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US 10,093,615 B2Granted
Process for preparing isocyanates in dialkyl carbonates as solvent
AssigneeBASF SE
InventorsManfred Heilig, Thomas Schulz, Torsten Mattke, Filip Nevejans, Kai Thiele, Stefan Maixner
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Abstract
The invention relates to a process for preparing isocyanates by reacting primary amines with phosgene in a solvent, where the solvent comprises a dialkyl carbonate.
Claims7
A process for preparing a polymethylenepoly phenylene polyisocyanate, the process comprising:
- reacting a polymethylenepolyphenylenepolyamine with phosgene in a solvent, to obtain the polymethylenepoly phenylene polyisocyanate,
- wherein:
- the solvent comprises a dialkyl carbonate;
- the reaction is carried out in at least two stages, with the first stage being carried out in a mixing device at a temperature ranging from 80 to 190° C., and the second stage being carried out in at least one residence apparatus;
- and
- the mixing device comprises a nozzle.
3 more elements
Dependencies are inferred from the claim text.