Ex Parte Vyas et al

Board of Patent Appeals and Interferences

Jul 21, 2011

11089525 (B.P.A.I. Jul. 21, 2011)

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.
11/089,525 03/24/2005 Gayatri Vyas GP-306114 1172
65798 7590 07/22/2011
MILLER IP GROUP, PLC
GENERAL MOTORS CORPORATION
42690 WOODWARD AVENUE
SUITE 200
BLOOMFIELD HILLS, MI 48304
EXAMINER
SCULLY, STEVEN M
ART UNIT PAPER NUMBER
1727
MAIL DATE DELIVERY MODE
07/22/2011 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 GAYATRI VYAS,
Richard H. Blunk, Thomas A. Trabold, Reena L. Datta, and
Keith E. Newman
________________

Appeal 2010-003749
Application 11/089,525
Technology Center 1700
________________

Before BEVERLY A. FRANKLIN, MARK NAGUMO, and
KAREN M. HASTINGS, Administrative Patent Judges.

NAGUMO, Administrative Patent Judge.

DECISION ON APPEAL1

1 See related Appeal 2009-014718 in application 11/089,526, also decided
on this day.
Appeal 2010-003749
Application 11/089,525

2
A. Introduction2
Gayatri Vyas, Richard H. Blunk, Thomas A. Trabold, Reena L. Datta,
and Keith E. Newman (“Vyas”) timely appeal under 35 U.S.C. § 134(a)
from the final rejection3 of claims 1-7 and 9-20.4 We have jurisdiction.
35 U.S.C. § 6. We AFFIRM.
The subject matter on appeal relates to fuel cells in which the
hydrogen fluoride (“HF”) generated from the perfluorosulfonic acid
membrane commonly used in proton exchange membrane fuel cells etches a
hydrophilic metal oxide layer deposited on the surface of the flow field
(“bipolar”) plates. The flow field plates separate the cathodic (hydrogen
gas) side of the fuel cell from the anodic (oxygen gas) side of the adjacent
fuel cell in a stack of fuel cells. (Spec. 1-2, [004]-[006].) The hydrophilic
metal oxide layer helps prevent blockage of the gas channels in the plate by
water produced by the reactions in the cell that would otherwise bead up on
the hydrophobic metal oxides of typical metal flow field plates.
(Id. at 2 [0007], 3 [0009].) The thickness of the hydrophilic metal oxide
layer is selected such that the etch rate continuously exposes a clean metal

2 Application 11/089,525, Durable Hydrophilic Coatings for Fuel Cell
Bipolar Plates, filed 24 March 2005. The specification is referred to as the
“525 Specification,” and is cited as “Spec.” The real party in interest is
listed as General Motors Corp. (Appeal Brief, filed 17 June 2009
(“Br.”), 1.)
3 Office action mailed 23 January 2009 (“Final Rejection”; cited as “FR”).
4 The Examiner has objected to claim 8 (FR 1), the only other claim, which
is not before us.
Appeal 2010-003749
Application 11/089,525

3
oxide surface, and also so that the hydrophilic metal oxide layer is not
etched away prior to a predetermined lifetime of the cell.5
The cleansing effect of the hydrogen fluoride is said to remove
contaminants that would otherwise collect on and significantly reduce the
hydrophilicity of the metal oxide layers. Fuel cells that do not use a
perfluorosulfonic acid membrane can be provided with a separate hydrogen
fluoride source that injects a dilute HF solution into one or both of the
hydrogen or oxygen gas streams. (Spec. 5 [0013]-[0014].)
Representative Claim 1 reads:
1. A fuel cell comprising a flow field plate being made of a
plate material,
said flow field plate including
a plurality of flow channels responsive to a
reactant gas,
said flow field plate further including
an outer layer that makes the flow field plate
hydrophilic,
wherein the material of the outer layer and the
thickness of the outer layer are selected so that
hydrofluoric acid within the fuel cell etches away
an outer surface of the layer at a rate so that a clean
surface of the outer layer is continuously exposed,
but
the outer layer is not completely etched away over
a predetermined lifetime of the fuel cell.
(Claims App., Br. 10; indentation and paragraphing added.)

5 The structure of the fuel cells and the flow field plates, and additional
benefits of the hydrophilic character of the selected metal oxides are
discussed in related appeal 2009-014718.
Appeal 2010-003749
Application 11/089,525

4
The Examiner has maintained the following grounds of rejection:6
A. Claims 1-7 and 9-20 stand rejected under 35 U.S.C. § 102(b),
alternatively under 103(a) in view of Ohara.7
B. Claims 1-5 and 11-14 stand rejected under obviousness-type
double patenting in view of Vyas 526, claims 1-3.8
C. Claims 1-5 and 11-14 stand rejected under obviousness-type
double patenting in view of Vyas 489, claims 1-2.9
B. Discussion
Findings of fact throughout this Opinion are supported by a
preponderance of the evidence of record.
Ohara
Vyas argues that Ohara does not anticipate or render the claimed
subject matter obvious. In Vyas’s view, Ohara does not teach or suggest
selecting the material of the outer layer and the thickness of the outer layer
so the outer layer is etched at a rate suitable to continuously expose a clean
surface of the outer layer and such that the outer layer is not completely
removed before the end of the useful life of the fuel cell. (Br. 5, 6.) In
particular, Vyas argues that, in paragraph [0173], Ohara states that the metal

6 Examiner’s Answer mailed 17 September 2009 (“Ans.”).
7 Hideo Ohara et al., Polymer Electrolyte Fuel Cell, United States Patent
Application Publication 2003/0003345 A1 (2003)
8 Gayatri Vyas et al., 11/089,526, filed 24 March 2005; Examiner affirmed
in appeal 2009-014718, decided on this day.
9 Gayatri Vyas et al., 11/068,489, filed 25 February 2005; Examiner
reversed in appeal 2010-004061 (9 May 2011); notice of allowance
mailed 1 June 2011.
Appeal 2010-003749
Application 11/089,525

5
oxide films (0.5 to 0.05 μm [500 nm to 50 nm] thick) formed on the gas flow
channels were cleaned, “while recovering the defect and reproducing the
metal oxide film on the surface of the gas flow channels.” (Br. 5, 1st full
para, quoting Ohara [0173]; cf. 6, 1st full para.) Vyas concludes that
because Ohara does not teach or suggest the relation between the thickness
of the layer and the etching rate by hydrofluoric acid, neither the anticipation
nor the obviousness rejections are proper.
Vyas does not argue for the separate patentability of any claims.
Accordingly, all claims stand or fall with claim 1.
The Examiner found, and Vyas does not dispute, that Ohara describes
fuel cell stacks based on a NAFION® [a sulfonated tetrafluoroethylene
copolymer sold by DuPont] polymer electrolyte membrane, with metal
conductive separator plates made from stainless steel (aluminum or titanium
are also said to be useful) and coated with metal oxides including the
hydrophilic species Al2O3 and Nb2O5, from 50 to 500 nm thick. (FR. 3;
Ans. 3.) The Examiner finds further that Ohara describes a continuous
driving test of 8000 hours, after which the oxide layer was not etched away.
(FR 3, and Ans. 4, both citing Ohara 13 [0168].) The Examiner argues that
the Nafion® membrane will release hydrofluoric acid under the fuel cell
operating conditions, that the hydrofluoric acid will etch the metal oxide
layer, and that the thickness dictates, in part, the lifetime of the cell.
(FR 4, 5; Ans. 4, 5) The Examiner argues further that a recitation of the
manner of operation of an apparatus does not distinguish a claimed
apparatus from a prior art apparatus that satisfies all the recited structural
limitations, and concludes that the fuel cells described by Ohara anticipate
Appeal 2010-003749
Application 11/089,525

6
the claimed fuel cells. (FR 3; Ans. 3) In the alternative, the Examiner
argues that Ohara teaches that the thickness of the metal oxide layer is a
result effective variable with respect to the variation in the fuel cell output,
so selection of the thickness in a given range would have been obvious.
(FR 3, 4; Ans 3-4, 5.)
As the predecessor to our reviewing court observed forty years ago,
“‘[f]unctional’ terminology may render a claim quite broad. By its own
literal terms a claim employing such language covers any and all
embodiments which perform the recited function.” In re Swinehart, 439
F.2d 210, 213 (CCPA 1971). Moreover, it is settled law that when the PTO
identifies prior art that is the same or substantially the same as claimed
subject matter, the burden shifts to the applicant to come forward with
evidence and argument showing that the prior art products do not necessarily
or inherently possess the characteristics of the claimed product. In re Best,
562 F.2d 1252, 1254-55 (CCPA 1977).
In the present appeal, the undisputed overlap in the range of preferred
metal oxide thicknesses taught by Ohara and the undisputed similarity of the
fuel cells in other material respects provide a strong expectation that the
operating properties of the fuel cells will be similar. Vyas has failed to come
forward with credible evidence or argument showing that the fuel cells
taught or suggested by Ohara are patentably distinct from the fuel cells for
which Vyas is seeking exclusionary protection. In particular, Vyas has
failed to demonstrate that the recited etching does not occur in the Ohara
fuel cells, or that the outer layer is completely etched away prior to “a
predetermined lifetime of the fuel cell,” as required by claim 1.
Appeal 2010-003749
Application 11/089,525

7
In this regard, the Examiner’s observations regarding the failure of the
method of operating a device to distinguish a claim to the underlying device
are well taken. See In re Casey, 370 F.2d 576, 580 (CCPA 1967) (“The
manner or method in which such machine is to be utilized is not germane to
the issue of patentability of the machine itself.”) Elementary chemical and
physical considerations indicate that the lifetime of a fuel cell depends in
large measure on the conditions under which it is operated. Example 10 of
Ohara, described in paragraphs [0171] through [0173], on which Vyas bases
the arguments against the prior art rejections, provides strong evidence that
operating conditions affect the output, and by reasonable inference, the
lifetime, of the exemplified fuel cells. Table 9 lists the output of various fuel
cells, two of which have oxides preferred by Vyas (Al2O3 and Ta2O5),
operated under continuous driving method A, and under driving method B,
in which oxidant gas was provided to both the fuel gas flow channel and the
oxidant gas flow channel at every 2000 hours. Table 9 shows that the
decrease in output power of the fuel cell was less for method B in every
case. It is reasonable to conclude that the useful lifetime of the fuel cells is
longer when operated under method B. Thus, the evidence of record
illustrates the breadth of the claims.
Particularly in light of the breadth of the claims, we are not persuaded
by Vyas’s arguments that the Examiner erred harmfully in holding the
claimed fuel cells obvious in view of those described and suggested by
Ohara.
Appeal 2010-003749
Application 11/089,525

8
Provisional obviousness-type double patenting rejections
Vyas raises essentially the same argument against the rejections in
view of claims in the copending applications, namely that those claims “do
not claim the relationship between selecting the material of the outer layer
and the thickness of the outer layer in relationship to the etch rate of [the]
hydrofluoric acid and the lifetime of the fuel cell.” (Br. 7, 8; cf. Reply 3, last
para.) As discussed in our consideration of the prior art rejection, whether
the prior art recognizes a now-recited or newly discovered property of an old
apparatus is not relevant to patentability. We conclude that Vyas’s
arguments fail to demonstrate harmful error in the Examiners’ provisional
obviousness-type double patenting rejections.
C. Order
We AFFIRM the rejection of claims 1-7 and 9-20 under
35 U.S.C. § 102(b), alternatively under § 103(a) in view of Ohara.
We AFFIRM the rejection of claims 1-5 and 11-14 under
obviousness-type double patenting in view of Vyas 526, claims 1-3.
We AFFIRM the rejection of claims 1-5 and 11-14 under
obviousness-type double patenting in view of Vyas 489, claims 1-2.
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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