Appeal No. 1998-2300
Application No. 08/366,762
Garcia and Gonzalez-Oliver to provide motivation for using a chlorine or thionyl chloride
atmosphere in the calcination process.
Gonzalez-Oliver discloses that gases such as chlorine provide an oxidizing
atmosphere which is suitable for dehydroxylation of silica glass. Mehrotra discloses that
an inert atmosphere is important during calcination, especially at temperature greater than
o
1000 C, so as to reduce devitrification and reduce the formation of crystalline phases.
(Column 5, lines 47-58). Mehrota teaches away from using an oxidizing atmosphere. The
Examiner has not satisfactorily explained why the applied references would have fairly
suggested to one of ordinary skill in the art the need of an oxidizing atmosphere for
dehydroxylation of silica during calcination given Mehrotra’s teachings regarding the
elimination of oxidizing gases such as air and oxygen. The Examiner has not established
that a chlorine atmosphere would have been considered, by one of ordinary skill in the art,
to be a suitable substitute for the inert atmosphere of Mehrotra on this record. This is
especially so given the differences of the starting materials and the process of
Gonzalez-Oliver and Mehrotra. We therefore reverse the rejection of claims 1, 3 and 4.
In the absence of sufficient factual evidence or scientific rationale to establish why
and how a skilled artisan would have arrived at the subject matter of claims 1, 3 and 4 from
the combination of Mehrotra, Menashi, Gonzalez-Oliver and Garcia., we find that the initial
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