Abstract: Branched polypropylene compositions which have improved melt strength and good processability are provided. The branched polypropylene compositions of the present invention have a polydispersity of less than 4.0 and a melt point greater than 90° C. Further, the weight average branching index g of the polypropylene compositions is less than 0.95. Additionally, a novel process is provided for efficiently producing a branched polypropylene composition comprising:
a) contacting propylene monomers in a reactor with an inert hydrocarbon solvent or diluent and a catalyst composition comprising one or more single site catalyst compounds capable of producing stereospecific polypropylene at a temperature from about 40° C. to about 120° C., wherein the ratio in the reactor of the propylene monomers to the inert hydrocarbon solvent or diluent is less than 9.
Type:
Grant
Filed:
August 17, 1999
Date of Patent:
May 1, 2001
Assignee:
Exxon Chemical Patents Inc.
Inventors:
Weiqing Weng, Eric J. Markel, Armenag H. Dekmezian, Palanisamy Arjunan