阅读说明：本技术 一种超高分子量聚乙烯粉料及其制备方法 (Ultra-high molecular weight polyethylene powder and preparation method thereof ) 是由 郭正阳 周俊领 王迎 唐璐 刘萃莲 雷世龙 于 2019-10-28 设计创作，主要内容包括：本发明提供属于烯烃聚合领域,涉及一种超高分子量聚乙烯粉料及其制备方法。以粉料的重量为基准,以元素计,所述粉料中铝含量为10～100ppm,钛含量为0.1～5ppm,镁含量为1～10ppm,卤素含量为5～40ppm,磷含量为0.05～1ppm,所述粉料的粘均分子量为500～1000万,粉料颗粒的平均球形度在0.65～0.95之间,且球形度为0.8以上的粉料颗粒的比例大于75％。本发明的超高分子量聚乙烯粉末中微量元素的含量低,同时,聚合物分子量较大,且粉料球形度较高。(The invention belongs to the field of olefin polymerization, and relates to ultra-high molecular weight polyethylene powder and a preparation method thereof. The weight of the powder is taken as a reference, the content of aluminum in the powder is 10-100 ppm, the content of titanium is 0.1-5 ppm, the content of magnesium is 1-10 ppm, the content of halogen is 5-40 ppm, the content of phosphorus is 0.05-1 ppm, the viscosity average molecular weight of the powder is 500-1000 ten thousand, the average sphericity of powder particles is 0.65-0.95, and the proportion of the powder particles with the sphericity of more than 0.8 is more than 75 percent. The ultra-high molecular weight polyethylene powder has low content of trace elements, and meanwhile, the polymer has larger molecular weight and higher sphericity of the powder.)

1. The ultrahigh molecular weight polyethylene powder is characterized in that the powder contains 10-100 ppm of aluminum, 0.1-5 ppm of titanium, 1-10 ppm of magnesium, 5-40 ppm of halogen and 0.05-1 ppm of phosphorus by taking the weight of the powder as a reference and the content of powder particles with the sphericity of more than 0.8 is more than 75 percent by elements, wherein the viscosity average molecular weight of the powder is 500-1000 ten thousand, the average sphericity of the powder particles is 0.65-0.95.

2. The ultra-high molecular weight polyethylene powder according to claim 1, wherein the powder contains 30 to 80ppm of aluminum, 1 to 4ppm of titanium, 3 to 8ppm of magnesium, 10 to 30ppm of halogen, 0.1 to 0.6ppm of phosphorus, 550 to 900 ten thousand of viscosity average molecular weight, 0.7 to 0.92 of average sphericity of powder particles, and more than 80% of powder particles having a sphericity of 0.8, in terms of elements, based on the weight of the powder.

3. A preparation method of ultra-high molecular weight polyethylene powder comprises the following steps: polymerizing ethylene in the presence of a magnesium-titanium-containing solid catalyst component and an organic aluminum compound to obtain the ultrahigh molecular weight polyethylene powder, wherein the magnesium-titanium-containing solid catalyst component contains titanium element, magnesium element, an alkoxy compound, phosphorus element and halogen, and the content of the titanium element is 1-15 wt%, the content of the magnesium element is 10-30 wt%, the content of the phosphorus element is 0.01-1 wt%, the content of the alkoxy compound is 1-10 wt%, and the content of the halogen is 40-70 wt%, based on the total weight of the solid catalyst component; the angle of repose of the solid catalyst component is 20-40 degrees.

4. The preparation method according to claim 3, wherein the content of the titanium element is 2 to 10 wt%, the content of the magnesium element is 15 to 25 wt%, the content of the phosphorus element is 0.1 to 0.8 wt%, the content of the alkoxide compound is 2 to 8 wt%, and the content of the halogen element is 50 to 65 wt%, based on the total weight of the solid catalyst component; the angle of repose of the solid catalyst component is 25-35 °.

5. The production method according to claim 3 or 4, wherein the solid catalyst component has an average particle diameter of 2 to 10 micrometers, preferably 3 to 8 micrometers; the bulk density is 0.30 to 0.50 g/ml, preferably 0.35 to 0.45 g/ml.

6. The production method according to claim 3, wherein the magnesium-titanium-containing solid catalyst component A is produced by a method comprising the steps of: dissolving a magnesium compound in a solvent system containing at least one organic epoxy compound, at least one organic phosphorus compound, at least one organic alcohol compound and at least one inert diluent to form a uniform solution, adding a precipitation aid into the solution, then reducing the temperature of the system and adding a titanium compound to obtain a suspension system containing a solid component, then raising the temperature of the system, and filtering, washing and drying the suspension system to obtain the solid catalyst component; wherein the titanium compound is added into the system for multiple times.

7. The preparation method according to claim 6, wherein the amount of the first added titanium compound is 5 to 30%, preferably 7 to 20%, and more preferably 9 to 15% of the total amount of the total titanium compounds; the time interval between the first addition of the titanium compound and the next addition of the titanium compound is 20-80%, preferably 30-70% of the total time required for adding all the titanium compounds into the system.

8. The method according to claim 7, wherein a part of the titanium compound is added during the cooling of the system, and the rest of the titanium compound is added after the cooling of the system.

9. The preparation method according to claim 8, wherein the titanium compound is added to the system in two times, a first part of the titanium compound is added during the cooling process of the system, and the rest is added after the cooling process of the system; preferably, when the system is cooled to the first target temperature, a first part of the titanium compound is added, then the system is continuously cooled to the final target temperature, and the rest part of the titanium compound is added.

10. The production method according to claim 6, wherein the system temperature is reduced to-30 ℃ to 30 ℃, preferably to-30 ℃ to 10 ℃.

11. The preparation method of claim 6, wherein the temperature of the suspension system is raised to 60-110 ℃, and the method further comprises stirring the suspension system at the temperature for 0.5-8 h, and then filtering, washing and drying the suspension system.

12. The process according to any one of claims 6 to 11, wherein the titanium compound has the formula ti (or)_aX_bWherein R is C₁～C₁₄X is a halogen atom, a is an integer of 0 to 2, b is an integer of 0 to 4, a + b is 3 or 4; preferably at least one selected from the group consisting of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium tetrabutoxide, titanium tetraethoxide, titanium chlorotriethoxy, titanium dichlorodiethoxide, titanium trichloromonoethoxy and titanium trichloride, and furtherThe step (b) is preferably at least one selected from titanium tetrachloride, titanium monochloroethoxide and titanium trichloride;

the titanium compound is added in the form of a titanium halide, or a mixture of a titanium halide and an inert diluent.

13. The production method according to any one of claims 6 to 11,

the magnesium compound is at least one of magnesium halide, magnesium alcoholate and magnesium haloalcoholate;

the organic epoxy compound is selected from C₂～C₈At least one of an oxide, glycidyl ether and internal ether of an aliphatic olefin, diolefin or halogenated aliphatic olefin or diolefin of (a);

the organophosphorus compound is selected from hydrocarbyl and/or halohydrocarbyl esters of orthophosphoric acid and/or phosphorous acid;

the organic alcohol compound is selected from C₂～C₁₀The fatty alcohol of (a);

the precipitation aid is selected from at least one of organic acid, organic acid anhydride, organic ether and organic ketone;

the inert diluent is selected from C₆～C₁₀And/or C₆～C₈The aromatic hydrocarbon of (1).

14. The production method according to any one of claims 6 to 11, wherein the organic epoxy compound is used in an amount of 0.2 to 10 moles, preferably 0.5 to 4 moles, per mole of the magnesium halide; the dosage of the organic phosphorus compound is 0.1-3 mol, preferably 0.3-1 mol; the amount of the organic alcohol compound is 0.1 to 10 moles, preferably 0.5 to 5 moles; the dosage of the inert diluent is 0.5-5L; the amount of the titanium compound is 1 to 15 mol, preferably 2 to 10 mol.

15. The production method according to any one of claims 6 to 11, wherein the molar ratio of aluminum in the organoaluminum compound to titanium in the magnesium-titanium-containing solid catalyst component is 5 to 5000: 1, preferably 20 to 500: 1.

16. the method according to any one of claims 6 to 11, wherein the polymerization temperature is 30 to 120 ℃, preferably 40 to 90 ℃; the polymerization pressure is 0.05 to 10MPa, preferably 0.1 to 5 MPa.

17. Ultra-high molecular weight polyethylene powder obtainable by the process according to any one of claims 3 to 16.

Technical Field

The invention belongs to the field of olefin polymerization, and particularly relates to ultra-high molecular weight polyethylene powder and a preparation method thereof.

Background

Ultra-High Molecular Weight Polyethylene (UHMWPE) is a thermoplastic engineering plastic with a linear structure, and has the performances of impact resistance, abrasion resistance, chemical corrosion resistance, low temperature resistance, stress cracking resistance, adhesion resistance, excellent insulativity, safety, sanitation, self-lubricity and the like which are incomparable with other engineering plastics. Polyethylene having a viscosity average molecular weight of more than 170 ten thousand is generally called ultra high molecular weight polyethylene.

Ultra-high molecular weight polyethylene has a high molecular weight and a low melt index, and the product mainly exists in the form of powder. The morphology, the particle size distribution and thus the bulk density of the powder are important characteristics with which its processability is linked. When producing ultra-high molecular weight polyethylene finished products with impact resistance, wear resistance, self-lubricity and the like, compression molding processing is mainly adopted, and overflow type molds are mostly adopted during processing, and the molds require smaller compression ratio of molding materials. Therefore, when UHMWPE is processed by compression molding, the powder bulk density is as high as possible, and the volume difference before and after compression molding is reduced: on one hand, the powder particles are expected to have small porosity and solid interior; on the other hand, the powder particles are expected to have good particle size distribution and few gaps among the particles. In addition, the shape, the particle size distribution and the bulk density of the powder have great influence on the production process and the storage, and the powder close to a spherical shape is beneficial to smooth transmission for conveying; for drying, coarse particles with narrower particle size distribution and higher bulk density are beneficial for reducing energy consumption; for storage, a high bulk density may reduce storage space. Therefore, the morphology, particle size distribution and resulting bulk density of the ultra high molecular weight polyethylene powder is of critical importance.

It is known that the production of polyethylene uses a ziegler-natta catalyst system, and in the polymerization of olefins, in particular the homopolymerization of ethylene or the copolymerization of ethylene and α -olefins, catalyst components based on magnesium, titanium, halogen and an electron donor are mostly used. The morphology of the polymer is an approximate replication of the catalyst morphology, and for ultra-high molecular weight polyethylene, the morphology and particle size distribution of the catalyst have important effects.

Early production of UHMWPE using attrition catalysts suffered from the disadvantages of low activity and high meal count. With the research and development of a Ziegler-Natta catalyst system, a grinding catalyst is gradually replaced by a reaction catalyst, the activity of the catalyst is greatly improved, and the problems of activity and coarse powder are solved when the reaction catalyst is used for producing UHMWPE, but the bulk density of the UHMWPE product is not high.

For ultra-high molecular weight polyethylene powder, the molecular weight is important, and the product performance can be greatly influenced. Generally, as the molecular weight increases, the strength of the product increases, especially for fiber products, and a larger molecular weight is very beneficial to improve the performance of the product.

In addition, it is very interesting to reduce the content of trace elements in the ultra-high molecular weight polyethylene powder, since this material, when applied to human implants, is preferably completely inert and should not have biological activity, thus limiting the content of some trace elements very severely, otherwise it will have negative effects on the organism.

Therefore, it is necessary to develop an ultra-high molecular weight polyethylene having various properties.

Disclosure of Invention

The invention aims to provide ultra-high molecular weight polyethylene powder and a preparation method thereof.

The invention provides an ultrahigh molecular weight polyethylene powder, which comprises, by element, 10-100 ppm of aluminum, 0.1-5 ppm of titanium, 1-10 ppm of magnesium, 5-40 ppm of halogen and 0.05-1 ppm of phosphorus, wherein the powder has a viscosity average molecular weight of 500-1000 ten thousand, the average sphericity of powder particles is 0.65-0.95, and the proportion of powder particles with a sphericity of 0.8 or more is more than 75%.

The second aspect of the present invention provides a method for preparing ultra-high molecular weight polyethylene powder, comprising the steps of: polymerizing ethylene in the presence of a magnesium-titanium-containing solid catalyst component and an organic aluminum compound to obtain the ultrahigh molecular weight polyethylene powder, wherein the magnesium-titanium-containing solid catalyst component A contains titanium element, magnesium element, an alkoxy compound, phosphorus element and halogen, and the content of the titanium element is 1-15 wt%, the content of the magnesium element is 10-30 wt%, the content of the phosphorus element is 0.01-1 wt%, the content of the alkoxy compound is 1-10 wt%, and the content of the halogen is 40-70 wt%, based on the total weight of the solid catalyst component; the angle of repose of the solid catalyst component is 20-40 degrees.

The third aspect of the present invention provides the ultrahigh molecular weight polyethylene powder obtained by the above production process.

The ultra-high molecular weight polyethylene powder has low content of trace elements, and meanwhile, the polymer has larger molecular weight and higher sphericity of the powder.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

The invention provides an ultrahigh molecular weight polyethylene powder, which comprises, by element, 10-100 ppm of aluminum, 0.1-5 ppm of titanium, 1-10 ppm of magnesium, 5-40 ppm of halogen and 0.05-1 ppm of phosphorus, wherein the powder has a viscosity average molecular weight of 500-1000 ten thousand, the average sphericity of powder particles is 0.65-0.95, and the proportion of powder particles with a sphericity of 0.8 or more is more than 75%.

According to the invention, preferably, the powder contains 30-80 ppm of aluminum, 1-4 ppm of titanium, 3-8 ppm of magnesium, 10-30 ppm of halogen and 0.1-0.6 ppm of phosphorus in terms of elements based on the weight of the powder, the viscosity average molecular weight of the powder is 550-900 ten thousand, the average sphericity of powder particles is 0.7-0.92, and the proportion of powder particles with a sphericity of more than 0.8 is more than 80%.

The second aspect of the present invention provides a method for preparing ultra-high molecular weight polyethylene powder, comprising the steps of: polymerizing ethylene in the presence of a magnesium-titanium-containing solid catalyst component and an organic aluminum compound to obtain the ultrahigh molecular weight polyethylene powder, wherein the magnesium-titanium-containing solid catalyst component A contains titanium element, magnesium element, an alkoxy compound, phosphorus element and halogen, and the content of the titanium element is 1-15 wt%, the content of the magnesium element is 10-30 wt%, the content of the phosphorus element is 0.01-1 wt%, the content of the alkoxy compound is 1-10 wt%, and the content of the halogen is 40-70 wt%, based on the total weight of the solid catalyst component; the angle of repose of the solid catalyst component is 20-40 degrees.

According to the present invention, preferably, the content of the titanium element is 2 to 10 wt%, the content of the magnesium element is 15 to 25 wt%, the content of the phosphorus element is 0.1 to 0.8 wt%, the content of the alkoxy compound is 2 to 8 wt%, and the content of the halogen element is 50 to 65 wt%, based on the total weight of the solid catalyst component.

According to the present invention, it is preferable that the angle of repose of the solid catalyst component is 25 to 35 °.

According to the present invention, preferably, the average particle size of the solid catalyst component is 2 to 10 micrometers, preferably 3 to 8 micrometers; the bulk density is 0.30 to 0.50 g/ml, preferably 0.35 to 0.45 g/ml.

In the invention, the average particle size of the magnesium-containing titanium catalyst component is controlled to be 2-10 microns, when the particle size is too large, the obtained polyethylene powder has a thicker average particle size and a particle shape which does not tend to be spherical, the stacking density of the powder is lower, and when the particle size is too small, the yield of the magnesium-containing titanium catalyst component is influenced.

In the present invention, the catalyst particle size distribution is determined by means of a Mastersizer 2000 instrument (Malvern, UK). The bulk density of the solid catalyst component is determined by reference to ASTM D1895-96; the angle of repose of the solid component of the catalyst is determined with reference to GB-T11986-98.

According to the invention, the magnesium-titanium-containing solid catalyst component A is prepared by a method comprising the following steps: dissolving a magnesium compound in a solvent system containing at least one organic epoxy compound, at least one organic phosphorus compound, at least one organic alcohol compound and at least one inert diluent to form a uniform solution, adding a precipitation aid into the solution, then reducing the temperature of the system and adding a titanium compound to obtain a suspension system containing a solid component, then raising the temperature of the system, and filtering, washing and drying the suspension system to obtain the solid catalyst component; wherein the titanium compound is added into the system for multiple times.

Compared with the prior art, the method optimizes the adding mode of the titanium compound, and in the prior art, the titanium compound is added into the system at one time. The inventors of the present invention have found in their studies that the addition of a titanium compound in portions improves the morphology and performance parameters of the resulting solid catalyst component.

In the present invention, the number of times of adding the titanium compound is not particularly limited, and may be two, three, or more.

According to the method of the present invention, preferably, the amount of the first added titanium compound is 5 to 30%, preferably 7 to 20%, and more preferably 9 to 15% of the total amount of the titanium compounds added; the time interval between the first addition of the titanium compound and the next addition of the titanium compound is 20-80%, preferably 30-70% of the total time required for adding all the titanium compounds into the system. The morphology and performance parameters of the obtained solid catalyst component can be further improved by further finely controlling the addition mode of the titanium compound.

In the method of the invention, the titanium compound can be added at the initial stage of cooling the system, at the middle stage of cooling or after the cooling is finished. Preferably, part of the titanium compound is added during the cooling process of the system, and the rest of the titanium compound is added after the cooling process of the system.

From the viewpoint of considering both the performance of the obtained solid catalyst component and the convenience of operation, the titanium compound is added into the system twice, the first part of the titanium compound is added in the process of cooling the system, and the rest is added after the process of cooling the system. More specifically, when the system is cooled to a first target temperature, a first portion of the titanium compound is added, then the system is continuously cooled to a final target temperature, and the remaining portion of the titanium compound is added.

Generally, in the preparation of the solid catalyst component, the temperature of the system (i.e., the final target temperature) is lowered to-30 ℃ to 30 ℃, preferably to-30 ℃ to 10 ℃.

According to a specific embodiment of the invention, when the temperature of the system is reduced to-15 ℃ to 0 ℃, a first part of titanium compound is added, then the temperature of the system is continuously reduced to-30 ℃ to-20 ℃, and the rest part of titanium compound is added.

In a manner similar to the manner in which the titanium compound is added in the prior art, the titanium compound is added slowly dropwise each time.

According to a specific embodiment of the invention, the temperature of the system is raised to 60-110 ℃, the method further comprises stirring the suspension system for 0.5-8 hours at the temperature, and then filtering, washing and drying the suspension system.

According to the present invention, the formation of a homogeneous solution may be achieved using conditions conventional in the art, such as by heating to facilitate dissolution of the components, for example at a temperature of 50-60 ℃.

In the present invention, the titanium compound may be various titanium compounds commonly used in the preparation of solid components of olefin polymerization catalysts, for example, the titanium compound has the general formula Ti (OR)_aX_bWherein R is C₁～C₁₄X is a halogen atom, a is an integer of 0 to 2, b is an integer of 0 to 4, a + b is 3 or 4; it is preferably at least one selected from the group consisting of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, tetrabutoxytitanium, tetraethoxytitanium, chlorotriethoxytitanium, dichlorodiethoxytitanium, trichloromonoethoxytitanium and titanium trichloride, and it is further preferably at least one selected from the group consisting of titanium tetrachloride, trichloromonoethoxytitanium and titanium trichloride. The titanium compound may be added in the form of a halide of titanium alone or in the form of a mixture of a halide of titanium with an inert diluent.

The particular types of components used in the present invention can be selected as is conventional in the art.

The magnesium compound may be at least one of a halide of magnesium, an alcoholate of magnesium, and a haloalcoholate of magnesium; specifically, the method includes but is not limited to: magnesium chloride.

The organic epoxy compound may be selected from C₂～C₈At least one of an oxide, glycidyl ether and internal ether of an aliphatic olefin, diolefin or halogenated aliphatic olefin or diolefin of (a); specifically, the method includes but is not limited to: ethylene oxide, propylene oxide, butylene oxide, butadiene double oxide, epichlorohydrin, methyl glycidyl ether, diglycidyl ether, or mixtures thereof.

The organophosphorus compound is selected from hydrocarbyl and/or halohydrocarbyl esters of orthophosphoric acid and/or phosphorous acid; specifically, the method includes but is not limited to: trimethyl orthophosphate, triethyl orthophosphate, tributyl orthophosphate, triphenyl orthophosphate, trimethyl phosphite, triethyl phosphite, tributyl phosphite, benzyl phosphite, or mixtures thereof.

The organic alcohol compound is selected from C₂～C₁₀The fatty alcohol of (a); specifically, the method includes but is not limited to: methanol, ethanol, propanol, butanol, hexanol, diethylhexanol, or mixtures thereof.

The precipitation aid is selected from at least one of organic acid, organic acid anhydride, organic ether and organic ketone; specifically, the method includes but is not limited to: acetic anhydride, phthalic anhydride, succinic anhydride, maleic anhydride, pyromellitic dianhydride, acetic acid, propionic acid, butyric acid, acrylic acid, methacrylic acid, acetone, methyl ethyl ketone, benzophenone, methyl ether, ethyl ether, propyl ether, butyl ether, pentyl ether, or a mixture thereof.

The inert diluent is selected from C₆～C₁₀And/or C₆～C₈The aromatic hydrocarbon of (1). Specifically, the method includes but is not limited to: hexane, heptane, octane, decane, benzene, toluene, xylene, or a mixture thereof, or a derivative thereof.

The amounts of the above components may also be selected as is conventional in the art. Specifically, the amount of the organic epoxy compound is 0.2 to 10 mol, preferably 0.5 to 4 mol, per mol of the magnesium halide; the dosage of the organic phosphorus compound is 0.1-3 mol, preferably 0.3-1 mol; the amount of the organic alcohol compound is 0.1 to 10 moles, preferably 0.5 to 5 moles; the dosage of the inert diluent is 0.5-5L; the amount of the titanium compound is 1 to 15 mol, preferably 2 to 10 mol.

In the catalytic system, the molar ratio of aluminum in the organic aluminum compound to titanium in the magnesium-containing titanium catalyst component is 5-5000: 1, preferably 20 to 500: 1.

in the present invention, the ethylene polymerization is preferably carried out in a slurry state, and the solvent may be a straight or branched alkane such as hexane, heptane, octane, decane or derivatives thereof, etc.

In the invention, the temperature of ethylene polymerization is preferably controlled to be 30-120 ℃, and is further preferably carried out at 40-90 ℃, when the temperature is too high, the ethylene molecules are easy to generate free radical polymerization, and the molecular weight of the prepared polyethylene is not high; too low a temperature results in a catalyst with low activity or no polymerization.

In the invention, the pressure of ethylene polymerization is preferably controlled to be 0.05-10 MPa, and further preferably 0.1-5 MPa, when the pressure is too high, the concentration of ethylene monomer is increased, the activity of the catalyst is high, and the bulk density of the prepared polyethylene powder is reduced; the pressure is too low and the catalyst has low activity or does not polymerize.

The time for ethylene polymerization is not particularly limited, and can be controlled within 0.5-10 h.

The invention also provides the ultra-high molecular weight polyethylene powder prepared by the preparation method.

The present invention will be further described with reference to the following examples, but the scope of the present invention is not limited to these examples.

In the following examples:

polymer molecular weight (Mw): and (4) measuring by a viscosity method.

Elemental analysis: x-ray fluorescence analysis.

Sphericity of the polymer: measured by a CAMSIZER particle analyzer.

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

The apparent Bulk Density (BD) of the catalyst and polymer was determined in accordance with ASTM D1895-96.

The angle of repose is determined with reference to GB-T11986-98.

The contents of elements titanium, magnesium and chlorine in the catalyst are determined by a chemical analysis method, the content of alkoxy is determined by gas chromatography, and the content of phosphorus is determined by X-ray energy spectrum analysis.

Catalyst component ethylene polymerization evaluation method: a2-liter polymerization vessel was alternately charged with nitrogen and evacuated three times, and 1.0 liter of n-hexane, 2mmol of triethylaluminum and 10 mg of the above solid catalyst component were added. The temperature of the reaction kettle is raised to 60 ℃, then ethylene is introduced until the kettle pressure is 0.7MPa, and the reaction lasts for 2 hours. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 1

1. Preparation of solid catalyst component

Adding 4.8 g of magnesium chloride, 55 ml of toluene, 3.0 ml of epoxy chloropropane, 3.6 ml of tributyl phosphate and 7.6 ml of ethanol into a reaction kettle, reacting for one hour under the conditions of stirring speed of 450rpm and temperature of 55 ℃, adding 0.8 g of phthalic anhydride, continuing to react for one hour, cooling to-10 ℃, slowly adding 20 ml of mixed solution consisting of 80 ml of titanium tetrachloride and 200 ml of toluene dropwise for 30min, cooling to-30 ℃ after 60min, and adding the rest of mixed solution dropwise for 90 min. Heating to 80 ℃ within 4 hours, keeping the temperature constant for 1.5 hours, filtering out mother liquor, washing twice with 120 ml of toluene at 60 ℃, then washing 4 times with hexane, and drying the residual solid product to obtain the solid catalyst component.

2. Preparation of ultra-high molecular weight polyethylene powder

A2-liter polymerization kettle is alternately filled with nitrogen and vacuumized for three times, 1-liter normal hexane, 2mmol triethyl aluminum and 8 mg solid catalyst components are added, the temperature is raised to 50 ℃, ethylene is added to maintain the kettle pressure at 0.7MPa, and the reaction is carried out for 3.5 hours at 50 ℃. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 2

1. Preparation of solid catalyst component

The procedure is as in example 1.

2. Preparation of ultra-high molecular weight polyethylene powder

A2-liter polymerization kettle is alternately filled with nitrogen and vacuumized for three times, 1-liter normal hexane, 1mmol triethyl aluminum and 6 mg solid catalyst components are added, the temperature is raised to 60 ℃, ethylene is added to maintain the kettle pressure at 0.5MPa, and the reaction is carried out for 5 hours at 60 ℃. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 3

1. Preparation of solid catalyst component

The procedure is as in example 1.

2. Preparation of ultra-high molecular weight polyethylene powder

A2-liter polymerization kettle is alternately filled with nitrogen and vacuumized for three times, 1-liter normal hexane, 2mmol triethyl aluminum and 10 mg solid catalyst components are added, the temperature is raised to 50 ℃, ethylene is added to maintain the kettle pressure at 0.7MPa, and the reaction is carried out for 5 hours at 50 ℃. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 4

1. Preparation of solid catalyst component

The procedure is as in example 1.

2. Preparation of ultra-high molecular weight polyethylene powder

A2-liter polymerization kettle is alternately filled with nitrogen and vacuumized for three times, 1-liter normal hexane, 1mmol triethyl aluminum and 8 mg solid catalyst components are added, the temperature is raised to 50 ℃, ethylene is added to maintain the kettle pressure at 0.7MPa, and the reaction is carried out for 5 hours at 50 ℃. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 5

1. Preparation of solid catalyst component

The procedure is as in example 1.

2. Preparation of ultra-high molecular weight polyethylene powder

A2-liter polymerization kettle is alternately filled with nitrogen and vacuumized for three times, 1-liter normal hexane, 2mmol triethyl aluminum and 6 mg solid catalyst components are added, the temperature is raised to 60 ℃, ethylene is added to maintain the kettle pressure at 0.5MPa, and the reaction is carried out for 8 hours at 50 ℃. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 6

1. Preparation of solid catalyst component

The procedure is as in example 1.

2. Preparation of ultra-high molecular weight polyethylene powder

A2-liter polymerization kettle is alternately filled with nitrogen and vacuumized for three times, 1-liter normal hexane, 2mmol triethyl aluminum and 10 mg solid catalyst components are added, the temperature is raised to 50 ℃, ethylene is added to maintain the kettle pressure at 0.7MPa, and the reaction is carried out for 8 hours at 50 ℃. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 7

1. Preparation of solid catalyst component

Adding 9.6 g of anhydrous magnesium chloride, 110 ml of toluene, 6.0 ml of epoxy chloropropane, 7.2 ml of tributyl phosphate and 15.2 ml of ethanol into a reaction kettle repeatedly replaced by high-purity nitrogen in sequence, reacting for 1 hour at the temperature of 55 ℃, then adding 1.6 g of phthalic anhydride, continuing to react for 1 hour, cooling to-20 ℃, slowly adding 30 ml of mixed solution consisting of 80 ml of titanium tetrachloride and 200 ml of toluene dropwise for 30 minutes, cooling to-30 ℃ after 60 minutes, and adding the rest of the mixed solution dropwise for 120 minutes. Heating to 90 ℃ within 4 hours, keeping the temperature for 1.5 hours, filtering out mother liquor, washing with toluene twice, then washing with hexane for 3 times, and drying the residual solid product to obtain the solid titanium catalyst component.

2. Preparation of ultra-high molecular weight polyethylene powder

A2-liter polymerization kettle is alternately filled with nitrogen and vacuumized for three times, 1-liter normal hexane, 2mmol triethyl aluminum and 7 mg solid catalyst components are added, the temperature is raised to 50 ℃, ethylene is added to maintain the kettle pressure at 0.7MPa, and the reaction is carried out for 5 hours at 50 ℃. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 8

1. Preparation of solid catalyst component

Adding 9.6 g of anhydrous magnesium chloride, 110 ml of toluene, 6.0 ml of epoxy chloropropane, 7.2 ml of tributyl phosphate and 15.2 ml of ethanol into a reaction kettle repeatedly replaced by high-purity nitrogen in sequence, reacting for 1 hour at the temperature of 55 ℃, then adding 1.6 g of phthalic anhydride, continuing to react for 1 hour, cooling to-10 ℃, slowly adding 80 ml of mixed solution consisting of 80 ml of titanium tetrachloride and 200 ml of toluene dropwise for 60 minutes, cooling to-30 ℃ after 60 minutes, and adding the rest of the mixed solution dropwise for 60 minutes. Heating to 90 ℃ within 4 hours, keeping the temperature for 1.5 hours, filtering out mother liquor, washing with toluene twice, then washing with hexane for 3 times, and drying the residual solid product to obtain the solid titanium catalyst component.

2. Preparation of ultra-high molecular weight polyethylene powder

A2-liter polymerization kettle is alternately filled with nitrogen and vacuumized for three times, 1-liter normal hexane, 2mmol triethyl aluminum and 8 mg solid catalyst components are added, the temperature is raised to 50 ℃, ethylene is added to maintain the kettle pressure at 0.7MPa, and the reaction is carried out for 5 hours at 50 ℃. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 9

1. Preparation of solid catalyst component

Adding 9.6 g of anhydrous magnesium chloride, 110 ml of toluene, 6.0 ml of epoxy chloropropane, 7.2 ml of tributyl phosphate and 15.2 ml of ethanol into a reaction kettle repeatedly replaced by high-purity nitrogen in sequence, reacting for 1 hour at the temperature of 55 ℃, then adding 1.6 g of phthalic anhydride, continuing to react for 1 hour, cooling to-10 ℃, slowly adding 30 ml of mixed solution consisting of 80 ml of titanium tetrachloride and 200 ml of toluene dropwise for 30 minutes, cooling to-30 ℃ after 90 minutes, and adding the rest of the mixed solution dropwise for 90 minutes. Heating to 90 ℃ within 4 hours, keeping the temperature for 1.5 hours, filtering out mother liquor, washing with toluene twice, then washing with hexane for 3 times, and drying the residual solid product to obtain the solid titanium catalyst component.

2. Preparation of ultra-high molecular weight polyethylene powder

The procedure is as in example 8. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 10

1. Preparation of solid catalyst component

Adding 9.6 g of anhydrous magnesium chloride, 110 ml of toluene, 6.0 ml of epoxy chloropropane, 7.2 ml of tributyl phosphate and 15.2 ml of ethanol into a reaction kettle repeatedly replaced by high-purity nitrogen in sequence, reacting for 1 hour at the temperature of 55 ℃, then adding 1.6 g of phthalic anhydride, continuing to react for 1 hour, cooling to-10 ℃, slowly adding 50 ml of mixed solution consisting of 80 ml of titanium tetrachloride and 200 ml of toluene dropwise for 45 minutes, cooling to-30 ℃ after 120 minutes, and adding the rest of the mixed solution dropwise for 120 minutes. Heating to 90 ℃ within 4 hours, keeping the temperature for 1.5 hours, filtering out mother liquor, washing with toluene twice, then washing with hexane for 3 times, and drying the residual solid product to obtain the solid titanium catalyst component.

2. Preparation of ultra-high molecular weight polyethylene powder

The procedure is as in example 8. And after the reaction is finished, cooling, separating and collecting the polymer.

Example 11

1. Preparation of solid catalyst component

Adding 9.6 g of anhydrous magnesium chloride, 110 ml of toluene, 6.0 ml of epoxy chloropropane, 7.2 ml of tributyl phosphate and 15.2 ml of ethanol into a reaction kettle repeatedly replaced by high-purity nitrogen in sequence, reacting for 1 hour at the temperature of 55 ℃, then adding 1.6 g of phthalic anhydride, continuing to react for 1 hour, cooling to-10 ℃, slowly adding 30 ml of mixed solution consisting of 80 ml of titanium tetrachloride and 200 ml of toluene dropwise for 30 minutes, keeping for 90 minutes, and adding the rest of mixed solution dropwise for 90 minutes. Heating to 90 ℃ within 4 hours, keeping the temperature for 1.5 hours, filtering out mother liquor, washing with toluene twice, then washing with hexane for 3 times, and drying the residual solid product to obtain the solid titanium catalyst component.

2. Preparation of ultra-high molecular weight polyethylene powder

The procedure is as in example 8. And after the reaction is finished, cooling, separating and collecting the polymer.

Comparative example 1

1. Preparation of solid catalyst component

In a reaction kettle repeatedly replaced by high-purity nitrogen, 9.6 g of anhydrous magnesium chloride, 110 ml of toluene, 6.0 ml of epichlorohydrin, 7.2 ml of tributyl phosphate and 15.2 ml of ethanol are sequentially added, the mixture is reacted for 1 hour at the temperature of 55 ℃, then 1.6 g of phthalic anhydride is added, the reaction is continued for 1 hour, the temperature is reduced to-30 ℃, 80 ml of titanium tetrachloride is dropwise added at the temperature, the temperature is increased to 90 ℃ within 4 hours, the temperature is kept for 1.5 hours, then mother liquor is filtered, the mother liquor is washed twice by toluene, then the mother liquor is washed by hexane for 3 times, and the residual solid product is dried to obtain the solid titanium catalyst component.

2. Preparation of ultra-high molecular weight polyethylene powder

The procedure is as in example 3. And after the reaction is finished, cooling, separating and collecting the polymer.

Test example

The catalyst components prepared in the above examples and comparative examples have test data as shown in the following Table 1, polymerization conditions as shown in the following Table 2, and powder lot data as shown in the following Table 3.

Table 1 catalyst testing data

TABLE 2 polymerization conditions for the examples and comparative examples

TABLE 3 test data for powders prepared in the examples and comparative examples

As can be seen from Table 3, the ultra-high molecular weight polyethylene powder of the present invention has a low content of trace elements, a large viscosity-average molecular weight of the polymer, and a high degree of sphericity of the powder.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

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.