Patent ID: 6486270
Filing Date: 2002-11-26
Classification: C08F,C08L,Y10S

Abstract:
A multiple zone process which comprises:(a) polymerizing an olefin mixture that comprises: (i) from about 85 to about 98 wt % of ethylene; and (ii) from about 2 to about 15 wt % of a C3 to C10 &agr;-olefin in a first reaction zone in the presence of a Ziegler catalyst at a hydrogen to ethylene molar ratio in the vapor space within the range of about 1/1 to about 10/1 at a temperature within the range of about 65Â° C. to about 110Â° C. to produce a first polymer that has an MI2 within the range of about 50 to about 600 dg/min and density from about 0.94 to about 0.97 g/cc; (b) removing volatile materials from the first polymer; and (c) transferring the first polymer to a second reaction zone and continuing the polymerization in the second reaction zone by adding more of the olefin mixture at a temperature within the range of about 60Â° C. to about 110Â° C. at a hydrogen to ethylene molar ratio within the range of about 0.0005/1 to about 0.8/1 to produce a second polymer having a density within the range of about 0.92 to about 0.944 g/cc and an MI2 within the range from 0.01 to about 0.5 dg/min; wherein about 35 wt % to about 65 wt % of the total polymer is produced in the first reaction zone.