Ex Parte Hamada et al

Board of Patent Appeals and Interferences

Feb 25, 2011

10467856 (B.P.A.I. Feb. 25, 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.
10/467,856 02/19/2004 Yuji Hamada 50024-016 4161
20277 7590 02/28/2011
MCDERMOTT WILL & EMERY LLP
600 13TH STREET, N.W.
WASHINGTON, DC 20005-3096
EXAMINER
YAMNITZKY, MARIE ROSE
ART UNIT PAPER NUMBER
1786
MAIL DATE DELIVERY MODE
02/28/2011 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 YUJI HAMADA and
NORIYUKI MATSUSUE
____________

Appeal 2009-005724
Application 10/467,856
Technology Center 1700
____________

Before CHUNG K. PAK, CHARLES F. WARREN, and
PETER F. KRATZ, Administrative Patent Judges.

KRATZ, Administrative Patent Judge.

DECISION ON APPEAL1

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 2009-005724
Application 10/467,856

2
This is a decision on an appeal under 35 U.S.C. § 134 from the
Examiner’s final rejection of claims 1, 14, 17-21, 23-26, and 34-36. We
have jurisdiction pursuant to 35 U.S.C. § 6.

Appellants’ claimed invention encompassed by the appealed claims is
directed to an electroluminescent device including a luminescent layer that
includes an organic compound having a specified molecular structure
composed of iridium and a quinoline derivative, a luminescent material
having such an organic compound, and organic compounds having such
molecular structures.
Claims 1, 14, 26, 34, and 35 are illustrative and are reproduced below
from the Claims Appendix to the Appeal Brief filed August 04, 2008:
1. An organic electroluminescent device, comprising:
a hole injection electrode;
an electron injection electrode; and
a luminescent layer provided between said hole injection
electrode and said electron injection electrode, wherein
said luminescent layer includes a compound composed of
iridium and a quinoline derivative,
wherein said compound composed of the iridium and the
quinoline derivative has a molecular structure represented by
formula (1) shown below:

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where R1 is a hydrogen atom, a halogen atom or a
substituent, and A is a substituent, and wherein said A has a
molecular structure selected from the group consisting of
formula (Al)
,
formula (A2)
,
formula (A3)
,
formula (A5)
,
formula (A6)
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, and
formula (A11)
,
where R2, R3, R4, R6, R7, and R12 are either hydrogen
atoms, halogen atoms, or substituents.
14. An organic electroluminescent device, comprising:
a hole injection electrode;
an electron injection electrode; and
a luminescent layer provided between said hole injection
electrode and said electron injection electrode, wherein
said luminescent layer includes a compound composed of
iridium and a quinoline derivative, wherein said compound
composed of iridium and a quinoline derivative has a molecular
structure represented by a formula (2) shown below:

where R21 is a hydrogen atom, a halogen atom or a
substituent, A is a substituent, and D is a substituent forming a
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ring, wherein said D has a molecular structure represented by a
formula (D2) shown below:

where R24 is a hydrogen atom, a halogen atom or a
substituent.
26. A luminescent material having a molecular structure
represented by a formula (2) shown below:

where R2 1 is a hydrogen atom, a halogen atom or a
substituent, A is a substituent, and D is a substituent forming a
ring, wherein said D has a molecular structure represented by a
formula (D2) shown below:

where R24 is a hydrogen atom, a halogen atom or a
substituent.
34. An organic compound having a molecular structure
represented by a formula (C7) shown below
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.
35. An organic compound having a molecular structure
represented by a formula (C8) shown below
.

The Examiner relies on the following prior art references2 as evidence
in rejecting the appealed claims:
Igarashi et al. US 2001/0019782 A1 Sept. 6, 2001
Thompson et al. US 2002/0034656 A1 Mar. 21, 2002
Petrov et al. WO 02/02714 A2 Jan. 10, 2002

Claims 14, 19, and 26 stand rejected under 35 U.S.C. § 103(a) as
being unpatentable over Petrov in view of Thompson. Claims 1, 23, 24, 34,
and 35 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over
Igarashi. Claim 25 stands rejected under 35 U.S.C. § 103(a) as being
unpatentable over Igarashi in view of Thompson. Claims 14, 17-21, and 26

2 Appellants do not dispute that the subject matter described and taught by
the applied references is available prior art to the subject Application for
Patent.
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stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Igarashi
in view of Thompson. Claim 36 stands rejected under 35 U.S.C. § 103(a) as
being unpatentable over Igarashi in view of Thompson.
We adopt the Examiner’s factual findings as our own and we affirm
the stated rejections for substantially the reasons set forth by the Examiner in
the Examiner’s Answer. We offer the following for emphasis only.

PRINCIPLES OF LAW
Section 103(a) forbids issuance of a patent when “the differences
between the subject matter sought to be patented and the prior art are such
that the subject matter as a whole would have been obvious at the time the
invention was made to a person having ordinary skill in the art to which said
subject matter pertains.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 406
(2007).
KSR reaffirms the analytical framework set out in Graham v. John
Deere Co., 383 U.S. 1 (1966), which states that an objective obviousness
analysis includes: (1) determining the scope and content of the prior art; (2)
ascertaining the differences between the prior art and the claims at issue; and
(3) resolving the level of ordinary skill in the pertinent art. KSR, 550 U.S. at
407. Secondary considerations such as commercial success, long felt but
unsolved needs, or failure of others “might be utilized to give light to the
circumstances surrounding the origin of the subject matter sought to be
patented.” Id. (quoting Graham, 383 U.S. at 17-18).
While KSR explains that an obviousness “analysis need not seek out
precise [prior art] teachings,” it nonetheless did not dispense with the need
for evaluating the evidence to determine whether a person having ordinary
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skill in the art would have had “an apparent reason to” arrive at the claimed
subject matter. Id., 550 U.S. at 418. See also DyStar Textilfarben GmbH &
Co. Deutschland KG v. C.H. Patrick Co., 464 F.3d 1356, 1367 (Fed. Cir.
2006) (“Our suggestion test is in actuality quite flexible and not only
permits, but requires, consideration of common knowledge and common
sense”); Alza Corp. v. Mylan Labs., Inc., 464 F.3d 1286, 1291 (Fed. Cir.
2006) (“There is flexibility in our obviousness jurisprudence because a
motivation may be found implicitly in the prior art. We do not have a rigid
test that requires an actual teaching to combine . . . .”).
“The test for obviousness is not whether the features of a secondary
reference may be bodily incorporated into the structure of the primary
reference . . . [r]ather, the test is what the combined teachings of the
references would have suggested to those of ordinary skill in the art.” In re
Keller, 642 F.2d 413, 425 (CCPA 1981). See In re Payne, 606 F.2d 303,
313-14 (CCPA 1979) (“An obviousness rejection based on similarity in
chemical structure and function entails the motivation of one skilled in the
art to make a claimed compound, in the expectation that compounds similar
in structure will have similar properties.”); see also, e.g., In re Dillon, 919
F.2d 688, 692-93 (Fed. Cir. 1990)(in banc) (“This court . . . reaffirms that
structural similarity between claimed and prior art subject matter, proved by
combining references or otherwise, where the prior art gives reason or
motivation to make the claimed compositions, creates a prima facie case of
obviousness, and that the burden (and opportunity) then falls on an applicant
to rebut that prima facie case.”).
“A known or obvious composition does not become patentable simply
because it has been described as somewhat inferior to some other product for
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the same use.” In re Gurley, 27 F.3d 551, 553 (Fed. Cir. 1994). “[T]he fact
that a specific [embodiment] is taught to be preferred is not controlling,
since all disclosures of the prior art, including unpreferred embodiments,
must be considered.” Merck & Co. v. Biocraft Labs., Inc., 874 F.2d 804,
807 (Fed. Cir. 1989).
[W]here the prior art gives reason or motivation to make the
claimed [invention] . . . the burden (and opportunity) then falls
on an applicant to rebut that prima facie case. Such rebuttal or
argument can consist of . . . any other argument or presentation
of evidence that is pertinent.
Dillon, 919 F.2d at 692-93.

DISCUSSION
Rejection over Petrov and Thompson
Appellants argue rejected claims 14 and 19 together. We consider
claim 14 the representative claim for the first claim grouping of claims 14
and 19. Claim 26 is argued separately. However, the thrust of Appellants’
argument is the same for separately argued claim 26 as it is for claim 14 and
focuses on the propriety of the Examiner’s proposed substitution of a
picolinate ligand for an acetylacetonate ligand employed in a corresponding
iridium complex taught or suggested by Petrov for use as an
electroluminescent material, which material/compound can be used in a
luminescent layer of an organic electroluminescent device of Petrov.
Accordingly, we consider separately argued claim 26 to stand or fall
together with claim 14 because the ostensibly separate arguments for claim
26 do not differ substantively. Indeed, claim 26 is broader than claim 14 in
that claim 26 is drawn to a luminescent material containing a compound of
the specified formula, whereas claim 14 requires a device including
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electrodes and a luminescent layer, which layer includes a compound of the
specified formula.
Appellants do not dispute that Petrov teaches or suggests a device that
includes a hole injection electrode, an electron injection electrode, and a
luminescent layer there between, which luminescent layer can include a
compound composed of iridium and a quinoline derivative generally
corresponding to the formula 2 of appealed representative claim 14 but for
the picolinate ligand of formula D2 (Ans. 4; Petrov, formula III, p. 3; p. 5, ll.
27-28; formula IV, p. 7; see generally App. Br. and Reply Br.). Similarly,
Appellants do not dispute that Petrov discloses a luminescent material
having a molecular structure corresponding to formula 2 as set forth in claim
26 but for the picolinate ligand.
In this regard, the Examiner has found that “Petrov et al. explicitly
teach acetylacetonate ligands as bidentate ligands, but do not explicitly teach
picolinate ligands” (Ans. 4; Petrov, p. 5, ll. 27-30).
The Examiner has found that:
Thompson et al. disclose transition metal complexes of
the formula L2MX that may be used as an electroluminescent
material in an electroluminescent device. Thompson et al.
disclose acetylacetonate and picolinate as suitable alternatives
for the X ligand. Thompson et al. disclose that the choice of X
ligand can affect the peak emission wavelength of the complex.
For example, see the abstract, Fig. 11 and paragraphs [0058]
and [0183].
Ans. 4.
Thompson teaches that the electroluminescent material may be in a
separate emissive layer located between a hole transporting layer and an
electron transporting layer (para. 0018). Thompson indicates that a small
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blue shift of about 15 nm from strong green emissions would occur if
picolinic acid were substituted for acetyl acetone in forming the X ligand of
an iridium metal complex where the L ligand is formed from phenyl
pyridine (ppy) (para. 0058).
The Examiner essentially argues that one of ordinary skill in the art
would have been prompted to use a picolinate ligand instead of an
acetylacetonate ligand in the organometallic compounds of Formula IV of
Petrov in forming an emissive layer of the electroluminescent device of
Petrov based on the added teachings of Thompson showing that these
ligands are alternatives in forming compounds used for substantially the
same purposes in light emissive layers and that they have a known color
shift potential that would reasonably be expected to accrue upon effecting
such a substitution, and thereby guide an artisan of ordinary skill in selecting
picolinate ligand for use in the organometallic complex of Petrov (Ans. 5).
Appellants do not dispute that Thompson discloses an organometallic
complex for use as light emitters in a light emissive (luminescent) layer in
organic LEDs, wherein an iridium complex is of the aforementioned formula
L2MX, wherein X can either be a picolinate ligand or an acetlyacetonate
ligand (see generally App. Br. and Reply Br.).
Rather, Appellants introduce a principal issue before us with respect
to the Examiner’s fist presented rejection by urging that “[t]here is no
suggestion in Thompson et al. to substitute a picolinate group in place of the
acetylacetonate group of Petrov et al.” (App. Br. 8 and 11).
The principal issue is:
Has the Examiner articulated a reasonable rationale establishing that
one of ordinary skill in the art would have been prompted to employ a
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picolinate ligand in place of the acetlyacetonate ligand used by Petrov in
iridium compounds otherwise corresponding to those called for in appealed
claims 14 and/or 26 with a reasonable expectation that such picolinate ligand
containing compounds would have similar properties; and, thus would have
been used by an ordinary skilled artisan in a luminescent layer of an organic
electroluminescent device of Petrov given the additional teachings of
Thompson?
We answer this question in the affirmative.
Analysis
Appellants argue that the blue shift in emission away from the green
emission furnished with an acetylacetonate group for a particular iridium
complex, as taught to occur by Thompson when a picolinate group is
employed in place of the acetylacetonate group for that particular iridium
compound, is at odds with an objective of providing an organic
electroluminescent device with high luminescent red-orange light as is the
case for Appellants’ invention (Ans. 8, and 11-12; Reply Br. 1-2). Based
thereon and on an alleged lack of a specific suggestion or evidence of benefit
for the Examiner’s proposed substitution of ligand in Petrov in the applied
references, Appellants urge that the Examiner’s proposed combination of
Petrov and Thompson in rejecting representative claim 14 is based on
impermissible hindsight. In this regard, Appellants maintain that the
rejection appears to be premised on a legally insufficient factual predicate
and lacks evidence of motivation for the Examiner’s proposed modification
of Petrov with respect to the Examiner’s obviousness rejection of claim 14
and claim 26 (App. Br. 8-14).
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We are not persuaded by these arguments, including the blue shift
away from red-orange argument, for reasons articulated by the Examiner in
the Answer (Ans. 13-15), which rebuttal we incorporate by reference herein.
In this regard, we note that Appellants have not persuasively argued that
Thompson’s teachings are at odds with the objectives of Petrov in forming
devices using “electroluminescent compounds having improved efficiency”
so as to contraindicate the proposed combination of references (Petrov, p. 1,
ll. 36-37; Thompson, abstract, paras. 0046, 0050, 0111). Indeed, Petrov
generally teaches that the L' and L" ligands of the iridium complexes can be
selected from “conventional ligands known to transition metal coordination
chemistry” and exemplify acetylacetonate (p. 5, ll. 20-30; see Thompson,
paras. 0058, 0071 and 0183). Hence, one of ordinary skill in the art would
have had ample direction from Thompson taken together with Petrov to
select a picolinate group as an alternative conventional ligand for use in
Petrov’s iridium emitter complex, for reasons suggested by Thompson; such
as, for use in color tuning the iridium organometallic complexes of Petrov
(Ans. 4; Petrov; p. 7, Formula IV; Thompson, paras. 0058, 0071, and 0183;
Fig. 11).
It follows that we shall sustain the Examiner’s obviousness rejection
of claims 14, 19, and 26 over Petrov in view of Thompson.

Rejection over Igarashi
Appellants argue rejected claims 1, 23 and 24 together as a group and
rejected claims 34 and 35 separately. Accordingly, we consider claim 1 as
the representative claim for the group of claims 1, 23 and 24.
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We have considered claims 34 and/or 35 separately to the extent
separately argued. However, we shall primarily focus on claim 1. This is so
given that the Examiner’s obviousness assessment of claims 34 and 35 and
Appellants’ arguments to the contrary run parallel to the Examiner’s
obviousness assessment of representative claim 1 in so far as it is based on
the A2 and/or A3 choices embraced in claim 1.
We agree with the Examiner’s obviousness determination not
withstanding the arguments presented against such a determination by
Appellants in the Appeal Brief and the Reply Brief.3 In this regard, the
Examiner’s determination that Igarashi discloses iridium compounds
composed of iridium and quinoline derivatives, which compounds are
described or suggested as being useful in a luminescent layer of an
electroluminescent (EL) device, is not disputed by Appellants (Compare
page 5 of the Examiner’s Answer with the arguments in the Appeal Brief
and the Reply Brief).
Igarashi discloses or suggests that the luminescent layer, including the
iridium complex, is located between electrodes, such as a hole injection
layer and a hole transporting layer in the EL device (paras. 0028 and 0137).
As indicated above, the Examiner bases the maintained obviousness
of claim 1, at least in part, on the alleged obviousness, over Igarashi, of
iridium compounds corresponding to the A1 and/or A2 compound groupings
of compounds within the scope of the claim 1 requirements for a specified

3 The Examiner furnishes further alternative bases for the assessment of the
obviousness of claim 1 over Igarashi based, in part, on claim 1 being
inclusive of other compounds, such as A of formula A3, which are claimed
options the Examiner also maintains that Igarashi provides suggestion for
(Ans. 7).
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formula 1 compound being included in the luminescent layer of the device
recited in claim 1. Rejected independent claim 1 requires an organic
electroluminescent device having a luminescent layer that includes an
iridium and quinoline derivative-containing compound of formula 1 as set
forth in claim 1. As noted by the Examiner (Ans. 6),
Formula (1) as defined in present independent claim 1
encompasses an iridium compound having three substituted or
unsubstituted naphthylquinoline ligands (when A has a
structure selected from formula (A1), (A2) or (A3)), three
substituted or unsubstituted quinolinylquinoline ligands (when
A has a structure selected from formula (A5) or (A6)) or three
substituted or unsubstituted pyridylquinoline ligands (when A
has a structure of formula (A11)).
Correspondingly, rejected claims 34 and 35 are drawn to organic
compounds of formulas C7 or C8, respectively, as set forth therein. As
noted by the Examiner (id.):
Present claims 34 and 35 require an iridium compound
having three substituted or unsubstituted naphthylquinoline
ligands. The compound of claim 34 has a molecular structure
of formula (1) in which A is (A2). The compound of claim 35
has a molecular structure of formula (1) in which A is (A1).
The Examiner has determined that (id.):
With respect to the present claim embodiment having
naphthylquinoline ligands in which A has a structure of formula
(A1) or (A2), Igarashi et al. disclose iridium complexes
comprising two such naphthylquinoline ligands, but do not
disclose a specific example of a compound having three such
ligands (see Igarashi’s complexes of formulae (2-4) and (2-12)).
In Igarashi’s complexes, all ligands may be orthometalating
ligands, and all orthometalating ligands may be the same
ligand. It would have been prima facie obvious to one of
ordinary skill in the art at the time of the invention to make
compounds similar to the specific complexes disclosed in the
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prior art, and within the guidelines of the prior art, in order to
provide additional complexes suitable for the purposes of the
prior art. One of ordinary skill in the art, given prior art
complexes such as the complexes of formulae (2-1), (2-4), (2-
10) and (2-12), which are disclosed as suitable for the same
purpose, would have reasonably expected that iridium
complexes similar to (2-4) and (2-12) but having three
naphthylquinoline ligands and no acetylacetonate ligand would
have similar properties and could be used for the same purpose.
Appellants do not dispute the Examiner’s determination that the
device embraced by representative claim 1, and correspondingly, the
compounds within the scope of claims 34 and/or 35, differ from the device
and/or compounds of Igarashi’s formulae 2-4 and 2-12 by providing for
iridium complexes comprising three naphthylquinoline ligands, whereas
Igarashi’s formulae 2-4 and 2-12 only provides for two such
naphthylquinoline ligands together with an acetylacetonate ligand in an
iridium complex (Formula 1 compounds with an A substituent of formulae
A1 or A2 as in claim 1 or the C7 and C8 compounds of claims 34 and 35,
respectively). See generally App. Br. and Reply Br.
Rather, Appellants disagree with the Examiner’s obviousness
assessment of representative claim 1 based on the encompassed A1 and A2
choices for A, and the Examiner’s obviousness determination of the
compounds of claims 34 and 35 over Igarashi, by asserting that the
Examiner appears to be engaging in impermissible hindsight reasoning as
there is no motivation to employ three naphthylquinoline ligands in an
iridium complex based on Igarashi’s teachings and the Examiner’s
obviousness assessment lacks factual support (App. Br. 15-25). Appellants
argue that a tri-naphthyl substituted iridium would contain 12 additional
carbon atoms over a tri-phenyl substituted iridium and seemingly speculate
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that steric hindrance considerations could militate against an ordinarily
skilled artisan arriving at the claimed use of three naphthylquinoline ligands
in an iridium complex based on the teachings of Igarashi with respect to
employing three identical ligands in other iridium compounds, such as a tri-
phenyl substituted iridium (App. Br. 15, 19, and 22-23; Reply Br. 2).
We are not persuaded that Appellants have indicated any substantive
error in the Examiner’s obviousness assessment with these arguments for
reasons presented by the Examiner (Ans. 15-17). As found by the Examiner,
Igarashi discloses or suggests iridium complexes wherein all three ligands
are the same, such as the phenylquinoline of formula 2-10 of Igarashi, as an
alternative to a compound of a formula wherein only two of the same
phenylquinoline ligands are used along with an acetylacetonate ligand, such
as the compounds of formula 2-1. The compounds of formulae 2-1 and 2-10
are presented as alternatives to the compounds of Formulae 2-4 and 2-12 of
Igarashi.
Moreover, Igarashi provides a more generic disclosure that embraces
iridium compounds having three ligands that are the same (para. 0043 and
para 0085; formulae 1-60, 1-61, and 1-62). Thus, Igarashi generally
indicates the alternativeness of phenyl-containing and naphthyl-containing
groups as part of an aryl substituted nitrogen-containing heterocyclic
derivative ligand for the iridium complex (see, e.g., paras. 0042, 0043, 0085,
etc.).
Based on the disclosed alternative Example compound formulae and
the more generic disclosure of Igarashi that encompasses or suggests iridium
compounds having three ligands that are the same, such as an iridium
complex having three phenylquinoline ligands as exemplified in formula 2-
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10, as well as the suggestion of complexes having three naphthylquinoline
ligands, we agree with the Examiner that one of ordinary skill in the art
would have been led to an iridium complex having three naphthylquinoline
ligands as embraced by each of claims 34 and 35, and to use such an iridium
complex as part of a luminescent layer in a device within the scope of
representative claim 1 with a reasonable expectation of success in so doing
(Ans. 5-6 and 15-17). See KSR, 550 U.S. at 418 (In making an obviousness
determination, one of ordinary skill in the art “can take account of the
inferences and creative steps that a person of ordinary skill in the art would
employ.”); Dillon, 919 F.2d at 692 (“This court . . . reaffirms that structural
similarity between claimed and prior art subject matter, proved by
combining references or otherwise, where the prior art gives reason or
motivation to make the claimed compositions, creates a prima facie case of
obviousness.”); When the similarity in chemical structures and functions
between the prior art and claimed compounds is sufficiently close, a prima
facie case of obviousness is established. See In re Hoch, 428 F.2d 1341,
1343 (CCPA 1970).
In making this obviousness determination, we have been mindful and
considered Appellants’ conjecture about steric hindrance being a
consideration that may have resulted in one of ordinary skill in the art
lacking a reasonable expectation of success for going forward with
complexes having three naphthylquinoline ligands as emitter compounds
(App. Br. 15, 19, and 22-23; Reply Br. 2). However, based on the overall
teachings of Igarashi and for reasons expressed by the Examiner, we have
determined such supposition carries no persuasive countervailing weight
(Ans. 17).
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While unnecessary to our disposition of this rejection with respect to
representative claim 1 for reasons set forth above, we further note our
agreement with the Examiner’s alternative obviousness assessment of
representative claim 1 based on the obviousness of selecting compounds for
the emitter layer that fit formula 1 wherein the A substituent is selected from
A3, A5, A6, or A11 (Ans. 7 and 16-17).
On this record, we sustain the Examiner’s obviousness rejection over
Igarashi.

Rejections over Igarashi and Thompson
Claim 25.
Dependent claim 25 requires a hole blocking layer interposed between
an electron injection electrode and a luminescent layer in a device as set
forth in claim 1, the blocking layer having a higher ionization potential than
the luminescent layer.
The Examiner relies on Thompson for teaching a blocking layer
located between a cathode and an electroluminescent layer with the requisite
relative ionization potential, which feature the Examiner found would have
been recognized as obvious and advantageous by one of ordinary skill in the
art to employ in Igarashi’s device (Ans. 8-9).
Appellants argue for allowance based on the luminescent layer
compound of claim 1 while asserting a lack of suggestion in Thompson for
such a compound. This argument is non-persuasive as Igarashi would have
reasonably suggested to an ordinarily skilled artisan such a luminescent
layer compound for reasons expressed above and in the Examiner’s Answer.
Claims 14, 17-21, and 26
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Claim 14 requires a device with an EL layer that includes an iridium
compound of a formula 2 having two quinoline derivative ligands and a
picolinate ligand (formula D2). Independent claim 26 requires a
luminescent material having a molecular structure corresponding to the
claim 14 compound. Appellants argue claims 14 and 17-21 together as a
group and separately present substantially the same arguments for
independent claim 26 in opposition to the Examiner’s rejection over the
combined teachings of Igarashi and Thompson (App. Br. 26-32). We select
claim 14 as representative.
We reference the Examiner’s statement of rejection as presented in the
Answer and we substantially agree with the Examiner’s reasoning
establishing, prima facie, that an ordinary skilled artisan would have been
led to substitute a picolinate ligand, as taught by Thompson, for one of
Igarashi’s iridium complex ligands, such as an acetylacetonate ligand of
Igarashi, with a reasonable expectation of success in forming a workable
luminescent material and device containing the same (Ans. 9-11 and 18).
As pointed out by the Examiner, Igarashi discloses luminescent
material compounds including iridium complexes having naphthylquinoline
ligands but which lack the picolinate ligand (Ans. 9; see, for example,
Igarashi’s compounds of formulae 2-4 and 2-12, which include an
acetylacetonate ligand and two naphthylquinoline ligands; see also paras.
0044, 0114 and 0123 and 0124). Moreover, Igarashi discloses luminescent
material compounds including iridium complexes having a phenylquinoline
ligand but which lack the picolinate ligand (see, for example, Igarashi’s
compound of formulae 2-1, which includes an acetylacetonate ligand and
two phenylquinoline ligands).
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Thompson, as discussed above with respect to the rejection over
Petrov and Thompson, teaches acetylacetonate and picolinate as suitable
alternatives for the X ligand of a transition metal complex of formula L2MX
that may be used as an electroluminescent material in an electroluminescent
device.
Based on the combined teachings of Thompson and Igarashi, the
Examiner reasonably determined that:
It would have been an obvious modification to one of
ordinary skill in the art at the time of the invention, having
knowledge of the teachings of Thompson et al., to include a
picolinate ligand in Igarashi's iridium complexes in order to
provide additional complexes suitable for Igarashi’s purposes.
One of ordinary skill in the art would have had a reasonable
expectation of success given Thompson’s teachings that
acetylacetonate and picolinate ligands are suitable for transition
metal complexes such as iridium complexes that can be used
for the same purposes as Igarashi’s complexes. Further, one of
ordinary skill in the art would have been guided in the selection
of particular combinations of orthometalating ligands and
ancillary ligands by the effect that particular ligands and
combinations of ligands would have on the overall properties of
the complex.
Ans. 11.
As noted in the Examiner’s rebuttal of Appellants’ arguments (Ans.
18), the arguments run substantially parallel to those made against the
Examiner’s rejection of claim 14 over Petrov in view of Thompson,
discussed above.
Upon due consideration of Appellants’ arguments, we determine that
these arguments, corresponding to the similar arguments waged against the
aforementioned rejection over Petrov and Thompson, are not persuasive of
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Application 10/467,856

22
substantive error in the Examiner’s obviousness assessment of representative
claim 14 over Igarashi and Thompson for reasons set forth by the Examiner.

Claim 36
Claim 36 depends on claim 26 and Appellants invoke the arguments
made for the patentability of claim 26 based on the picolinate ligand
(substituent) of the iridium complex, once again, for dependent claim 36
(App. Br. 32-33).
Those arguments are not persuasive for reasons set forth by the
Examiner and for reasons as noted above with respect to our discussion of
representative claim 14, which reasons and discussion apply mutatis
mutandis to the arguments made against the Examiner’s rejection of claim
36 based on the compound of the EL material of claim 26.
In addition, Appellants maintain that “Igarashi et al. and Thompson et
al. do not suggest the unexpected improvement in maximal luminance and
luminous efficiency, as shown in Table 1” (App. Br. 33). Appellants assert
that the luminescent material of claim 36 and Inventive Example 6 of the
Specification correspond to formula C3 of the Specification (id.).
However, it is well settled that the burden rests with Appellants to
establish that the asserted results presented as being associated with the
claimed invention are unexpected, the comparisons are with the closest prior
art, and they are commensurate in scope with the claimed subject matter.
See In re Klosak, 455 F.2d 1077, 1080 (CCPA 1972). Here, Appellants have
not argued unexpected results on the basis of such a comparison with the
closest prior art to claim 36. Indeed, the asserted unexpectedness appears to
be mere attorney argument. We agree with the Examiner’s criticism that the
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23
Specification concludes that the results are concentration dependent for the
particular EL device tested with a compound of formula C3 (Ans. 19; Spec.
50, ll. 11-14). In this regard, claim 36 is not drawn to a particular
concentration of the claimed iridium complex as part of a device made in
accordance with Example 6. Also, claim 6 does not require an ITO hole
injection electrode, a hole transport layer constructed as used in the tests, a
hole blocking layer, a luminescent layer host material, and the specified
electron injection electrode as employed in Example 6 (See Spec. 44, ll. 4-10
and Spec. Example 1 as referenced thereat). It follows that Appellants have
not met the requisite burden for the claimed subject matter based on the
narrow showing with respect to Specification Example 6 so as to establish
unexpected results in improved maximal luminance and luminous efficiency
for material of the breadth of claim 36.
Based on the totality of the record, including due consideration of
Appellants’ evidence and arguments, we determine that the preponderance
of evidence weighs most heavily in favor of an obviousness determination
for the claimed subject matter. Accordingly, we affirm the grounds of
rejection presented in this appeal for the reasons stated in the Answer and
above.

ORDER
The Examiner’s decision to reject claims 14, 19, and 26 under 35
U.S.C. § 103(a) as being unpatentable over Petrov in view of Thompson; to
reject claims 1, 23, 24, 34, and 35 under 35 U.S.C. § 103(a) as being
unpatentable over Igarashi; and to reject claims 14, 17-21, 25, 26, and 36
Appeal 2009-005724
Application 10/467,856

24
under 35 U.S.C. § 103(a) as being unpatentable over Igarashi in view of
Thompson, the latter in three separately stated rejections, is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 CFR § 1.136(a).

AFFIRMED

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