Appeal No. 95-0992
Application 08/014,104
amalgam made of a mixture of tin, silver and mercury would have
an EE no greater than 0.851. The examiner’s position is that
since platinum and gold have electrode potentials of -1.2 and
1.68 volts, respectively, which are greater than the absolute
value of the EE of such an amalgam as recited in appellant’s
claim 1 and are greater than 0.8 volts as recited in appellant’s
claim 21, a primer which includes either of these metals would
fall within the scope of appellant’s claims (answer, page 6).
As explained on page 16.3 of the Chemist’s Handbook, since
the oxidation strengths of Pt and Au are greater than those of+2 +
Sn , Ag and Hg , Pt and Au may oxidize the amalgam elemental+2 + +2 +2 +
metals. Stoner does not disclose use of Pt and Au but, rather,+2 +
discloses use of elemental Pt and Au (col. 3, line 55). Platinum
can exist only in the 0, +2 and +4 valence states, and gold can
exist only in the 0, +1 and +3 valence states. The examiner has
not explained, and it is not apparent, how Pt or Au in the
elemental (i.e., 0 valence) state can serve as an oxidant and
thereby be reduced to a lower valence state. The oxidation-
reduction half-reaction potentials relied upon by the examiner
indicate that Pt and Au may serve as an oxidant, but do not+2 +
indicate that Stoner’s elemental platinum or gold may do so.
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