Appeal No. 2006-2694
Application No. 09/910,968
nitroxyl inhibitors above 115°C conversely causes a loss of inhibitor
efficiency, Appellants urge that one skilled in the art
could hardly be expected to think of following the teaching of
Higgins et al. to supplement the deficiencies of Arhancet. In
other words, the behavior of dinitrophenols and nit[r]oxyl
compounds are so totally different that the skilled practitioner
would have no motivation whatsoever to combine the teaching
of Higgins et al. with the teaching of Arhancet to come up with
the present invention.
(Br. 6-7.)
We do not find Appellants’ argument persuasive. As discussed supra,
one of ordinary skill in the art would have recognized, from Higgins’
teachings, the cost benefits of recycling and reusing the nitroxyl inhibitor in
Arhancet’s process.
In our view, the industry’s recognition that recycling nitroxyl inhibitor
above 115°C results in reduced inhibitor efficiency would not have led one
of skill to altogether forego the cost savings of recycling the nitroxyl
inhibitor. Rather, as also discussed supra, the art-recognized fact that
recycling nitroxyl inhibitors above 115°C had undesirable effects would
have led one of skill to use temperatures below that, as recited in claim 1.
To summarize, claim 1 recites a temperature range disclosed by
Arhancet to be suitable for preparing styrene monomer in the presence of
nitroxyl inhibitor. The temperature range recited in claim 1 also avoids the
art-recognized problem of reduced efficiency of recycled nitroxyl inhibitors.
Because the prior art suggests performing the claimed recycling step under the
claimed process conditions, we agree with the Examiner that one of ordinary
skill would have considered claims 1 and 2 obvious over the prior art.
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