Bayer Aktiengesellschaft

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Bayer Materialscience Ag

Covestro Deutschland Ag

Thomas Elsner

Christian Kords

J&uuml;rgen Heuser

Klemens Kohlgr&uuml;ber

Werner Rasshofer

Joachim Wagner

Rolf Wehrmann

Johann Rechner

Alexander Karbach

Steffen K&uuml;hling

Clemens Casper

Wolfgang Lindner

Robert Becker

Hans-Albrecht Freitag

Arno Nennemann

Heinrich Wolfers

Michael Traving

Rafael Warsitz

Sascha Plug

Gerd Goldmann

Daniel-Gordon Duff

Helmut Meyer

Werner Bäcker

Eberhard Jurgens

Manfred Schutte

Paul Viroux

Guido Naberfeld

J&ouml;rgen Weinschenck

Jurgen Faehndrich

Patrick Theato

Wulf Wendeborn

Daniel Kessler

Gerhard Langstein

Stephan Bahnmuler

Peter Tappe

Julia Hitzbleck

Stefan Bahnmüller

A method for separating electrolyte-containing water from an organic phase by means of permeation on a hydrophobic separating means. The permeated organic solution is substantially depleted in water and the retained water is enriched with electrolytes.

Method for separating an organic phase from an electrolyte-containing aqueous and organic phase

An apparatus for degassing plastic materials, e.g., high molecular weight polycarbonate solutions, is described. The apparatus includes a double-shaft extruder having a length-to-diameter ratio of less than or equal to 40, which comprises: (i) two co-rotating and meshing shafts; (ii) an intake opening; and (iii) upstream and downstream portions relative to the intake opening. The shafts of the extruder are designed with a double lead in a degassing zone, and with a triple lead in a pressure build-up zone. Each of the degassing and the pressure build-up zones are down-stream from the intake opening, and the pressure build-up zone is further down-stream than the degassing zone. Also described is a process for degassing plastic materials, which involves providing the described double-shaft co-rotating extruder, into which plastic material is fed, processed and degassed. Entraining agents, such as nitrogen, and other processing additives may be introduced into an extruder during the process of the present invention.

Device and method for degassing plastics

A strand devolatilizer that includes a degassing container, a product inlet, a product distributor, a product outlet and a vapor outlet is disclosed. The product distributor is in the form of a tube distributor with at least one distributor tube ( ) and a plurality of die tubes ( ) arranged in parallel, each containing a plurality of apertures ( ) in the tube wall. The die tubes ( ) are preferably arranged in several planes one above the other and staggered laterally relative to one another.

Strand evaporator

A process for producing polymer pellets is disclosed. The process that is particular suitable for making polycarbonate pellets entails extruding a polymer melt, cooling the extrudate by contacting it with a cooling fluid and pelletizing the solidified polymer. The process is characterized in that the cooling fluid has a solids particle content of at most 10 ppm.

High-purity polymer granules and method for the production thereof

A device and process for the removal of volatile constituents from polymers is disclosed. The device entails a container having an inlet for a polymer solution, an outlet for the volatile components, an outflow for the polymer from which the volatile components have been removed and a heat exchanger. The heat exchanger is characterized in that it contains a plurality of specially structured channels.

Device and method for removing volatile components from polymer solutions

The present invention provides a polycarbonate having a low particle content, a process for producing high-purity polycarbonate and polycarbonate of maximum purity and molded products made from such polycarbonate.

Method for the production of highly pure polycarbonate and ultrapure polycarbonate

A process for preparing a vacuole-free polymer is disclosed. Extruded polymer resin is cooled at a rate of less than 50&deg; C./sec. to a temperature that is 1 to 20&deg; C. above the glass transition temperature of the polymer resin and the resin is then cut.

Vacuole-free polymer granulates

Described is a multi-stage, continuous process for evaporating and concentrating feed polymer solutions. In a first stage (a) of the process, the feed polymer solution is concentrated by passing it through one of (i) a combination of a tubular heat exchanger with one of a thin-film evaporator and a coiled tube evaporator, and (ii) a tubular heat exchanger. Each evaporator of (i) having a downstream separator. In a further stage (b), the intermediate polymer solution of the first stage is further concentrated and degassed to form a product polymer in a tubular heat exchanger having a downstream separator. The tubular heat exchanger of the further stage has an inside diameter of from 5 to 30 mm, and a length of from 0.5 to 4 m, and the throughput per heat exchanger tube being from 5 to 30 kg/h, based on the polymer. An entrainer is introduced into a delivery device located downstream from the separator of further stage (b). The product concentrated/degassed polymer of further stage (b) is then isolated and optionally granulated. Also described is an apparatus for evaporating and concentrating feed polymer solutions.

Method and device for evaporating polymer solutions of thermoplastic polymers, and a polycarbonate which can be obtained by evaporation

This invention relates to a multistep process for evaporating polymer solutions of thermoplastic polymers and for removing volatile constituents from thermoplastic polymers by indirect heat exchange. The invention relates in particular to a process for evaporating volatile constituents out of polymer solutions using shell-and-tube heat exchangers having a special geometry, coiled-tube evaporators and extrusion evaporators.

Method for evaporating polymer solutions of thermoplastic polymers

A process of evaporating a viscous polymer solution is described. The process includes: (a) providing a viscous polymer solution including at least 30 wt. % of solvents and monomers; (b) introducing the viscous polymer solution into a heated helix ( ), the heated helix having a vapor exit velocity of 200 to 300 m/s, (a film flow including a two-phase mixture of polymer melt, and solvent vapors and monomer vapors being formed within the helix); (c) forwarding the film flow from helix ( ) into a heated vapor separator ( ); (d) expanding the two-phase mixture of polymer melt, and solvent vapors and monomer vapors of the film flow within vapor separator ( ) at an absolute pressure of 10 mbar to 800 mbar, (a bottom product including a concentrated melt of the polymer is formed within the vapor separator); and (e) withdrawing the bottom product from vapor separator ( ). Each of the helix ( ) and vapor separator ( ) have a separate heating device, and each of heating device independently provides a temperature that is above the softening point of the polymer.

Method for isolating polymers from solutions

A method for removing volatile components from polymer solutions is disclosed. The method, yielding products having low content of residual volatile components and causing no thermal damage to the polymer, entails using apparatuses in which surfaces which come into contact with the product are made from materials which are low in iron content.

Methods for removing volatile components from polymer solutions

Thermoplastically processable thermotropic molding compounds of thermotropic polycondensates and 0.05 to 5% by weight functionalized polymers, such as for example functionalized polybutadiene oils, polyethylene or polypropylene.

Thermoplastically processable thermotropic molding compounds

Mosquito coils are resistant to breakage, light, flat and ensure a good active substance yield if they consist of a wood-chip and/or fiber material of a density of only 0.4 to 0.7 kg/dm.sup.3 and preferably have a thickness of 1 to 4.5 mm, the active substance being applied to the spiral (1) as a layer (2).

Mosquito coil and process for producing mosquito coils

A process for the continuous production of laminated sheet materials of thermoplastic polymers, reinforcing fibers and metals, in which endless sheets of reinforcing fibers, thermoplastic polymers and metals are combined in layers and the layers thus combined are continuously exposed for 0.1 to 10 minutes to a pressure of 0.5 to 50 bar at a temperature 20.degree. to 150.degree. C. above the melting temperature of the thermoplastic polymer.

Process for the continuous production of laminated sheets

The present invention is directed to a process of thermoplastically molding a specific foam composition. The composition is formed by reacting an isocyanate and a relatively low molecular weight tri or higher polyol in the presence of a blowing agent.

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Düsseldorf, Germany

Thomas Elsner