DRY POLYMERIZATION OF OLEFINS IN REACTION VESSELS ARRANGED IN SERIES

摘要

Dry polymerization of olefins is conducted in a smoother and more flexible manner in a series of reaction vessels in which the solid polymer being formed is maintained in the fluidized state by an upward stream of a gaseous mixture containing the olefin to be polymerized. The polymer under formation circulates succesively from the first vessel to the last. A transition metal compound catalyst and an organometallic co-catalyst are introduced into the first vessel to initiate the reaction. The stream of gas issuing from each vessel is recycled to the respective vessel and the amount of cocatalyst introduced into the first vessel is such that the atomic ratio of the metal of the co-catalyst to the transition metal of the catalyst is between 0.1 and 10, In addition, a further organo-metallic co-catalyst is introduced into at least one vessel other than the first in a metal to catalyst metal atomic ratio between 0,1 and 20. The polyolefin products are in powder form of relatively uniform size which leads to advantages during fabrication of articles therefrom.