To provide an apparatus for producing an aromatic polyisocyanate by which the aromatic polyisocyanate can be obtained stably over a long period by preventing the formation of a fixed material in a heat exchanger and the plugging of a pipe in the heat exchanger in a phosgenation reaction in the production of the aromatic polyisocyanate; and to provide a method for producing the aromatic polyisocyanate.
The method for producing the aromatic polyisocyanate comprises a step for reacting an aromatic polyamine with phosgene, a step for cooling a vapor extracted from the reactor 1 by a heat exchanger 2, a step for separating the cooled fluid by a vapor-liquid separator 3 to a vapor component and a liquid component, and a step for refeeding the separated liquid component to the reactor 1. The aromatic amine is reacted with the phosgene in a solvent while spraying the solvent for preventing the aromatic polyisocyanate from dispersing from the reactor and flowing in the heat exchanger.
IZUKAWA TSUKURU
Koji Makimura
Chihata Takahata
Toru Suzuki