Introduction to diphenylmethane diisocyanate_Kain Industrial Additive

synthesis method【1】 diphenylmethane diisocyanate, mdi, generally has three isomers: diphenylmethane diisocyanate is mainly used in polyurethane resins as 4,41-mdi. the synthesis process is divided into two steps: condensation of diamine (i.e., diphenylmethanediamine) and phosgenation reaction of diamine. 1. condensation of diphenylmethanediamine there are two phenomena in the condensation reaction of aniline and formaldehyde. the first…