DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant's arguments filed 3/4/2026 have been fully considered but are not persuasive. Applicant’s amendments to Claim 1 further define the dispersion diameter in relation to the overall thickness of the A-layer. These amendments are supported by the instant disclosure.
In section (i) of Applicant’s reply, Applicant states:
[…] The newly added A-layer thickness limitation provides an essential dimensional context for the dispersion requirement. In an A-layer having a thickness of only 2-10 µm, a dispersion diameter of 0.55 µm or less ensures that the ion-conducting hydrocarbon polymer is finely and uniformly distributed throughout the thickness of the layer. The sub-micron dispersion permits homogeneous integration within the thin layer without forming localized domains that would disrupt structural continuity.
In section (iii) of Applicant’s reply, Applicant also states:
Accordingly, a person of ordinary skill in the art following Ota would be motivated to increase particle size and localize the hydrocarbon polymer at the interface to form bulk regions that enhance bondability. Ota provides no suggestion-explicit or implicit-that reducing particle size to 0.55 µm or less and uniformly dispersing the polymer throughout a 2-10 µm A-layer would be desirable. Rather, such a modification would undermine Ota's stated objective of forming a bulk interfacial region.
Although Applicant argues the ion-conducting hydrocarbon polymer of the present invention “is finely and uniformly distributed throughout the thickness of the layer,” this position contradicts the instant specification and claimed invention. The instant specification promotes a non-uniform distribution of the ion-conducting hydrocarbon polymer in the A-layer. See [0046-0053] of the instant specification and instant Fig. 1, described in [0039] as showing “the ion-conducting hydrocarbon polymer (P) is dispersed in the A-layer.”
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17/911,870 – Fig. 1
The instant specification teaches “according to the present invention, substantially no ion-conducting hydrocarbon polymer is preferably present in the outer side of the A-layer,” and “it is preferable that the dispersion of the ion-conducting hydrocarbon polymer in the A-layer is present at high density in the region on the side of the interface between the A-layer and the B-layer, and substantially not present in the outer side of the A-layer” ([0050-0053]). Therefore, Applicant’s arguments against the prior art teaching an uneven distribution of the ion-conducting polymer in the A-layer is not commensurate to the instant invention (and its claims), and therefore is not persuasive.
Applicant’s reply filed 3/4/2026 also states Claim 21 has been added. Although the claim has a “(New)” status identifier, Claim 21 (“The electrolyte membrane according to claim 1, wherein the B-layer does not include the non-ion-conducting fluorinated polymer”) was previously filed on 7/7/2025 and has already been examined. The Non-Final Rejection mailed 12/12/2025 includes a rejection of Claim 21 using prior art. If Applicant intends to continue prosecution for this application, please ensure the next set of claims has an updated status identifier for Claim 21 (i.e., Previously Presented, Currently Amended, or Canceled).
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 4-8, 13, 15, 20, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Noguchi, JP 5084097 B2*, and further in view of Akiyama et al., US 20100068592 A1* and Kai et al., WO 2019107219 A1 (US 20200358066 A1 cited herein, see enclosed PTO-892).
* reference cited and relied upon in previous action
Regarding Claim 1, Noguchi discloses an electrolyte membrane (composite electrolyte membrane [0041]) comprising at least the following:
an A-layer (anti-oxidation/redox layer [0042]) composed of an ion-conducting fluorinated polymer (fluorine-containing ion-conductive resin [0017]) uniformly mixed with a non-ion-conducting fluorinated polymer (non-ionic conductive fluororesin [0017]; “uniformly mixed” limitation met by the A-layer solution being a mixture of the two resins [0014], Examples 2 and 3 [0059-0060]); and
a B-layer (hydrocarbon electrolyte membrane [0043]) composed of an ion-conducting hydrocarbon polymer (proton-conducting hydrocarbon polymer/hydrocarbon-based ion-conductive resin [0043-0047]); and
wherein said A-layer is a layer in which the ion-conducting fluorinated polymer and the non-ion-conducting fluorinated polymer are completely mixed uniformly (a mixture of an ion-conductive resin and a non-ion-conductive resin [0050]).
Noguchi does not disclose “the A-layer is directly laminated on the B-layer.” Additionally, although Noguchi discloses examples where the A-layer appears to be thinner than the B-layer ([0057-0060]), Noguchi does not disclose “the A-layer thickness is 2 µm to 10 µm.” However, motivation to laminate a thin fluorinated proton-conducting layer (A-layer) and thick hydrocarbon-based layer (B-layer) together to form a composite membrane is taught by Akiyama et al.
Akiyama teaches a composite electrolyte membrane wherein a thin A-layer (fluorinated ionomer layer [0061-0062]; 0.1 µm to 5 µm thick [0023-0027]) is laminated on a thick B-layer (hydrocarbon-based PEM [0062]; 25 µm to 200 µm thick [0027-0032]). Akiyama discloses hot pressing a thin, proton-conducting layer (A-layer) to a thick hydrocarbon membrane (B-layer) creates a membrane assembly that has improved bonding between electrodes, lower contact resistance between the layers, and increased conductivity ([0060-0068, 0078], lamination process [0071, 0075]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to laminate the A-layer and B-layer of Noguchi to each other, have the A-layer thickness be 0.1 µm to 5 µm, and have the B-layer thickness be 25 µm to 200 µm, in the electrolyte membrane of Noguchi, as Akiyama teaches laminating a thin A-layer to a thick B-layer improves bonding between electrodes, lowers contact resistance, and increases conductivity.
Modified Noguchi does not disclose the ion-conducting hydrocarbon polymer is dispersed in the A-layer “with a dispersion diameter of 0.55 µm or less.” However, this limitation is taught by Kai et al.
Kai teaches a battery separator comprising a fluorinated polymer A-layer (second layer 3, Resin B: preferably copolymers of vinylidene fluoride and hexafluoropropylene [0018, 0052-0055, 0058]; consistent with [0049-0050] of Noguchi) and a polymer B-layer (first layer 2, Resin A [0034-0045, 0058], Fig. 2). Kai teaches a mixed layer 9 where the B-layer 2 is dispersed into the A-layer 3, and the mixed layer has a preferable thickness of 0.2 μm or more and 0.5 μm or less ([0076, 0092], Fig. 2; mixed layer thickness is analogous to the claimed “dispersion diameter”). Kai teaches the mixed layer must be thick enough to receive the benefit of adhering the A- and B-layers to each other, but too thick of a mixed are will lead to a decrease in the battery characteristics ([0074-0076]). Kai also teaches a separator with this structure can be created via lamination ([0058-0059]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to have the ion-conducting hydrocarbon polymer of modified Noguchi be dispersed in the A-layer of modified Noguchi, with a dispersion diameter of 0.2 μm or more and 0.5 μm or less, as Kai teaches this dispersion diameter range will adhere the A- and B-layers to each other without negative impacts on the battery characteristics.
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Kai – Annotated Fig. 2
Regarding Claim 4, modified Noguchi discloses all limitations as set forth above. Modified Noguchi discloses a thickness of said A-layer is (t1) (Akiyama, thickness of 0.1 µm to 5 µm), and
a shortest distance from an outer side of said A-layer to the hydrocarbon polymer in said A-layer is (t2) (t2 would be the distance from the outer side of the A-layer to the point where the mixed layer 9 extends the farthest into the A-layer), and
(t1) - (t2) > 0 (Kai, the mixed layer 9 should not extend too far into the second layer 3 [0074-0076]).
Regarding Claim 5, modified Noguchi discloses all limitations as set forth above. Modified Noguchi does not specifically disclose the electrolyte membrane has the claimed “lowest crystal melting peak temperature” required by Claim 5.
However, modified Noguchi meets all claimed limitations for the electrolyte membrane in Claim 1, and therefore the electrolyte membrane of modified Noguchi would possess the claimed lowest crystal melting peak temperature. Products of identical composition may not have mutually exclusive properties. See MPEP 2112.01 and In re Spada 15 USPQ2d 1655,1658 (Fed. Circ. 1990).
Alternatively, if the electrolyte membrane of modified Noguchi does not have the properties as claimed, then it must be due to a limitation that is not currently claimed. Since the USPTO cannot conduct experiments, the burden of proof is shifted to the applicant to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977).
Regarding Claim 6, modified Noguchi discloses all limitations as set forth above. Modified Noguchi discloses non-ion-conducting fluorinated polymer is at least one selected from the group consisting of poly(vinylidene fluoride), and a copolymer of vinylidene fluoride and another fluorine-containing monomer (Noguchi, non-ionic conductive fluororesin may be polyvinylidene fluoride or a vinylidene fluoride-hexafluoropropylene copolymer [0017, 0049-0050]).
Regarding Claim 7, modified Noguchi discloses all limitations as set forth above. Modified Noguchi discloses the non-ion-conducting fluorinated polymer is a copolymer of vinylidene fluoride and another fluorine-containing monomer (Noguchi, vinylidene fluoride-trifluoroethylene copolymer or vinylidene fluoride-hexafluoropropylene copolymer, [0017, 0049-0050]).
Regarding Claim 8, modified Noguchi discloses all limitations as set forth above. Modified Noguchi discloses the non-ion-conducting fluorinated polymer is a copolymer of vinylidene fluoride and hexafluoropropylene (Noguchi, vinylidene fluoride-hexafluoropropylene copolymer [0049-0050]).
Regarding Claim 13, modified Noguchi discloses all limitations as set forth above. Modified Noguchi does not specifically disclose the electrolyte membrane has the claimed “active material permeation rate” required by Claim 13.
However, modified Noguchi meets all claimed limitations for the electrolyte membrane in Claim 1, and therefore the electrolyte membrane of modified Noguchi would possess the claimed active material permeation rate. Products of identical composition may not have mutually exclusive properties. See MPEP 2112.01 and In re Spada 15 USPQ2d 1655,1658 (Fed. Circ. 1990).
Alternatively, if the electrolyte membrane of modified Noguchi does not have the properties as claimed, then it must be due to a limitation that is not currently claimed. Since the USPTO cannot conduct experiments, the burden of proof is shifted to the applicant to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977).
Regarding Claim 15, modified Noguchi discloses all limitations as set forth above. Modified Noguchi discloses the A-layer is laminated on only one face of the B-layer (Noguchi, adjacent to catalyst layer [0042], Examples 2 and 3 [0059-0060], Fig. 2).
Regarding Claim 20, modified Noguchi discloses all limitations as set forth above. Modified Noguchi discloses a thickness of said B-layer is 20 µm or more and 200 µm or less (Akiyama, 25 µm to 200 µm thick [0027-0032]; See Claim 1).
Regarding Claim 21, modified Noguchi discloses all limitations as set forth above. Modified Noguchi discloses an embodiment of the electrolyte membrane wherein the B-layer includes a hydrocarbon-based non-ion-conductive resin instead of the non-ion-conducting fluorinated polymer (Noguchi, [0042-0043]), thus meeting the limitation “wherein the B-layer does not include the non-ion-conducting fluorinated polymer.”
A reference disclosing optional inclusion of a particular component teaches compositions that both do and do not contain that component. See also Upsher-Smith Labs. v. Pamlab, LLC, 412 F.3d 1319, 1323, 75 USPQ2d 1213, 1215 (Fed. Cir. 2005). See MPEP 2123.I.
Claims 9 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over modified Noguchi as applied to Claim 1 above, and further in view of Lin et al., “Study of Blend Membranes Consisting of Nafion and Vinylidene Fluoride–Hexafluoropropylene Copolymer,” Journal of Applied Polymer Science, Vol. 70, pg. 121–127 (1998).
Regarding Claim 9, modified Noguchi discloses all limitations as set forth above. Although Modified Noguchi discloses the A-layer comprises an ion-conducting fluorinated polymer and a non-ion-conducting fluorinated polymer (Noguchi, fluorine-containing ion-conductive resin mixed with a non-ionic conductive fluororesin [0017]), modified Noguchi does not disclose the claimed “mass ratio of the ion-conducting fluorinated polymer to the non-ion-conducting fluorinated polymer is 25:75 to 55:45” as required by Claim 9. However, Lin teaches the effects of varying the ratio of an ion-conducting fluorinated polymer to a non-ion-conducting fluorinated polymer.
Lin teaches an electrolyte membrane composed of an ion-conducting fluorinated polymer (Nafion®/a perfluoropolymer; pg. 121-122) and a non-ion-conducting fluorinated polymer (VDF-HFP; a copolymer of vinylidene fluoride and hexafluoropropylene; pg. 122). Lin teaches as the amount of non-ion-conductive VDF-HFP in an electrolyte membrane rises (thus lowering the amount of ion-conductive Nafion® in the electrolyte membrane), the methanol barrier property becomes more favorable (Fig. 3, pg. 123-124). Although increasing content of VDF-HFP in the electrolyte membrane is beneficial, Lin also discloses increasing the content of the VDF-HFP in the electrolyte membrane decreases the membrane conductivity (Fig. 2, pg. 122-123).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to optimize, by routine experimentation, the mass ratio of the ion-conducting fluorinated polymer to the non-ion-conducting fluorinated polymer in the electrolyte membrane of modified Noguchi, in order to receive the benefit of better methanol transport, yet not negatively impact conductivity, as taught by Lin.
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Lin – Fig. 3 (left) and Fig. 2 (right)
Regarding Claim 19, modified Noguchi discloses all limitations as set forth above. Modified Noguchi does not disclose “a mass ratio of said ion-conducting fluorinated polymer to said non-ion-conducting fluorinated polymer in said A-layer is in a range of from 25:75 to 55:45” as required by Claim 19. However, Lin teaches the effects of varying the ratio of an ion-conducting fluorinated polymer to a non-ion-conducting fluorinated polymer.
Lin teaches an electrolyte membrane composed of an ion-conducting fluorinated polymer (Nafion®/a perfluoropolymer; pg. 121-122) and a non-ion-conducting fluorinated polymer (VDF-HFP; a copolymer of vinylidene fluoride and hexafluoropropylene; pg. 122). Lin teaches as the amount of non-ion-conductive VDF-HFP in an electrolyte membrane rises (thus lowering the amount of ion-conductive Nafion® in the electrolyte membrane), the methanol barrier property becomes more favorable (Fig. 3, pg. 123-124). Although increasing content of VDF-HFP in the electrolyte membrane is beneficial, Lin also discloses increasing the content of the VDF-HFP in the electrolyte membrane decreases the membrane conductivity (Fig. 2, pg. 122-123).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to optimize, by routine experimentation, the mass ratio of the ion-conducting fluorinated polymer to the non-ion-conducting fluorinated polymer in the electrolyte membrane of modified Noguchi, in order to receive the benefit of better methanol transport, yet not negatively impact conductivity, as taught by Lin. Where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art [MPEP 2144.05].
Modified Noguchi also discloses the B-layer contains a non-ion-conducting polymer (Noguchi, non-ion-conductive resin [0046]), but does not specifically disclose the non-ion-conducting polymer is “in an amount of 30 parts by mass or less” as required by Claim 19.
However, modified Noguchi teaches including a non-ion conductive resin in the B-layer will improve the stability against oxidation and reduction, but “the mixing ratio is limited,” as including too much of the non-ion conductive resin in the B-layer will reduce the ionic conductivity of the layer ([0046]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to optimize, by routine experimentation, the mass ratio of a non-ion-conducting polymer in B-layer of modified Noguchi, by having enough of the non-ion conductive resin to improve the stability against oxidation and reduction, yet not too much to negatively impact conductivity, as taught by Noguchi. Where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art [MPEP 2144.05].
Claims 10-12, 14, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over modified Noguchi as applied to Claim 1 above, and further in view of Izuhara et al., US 20090208806 A1 (see enclosed PTO-892).
Regarding Claim 10, modified Noguchi discloses all limitations as set forth above. Modified Noguchi does not disclose the the ion-conducting hydrocarbon polymer contains a structural unit represented by the claimed formulas. However, this limitation is taught by Izuhara.
Izuhara teaches an electrolyte membrane layer comprising a hydrocarbon-based polymer (Examples 1-12 and 17-24 [0275-0318, 0353-0379]), wherein the polymer contains a structural unit represented by the claimed formulas:
2,2-bis(4-hydroxyphenyl)-1,3-dioxolane (K-DHBP) having formula G1 used in Examples 1-12 and 17-24 (Synthesis Examples 1 and 3 [0271-0272, 0287-0289]), consistent with K-DHBP as an ion-conducting hydrocarbon polymer in instant disclosure (see Synthesis Example 1, [0197-0198] of the published application US 20230120463 A1).
disodium 3,3'-disulfonate-4,4'-difluorobenzophenone having formula G2 used in Examples 1-12 and 17-24 (Synthesis Example 2 [0273-0274]), consistent with disodium 3,3'-disulfonate-4,4'-difluorobenzophenone as an ion-conducting hydrocarbon polymer in instant disclosure (see Synthesis Example 2, [0199-0200] of the published application US 20230120463 A1).
Izuhara teaches the K-DHBP and/or disodium 3,3'-disulfonate-4,4'-difluorobenzophenone constituents can be obtained in excellent yield, are easily hydrolyzed, and exhibit excellent proton conductivity and fuel barrier properties when used in a polymer electrolyte membrane ([0083, 0087, 0356], Table 2). Examiner notes Izuhara and Noguchi both share a goal of obtaining a polymer electrolyte material exhibiting high mechanical strength and high conductivity (Izuhara [0012], Noguchi [0043-0046]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to use the ion-conducting hydrocarbon polymer of Izuhara in the A-layer of modified Noguchi, and would have been motivated to do so, as Izuhara teaches the ion-conducting hydrocarbon polymer exhibits excellent proton conductivity and fuel barrier properties when used in a polymer electrolyte membrane.
Regarding Claim 11, modified Noguchi discloses all limitations as set forth above. Modified Noguchi discloses the ion-conducting hydrocarbon polymer is a random copolymer (Izuhara, sulfonic acid group may be introduced by block copolymerization or random copolymerization; In case fuel barrier properties and low moisture content are required, random copolymerization is more preferable. In case proton conductivity and high moisture content are required, block copolymerization is more preferably used [0101]).
Regarding Claim 12, modified Noguchi discloses all limitations as set forth above. Modified Noguchi discloses the ion-conducting hydrocarbon polymer has a weight-average molecular weight of 300,000 or more (Izuhara, molecular weight of the resulting polymer used as the polymer electrolyte material is more preferably from 1,000 to 5,000,000 [0121]; Example 17: molecular weight of 350,000 [0353], Example 18: molecular weight of 330,000 [0358]).
Regarding Claim 14, modified Noguchi discloses all limitations as set forth above. Modified Noguchi does not disclose the electrolyte membrane has a tensile modulus of “0.5 GPa or more at 23 °C and 50% RH” as required by Claim 14. However, this limitation is also taught by Izuhara.
Izuhara teaches in order to obtain long-term durability of a polymer electrolyte membrane, the membrane should have a tensile elastic modulus of 0.8 GPa or more and 5 GPa or less in an atmosphere at 25 °C and a relative humidity of 60% ([0165]). Izuhara teaches when the tensile elastic modulus is less than 0.8 GPa, long-term durability may become insufficient because of poor resistance to creep, and when the tensile elastic modulus is more than 5 GPa, adhesion to the catalyst layer may decrease or the membrane is likely to be broken because of insufficient toughness ([0165]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to optimize, by routine experimentation, the tensile elastic modulus of the electrolyte membrane of modified Noguchi, as Izuhara teaches too low of an elastic modulus will affect long term durability, while too high of an elastic modulus will negatively affect adhesion and toughness of the membrane.
Where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art [MPEP 2144.05].
Regarding Claim 16, modified Noguchi discloses all limitations as set forth above. Modified Noguchi discloses the electrolyte membrane is used in a fuel cell (Noguchi, [0014]), not “in a redox-flow battery” as required by Claim 16. However, this limitation is also taught by Izuhara.
Izuhara teaches the polymer electrolyte is preferably used for various electrochemical purposes, wherein “the electrochemical purposes include, for example, a fuel cell, a redox flow cell, a water electrolysis apparatus, and a chloroalkali electrolysis apparatus” ([0168]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to try using the electrolyte membrane of modified Noguchi in a redox flow battery, and would have a reasonable expectation of success, as Izuhara teaches the polymer electrolyte membrane may be used in a redox flow cell.
Regarding Izuhara teaching “a fuel cell is most preferable” for the polymer electrolyte membrane ([0168]), disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971) [MPEP 2123].
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 BETHANY C GARCIA whose telephone number is (571)272-2475. The examiner can normally be reached Mon-Fri, 0800 - 1730 MT.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Allison Bourke can be reached at 303-297-4684. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/BETHANY C GARCIA/Examiner, Art Unit 1721
/ALLISON BOURKE/Supervisory Patent Examiner, Art Unit 1721
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