Ex Parte Berta et al

Patent Trial and Appeal Board

Sep 19, 2013

11235478 (P.T.A.B. Sep. 19, 2013)

UNITED STATES PATENT AND TRADEMARKOFFICE
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.
11/235,478 09/26/2005 Thomas Berta MI/252 4035
28596 7590 09/19/2013
W. L. GORE & ASSOCIATES, INC.
551 PAPER MILL ROAD
P. O. BOX 9206
NEWARK, DE 19714-9206
EXAMINER
ARCIERO, ADAM A
ART UNIT PAPER NUMBER
1727
MAIL DATE DELIVERY MODE
09/19/2013 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 THOMAS BERTA, WILLIAM SHAMROCK, and
WEN LIU
____________

Appeal 2012-006960
Application 11/235,478
Technology Center 1700
____________

Before CHARLES F. WARREN, TERRY J. OWENS, and
PETER J. KRATZ, Administrative Patent Judges.

KRATZ, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on an appeal under 35 U.S.C. § 134 from the
Examiner’s final rejection of claims 1-4, 30, and 37. We have jurisdiction
pursuant to 35 U.S.C. § 6.

Appeal 2012-006960
Application 11/235,478

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Appellants’ claimed invention is directed to a solid polymer
electrolyte membrane having first and second opposing surfaces, the
membrane including at least one expanded PTFE membrane with a porous
microstructure disposed within and impregnated by at least one ion
exchange material and a plurality of small carbon particles supporting a
platinum catalyst that are dispersed within the ion exchange material
between said expanded PTFE membrane and the first surface to form a
substantially occlusive, electronic insulating composite layer, which
membrane is disclosed as having a long life (Spec. 9, ll. 19-32 and 16, l. 32 -
17, l. 32).
Appellants’ disclosure provides that a Gurley value1 of greater than
10,000 s is indicative of a substantially occlusive material and that a
catalyst-containing composite layer having electronically insulating
properties is marked by impendence data (spectrums) associated with
ionically conductive membranes that are insulators, such as the impendence
spectra of Comparative Example 7 involving a non-catalytic ionically
conductive membrane that is an electrical insulator (Spec. 47- 48; Example
13). Claim 1, the only independent claim on appeal, is illustrative and
reproduced below:
1. A solid polymer electrolyte membrane having a first
surface and a second surface opposite said first surface, said
solid polymer electrolyte membrane having a failure force
greater than about 115 grams and comprising a composite
membrane consisting essentially of (a) at least one expanded
PTFE membrane having a porous microstructure of polymeric
fibrils, (b) at least one ion exchange material, wherein said

1 The Gurley air flow test can be conducted with a Gurley Densometer
Model 4110 (Gurley Precision Instruments, Troy, NY) (Spec. 42).
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Application 11/235,478

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porous microstructure of the expanded PTFE membrane is
disposed within and impregnated by said ion exchange material
so as to render an interior volume of the expanded PTFE
membrane substantially occlusive; and (c) a plurality of first
carbon particles supporting a catalyst comprising platinum
dispersed within said ion exchange material between said
expanded PTFE membrane and said first surface to form a
substantially occlusive, electronically insulating first composite
layer, wherein a plurality of said first carbon particles has a
particle size less than about 75 nm.

The Examiner relies on the following prior art references as evidence
in rejecting the appealed claims:
Kato US 6,054,230 Apr. 25, 2000
Shinn US 2003/0114297 A1 Jun. 19, 2003

The Examiner maintains the following ground of rejection2:
Claims 1-4, 30, and 37 stand rejected under 35 U.S.C. § 103(a) as
being unpatentable over Kato in view of Shinn.
We reverse the stated rejection. Our reasoning follows.
All of the appealed claims require a solid polymer electrolyte
membrane having first and second opposing surfaces, which solid polymer
electrolyte membrane includes ion exchange material, an expanded PTFE
membrane having a porous microstructure disposed within and impregnated
by the ion exchange material rendering the interior volume of the expanded
PTFE membrane substantially occlusive, and a plurality of carbon particles
of a specified size range, which particles support a platinum catalyst and are

2 Previously maintained rejections of the appealed claims under the first and
second paragraphs of 35 U.S.C. § 112 were withdrawn by the Examiner
(Ans. 4).
Appeal 2012-006960
Application 11/235,478

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dispersed within the ion exchange material between the expanded PTFE
membrane and the first surface to form a substantially occlusive,
electronically insulating first composite layer (see claim 1).
Kato discloses that catalyst material is introduced into an electrode
that is joined to a solid polymer ion exchange membrane (col. 4, ll. 16-22).
Kato discloses that the electrode and electrode support formation can be
tailored so as to include platinum –supported carbon particles in the
electrode/electrode support structure and provide for desired gas diffusivity
and electronic conduction properties of the electrode/electrode support (col.
5, ll. 14-43; col. 6, ll. 21-37; col. 7, l. 45 - col. 8, l. 5; Example 8).
Shinn discloses a membrane electrode assembly having a plurality of
protuberances that is said to have enhanced power density characteristics
(Abstract). Shinn coats a catalyst on a supporting body (electrode preferably
made with carbon paper) of the membrane electrode assembly (paras. 0058-
0063 and 0106-0116).
It is well settled that the burden of establishing a prima facie case of
non-patentability resides with the Examiner. See In re Piasecki, 745 F.2d
1468, 1472 (Fed. Cir. 1984). Here, the Examiner’s relies on a combination
of Kato and Shinn and the assertion that the electrode support layer structure
of Kato standing without the electrode carbon paper collector sheets is
inherently a non-conductive (electrically insulating) substantially occlusive
composite layer (Ans. 5-9). The Examiner bases this inherency position, at
least in part, on the assertion that the expanded PTFE electrode structure of
Kato is impregnated with ion exchange resin and carbon-supporting
platinum catalyst and is the same structure as claimed by Appellants and,
consequently, inherently has the same properties (Ans. 7-9). In so doing, the
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Application 11/235,478

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Examiner principally relies on Example 8 and disclosure found at column 7,
lines 29-44 of Kato (Ans. 8).
The Examiner maintains that the electrode support (outer layers) of
Kato can include an “expanded PTFE membrane impregnated with catalyst
materials and solid polymer ion exchange resin (col. 7, ll. 29-44)” and that
“[t]he electrode support layers of Kato, standing without the carbon paper
collector sheets, form non-conductive and occlusive composite layers which
stand between the PTFE membrane and a first surface (col. 7, lines 29-44
and col. 12-col. 13, Example 8)” (Ans. 5 and 8).
The Examiner further maintains that “such properties are inherent,
given that both Kato and Shinn et al. and the present application utilize the
same expanded PTFE impregnated with ion exchange material and carbon-
supporting catalyst” (Ans. 8).
In this latter regard, the Examiner relies on Shinn for allegedly
teaching that “a method for improving the efficiency of a catalyst is to use
supported Pt/C whereby platinum is coated on a surface of a minute carbon
particle of 2~5nm size (paragraphs 38-40)” and the Examiner seems to
maintain that the use of such a carbon particle size in Kato would have been
obvious to one of ordinary skill in the art (Ans. 6).
However and as argued by Appellants, the Examiner has not
established a reasonable basis founded in Kato for asserting that the
electrode/electrode support layer of Kato, as relied upon by the Examiner
and which is disclosed as providing for gas diffusion, would inherently
possess electrically insulating and substantially occlusive properties and/or
that the relied upon disclosures reasonably suggest that the
electrode/electrode support should be formed in a manner whereby such
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properties are sought for the electrode support or electrode of Kato (App. Br.
9 and 10; Reply Br. 2-5). For instance, Example 8 of Kato, which is relied
upon by the Examiner, provides for utilizing an impregnation composition
that includes 75 weight percent of carbon black supported platinum and 25
weight percent ion exchange resin and then applies the liquid impregnating
composition after carbon paper is attached to an expanded PTFE electrode
support film, which electrode structure is joined with a solid polymer
electrolyte membrane to from a composite structure (col. 12, l. 50 – col. 13,
l. 15).
The Examiner has not carried the burden to reasonably establish that
this electrode structure of Kato impregnated with a composition including
such a high concentration of platinum supported carbon black, before or
after joining to a solid polymer electrolyte membrane, corresponds to
Appellants’ disclosed and claimed solid polymer electrolyte membrane,
which solid polymer electrolyte membrane includes a substantially occlusive
and electrically insulating composite layer, as argued by Appellants (Reply
Br. 3-5; App. Br. 10; see, e.g.,Spec. Example 13, pp. 47-49). In this regard,
the electrode structure of Kato is disclosed as being gas permeable
(providing for gas diffusion) and, as an electrode, is electrically conductive
(col. 2, ll. 8-11, col. 5, ll. 35-43, col. 6, ll. 21-37, col. 7, l. 29 - col. 8, l. 5;
Example 8). Moreover, the Examiner has not established that Shinn cures
the aforementioned deficiencies in the teachings of Kato with respect to
teaching and/or suggesting the claimed solid polymer electrolyte membrane
including a substantially occlusive and electrically insulating composite
layer, as claimed.
On this record, we reverse the Examiner’s obviousness rejection.
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CONCLUSION/ORDER
The Examiner’s decision to reject the appealed claims is reversed.

REVERSED

kmm