Covestro Deutschland Ag

Bayer Materialscience Ag

Bayer Intellectual Property Gmbh

Thomas Voigt

Reinhard Halpaap

Frank Richter

Martin Brahm

Irene Cristina Latorre Martinez

Claudine Stoye

Sascha Tadjbach

Anna-Marie Zorn

Joerg Morawski

Thomas Guttmann

The invention relates to a method for recovering a diisocyanate which is solid at room temperature from a distillation residue from a process for producing the diisocyanate, comprising the following steps: (i) mixing the distillation residue with a bitumen such that a mixture is obtained which contains 70 to 90 wt % of the distillation residue and 10 to 30 wt % of the bitumen, each in relation to the mixture, (ii) distilling the mixture in a thin-film evaporator or a falling film evaporator to obtain a sump discharge and a gaseous product stream, (iii) condensing the gaseous product stream and obtaining a solid containing the diisocyanate which is solid at room temperature. The invention further relates to the use of a thin-film evaporator or falling film evaporator, to a composition containing the diisocyanate which is solid at room temperature, and to a method for producing an elastomer from this composition and to the elastomer itself.

Method for diisocyanate recovery from distillation residues with bitumen

The invention relates to a new industrial process for producing low-monomer-content organic polyisocyanates by oligomerization of organic diisocyanates in a two-phase system.

Process for producing low-monomer-content organic polyisocyanates

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Langenfeld, Germany

Thomas Voigt