UNITED STATES PATENT AND TRADEMARK OFFICE
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`Duk San Neolux Co., Ltd.,
`Petitioner
`
`v.
`
`Idemitsu Kosan Co., Ltd.,
`Patent Owner
`
`IPR2016-00148
`
`PETITIONER’S REPLY
`
`Mail Stop PATENT BOARD
`Patent Trial and Appeal Board
`US Patent and Trademark Office
`P.O. Box 1450
`Alexandria, VA 22313-1450
`
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`Duk San Neolux Co., Ltd.,
`Petitioner
`
`v.
`
`Idemitsu Kosan Co., Ltd.,
`Patent Owner
`
`IPR2016-00148
`
`PETITIONER’S REPLY
`
`Mail Stop PATENT BOARD
`Patent Trial and Appeal Board
`US Patent and Trademark Office
`P.O. Box 1450
`Alexandria, VA 22313-1450
`
`
`
`TABLE OF CONTENTS
`
`I.
`
`II.
`
`Challenged Claims 1, 3, 4, and 14-26 Are Obvious over Heil in view of
`Kawaguchi ...................................................................................................... 3
`A. Claims 1, 3, 4, 15, 16 and 21-26 .......................................................... 3
`B. Claims 14 and 17-20…………………………………………………18
`
`Challenged Claims 1, 3, 4, 15, 16 and 22-26 are Obvious over Kai in View
`of Kawaguchi................................................................................................ 19
`
`III. Challenged Claim 21 Obvious over Kai with Kawaguchi and Heil .............25
`
`IV. Conclusion .....................................................................................................26
`
`2
`
`
`
`I.
`
`CHALLENGED CLAIMS 1, 3, 4, AND 14-26 ARE OBVIOUS OVER
`HEIL IN VIEW OF KAWAGUCHI
`
`A. Claims 1, 3, 4, 15, 16 and 21-26
`
`Heil teaches compounds for use as a material for an OLED, including
`
`compounds of Formula 2(a): (DSN-1015, 10:20-25)
`
`Kawaguchi is directed to heteroacene compounds possessing improved
`
`properties for potential use in active layers of OFETs having the formula:
`
`in which R is H or alkoxy. (DSN-1016, Abstract; 2:34-44)
`
`In summary, Petitioner has submitted that the POSITA would have selected
`
`the hetero bridging atoms N/O of Kawaguchi for the Xs of Heil because: (1)
`
`Kawaguchi teaches improved oxidative stability provided by the N/O heteroatom
`3
`
`
`
`arrangement compared with the N/N heteroatom arrangement (DSN-1016, 2:34-
`
`43) and (2) Heil includes N (Heil’s preferred heteroatom – DSN-1015, 12:23-24)
`
`and O within its Xs possibilities, and within a small grouping of “X” atoms (DSN-
`
`1015, 6:18-21).
`
`Patent Owner argues that (1) Petitioner has not addressed the structural
`
`differences between the compounds of Heil and the compounds of Kawaguchi and
`
`how those differences would affect the expectation of success upon making the
`
`proposed modifications and (2) Kawaguchi does not disclose or suggest the
`
`improved oxidative stability of the N/O arrangement in a modified Heil compound.
`
`(Paper 13, 15-27)
`
`In reply, and as explained more fully hereinbelow, (A) the structural
`
`differences between the compounds of Heil and the compounds of Kawaguchi (1)
`
`do not affect the expectation of success and (2) are easily modified where needed
`
`by the POSITA for converting potential OFET compounds into OLED compounds,
`
`and (B) Kawaguchi does disclose the improved oxidative stability of the N/O
`
`heteroatom arrangement compared to the N/N heteroatom arrangement, and this
`
`would translate into a similarly modified Heil compound.
`
`The linking atoms “X” set forth in Heil in its broadest statement thereof are
`
`B, C, Si, O, S, N and P (DSN-1015, 6:18-21), and three of these disclosed seven
`
`atoms have been selected to be set forth in claim 1 of the ‘870 patent. One of two
`
`4
`
`
`
`particularly preferred linking atoms “X” of Heil is the heteroatom N (12:23-24).
`
`Thus, there is a direct teaching and direction in Heil regarding its heteroacene
`
`compounds, that at least one of its “Xs” is selected as the heteroatom N, which is
`
`in turn substituted by R1. A number of the Heil example heteroacene compounds
`
`depict one or two of the “X” linking atoms as N; see compounds 4, 29 and 51 of
`
`Heil as compounds containing two N atoms (13:15, 15:33; 18:5). Of significance,
`
`note Heil compound 52 in which one “X” is N and the other is another Heil linking
`
`atom, C in this case (18:5), a clear teaching by Heil that when one “X” is N, the
`
`other “X” need not be N but can be selected from one of the remaining six linking
`
`atoms of Heil.
`
`Therefore, the Patent Owner is incorrect in alleging that Heil’s exemplary
`
`compounds always have identical divalent bridges (Paper 13, p. 13). To the
`
`contrary, Heil’s Xs need not be identical, and there is a clear direction and
`
`5
`
`
`
`preference in Heil for selection of at least one of its Xs as the hetero atom N in the
`
`Heil heteroacene compounds.
`
`Kawaguchi’s compounds of the N/O type possess enhanced stability
`
`regarding air degradation and/or photooxidation, as compared with a similar
`
`symmetrical (N/N) compound DSN-1016, 2:34-44). Kawaguchi includes
`
`experimental data to this effect. See Table 2 at 4, where compounds 1a, 1c and 1d
`
`(N/O compounds) possess lower EHOMO values (lower the EHOMO value, the greater
`
`the resistance to oxidative degradation – see text at 4, above Table 2) than DPh-1C
`
`(N/N compound). Thus, Kawaguchi teaches that heteroatom selection as bridging
`
`atoms in heteroacenes affects air degradation and/or photooxidation of heteroacene
`
`compounds. Since Heil prefers N as a linking heteroatom in its heteroacene
`
`compounds for improved overall OLED performance (DSN-1015, 4:26-33), the
`
`POSITA from Kawaguchi is motivated to move from the N/N selection of Heil
`
`(e.g., compound 4 as below, DSN-1015, 13:13-20) to the O/N heteroatom selection
`
`of Kawaguchi as bridging atoms for OLED compounds possessing improved
`
`oxidation resistance.
`
`6
`
`
`
`The POSITA would predict with a reasonable expectation of success that
`
`these heteroacene compounds (N/O or N/S1 as bridging atoms) would be
`
`characterized by retention of the improved OLED properties of Heil with better
`
`oxidation resistance as compared with the example heteroacene compounds of Heil
`
`containing two N bridging atoms. As explained by Dr. Schwartz (DSN-1033,
`
`¶16), and as evidenced by Hu (DSN-1032), it was known in the art that
`
`Kawaguchi’s N/N type compound DPh-IC, which has the same structure as
`
`compound 6 of Hu as depicted below and is only different from Kawaguchi’s new
`
`N/O type compound in that it has N-phenyl on the heteroacene core instead of O,
`
`is a useful OLED material.
`
`1 As explained later for claim 14, the N/S arrangement is understood by the
`N/O arrangement of Kawaguchi coupled with other evidence.
`
`7
`
`
`
`Accordingly, the POSITA would have been motivated to use the N/O
`
`bridging atoms suggested by Kawaguchi in place of the N/N hetero compounds of
`
`Heil, for improving oxidative stability in OLED materials, a predictable result.
`
`Also, patent Owner’s expert admitted that the Kawaguchi compounds can be used
`
`in OLEDs. DSN-1027, 22:2-8.
`
`Heil prefers compounds of the cis or trans configuration as evidenced by its
`
`formulas (2a), (3a) and (4a) (DSN-1015-9:20-35). Furthermore, Heil Formula (2a)
`
`is represented by a number of the Heil example heteroacene compounds, including
`
`those having the N/N arrangement. (See Heil compound 4 shown above).
`
`Petitioner has not arbitrarily selected Formula (2a) of Heil with Xs as N for
`
`potential modification in view of Kawaguchi. When the entire disclosure of Heil is
`
`considered, the POSITA is taught that cis and trans configurations of the bridging
`
`atoms are equally preferred and that a preferred bridging atom for heteroacenes is
`
`N. The fact that Heil only tests one compound for OLED usage, which is not a
`
`heteroacene, can not detract from the remainder of its disclosure. The POSITA in
`
`8
`
`
`
`evaluating Heil’s disclosure as related to heteroacenes, would not focus at all on
`
`the non-heteroacene disclosure of Heil, but only on its heteroacene disclosure,
`
`which is the subject matter (heteroacene materials) of the challenged claims. The
`
`POSITA from Heil in studying heteroacenes would not consider its single tested
`
`compound because it is not a heteroacene, but would consider the preferred
`
`heteroacene structures of Heil such as represented by its exemplary compound 4,
`
`illustrating a preferred N/N bridging arrangement in a preferred cis configuration,
`
`when undertaking research and analysis of the art for improving OLEDs based on
`
`heteroacenes. The same analysis is useful in evaluating obviousness based on a
`
`combination of references, where the secondary reference relates to preferred
`
`teachings of the primary reference, which is the case here. Kawaguchi only relates
`
`to heteroacenes. The POSITA, with Heil and Kawaguchi in front of him, and
`
`wanting to apply the improved oxidative stability characteristic of Kawaguchi
`
`would only focus upon the heteroacene disclosure of Heil and would not consider
`
`at all the non-heteroacene parts of Heil. See Schwartz Declaration(DSN-1033) at
`
`¶51.
`
`Certainly, Kawaguchi differs from Heil in setting forth a central benzene
`
`instead of naphthalene. But, as explained by Dr. Schwartz (DSN-1033, ¶57), that
`
`difference does not affect the significant teaching of Kawaguchi regarding the
`
`employment of an O bridging atom with a N bridging atom in a heteroacene
`
`9
`
`
`
`backbone for improved environmental stability as compared with a similar
`
`compound possessing two N bridging atoms. This teaching of Kawaguchi is not
`
`dependent upon the end use of Kawaguchi’s new compounds. The important point
`
`is that an N/O configuration, if placed in the Heil structure, would be more
`
`environmentally stable than an N/N configuration shown by Heil in its example
`
`compound 4. This conclusion is independent of potential use as an OFET material
`
`or as an OLED material. Since Heil specifically discloses that its X can be O, the
`
`selection of the O/N bridging atom combination would not affect the end use of
`
`such a modified Heil compound as an OLED material. But even if that were the
`
`case, the POSITA knows from the level of art as evidenced by articles by Anthony
`
`(Patent Owner’s expert) (“Anthony”, DSN-1031) and Moorthy (DSN-1030) that
`
`the addition of one or more bulky chains converts an OFET material to an OLED
`
`material. DSN-1033, ¶58.
`
`Moorthy and Anthony discuss the effect of bulky substituent(s) substituted
`
`on luminescent compounds that otherwise exhibit significant π-stacking so as to
`
`sterically hinder their π-stacking in the solid state. Such compounds without steric
`
`hindrance have not found general usefulness as OLED materials, although being
`
`highly fluorescent in solution; this is because their emission in the solid state is
`
`suppressed due to the formation of excimers or aggregates due to their excessive π-
`
`stacking, as explained by Dr. Schwartz (DSN-1033, ¶59).
`
`10
`
`
`
`Moorthy deals with tetraphenylpyrene, useful as an OFET material but not
`
`as an OLED material due to its π-stacking in the solid state. Moorthy adds a
`
`plurality of methyl groups as substituents on each phenyl substituent on the pyrene
`
`nucleus to produce steric hindrance between adjacent molecules for preventing
`
`excessive π-stacking and molecular aggregation in the solid state. Such materials
`
`then become useful as OLED luminescent materials, exhibiting reduced
`
`luminescence quenching. DSN-1030, 1:Abstract; 1-2:bridging paragraph; 2:
`
`bridging paragraph of cols.; 4: right col., 21-31. See also DSN-1033, ¶¶37.
`
`Anthony describes that the addition of bulky naphthalene substituents at the
`
`9 and 10 positions of anthracene for breaking up aggregation (caused by π-
`
`stacking) in the solid state for providing effective OLED materials (DSN-1031,
`
`4:2.2 Anthracene Derivatives in Light-Emitting Diodes). Anthony also describes
`
`the employment of bulky phenyl substituents on multiple pyrene units of a single
`
`compound for providing steric hindrance, resulting in an OLED material (4: right
`
`col. 5-22). See also DSN-1033, ¶38.
`
`From Moorthy and Anthony, the POSITA, if needed, would add a bulkier
`
`substituent(s) to Kawaguchi’s new compounds, or to the Heil N/N compounds as
`
`modified by Kawaguchi for providing an N/O compound, for hindering their
`
`aggregation in the solid state, providing for efficient OLED materials (DSN-1033,
`
`¶603). This is illustrated by Toray, especially Toray compound 137 (DSN-1029,
`
`11
`
`
`
`34; Abstract). Toray compound 137 as depicted below has the exact backbone of
`
`Kawaguchi compounds Ar-BFCs but has added a bulky group as a substituent off
`
`of the phenyl group attached to the carbazole N, thereby providing steric
`
`hindrance.
`
`\
`
`Toray Compound 137
`
`The need for one or more bulky side chains on the heteroacene backbone for
`
`OLED performance would motivate the POSITA away from a Kawaguchi
`
`DBBDF-type structure (O/O bridging atoms) and toward the O/N arrangement of
`
`bridging atoms since the bulky side chain is readily introduced as a substituent of
`
`the N atom as illustrated by the state of the art of Toray. Thus, the N/O bridging
`
`atoms provide improved oxidative stability coupled with a convenient means for
`
`introducing a side chain for converting a potential OFET compound into an OLED
`
`compound, all of which is known to the POSITA from Kawaguchi (with the state
`
`of the art as represented by Anthony, Moorthy and Toray-and as acknowledged by
`
`Anthony DSN-1027, 29:14-18). This result is predictable and expected from the
`
`12
`
`
`
`prior art in combining Heil with Kawaguchi. Mere routine experimentation would
`
`be required in determining the side chain appropriate for OLED characteristics,
`
`bearing in mind the preferred heteroaryl R1 moiety (pyridino noted by the
`
`Examiner) of Heil (DSN-1015, 7:7,8:27). The same chemical backbone is
`
`effective for both OFET and OLED utilities. DSN-1027, 55:16-17.
`
`Patent Owner argues that symmetrical C(R1)2 divalent bridges would be
`
`expected to have a higher oxidative stability than O/N divalent bridges; however,
`
`no data is of record by Patent Owner testing the oxidative stability of such a cyclic
`
`C(R1)2 compound. As Dr. Schwartz explains (DSN-1033, ¶¶61), the stability order
`
`for the cyclic compounds of carbazole, dibenzofuran, fluorene and
`
`dibenzothiophene may be different from what Patent Owner argues, when
`
`oxidative stability is actually measured. This is especially true because Dr.
`
`Anthony’s position is based on isopropyl, methoxy and dimethylamine as
`
`substituents and not on complex cyclic structures including C, O and/or N in their
`
`ring(s). (IDK-2007,¶75 as supported by IDK-2021 where under the heading
`
`“Substituent”, values for N(Me)2, isopropyl and OMe are provided.) Further, as
`
`Dr. Schwartz explains (DSN-1033, ¶62) heteroacenes were already used in the
`
`OLED art, with carbazoles and indolocarbazoles being particularly selected.
`
`Going away from the heteroacenes to the acenes (or acene derivatives), with all
`
`carbon atoms in the backbone skeleton, would cause loss of certain advantages of
`
`13
`
`
`
`the hetreroacenes, including the combination of appropriately placed HOMO and
`
`LUMO levels, band gaps, and degree of luminescence. A POSITA would start
`
`with what is known to work in OLEDs, i.e., heteroacenes, and then seek
`
`guidance from Kawaguchi for improving the oxidation resistance of the known
`
`Heil heteroacene compounds.
`
`Regardless, the new N/O structures of Kawaguchi are shown by actual data
`
`to possess better oxidative stability as compared with N/N-type compounds, and
`
`also, importantly, Kawaguchi also directs the POSITA to select an N atom as an X
`
`atom of Heil.
`
`Kawaguchi deals with heteroacenes and their improved oxidative stability;
`
`the C(R1)2 structures of Heil are not heteroacenes. Thus, the POSITA with Heil
`
`and Kawaguchi in front of him, would look to improve the heteroacene structures
`
`of Heil, of which the N/N bridging atom structure would be preferred. The
`
`POSITA would modify the N/N bridging atom heteroacene structure to the O/N
`
`bridging atom heteroacene structure with a reasonable expectation of success in
`
`preparing an OLED compound with improved oxidative stability, a predictable
`
`result. At the most, the POSITA might need to consider altering the methylphenyl
`
`side chain (N substituent) of Heil compound 4 once one of its N atoms has been
`
`changed to the O atom, for good OLED performance as taught by Anthony,
`
`Moorthy and Toray. A preferred R1 of Heil is a heteroaryl group having 2-16 C
`
`14
`
`
`
`atoms (DSN-1015-11:7-8, 13-14). At least one R1 of Heil must be aryl (which may
`
`be substituted by heteroaryl) or heteroaryl (5:30-33; 6:12-14,28-29). Heil recites
`
`that R1 can be a heteroaryl, like a pyridine group (8:27). Thus, Heil directly
`
`teaches the R1 substituent of the challenged claim 1.
`
`Thus, Patent Owner is not correct in alleging that the proposed modification
`
`of Heil’s compounds as taught by Kawaguchi would be deleterious, rendering
`
`Heil’s compounds including such modification as non-functional. This fallacy is
`
`illustrated by Heil compound 14 (DSN-1015-14:15) where both Xs are O,
`
`preventing the addition of bulky side chains to those X atoms; instead, a bulky
`
`naphthalene group is attached to each side of the heteroacene backbone for
`
`breaking up aggregation in the solid state and resulting in a Heil OLED compound.
`
`Patent Owner discusses in great detail the architecture of OFET and OLED
`
`compounds and the charge transport axis of each. Patent Owner argues that the
`
`proposed modification as taught by Kawaguchi to Heil’s compounds would render
`
`Heil’s modified compounds unsatisfactory for their intended use (Paper 13, 32-49).
`
`This position is based on Kawaguchi’s discussion of -stacking, which according
`
`to Patent Owner causes unwanted aggregation, increased quenching in the solid
`
`state and unwanted excimer formation. This entire discussion is nothing more than
`
`a smokescreen. The important teaching of Kawaguchi is that the addition of an O
`
`atom to the heteroacene backbone – i.e., modification of the indolocarbazole DPh-
`
`15
`
`
`
`IC with the N/N arrangement to the benzofuranocarbazole Ar-BFCs with the N/O
`
`arrangement - provides improved oxidative stability (DSN-1033, ¶63) and that
`
`teaching is true regardless of the end utility for the compound. Further, as
`
`explained above, and as supported by Dr. Schwartz (DSN-1033,¶¶64,66), Anthony
`
`, Moorthy, and Toray, there is nothing magical about converting an OFET
`
`compound, where needed or desirable, into an OLED compound. For example, if
`
`the substitution of an O atom for one of the N atoms of Heil compound 4 did
`
`increase π-stacking to an undesirable degree, only routine experimentation would
`
`be needed to remedy the problem, as illustrated by the bulky groups on other of the
`
`Heil exemplary compounds. Patent Owner’s expert in this regard admitted that
`
`Kawaguchi’s compounds can be used for OLEDs (DSN-1027, 22:2-8) and that a
`
`potential OLED compound can be tuned by the POSITA to avoid π-stacking (Id.
`
`57:10-58:2).
`
`Patent Owner also argues that a proper lead compound analysis of Heil has
`
`not been made, submitting that Heil only tests one compound, compound D3, for
`
`OLED properties and that compound has C/C bridging atoms. In this position,
`
`Patent Owner ignores the relevant technical field related to the invention and, from
`
`that, the portion of Heil related to the relevant technical field. Claim 1 of the ‘870
`
`patent claims a material for an organic electroluminescence (El) device represented
`
`by the structural formula (1) or (2), both of which are depicting heteroacene
`
`16
`
`
`
`compounds. Thus, the relevant technical field is heteroacene compounds for use in
`
`El devices, such as OLEDs. The disclosure of Heil is broader than the relevant
`
`field, as being inclusive of El device materials which are and are not heteroacenes.
`
`Patent Owner relies on the non-heteroacene portion of Heil in its lead compound
`
`analysis. Within the heteroacene disclosure of Heil, N is the preferred heteroatom
`
`(DSN-1015, 12:23-24). Within its exemplary compounds, Heil includes three
`
`compounds having the N/N configuration for their divalent bridges, each of which
`
`could be initially selected as a lead compound. Compounds 4 (13:15) and 29
`
`(15:33) of Heil are preferred cis structures while compound 51 (18:5) is of a
`
`preferred trans configuration. Kawaguchi’s new compounds of the O/N bridging
`
`atom configuration contain a substituted or unsubstituted phenyl group on the
`
`carbazole N atom; Heil compounds 4 and 51 carry substituted and unsubstituted
`
`phenyl rings off of both of their N atoms. Either could be equally chosen as a lead
`
`compound. Compound 4 meets the criteria of being of the preferred cis
`
`configuration and containing the preferred N atoms, as a lead compound. In
`
`compound 4 substitution of the O atom from Kawaguchi for one of the N-
`
`methylphenyl moieties thereof, provides the El material of the challenged claim 1.
`
`DSN-1033, ¶¶69-70. This conclusion of obviousness is proper under the principles
`
`of In re Dillon, 919 F.2d 688 (Fed. Cir. 1990) (en banc) (close structural
`
`similarity) and Genetics Inst., LLC v. Novartis Vaccines and Diagnostics, Inc., 655
`
`17
`
`
`
`F.3d 1291,1304 (need for a reason for the modification) and also on a leading
`
`compound analysis, Eisai Co. Ltd. v. Dr. Reddy’s Labs Ltd., 533 F.3d 1353, 1357
`
`(Fed Cir. 2008) (obviousness based on structural similarity can be proved by
`
`motivation leading the skilled artisan to select and modify a known compound ( i.e.
`
`a lead compound) to achieve the claimed compound).
`
`Heil in its above Formula (2a) depicts the unsubstituted naphthalene group
`
`of claims 16 and 21. Patent Owner has not argued separate patentability of any of
`
`the dependent claims; the dependent claims stand or fall with claim 1.
`
`Clearly, claims 1, 3, 4, 15, 16 and 21-26 are prima facie obvious over Heil
`
`with Kawaguchi.
`
`B. Claims 14 and 17-20
`
`Claim 14 claims the device of claim 1 wherein X2 is S.
`
`As explained by Dr. Schwartz (DSN-1033, ¶74), N and S are both
`
`chalcogens often used interchangeably. For example, as expected from Heil, both
`
`would change the electron donating/hole mobility balance of a parent compound
`
`when in a bridging relationship with a bridging N atom of a heteroacene structure,
`
`for providing improved charge balance (Id.). Kawaguchi in Table 2 (DSN-1016,
`
`4) teaches that the fine tuning of HOMO and LUMO values can be achieved by
`
`selection of heteroatoms (e.g., the used N/O, and analogous atoms such as N/S) as
`
`bridging atoms in a backbone of the challenged claim 1 in a trans configuration.
`
`18
`
`
`
`This information would motivate the POSITA to use the N/O type compounds or
`
`N/O type core skeletons (benzofuranocarbazole) as OLED materials. Although
`
`Kawaguchi did not employ an N/S combination of heteroatoms, it would have been
`
`obvious for the POSITA to do so because of the close chemical and
`
`electrochemical relationships between O and S atoms. See DSN-1033,¶¶72-74).
`
`Moreover, when asked about the relative stabilities of heteroacenes with S
`
`substituted in place of O, Dr. Anthony said that “in general, thiophenes [5
`
`membered aromatic rings with an S atom] are harder to oxidize than furans [5
`
`membered aromatic rings with an O atom]”, (p. 49 lines 19-20) indicating that
`
`additional tuning stability/HOMO level by substituting S for O would be an
`
`obvious thing to do. DSN 1033, ¶73. This is especially true here as two of Heil’s
`
`exemplary compounds employ S bridging units in the heteroacene backbone, Heil
`
`compounds 15 and 19 (DSN1016-14:20;15:5) The POSITA is taught N/X units
`
`from Heil compound 52 (18:5), N/O bridging units from Kawaguchi and by
`
`extension of Kawaguchi and Heil compounds 15 and 19, an N/S bridging unit
`
`configuration. Accordingly, the challenged claims 14 and 17-20 are prima facie
`
`obvious.
`
`The challenged claims 18 and 19 are prima facie obvious at least for the
`
`reasons set forth in the Petition (Paper 1, 45: 1-9; 51:13-15)
`
`19
`
`
`
`II.
`
`CHALLENGED CLAIMS 1, 3, 4, 15, 16 AND 22-26 ARE OBVIOUS
`OVER KAI IN VIEW OF KAWAGUCHI
`
`Kai describes cis and trans type heteroacene compounds useful as host
`
`materials for phosphorescent dopants in the light emitting layer of OLEDs (DSN-
`
`1019, Abstract). The cis compounds of Kai possess the general formula (2):
`
`in which, X is N or CH and at least one of the Xs is N; Ar1 to Ar3 each
`
`represent a substituted or unsubstituted non-condensed aromatic hydrocarbon or
`
`aromatic heterocyclic group; and Ar2 and Ar3 each may form a condensed ring
`
`with the X-containing ring (¶¶14-15). Preferably, one, two or three of Xs are N
`
`atoms (¶ 22). The Kai trans compounds are analogous to the Kai cis compounds.
`
`Kawaguchi is discussed in detail in Section I., above. Petitioner submits that
`
`a POSITA, looking to improving upon the compounds of Kai, would have
`
`substituted an O atom for the N-Ar1 bridge of Kai for increasing the oxidative
`
`stability of the Kai cis compounds.
`
`Patent Owner argues that an explanation as to why a skilled artisan would
`
`have been motivated to modify the cis compounds of Kai by replacing the N-Ar1
`20
`
`
`
`moiety rather than the N-X-containing ring moiety with an O atom has not been
`
`provided. That is not the case. As fully explained in the Petition (Paper 1, ¶
`
`bridging 53-54), the POSITA would routinely modify the Kai cis or trans
`
`compounds by substituting an O atom for the N-Ar1 (N-phenyl) moiety of Kai
`
`(DSN-1019, ¶13). Motivation is provided by the improved stability of the
`
`Kawaguchi-type asymmetric structure, a characteristic, desired in the organic
`
`compounds used in EL devices, such as the compounds of Kai. The improved
`
`compounds of Kawaguchi possess an O in a position shown for N-phenyl in the
`
`earlier Kawaguchi compound (DPh-1C) (2:28-32, 44). Therefore, the POSITA is
`
`motivated to substitute O for N-phenyl in the compounds of Kai (e.g., compound
`
`3) as opposed to substituting O for the N-heteroaryl moiety in Kai. The art of
`
`Kawaguchi provides a good reason (better environmental stability) for pursuing
`
`this option.
`
`Patent Owner argues that the experimental data in Kai prove that both the
`
`carbazole N atom (to which the X-containing ring is attached) and the indole N
`
`atom (to which Ar1 is attached) are essential and cannot be modified in the
`
`compounds of Kai. That is not the case. As the Patent Owner’s expert admitted,
`
`the POSITA would look everywhere within the Kai compounds for their possible
`
`modification (DSN-1027, 65:10-13,18) including either the carbazole N atom with
`
`21
`
`
`
`X-containing ring or the indole N atom with Ar1 (Id.), taking into consideration
`
`what is easy to modify based on educated guesses (65:21-22; 66:2). DSN-1033,¶76
`
`The experimental data Patent Owner relies on is reproduced below, along
`
`with the structures of the tested compounds as shown in Kai (¶¶31-33, 39). The
`
`data teaches the POSITA that Kai compound 3 possesses the best voltage (4.9 V)
`
`and luminous efficiency (18.3 lm/W) combination of the Kai tested compounds.
`
`The data teaches the POSITA from comparing Kai compound 3 with compounds
`
`29 and 37 that increasing the size of the Ar1 moiety increases voltage and decreases
`
`luminous efficiency, suggesting that a small moiety would be preferred at that
`
`location of the Kai molecule. The data also teaches the POSITA from comparing
`
`Kai compound 3 with compounds 1 and 2, a significance on those properties is
`
`provided by the number of N atoms in the X-containing ring attached to the
`
`carbazole N atom, progressing from 1 to 2 to 3 N atoms in the X-containing ring
`
`along with decreasing voltage and increasing luminous efficiency as the number of
`
`N atoms increases (Also, see DSN-1027, 62:16-21). The data further teaches the
`
`POSITA from comparing Kai compound 37 with compound 114 that the cis
`
`configuration of compound 37 shows improved luminescence (cd/m2) (2280 vs.
`
`1970) and luminous efficiency (lm/W) (11.0 vs. 10.1) over the trans configuration
`
`of compound 114.Table 3 (DSN-1019, ¶79). DSN-1033,¶77.
`
`Compound
`No.
`
`Luminance
`(cd/m2)
`22
`
`Voltage
`(V)
`
`Luminous
`efficiency
`
`
`
`Example 10
`Example 10
`Example 11
`Examplell
`Example 12
`Example 12
`Example 13
`Example 13
`Example 14
`Example 14
`Example 15
`Examp1e15
`Example 16
`
`3
`114
`116
`2
`29
`37
`1
`
`2850
`
`2850
`1970
`3100
`2900
`3320
`2280
`2740
`
`4.9
`
`4.9
`6.1
`7.9
`5.5
`6.3
`6.5
`6.7
`
`(lm/W)
`(lm/W)
`
`18.3
`18.3
`10.1
`10.1
`12.3
`12.3
`16.6
`16-6
`16.6
`16-6
`11.0
`11-0
`12.8
`12.8
`
`23
`
`23
`
`
`
`Substituting an O atom for the N-phenyl moiety in compound 3 of Kai
`
`would be expected to maintain its desired OLED characteristics while increasing
`
`its environmental stability. DSN-1033,¶¶
`
`78-79 If a lead compound analysis were made with respect to Kai, Kai
`
`compound 3 would be selected as the lead compound, since it possesses the best
`
`combination of OLED characteristics. DSN-1019, ¶79; DSN-1027, 60:22-25.
`
`Then, from Kawaguchi, where an N-phenyl group is being replaced by an O atom,
`
`the same substitution would be made in Kai compound 3 in its indole moiety for
`
`providing a compound within claim 1 of the ‘870 patent, a predictable result with
`
`the expectation of improved environmental stability for the new compound as
`
`compared to Kai compound 3. DSN-1033,¶80. The skilled artisan would expect
`
`retention of Kai’s OLED properties in view of the large, bulky substituent on the
`
`Kai carbazole N atom.
`
`Accordingly, Kai with Kawaguchi presents a prima facie case of
`
`obviousness of the challenged claims 1, 3, 4, 15, 16 and 24-26.
`
`Claims 22 and 23 are also prima facie obvious over Kai with Kawaguchi.
`
`As to claim 22, Patent Owner admits that dihydroacridine of claim 22 is literally
`
`within the Kai description of the substituent on the carbazole N atom of Kai (Paper
`
`13, 68:6-7). Thus, claim 22 is obvious.
`
`24
`
`
`
`As to claim 23, each of pyridine, pyrimidine and pyrazine falls within the X-
`
`containing ring of formula (1) of Kai (DSN-1019, ¶14), as these groups are
`
`depicted in the Response (Paper 13, 67). Claim 23 depends upon claim 1, reciting
`
`in its description of R1 that R1 can be substituted, with substituent possibilities
`
`being an unsubstituted phenyl group or an aromatic heterocyclic group. These two
`
`substituent possibilities are precisely the Ar2 and Ar3 definitions at Kai (¶14) – a
`
`non-condensed aromatic hydrocarbon group or a non-condensed aromatic
`
`heterocyclic group. Claim 23 does not require that its recited groups be
`
`unsubstituted. From claim 1, the groups of claim 23 can be substituted or
`
`unsubstituted. As such, claim 23 is prima facie obvious over Kai with Kawaguchi.
`
`III. CHALLENGED CLAIM 21 OBVIOUS OVER KAI WITH
`KAWAGUCHI AND HEIL
`
`Claim 21 is dependent upon claim 1 and recites that Ar2 is an unsubstituted
`
`naphthalene group. Patent Owner admits that the Kai cis compounds of Kai
`
`formula (2) can be modified to have a naphthalene core as disclosed by Heil (Paper
`
`13, 73:11-12), which, of course, meets the limitation of claim 21.
`
`Claim 1 is obvious over Kai with Kawaguchi for the reasons discussed
`
`above in Section II. The issue then is whether it is obvious to modify the central
`
`ring of Kai to that of Heil. Petitioner submits that is the case. Both Kai and Heil
`
`are directed to improved OLED properties of OLEDs. The use of the central core
`
`25
`
`
`
`of Heil in the Kai formula (2) compounds would be expected to maintain the
`
`OLED characteristics of Kai’s compounds (as modified by Kawaguchi’s teachings)
`
`while providing projected improvements of Heil’s compounds (in efficiency and
`
`lifetime – DSN-1015, 4:28-30), a predictable and expected result from Heil. Patent
`
`Owner argues that the addition of the second benzene ring would be expected to
`
`provide undesirable traits in the new compounds with respect to absorption spectra
`
`and potential π-stacking interactions. These arguments make no sense. They
`
`question the veracity of the Heil reference without providing any supporting
`
`experimental data. See Heil at 4:18-33. Once claim 1 is found to be obvious,
`
`claim 21 is also prima facie obvious with the addition of the Heil reference to the
`
`combination of Kai with Kawaguchi.
`
`IV. CONCLUSION
`
`Petitioner has established the obviousness of claims 1, 3, 4, and 14-26 of the
`
`‘870 patent by a preponderance of the evidence. Accordingly, those claims should
`
`be canceled from the ‘870 patent.
`
`Respectfully submitted,
`
`VORYS, SATER, SEYMOUR AND PEASE LLP
`
`Date: November 16, 2016
`
`/William H. Oldach III/
`William H. Oldach III
`Attorney for Petitioner
`
`26
`
`
`
`DUK SAN NEOLUX CO., LTD.
`Registration No. 42,048
`
`VORYS, SATER, SEYMOUR AND PEASE LLP
`1909 K Street NW, Ninth Floor
`Washington, D.C. 20006-1152
`Tel: 202-467-8800 / Fax: 202-533-9187
`
`27
`
`
`
`CERTIFICATE OF COMPLIANCE
`
`Pursuant to 37 C.F.R. § 42.24(d), the undersigned certifies that this Reply
`
`complies with the type-volume limitation of 37 C.F.R. § 42.24(a). The word count
`
`application of the word processing program used to prepare this Reply indicates
`
`that the Reply contains 4,839 words, excluding the parts of the brief exempted by
`
`37 C.F.R. § 42.24(a)(1).
`
`Respectfully submitted,
`
`VORYS, SATER, SEYMOUR AND PEASE LLP
`
`Date: November 16, 2016
`
`/William H. Oldach III/
`William H. Oldach III
`Attorney for Petitioner
`DUK SAN NEOLUX CO., LTD.
`Registration No. 42,048
`
`VORYS, SATER, SEYMOUR AND PEASE LLP
`1909 K Street NW, Ninth Floo
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