Appeal No. 1998-2190
Application No. 08/593,266
teaches coating of the zinc powder with indium to increase zinc
resistance to corrosion and prevent deterioration of its discharge
performance, thus eliminating the need for mercury and the chance
of environmental pollution from the disposal of mercury (id.).
We determine that Tada specifically discloses the use of
indium sulfate to coat a zinc alloy powder (col. 3, ll. 50-63).
Accordingly, we determine that Tada discloses an alkaline primary
battery without mercury (col. 1, ll. 59-66) comprising an
electrolyte (e.g., aqueous potassium hydroxide; see col. 4, ll. 10-
11); a positive electrode (e.g., manganese dioxide; see col. 4, ll.
5-7); and a negative electrode having a mercuryless zinc alloy
powder active material (col. 2, ll. 28-30) wherein the negative
electrode contains an indium compound such as indium sulfate (col.
3, ll. 50-63). Although Tada discloses the use of zinc alloy
powder as the active material of the negative electrode (see col.
3, ll. 1-21), this reference also teaches the use of pure zinc
powder, although pure zinc does not produce the best results (see
col. 4, l. 12, and Comparative Example 3). See In re Lamberti, 545
F.2d 747, 750, 192 USPQ 278, 280 (CCPA 1976)(All disclosures of a
reference must be considered in an analysis of obviousness, even
unpreferred embodiments).
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