Removal of residual catalyst from polyolefin polymers
US4278788A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1979 |
| Grant date | Jul 14, 1981 |
| Priority date | — |
| Expiry date | Mar 16, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F6/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An improved method for reducing the halogen content of a particulate polyolefin formed by catalytic polymerization of an olefin in the presence of a Ziegler-Natta catalyst is taught which comprises the steps of causing the polyolefin in the dry state to flow into a gas phase fluidized bed, contacting the polyolefin in the fluidized bed with a gas comprising 0.05% to 0.2% alkylene oxide, 5% to 30% water, and the balance inert gas such that the alkylene oxide reacts with halogens present in the polyolefin to form an alkylene halohydrin, removing the alkylene halohydrin from the fluidized bed and thus reducing the halogen content of the polyolefin. The improvement comprises regenerating the alkylene oxide by contacting the inert gas containing alkylene halohydrin with a caustic solution in alcohol or water and recovering therefrom alkylene oxide formed by the reaction of the alkylene halohydrin and the caustic solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.