Appeal No. 2001-2554 5
Application No. 08/925,321
according to the sulfate process. See page 3, lines 48-51. We find that the pulp has an
initial Kappa number preferably from 10 up to 20. See page 3, lines 52-54. The acid
treatment is carried out at a temperature between about 10 up to about 95oC and
preferably from 40 up to 80oC. See page 3, lines 55-56. We find that Example 1 utilizes
a sulfate pulp having a Kappa number of 17. The pulp is acid treated at a pH of 2.0, and
at a temperature of 60o C for 30 minutes. Additional treatments at a pH of 2.3 and 4.7
resulted in a Kappa number lower than the initial Kappa number by more than 2 Kappa
units. See Table 1.
Each of the secondary references to Lachenal and Marechal are likewise directed to
acid treatment of pulp. Lachenal discloses that, “the best sequence seems to be an AP
sequence where the alkaline peroxide step is preceded by a hot (70o C) acid
pretreatment.” See page 147, left-hand column. Lachenal discloses that, “raising the
temperature in the acid treatment results in a further decrease of Kappa No after the P
stage.” Id. We find that a temperature range of 20 to 90o C is disclosed in Table 4 for a
time of 120 minutes, at a consistency of 12% utilizing 2% sulfuric acid. We concur with
the findings in the first declaration of Vuorinen that 2% sulfuric acid results in a pH less
than about 2.
Marechal discloses treating pulp having a Kappa number of 24.8 and a solids
consistency within the range of 0.1 - 50% required by claim 1 at a pH of 2. See page
263. We find that the pH of the suspension was 2.18 and the suspension was heated for
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