Bayer Materialscience Ag

Covestro Deutschland Ag

Ewa Gebauer-Henke

Reinhard Halpaap

Christoph Gürtler

Walter Leitner

Thomas Ernst Müller

Christoph Thiebes

Isabel U Castro Cevallos

Patrick Tomkins

Thomas Müller

A catalytic process for hydrogenating aromatic di- and polyamines with the aid of a selected catalyst system is provided, which comprises a mixture of a first heterogeneous catalyst and a second heterogeneous catalyst and a nitro compound (nitrate and/or nitrite salt). The first and second heterogeneous catalyst each independently comprise a metal selected from the group consisting of Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd and/or Pt and the metal selected for the second heterogeneous catalyst is different from the metal selected for the first heterogeneous catalyst. Hydrogenation of aromatic rings having two or more amino groups bound to the aromatic ring produces cycloaliphatic di- and polyamines, which are useful chemical intermediates, e.g., for further reaction with epoxides or isocyanates. The amino groups may also be converted to isocyanates via reaction with phosgene. The resulting cycloaliphatic di- and polyisocyanates may also be used as monomers for making polymers.

Process for hydrogenating aromatic di- and polyamines

A process for hydrogenating aromatic di- and polyamines is provided comprising the steps of reacting the aromatic amine with hydrogen in the presence of a catalytic system, wherein the catalytic system comprises a heterogeneous catalyst comprising a metal selected from the group consisting of Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd and/or Pt and a support, and wherein the catalyst system further comprises an organic nitro compound. Hydrogenation of aromatic di- and polyamines having two or more amino groups bound to the aromatic ring produces cycloaliphatic di- and polyamines, which are useful chemical intermediates, e.g., for further reaction with epoxides or isocyanates. The amino groups may also be converted to isocyanates via reaction with phosgene. The resulting cycloaliphatic di- and polyisocyanates may also be used as monomers for making polymers.

Process for hydrogenating aromatic di- and polyamines to cycloaliphatic di- and polyamines

Growing community of inventors

Aachen, Germany

Ewa Gebauer-Henke