Bayer Aktiengesellschaft

Steffen Kuhling

Hans-Josef Buysch

Gottfried Zaby

Wolfgang Alewelt

Hermann Kauth

Uwe Hucks

Norbert Schon

Pieter Ooms

Thomas Fischer

Dieter Freitag

Franz Ferdinand Rhiel

Claus H Wulff

Rolf Bachmann

Johann Rechner

Edgar Leitz

Jurgen Kirsch

Martin Ullrich

Carsten Hesse

Kaspar Hallenberger

Siegfried Anders

Wolfgang Jakob

Clemens Casper

Heinrich Schuchardt

Hartwig Hocker

Helmut Keul

Werner Verhoeven

Hartmut Lower

Jurgen Dahmer

Klaus Schebesta

Hugo Obermann

Eric Bischof

Gunther Jeromin

Annett Konig

The present invention relates to a process for the continuous production of carbonates having aromatic ester groups by the reaction of aromatic hydroxy compounds with phosgene in the presence of heterogeneous catalysts, phosgene still present being removed from the stream of waste gas by returning the waste gas to an additional reactor.

Process for the continuous production of aryl carbonates

The invention relates to a process for the production of multilayer plastic sheets from special branched polycarbonates.

Process for the production of multilayer plastic sheets

The present invention relates to a process for the continuous production of carbonates having aromatic ester groups by reacting aromatic hydroxy compounds with phosgene in the gas phase in the presence of heterogeneous catalysts.

The present invention provides a process for the isolation of partially crystalline polycarbonate powder or oligocarbonate powder from solutions thereof, in which process the organic solvent of a polycarbonate solution is vaporized in a heat exchanger, optionally with incorporation of steam, or in a holding tube with incorporation of steam and the pasty mixture of concentrated solution, solvent vapor and optionally water is separated in a separator. In this process, the solvent vapor is condensed in a heat exchanger downstream from the separator. The solvent is vaporized in the heat exchanger by indirect input of heat through the heat exchanger walls and vaporization may be promoted by preheating the polycarbonate or oligocarbonate solution in an upstream heat exchanger or by introducing steam or both.

Process for the isolation of partially crystalline polycarbonate powder

The present invention provides a process for the production of poly(diorganosiloxane)/polycarbonate block copolymers in a melt using specific transesterification catalysts.

Process for the production of poly (diorganosiloxane)/polycarbonate

The invention relates to a two-step melt process for the production of thermoplastic, solvent-free, low-branching polycarbonates with low --OH terminal group content using a self-cleaning high-viscosity reactor.

Two-step process for the production of thermoplastic polycarbonate

The present invention relates to a transesterification process for producing thermoplastic polycarbonates with the use of fixed bed catalysts.

Process for producing thermoplastic polycarbonate

The invention relates to a process for preparing a diaryl carbonate by oxidative carbonylation of the basic aromatic hydroxy compound, in which the aromatic hydroxy compound is the one which is eliminated during melt polycondensation of this diaryl carbonate with a bisphenol. Accordingly the invention also relates to the preparation of polycarbonates by melt polycondensation of diaryl carbonates with bisphenols in which the aromatic hydroxy compounds which is eliminated is used again to prepare the diaryl carbonate. In the event that the aromatic hydroxy compound eliminated is also the basic unit in the bisphenol used, proportions of it may be used to prepare both the diaryl carbonate and the bisphenol.

Process for preparing diaryl carbonates and the polycarbonates

The present invention relates to a distillation process for the purification of carbonic acid diaryl esters.

Process for the purification of carbonic acid diaryl ester

The present invention relates to a process for the continuous production of diaryl carbonates by reaction of aromatic hydroxy compounds with phosgene in the presence of heterogeneous catalysts.

Process for the continuous production of diaryl carbonates

The invention relates to a process for the chemical recycling of polycarbonates by catalyzed reaction with diaryl carbonates to oligocarbonates which are crystallized, purified and then polycondensed back to polycarbonates, insoluble constituents optionally being removed before the crystallization step.

Process for the chemical recycling of polycarbonates

The invention relates to a transesterification process for the production of thermoplastic, solventless oligo-/polycarbonates in which aromatic diphenols and carbonic acid diaryl esters are combined and reacted in gaseous form.

Process for the production of thermoplastic polycarbonate

The present invention provides a two-stage melt process for the manufacture of thermoplastic, solvent-free, low-branched polycarbonates with low OH end-group contents with the use of ammonium or phophonium catalysts in the first stage and alkali and alkaline earth catalysts in the second stage.

Two-stage process for the manufacture of thermoplastic polycarbonate

The present invention provides a melt process for the manufacture of thermoplastic solvent-free polycarbonates with the use of a continuously operated tubular reactor for monophenol vaporization.

Process for the manufacture of thermoplastic polycarbonate

An improvement to the transesterification process for the production of aromatic polycarbonates is disclosed. Into the melt which contains diphenols, carbonic acid diaryl esters and optionally branching agents and at temperatures of 130.degree. C. to 400.degree. C. and in the presence of catalysts there is mixed or passing thereover inert gas in a quantity of at least 0.5 Nm3 per kg of polycarbonate melt.

Growing community of inventors

Meerbusch, Germany

Steffen Kuhling