LOW PRESSURE COPOLYMERIZATION OF ETHYLENE WITH (ALPHA)-OLEFINS AND ETHYLENE COPOLYMERS HAVING A LOW RESIDUAL MONOMER CONTENT

摘要

Ethylene/ alpha -olefin copolymers are prepared by catalytic dry-phase copolymerization of the monomers in a stirred or fluidized polymerization zone, transfer of the resulting mixture of solid copolymer and unconverted gaseous monomer into a let-down zone and separation of the mixture, after pressure reduction, into a gaseous phase and a solid phase, by a continuous process in which the solid phase is continuously flushed beforehand with gaseous ethylene and then flushed with a mixture of nitrogen and steam. The ethylene copolymers are very substantially free of residual monomers and odor and flavor substances.