PROCESS FOR THE PRODUCTION OF 4,4'-DIAMINO- DICYCLOHEXYLMETHANE WITH A LOW TRANS-TRANS ISOMER CONTENT BY THE CATALYTIC HYDROGENATION OF 4,4'- DIAMINO-DIPHENYLMETHANE

摘要

PROCESS FOR THE PRODUCTION OF4,4'-DIAMINO-DICYCLOHEXYLMETHANEWITH A LOW OF TRANS-TRANS ISOMERCONTENT BY THE CATALYTICHYDROGENATION OF 4 4'-DIAMINO-DIPHENYLMETHANEABSTRACT OF THE DISCLOSUREThe present invention is directed to a processfor the catalytic hydrogenation of a starting materialcontaining 4,4'-diamino-diphenylmethane (4,4'-MDA) orits mixtures with 2,4'-diamino-diphenylmethane,2,2'-diamino-diphenylmethane and/or higher ringcompounds of the diphenylmethane series to ahydrogenation product having a trans-trans isomercontent of 4,4'-diamino-dicyclohexylmethane (4,4'-HMDA)of about 15 to 40 weight percent, based on the diaminecontent of the hydrogenated product, by continuouslyhydrogenating in at least one fixed bed reactor at atemperature of about 100 to 190°C and a pressure ofabout 50 to 350 bar in the presence of a rutheniumcatalyst on a catalyst support having a BET surface areaof about 70 to 280 m2/g and an average pore diameter dpof about 10 to 320 .ANG., the catalyst being prepared byimpregnating the catalyst support to a penetration depthof at least about 50 µm with a soluble rutheniumcompound in an amount sufficient to provide a catalystcontaining about 0.1 to 5 weight percent ruthenium andsubsequently reducing the soluble ruthenium compound toruthenium.