Published July 1979
In this supplementary report, several processes for manufacture of TDI and PMPPI/MDI are compared; methyl isocyanate production is described and evaluated; other isocyanates and isocyanate adducts are described. The following are some of the important findings.
The carbonylation process for making TDI or PMPPI requires higher capital outlay than the phosgenation process, and also higher production cost, based on prevailing prices of raw material. The situation may change to some extent If cheap carbon monoxide is available.
For making PMPPI or MD1 by phosgenation, a clay-catalyzed process based on an Upjohn patent for making the starting amine has some cost advantage over the conventional RCl-catalyzed process and also over other new processes claimed in patents.
