申请人:WANHUA CHEMICAL GROUP CO., LTD.
公开号:US20160068472A1
公开(公告)日:2016-03-10
Disclosed is a method for preparing diamino-dicyclohexyl methane (H
12
MDA) 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′-H
12
MDA. 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′-H
12
MDA having the trans-trans isomer content of 16˜24 wt % is produced, and the mixture of 2,4′-H
12
MDA and 4,4′-H
12
MDA is also produced, wherein the content of 2,4′-H
12
MDA in the mixture is 4˜15 wt %.
本发明公开了一种通过氢化二氨基二苯甲烷(MDA)制备二氨基二环己基甲烷(H12MDA)的方法。在该过程中,首先将起始材料4,4'-MDA氢化制备4,4'-H12MDA。当催化剂活性降低时,将进料从4,4'-MDA切换到2,4'-MDA和4,4'-MDA的混合物,当转化稳定后,再将进料切换回4,4'-MDA。失活的催化剂通过将进料切换到2,4'-MDA和4,4'-MDA的混合物上线活化。制备出具有16~24重量%的顺式-顺式异构体含量的4,4'-H12MDA,以及2,4'-H12MDA和4,4'-H12MDA的混合物,其中混合物中2,4'-H12MDA的含量为4~15重量%。