Appeal No. 1997-0090
Application No. 08/083,183
This final stage with hydrogen peroxide is
carried out, in accordance with the invention,
in the presence of at least one stabilising
agent. The known stabilising agents of
peroxygenated products are well suited.
Contrary to the examiner’s assertions and implicit conclusions
in the answer at page 7, the above disclosure in appellants’
specification does not constitute an unequivocal admission
that the use of a stabilizing agent during peroxide bleaching
is well known in the art in prior art processes for bleaching
chemical paper pulp. In fact, the Lundgren reference relied2
upon by the examiner as his “primary reference”, teaches that
in processes for bleaching mechanical pulps, as opposed to
chemical paper pulps, the activity of hydrogen peroxide in an
alkaline bleaching stage is controlled by the addition of
silicates such as the commonly used stabilizing agent, sodium
silicate, and that failure to include silicate in the
bleaching composition will prevent the mechanical pulp from
gaining the best obtainable brightness. However, with respect
to chemical pulps, Lundgren teaches that “[t]he addition of
2The technical differences between processes for
bleaching “mechanical” pulps and “chemical” pulps are
described in paragraphs 10-16 at pages 3-5 of the Devenyns
declaration.
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