CN111499777B - A kind of ultra-high molecular weight polyethylene catalyst and its preparation method and application - Google Patents

Abstract

The invention provides an ultra-high molecular weight polyethylene catalyst, which comprises a general formula (MgX' ₂ )(R ¹ MgX') _p Mg _q [(TiOR ² ) ₄ ] _x [Si(OR ³ ) ₄ ] _y The active carrier of the active carrier and the semi-metallocene active component loaded on the active carrier, the catalyst has a high titanium loading capacity and high catalytic activity; the invention also provides a preparation method of the catalyst, which is activated after the carrier is prepared by using a solvent method The carrier, after obtaining the active carrier liquid, supports the semi-metallocene active component, the preparation conditions are mild, and the operation is simple; and when the catalyst is used to catalyze the homopolymerization of ethylene, the reaction conditions are mild, and the super High molecular weight polyethylene has high industrial application value.

Description

A kind of ultra-high molecular weight polyethylene catalyst and its preparation method and application

technical field

The invention relates to the technical field of ethylene polymerization catalysts, in particular to an ultra-high molecular weight polyethylene catalyst and its preparation method and application.

Background technique

Ultra-high molecular weight polyethylene (UHMWPE) is a kind of linear structure polyethylene with extremely large relative molecular weight. It has been widely researched and applied due to its many excellent properties different from general-purpose polyethylene. UHMWPE fiber is a high-performance fiber prepared by gel spinning UHMWPE raw material. It has high strength, high modulus and excellent mechanical properties. It has been widely used in military industry, national defense and other fields. Generally speaking, the relative molecular mass distribution, particle shape, particle size distribution and other performance parameters of UHMWPE powder will be affected by factors such as catalyst and polymerization process, and these performance parameters will affect the processability of polymer powder, and then affect product performance. Therefore, in order to obtain UHMWPE fibers with excellent properties, it is necessary to explore the two aspects of UHMWPE raw materials and fiber preparation. To prepare ultra-strong polyethylene fibers, there are special requirements for UHMWPE. In addition to having a molecular weight higher than 4 million, it also requires a narrow molecular weight distribution. The molecular weight distribution of ultra-high molecular weight polyethylene almost plays a role in the performance of high-modulus polyethylene fibers. decisive role. It also requires high catalytic activity, so that the resulting UHMWPE has lower ash powder; at the same time, the obtained polyethylene particles have a high bulk density and a uniform distribution (that is, a narrow particle size distribution), and the particle size cannot be too large or too small. The average particle size is usually In 35 ~ 150μm.

In the prior art, ordinary Ziegler-Natta catalysts can only prepare ultra-high molecular weight polyethylene with a wide molecular weight distribution. Metallocene catalysts can prepare ultra-high molecular weight polyethylene with narrow molecular weight distribution, but due to the characteristics of metallocene catalysts, the obtained polyethylene molecular weight is not high enough. The non-metallocene catalysts with a single active center can prepare ultra-high molecular weight polyethylene with a molecular weight distribution between Ziegler-Natta catalysts and metallocene catalysts.

The non-metallocene catalysts that appeared in the mid-to-late 1990s have reached or even surpassed metallocene catalysts in some performance aspects, becoming the third generation of olefin polymerization catalysts after Ziegler-Natta and metallocene catalysts. Therefore, the catalyst or catalyst system based on this non-metallocene catalyst is attracting more and more attention, which provides a new way for the production of ultra-high molecular weight polyethylene.

US6265504B1 discloses a method for preparing ultra-high molecular weight polyethylene. The ultra-high molecular weight has an average molecular weight greater than 3 million and a molecular weight distribution of less than 5. The catalyst used is a single-site catalyst containing a heteroatom ligand, but it is a homogeneous catalyst. The ultra-high molecular weight polyethylene prepared by this type of catalyst has a poor shape and lacks the significance of practical application.

US2003/0130448A1 discloses a preparation process of ultra-high molecular weight polyethylene, which uses a supported single-site catalyst, uses a non-methylaluminoxane activator and is free of α-olefins, aromatic solvents and hydrogen polymerization under conditions. The process significantly increases the catalytic activity of the catalyst, and the prepared ultra-high molecular weight polyethylene has improved strength and impact properties. However, this patent not only has a complicated loading process but also requires relatively harsh polymerization conditions, and cannot adjust the molecular weight of ultra-high molecular weight polyethylene through commonly used hydrogen adjustment.

CN101654492A discloses the use of a supported non-metallocene catalyst to polymerize ethylene to obtain ultra-high molecular weight polyethylene under slurry polymerization conditions, but the particle size of ultra-high molecular weight polyethylene is too large, reaching about 800 μm, which has no practical value.

CN107936164A discloses a Schiffer's alkali-supported non-metallocene catalyst, which polymerizes ethylene to obtain ultra-high molecular weight polyethylene under slurry polymerization conditions, but the polymerization conditions are too harsh and need to be polymerized under a pressure of 2 MPa. The design pressure of ultra-high molecular weight polyethylene devices in the world is generally lower than 1MPa, and the current stage lacks practical application value.

CN100569808A discloses a preparation method of a supported non-metallocene catalyst, adopting the new ecological magnesium chloride generated by the reaction of magnesium powder and fluoroalkane as a carrier, and the pyrrole formaldehyde aniline ligand is first reacted with the carrier through the method of in-situ loading, Furthermore, transition metal halide _MX4 is added to react with the ligand compound to form a polymerization active component, so that the synthesis of the catalyst is directly carried out on the carrier to obtain a supported catalyst. Adopting this method to support non-metallocene catalysts can improve the catalytic activity, but there will be Ziegler-Natta catalyst components in the catalyst obtained by this support, so the molecular weight distribution of polyethylene is not narrow enough.

In summary, the existing catalysts used for the production of polyethylene have low catalytic activity, and the shape, particle size, molecular weight and molecular weight distribution of the prepared polyethylene are difficult to meet the requirements of ultra-high molecular weight polyethylene. Catalysts that overcome the above defects are the key to further promote the production and application of ultra-high molecular weight.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides an ultra-high molecular weight polyethylene catalyst, which comprises a general formula of (MgX' ₂ )(R ¹ MgX') _p Mg _q [(TiOR ² ) ₄ ] _x [Si( The active carrier of OR ³ ) ₄ ] _y and the semi-metallocene active component loaded on the active carrier, the catalyst has high titanium loading and high catalytic activity; the present invention also provides a preparation method of the catalyst, by using a solvent After the carrier is prepared by the method, the carrier is activated, and after the active carrier is obtained, the semi-metallocene active component is loaded on it. The preparation conditions are mild, the operation is simple, and the titanium loading capacity is high; when the catalyst is used to catalyze the homopolymerization of ethylene, the reaction conditions Mild, high molecular weight polyethylene with a molecular weight of 200,000 to 10 million can be obtained, the average particle size can be <130 μm, the molecular weight distribution Mw/Mn<3.2, and the catalytic activity can reach more than 26,000 g polyethylene/g catalyst. Value.

For reaching this purpose, the present invention adopts following technical scheme:

In a first aspect, the present invention provides an ultra-high molecular weight polyethylene catalyst, which overcomes the problem that the catalyst comprises (MgX' ₂ )(R ¹ MgX') _p Mg _q [(TiOR ² ) ₄ ] _x [Si(OR ³ ) ₄ ] _y 's active carrier and the semi-metallocene active component loaded on the active carrier; in the general formula of the active carrier, X' is a halogen, R ¹ and R ² are selected from C2～C4 Alkyl group, ^R3 is selected from C1～C3 alkyl group, p value is 0.4～0.8, q value is 0.02～0.15, x value is 0.03～0.09, y value is 0.1～0.3; The preparation method of described catalyst comprises: The carrier a having the general formula is mixed with a solvent to obtain a reaction liquid, and an aluminum alkyl is added to the reaction liquid to obtain an active carrier liquid, and then the active carrier liquid is reacted with a semi-metallocene active component, and the semi-metallocene The metal active component is supported on the active carrier to prepare the catalyst.

In the ultra-high molecular weight polyethylene catalyst provided by the present invention, a compound with the general formula (MgX' ₂ )(R ¹ MgX') _p Mg _q [(TiOR ² ) ₄ ] _x [Si(OR ³ ) ₄ ] _y is used as the active compound The carrier, compared with the existing magnesium halide carrier, the carrier is an in-situ magnesium halide, which has a large specific surface area and high overall catalytic activity, and the carrier itself has a shape so that it can better control the shape and shape of the final polyethylene product. Particle size; and the active carrier liquid after the activation of alkylaluminum in the solvent reacts with the semi-metallocene active component for loading, so that the catalyst has a high titanium loading capacity and high catalytic activity, and there will be no Ziegler-Natural residues in the catalyst. The catalyst component of the tower, the molecular weight distribution of the finally catalyzed polyethylene is narrow, and can be better used in the preparation of ultra-high molecular weight polyethylene.

Wherein, R ¹ and R ² are respectively selected from C2-C4 alkyl groups, such as ethyl, propyl or butyl, and R ¹ and R ² may be the same or different.

R ³ is selected from C1-C3 alkyl groups, such as methyl, ethyl or propyl.

The p value is 0.4 to 0.8, for example, it may be 0.4, 0.5, 0.6, 0.7 or 0.8.

The value of q is 0.02 to 0.15, for example, 0.02, 0.03, 0.04, 0.05, 0.08, 0.1, 0.12, 0.13, or 0.15.

The value of x is 0.03-0.09, for example, it can be 0.03, 0.04, 0.05, 0.06, 0.07, 0.08 or 0.09.

The value of y is 0.1-0.3, for example, 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.23, 0.25, or 0.3.

Preferably, in the general formula of the active magnesium chloride, X' is chlorine.

Preferably, the addition of the alkylaluminum is dropwise.

Preferably, the molar ratio of the aluminum alkyl to the magnesium halide in the carrier a is 0.2-1.0:1, for example, it can be 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1 , 0.8:1, 0.9:1 or 1.0:1, etc., preferably 0.4 to 0.8:1.

Preferably, the p value is 0.5-0.7.

Preferably, the value of q is 0.05-0.1.

Preferably, the value of x is 0.04-0.08.

Preferably, the value of y is 0.1-0.3.

The ultra-high molecular weight polyethylene in the present invention refers to polyethylene with a molecular weight of 200,000 to 10,000,000.

Preferably, the titanium content in the catalyst is 0.1-10% by weight, such as 0.1% by weight, 0.2% by weight, 0.5% by weight, 0.8% by weight, 1% by weight, 2% by weight, 3% by weight, and 4% by weight %, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, or 10% by weight, etc., preferably 5.1 to 9.5% by weight.

In the present invention, the titanium loading is preferably 5.1-9.5% by weight, and the titanium content in the catalyst is high, so that the catalytic activity of the overall catalyst is high.

Preferably, the general formula of the semi-metallocene active component is formula (1):

The semi-metallocene active component of the present invention adopts the semi-metallocene active component containing β-diketone derivative ligand, and the prepared catalyst has a high titanium loading capacity and has good fluidity and strength.

Preferably, in the general formula (1), R and R' are each independently a C1-C12 alkyl group, a C6-C9 alkaryl group or a C1-C12 perfluoroalkyl group; Cp' is a Ligand group of the ene skeleton, there are 1 to 5 substituents R ⁴ on the cyclopentadiene skeleton, and two adjacent substituents on the cyclopentadiene skeleton can be connected to each other to form a condensed Ring, R ⁴ is selected from hydrogen, C1-C18 alkyl or perfluoroalkyl, C6-C24 aralkyl or alkaryl. X is halogen, and n is an integer of 1-3.

Preferably, R and R' in the general formula (1) are each independently a C1-C12 alkyl group, a C6-C9 alkaryl group or a C1-C12 perfluoroalkyl group, and R and R' can be the same or different , such as methyl, propyl or benzyl, etc., preferably C1-C3 alkyl, C6-C9 alkaryl or C1-C3 perfluoroalkyl, more preferably methyl or phenyl;

Preferably, the Cp' is cyclopentadienyl, fluorenyl, indenyl or cyclopentadienyl, fluorenyl or indenyl in which at least one hydrogen atom is substituted by C1-C4 alkyl, such as methylcyclopentadiene Alkenyl, butylcyclopentadienyl, 1-butyl-3-methylcyclopentadienyl or pentamethylcyclopentadienyl, etc., preferably cyclopentadienyl in which at least one hydrogen atom is replaced by a C1-C4 alkyl group alkenyl, fluorenyl or indenyl, more preferably cyclopentadienyl, butylcyclopentadienyl, pentamethylcyclopentadienyl, indenyl or fluorenyl.

Preferably, said X is chlorine.

Preferably, the compounds of the general formula (1) are: cyclopentadiene-(acetylacetonate)-titanium difluoride, cyclopentadiene-bis(acetylacetonate)-titanium chloride, cyclopentadiene-tri (Acetylacetonate) titanium, cyclopentadiene-(diformylmethane)-titanium difluoride, cyclopentadiene-bis(dibenzoylmethane)-titanium fluoride, cyclopentadiene tri(diphenyl Formylmethane) titanium, methylcyclopentadiene-(acetylacetonate)-titanium dichloride, methylcyclopentadiene-di(acetylacetonate)-titanium chloride, methylcyclopentadiene-tri(acetylacetonate) Acetone) titanium, methylcyclopentadiene (dibenzoylmethane)-titanium difluoride, methylcyclopentadiene-di(dibenzoylmethane)-titanium fluoride, methylcyclopentadiene- Tris(dibenzoylmethane)titanium, Butylcyclopentadiene-(acetylacetonate)-titanium dichloride, Butylcyclopentadiene-di(acetylacetonate)-titanium chloride, Butylcyclopentadiene-tris(acetylacetonate) Titanium, butylcyclopentadiene-(dibenzoylmethane)-titanium dichloride, butylcyclopentadiene-bis(dibenzoylmethane)titanium fluoride, butylcyclopentadiene-tris(dibenzoylmethane)titanium , Pentamethylcyclopentadiene-(acetylacetonate)titanium dichloride, pentamethylcyclopentadiene-di(acetylacetonate)-titanium chloride, pentamethylcyclopentadiene-tri(acetylacetonate)titanium , Pentamethylcyclopentadiene-(dibenzoylmethane)-titanium dichloride, Pentamethylcyclopentadiene bis(dibenzoylmethane)-titanium fluoride, Pentamethylcyclopentadiene- Tris(dibenzoylmethane)titanium, cyclopentadiene-(trifluoroacetylacetonate)titanium difluoride, cyclopentadiene-bis(trichloroacetylacetonate)titanium chloride, cyclopentadiene-tri(trifluoroacetylacetonate)titanium chloride Fluoroacetylacetonate) titanium, methylcyclopentadiene (trifluoroacetylacetonate) titanium difluoride, methylcyclopentadiene-bis(trifluoroacetylacetonate) titanium chloride, methylcyclopentadiene-tri( Titanium trifluoroacetylacetonate, indenyl-(acetylacetonate)-titanium difluoride, indenyl-di(acetylacetonate)-titanium chloride, indenyl-tri(acetylacetonate)titanium, indenyl-(dibenzoyl Methane)-titanium difluoride, indenyl-bis(dibenzoylmethane)titanium fluoride or indenyl-tris(dibenzoylmethane)titanium, etc.

Preferably, the catalytic activity of the catalyst is >2.2×10 ⁴ g polyethylene/g catalyst, such as 2.2×10 ⁴ g polyethylene/g catalyst, 2.3×10 ⁴ g polyethylene/g catalyst, 2.5×10 ⁴ g polyethylene/g catalyst, 2.6×10 ⁴ g polyethylene/g catalyst, 3.0×10 ⁴ g polyethylene/g catalyst, 3.2×10 ⁴ g polyethylene/g catalyst, 3.5×10 ⁴ g polyethylene/g catalyst , 4×10 ⁴ g polyethylene/g catalyst, etc., preferably >2.5×10 ⁴ g polyethylene/g catalyst.

Preferably, the average particle size of the catalyst is 4-8 μm, for example, 4 μm, 5 μm, 6 μm, 7 μm or 8 μm.

Preferably, the ultra-high molecular weight polyethylene is polyethylene with a molecular weight of 200,000 to 10 million, such as 200,000, 300,000, 500,000, 1 million, 1.5 million, 2 million, 2.5 million, 3 million, 4 million 10,000, 5 million, 6 million, 7 million, 8 million, 9 million or 10 million, etc., preferably polyethylene with a molecular weight of 1.5 to 10 million.

Preferably, the catalyst is a single-site catalyst.

In the present invention, the catalytic activity of the catalyst is represented by gPE/gCat, which refers to the number of grams of ultra-high molecular weight polyethylene catalyzed per gram of catalyst under certain polymerization conditions.

In a second aspect, the present invention provides a method for preparing the ultra-high molecular weight polyethylene catalyst described in the first aspect, the method comprising: (MgX' ₂ )(R ¹ MgX') _p Mg _q [(TiOR ² ) ₄ ] _x [Si(OR ³ ) ₄ ] _y carrier a is mixed with a solvent to obtain a reaction liquid, adding an aluminum alkyl to the reaction liquid to obtain an active carrier liquid, and then combining the active carrier liquid with the semimetallocene active Component reaction, the semi-metallocene active component is supported on the active carrier to prepare the catalyst;

Wherein, R ¹ and R ² are selected from C2-C4 alkyl groups respectively, R ³ is selected from C1-C3 alkyl groups, p value is 0.4-0.8, q value is 0.02-0.15, x value is 0.03-0.09, y The value is 0.1 to 0.3.

In the present invention, the active carrier with the above general formula is used to load the semi-metallocene active component. Compared with the conventional anhydrous magnesium chloride loaded semi-metallocene component, the active carrier has a larger specific surface area and higher catalytic activity.

Wherein, R ¹ and R ² are respectively selected from C2-C4 alkyl groups, such as ethyl, propyl or butyl, and R ¹ and R ² may be the same or different.

R ³ is selected from C1-C3 alkyl groups, such as methyl, ethyl or propyl, etc.

The p value is 0.4 to 0.8, for example, it may be 0.4, 0.5, 0.6, 0.7 or 0.8.

The value of q is 0.02 to 0.15, for example, 0.02, 0.03, 0.04, 0.05, 0.08, 0.1, 0.12, 0.13, or 0.15.

The value of x is 0.03-0.09, for example, it can be 0.03, 0.04, 0.05, 0.06, 0.07, 0.08 or 0.09.

The value of y is 0.1-0.3, for example, 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.23, 0.25, or 0.3.

Preferably, the method comprises:

(1) Mix magnesium and solvent I, add electron donor compound and haloalkane after stirring, and separate solid and liquid after reaction to obtain carrier a;

(2) The carrier a prepared in step (1) is activated to obtain an active carrier liquid;

(3) After mixing and reacting the active carrier liquid obtained in step (2) with the semimetallocene active component, the solid-liquid separation is carried out to obtain the catalyst.

Preferably, in the general formula of the active magnesium chloride, X' is chlorine.

Preferably, the p value is 0.5-0.7.

Preferably, the value of q is 0.05-0.1.

Preferably, the value of x is 0.04-0.08.

Preferably, the value of y is 0.1-0.3.

Preferably, the magnesium in step (1) is magnesium powder.

Preferably, the solvent I is a hydrocarbon solvent.

Preferably, the electron donor compound includes a mixture of Ti(OR ² ) ₄ and Si(OR ³ ) ₄ , wherein R ² is selected from C2-C4 alkyl groups, such as ethyl, propyl or butyl Etc., R ³ is selected from C1～C3 alkyl groups, such as methyl, ethyl or propyl, etc.

Preferably, the molar ratio of Ti(OR ² ) ₄ to magnesium in the electron donor compound is 0.01-0.05:1, such as 0.01:1, 0.02:1, 0.03:1, 0.04:1 or 0.05:1 wait.

Preferably, the molar ratio of Si(OR ³ ) ₄ to magnesium in the electron donor compound is 0.05-0.5:1, such as 0.05:1, 0.06:1, 0.08:1, 0.1:1, 0.15:1 , 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1 or 0.5:1, etc.

Preferably, the haloalkane is a monohaloalkane.

Preferably, the halogenated alkanes are chlorinated alkanes, preferably chloropropane, chlorobutane, chloroisobutane, chloro-tert-butane or chloroisopentane.

Preferably, the molar ratio of the haloalkane to magnesium is 2 to 8:1, for example, it can be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1 or 8:1, etc. .

Preferably, iodine is also added after the stirring.

Preferably, the reaction temperature is 20-100°C, for example, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or 100°C.

Preferably, the step (1) includes: mixing magnesium and solvent I, adding an electron donor compound after stirring, adding halogenated alkanes after stirring, and performing solid-liquid separation after reaction to obtain carrier a.

Preferably, the solid phase after the solid-liquid separation is washed and dried to obtain the carrier a.

Preferably, the activation treatment in step (2) includes: mixing the carrier a prepared in step (1) with solvent II and solvent III, heating and stirring, then cooling to obtain a reaction liquid, adding an alkyl group to the reaction liquid Aluminum, heat up to obtain active carrier liquid.

Preferably, the active carrier liquid is a slurry of active carrier.

Preferably, the solvent II is a non-polar organic solvent, preferably a C5-C20 alkane, such as pentane, hexane, heptane or octane.

Preferably, the solvent III is aliphatic alcohol, such as methanol, ethanol, propanol, butanol, pentanol or heptanol.

Preferably, the general formula of the fatty alcohol is R ⁵ OH, wherein R ⁵ is selected from C1-C8 alkyl groups, such as methyl, ethyl, propyl, butyl, pentyl or heptyl, etc.

Preferably, the fatty alcohol is dry fatty alcohol.

Preferably, the molar ratio of the solvent III to the magnesium halide in the carrier a is 0.2-1.0:1, such as 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1 or 1.0:1, etc., preferably 0.4-0.8:1.

The present invention strictly controls the molar ratio of the solvent III to the magnesium halide in the carrier a to be 0.2-1.0:1, so as to better improve the activity of the carrier a, facilitate its subsequent loading of semi-metallocene components, and finally improve the catalytic activity of the catalyst.

Preferably, the cooling includes: cooling to 0-20°C, for example, 0°C, -2°C, -5°C, -10°C, -12°C, -15°C, -18°C or -20°C, etc. .

Preferably, the addition of the alkylaluminum is dropwise.

Preferably, the molar ratio of the aluminum alkyl to the magnesium halide in the carrier a is 0.2-1.0:1, for example, it can be 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1 , 0.8:1, 0.9:1 or 1.0:1, etc., preferably 0.4 to 0.8:1.

Preferably, the added amount of the aluminum alkyl is 1.1 times that of the fatty alcohol on a molar basis.

Preferably, the temperature increase includes: increasing the temperature to 10-30°C, such as 10°C, 12°C, 15°C, 17°C, 18°C, 20°C, 22°C, 25°C, 28°C or 30°C.

Preferably, the mixing reaction in step (3) includes: dissolving the semi-metallocene active component in solvent IV to obtain a semi-metallocene solution, and then reacting after mixing the semi-metallocene solution with an active carrier liquid.

Preferably, the semi-metallocene solution is dropped into the active carrier liquid and mixed.

Preferably, the solvent IV is a polar organic solvent.

Preferably, the polar organic solvent includes halogenated alkanes containing 1 to 3 carbon atoms, preferably 1 to 3 halogen atoms, such as monobromoalkanes, dichloroalkanes or trichloroalkanes.

Preferably, the mass of the polar organic solvent is 5 to 200 times the weight of the semi-metallocene active component, such as 5 times, 10 times, 20 times, 25 times, 30 times, 50 times, 100 times, 150 times times, 180 times, 190 times or 200 times, etc.

Preferably, the molar ratio of the magnesium halide in the active carrier liquid to the semimetallocene active component is 5 to 500:1, for example, it can be 5:1, 10:1, 20:1, 50:1, 100:1 1. 200:1, 300:1, 400:1 or 500:1, preferably 5-50:1.

In the present invention, it is preferable to control the molar ratio of the magnesium halide in the active carrier liquid to the active component of the semimetallocene at 5-50:1, which can further increase the amount of titanium loaded, thereby finally improving the catalytic activity of the catalyst.

Preferably, the reaction temperature is 10-70°C, such as 10°C, 20°C, 30°C, 40°C, 50°C, 60°C or 70°C, preferably 10-30°C.

Preferably, the reaction time is 0.5-72h, such as 0.5h, 1h, 1.2h, 2h, 3h, 5h, 10h, 12h, 15h, 20h, 25h, 30h, 35h, 40h, 45h, 50h, 60h, 70h or 72h, etc., preferably 0.5-2h.

Preferably, the reaction is carried out with stirring.

Preferably, the polar organic solvent is a chlorinated alkane, such as dichloromethane, trimethanedichloroethane, carbon tetrachloride, dichloroethane or trichloroethane, etc., more preferably dichloromethane , trimethane dichloroethane or carbon tetrachloride.

Preferably, the preparation method of the semi-metallocene active component of the general formula (1) comprises the following steps:

(1) Make TiX ₄ and the β-diketone compound having the general formula R"'-C(O)-CH ₂ -C(O)-R"" in diethyl ether at a molar ratio of 1:1 to 3 React at reflux temperature, remove solvent, obtain β-diketone titanium compound;

(2) In an organic solvent, the alkali metal salt Cp'M of the cyclopentadiene skeleton compound is reacted with the β-diketone titanium compound in an equimolar ratio, the reaction is carried out, the solvent is removed and dried to obtain the formula (1) The semi-metallocene active components described above.

Wherein, M in the Cp'M is an alkali metal, such as sodium or potassium, preferably sodium.

Preferably, in the step (1) of the preparation method of the semi-metallocene active component, the β-diketone titanium compound is first dissolved in toluene to prepare a solution, and then Cp'M is added.

Preferably, in the step (2) of the preparation method of the semi-metallocene active component, the reaction temperature is -15 to 25°C, for example, it can be -15°C, -10°C, -5°C, 0°C, 5°C , 10°C, 15°C or 20°C, etc.

Preferably, in the step (2) of the preparation method of the semi-metallocene active component, before drying, the solid matter is washed with ether, or the solid matter is recrystallized and purified.

Preferably, the solvent used for the recrystallization is a polar organic solvent, such as halogenated alkanes and the like.

Preferably, the drying temperature is 50-60°C, such as 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C.

The present invention has no limitation on the above-mentioned drying time, and the drying time can be determined according to needs, for example, it can be 1h, 2h, 3h, 4h, 5h, 8h, 10h, 12h, 14h, 15h, 20h or 40h, etc., preferably 3～12h .

Preferably, R"' and R"" in the β-diketone titanium compound are C1-C3 alkyl, C1-C3 perfluoroalkyl or C6-C9 alkaryl.

Preferably, the β-diketone titanium compound is acetylacetone, dibenzoylmethane, triacetylacetone. The preferred β-diketone titanium compound is (acetylacetonate) titanium trichloride, di(acetylacetonate) dichloride Titanium, tris(acetylacetonate)titanium chloride, (dibenzoylmethane)titanium trichloride, bis(dibenzoylmethane)titanium dichloride, tris(dibenzoylmethane)titanium chloride, (tri (fluoroacetylacetonate)titanium trichloride, (trifluoroacetylacetonate)titanium dichloride or tris(trifluoroacetylacetonate)titanium chloride.

Preferably, the preparation method of Cp'M comprises: reacting a compound Cp'H having a cyclopentadiene skeleton with an equimolar amount of an alkali metal compound in an ether solvent, and then removing the solvent to obtain a cyclopentadiene-containing Alkali metal salts of diene skeleton ligands.

Preferably, in the preparation method of Cp'M, the alkali metal compound is first dissolved in ether, and then the ether solution of Cp'H is added.

Preferably, in the preparation method of Cp'M, first dissolve Cp'H in ether, and then add the ether solution of the alkali metal compound.

Preferably, the temperature of the reaction is controlled at -44°C to 150°C, such as -44°C, -40°C, -30°C, -25°C, -20°C, -10°C, 0°C, 5°C, 10°C °C, 20°C, 50°C, 100°C, or 150°C, etc., preferably -10 to 115°C.

Preferably, the reaction time is 1 to 5 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours or 5 hours.

Preferably, the addition amount of the ether solvent is controlled at 3 to 5 times the total weight of Cp'H and alkali metal compound reactants, for example, it can be 3 times, 3.2 times, 3.5 times, 3.8 times, 4 times, 4.2 times , 4.5 times, 4.8 times or 5 times, etc.

Preferably, the ether solvent is diethyl ether or tetrahydrofuran.

Preferably, the alkali metal compound is selected from alkali metals, alkali metal hydrides, alkyls or amides, preferably sodium, potassium, butyllithium, sodium hydride, potassium hydride, kryptonium or radonylpotassium.

Preferably, the alkyl group in the alkylate is a C1-C24 alkyl group, such as methyl, butyl or pentyl, etc.

As a preferred technical solution of the present invention, the method comprises the steps of:

(1) Mix magnesium powder and hydrocarbon solvent, add the mixture of Ti(OR ² ) ₄ and Si(OR ³ ) ₄ as electron donor compound after stirring, react and stir at 50-80°C for 1-5 hours, then add dry The halogenated alkanes are continuously reacted at 20-100°C for 2-5 hours, and the solid phase after solid-liquid separation is washed and dried to obtain carrier a, the general formula of which is (MgX' ₂ )(R ¹ MgX ') _p Mg _q [(TiOR ² ) ₄ ] _x [Si(OR ³ ) ₄ ] _y ; wherein, R ¹ and R ² are selected from C2-C4 alkyl groups, and R ³ is selected from C1-C3 alkyl groups , the p value is 0.4~0.8, the q value is 0.02~0.15, the x value is 0.03~0.09, and the y value is 0.1~0.3;

Wherein, the molar ratio of Ti(OR ² ) ₄ to magnesium in the electron donor compound is 0.01-0.05:1, the molar ratio of Si(OR ³ ) ₄ to magnesium is 0.05-0.5:1, and the halogenated alkane and The molar ratio of magnesium is 2～8:1;

(2) The carrier a prepared in step (1) is mixed with a non-polar organic solvent and aliphatic alcohol with the general formula R ⁵ OH, heated to 40-60°C and stirred for 0.8-3 hours, then cooled to 0-20°C, Obtaining a reaction solution, adding aluminum alkyl dropwise to the reaction solution, raising the temperature to 10-30°C to obtain an active carrier solution;

Wherein, R ^is selected from C1～C8 alkyl groups, the molar ratio of the non-polar organic solvent to the magnesium halide in the carrier a is 0.2～1.0:1; the molar ratio of the aluminum alkyl to the magnesium halide in the carrier a 0.2～1.0:1;

(3) dissolving the semi-metallocene active component in a polar organic solvent to obtain a semi-metallocene solution, then dripping the semi-metallocene solution into the active carrier liquid obtained in step (2), react after mixing, and Solid-liquid separation and drying yielded the catalyst.

In a third aspect, the present invention provides the application of the ultra-high molecular weight polyethylene catalyst described in the first aspect in catalytic polymerization of ethylene.

The ethylene catalyst provided by the present invention is used in ethylene polymerization, not only can increase the molecular weight of polyethylene, but also because the catalyst itself has a good particle shape, it can better control the shape and particle size of the obtained polyethylene, so that the obtained polyethylene The molecular weight distribution is narrow, especially suitable for the preparation process of ultra-high molecular weight polyethylene with high requirements on shape and molecular weight distribution.

Preferably, the catalytic polymerization of ethylene includes: homopolymerization of ethylene or copolymerization of ethylene and α-olefin.

Preferably, the α-olefin includes any one or a combination of at least two of butene, olefin, hexene or styrene.

Preferably, the application includes: performing a polymerization reaction under the action of a catalyst to obtain a polymer.

Preferably, the catalyst is polymerized under the action of a co-catalyst to obtain polyethylene.

Preferably, the cocatalyst comprises any one or at least two of trimethylaluminum, triethylaluminum, triisobutylaluminum, monochlorodiethylaluminum, methylalumoxane or organoboride combination.

Preferably, the molar ratio of the aluminum in the cocatalyst to the titanium in the catalyst is 10 to 500:1, such as 10:1, 20:1, 30:1, 50:1, 150:1, 200:1 1. 300:1, 400:1 or 500:1, etc., preferably 30-200:1.

Preferably, the polymerization reaction is carried out in an organic solvent.

Preferably, the organic solvent has a boiling point of 30-150°C, for example, 30°C, 40°C, 50°C, 60°C, 80°C, 90°C, 100°C or 150°C.

Preferably, the organic solvent includes any one or a combination of at least two of n-hexane, n-heptane, 120# solvent oil, 90# solvent oil, methylene chloride, toluene or xylene, wherein the typical non-limiting The combination is the combination of n-hexane and n-heptane, the combination of n-hexane and 120# solvent oil, the combination of 120# solvent oil and n-heptane, the combination of toluene and 120# solvent oil, the combination of n-hexane and toluene, the combination of 120# solvent Combination of oil and 90# solvent oil.

Preferably, the temperature of the polymerization reaction is 30-90°C, such as 30°C, 40°C, 50°C, 60°C, 70°C, 80°C or 90°C.

Preferably, the molecular weight of polyethylene obtained from the polymerization reaction is 200,000 to 10 million, for example, 200,000, 300,000, 500,000, 1 million, 1.5 million, 2 million, 2.5 million, 3 million, 4 million, 5 million 10,000, 6 million, 7 million, 8 million, 9 million, or 10 million, etc., preferably 1.5 million to 10 million.

Preferably, the average particle diameter of the polyethylene obtained by the polymerization reaction is ≤130 μm, for example, 80 μm, 90 μm, 100 μm, 101 μm, 102 μm, 110 μm, 120 μm, 125 μm or 130 μm.

Preferably, the polyethylene obtained from the polymerization reaction has a bulk density ≥ 0.44g/cm ³ , for example, 0.44g/cm ³ , 0.45g/cm ³ , 0.48g/cm ³ , 0.49g/cm ³ or 0.5g /cm ³ etc.

Preferably, the molecular weight distribution of the polymerization reaction Mw/Mn<3.2, for example, may be 3.19, 3.18, 3.17, 3.16, 3.15, 3.14, 3.12, 3.08, 3.02, 3, 2.98, 2.8 or 2.5.

Compared with the prior art, the present invention has at least the following beneficial effects:

(1) The ultra-high molecular weight polyethylene catalyst provided by the present invention is obtained by adopting the general formula (MgX' ₂ )(R ¹ MgX') _p Mg _q [(TiOR ² ) ₄ ] _x [Si(OR ³ ) ₄ ] _Y The active carrier loads the semi-metallocene active component, and can obtain a catalyst with good particle shape, in which the titanium loading is high, and the catalytic activity is above 2.2×10 ⁴ g polyethylene/g catalyst, and under optimal conditions, it is 2.6×10 ⁴ g More than polyethylene/g catalyst;

(2) In the preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present invention, an activated magnesium halide carrier is obtained after direct reaction and activation of magnesium with a solvent and a halogenated alkane, which has a large specific surface area, higher catalytic activity, and a simple preparation method;

(3) When the ultra-high molecular weight polyethylene catalyst provided by the present invention is used for polyethylene preparation, high molecular weight polyethylene with a molecular weight of 200,000 to 10 million can be obtained, its average particle diameter≤130 μm, and molecular weight distribution Mw/Mn<3.2, which can Better meet the preparation requirements of ultra-high molecular weight polyethylene.

Description of drawings

Fig. 1 is an XRD diffraction pattern of carrier a in ultra-high molecular weight polyethylene catalyst A provided in Example 1 of the present invention.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation methods.

The present invention will be further described in detail below. However, the following examples are only simple examples of the present invention, and do not represent or limit the protection scope of the present invention, and the protection scope of the present invention shall be determined by the claims.

1. Embodiment

Example 1

_This embodiment _{provides an} ultra _- high molecular _{weight polyethylene} catalyst _{A ,} said _catalyst A comprising ) ₄ ] _0.23 active carrier and the semi-metallocene active component loaded on the active carrier; the semi-metallocene active component is cyclopentadiene-(dibenzoylmethane) titanium dichloride.

The preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present embodiment is as follows:

1. Preparation of semi-metallocene active components

(1) concentration is 4.74 % by weight of TiCl ₄ ether solution, 5.6 % by weight of dibenzoylmethane ether solution is added in airtight container, and make TiCl ₄ The mol ratio with dibenzoylmethane is 1:1, Stir and heat to reflux temperature, react for 1 h, filter, and wash the solid with ether three times to obtain (dibenzoylmethane)titanium trichloride;

(2) Dissolve 5.5 mL of cyclopentadiene in 25 mL of tetrahydrofuran, add 1.4 g of sodium metal at -10°C for 2 hours, and remove the solvent under reduced pressure to obtain 4.67 g of sodium cyclopentadiene;

(3) (dibenzoylmethane) titanium trichloride is dissolved in toluene and is made into the solution of 94.35% by weight, then at 10 ℃, adding concentration is the toluene solution of sodium cyclopentadiene of 22.02% by weight, and make (two The molar ratio of benzoylmethane) titanium chloride to cyclopentadiene sodium is 1:1, stirred and reacted at 20°C for 5h, filtered, washed with ether for 3 times, and dried at 50°C for 2h to obtain cyclopentadiene-(di benzoylmethane) titanium dichloride.

2. Preparation of active carrier

(1) Place in a 500ml three-neck flask replaced by nitrogen, add 150ml hexane, 6mmolL n-butyl titanate, 36mmolL tetraethyl orthosilicate and 0.02g iodine, heat to 75°C and stir for 2h to activate, the stirring speed is 800r /min, drop 1moL of dry n-chlorobutane, an obvious reaction can be observed, continue to react for 3 h, filter, wash the obtained solid with hexane and dry to obtain a carrier a with a particle size of 5 μm, the composition is : (MgCl ₂ )(BuMgCl) _0.58 Mg _0.08 [Ti(OC ₄ H ₉ ) ₄ ] _0.07 [Si(OC ₂ H ₅ ) ₄ ] _0.23 , the element analysis result of the carrier is, measured value (theoretical value): Mg: 17.15wt% (17.05wt%), Ti: 1.46wt% (1.42wt%), Si: 2.69wt% (2.73wt%), C: 26.65wt% (26.80wt%), H: 5.37wt% ( 5.25 wt%). Its XRD diffraction pattern is shown in Figure 1. In the XRD pattern of Figure 1, a slightly broad peak at 20° to 22° produced by BuMgCl appears; and δ-MgCl ₂ is actually α-MgCl ₂ and β- Mixed crystal of two crystal structures of MgCl ₂ , the broad peak at 32.3° in the spectrum corresponds to the 101 crystal plane diffraction peak of β-MgCl ₂ , and the two small shoulders appearing on this broad peak correspond to α- The diffraction peaks of the 012 and 104 crystal planes of MgCl ₂ .

(2) In a 250ml three-necked flask replaced with nitrogen, add 4.7g of carrier a (containing 20.0mmoL of magnesium chloride) prepared in step (1), 50ml of n-decane and 16.0mmoL of isooctyl alcohol, heat up to 50°C and stir for 1h. Then cool to -10°C, slowly add 17.6mmoL triethylaluminum dropwise within 30min, after the dropwise addition, raise the temperature to 20°C to obtain an active carrier solution.

3. Preparation of supported catalyst

Slowly drop 100mL of dichloromethane solution dissolved with 16mmoL cyclopentadiene-(dibenzoylmethane)titanium dichloride into the reaction flask containing the active carrier liquid, stir and react at 20°C for 5h, stop stirring, After filtration, the solid was dried at 20° C. for 6 h to obtain 13.2 g of brown Catalyst A.

Example 2

_{This embodiment provides} an ultra-high _- molecular _- weight _{polyethylene catalyst B} , said catalyst B _comprising ) ₄ ] _0.23 active carrier and the semi-metallocene active component loaded on the active carrier; the semi-metallocene active component is butylcyclopentadiene-(dibenzoylmethane) titanium dichloride.

The preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present embodiment is as follows:

1. Preparation of semi-metallocene active components

The step of described preparation semi-metallocene active component except that in step (2) replaces cyclopentadiene with butyl cyclopentadiene and makes butyl cyclopentadiene sodium; In step (3), use the butyl cyclopentadiene that concentration is 16mmoL The reaction of the toluene solution of sodium dimethene was the same as in Example 1 except that butylcyclopentadiene-(dibenzoylmethane) titanium dichloride was finally obtained.

2. Preparation of active carrier

The steps for preparing the active carrier are the same as in Example 1.

3. Preparation of supported catalyst

The step of preparing supported catalyst is except that 60mL is dissolved with the dichloromethane solution of 16mmoL butylcyclopentadiene-(dibenzoylmethane) titanium dichloride, obtains 13.32g brown catalyst B, all the other are identical with embodiment 1 .

Example 3

_This embodiment provides _an ultra-high _{molecular weight polyethylene catalyst C ,} said catalyst C _comprising ) ₄ ] _0.23 active carrier and the semi-metallocene active component loaded on the active carrier; the semi-metallocene active component is indenyl-(dibenzoylmethane) titanium dichloride.

The preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present embodiment is as follows:

1. Preparation of semi-metallocene active components

The step of preparing the semi-metallocene active component is except that indene is used to replace cyclopentadiene to obtain indenyl sodium in step (2); in step (3), the toluene solution of indenyl sodium with a concentration of 24.67% by weight is used to react , and finally obtained indenyl-(dibenzoylmethane) titanium dichloride, the rest are the same as in Example 1.

2. Preparation of active carrier

The steps for preparing the active carrier are the same as in Example 1.

3. Preparation of supported catalyst

The step of preparing the supported catalyst was the same as in Example 1 except that 60 mL of indenyl-(dibenzoylmethane)titanium dichloride dichloromethane solution was dissolved in 60 mL to obtain 14.22 g of brown catalyst C.

Example 4

_This embodiment provides _an ultra _{- high molecular weight polyethylene} catalyst D _, said catalyst _D comprising ) ₄ ] _0.23 active carrier and the semi-metallocene active component loaded on the active carrier; the semi-metallocene active component is cyclopentadiene-(acetylacetonate) titanium dichloride.

The preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present embodiment is as follows:

1. Preparation of semi-metallocene active components

(1) The concentration is that 4.47% by weight of TiCl ₄ ethyl ether solution, the concentration is that the acetone solution of 2.51% by weight of acetylacetone is added in the airtight reactor, and the molar ratio of TiCl ₄ and acetylacetone is 1:1, stirring and heating to Reflux temperature, react for 1h, remove diethyl ether by filtration, wash the solid with diethyl ether 3 times to obtain (acetylacetonate)titanium trichloride;

(2) Dissolving the above-mentioned (acetylacetonate) titanium trichloride in toluene to make a 63.37% by weight solution, adding a concentration of 2.0% by weight toluene solution of sodium cyclopentadiene at -10°C, and making cyclopentadiene The molar ratio of sodium to (acetylacetonate)titanium trichloride was 1:1, stirred and reacted at 20°C for 5h, filtered to remove toluene, washed the solid with diethyl ether three times, then dissolved the solid with 30mL of dichloromethane, filtered to remove insoluble matter, Concentrate the filtrate to dryness and dry at 50°C for 4h to obtain cyclopentadiene-(acetylacetonate)-titanium dichloride.

2. Preparation of active carrier

The steps for preparing the active carrier are the same as in Example 1.

3. Preparation of supported catalyst

The step of preparing the supported catalyst was the same as in Example 1 except that 60 mL of dichloromethane solution dissolved with 16 mmoL cyclopentadiene-(acetylacetonate) titanium dichloride was used to obtain 11.32 g of brown catalyst D.

Example 5

_{This embodiment} provides _an ultra _- high _{molecular weight} polyethylene catalyst E _, said _{catalyst E} comprising ) ₄ ] _0.23 active carrier and the semi-metallocene active component loaded on the active carrier; the semi-metallocene active component is butylcyclopentadiene-(acetylacetonate)-titanium dichloride.

The preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present embodiment is as follows:

1. Preparation of semi-metallocene active components

The step of preparing the semi-metallocene active component is in addition to reacting with butylcyclopentadiene sodium and (acetylacetonate) titanium trichloride to prepare the active component butylcyclopentadiene-(acetylacetonate)-titanium dichloride, All the other are identical with embodiment 4.

2. Preparation of active carrier

The steps for preparing the active carrier are the same as in Example 4.

3. Preparation of supported catalyst

The step of preparing the supported catalyst was the same as in Example 4 except that 60 mL of dichloromethane solution dissolved with 16 mmoL butylcyclopentadiene-(acetylacetonate) titanium dichloride was used to obtain 12.32 g of brown catalyst E.

Example 6

_{This embodiment} provides _an ultra _- high _{molecular weight} polyethylene catalyst E _, said _{catalyst E} comprising ) ₄ ] _0.23 active carrier and the semi-metallocene active component loaded on the active carrier; the semi-metallocene active component is indenyl-(acetylacetonate)-titanium dichloride.

The preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present embodiment is as follows:

1. Preparation of semi-metallocene active components

In the step of preparing the semi-metallocene active component, the active component indenyl-(acetylacetonate)-titanium dichloride is prepared by reacting indenylcyclopentadiene sodium with (acetylacetonate) titanium trichloride, All the other are identical with embodiment 4.

2. Preparation of active carrier

The steps for preparing the active carrier are the same as in Example 4.

3. Preparation of supported catalyst

The step of preparing the supported catalyst was the same as in Example 4 except that 13.2 g of brown catalyst F was obtained by reacting with 60 mL of indenyl-(acetylacetonate)-titanium dichloride dichloromethane solution dissolved in 60 mL.

Example 7

_This embodiment provides _an ultra _- high _{molecular weight polyethylene} catalyst G _, said _catalyst G _comprising ) ₄ ] _0.23 active carrier and the semi-metallocene active component loaded on the active carrier; the semi-metallocene active component is cyclopentadiene-two (dibenzoylmethane) titanium chloride.

The preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present embodiment is as follows:

1. Preparation of semi-metallocene active components

The step of described preparation semi-metallocene active component except _TiCl in the step (1) The mol ratio with dibenzoylmethane is 1:2, makes two (dibenzoylmethane) titanium dichlorides, step ( In 2), the toluene solution of di(dibenzoylmethane)titanium dichloride was used to react to finally obtain cyclopentadiene-bis(dibenzoylmethane)titanium chloride, and the rest were the same as in Example 1.

2. Preparation of active carrier

The steps for preparing the active carrier are the same as in Example 1.

3. Preparation of supported catalyst

The step of preparing the supported catalyst was reacted with 60mL of cyclopentadiene-bis(dibenzoylmethane)titanium dichloride dichloromethane solution to react with 60mL to obtain 13.08g of brown catalyst G, all the others were the same as those in Example 1 is the same.

Example 8

_This embodiment provides _an ultra _{- high} molecular _{weight polyethylene} catalyst _{H ,} said catalyst H _comprising ) ₄ ] _0.23 active carrier and the semi-metallocene active component loaded on the active carrier; the semi-metallocene active component is cyclopentadiene-(dibenzoylmethane) titanium dichloride.

The preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present embodiment is as follows:

1. Preparation of semi-metallocene active components

The steps for preparing the semi-metallocene active component are the same as in Example 1.

2. Preparation of active carrier

The steps for preparing the active carrier were all the same as in Example 1 except that the amount of isooctyl alcohol in step (2) was changed to 12mmoL, and triethylaluminum was changed to 12.2mmoL.

3. Preparation of supported catalyst

The step of preparing the supported catalyst was the same as in Example 1 except that the amount of cyclopentadiene-(dibenzoylmethane)titanium dichloride was changed to 12.0mmoL to obtain 11.1g of brown catalyst H.

Example 9

This embodiment provides an ultra-high molecular weight polyethylene catalyst I, the catalyst I comprising a general formula (MgCl ₂ )(BuMgCl) _0.58 Mg _0.04 [(TiOC ₄ H ₉ ) ₄ ] _0.04 [Si(OC ₂ H ₅ ) ₄ ] _0.12 active carrier and the semi-metallocene active component loaded on the active carrier; the semi-metallocene active component is cyclopentadiene-(dibenzoylmethane) titanium dichloride.

The preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present embodiment is as follows:

1. Preparation of semi-metallocene active components

The steps for preparing the semi-metallocene active component are the same as in Example 1.

2. Preparation of active carrier

The carrier was prepared according to the method of Example 1, except that the addition of n-butyl titanate was 3 mmol, and the addition of tetraethyl orthosilicate was 18 mmol. After drying, the composition formula was as follows to obtain a carrier b with a particle size of 5 μm, The composition is: (MgCl ₂ )(BuMgCl) _0.58 Mg _0.04 [(TiOC ₄ H ₉ ) ₄ ] _0.04 [Si(OC ₂ H ₅ ) ₄ ] _0.12 ; measured value (theoretical value): Mg: 19.21% (19.44%) , Ti: 0.962% (0.945%), Si: 1.71% (1.66%), C: 23.57% (23.24%), H: 4.63% (4.50%).

3. Preparation of supported catalyst

The steps for preparing the supported catalyst are the same as in Example 1 except that 12.3g of brown catalyst I will be obtained.

Example 10

This embodiment provides an ultra-high molecular weight polyethylene catalyst J, said catalyst J comprising a general formula (MgCl ₂ )(BuMgCl) _0.58 Mg _0.06 [(TiOC ₄ H ₉ ) ₄ ] _0.04 [Si(OC ₂ H ₅ ) ₄ ] _0.24 active carrier and the semi-metallocene active component loaded on the active carrier; the semi-metallocene active component is cyclopentadiene-(dibenzoylmethane) titanium dichloride.

The preparation method of the ultra-high molecular weight polyethylene catalyst provided by the present embodiment is as follows:

1. Preparation of semi-metallocene active components

The steps for preparing the semi-metallocene active component are the same as in Example 1.

2. Preparation of active carrier

The carrier was prepared according to the method of Example 1, except that the addition of n-butyl titanate was 3 mmol, and the addition of tetraethyl orthosilicate was 18 mmol. After drying, the composition formula was as follows to obtain a carrier c with a particle size of 5 μm. The composition is: (MgCl ₂ )(BuMgCl) _0.58 Mg _0.06 [(TiOC ₄ H ₉ ) ₄ ] _0.04 [Si(OC ₂ H ₅ ) ₄ ] _0.24 .

3. Preparation of supported catalyst

The steps for preparing the supported catalyst are the same as in Example 1 except that 12.8 g of brown catalyst J will be obtained.

Comparative example 1

This comparative example provides a kind of polyethylene catalyst K, and described catalyst K comprises anhydrous magnesium chloride support and the semi-metallocene active component that is loaded on the described anhydrous magnesium chloride support; Said semi-metallocene active component is cyclopentadiene Alkene-(dibenzoylmethane)titanium dichloride.

The preparation method of the polyethylene catalyst provided in this comparative example is the same as that of Example 1 except that the carrier a is not prepared and commercially available anhydrous magnesium chloride is used instead of the carrier a.

2. Application and Application Results

1. Application method

In a 10L stainless steel autoclave, after nitrogen replacement, 3L of dehydrated hexane, a hexane solution of triethylaluminum (200 by Al/Ti molar ratio), and 20 mg of the catalyst prepared in the above examples and comparative examples were added successively, Raise the temperature to 60°C, and then feed ethylene until the pressure of the kettle is 0.6MPa (gauge pressure). At 70°C, keep the pressure of the kettle at 0.6MPa and perform a polymerization reaction for 2 hours to obtain a UHMWPE polyethylene product.

2. Determination method:

Element detection of semi-metallocene active components: C content and H content are detected by elemental analyzer.

Content detection of titanium, magnesium and other elements in the catalyst: detection of titanium content by plasma emission spectrometry (ICP).

Polyethylene physical properties: apparent density is measured by ASTM-D-1895 method;

Viscosity-average molecular weight measures the intrinsic viscosity of polymer according to GB1841-1980, and calculates by equation Mη=5.37×(η) ^1.37 ;

The molecular weight distribution is determined by high-temperature gel chromatography for Mw and Mn, and then calculated by Mw/Mn; wherein, Mw is the weight-average molecular weight, and Mn is the number-average molecular weight;

The particle size was determined by a laser particle analyzer (MastersizerX, Malvern); where D10, D50 and D90 refer to the particle size of 10%, 50% and 90% by mass percentage respectively. D50 is defined as the average particle distribution, and the particle size distribution is defined as (D90-D10)/D50.

3. Measurement results

Table 1 shows the detection results of the semi-metallocene active component elements and the titanium content in the catalyst in the above examples and comparative examples.

Table 1

After applying the catalysts obtained in the above examples and comparative examples to polyethylene polymerization, the measured catalytic activity and properties of the obtained polyethylene are shown in Table 2.

Table 2

From Table 1 and Table 2, the following points can be seen:

(1) Comprehensive embodiment 1～10 can find out, and embodiment 1～10 adopts novel active magnesium chloride carrier, and adopts new activation method, the catalyst obtained has higher titanium load, and its titanium load ≥ 5.13wt %, the catalytic activity is ≥2.2×10 ⁴ gPE/gcat, the bulk density of the prepared polyethylene is ≥0.43g/cm ³ , the particle size is between 100-130μm, the particle size is small and the distribution is narrow, and it can be used for industrial production;

(2) comprehensive embodiment 1 and comparative example 1 can find out, under the situation of loading identical half-metallocene active component, embodiment 1 adopts the active magnesium chloride carrier that the application provides, compares comparative example 1 and adopts commercially available magnesium chloride carrier Speaking, the titanium loading in Example 1 is 5.92wt%, while the titanium loading in Comparative Example 1 is only 5.62wt%, and the catalytic activity of the catalyst in Example 1 is higher than that of the catalyst in Comparative Example 1, The bulk density of the obtained polyethylene product is larger than that in Comparative Example 1, and the particle size is small and the particle size distribution is narrow. This shows that the present invention improves the titanium loading of the catalyst by adopting the novel magnesium chloride active carrier, and finally improves the catalytic performance. Activity, and the bulk density and particle size distribution of the obtained polyethylene products are more suitable for industrial production.

_{In summary} , ^the ultra-high _molecular ^weight _polyethylene catalyst provided by _the present _invention ^contains The active carrier of _y and the semi-metallocene active component loaded on the active carrier not only have a high titanium loading capacity, but also have a high titanium loading content of ≥ 5.13 wt%, high catalytic activity, and a catalytic activity of ≥ 2.2×10 ⁴ gPE/gcat, The bulk density of the prepared polyethylene is ≥0.43g/cm ³ , the particle size is between 100-130μm, the particle size is small and the distribution is narrow; the carrier is activated after the carrier is obtained by the solvent method, and the active carrier solution is obtained in the other The semi-metallocene active component is loaded on the surface, the preparation condition is mild, and the operation is simple.

The applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned examples, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow process can be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

Claims (78)

1. The ultrahigh molecular weight polyethylene catalyst is characterized by comprising a catalyst with the general formula of (MgX' ₂ )(R ¹ MgX') _p Mg _q [(TiOR ² ) ₄ ] _x [Si(OR ³ ) ₄ ] _y And a half-metallocene active component loaded on the active carrier;

in the general formula of the active carrier, X' is halogen, R ¹ And R ² Are respectively selected from C2-C4 alkyl, R ³ Selected from C1-C3 alkyl, p value is 0.4-0.8, q value is 0.02-0.15, x value is 0.03-0.09, y value is 0.1-0.3;

the general formula of the half metallocene active component is shown as a formula (1):

in the general formula (1), R and R' are respectively and independently C1-C12 alkyl, C6-C9 alkylaryl or C1-C12 perfluoroalkyl; cp' is a ligand group containing cyclopentadiene skeleton with 1-5 substituents R ⁴ Two adjacent substituents on the cyclopentadiene skeleton may be connected to each other to form a condensed ring of at least two members, R ⁴ Selected from hydrogen, C1-C18 alkyl or perfluoroalkyl, and C6-C24 aralkyl or alkaryl; x is halogen, and n is an integer of 1 to 3;

the ultra-high molecular weight polyethylene is polyethylene with the molecular weight of 20-1000 ten thousand;

the preparation method of the catalyst comprises the following steps: mixing a carrier a with the general formula with a solvent, wherein the solvent comprises a solvent II and a solvent III, the solvent II is a nonpolar organic solvent, the solvent III is aliphatic alcohol, obtaining a reaction liquid, adding alkyl aluminum into the reaction liquid, obtaining an active carrier liquid, reacting the active carrier liquid with a half-metallocene active component, and loading the half-metallocene active component on the active carrier to obtain the catalyst.

2. The catalyst according to claim 1, wherein in the general formula of the active support, X' is chlorine.

3. The catalyst of claim 1, wherein the p value is from 0.5 to 0.7.

4. The catalyst of claim 1 wherein the q value is from 0.05 to 0.1.

5. The catalyst of claim 1, wherein x has a value of 0.04 to 0.08.

6. The catalyst of claim 1, wherein the titanium content in the catalyst is from 0.1 to 10 wt.%.

7. The catalyst of claim 6, wherein the titanium content in the catalyst is 5.1 to 9.5 wt.%.

8. The catalyst according to claim 1, wherein R and R' in the general formula (1) are each independently C1-C3 alkyl, C1-C3 perfluoroalkyl, or C6-C9 alkylaryl.

9. The catalyst of claim 1, wherein Cp' is a cyclopentadienyl, fluorenyl, or indenyl group.

10. The catalyst according to claim 9, wherein Cp' is a cyclopentadienyl, fluorenyl or indenyl group substituted on at least one hydrogen atom by a C1-C4 alkyl group.

11. The catalyst of claim 10, wherein Cp' is cyclopentadienyl, butylcyclopentadienyl, pentamethylcyclopentadienyl, indenyl, or fluorenyl.

12. The catalyst according to claim 1, wherein X in the general formula (1) is chlorine.

13. The catalyst of claim 1, wherein the aluminum alkyl is added dropwise.

14. The catalyst according to claim 1, wherein the molar ratio of the alkyl aluminum to the magnesium halide in the support a is 0.2 to 1.0.

15. The catalyst according to claim 14, wherein the molar ratio of the alkyl aluminum to the magnesium halide in the carrier a is 0.4 to 0.8.

16. The catalyst according to claim 1, wherein the catalyst has a catalytic activity > 2.2 x 10 ⁴ g polyethylene/g catalyst.

17. The catalyst of claim 16, wherein the catalyst has a catalytic activity > 2.5 x 10 ⁴ g polyethylene/g catalyst.

18. The catalyst of claim 1 wherein the ultra high molecular weight polyethylene is a polyethylene having a molecular weight of from 150 to 1000 million.

19. The catalyst according to claim 1, wherein the catalyst has an average particle diameter of 4 to 8 μm.

20. The catalyst of claim 1, wherein the catalyst is a single site catalyst.

21. The method for preparing an ultra-high molecular weight polyethylene catalyst according to any one of claims 1 to 20, wherein the method comprises: is represented by the general formula (MgX' ₂ )(R ¹ MgX') _p Mg _q [(TiOR ² ) ₄ ] _x [Si(OR ³ ) ₄ ] _y Mixing the carrier a with a solvent, wherein the solvent comprises a solvent II and a solvent III, the solvent II is a non-polar organic solvent, the solvent III is aliphatic alcohol to obtain a reaction solution, adding alkyl aluminum into the reaction solution to obtain an active carrier solution, reacting the active carrier solution with a half-metallocene active component, and loading the half-metallocene active component on the active carrier to obtain the catalyst;

wherein R is ¹ And R ² Are respectively selected from C2-C4 alkyl, R ³ Is selected from C1-C3 alkyl, p value is 0.4-0.8, q value is 0.02-0.15, x value is 0.03-0.09, y value is 0.1-0.3.

22. The method of claim 21, wherein the method comprises:

(1) Mixing magnesium and a solvent I, adding an electron donor compound and halogenated alkane after stirring, and carrying out solid-liquid separation after reaction to obtain a carrier a;

(2) Mixing the carrier a prepared in the step (1) with a solvent II and a solvent III, wherein the solvent II is a non-polar organic solvent, the solvent III is aliphatic alcohol, heating and stirring, cooling to obtain a reaction solution, adding alkyl aluminum into the reaction solution, and heating to obtain an active carrier solution;

(3) And (3) mixing the active carrier liquid obtained in the step (2) with a half metallocene active component for reaction, and then carrying out solid-liquid separation to obtain the catalyst.

23. The method according to claim 21, wherein the support has the formula wherein X' is chlorine.

24. The method of claim 21, wherein the p value is 0.5 to 0.7.

25. The method of claim 21, wherein the q value is 0.05 to 0.1.

26. The method of claim 21, wherein x has a value of 0.04 to 0.08.

27. The method of claim 22, wherein the magnesium in step (1) is magnesium powder.

28. The process of claim 22, wherein the solvent i is a hydrocarbon solvent.

29. The method according to claim 22, wherein the electron donor compound comprises Ti (OR) ² ) ₄ And Si (OR) ³ ) ₄ In which R is ² Selected from C2-C4 alkyl, R ³ Is selected from C1-C3 alkyl.

30. The method of claim 29, wherein the electron donor compound comprises Ti (OR) ² ) ₄ The molar ratio to magnesium is 0.01 to 0.05.

31. The method of claim 29, wherein Si (OR) in the electron donor compound ³ ) ₄ The molar ratio of magnesium to magnesium is 0.05 to 0.5.

32. The method of claim 22, wherein the haloalkane is a monohaloalkane.

33. The method of claim 32, wherein the haloalkane is a chloroalkane.

34. The method of claim 33, wherein the haloalkane is chloropropane, n-butyl chloride, isobutane chloride, tert-butyl chloride, or isopentane chloride.

35. The process according to claim 22, wherein the molar ratio of haloalkane to magnesium is 2 to 8.

36. The method of claim 22, wherein iodine is added after said stirring of step (1).

37. The method of claim 22, wherein the temperature of the reaction of step (1) is 20 to 100 ℃.

38. The method of claim 22, wherein step (1) comprises: mixing magnesium and the solvent I, adding the electron donor compound after stirring, continuously stirring, adding the halogenated alkane, and carrying out solid-liquid separation after reaction to obtain the carrier a.

39. The method according to claim 22, wherein the solid phase after the solid-liquid separation in step (1) is washed and dried to obtain the carrier a.

40. The method of claim 22, wherein the active carrier fluid is a slurry of active carriers.

41. The method as claimed in claim 22, wherein the solvent II is a C5-C20 alkane.

42. The method of claim 22, wherein the fatty alcohol has the formula R ⁵ OH, wherein R ⁵ Is selected from C1-C8 alkyl.

43. The process according to claim 22, wherein the molar ratio of the solvent iii to the magnesium halide in the support a is from 0.2 to 1.0.

44. The method as claimed in claim 43, wherein the molar ratio of the solvent III to the magnesium halide in the carrier a is 0.4-0.8.

45. The method of claim 22, wherein the aluminum alkyl is added dropwise.

46. The process according to claim 22, wherein the molar ratio of the alkylaluminum to the magnesium halide in the support a is from 0.2 to 1.0.

47. The process of claim 46, wherein the molar ratio of the alkyl aluminum to the magnesium halide in the carrier a is 0.4 to 0.8.

48. The method of claim 22, wherein the mixing reaction in step (3) comprises: dissolving a half-metallocene active component in a solvent IV to obtain a half-metallocene solution, and mixing the half-metallocene solution with an active carrier liquid for reaction.

49. The method of claim 48, wherein the half-metallocene solution is dripped into the active carrier liquid and mixed.

50. The method as claimed in claim 48, wherein the solvent IV is a polar organic solvent.

51. The method of claim 50, wherein the polar organic solvent comprises a halogenated alkane comprising 1 to 3 carbon atoms.

52. The method of claim 51, wherein the polar organic solvent is a chlorinated alkane.

53. The method as claimed in claim 50, wherein the mass of the polar organic solvent is 5 to 200 times of the weight of the half-metallocene active component.

54. The method as claimed in claim 48, wherein the molar ratio of magnesium halide to half-metallocene active component in the active carrier fluid is 5 to 500.

55. The method as claimed in claim 54, wherein the molar ratio of magnesium halide to half-metallocene active component in the active carrier fluid is 5 to 50.

56. The process of claim 48, wherein the temperature of the reaction is 10 to 70 ℃.

57. The method as claimed in claim 56, wherein the reaction temperature is 10-30 ℃.

58. The method of claim 48, wherein the reaction time is 0.5 to 72 hours.

59. The method of claim 58, wherein the reaction time is 0.5 to 2 hours.

60. The process of claim 48, wherein the reaction is carried out under agitation.

61. The method according to claim 22, characterized in that it comprises the steps of:

(1) Mixing magnesium powder and hydrocarbon solvent, stirring, and adding Ti (OR) ² ) ₄ And Si (OR) ³ ) ₄ The mixture is used as electron donor compound, and after reaction and stirring at 50-80 deg.c for 1-5 hr, the mixture is added with dry alkyl halide at 20-100 deg.cContinuously reacting for 2-5 h, washing and drying the solid phase subjected to solid-liquid separation to obtain a carrier a, wherein the general formula of the carrier a is (MgX' ₂ )(R ¹ MgX') _p Mg _q [(TiOR ² ) ₄ ] _x [Si(OR ³ ) ₄ ] _y (ii) a Wherein R is ¹ And R ² Are respectively selected from C2-C4 alkyl, R ³ Selected from C1-C3 alkyl, p value is 0.4-0.8, q value is 0.02-0.15, x value is 0.03-0.09, y value is 0.1-0.3;

wherein Ti (OR) is contained in the electron donor compound ² ) ₄ A molar ratio to magnesium of 0.01 to 0.05 ³ ) ₄ The molar ratio of the halogenated alkane to the magnesium is 0.05-0.5, and the molar ratio of the halogenated alkane to the magnesium is 2-8;

(2) The carrier a prepared in the step (1) is a nonpolar organic solvent and has a general formula of R ⁵ Mixing OH fatty alcohol, heating to 40-60 ℃, stirring for 0.8-3 h, cooling to 0-20 ℃ to obtain a reaction solution, dropwise adding alkyl aluminum into the reaction solution, and heating to 10-30 ℃ to obtain an active carrier solution;

wherein R is ⁵ Is selected from C1-C8 alkyl, the molar ratio of the non-polar organic solvent to the magnesium halide in the carrier a is 0.2-1.0; the molar ratio of the alkyl aluminum to the magnesium halide in the carrier a is 0.2-1.0;

(3) And (3) dissolving a half-metallocene active component in a polar organic solvent to obtain a half-metallocene solution, dripping the half-metallocene solution into the active carrier liquid obtained in the step (2), mixing, reacting, and carrying out solid-liquid separation and drying to obtain the catalyst.

62. Use of an ultra high molecular weight polyethylene catalyst according to any of claims 1 to 20 in the catalytic polymerization of ethylene.

63. The use according to claim 62, wherein the ethylene catalytic polymerization comprises: homopolymerization of ethylene or copolymerization of ethylene and alpha-olefin.

64. The application according to claim 62, wherein the application comprises: and carrying out polymerization reaction under the action of a catalyst to obtain the polymer.

65. The use of claim 64, wherein the catalyst is polymerized by the presence of a cocatalyst to produce polyethylene.

66. The use of claim 65, wherein the cocatalyst comprises any one or a combination of at least two of trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum monochloride, methylalumoxane, or an organic boride.

67. The use according to claim 65, wherein the molar ratio of aluminium in the cocatalyst to titanium in the catalyst is in the range of 10 to 500.

68. The use according to claim 67, wherein the molar ratio of aluminium in the cocatalyst to titanium in the catalyst is in the range of 30 to 200.

69. The use according to claim 64, wherein the polymerization is carried out in an organic solvent.

70. The use according to claim 69, wherein the organic solvent has a boiling point of 30 to 150 ℃.

71. The use according to claim 69, wherein the organic solvent comprises any one of n-hexane, n-heptane, 120# solvent oil, 90# solvent oil, dichloromethane, toluene or xylene or a combination of at least two thereof.

72. The use according to claim 64, wherein the polymerization temperature is between 10 and 110 ℃.

73. The use according to claim 72, wherein the polymerization temperature is between 50 and 90 ℃.

74. The use according to claim 65, wherein the polyethylene obtained by the polymerization reaction has a molecular weight of 20 to 1000 ten thousand.

75. The use according to claim 74, wherein the polyethylene obtained by said polymerization has a molecular weight of 150 to 1000 ten thousand.

76. The use according to claim 65, wherein the polyethylene obtained by the polymerization reaction has an average particle size of 130 μm or less.

77. The use according to claim 65, wherein the polyethylene obtained by the polymerization reaction has a bulk density of 0.44g/cm or more ³ 。

78. Use according to claim 65, wherein the polymerization reaction has a molecular weight distribution Mw/Mn <3.2.

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