Appeal No. 95-2233
Application 07/978,014
Ligninsulfonate has been considered the
binder of choice in WDG systems. Polyvinyl-
pyrrolidone, in combination with urea, has
been suggested for the same use (Canadian
Patent 1,209,363).
This is the starting point or “jumping off” point of applicants’
invention. As stated in Pro-Mold v. Great Lakes Plastics, 75
F.3d 1568, 1573, 37 USPQ2d 1626, 1629-30 (Fed. Cir. 1996), “[w]e
start from the self-evident proposition that mankind, in
particular, inventors, strive to improve that which already
exists.”
The question arises whether it would have been obvious, at
the time applicants’ invention was made, to use a copolymer of
vinylpyrrolidone and vinyl acetate or a polyvinylpyrrolidone
grafted with butene as the binder in WDG systems. On return of
this application to the examining corps, we recommend that the
examiner consider that question. In so doing, the examiner
should take into account not only the above-quoted description of
prior art set forth in the specification but also the Narayanan
patent and the trade literature enclosed with Paper No. 3 filed3
November 4, 1993.
The Narayanan patent constitutes legally available prior art
3 In our judgment, Narayanan constitutes the closest prior art relied on
in the Examiner’s Answer.
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