DETAILED ACTION
Response to Amendment
In the amendment dated 8/14/2026, the following has occurred: Claim 1 has been amended; and new Claims 9-10 have been added.
Claims 1-10 are pending. This communication is a Final Rejection in response to the "Amendment" and "Remarks" filed on 8/14/2026.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim Rejections - 35 USC § 103
Claims 1-6 and 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over US 2008/0199755 A1 (US’755) in view of EP 2351785 A1 (EP’785).
As to Claim 1:
US’755 discloses an ionomer comprising a polymer having quaternary ammonium repeating units and capable of conducting anions (US’755, [0006], [0010]). US’755 further discloses cyclopolymerization of its monomers and a preferred cyclic ammonium polymer structure. Selecting A as a bond, the ring-forming groups R² and R³ of US’755 as methylene, and R⁴ and R⁵ as CH provides the five-membered pyrrolidinium ring incorporated into the carbon backbone shown in Formula 1 of the claim (US’755, [0011], [0025], [0036], [0038]).
For the substituents specified in Claim 1, US’755 expressly identifies methyl as the most preferred alkyl selection for its R¹, corresponding to the claimed R₁ being –(CH₂)ₓCH₃ with x = 0 (US’755, [0045]). US’755 also discloses the monofunctional monomer of Formula IV with an R⁶′ substituent on the ammonium nitrogen and expressly identifies perfluoromethyl as a selection for R⁶′. Selecting that substituent provides the claimed R₃ being –(CH₂)ₓ(CF₂)ᵧCF₃ with x = 0 and y = 0 (US’755, [0042], [0051]).
The rejection applies the embodiment of Claim 1 in which m = 0. US’755 discloses monomers having r = 1, including Formula IV, separately from its multifunctional monomers having r greater than one that form polymer networks (US’755, [0041]–[0043]). Selecting the monofunctional embodiment supplies the noncrosslinked repeating-unit structure. Under the construction that m and n express normalized composition, this corresponds to m = 0 and n = 100 − m = 100. Because the m-containing unit is absent, the R₂-containing crosslink is also absent; the listed R₂ alternatives therefore do not require an additional structural feature in this embodiment.
However, US’755 does not expressly disclose the selected polymer in the hydroxide-counterion form required by Formula 1. Its listed counterions include halides, but hydroxide is not expressly identified in that list (US’755, [0037]). US’755 also does not expressly report a fluorine atom content of 10 to 67 F% for the selected methyl/perfluoromethyl polymer.
EP’785 discloses diallylammonium-derived anion-exchange polymers having five-membered cyclic ammonium groups and expressly identifies hydroxide as a counterion (EP’785, Pg. 8). EP’785 further teaches that the initially obtained counterion is normally a halide and should preferably be exchanged for hydroxide when the membrane is used as a hydroxide-conducting fuel-cell membrane, to promote high fuel-cell output. It specifically teaches accomplishing this exchange by immersion in aqueous sodium hydroxide or potassium hydroxide (EP’785, Pg. 15). Applying that teaching to the halide form permitted by US’755 supplies the hydroxide counterion of claimed Formula 1.
For the selected noncrosslinked polymer having methyl and trifluoromethyl nitrogen substituents, the idealized hydroxide-form repeating-unit composition is C₈H₁₄F₃NO. Counting all atoms in that repeating unit, its calculated fluorine atom content is 3/(8 + 14 + 3 + 1 + 1) × 100 = approximately 11.1%, within the claimed range of 10 to 67 F%. This value is a stoichiometric calculation from the selected structure and hydroxide counterion, rather than an experimental value reported by either reference (US’755, [0011], [0036], [0042], [0045], [0051]; EP’785, Pgs. 8, 15).
US’755 and EP’785 are analogous art because both concern ionically conducting polymers containing quaternary ammonium groups for membrane applications, including fuel cells. US’755 expressly identifies anion conduction and fuel-cell membrane use, while EP’785 addresses hydroxide-conducting anion-exchange membranes for fuel cells (US’755, [0010], [0061]; EP’785, Pgs. 8, 15).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to select the expressly identified methyl and perfluoromethyl substituents in US’755’s monofunctional cyclic ammonium polymer embodiment and exchange its halide counterions for hydroxide according to EP’785, thereby adapting the polymer for hydroxide-conducting fuel-cell use and promoting the high output expressly identified by EP’785 (US’755, [0037], [0041]–[0042], [0045], [0051], [0061]; EP’785, Pg. 15).
As to Claim 2:
See the rejection of claim 1 for the inherited limitations. Regarding the additional limitation that “a molecular weight of a repeating unit of the compound is 150 to 667,” US’755 discloses cyclopolymerization of ammonium-containing monomers and a preferred cyclic polymer structure in which A may be a bond, providing the five-membered ring structure relevant here (US’755, [0025], [0036]). US’755 further discloses monofunctional monomers of Formula IV having an R¹ substituent and an R⁶′ substituent attached to the ammonium nitrogen; expressly identifies methyl as the most preferred R¹ substituent; and identifies perfluoromethyl as an R⁶′ substituent (US’755, [0041]–[0042], [0045], [0051]). Selecting the diallyl structure with methyl and perfluoromethyl nitrogen substituents provides the noncrosslinked repeating-unit structure used in the claim 1 analysis, corresponding to the claimed R₁ = CH₃ and R₃ = CF₃ embodiment (US’755, [0011], [0036], [0038], [0042], [0045], [0051]).
However, US’755 does not expressly identify hydroxide among its listed counterions or report a molecular weight of 150 to 667 for the selected repeating unit (US’755, [0037]).
EP’785 discloses diallyl-ammonium-derived polymers containing five-membered pyrrolidinium anion-exchange groups and expressly identifies hydroxide as a counterion (EP’785, Pg. 8). EP’785 further teaches exchanging the counterion to hydroxide by immersion in aqueous sodium hydroxide or potassium hydroxide, explaining that the hydroxide form is preferred for promoting high fuel-cell output when the membrane functions as a hydroxide-ion-conducting separator (EP’785, Pg. 15). Applying that counterion exchange to the selected methyl/perfluoromethyl-substituted repeating unit of US’755 yields the repeat formula C₈H₁₄F₃NO, including one hydroxide counterion. Its calculated molecular weight is approximately 197.20, which falls within the claimed range of 150 to 667. This value is a calculated consequence of the selected structure and counterion, not an expressly reported value in EP’785. EP’785 also expressly explains that decreasing molecular weight per anion-exchange structure increases the number of exchange groups per unit resin weight and thereby increases anion-exchange capacity (EP’785, Pg. 8).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to convert the selected methyl/perfluoromethyl-substituted polymer of US’755 to its hydroxide form as taught by EP’785 to provide hydroxide-ion conduction and promote high fuel-cell output, thereby obtaining the selected repeating unit having a calculated molecular weight of approximately 197.20, within the claimed range of 150 to 667.
As to Claim 3:
See the rejection of claim 1 for the inherited limitations. Regarding the additional limitation that “the fluorine atom content of the compound is 15 to 30 F%,” US’755 discloses cyclopolymerization of ammonium-containing monomers and a preferred cyclic polymer structure in which A may be a bond, providing the five-membered ring structure relevant to the claimed compound (US’755, [0025], [0036]). US’755 further discloses monofunctional monomers of Formula IV having nitrogen substituents R¹ and R⁶′; identifies methyl as the most preferred R¹ substituent; and identifies perfluoroalkyl groups having one to three carbon atoms as suitable R⁶′ substituents (US’755, [0041]–[0042], [0045], [0051]). Selecting the three-carbon, straight-chain perfluoroalkyl member provides R⁶′ = –CF₂CF₂CF₃, corresponding to the claimed R₃ = –(CH₂)ₓ(CF₂)ᵧCF₃ with x = 0 and y = 2, while methyl corresponds to the claimed R₁ with x = 0 (US’755, [0045]–[0046], [0051]). This selection uses the noncrosslinked embodiment corresponding to m = 0 and n = 100 under the composition-proportion construction of claim 1.
However, US’755 does not expressly report a fluorine atom content of 15 to 30 F% for that selected polymer and does not expressly identify hydroxide among its listed counterions (US’755, [0037]).
EP’785 discloses diallyl-ammonium-derived polymers having five-membered pyrrolidinium anion-exchange groups and expressly identifies hydroxide as a counterion (EP’785, Pg. 8). EP’785 further teaches converting the counterion to hydroxide by immersion in aqueous sodium hydroxide or potassium hydroxide and explains that hydroxide exchange is preferred for promoting high fuel-cell output when the membrane serves as a hydroxide-ion-conducting separator (EP’785, Pg. 15).
Applying that hydroxide-counterion teaching to the selected methyl/perfluoropropyl-substituted repeating structure of US’755 yields the repeat formula C₁₀H₁₄F₇NO, including one hydroxide counterion. On an atom-count basis, its fluorine content is calculated as:
F% = [7 ÷ (10 + 14 + 7 + 1 + 1)] × 100 = 21.21%.
Accordingly, the selected hydroxide-form structure has a calculated fluorine atom content within the claimed range of 15 to 30 F%. The numerical value follows from the identified structure and counterion; EP’785 supplies the hydroxide-exchange teaching, rather than an express disclosure of the claimed fluorine-content range (US’755, [0011], [0036], [0038], [0042], [0045]–[0046], [0051]; EP’785, Pgs. 8, 15).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to select the methyl/perfluoropropyl-substituted polymer of US’755 and exchange its counterion to hydroxide as taught by EP’785, to reduce the tendency toward crystallinity and provide hydroxide-ion conduction for high fuel-cell output, thereby obtaining the selected structure having a calculated fluorine atom content of 21.21%, within the claimed range.
As to Claim 4:
See the rejection of claim 1 for the inherited limitations. Regarding the additional limitation that “a ratio of the m and the n (m/n) is 0 to 1,” US’755 discloses polymerization of compounds of Formula III in which r is 1 and further depicts these monomers in Formula IV, with R⁶′ representing a substituent attached to the ammonium nitrogen (US’755, [0041]–[0042]). US’755 separately identifies compounds having r greater than 1 and a bridging R⁶ group as monomers capable of forming polymer networks (US’755, [0043]–[0044]).
Selecting the Formula IV monomer having methyl as R¹ and perfluoromethyl as R⁶′, as identified in US’755, provides the noncrosslinked methyl/perfluoromethyl-substituted embodiment addressed in the rejection of claim 1 (US’755, [0036], [0042], [0045], [0051]). This selected structure lacks the connection between two ammonium nitrogen atoms represented by the m portion of claimed Formula 1. Accordingly, under the composition-proportion construction, m = 0 and n = 100, giving m/n = 0/100 = 0, which falls within the claimed range of 0 to 1. This ratio follows from the selected structure; US’755 does not use the applicant’s m and n notation.
As to Claim 5:
See the rejection of claim 1 for the inherited limitations. Regarding the additional limitation that “the x is an integer from 0 to 20,” US’755 discloses monofunctional monomers of Formula IV having R¹ and R⁶′ substituents attached to the ammonium nitrogen (US’755, [0041]–[0042]). US’755 expressly identifies methyl as the most preferred R¹ substituent and perfluoromethyl as a suitable R⁶′ substituent (US’755, [0045], [0051]).
The disclosed methyl substituent corresponds to the claimed R₁ = –(CH₂)ₓCH₃ with x = 0. The disclosed perfluoromethyl substituent corresponds to the claimed R₃ = –(CH₂)ₓ(CF₂)ᵧCF₃ with x = 0 and y = 0. Accordingly, both selected substituents satisfy the additional limitation because x = 0 falls within the claimed integer range of 0 to 20 (US’755, [0042], [0045], [0051]). In the selected noncrosslinked embodiment corresponding to m = 0, the R₂-containing crosslinking portion is absent.
As to Claim 6:
For the ionomer incorporated by reference to claim 1, see the rejection of claim 1. US’755 discloses an ionically conductive polymer capable of anionic conduction (US’755, [0010]); forming the polymer into a self-supporting membrane or incorporating it into a supporting substrate, including within the pores of a porous substrate (US’755, [0057]–[0059]); and using the resulting ionically conductive membrane in a fuel cell (US’755, [0061]). These disclosures provide the polymer-containing membrane to be incorporated into the claimed membrane electrode assembly.
However, US’755 does not expressly disclose the complete claimed arrangement of a cathode electrode, an opposing anode electrode, and an electrolyte membrane positioned between those electrodes. US’755 also does not expressly identify hydroxide among its listed counterions, as required by the claim 1 ionomer incorporated into claim 6 (US’755, [0037]).
EP’785 discloses a membrane electrode assembly having an oxidizing-agent-side gas diffusion electrode 5, corresponding to the claimed cathode electrode; a fuel-side gas diffusion electrode 4, corresponding to the claimed anode electrode; and a solid polymer electrolyte membrane 6, with the two electrodes bonded to opposite surfaces of the membrane (EP’785, Pg. 2). EP’785 explains that, during operation with an anion-exchange membrane, oxygen and water react at electrode 5 to generate hydroxide ions, while fuel reacts at electrode 4 and releases electrons that pass through the external circuit to electrode 5, establishing their respective cathode and anode functions (EP’785, Pg. 3).
EP’785 further expressly teaches bonding the fuel-side and oxidizing-agent-side electrodes to the two surfaces of its anion-exchange membrane to form an electrolyte membrane-electrode assembly, thereby placing the anode opposite the cathode and the electrolyte membrane between them (EP’785, Pgs. 15–16). EP’785 supplies concrete assembly methods, including coating catalyst compositions onto electrode supports or the membrane and thermally bonding the electrodes to the membrane (EP’785, Pg. 16). EP’785 additionally teaches converting the membrane’s counterions to hydroxide using aqueous sodium hydroxide or potassium hydroxide to promote high fuel-cell output (EP’785, Pg. 15).
In the proposed combination, the selected US’755 ionomer, modified according to EP’785 as explained in the rejection of claim 1, is incorporated into the electrolyte membrane using US’755’s disclosed membrane construction. That membrane is positioned between the opposing electrodes according to EP’785’s assembly teaching. The electrolyte membrane therefore comprises the claim 1 ionomer, satisfying the requirement that at least one of the cathode electrode, anode electrode, and electrolyte membrane comprises that ionomer (US’755, [0057]–[0059], [0061]; EP’785, Pgs. 15–16).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to incorporate the selected US’755 ionomer, converted to hydroxide form as taught by EP’785, into an electrolyte membrane bonded between opposing anode and cathode electrodes according to EP’785, to implement US’755’s expressly disclosed fuel-cell application while providing hydroxide-ion conduction and promoting high fuel-cell output.
As to Claim 8:
See the rejection of claim 6 for the membrane electrode assembly, including its incorporation of the ionomer of claim 1. Regarding the additional limitation of “a fuel cell comprising the membrane electrode assembly of claim 6,” US’755 expressly discloses using its ionically conductive membrane in a fuel cell (US’755, [0061]). US’755 further discloses a fuel cell including its solid ionically conductive polymer and states that the fuel cell may include the disclosed ionically conductive membrane (US’755, [0070]). Although paragraph [0070] identifies a proton-conductive membrane as preferred, US’755 also expressly discloses anionically conducting polymers (US’755, [0010]). US’755 therefore supplies an express fuel-cell application for its polymer-containing membrane.
As to Claim 9:
Claim 9 depends from claim 1 and further requires that m be an integer from 1 to 100. See the rejection of claim 1 for the common ionomer, cyclic ammonium backbone, and substituent teachings. For claim 9, the noncrosslinked embodiment used in that rejection is modified to incorporate the crosslinked units discussed below.
US’755 discloses ionically conductive polymers having quaternary ammonium repeating units, including polymers capable of anionic conduction (US’755, [0006], [0010]). Its cyclopolymerization disclosure and preferred polymer structure provide the claimed five-membered pyrrolidinium backbone when A is a bond and the ring-forming groups are selected as methylene and CH (US’755, [0011], [0025], [0036], [0038]). US’755 identifies methyl as its most preferred R¹ substituent and expressly identifies perfluoromethyl as an R⁶′ substituent for its monofunctional monomer. These selections correspond to the claimed R₁ being methyl and R₃ being trifluoromethyl in the noncrosslinked units (US’755, [0042], [0045], [0051]).
US’755 also discloses multifunctional monomers having a bridging group connecting multiple polymerizable ammonium moieties, particularly prefers the embodiment having two such moieties, and teaches that polymerization produces polymer networks. It additionally permits copolymerization with another monomeric compound (US’755, [0039]–[0044], [0054]). Thus, US’755 teaches both the selected noncrosslinked-unit chemistry and the use of multifunctional ammonium monomers to form networks.
However, US’755 does not expressly disclose the selected fluorinated copolymer having the claimed crosslinked and noncrosslinked units at m = 2 and n = 98, hydroxide counterions, and a reported fluorine atom content within the inherited 10–67 F% range.
EP’785 discloses a crosslinked pyrrolidinium anion-exchange polymer containing bis(N-methyl-pyrrolidinium)butane crosslinking units together with noncrosslinked pyrrolidinium units. Its butane bridge connects the two ammonium nitrogens through –CH₂–(CH₂)₂–CH₂–, corresponding to the claimed crosslinked unit with R₁ being methyl and R₂ being –(CH₂)₂–. EP’785 expressly identifies a preferred molar ratio of crosslinking units to noncrosslinked units from 2:98 to 40:60. Selecting the disclosed 2:98 endpoint supplies m = 2 and n = 98 under the normalized-composition construction, satisfying m being an integer from 1 to 100 and n = 100 − m (EP’785, Pg. 9).
EP’785 further identifies N,N,N′,N′-tetraallyl-N,N′-dimethylbutane diammonium dichloride as a suitable crosslinking agent. It teaches selecting the crosslinker-to-monomer ratio to provide sufficient crosslink density to prevent elution during use while retaining high ionic conductivity (EP’785, Pg. 11). Applying this crosslinking teaching to US’755’s selected methyl/trifluoromethyl monomer supplies the claimed crosslinked units while retaining fluorinated noncrosslinked units. US’755’s express network-formation and copolymerization teachings provide a technical basis for this proposed incorporation of EP’785’s diallylammonium crosslinker (US’755, [0043]–[0044], [0054]; EP’785, Pg. 11).
EP’785 also expressly discloses hydroxide counterions and teaches exchanging initially present halide counterions for hydroxide by treatment with aqueous sodium hydroxide or potassium hydroxide. It recommends hydroxide exchange for hydroxide-conducting fuel-cell membranes to promote high fuel-cell output (EP’785, Pgs. 8, 15).
For the proposed hydroxide-form copolymer, each methyl/trifluoromethyl noncrosslinked unit has the idealized composition C₈H₁₄F₃NO, and each butane-linked crosslinking unit, including both pyrrolidinium groups and their hydroxide counterions, has the composition C₁₈H₃₆N₂O₂. At a 2:98 molar ratio, the calculated fluorine atom percentage, counting all atoms, is:
100 × [98 × 3] ÷ [2 × 58 + 98 × 27] = approximately 10.64%.
Accordingly, the selected combination falls within the inherited 10–67 F% range. This is a calculation from the proposed structures and composition, not a measured value reported by either reference (US’755, [0011], [0036], [0042], [0045], [0051]; EP’785, Pgs. 9, 15).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to incorporate EP’785’s butane-linked ammonium crosslinking units into US’755’s selected fluorinated polymer at the disclosed 2:98 ratio and exchange the counterions for hydroxide, to resist elution while retaining ionic conductivity and promote high output in hydroxide-conducting fuel-cell use (US’755, [0043]–[0044], [0054], [0061]; EP’785, Pgs. 9, 11, 15).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over US 2008/0199755 A1 (US’755) in view of EP 2351785 A1 (EP’785), as applied to Claim 6 above, and further in view of US 2016/0107154 A1 (US’154).
As to Claim 7:
Regarding the ionomer of claim 1 incorporated through claim 6, see the rejection of claim 1 over US’755 in view of EP’785. US’755 further discloses forming its ionically conductive polymer into a self-supporting membrane or incorporating the polymer into a supporting substrate (US’755, [0057]–[0059]); and using the resulting ionically conductive membrane in an electrochemical device, including a fuel cell (US’755, [0061], [0070]).
However, US’755 does not expressly disclose the complete membrane electrode assembly arrangement recited in claim 6, including opposed cathode and anode electrodes with the electrolyte membrane positioned between them, or use of that assembly in a water electrolysis device as required by claim 7.
EP’785 discloses a membrane electrode assembly having a fuel-side gas diffusion electrode and an oxidizing-agent-side gas diffusion electrode bonded to opposite surfaces of an anion-exchange electrolyte membrane, thereby providing opposed electrodes with the electrolyte membrane positioned between them (EP’785, Pgs. 15–16). EP’785 also discloses converting the membrane’s quaternary-ammonium counterions to hydroxide ions using aqueous sodium hydroxide or potassium hydroxide (EP’785, Pg. 15). Applying this assembly arrangement to the ionomer membrane of US’755, as modified by EP’785 in the rejection of claim 1, places the ionomer in the electrolyte membrane and thus provides the alternative in claim 6 requiring at least the electrolyte membrane to comprise the ionomer.
US’154 discloses a water electrolysis device comprising an anion-exchange membrane positioned between a cathode and an anode. Specifically, Example 10 expressly demonstrates use of its membranes in water electrolyzers (US’154, [0180]). The membrane is sandwiched between the electrodes with their catalysts facing the membrane, and the assembly is mounted in cell hardware having flow fields. Aqueous 1 M KOH is supplied to both electrode chambers, and the device is operated under an applied potential or at constant current (US’154, [0181]). US’154 additionally teaches that using an anion-exchange membrane permits nonprecious-metal catalysts, exemplified by nickel foam used as both electrodes (US’154, [0182]).
The references are analogous art because they concern ion-conducting polymer membranes and their incorporation into electrochemical cells. US’755 teaches conductive membranes for fuel cells; EP’785 teaches hydroxide-conducting membranes and membrane electrode assemblies; and US’154 teaches membrane electrode assemblies for both water electrolysis and alkaline fuel-cell operation (US’755, [0057], [0061]; EP’785, Pgs. 15–16; US’154, [0180]–[0184]). EP’785’s teaching of alkaline-resistant anion-exchange resins provides a reason to employ such a membrane in the alkaline water-electrolysis environment expressly disclosed by US’154 (EP’785, Pgs. 9–10; US’154, [0181]).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to incorporate the US’755 ionomer membrane, as modified by EP’785, into the opposed-electrode water-electrolysis arrangement taught by US’154, to provide anion transport between the electrodes in alkaline water electrolysis while permitting the use of nonprecious-metal catalysts (EP’785, Pgs. 9–10, 15; US’154, [0180]–[0182]).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over US 2008/0199755 A1 (US’755) in view of EP 2351785 A1 (EP’785), as applied to Claim 1 above, and further in view of Shirase et al., “Properties and Morphologies of Anion-Exchange Membranes with Different Lengths of Fluorinated Hydrophobic Chains” (Shirase).
As to Claim 10:
Regarding the ionomer of claim 1, see the rejection of claim 1 over US’755 in view of EP’785. US’755 additionally discloses selecting polymer-network properties through the nature of the bridging group, the amount of chain terminator, and the polymerization conditions (US’755, [0043]–[0044]); alkyl and perfluoroalkyl substituents and fluorinated bridging groups, including –CH₂–(CF₂)ₓ–CH₂– (US’755, [0045]–[0053], Table 1); and use of the resulting ionically conductive polymers as membranes, including membranes for fuel cells (US’755, [0057], [0061]).
However, US’755 does not expressly disclose that the ionomer has an ion exchange capability of 1.74 to 2.39 mmol/g.
EP’785 discloses pyrrolidinium-containing anion-exchange resins and teaches that decreasing the molecular weight per ion-exchange structure increases the number of anion-exchange groups per unit weight of resin, thereby increasing its anion-exchange capacity. EP’785 further teaches selecting substituents to balance chemical stability and exchange capacity (EP’785, Pg. 8). EP’785 also discloses converting the counterions of the quaternary ammonium groups to hydroxide ions using aqueous sodium hydroxide or potassium hydroxide, for use in hydroxide-conducting fuel-cell membranes (EP’785, Pg. 15). Accordingly, EP’785 identifies the molecular weight associated with each exchange group as a structural variable affecting the resin’s exchange capacity.
Shirase discloses a fluorinated quaternary-ammonium anion-exchange polymer, QPAF(C4)-4, having a measured ion-exchange capacity of 2.0 meq/g, compared with a composition-based target of 2.1 meq/g (Shirase, Pg. 2). For monovalent exchange sites, 2.0 meq/g corresponds numerically to 2.0 mmol/g and falls within the claimed range. Shirase measures capacity by titrating chloride released from the chloride-form polymer membrane and reports individual determinations of 2.09, 1.98, and 1.93 meq/g (Shirase, Pg. 8). Shirase also teaches preparing the hydroxide form by treatment with aqueous potassium hydroxide (Shirase, Pg. 8).
Shirase further demonstrates that IEC affects water uptake and hydroxide conductivity: increasing IEC increases water uptake, while sufficiently high IEC can reduce conductivity through excessive swelling (Shirase, Pg. 4). These results provide a reason to balance exchange-group density and water uptake when selecting the composition of an anion-exchange polymer. Shirase is relied upon for its demonstrated capacity and structure–property relationships; its aromatic polymer backbone is not identified as the Formula 1 backbone.
The references are analogous art because each concerns ion-conducting polymer materials for membranes used in fuel cells. US’755 addresses conductive polymer structures and membrane applications; EP’785 addresses hydroxide-conducting pyrrolidinium resins; and Shirase addresses the effects of fluorinated polymer structure and IEC on anion-exchange membrane performance (US’755, [0043]–[0044], [0057], [0061]; EP’785, Pgs. 8, 15; Shirase, Pgs. 1–2, 4).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to adjust the exchange-group density of the US’755 ionomer, as modified by EP’785, toward an IEC of approximately 2.0 mmol/g, following EP’785’s relationship between molecular weight and exchange capacity and Shirase’s demonstrated in-range capacity, to balance hydroxide conduction and water uptake.
Response to Arguments
Applicant's arguments filed 8/14/26 have been fully considered but they are not persuasive.
Regarding Applicant’s argument that the references do not disclose the fluorine content of amended claim 1, the revised analysis identifies a particular composition and calculates its fluorine content. Selecting the noncrosslinked methyl/perfluoromethyl-substituted embodiment of US’755 and converting its counterion to hydroxide according to EP’785 provides the repeat composition C₈H₁₄F₃NO (US’755, [0036], [0038], [0041]–[0042], [0045], [0051]; EP’785, Pgs. 8, 15). This embodiment corresponds to m = 0, n = 100, R₁ = CH₃, and R₃ = CF₃ under the stated construction of Formula 1. Counting all atoms in the hydroxide-form repeat composition, its fluorine content is:
F% = [3 ÷ (8 + 14 + 3 + 1 + 1)] × 100 = 11.11%.
The calculated value falls within claim 1’s range of 10 to 67 F%. This finding concerns the identified structure; it does not presume that every polymer within US’755’s broader disclosure satisfies the claimed range.
Regarding amended claim 3’s narrower range of 15 to 30 F%, US’755’s disclosed one-to-three-carbon perfluoroalkyl class also includes the straight-chain perfluoropropyl substituent, –CF₂CF₂CF₃ (US’755, [0046], [0051]). Selecting that substituent together with the preferred methyl substituent and applying EP’785’s hydroxide exchange provides the repeat composition C₁₀H₁₄F₇NO. Its calculated fluorine atom content is:
F% = [7 ÷ (10 + 14 + 7 + 1 + 1)] × 100 = 21.21%.
That value falls within claim 3’s range. US’755 additionally explains that larger quaternary-ammonium cations generally reduce the tendency toward crystallinity, providing a reference-based reason to select the larger member of its disclosed perfluoroalkyl series for an ionically conductive polymer (US’755, [0006]–[0008], [0051]).
Neither calculated percentage is presented as an experimental value expressly reported in the references. Rather, each follows from the identified repeat composition after the proposed counterion exchange. An inherent property may support an obviousness rejection when it necessarily results from the established combination; a merely possible property is insufficient. The present calculations identify the compositional basis for the particular numerical findings. See MPEP § 2112.
The reason for combining the references is also supported by their disclosures. US’755 teaches anionic conduction and expressly proposes using its conductive polymers as fuel-cell membranes (US’755, [0010], [0057], [0061]). EP’785 teaches hydroxide counterions for pyrrolidinium-containing anion-exchange polymers and provides a method of exchanging the counterion using aqueous sodium hydroxide or potassium hydroxide. EP’785 expressly associates hydroxide exchange with obtaining high fuel-cell output (EP’785, Pgs. 8, 15). Both references therefore concern ion-conducting polymer membranes for fuel cells, and EP’785 supplies a counterion-exchange technique directed to that shared application. The proposed modification follows these teachings, without using Applicant’s fluorine-content/IEC results as the motivation for the modification.
Regarding Applicant’s arguments concerning claims 2, 4, and 5, the revised combination supplies particular embodiments meeting their additional limitations. The selected methyl/perfluoromethyl hydroxide-form repeat composition has a calculated molecular weight of approximately 197.20, within claim 2’s range of 150 to 667. Its noncrosslinked composition corresponds to m = 0 and n = 100, giving m/n = 0 within claim 4’s range. Methyl and perfluoromethyl correspond to x = 0 in the claimed substituent definitions, within claim 5’s range of 0 to 20 (US’755, [0041]–[0042], [0045], [0051]; EP’785, Pg. 15). These findings address the additional limitations independently of the previously applied Japanese reference.
Regarding claims 6 and 8, US’755 expressly discloses polymer-containing membranes and their use in fuel cells (US’755, [0057]–[0059], [0061], [0070]). EP’785 discloses an electrolyte membrane positioned between opposing fuel-side and oxidizing-agent-side electrodes, bonded to the membrane to form a membrane electrode assembly, and incorporation of that assembly into a fuel cell (EP’785, Pgs. 2–3, 15–16). Incorporating the selected ionomer into the electrolyte membrane satisfies the requirement that at least one of the electrodes or the electrolyte membrane comprises the claim 1 ionomer. Accordingly, the arguments directed to the previously applied fluorination reference do not independently distinguish these assembly and fuel-cell limitations.
Regarding new claim 9, its requirement that m be 1 to 100 is addressed through a crosslinked embodiment rather than the m = 0 embodiment. US’755 teaches network formation using bridging monomers, while EP’785 expressly discloses a bis(N-methyl-pyrrolidinium)butane crosslink structure and a particularly preferred crosslink-site-to-noncrosslinked-unit ratio of 2:98 to 40:60 (US’755, [0043]–[0044]; EP’785, Pgs. 8–9). EP’785 associates these structures with stability, ease of production, and ion conductivity, and explains that ion-exchanging crosslink sites retain exchange capacity (EP’785, Pgs. 8–9).
Applying the disclosed 2:98 ratio to the selected US’755 methyl/perfluoromethyl units gives m = 2 and n = 98 when each bis-pyrrolidinium crosslink is counted as one m unit. The hydroxide-form crosslink pair has composition C₁₈H₃₆N₂O₂, and the noncrosslinked unit has composition C₈H₁₄F₃NO. A compositional basis of two crosslink units and 98 noncrosslinked units therefore gives C₈₂₀H₁₄₄₄F₂₉₄N₁₀₂O₁₀₂ and a calculated fluorine atom content of approximately 10.64%. This proposed crosslinked composition satisfies both the positive-m requirement and claim 1’s fluorine-content range under the stated constructions. The calculation concerns the proposed combination; EP’785 does not itself report this fluorinated composition.
For the reasons above, applicant's arguments have been fully considered but they are not persuasive.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JIMMY K VO whose telephone number is (571)272-3242. The examiner can normally be reached Monday - Friday, 8 am to 6 pm EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Barbara Gilliam can be reached at (571) 272-1330. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JIMMY VO/
Primary Examiner
Art Unit 1723
/JIMMY VO/Primary Examiner, Art Unit 1723
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