19 results about "Methylaluminoxane" patented technology

The invention provides a preparation method of an antistatic metallocene catalyst. The method comprises the following steps: carrying out thermal activation treatment on a silica gel carrier; loading alkyl tin chloride on the silica gel carrier to obtain an alkyl tin chloride modified silica gel carrier; adding methylaluminoxane into the alkyl tin chloride modified silica gel carrier to obtain a methylaluminoxane / alkyl tin chloride modified silica gel carrier; adding a metallocene compound into the methylaluminoxane / alkyl tin chloride modified silica gel carrier for heating reaction, and then adding an antistatic agent to obtain the antistatic metallocene catalyst. Alkyl tin chloride is used for modifying a silica gel carrier and reacts with hydroxyl to greatly eliminate the hydroxyl; the loading capacity can be improved by combining with MAO, and metallocene combination sites can be increased; after the antistatic agent is added, static electricity generated in the reaction process is reduced, the flaking phenomenon is reduced, and the static electricity range can be controlled to be + / -0.02 KV.

The application discloses a preparation method of a single-center catalyst system and application thereof, and the preparation method comprises the following steps: (1) performing vacuum distillation on a modified methylaluminoxane solution, separating out a solvent and aluminum alkyl to obtain a solid product; (2) dissolving the solid product obtained in step (1) with a pentane solution to obtain a homogeneous solution with different aluminum contents; and (3) combining the homogeneous solution obtained in step (2) with a single-active-center catalyst to form a catalyst system. When the single-active-center catalyst system is used for preparing polyethylene wax, different solvents can be avoided from being introduced into a polymerization system, a process flow of the polyethylene wax is simplified, and energy consumption for solvent separation is reduced; reduction of active aluminum helps to improve polymerization activity, the obtained polyethylene wax has lower metal content and narrower molecular weight distribution, the devolatilization efficiency of the polyethylene wax is improved, and the obtained polymer has a VOCs content lower than 20 ppm.

The invention provides an antistatic metallocene catalyst and application thereof. The antistatic metallocene catalyst comprises an antistatic agent / methylaluminoxane / alkyl tin chloride / silica gel carrier and a metallocene compound loaded on the carrier; the antistatic agent / methylaluminoxane / alkyl tin chloride / silica gel carrier is a silica gel carrier modified by an antistatic agent, methylaluminoxane and alkyl tin chloride. Alkyl tin chloride is used for modifying a silica gel carrier and reacts with hydroxyl to greatly eliminate the hydroxyl; the loading capacity can be improved by combining with MAO, and metallocene combination sites can be increased; after the antistatic agent is added, static electricity generated in the reaction process is reduced, the flaking phenomenon is reduced, and the static electricity range can be controlled to be + / -0.02 KV.

The invention provides a method and a system for treating methylaluminoxane gel. The method comprises the following steps: mixing cyclohexane of which the water content is not less than 100ppm and methylaluminoxane gel, and cleaning; the temperature of the cleaning treatment is not higher than 50 DEG C, and the cleaning treatment is carried out at the stirring rotating speed of 50-500rpm. According to the method, gel gathered on the olefin oligomerization cocatalyst storage tank can be removed, and the activity of the catalyst is not influenced.

The present application relates to a kind of composite carrier loaded polyolefin catalyst and its preparation method and application, catalyst is with metal organic framework modified cellulose composite material as carrier, in situ load metallocene compound as catalytically active component;Preparation method includes the following steps: (1) with cellulose powder, metallocene compound, metal salt and organic ligand as raw material, preparation is obtained metallocene@MOFs / cellulose;(2) metallocene@MOFs / cellulose is dispersed in solvent, methylaluminoxane solution is added to carry out reaction, and the composite carrier loaded polyolefin catalyst of the present application is obtained.Compared with prior art, the preparation process of the present application is simple and fast, and the ash content in the polymer powder produced by the polymerization reaction using the catalyst of the present application is reduced by 75% compared with the existing silica gel carrier.

This invention relates to catalyst compositions for the selective oligomerization of ethylene, particularly for the tetramerization of ethylene into 1-octene, comprising: - a chromium-based metal precursor; - a heteroatom ligand; - a supported methylaluminoxane on an inorganic support; - an additive in the form of an aluminum-based compound; wherein the composition has a molar ratio of aluminum in the supported methylaluminoxane on the inorganic support to chromium in the metal precursor greater than 250, and a molar ratio of aluminum in the additive to chromium in the metal precursor greater than 200.

This invention discloses a method for preparing low-entanglement ultra-high molecular weight polyethylene using an ONN-type Group IV metal catalyst at high temperature. Using methylaluminoxane (MAO) as a co-catalyst, homopolymerization of ethylene is carried out at a polymerization temperature of 50-110 °C and an ethylene pressure of 10-40 atm to obtain a weight-average molecular weight polyethylene (MAH). M w (Greater than 2.5 × 10) 6 g·mol ‑1 Ultra-high molecular weight polyethylene (UHMWPE) was obtained. The resulting virgin particles exhibited a low-entanglement structure, specifically characterized by: a ≥90% decrease or disappearance of the high-temperature melting peak area after DSC annealing; a storage modulus that increased to more than twice its initial value over time during rheological testing at 160 °C; a lamellar or petal-like crystal morphology as shown by scanning electron microscopy; and the ability to be directly pressed into transparent self-supporting films at room temperature. The Ti1 / MAO system, at 110 °C and 40 atm, still yielded a molecular weight of approximately 2.0 × 10⁻⁶. 6 g·mol ‑1 The polyethylene produced exhibits a tensile strength of 40 MPa and an elongation at break of 576% after hot pressing. This invention enables the direct preparation of low-entanglement UHMWPE under industrial-grade high-temperature and high-pressure conditions, resulting in significantly superior processing performance compared to traditional highly entangled products.

This invention belongs to the field of petrochemical catalysis technology and relates to a controlled hydrolysis method for trimethylaluminum and its application. The technical features of this invention are as follows: First, hydrated aluminum sulfate is recrystallized in an aqueous solution containing the antisolvent ethanol to prepare small-crystal, plate-like recrystallized hydrated aluminum sulfate. Second, the recrystallized hydrated aluminum sulfate is subjected to low-temperature drying to adjust its water of crystallization content, obtaining a small-crystal, plate-like aluminum sulfate hydrolysant with a specific water of crystallization content. Third, trimethylaluminum is hydrolyzed using the aluminum sulfate hydrolysant with a specific water of crystallization content, controlling the rate and extent of hydrolysis to obtain a methylaluminoxane co-catalyst solution containing aluminum sulfate. The methylaluminoxane co-catalyst solution containing aluminum sulfate prepared by the method of this invention does not require desalting treatment and can be directly used to construct a PNP-Cr ethylene selective tetramerization catalytic system, providing an option for reducing the manufacturing cost of methylaluminoxane and enabling on-site production and use of methylaluminoxane.

This invention belongs to the field of catalytic materials technology, specifically relating to a pyridinediimide cobalt complex and its preparation method, as well as a method for preparing 1-hexene. A pyridinediimide cobalt complex has the structural formula: ; wherein, R... 1 Selected from fluorine, chlorine, bromine, ester, cyano, benzyl, and hydrogen; R 2 Selected from methyl, ethyl, isopropyl, fluorine, hydrogen, trifluoromethyl, methoxy, R 2 The positions are ortho, para, and meta of aniline; R 3 Selected from cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and hydrogen. This cobalt pyridine diimine complex, under the co-catalysis of methylaluminoxane (MAO), can catalyze the selective oligomerization of propylene to prepare 1-hexene. The oligomerization reaction conditions are mild, and the resulting polyethylene significantly reduces the symmetry and regularity of the polymer chain segments, thereby weakening its crystallinity. While maintaining mechanical strength, it also exhibits excellent flexibility, resistance to environmental stress cracking, and low-temperature impact resistance.

The application belongs to the technical field of conjugated diene polymerization, and particularly relates to a phosphine quinoline ligand, a phosphine quinoline iron complex, a preparation method thereof and application thereof in catalyzing conjugated diene polymerization. The phosphine quinoline ligand and the iron complex are respectively shown as formula I and formula II. The iron complex is a bidentate N, P-coordination catalyst, has a single catalytic active center, and can realize high-activity and high-selectivity polymerization of conjugated dienes by regulating ligand electronic effects, space effects and polymerization conditions. The iron complex only needs 5 equivalents of dry methylaluminoxane to be activated, and still maintains high activity at high temperature (100 DEG C). The obtained polyconjugated diene has narrow molecular weight distribution, and microstructure (cis-1, 4, trans-1, 4, 3, 4 or 1, 2) can be accurately regulated. The reaction system is green, environmentally friendly, low in cost and excellent in thermal stability, and is suitable for industrialized production of high-performance elastomer materials.

The application discloses a metallocene catalyst, which comprises an inorganic carrier, polyethylene polycarboxylic acid ester and a cocatalyst methylaluminoxane (MAO) adsorbed on the inorganic carrier, and a metallocene compound combined with the MAO. The metallocene catalyst of the application can catalyze a polymerization reaction at a higher temperature, has high catalytic activity, and does not cause a stuck kettle in the polymerization reaction, and can produce ultrahigh melt flow rate polyethylene through hydrogen regulation in the polymerization process.

The application provides a method for synthesizing methylaluminoxane by hydrolysis of trimethylaluminum. A solid material is used to disperse trimethylaluminum, and a slurry is formed by stirring in an organic solvent. The slurry is reacted with injected water or ice at a controlled temperature to synthesize methylaluminoxane (MAO). The solid material is a methyl-containing alumina which is insoluble in the organic solvent and can efficiently adsorb and disperse trimethylaluminum. Using the solid material, methylaluminoxane can be produced at a high yield, and the reaction is stable and controllable.

A hybrid supported metallocene catalyst including a first layer based on hydroxide-functionalized hexagonal boron nitride, at least partially reacted with methylaluminoxane through an oxygen atom of hydroxyl groups of the hydroxide-functionalized hexagonal boron nitride. The hybrid support is in the form of layered nanosheets with a longest dimension of 50 to 500 nm.

The application belongs to the technical field of forming die materials, and particularly relates to a modified polydicyclopentadiene material and a preparation method and application thereof. Raw materials of the modified polydicyclopentadiene material include A component and B component; the A component includes the following raw material components in parts by weight: 100 parts of dicyclopentadiene, 8-12 parts of a methacryl cage type silsesquioxane, 4-6 parts of a butene-ethylene-styrene copolymer, and 2-3 parts of methylaluminoxane. The modified polydicyclopentadiene material provided by the application has high high-temperature stability, long service life and the like.

The application discloses a preparation method of melt-blown polyethylene resin, which comprises the following steps: adding a metallocene catalyst, an activator, ethylene and a comonomer, and a molecular weight regulator into a polymerization reactor to perform a polymerization reaction, so as to obtain a polyethylene copolymer; and performing degassing and granulation on the polyethylene copolymer, so as to obtain the melt-blown polyethylene resin; the metallocene catalyst comprises an inorganic carrier, polyethylene polyol and a cocatalyst methylaluminoxane (MAO) adsorbed on the inorganic carrier, and a metallocene compound combined with the MAO. In the preparation method of the melt-blown polyethylene resin, the metallocene catalyst is used, the metallocene catalyst can catalyze the ethylene polymerization reaction at a high temperature, has high catalytic activity, and the polymerization reaction is not sticky in the kettle, and the ultrahigh melt flow rate polyethylene can be prepared through hydrogen regulation in the polymerization process.

The application discloses a metallocene catalyst for melt-blown polyethylene, which comprises an inorganic carrier, polyethylene polyol and a cocatalyst methylaluminoxane (MAO) adsorbed on the inorganic carrier, and a metallocene compound combined with the MAO. The metallocene catalyst has high catalytic activity in catalyzing the ethylene polymerization reaction at a high temperature, and the polymerization reaction is not sticky. The ultrahigh melt flow rate polyethylene can be prepared through hydrogen modulation in the polymerization process.

This invention relates to an oligomerization method, preferably for the tetramerization of ethylene into 1-octene, the method comprising the step of injecting at least four compounds into an oligomerization reactor: - a chromium-based metal precursor; - a heteroatom ligand; - a supported methylaluminoxane on an inorganic support; - an additive in the form of an aluminum-based compound; wherein the chromium-based metal precursor and the heteroatom ligand are never in contact with the supported methylaluminoxane on the inorganic support in the absence of the additive in the form of an aluminum-based compound.

This invention discloses a Co-CFA-1-based butadiene polymerization catalyst and its preparation method. The butadiene polymerization catalyst comprises Co-CFA-1, a co-catalyst, and toluene solvent. The Co-CFA-1 is prepared by heating a dispersion of CFA-1 and cobalt acetate tetrahydrate in NMF at 55–65°C for 18–30 hours, followed by filtration, washing, and vacuum drying to obtain Co-CFA-1. The co-catalyst is composed of alkylaluminum and methylaluminoxane, wherein the alkylaluminum is selected from at least one of diethylaluminum chloride, triisobutylaluminum, and diethylaluminum chloride. This invention provides the application of the Co-CFA-1-based butadiene polymerization catalyst in the preparation of cis-polybutadiene, which can produce high-quality polybutadiene rubber products with high cis-structure content, controllable molecular weight, and narrow molecular weight distribution, and the product yield is high.

Processes of polymerizing olefin monomers. The process includes reacting ethylene and optionally one or more olefin monomers in the presence of a catalyst system, wherein the catalyst system comprises: hydrocarbyl-modified methylaluminoxane having less than 25 mole percent trihydrocarbyl aluminum compounds AlRA1RB1RC1 based on the total moles of aluminum, where RA1, RB1, and RC1 are independently linear (C1-C40)alkyl, branched (C1-C40)alkyl, or (C6-C40)aryl; and one or more procatalysts comprising a metal-ligand complex according to formula (I): (Formula (I)).