Process for controlling the MWD of a broad/bimodal resin produced in a single reactor
US5525678A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1994 |
| Grant date | Jun 11, 1996 |
| Priority date | — |
| Expiry date | Sep 22, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F4/61916
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A bimetallic catalyst produces broad or bimodal molecular weight distribution polyolefin resin whose composition depends on the ratio of the concentration of the two metals of the catalyst producing the HMW and LMW components. The bimetallic catalyst produces a broad/bimodal MWD resin whose HMW and LMW components depend on the relative productivity of each of the transition metal sites of the catalyst. Water and/or carbon dioxide are cofed to the polymerization reactor at levels necessary to modify the weight fractions of the HMW and LMW components, thus achieving a target molecular weight distribution, MWD. The invention allows the resin MWD to be adjusted in the reactor. The weight fraction of the high molecular weight component decreases with the addition of the water and or the carbon dioxide and the FI of the overall product increases with a decrease in the HMW component weight fraction in the product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.