Buchanan Ingersoll & Rooney
Method for preparing diamino-dicyclohexyl methane
Disclosed is a method for preparing diamino-dicyclohexyl methane (H12MDA) by hydrogenation of diamino-diphenyl methane (MDA). In the process, 4,4′-MDA used as the starting material is firstly hydrogenated to prepare 4,4′-H12MDA. When the activity of the catalyst is reduced, the feed is switched from 4,4′-MDA to the mixture of 2,4′-MDA and 4,4′-MDA, and then when the conversion is stabilized, the feed is switched to 4,4′-MDA again. The deactivated catalyst is activated on line by switching the feed to the mixture of 2,4′-MDA and 4,4′-MDA. 4,4′-H12MDA having the trans-trans isomer content of 16˜24 wt % is produced, and the mixture of 2,4′-H12MDA and 4,4′-H12MDA is also produced, wherein the content of 2,4′-H12MDA in the mixture is 4˜15 wt %.
Wanhua Chemical Group Co., Ltd.
C C B Y B
C07C C07C B01J Y02P B01J
inventional additional inventional additional inventional
Shan Yuan Congying Zhipeng Weijia Hao Zhenguo Weiqi Hao Xin Lei Qingmei Jinhong
Gao Li Zhang Liu Wang Chen Liu Hua Ding Li Tang Jiang Song