Patent ID: 11939280
Assignee: WANHUA CHEMICAL GROUP CO., LTD.
Field: Organic fine chemistry (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 0:
1. A method for preparing isophorone diisocyanate, comprising the following steps:
(1) reacting isophorone with hydrogen cyanide in the presence of a catalyst to obtain isophorone nitrile;
(2) reacting the isophorone nitrile obtained in step (1) with ammonia gas and hydrogen in the presence of a catalyst to obtain isophorone diamine; and
(3) subjecting the isophorone diamine to a phosgenation reaction to obtain isophorone diisocyanate,
wherein the content of impurities containing a secondary amine group in the isophorone diamine that is subjected to the phosgenation reaction in step (3) is less than or equal to 0.5 wt %.