Bruce F Story

US Patent:

6538080, Mar 25, 2003

Filed:

Feb 4, 2000

Appl. No.:

09/498912

Inventors:

Robert D. Swindoll - Richwood TX
Bruce A. Story - Lake Jackson TX
Brian W. S. Kolthammer - Lake Jackson TX
Kevin P. Peil - Auburn MI
David R. Wilson - Midland MI
James C. Stevens - Richmond TX

Assignee:

BP Chemicals Limited - London

International Classification:

C08F 442

US Classification:

526160, 526127, 526 65, 526129, 526901, 526280, 526281, 526282, 526943, 502155, 502120, 525 53

Abstract:

A gas phase fluidized bed process is described for producing ethylene polymers having improved processability and an MWD of less than about 2. 9. Multiple reactors in series or parallel may be used to produce in-situ blended polymers. Each reactor can separately have a constrained geometry catalyst or a conventional Ziegler-Natta catalyst as needed for obtaining in-situ blended polymer with the desired properties as long as there is a constrained geometry catalyst in at least one reactor. Olefin polymers can be produced according to this invention which have low susceptibility to melt fracture, even under high shear stress conditions.

US Patent:

60254483, Feb 15, 2000

Filed:

Jun 3, 1996

Appl. No.:

8/659976

Inventors:

Robert D. Swindoll - Richwood TX
Bruce A. Story - Lake Jackson TX
Brian W. S. Kolthammer - Lake Jackson TX
Kevin P. Peil - Auburn MI
David R. Wilson - Midland MI
James C. Stevens - Richmond TX

Assignee:

The Dow Chemical Company - Midland MI

International Classification:

C08F 234

US Classification:

526127

Abstract:

A gas phase fluidized bed process is described for producing ethylene polymers having improved processability and an MWD of less than about 2. 9. Multiple reactors in series or parallel may be used to produce in-situ blended polymers. Each reactor can separately have a constrained geometry catalyst or a conventional Ziegler-Natta catalyst as needed for obtaining in-situ blended polymer with the desired properties as long as there is a constrained geometry catalyst in at least one reactor. Olefin polymers can be produced according to this invention which have low susceptibility to melt fracture, even under high shear stress conditions.