Patent ID: 7449527

Claim:
A process for producing a polyolefin having a multimodal molecular weight distribution, which process comprises: (a) polymerizing a first olefin monomer in the presence of a bis-indenyl metallocene catalyst, to form a first multimodal polyolefin component, said bis-indenyl metallocene catalyst being represented by formula (I): (Ind) 2 R″MQ p (I) wherein: each Ind is the same or different and is a substituted or unsubstituted indenyl group, or a substituted or unsubstituted tetrahydroindenyl group; R″ is a structural bridge imparting stereorigidity to the component; M is a metal atom from group IVB, VB or VIB of the periodic table; p is the valence of M minus 2; and each Q is a hydrocarbon having from 1-20 carbon atoms or is a halogen; and (b) polymerizing a second olefin monomer in the presence of a second metallocene catalyst to form a second polyolefin component, said second metallocene catalyst being represented by formula (II): R″(CpR 1 R 2 R 3 )(Cp′R′ n )MQ 2 (II) wherein: Cp is a substituted or unsubstituted cyclopentadienyl ring; C p ′ is a substituted or unsubstituted fluorenyl group; R″ is a structural bridge imparting stereorigidity to the component; R 1 is a substituent on the cyclopentadienyl ring which is distal to the bridge, which distal substituent comprises a hydrogen or a bulky group of the formula XR* 3 in which X is chosen from Group IVA, and each R* is the same or different and chosen from hydrogen or hydrocarbyl of from 1-20 carbon atoms; R 2 is a substituent on the cyclopentadienyl ring which is proximal to the bridge and positioned non-vicinal to the distal substituent and is a hydrogen or is of the formula YR# 3 in which Y is chosen from group IVA, and each R# is the same or different and chosen from hydrogen or hydrocarbyl of 1-7 carbon atoms, R 3 is a substituent on the cyclopentadienyl ring which is proximal to the bridge and is a hydrogen or is of the formula ZR$ 3 , in which Z is chosen from group IVA, and each R$ is the same or different and chosen from hydrogen or hydrocarbyl of 1-7 carbon atoms; n is an integer of from 0-8; each R′ is the same or different and is a group AR′″ 3 in which A is chosen from group IVA and each R′″ is the same or different and chose from hydrogen or a hydrocarbyl having 1-20 carbon atoms; wherein X, Y, Z and A are independently selected from carbon and silicon; M is a Group IVB transition metal or vanadium; and each Q is hydrocarbyl having 1-20 carbon atoms or is a halogen; and wherein the molecular weight distribution of the first polyolefin component overlaps with the molecular weight distribution of the second polyolefin component; and wherein the steps (a) and (b) are carried out in the same reaction zone.