Preparation of finely divided homopolymers and copolymers of ethene using a liquid alkane as reaction medium

摘要

A process for the continuous preparation of finely divided homopolymers and copolymers of ethene by catalytic polymerization in a circular tube reactor using a liquid alkane as reaction medium in which the ethene or ethene/comonomer mixture to be polymerized is present in dissolved form and the polymer formed is present in suspended form and running the reaction mixture as a cycle stream to which the feed materials are added by bleeding in and from which the polymer formed is withdrawn by bleeding out reaction mixture, comprising (a) maintaining the mean concentration Cm of polymer in the cycle stream at a value within a certain range and (b) effecting the bleeding out of reaction mixture at a point of the cycle stream at which the concentration of polymer has a value which is lower than the mean concentration Cm by a distinct and definite amount.