36 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 invention provides a supported metallocene catalyst, a preparation method of the supported metallocene catalyst, an ethylene homopolymerization reaction method and an ethylene and alpha-olefin copolymerization reaction method. The supported metallocene catalyst comprises a carrier, and a metallocene compound and a cocatalyst which are supported on the carrier, the carrier is selected from silicon dioxide and / or aluminum oxide; the metallocene compound has a structure as shown in a formula I. Formula I. The polymer particles are regular, and the phenomenon that the reactor adheres to the kettle is relieved; in addition, when the supported metallocene catalyst is used for copolymerization of ethylene and alpha-olefin by adopting a slurry polymerization process, the polymerization activity can be improved, the cost is reduced, and the dosage of methylaluminoxane is reduced.

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 present invention relates to an efficient process for the preparation of highly active polymerization co-catalysts by reacting methylaluminoxane residues with C6-C18-alkyl aluminum compounds in the presence of a hydrocarbon solvent.

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.

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.

The invention discloses a synthesis method of oligomerized methylaluminoxane. According to the method, alkyl aluminum of C2 or above is used as a starting raw material, n value distribution of generated MAO can be effectively controlled, high-oligomerization-degree MAO small in molecular weight distribution range and narrow in n value distribution is obtained, the MAO product catalytic activity is relatively concentrated, the method is especially suitable for a process for preparing high-carbon alpha-olefin through ethylene oligomerization, and the selectivity of target alpha-olefin can be remarkably improved.

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.

A method for polymerizing olefin monomers. The method comprises reacting ethylene and optionally one or more olefin monomers in the presence of a catalytic system, wherein the catalytic system comprises: AlR having a content of less than 50 mol% based on the total molar amount of aluminum. A1 R B1 R C1 Modified hydrocarbon methylaluminoxane, wherein R A1 R B1 and R C1 Independently for straight chains (C1-C) 40 Alkyl groups, branched (C1-C) 40 )alkyl or (C6-C 40 ) aryl; and one or more metal-ligand complexes according to formula (I).

The application discloses an isocyanate polymerization catalyst and a preparation method thereof, and an isocyanate tar purification method. The polymerization catalyst comprises a main catalyst quaternary ammonium base, a first additive methylaluminoxane and / or trimethyl gallium, and a second additive sodium fatty acid. A mixed solution containing isocyanate polymers, urea, and isocyanate monomers in the system is removed of the monomers by catalytic polymerization in a reactor and by adding the catalyst to obtain isocyanate polymers, which are applied to downstream fields such as boards and adhesives. The application can convert waste tar liquid into by-products for sale, has significant economic benefits, and reduces the waste liquid treatment capacity of the running device and the operation cost of the device.

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 provides a supported metallocene catalyst and a preparation method, an ethylene homopolymerization method and an ethylene and alpha-olefin copolymerization method. The supported metallocene catalyst comprises a carrier and a metallocene compound and a cocatalyst supported on the carrier; the carrier is selected from silica and / or alumina; the metallocene compound has a structure as shown in formula I. Formula I. The polymer particles of the application are regular, and the reactor sticking phenomenon is reduced; in addition, when the supported metallocene catalyst is used for ethylene and alpha-olefin copolymerization by using a slurry polymerization process, the polymerization activity can be improved, the cost is reduced, and the amount of methylaluminoxane is reduced.

The disclosure provides a catalyst composition for the oligomerization of ethylene to produce one or more linear alpha olefins, the catalyst composition including a chromium compound, a heteroatomic multidentate ligand having an NPNPN backbone, wherein each P is an optionally substituted phosphino group and each N is an optionally substituted amino group, a methylaluminoxane, and triethyl-aluminum.

To provide a polymerization catalyst having excellent copolymerizability capable of efficiently producing a low density and high molecular weight polymer, particularly an ethylene-based polymer and to provide a method for producing an ethylene-based polymer using the same.SOLUTION: There are provided: a polymerization catalyst which comprises a transition metal compound having an electron-donating substituent at a specific site, an organic aliphatic group-modified clay, one or more activation co-catalysts selected from the group consisting of a specific boron compound, a specific aluminum compound, methylaluminoxane and (methyl-isobutyl)aluminoxane and an organic aluminum compound; and a method for producing an ethylene-based polymer using the same.SELECTED DRAWING: None

This invention discloses a silica-supported metallocene polyethylene catalyst, its preparation, and its application. The catalyst mainly consists of a hierarchical porous silica microsphere support, methylaluminoxane, and a zirconium-centered metallocene compound. The hierarchical porous silica microspheres of this invention not only possess microporous, mesoporous, and macroporous structures, but also allow for precise control of the proportions of each pore type. The catalyst obtained after metallocene loading treatment exhibits adjustable particle size and narrow particle size distribution. The process is simple and the preparation conditions are mild, resulting in high catalytic activity and a polymer with excellent particle morphology.

Processes of polymerizing olefin monomers. The process comprising reacting ethylene and optionally one or more olefin monomers in the presence of a catalyst system, wherein the catalyst system comprises: an activator; hydrocarbyl-modified methylaluminoxane having less than 25 mole percent trihydrocarbyl aluminum compounds A1RA1RB1RC1 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 metal-ligand complexes according to formula (I):

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 invention discloses a self-activation catalyst for catalyzing ethylene tetramerization to prepare 1-octylene, a preparation method and an application method. The self-activation catalyst comprises an aryl ether-silicon bridged diphosphine ligand chromium complex [L1L2Cr] < + > and tetraphenyl boron anions paired with the aryl ether-silicon bridged diphosphine ligand chromium complex [L1L2Cr] < + >; the aryl ether-silicon bridged diphosphine ligand chromium complex [L1L2Cr] < + > has a structure as shown in a formula (1). When the self-activation catalyst is used, 1-octene can be obtained through self-activation catalysis of ethylene tetramerization in inert solvents such as methylcyclohexane without cocatalysts such as methylaluminoxane or aluminum alkyl, catalyst preparation steps are simplified, and reaction cost is reduced.

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 present disclosure relates to a precursor for preparing an activator in a catalyst system for olefin polymerization and a process for producing the precursor, the catalyst system, and a polyolefin. In at least one embodiment, the aluminoxane precursor comprises (i) a reaction product of at least one non-hydrolyzable oxygen-containing compound and at least one hydrocarbyl aluminum; and (ii) an aliphatic hydrocarbon fluid. The reaction product can be formed by reacting the non-hydrolyzable oxygen-containing compound and the hydrocarbyl aluminum in the presence of the aliphatic hydrocarbon fluid. 1 The first set of signals in the region from about 4.5 ppm to about 5.1 ppm and the second set of signals in the region from about 5.1 ppm to about 6.5 ppm in the H NMR spectrum are confirmed. The ratio of the first set of signals to the second set of signals is greater than or equal to about 2.8. The aluminoxane precursor is susceptible to storage and transportation compared to MAO, which is an intermediate product in a conventional process for forming supported aluminoxanes.

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 invention discloses a supported metallocene catalyst for ethylene polymerization and application of the supported metallocene catalyst. The supported metallocene catalyst comprises an alkyl tin chloride / methylaluminoxane / silica gel carrier and a metallocene compound supported on the carrier; the alkyl tin chloride / methylaluminoxane / silica gel carrier is a silica gel carrier modified by alkyl tin chloride and methylaluminoxane. Alkyl tin chloride is used for modifying a silica gel carrier, the compound can react with hydroxyl, and a large amount of hydroxyl is eliminated; and the metallocene can be combined with MAO, so that certain space barrier exists between the MAO and the surface of the silica gel, the crowding effect is weakened, the loading capacity is improved, and metallocene combination sites are increased.

The invention discloses a preparation method of a supported metallocene catalyst for ethylene polymerization. The preparation method comprises the following steps: carrying out thermal activation treatment on a silica gel carrier; modifying the thermally activated silica gel carrier by using alkyl tin chloride to obtain an alkyl tin chloride / silica gel carrier; modifying the alkyl tin chloride / silica gel carrier by using methylaluminoxane to obtain an alkyl tin chloride / methylaluminoxane / silica gel carrier; and then loading a metallocene compound to obtain the loaded metallocene catalyst. Alkyl tin chloride is used for modifying a silica gel carrier, the compound can react with hydroxyl, and a large amount of hydroxyl is eliminated; and the metallocene can be combined with MAO, so that certain space barrier exists between the MAO and the surface of the silica gel, the crowding effect is weakened, the loading capacity is improved, and metallocene combination sites are increased.

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.