Bayer Aktiengesellschaft

Jürgen Heuser

Christian Kords

Hermann Kauth

Thomas König

Klemens Kohlgrüber

Günther Holdenried

A continuous process for mixing polymer melts with additives, in particular polycarbonate melts with additives in liquid form, in solution or in dispersion is described. The additives are added to a main stream of polymer melt and are then mixed, preferably directly, with the main stream in a static mixer.

Process for mixing polymer melts with additives

An improvement in the continuous two-phase interfacial condensation process for preparing polycarbonate is disclosed. In the process that entails at least one diphenol, phosgene, at least one chain terminator, and optionally branching agents and is carried out in the presence of a catalyst the improvement comprising maintaining the concentration of the catalyst at a level of at least 0.012 mol per mol of diphenol.

Process for the preparation of polycarbonates

A process for producing phosgene having low content of carbon tetrachloride is disclosed. The process entails reacting carbon monoxide with chlorine in the presence of elemental carbon, in a reactor. Critically the temperature of the gas stream emerging from the reactor is restricted to 30 to 80&#xb0; C. and its pressure, measured directly downstream from said reactor is restricted to 120 to 400 kPa. The phosgene thus produced has a content of carbon tetrachloride that is less than 150 ppm.

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Krefeld, Germany

Jürgen Heuser