Ex Parte Lu et al

Patent Trial and Appeal Board

Oct 21, 2013

11201713 (P.T.A.B. Oct. 21, 2013)

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.
11/201,713 08/11/2005 Jian Lu TH2224 (US) 6239
23632 7590 10/22/2013
SHELL OIL COMPANY
P O BOX 2463
HOUSTON, TX 77252-2463
EXAMINER
OH, TAYLOR V
ART UNIT PAPER NUMBER
1622
MAIL DATE DELIVERY MODE
10/22/2013 PAPER
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.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte JIAN LU,
DIEN HIEN DUONG, and
NGA THIHUYEN VI
__________

Appeal 2012-002969
Application 11/201,713
Technology Center 1600
__________

Before MELANIE L. McCOLLUM, JEFFREY N. FREDMAN, and
ULRIKE W. JENKS, Administrative Patent Judges.

FREDMAN, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal1 under 35 U.S.C. § 134 involving claims to a method
of preparing a shaped epoxidation catalyst. The Examiner rejected the
claims as obvious. We have jurisdiction under 35 U.S.C. § 6(b). We affirm.

1 Appellants identify the Real Party in Interest as Shell Oil Company (see
App. Br. 2).
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Statement of the Case
Background
The Specification teaches “it remains highly desirable to improve the
performance of olefin epoxidation catalysts, in respect of one or more of
their activity, selectivity[,] and stability” (Spec. 3, ll. 25-28). “The invention
relates to a method of preparing a shaped catalyst, and a shaped catalyst
which is obtainable by the method” (Spec. 1, ll. 17-19).
The Claims
Claims 1-22, 25, and 26 are on appeal. Appellants do not present
arguments for the separate patentability of claims other than representative
claim 1. Thus, all claims stand or fall with the corresponding representative
claim. 37 C.F.R. § 41.37(c)(l)(vii) (2011). Claim 1 reads as follows:
1. A method of preparing a shaped epoxidation catalyst,
which method comprises moulding a dough into shaped particles
and drying at least a portion of the shaped particles at a
temperature below 1000 °C, wherein the dough comprises a
support material, or a precursor thereof, a silver component, and
a further element or compound thereof which acts as a promoter
when the shaped catalyst is used as an epoxidation catalyst.

The issue
The Examiner rejected claims 1-22, 25, and 26 under 35 U.S.C. §
103(a) as obvious over Rubinstein2 and Notermann3 (Ans. 5-10).
The Examiner finds that “Rubinstein expressly teaches the preparation
of a paste comprising a uniform mixture of i) at least one alkaline earth
metal carbonate support, ii) a liquid medium, iii) a silver bonding additive;

2 Rubinstein et al., WO 2004/030813 A1, published Apr. 15, 2004.
3 Notermann et al., US 4,994,587, issued Feb. 19, 1991.
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and iv) at least one extrusion aid” (Ans. 8). The Examiner finds that
Notermann teaches “the silver catalytic system for epoxidation for alkenes
employing low sodium catalyst supports. The silver is coated or deposited
on a solid porous carrier by means of using a solubilizing agent solvent”
(id.).
The issue with respect to this rejection is: Does the evidence of
record support the Examiner’s conclusion that Rubinstein and Notermann
render claim 1 obvious?
Findings of Fact
1. Rubinstein teaches
a shaped silver bonded alkaline earth metal carbonate
catalyst support may be prepared by:
(a) preparing a paste comprising a uniform mixture of
(i) calcium carbonate;
(ii) at least one solvent;
(iii) a silver oxalate ethylenediamine complex;
and
(iv) at least one extrusion aid;
(b) forming a shaped particle from said paste; and
(c) drying and calcining said shaped particle.

(Rubinstein 5, ll. 10-14.)
2. Rubinstein teaches that the “support may be formed into shaped
particles, for example, chunks, pieces, and the like. Preferably, for use in a
tubular fixed bed reactor, they are formed into a rounded shape, for example
in the form of spheres, pellets, cylinders, rings, wagon wheels, or tablets”
(Rubinstein 4, ll. 28-31).
3. The Specification teaches that the “dough comprises a silver
component. . . . [T]he silver component may comprise a compound of
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cationic silver. . . . Suitable cationic silver compounds are, for example . . .
oxalates . . . or as an amine complex. . . . A preferred cationic silver
compound is a silver/1,2-ethylene diamine oxalate complex” (Spec. 9, ll. 1-
28).
4. Rubinstein teaches that the “silver bonding additive may
preferably be an aqueous silver oxalate amine solution having a
concentration of silver from 15% to 33% by weight . . . . The preferred
amine is ethylenediamine” (Rubinstein 4, ll. 3-6).
5. Rubinstein teaches that the “shaped support precursor is freed
of uncombined and loosely held water by an initial, moderate heating, for
example at a temperature in the range from 100 °C to 215 °C. Following
this drying procedure, the calcination may be carried out in a dry or humid
atmosphere at a temperature in the range from 200 °C to 950 °C”
(Rubinstein 5, ll. 1-4).
6. The Specification teaches that the
dough may comprise, as an additional component, a further
element or compound thereof which acts as a promoter when
the shaped catalyst is used as an epoxidation catalyst.
Eligible further elements may be selected from the group of .
. . Group IA metals . . . . Preferably the Group IA metals are
selected from lithium, potassium, rubidium and cesium.

(Spec. 10, ll. 1-11.)
7. Rubinstein teaches that “the support is impregnated with a
liquid composition of compounds of silver, potassium, sodium and/or
lithium and, if desirable with further compounds of, for example, one or
more of rubidium and/or, cesium” (Rubinstein 6, ll. 1-4).
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8. The Specification teaches that the “support material for use in
this invention may be natural or artificial inorganic particulate materials and
they may include . . . alkaline earth metal carbonates, for example calcium
carbonate” (Spec. 5, ll. 13-17).
9. Rubinstein teaches that:
silver-amine-oxalate stock solution was prepared by the
following procedure: 415 g of reagent-grade sodium
hydroxide were dissolved in 2340 ml de-ionized water and
the temperature was adjusted to 50 °C. 1699 g high purity
“Spectropure” silver nitrate was dissolved in 2100 m1 de-
ionized water and the temperature was adjusted to 50 °C.
The sodium hydroxide solution was added slowly to the
silver nitrate solution, with stirring, while maintaining a
solution temperature of 50 °C. . . .
630 g of high-purity oxalic acid dihydrate were added
in approximately 100 g increments. . . . The resulting
solution contained approximately 27-33 %w silver.
The above stock solution was used to prepare the
silver doped calcium carbonate supports.

(Rubinstein 10, ll. 10-30, Example 1A.)
10. Rubinstein teaches the preparation of the support itself,
teaching that the:
calcium carbonate supports . . . were prepared as follows:
100 parts by weight (pbw) calcium carbonate (CaCO3)
mixed with 2 pbw of an organic extrusion aid such as starch.
Sufficient water was added to make the mixture extrudable
(45 pbw silver solution) and the resulting composition was
mixed until homogeneous and extrudable. The resulting
paste was forced through a 3 mm die. The resulting
extrudate was dried overnight at 100 °C and then fired as
follows: 1 hour ramp to 110 °C held for 1 hour, then 4 hour
ramp to 240 °C and held for 1 hour and finally a 4 hour 10
ramp to 500 °C and held for 5 hours.
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(Rubinstein 11, ll. 3-10).
11. Rubinstein teaches that “the promoters may be impregnated in
one or more separate steps, prior to silver impregnation, after silver
impregnation or intermediate to separate silver impregnation steps”
(Rubinstein 6, ll. 15-17).
12. Notermann teaches that the “silver may be introduced to the
solvent or complexing/solubilizing agent as an oxide or a salt, such as nitrate
or carboxylate, for example, an acetate, propionate, butyrate, oxalate,
malonate, malate, maleate, lactate, citrate, phthalate, generally the silver
salts of higher fatty acids, and the like” (Notermann, col. 15, ll. 54-60).
13. The Specification teaches that “[c]atalysts prepared in
accordance with this invention can exhibit unexpectedly an improved
performance in olefin epoxidation relative to catalysts prepared from the
same materials, wherein however the silver component is deposited on an
already shaped support” (Spec. 4, ll. 19-23).
14. Table I of the Specification is reproduced below:

“The initial performance values for selectivity and temperature of each of
the catalysts are reported in Table I” (Spec. 27, ll. 26-28).
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Principles of Law
“The combination of familiar elements according to known methods
is likely to be obvious when it does no more than yield predictable results.”
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007). “If a person of
ordinary skill can implement a predictable variation, § 103 likely bars its
patentability.” Id. at 417.
Analysis
Rubinstein teaches a preparing “catalysts useful in olefin epoxidation
processes” (Rubinstein 3, l. 5) where “the “support may be formed into
shaped particles” (Rubinstein 4, ll. 28-31; FF 2) and where the “shaped
support precursor is freed of uncombined and loosely held water by an
initial, moderate heating, for example at a temperature in the range from 100
°C to 215 °C” (Rubinstein 5, ll. 1-3; FF 5). Rubinstein teaches an
epoxidation catalyst composed of identical components as those taught in
the instant Specification, including a support material, a silver component,
and a “promoter compound” as required by claim 1.
The Specification teaches that the “support material . . . may include .
. . alkaline earth metal carbonates, for example calcium carbonate” (Spec. 5,
ll. 13-17; FF 8). Rubinstein teaches an alkaline earth metal carbonate
catalyst support which includes calcium carbonate (FF 1).
The Specification teaches that the “dough comprises a silver
component. . . . [T]he silver component may comprise a compound of
cationic silver. . . . A preferred cationic silver compound is a silver/1,2-
ethylene diamine oxalate complex” (Spec. 9, ll. 1-28; FF 3). Rubinstein
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teaches incorporation of silver compounds into the dough, including “a
silver oxalate ethylenediamine complex” (Rubinstein 5, l. 12; FF 1, 4).
The Specification teaches regarding the promoter element that
“[e]ligible further elements may be selected from the group of . . . Group IA
metals . . . . Most preferably the Group IA metal is lithium, potassium
and/or cesium” (Spec. 10, ll. 1-13; FF 6). Rubinstein teaches that “the
support is impregnated with a liquid composition of compounds of silver,
potassium, sodium and/or lithium and, if desirable with further compounds
of, for example, one or more of rubidium and/or, cesium” (Rubinstein 6, ll.
1-4; FF 7).
Rubinstein’s method of preparing the epoxidation catalyst, while
clearly incorporating the silver into the dough (FF 4), does not clearly
indicate whether the promoter component is incorporated into the dough or
whether the promoter component is added after the dough has been extruded
(see FF 7).
However, Rubinstein’s examples demonstrate the inclusion of
sodium, a Group IA metal, into the silver-amine-oxalate stock solution, prior
to formation of the dough or paste, where Rubinstein teaches that:
silver-amine-oxalate stock solution was prepared by the
following procedure: 415 g of reagent-grade sodium
hydroxide were dissolved in 2340 ml de-ionized water and
the temperature was adjusted to 50 °C. 1699 g high purity
“Spectropure” silver nitrate was dissolved in 2100 m1 de-
ionized water and the temperature was adjusted to 50 °C.
The sodium hydroxide solution was added slowly to the
silver nitrate solution, with stirring, while maintaining a
solution temperature of 50 °C. . . .
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630 g of high-purity oxalic acid dihydrate were added
in approximately 100 g increments. . . . The resulting
solution contained approximately 27-33 %w silver.
The above stock solution was used to prepare the
silver doped calcium carbonate supports.

(Rubinstein 10, ll. 10-30, Example 1A, FF 9.) Rubinstein then teaches the
preparation of the support itself, teaching that the:
calcium carbonate supports . . . were prepared as follows:
100 parts by weight (pbw) calcium carbonate (CaCO3)
mixed with 2 pbw of an organic extrusion aid such as starch.
Sufficient water was added to make the mixture extrudable
(45 pbw silver solution) and the resulting composition was
mixed until homogeneous and extrudable. The resulting
paste was forced through a 3 mm die. The resulting
extrudate was dried overnight at 100 °C and then fired as
follows: 1 hour ramp to 110°C held for 1 hour, then 4 hour
ramp to 240 °C and held for 1 hour and finally a 4 hour
ramp to 500°C and held for 5 hours.

(Rubinstein 11, ll. 3-10; Examples 1B-16, FF 10.)
Thus, Rubinstein, in Examples 1A and 1B-16, prepares an epoxidation
catalyst formed from a dough which comprises calcium carbonate, a support
material (FF 1, 8, 10), a silver component, (FF 9-10), and sodium, a Group
IA metal (FF 9-10). Rubinstein teaches that the resultant support was forced
through a die and dried at temperatures less than 100 °C (FF 10). The
process shown in Examples 1A and 1B-16 reasonably appears to satisfy each
of the requirements of claim 1. Rubinstein’s examples 1A and 1B-16
therefore render obvious the method of claim 1.
Moreover, Rubinstein suggests that “the promoters may be
impregnated in one or more separate steps, prior to silver impregnation, after
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silver impregnation or intermediate to separate silver impregnation steps”
(Rubinstein 6, ll. 15-17; FF 11). This is reasonably interpreted as a
suggestion to incorporate the promoter into the dough, since Rubinstein
exemplifes a method where the silver may be incorporated into the dough
itself (FF 1, 9, 10).
Appellants contend that the “method of impregnating a catalyst carrier
with a silver solution is significantly different than a method in which the
silver is mixed in the dough before it is formed into shaped particles and
dried. There is nothing in the Rubinstein reference that teaches or suggests
the claimed method” (App. Br. 3). Appellants contend that “[m]ixing the
silver component and the promoter component with the support material to
form a dough is a different process than forming a support and impregnating
it with a silver component and a promoter component” (id. at 4).
We are not persuaded. Rubinstein teaches and exemplifies methods
where the silver is mixed in the dough before it is formed into shaped
particles (FF 1, 9, 10) as discussed above. Further, Rubinstein teaches a
method in which a promoter, sodium, a Group IA metal, is incorporated into
the dough before it is formed into shaped particles (FF 9, 10).
Finally, while impregnating may be different than incorporating the
promoter into the dough, Rubinstein is reasonably interpreted as suggesting
to the ordinary artisan that the promoters may be incorporated into the
catalyst at a variety of different steps, which would have rendered
incorporation into the dough obvious in light of Rubinstein’s express
teaching that “the promoters may be impregnated in one or more separate
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steps, prior to silver impregnation, after silver impregnation or intermediate
to separate silver impregnation steps” (Rubinstein 6, ll. 15-17; FF 11).
Appellants contend that “the present invention can exhibit
unexpectedly an improved performance in olefin epoxidation relative to
catalysts prepared from the same materials, wherein the silver component is
deposited on an already shaped support” (App. Br. 4).
We are not persuaded. As an initial matter, Appellants did not
compare their claimed method to the closest prior art, which would be
Examples 1A and 1B-16 of Rubinstein, where sodium was present as a
promoter and both silver and sodium were incorporated into the dough (FF
9-10), but rather compared a dough with the silver and promoters
incorporated therein with shaped particles which were soaked in a silver and
promoter solution (see Spec. 24, ll. 19-30). See In re Baxter Travenol Labs.,
952 F.2d 388, 392 (Fed. Cir. 1991) (“[W]hen unexpected results are used as
evidence of nonobviousness, the results must be shown to be unexpected
compared with the closest prior art.”).
In addition, claim 1 is broadly drawn to the use of any silver solution,
while the asserted results are limited to the use of silver-1,2-ethylene
diamine-oxalate with silver oxide. See In re Tiffin, 448 F.2d 791, 792
(CCPA 1971) (“objective evidence of non-obviousness must be
commensurate in scope with the claims which the evidence is offered to
support”).
Lastly, as we review the results, themselves, we agree with the
Examiner that the differences shown are minimal (see Ans. 14). Control
Example B actually shows a higher selectivity than inventive Examples C
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and D, and a very similar initial activity temperature to inventive Example D
(FF 14). Even the selectivity after 0.5 kTon/m3 of control Example B at 86.6
differs from inventive example 87.3 by less than 1%. There is no
explanation why results with such minimal differences from the control
examples are unexpected, since the ordinary artisan would have reasonably
expected some differences to occur using any compositions prepared by
slightly different processes, when testing was performed. See In re Klosak,
455 F.2d 1077, 1080 (CCPA 1972) (“it is not enough to show that results are
obtained which differ from those obtained in the prior art: that difference
must be shown to be an unexpected difference”). Appellants have not made
this showing, since there is no explanation why the small differences
between control Example B and Examples A and C-F would have been
unexpected differences.
Conclusion of Law
The evidence of record supports the Examiner’s conclusion that
Rubinstein and Notermann render claim 1 obvious.
SUMMARY
In summary, we affirm the rejection of claim 1 under 35 U.S.C. §
103(a) as obvious over Rubinstein and Notermann. Pursuant to 37 C.F.R. §
41.37(c)(1), we also affirm the rejection of claims 2-22, 25, and 26, as these
claims were not argued separately.

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

AFFIRMED

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