Bayer Aktiengesellschaft

Covestro Deutschland Ag

Bayer Materialscience Ag

Bayer Intellectual Property Gmbh

Lanxess Deutschland Gmbh

Bayer Technology Services Gmbh

Arlanxeo Deutschland Gmbh

Klemens Kohlgrüber

Thomas König

Gottfried Zaby

Michael Bierdel

Jörg Kirchhoff

Hugo Obermann

Johann Rechner

Claus H Wulff

Ulrich Liesenfelder

Johan Vanden Eynde

Clemens Casper

Dirk Van Meirvenne

Steffen Kuhling

Heinrich Schuchardt

Peter Jähn

Helmut Meyer

Johan Vaes

Steffen Kühling

Thomas Bamberger

Ing Johan Vaes

Uwe Hucks

Hanns-Ingolf Paul

Richard Weider

Martin Ullrich

Christian Kords

Alfred Eitel

Thomas Fischer

Tony Van Osselaer

Rolf Bachmann

Reiner Rudolf

Udo Wiesner

Hans-Jürgen Thiem

Gabriel Denecker

Helmut Brod

Franz Ferdinand Rhiel

Carsten Conzen

Thomas Koenig

Melanie Möthrath

Bert Ruytinx

Klaus Schebesta

Frank Bruynseels

Frank Weyrich

Jürgen Heuser

Stefaan De Vos

René De Cleyn

Michael König

Jens Hepperle

Ricarda Nothelle

Peter Rudolph

Jörg Krüger

Günther Holdenried

The invention relates to a process for extruding plastic compositions, in particular polymer melts and mixtures of polymer melts, above all thermoplastics and elastomers, particularly preferably polycarbonate and polycarbonate blends, also with the incorporation of other substances such as for example solids, liquids, gases or other polymers or other polymer blends with improved optical characteristics, with the assistance of a multi-screw extruder with specific screw geometries.

Method for extruding plastic materials

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 a process for extruding plastic compositions. The process in particular relates to the conveying, kneading and/or mixing of plastic compositions, in particular of polymer melts and mixtures of polymer melts, above all thermoplastics and elastomers, particularly preferably polycarbonate and polycarbonate blends, also with the incorporation of other substances such as for example solids, liquids, gases or other polymers or other polymer blends.

Method for extruding plastic masses

The invention is directed to an extruder (), particularly for extruding a synthetic rubber product, which comprises a barrel (), one or several extruder elements (), particularly one or several extruder screws and/or a kneader elements (), arranged inside the barrel () for conveying the product, optionally an inlet port for feeding a stripping agent into the barrel () and an outlet port for removing volatile compounds from the product and, where applicable, the stripping agent. According to the invention a perforated die plate () is fixed to the barrel () in flow direction before the outlet port. Since the die plate () is not fixed to the extruder elements () but to the barrel () a circumferential clearance between the die plate () and the barrel () is prevented so that no extruded material is passing the die plate () radially outside. Parts of the extruded material comprising a low surface area to volume ratio are prevented so that the evaporation of volatile compounds is facilitated.

Extruder with integrated die plate and method for degasing polymer mixtures

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

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 heatable tubular devolatilizer and a vented extruder.

Evaporator apparatus () for the treatment of viscous media comprised of at least a feed chamber () having a perforated tray (), a tube-bundle heat exchanger () connected thereto having perpendicularly arranged tubes () and a devolatilization chamber () connected thereto, a discharge unit () for the product and a vapor take-off () for removing volatile components, the tubes () of the heat exchanger () having a rectangular cross section over the greater part of their length.

Process and apparatus for removing volatile substances from highly viscous media

Static mixer module, consisting of a disc which is provided with a multiplicity of orifices () and is structured on its front side and on its rear side by means of channels (), and in which the orifices () are made in the flanks () of the inlet channels () and open into the flanks () of the mixing channels (). Furthermore, a mixer arrangement is described, which consists of at least two static mixer elements arranged one behind the other, at least one mixer element being a disc-shaped static mixer module. The mixer module and the mixer arrangement are used in pipelines and housings through which a flow passes.

Static mixer module

A combination static mixer and heat exchanger having heat exchanger tubes () which are provided over their circumference with fins () which have a static mixing effect.

Mixer/heat exchanger

Rubber-free copolymers of unsaturated monomers selected from the group comprising styrenes and vinyl cyanides are disclosed. The copolymers that contain 65 to 80 wt. %, of styrene and 20 to 35 wt. % of acrylonitrile are characterized in their low content of residual monomers and improved physical properties. Also disclosed are a process and a device for the preparation of these copolymers.

Copolymers, devoid of rubber, with low residual monomer content and a method and device for producing the same

A process for concentrating polymers by evaporation is disclosed. The process entails (i) obtaining a mixture containing a polymer and volatile component, the volatile components being present in the mixture at an amount less than 20 wt. % relative to the weight of the mixture, and (ii) introducing the mixture in a downward direction under pressure through a plurality of nozzles arranged vertically and next to one another into a degassing container to form an extrudate. The volatile component contains at least one of residual monomers, oligomers and solvents, and the throughput of the mixture per nozzle is 0.3 to 2 kg/h. The vapor pressure of the volatile component of the extrudate is more than 2.5 bar, and the absolute pressure in the degassing container is 50 to 5000 Pa. The polymer prepared by the process is characterized in that it contains volatile components in an amount of less than 300 ppm.

Process for separating volatile components from polymers

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

A process for the isolation of polycarbonate produced by the interfacial polymerization process is disclosed. Accordingly, the process entails (a) evaporating the organic solvent from the solution that contains solvent and polycarbonate to obtain a material system that contains 90 to 99.95% polycarbonate, the percent being relative to the weight of the system, and (b) passing the material system through inlet openings of a separating vessel to obtain a plurality of streams of polycarbonate, on entry into the inlet openings said material system being supersaturated with volatile constituents to an extent of at least 1 bar and having a temperature of 250&#xb0; to 340&#xb0; C. and a flow rate of 0.1 to 20 kg/hour, and (c) degassing the streams in the separating vessel wherein the pressure is 0.1 to 20 mbar to effect degassing of the polycarbonate.

Process for the production of polycarbonate

The invention describes a process for the preparation of polycarbonate. The process includes

Process for the preparation of polycarbonate

Mixer comprising a housing having filling and emptying openings, two corotating stirrers and drivers for the stirrers, one of the stirrers being arranged centrally in the housing and having at least a drive shaft and at least one transverse beam fitted to the drive shaft and at least one stirring arm fitted at their ends to the transverse beam.

Dynamic mixer

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Kürten, Germany

Klemens Kohlgrüber