165 results about "Ethylene polymerization" patented technology

The invention discloses a method for producing multimodal polyethylene through series connection of multiple reactors, and belongs to the field of olefin polymerization. The low-molecular-weight or medium-molecular-weight ethylene polymer is produced through polymerization in the first reactor, the obtained product enters the intermediate treatment unit to remove hydrogen, and then part of the product is shunted to enter the second reactor to be mixed with the ultra-high-molecular-weight ethylene polymer produced through ethylene polymerization in the second reactor; all polymers of the second reactor are returned to the intermediate treatment unit, and the rest products after hydrogen removal enter a third reactor and are mixed with high-molecular-weight ethylene polymers generated by copolymerization of ethylene and comonomers in the third reactor to generate multimodal polyethylene. The multimodal polyethylene produced by the method is wide in molecular weight distribution, and the molecular weight of ultra-high molecular weight polyethylene is flexible to regulate and control. According to the invention, material circulation between the third reactor and the second reactor is adopted, molecular chain-level mixing among the components is achieved, the compatibility is good, and the mechanical property is more excellent.

A process for preparing a solid catalyst component containing Mg, Ti, and an internal electron donor formed in-situ is provided. The solid catalyst component is suitable for producing polyethylene and its copolymers, and said process shows a combination of high productivity and high bulk density of ethylene polymers, lower soluble fraction, uniform particle morphology, and adjustable control of molecular weight distribution to allow controlled improvement in product properties as per specific requirements.

The invention discloses a marine polyethylene insulated cable material and a preparation method thereof, and relates to the technical field of cable materials. According to the invention, the p-hydroxycinnamyl alcohol modified low-density polyethylene is taken as a core, and a rigid benzene ring is introduced, so that the anti-aging performance and the mechanical performance of the polyethylene cable material are remarkably improved; then polyimide is attracted by hydroxyl to coat the surface of the cable, so that the waterproof and corrosion-resistant performance of the cable is improved; and then blending with the modified filler and the 5-methoxy-2-methylphenol, so that the mechanical property of the cable is improved, and the corrosion resistance and the waterproof effect are realized at the same time. The modified filler takes prismatic barium sulfate particles as a raw material, so that the mechanical property of a polymer is remarkably improved, and the ageing resistance of the cable material is enhanced by matching with barium sulfate; and 4-methacryloxybenzophenone and ethylene are polymerized to form an anti-ultraviolet liquid with certain viscosity, and barium sulfate particles are in different orientations under ultrasonic oscillation by virtue of the viscosity of the anti-ultraviolet liquid, so that the mechanical property and photo-thermal aging resistance of the cable are improved.

The application discloses an ethylene and alpha-olefin copolymerization evaluation test device, which comprises an olefin mixed gas distribution device, a polymerization reactor, a temperature control unit, a pressure control unit and a stirring device. The polymerization reactor is connected with the olefin mixed gas distribution device, the temperature control unit is connected with the polymerization reactor, and the pressure control unit is connected with the polymerization reactor. The stirring device comprises a stirring shaft and a stirring paddle. The stirring shaft is a hollow structure with a gas flow pipeline inside. One end of the stirring shaft penetrates through a cover of the polymerization reactor and is provided with a gas inlet. The other end of the stirring shaft is connected with the stirring paddle. The stirring paddle is arranged at the bottom of the polymerization reactor. At least one gas outlet is arranged on the stirring paddle. The ethylene and alpha-olefin copolymerization evaluation test device can increase the contact amount of ethylene and alpha-olefin with a catalyst. The ethylene and alpha-olefin copolymerization evaluation test device can be used for evaluating ethylene polymerization, and the catalyst activity can be accurately evaluated.

The invention discloses a catalyst component for olefin polymerization, a catalyst, a preparation method and application, and relates to the technical field of olefin polymerization catalysts. The catalyst component comprises reaction products of the following components: a magnesium-containing compound solution, an organic anhydride compound, a titanium compound, an acetate compound, a first alcohol compound and an aromatic ester compound, in the catalyst component, the molar ratio of the magnesium element to the organic anhydride compound to the titanium compound to the acetate compound to the first alcohol compound to the aromatic ester compound is 1: (0.01-1): (2-30): (0.01-10.0): (0.05-10.0): (0.01-5.0). The catalyst component prepared by the preparation method provided by the invention is concentrated in particle size distribution, the catalyst containing the catalyst component has higher polymerization activity, the hydrogen regulation sensitivity under the condition of high hydrogen-ethyl ratio is greatly improved, the hydrogen regulation sensitivity under the condition of low hydrogen-ethyl ratio is moderate, and the catalyst component is suitable for industrial production. The catalyst can catalyze ethylene polymerization to obtain powder particles with high bulk density, the content of fine powder with the size smaller than 75 microns in the polymerized powder is greatly reduced, and almost no fine powder exists.

Organometallic complexes are described which are useful as pre-polymerization catalysts which may form part of olefin polymerization catalyst systems. The catalyst systems find use in the polymerization of ethylene, optionally with one or more C3-12 alpha-olefin comonomers. The organometallic complexes are broadly represented by formula I:wherein L is a bridging group containing a contiguous chain of atoms connecting P with Cy, wherein the contiguous chain contains 2 or 3 atoms and wherein Cy is a cyclopentadienyl-type ligand. The olefin polymerization catalyst system is effective at polymerizing ethylene with alpha-olefins in a solution phase polymerization process at high temperatures and produces ethylene copolymers with high molecular weight and high degrees of alpha-olefin incorporation. Pre-metallation compounds, metallation processes and synthetic methods to make the organometallic complexes as well as polymerization processes are also described.

Processes of polymerizing olefin monomers and catalyst systems. The catalyst systems include a non-hydrogen-generating post-metallocene procatalyst; a co-catalyst; and a hydrogenation procatalyst having the formula Cp2TiXnTiCp2 or Cp2TiXn, in which each Cp is cyclopentadienyl substituted with at least one (C1-C10)alkyl; each X is independently monoanionic or neutral, wherein each X is independently (C1-C40)hydrocarbon, (C1-C40)heterohydrocarbon, (C1-C40)hydrocarbyl, (C1-C40)heterohydrocarbyl, or a halogen atom; and n is 1 or 2.

The present disclosure provides a process. In an embodiment, the process includes introducing an antifoulant into an ethylene feed of a reactor system. The reactor system includes the ethylene feed, a hyper-compressor, a preheater and a polymerization reactor. The ethylene feed is located upstream of the hyper-compressor. The antifoulant consists of an inhibitor, molecular oxygen, and optionally a solvent. As the ethylene feed is located upstream of the hyper-compressor, the process includes introducing the antifoulant into the ethylene feed upstream of the hyper-compressor. The process further includes adding a free radical initiator to the polymerization reactor. The process further includes polymerizing the ethylene in the polymerization reactor under high pressure free-radical polymerization conditions, and forming an ethylene-based polymer.

The present application relates to a kind of diimine ligand with the general structure shown in formula L, the post-transition metal catalyst prepared by its coordination and its preparation method and application, wherein R1-R6 are independently selected from H, C1-C6 alkyl, C1-C6 alkoxy, C6-C 12 Aryl or halogen. The present application constructs diimine post-transition metal catalyst with different chemical environment of bimetallic active site and rigid parent ring skeleton structure, not only improves catalytic activity and thermal stability, but also can be used for preparing bimodal UHMWPE by ethylene polymerization.

This invention relates to the field of catalyst synthesis technology, and more particularly to an alkoxytitanium non-metallocene catalyst for preparing polyethylene wax and its preparation method. The alkoxytitanium catalyst prepared by this invention can directly carry out ethylene polymerization. The polymerization process is simple, requires only a small amount of alkyl aluminum halides for impurity removal, and exhibits high catalytic activity. It requires no additional organoboron compounds or methylchlorooxyalkane, nor does it require chain transfer agents to adjust molecular weight. It has a novel structure, outstanding catalytic activity, and a simple synthesis process with diverse ligand designs. By designing different types of ligands, the molecular weight and activity of the polymer can be effectively improved, achieving precise control over catalyst activity and selectivity, thereby obtaining olefin polymers with specific structures and properties. This characteristic provides broad prospects for the preparation of polymer materials with specific properties and applications.

The invention discloses a supported metallocene catalyst and a preparation method and application thereof, the supported metallocene catalyst comprises a mixture and / or a reaction product of the following components: (A) a reaction mixture of modified alkylaluminoxane and a modified compound, the modified compound being selected from at least one of benzoic acid and substituted benzoic acid; (B) a carrier; (C) a metallocene compound; and (D) an alkane. The supported metallocene catalyst disclosed by the invention is completely prepared by using an alkane solvent, so that the problems caused by using an aromatic hydrocarbon solvent are avoided, the production process of the catalyst is simplified, and industrial implementation is facilitated. The content of Al in the prepared catalyst is larger than 6% by weight, the content of transition metal elements is 0.05-1% by weight, the loading efficiency of the modified methylaluminoxane is improved, the catalyst is used for ethylene polymerization reaction, the performance is good, and the polymerization activity is obviously improved.

The present invention provides a catalyst composition and a preparation method therefor, and a preparation method for high melt strength polyethylene. The catalyst composition comprises a main catalyst and a co-catalyst; the co-catalyst comprises an alkylaluminum compound and a pyridine compound; and the main catalyst is prepared by reacting a magnesium compound, a silicon compound and a titanium compound in a molar ratio of 1:0.1-10:0.05-3. When catalyzing ethylene polymerization, the catalyst composition of the present invention can significantly improve the melt strength of a polymerization product.

Disclosed are metallocene compounds, catalyst compositions and methods for making catalyst compositions, and processes for polymerizing olefins. In an aspect, a series of cyclopentadienyl tert-butyl fluorenyl metallocenes featuring various alkylsulfide groups on a carbon bridge linking the cyclopentadienyl tert-butyl fluorenyl ligands were prepared and evaluated as ethylene polymerization catalysts in the presence of metallocene activators, such as solid super acids (SSA). The metallocenes containing these tethered alkylsulfide substituents provide catalysts which exhibited excellent ethylene polymerization activities comparable to the analogous metallocenes containing tethered olefins and polyethylenes with reduced long chain branching (LCB) relative to metallocenes with a saturated hydrocarbyl tether.

The present invention provides a Ziegler-Natta catalyst system for ethylene polymerization, its preparation method and application. The catalyst system includes a solid phase component and a cocatalyst. The solid phase component includes a porous organic polymer carrier, a magnesium compound and a titanium compound. The porous organic polymer carrier is a copolymer comprising divinylbenzene and a sulfonic acid group-containing functional monomer. Through the design and preparation at the carrier level, the catalyst system of the present invention obtains a Ziegler-Natta catalyst for olefins. During the preparation process, no additional internal electron donor needs to be added, and the catalyst can be used to prepare ultra-high molecular weight polyethylene with a viscosity-average molecular weight up to 7 million.

This invention discloses an asymmetric (α-diimine) nickel-olefin catalyst based on ethylene acenaphthene as its framework, its preparation method, and its applications. The structural formula of the catalyst is shown in Formula (I), where X is chlorine or bromine. The catalyst has a simple preparation process and exhibits results contrary to conventional experimental observations when catalyzing ethylene polymerization: larger substituents lead to higher crystallinity in the polymerization product. Furthermore, this type of catalyst also exhibits good thermal stability and polymerization activity, showing promising prospects for industrial applications. Formula (I)

The application relates to the technical field of olefin polymerization, and discloses an ether metal complex and a preparation method and application thereof. The structural formula of the ether metal complex is shown in formula (I): wherein R1, R2, R3 and R4 are each independently selected from one of hydrogen, C1-C10 alkyl and halogen; X is each selected from O or S; and M is selected from IVB group metal. The ether metal complex is applied to ethylene polymerization as a catalyst, has high reactivity, good thermal stability, shows extremely strong control performance on the molecular weight of polyethylene wax, and highly linear low-molecular-weight polyethylene is obtained. Formula (I)

The invention provides a covalent organic framework-based olefin polymerization catalyst as well as a preparation method and application thereof, the covalent organic framework-based olefin polymerization catalyst is prepared by taking an amino monomer and an aldehyde monomer as raw materials, carrying out Schiff base condensation reaction through a solvothermal method to form a porous material, and then carrying out zirconium metallization coordination reaction on the porous material, wherein the structural formula of the amino monomer is # imgabs 0 #, and the structural formula of the aldehyde group monomer is # imgabs 1 #. The preparation method comprises the following steps: firstly, carrying out condensation reaction on the amino monomer and the aldehyde group monomer to successfully synthesize an intermediate; and carrying out zirconium metallization coordination reaction on the intermediate and ZrCl4 to obtain a target catalyst, wherein pore channels of the catalyst are a zirconium metal catalyst Zr-TFPB-DDA with a covalent organic framework as a carrier, wherein the covalent organic framework is modified by hydroxyl. The synthesis route is reasonable in design and high in yield, the catalyst integrates a high-porosity structure and high catalytic activity, the core value of the catalyst is that the precise regulation and control capability on the molecular weight of an ethylene polymerization product can be remarkably enhanced, and the catalyst is difficult to reach by a traditional catalyst.

The invention discloses an optimization method, device and equipment for polyethylene polymerization parameters and a storage medium, and belongs to the technical field of material design. The optimization method comprises the following steps: acquiring a plurality of polyethylene polymerization parameter groups and polyethylene performance index requirements; determining a polyethylene performance index prediction model corresponding to the polyethylene performance index demand; determining a plurality of predicted polyethylene performance index values based on the polyethylene performance index prediction model and a preset polyethylene polymerization constraint condition; determining a total performance index loss value according to each predicted polyethylene performance index value and a polyethylene performance index demand; generating a new polyethylene polymerization parameter group according to the total performance index loss value; according to the new polyethylene polymerization parameter group, updating the plurality of polyethylene polymerization parameter groups to obtain an updated polyethylene polymerization parameter group; and determining the polyethylene polymerization parameter group with the minimum loss value as a target polyethylene polymerization parameter group. The optimization efficiency of the polyethylene polymerization parameters can be improved.

The invention relates to a preparation method of branched polyethylene and the branched polyethylene obtained by the method. According to the invention, the polyethylene preparation method with two ethylene polymerization steps connected in series is adopted, and different specific catalysts are used in different steps, so that the molecular weight and molecular weight distribution of polyethylene can be regulated and controlled without a complicated catalyst structure and harsh reaction conditions; the molecular weight distribution of polyethylene is improved, and the processability of polyethylene is improved.

The application discloses a supported nickel catalyst and a method for catalyzing ethylene polymerization, and belongs to the technical field of ethylene polymerization. The supported nickel catalyst is prepared by mixing and reacting alkyl magnesium, chlorinated alkyl aluminum and a nickel complex shown in formula 1; wherein R and R' are independently selected from C1-C 10 alkyl, C6-C 18 aryl, C6-C 18 heteroaryl, C1-C 30 alkoxy, C2-C 30 alkylamino, C6-C 30 aryloxy, C6-C 30 arlamino, C 10 -C 30 aralkyl, C3-C 30 siloxy, halogen, nitro, one or more of which. The supported nickel catalyst has excellent stability and high catalytic activity, and can be mass-produced and applied. The supported nickel catalyst can be used for catalyzing ethylene polymerization to obtain ultrahigh molecular weight polyethylene which is low in branching degree, narrow in molecular weight distribution, good in mechanical property, easy to process and free of sticky kettle phenomenon.

Metallocene solutions containing trimethylaluminum, a C4-C8 alkane solvent, and a metallocene compound in an amount from 0.2 to 8 mg per mL of the metallocene solution are described. Catalyst compositions incorporating these metallocene solutions plus an activator-support and an organoaluminum compound can be utilized in polymerization processes to produce polyethylene products.

The invention discloses an alkoxy magnesium carrier for olefin polymerization, a preparation method, a catalyst and an olefin polymerization method. The alkoxy magnesium carrier is prepared from the following raw materials: magnesium powder, mixed alcohol, a halogenating agent, a compound A with a structure as shown in a formula (I) and an inert solvent. The alkoxy magnesium carrier, the titanium-containing compound, the internal electron donor compound and the aluminum-containing compound can be used for preparing the Ziegler-Natta catalyst for olefin polymerization. The alkoxy magnesium carrier is excellent in morphology, controllable in particle size and narrow in particle size distribution, the alkoxy magnesium carrier is not prone to breakage when used for preparing an alkoxy magnesium carrier type catalyst for ethylene polymerization, and the prepared catalyst has the advantages of being high in activity, excellent in hydrogen regulation performance and the like.

The present invention provides a catalyst component for ethylene polymerization or copolymerization based on an alkoxymagnesium support, a preparation method, and its application. The catalyst component is a solid material containing titanium, magnesium, and aluminum. It is prepared by first activating the alkoxymagnesium support with an organoaluminum compound and then adding a titanium compound to the support for titanium loading. The catalyst component is suitable for various ethylene polymerization or copolymerization processes and exhibits high activity, good hydrogen regulation, high bulk density, and low fines content.

The invention provides a turtle-shaped nickel complex as well as a preparation method and application thereof. The preparation method of the nickel complex comprises the following steps: 1) preparing a butanedione diimine ligand; and 2) under the protection of inert gas, reacting the butanedione diimine ligand obtained in the step 1) with (DME) NiBr2 in the presence of an organic solvent at room temperature for 24 hours to obtain the turtle-shaped nickel complex. The turtle-shaped nickel complex is activated with sesquethyl aluminum chloride (EASC) and shows high activity on ethylene polymerization, polyethylene with high linearity, high molecular weight and narrow molecular weight distribution can be obtained, the highest catalytic activity can reach 1.87 * 10 < 7 > g mol <-1 > h <-1 >, and the highest molecular weight of polyethylene can reach 8.73 * 10 < 5 > g mol <-1 >.

The invention relates to the technical field of polyolefin catalysts, and particularly discloses a phenoxy imine compound, a preparation method and application thereof, an olefin polymer and a preparation method thereof. The phenoxy imine compound has the following structural formula, in the structural formula, R1 is selected from tertiary butyl, isopropyl, tertiary butyl, cycloalkyl or adamantyl; r2 is selected from cyclopentyl or cyclohexyl; ad is adamantyl; m is selected from Ti or Zr; and X is selected from Cl, Br or-NMe2. The phenoxy imine compound is applied to catalysis of ethylene polymerization and ethylene and alpha-olefin copolymerization reaction, shows high reaction activity, thermal stability and extremely strong regulation and control performance on polyolefin molecular weight, and has wide industrial application prospects.

The present application relates to the field of ethylene modified polyvinyl alcohol preparation, in particular to a method for preparing ethylene modified polyvinyl alcohol. The method comprises: (1) polymerizing ethylene ester monomer and ethylene in the presence of solvent and initiator to obtain a polymerization liquid; (2) sequentially performing alcoholysis treatment and separation treatment on the polymerization liquid to obtain ethylene modified polyvinyl alcohol; wherein the polymerization reaction system used in the polymerization reaction comprises: sequentially connected oxygen removal device and reaction device; the oxygen removal device comprises an oxygen remover tank body, a liquid monomer feeding port and a bubbling gas feeding port arranged at the top of the oxygen remover tank body; the reaction device comprises a reactor tank body, a deoxygenated liquid monomer feeding port and a gas phase monomer feeding port arranged at the top of the reactor tank body, and a heat exchanger arranged in the reactor tank body. The problems of low heat removal efficiency and high safety risk in the polymerization process of ethylene ester monomer and ethylene can be solved.

The present application provides a method for preparing polyethylene wax by using metallocene catalyst, which comprises polymerizing ethylene in the presence of metallocene catalyst to prepare polyethylene wax; the metallocene catalyst comprises metallocene compound and activator selected from alkyl aluminum and / or borate. The polyethylene wax prepared by the method of the present application has a viscosity average molecular weight of 1000-10000 and a molecular weight distribution of 1.5-3; the polyethylene wax has a relatively narrow molecular weight distribution, and the preparation method is simple and economical, and has a good industrial application prospect.

The utility model provides a tower type reaction system for producing PAO or POE through ethylene polymerization. The reaction system comprises a tower type reactor, wherein a baffling assembly and a strengthening unit are sequentially arranged in the tower type reactor, the baffling assembly comprises a plurality of arc-shaped baffle plates and buckles used for fixedly connecting the arc-shaped baffle plates with the tower type reactor, and the arc-shaped baffle plates are distributed in the tower type reactor in a staggered manner; the distance between the arc-shaped baffle plate positioned at the bottom in the plurality of arc-shaped baffle plates and the strengthening unit is 0.8-1.2 times of the tower diameter of the tower reactor; the top of the tower reactor is also provided with a product outlet, the bottom of the tower reactor is provided with a feed port and a circulating feed port, the bottom of the tower reactor is also provided with a circulating discharge port, and the feed port and the circulating feed port are both communicated into the strengthening unit. According to the utility model, the polymerization degree of polymerization reaction is controlled by using the tower type reactor and the arc-shaped baffle plate.

This invention discloses a phenyl-modified, biasymmetric (α-diimine) nickel olefin catalyst based on acenaphthoquinone as its framework, its preparation method, and its applications. The catalyst's structural formula is shown in Formula (I), where X is chlorine or bromine. The catalyst has a simple preparation process and, when used as a co-catalyst for ethylene polymerization, exhibits results contrary to conventional experimental observations: larger substituents lead to lower molecular weight, better flowability, and dispersibility in the polymerized product, showing broad application prospects in the elastomer field. Furthermore, this type of catalyst also exhibits good thermal stability and polymerization activity, demonstrating promising industrial application prospects. Formula (I).