Methods for controlling polymer properties
US10227428B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 2014 |
| Grant date | Mar 12, 2019 |
| Priority date | — |
| Expiry date | Sep 25, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L23/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed herein are methods of controlling polymer properties in polymerization processes that use a chromium-based catalyst. An embodiment discloses a method of producing a polyolefin comprising: contacting a reaction mixture and a reduced chromium oxide catalyst in a gas-phase reactor to produce the polyolefin, wherein the reaction mixture comprises a monomer and a co-monomer; and changing a reaction temperature in the gas-phase reactor by about 1° C. or more whereby a gas molar ratio of the co-monomer to the monomer is changed by about 2% or more and a co-monomer content of the polyolefin at substantially constant density is changed by about 2% or more. Additional methods and compositions are also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.