Bayer Aktiengesellschaft

Bayer Materialscience Ag

Covestro Deutschland Ag

Bayer Ag Konzernverwaltung Rp

Bayer Intellectual Property Gmbh

Lanxess Deutschland Gmbh

Bayer Materialscience, LLC

Kaspar Hallenberger

Johann Rechner

Johan Vanden Eynde

Pieter Ooms

Georg Ronge

Ricarda Leiberich

Karl-Heinz Köhler

Gabriel Denecker

Claus H Wulff

Carsten Hesse

Claus-Peter Reisinger

Ursula Jansen

Jurgen Hinz

Hans-Josef Buysch

Alexander Klausener

Helmut Waldmann

Paul Wagner

Hans-Joachim Traenckner

Uwe Hucks

Ottfried Schlak

Gerhard Fennhoff

Steffen Kuhling

Michael Prein

Heinz Landscheidt

Johannes Kaulen

Wolfram Wagner

Alfred Eitel

Silke Kratschmer

Steffen K&uuml;hling

Tony Van Osselaer

Christine Mendoza-Frohn

Heinz-Ulrich Blank

Karl-Heinz Mitschke

Hans-Ulrich Dummersdorf

Andre Düx

Florian Lipski

Rob Eek

Henning Kahnis

Korbinian Krämer

Werner Verhoeven

Heinrich Steude

Martin Friedrich

Matthias Böhm

Kurt-Peter Meurer

Johan Vaes

Weerachanan Somhom

Ignace Hooftman

Domien Sluyts

Rafael Warsitz

Dieter Heinz

Zoltan Kricsfalussy

Ludwig Deibele

Hans-Martin Weber

Gerhard Ruffert

Wim Wuytack

Nikolaus Janke

Werner B&auml;cker

Gunther Jeromin

Andreas Chrisochoou

Gunther Rauchschwalbe

Helmut Mothes

Willy Van Herck

Frank Quaeyhaegens

Oliver Pfohl

Reinhard Pech

Guenter Olf

Karl-Heinz KÖHLER

Günther Olf

Vanden Johan Eynde

Anke Hielscher

Eric F Boonstra

John M Teepe

Renae M Vandekemp

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 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 provides a process for preparing diaryl carbonates from dialkyl carbonates and aromatic hydroxyl compounds using at least two reaction columns, a process section for recovering the dialkyl carbonate used in the reaction and for removing the alcohol of reaction, one or more process steps for removing the by-products obtained in the process which have a boiling point between that of the dialkyl carbonate and that of the alkyl aryl carbonate formed during the preparation of the diaryl carbonate, and a process step for further purification of the diaryl carbonate obtained from the reaction columns.

Process for preparing diaryl carbonates from dialkyl carbonates

The invention relates to a process for preparing diaryl carbonates and/or alkyl aryl carbonates from dialkyl carbonates and aromatic hydroxy compounds using a reactive dividing wall column.

Process for preparing diaryl carbonates or alkyl aryl carbonates from dialkyl carbonates

Processes comprising: reacting a dialkyl carbonate and an aromatic hydroxy compound in the presence of a transesterification catalyst in a first reaction column, the first reaction column comprising a top section, a bottom section, a rectifying section in an upper portion of the column and a reaction zone below the rectifying section; feeding a bottom product from the first reaction column to a further reaction column; the bottom product comprising a diaryl carbonate, an alkylaryl carbonate, or both, and residual unreacted dialkyl carbonate and aromatic hydroxy compound; the further reaction column comprising a top section, a rectifying section in an upper portion of the column and a reaction zone below the rectifying section; and reacting the residual unreacted dialkyl carbonate and aromatic hydroxy compound in the further reaction column; feeding a process stream to a distillation column, the process stream comprising a mixture of unreacted dialkyl carbonate and one or more reaction-product alcohols drawn from the first reaction column, the further reaction column, or both, such that the unreacted dialkyl carbonate is separated from the one or more reaction-product alcohols; and recycling the separated, unreacted dialkyl carbonate to the first reaction column; wherein the further reaction column comprises one or more condensers, and heat of condensation from the one or more condensers is fed back into the process.

Processes for preparing diaryl and/or alkylaryl carbonates from dialkyl carbonates

Processes comprising: transesterifying a dialkyl carbonate and an aromatic hydroxyl compound in the presence of a transesterification catalyst to provide a diaryl carbonate product comprising the transesterification catalyst as an impurity; subjecting the diaryl carbonate product to distillation in a first distillation column having an upper part and a lower part, wherein the upper part comprises a rectifying section and the lower part comprises a stripping section; and withdrawing a first sidestream from the first distillation column, wherein the first sidestream comprises a purified diaryl carbonate.

Processes for purifying diaryl carbonates

The invention provides a process for the preparation of diaryl carbonates and/or alkylaryl carbonates from dialkyl carbonates and aromatic hydroxy compounds using one or more intermediate condensers for improving heat integration.

Process for the preparation of diaryl carbonates or arylalkyl carbonates from dialkyl carbonates

An improvement to the melt transesterification reaction of diaryl carbonate with dihydroxy aryl compound is disclosed. The improvement entails the following steps (i) introducing the resulting vapor stream at the mid-height of a first distillation column, and (ii) separating the vapor stream into a top product containing high purity monohydroxy aryl compound and a first bottom product, and (iii) recycling the high purity monohydroxy aryl compound of (ii) to the reaction, and (iv) introducing the first bottom product at mid-height of a second distillation column, and (v) separating said first bottom product into high boiling bottom by-product and overhead remaining constituents, and (vi) introducing the overhead remaining constituents at mid-height of a third distillation column, and (vii) separating said overhead remaining constituents into overhead low-boiling fractions and bottom or product side stream that contains diaryl carbonate product, and (viii) recycling the diaryl carbonate product directly to the transesterification reaction.

Process for producing polycarbonate

Preparation of triethyl phosphate

A process for the work up of a reaction mixture obtained from the preparation of diaryl carbonate by direct carbonylation of aromatic hydroxy compounds is disclosed. The process entails obtaining a reaction mixture that contains diaryl carbonate, aromatic hydroxy compound, water, base and quaternary salt, separating the mixture in a distillation apparatus having only one theoretical separation stage into a liquid phase and a gas phase and recycling the liquid phase without further work up to the reaction step of the direct carbonylation.

Method for reprocessing reaction mixtures containing diaryl carbonate

A process for the work up of reaction mixtures containing diaryl carbonate, aromatic hydroxy compound, water, base and quaternary salt, which are obtained in the preparation of diaryl carbonates by direct carbonylation of aromatic hydroxy compounds, is described. In the process of the present invention an adduct of diaryl carbonate and aromatic hydroxy compound is crystallized from the reaction mixture. A distillate comprising aromatic hydroxy compound is removed from the liquid phase either prior to or after crystallization of the adduct of diaryl carbonate and aromatic hydroxy compound. The liquid phase remaining after the crystallization and distillation steps may be recycled, without further work up, back to the direct carbonylation process step by which the diaryl carbonate is initially prepared.

The present invention relates to a process for preparing phosphoric acid esters, in particular monomeric bisaryl diphosphates, or bridged phosphates.

Process for preparing phosphoric acid esters

The present invention relates to a process for the production of bis(4-hydroxyaryl)alkanes by an acid-catalyzed reaction between aromatic hydroxy compounds and ketones, in which the temperature, ketone content and water content of a liquid reaction mixture are adjusted by means of a suitably composed gas phase.

Method for producing bis(4-hydroxyaryl)alkanes

A process for preparing bisphenol A which has a purity of at least 99.95 wt. % of p,p-bisphenol A (BPA). Thermally stable and colour-stable BPA purified in accordance with the invention produces improved thermal and colour stability and improved optical transparency in polymers such as e.g. polycarbonates prepared therefrom.

Process for the purification of bisphenol

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Leverkusen, Germany

Kaspar Hallenberger