Appeal No. 1999-0761 5
Application No. 08/174, 957
solvent treatment, as usual, removes the bulk of oils and greases. This is followed by
mild etching in alkaline cleaner, containing typically 25 g/L of sodium carbonate and 25
g/L of trisodium phosphate at 70-85o C for 1 to 3 min.” Id.
Based upon the above findings, we conclude that the person having ordinary skill
in the art would be directed to use the specific alkaline etchant for aluminum alloys
disclosed by Lowenheim at page 90 or would be directed to add a chelating agent to the
etchant disclosed by the admitted prior art. On the record before us, however, the fact
that other etchants are known or that chelating agents may be added to etchant
compositions, does not provide the requisite motivation to delete the aqueous acidic
etching solution having a pH of 2 or less from the admitted prior art, and add a chelating
agent thereto in order to result in a single step process of exposing the surface to an
aqueous solution containing a chelating agent wherein the aqueous solution consists of
a solution having a pH of 7 or higher as required by the claimed subject matter. See In
re Dembiczak, 175 F.3d 994, 999, 50 USPQ2d 1614, 1617 (Fed. Cir. 1999) ("[T]he best
defense against the subtle but powerful attraction of a hindsight-based obviousness
analysis is rigorous application of the requirement for a showing of the teaching or
motivation to combine prior art references.")
As to the second rejection directed to Chakrabarti, the reference is directed the
preparation of the aluminum alloys of the claimed subject matter and does not
contribute in any manner to the deficiencies in combining the admitted prior art with
Lowenheim.
Page: Previous 1 2 3 4 5 6 7 Next
Last modified: November 3, 2007