IDEMITSU KOSAN CO., LTD.

Patent Trials and Appeals Board

Nov 24, 2021

2021000336 (P.T.A.B. Nov. 24, 2021)

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.
16/523,863 07/26/2019 Sayaka MIZUTANI 523074US 3841
22850 7590 11/24/2021
OBLON, MCCLELLAND, MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA, VA 22314
EXAMINER
BOHATY, ANDREW K
ART UNIT PAPER NUMBER
1759
NOTIFICATION DATE DELIVERY MODE
11/24/2021 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
OBLONPAT@OBLON.COM
iahmadi@oblon.com
patentdocket@oblon.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte SAYAKA MIZUTANI and TAKAYASU SADO
____________

Appeal 2021-000336
Application 16/523,863
Technology Center 1700
____________
Before GEORGE C. BEST, N. WHITNEY WILSON, and
CHRISTOPHER C. KENNEDY, Administrative Patent Judges.
BEST, Administrative Patent Judge.
DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 2 and 26–32 of Application 16/523,863.
Final Act. (January 16, 2020). We have jurisdiction under 35 U.S.C. § 6.
For the reasons set forth below, we reverse.
I. BACKGROUND
The ’863 Application describes an organic electroluminescence
device (“organic EL device”) and aromatic heterocyclic compounds that can

1 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. Appellant
identifies Idemitsu Kosan Co., Ltd., as the real party in interest. Appeal
Br. 1.
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be used in such a device. Spec. ¶ 1. The organic EL device is said to emit at
a high efficiency and be driven at a lower voltage than the prior art due to
the specific aromatic heterocyclic derivative compounds used in the organic
EL device material. Id. ¶ 6.
Claim 2 is representative of the ’863 Application’s claims and is
reproduced below from the Appeal Brief’s Claims Appendix.
2. An aromatic heterocyclic derivative of formula (4):
wherein:
X1, X2, and X3 are each a nitrogen atom;
Ar2 is an unsubstituted terphenyl group;
Ar1 and A are represented by a formula (5) below,
(HAr)a—L1 — (5)
wherein:
HAr is represented by a formula (6) below;
a is 1:
L1 is a single bond;
wherein:
Y1 is an oxygen atom;
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X11 and X18 are each CR13;
one of X12 and X17 is a carbon atom bonded to a carbon atom of
the six membered ring of formula (4) by L1 as a single bond and the
other of X12 and X17 is CR13 and X13 to X16 are each CR13;
and
R13 is a hydrogen atom.
Appeal Br. 12–13.
II. REJECTION
On appeal, the Examiner maintains the following rejection: Claims 2
and 26–32 are rejected under 35 U.S.C. § 103(a) as unpatentable over
Nakano2 as evidenced by Suzuki.3, 4 Final Act. 4.
III. DISCUSSION
Appellant argues for reversal of the rejection of independent claim
2—the only independent claim on appeal. Appeal Br. 5–11. Appellant also
present separate arguments for reversal of the rejection of claims 30–32. Id.

2 US 2007/0141387 A1, published June 21, 2007.
3 The Examiner does not specifically identify which prior art document is
identified to as “Suzuki.” In the Reply Brief, Appellant speculates that the
Examiner intended to cite US 2011/0114928 A1, published May 19, 2011.
Reply Br. 2. Rather than enter a pro forma reversal of the rejection so that
the Examiner can identify Suzuki, we address the merits of Appellant’s
arguments.
4 The Examiner does not include Suzuki in the summary statement of the
rejection. Final Act. 4. The Examiner, however, cites Suzuki as evidence
that changing the attachment point of a dibenzofuran to the core of the
heterocyclic aromatic derivative should not significantly affect the properties
of the compounds. Id. at 8. We, therefore, have modified the summary
statement of the rejection to include Suzuki.
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at 11. Because we reverse the rejection of claim 2, we do not address
Appellant’s arguments regarding claims 30–32.
Appellant’s arguments for reversal of the rejection of claims 2 and
26–32 focus on the structure of the HAr moieties in the claimed aromatic
heterocyclic derivative. Appeal Br. 5–11. As specified in claim 2, each HAr
moiety is a dibenzofuran attached by a single bond to the triazine core of the
aromatic heterocyclic derivative. We note that Appellant and the Examiner
use inconsistent numbering conventions for substituent locations on the
dibenzofuran ring. In this opinion, we use the numbering scheme used by
Appellant, which we understand to be consistent with conventional
nomenclature. This numbering system is shown in the diagram reproduced
below.
A diagram showing the position numbering
for a dibenzofuran ring used in this opinion.
Appeal Br. 5.
We alter the numbering used by the Examiner in the Final Action and the
Examiner’s Answer to conform to the above-illustrated numbering system.
Using the numbering system shown above, claim 2 specifies that each
HAr moiety is attached to the triazine core at the 3 position of the
dibenzofuran ring system, i.e., HAr is a 3-dibenzofuranyl group.
With respect to the HAr moieties, the Examiner found that Nakano
describes a number of compounds in which core of the heterocyclic aromatic
derivative is attached to the dibenzofuran at the 4 position. Final Act. 5–6.
The Examiner further found that Nakano does not describe heterocyclic
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aromatic derivatives with a core that is attached to the dibenzofuran moieties
at the 2 position. Id. at 6. The Examiner then found that it would have been
obvious at the time of the invention “to modify the compounds of Nakano so
that the dibenzofuran groups and the dibenzothiophene groups were attached
at the [2] position and not the [4] position.” Id. at 8.
This finding is insufficient to support a prima facie case of
obviousness. As noted above, independent claim 2 requires that the triazine
core of the heterocyclic aromatic derivative be attached at the 3 position of
the dibenzofuran.
In the Answer, the Examiner remedies this defect, specifically finding
that it would have been obvious to attach the triazine core to the 3 position
of the dibenzofuran rings. Ans. 14–15. The Examiner found that a person
having ordinary skill in the art would have been motivated to make this
change because it would have been expected that positional isomers of the
prior art compounds—i.e., changing the 4-dibenzofuranyl groups to 3-
dibenzofuranyl groups—would yield compounds with similar properties. Id.
at 12–16 (citing In re Dillon, 919 F.2d 668 (Fed. Cir. 1991); In re Payne,
606 F.2d 303 (CCPA 1979); In re Papesch, 315 F.2d 381 (CCPA 1963)).
Appellant argues that this new finding is erroneous because a person
having ordinary skill in the art would not have expected the heterocyclic
aromatic derivatives containing the 3-dibenzofuranyl groups to have similar
properties to the prior art, which contains 4-dibenzofuranyl groups. Reply
Br. 2–3. In the alternative, Appellant argues that it has presented sufficient
evidence of unexpected results to overcome any prima facie case of
obviousness. Appeal Br. 6–9; Reply Br. 4.
We address these arguments in turn.
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First, Appellant argues that a person having ordinary skill in the art
would not have expected that changing the 4-dibenzofuranyl groups to 3-
dibenzofuranyl groups would result in heterocyclic aromatic derivatives with
substantially similar properties. Reply Br. 2–3. We agree with Appellant.
The electroluminescent behavior of the claimed and prior art compounds
depend on the relative energy levels of their molecular orbitals. As
Appellant points out, the change from 4-dibenzofuranyl groups to 3-
dibenzofuranyl groups is significant due to the resonance behavior of the
aromatic rings in the dibenzofuran. Id. Attachment of the triazine core to
the 4 position puts it in an ortho- position relative to the oxygen heteroatom.
As Appellant explains, the 3-dibenzofuranyl groups have the triazine core
located at the meta- position relative to the oxygen atom. At the time of
filing, a person having ordinary skill in the art would have expected this
change in location to substantially change the nature of the interaction
between the electron orbitals of the triazine and the electron orbitals of the
dibenzofuran. In particular, the person having ordinary skill in the art would
expect the oxygen atom to have a much smaller effect on the properties of
the heterocyclic aromatic derivative when 3-dibenzofuranyl groups are used
because the oxygen atom has a smaller effect on the electrons of the triazine
when it is located in the meta- position.
Second, Appellant presents evidence of unexpected differences
between the properties of the claimed heterocyclic aromatic derivatives and
the prior art.5 As shown in the Saito Declaration, compounds within the

5 As we have explained, a person having ordinary skill in the art would have
expected the claimed compounds to differ from the prior art. The ordinarily
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scope of claim 2 require lower voltage and have longer lifetimes than prior
art compounds in an EL device. Appeal Br. 6–7.
The Examiner concluded that the results presented in the Saito
Declaration were not sufficient to overcome the prima facie case of
obviousness. Answer 16–18. In particular, the Examiner determined that the
results were not commensurate in scope with the claims. Id. The Examiner
reasoned that the Saito Declaration demonstrated changes in the properties
of an EL device and not changes in the properties of compounds themselves.
Id. at 16.
We are not persuaded by the Examiner’s reasoning. The prior art and
claimed compounds were tested in EL devices that were otherwise identical.
Saito Decl. 2–3. Thus, the differences in the EL devices’ properties are the
result of the different properties of the host materials used in the devices.
Appellant, therefore, has demonstrated that the claimed compounds have
unexpected properties relative to prior art compounds. After consideration of
all of the evidence for and against an obviousness determination, we
conclude that the Examiner has not demonstrated that the differences
between the prior art and the claimed subject matter would have been
obvious.
In view of the foregoing, we reverse the rejection of claim 2. Thus, we
also reverse the rejection of claims 26–32.

skilled artisan, however, would not have been able to predict whether these
differences would result in improved properties relative to the prior art.
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IV. CONCLUSION
In summary:
Claim(s)
Rejected
35
U.S.C. § Reference(s)/Basis Affirmed Reversed
2, 26–32 103(a) Nakano, Suzuki 2, 26–32
REVERSED