| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a polyisocyanate by which a reaction liquid can be circulated in a circulation line without installing a particular solution-sending means, and the removal of hydrogen chloride from the reaction liquid can be achieved stably; and to provide a production installation for carrying out the method. SOLUTION: The circulation line 11 which is a closed line, a heat-exchanger 12 installed in the midway of the circulation line 11, and a thermosiphon current-circulating part 10 having a dehydrochlorination vessel 9 are connected to the downstream side of an isocyanation reaction vessel 2. The reaction liquid is circulated in the circulation line 11 by the thermosiphon by subjecting the heat exchanger 12 to a sampled-data control by a temperature-controlling part 13. COPYRIGHT: (C)2007,JPO&INPIT
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