PROCEDIMIENTO PARA LA SEPARACION DE DIFENILMETANDIISOCIATO A PARTIR DE UNA MEZCLA EN BRUTO Y NO DESTILADA DE POLIISO- CIANATOS.

摘要

1423993 Crystallisation of isocyanates IMPERIAL CHEMICAL INDUSTRIES Ltd 12 April 1973 [4 May 1972] 20847/72 Heading C2C [Also in Division C3] Diphenylmethane diisocyanate is separated from a crude undistilled polyisocyanate mixture obtained by the phosgenation of the mixed polyamines from an aniline/formaldehyde condensate by crystallizing the diisocyanate from the crude undistilled polyisocyanate which has not been subjected to a period of heating in excess of 5 minutes at above 150‹ C.