Patent ID: 7105700

Claim:
A process for the preparation of methane diphenyl diamine or a mixture of methane diphenyl diamine and its higher homologues having the general formula (I): where R is independently selected from hydrogen, a C1 to C8 alkyl group, a C4 to C10 cycloalkyl group or a C6 to C12 aromatic group and n is a whole number from 1 to 5 so as to give a functionality from 2 and 6, which comprises carrying out the re-arrangement reaction of the intermediate having general formula (II): in the presence of a zeolite in acid form with a “spaciousness index” from 2.5 to 19 modified on the surface by a process comprising i) one or more treatments with an aqueous solution comprising phosphoric acid and/or boric acid, as is, and, optionally, comprising a salt thereof, ii) removal of at least part of the solvent and iii) calcining the treated catalyst.