Thermal enhancement of the purification process for interfacial polycarbonate and copolymer polycarbonates
US9617380B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 2014 |
| Grant date | Apr 11, 2017 |
| Priority date | — |
| Expiry date | Jul 25, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/406
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
In an embodiment, a process of purifying a polycarbonate comprises: polymerizing a dihydroxy compound and a carbonate source via an interfacial reaction in the presence of a catalyst to form a product mixture comprising an aqueous phase and an organic phase, wherein the organic phase comprises the polycarbonate, the catalyst, ions, and a solvent having a boiling point Tb; heating the product mixture to greater than or equal to Tb; separating the aqueous phase and the organic phase at a temperature greater than or equal to Tb to form a separated organic phase and a separated aqueous phase; extracting the catalyst from the separated organic phase; and extracting the ions from the separated organic phase; wherein if a centrifuge is used in the extracting of the catalyst, the extracting of the ions, or both, the process further comprises cooling a stream entering the centrifuge to less than Tb.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.