Steven Wayne Lambert

US Patent:

20230056312, Feb 23, 2023

Filed:

Jan 7, 2021

Appl. No.:

17/791389

Inventors:

- Baytown TX, US
Christopher G. BAUCH - Seabrook TX, US
Todd S. EDWARDS - League City TX, US
Mark S. CHAHL - Friendswood TX, US
Blu E. ENGLEHORN - Houston TX, US
Khoa TO - Baytown TX, US
Steven L. LAMBERT - Webster TX, US

Assignee:

ExxonMobil Chemical Patents Inc. - Baytown TX

International Classification:

C08F 110/06
C08L 23/14

Abstract:

Provided are methods for producing bimodal polyolefins comprising the steps of contacting α-olefin monomers with a catalyst in slurry polymerization conditions in the presence of zero to minimum hydrogen to produce a high molecular weight polyolefin and contacting additional α-olefin monomers in gas phase polymerization conditions and the high molecular weight polyolefin and the catalyst to produce bimodal polyolefin having high stiffness and broad molecular weight distribution. An additional step of polymerizing the bimodal polyolefin with a comonomer in a second gas phase can provide a bimodal impact copolymer having high stiffness and broad molecular weight distribution. Among the advantages of the present methods, bimodal polyolefins can be produced in a continuous process between a slurry polymerization reactor and a gas phase polymerization reactor without a venting step in between and with minimal hydrogen in the slurry polymerization reactor.