Bayer Aktiengesellschaft

Frank D&ouml;bert

Paul Wagner

Winfried Joentgen

Torsten Groth

Alexander Klausener

Ulrich Liesenfelder

Eberhard Zirngiebl

Georg Ronge

Rolf Feller

Thomas Menzel

Thomas Roick

Klaus-Peter Heise

Wolfgang Eymann

Hans-Martin Weber

Eckhard Wenderoth

Ralf Demuth

Harald Petersen

J&ouml;rgen Weinschenck

Thomas W&uuml;rminghausen

The present invention relates to a process for the continuous isothermal preparation of mononitrotoluenes with concentration of the resultant waste sulfuric acid and recycling of the concentrated waste sulfuric acid to the process.

Continuous isothermal process for preparing mononitrotoluenes

The present invention relates to a process for preparing trimethylol compounds and formic acid by reaction of formaldehyde and aldehydes in the presence of a nitrogen base and distillation of the resulting reaction mixture in the presence of an auxiliary.

Process for preparing trimethylol compounds and formic acid

A process for the preparation of iminodisuccinic acid alkali metal salts by reaction of maleic acid and ammonia in an aqueous medium in the presence of alkali metal hydroxides and working up thereof.

Preparation and use of iminodisuccinic acid salts

The invention relates to a method for carrying out polycondensation reactions, according to which the polycondensation of a monomeric starting material is carried out with external supply of heat in a reactor combination which has at least two stages and is composed of a pre-reactor and a high-viscosity reactor, where the low-molecular-weight elimination products produced are removed by evaporation. In the pre-reactor, the reaction product is concentrated to give a high-viscosity preliminary product. The high-viscosity preliminary product is then fed to the high-viscosity reactor, in which it reacts to completion with simultaneous introduction of thermal and mechanical energy and with a residence time of from 20 s to 60 min to give a polycondensation product.

Method for carrying out polycondensation reactions

Growing community of inventors

Kö'ln, Germany

Frank Döbert

Growing community of inventors

Kö'ln, Germany

Frank D&ouml;bert

Frank Döbert