Purification of polycarbonate and polyester carbonate waste

US5151452A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gerhard Fennhoff · Willich, DE
• Wolfgang Jakob · Moers, DE
• Manfred Ehlert · Dormagen, DE
• Dieter Freitag · Krefeld, DE

Key dates

• Filing date: Sep 17, 1991
• Grant date: Sep 29, 1992
• Expiry date: Sep 17, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02W30/62
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A process is disclosed for the purification of lacquer-and optionally dye and metal- containing waste of thermoplastic aromatic polycarbonates and/or thermoplastic aromatic polyester carbonates. The waste which result upon the production of moldings, such as audio compact discs, lenses for spectacles or head-lamp reflectors is processed in accordance with the invention to yield useful resin suitable for reprocessing as a molding resin. In accordance with the process, the waste is first size-reduced and then heated with acid to the reflux temperature while stirring. After a water wash there is followed a drying step. In accordance with the process, in instances where the waste does not originally contain metal, the metal in powder form is added before the acid treatment.