Bayer Intellectual Property Gmbh

Bayer Materialscience Ag

Covestro Deutschland Ag

Stefaan De Vos

Wolfgang Ebert

Alexander Meyer

Wilfried Haese

Thomas König

Johan Vanden Eynde

Hermann Kauth

Klemens Kohlgrüber

Bert Ruytinx

Uli Franz

Johan Vaes

Ing Johan Vaes

Helmut Einberger

Andreas Frankenau

Christian Eh

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

An improvement to the phase interface process of preparing aromatic polycarbonate is disclosed. The process is characterized in that the phosgenation is carried out at 0 to 40&#xb0; C., and in that the temperature of the reaction mixture at the time of addition of the catalyst at 10 to 40&#xb0; C., and in that the molar ratio of aromatic dihydroxy compounds to phosgene at 1:1.05 to 1:1.20. The polycarbonate thus produced is characterized in its low content of carbamates, making it particularly suitable for the preparation of optical storage media.

Process for the preparation of polycarbonates

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Rayong, Thailand

Stefaan De Vos