Basf Aktiengesellschaft

Otto Mattner

Franz Merger

Wolfgang Schwarz

Peter Magnussen

Andreas Otterbach

Eckhardt Brandt

Friedrich Towae

Roland Minges

Hans Volkmar Schwarz

Hans V Schwarz

In a reactor for the thermal cleavage of mono- and polyfunctional carbamic esters into the corresponding isocyanates and the hydroxyl component in the liquid phase, the geometry of the reactor, defined by the degassing area in relation to the volume and the arrangement of the heating surfaces, permits cleavage in a two-phase mixture which has a volumetric gas content of more than 50%.

Thermal cleavage of carbamic esters

A multistep process for the continuous preparation of organic polyisocyanates, preferably aliphatic or cycloaliphatic diisocyanates, by reacting the corresponding organic polyamines with carbonic acid derivatives and alcohols to give monomeric polyurethanes and pyrolyzing the latter involves separating the resultant polyisocyanates and worthless residues in certain reaction steps and recycling the reusable by-products into earlier steps.

Multistep, continuous preparation of organic polyisocyanates

A process for the pyrolysis of mono-, di-, and polyurethanes to the corresponding mono-, di-, and polyisocyanates wherein the urethane to be cleaved is heated under pressure and sprayed through a nozzle into a pyrolysis chamber maintained at reduced pressure. The isocyanate and alcohol cleavage products are separated by fractional condensation.

Process for the preparation of isocyanates through the thermal cleavage

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Speyer, Germany

Otto Mattner