Ex Parte Du Cauze De Nazelle

Board of Patent Appeals and Interferences

Jan 22, 2010

11049839 (B.P.A.I. Jan. 22, 2010)

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.
11/049,839 02/03/2005 Gerard Du Cauze De Nazelle TS1441 (US) 3070
7590 01/22/2010
Jennifer D. Adamson
Shell Oil Company
Legal - Intellectual Property
P.O. Box 2463
Houston, TX 77252-2463
EXAMINER
DENTZ, BERNARD I
ART UNIT PAPER NUMBER
1625
MAIL DATE DELIVERY MODE
01/22/2010 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 BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte GERARD DU CAUZE DE NAZELLE
__________

Appeal 2009-009468
Application 11/049,839
Technology Center 1600
__________

Decided: January 22, 2010
__________

Before DEMETRA J. MILLS, ERIC GRIMES, and LORA M. GREEN,
Administrative Patent Judges.

GRIMES, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to a process
for making alkylene oxide. The Examiner has rejected the claims as
obvious. We have jurisdiction under 35 U.S.C. § 6(b). We affirm.
STATEMENT OF THE CASE
The Specification discloses that “[p]rocesses for preparing propylene
oxide employing organic hydroperoxides are known in the art” (Spec. 1).
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The Specification also discloses that
the temperature of the mixture of hydroperoxide and alkene is
usually increased before use in the epoxidation process. This
ensures best use of the catalyst employed. However, it was
found that the heat exchanger used for increasing the
temperature of the mixture, fouled quickly when contacted with
the mixture of hydroperoxide and alkene.
(Id.) The Specification discloses increasing the temperature of the reaction
mixture to be contacted with the epoxidation catalyst by “increasing the
temperature of the alkene only” (id. at 2).
Claims 1-12 are on appeal. The claims have not been argued
separately and therefore stand or fall together. 37 C.F.R. § 41.37(c)(1)(vii).
Claim 1 is representative and reads as follows:
1. A process for the preparation of alkylene oxide which process
comprises:
(a) oxidizing an organic compound to obtain a hydroperoxide
containing stream;
(b) washing the hydroperoxide stream with a basic aqueous solution;
(c) washing the hydroperoxide stream of step (b) with water;
(d) optionally subjecting the hydroperoxide stream obtained in step (c)
to distillation;
(e) contacting at least part of the hydroperoxide stream obtained in
step (c) and/or (d) with an alkene and a heterogeneous catalyst to obtain a
reaction mixture containing a hydroxyl containing compound and alkylene
oxide; and,
(f) separating at least part of the alkylene oxide from the reaction
mixture,
in which process the alkene added in step (e) has a temperature of
from 60°C to 120°C and the temperature of the hydroperoxide stream
contacted with the alkene is similar to the temperature of the hydroperoxide
stream obtained in step (c) and/or (d).
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OBVIOUSNESS
Issue
The Examiner has rejected claims 1-12 under 35 U.S.C. §103(a) as
being obvious in view of Lin,1 Oku,2 and Wulff.3
The Examiner finds that Lin “discloses all of the instant process steps
except for the limitations on the temperature of the alkene stream and the
hydroperoxide stream in step (e)” (Ans. 3). The Examiner reasons that one
ordinary skill in the art “would know not to substantially increase the
temperature of said hydroperoxide stream” (id. at 4) because Lin discloses
that “the hydroperoxide containing reaction mixture is at a temperature of 90
to 160 degrees C when it is removed from the reactor and that there is a
tendency for substantial decomposition of the hydroperoxide as a function of
time at this temperature range” (id. at 4-5), and Oku discloses that
“decomposition [of hydroperoxide] is directly proportional to the
temperature and the concentration of hydroperoxide” (id. at 5). The
Examiner also finds that Wulff discloses an embodiment in which the
hydroperoxide is added in increments “to a mixture of the alkene reactant,
the catalyst and the solvent maintained at reaction temperatures …
preferably from 50 degrees C. to 150 degrees C” (id. at 7-8).
Appellant contends that the Examiner erred in finding that the cited
references “teach or suggest that the temperature of the hydroperoxide
stream contacted with the alkene is similar to the temperature of the

1 Lin et al., US 5,883,268, Mar. 16, 1999
2 Oku et al., EP 1266895A1, Dec. 18, 2002
3 Wulff et al., US 4,367,342, Jan. 4, 1983
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hydroperoxide stream obtained in a washing or optional distillation step”
(Appeal Br. 4).
The issue presented is: Does the evidence of record support the
Examiner’s conclusion that the references suggest a method of making an
alkylene oxide in which the hydroperoxide stream is not heated between the
washing step and the step of being contacted with an alkene and a
heterogeneous catalyst?
Findings of Fact
1. Lin discloses a process in which, for example, a stream comprising
ethylbenzene and ethylbenzene hydroperoxide “can be used to great
advantage in the catalytic epoxidation of propylene to form propylene oxide
using a solid heterogeneous titanium containing catalyst” (Lin, col. 4, ll. 6-
10).
2. Lin discloses the following sequence of reaction steps:
[A] peroxidation reaction product mixture … is contacted with
aqueous base … and the resulting mixture is phase separated
into separate aqueous and organic phases. The organic phase,
which contains some base, is water washed to separate the basic
materials and the resulting organic phase is stripped of water
and can then advantageously be used in the solid catalyzed
epoxidation of an olefin.
(Id. at col. 1, ll. 40-57.)
3. Appellant’s Specification discloses that the “washing of step (b)
comprises both contacting with the basic aqueous solution and separating
into a hydrocarbonaceous phase and an aqueous phase” (Spec. 4: 14-16).
4. Lin discloses that the temperature of the peroxidation reaction
(which is the reaction that produces the hydroperoxide-containing mixture)
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is generally about 90° to 160° C, at which “temperature there is a tendency
for substantial decomposition of the hydroperoxide as a function of time”
(id. at col. 2, ll. 16-21).
5. Lin discloses that the hydroperoxide-containing product of the
peroxidation reaction is preferably “rapidly cooled from the peroxidation
reaction temperature to a temperature which is at least 20°C. lower than the
peroxidation reaction temperature, and preferably to below 100°C.” (id. at
col. 1, ll. 45-48) before being contacted with an aqueous base and
subsequently water-washed.
6. Oku discloses a process for producing propylene oxide that
comprises an epoxidation step “in which isopropylbenzene hydroperoxide
… is reacted with propylene to obtain propylene oxide” (Oku, abstract).
7. Oku discloses that the isopropylbenzene hydroperoxide supplied in
the epoxidation step should not be subjected to temperatures higher than the
“temperature (t °C) represented by the following equation (1),
t(°C)=150 - 0.8 x W
W: content (% by weight) of isopropylbenzene hydroperoxide
in a solution containing isopropylbenzene hydroperoxide.”
(Id. at col. 1, l. 56 – col. 2, l. 6.)
8. Oku discloses that if the isopropylbenzene hydroperoxide
temperature exceeds the temperature represented by equation (1), a
substance that poisons the epoxidation catalyst is formed and the
isopropylbenzene hydroperoxide undergoes heat decomposition (id. at col. 4,
ll. 24-31).
9. Oku provides examples showing that heating an isopropylbenzene
hydroperoxide solution to a temperature above that indicated by equation
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(1) resulted in roughly ten-fold greater decomposition of the compound
(Oku, col. 5, ll. 15-51).
10. Wulff discloses the “epoxidation of alkenes with hydrocarbon
hydroperoxides … with a catalyst composition of an inorganic oxygen
compound of silicon and an oxide or hydroxide of titanium in chemical
combination” (Wulff, col. 2, ll. 9-13).
11. Wulff discloses that, in one embodiment, “one reactant is added
to the remaining reaction mixture components in increments, as by adding
the hydroperoxide to a mixture of the alkene reactant, the catalyst and the
solvent maintained at reaction temperatures” (id. at col. 6, ll. 32-36).
12. Wulff discloses that “the epoxidation process is conducted at
moderate temperatures and pressures. Suitable reaction temperatures vary
from about 25°C. to about 200°C., but preferably from 50°C. to 150°C.”
(Id. at col. 6, ll. 41-45).
Principles of Law
“[W]hen the question is whether a patent claiming the combination of
elements of prior art is obvious,” the answer depends on “whether the
improvement is more than the predictable use of prior art elements according
to their established functions.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398,
417 (2007).
Analysis
Claim 1 is directed to a process for the preparation of alkylene oxide
in which a hydroperoxide-containing stream is washed with a basic aqueous
solution and then with water, and the washed hydroperoxide stream is
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contacted with an alkene and a heterogeneous catalyst. Claim 1 also
requires that the alkene has a temperature of from 60°C to 120°C and that
the temperature of the hydroperoxide stream contacted with the alkene is
similar to the temperature of the hydroperoxide stream in the water-washing
step.
Lin discloses a method of making an alkylene oxide (e.g., propylene
oxide) that comprises each of the steps required by claim 1. Lin also
discloses that hydroperoxides decompose at the peroxidation temperature
and should be rapidly cooled from the peroxidation reaction temperature, to
a temperature preferably below 100°C. Oku discloses that isopropylbenzene
hydroperoxide shows heat instability and should not be heated above a
certain temperature (that depends on its concentration) prior to use in an
epoxidation reaction. Wulff discloses an epoxidation reaction in which the
hydroperoxide reactant is added in increments to a mixture of the alkene
reactant, the catalyst and the solvent maintained at reaction temperature.
In view of these disclosures, it would have been obvious to one of
skill in the art to modify the Lin epoxidation reaction so that the
hydroperoxide is not heated between the washing and epoxidation steps, but
is added to a heated reaction mixture, because Lin and Oku disclose the heat
instability of hydroperoxides and Wulff discloses adding hydroperoxide to a
heated reaction mixture.
Appellant contends that the cited references do not “teach or suggest
that the temperature of the hydroperoxide stream contacted with the alkene
is similar to the temperature of the hydroperoxide stream obtained in a
washing or optional distillation step” (Appeal Br. 4). Appellant contends
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that the Examiner’s reliance of Wulff is misplaced because Wulff does not
“mention the temperature of the hydroperoxide stream or discuss the
problems associated with heating the hydroperoxide stream” (Id.).
This argument is not persuasive. Wulff discloses that the
hydroperoxide is added stepwise to a heated mixture of the alkene, solvent,
and catalyst. Lin and Oku both disclose that hydroperoxides decompose at
high temperatures, and disclose limiting their exposure to high temperatures
for best results in an epoxidation reaction. Thus, the combination of the
references would have suggested to a person of ordinary skill in the art that a
hydroperoxide that has not been heated may be added, after water-washing,
in incremental amounts, to an epoxidation reaction.
Conclusion of Law
The evidence of record supports the Examiner’s conclusion that the
cited references suggest a method of making an alkylene oxide in which the
hydroperoxide stream is not heated between the washing step and the step of
being contacted with an alkene and a heterogeneous catalyst.
SUMMARY
We affirm the rejection of claims 1-12 under 35 U.S.C. §103(a) as
being obvious in view of Lin, Oku and Wulff.
TIME PERIOD FOR RESPONSE
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
Appeal 2009-009468
Application 11/049,839

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lp

JENNIFER D. ADAMSON
SHELL OIL COMPANY
LEGAL - INTELLECTUAL PROPERTY
P.O. BOX 2463
HOUSTON TX 77252-2463