摘要:
Catalysts suitable for preparation of a polyethylene which comprises ethylene homopolymers and/or copolymers of ethylene with 1-alkenes and has a molar mass distribution width Mw/Mn of from 5 to 30, a density of from 0.92 to 0.955 g/cm3, a weight average molar mass Mw of from 50000 g/mol to 500 000 g/mol and has from 0.01 to 20 branches/1000 carbon atoms and a z-average molar mass Mz of less than 1 million g/mol.
摘要:
A polymerization process for copolymerizing ethylene and a series of α-olefins to form a branched polyethylene, in which the series of α-olefins is generated in-situ by an ethylene oligomerization catalyst, is improved if the oligomerization catalyst has a Schulz-Flory constant of about 0.30 to about 0.55. This makes very little higher molecular weight α-olefins, which allows for easy removal of unpolymerized α-olefins from the polyolefin product.
摘要:
The present invention relates to a supported, treated catalyst system and its use in a process for polymerizing olefin(s). More particularly, it provides a supported, treated catalyst system produced by a process comprising the steps of: (a) forming a supported bimetallic catalyst system comprising a first catalyst component and a metallocene catalyst compound; and (b) contacting the supported bimetallic catalyst system of (a) with at least one methylalumoxane-activatable compound.
摘要:
This invention relates to a catalyst system comprising a half sandwich chromocene compound featuring a tethered N-donor, with an alumoxane and consequent supportation on silica produces a catalyst that produces ultra-high molecular weight polyethylene and that further supportation of a catalyst capable of producing linear low density polyethylene produces a multiple-catalyst system on the same support, capable of producing polyethylene with a bimodal molecular weight distribution and excellent molecular weight.
摘要:
The present invention relates to a supported, treated catalyst system and its use in a process for polymerizing olefin(s). More particularly, it provides a supported, treated catalyst system produced by a process comprising the steps of: (a) forming a supported bimetallic catalyst system comprising a first catalyst component and a metallocene catalyst compound; and (b) contacting the supported bimetallic catalyst system of (a) with at least one methylalumoxane-activatable compound.
摘要:
Supported catalyst systems are provided comprising (a) a transition metal compound, (b) an activator comprising (iii) an aluminoxane or (iv) a Group lilA metal or metalloid compound, and (c) a support material comprising an inorganic metal oxide, inorganic metal halide or polymeric material or mixtures thereof characterised in that the support material has been pretreated with a source of a transition metal atom. The preferred transition metal compounds are metallocenes and the source of the transition metal atom is typically a ferrous or cupric metal salt. The supported catalyst systems show improved activity and also may reduce fouling in gas phase fluidised bed processes.
摘要:
The present invention is a process for producing a catalyst system to produce polymer blends in a single reactor, polymer blends of isotactic polyolefins and syndiotactic polyolefins. The catalyst system is a combination of at least one metallocene catalyst and at least one conventional supported Ziegler-Natta catalyst. The multi-catalyst system is obtained by mixing the components of at least one metallocene catalyst and at least one conventional supported Ziegler-Natta catalyst. The metallocene catalyst comprises a metallocene compound and an ionizing agent. The conventional supported Ziegler-Natta catalyst comprises an aluminum alkyl and a transition metal compound with, optionally, an electron donor.
摘要:
IN THE PROCESS FOR POLYMERIZING ETHYLENE OR COPOLYMERIZING ETHYLENE WITH A COMONOMER SELECTED FROM THE GROUP CONSISTING OF 1-OLEFINES HAVING FROM 3 TO 8 CARBON ATOMS AND DIOLEFINES HAVING FROM 4 TO 10 CARBON ATOMS, IN AN INERT SOLVENT IN THE PRESENCE OF A CATALYST COMPRISING A TITAMIUM OR VANADIUM HALOGEN COMPOUND BONDED ONTO THE SURFACE OF INORGANC SOLID PARTICLES, AND AN ORGANOALUMINUM COMPOUND OR A DIALKYL ZINC; AN IMPROVEMENT WHEREIN SAID INORGANIC SOLID PARTICLES ARE PARTICLES OF A SYNTHETIC DOUBLE OXIDE OF MAGNESIUM AND ALUMINUM, AND SAID SYNTHETIC DOUBLE OXIDE HAS THE ATOMIC RADIO OF MG/AL IN THE RANGE OF FROM 0.02 TO 100.