Appeal No. 96-1787
Application No. 08/372,482
However, the examiner fails to provide any evidence or
technical explanation to support the bald assertion in the
Answer (page 4) that those of ordinary skill in the art would
not have expected this difference to have an effect upon
surface active properties “since it is the polyether groups
(which are the same in both surfactants) that provide the
surface active properties.”
More to the point, we find no suggestion or guidance in
Hill to use siloxane surfactants having tetrafunctional “Q”
units. As noted by appellants, the presence of such units
would apparently result in significant structural differences
(“cross-linked” configurations) over the siloxane molecules of
Hill. That, and the fact that Hill suggests there is more to
vesicle formation than general surface activity, militate
against a reasonable expectation of success in substituting
the siloxane surfactants of Kanner for those of Hill. Indeed,
Hill clearly suggests that
vesicle formation by particular siloxane surfactants is
surprising and unexpected, apart from knowledge of their
surface active properties. In this regard, see Hill at column
5, line 61
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