Appeal No. 96-2425
Application 08/094,933
Bolton discloses a process wherein a reaction product
containing methylene diphenylamine is prepared by reacting
aniline and formaldehyde in the presence of an acid catalyst
(col. 2, lines 6-9). The acid is partially neutralized at the
condensation stage, which is the stage at which the aniline
and formaldehyde react in the presence of the acid (col. 2,
lines 13-15, 38-43 and 66). This stage takes place before the
digestion stage, which is the stage at which the intermediate
aminobenzylamines rearrange to form the reaction product
containing methylene diphenylamine and polymethylene
polyphenyl (col. 2, lines 44-50 and 66-68). Thus, Bolton’s
process differs from that of appellants in that Bolton’s
partial neutralization takes place during the condensation
stage whereas appellants’ partial neutralization takes place
during the digestion stage.
Appellants argue that because they partially neutralize
their catalyst during the digestion stage rather than the
condensation stage, the rearrangement of the intermediates of
methylene diphenylamine does not proceed in the same manner as
in Bolton’s process and that, therefore, appellants’ product
is not the same as that of Bolton (brief, pages 7-8).
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