摘要:
The productivity of a catalyst in a gas phase polymerization of olefins (e.g. grams of polymer per gram of catalyst) may be increased by including in the gas phase from 1 to 20 weight % of an inert non-polymerizable hydrocarbon. The hydrocarbon may be in gaseous form but preferably is in liquid form.
摘要:
The present invention provides a novel process for preparing a catalyst useful in gas phase polymerization of olefins wherein the physical properties of the polymer and the productivity of the catalyst can be altered depending on the sequence of addition of the catalyst components. The catalyst consists of compounds of Ti, Mg, Al and optionally an electron donor supported on an amorphous support.
摘要:
There are a number of recent developments relating to co- and homopolymers of vinyl aromatic monomers. There are syndiotactic polymers of styrene, there are pseudo random polymers of styrene and ethylene. The present invention seeks to provide novel pseudoblock polymers of styrene and ethylene in which at least 10 weight % of the vinyl aromatic monomer is incorporated in the form of one or more atactic pseudoblocks.
摘要:
Organometallic complexes having two phosphinimine ligands and at least one activatable ligand are catalyst components for olefin polymerization. Preferred polymerization systems are prepared by combining the organometallic complexes with an ionic activator and/or an alumoxane. Preferred catalyst components contain titanium, zirconium, or hafnium and are activated with an ionic activator to form catalysts for ethylene polymerization.
摘要:
The present invention provides a process for preparing a catalyst useful in gas phase polymerization of olefins wherein the hydrogen response of the catalyst can be improved by using a ketone as the electron donor in the catalyst. The catalyst consists of compounds of Ti, Mg, Al and a ketone preferably supported on an amorphous support.