71 results about "Hydrocarbon solvents" patented technology

A borate compound-containing composition soluble in hydrocarbon solvents. A composition containing base A, or a compound having a total carbon number of not less than 8 and represented by the formula (5):wherein R and R′ are each independently an optionally substituted C1-30 alkyl group, an optionally substituted C3-15 cycloalkyl group, or an optionally substituted C6-14 aryl group; anda borate compound represented by the following formula (1):wherein R1, R2, R3 and R4 are each independently a C6-14 aryl group substituted by one or more fluorine atoms or fluoro C1-4 alkyl groups; and[A-H]+ is a base A-derived cation. A method for producing a polymer, by polymerizing at least one kind of monomer selected from the group consisting of olefins and dienes by using the composition A as a cocatalyst.

This application discloses an integrated cleaning device, relating to the field of cleaning equipment, comprising a frame; a loading rack installed at one end of the frame; a unloading rack installed at the other end of the frame; a transfer mechanism installed on the frame and used for transferring optical components; a hydrocarbon cleaning unit installed on the frame and adjacent to the loading rack, the hydrocarbon cleaning unit being used to clean optical components using hydrocarbon solvents; and an HFE cleaning unit installed on the frame and adjacent to the unloading rack. This application reduces the footprint by integrating the hydrocarbon cleaning unit and the HFE cleaning unit onto the frame; it reduces mutual interference and improves safety by physically isolating the hydrocarbon cleaning unit and the HFE cleaning unit with partitions; and it prevents large amounts of hydrocarbon solvent from entering the next process by using air knife purging, greatly reducing the contamination load of subsequent HFE solvents and minimizing cross-contamination.

The present disclosure describes compositions for restoring and protecting vinyl, rubber, and plastic (VRP) surfaces, wherein the compositions include at least two silicone fluids. In embodiments, the compositions include a first silicone fluid and a second silicone fluid, one or more mineral oils, one or more rheology modifiers, one or more hydrocarbon solvents, water, and optionally one or more preservatives. The present disclosure also describes a method of preparing the composition, wherein the method includes slowly adding the one or more hydrocarbon solvents to the water that is moving at a slow speed to form a solution, continuing mixing, and adding the one or more rheology modifiers to the solution and mixing, continuing mixing and adding to the solution in the following order: the one or more mineral oils; the first silicone fluid, the silicone second fluid, and optionally adding the one or more preservatives and continue mixing.

The application discloses an interface control liquid for prelithiation electrodes, a preparation method and application, and the interface control liquid comprises a solvent and a metal salt; the solvent comprises one or more of an ether solvent, an ester solvent, a ketone solvent, a hydrocarbon solvent, a nitrile solvent or deionized water; the metal salt comprises one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium bisoxalate borate, lithium bisfluorosulfonimide, lithium bistrifluoromethylsulfonimide, lithium perchlorate, lithium fluoride and lithium chloride; the concentration of the metal salt is 0.001 g / mL-10 g / mL; the prelithiation electrode is obtained by supplementing lithium to an electrode by a chemical prelithiation solution; the interface control liquid is used for modifying the prelithiation electrode, the metal salt of the interface control liquid reacts with the chemical prelithiation solution remaining on the surface of the prelithiation electrode, and a solid electrolyte layer containing inorganic lithium salt is generated on the surface of the prelithiation electrode; wherein, the content of the inorganic lithium salt is between 5% and 90%.

The invention discloses a preparation method of an alkylaluminoxane solution, and belongs to the field of alkylaluminoxane preparation. The method comprises the following steps: firstly, performing vacuum drying on an aluminum hydroxide solid at high temperature to remove moisture adsorbed by the aluminum hydroxide solid; then dispersing aluminum hydroxide in an anhydrous hydrocarbon solvent under anhydrous and anaerobic conditions, adding a hydrocarbon solution of trimethylaluminum, and preparing alkylaluminoxo alkyl substrate through double decomposition reaction of the aluminum hydroxide and the trimethylaluminum; and respectively adding aluminum alkyl and inorganic salt hydrate into the alkyl aluminoxane base, reacting at a set temperature, and filtering to remove inorganic salt by-products after the reaction is completed, thereby obtaining the alkyl aluminoxane solution. The method disclosed by the invention is mild in reaction, high in yield and few in byproducts.

The method produces hollow particles which have a high void ratio, which can reduce the residual amount of a sparingly water-soluble solvent used in the production process, and which are less likely to collapse. The method for producing hollow particles which comprise a shell and a hollow portion and which have a void ratio of 50% or more and 90% or less, wherein a suspension treatment of a mixture liquid containing a polymerizable monomer for shell, a polar resin, a hydrocarbon solvent, a sparingly water-soluble inorganic metal salt as a dispersant, and an aqueous medium is carried out to prepare a suspension in which droplets of a monomer composition containing the polymerizable monomer for shell, the polar resin and the hydrocarbon solvent are dispersed in the aqueous medium; a polymerization reaction of the suspension is carried out; and the hydrocarbon solvent is removed from the obtained hollow particles.

The present invention relates to the fields of synthesis of polymer materials and exploitation of oil and gas reservoirs, and discloses a water-soluble thermosetting resin, a preparation method thereof, a curable resin composition, an epoxy resin product and a preparation method thereof. The water-soluble thermosetting resin has a structure shown in Formula I: wherein, R1 is an alkylene group with 1 to 4 carbon atoms; A is wherein, R2 and R3 are each independently H, CH3, CF3 or CH2CH3; M1 and M2 are each independently H, K or Na, and at least one of M1 and M2 is H; 0 < m1 + m2 ≤ 8. This water-soluble thermosetting resin has a specific structure, and the epoxy resin product prepared therefrom has a low swelling rate in water and hydrocarbon solvents and a high pressure-bearing strength after a long time at high temperature.

The present application provides a preparation method of an aromatic hydrocarbon oligomer, the preparation method including: subjecting an aromatic hydrocarbon compound to an oligomerization reaction under the catalysis of a chloroaluminate ionic liquid to obtain the aromatic hydrocarbon oligomer, where the oligomerization reaction is carried out in a solvent system, and the solvent is selected from chlorinated hydrocarbon solvents, and the aromatic hydrocarbon compound is selected from fused-ring aromatic hydrocarbons with 2 to 4 rings. The preparation method of the present application can efficiently prepare aromatic hydrocarbon oligomers with simple composition and narrow molecular weight distribution under mild conditions, thereby providing a high-quality precursor for the preparation of high-quality mesophase pitch.

To provide a nonaqueous dispersion resin composition capable of forming a coating material excellent in weather resistance and pigment dispersibility, and a coating material containing the nonaqueous dispersion resin composition.SOLUTION: The nonaqueous dispersion resin composition contains an organic solvent containing a hydrocarbon solvent, and a nonaqueous dispersion resin having a core and a shell covering the core. The core is a polymer of the core polymerization component. The polymer of the core polymerization component is substantially insoluble in an organic solvent. The shell is a polymer of the shell polymerization component. The polymer of the shell polymerization component is soluble in an organic solvent. The shell has an acid number of at least 0. 5mgKOH / g and no greater than 4. 0mgKOH / g. Acid values of the non-aqueous dispersion-type resins are 0. 5mgKOH / g or more and 6. 0mgKOH / g or less. The amine value of the non-aqueous dispersion-type resins is 0. 2mgKOH / g or more and 4. 0mgKOH / g or less. The non-aqueous dispersion resin composition has a hindered amino group.SELECTED DRAWING: None

The invention discloses a preparation process for producing high-strength polyethylene fibers. The technological process comprises the following steps: mixing an ultra-high molecular weight polyethylene raw material and a halogenated hydrocarbon solvent in proportion, swelling and pre-dissolving by a first-step screw rod, dissolving by a second-step screw rod, filtering by a filter, pumping by a metering pump, spinning, cooling by chilled water, drying, carrying out gas-phase separation on the solvent, carrying out multi-stage drafting, and rolling according to the deep processing requirement of the fiber. The method has the beneficial effects that halogenated hydrocarbon is selected as a solvent, the swelling temperature of the stepped screw is reduced by about 40% compared with the temperature in the prior art, and the energy consumption is reduced; the extraction process is omitted, the equipment capital investment can be reduced by about 30%, the production cost can be reduced by about 40%, the production cost can be reduced by about 40% compared with the total production cost in the prior art, and the produced economic benefits are remarkable.

To provide a lightweight fiber-reinforced molded body. [Solution] A method for producing a fiber-reinforced molded article, comprising the steps of: preparing a mixture containing a first polymerizable monomer, a hydrocarbon solvent, a dispersion stabilizer, and an aqueous medium; preparing a suspension by suspending the mixture; and subjecting the suspension to a polymerization reaction, wherein the mixture contains a crosslinkable monomer as the first polymerizable monomer, the content of the crosslinkable monomer in 100 parts by mass of the first polymerizable monomer is 80 parts by mass or more, and when the polymerization conversion rate of the first polymerizable monomer reaches 93% by mass or more, a second polymerizable monomer having a solubility of 0.3 g / L or more in distilled water at 20°C is added and subjected to a further polymerization reaction to produce hollow particles; preparing a resin composition containing the obtained hollow particles, a matrix resin, and a solvent; and impregnating reinforcing fibers with the resin composition.

The invention relates to a preparation method of a caffeine impurity C. The preparation method of the caffeine impurity C can effectively solve the problems of preparation of the caffeine impurity C, effective control of impurity content in caffeine and guarantee of coffee quality, and the preparation method comprises the following steps: mixing theophylline, a catalyst triethylene diamine, N, N-dimethylformamide and dimethyl carbonate, heating for reaction, distilling, adding water for recrystallization, and filtering to obtain the caffeine impurity C. Recrystallized jellyfish liquid is obtained; and adding a halogenated hydrocarbon solvent, standing until a solid is separated out between the water layer and the halogenated hydrocarbon solvent layer, filtering, and drying to obtain the product. The invention provides the caffeine impurity preparation method which is simple and easy to implement, mild in condition and low in energy consumption and pollution, so that the preparation vacancy of the impurity at present is filled up, powerful technical support is provided for quality research and quality control of caffeine, and the method has practical popularization and application values.

This invention specifically relates to a boron-oxygen ligand-stabilized rare-earth or alkaline-earth metal catalyst, its preparation method, and its application, belonging to the field of catalyst synthesis technology. The catalyst has the structure shown in Formula I, where M is a rare-earth or alkaline-earth metal ion and D is an ether or pyridine ligand. The preparation method involves reacting a boron-oxygen ligand with a rare-earth alkyl or amino compound, or an alkaline-earth metal amino compound, in a hydrocarbon solvent, followed by post-treatment to obtain the target catalyst. This method has few steps, is simple to operate, and yields catalysts with diverse structures, exhibiting excellent catalytic activity and stability. The catalyst of this invention is used to catalyze the trimerization of isocyanates to prepare isocyanurates, offering advantages such as simple activation, high catalytic activity, mild reaction conditions, low catalyst dosage, and a wide range of applicable substrates. It overcomes the shortcomings of traditional catalytic systems, such as poor stability, large dosage, harsh reaction conditions, and low conversion rates, demonstrating promising industrial application prospects.

The invention provides medical polypropylene and a preparation method thereof. The preparation method comprises the following steps: polymerizing propylene to obtain a polypropylene crude product; sequentially purifying, drying and granulating the polypropylene crude product to obtain the medical polypropylene, a purifying agent adopted for purification comprises a C5-C20 alkane solvent and a difunctional group additive; the weight ratio of the hydrocarbon solvent to the difunctional group additive is (1-13): (1-3). The medical polypropylene prepared by the preparation method is relatively low in precipitate content.

A thermoplastic resin composition containing: a thermoplastic resin (L); a paraffin-based hydrocarbon solvent (M); and a styrene-based elastomer (N), wherein the thermoplastic resin (L) is one or more selected from the group consisting of a polycarbonate resin and a resin containing, as structural units, a rubber-based polymer, a vinyl cyanide-based monomer, and an aromatic vinyl-based monomer, the paraffin-based hydrocarbon solvent (M) has an aniline point of 110°C or higher, and the styrene-based elastomer (N) is a block copolymer containing a polymer block having polystyrene and a polymer block having a conjugated diene compound. The thermoplastic resin composition has excellent silent properties while maintaining or improving the low-temperature impact resistance of the thermoplastic resin.

The present invention relates to a cleaning agent composition which is excellent in cleaning property and does not corrode plastic substrates such as polycarbonate and polystyrene which are not resistant to solvents. The cleaning agent composition of the present invention comprises the following (A) to (C) components, the mass ratio of the (A) component and the (B) component being 11:89 to 99:1, (A) cis-1-chloro-3,3,3-trifluoropropene, (B) one or more compounds selected from the group consisting of hydrofluoroolefins, hydrofluorocarbons and hydrofluoroethers which do not contain a chlorine atom, and (C) a hydrocarbon solvent.

The application provides a preparation method of solution polymerized styrene-butadiene rubber, and the method comprises the following steps: in the presence of a hydrocarbon solvent, an organic lithium is used as an initiator, an ether compound is used as a random aid, an anionic copolymerization reaction of a monovinyl aromatic compound and a conjugated diene compound is carried out, after the monomer conversion rate reaches more than 95%, a mixture of nitrogen-containing star-shaped and linear coupling agents is added, the molar ratio of the two coupling agents is 1:(1.5-15), and then antioxidants, a terminating agent, flocculation, drying and other steps are added to obtain the solution polymerized styrene-butadiene rubber product. The solution polymerized styrene-butadiene rubber with a relatively wide three-peak molecular weight distribution is obtained under the action of the special composite coupling agent, so that the processing performance of the rubber is improved; the rubber matrix after nitrogen functionalization can obviously improve the dispersity of carbon black therein, fully plays the reinforcing role of the carbon black, obviously improves the tensile strength of the rubber compound, and can make the tire simultaneously obtain excellent characteristics of low rolling resistance and high anti-wet skid resistance.

The invention discloses a cleaning agent for cleaning a nickel-plated battery shell and a preparation method of the cleaning agent, and belongs to the technical field of cleaning agents. The cleaning agent is prepared by compounding 30-80 parts by mass of a hydrocarbon solvent, 10-30 parts by mass of an alcohol ether solvent, 2-10 parts by mass of a surfactant, 1-5 parts by mass of a penetrant and 0.2-3 parts by mass of a self-made auxiliary agent. Wherein the self-made auxiliary agent is prepared from isooctyl alcohol, cyclohexanol, triethanolamine, dodecanedioic acid and dipropylene glycol butyl ether according to a specific proportion and a reaction process, and organic amine salt with surface activity and a corrosion inhibition function is generated in a system. The cleaning agent can synchronously and efficiently remove polar and non-polar pollutants on the surface of a nickel-plated battery shell through the synergistic effect of all the components, and can deeply penetrate into micropore gaps to complete precise cleaning by means of the ultralow surface tension of the fluorocarbon penetrant, meanwhile, a protective film is formed on the surface of a nickel-plated layer, and zero damage in the cleaning process is achieved. The product is good in stability, high in environmental protection property, simple and convenient in preparation method and suitable for industrial production.

The present invention relates to a tris(hydroxymethyl)aminomethane hydrochloride preparation method and, specifically, to a high-purity tris(hydroxymethyl)aminomethane hydrochloride preparation method, which does not use a main solvent, and thus is economical and eco-friendly. The tris(hydroxymethyl)aminomethane hydrochloride preparation method of the present invention exhibits a high conversion rate and selectivity, and provides an economical and eco-friendly preparation method by establishing a solvent recovery and reuse system that recirculates a hydrocarbon solvent, which is an antisolvent, during crystallization, and minimizes solvent loss.

The invention provides a preparation method of a vanadium polyethylene catalyst, which comprises the following steps: mixing and reacting a mixed solution of iodine, chloralkane and ether with metal magnesium to obtain an organic magnesium solution; the method comprises the following steps: mixing an organic magnesium solution with fatty acid ester for reaction to obtain a mixture, and then mixing the mixture with a chlorination reagent for reaction to obtain a solid magnesium-containing product; preparing a hydrocarbon solution of a solid magnesium-containing product, and mixing the hydrocarbon solution with an aluminum alkyl compound for reaction to obtain a magnesium-containing carrier; finally, adding a hydrocarbon solvent into the magnesium-containing carrier to obtain a magnesium-containing carrier suspension; wherein the chlorination reagent comprises halogenated aromatic hydrocarbon and carbon tetrachloride; and mixing the magnesium-containing carrier suspension and the vanadium-containing solution for reaction to obtain the vanadium polyethylene catalyst. The preparation method can further reduce the content of phenyl-containing compounds in the synthesis process of the vanadium polyethylene catalyst, and further improve the environmental friendliness of a polymerization product; the vanadium polyethylene catalyst prepared by the method is relatively high in vanadium content and has relatively high polymerization activity.

This invention provides a method for decolorizing a steroid intermediate dihydroxy compound, relating to the field of pharmaceutical and chemical technology. The method includes: dissolving the crude dihydroxy compound in a halogenated hydrocarbon solvent; adjusting the pH of the system to 8.0-9.5 with an inorganic base; adding an aqueous sodium hypochlorite solution for chemical oxidation decolorization while maintaining this pH value; determining the reaction endpoint by monitoring color change or redox potential; adjusting the pH after the reaction with a weak acid, followed by separation, concentration, and crystallization to obtain the final product. This invention utilizes the selective oxidation effect of sodium hypochlorite in a specific pH buffer system, replacing the traditional physical adsorption decolorization with activated carbon. While effectively removing fermentation pigments, it avoids the oxidative damage of the 11-hydroxyl group in the steroid skeleton. The product has high purity, produces no waste activated carbon solid waste, is simple to operate, and is easily scaled up industrially.

The present invention relates to a process for preparing an alpha-olefin feed stream comprising providing a low-pressure initial stream comprising a hydrocarbon solvent at a low pressure level in the range of from below atmospheric pressure to 15 barg; pressurizing the low-pressure initial stream to a medium pressure level in the range of from greater than 15 to 45 barg to form a medium-pressure initial stream; pressurizing the medium-pressure initial stream to a high pressure level in the range of from greater than 45 to 300 barg to form a high-pressure initial stream; wherein a monomer stream comprising an alpha-olefin monomer is introduced into the medium-pressure initial stream at medium pressure level and / or into the high-pressure initial stream at high pressure level, and one or more comonomer streams comprising at least one alpha-olefin comonomer is / are introduced into the low-pressure initial stream at low pressure level, and / or into the medium-pressure initial stream at medium pressure level, and / or into the high-pressure initial stream at high pressure level; to form an alpha olefin feed stream. Alternatively, the medium pressure level may be left out, wherein a monomer stream comprising an alpha-olefin monomer is introduced into the high-pressure initial stream at high pressure level; and one or more comonomer streams comprising at least one alpha-olefin comonomer is / are introduced into the low-pressure initial stream at low pressure level, and / or into the high-pressure initial stream at high pressure level; to form said alpha olefin feed stream. The above processes enable solution polymerisation with reduced process complexity and increased process economics.

The application discloses a synthesis method of 4-(aminoalkyl) benzene sulfonic acid compound and relates to the technical field of organic synthesis. Benzylamine or phenethylamine is dissolved in a halogenated hydrocarbon solvent, the temperature is lowered to 0-5 DEG C, chlorosulfonic acid is added dropwise for sulfonation reaction, after dropwise addition is completed, the temperature is raised to 40-65 DEG C for reaction until the raw material is completely reacted, the temperature is lowered to 0-5 DEG C, then C1-C4 alcohol solvent containing trace moisture is added into the reaction system as a quenching agent for quenching, after quenching, the halogenated hydrocarbon solvent is recovered by distillation, the remaining substance is cooled, crystallized, filtered and dried, and 4-(aminoalkyl) benzene sulfonic acid is obtained. In the application, n-butanol containing trace moisture (0.5-8%) is used as a quenching agent, the reaction of chlorosulfonic acid and water is diluted and buffered by alcohol, the heat release is gentle, there is no risk of material shock, and the operation safety is far superior to traditional ice water quenching.

To provide a curing agent for epoxy resins that exhibits good curing properties at low temperatures, has excellent surface gloss in the resulting cured product, and leaves minimal traces of water droplets. [Solution] An epoxy resin curing agent containing as essential components a condensate (A) of an amine compound (a) having at least two primary amino groups in one molecule, formaldehydes (b), and a phenol compound (c) which may have an alkyl group having 1 to 12 carbon atoms, a petroleum resin (B) which is a C5-9 aromatic hydrocarbon fraction polymer, a hydrocarbon solvent (C) with a boiling point of 150°C or higher, and a compound (D) having a tertiary amino group, wherein the mass ratio of each component is in the range of condensate (A) / petroleum resin (B) = 1 to 10, petroleum resin (B) / hydrocarbon solvent (C) = 0.5 to 2.0, and condensate (A) / compound (D) = 1.5 to 4.5.

This invention relates to the field of inactivator recovery technology, specifically a method for recovering amine / alcohol inactivators from ethylene oligomerization catalyst waste liquid. The method includes: injecting the ethylene oligomerization catalyst waste liquid and an inorganic salt treatment agent into a treatment vessel, where they are thoroughly mixed and reacted to obtain a premix; passing the premix through a solid filter to separate the filter residue and filtrate, thus completing the harmless conversion of the waste catalyst; injecting the filtrate into flash evaporator 1 for a first flash evaporation, and injecting the liquid phase from flash evaporator 1 into flash evaporator 2 for a second flash evaporation; cooling the gas phase separated by the second flash evaporation in a cooler to achieve the recovery of amine / alcohol inactivators. This invention first uses a low-cost inorganic salt treatment agent to convert the waste catalyst into a harmless solid, eliminating the need for traditional incineration and reducing environmental pollution; then, through two flash evaporation purification processes, amine / alcohol inactivators and hydrocarbon solvents can be recovered by distillation, reducing process costs.

The invention belongs to the field of implants, and relates to a dental implant and a surface cleaning method thereof.The dental implant is subjected to degreasing and pre-cleaning through heating ultrasound, and a pre-cleaned dental implant is obtained; the method comprises the following steps: putting a pre-cleaned dental implant into a first hydrocarbon solvent, carrying out first-time hydrocarbon cleaning under a first vacuum high-temperature condition, then putting the pre-cleaned dental implant into a second hydrocarbon solvent, carrying out second-time hydrocarbon cleaning under a second vacuum high-temperature condition, and carrying out vacuum drying treatment to obtain a hydrocarbon-cleaned dental implant; carrying out sand blasting and acid etching treatment on the hydrocarbon cleaned dental implant, then putting the hydrocarbon cleaned dental implant into an alkaline cleaning agent for cleaning, and drying to obtain a pretreated dental implant; preparing an antibacterial treatment solution; the pretreated dental implant is placed in an antibacterial treatment solution to be subjected to standing treatment, drying treatment is conducted after standing treatment is completed, and the dental implant with the antibacterial surface is obtained. According to the technical scheme provided by the invention, residues on the surface of the dental implant and in micro-pores can be efficiently dissolved, stripped and removed, and the antibacterial property of the dental implant is improved.

Sustained release biologics can be prepared by emulsifying a Solid-in-Hydrocarbon (S / H) mixture in a fluorocarbon solution to form an emulsion of the S / H in the fluorocarbon solution. Advantageously, the Solid-in-Hydrocarbon (S / H) mixture can be prepared by dispersing spray dried biologic particles in a solution of a sustained release polymer in a hydrocarbon solvent. Further, the spray dried biologic particles can be prepared by atomizing a feed solution including a biologic drug in an aqueous carrier to form an aerosol and exposing the aerosol to a stream of drying gas at a temperature of greater than about 80 °C, e.g., from about 80 °C to about 150 °C, to dry the aerosol to form the spray dried biologic particles. In some aspects, emulsifying the S / H mixture in the fluorocarbon solution can be carried out with a microporous membrane.

This invention belongs to the field of lithium industry technology, and particularly relates to an alkyl lithium filtration process, comprising the following steps: Step 1: Under the protection of argon gas, lithium metal particles and hydrocarbon solvent are added to a washing vessel, allowing the lithium metal particles to be washed to remove surface impurities; Step 2: Under the protection of argon gas, the washed lithium metal particles are added to a synthesis vessel, followed by the addition of hydrocarbon solvent, and the total solvent volume is adjusted to a specified value; Step 3: Chlorinated alkanes are added to the synthesis vessel using a mixed droplet method, and the chlorinated alkanes react fully with the lithium metal particles and hydrocarbon solvent in the reaction vessel at a specific temperature. When filtering the alkyl lithium solution, as the drive shaft rotates forward, the alkyl lithium solution sprayed through the through-holes on the drive shaft can be evenly sprayed onto the surface of the rotating sintered mesh filter element, thereby improving the filtration effect of the sintered mesh filter element on the alkyl lithium solution.

The invention provides a method for preparing bimodal / wide molecular weight distribution polyethylene by using a single reactor, which comprises the following steps of: catalyzing ethylene homopolymerization or copolymerization of ethylene and alpha-olefin by using a hydrocarbon solvent as a dispersing agent and using a vanadium polyethylene catalyst and aluminum alkyl as a main catalyst and a cocatalyst respectively, hydrogen is used as a polymer molecular weight regulator in the reaction process; wherein the vanadium polyethylene catalyst comprises a magnesium-containing carrier and a vanadium compound loaded on the magnesium-containing carrier, the total weight of the vanadium polyethylene catalyst is 100%, the mass content of active metal vanadium is not less than 3.8%, the average particle size of the vanadium polyethylene catalyst is 9.0-13.5 [mu] m, and the particle size distribution SPAN value is less than 1. The vanadium polyethylene catalyst used in the invention has higher polymerization activity, and the obtained polymer has higher apparent density and lower fine powder and oligomer, and can be used for developing special resins for high-strength films, pressure-resistant pipes and the like.

The application discloses a preparation method of a piperidine compound. The application specifically provides a preparation method of a piperidine compound, which comprises the following steps: compound 1-8 and compound 1-9 are subjected to a condensation reaction in an organic solvent in the presence of a base and 18-crown-6 to obtain compound 1-11; the base is LiHMDS and / or NaHMDS; and the solvent is selected from one or more of benzene solvents, halogenated hydrocarbon solvents and furan solvents. The preparation method of the application can increase the proportion of Z configuration in the product from about 30% to about 45%, and the proportion of Z configuration in the product is even increased to more than 89% in some methods, so that the yield of the target product is greatly improved.