Covestro Deutschland Ag

Bayer Intellectual Property Gmbh

Ing Johan Vaes

Johan Vanden Eynde

Johann Rechner

Thomas König

Michael Bierdel

Klemens Kohlgrüber

Bert Ruytinx

Frank Bruynseels

Jörg Kirchhoff

Thomas Koenig

Joerg Kirchhoff

Klemens Kohlgrueber

Stefaan De Vos

The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Ultra-high purity polycarbonates having good inherent color and thermal resistance and a device and a method for producing the same

The invention relates to an apparatus and a process for devolatilizing solvent-containing polycarbonate solutions. By employing the inventive apparatus, polycarbonates with low residual values of volatile constituents are produced from solvent-containing polymer melts, which improved optical properties, especially yellowness index, with the aid of an apparatus combination of a flash devolatilizer and a vented extruder.

Device and method for degassing solvent-containing polycarbonate solutions

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Kalmthout, Belgium

Ing Johan Vaes