Appeal No. 2002-0928
Application 09/315,251
containing the spherical particles is filtered to recover the
spherical particles and the spherical particles are thereafter
sintered at from 1000°C to 1300°C. In Example 1, zirconium oxide
having a particle size of 0.005 :m (5 nanometers) was added to
water with a surface active agent and was dispersed using
ultrasound. Polyvinyl alcohol (PVA) was subsequently added to the
zirconium oxide/surface active agent mixture forming a suspension.
The suspension was dropped into a high boiling liquid and allowed
to disperse and the suspension transformed into spherical
particles. Water was removed resulting in zirconium oxide/PVA
microspheres. The zirconium oxide/PVA microspheres were sintered at
1000°C to obtain zirconium oxide microspheres which were shown
under an electron microscope to have a particle size of about 50
:m.
The examiner concludes that it would have been obvious to have
used ultrasound in Gitzhofer to provide therein a more uniform
dispersion because both references deal with small particles and
Gitzhofer teaches the desirability of preventing agglomeration. The
examiner reasons that because the terminology "small particles" in
Gitzhofer would include micron and nanometer size particles and
because Ozaki discloses 5 nanometer sized particles, the references
are properly combined. We disagree.
In the first instance, the claimed method requires more than
a particular particle size. The claimed method also requires a
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