Ex Parte Nasholm

Board of Patent Appeals and Interferences

May 8, 2008

10472297 (B.P.A.I. May. 8, 2008)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte ANN-SOFI NASHOLM
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Appeal 2008-2265
Application 10/472,297
Technology Center 1700
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Decided: May 8, 2008
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Before CHUNG K. PAK, LINDA M. GAUDETTE, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.

PAK, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on an appeal under 35 U.S.C. § 134 from the
Examiner's final rejection of claims 7 through 16, all of the claims pending
in the above-identified application. We have jurisdiction pursuant to 35
U.S.C. § 6.

We AFFIRM.
Appeal 2008-2265
Application 10/472,297

STATEMENT OF THE CASE
The subject matter on appeal is directed to a method of end bleaching
pulp. According to Appellant, pulp containing metal ions from alkaline
bleaching stages is bleached with chlorine dioxide in the first chlorine
dioxide stage. (Spec. 3). The resulting pulp is washed and pressed to
remove a substantial amount of an aqueous drainage containing metal ions
and then diluted with sodium hydroxide for alkali extraction, which
according to Appellant, reduces the formation of undesirable calcium
compounds such as calcium oxalate. (Spec. 2 and 6). Finally, the pulp is
bleached with chlorine dioxide in the second chlorine dioxide reactor.
(Spec. 6). Further details of the appealed subject matter are recited in claim
7, which is reproduced below:
7. A method for end bleaching of pulp containing metal ions after a
sequence of alkaline bleaching stages comprising:

a first chlorine dioxide stage;

washing and dewatering said pulp to a concentration of 25-50% for
removal of out-dissolved metal ions;

adding alkali to said pulp for extraction and fast increase of pH to 8-
14;

providing said pulp with acid and chlorine dioxide; and

a second chlorine dioxide stage.

As evidence of unpatentability of the claimed subject matter, the
Examiner has relied upon the following references:
Histed 4,238,281 Dec. 9, 1980
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Application 10/472,297

Cronlund EP 0 480 469 Apr. 4, 1992
Färnstrand 5,589,031 Dec. 31, 1996
Maples 5,938,892 Aug. 17, 1999

Gullichsen et al., Papermaking Science and Technology, Book 6A:
Chemical Pulping, A642-A657 (Gummerus Printing, 1999) (hereinafter
"Gullichsen")

The Examiner has rejected claims 7 through 16 under 35 U.S.C. §
103(a) as unpatentable over the combined disclosures of Cronlund, Histed,
Färnstrand, Maples, and Gullichsen.
Appellant appeals from the Examiner’s decision rejecting claims 7
through 16 under 35 U.S.C. § 103(a).

PRINCIPLES OF LAW, RELEVANT FACTUAL FINDINGS, ISSUES, AND
ANALYSES
Under 35 U.S.C. § 103, the factual inquiry into obviousness requires a
determination of: (1) the scope and content of the prior art; (2) the
differences between the claimed subject matter and the prior art; (3) the level
of ordinary skill in the art; and (4) secondary considerations. Graham v.
John Deere Co., 383 U.S. 1, 17-18 (1966). “[A]nalysis [of whether the
subject matter of a claim would have been obvious] need not seek out
precise teachings directed to the specific subject matter of the challenged
claim, for a court can take account of the inferences and creative steps that a
person of ordinary skill in the art would employ.” KSR Int’l. Co. v. Teleflex
Inc., 127 S. Ct. 1727, 1741 (2007).
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Application 10/472,297

We begin by noting that Appellant does not separately argue any of
the dependent claims. Therefore, we choose claim 7 as the representative
claim consistent with 37 C.F.R. § 41.37(c)(1)(vii) (2005).
As is apparent from the record, Appellant does not dispute the
Examiner's finding that Cronlund discloses a method for end bleaching pulp
after a sequence of alkaline bleaching stages comprising bleaching the pulp
in vessel 133 (first chlorine dioxide stage); washing and dewatering the pulp
to remove the bleaching filtrates at washer 14; dissolving and removing
(extracting) any chlorine dioxide bleaching reaction products from the
resulting pulp at mixer 141 via sodium hydroxide (alkali); and bleaching the
pulp in vessel 153 with chlorine dioxide (second chlorine dioxide stage).
(Compare Ans. 3-7 with App. Br. 10-13 and Reply Br. 1-3.)
Rather, Appellant argues that the applied prior art references do not
teach or suggest (1) dewatering the pulp to a concentration1 of 25 to 50%;
(2) dewatering the pulp to remove metal ions; (3) adding alkali to the pulp in
order to obtain a fast increase of its pH; and (4) adding alkali to change the
pulp's pH to 8-14. (App. Br. 10-13).
Thus, Appellant raises the following four dispositive issues: (1)
whether Cronlund teaches or would have suggested that the pulp exiting the
first chlorine dioxide stage is dewatered to a concentration of "25% [to]
50%" as required by claim 7; (2) whether Cronlund teaches or would have
suggested that its dewatering step "[removes] out-dissolved metal ions" as
required by claim 7; (3) whether Cronlund teaches or would have suggested

1 Because both Appellant and the Examiner use the terms "concentration"
and "consistency" interchangeably, we do the same. (Compare Spec. 3
through 6 and App. Br. 10-13 and Reply Br. 1-3 with Ans. 3-10).
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Application 10/472,297

adding alkali to the pulp for a "fast increase of [the] pH" as required by
claim 7; and (4) whether Cronlund teaches or would have suggested adding
alkali to the pulp "[to change the] pH to 8-14" as required by claim 7. We
answer all of these issues in seriatim.2
With respect to issue (1), Appellant does not dispute the Examiner's
finding that Cronlund discloses in one preferred embodiment that the pulp is
washed and then dewatered to obtain a pulp concentration of about 9 to
15%, preferably about 11 to 12%, prior to being subjected to either an
oxidative extraction stage (E0) involving alkali extraction or an alkali
extraction stage (E) 3. (Compare Ans. 7-8 with App. Br. 10-13 and Reply
Br. 1-2). Although Cronlund does not disclose the claimed pulp
concentration in this particular embodiment as argued by Appellant (App.
Br. 11), we find that Cronlund discloses (p. 10, ll. 10-43) in a broader
embodiment that the pulp is dewatered to obtain a pulp concentration of
about 9% to about 40%, preferably about 10% to about 12%, prior to being
treated in the oxidative alkali extraction stage (E0).
Thus, we agree with the Examiner's determination (App. Br. 3) that it
would have been prima facie obvious to one of ordinary skill in the art to
dewater the pulp to obtain a workable pulp concentration of 9% to 40%, as

2 Histed and Färnstrand are cumulative to Cronlund, Maples and Gullichsen
with respect to our consideration of the rejection of representative claim 7.
3 Cronlund teaches (pp. 7-8) that the oxidative extraction stage (E0)
involving alkali extraction, like the alkali extraction stage (E), mixes the
pulp with a 2% sodium hydroxide (alkali) solution, which dissolves and
removes chlorine dioxide bleaching reaction products. Indeed, Appellant
does not dispute the Examiner’s finding that either of these extraction stages
corresponds to the claimed alkali extraction step. (Compare Ans. 3-7 with
App. Br. 10-13 and Reply Br. 1-3).

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suggested by Cronlund, prior to being subjected to an oxidative alkali
extraction stage (E0) within the meaning of § 103(a). “In cases involving
overlapping ranges, we and our predecessor court have consistently held that
even a slight overlap in range establishes a prima facie case of obviousness.”
In re Peterson, 315 F.3d 1325, 1329 (Fed. Cir. 2003).
With respect to issue (2), Appellant does not dispute the presence of
metals in the pulp after the alkaline bleaching stages. (Compare Ans. 3-7
with App. Br. 10-13 and Reply Br. 1-3). Indeed, Maples explains that
Cronlund’s pulp necessarily contains metal impurities by stating (col. 3, ll.
1-2) that "various metals such as calcium, magnesium, manganese[,] and
potassium enter the pulp mill with the wood supply." This pulp, according
to page 11, lines 35-36 of Cronlund, is mixed with chlorine dioxide (bleach)
at a pH of 2 in vessel 133 (first chlorine dioxide stage). Maples explains that
the metal ion impurities in Cronlund's pulp would necessarily be removed as
bleaching filtrates under the acid condition taught by Cronlund.
Specifically, Maples explains:
These metals if not adequately purged from the pulping and bleaching
operations can cause operating problems. In current operations
these metals are released from the pulp [in the form of metal ions]
in the first acidic stage of the bleach plant due to the low pH (2-3)
of operation and are purged to the sewer along with filtrate from
this same first stage. Pulp is thoroughly washed as it leaves the
first acidic stage of bleaching to prevent any entrained liquor
containing solubilized metals from being carried into later stages
of bleaching. If not adequately removed in the first acidic stage of
bleaching, manganese and iron can affect bleaching in the later stages
by limiting brightness development and increasing chemical
consumption. (Emphasis Added).

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Maples, col. 3, ll. 3-15. Therefore, we agree with the Examiner that
Cronlund's dewatering step at washer 14 necessarily "[removes] out-
dissolved metal ions" as required by claim 7.
With respect to issue (3), we find that Cronlund teaches, inter alia,
adding the same specific amount of an alkali to a highly concentrated pulp or
a less concentrated pulp (those containing more water) in an alkali extraction
step as indicated supra. Therefore, we determine that Cronlund would have
suggested adding the alkali to the highly concentrated pulp in the alkali
extraction step with a reasonable expectation of obtaining a fast increase in
the pH relative to the less concentrated pulp added with the alkali.
With respect to issue (4), we find that Cronlund specifically teaches
the claim 7 limitation of "adding alkali to the pulp [to change the] pH to 8-
14" as Cronlund discloses (p. 7, ll. 47-49, p. 10, ll. 35-38, and p. 13, ll. 29-
32) adjusting the pH of the pulp via sodium hydroxide (alkali) to a pH of 11.
See Titanium Metals Corp. v. Banner, 778 F.2d 775, 783 (Fed. Cir. 1985)
(holding that a prior art titanium alloy containing 0.75% nickel and 0.25%
molybdenum read on the claimed titanium alloy having 0.6-0.9% nickel and
0.2-0.4% molybdenum). Moreover, we find that the Examiner has correctly
determined at page 5 of the Answer that the claimed pH condition is
conventional in a known pulp alkali extraction stage, including that
described in Cronlund, as evidenced by Gullichsen at page A644.
Accordingly, based on the factual findings set forth in the Answer and
above, we determine that the preponderance of evidence weighs most
heavily in favor of obviousness of the subject matter defined by claims 7
through 16 within the meaning of 35 U.S.C. § 103.

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ORDER
The decision of the Examiner is affirmed.

TIME PERIOD
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

PL Initial:
sld

LERNER, DAVID, LITTENBERG,
KRUMHOLZ & MENTLIK
600 SOUTH AVENUE WEST
WESTFIELD, NJ 07090
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