| 摘要 |
<p>Organic isocyanates are obtained by reacting phosgene with a primary polyamine in the presence of an inert organic diluent, the initial chemical combination of the reactants being performed by separately introducing liquid phosgene and a solution of the primary amine in an inert liquid organic diluent into a tubular reactor through which a stream of a mixture of phosgene and the initial reaction products in the same solvent is passed continuously by recirculation. The temperature in the tubular reactor is preferably maintained at 8-50 DEG C. and the pressure is atmospheric or slightly above. Suitable organic diluents are, e.g., toluene, xylene, mono- and di-chlorbenzene, chlortoluene, trichlorofluoromethane, ethyl, butyl and hexyl acetates and dimethyl and diethyl carbonates. The process may be used to produce, for example, tolylene 2,4- and 2,6-diisocyanate, diphenylmethane - 4,41 - diisocyanate, 3 - methyl - diphenylmethane - 4,41-diisocyanate, m- and p-phenylene diisocyanate diphenyl - 4,41 - diisocyanate and naphthalene-1,5-diisocyanate.</p> |
