Patent ID: 8076429
Filing Date: 2011-12-13
Classification: C08F,C08L

Abstract:
1. A method of making a random block copolymer comprising: a) introducing into a first reaction zone a polymerization catalyst and a first feed containing from about 0.5 parts by weight to about 6 parts by weight of ethylene and from about 94 parts by weight to about 99.5 parts by weight propylene; b) copolymerizing the ethylene and propylene under first polymerization reaction conditions to provide a copolymer A with active catalyst embedded therein; c) introducing the copolymer A into a second reaction zone; d) introducing to the second reaction zone a second feed containing from about 8 parts by weight to about 40 parts by weight of ethylene and from about 60 parts by weight to about 92 parts by weight propylene; e) copolymerizing the ethylene and propylene of the second feed to provide a copolymer B wherein the copolymer B is copolymerized with the copolymer A under second polymerization reaction conditions and in such proportion as to provide a random block copolymer containing from about 75 wt. % to about 95 wt. % blocks of copolymer A and about 5 wt. % to about 25 wt. % blocks of copolymer B.