Appeal 2007-0128
Reexamination Control 90/006,208
Patent 5,573,648
that:
In all of the foregoing techniques, it has been necessary to utilize
liquid-based emulsion and several processing steps to form film of the
electrode material and thereafter bind or press the sheet of electrode
material upon the ion exchange membrane, or it has been necessary to
use binders and substantial quantities of expensive catalyst materials
to prepare membrane and electrode structures. It has also been
necessary to utilize large loadings of catalyst to make acceptable
electrodes in these prior art methods. The process for preparing the
electrodes using prior art ink compositions is inefficient and the
reproducibility is poor.
****
By prior art techniques, it has been impossible to prepare membrane
and electrode structures having loadings of the unsupported catalyst
materials as low as 3.0 mg per cm2 or even lower with no compromise
in the integrity of the membrane or the performance of the membrane
and electrode structure in various fuel cells, gas generating systems
and other devices.
(Grot >860, col. 1, line 40 to col. 2, line 14 and col. 3, ll. 4-15).
18) Grot '860 states that its membrane and electrode cell represents and
improvement over prior art cells and that its electrodes have "excellent
characteristics." (Id. at col. 3, ll. 49-62). Grot specifically identifies the benefits of
Grot’s electrodes as follows:
The electrode ink is printed, coated or bonded onto the surface of the
membrane by methods known in the art. The ink readily adheres to
the membrane thereby reducing the likelihood of delamination of the
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