Patent ID: 9580380
Date: 2017-02-28
CPC Classifications: B01J,C07C,Y02P

Claim:
1. A continuous method for preparing diamino-dicyclohexyl methane, wherein said continuous method comprises the following steps: 1) 4,4′-diamino-diphenyl methane feed is hydrogenated in a reactor packed with catalyst to prepare 4,4′-diamino-dicyclohexyl methane at the conversion of 98-99.99%; 2) When the conversion in step 1) is 90-98%, the feed is switched from 4,4′-diamino-diphenyl methane to a mixture of 2,4′-diamino-diphenyl methane and 4,4′-diamino-diphenyl methane, and the hydrogenation reaction is continued to prepare 2,4′-diamino-dicyclohexyl methane and 4,4′-diamino-dicyclohexyl methane; 3) After the conversion of the mixture of 2,4′-diamino-diphenyl methane and 4,4′-diamino-diphenyl methane in step 2) is ≧90% and the reaction is lasted at said conversion for 20-40 h, the feed is switched from the mixture of 2,4′-diamino-diphenyl methane and 4,4′-diamino-diphenyl methane to 4,4′-diamino-diphenyl methane, and the hydrogenation reaction is continued to prepare 4,4′-diamino-dicyclohexyl methane.