Detailed Action
This is a Non-Final Office action based on application 19/280,139 filed on 25 July 2025. The application is a continuation-in-part of PCT/ IL2024 /050787 with priority to US provisional application 63/532757 filed 15 August 2023.
Claims 1-21 are pending, claims 19-21 are withdrawn by this action, and claims 1-18 have been fully considered.
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 .
Election/Restrictions
Restriction to one of the following inventions is required under 35 U.S.C. 121:
I. Claims 1-18, drawn to a substrate, an oxygen electrode comprising the substrate, and various AEM electrochemical devices comprising the electrode, classified in H01M 4/86, H01M 4/98, H01M 8/083, C25B 11/03.
II. Claims 19-21, drawn to a method of forming an electrode and assembling a regenerative fuel cell containing the electrode, classified in H01M 4/88, H01M 8/18.
The inventions are independent or distinct, each from the other because:
Inventions I and II are related as process of making and product made. The inventions are distinct if either or both of the following can be shown: (1) that the process as claimed can be used to make another and materially different product or (2) that the product as claimed can be made by another and materially different process (MPEP § 806.05(f)). In the instant case the oxygen electrode substrate of claim 1 can be made by a process that does not include the steps, recited in claim 18, of configuring an AEM reversible device to operate alternately as a fuel cell and as an electrolyzer by using a hydrogen electrode, a membrane, an alkaline electrolyte and an oxygen electrode.
Restriction for examination purposes as indicated is proper because all the inventions listed in this action are independent or distinct for the reasons given above and there would be a serious search and/or examination burden if restriction were not required because one or more of the following reasons apply:
the inventions have acquired separate statuses in the art in view of their different statutory categories;
the inventions have acquired separate statuses in the art due to their recognized divergent subject matter;
the inventions require a different field of search (e.g., searching different classes/subclasses or electronic resources, or employing different search strategies or search queries;
the prior art applicable to one invention would likely not be applicable to another invention;
and/or the inventions are likely to raise different non-prior art issues (i.e., under 35 U.S.C. § 101 and/or 112).
Applicant is advised that the reply to this requirement to be complete must include (i) an election of an invention to be examined even though the requirement may be traversed (37 CFR 1.143) and (ii) identification of the claims encompassing the elected invention.
The election of an invention may be made with or without traverse. To reserve a right to petition, the election must be made with traverse. If the reply does not distinctly and specifically point out supposed errors in the restriction requirement, the election shall be treated as an election without traverse. Traversal must be presented at the time of election in order to be considered timely. Failure to timely traverse the requirement will result in the loss of right to petition under 37 CFR 1.144. If claims are added after the election, applicant must indicate which of these claims are readable upon the elected invention.
Should applicant traverse on the ground that the inventions are not patentably distinct, applicant should submit evidence or identify such evidence now of record showing the inventions to be obvious variants or clearly admit on the record that this is the case. In either instance, if the examiner finds one of the inventions unpatentable over the prior art, the evidence or admission may be used in a rejection under 35 U.S.C. 103 or pre-AIA 35 U.S.C. 103(a) of the other invention.
During a telephone conversation with applicant’s attorney Brendan Mee on 28 January 2026, a provisional election was made without traverse to prosecute the invention of group 1, claims 1-18. Affirmation of this election must be made by applicant in replying to this Office action. Claims 19-21 are withdrawn from further consideration by the examiner, 37 CFR 1.142(b), as being drawn to a non-elected invention.
Applicant is reminded that upon the cancelation of claims to a non-elected invention, the inventorship must be corrected in compliance with 37 CFR 1.48(a) if one or more of the currently named inventors is no longer an inventor of at least one claim remaining in the application. A request to correct inventorship under 37 CFR 1.48(a) must be accompanied by an application data sheet in accordance with 37 CFR 1.76 that identifies each inventor by his or her legal name and by the processing fee required under 37 CFR 1.17(i).
The examiner has required restriction between product or apparatus claims and process claims. Where applicant elects claims directed to the product/apparatus, and all product/apparatus claims are subsequently found allowable, withdrawn process claims that include all the limitations of the allowable product/apparatus claims should be considered for rejoinder. All claims directed to a nonelected process invention must include all the limitations of an allowable product/apparatus claim for that process invention to be rejoined.
In the event of rejoinder, the requirement for restriction between the product/apparatus claims and the rejoined process claims will be withdrawn, and the rejoined process claims will be fully examined for patentability in accordance with 37 CFR 1.104. Thus, to be allowable, the rejoined claims must meet all criteria for patentability including the requirements of 35 U.S.C. 101, 102, 103 and 112. Until all claims to the elected product/apparatus are found allowable, an otherwise proper restriction requirement between product/apparatus claims and process claims may be maintained. Withdrawn process claims that are not commensurate in scope with an allowable product/apparatus claim will not be rejoined. See MPEP § 821.04. Additionally, in order for rejoinder to occur, applicant is advised that the process claims should be amended during prosecution to require the limitations of the product/apparatus claims. Failure to do so may result in no rejoinder. Further, note that the prohibition against double patenting rejections of 35 U.S.C. 121 does not apply where the restriction requirement is withdrawn by the examiner before the patent issues. See MPEP § 804.01.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 9, 13, and 14 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 9 recites that "the MTL is post-treated". There is insufficient antecedent basis for an “MTL”. Examiner believes “the MTL” is a typographical error intended to refer to either the PTL or the MPL. However, as we cannot tell which one of these two elements “MTL” intends to refer to, the claim scope is unclear. Appropriate correction is required. For the purpose of treatment against the art in this action, Examiner interprets that claim 9 recites “... wherein the MPL is post-treated ...”.
Claim 13 recites “the hydrophilicity gradient across the MPL is further enhanced by different binder characteristics across the MPL”. However, neither the claim nor the specification establishes what baseline the claimed gradient is enhanced relative to. Therefore this claim is indefinite, because a limitation of the claim is defined by reference to an outside object which itself is not clearly defined.
Claim 14 recites “the oxygen electrode of claim 8”. There is insufficient antecedent basis for an oxygen electrode in claim 8. Antecedent basis would be present in claim 14 if this claim were dependent on claim 10 rather than claim 8. For the purpose of treatment against the art in this action, Examiner interprets that claim 14 depends from claim 10.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-13 are rejected under 35 U.S.C. 103 as being unpatentable over Darland Jr et al (US 3,423,247 A).
Regarding claim 1, Darland Jr teaches a substrate for producing an oxygen electrode (col 2 ln 58-60, “an electrode suitable for use in a fuel cell and as a cathode for a gas-depolarizable cell”; col 6 ln 28-58, the electrode is used as the oxygen electrode in various electrochemical cells), the substrate comprising: a porous transport layer (PTL) (figure 1-2, “Zone B”; col 3 ln 61 – col 4 ln 3), and a microporous layer (MPL) (figure 1-2, “Zone A”; col 3 ln 36-60), wherein the MPL is attached to the PTL to provide electric conductivity thereto (col 4 ln 3-9), and to yield a predefined pore size distribution of the substrate (col 3 ln 22-27), wherein pore sizes of the PTL are in a size range of from 1 to 20 µm (col 4 ln 2-3), which overlaps the claimed range of larger than 10 µm, and resulting pore sizes of the MPL of the substrate are in a range of from 0.1 to 1.0 µm (col 3 ln 58-60), which is inside the claimed range of below 10 µm.
While Darland Jr teaches pore sizes of the PTL are in a size range of from 1 to 20 µm (col 4 ln 2-3), Darland Jr does not specify that pore sizes of the PTL are necessarily within the range of larger than 10 µm. However it would have been obvious to have selected and utilized a thickness within the disclosed range, including those amounts that overlap within the claimed range, in order to achieve a suitable balance of gas permeability and liquid repellency as disclosed in Darland Jr (col 3 ln 59 – col 4 ln 3). It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I).
Darland Jr teaches in one embodiment that the PTL may be made of metal fibers comprising nickel (the example of col 6 ln 59 – col 7 ln 35, the PTL is sintered metal plaque with nickel wire screen embedded in it). Darland Jr teaches in another embodiment that the MPL may comprise nickel (col 5 ln 74 – col 6 ln 1, “the active zone may be made of a finely divided high surface area metal powder, such as Raney nickel”). Darland Jr does not explicitly disclose an example wherein both the PTL and the MPL are made of nickel. However, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to select suitable materials for each of these subcomponents from among the finite options disclosed in Darland Jr and thereby arrive at a composition in which the PTL is nickel and the MPL is also nickel. The selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art [MPEP § 2144.07].
Regarding claim 2, Darland Jr renders obvious the substrate of claim 1. Darland Jr teaches the MPL pore sizes are in a range of from 0.1 to 1.0 µm (col 3 ln 58-60), which is inside the claimed range of between 0.1 and 5 microns. Darland Jr teaches the PTL pore sizes are in a range of from 1 to 20 µm (col 4 ln 2-3), which overlaps the claimed range of 10 to 25 µm, but does not specifically teach a pore size in the overlapping portion of the ranges. However it would have been obvious to have selected and utilized a thickness within the disclosed range, including those amounts that overlap within the claimed range, in order to achieve a suitable balance of gas permeability and liquid repellency as disclosed in Darland Jr (col 3 ln 59 – col 4 ln 3). It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I).
Regarding claim 3, Darland Jr renders obvious the substrate of claim 1. Darland Jr further teaches wherein the MPL comprises pore forming agents configured to regulate and control pore sizes within the MPL (in the embodiment of col 9 ln 20-37, the MPL pores are filled with a blocking agent that prevents wetproofing agent from infiltrating that region during a wetproofing process step. The blocking agent is later dissolved away to yield non-wetproofed pores of a controlled size).
Regarding claim 4, Darland Jr renders obvious the substrate of claim 1, and further teaches wherein the MPL comprises binders (col 3 ln col 3 ln 43-45, “active particles in zone A are bonded together by a suitable binder) that are resistant to high pH conditions (in the Example of col 6 ln 59 – col 7 ln 35, a MPL is assembled by spray coating carbon black active particles and binders of fluorinated resin and polyethylene. The finished electrode is then used as an oxygen electrode where it “exhibited very reliable and reproducible voltage outputs” in an electrolyte of 9 N KOH. It follows that its material constituents of the electrode (including the binders) must be stable in high pH conditions. Note also that instant para [0028] says both polyethylene and fluorinated polymers are suitable binders for use in the presently claimed MPL).
Regarding claim 5, Darland Jr renders obvious the substrate of claim 1, and further teaches the MPL comprises multiple layers that are configured to form a gradient across the MPL with respect to pore size and/or hydrophilicity (col 4 ln 30-54).
Regarding claim 6, Darland Jr renders obvious the substrate of claim 1. The further limitation of claim 6, wherein the substrate is “post treated to eliminate a passivated layer from the metal of the PTL and the MPL, to remove pore forming components from MPL, to adhere the MPL to the PTL and/or to stabilize MPL components within the MPL layer”, is directed to the process by which the claimed product is made. However, claim 6 is a product claim, so the determination of patentability is based on the product itself and does not depend on its method of production. Since the process step recited in claim 6 does not appear to imply any physical feature that could be relied upon to differentiate the claimed product from the prior art product, the product of Darland Jr would read on this claim regardless of whether or not Darland Jr disclosed the claimed post treatment. Also, Darland Jr discloses post treating the substrate to eliminate wetproofing material (a passivating layer) from the metal of the PTL and MPL (col 7 ln 65 – col 8 ln 41) and/or to remove pore forming components from the MPL (col 9 ln 20-70).
Regarding claim 7, Darland Jr renders obvious the substate of claim 1 and further teaches wherein the MPL is attached to the PTL (col 4 ln 6-10, “particles in both zones ... in contact with each other and/or by the use of a conductive binder”). The further limitation of claim 7, where the MPL and PTL are attached “by at least one of printing, spraying, applying hot pressing, calendaring or roll pressing”, is directed to the process by which the claimed product is made. However, claim 7 is a product claim, so the determination of patentability is based on the product itself and does not depend on its method of production. Since the process limitation recited in claim 7 does not appear to imply any physical feature that could be relied upon to differentiate the claimed product from the prior art product, the product of Darland Jr would read on this claim regardless of whether or not Darland Jr disclosed the claimed attachment method. Also, Darland Jr discloses attaching the MPL to the PTL by hot pressing (col 4 ln 55 – col 5 ln 67).
Regarding claim 8, Darland Jr renders obvious the substate of claim 1. The further limitation of claim 8, “wherein the PTL is pre-treated before attaching the MPL thereto, to enhance adhesion and improve an electric contact of the MPL to the PTL”, is directed to the process by which the claimed product is made. However, claim 8 is a product claim, so the determination of patentability is based on the product itself and does not depend on its method of production. Since the process step recited in claim 8 does not appear to imply any physical feature that could be relied upon to differentiate the claimed product from the prior art product, the product of Darland Jr would read on this claim regardless of whether or not Darland Jr disclosed pre-treating the PTL before attaching the MPL thereto. Also, Darland Jr discloses spray coating the PTL with binder before attaching the MPL (col 6 ln 61-66), thereby pre-treating the PTL in a manner that would apparently enhance adhesion.
Regarding claim 9, Darland Jr renders obvious the substate of claim 1. The further limitation of claim 9, “wherein the MTL is post-treated after attaching the MPL to the PTL”, is directed to the process by which the claimed product is made. However, claim 9 is a product claim, so the determination of patentability is based on the product itself and does not depend on its method of production. Since the process step recited in claim 9 does not appear to imply any physical feature that could be relied upon to differentiate the claimed product from the prior art product, the product of Darland Jr would read on this claim regardless of whether or not Darland Jr disclosed post-treating the MPL after attaching the MPL to the PTL. Moreover, in an example, Darland JR discloses post-treating the MPL after attaching the MPL to the PTL (col 7 ln 65 – col 8 ln 41).
Regarding claim 10, Darland Jr renders obvious the substrate of claim 1, and further discloses an oxygen electrode (col 2 ln 58-60, “an electrode suitable for use in a fuel cell and as a cathode for a gas-depolarizable cell”; col 6 ln 28-58, the electrode is used as the oxygen electrode in various electrochemical cells) comprising said substrate and further having a catalyst material deposited on the MPL of the substrate, forming a catalyst layer thereupon (figure 2, layer 11 is deposited on the layers 12, 13 of MPL zone A; col 6 ln 28-31, layer 11 is catalyzed; in an alternative example, col 7 ln 12-20, after the PTL and MPL were attached together, a catalyst material was then deposited on the MPL to form a catalyzed layer).
Regarding claim 11, Darland Jr renders obvious the oxygen electrode of claim 10 and further teaches the MPL comprises a gradient of pore distribution thereacross, with small pores near the catalyst layer and larger pores farther from the catalyst layer (figure 2; col 4 ln 30-54). The functional features recited in claim 11 (i.e., wherein the small pores near the catalyst layer function “to enhance electric contact thereto and decrease electrode resistance”, and the larger pores farther from the catalyst layer function “to optionally facilitate and enhance O2 gas release during operation”) do not appear to carry any patentable weight, since these functional features emerge from the claimed structure. That is to say, since Darland Jr discloses the structure of a gradient of pore sizes with small pores near the catalyst layer and larger pores farther from the catalyst layer, as claimed, then the recited functions that emerge from this structure are inherently present in Darland Jr’s electrode. See MPEP 2112 – 2112.01.
Regarding claim 12, Darland Jr renders obvious the oxygen electrode of claim 10 and further teaches the MPL comprises a hydrophilicity gradient, exhibiting a more hydrophilic structure near the catalyst layer and a more hydrophobic composition farther from the catalyst layer (col 4 ln 30-54). The functional features recited in claim 12 (i.e., wherein the more hydrophilic region near the catalyst layer facilitates water and/or electrolyte distribution, and the more hydrophobic composition further from the catalyst layer enhances gas removal from O2 release areas) do not appear to carry any patentable weight, since these functional features emerge from the claimed structure. That is to say, since Darland Jr discloses the structure of a hydrophilicity gradient, with greater hydrophilicity near the catalyst layer and greater hydrophobicity farther from the catalyst layer, then the recited functions that emerge from this structure are inherently present in Darland Jr’s electrode. See MPEP 2112 – 2112.01.
Regarding claim 13, Darland Jr renders obvious the oxygen electrode of claim 12, and further teaches the hydrophilicity gradient across the MPL is further enhanced by different binder characteristics across the MPL (col 4 ln 60 - col 5 ln 9, successive layers farther from the catalyst layer have increasing amounts of polyethylene binder, and the farthest layers have polytetrafluoroethylene included in the binder; col 5 ln 34 – 42).
Claims 14-18 are rejected under 35 U.S.C. 103 as being unpatentable Beachy et al (US 2018/0327917 A1), in view of Darland Jr.
Regarding claims 14, 15, and 17, Beachy discloses an AEM reversible device, configured to operate both as a fuel cell and as an electrolyzer (abstract), comprising a hydrogen electrode (para [0038], “a hydrogen electrode in which hydrogen evolution and hydrogen oxidation can occur”; para [0048], [0056], figure 1C), a membrane (figure 1A #400; para [0057], “membrane (AEM) 400”), an alkaline electrolyte (para [0038], “a porous matrix layer that may be permeated with aqueous liquid electrolyte”; para [0037], “preferred ... aqueous KOH ... as the electrolyte”; para [0049], [0056]) and an oxygen electrode (para [0038], “an oxygen electrode in which oxygen evolution and oxygen reduction can occur”; figure 1A #750; para [0057], “oxygen electrode (750)”), wherein the oxygen electrode comprises of a first layer comprising nickel fibers (para [0057], “the oxygen electrode current collector (850) may be nickel mesh”; figure 1A), a second layer comprising nickel (para [0057], “and the oxygen electrode (750) may be nickel foam”; figure 1A), and having a catalyst material deposited on the second layer, forming a catalyst layer thereupon (para [0057], “coated with a mixture of catalyst and binder”).
However, Beachy does not teach that the nickel-mesh layer of the oxygen electrode is a PTL having pore size of greater than 10 microns and the nickel-foam layer of the oxygen electrode is a MPL having pore of less than 10 microns, as required by claim 1, from which claim 10 depends. In this sense, the oxygen electrode disclosed in Beachy is different than the oxygen electrode of claim 10.
Darland Jr teaches an oxygen electrode (col 2 ln 58-60, “an electrode suitable for use in a fuel cell and as a cathode for a gas-depolarizable cell”; col 6 ln 28-58, the electrode is used as the oxygen electrode in various electrochemical cells), comprising a substrate comprising: a porous transport layer (PTL) (figure 1-2, “Zone B”; col 3 ln 61 – col 4 ln 3), and a microporous layer (MPL) (figure 1-2, “Zone A”; col 3 ln 36-60), wherein the MPL is attached to the PTL to provide electric conductivity thereto (col 4 ln 3-9), and to yield a predefined pore size distribution of the substrate (col 3 ln 22-27), wherein pore sizes of the PTL are in a size range of from 1 to 20 µm (col 4 ln 2-3), which overlaps the claimed range of larger than 10 µm, and resulting pore sizes of the MPL of the substrate are in a range of from 0.1 to 1.0 µm (col 3 ln 58-60), which is inside the claimed range of below 10 µm.
Darland Jr teaches that the MPL is relatively hydrophilic in addition to having smaller pore sizes, so that it is wetted with the liquid electrolyte (col 3 ln 36-60). Meanwhile the PTL is formed with relatively hydrophobic material and with a larger pore size, so that liquid electrolyte is excluded from the PTL and the PTL is configured to transport gas phase reactants (col 3 ln 61 – col 4 ln 3).
Darland Jr teaches that the electrode having the disclosed gradation in pore size and electrolyte repellency is particularly suitable for use as an oxygen electrode as e.g. in alkaline fuel cell applications, because the micropores of the electrode allow electrolyte to partially penetrate the electrode without wholly flooding the electrode (col 3 ln 5-27; col 3 ln 55-60; col 3 ln 75-col 4 ln 3).
Darland Jr also teaches that the PTL may be made of metal fibers comprising nickel (the example of col 6 ln 59 – col 7 ln 35, the PTL is sintered metal plaque with nickel wire screen embedded in it), and that the MPL may also comprise nickel (col 5 ln 74 – col 6 ln 1, “the active zone may be made of a finely divided high surface area metal powder, such as Raney nickel”), implying that Darland Jr’s teachings can be applied with reasonable expectation of success to other nickel-based oxygen electrodes, such as the nickel-based oxygen electrode used in Beachy’s device.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Beachy’s device by structuring the nickel-based oxygen electrode as an electrode which has a relatively hydrophilic MPL with relatively small pores, and a relatively hydrophobic PTL with relatively larger pores, based on Darland Jr’s teaching that an oxygen electrode with this structure achieves good activity in an electrochemical cell by virtue of being partially wetted, but not flooded, with the cell’s aqueous electrolyte. It would also have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to design the MPL with a pore size within the claimed range of less than 10 µm as taught in Darland Jr (col 3 ln 58-60), and, to design the PTL with a pore size in the disclosed range of Darland Jr of from 1 to 20 µm (col 4 ln 2-3) including those amounts that are within the claimed range of greater than 10 µm, based on Darland Jr’s teachings that these pore size ranges are suitable for the above purpose. It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I).
Regarding claims 16 and 18, Beachy in view of Darland Jr renders obvious a device which is both the AEM electrolyzer of claim 15 and the AEM reversible device of claim 17. Darland Jr further teaches that the MPL comprises a gradient of pore distribution thereacross, with small pores near the catalyst layer and larger pores farther from the catalyst layer (figure 2; col 4 ln 30-54), and also that the MPL comprises a hydrophilicity gradient, exhibiting a more hydrophilic structure near the catalyst layer and a more hydrophobic composition farther from the catalyst layer (col 4 ln 30-54). Darland Jr further teaches that the MPL comprises binders (col 3 ln col 3 ln 43-45, “active particles in zone A are bonded together by a suitable binder) that are resistant to high pH conditions (in the Example of col 6 ln 59 – col 7 ln 35, a MPL is assembled by spray coating carbon black active particles and binders of fluorinated resin and polyethylene. The finished electrode is then used as an oxygen electrode where it “exhibited very reliable and reproducible voltage outputs” in an electrolyte of 9 N KOH. It follows that its material constituents of the electrode (including the binders) must be stable in high pH conditions. Note also that instant para [0028] says both polyethylene and fluorinated polymers are suitable binders for use in the presently claimed MPL), wherein the hydrophilicity gradient across the MPL is further enhanced by different binder characteristics across the MPL (col 4 ln 60 - col 5 ln 9, successive layers farther from the catalyst layer have increasing amounts of polyethylene binder, and the farthest layers have polytetrafluoroethylene included in the binder; col 5 ln 34 – 42).
The functional features recited in claims 16 and 18 (i.e., wherein the small pores near the catalyst layer function “to enhance electric contact thereto and decrease electrode resistance”, the larger pores farther from the catalyst layer function “to optionally facilitate and enhance O2 gas release during operation”, wherein the more hydrophilic region near the catalyst layer functions to “facilitate water and/or electrolyte distribution”, and the more hydrophobic composition further from the catalyst layer functions to “enhance gas removal from O2 release areas”) do not appear to carry any patentable weight, since these functional features emerge from the claimed structure. That is to say, since Darland Jr discloses the structure of a pore size gradient with small pores near the catalyst layer and larger pores farther from the catalyst layer, and a hydrophilicity gradient with greater hydrophilicity near the catalyst layer and greater hydrophobicity farther from the catalyst layer, as claimed, then the recited functions that emerge from this structure are inherently present in Darland Jr’s electrode. See MPEP 2112 – 2112.01.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 2,716,670 A to Bacon discloses an alkaline fuel cell comprising an oxygen electrode comprising a porous transport layer (PTL), and a microporous layer (MPL), wherein both layers are made of nickel.
US 2,969,315 A to Bacon discloses a bipolar electrode for use in an alkaline fuel cell stack, comprising a central nickel plate, PTLs on either side of the central plate, and MPLs coated on the PTLs, wherein the PTLs and MPLs are made of nickel.
US 3,215,563 A to Clemm discloses an oxygen electrode for use in alkaline fuel cells, comprising a metal mesh backing with a microporous nickel coating deposited thereon.
US 2013/0337366 A1 to Blanchet et al discloses an oxygen electrode substrate comprising a PTL of nickel-fiber felt with a MPL laminated thereon.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Andrew R Koltonow whose telephone number is (571)272-7713. The examiner can normally be reached Monday - Friday, 10:00 - 6:00 ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Luan V Van can be reached at (571) 272-8521. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ANDREW KOLTONOW/Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795