Covestro Deutschland Ag

Bayer Materialscience Ag

Bayer Aktiengesellschaft

Bayer Intellectual Property Gmbh

Karl-Heinz Köhler

Rolf Wehrmann

Pieter Ooms

Stephan Konrad

Johan Vanden Eynde

Gabriel Denecker

Helmut-Werner Heuer

Georg Ronge

Kaspar Hallenberger

Ricarda Leiberich

Korbinian Krämer

Werner Breuer

Daniel Koch

Andre Düx

Florian Lipski

Henning Kahnis

Christian Münnich

Marc Buts

Franky Bruynseels

Weerachanan Somhom

Heinrich Hähnsen

Herbert Ungerechts

Friedhelm Risse

Ralph Schellen

Carsten Buchaly

Frank Guldentops

Herbert Blaschke

The invention relates to aromatic polycarbonates which comprise dioxydiarylcycloalkane structural units, and which have improved optical and thermal properties. It also relates to an improved process to produce the said polycarbonates from dihydroxydiphenylcycloalkanes, and also to mixtures of these polycarbonates with polymers, with fillers, with dyes and with conventional additives.

Polycarbonate composition having improved optical and thermal properties

The invention concerns a method for producing diaryl carbonates from monophenols and phosgene or chloroformic acid aryl esters in the presence of at least one optionally substituted pyridine or the hydrochloride salt thereof as catalyst, and the recovery and reinjection thereof back into the method. The method is carried out at least partially in a liquid phase without the use of an additional solvent, the catalyst being separated by means of distillation and recovered.

Method for producing diaryl carbonates

The invention concerns a method for producing diaryl carbonates from monophenols and phosgene or chloroformic acid aryl esters in the presence of an optionally substituted pyridine or the hydrochloride salt thereof as catalyst, and the recovery and reinjection thereof back into the method. The method is carried out at least partially in a liquid phase without the use of an additional solvent, the catalyst being separated by means of crystallization and recovered.

The invention relates to aromatic polycarbonates which comprise dioxydiarylcycloalkane structural units, and which have improved optical and thermal properties. It also relates to an improved process to produce the said polycarbonates from dihydroxydiphenylcyloalkanes, and also to mixtures of these polycarbonates with polymers, with fillers, with dyes and with conventional additives.

The present application relates to a method for the continuous production of diaryl carbonate from phosgene and of at least one monohydroxy compound (monophenol) in the presence of catalysts, and to the use thereof for the production of polycarbonates.

Method for producing diaryl carbonate

The invention relates to a polycarbonate composition having reduced subsequent yellowing of the mouldings produced therefrom on heat ageing and having good optical properties of the polycarbonate composition on processing.

Polycarbonate composition having improved heat stability

The present invention is directed to a composition comprising a tris-hydroxyaryl compound having a metal ion impurity content of less than 10 ppm and to a process for the purification of tris-hydroxyaryl compound having a metal ion impurity, comprising at least the following steps:

Purification of tris-hydroxyaryl compounds

The present invention relates to an aromatic branched polycarbonate, produced via melt transesterification of a bisphenol with a diaryl carbonate in the presence of a branching agent, wherein the aromatic branched polycarbonate comprises branching point structures and structures of formula (D) wherein X is a single bond, C1- to C6-alkylene, C2- to C5-alkylidene or C5- to C6-cycloalkylidene, optionally substituted by C1- to C6-alkyl; wherein the amount of D in the aromatic branched polycarbonate is in the range of from 5 to 450 mg per kg of the aromatic branched polycarbonate; and wherein the ratio of the total branching point structures to the total structures of the formula D in the aromatic branched polycarbonate is in the range of from 8 to 200.

Branched melt polycarbonate with low content of defective structures

The invention relates to a polycarbonate composition with improved melt-flowability together with good optical properties and together with good hydrolysis resistance.

Polycarbonate composition with improved melt-flowability

A generator including a double-chamber lock comprising two tapered or vertical chambers lined with ceramics or plastics, as a charging device, at least one tubular shaft furnace comprising a water-cooled double jacket of steel, a double-walled, water-cooled inlet nozzle of copper for a gasification mixture, arranged centrally in the tubular shaft furnace above the base, a dry dust-removing device, and optionally a desulfurising device. The double-chamber lock has a mechanism which causes one of the chambers to open when the lower chamber of the double-chamber lock is flushed with inert gas after charging/opening operations, and the inlet nozzle constitutes the mixing member for the constituents of the gasification mixture, the inlet nozzle has a radius of curvature of the surface of the cylindrical portion of the nozzle which continuously becomes smaller to the outlet opening, and the direction of flow of the gases leaving the inlet nozzle is directed upwards.

CO generator

The present invention provides a process for the preparation of carbon monoxide gas (CO gas) that is free of sulfur compounds to the greatest possible extent and a process to use that gas in chemical syntheses, for example, for the synthesis of phosgene from carbon monoxide and chlorine.

Growing community of inventors

Aachen-Brand, Germany

Karl-Heinz Köhler