Patent ID: 9353203
Filing Date: 2016-05-31
CPC Classification: C08F,C08L

Claim Text:
1. A process for the preparation of a polypropylene (PP) in a sequential polymerization process comprising at least two polymerization reactors (R1 and R2) connected in series, wherein the polymerization in the at least two polymerization reactors (R1 and R2) takes place in the presence of a Ziegler-Natta catalyst (ZN-C), and said Ziegler-Natta catalyst (ZN-C) comprises (a) a pro-catalyst (PC) comprising (b) a co-catalyst (Co), and (c) an external donor (ED), wherein the ratio of Ziegler-Natty catalyst (ZN-C) feed rate to propylene (C3) feed rate in the first polymerization reactor (R1) is 1.0 to 4.5 g/t.