| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing an isocyanate, capable of simply and economically producing the highly pure isocyanate from carbamate at a high reaction rate with high selectivity in a high yield, by using a low-cost silicate-based catalyst which can be easily separated from a reaction medium through filtration, centrifugal separation or the like. SOLUTION: This method for producing the isocyanate comprises subjecting the carbamate to catalytic thermal decomposition in an organic solvent, wherein a natural silicate or synthesized silicate is used as the catalyst. Clay is preferably used as the natural silicate, and montmorillonite or H+-modified bentonite is more preferably used as the natural silicate. Zeolite is preferably used as the synthesized silicate, and ZSM-5, TS-1, TS-2, ZSM-11, Linde X, Linde Y, Faujesite (R) or Mordenite (R) is more preferably used as the synthesized silicate. N-Carbomethoxyaniline, 1,2-dichlorobenzene and montmorillonite are exemplified as the carbamate, the solvent and the catalyst, respectively. |
