Patent · US Active

Process for the continuous preparation of (cyclo)aliphatic diisocyanates

US8816125B2 · kind B2 · utility

4Cited by

10References

14Claims

0Family size

Assignee

EVONIK DEGUSSA GMBH · DE

Inventors

Hans-Werner Michalczak · Herne, DE
Stephan Kohlstruk · Marl, DE
Manfred Kreczinski · Herne, DE
Gerda Grund · Coesfeld, DE
Rainer Lomoelder · Munster, DE

Key dates

Filing date	Nov 5, 2007
Grant date	Aug 26, 2014
Priority date	—
Expiry date	Sep 24, 2029

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C2601/14
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

The invention relates to a multi-stage process for the continuous, phosgene-free preparation of (cyclo)aliphatic diisocyanates that comprises the conversion of (cyclo)aliphatic diamines into the corresponding (cyclo)alkylene biscarbamates and the thermal cleaving of the latter into the (cyclo)alkylene diisocyanates and alcohol. The urea used in accordance with the invention and also the urea employed for the preparation of urea equivalents (e.g. alkyl carbonates, alkyl carbamates) as a possible precursor for the synthesis of the (cyclo)aliphatic biscarbamates is unconditioned.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.