GB942749A - Production of olefin polymers - Google Patents

Abstract

A cyclic process for polymerizing an olefin comprises passing the olefin through a cooling zone and then into a reaction zone, introducing catalyst at the inlet of the reaction zone, diluting a major portion of the reaction zone effluent with incoming olefin charge comprising fresh charge and recycled unreacted olefin in an amount sufficient to stop the reaction, recycling the thus diluted portion of the reaction zone effluent through the cooling zone and reaction zone, withdrawing the residual minor portion of the reaction zone effluent for product recovery and recycling unreacted olefin from said residual minor portion to the incoming olefin charge. Catalyst in the withdrawn stream may be converted to an adduct (e.g. by the use of NH3) which is then removed prior to the addition of an oil to form a solution of polymer in lubricating oil. The process is applicable to the polymerization of propylene, alpha-methyl styrene, butene and butene/isobutene mixture, but is advantageously applied to the polymerization of isobutylene using BF3 as catalyst. Up to 20% of closely boiling hydrocarbons also may be present. The invention is illustrated by reference to a suitable apparatus.