Abstract:
HIGH DENSITY POLYETHYLENE IS FREED OF CATALYST METAL RESIDUES BY CONTACTING WITH A MIXTURE OF AN ANHYDROUS ALCOHOL AND A HYDROCARBON, WHICH IS THE SAME AS THAT USED AS THE SUSPENSION MEDIUM IN THE FORMATION OF THE POLYETHYLENE. IT IS PREFERRED TO CARRY OUT THE CONTACTING IN A COUNTERCURRENT APPARATUS IN WHICH THE POLYETHYLENE FLOWS DOWNWARDLY AGAINST AN UPWARDLY MOVING STREAM FORMED FROM THE ANHYDROUS ALCOHOL AND THE HYDROCARBON.
Abstract:
A new catalyst system, for the homo- and copolymerization of olefins, conjugated or unconjugated dienes or mixtures thereof, is composed of a Ziegler catalyst transition metal compound and an aluminum compound having the general formula:
wherein X is hydrogen or halogen; both R''s are hydrocarbon radicals; and R'' is an unsaturated or saturated aliphatic divalent hydrocarbon radical, unsubstituted cycloalkyl radical or unsubstituted aryl radical.
Abstract:
A process for the stercospecific polymerization of conjugated diene by polymerizing in the presence of a catalyst comprising a compound of a transition metal of titanium vanadium zirconium, cobolt, manganese and nickel and a polyiminic polymer.