Reducing ionic impurities content in aromatic polycarbonate resins
US5907027A · kind A · utility
4Cited by
4References
16Claims
0Family size
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Key dates
| Filing date | May 20, 1998 |
| Grant date | May 25, 1999 |
| Priority date | — |
| Expiry date | May 20, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L69/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An aromatic polycarbonate composition having less than 400 parts per billion each of ionic impurities, particularly sulfate, chloride and fluoride ions prepared by devolatilizing the ionic impurities from a polycarbonate composition employing an aqueous medium of about 1% by weight based on the weight of the polycarbonate composition. Preferably the devolatilizing is carried out in an extruder during compounding the polycarbonate composition and preferably under a vacuum. Also, the extruded strands of polycarbonate resin are quenched in a deionized water bath.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.