Ex Parte Khatua et al

Board of Patent Appeals and Interferences

Sep 15, 2010

11563723 (B.P.A.I. Sep. 15, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
________________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
________________

Ex parte BHANU BHUSAN KHATUA,
SUMANDA BANDYOPADHYAY, SOUMYADEB GHOSH,
HARI NADATHUR SESHADRI, and
FRANCISCUS PETRUS MARIA MERCX
________________

Appeal 2010-007949
Application 11/563,723
Technology Center 1700
________________

Before CHARLES F. WARREN, TERRY J. OWENS, and
CATHERINE Q. TIMM, Administrative Patent Judges.

OWENS, Administrative Patent Judge.

DECISION ON APPEAL1
STATEMENT OF THE CASE

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, or for filing a request for rehearing,
as recited in 37 C.F.R. § 41.52, begins to run from the “MAIL DATE”
(paper delivery mode) or the “NOTIFICATION DATE” (electronic delivery
mode) shown on the PTOL-90A cover letter attached to this decision.
Appeal 2010-007949
Application 11/563,723

2
The Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1-7, 10, 11 and 16-27. Claims 8, 9 and 12-15, which are
all of the other pending claims, stand withdrawn from consideration by the
Examiner. We have jurisdiction under 35 U.S.C. § 6(b).
The Invention
The Appellants claim an article which can be a heating device or can
be used in a circuit opening device. Claim 1 is illustrative:
1. An article comprising a composition comprising:

a polymer matrix; and

a doped filler dispersed in the polymer matrix, and the
doped filler is electrically conducting in a temperature range
and the doped filler has a Curie temperature, and

the composition has a trip temperature at which the
electrical resistance of the composition increases with an
increase in temperature, and the trip temperature of the
composition is determined by the Curie temperature of the
doped filler; and

the doped filler is present in the polymeric matrix in an
amount determined by a property of one or both of the
polymeric matrix or the doped filler;

wherein the composition is melt-mixable such that the
composition is capable of being injection molded to form the
article.[2]

2 The Appellants state that the trip temperature is the “temperature at which
electrical resistance of the composition increases with increase in
temperature” (Spec. ¶ 0007) and that “[t]he Curie temperature of a
piezoelectric filler is the temperature above which the material may lose its
spontaneous polarization and piezoelectric characteristics” (Spec. ¶ 0023).
Appeal 2010-007949
Application 11/563,723

3
The References
References relied upon by the Examiner
Barma 5,106,538 Apr. 21, 1992
Enomoto 5,219,811 Jun. 15, 1993
Reference relied upon by the Appellants
Fouts 4,545,926 Oct. 8, 1985
The Rejections
The claims stand rejected as follows: claims 1-7, 10, 11 and 16-26
under 35 U.S.C. § 102(b) or, in the alternative, under 35 U.S.C. § 103 over
Barma, and claim 27 under 35 U.S.C. § 103 over Barma in view of
Enomoto.3
OPINION
We affirm the rejections.
Issue
Have the Appellants indicated reversible error in the Examiner’s
determination that Barma discloses, or would have rendered prima facie
obvious, to one of ordinary skill in the art, a composition which has a trip
temperature determined by the Curie temperature of the composition’s
doped filler and is capable of being injected molded to form an article?

3 A rejection of claims 1-7, 10, 11 and 16-27 under 35 U.S.C. § 103 over
Fouts in view of Yamakawa (JP 59-122524) is withdrawn in the Examiner’s
Answer (Ans. 3) and a provisional obviousness-type double patenting
rejection of claims 1 and 25-27 over claims 1-7 and 28 of copending
application no. 11/483,480 (filed Jul. 10, 2006) is moot because that
application has been abandoned.
Appeal 2010-007949
Application 11/563,723

4
Findings of Fact
Barma discloses compositions which can exhibit PTC (positive
temperature coefficient), ZTC (zero temperature coefficient) or NTC
(negative temperature coefficient) behavior depending on the nature of the
composition’s conductive filler (abstract; col. 2, ll. 18-21). In preferred
embodiments the conductive filler is a nonpolymeric material exhibiting
PTC behavior such as doped barium titanate or another PTC ceramic
(col. 13, ll. 60-65; col. 15, ll. 65-68).
Analysis
The Appellants argue, in reliance upon Barma’s column 13, lines 49-
52, that the PTC characteristics of the composition depend upon the
crystalline phase transition of the polymer, not upon the type of filler
(Br. 11-12).
The portion of Barma relied upon by the Appellants pertains to an
embodiment wherein the filler is a polymer, preferably a crystalline
thermoplastic polymer. Barma, however, teaches that in other embodiments
the filler can be doped barium titanate (col. 13, ll. 60-65; col. 15, ll. 64-68)
which is one of the Appellants’ doped electrically conducting fillers
(Spec. ¶¶ 0096-97).
The Appellants argue that Barma’s filler is dispersed in a first
polymer to form particulates which are dispersed in a second polymer matrix
to produce a structure having different electrical properties than the
Appellants’ composition (Br. 12). In support of that argument the
Appellants point out that Fouts discloses preferred PTC compositions
containing carbon black (col. 4, ll. 59-65), whereas Barma at column 13,
lines 62-64 discloses compositions containing carbon black that exhibit NTC
Appeal 2010-007949
Application 11/563,723

5
or ZTC behavior (Br. 12). The Appellants argue that Barma’s crystalline
polymers change what would normally be a PTC composition to an NTC
composition and that, therefore, Barma’s switching temperature (which
corresponds to the Appellants’ trip temperature) is determined by the
crystalline polymer, not the filler (Br. 12-13). The Appellants provide tables
which show that when Barma’s filler is carbon black (which, the Appellants
acknowledge, is not known to have a Curie temperature) the switching
temperature depends upon the polymer composition (Reply Br. 6).4
Barma discloses in one embodiment that the conductive filler is
“preferably a composite filler” (col. 7, ll. 16-24). The “preferably” indicates
that the filler can be a non-composite filler such as the disclosed doped
barium titanate. A composition containing doped barium titanate appears to
anticipate the Appellants’ composition because the Appellants’ filler can be
doped barium titanate and both Barma (col. 16, ll. 13-14) and the Appellants
(Spec. ¶¶ 0055, 0058) indicate that polymers generally are suitable as the
matrix polymer. Moreover, many of Barma’s exemplified matrix polymers,
e.g., polyethylene, poly(aryl)etherketones, polyetheretherketone,
polyphenylenesulfide and polyimides (col. 12, ll. 3-7; col. 16, ll. 13-26) are
among those used by the Appellants (Spec. ¶¶ 0059-60).

4 The Appellants argue that in their samples 18 and 19 in Fig. 8 the polymer
is polybutylene terephthalate and the trip temperatures are around 110°C
(Reply Br. 7). The Appellants’ Specification discloses that the polymer in
the Fig. 8 examples is polybutylene terephthalate, but also discloses that it is
nylon-6 (Spec. ¶ 0108). Thus, it is not clear whether the polymer is different
from the nylon-6 in other examples. Also, the trip temperature for sample
19 in Fig. 8 appears to be closer to 90°C than 110°C.
Appeal 2010-007949
Application 11/563,723

6
Alternatively, even if Barma’s filler is a composite filler, the
compositions to which Barma would have led one of ordinary skill in the art,
through no more than ordinary creativity, include compositions falling
within the Appellants’ claims. See KSR Int’l. Co. v. Teleflex Inc., 550 U.S.
398, 418 (2007) (In making an obviousness determination one “can take
account of the inferences and creative steps that a person of ordinary skill in
the art would employ”). Barma teaches that the filler and matrix polymers
preferably are the same (col. 16, ll. 48-53). If, for example, Barma’s
polyetheretherketone is used as the matrix polymer and the filler polymer
surrounding the doped barium titanate, the melting point of the polymer, as
indicated by the Appellants’ Table 2 (Reply Br. 6), is 343°C. As indicated
by Enomoto the Curie temperature of barium titanate usually is about 120°C
and can be shifted up or down by doping (col. 1, ll. 23-29). Because that
Curie temperature is way below polyetheretherketone’s 343°C melting point
it appears that, as required by the Appellants’ claims, the trip temperature of
the composition would be determined by the doped barium titanate rather
than the polyetheretherketone.
The Appellants argue, in reliance upon Barma’s column 9, lines 61-
66, that the composition cannot be subjected to shear and, therefore, cannot
be injected molded because the shear would cause the filler to be displaced
from the composite filler into the matrix polymer such that the composite
filler loses its desired identity in the matrix (Br. 13-14).
The shear in the portion of Barma relied upon by the Appellants
pertains to shear during preparation of the composition. Barma teaches that
the prepared composition can be shaped by injection molding (col. 11, ll. 57-
60). Thus, the shear involved in shaping the composition by injection
Appeal 2010-007949
Application 11/563,723

7
molding does not appear to be sufficient to cause the loss of identity which
Barma indicates (col. 9, ll. 61-66) would be caused by the shear required for
preparing the composition.
Conclusion of Law
The Appellants have not indicated reversible error in the Examiner’s
determination that Barma discloses, or would have rendered prima facie
obvious, to one of ordinary skill in the art, a composition which has a trip
temperature determined by the Curie temperature of the composition’s
doped filler and is capable of being injected molded to form an article.
DECISION/ORDER
The rejections of claims 1-7, 10, 11 and 16-26 under
35 U.S.C. § 102(b) or, in the alternative, under 35 U.S.C. § 103 over Barma,
and claim 27 under 35 U.S.C. § 103 over Barma in view of Enomoto are
affirmed.
It is ordered that the Examiner’s decision is affirmed.
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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