Covestro Deutschland Ag

Covestro Intellectual Property Gmbh & Co. Kg

Anna-Marie Zorn

Michael Merkel

Rainer Bellinghausen

Ralph Weber

Irene Cristina Latorre Martinez

Claudine Stoye

Thomas Voigt

Sascha Tadjbach

Pascal Scherpian

Joerg Morawski

Thomas Guttmann

Karl H Wuehrer

Erkan Durgut

Thomas Schucht

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 present invention relates to a bulk material comprising solid diisocyanate, especially naphthalene 1,5-diisocyanate or p-phenylene diisocyanate, to a process for production thereof, and to a process for preparing isocyanate prepolymers using the bulk material of the invention, to the isocyanate prepolymers themselves and to the use thereof for preparation of polyurethane elastomers, especially cast polyurethane elastomers.

Bulk material comprising solid diisocyanates and prepolymers containing urethane groups obtainable therefrom

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Ettlingen, Germany

Anna-Marie Zorn