Ex Parte Ohata et al

Board of Patent Appeals and Interferences

May 7, 2012

10769866 (B.P.A.I. May. 7, 2012)

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.
10/769,866 02/03/2004 Tsumoru Ohata 43888-293 9230
7590 05/07/2012
MCDERMOTT, WILL & EMERY
600 13th Street, N.W.
WASHINGTON, DC 20005-3096
EXAMINER
LAIOS, MARIA J
ART UNIT PAPER NUMBER
1727
MAIL DATE DELIVERY MODE
05/07/2012 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 TSUMORU OHATA
and Masao Fukunaga
________________

Appeal 2010-008438
Application 10/769,866
Technology Center 1700
________________

Before ADRIENE LEPIANE HANLON, PETER F. KRATZ, and
MARK NAGUMO, Administrative Patent Judges.

NAGUMO, Administrative Patent Judge.

DECISION ON APPEAL
Appeal 2010-008438
Application 10/769,866

2
A. Introduction1
Tsumoru Ohata and Masao Fukunaga (“Ohata”) timely appeal under
35 U.S.C. § 134(a) from the final rejection2 of claims 1-8, which are all of
the pending claims. We have jurisdiction. 35 U.S.C. § 6. We AFFIRM.
The subject matter on appeal relates to a process of producing a
battery electrode wherein the electrode active material comprises carbon
nanotubes dispersed in a resin. During blending into a resin, the carbon
nanotubes, which are said to be initially tangled and twisted with one
another, become unraveled and straightened. (Spec., para. bridging 5-6.)
The 866 Specification teaches that “[t]he unraveled and straightened carbon
nanotubes . . . are expected to form an excellent conductive path in an
electrode,” even at low concentrations of nanotubes. (Id. at 6. ll. 2-4.) The
Specification also teaches that although the carbon nanotubes are not
damaged by shearing forces during mixing (id. at 5, 4th full para.), it is
nonetheless difficult to disperse carbon nanotubes into resins. (Id. at 7, 2d
full para.) Thus, the critical step in the claimed electrode manufacturing
process is said to be the production of masterbatch pellets that consist
essentially of carbon nanotubes dispersed in a resin.
The claimed process then proceeds by blending the masterbatch
pellets with an electrode active material and a dispersion medium to form a

1 Application 10/769,866, Electrode for a Battery and Production Method
Thereof, filed 3 February 2004, claiming the benefit of an application filed
in Japan on 19 February 2003. The specification is referred to as the
“866 Specification,” and is cited as “Spec.” The real party in interest is
listed as Panasonic Corp. (Appeal Brief, filed 17 April 2009 (“Br.”), 2.)
2 Office action mailed 2 December 2008 (“Final Rejection”; cited as “FR”).
Appeal 2010-008438
Application 10/769,866

3
paste; spreading the paste onto an electrode substrate; drying and rolling the
coated substrate to form an electrode plate; and cutting the electrode plate to
the desired shape.
Typical materials for a positive electrode are said to include various
lithium-transition metal oxides (Spec. 9, 1st full para.), while the substrate is
desirably aluminum or an aluminum alloy (id. at 3, last full para.) Typical
materials for a negative electrode are said to include graphite as the
electrode active material (id. at 9, 2d full para.), and copper, nickel, iron, or
an alloy of these metals as the substrate (id. at para. bridging 3-4). The
binder resin for both the positive and negative electrodes is preferably
polyvinylidene fluoride [“PVDF”] (id. at para. bridging 7-8), with N-methyl-
2-pyrrolidone as a dispersion medium (id. at 8, 2d full para.).
Representative Claim 1 reads:
1. A method for producing an electrode for a battery
comprising the steps of:
(a) producing masterbatch pellets consisting essentially
of carbon nanotubes and a resin;
(b) blending an electrode material mixture containing at
least said masterbatch pellets and an electrode active
material with a dispersion medium to prepare an
electrode material mixture paste;
(c) applying said electrode material mixture paste onto an
electrode substrate and then drying and rolling said
electrode material mixture paste coated on said electrode
substrate to obtain an electrode plate; and
(d) cutting said electrode plate to obtain an electrode with
a predetermined shape.
(Claims App., Br. 11; indentation and emphasis added.)
Appeal 2010-008438
Application 10/769,866

4
The Examiner maintains the following ground of rejection:3
Claims 1-8 stand rejected under 35 U.S.C. § 103(a) in view of the
combined teachings of Iwamoto4 and Niu.5
B. Discussion
Findings of fact throughout this Opinion are supported by a
preponderance of the evidence of record.
Initially, we observe that Ohata does not present arguments for the
separate patentability of any claims other than claims 1 and 4. Claims 2, 3
and 5-8 therefore stand or fall with claim 1. 37 C.F.R. § 41.37(c)(1)(vii)
(2007).
Claim 1
The Examiner finds—and Ohata does not dispute—that Iwamoto
describes a processes of making a negative electrode by blending an
electrode active material, a conducting agent, a binder [PVDF], and
dehydrated N-methylpyrrolidinone as a dispersing agent, coating a copper

3 Examiner’s Answer mailed 19 February 2010 (“Ans.”).
4 Kazuya Iwamoto et al., Non-Aqueous Electrochemical Apparatus, U.S.
Patent Application Publication 2002/0039677 A1 (4 April 2002), based on
an application filed 10 July 2001.
5 Chunming Niu et al., Polyvinylidene Fluoride Composites and Methods
for Preparing Same, U.S. Patent Application Publication 2003/0089890 A1
(15 May 2003), based on an application filed 11 July 2001.
Appeal 2010-008438
Application 10/769,866

5
foil, drying the coat, and rolling the coated foil. (Ans. 3, citing
Iwamoto 10 para [0121].)6
The Examiner finds that Iwamoto does not disclose certain steps
recited in claim 1, namely the preparation of masterbatch pellets consisting
essentially of carbon nanotubes and a resin, blending such masterbatch
pellets with an electrode active material (Ans. 4, 1st para.), or cutting the
electrode plate (id. at 5, 2d full para.).
The Examiner finds that Niu teaches the preparation of masterbatch
nanotube-PVDF composites at ratios ranging from 0.5 to 20 weight percent
nanotubes (Ans. 4, 2d full para., citing Niu 3 [0035]) by mixing the
components in a Brabender mixer. (Id.,1st full para., citing Niu 5 [0061].)
The composite may then be “molded as necessary using compression or
injection molding equipment and methods known in the art.” (Niu 5 [0062];
Ans. 4, 1st full para.) The Examiner argues that it is well known to add
conductive agents in powder form to the electrode material, and therefore
that it would have been obvious to mold the composite of Niu into a powder,
which, according to the Examiner, can be considered pellets, “in order to
effectively incorporate the composite conductive agent into the electrode
active material.” (Ans. 4, 1st full para., last sentence.)
The Examiner concludes that it would have been obvious to include
the PVDF-nanotube composites taught by Niu in the electrodes taught by

6 The substance of the Examiner’s rejection as stated in the Answer is also
found in the Final Rejection at pages 2-5. For brevity, we cite only the
Answer.
Appeal 2010-008438
Application 10/769,866

6
Iwamoto because Niu teaches the use of this composite to enhance the
electrical conductivity of the electrodes. (Ans., para. bridging 4-5.)
In Ohata’s view, Niu fails to teach or suggest the formation of a
masterbatch, particularly in the form of pellets. (Br. 5, last para.) Rather,
Ohata argues, Niu teaches a solvent-precipitation method of preparing the
PVDF-nanotube composite, which would result in the formation of a
powder, not a pellet form. (Reply 8, 3d full para.)7 The additional
compression or injection molding mentioned by Niu, according to Ohata,
“is only contemplated as an additional step after the powder composite is
formed.” (Id.) Moreover, Ohata urges, the disclosure that the solvent
method is preferred over the melt compound method because the former
yields better electrical conductors amounts to a teaching away from using
the melt compound process. (Id. at 2d full para.)
Ohata’s arguments are not persuasive of harmful error in the
Examiner’s rejection. As the Examiner finds (FR 4, ll. 2-5; Ans. 4,
ll. 18-21), Niu does teach the formation of masterbatch nanotube-PVDF
composites. In particular, the Examiner finds (FR 6, ll. 3-8; Ans. 7, ll. 8-11)
that Niu teaches that “PVDF composites may also be prepared by a melt
compounding process” (Niu 5 [0061]; emphasis added), in addition to the
more-preferred solvent-precipitation process. It is well established that the
teaching of a more preferred process is not a teaching away from the less
preferred process. E.g., “in a section 103 inquiry, the fact that a specific
[embodiment] is taught to be preferred is not controlling, since all

7 Reply Brief filed 25 March 2010 (“Reply”).
Appeal 2010-008438
Application 10/769,866

7
disclosures of the prior art, including unpreferred embodiments, must be
considered.” Merck & Co. Inc. v. Biocraft Labs., Inc., 874 F.2d 804, 807
(Fed. Cir. 1989) (internal quote and citation omitted).
We reject Ohata’s arguments that the further molding taught by Niu
applies only to composites prepared by the solvent precipitation molding, as
they are contradicted by Niu Examples VII and VIII (Niu 8 [0080]
through 9 [0095]). Examples VII and VIII present numerous examples of
nanotube-polymer composites, including composites of nanotubes and
PVDF, prepared by melt-blending. In the words of Niu, “[o]nce
compounded, flat sheets were prepared by pressing small pieces of the
composite between thin, chromed plates.” (Niu 8 [0080].) 8 On this record,
it would have been obvious to form the nanotube-PVDF mixtures produced
in the Brabender mixer into small pieces—e.g., pellets—for ease of
subsequent handling, including the blending of various components as
taught by Iwamoto.9

8 In this regard, we note further that Niu Example IX describes, in prophetic
fashion, multilayer structures that can be prepared as sheets or tubing.
(Id. at 9 [0096]-[0097].) Although Niu does not describe the form in which
the nanotube-PVDF composite might be provided, we take official notice
that polymer stock materials are typically fed as pellets to extruders via
hoppers.
9 We also note that the Examiner acknowledged Ohata’s arguments based
on dictionary definitions and recognized that the earlier arguments based on
the alleged equivalence of powders and pellets were not supported. (Ans.,
para. bridging 7-8.) The Examiner withdrew those arguments and based her
case for obviousness on the grounds that that pellet formation is a well-
known process in working with polymers, and that it would have been
Appeal 2010-008438
Application 10/769,866

8
We conclude that Ohata has not shown harmful error in the
Examiner’s rejection of independent claim 1.
Claim 4
Ohata argues (Br. 4, last para., penultimate sentence) that “[t]he
Examiner concedes that neither prior art reference teaches . . . the claimed
amount of carbon nanotubes.” The Examiner’s reliance (Ans. 3, last para.,
and 5, last para) on the broad teaching in Iwamoto of a 1-30% by weight of
conductive additives is, in Ohata’s view, insufficient to establish prima facie
obviousness of the 0.2 to 3 parts by weight of nanotubes per 100 parts by
weight of the electroactive material required by claim 4. (Br. 8-9;
Reply 10-11.) Ohata argues that the artisan would not have attempted such
small amounts of nanotubes, and that “obtaining the improved conductivity
by using only a small amount of carbon nanotubes such as 0.2 to 3 parts by
weight would have been difficult and unobvious.” (Br. 8, 3d full para.;
Reply 11, 1st para.) Moreover, comparison of the inventive examples with
Comparative Example 1 (Spec. 17, Table 3), illustrates, according to Ohata,
a substantial and unexpected improvement due to the use of the masterbatch.
(Br. 9; Reply 11.)
Our reviewing court has held that “a prima facie case of obviousness
arises when the ranges of a claimed composition overlap the ranges
disclosed in the prior art.” In re Harris, 409 F.3d 1339, 1341 (Fed.

obvious to blend the nanotube-PVDF pellets in view of Niu with the other
electrode-active components taught by Iwamoto. (Id. at 8.)
Appeal 2010-008438
Application 10/769,866

9
Cir. 2005). Here, the range of 1-30% taught by Iwamoto overlaps the range
of 0.2 to 3% recited in claim 4.
The Examiner also repeatedly pointed out that Niu teaches composite
masterbatches that contain 0.5-20 percent nanotubes. (FR 4, l. 3 and Ans. 4,
last para., both times citing Niu 3 [0035].) In particular, Niu teaches that
“PVDF composites containing carbon nanotubes in an amount as little as 1%
or less by weight have an exceptionally low bulk resistivity compared to the
pure PVDF polymer or copolymer.” (Niu 3 [0035].) The same point is
made in Niu Example 1. (Niu 5 [0066], cited to us by Ohata (Br. 6, ll. 2-3),
albeit to illustrate molding into a thin sheet). As shown by Example I,
batches 1-4 in Table 1, the resistivity drops from a high value
of 300,000 Ohm-cm at 0.20% nanotubes to about 1.2 Ohm-cm at 3.01%
nanotubes.10 Niu teaches further that “[i]n order for a plastic article to be
used as a conductive element like a current collector or separator plate in an
electrochemical cell, resistivity less than 102 ohm/cm [sic: ohm-cm] is
required.” (Niu 1 [0010], last sentence.)11 The weight of this evidence of
record indicates that a person having ordinary skill in the art would have
expected, reasonably, that small amounts of nanotubes, especially in the
range of about 1-3%, dispersed in PVDF, would have provided a suitably
conductive PVDF-based material for the electrodes taught by Iwamoto.

10 See also Niu 5 [0067], essentially repeating the content of para. [0035]
and para. [0036].
11 We are confident that both the Examiner and Ohata were aware of these
additional disclosures, but inadvertently overlooked them when preparing
their arguments.
Appeal 2010-008438
Application 10/769,866

10
We thus hold that Ohata has not demonstrated harmful error in the
Examiner’s prima facie case of obviousness as to claim 4.
Whether results produced by a claimed invention are unexpected is a
question of fact. Harris, 409 F.3d at 1341. The burdens of production and
persuasion are on the applicant to demonstrate that the claimed limitations
produce unexpected results. In re Geisler, 116 F.3d 1465, 1470 (Fed. Cir.
1997). As for the unexpected results urged by Ohata (Examples 1-3 versus
Comparative Example 1), the only performance parameters provided
(battery capacity and capacity retention rate) are, on the present record,
insufficiently related to the properties disclosed by Niu, to permit an
evaluation of whether the results would have been unexpected.
We AFFIRM the rejection of claim 4.
C. Order
We AFFIRM the rejection of claims 1-8 under 35 U.S.C. § 103(a) in
view of the combined teachings of Iwamoto and Niu.
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
bar