Bayer Aktiengesellschaft

Miles Inc.

Bayer Do Brasil S.a.

Covestro Deutschland Ag

Rudolf Uchdorf

Stefan Wershofen

Hartmut Knofel

Michael Brockelt

Alfred Mitschker

Hans-Georg Pirkl

Fritz Pohl

Torsten Hagen

Richard Adamson

Daniel Koch

Marcel Petinaux

Hans-Peter Schal

Christian Konig

Manfred L Gallus

Wilhelm Bruening

Franz-Moritz Richter

Reinhold Wullner

William C Forester

The invention relates to an improved process for the production of polynuclear aromatic polyamines by condensation of aniline with formaldehyde in the presence of water and acidic catalysts and working up of the reaction mixture by extraction with a hydrophobic solvent, the acid catalyst accumulating in the aqueous phase of the extraction step being reused.

Process for the production of polynuclear aromatic polyamines

A process for production of polyamines of the diphenylmethane series through a condensation reaction of aniline with formaldehyde in the presence of an acid catalyst, neutralization of the acid catalyst after reaction completion, and distillation of the resultant polyamine mixture is described. The key feature of the process is the abrupt increase in reaction temperature after the condensation reaction or after the first rearrangement step.

Process for the production of polyamine mixtures of the

This invention relates to an improved process for the preparation of polynuclear aromatic polyamines in which the reaction product is prepared by condensing aniline with formaldehyde in the presence of water and acidic catalysts and is worked up by extraction with a hydrophobic solvent. The acid catalyst that accumulates in the aqueous phase during the extraction process is reused.

The present invention relates to an improved process for the preparation of multinuclear aromatic polyamines by the condensation of aniline with formaldehyde in the presence of water and acid catalysts and working up of the reaction mixture by extraction with a hydrophobic solvent. The acid catalyst obtained in the aqueous phase of extraction is reused.

Process for the preparation of multinuclear aromatic polyamines

A process for the selective removal of sulfur-containing gases from industrial gases or waste gases by treatment of gases with basic substances, characterized in that the basic substances are carrier materials containing tertiary amino groups corresponding to the following formula: ##STR1## in which m and n individually are 1 or 2,

Process for the removal of sulfur-containing gases

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Krefeld, Germany

Rudolf Uchdorf