The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 23, 1993
Filed:
Sep. 21, 1989
George H Schmelzer, Pittsburgh, PA (US);
Gary F Allen, New Martinsville, WV (US);
Guenther K Bub, Marl, DE;
Werner Otte, Dorsten, DE;
Miles, Inc., Pittsburgh, PA (US);
Huls Aktiengesellschaft, Marl, DE;
Abstract
The present invention is directed to a process for the catalytic hydrogenation of a starting material containing 4,4'-diamino-diphenylmethane (4,4'-MDA) or its mixtures with 2,4'-diamino-diphenylmethane, 2,2'-diamino-diphenylmethane and/or higher ring compounds of the diphenylmethane series to a hydrogenation product having a trans-trans isomer content of 4,4'-diamino-dicyclohexylmethane (4,4'-HMDA) of about 15 to 40 weight percent, based on the diamine content of the hydrogenated product, by continuously hydrogenating in at least one fixed bed reactor at a temperature of about 100.degree. to 190.degree. C. and a pressure of about 50 to 350 bar in the presence of a ruthenium catalyst on a catalyst support having a BET surface area of about 70 to 280 m.sup.2 /g and an average pore diameter d.sub.p of about 10 to 320 .ANG., the catalyst being prepared by impregnating the catalyst support to a penetration depth of at least about 50 .mu.m with a soluble ruthenium compound in an amount sufficient to provide a catalyst containing about 0.1 to 5 weight percent ruthenium and subsequently reducing the soluble ruthenium compound to ruthenium.