Trials@uspto.gov
`571-272-7822
`
`Paper No. 13
`
` Entered: March 12, 2018
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`BASF SE,
`Petitioner,
`
`v.
`
`FRESENIUS MEDICAL CARE HOLDINGS, INC.,
`Patent Owner.
`____________
`
`Case IPR2017-01948
`Patent 9,353,220 B2
`____________
`
`
`
`Before JO-ANNE M. KOKOSKI, CHRISTOPHER M. KAISER, and
`JEFFREY W. ABRAHAM, Administrative Patent Judges.
`
`
`ABRAHAM, Administrative Patent Judge.
`
`
`
`
`DECISION
`Institution of Inter Partes Review
`37 C.F.R. § 42.108
`
`
`
`
`
`
`
`
`
`
`
`

`

`IPR2017-01948
`Patent 9,353,220 B2
`
`
`
`I. INTRODUCTION
`
`BASF SE (“Petitioner”) filed a Petition seeking inter partes review of
`
`claims 1–19 of U.S. Patent No. 9,353,220 B2 (Ex. 1001, “the ’220 patent”).
`
`Paper 1 (“Pet.”). Fresenius Medical Care Holdings, Inc. (“Patent Owner”)
`
`filed a Patent Owner Preliminary Response to the Petition. Paper 12
`
`(“Prelim. Resp.”). Applying the standard set forth in 35 U.S.C. § 314(a),
`
`which requires demonstration of a reasonable likelihood that Petitioner
`
`would prevail with respect to at least one challenged claim, we institute an
`
`inter partes review of claims 1–15 and 19 as discussed below.
`
`Our findings of fact and conclusions of law are based on the record
`
`developed thus far. This is not a final decision as to the patentability of any
`
`challenged claim. Any final decision will be based on the full record
`
`developed during trial.
`
`II. BACKGROUND
`
`A. Related Proceedings
`
`The parties indicate that they are not aware of any related
`
`proceedings. Pet. 1; Paper 5, 1.
`
`B. The ’220 Patent
`
`The ’220 patent, titled “Process for Making Polyarylethers and Use in
`
`Membrane Preparation,” issued on May 31, 2016. Ex. 1001, at [54], [45].
`
`The ’220 patent is directed to methods for making polyarylethers without the
`
`use of azeotropic cosolvents. Id. at [57], 1:6–8.
`
`The ’220 patent explains that commercially used polyarylethers
`
`prepared in dipolar aprotic solvents form water as a reaction byproduct. Id.
`
`at 1:11–16. Because water is a poison to these reactions, azeotropic co-
`
`solvents have been used to remove the water azeotropically during
`
`
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`2
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`IPR2017-01948
`Patent 9,353,220 B2
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`polymerization. Id. at 1:14–18. The ’220 patent states that “[i]n general,
`
`these polyarylethers have to be isolated from the solvents, and are marketed
`
`either as pellets or powders. An end-user, such as a membrane
`
`manufacturer, redissolves these polymers in an appropriate solvent to make
`
`membranes out of solution of the redissolved polymers.” Id. at 1:18–23.
`
`The ’220 patent teaches that “[t]he absence of azeotropic cosolvents in
`
`the polyarylether reactor solution eases solvent recovery requirements” and
`
`“permits the direct use of such reactor solutions in the preparation of
`
`membranes and coatings without the need to isolate the polymer product
`
`from the azeotrope solvent or other solvent before product preparation.” Id.
`
`at 4:22–29. The ’220 patent discloses a process for preparing a
`
`polyarylether comprising (1) reacting polyarylether-forming reactants in a
`
`reactor solution comprising polar aprotic solvent(s) and the polyarylether
`
`forming reactants, (2) maintaining the desired reaction temperature of the
`
`polar aprotic solvent(s), (3) removing water in the absence of azeotrope
`
`forming cosolvent(s), and (4) optionally adding fresh polar aprotic solvent to
`
`the reactor solution in a substantially equal amount to the polar aprotic
`
`solvent removed from the reactor solution during the reaction. Id. at 4:48–
`
`57.
`
`C. Challenged Claims
`
`Petitioner challenges claims 1–19 of the ’220 patent. Independent
`
`claim 1 is illustrative, and is reproduced below:
`
`1. A process for preparation of at least one polyarylether
`comprising reacting polyarylether forming reactants in a
`reactor solution, said reaction solution comprising at least
`one polar aprotic solvent and the polyarylether forming
`reactants with removing of water in the absence of azeotrope
`forming cosolvent and adding fresh polar aprotic solvent to
`the reactor solution in substantially equal amount to any
`
`
`
`3
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`

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`IPR2017-01948
`Patent 9,353,220 B2
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`polar aprotic solvent removed from the reactor solution
`during the reacting, wherein the polar aprotic solvent is
`dimethylacetamide, N-methylpyrrolidone,
`dimethylsulfoxide, diphenylsulfone, or any combinations
`thereof.
`
`Id. at 27:26–36. Claim 19, the only other independent claim
`
`challenged, is substantially similar to claim 1 and further requires that
`
`the claimed process “is conducted with a stoichiometric excess of one
`
`of the two polyarylether forming reactants such that the final product
`
`contains substantially less of the stoichiometrically deficient reactant
`
`and the reaction is self-terminating.” Id. at 28:39–54.
`
`D. The Asserted Grounds
`
`Petitioner asserts the following grounds of unpatentability:
`
`Reference(s)
`
`Statutory
`Basis
`
`Claim(s) Challenged
`
`Weber1
`
`Weber
`
`Weber
`
`Weber and Odian2
`
`Weber, Ittemann,3 and
`Odian
`
`Weber and Chen4
`
`§ 102(a)
`
`1, 2, 4, 5, 8–10, 14, and 15
`
`§ 103
`
`§ 103
`
`§ 103
`
`§ 103
`
`§ 103
`
`15
`
`6, 7
`
`12, 13, 19
`
`11
`
`16–18
`
`
`1 Weber et al., U.S. Pub. No. 2016/0114296 A1, published Apr. 28, 2016
`(“Weber,” Ex. 1004).
`2 Odian, Principles of Polymerization, 4th Ed., 2004 (“Odian, “Ex. 1008”).
`3 Ittemann et al., U.S. Patent No. 5,008,364, issued Apr. 16, 1991
`(“Ittemann,” Ex. 1011).
`4 Chen et al., Chinese Patent Application Pub. No. CN 1631941A, published
`June 29, 2005 (“Chen,” Ex. 1009).
`
`
`
`4
`
`

`

`IPR2017-01948
`Patent 9,353,220 B2
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`Dienes5
`
`Dienes
`
`Dienes and Odian
`
`Li I6
`
`Li I
`
`Li I
`
`Li I and Chen
`
`Li I and Li II7
`
`
`
`§102(a)
`
`1, 2, 4–6, 8, and 9
`
`§ 103
`
`§ 103
`
`§ 102(a)
`
`§ 103
`
`§ 103
`
`§ 103
`
`§ 103
`
`3, 7, 10, 14, and 15
`
`19
`
`1, 3, 5, 7, 8, 10, 12–14, and
`19
`1, 3, 5, 7, 8, 10, 12-14, and
`19
`
`11
`
`18
`
`19
`
`Petitioner also relies on the declaration of Robson F. Storey, Ph.D.
`
`(“the Storey Declaration,” Ex. 1003).
`
`III. ANALYSIS
`
`A. Claim Construction
`
`In an inter partes review, claim terms in an unexpired patent are
`
`interpreted according to their broadest reasonable construction in light of the
`
`specification of the patent in which they appear. 37 C.F.R. § 42.100(b);
`
`Cuozzo Speed Techs., LLC v. Lee, 136 S. Ct. 2131, 2144–46 (2016)
`
`(upholding the use of the broadest reasonable interpretation standard).
`
`
`5 Dienes et al., U.S. Pub. No. 2009/0275725 A1, published Nov. 5, 2009
`(“Dienes,” Ex. 1005).
`6 Li et al., Poly(arylene ether sulfone) Statistical Copolymers Bearing
`Perfluoroalkylsulfonic Acid Moieties, MACROMOLECULES 44, 694–702
`(2011) (“Li I,” Ex. 1006). The parties refer to this as Li (Macromolecules).
`7 Li et al., Poly(arylene ether sulfone) multi-block copolymers bearing
`perfluoroalkylsulfonic acid groups, POLYMER (2011), 1–10 (“Li II,”
`Ex. 1010). The parties refer to this as Li (Polymer).
`
`
`
`5
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`IPR2017-01948
`Patent 9,353,220 B2
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`Petitioner offers constructions for several terms. Pet. 11–14. Patent
`
`Owner contends “all of the claim terms for which Petitioner advances
`
`construction are well understood by one of ordinary skill in the art in the
`
`context of the disclosure of the ’220 Patent” and do not require construction.
`
`Prelim. Resp. 10.
`
`Upon review of the parties’ arguments and supporting information, we
`
`determine that no express claim construction is necessary for purposes of
`
`this Decision. See Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d
`
`795, 803 (Fed. Cir. 1999) (“[O]nly those terms need be construed that are in
`
`controversy, and only to the extent necessary to resolve the controversy.”).
`
`B. References
`
`i. Weber (Ex. 1004)
`
`Weber discloses membranes comprising polyarylene ether blocks and
`
`processes for making them. Ex. 1004, at [57], ¶ 3. Weber’s polyarylene
`
`ethers are “typically prepared by polycondensation of suitable starting
`
`compounds in dipolar aprotic solvents at elevated temperature.” Id. ¶ 25.
`
`Weber states that N-methyl-2-pyrrolidone (NMP) is a preferred solvent. Id.
`
`¶ 74. Weber discloses several examples of processes for preparing polymers
`
`wherein water formed during the reaction was “continuously removed by
`
`distillation” and “[t]he solvent level inside the reactor was maintained at a
`
`constant level by addition of further NMP.” E.g., id. ¶¶ 390, 394, 398, 402,
`
`and 406. Weber also discloses several examples of processes for preparing
`
`membranes from the polymers, wherein the first step involves dissolving the
`
`polymer in NMP. Id. ¶¶ 416–430.
`
`ii.
`
`Ittemann (Ex. 1011)
`
`Ittemann is directed to “[t]hermoplastic molding materials which are
`
`stable at high temperatures and are based on polyaryl ether sulfones.”
`
`
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`6
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`IPR2017-01948
`Patent 9,353,220 B2
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`Ex. 1011, Abstract. Ittemann states that its materials “may be prepared by a
`
`conventional process for the preparation of polyaryl ether sulfones . . . as
`
`described in the literature.” Id. at 13:23–26. Ittemann indicates that reaction
`
`temperature is generally from 130o C to 220o C, and total reaction time
`
`“depends on the desired degree of condensation but is in general from 0.1 to
`
`15 hours.” Id. at 13:52–56. Ittemann also states that “[r]eaction in aprotic
`
`polar solvents in the presence of anhydrous alkali metal carbonates as
`
`catalysts is particularly suitable” (id. at 13:31–33), and discusses removing
`
`water formed during the polycondensation “with the aid of an azeotrope
`
`former, by means of reduced pressure, or, preferably, by passing in a stream
`
`of nitrogen and distillation” (id. at 13:43–46).
`
`iii. Odian (Ex. 1008)
`
`Odian is a book titled “Principles of Polymerization,” which
`
`“describes the physical and organic chemistry of the reactions by which
`
`polymer molecules are synthesized.” Ex. 1008, xxiii. It contains a wide
`
`range of information about polymerization, and can “serve as a self-
`
`educating introduction to polymer synthesis” for chemists with no
`
`background in polymers. Id.
`
`iv. Chen (Ex. 1009)
`
` Chen relates to “a method for continuous preparation of polysulfone
`
`amide spinning solution with a twin-screw extruder.” Ex. 1009, 7. Chen
`
`describes the “currently available” method of preparing polysulfonide amide
`
`solutions that can be directly used for spinning, which involves dissolving 4’
`
`4-diaminodiphenylsulfone (4’ 4-DDS) and 3’ 3-diaminodiphenylsulfone (3’
`
`3-DDS) in an amide solution, and polymerizing the solution with
`
`paraphthaloyl chloride (TPC) at a low temperature to prepare polysulfone
`
`amide. Id. at 6.
`
`
`
`7
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`Patent 9,353,220 B2
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`According to Chen,
`
`the disadvantage of the method is that it used a discontinuous
`manner, the reaction heat is difficult to be removed, local
`overheating easily results in diversity of molecular weight.
`Moreover, the reaction system contains a great amount of salt,
`which makes it difficult to subsequently water-wash the fiber
`produced, and residual salt
`in final fiber product will
`significantly decrease the physical and mechanical properties,
`electrical insulation property of the fibers.
`
`Id. at 6–7.
`
`
`
`Chen’s method for preparing polysulfone amide solutions that can be
`
`directly used for spinning seeks to overcome these disadvantages. Id. at 7.
`
`Chen’s method includes dissolving (4’ 4-DDS) and (3’ 3-DDS) in a polar
`
`solvent, mixing the solution with TPC to generate a prepolymerization
`
`product including hydrogen chloride, loading the prepolymer into a twin-
`
`screw extruder and extruding polysulfonide-amide-containing hydrogen
`
`chloride (referred to as the polymerization step), and neutralizing hydrogen
`
`chloride with hydroxide or oxide of alkali metals. Id. at 7–8. Chen explains
`
`that the use of a twin-screw extruder allows for continuous low-temperature
`
`polymerization, which helps solve the heat dissipation problem in the
`
`reaction system and “avoid the inhomogeneity problem of polymer
`
`molecular weight.” Id. at 7. Chen’s method also partially removes
`
`hydrogen chloride gas, decreasing the use of a neutralizer and the amount of
`
`salts in the final system. Id. Chen explains that its method also increases the
`
`solid content of the reaction system, which enhances production efficiency.
`
`Id.
`
`v. Dienes (Ex. 1005)
`
`Dienes relates to a process for forming polysulfones having improved
`
`optical properties, wherein the polymerization is carried out in basic, aprotic
`
`
`
`8
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`IPR2017-01948
`Patent 9,353,220 B2
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`solvents. Ex. 1005, at Abstract, ¶¶ 5, 6. Dienes discloses forming moldings,
`
`films, membranes, and foams from the polymers produced according to its
`
`claimed process. Id. ¶ 2. Dienes’ process includes dissolving equimolar
`
`amounts of dried monomers in NMP while stirring and heating to 190o C.
`
`Id. ¶ 13. Dienes states that “[t]he water of reaction was distilled off and the
`
`level was kept constant by adding NMP during the reaction.” Id. Dienes
`
`stops the reaction by dilution with cold NMP, passes methyl chloride and
`
`then nitrogen into the solution, cools the solution, and precipitates the
`
`polymer in water. Id.
`
`vi. Li I (Ex. 1006)
`
`Li I discloses the synthesis of poly(arylene ether sulfone)s for use in
`
`fuel cell membranes. Ex. 1006, 694. According to Li I, “[p]oly(arylene
`
`ether sulfone)s (PAES) were prepared by homopolymerization of HPPS[8]
`
`with bis(4-fluorophenyl) sulfone (FPS) and copolymerization of varying
`
`molar ratios of HPPS/biphenol (BP) with FPS.” Id. For the
`
`homopolymerization of HPPS, Li I teaches combining monomers in DMAc,
`
`heating the reaction at 180o C overnight, cooling the reaction to room
`
`temperature, and then adding 2.0 mL of DMAc “to replace that which was
`
`lost due to evaporation and to adjust the viscosity for precipitation.” Id. at
`
`696. Li I discloses a similar procedure for copolymer synthesis. Id.
`
`Li I also explains that
`
`Traditionally for poly(arylene ether sulfone) preparations,
`toluene has been used as an azeotroping agent to drive the
`reaction to completion. However, codistillation of the toluene-
`miscible diisopropylethylamine was found to prevent efficient
`separation of water in the Dean-Stark receiving flask. We
`
`
`8 HPPS is N,N-diisopropylethylammonium 2,2-bis(p-hydroxyphenyl)
`Pentafluoropropanesulfonate. Ex. 1006, 694.
`
`
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`IPR2017-01948
`Patent 9,353,220 B2
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`therefore discontinued the use of toluene and instead used a
`slow N2 purge to sweep water and diisopropylethylamine from
`the reactor headspace.
`
`Id. at 698.
`
`vii. Li II (Ex. 1010)
`
`Li II discloses the synthesis of poly(arylene ether sulfone) multi-block
`
`copolymers for use in fuel cell membranes. The formation of these
`
`copolymers in Li II includes synthesizing hydrophilic prepolymers by
`
`reacting HPPS with FPS (with a stoichiometric excess of FPS) and
`
`hydrophobic prepolymers by reacting BP with FPS (with a stoichiometric
`
`excess of BP). Ex. 1010, at Abstract, 3–4. Li II provides a table setting
`
`forth the charge amounts and product yields for the hydrophilic prepolymer
`
`syntheses. Id. at 3, Table 1. To form poly(arylene ether sulfone)
`
`copolymers, Li II teaches combining specific amounts of the hydrophobic
`
`and hydrophilic prepolymers. Id. at 3–4, Table 2.
`
`C. Challenges Based on Weber
`
`1. Claims 1, 2, 4, 5, 8–10, 14, and 15 – Anticipated by Weber
`
`Petitioner contends that Weber teaches every element of claims 1, 2,
`
`4, 5, 8–10, 14, and 15. Pet. 15–24. Petitioner presents arguments and
`
`information, including claim charts, demonstrating where Weber discloses
`
`each limitation of these claims. Id.
`
`Petitioner contends that Weber teaches producing polyarylene ether
`
`blocks by “polycondensation of suitable starting compounds in dipolar
`
`aprotic solvents at elevated temperature.” Id. at 16 (quoting Ex. 1004 ¶ 25).
`
`Petitioner directs us to example 3 of Weber, which combines DCDPS (4,4’-
`
`dichlorodiphenylsulfone), DHDPS (4,4’-dihydroxydiphenylsulfone) and a
`
`copolymer with NMP, a polar aprotic solvent. Id. (citing Ex. 1004 ¶¶ 388–
`
`407). Petitioner contends this disclosure meets claim 1’s recitation of a
`
`
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`10
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`IPR2017-01948
`Patent 9,353,220 B2
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`“process for preparation of at least one polyarylether comprising reacting
`
`polyarylether forming reactants in a reactor solution, said reaction solution
`
`comprising at least one polar aprotic solvent and the polyarylether forming
`
`reactants.” Ex. 1001, 27:26–29; Pet. 15–16.
`
`Claim 1 further requires “removing of water in the absence of
`
`azeotrope forming cosolvent.” Ex. 1001, 27:30–31. Petitioner directs us to
`
`Examples 3–7 of Weber, noting that Weber states “[t]he water that was
`
`formed in the reaction was continuously removed by distillation.” Pet. 16–
`
`17 (citing Ex. 1004 ¶¶ 388–407). Petitioner further notes that the only
`
`solvent in Examples 3–7 is NMP, which is a polar aprotic solvent, and that,
`
`according to Weber, its processes “‘normally do not require . . . the use of
`
`entrainers,’ that is, azeotrope formers.” Id. at 17 (citing Ex. 1004 ¶ 360).
`
`Petitioner also notes that NMP is one of the polar aprotic solvents listed in
`
`claim 1. Id. at 18; Ex. 1001, 27:34–36.
`
`As to the claim 1 requirement of “adding fresh polar aprotic solvent to
`
`the reactor solution in substantially equal amount to any polar aprotic
`
`solvent removed from the reactor solution during the reacting” (Ex. 1001,
`
`27:31–34), Petitioner further notes that in Examples 3–7, Weber states “[t]he
`
`solvent level inside the reactor was maintained at a constant level by
`
`addition of further NMP” (Pet. 17–18 (citing Ex. 1004 ¶¶ 388–407)).
`
`
`
`Petitioner provides similar arguments and information with respect to
`
`dependent claims 2, 4, 5, 8–10, 14, and 15. Pet. 18–24. At this stage of the
`
`proceeding, Patent Owner does not address Petitioner’s arguments. Prelim.
`
`Resp. 3 (“Although Patent Owner does not address the grounds pertaining to
`
`claims 1–15 and 19 of the ’220 Patent in this Preliminary Response, Patent
`
`Owner reserves the right to present arguments in this proceeding should the
`
`Board institute trial with respect to those claims.”).
`
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`IPR2017-01948
`Patent 9,353,220 B2
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`
`
`After reviewing the Petition, the Preliminary Response, and the
`
`evidence of record, we find Petitioner’s explanation of where Weber teaches
`
`each of the claim limitations is reasonable. We, therefore, determine that the
`
`record before us establishes a reasonable likelihood that Petitioner would
`
`prevail on its assertion that Weber anticipates claims 1, 2, 4, 5, 8–10, 14, and
`
`15.
`
`2. Claim 15 – Obvious over Weber
`
`Claim 15 recites, “[t]he process of claim 1 further comprising making
`
`a flat sheet or hollow fiber with polyarylether product of the reacting.”
`
`Ex. 1001, 28:20–22. In challenging claim 15 as anticipated by Weber,
`
`Petitioner argues that Weber expressly discloses flat sheets. Pet. 24. Here,
`
`Petitioner presents an alternative argument based on a narrow interpretation
`
`of claim 15, namely one that requires a hollow fiber. Id. at 25. Patent
`
`Owner, however, does not propose such a narrow interpretation of claim 15.
`
`Nor, based on the plain language of the claim itself, do we interpret claim 15
`
`to require a hollow fiber. Rather, claim 15 requires either a flat sheet or,
`
`alternatively, a hollow fiber. In view of this interpretation, and Petitioner’s
`
`position that Weber anticipates claim 15 based on its express disclosure of a
`
`flat sheet, we consider this challenge to be moot.
`
`3. Claims 6 and 7 – Obvious over Weber
`
`Claims 6 and 7 depend from claim 1, and require that the
`
`polyarylether is a polyethersulfone (claim 6) or polyphenylsulfone (claim 7).
`
`Petitioner contends that Weber renders obvious these claims based on its
`
`disclosure that “[i]n preferred embodiments, polyarylene oxide blocks in
`
`block copolymers are polysulfones, polyethersulfones or
`
`polyphenylenesulfones.” Pet. 26 (quoting Ex. 1004 ¶ 108).
`
`Patent Owner does not address Petitioner’s arguments.
`
`
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`After reviewing the Petition, the Preliminary Response, and the
`
`evidence of record, we find Petitioner’s explanation of where Weber teaches
`
`or suggests each of the claim limitations is reasonable. We, therefore,
`
`determine that the record before us establishes a reasonable likelihood that
`
`Petitioner would prevail on its assertion that the subject matter of claims 6
`
`and 7 would have been obvious in view of Weber.
`
`4. Claims 12, 13, and 19 – Obvious over Weber in view of Odian
`
`Claims 12 and 13 depend from claim 1 and further require the
`
`polyarylether produced by the reaction to have a weight average molecular
`
`weight from about 40,000 to about 120,000 (claim 12) or about 60,000 to
`
`about 85,000 (claim 13). Petitioner notes that Weber discloses average
`
`molecular weight values for suitable copolymers ranging from 5000 to
`
`150,000, but recognizes that Weber “does not appear to provide any
`
`examples of polyarylene ethers on the high end of its broadest overlapping
`
`range.” Id. at 27. Petitioner asserts that Odian discloses a relationship
`
`between high molecular weight and strength, and, therefore, “teaches the
`
`desirability of achieving high molecular weight of a polymer.” Id. (citing
`
`Ex. 1008, 50). In view of this, Petitioner argues that it would have been
`
`obvious to a person of ordinary skill in the art to use a molecular weight in
`
`the higher range of the acceptable molecular weights disclosed by Weber.
`
`Id.
`
`
`
`
`
`Patent Owner does not address these arguments.
`
`We determine that the record before us establishes a reasonable
`
`likelihood that Petitioner would prevail on its assertion that the subject
`
`matter of claims 12 and 13 would have been obvious in view of Weber and
`
`Odian. Petitioner’s explanation of how each claim limitation is taught or
`
`suggested by the combination of prior art references is reasonable. See, e.g.,
`
`
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`13
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`Patent 9,353,220 B2
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`id. at 27–28. Additionally, Petitioner’s explanation that Odian teaches the
`
`desirability of higher molecular weights, supports, on this record,
`
`Petitioner’s assertion that a person of ordinary skill in the art would have had
`
`reason to combine the teachings of the prior art references to arrive at the
`
`claimed subject matter, and would have done so with a reasonable
`
`expectation of success.
`
`
`
`Independent claim 19 contains the same limitations recited in claim 1,
`
`and further requires that the claimed process “is conducted with a
`
`stoichiometric excess of one of the two polyarylether forming reactants such
`
`that the final product contains substantially less of the stoichiometrically
`
`deficient reactant and the reaction is self-terminating.” Ex. 1001, 28:39–54.
`
`For the common limitations in claims 1 and 19, Petitioner relies on the same
`
`arguments and information presented with regard to its challenge that Weber
`
`anticipates claim 1. Pet. 29–31. Petitioner acknowledges that Weber does
`
`not disclose the additional limitation present in claim 19, but asserts that
`
`Odian teaches adjusting the concentration of ingredients so they are slightly
`
`nonstoichiometric, causing polymerization to “proceed[] to a point at which
`
`one reactant is completely used up and all the chain ends possess the same
`
`functional group – the group that is in excess.” Id. at 32 (quoting Ex. 1008,
`
`74). According to Petitioner, the reaction in Odian
`
`leave[s] essentially no stoichiometrically-deficient reactant in
`the non-polymerized portions of the reaction mixture after
`polymerization. The skilled artisan would therefore employ a
`stoichiometric excess of one of
`the reactants with
`the
`motivation to control the polymerization and therefore the
`resulting properties, with the additional result that the final
`product would
`contain
`substantially
`less
`of
`the
`stoichiometrically deficient reactant.
`
`Id. at 32–33.
`
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`Patent 9,353,220 B2
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`
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`Patent Owner does not address this argument.
`
`Upon review, we determine that the record before us establishes a
`
`reasonable likelihood that Petitioner would prevail on its assertion that the
`
`subject matter of claim 19 would have been obvious in view of Weber and
`
`Odian. Petitioner’s explanation of how each claim limitation is taught or
`
`suggested by the combination of prior art references is reasonable. See, e.g.,
`
`Pet. 32–33. Additionally, Petitioner’s explanation that, in view of Odian, a
`
`person of ordinary skill in the art would have been motivated to employ a
`
`stoichiometric excess of one reactant to control the polymerization and
`
`resultant properties, supports, on this record, Petitioner’s assertion that a
`
`person of ordinary skill in the art would have had reason to combine the
`
`teachings of the prior art references to arrive at the claimed subject matter,
`
`and would have done so with a reasonable expectation of success. See, e.g.,
`
`Ex. 1008, 74.
`
`5. Claim 11 – Obvious over Weber in view of Ittemann and Odian
`
`Claim 11 depends from claim 1 and further requires that “the reacting
`
`is conducted for about 15 to about 30 hours.” Ex. 1001, 28:8–9. Petitioner
`
`acknowledges Weber does not explicitly teach reaction times, but notes that
`
`Ittemann teaches reaction times ranging from 0.1 to 15 hours. Pet. 34 (citing
`
`Ex. 1011, 13:52–56). Petitioner contends Odian “teaches the desirability of
`
`being able to achieve sufficiently high molecular weight, without which the
`
`polymer may not have the desirable strength characteristics.” Id. at 35
`
`(citing Ex. 1008, 50). Petitioner further contends Odian discloses a
`
`correlation between long reaction times and high molecular weight reaction
`
`products. Id. (citing Ex. 1008, 51). Petitioner thus argues that a person of
`
`ordinary skill in the art “would understand that, taken together, Ittemann and
`
`Odian provide a motivation to use Ittemann’s higher-end reaction time of 15
`
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`IPR2017-01948
`Patent 9,353,220 B2
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`hours for the same type of reaction in Weber in order to improve the strength
`
`characteristics of the resulting polymer,” and would have had a reasonable
`
`expectation of success in achieving a polymer with a higher molecular
`
`weight. Id. (citing Ex. 1003 ¶¶ 122–125).
`
`Patent Owner does not address Petitioner’s arguments.
`
`Upon review, we determine that the record before us establishes a
`
`reasonable likelihood that Petitioner would prevail on its assertion that the
`
`subject matter of claim 11 would have been obvious in view of Weber,
`
`Ittemann, and Odian. Petitioner’s explanation of how each claim limitation
`
`is taught or suggested by the combination of prior art references is
`
`reasonable. See, e.g., Pet. 34–35. Additionally, Petitioner’s explanation that
`
`Ittemann teaches longer reaction times, and Odian teaches the desirability of
`
`higher molecular weight polymers, which can be formed using longer
`
`reaction times, supports, on this record, Petitioner’s assertion that a person
`
`of ordinary skill in the art would have had reason to combine the teachings
`
`of the prior art references to arrive at the claimed subject matter, and would
`
`have done so with a reasonable expectation of success.
`
`6. Claims 16–18 – Obvious over Weber in view of Chen
`
`Claim 16 depends from claim 1 and further requires “directly spinning
`
`the reactor solution after the reacting through a spinneret to form hollow
`
`fibers without previously isolating polyarylether product of the reacting from
`
`the polar aprotic solvent.” Ex. 1001, 28:23–27. Claims 17 and 18 contain
`
`similar limitations regarding directly spinning a coating solution or directly
`
`making a coating without previously isolating polyarylether product from
`
`the solvent. Id. at 28:28–39.
`
`According to Petitioner, Weber does not teach directly spinning a
`
`reactor solution without previously isolating the reaction product from the
`
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`polar aprotic solvent. Pet. 36. Petitioner thus relies on Chen’s disclosure of
`
`preparing a polysulfone amide solution and using the solution for spinning.
`
`Id. (citing Ex. 1009, at Abstract). Petitioner contends that although Chen
`
`pertains to polysulfone amides and not polyarylethers as recited in the
`
`claims, “[a]pplying the direct spinning of Chen to the spinning of a
`
`polyarylether . . . would be within the level of skill in the art” because both
`
`types of polymers contain aromatic groups and both references disclose
`
`processing their polymers at high temperatures. Id. at 37. Petitioner further
`
`contends that the amide groups in Chen form hydrogen bonds, whereas the
`
`ether groups in polyarylethers do not, making the claimed polyarylethers
`
`more flexible and easier to spin than Chen’s polysulfone amides. Id. (citing
`
`Ex. 1003 ¶¶ 127–130; Ex. 1012 at Abstract). Additionally, Petitioner asserts
`
`that a person of ordinary skill in the art would have been “motivated via
`
`Chen by a desire for efficiency in an industrial production process to directly
`
`spin a reactor solution from Weber into hollow fibers without previously
`
`isolating polyarylether product from the polar aprotic solvent.” Id.
`
`Patent Owner argues that Petitioner fails to explain adequately why
`
`the presence of aromatic groups in the polymers of both Chen and Weber
`
`would have provided a reason for a person of ordinary skill in the art to
`
`modify Weber’s process in view of Chen. According to Patent Owner,
`
`polymers with aromatic groups encompass a “vast class of compositions,”
`
`and Petitioner fails to provide any evidence that a person of ordinary skill in
`
`the art would have expected all aromatic polymers to have similar properties
`
`for purposes of spinning. Prelim. Resp. 20; see also id. at 21 (arguing that
`
`chemistry is an unpredictable, experimental science).
`
`Patent Owner further asserts that the highest reaction temperature
`
`disclosed in Chen is 100o C, whereas all of the examples in Weber use
`
`
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`reaction temperatures of 190o C. Id. at 22. According to Patent Owner, “the
`
`major byproduct of Weber’s synthesis reaction is water that must be heated
`
`to significantly higher temperatures than those disclosed by Chen in order to
`
`drive Weber’s reaction to completion.” Id. (noting the byproduct of Chen’s
`
`reaction is hydrogen chloride). Patent Owner thus argues the evidence of
`
`record contradicts Petitioner’s assertion that “both Weber and Chen process
`
`their polymers at high temperatures.” Id. at 21–22 (citing Pet. 37).
`
`Patent Owner also challenges Petitioner’s argument that Weber’s
`
`polyarylethers are more flexible and easier to spin than Chen’s polysulfone
`
`amides because the amide groups in Chen form hydrogen bonds whereas the
`
`ether groups in Weber do not. Patent Owner argues that neither Petitioner
`
`nor Dr. Storey explain “how the alleged lack of hydrogen bonds would
`
`contribute to making the polyarylethers easier to spin than the polysulfone
`
`amides of Chen.” Id. at 23. Patent Owner also contends that polyarylethers
`
`can indeed form hydrogen bonds. Id.
`
`We are not persuaded by Petitioner’s arguments. It is undisputed that
`
`Weber and Chen are directed to different polymers. Pet. 37; Prelim. Resp.
`
`19. Petitioner attempts to overcome this by arguing that both types of
`
`polymers have aromatic groups. Pet. 36–37. Petitioner, however, never
`
`explains why or how this affects spinning, and does not adequately support
`
`the assertion that polyarylethers are more flexible and therefore easier to
`
`spin. Id. Petitioner cites to the Robson Declaration, but the declaration
`
`contains a verbatim recitation of what appears in the Petition itself.
`
`Compare Pet. 36–37, with Ex. 1003 ¶¶ 127–130. Moreover, Petitioner does
`
`not provide support for its assertion that a desire for efficiency would have
`
`motivated a person of ordinary skill in the art to directly spin Weber’s
`
`reactor solution. Pet. 37.
`
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`After reviewing the Petition, Preliminary Response, and the evidence
`
`of record, we find that Petitioner has failed to articulate sufficient reasoning
`
`with rational underpinning to support the lega