Ex Parte Lindner et al

Board of Patent Appeals and Interferences

Jun 23, 2010

10079479 (B.P.A.I. Jun. 23, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte GOTTLIEB-GEORG LINDNER, ROBERT KUHLMANN,
and CLAUS-PETER DREXEL
__________

Appeal 2010-000463
Application 10/079,479
Technology Center 1700
__________

Decided: June 23, 2010
__________

Before CHARLES F. WARREN, CATHERINE Q. TIMM, and STEPHEN
WALSH, Administrative Patent Judges.

WALSH, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(a) involving claims to a
precipitated silica. The Patent Examiner rejected the claims on the ground
of obviousness. We have jurisdiction under 35 U.S.C. § 6(b). We reverse.
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STATEMENT OF THE CASE
Claims 1, 4, 5, 10-12, 14-19 and 22-28, which are all the pending
claims, are on appeal. Claims 1 and 10 are representative and read as
follows:
1. A precipitated silica having the following physicochemical
characteristics:
BET surface area from 50 to 700 m2/g;
DBP absorption from 100 to 450 g/100 g;
Choline chloride absorption from 150 to 400 g/100 g (75%
absorption by weight aqueous
solution);
CTAB surface area from 50 to 3 50 m2/g;
DBP/choline chloride absorption less than 1.07; and
Sears number greater than 25 m1/5g.

10. A process for preparing precipitated silica, comprising:
simultaneously metering into an aqueous silicate solution more
aqueous silicate solution and a Lewis and/or Brønsted acid over a
precipitation period of 40 to 65 minutes followed by reacidifying the
mixture to a pH of 7-3.0 to provide an acidified mixture having a solid
content of the suspension of from 79.3 to 104 g/l,
optionally filtering the acidified mixture to obtain a filtered
precipitated silica,
optionally drying the filtered precipitated silica,
wherein the metered addition of the aqueous silicate solution
and the Lewis and/or Brønsted acid is carried out while maintaining a
constant alkali number in the mixture of at least 15, and
wherein the silica has the following physicochemical
characteristics:
BET surface area from 50 to 700 m2/g;
DBP absorption from 100 to 450 g/100 g;
Choline chloride absorption from 150 to 400 g/100 g (75%
absorption by weight aqueous
solution);
CTAB surface area from 50 to 350 m2/g;
DBP/choline chloride absorption less than 1.07; and
Sears number greater than 25 m1/5g.
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The Examiner rejected claims 1, 4, 5, 10-12, 14-19 and 22-28 under
35 U.S.C. § 103(a) as unpatentable over EP ’7551 and Türk.2

OBVIOUSNESS
The Issue
The Examiner’s position concerning the product claims is that
EP ‘755 described an example precipitated silica having physicochemical
characteristics reported “well within” the ranges recited in Appellants’ claim
1, but for the Sears number, which EP ‘755 did not disclose. (Ans. 4.) The
Examiner accepted Appellants’ Declaration evidence that the EP ‘755 silica
had a Sears number of 22.6 ± 0.25. (Id.) The Examiner found that “[e]ven
though the Sears value of the value of 22.6 +/- 0.25 for produc[t] C(13) as
disclosed in EP ‘755 is lower than the claimed value of ‘greater than 25 []’,
however, the value of ‘22.6’ would have suggested to one or ordinary skill in
the art a slightly higher value based upon a reasonable expectation of
success.” (Id.)
The Examiner’s position concerning the process claims is that EP
‘755 disclosed a process of precipitating silica “while maintaining a constant
alkali index of 7.” (Id. at 4-5.) As to the required characteristics recited in
the claims for the silica produced by Appellants’ process, the Examiner
found that EP ‘755 disclosed ranges for those characteristics that overlap the
claimed ranges, but for the Sears number. For the claimed process
limitations that differ from those described by EP ‘755, the Examiner
concluded that “[i]t would have been obvious . . . to optimize the process

1 EP 0937755, published Aug. 25, 1999.
2 US 4,001,379, issued to Günter Türk et al., Jan. 4, 1977.
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conditions, such as the duration of the ‘precipitation’ step, the solid content
after the precipitation step, the alkali number, the pH, etc., in EP ‘755 in
order to produce the desired silica, which is suitable as carrier for choline
chloride solution, with the properties listed above.” (Id. at 6.) According to
the Examiner, “[f]or the Sears number, since the product in EP ‘755 is
produced by the same process, i.e. constant alkali [number] process, and has
values for all other properties that at least overlap the claimed ranges, the
range for the Sears number for the product of EP ‘755 would also overlap
the claimed range.” (Id.)
As an alternative theory, the Examiner stated: “in the event that the
Sears number is dependent on the alkali number, Türk ‘370 is applied as
stated below.” (Id.) According to the Examiner, Türk taught that using a
constant alkali number to produce silica would result in a product suitable as
an animal feed additive, such as a choline chloride solution. (Id. at 7.) The
Examiner found that Türk taught precipitating silica “while maintaining the
alkali number substantially constant at a value within the range of 10-40.”
(Id.) The Examiner concluded that it would have been obvious to optimize
the alkali number used in the EP ‘755 to a “number between 10-40, as
suggested by Türk . . . because such conditions are known and desirable for
producing precipitated silica that is suitable as carriers for animal feed
additives, such as choline chloride solution.” (Id.) “Thus, when an alkali
number of higher than 15 is used in the process of EP ‘755, as suggested by
Türk [], the process of EP ‘755 would produce a precipitated silica with high
Sears number as required in the instant claims.” (Id.)
Concerning the product claims, Appellants point to the difference of
“at least 10% between the claimed Sears number and the Sears number of
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EP ‘755.” (App. Br. 9.) According to Appellants, the claimed increase is
“significant” and “not obvious.” (Id. at 10.) Relying on items 3 to 13 in the
Rule 132 Declaration of Dr. Lindner, Appellants argue that “[i]t is very
difficult to increase the Sears number and at the same time keep all other
parameters as claimed in the ranges as claimed,” and conclude that “based
on EP ‘755 there is no suggestion as to how to increase the Sears number to
greater than 25 ml/5g and keep” the other physicochemical characteristics
within the claimed ranges. (Id. at 10-11.)
Concerning the process claims, Appellants rely again on their
contention that the prior art had no suggestion as to how to increase the
Sears number, while keeping the other parameters within the claimed range.
According to Appellants, “[c]ontrary to the Examiner’s belie[f], there is no
linear relationship between all parameters.” (Id. at 11, citing the Lindner
Declaration.) Appellants read Türk as teaching that increasing the alkali
number would increase the DBP, and argue that “[e]ven assuming only a
minimal increase of the DBP from 216 g/100g to 220 g/100g, this would
cause that the ratio DBP/CC-absorption of example C13 of EP ‘755 would
increase to 1,073 which would be out of the claimed range of the present
invention.” (Id.)
The issues with respect to this rejection are:
does the evidence support finding that a Sears number of 22.6 ± 0.25
ml/5g suggested a Sears number greater than 25 ml/5g; and
does the evidence support finding that increasing the alkali number in
the prior art process would reasonably have been expected to yield a process
producing silica having the physicochemical characteristics recited in
Appellants’ process claims.
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Findings of Fact
1. EP ‘755 described “Example 3,” a process for preparing precipitated
silica (“Product C”). (EP ‘755 17-21.)
2. The process in EP ‘755’s Example 3 held the alkali number constant
at 7. (Id.)
3. EP ‘755 described Product C as having physicochemical
characteristics within the ranges claimed for Appellants’ product,
except for the Sears number. (Id. at 7-9.)
4. Türk described a process of precipitating silica in which the alkali
number is held constant within the range 10-40 during the
precipitation stage. (Türk, Claim 1.)
5. Appellants filed a “Declaration Under 37 C.F.R. § 1.132,” signed by
Dr. Gottlieb Georg Lindner. (Lindner Decl.)
6. According to Declarant Lindner, “[i]t is very difficult to increase the
Sears number and at the same time keep all other parameters as
claimed in the ranges claimed.” (Id. at ¶ 4.)
7. Declarant Lindner states: “[i]n fact, the prior art cited by the
Examiner discloses that increasing the alkaline number would lead to
an increase of the DBP (see Example 19 of Türk).” (Id. at ¶ 7.)
8. Declarant Lindner states:
[e]ven assuming only a minimal increase of the DBP from 216
g/100g to 220 g/100g, this would cause that the ratio DBP/CC-
absorption of example C13 of EP ‘755 would increase to 1,073
[sic, 1.073] which would be out of the claimed range of the
present invention. Türk, however, teaches that the increase of
the DBP would be higher than 4 g/100g. Thus, a person of
ordinary skill in the art starting with example C13 of EP ‘755
would not consider increasing the alkaline number because
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Türk teaches that this would cause a shift of the DBP/CC ratio
out of the claimed range.

(Id. at ¶ 9.)
9. Declarant Lindner states: “[e]ven considering the complete disclosure
of the manufacturing process disclosed in EP ‘755 in combination
with [the references cited in EP ‘755], it is found that there is no
disclosure by which a Sears number of > 25 could be achieved.” (Id.
at ¶¶ 11-12.)
10. Declarant Lindner states: “[t]he increase of the sears number . . . is
necessary to achieve a sufficient affinity between the silica of the
invention and hydrophilic liquids. Without such affinity the desired
DBP/CC ratio of below 1.07 could not be reached.” (Id. at ¶ 13.)

Principles of Law
“Rejections on obviousness grounds cannot be sustained by mere
conclusory statements; instead, there must be some articulated reasoning
with some rational underpinning to support the legal conclusion of
obviousness.” In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006), cited with
approval in KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 417-18 (2007).
“Obviousness does not require absolute predictability of success. . . .
[A]ll that is required is a reasonable expectation of success.” In re
O'Farrell, 853 F.2d 894, 903-04 (Fed. Cir. 1988).

Analysis
We first consider whether the Sears number for the prior art EP ‘755
silica, 22.6 ± 0.25 ml/5g, suggested the claimed Sears number, greater than
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25 ml/5g. The rejection found that it did, but we find no evidence presented
on this record that a person of ordinary skill in the art would have
understood a Sears number of 22.6 to have suggested a Sears number of
greater than 25. Without evidence supporting that finding, we conclude that
the rejection cannot be sustained. See Kahn, 441 F.3d at 988 (conclusory
statement insufficient to sustain obviousness). We will therefore reverse the
obviousness rejection of the product claims.
Concerning the process claims, Appellants dispute that it would have
been reasonable to expect to adapt EP ‘755 Example 3 with Türk’s higher
alkali number and still produce a silica having all the claimed characteristics.
Because Türk disclosed that a higher alkali number would yield product with
an increased DBP, Appellants argue that the expected DBP increase would
cause the expected product to have characteristics outside the claimed
DBP/CC ratio. (App. Br. 11, citing the Lindner Declaration.) The Examiner
responded: “[t]his argument is not persuasive, because as evidence [sic] by
EP ‘755, silica product with a DBP/CC ratio of 1.05, which is below the
required value of 1.07, and still have low Sears value (as calculated by
Appellants to be 22.6 mg/5g).” (Ans. 9.) We find the Examiner’s response
to this part of the Declaration unpersuasive because it appears to overlook
the fact that the claims require a Sears value “greater than 25 ml/5g,” not a
low Sears value.
The Examiner found that “there is no evidence on record to show that
by increasing the alkali number, only the DBP number increases while the
choline chloride absorption stays the same as stated in the assumption made
in item 9 of the Declaration by Dr. Lindner.” (Ans. 10.) The Examiner
reasoned that “in the event that both the DBP number and the choline
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chloride absorption increase with increasing alkali number, the ratio between
DBP number and the choline chloride absorption could still stay below
1.05.” (Id.) Thus, the Examiner states: “the constant alkali number might
cause not only the change in the DBP number but also the CC number so the
DBP/CC value might not be out of the claimed range as argued by
Appellants.” (Id. at 12.) We find this argument unpersuasive because it is
not based on evidence that changes in choline chloride absorption would
have followed changes in the alkali number, or would reasonably have been
expected to do so. More than the possibility that something “might” happen
is needed. See Kahn, 441 F.3d at 988 (conclusory statement insufficient to
sustain obviousness).

CONCLUSIONS
The evidence does not support finding that a Sears number of 22.6 ±
0.25 ml/5g suggested a Sears number greater than 25 ml/5g.
The evidence does not support finding that increasing the alkali
number in the prior art process would reasonably have been expected to
yield a process producing silica having the physicochemical characteristics
recited in Appellants’ process claims.
Because the evidence does not support findings needed to sustain the
proposed conclusion of obviousness, the obviousness rejection will not be
affirmed.

SUMMARY
We reverse the rejection of claims 1, 4, 5, 10-12, 14-19 and 22-28
under 35 U.S.C. § 103(a) as unpatentable over EP ’755 and Türk.
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Application 10/079,479

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REVERSED

lp

OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA VA 22314