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…