VERFAHREN ZUR DESTILLATION VON ROHEN ISOCYANATKONZENTRATEN.

摘要

A process is described for the separation and recovery of isocyanate monomers from isocyanate concentrates which leaves a residue which is liquid and burnable. The process for the separation and recovery of isocyanate monomers from isocyanate concentrates formed in the production of isocyanates and comprising a volatile isocyanate monomer and by-products comprises the steps of: (A) preparing a mixture comprising (A-1) the isocyanate concentrate; and (A-2) an oil solution comprising; (A-2-a) a major amount of hydrocarbon oil, and (A-2-b) a minor amount of at least one ashless dispersant; and (B) heating the mixture to an elevated temperature at reduced pressure whereby isocyanate monomer is distilled and recovered leaving a liquid residue. The presence of the oil solution in the mixture facilitates the distillation of the isocyanate concentrate, generally improves the yield of distilled isocyanate monomer, results in a residue which is liquid and easily removed from the distillation apparatus, and the liquid residue can generally be burned without difficulty.