PROCESS FOR THE PREPARATION OF MIXED ISOMERIC METHYLENE-BRIDGED POLYCYCLOHEXYL-POLYAMINES

摘要

A process is described for the preparation of mixed isomeric methylene-bridged polycyclohexylpolyamines wherein a mixed isomeric methylene-bridged polyphenyl polyamine mixture having a functionality of from about 2.0 to about 3.3 is pretreated by contacting the mixture and hydrogen with a nickel-containing hydrogenation catalyst at a temperature of from about 25.degree.C. to about 250.degree.C. under a pressure of about 500 to about 15,000 psig. The pretreated isomeric polyamine is then hydrogenated in the presence of ammonia under conventional hydrogenation conditions employing a ruthenium-containing hydrogenation catalyst. The pretreatment step allows the utilization of mixed isomeric methylene-bridged polyphenyl polyamine feed mixtures for the production of isomeric methylene-bridged polycyclohexylpolyamines in high yields without attendant deactivation of the ruthenium hydrogenation catalyst heretofore observed. The process is particularly applicable to continuous operation.