Supertransparent high impact strength random block copolymer

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 65 wt. % to about 97 wt. % blocks of copolymer A and about 3 wt. % to about 35 wt. % blocks of copolymer B;
• and
• wherein the polymerization catalyst comprises a Ziegler-Natta catalyst.