APPARATUS AND METHOD FOR PRODUCING AROMATIC POLYISOCYANATE

摘要

PROBLEM TO BE SOLVED: To provide an apparatus for producing an aromatic polyisocyanate with which the aromatic polyisocyanate can be obtained stably over a long period by preventing the formation of a fixedly deposited 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. SOLUTION: 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 using a heat exchanger 2, a step for separating the cooled fluid by using a vapor-liquid separator 3 to vapor and liquid, 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 from two or more pipes 13 for spraying the solvent for preventing the aromatic polyisocyanate from dispersing from the reactor and flowing in the heat exchanger 2. COPYRIGHT: (C)2004,JPO