Drexel, Claus-Peter et al.

Patent Trials and Appeals Board

Mar 6, 2020

13582177 - (D) (P.T.A.B. Mar. 6, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
13/582,177 08/31/2012 Claus-Peter Drexel 032301 R 730 3728
441 7590 03/06/2020
SMITH, GAMBRELL & RUSSELL, LLP
1055 Thomas Jefferson Street
Suite 400
WASHINGTON, DC 20007
EXAMINER
LAZARO, DOMINIC
ART UNIT PAPER NUMBER
1611
NOTIFICATION DATE DELIVERY MODE
03/06/2020 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
docketing@sgrlaw.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
_________________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
_________________

Ex parte CLAUS-PETER DREXEL, FRANK HASELHUHN,
FRANK HEINDL, RALF RAUSCH, and GUENTER STEIN
_________________

Appeal 2018-008254
Application 13/582,177
Technology Center 1600
_________________

Before DONALD E. ADAMS, DEBORAH KATZ, and JOHN G. NEW,
Administrative Patent Judges.

KATZ, Administrative Patent Judge.

DECISION ON APPEAL
Appellant1 seeks our review,2 under 35 U.S.C. § 134(a), of the
Examiner’s decision to reject claims 1–3, 12–16, 18–20, 23, 24 and 27–36.
We have jurisdiction under 35 U.S.C. § 6(b). We REVERSE.

1 We use the word “Appellant” as defined in 37 C.F.R. § 1.42. Appellant
identifies the real party-in-interest as Evonik Degussa GmbH. (Appeal Br.
3.)
2 We consider the Final Office Action issued May 5, 2017 (“Final Act.”), the
Appeal Brief filed January 4, 2018 (“Appeal Br.”), the Examiner’s Answer
issued on May 16, 2018 (“Ans.”) in reaching our decision.
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The Examiner rejected claims 1, 3, 23, 27–36 under 35 U.S.C.
§ 103(a) as unpatentable over Bouchara3 and Cabelka.4 (See Final Act. 3–
11.) The Examiner also rejected claims 2 and 24 under 35 U.S.C. § 103(a)
as unpatentable over Bouchara, Cabelka, and Deller.5 (See id. at 15–17.)
Appellant’s Specification is directed to granular silicas for use as
carrier material, such as to produce solid formulations from liquid
substances. (See Spec. 1.) Appellant reports that granular silicas of the
invention have three characteristics: [1] a sufficiently high porosity (reported
as “Hg pore volume”); [2] an optimized particle size (reported as “dQ3=10%”
and “dQ3=90%” for the fine and coarse fractions, respectively); and [3] better-
stabilized pore walls (reported as the ratio of the mean particle size (d50)
without ultrasound exposure to the mean particle size (d50u) after 3 min. of
ultrasound exposure element). (See Spec. 5.) According to Appellant, the
claimed granular silicas have increased mechanical stability high
absorptivity and optimal particle size distribution due to the recited particle
porosity [1], size [2], and stability [3]. (See Spec. 5.)
Appellant’s claim 1 recites6:
Granular silica having
 [1] an Hg pore volume (< 4 μm) of 0.90 ml/g to 1.30
ml/g,

3 U.S. Patent Application Publication 2009/0050557 A1, published
February 26, 2009.
4 U.S. Patent Application Publication 2010/0151038 Al, published
June 17, 2010.
5 U.S. Patent 5,776,240, issued July 7, 1998.
6 Claim 1 has been modified by adding bracketed numbers to the elements of
the claimed granular silica.
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 [2] a dQ3=10% of >428 μm with, at the same time, a dQ3=90%
of 923 μm to 2448 μm, and
 [3] a ratio of the d50 without ultrasound exposure to d50
after 3 min of ultrasound exposure of 2.10 to < 4.00, the
measurement being effected on a fraction of particles
from 400 to 500 µm.

(Appeal Br. 34.) Appellant’s independent claim 33 is similar, reciting
limitations on Hg pore volume, dQ3=10% and dQ3=90% particle size distribution,
and ratio of d50 without ultrasound exposure to d50 after three minutes of
ultrasound exposure, but different values for these limitations. (See Appeal
Br. 36.)
The third recited limitation on the claimed granular silica of claim 1,
the “ratio of the d50 without ultrasound exposure to d50 after 3 min of
ultrasound exposure of 2.10 to < 4.00, the measurement being effected on a
fraction of particles from 400 to 500 µm . . . ,” is a determination of how
much the particle size is reduced by mechanical stress and, therefore, is a
determination of the hardness of the silica. (See Spec. 11.)
Bouchara teaches granular silica characterized by pore volume and
mean particle size. (See Bouchara abstract, ¶¶ 6–9.) The granular silica of
Bouchara is also characterized by a cohesion index (“CI”), which is a
measure of the tendency of a sample to break or split up when handled or
used and is an expression of median particle diameter with and without
ultrasound treatment. (See Bouchara ¶¶ 10, 12–14, 16.) Bouchara teaches
granular silica with a CI of less than 0.25 or even less than 0.07. (Id.
¶ 25.)
The Examiner finds that the CI taught in Bouchara “appear[s]
substantially identical” to the d50 with and without ultrasound determinations
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in the instant application. (Final Act. 10–11.) The Examiner finds that a
400 to 500 µm fraction of Bouchara’s “highly cohesive” silica granules
would possess a ratio of d50 with and without ultrasound treatment of less
than 3.00 and greater than 1.00, rendering obvious the claimed d50 range.
(Id.)
The Examiner maintains that it would have reasonably been expected
that the silica taught in Bouchara would “maintain cohesiveness in order to
approach and overlap the instantly claimed d50 after 3 min of ultrasound”
because Bouchara teaches that the lower the CI, the higher the cohesion of
the sample and thus the lower the tendency of the sample to break or split
when used. (Ans. 28, citing Bouchara ¶ 16.) According to the Examiner,
the teaching in Bouchara of a CI of less than 0.25 is substantially identical to
the claimed range because
a fraction of Bouchara’s highly cohesive silica granules per
Cabelka would possess a 2.10 to 4.00 “d50” ratio of median
particle sizes (wherein the “d50” ratio of median particles sizes
is the “d50” without ultrasound exposure over the “d50” after 3
minutes of ultrasound exposure) similar to the granular silica of
the instant claims, thereby rendering obvious the requirement
for the ratio of median particle size (i.e., “d50”) without
ultrasound exposure to the “d50” after 3 minutes of ultrasound
exposure of “2.10 to < 4.00” (claim 1) and “2.50 to< 4.00”
(claim 33).

(Ans. 29.) Thus, the Examiner finds that the CI of the granular silica of
Bouchara is “substantially identical” to the d50 ratio of the claimed silica
and, thus, renders it obvious.
Appellant disagrees with these findings, arguing that Bouchara bases
its determinations on ultrasound treatment of only two minutes, whereas the
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claimed d50 determinations are of ultrasound treatment for three minutes.
(See Appeal Br. 23.) Appellant argues that there is no overlap between the
d50 values recited in claim 1 and the CI taught in Bouchara and they are not
substantially the same. (See Appeal Br. 23–24.)
To support these arguments, Appellant presents the affidavit of
inventor Claus-Peter Drexel, executed February 26, 2014 (“First Drexel
Affidavit”). Dr. Drexel reports that he performed tests on experimental
grade silica of 400 –500 µm to compare the effects of two versus three
minutes of ultrasound exposure. (First Drexel Affidavit 1–2.) Dr. Drexel
presents the results of these tests in Table I:

(First Drexel Affidavit 2.) According to Dr. Drexel, changing from a two
minute duration to a three minute duration was observed to yield a further
increase in the “D50-Ratio” of approximately 15.6%. (See First Drexel
Affidavit 2.) Dr. Drexel explains that “the term ‘Ratio d50P:d50A’ refers to the
ratio of the d50 prior to the ultrasound exposure (i.e., d50P) to the d50 after the
ultrasound exposure (i.e., d50A) of the tested granular silica.” (First Drexel
Affidavit 1–2.) Dr. Drexel concludes that “as evidenced by the foregoing
results in Table I, a difference in the duration of ultrasound exposure
(including a difference between 2 minutes and 3 minutes) will yield an
appreciable difference in the resulting D50-Ratio of the granular silica – with
longer durations yielding higher ratio values.” (First Drexel Affidavit 2.)
Dr. Drexel concludes further that “it is incorrect to suggest that exposing a
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granular silica to an ultrasound energy for a duration of 2 minutes can be
expected to yield substantially the same result as exposing the same granular
silica to an ultrasound energy for a duration of 3 minutes.” (First Drexel
Affidavit 4.)
Appellant presents a second affidavit by Dr. Drexel, executed August
26, 2016 (“Second Drexel Affidavit”). (See Appeal Br. 25.) In this
affidavit, Dr. Drexel reports the measurement of a silica sample (Tixosil®
38X) by laser diffraction without ultrasound treatment or with either two
minutes or three minutes of ultrasound treatment, but otherwise the same
conditions. (See Second Drexel Affidavit 1–2.) From the results reported
by Dr. Drexel, Tixosil® 38X has a two minute d50 ratio of 2.85 and a three
minute d50 ratio of 5.62. (See Second Drexel Affidavit 1–3.) Dr. Drexel
concludes
it is understood that while a silica may have a “2 min. d50 ratio”
that falls within a specified range, that same silica has been
shown to have a “3 min. d50 ratio” that does not fall within that
same range – as, for example, wherein the “2 min. d50 ratio” of
the Tixosil® 38X (at 2.85) is within a range of less than 4.00,
whereas the “3 min. d50 ratio” of the Tixosil® 38X (at 5.62) is
outside the range of less than 4.00.

(Second Drexel Affidavit 3.)
Appellant argues that this evidence shows that a two minute
ultrasound exposure will not necessarily yield a d50 ratio with the claimed
range and that it is unreasonable for the Examiner to rely on an apparent
similarity of the claimed range and the range taught in Bouchara based only
on a numerical similarity. (See Appeal Br. 25–26.)
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The Examiner dismisses Appellant’s arguments, stating that Appellant
focuses on the differing measurement criteria and not on the “high
cohesiveness” of Bouchara’s silica, which would provide it with “high bond
strength” and, thus, the same cohesiveness as the claimed silica. (Ans. 29.)
The Examiner explains the reliance on the cohesiveness determinations in
Bouchara, wherein
a silica that is much softer than either instantly claimed silica or
Bouchara is more likely to exhibit a “d50 initial/d50 2 min” at 2
minutes of ultrasound that is greater than 4.00, which would not
approach the instantly claimed “d50” after 3 minutes of
ultrasound since d50 decreases with increasing ultrasound
exposure times and the ratio increases, whereby the softer silica
would be distinguishable from that of the instant claims.

(Ans. 29.)
The Examiner fails to provide evidence of CI determinations, or d50
ratios that define silica with “high cohesiveness” or that define “softer”
silica. We are not persuaded by the Examiner’s reasoning because it is not
based on specific evidence that the silica of Bouchara would demonstrate a
d50 ratio within the claimed range. “[R]ejections 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.” KSR Int’l Co. v. Teleflex Inc., 550 U.S.
398, 418 (2007) (quoting In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006)).
The Examiner identifies Bouchara as the “closest prior art” and asserts
that Appellant has the burden to provide evidence distinguishing the claimed
silica from Bouchara’s silica. (Ans. 32.) Although the silica of Bouchara
may exhibit a CI at least overlapping with the claimed d50 ratio range, we
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disagree that merely being the “closest prior art” shifts the burden to
Appellant. Rather, it is the Examiner’s burden to show that the silica of
Bouchara is necessarily the same or overlapping with the claimed silica.
Only then does the burden shift to Appellant to show that despite the
appearance, they are not the same.
The Examiner also asserts that Appellant’s calculations regarding the
CI taught in Bouchara “does not preclude the ‘D50initial/D503min’ overlap of
Bouchara and the claimed silica” (Ans. 32), but the Examiner fails to direct
us to evidence that they necessarily overlap.
Appellant submitted evidence, specifically Dr. Drexel’s affidavits,
that persuades us that because the ratio of d50 at 1 minute to a d50 at 2
minutes does not indicate the same ratio of d50 at 1 minute to d50 at 3
minutes, the Examiner has failed to provide the required showing that the
prior art and the claimed ranges are necessarily the same.
The Examiner criticizes Dr. Drexel’s affidavits for several reasons.
(See Ans. 36–39.) First, the Examiner find that because Bouchara does not
teach the specific silica, “Tixosil® 38X” used in the studies reported by Dr.
Drexel in his second affidavit, the affidavit is not a comparison of the
particular silica of the closest prior art and mischaracterizes the rejection as
being based on the properties of any silica. (See Ans. 36–37.) The
Examiner states that the rejection is not based on any silica having a claimed
range of a “d50-0 min” to “d50-3 min” ratio, but instead on the particular, highly
cohesive silica of Bouchara. (Ans. 36.) According to the Examiner, absent
evidence to the contrary, Bouchara’s silica would be expected to possess the
claimed range of d50 ratio. (See id.)
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We disagree with the Examiner’s understanding of Dr. Drexel’s
second affidavit. Rather than being evidence of what Bouchara specifically
teaches regarding the cohesive index of the silica taught, we understand the
second affidavit to demonstrate that one of ordinary skill would not have
been able to determine the ratio of d50 with and without 3 minutes of
ultrasound treatment from data about the ratio with and without 2 minutes of
ultrasound treatment. We understand from Dr. Drexel’s second affidavit
that without knowing the CI that results from a ratio with three minutes of
ultrasound treatment, the Examiner’s finding that the silica of Bouchara is
substantially identical to the claimed silica. The Examiner fails to direct us
to evidence that the difference between two and three minutes of ultrasound
treatment would be inconsequential for the silica used in Bouchara, when it
provided for a different ratio with Tixosil® 38X.
The Examiner also rejects Appellant’s arguments based on Dr.
Drexel’s affidavits because the results reported in Tables II and III of the
first affidavit provide d50 ratios of particular particle fractions after one
minute and three minutes. (See Ans. 37–39.) According to the Examiner, it
would have been obvious to optimize the particle size distribution of the
silica taught in Bouchara to obtain the specific values recited in Appellant’s
claims. (See Ans. 37–39.)
We do not find the Examiner to be responsive to the evidence
presented in Dr. Drexel’s first affidavit. Rather than demonstrating whether
or not it would have been obvious to obtain granular silica of the recited
particle size, the data reported by Dr. Drexel shows that one of ordinary skill
would not have been able to determine that the silica of Bouchara has a d50
ratio claimed from the characteristics taught in Bouchara. Dr. Drexel
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concludes: “as evidenced by the foregoing results in Table II and Table III, a
difference in the particle fraction size will yield an appreciable difference in
the resulting D50-Ratio of the granular silica – with larger particle fractions
yielding higher ratio values.” (First Drexel Affidavit 3.) We find that the
reported data shows that it is inappropriate to draw the conclusion that the
d50 ratios reported in Bouchara are substantially identical to the claimed d50
ratios.
In regard to obviousness due to the ability of an ordinarily skilled
artisan to achieve the claimed d50 ratio through routine optimization, the
Examiner notes that Bouchara teaches calcination of silica by heat treatment.
(See Ans. 34–35, citing Bouchara ¶¶ 77–79.) The Examiner relates this heat
treatment to the heat treatment taught in Appellant’s Specification to achieve
calcination and hardening of the silica. (See Ans. 34–35.) The Examiner
finds that these disclosures demonstrate that calcination of silica is a result
effective variable affecting the high-bond strength of silica and being subject
to routine optimization. (See Ans. 35.) According to the Examiner,
[s]ince Bouchara describes a preparation for a high bond
strength silica involving similar drying conditions, as well as
similar treatments identified in appellant’s specification for
enhancing hardness, namely exposure to water, exposure to
alkaline, and calcination, it reasonably follows that Bouchara’s
silica would have the same hardness as the silica of the instant
application for exhibiting the claimed “d50-0 min” to “d50 3 min”
ratio range.

(Ans. 35 (emphasis added).)
We are not persuaded by the Examiner’s reasoning because the
Examiner does not demonstrate that the effect of heat or calcination on
hardness, or more importantly on the d50 ratio, was known to be a result
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effective variable from the teachings of Bouchara or elsewhere in the prior
art. The Examiner’s reliance on Appellant’s Specification does not persuade
us that ordinarily skilled artisans would have considered it routine to
optimize calcination to achieve a specific d50 ratio as claimed. See In re
Applied Materials, Inc., 692 F.3d 1289, 1295 (Fed. Cir. 2012) (“The
question is whether the dimensions were known to be result-effective
variables.”).
We are not persuaded that Bouchara teaches or suggests granular
silica having the ranges of d50 without ultrasound exposure to d50 after 3
minutes of ultrasound exposure required in claim 1 or claim 33. The basis of
the Examiner’s rejection is obviousness over Bouchara in view of Cabelka,
with Cabelka cited for its teaching of particle sizes, not a d50 ratio with and
without ultrasound exposure. (See Final Act. 4–5, citing Cabelka ¶ 24.)
Because Cabelka does not cure the deficiency of the Examiner’s findings
regarding Bouchara, we are persuaded by Appellant’s arguments that the
Examiner has failed to show that the granular silica recited in independent
claim 1 or 33 would have been obvious over Bouchara and Cabelka.
Similarly, in the rejection of dependent claims 2 and 24, the Examiner
cites Deller for its teaching that the pH granular silica can be altered during
pyrogenic preparation. (See Final Act. 15–17, citing Deller 6:12–19.)
Because the Examiner does not cite Deller for a d50 ratio with and without
ultrasound exposure, we are persuaded by Appellant’s argument that the
Examiner has failed to show why claims 2 and 24 would have been obvious
over Bouchara, Cabelka, and Deller.
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Conclusion
Upon consideration of the record and for the reasons given, we
reverse the Examiner’s rejections.
In summary:
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1, 3, 23, 27–
36
103 Bouchara, Cabelka 1, 3, 23, 27–
36
2, 24 103 Bouchara, Cabelka,
Deller
2, 24
Overall
Outcome
1–3, 23, 24,
27–36

REVERSED