Appeal No. 1996-3470
Application 08/313,179
prior art compositions. In addition, appellants allege that they
have unexpectedly discovered that the corrosion resistance of a
zinc surface which has been phosphated according to the process
of the present invention with a phosphate bath which is free of
both nitrite and nitrate is superior to the corrosion resistance
of coatings produced from the phosphating solutions containing
nitrite ions as described in the prior art references. However,
we observe that Gehmecker describes the phosphate coatings
provided by his process as providing advantageous protection
against corrosion, and we further observe that appellants have
made no comparative study with respect to the corrosion
resistance of coatings produced from the specific phosphating
solutions utilized by Gehmecker, particularly, Gehmecker's
working Example 12 which apparently contains no nitrite or
nitrate ions. We also observe that Gehmecker indicates that
preferred oxidizers include chlorates, bromates and peroxy
compounds which oxidizers may be used alone and not necessarily
in combination with nitrate or nitrite oxidizers. See Gehmecker
at column 3, lines 52 through 65. Moreover, although appellants
contend that comparative Example 2 in the specification
(specification, pages 12 through 16) illustrates the improvement
of a coating formed over that obtained by using a nickel
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