums and chlorinated alkanes, preferably at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-pentylaluminum, tri-n-octylaluminum, diethylaluminum chloride and ethylaluminum dichloride.

In a further preferred embodiment, the molar ratio of metallic aluminum in the cocatalyst to the metal in the procatalyst is from 200 to 5000.

According to some embodiments of the invention, the polymerization catalyst is prepared by a process comprising:

1) in the presence of a catalyst, refluxing 9, 10-dihydro-9, 10-ethylene anthracene-11, 12-diketone and substituted aniline in a solvent, and reacting to prepare an alpha-diimine ligand;

2) reacting the alpha-diimine ligand obtained in step 1) with (DME) NiX under anhydrous and oxygen-free conditions₂Carrying out coordination reaction to obtain the complex with the chemical structure shown as the formula (I).

In a preferred embodiment of the present invention, the catalyst in step 1) is acetic acid and/or the solvent in step 1) is ethanol.

In a preferred embodiment of the invention, the reaction temperature of the reaction is 70 to 80 ℃, preferably 78 ℃, and the reflux time is 1 to 7 days.

In a preferred embodiment of the invention, the molar ratio of the 9, 10-dihydro-9, 10-ethyleneanthracene-11, 12-dione to substituted aniline is from 1:1 to 1:10, preferably from 1:1 to 1: 3.

According to some embodiments of the invention, the specific preparation of the complex and the polymerization catalyst is as follows:

1. general methods for ligand Synthesis

a) Refluxing 9, 10-dihydro-9, 10-ethylene anthracene-11, 12-diketone and substituted aniline in ethanol solvent for 1-7 days by using acetic acid as a catalyst, filtering, removing the solvent, passing through an alkaline alumina column, leaching by using petroleum ether/ethyl acetate (20:1), and separating to obtain a product;

b) refluxing 9, 10-dihydro-9, 10-ethylene anthracene-11, 12-diketone and substituted aniline in toluene with p-toluenesulfonic acid as a catalyst for 1-7 days, evaporating the reaction solution to dryness, passing through an alkaline alumina column, leaching with petroleum ether/ethyl acetate (20:1), and separating to obtain the product.

All of the above synthesized 9, 10-dihydro-9, 10-ethyleneanthracene-11, 12-diimine ligands were confirmed by nuclear magnetic, infrared and elemental analysis.

2. General procedure for the Synthesis of Nickel (II) complexes

Under the protection of inert gas, dropwise adding a dichloromethane solution of (DME) NiCl2 or (DME) NiBr2 into a solution of a 9, 10-dihydro-9, 10-ethyleneanthracene-11, 12-diimine ligand according to a molar ratio (1: 1-1: 1.2), stirring at room temperature, precipitating, filtering, washing with diethyl ether, and then drying in vacuum to obtain the 9, 10-dihydro-9, 10-ethyleneanthracene-11, 12-diimine nickel complex.

The branched polyolefin compounds prepared and used in the present invention are described in chinese patent application No. 201410479028.8 entitled "an olefin polymerization catalyst and methods of making and using the same," which is incorporated herein by reference in its entirety.

According to some embodiments of the invention, the inorganic oxide support has a particle size of 0.01 to 10 μm, preferably 0.01 to 5 μm, more preferably 0.02 to 5 μm, and most preferably 0.05 to 1 μm.

According to some embodiments of the invention, the inorganic oxide support is an oxide of silicon and/or aluminum, preferably silica.

According to some preferred embodiments of the present invention, the inorganic oxide support is a silica support of 0.05 to 1 μm, and the catalyst particles formed using the support have good shape, high strength, and are not easily crushed.

According to some embodiments of the invention, the inorganic oxide support is present in an amount of from 5 to 50 wt%, based on the total weight of the catalyst component; preferably 10 to 40 wt%, more preferably 15 to 35 wt%.

According to some embodiments of the invention, the magnesium content is from 1 to 10 wt%, based on the total weight of the catalyst component; preferably 3-8 wt%.

According to some embodiments of the invention, the titanium is present in an amount of from 0.5 to 5 wt%, based on the total weight of the catalyst component; preferably 1-4 wt%.

According to some embodiments of the present invention, the electron donor compound is present in an amount of 5 to 40 wt%, based on the total weight of the catalyst component; preferably 10-35 wt%.

According to some embodiments of the invention, the branched olefin polymer content is from 0.1 to 5 wt%, based on the total weight of the catalyst component; preferably 0.3-3 wt%.

According to some embodiments of the invention, the molar ratio of magnesium to titanium in the catalyst component is from 0.1 to 10, preferably from 1 to 10, more preferably from 2 to 7.

According to some embodiments of the invention, the catalyst component comprises a magnesium compound, a titanium compound, an electron donor compound, an inorganic oxide support, and a branched olefin polymer.

According to some embodiments of the invention, the magnesium compound is a magnesium halide, preferably at least one selected from the group consisting of magnesium dichloride, magnesium dibromide and magnesium diiodide.

According to some embodiments of the invention, the titanium compound is a titanium halide, preferably titanium bromide or titanium chloride, more preferably the titanium compound is selected from at least one of titanium tribromide, titanium tetrabromide, titanium trichloride, and titanium tetrachloride.

According to some embodiments of the invention, the electron donor compound is selected from at least one of an ester, an ether, and a ketone compound.

In some preferred embodiments, the electron donor compound is selected from C₁-C₄Alkyl esters of saturated fatty carboxylic acids, C₇-C₈Alkyl esters of aromatic carboxylic acids, C₂-C₆Fatty ethers, C₃-C₄Cyclic ethers and C₃-C₆At least one saturated aliphatic ketone.

In some preferred embodiments, the electron donor compound is selected from at least one of methyl formate, ethyl formate, isopropyl formate, n-propyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, diethyl ether, propyl ether, hexyl ether, tetrahydrofuran, acetone, and methyl isobutyl ketone, wherein preferably is selected from one or more of methyl formate, ethyl acetate, butyl acetate, diethyl ether, hexyl ether, tetrahydrofuran, acetone, and methyl isobutyl ketone, and most preferably is tetrahydrofuran.

According to the present invention, the electron donor compounds may be used alone or in any combination.

In a second aspect, the present invention provides a process for the preparation of a catalyst component according to the first aspect of the invention, comprising the steps of:

(1) mixing a magnesium compound, a titanium compound, an electron donor compound, an inorganic oxide carrier and a branched olefin polymer to form a slurry;

(2) and spray-drying the obtained slurry to obtain the solid catalyst component.

According to some embodiments of the invention, the temperature of said mixing in step (1) is 60 ℃ to 80 ℃, preferably 60 ℃ to 70 ℃. In some embodiments, the temperature of the mixing is 65 ℃, 66 ℃, 67 ℃.

According to some embodiments of the invention, the pressure of the mixing in step (1) is ≦ 0.2 MPa.

According to the present invention, the mixing in step (1) is preferably carried out for a time period sufficient to completely dissolve the magnesium compound, and is usually not less than 2 hours. In some embodiments, the time of mixing is 2h, 3h, 4h, 6h, or 8 h.

According to some embodiments of the invention, in step (2), the slurry is cooled to 30-55 ℃ before spray-drying. In some embodiments, the resulting slurry is cooled to 35 ℃. In other embodiments, the resulting slurry is cooled to 50 ℃.

According to some embodiments of the invention, the inlet temperature of the spray drying is 80-240 ℃; preferably 120-180 deg.c, and in some embodiments the inlet temperature is 140 deg.c, and in other embodiments the inlet temperature is 150 deg.c.

According to some embodiments of the invention, the outlet temperature of the spray drying is 60-130 ℃, preferably 90-120 ℃, such as 90 ℃, 100 ℃, 110 ℃, 120 ℃ and any value in between.

According to some embodiments of the present invention, the inorganic oxide support is added in an amount of 3 to 10 wt%, preferably 4 wt% to 8 wt%, based on the total amount of the raw materials added.

According to some embodiments of the present invention, the magnesium compound is added in an amount of 3 to 10 wt%, preferably 3 wt% to 7 wt%, based on the total amount of the raw materials added.

According to some embodiments of the present invention, the titanium compound is added in an amount of 1 to 5 wt%, preferably 1 to 3 wt%, based on the total amount of the raw materials added.

According to some embodiments of the present invention, the electron donor compound is added in an amount of 70 to 90 wt%, preferably 75 to 88 wt%, based on the total amount of the raw materials added.

According to some embodiments of the present invention, the branched olefin polymer is added in an amount of 0.02 to 3 wt%, preferably 0.05 to 1 wt%, based on the total charge of the feedstock.

According to some embodiments of the present invention, in the step (1), the electron donor compound, the magnesium compound, the titanium compound and the branched olefin polymer are first mixed to prepare a mother liquor; and secondly, mixing the obtained mother liquor with an inorganic oxide carrier to obtain slurry.

According to some embodiments of the invention, the temperature of the first mixing is 60 ℃ to 80 ℃, preferably 60 ℃ to 70 ℃.

According to some embodiments of the invention, the temperature of the second mixing is 30-55 ℃.

According to the present invention, the reaction product of the magnesium, titanium, branched olefin polymer and electron donor compound may also be supported on the inorganic oxide support.

According to the invention, the inorganic oxide support is dry at the time of use, without adsorbed water. In preparing the slurry, a sufficient amount of inorganic oxide support should be added to form a slurry suitable for spray drying. According to some embodiments of the invention, the inorganic oxide support is present in the slurry in an amount of from 5 wt% to 50 wt%, preferably from 10 wt% to 30 wt%.

According to some embodiments of the present invention, in the step (1), the electron compound, the magnesium compound and the titanium compound are first contacted, the branched olefin polymer is added to the first contact product to perform a second contact, and then the obtained second contact product is third contacted with the inorganic oxide carrier to obtain a slurry,

according to some embodiments of the invention, the temperature of the first contacting is from 60 ℃ to 80 ℃, preferably from 60 ℃ to 70 ℃.

According to some embodiments of the invention, the temperature of the second reaction is between 30 and 55 ℃.

According to some embodiments of the invention, the temperature of the third reaction is between 30 and 55 ℃.

In a third aspect, the present invention provides a catalyst for the polymerisation of olefins comprising the reaction product of:

component a, the catalyst component of the present invention;

a component b, an organoaluminum compound,

according to some embodiments of the invention, the organoaluminum compound has the formula A1R_nX_3-nWherein R is hydrogen or alkyl with 1-20 carbon atoms, X is halogen, preferably chlorine, bromine or iodine, and n is more than 0 and less than or equal to 3.

According to some embodiments of the present invention, specific examples of the organoaluminum compound include, but are not limited to, one or more of triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, and diethylaluminum monochloride.

According to some embodiments of the present invention, the ratio of component b to component a is 5:1 to 500:1, preferably 10:1 to 200:1, in terms of molar ratio of aluminum to titanium. In some embodiments, the ratio of component b to component a is 100:1 in terms of a molar ratio of aluminum to titanium.

According to the present invention, the solid catalyst component obtained after spray-drying can be suitably used for the production of an ethylene polymer by reducing the titanium atom in the catalyst component to a state capable of efficiently polymerizing ethylene using an organoaluminum compound which is an activator component. Generally, the solid catalyst component obtained is reacted with an activator component in a hydrocarbon solvent to obtain a catalyst; the resulting catalyst component may also be reacted with an activator component during the polymerization process to initiate olefin polymerization.

According to the present invention, the hydrocarbon solvent is a hydrocarbon solvent which can dissolve reaction components without affecting the reaction, and may be, for example, isopentane, hexane, heptane, toluene, xylene, naphtha, mineral oil, and the like.

In a fourth aspect, the present invention provides a process for the polymerisation of olefins comprising polymerising olefins in the presence of a catalyst component according to the first aspect of the present invention and/or a catalyst component prepared by a process according to the second aspect of the present invention and/or a catalyst according to the third aspect of the present invention.

According to some embodiments of the invention, the alkene may be of the formula CH₂Wherein R is hydrogen or C₁-C₆Alkyl group of (1).

According to some embodiments of the invention, the olefin is selected from the group consisting of ethylene, propylene, butene, pentene, hexene, octene, and 4-methylpentene-1.

The olefin polymerization reaction of the present invention is carried out according to a known polymerization method, and may be carried out in a liquid phase or a gas phase, or may be carried out in an operation combining liquid phase and gas phase polymerization stages. Conventional techniques such as slurry, gas phase fluidized bed, solution, etc. are used, and are more suitable for gas phase polymerization.

The catalyst of the present invention may be used in the homopolymerization and copolymerization of olefin, and is especially suitable for the homopolymerization of ethylene or the copolymerization of ethylene and other alpha-olefin.

A fifth aspect of the invention provides the use of a catalyst component according to the first aspect of the invention and/or a catalyst component prepared according to the process of the second aspect of the invention and/or a catalyst according to the third aspect of the invention and/or a process according to the fourth aspect of the invention in the polymerisation of olefins.

Compared with the prior art, the invention has the following obvious advantages:

the catalyst component for olefin polymerization disclosed by the invention adopts superfine inorganic oxide as a carrier, an electron donor compound solvent is used for dissolving a magnesium compound, a branched olefin polymer and a titanium compound in a certain proportion are added, a high-activity catalyst is generated by a spray forming mode, the obtained catalyst is narrow in particle size distribution, easier to regulate and control the particle size, better in stability, and higher in stacking density of a polymer produced by the catalyst. In addition, the catalyst has high activity, and particularly in gas phase polymerization, the catalyst has little breakage and low fine powder content, and is very favorable for long-period stable operation of a gas phase fluidized bed.

Detailed Description

In order that the invention may be more readily understood, the following detailed description of the invention is given in conjunction with the examples which are given for purposes of illustration only and are not to be construed as limiting the scope of the invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

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 test method comprises the following steps:

1. activity: expressed as the weight of resin obtained per gram of catalyst component.

2. Polymer Melt Index (MI): the melt index was measured using a melt index measuring instrument model 6932 from CEAST, Italy.

3. Polymer apparent density (BD): the measurement was carried out in accordance with ASTM D1895-69.

4. Titanium, magnesium, silicon content: the measurement and analysis were carried out by using 7500cx ICP-MS element analyzer of Aglient, USA.

5. THF content: the measurement was carried out by Rayleigh P-300 gas chromatography.

6. Polymer content: the measurement was carried out using an AVANCE model 300 liquid NMR spectrometer from Bruker, Switzerland.

Example 1

(1) Preparation of catalyst component: to 2.5m³1400L of tetrahydrofuran and 15L of TiCl are added in sequence into the reaction kettle₄54 kg of anhydrous MgCl₂2.0 kg of branched polyethylene (ethylene homopolymer, number average molecular weight Mn 180000, molecular weight distribution 1.8; vinyl chain segment containing branched structure in branched polyethylene accounts for 35 mol% of the total chain segment content; methyl chain segment in branched polyethylene accounts for 75 mol% of the total chain segment content; crystallinity of branched polyethylene is 0), and the temperature was raised to 67 ℃ with stirring, and the temperature was maintained at this temperature for 6 hours. Then, the temperature was decreased to 35 ℃ and then 80 kg of silica gel (Cabot Corporation TS-610, particle size 0.05-0.5 μm) was added, the temperature was maintained at 65 ℃ and the mixture was stirred for 3 hours to form a slurry, and then the slurry was decreased to 50 ℃ and the spray drying of the slurry was started by a centrifugal spray dryer, spray conditions: the inlet temperature was 150 ℃ and the outlet temperature was 100 ℃ to give 230 kg of the solid catalyst component, of which the titanium content was 2.37 Wt%.

The branched polyethylene is prepared by referring to the method of Chinese patent CN 105482000B.

(2) Evaluation of ethylene slurry polymerization: adding 1L of hexane into a 2L polymerization kettle which is blown off by nitrogen, simultaneously adding 1 mL of 1mmol of triethyl aluminum and 0.02 g of the prepared catalyst component, wherein the molar ratio of aluminum to titanium is 100, heating to 75 ℃, adding 0.18Mpa of hydrogen, adding 0.75Mpa of ethylene after the hydrogenation is finished, heating to 85 ℃, reacting for 2 hours, cooling and discharging. The contents of the components in the catalyst components are shown in Table 1, and the polymerization results are shown in Table 2.

(3) Evaluation of ethylene gas phase polymerization: taking 1 kg of the prepared catalyst component, adding the catalyst component into a catalyst feeding preparation kettle, preparing the catalyst component and 10L of hexane into suspension, and feeding the suspension into a peristaltic pump

And (3) adding triethyl aluminum into the gas-phase fluidized bed, adjusting the molar ratio of aluminum to titanium to be 50, the reaction temperature to be 85 ℃, the hydrogen-ethylene ratio to be 0.19, and continuously polymerizing for one week. The polymerization results are shown in Table 2.

Example 2

(1) Preparation of catalyst component: the only difference from example 1 is that the branched polyethylene (ethylene homopolymer) added has a number average molecular weight Mn of 80000 and a molecular weight distribution of 1.6, and the branched polyethylene contains 27 mol% of vinyl segments having a branched structure based on the total segment content; the methyl branch accounts for 75 mol% of the total branch content in the branched polyethylene; the branched polyethylene had a crystallinity of 0 in an amount of 4.0 kg, and the titanium content of the resulting solid catalyst component was 2.29 Wt%.

(2) The evaluation method of slurry polymerization of ethylene was the same as in example 1, and the contents of the components in the catalyst components are shown in Table 1, and the polymerization results are shown in Table 2.

Example 3

(1) Preparation of catalyst component: a250 ml four-necked flask purged with nitrogen was charged first with 0.7 g TiCl₃3.5 g of anhydrous MgCl₂130m of 1 tetrahydrofuran, the temperature was raised to 66 ℃ with stirring, and the reaction was carried out at this temperature for 3 hours at constant temperature. Cooling to 35 ℃, adding 1.0 g of high-branching-degree polyethylene (ethylene homopolymer, the number average molecular weight Mn is 100000, the molecular weight distribution is 2.1, the content of a vinyl chain segment containing a branched chain structure in the branched polyethylene accounts for 33 mol% of the content of a total chain segment, the content of a methyl branched chain in the branched polyethylene accounts for 78 mol% of the content of the total chain segment, and the crystallinity of the branched polyethylene is 0), and continuing stirring for 1 hour to prepare the mother solution.

6 g of silica gel (Cabot Corporation TS-610, particle size 0.05-0.5 μm) was added to a 250m1 four-necked flask purged with nitrogen, and the mother liquor after cooling was added thereto, and stirred at 35 ℃ for 1 hour to obtain a slurry. The slurry was spray-dried using a spray dryer under the following spray conditions: the inlet temperature was 140 ℃ and the outlet temperature was 102 ℃ to obtain a solid catalyst component in which the titanium content was 1.07 Wt%.

Example 4

(1) Preparation of catalyst component: to 2.5m³1300L of tetrahydrofuran and 15 kg of TiCl are added in sequence into the reaction kettle₃54 kg of anhydrous MgCl₂1.2 kg of highly branched polyethylene (ethylene homopolymer, number average molecular weight Mn of 120000, molecular weight distribution of 1.5, branched polyethylene containing 34 mol% of vinyl chain segment having a branched structure, branched polyethylene containing 70 mol% of methyl chain segment, and branched polyethylene having crystallinity of 0), was reacted at a constant temperature of 67 ℃ for 6 hours with stirring. The temperature was reduced to 35 ℃ after which 80 kg of silica gel (Cabot Corporation TS-610, particle size 0.05-0.5 micron) was added, the temperature was maintained at 65 ℃ and stirred for 3 hours, after which the temperature was reduced to 50 ℃ and the slurry was initially spray dried using a centrifugal spray dryer under spray conditions: the inlet temperature was 140 ℃ and the outlet temperature was 94 ℃ to obtain 225 kg of the solid catalyst component, the titanium content of which was 2.27 Wt%.

(1) The evaluation method of slurry polymerization of ethylene was the same as in example 1, and the contents of the components in the catalyst components are shown in Table 1, and the polymerization results are shown in Table 2.

(2) The ethylene gas phase polymerization was evaluated in the same manner as in example 1, and the polymerization results are shown in Table 3.

Example 5

(1) Preparation of catalyst component: into a 250ml four-necked flask purged with nitrogen, 3.65 g of TiCl were added₄6.0 g of anhydrous MgCl₂0.2 g of highly branched polyethylene (number average molecular weight Mn 120000, molecular weight distribution 1.6, branched polyethylene containing branchesThe content of vinyl chain segments of the chain structure accounts for 27 mol% of the total chain segment content; the methyl branch accounts for 75 mol% of the total branch content in the branched polyethylene; the crystallinity of the branched polyethylene was 0), 120m1 of tetrahydrofuran, and the temperature was raised to 65 ℃ with stirring, and the reaction was carried out at this temperature for 4 hours. The temperature is reduced to 35 ℃.

6 g of silica gel (Cabot Corporation TS-610, particle size 0.05-0.5 μm) was added to a 250m1 four-necked flask purged with nitrogen, and the mother liquor after cooling was added thereto, and stirred at 35 ℃ for 1 hour to obtain a slurry. The slurry was spray-dried using a spray dryer under the following spray conditions: the inlet temperature was 150 ℃ and the outlet temperature was 110 ℃ to obtain a solid catalyst component in which the titanium content was 4.02 Wt%.

Comparative example 1

(1) Preparation of the catalyst component A250 m1 four-necked flask purged with nitrogen was charged first with 1.5 g TiCl₄4.0 g of anhydrous MgCl₂And 100mL of tetrahydrofuran, heating to 65 ℃ under stirring, and reacting at the constant temperature for 3 hours to obtain a mother solution. The temperature is reduced to 35 ℃.

To a 250ml three-necked flask purged with nitrogen, 6 g of silica gel (Cabot Corporation TS-610, particle size 0.02-0.1 μm) was added, and the mother liquor after cooling was added, maintained at 35 ℃ and stirred for 1 hour, and then the mother liquor after blending silica gel was spray-dried using a spray dryer under spray conditions: the inlet temperature was 155 ℃ and the outlet temperature was 110 ℃ to obtain a solid catalyst component in which the titanium content was 2.2 Wt%.

Comparative example 2

(1) Preparation of catalyst component: to 2.5m³1300L of tetrahydrofuran and 15 kg of TiCl are added in sequence into the reaction kettle₃54 kg of anhydrous MgCl₂1.0 kg of styrene-maleic anhydride alternating copolymer (number-average molecular weight Mn 60000) was heated to 67 ℃ with stirring, at which temperatureThe reaction was carried out at constant temperature for 6 hours. The temperature was reduced to 35 ℃ and then 80 kg of silica gel (Cabot Corporation TS-610, particle size 0.05-0.5 μm) was added, the temperature was maintained at 65 ℃ and stirred for 3 hours to obtain a slurry, and then the temperature was reduced to 50 ℃ and the slurry was spray-dried by a centrifugal spray dryer, under spray conditions: the inlet temperature was 140 ℃ and the outlet temperature was 94 ℃ to obtain 200 kg of a solid catalyst component having a titanium content of 2.27 Wt%.

The styrene maleic anhydride alternating copolymer is prepared by referring to the method of Chinese patent CN 110862472A.

TABLE 1 catalyst Components content of the components

Examples	Ti％	Mg％	Carrier%	THF％	Polymer%
						Example 1	2.37	6.1	28.5	26.1	0.85
Example 2	2.29	6.2	29.0	25.8	1.95
						Example 3	1.07	3.8	28.7	16.3	2.35
Example 4	2.27	6.2	33.9	26.2	0.53
						Example 5	4.02	7.3	15.8	29.9	0.65
Comparative example 1	2.20	6.2	18.6	28.5	0
						Comparative example 2	2.27	6.2	33.9	26.2	0.5

TABLE 2 evaluation results of slurry polymerization of ethylene

As can be seen from the data in Table 2, the catalyst obtained according to the invention has a higher polymerization activity and a higher bulk density of the polymer powder. More importantly, the catalyst particle size distribution index (span) is small, indicating that the particle size distribution is more uniform. The powder of the examples of the invention is significantly more concentrated from the results of the powder screening after polymerization.

TABLE 3 evaluation results of gas phase polymerization

As can be seen from the data in Table 3, the catalyst activity under pilot gas fluidized bed polymerization conditions was close to that of the pilot slurry runs, but the polymerization conditions were very different and not suitable for direct comparison. Under the same conditions, the catalysts of the examples have higher activity, and more importantly, the catalysts of the examples have the characteristics of concentrated powder particle size distribution and extremely less fine powder in gas phase polymerization, which has great significance for long-term operation of a fluidized bed.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.

Claims

1. A catalyst component for olefin polymerization, comprising a reaction product of a magnesium compound, a titanium compound, an electron donor compound and a branched olefin polymer, wherein an alkenyl segment having a branched structure accounts for 20 to 40 mol%, preferably 25 to 35 mol%, of the total segment content, and an inorganic oxide carrier;

preferably, the methyl branches in the branched olefin polymer constitute from 60 to 85 mol%, preferably from 65 to 80 mol%, of the total branched content.

2. The catalyst component according to claim 1 wherein the branched olefin polymer has a number average molecular weight of 30000 to 200000, preferably 80000 to 180000, a molecular weight distribution index of 1.5 to 2.7;

preferably, the branched olefin polymer has a crystallinity of ≦ 1%, preferably 0;

more preferably, the branched olefin polymer is a branched polyethylene.

3. The catalyst component according to claim 1 or 2, wherein the branched olefin polymer is a product of olefin polymerization in the presence of a polymerization catalyst comprising, as a main catalyst, a complex of the formula (I):

in the formula (1), X is halogen; r₁-R₈Can be the same or different and are each independently selected from hydrogen atom, halogen, C₁-C₂₀A hydrocarbon group, a heterocyclic compound group or an oxygen, nitrogen, boron, sulfur, phosphorus, silicon, germanium or tin atom-containing groupAn organic group of (a); and R is₁And R₂、R₅And R₆Optionally in the form of a ring with one another,

preferably, said X is selected from chlorine or bromine; r¹-R⁸May be the same or different and are each independently selected from methyl, ethyl or isopropyl, and R is²And R⁵Each independently selected from hydrogen, methyl, vinyl or bromo, and R¹And R²、R⁵And R⁶Optionally forming a ring with each other.

4. The catalyst component according to any of claims 1 to 3 characterized in that the particle size of the inorganic oxide support is 0.01-10 μm, preferably 0.01-5 μm, more preferably 0.02-5 μm, most preferably 0.05-1 μm;

preferably, the inorganic oxide support is an oxide of silicon and/or aluminum, preferably silica.

5. The catalyst component according to any of claims 1 to 4, characterized in that the inorganic oxide support content is 5 to 50 wt. -%, based on the total weight of the catalyst component; preferably 10 to 40 wt%, more preferably 15 to 35 wt%; and/or a magnesium content of 1-10 wt%; preferably 3 to 8 wt%; and/or the titanium content is 0.5 to 5 wt%; preferably 1-4 wt%; and/or the electron donor compound content is 5-40 wt%; preferably 10-35 wt%; more preferably 15 to 30 wt%; and/or a branched olefin polymer content of 0.1 to 5 wt%; preferably 0.3 to 3 wt%;

preferably, the molar ratio of magnesium to titanium in the catalyst component is from 0.1 to 10, preferably from 1 to 10, more preferably from 2 to 7.

6. A process for the preparation of the catalyst component according to any one of claims 1 to 5, comprising the steps of:

(1) mixing a magnesium compound, a titanium compound, an electron donor compound, an inorganic oxide carrier and a branched olefin polymer to form slurry;

(2) spray drying the obtained slurry to prepare a solid catalyst component;

preferably, the temperature of the mixing in the step (1) is 60-80 ℃, preferably 60-70 ℃; and/or the pressure of mixing is less than or equal to 0.2MPa, and/or the time of mixing is more than or equal to 2 hours.

7. The method according to claim 6, wherein in the step (2), the obtained slurry is cooled to 30-55 ℃ and then subjected to spray drying, preferably, the inlet temperature of the spray drying is 80-240 ℃; preferably 120 to 180 ℃; and/or the outlet temperature of the spray drying is 60-130 ℃, preferably 90-120 ℃.

8. The method according to claim 6 or 7, characterized in that the inorganic oxide support is added in an amount of 3-10 wt%, preferably 4-8 wt%, based on the total amount of raw materials added; and/or the magnesium compound is added in an amount of 3 to 10 wt%, preferably 3 to 7 wt%; and/or the titanium compound is added in an amount of 1 to 5 wt%, preferably 1 to 3 wt%; and/or the electron donor compound is added in an amount of 70-90 wt%, preferably 75-88 wt%; and/or the branched olefin polymer is added in an amount of 0.02 to 3 wt%, preferably 0.05 to 1 wt%.

9. The method as claimed in any one of claims 6 to 8, wherein in step (1), the electron donor compound, the magnesium compound, the titanium compound and the branched olefin polymer are first mixed to prepare a mother liquor; secondly mixing the obtained mother liquor and an inorganic oxide carrier to obtain slurry, preferably, the temperature of the first mixing is 60-80 ℃, preferably 60-70 ℃; and/or the temperature of the second mixing is 30-55 ℃.

10. The method as claimed in any one of claims 6 to 9, wherein in the step (1), the electron donor compound, the magnesium compound and the titanium compound are firstly contacted, the branched olefin polymer is added into the first contact product for second contact, and then the obtained second contact product is contacted with the inorganic oxide carrier for third contact to obtain slurry;

preferably, the temperature of the first contacting is from 60 ℃ to 80 ℃; and/or the temperature of the second contacting is 30-55 ℃; and/or the temperature of the third reaction is 30-55 ℃.

11. A catalyst for the polymerization of olefins comprising the reaction product of:

component a, a catalyst component according to any one of claims 1 to 5 or a catalyst component prepared according to the process of any one of claims 6 to 10;

component b, an organoaluminum compound;

preferably, the organoaluminum compound has the formula A1R_nX_3-nWherein R is hydrogen or alkyl with 1-20 carbon atoms, X is halogen, preferably chlorine, bromine or iodine, and n is more than 0 and less than or equal to 3.

12. A process for the polymerization of olefins comprising polymerizing an olefin in the presence of the catalyst component according to any of claims 1-5 or the catalyst component prepared according to the process of any of claims 6-10 or the catalyst according to claim 11, preferably the olefin has the general formula CH₂Wherein R is hydrogen or C₁-C₆Alkyl groups of (a); more preferably the olefin is selected from one or more of ethylene, propylene, butene, pentene, hexene, octene and 4-methylpentene-1.

13. Use of the catalyst component according to any one of claims 1 to 5 or the catalyst component prepared according to the process of any one of claims 6 to 10 or the catalyst according to claim 11 or the process of claim 12 in the polymerization of olefins, preferably the polymerization is a gas phase polymerization.