Abstract: Ethylene propylene copolymers, substantially free of diene, are described. The copolymers will have a uniform distribution of both tacticity and comonomer between copolymer chains. Further, the copolymers will exhibit a statistically insignificant intramolecular difference of tacticity. The copolymers are made in the presence of a metallocene catalyst.
Type:
Grant
Filed:
April 12, 2001
Date of Patent:
February 25, 2003
Assignee:
ExxonMobile Chemical Patents Inc.
Inventors:
Charles Cozewith, Sudhin Datta, Weiguo Hu
Abstract: A process/apparatus is disclosed for continuously separating a liquid medium comprising diluent and unreacted monomers from a polymerization effluent comprising diluent, unreacted monomers and polymer solids, comprising a continuous discharge of the polymerization effluent from a slurry reactor through a discharge valve and transfer conduit into a first intermediate pressure flash tank with a conical bottom defined by substantially straight sides inclined at an angle to that of horizontal equal to or greater than the angle of slide of the slurry/polymer solids and an exit seal chamber of such diameter (d) and length (l) as to maintain a desired volume of concentrated polymer solids/slurry in the exit seal chamber such as to form a pressure seal while continuously discharging a plug flow of concentrated polymer solids/slurry bottom product of said first flash tank from the exit seal chamber through a seal chamber exit reducer with inclined sides defined by substantially straight sides inclined at an angle to t
Type:
Grant
Filed:
October 5, 2000
Date of Patent:
November 20, 2001
Assignee:
ExxonMobil Chemical Patents Inc.
Inventors:
James A. Kendrick, Thomas W. Towles, Scott T. Roger