Appeal No. 1999-0678
Application No. 08/462,691
Sundman states (page 1) that:
The present invention relates to a method of
bleaching cellulosic containing material with
an oxidizing gas, particularly oxygen gas, in
an alkaline environment . . . . [Emphasis ours.]
To “eliminate the drawbacks of the prior art processes,” Sundman
teaches adding a foaming agent to the pulp suspension and
then utilizing the oxygen gas to effectuate foaming. See page 3.
According to Sundman (pages 3 and 4):
Thus, in accordance with the present teachings,
an improvement is provided in a method of bleaching
cellulosic material with an oxidizing gas in an alkaline
environment in which a pulp suspension which has a maximum
consistency of 15% is treated with an alkali solution
and the oxidizing gas for effecting removal of lignin
from the cellulosic material such treatment being effected
at elevated temperature and pressure, wherein the
improvement comprises transforming the pulp suspension into
a stable foam in the presence of a foaming agent.
Although Sundman states that oxygen may be substituted with,
inter alia, ozone, it does not teach or suggest a reaction
condition in which ozone can act as the only bleaching agent in
its bleaching process. Nor does Sundman teach or suggest that
its desired stable foam can be maintained at a condition other
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