BLOKK-KOPOLYMER OG FREMGANGSMAATE FOR DENS FREMSTILLING

摘要

A process for the preparation of ethylene-propylene block copolymers at high catalyst productivity rates resulting in polymer products having improved impact strength-polymerized ethylene content relationship. The improvement is obtained by reacting preformed propylene prepolymer still containing active catalyst residues with ethylene and propylene in a vapor phase reaction zone in the presence of additional aluminum trialkyl catalyst component introduced to the reaction zone. The polymer produced by the process exhibits excellent physical and mechanical properties.