Bayer Aktiengesellschaft

Jurgen Dahmer

Helmut Waldmann

Klaus Nachtkamp

Oswald Wilmes

Eric Bischof

Natalja Zubritskaya

Anatoly Bazanov

Alexandre Timofeev

Gennady Terechtchenko

Hans-Josef Buysch

Pieter Ooms

Norbert Schon

Steffen Kuhling

Christian Rasp

Georg Ronge

Gottfried Zaby

Herbert Stutz

Wolfgang Jakob

Heinrich Steude

Ludwig Deibele

Dieter Schleenstein

Wilfried Litz

Andreas Flink

Stephan Kabelac

Attila Molnar

Peter Briedenbach

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.

Process for the continuous production of aryl carbonates

The present invention relates to a process for preparing 2-methyl-2,4-diaminopentane by introducing acetone, ammonia and hydrogen into a two-zone reactor at a temperature of 20.degree. to 130.degree. C. and a pressure of 30 to 250 bar, wherein the first zone contains a cationic exchange resin containing NH.sub.4.sup..sym. groups or an aluminum oxide and/or silicon oxide catalyst and the second zone contains a hydrogenation catalyst containing nickel.

Process for the preparation of 2-methyl-2,4-diaminopentane

The present invention relates to a process for preparing 1,4-bis(aminomethyl)cyclohexane by reacting a 40 to 80 wt. % aqueous solution of 1,4-bis(hydroxymethyl)cyclohexane with a mixture of hydrogen and ammonia in the presence of a nickel/copper/chromium catalyst at a pressure of 100 to 250 bar and a temperature of 150.degree. to 250.degree. C.

Process for the preparation of 1,4-bis(aminomethyl) cyclohexane

This present invention relates to a process for thermally cracking carbamic acid esters into the corresponding isocyanate and hydroxyl compounds in the liquid phase, wherein the reaction proceeds as a reactive rectification in the stripping zone of a column and in an inert, high-boiling solvent, which acts as a buffer to keep the reaction away from the evaporator region of the column.

Process for thermally cracking carbamic acid esters

Low-boiling by-products are removed from diurethanes prepared by a phosgene-free process by carrier vapor distillation using alcohol vapor, preferably the vapor of the basic alcohol found in the diurethane, as the carrier vapor. The diurethanes freed of low-boiling by-products in this manner may be thermally decomposed to produce diisocyanates.

Process for removing by-products from diurethanes

Diisocyanates are produced by gas-phase phosgenation of aliphatic diamines having two primary amino groups in the 1,2- or 1,3-position to one another or by cycloaliphatic diamines having two primary amino groups in the 1,2- or 1,3-position to one another.

Process for the production of diisocyanates

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Krefeld, Germany

Jurgen Dahmer