Appeal No. 1998-0305
Application 08/385,110
would have been obvious to one of ordinary skill in the art to
use Thomson’s upwardly increasing column cross-sectional area
in Ohsol’s column to inhibit foaming. Ohsol, however,
does not indicate that the great deal of steam used by
Thomson, which is what renders desirable the use of Thomson’s
upwardly increasing column cross-sectional area, is desirable
in the process for which Ohsol uses his column, i.e., removing
monomer from an emulsion polymerization latex. Instead, Ohsol
teaches that it is advisable to design the column for vapor
velocities which are about 10 to about 50% of the entrainment
velocities that might be used for nonfoaming liquids (col. 5,
lines 66-71), and warns that use of a very low steam rate to
minimize foaming causes incomplete stripping or overexposure
of the latex (col. 4, lines 41-43).
The examiner has not adequately explained why, in view of
the above-discussed teachings by Ohsol of controlling foaming
by limiting vapor velocity and by various other means in the
process for which Ohsol’s apparatus is used, i.e., removing
monomer from an emulsion polymerization latex, one of ordinary
skill in the art would have been led by Thomson, which is
directed toward deodorizing fats and oils using a high vapor
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