CN113845613B - High-purity ultrahigh molecular weight polyethylene resin and production process thereof - Google Patents
High-purity ultrahigh molecular weight polyethylene resin and production process thereof Download PDFInfo
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Abstract
The invention provides a high-purity ultrahigh molecular weight polyethylene resin and a production process thereof, belonging to the technical field of ethylene polymerization catalysts. The production process comprises the following steps: (a) Adding a solvent, a cocatalyst and a catalyst into a complex reaction kettle to obtain a complex catalyst; (b) Adding linear alpha-olefin, solvent, cocatalyst and the complex catalyst into a prepolymerization reactor to carry out prepolymerization reaction to obtain a prepolymerization catalyst; (c) And continuously adding the prepolymerization catalyst and ethylene into a slurry polymerization reactor to perform polymerization reaction. The catalyst is mainly used for producing high-purity ultra-high molecular weight polyethylene resin, and the obtained polyethylene resin has lower impurity content and metal content, uniform components and narrow molecular weight distribution, and can meet the application of the ultra-high molecular weight polyethylene resin in the fields of medical treatment and electrician and electrical appliances.
Description
Technical Field
The invention belongs to the technical field of ethylene polymerization catalysts, and particularly relates to a high-purity ultrahigh molecular weight polyethylene resin and a production process thereof.
Background
Ultra-high molecular weight polyethylene is the engineering plastic with the best comprehensive performance, and the ultra-high molecular weight polyethylene has the best abrasion resistance, impact resistance, corrosion resistance, self-lubrication and impact energy absorption among the existing plastics and is internationally called as 'surprising material'. Due to its superior properties, ultra-high molecular weight polyethylene has been widely used in the fields of textiles, paper making, packaging, transportation, machinery, chemical engineering, mining, petroleum, agriculture, construction, electrical, food, medical, sports, etc., and has begun to enter the fields of conventional weapons, ships, automobiles, etc.
The application of ultra-high molecular weight polyethylene is different according to the molecular weight of the ultra-high molecular weight polyethylene. Ultra-high molecular weight polyethylene resins, such as those with molecular weights >400 million, are used primarily for the production of fibers; the ultra-high molecular weight polyethylene resin with the molecular weight of 200-400 ten thousand is mainly used for producing pipes and plates; the ultra-high molecular weight polyethylene resin with the molecular weight of 50-100 ten thousand is mainly used for producing the lithium ion battery diaphragm.
The ultra-high molecular weight polyethylene resin is used as the lithium ion battery diaphragm, and the polyethylene resin is mainly obtained by plasticizing extrusion and biaxial tension, so that the structure and the performance of the polyethylene resin raw material have direct influence on the processing process, and directly determine the mechanical property of the microporous diaphragm. However, the ash content of the used ultra-high molecular weight polyethylene raw material of the current domestic diaphragm is usually 200-400 ppm, the residual amount of metal impurities is high, pinholes and crystal points are easy to appear on the surface of the produced microporous diaphragm, the puncture resistance strength of the microporous diaphragm is reduced, and the higher metal impurities can also cause adverse effects on the capacity and the cruising ability of the battery.
The medical application of the ultra-high molecular weight polyethylene is mainly concentrated in medical materials such as joint replacement materials, tissue scaffolds, blood transfer pumps, packaging bags and the like, and the safety is very important because the ultra-high molecular weight polyethylene is used for human biological materials, so that the polymer needs high purity and low impurity content.
The production process of the ultra-high molecular weight polyethylene mainly comprises a solution method, a slurry method and a gas phase method. Among them, the slurry process is a major production process at present, and adopts a traditional Ziegler-Natta catalyst system. In the catalyst system, the main components of the catalyst comprise titanium (active center), magnesium and other elements, and the main components of the cocatalyst comprise aluminum and the like.
Hydrogen is usually added as a chain transfer agent during the polymerization reaction to adjust the molecular weight of the polymerization product. Because the molecular weight of the product is higher, the amount of hydrogen used for adjusting the molecular weight is less, generally 0-20 g hydrogen/ton product, and because the amount of hydrogen required is very small, the control of the hydrogen concentration in the reactor is a difficult problem in the actual industrial production. In general, the fluctuation of hydrogen concentration in the reactor is large, which easily results in a wide molecular weight distribution of the product ultra-high molecular weight polyethylene resin, and further affects the mechanical properties, mechanical strength, wear resistance and the like of the resin.
Therefore, the catalyst suitable for the production of the ultra-high molecular weight polyethylene resin is developed, the problem that the production is difficult to control due to the fact that the amount of added hydrogen is small when the molecular weight is adjusted is solved, and the obtained ultra-high molecular weight polyethylene resin has the advantages of narrow molecular weight distribution and uniform polymer particle size distribution and has important significance.
Disclosure of Invention
The invention provides a high-purity ultra-high molecular weight polyethylene resin and a production process thereof, which realize the purpose of adjusting the molecular weight of a product by changing the polymerization reaction temperature in the polymerization reaction process, thereby solving the problem that the molecular weight distribution of the polymerization product is widened due to large fluctuation of the hydrogen concentration in a reactor by adopting hydrogen as a chain transfer agent.
The invention provides a production process of high-purity ultrahigh molecular weight polyethylene resin, which comprises the following steps:
(a) Adding a solvent, a cocatalyst and a catalyst into a complex reaction kettle to obtain a complex catalyst;
(b) Adding linear alpha-olefin (LAO), a solvent, a cocatalyst and the complex catalyst into a prepolymerization reaction kettle to carry out prepolymerization reaction to obtain a prepolymerization catalyst;
(c) Continuously adding the prepolymerization catalyst and ethylene into a slurry polymerization reactor to carry out polymerization reaction;
wherein the catalyst comprises a magnesium compound, a titanium compound and an azo electron donor compound; the azo electron donor compound comprises at least one of azo compounds such as azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptonitrile, azobisisobutyronitrile formamide, azobisdicyclohexyl carbonitrile, dimethyl azobisisobutyrate, azobisisobutyramidine hydrochloride, azobisisopropylimidazoline hydrochloride and azobiscyanovaleric acid.
Further, in the step (a), the concentration of the catalyst in the system is 0.01 g/L-50.0 g/L; the molar ratio of the cocatalyst to the catalyst is (1-50) to 1;
in the step (b), the concentration of the complex catalyst is 0.001 g/L-1.0 g/L, the concentration of the linear alpha-olefin is 0.01 g/L-1.0 g/L, and the molar ratio of the cocatalyst to the complex catalyst is (10-200): 1.
Further, the cocatalyst is an organic aluminum compound; the organic aluminum compound has a general formula of AlR n X 3-n Wherein R is hydrogen or a hydrocarbon group having l to 20 carbon atoms, X is halogen, 0<n≤3。
Further, the solvent is a hydrocarbon solvent; preferably, the hydrocarbon solvent includes at least one of aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon, and halogenated hydrocarbon.
Further, in step (b), the linear alpha-olefin comprises at least one of 1-butene, 1-hexene or 1-octene.
Further, in the step (c), propylene, 1-butene, 1-hexene or 1-octene may be added as a comonomer.
Further, in the step (c), the temperature of the polymerization reaction is 65-88 ℃; the pressure of the polymerization reaction is 0.3MPa to 0.8MPa; the time of the polymerization reaction is 3 to 5 hours.
Further, the method also comprises the step (d) of post-processing:
and (c) carrying out flash evaporation, primary centrifugal separation, washing, secondary centrifugal separation, drying and screening on the product obtained in the step (c) to obtain the high-purity ultrahigh molecular weight polyethylene resin.
Further, the detergent used for washing comprises C 1 ～C 10 Alcohol of (1), C 1 ～C 10 Ether of (C) 1 ～C 10 Aldehyde of (2), C 1 ～C 10 The ketone of (1).
The invention also provides the high-purity ultrahigh molecular weight polyethylene resin prepared by any one of the production processes.
The invention has the following advantages:
the production process of the high-purity ultrahigh molecular weight polyethylene resin provided by the invention selects the temperature-sensitive ultrahigh molecular weight polyethylene catalyst, adopts the azo compound as the internal electron donor, can achieve the purpose of adjusting the molecular weight of the product by adjusting the reaction temperature, and avoids the problem of wider molecular weight distribution of the product caused by large fluctuation of hydrogen concentration when the molecular weight of the product is adjusted by adopting hydrogen. The obtained catalyst has the advantages of regular particle shape, good particle size distribution, less fine powder of a polymerization product, high stacking density and high catalytic efficiency. When the catalyst is used for producing high-purity ultrahigh molecular weight polyethylene resin, the obtained polyethylene resin has lower impurity content and metal content, uniform components and narrow molecular weight distribution, and can meet the application of the ultrahigh molecular weight polyethylene resin in the fields of medical treatment and electrics and electrical appliances.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a schematic diagram of a process for producing high purity ultra-high molecular weight polyethylene according to an embodiment of the present invention;
FIG. 2 shows an ultra-high molecular weight polyethylene cast sheet and a microporous film obtained in test example 1 of the present invention;
FIG. 3 is an SEM photograph of the temperature sensitive Ziegler-Natta catalyst obtained in preparation example 1 of the present invention;
wherein, fig. 1 is labeled as follows:
1-a complex reaction kettle; 2-a prepolymerization reactor; 3-slurry polymerization reactor; 4-flash evaporation kettle; 5-a compressor; 6-primary centrifuge; 7-washing the kettle; 8-secondary centrifuge; 9-a dryer; 10-vibrating screen.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.
In the prior art, an azo compound is one of common free radical polymerization initiators, is easy to decompose at a certain temperature to form free radicals, and has a weak bond on a molecular structure. The invention uses azo compounds as internal electron donor for ethylene polymerization Ziegler-Natta catalyst, and at polymerization temperature (65-88 ℃), the azo compounds of the internal electron donor can generate free radicals according to different bond dissociation energies, thereby changing the chemical structure of the active center of the Ziegler-Natta catalyst and further influencing the molecular weight of the product polyethylene.
In a first aspect, an embodiment of the present invention provides a temperature-sensitive ultrahigh molecular weight polyethylene catalyst, including a magnesium compound, a titanium compound, and an azo electron donor compound;
wherein the azo electron donor compound comprises at least one of azo compounds such as azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptonitrile, azobisisobutyro-cyano formamide, azobisdicyclohexyl carbonitrile, dimethyl azobisisobutyrate, azobisisobutyramidine hydrochloride, azobisisopropylimidazoline hydrochloride and azobiscyanovaleric acid.
According to the temperature-sensitive ultrahigh molecular weight polyethylene catalyst provided by the embodiment of the invention, the azo compound is used as an internal electron donor, the purpose of regulating the molecular weight of the product can be achieved by regulating the reaction temperature, and the problem of wider molecular weight distribution of the product caused by large hydrogen concentration fluctuation when hydrogen is used for regulating the molecular weight of the product is avoided. The obtained catalyst has the advantages of regular particle shape, good particle size distribution, less fine powder of a polymerization product, high stacking density and high catalytic efficiency. When the method is used for producing high-purity ultrahigh molecular weight polyethylene resin, the obtained polyethylene resin has lower impurity content and metal content, uniform components and narrow molecular weight distribution.
In one embodiment of the present invention, the magnesium compound is obtained by dissolving magnesium halide in a solvent containing organic alcohol or a halide of organic alcohol.
The magnesium compound may be a magnesium halide compound, specifically a magnesium dihalide compound, an alkyl magnesium halide compound, an alkoxy magnesium halide compound, an aryloxy magnesium halide, or the like.
Preferably, magnesium dihalide compounds such as magnesium chloride, magnesium iodide, magnesium fluoride, and magnesium bromide; alkyl magnesium halide compounds such as methyl magnesium halide, ethyl magnesium halide, propyl magnesium halide, butyl magnesium halide, isobutyl magnesium halide, hexyl magnesium halide, and amyl magnesium halide; alkoxy magnesium halide compounds such as methoxy magnesium halide, ethoxy magnesium halide, isopropoxy magnesium halide, butoxy magnesium halide and octyloxy magnesium halide; aryloxymagnesium halides such as phenoxymagnesium halide and methylphenoxymagnesium halide. Specifically, the magnesium compound may be a magnesium halide, particularly magnesium chloride or alkylmagnesium chloride having an alkyl group of 1 to 10 carbon atoms; alkoxymagnesium chloride having an alkoxy group of 1 to 10 carbon atoms; aryloxy magnesium chloride having an aryloxy group of 6 to 20 carbon atoms. The magnesium compound according to the embodiment of the present invention may be used as a single compound or a mixture of two or more compounds. The above magnesium compound can be effectively used in the form of a complex compound with other metals. The magnesium solution used may be prepared by dissolving the magnesium compound in an alcohol in the presence or absence of a hydrocarbon solvent to prepare a solution.
In one embodiment of the present invention, the organic alcohol includes a linear or branched alkyl alcohol having 1 to 10 carbon atoms, a cycloalkanol having 3 to 10 carbon atoms, or an aryl alcohol having 7 to 20 carbon atoms. Specifically, the organic alcohol may include alcohols having 1 to 20 carbon atoms, such as methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, decanol, dodecanol, tetradecanol, hexadecanol, octadecanol, benzyl alcohol, phenethyl alcohol, isopropylbenzyl alcohol, and cumyl alcohol; preferably, the alcohol is selected from alcohols containing 1 to 12 carbon atoms.
In one embodiment of the present invention, the titanium compound has a general formula of Ti (OR) a X b Wherein R is C 1 ～C 10 X is halogen, a is 0, 1, 2 or 3, b is an integer from 1 to 4, a + b =3 or 4. The titanium compound used may be a titanium halide or a titanium alkoxy halide, wherein the alkoxy functional group may have 1 to 20 carbon atoms. Mixtures of these compounds are also possible, where appropriate. Preferably, the titanium compound is a titanium halide or an alkoxy titanium halide in which the alkoxy functional group has 1 to 8 carbon atoms; more preferably, the titanium compound is a titanium tetrahalide.
In one embodiment of the present invention, the organic alcohol content is 0.1 to 10.0 mol, the azo electron donor compound content is 0.001 to 0.1 mol, and the titanium compound content is 1.0 to 15.0 mol, based on each mol of magnesium halide.
In a second aspect, an embodiment of the present invention further provides a method for preparing any one of the catalysts, including the following steps:
(1) Preparation of the magnesium compound: dissolving magnesium halide in a solvent containing organic alcohol or organic alcohol halide, and adding an inert diluent to obtain a homogeneous magnesium solution;
(2) And adding a titanium compound and an azo electron donor compound into the homogeneous magnesium solution, reacting, removing unreacted substances and a solvent, and washing to obtain the titanium catalyst.
The preparation method of the catalyst provided by the embodiment of the invention is simple to operate, has lower production cost, and can be used for industrial production to prepare high-purity ultrahigh molecular weight polyethylene resin.
In step (1) of the inventive example, the average particle size and the particle size distribution of the resulting catalyst were correlated with the type of alcohol used, the amount of alcohol used, the type of magnesium compound, and the ratio of magnesium compound to alcohol.
Preferably, the dissolving temperature is-25 to 125 ℃; more preferably, the temperature of dissolution is 50 to 125 ℃. The temperature of dissolution may vary depending on the type and amount of alcohol used, at least about-25 deg.C, preferably about-20 to 150 deg.C, or more preferably about-10 to 110 deg.C. The reaction time may be about 15 minutes to 10 hours, or preferably about 30 minutes to 4 hours.
Preferably, the inert diluent comprises at least one of decane, heptane, hexane, paraffin;
the titanium catalyst is a granular solid titanium catalyst. After the reaction, the solid gradually precipitated and formed particles. And washed with an inert diluent.
In step (2) of the example of the present invention, when the solution of the magnesium composition is reacted with the titanium compound, the shape and size of the precipitated solid titanium catalyst component mainly depend on the reaction conditions. In order to control the particle shape, it may be preferable to react the magnesium compound solution with a mixture of a titanium compound, an azo-based electron donor compound at a sufficiently low temperature to produce a solid substance composition. The azo electron donor compound can be added into the system before the magnesium compound solution contacts with the titanium compound, or can be added into the system after the magnesium compound solution contacts with the titanium compound.
In an embodiment of the present invention, the step (2) specifically includes:
adding an azo electron donor compound into a magnesium compound to obtain a reaction solution; and (2) carrying out a first reaction on the reaction liquid and a titanium compound at a temperature of between 24 and 10 ℃, then heating to 80 to 125 ℃, carrying out a second reaction, removing unreacted substances and a solvent, and washing to obtain the titanium catalyst.
In another embodiment of the present invention, the step (2) specifically includes:
and (2) carrying out a third reaction on a magnesium compound and a titanium compound at the temperature of between 24 and 10 ℃, adding an azo electron donor compound, heating to 80 to 125 ℃, removing unreacted substances and a solvent after a fourth reaction, and washing to obtain the titanium catalyst.
Preferably, the time of the first reaction, the second reaction, the third reaction and the fourth reaction is 1 to 4 hours, 1 to 5 hours and 1 to 4 hours respectively; more preferably, the first reaction, the second reaction, the third reaction and the fourth reaction are carried out for 3 to 4 hours, 4 to 5 hours and 3 to 4 hours, respectively.
In a third aspect, an embodiment of the present invention further provides a catalyst system, including the catalyst described in any one of the above or the catalyst prepared by the preparation method described in any one of the above.
Further, the catalyst system also comprises a cocatalyst of an organic aluminum compound; wherein the organic aluminum compound has a general formula of AlR n X 3-n Wherein R is hydrogen or a hydrocarbon group having l to 20 carbon atoms, X is halogen, 0<n is less than or equal to 3. In the examples of the present invention, the organoaluminum compound is trialkylaluminum having an alkyl group of 1 to 6 carbon atoms, such as triethylaluminum and triisobutylaluminum, or a mixture thereof. Organoaluminum compounds having one or more halogen or hydride groups, such as ethylaluminum dichloride, diethylaluminum chloride, ethylaluminum sesquichloride, or diisobutylaluminum hydride, may also be used, where appropriate.
Further, the molar ratio of aluminum in the organoaluminum compound to titanium in the catalyst is 10 to 1000. Preferably 20 to 200.
The catalyst system of the invention comprises: (1) The solid titanium complex catalyst comprising magnesium, titanium and an electron donor compound; (2) an alkyl metal compound or an aluminum oxy metal compound.
In a fourth aspect, an embodiment of the present invention further provides a use of any one of the catalyst systems described above in the production of ultra-high molecular weight polyethylene by polymerization of ethylene.
In a fifth aspect, an embodiment of the present invention further provides a process for producing a high-purity ultrahigh molecular weight polyethylene resin, including the following steps:
(a) Adding a solvent, a cocatalyst and a catalyst into a complex reaction kettle to obtain a complex catalyst;
(b) Adding linear alpha-olefin, solvent, cocatalyst and the complex catalyst into a prepolymerization reactor to carry out prepolymerization reaction to obtain a prepolymerization catalyst;
(c) Continuously adding a prepolymerization catalyst and ethylene into a slurry polymerization reaction kettle to carry out polymerization reaction;
wherein the catalyst comprises a magnesium compound, a titanium compound and an azo electron donor compound; the azo electron donor compound comprises at least one of azo compounds such as azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptonitrile, azobisisobutyro-cyano formamide, azobisdicyclohexyl carbonitrile, dimethyl azobisisobutyrate, azobisisobutyramidine hydrochloride, azobisisopropylimidazoline hydrochloride, azobiscyanovaleric acid and the like.
The production process of the high-purity ultra-high molecular weight polyethylene resin provided by the embodiment of the invention improves the catalytic efficiency by selecting a specific catalyst system. Meanwhile, the conventional polymerization production process is changed, unit operations such as washing and deashing are added, so that the finally obtained polyethylene resin has lower impurity content and metal content, uniform components and narrow molecular weight distribution, and can meet the application of the ultra-high molecular weight polyethylene resin in the fields of medical treatment and electrical appliances.
In one embodiment of the present invention, the cocatalyst is an organoaluminum compound; wherein the organic aluminum compound has a general formula of AlR n X 3-n Wherein R is hydrogen or a hydrocarbon group having l to 20 carbon atoms, X is halogen, 0<n≤3。
In one embodiment of the present invention, the solvent is a hydrocarbon solvent; the hydrocarbon solvent comprises at least one of aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon and halogenated hydrocarbon.
Preferably, the aliphatic hydrocarbon may be pentane, hexane, heptane, octane, decane, or kerosene; the alicyclic hydrocarbon can be cyclobenzene, methylcyclobenzene, cyclohexane or methylcyclohexane; the aromatic hydrocarbon may be benzene, toluene, xylene or ethylbenzene, etc.; the halogenated hydrocarbon can be dichloropropanol, dichloroethylene, trichloroethylene, carbon tetrachloride or chlorobenzene, etc.
In one embodiment of the invention, in the step (a), the concentration of the catalyst in the system is 0.01 g/L-50.0 g/L; the molar ratio of the cocatalyst to the catalyst is (1-50): 1.
In one embodiment of the invention, in the step (b), the concentration of the complex catalyst is 0.001 g/L-1.0 g/L, the concentration of the linear alpha-olefin is 0.01 g/L-1.0 g/L, and the molar ratio of the cocatalyst to the complex catalyst is (10-200): 1.
In one embodiment of the present invention, in step (b), the linear alpha-olefin comprises at least one of 1-butene, 1-hexene or 1-octene. In the step (b), the prepolymerization is carried out at normal temperature and pressure.
In one embodiment of the present invention, step (c) further comprises adding propylene, 1-butene, 1-hexene or 1-octene as a comonomer. Specifically, the copolymerization amount of the resin linear alpha-olefin obtained by copolymerization is less than 1.0wt%.
In one embodiment of the present invention, in step (c), the polymerization temperature is 65-88 ℃; the pressure of the polymerization reaction is 0.3MPa to 0.8MPa; the time of the polymerization reaction is 3 to 5 hours.
In an embodiment of the present invention, the production process further includes, after the step (d):
and (c) carrying out flash evaporation, primary centrifugal separation, washing, secondary centrifugal separation, drying and screening on the product obtained in the step (c) to obtain the high-purity ultrahigh molecular weight polyethylene resin.
In one embodiment of the invention, the detergent used for washing comprises C 1 ～C 10 Alcohol of (1), C 1 ～C 10 Ether of (C) 1 ～C 10 Aldehyde of (2), C 1 ～C 10 The ketone of (1).
Specifically, C 1 ～C 10 The alcohol includes methanol, ethanol, propanol, butanol, hexanol, ethylene glycol, glycerol, pentaerythritol, etc., C 1 ～C 10 The ether includes diethyl ether, dimethyl ether, butyl ether, amyl ether and the like, C 1 ～C 10 The aldehyde of the ether of (A) includes formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, caproaldehyde and the like, C 1 ～C 10 The aldehyde of (b) includes acetone, butanone, pentanone, hexanone, and the like. Preferably, the detergent is ethanol, isopropanol,Butanol and octanol are used as detergents, and isopropanol is more preferable as a solvent.
In the embodiment of the invention:
step (a) complexation: adding solvent, cocatalyst and catalyst into the complex reaction kettle to pre-activate the active center of the catalyst. The complexing process is a reduction process of the catalyst active metal under the action of a cocatalyst of aluminum alkyl to form a catalytic active center. The reduction process is carried out under mild conditions, which is favorable for uniformly distributing the formed active centers in catalyst particles and keeping the obtained catalyst at higher catalytic efficiency.
Step (b) prepolymerization: adding a solvent, a cocatalyst, the complex catalyst in the step (1) and linear alpha-olefin capable of carrying out polymerization reaction into a prepolymerization reaction kettle. The prepolymerization aims to fully disperse catalyst particles, reduce the adhesion among the catalyst particles, avoid the adhesion among the polymer particles when the polymer particles are obtained through a replication effect in the polymerization process, and is beneficial to obtaining the polymer particles with uniform particle distribution, low fine powder content and high bulk density. The linear alpha-olefin used for the prepolymerization may be propylene, 1-butene, 1-hexene, 1-octene, etc.
Step (c) polymerization: continuously adding the dispersed catalyst and ethylene into a slurry polymerization reaction kettle for polymerization; optionally, a linear alpha-olefin is added. The linear alpha-olefin to be used in the polymerization may be propylene, 1-butene, 1-hexene, 1-octene, etc.
Step (d): and flash evaporation, primary centrifugal separation, washing, secondary centrifugal separation, drying and screening are carried out to obtain the high-purity ultrahigh molecular weight polyethylene resin.
Flash evaporation: the material flowing out of the slurry polymerization reaction kettle is subjected to a flash evaporation process to realize gas-liquid separation, and gas-phase light components and unreacted ethylene are compressed by a compressor and then returned to the reaction kettle for cyclic utilization; the slurry containing the solvent enters a centrifugal separation.
Primary centrifugal separation: and (3) performing solid-liquid separation on the polymer slurry subjected to flash evaporation by using a centrifugal machine to obtain a polymer filter cake and a recovered solvent. The moisture content of the discharged filter cake after centrifugation is less than or equal to 30wt%; the solid content of the discharged mother liquor is less than or equal to 0.5wt%. The solvent recovered by the first centrifugal separation is returned to the slurry polymerization reaction kettle for cyclic utilization, and the filter cake after the centrifugation enters the washing and deashing process.
Washing and deliming: the purpose of washing and deashing is to further wash and remove impurities in the wet material by using a detergent to remove catalyst residual components in the polymer particles. The material washed by the detergent enters a secondary centrifugal separation process.
And (3) secondary centrifugal separation: and (3) carrying out solid-liquid separation on the washed and deashed polymer slurry by adopting a centrifugal machine to obtain a polymer filter cake and recover the detergent. And (4) the polymer filter cake enters a drying unit, and the recovered washing agent returns to the washing kettle for recycling after secondary centrifugation.
And (3) drying: the drying process can adopt a gas-phase fluidized bed drying system or a rotary kiln drying system, and aims to remove residual detergent, volatile matters and the like in the high-purity ultrahigh molecular weight polyethylene resin. The drying process is to dry the polymer filter cake after washing and secondary centrifugal separation to remove water and volatile matter, wherein the water content of the dried product is less than or equal to 0.15wt%, and the content of organic volatile matter is less than or equal to 300ppm.
Screening: and classifying the dried high-purity ultrahigh molecular weight polyethylene product by using a sample separating sieve, and removing large particles to obtain the high-purity ultrahigh molecular weight polyethylene product.
In the embodiment of the invention, the production process is carried out in the device shown in FIG. 1. As shown in fig. 1, a complex reaction kettle, a prepolymerization reaction kettle and a slurry polymerization reaction kettle are arranged to carry out complex reaction, prepolymerization reaction and slurry polymerization reaction respectively, a flash evaporation kettle is arranged to carry out flash evaporation, and a primary centrifuge and a secondary centrifuge are arranged to carry out primary washing and secondary washing respectively; setting a washing kettle for washing; screening by using a vibrating screen; drying with a dryer.
In a sixth aspect, an embodiment of the present invention further provides a high-purity ultrahigh molecular weight polyethylene resin prepared by any one of the above production processes. The weight average relative molecular mass of the high-purity ultrahigh molecular weight polyethylene resin is 5.0 multiplied by 10 5 ～50.0×10 5 The relative molecular mass distribution is 3.0-5.0, and the density is 0.940-0.960 g/cm 3 Ash content, ash content<30ppm. And the obtained product has Al element content<5ppm, ti element content<1ppm, mg element content<2ppm, cl element content<20ppm。
The high-purity ultrahigh molecular weight polyethylene resin has lower impurity content and metal content than the conventional ultrahigh molecular weight polyethylene resin, has uniform components and narrow molecular weight distribution, and can meet the application of the ultrahigh molecular weight polyethylene resin in the fields of medical treatment and electricians and electrical appliances.
In a seventh aspect, an embodiment of the present invention further provides an application of the high-purity ultrahigh molecular weight polyethylene resin prepared in any one of the foregoing fields in the fields of food, electronics and electricity.
For example, the high-purity ultrahigh molecular weight polyethylene resin prepared by any one of the methods is applied to a lithium ion battery separator. The microporous diaphragm produced by the ultra-high molecular weight polyethylene resin has uniform pore size distribution and less pinholes and crystal points, thereby improving the tensile strength and puncture resistance of the diaphragm. The invention provides a high-purity ultrahigh molecular weight polyethylene resin with improved processability and mechanical property, which improves the yield of the existing microporous diaphragm for the wet-process lithium ion battery.
For example, the high-purity ultrahigh molecular weight polyethylene resin prepared by any one of the above methods is applied to the preparation of medical materials. The medical material comprises a joint replacement material, a tissue bracket, a blood delivery pump, a packaging bag and the like.
The present invention will be described in detail with reference to examples.
Preparation example 1A preparation method of a temperature-sensitive ultrahigh molecular weight polyethylene catalyst comprises the following steps:
4.76 g (50 mmol) of anhydrous MgCl 2 75 ml of decane and 16.3 g (125 mmol) of isooctanol are heated to 125 ℃ and reacted for 3 hours at constant temperature to obtain a homogeneous transparent solution.
Cooling the solution to 50 ℃ and adding 1 to the solution5mmol of azobisisobutyronitrile and stirring at this temperature for 2 hours to dissolve azobisisobutyronitrile into the solution. The resulting homogeneous solution was cooled to room temperature and then added dropwise, with stirring, over 1 hour to 150mL (1.365 mol) of TiCl maintained at-20 deg.C 4 In (1). After the addition was complete, the mixture was held at-20 ℃ for 1 hour, then the temperature was raised to 100 ℃ with stirring at a certain ramp rate and held at this temperature for 2 hours. After the reaction was completed for 2 hours, the resultant solid was separated by hot filtration. And (3) fully washing the solid catalyst by using decane and hexane respectively until precipitated titanium cannot be detected in the cleaning solution, and drying to obtain the solid titanium catalyst component.
The catalyst characterization results are shown in table 1. The SEM image of the catalyst is shown in fig. 3. As can be seen from the results of fig. 3: the catalyst particles are in a sphere-like shape, the particle size distribution is uniform, and the fine powder is less. According to the Ziegler-Natta catalyst ethylene coordination polymerization mechanism, the polyethylene particles produced in the ethylene polymerization process are in the form of replica catalyst particles, so that the obtained polyethylene particles are uniform in particle distribution and less in fine powder.
Preparation exampleA preparation method of a temperature-sensitive ultrahigh molecular weight polyethylene catalyst comprises the following steps:
4.76 g (50 mmol) of anhydrous MgCl 2 75 ml of decane and 16.3 g (125 mmol) of isooctanol were heated to 125 ℃ and reacted at a constant temperature for 3 hours to obtain a homogeneous solution.
The above solution was cooled to 50 ℃ and 1.5mmol of azobisisovaleronitrile was added to the solution, and stirred at the temperature for 2 hours to dissolve azobisisovaleronitrile into the solution. The resulting homogeneous solution was cooled to room temperature and then added dropwise, with stirring, over 1 hour to 150mL (1.365 mol) of TiCl maintained at-20 deg.C 4 In (1). After the addition was complete, the mixture was held at-20 ℃ for 1 hour, then the temperature was raised to 100 ℃ with stirring at a certain ramp rate and held at this temperature for 2 hours. After the reaction was completed for 2 hours, the resultant solid was separated by hot filtration. Washing the solid catalyst with decane and hexane respectively until the solid catalyst is in the washing liquidThe precipitated titanium compound is not detected, and a solid titanium catalyst component is obtained after drying.
The catalyst characterization results are shown in table 1.
Preparation example 3A preparation method of a temperature-sensitive ultrahigh molecular weight polyethylene catalyst comprises the following steps:
4.76 g (50 mmol) of anhydrous magnesium chloride, 75 ml of decane and 16.3 g (125 mmol) of isooctanol were heated to 125 ℃ and reacted at a constant temperature for 3 hours to obtain a homogeneous solution.
The above solution was cooled to 50 ℃ and 1.5mmol of azobisisoheptonitrile was added to the solution, and stirred at that temperature for 2 hours to dissolve the azobisisoheptonitrile into the solution. The resulting homogeneous solution was cooled to room temperature and then added dropwise, with stirring, over 1 hour to 150mL (1.365 mol) of TiCl maintained at-20 deg.C 4 In (1). After the addition, the mixture was kept at-20 ℃ for 1 hour, and then the temperature was raised to 100 ℃ with stirring at a certain temperature rise rate and kept at this temperature for 2 hours. After the reaction was completed for 2 hours, the resultant solid was separated by hot filtration. And fully washing the solid catalyst with decane and hexane respectively until no precipitated titanium compound is detected in the cleaning solution, and drying to obtain the solid titanium catalyst component. The catalyst characterization results are shown in table 1.
Preparation example 4A preparation method of a temperature-sensitive ultra-high molecular weight polyethylene catalyst comprises the following steps:
4.76 g (50 mmol) of anhydrous magnesium chloride, 75 ml of decane and 16.3 g (125 mmol) of isooctanol were heated to 125 ℃ and reacted at a constant temperature for 3 hours to obtain a homogeneous solution.
The above solution was cooled to 50 ℃ and 1.5mmol of azoisobutyrylcyanecarboxamide was added to the solution, and stirred at that temperature for 2 hours to dissolve the azoisobutyrylcyanecarboxamide in the solution. The resulting homogeneous solution was cooled to room temperature and then added dropwise, with stirring, over 1 hour to 150mL (1.365 mol) of TiCl maintained at-20 deg.C 4 In (1). After the completion of the dropping, the mixture was kept at-20 ℃ for 1 hour and then stirred atThe temperature was raised to 100 ℃ at a certain ramp rate and held at this temperature for 2 hours. After the reaction was completed for 2 hours, the resultant solid was separated by hot filtration. And fully washing the solid catalyst with decane and hexane respectively until no precipitated titanium compound is detected in the cleaning solution, and drying to obtain the solid titanium catalyst component.
The catalyst characterization results are shown in table 1.
Preparation example 5A preparation method of a temperature-sensitive ultra-high molecular weight polyethylene catalyst comprises the following steps:
4.76 g (50 mmol) of anhydrous magnesium chloride, 75 ml of decane and 16.3 g (125 mmol) of isooctanol were heated to 125 ℃ and reacted at a constant temperature for 3 hours to obtain a homogeneous solution.
The above solution was cooled to 50 ℃ and 1.5mmol of azobiscyclohexylcarbonitrile was added to the solution, and stirred at that temperature for 2 hours to dissolve the azobiscyclohexylcarbonitrile in the solution. The resulting homogeneous solution was cooled to room temperature and then added dropwise, with stirring, over 1 hour to 150mL (1.365 mol) of TiCl maintained at-20 deg.C 4 In (1). After the addition was complete, the mixture was held at-20 ℃ for 1 hour, then the temperature was raised to 100 ℃ with stirring at a certain ramp rate and held at this temperature for 2 hours. After the reaction was completed for 2 hours, the resultant solid was separated by hot filtration. And fully washing the solid catalyst with decane and hexane respectively until no precipitated titanium compound is detected in the cleaning solution, and drying to obtain the solid titanium catalyst component.
The catalyst characterization results are shown in table 1.
Preparation example 6A preparation method of a temperature-sensitive ultrahigh molecular weight polyethylene catalyst comprises the following steps:
4.76 g (50 mmol) of anhydrous magnesium chloride, 75 ml of decane and 16.3 g (125 mmol) of isooctanol were heated to 125 ℃ and reacted at a constant temperature for 3 hours to obtain a homogeneous solution.
The solution is cooled to 50 ℃ and 1.5mmol of dimethyl azodiisobutyrate are added to the solution and stirred at this temperatureFor 2 hours to dissolve the dimethyl azodiisobutyrate in the solution. The resulting homogeneous solution was cooled to room temperature and then added dropwise, with stirring, over 1 hour to 150mL (1.365 mol) of TiCl maintained at-20 deg.C 4 In (1). After the addition was complete, the mixture was held at-20 ℃ for 1 hour, then the temperature was raised to 100 ℃ with stirring at a certain ramp rate and held at this temperature for 2 hours. After the reaction was completed for 2 hours, the resultant solid was separated by hot filtration. And fully washing the solid catalyst by using decane and hexane respectively until no precipitated titanium compound is detected in a cleaning solution, and drying to obtain the solid titanium catalyst component.
The catalyst characterization results are shown in table 1.
Preparation example 7A preparation method of a temperature-sensitive ultrahigh molecular weight polyethylene catalyst comprises the following steps:
4.76 g (50 mmol) of anhydrous magnesium chloride, 75 ml of decane and 16.3 g (125 mmol) of isooctanol were heated to 125 ℃ and reacted at constant temperature for 3 hours to obtain a homogeneous solution.
The above solution was cooled to 50 ℃ and 1.5mmol of azobisisobutyramidine hydrochloride was added to the solution, and stirred at that temperature for 2 hours to dissolve the azobisisobutyramidine hydrochloride in the solution. The resulting homogeneous solution was cooled to room temperature and then added dropwise, with stirring, over 1 hour to 150mL (1.365 mol) of TiCl maintained at-20 deg.C 4 In (1). After the addition was complete, the mixture was held at-20 ℃ for 1 hour, then the temperature was raised to 100 ℃ with stirring at a certain ramp rate and held at this temperature for 2 hours. After the reaction was completed for 2 hours, the resultant solid was separated by hot filtration. And fully washing the solid catalyst by using decane and hexane respectively until no precipitated titanium compound is detected in a cleaning solution, and drying to obtain the solid titanium catalyst component.
The catalyst characterization results are shown in table 1.
Preparation example 8A preparation method of a temperature-sensitive ultra-high molecular weight polyethylene catalyst comprises the following steps:
4.76 g (50 mmol) of anhydrous magnesium chloride, 75 ml of decane and 16.3 g (125 mmol) of isooctanol were heated to 125 ℃ and reacted at a constant temperature for 3 hours to obtain a homogeneous solution.
The above solution was cooled to 50 ℃ and 1.5mmol of azobisisopropylimidazoline hydrochloride was added to the solution, and stirred at that temperature for 2 hours to dissolve the azobisisopropylimidazoline hydrochloride in the solution. The resulting homogeneous solution was cooled to room temperature and then added dropwise, with stirring, over 1 hour to 150mL (1.365 mol) of TiCl maintained at-20 deg.C 4 In (1). After the addition was complete, the mixture was held at-20 ℃ for 1 hour, then the temperature was raised to 100 ℃ with stirring at a certain ramp rate and held at this temperature for 2 hours. After the reaction was completed for 2 hours, the resultant solid was separated by hot filtration. And fully washing the solid catalyst with decane and hexane respectively until no precipitated titanium compound is detected in the cleaning solution, and drying to obtain the solid titanium catalyst component.
The catalyst characterization results are shown in table 1.
Example 1A production process of high-purity ultrahigh molecular weight polyethylene resin comprises the following steps:
the preparation process of the high-purity ultrahigh molecular weight polyethylene resin comprises the following steps:
(1) Complexation (batch operation):
adding solvent hexane 1.3m into a complex reaction kettle 3 And a diluted 12wt% cocatalyst of triethylaluminum 0.024m 3 (16.75 mol Al), supported ethylene polymerization Ziegler-Natta catalyst 49L (0.49 kg catalyst, 0.46mol Ti) at a concentration of 10g/L as described in example 1, al/Ti molar ratio of 36.4. Stirring and mixing for 1 hour under the protection of nitrogen, and carrying out a complex reaction of the catalyst;
(2) Prepolymerization (batch operation):
refined hexane 9.37m is added into a prepolymerization reactor 3 Diluted triethyl aluminium 0.046m 3 1.4m of the above-mentioned complexed catalyst suspension 3 And for prepolymerization3.2kg of 1-butene, wherein the concentration of the 1-butene is 0.296g/L, the concentration of the catalyst is 0.045g/L, and the pre-polymerization reaction is stirred for 1 hour under the protection of nitrogen; the total mole number of triethyl aluminum in the prepolymerization kettle is as follows: 49.298mol, the mole number of catalyst Ti is 0.46mol, al/Ti = 107.17;
(3) Polymerization (continuous operation):
continuously injecting 1348kg/h of ethylene, 1179.46kg/h of suspension after prepolymerization and a certain amount of mother liquor after centrifugal separation into a polymerization reaction kettle, carrying out polymerization reaction at 85-87 ℃, and allowing the materials to stay in the reaction kettle for about 3.5 hours averagely to obtain the ultrahigh molecular weight polyethylene resin.
(4) Centrifugal separation (continuous operation)
After volatile components of materials flowing out of the reaction kettle are removed through flash evaporation, the materials enter a centrifugal separation step to remove most of solvents; the centrifuged solvent is returned to the slurry polymerization reactor for recycling.
(5) Washing (batch operation)
And (3) putting the polymer filter cake obtained after centrifugal separation into a washing kettle, fully washing the filter cake by using isopropanol, wherein the retention time of the materials in the washing kettle is about 1h, and the washing temperature is 90 ℃.
(6) Drying (continuous operation)
And (3) performing secondary centrifugal separation on the material flowing out of the washing kettle, and treating the separated material by using a drying system and a screening system to obtain the high-purity ultrahigh molecular weight polyethylene resin.
Example 2
The difference from example 1 is that triisobutylaluminum is used as the cocatalyst. The specific production process control parameters of each reaction kettle are shown in table 1. The results of the analytical characterization of the high purity ultra high molecular weight polyethylene resin are shown in Table 2.
Example 3
The same as example 1 except that the linear alpha-olefin for the prepolymerization was 1-hexene and the amount added was 3.0 kg/batch. The specific production process control parameters of each reaction kettle are shown in table 1. The results of the analytical characterization of the high purity ultra high molecular weight polyethylene resin are shown in Table 2.
Example 4
The same as example 1 except that the polymerization temperature was 80 ℃ to 82 ℃. The specific production process control parameters of each reaction kettle are shown in table 1. The analytical characterization results of the high purity ultra high molecular weight polyethylene resin are shown in table 2.
Example 5
The same as example 1 except that the polymerization temperature was 70 ℃ to 72 ℃. The specific production process control parameters of each reaction kettle are shown in table 1. The results of the analytical characterization of the high purity ultra high molecular weight polyethylene resin are shown in Table 2.
Example 6
The same as example 1 except that the washing temperature was 80 ℃. The specific production process control parameters of each reaction kettle are shown in table 1. The analytical characterization results of the high purity ultra high molecular weight polyethylene resin are shown in table 2.
Example 7
The difference from example 1 is that the washing residence time is 0.5h. The specific production process control parameters of each reaction kettle are shown in table 1. The results of the analytical characterization of the high purity ultra high molecular weight polyethylene resin are shown in Table 2.
Example 8
The difference from example 1 is that the detergent is ethanol. The specific production process control parameters of each reaction kettle are shown in table 1. The results of the analytical characterization of the high purity ultra high molecular weight polyethylene resin are shown in Table 2.
Example 9
The same as example 1 except that the supported ethylene polymerization Ziegler-Natta catalyst as described in preparative example 2.
Example 10
The same as example 1 except that the supported ethylene polymerization Ziegler-Natta catalyst as described in preparative example 3.
Example 11
The same as example 1 except that the supported ethylene polymerization Ziegler-Natta catalyst as described in preparative example 4.
Example 12
The same as example 1 except that the supported ethylene polymerization Ziegler-Natta catalyst as described in preparative example 5.
Example 13
The same as example 1 except that the supported ethylene polymerization Ziegler-Natta catalyst as described in preparative example 6.
Example 14
The same as example 1 except that the supported ethylene polymerization Ziegler-Natta catalyst as described in preparative example 7.
Example 15
The same as example 1 except that the supported ethylene polymerization Ziegler-Natta catalyst as described in preparative example 8.
In examples 1 to 15, the specific production process control parameters of each reaction vessel are shown in Table 2. The results of the analytical characterization of the high purity ultra high molecular weight polyethylene resin are shown in Table 3.
Test example 1
The high-purity ultrahigh molecular weight polyethylene obtained in example 1 was used as a raw material, blended with white oil in a certain ratio, and the plasticizing effect of the extrusion process was observed by twin-screw extrusion (see fig. 2A). And (3) stretching the cast sheet into a film by using a biaxial tensile testing machine, testing the performance of the extracted and dried film, wherein the micro-mountain-out structure of the diaphragm is shown in figures 2B and 2C, and the performance index of the diaphragm is shown in table 4. As can be seen in FIG. 2A, the cast UHMWPE/white oil flakes extruded from the twin screw extruder were uniform and free of sharkskin. As can be seen from fig. 2B and C, after biaxial stretching and washing to remove the solvent, the obtained microporous membrane has a relatively uniform microporous structure, and the UHMWPE raw material used on the surface has suitable molecular weight, molecular weight distribution and aggregation structure characteristics, and is suitable for use as a raw material for producing a separator.
Test example 2
High-purity ultrahigh molecular weight polyethylene obtained in example 2 was used as a raw material, blended with white oil in a certain ratio, and subjected to twin-screw extrusion to prepare a cast sheet. And (3) stretching the cast sheet into a film by using a biaxial tensile testing machine, and testing the performance of the extracted and dried film, wherein the performance index of the diaphragm is shown in table 4.
Test example 3
High-purity ultrahigh molecular weight polyethylene obtained in example 3 was used as a raw material, blended with white oil in a certain ratio, and subjected to twin-screw extrusion to prepare a cast sheet. And (3) stretching the cast sheet into a film by using a biaxial tensile testing machine, and testing the performance of the extracted and dried film, wherein the performance index of the diaphragm is shown in table 4.
The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.
TABLE 1 analytical characterization of the catalyst
Claims (10)
1. A production process of high-purity ultra-high molecular weight polyethylene resin is characterized by comprising the following steps:
(a) Adding a solvent, a cocatalyst and a catalyst into a complex reaction kettle to obtain a complex catalyst;
(b) Adding linear alpha-olefin, solvent, cocatalyst and the complex catalyst into a prepolymerization reactor to carry out prepolymerization reaction to obtain a prepolymerization catalyst;
(c) Continuously adding the prepolymerization catalyst and ethylene into a slurry polymerization reactor to carry out polymerization reaction;
wherein the catalyst comprises a magnesium compound, a titanium compound and an azo electron donor compound;
the azo electron donor compound comprises at least one of azodiisobutyronitrile, azodiisovaleronitrile, azodiisoheptanonitrile, azoisobutyronitrile formamide, azodicyclohexyl carbonitrile, azodiisobutyronitrile dimethyl ester, azodiisobutyl amidine hydrochloride, azodiisopropyl imidazoline hydrochloride and azodicyan valerate;
the magnesium compound is obtained by dissolving magnesium halide in a solvent containing organic alcohol or a halide of organic alcohol;
the titanium compound has a general formula of Ti (OR) a X b In which R is C 1 ~C 10 X is halogen, a is 0, 1, 2 or 3, b is an integer from 1 to 4, a + b =3 or 4;
the content of the organic alcohol is 0.1 to 10.0 mol, the content of the azo electron donor compound is 0.001 to 0.1 mol, and the content of the titanium compound is 1.0 to 15.0 mol based on each mol of the magnesium halide;
the preparation method of the catalyst comprises the following steps:
(1) Preparation of the magnesium compound: dissolving magnesium halide in a solvent containing organic alcohol or a halide of the organic alcohol, and adding an inert diluent to obtain a homogeneous magnesium solution;
(2) Adding a titanium compound and an azo electron donor compound into the homogeneous magnesium solution, reacting, removing unreacted substances and a solvent, and washing to obtain a titanium catalyst;
wherein, the step (2) specifically comprises the following steps:
adding an azo electron donor compound into a magnesium compound to obtain a reaction solution; the reaction liquid and a titanium compound are subjected to a first reaction at a temperature of-24-10 ℃, then the temperature is increased to 80-125 ℃, a second reaction is carried out, unreacted materials and a solvent are removed, and the titanium catalyst is obtained by washing;
or, the step (2) specifically comprises:
and (3) carrying out a third reaction on a magnesium compound and a titanium compound at the temperature of-24-10 ℃, adding an azo electron donor compound, heating to 80-125 ℃, carrying out a fourth reaction, removing unreacted materials and a solvent, and washing to obtain the titanium catalyst.
2. The production process according to claim 1,
in the step (a), the concentration of the catalyst in the system is 0.01-50.0 g/L; the molar ratio of the cocatalyst to the catalyst is (1 to 50) 1;
in the step (b), the concentration of the complex catalyst is 0.001-1.0 g/L, the concentration of the linear alpha-olefin is 0.01-1.0 g/L, and the molar ratio of the cocatalyst to the complex catalyst is (10-200): 1.
3. The production process according to claim 1,
the cocatalyst is an organic aluminum compound; the organic aluminum compound has a general formula of AlR n X 3-n Wherein R is hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, X is halogen, 0<n≤3。
4. The production process according to claim 1,
the solvent is a hydrocarbon solvent.
5. The production process according to claim 4,
the hydrocarbon solvent comprises at least one of aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon and halogenated hydrocarbon.
6. The production process according to claim 1,
in step (b), the linear alpha-olefin comprises at least one of 1-butene, 1-hexene or 1-octene.
7. The production process according to claim 1,
in step (c), propylene, 1-butene, 1-hexene or 1-octene is added as a comonomer.
8. The production process according to claim 1,
in the step (c), the temperature of the polymerization reaction is 65-88 ℃; the pressure of the polymerization reaction is 0.3MPa to 0.8MPa; the time of the polymerization reaction is 3 to 5h.
9. The production process according to claim 1,
further comprising, step (d) post-processing:
and (c) carrying out flash evaporation, primary centrifugal separation, washing, secondary centrifugal separation, drying and screening on the product obtained in the step (c) to obtain the high-purity ultrahigh molecular weight polyethylene resin.
10. The production process according to claim 9,
the detergent used for washing is selected from C 1 ~C 10 Alcohol of (1), C 1 ~C 10 Ether of (C) 1 ~C 10 Aldehyde or C of 1 ~C 10 The ketone of (1).
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