Patent ID: 6949612
Filing Date: 2005-09-27
Classification: C08F,Y10S

Abstract:
1. A process for transitioning from a first polymerization reaction conducted in the presence of a first catalyst to a second polymerization reaction conducted in the presence of a second catalyst wherein the first and second catalysts are incompatible, the process comprising: (a) discontinuing the introduction of the first catalyst into a reactor having a bed of polymer, wherein the first catalyst comprises a metallocene catalyst; (b) introducing and dispersing in the reactor at least one deactivating agent selected from the group consisting of oxygen, air, carbon monoxide, carbon dioxide, water, oleic acid, and ammonia in an amount sufficient to substantially halt the first polymerization reaction; (c) purging the reactor with an inert gas to substantially remove unreacted deactivating agent from the reactor; and (d) introducing the second catalyst into the reactor wherein the second catalyst comprises a traditional Ziegler-Natta catalyst;