Publication number: 20160068472
Abstract: 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 %.
Type:
Application
Filed:
November 22, 2013
Publication date:
March 10, 2016
Applicants:
WANHUA CHEMICAL (NINGBO) CO., LTD., WANHUA CHEMICAL GROUP CO., LTD.
Inventors:
Xin LI, Hao CHEN, Congying ZHANG, Shan GAO, Zhenguo LIU, Weijia WANG, Lei TANG, Zhipeng LIU, Yuan LI, Qingmei JIANG, Jinhong SONG, Weiqi HUA, Hao DING