Patent ID: 6800700
Filing Date: 2004-10-05
Classification: C08F

Abstract:
In a liquid pool process for polymerizing propylene, which process employs a first catalyst that produces a substantially-amorphous, fouling, first propylene polymer that is insoluble in liquid propylene and has any weight-average molecular weight in the range between 10,000 and 2,000,000, including every weight-average molecular weight therebetween, wherein the improvement comprises: the presence in the polymerization reactor of a second catalyst that produces a second propylene polymer that is insoluble in liquid propylene and that exists in th form of a powder, simultaneously with the first propylene polymer and in an effective amount sufficient to provide a coating of the second polymer powder about the fouling first propylene polymer during the formation of the first polymer that is effective to eliminate or substantially reduce the tendency of the first polymer to adhere to the walls of the polymerization reactor, thus yielding a propylene polymer product predominantly exhibiting the beneficial physical properties of the first propylene polymer while existing in a physical form that may be readily handled, and processed by those in the polymer-product manufacturing industries using conventional equipment, wherein said second catalyst is selected from the group consisting of: Rac-ethylenebis(1-indenyl) zirconium dichloride and Dimethylsilylbis(1-indenyl)zirconiumdichloride.