Patent ID: 7470756
Filing Date: 2008-12-30
Classification: C08F

Abstract:
1. A process for preparing a propylene random copolymer comprising propylene and a comonomer, said comonomer being ethylene or an α-olefin comprising at least four carbon atoms, the process comprising: polymerising a first amount of the propylene with a first amount of the comonomer in the presence of a catalyst in a first reaction zone including at least one slurry reactor to give a slurry reactor product; transferring the slurry reactor product to a second reaction zone including at least one gas phase reactor; and polymerising a second amount of the propylene with a second amount of the comonomer in said gas phase reactor in the presence of the slurry reactor product to produce the propylene random copolymer, the propylene random copolymer consisting of the slurry reactor product and a gas phase product; wherein the temperature in the gas phase reactor is at least 10° C. higher than the temperature in the slurry reactor, the temperature in the gas phase reactor is 80° C. or more, and the temperature in the slurry reactor is 70° C. or more; and wherein the propylene random copolymer has a xylene solubles content of from 5 to 15 weight percent and an elution interval of 50° C. or more.