Process for the isomeric separation of isocyanates
AssigneeBayer Aktiengesellschaft
InventorsRüdiger Drope, Dieter Grenner, Hartmut Hetzel, Hans-Peter Schal, Gerhard Wegener
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Abstract
A process is described for obtaining pure isocyanate isomers from a mixture of isocyanate isomers by suspension crystallization and the isolation of isomerically pure crystals, which is characterized in that, prior to the isolation of the crystals, 5 to 40% by weight of the crystals produced are remelted while simultaneously increasing the temperature of the crystal slurry by 4.5 to 9° C.
Claims11
A process for obtaining pure isocyanate isomers from a mixture of isocyanate isomers by suspension crystallization and the isolation of isomerically pure crystals, characterized in that prior to the isolation of the crystals, 5 to 40% by weight of the crystals produced are remelted while simultaneously increasing the temperature of the crystal slurry by 4.5 to 9° C.
Dependencies are inferred from the claim text.