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 Amendments
This is a final office action in response to applicant's arguments and remarks filed on 04/24/2026.
Status of Rejections
The previous rejection of claim 13 is maintained and modified only in response to the amendments to the claims.
All other previous rejections are withdrawn in view of applicant’s amendments.
New grounds of rejection are necessitated by applicant’s amendments.
Claims 1-6 and 8-18 are pending and under consideration for this Office Action.
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 1-6, 8-12, 14-16 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Oda et al. (U.S. Patent No. 4,465,570) in view of Yamaki et al. (U.S. 2014/0360868), and further in view of Okamoto et al. (U.S. Patent No. 4,384,941).
Regarding claim 1, Oda teaches a membrane electrode assembly (see e.g. Col. 2, lines 18-20, and Col. 4, lines 12-15, assembly of anode and cathode bonded to either side of cation exchange membrane), comprising:
an anode having a first catalyst layer (see e.g. Col. 2, lines 22-23 and 47-53, anode comprising porous layer formed by suitable substances suitable for anode reaction) and a first gas diffusion layer (see e.g. Col. 4, lines 27-32, and Col. 5, lines 41-43, current collector comprising porous material such as a net, i.e. gas diffusion layer, brought into contact with anode);
a cathode having a second catalyst layer (see e.g. see e.g. Col. 2, lines 22-23 and 53-61, cathode comprising porous layer formed by substances suitable for cathode reaction) and a second gas diffusion layer (see e.g. Col. 4, lines 27-32, and Col. 5, lines 41-43, current collector comprising porous material such as a net, i.e. gas diffusion layer, brought into contact with anode); and
a polymer electrolyte membrane formed between the anode and the cathode (see e.g. Col. 2, lines 18-20, and Col. 3, lines 18-19, anode and cathode contacting either side of polymer cation exchange membrane),
wherein the polymer electrolyte membrane is formed between the first catalyst layer and the second catalyst layer, the first catalyst layer is formed between the first gas diffusion layer and the polymer electrolyte membrane, the second catalyst layer is formed between the second gas diffusion layer and the polymer electrolyte membrane (see e.g. Col. 4, lines 12-15 and 27-29, cation exchange membrane coated with anode and cathode on either side with current collector brought into contact with outer surface of each porous electrode), the polymer electrolyte membrane comprises a fluorinated polymer having ion exchange groups (see e.g. Col. 3, lines 18-22, fluorinated polymer having cation-exchange group), and a fabric (see e.g. Col. 4, lines 5-7, membrane reinforced by fabric such as cloth).
Oda does not explicitly teach the fabric being woven with an aperture ratio of 50%, a denier number of warp yarns and a denier number of weft yarns of the woven fabric being each independently from 2 to 49.8, the warp yarns having a density of at least 70 yarns/inch and at most 200 yarns/inch, and the weft yarns having a density of at least 70 yarns/inch and at most 200 yarns/inch.
Yamaki teaches an electrolyte membrane for use in an electrolytic cell (see e.g. Abstract) comprising a fluoropolymer and reinforced with a woven fabric (see e.g. Paragraph 0023), wherein the fabric has a linear reinforcing thread density, i.e. in each of the respective warp and weft directions, of preferably 3 to 50 number/cm, equal to 7.62-127 yarns/inch (see e.g. Paragraph 0035, lines 1-3 and Paragraph 0036, lines 1-4), a denier number of preferably 25-400 (see e.g. Paragraph 0045, lines 1-3) and an open area ratio of preferably 70-90% (see e.g. Paragraph 0038, lines 1-4) to provide sufficient mechanical strength while keeping the resistance and thus electrolysis voltage sufficiently suppressed (see e.g. Paragraph 0035, lines 3-9, Paragraph 0038, lines 4-10, and Paragraph 0045, lines 3-9), the thread density and denier number both overlapping claimed ranges of the present invention.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the fabric of Oda to be a woven fabric with a warp and weft linear thread density of 7.62-127 yarns/inch, a denier number of 25-400 and an aperture ratio of 70-90% as taught by Yamaki to provide the reinforcing fabric with sufficient mechanical strength while keeping the resistance and this electrolysis voltage sufficiently suppressed. MPEP § 2144.05 I states “In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists.”
Modified Oda does not explicitly teach a relation of Y≤240X-170 being satisfied, where a membrane thickness of the polymer electrolyte membrane is Y µm and an ion exchange capacity of the fluorinated polymer is X meq/g dry resin. Oda does however teach the membrane thickness being in a range of preferably 50 to 400 µm (see e.g. Oda Col. 4, lines 9-11), and the ion exchange capacity preferably being in a range of 0.8 to 2.0 meq/g dry resin (see e.g. Oda Col. 3, lines 22-25), the two ranges including combinations that meet the claimed relation.
Okamoto teaches a cation exchange membrane for water electrolysis (see e.g. Abstract) which has exemplary membrane thickness and ion exchange capacity combinations of 100 µm and 1.9 meq/g-dry resin, 100 µm and 1.6 meq/g-dry resin, and 150 µm and 1.7 meq/g-dry resin (see e.g. Col. 4, lines 66-67, Col. 5, lines 14-17 and 44-49, and Col. 6, lines 44-52), all of which satisfy the claimed relation of Y≤240X-170.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the membrane thickness and ion exchange capacity of modified Oda to be 100 µm and 1.9 meq/g-dry resin, 100 µm and 1.6 meq/g-dry resin, and 150 µm and 1.7 meq/g-dry resin, which satisfy the relation of Y≤240X-170, as taught by Okamoto as particular suitable combinations of thicknesses and ion exchange capacities for a cation exchange membrane for water electrolysis that each fall within the ranges already preferred by Oda. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Regarding claim 2, Oda as modified by Yamaki teaches the aperture ratio of the woven fabric being 70% to 90% (see e.g. Yamaki Paragraph 0038, lines 1-4), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 3, Oda as modified by Yamaki teaches the denier number of the warp yarns and the denier number of the weft yarns being each 25 to 400 (see e.g. Yamaki Paragraph 0045, lines 1-3), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 4, Oda as modified by Okamoto teaches the membrane thickness Y of the polymer electrolyte membrane being 100 or 150 µm (see e.g. Okamoto Col. 4, lines 66-67, Col. 5, lines 14-17 and 44-49, and Col. 6, lines 44-52).
Regarding claim 5, Oda as modified by Okamoto teaches the ion exchange capacity X of the fluorinated polymer being 1.9, 1.6 or 1.7 meq/g dry resin (see e.g. Okamoto Col. 4, lines 66-67, Col. 5, lines 14-17 and 44-49, and Col. 6, lines 44-52).
Regarding claim 6, modified Oda teaches the warp yarns and the weft yarns including polytetrafluoroethylene (see e.g. Oda Col. 4, lines 5-8).
Regarding claim 8, modified Oda teaches the ion exchange groups being sulfonic acid type functional groups (see e.g. Oda Col. 3, lines 18-20).
Regarding claim 9, modified Oda teaches the fluorinated polymer including units based on a fluorinated olefin (see e.g. Oda Col. 3, lines 26-35, unit (a) comprising fluorinated olefins with -CF2-CXX’-structure) and units having a sulfonic acid type functional group and a fluorine atom (see e.g. Oda Col. 3, lines 26-49, unit (b) containing F atoms, where Y represents a compound including A which may be a sulfonic acid group -SO3M).
Regarding claim 10, modified Oda teaches the fluorinated olefin being a C2 fluoroolefin having at least 2 fluorine atoms (see e.g. Oda Col. 3, lines 26-35, unit (a) with -CF2-CXX’-structure, where X and X’ may include further F atoms).
Regarding claim 11, modified Oda teaches the units having a sulfonic acid type functional group and a fluorine atom being units of –[CF2-CF(-L-(SO3Mn)]-, where L is an n+1 valent perfluorohydrocarbon group which may contain an etheric oxygen atom, M is a hydrogen atom or an alkali metal, and n is 1 (see e.g. Oda Col. 3, lines 26-49, unit (b) where X may be F, Y may be one of the additional structures below, A may be -SO3M, and M may be hydrogen or an alkali metal).
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Regarding claim 12, modified Oda teaches a water electrolysis apparatus comprising the membrane electrode assembly of claim 1 (see e.g. Oda Col. 2, lines 7-13, and Col. 4, lines 33-50, electrolytic cell for water electrolysis comprising the membrane-contacting anode and cathode).
Regarding claim 14, modified Oda teaches the fluorinated polymer including units based on a fluorinated olefin (see e.g. Oda Col. 3, lines 26-35, unit (a) comprising fluorinated olefins with -CF2-CXX’-structure) and units having a sulfonic acid type functional group and a fluorine atom (see e.g. Oda Col. 3, lines 26-49, unit (b) containing F atoms, where Y represents a compound including A which may be a sulfonic acid group -SO3M), and the units having a sulfonic acid type functional group and a fluorine atom including a unit of formula (1-5), wherein M is a hydrogen atom or alkali metal, x is 1, y is an integer from 1 to 10, z is 1 and Y is F (see e.g. Oda Col. 3, lines 26-49, unit (b) with the exemplary Y structure shown below, where X may F, A may be -SO3M, M is hydrogen or an alkali metal, x and y are each an integer from 1 to 10 and Z and R may each be -F), the subscript integers falling within or encompassing the ranges of the formula of the present invention (see MPEP § 2144.05 I as cited above).
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Regarding claims 15-16, the claimed limitations are related to a property of the membrane electrode assembly in use. MPEP § 2114 states “"[A]pparatus claims cover what a device is, not what a device does."…A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim.”. MPEP § 2112.01 I also states “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established.”. Modified Oda teaches all the structural limitations of the claimed assembly as stated above, and would therefore be expected to exhibit similar properties in use. Furthermore, the “electrolysis voltage” can be influenced by a number of factors such as specific ion exchange group of the membrane fluorinated polymer and concentration of the used aqueous solution, as evidenced by Oda (see e.g. Oda Col. 3, lines 53-59, and Col. 4, lines 56-62), or reinforcing fabric thread density, open area ratio and denier number, as evidenced by Yamaki (see e.g. Yamaki Paragraph 0035, lines 3-9, Paragraph 0038, lines 4-10, and Paragraph 0045, lines 3-9). As the claim only specifies the compared water electrolyzer comprising a membrane electrode assembly which does not satisfy the relation of Y≤240X-170, such a compared electrolyzer could have a higher voltage, including one at least 0.10 V more, for a variety of other such reasons in the chosen operation of the electrolyzer incorporating the membrane electrode assembly. Though there is no specific data for the assembly of modified Oda, being a combination, the examples taught by Okamoto that satisfy the relation are exemplified with electrolysis voltages of 2.5 V and 2.6 V (see e.g. Okamoto Col. 5, lines 35-37 and 51-52, and Col. 6, lines 55-56), which are 0.2 V and 0.1 V lower than the 2.7 V electrolysis voltage of at least one of the examples that does not satisfy the relation (see e.g. Okamoto Col. 6, lines 37-38). Oda itself also teaches cells with the membranes having voltages, dependent partially on current density, of 1.5-1.82 V (see e.g. Oda Tables in Cols. 5-6), which are also lower than said 2.7 V.
Regarding claim 18, modified Oda teaches the warp yarns and the weft yarns consisting of polytetrafluoroethylene (see e.g. Oda Col. 4, lines 5-8).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Higuchi (JP H06306193 A, citations based on translation) in view of Hiyoshi, and further in view of Okamoto and Umemura et al. (U.S. 2009/0306233).
Regarding claim 13, Higuchi teaches a polymer electrolyte membrane (see e.g. Paragraph 0004, cation exchange membrane), comprising:
a fluorinated polymer having ion exchange groups (see e.g. Paragraph 0032, lines 1-3, fluorine-containing polymer with cation exchange groups); and
a woven fabric (see e.g. Paragraph 0012, lines 3-5, and Paragraph 0013, lines 6-8),
wherein a denier number of warp yarns and a denier number of weft yarns constituting the woven fabric are each independently 20 to 170 (see e.g. Paragraph 0014, lines 1-2, yarn diameter in both directions, i.e. warp and weft), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above), the warp yarns having a density of 8 to 150 yarns/inch and the weft yarns having a density of 8 to 150 yarns/inch (see e.g. Paragraph 0014, lines 1-2, yarn density in both directions, i.e. warp and weft),
wherein the fluorinated polymer contains units based on a fluorinated olefin (see e.g. Paragraph 0032, line 4, fluorinated vinyl monomer such as TFE or chlorotrifluoroethylene, which are exemplary fluoroolefins as described in paragraph 0033 of the instant specification) and units having a sulfonic acid type functional group and a fluorine atom (see e.g. Paragraph 0032, line 5, fluorovinyl monomer containing sulfonic acid ion exchange group).
Higuchi does not explicitly teach the aperture ratio of the woven fabric being at least 50%, but does teach it generally having a stable aperture ratio (see e.g. Paragraph 0013, line 7).
Hiyoshi teaches a cation exchange membrane for electrolysis (see e.g. Paragraph 0001, lines 1-2) comprising a reinforcing woven fabric (see e.g. Paragraph 0038) with an opening rate of 55% to 95%, preferably 60% to 90%, to prevent the electrical shielding ratio from being large and ensure that a substantial reinforcing effect is obtained (see e.g. Paragraph 0040).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the aperture ratio of the woven fabric of Higuchi to be 55% to 95%, preferably 60% to 90%, as taught by Hiyoshi to prevent the electrical shielding ratio from being large and ensure that a substantial reinforcing effect is obtained.
Modified Higuchi does not explicitly teach a relation of Y≤240X-170 being satisfied, where the membrane thickness of the polymer electrolyte membrane is Y µm, and the ion exchange capacity of the fluorinated polymer is X meq/g dry resin. Higuchi does however teach the membrane thickness being within the range of 100 to 500 µm (see e.g. Paragraph 0039, lines 4-5), and the ion exchange capacity being between 0.8 to 2.0 meq/g (see e.g. Paragraph 0037, lines 1-2), the two ranges including combinations that meet the claimed relation.
Okamoto teaches a cation exchange membrane for electrolysis (see e.g. Abstract) which has exemplary membrane thickness and ion exchange capacity combinations of 100 µm and 1.9 meq/g-dry resin, 100 µm and 1.6 meq/g-dry resin, and 150 µm and 1.7 meq/g-dry resin (see e.g. Col. 4, lines 66-67, Col. 5, lines 14-17 and 44-49, and Col. 6, lines 44-52), all of which satisfy the claimed relation of Y≤240X-170.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the membrane thickness and ion exchange capacity of modified Higuchi to be 100 µm and 1.9 meq/g-dry resin, 100 µm and 1.6 meq/g-dry resin, and 150 µm and 1.7 meq/g-dry resin, which satisfy the relation of Y≤240X-170, as taught by Okamoto as particular suitable combinations of thicknesses and ion exchange capacities for a cation exchange membrane for electrolysis that each fall within the ranges already preferred by Higuchi. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Modified Higuchi does not explicitly teach the units having a sulfonic acid type functional group and a fluorine atom conforming to formula (1-4).
Umemura teaches an ion exchange membrane for alkaline chloride electrolysis (see e.g. Abstract) comprising a polymer having units of the formula (1-4) (equivalent formula M1 shown below), wherein Rf1 (OCF2RF12 in formula M1) is a perfluoroalkylene group which may contain an oxygen atom between carbon atom-carbon atom, Rf2 (RF11 in formula M1) is a single bond or a perfluoroalkylene group which may contain an oxygen atom between carbon atom-carbon atom, Rf3 is a single bond, r is 0 or 1, m is 1, and M is a hydrogen atom or an alkali metal (see e.g. Paragraphs 0019 and 0034, polymer having units U1, preferably units M1 shown below), the polymer having units of this formula providing the membrane with low electrical resistance and sufficient mechanical strength as compared with a membrane made of a conventional polymer (see e.g. Paragraph 0135)
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It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the units of the fluoropolymer of modified Higuchi to conform to formula (1-4) as taught by Umemura to provide the membrane with low electrical resistance and sufficient mechanical strength as compared with a membrane made of a conventional polymer.
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Oda, Yamaki and Okamoto, as applied to claim 1 above, and further in view of Verbrugge (U.S. Patent No. 5,284,571).
Regarding claim 17, modified Oda teaches all the limitations of the membrane electrode assembly of claim 1 as stated above. Modified Oda does not explicitly teach the gas diffusion layer comprising a carbon material selected from the group consisting of carbon paper, carbon cloth, carbon felt and PTFE, but does generally teach it being a current collector comprising a porous material such as a net (see e.g. Oda Col. 4, lines 27-32, and Col. 5, lines 41-43).
Verbrugge teaches an electrochemical cell comprising a membrane electrode assembly in which carbon cloth current collectors are provided adjacent the outside of the MEA (see e.g. Fig. 1 and Col. 3, lines 23-36).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the gas diffusion layer of modified Oda to comprise carbon cloth as taught by Verbrugge as a particular suitable material for use as a porous current collector in an electrochemical cell comprising a membrane electrode assembly. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results. Further, MPEP § 2144.07 states “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)”.
Response to Arguments
Applicant’s arguments, see page 10, filed 04/24/2026, with respect to the rejection(s) of claim(s) 1 under 35 USC 103 over Oda in view of Keating, Hiyoshi and Okamoto, particularly regarding the amended denier number range, have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Oda, Yamaki and Okamoto.
Applicant's arguments filed 04/24/2026 have been fully considered but they are not all persuasive.
On pages 8-10, Applicant argues that the Office Action foes not explain why the person of ordinary skill would have been motivated to make the combinations or would have had a reasonable expectation of success, particularly because Okamoto also discloses membranes with thicknesses and ion exchange capacities that do not satisfy the claimed Y≤240X-170 relation and considers them to be equally successful. This is not considered persuasive. Oda teaches preferred ranges of both membrane thickness and ion exchange capacity (see e.g. Oda Col. 3, lines 22-25, and Col. 4, lines 9-11, 50 to 400 µm and 0.8 to 2.0 meq/g). Okamoto teaches specific examples of combinations of thicknesses and ion exchange capacities, within both of the preferred ranges of Oda, that satisfy the claimed relation and are successfully used in a membrane for electrolysis (see e.g. Okamoto Abstract, Col. 4, lines 66-67, Col. 5, lines 14-17 and 44-49, and Col. 6, lines 44-52, 100 µm and 1.9 meq/g, 100 µm and 1.6 meq/g, and 150 µm and 1.7 meq/g), thus supporting the obviousness of the combination of elements (see MPEP § 2143(I)(A) as cited in the rejection). Regardless of whether other combinations with thicknesses and ion exchange capacities that do not satisfy the claimed requirement would also be considered “successful”, the structure of the combination itself is considered obvious. Furthermore, it is not required for the prior art to be combined based on the same reason as the instant disclosure, or for the prior art to recognize all disclosed benefits or disclosed degree of “success” of the combination, as long as the combination teaches all the structural limitations of the claimed apparatus. MPEP § 2112.01 I states “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established.”. MPEP § 2112 also states ““There is no requirement that a person of ordinary skill in the art would have recognized the inherent disclosure at the relevant time, but only that the subject matter is in fact inherent in the prior art reference.””.
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.
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/M.S.J./Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795
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