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 .
This office action addresses pending claims 1 and 3-11. Claims 1 and 5 were amended, claim 2 was cancelled, and claims 6-11 were added in the response filed 5/15/2026.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 5/6/2025 was filed after the mailing date of the non-final office action on 4/1/2026. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
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 1 and 3-11 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 1 at lines 21-22 recites “a sacrificial electrolytic corrosion surface area W D that is a product” is unclear. The original claim 2, from which this limitation was found, had stated “surface area W x D that is a product”.
Claim 9 recites “an ionic conductivity of the separator is 1 µS/cm2 to 8 1 µS/cm2”. However, ionic conductivity is usually measured in siemens per meter (S/m) as the measurement is a movement of ions through a material, and not in siemens per meter-squared (S/m2). Therefore, the claimed physical parameter unit measurement is unclear.
Claims 3-11 are rejected for being dependent thereon.
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.
Claim(s) 1, 5-8, and 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshimura et al. (US 2013/0157160) in view of Kajiwara et al. (US 2019/0288321).
Regarding claim 1, Yoshimura discloses a polymer electrolyte fuel cell 10 composed of a plurality of stacked cells 12 ([0048], Fig 1). Each cell 12 includes a membrane 14 [insulating sheet], catalyst layers 16, gas diffusion layers 18, and separators 22 with gas channels 20 for supply reactants to the anode and cathode [cathode separator and anode separator] ([0049]-[0052], Fig 1).
The separators 22, 26 have penetration holes 30a-f, wherein penetration holes 30e and 30f define a refrigerant coolant supply manifold and refrigerant recovery manifold [coolant manifolds] ([0054],[0057], Fig 1). Seal members 32,34 enclose the gas channels 20 and the penetration holes 30a-30d ([0059]).
Protrusions 52,52’ [sacrificial electrolytic corrosion region formed by providing protrusions] are formed on the separators 22 and 26 ([0091], [0098]), and protrude into the refrigerant manifold 50 [therefore, the protrusions have a region that is not adhered to the insulating sheet {membrane 14} adjacent in a laminating direction], with the region adjacent the protrusion being adhered to the insulating sheet {membrane 14} ([0064], Fig 2A-B and 8).
The protrusions are formed on both separators 22,26 ([0065]) [therefore formed on both the cathode and anode separator].
The separators 22,26 have a shape, at the coolant lead-in/out part adjacent the protrusion, of a flat plate that is in contact with the insulating sheet (Fig 2B).
While Yoshimura discloses the conductive separator is a metal material ([0053]), Yoshimura does not explicitly disclose that the separator is made of stainless steel. In addition, Yoshimura does not explicitly disclose wherein a shape of the separator in the region other than the coolant lead-in or lead-out region is an uneven shape that is at least partially out of contact with the insulating sheet.
Kajiwara discloses a fuel cell stack in which unit cells 60 are stacked, wherein the unit cells includes: a membrane electrode assembly 20; an insulating member 40; a first separator 33a; a second separator 33c; and a gasket (abstract, [0027]-[0028], Fig 1). Separators 33a and 33c are each made of a material with a gas blocking property and electro-conductivity, are thin plate shaped members formed of a metal such as pressed stainless steel, titanium, or titanium alloy ([0030]). The separators 33a/c include coolant flow path portions 35a/35c formed on one of the surfaces ([0030], Fig 1). Separator 33a includes holes a2 and a5 and separator 33c includes holes c2 and c5 as part of the coolant inlets and outlets (Fig 1).
Protruding portions 36a1, protruding portions 36a2, a protruding portion 36a3, a protruding portion 36a4, recessed portions 37a, recessed portions 38a, and recessed portions 38a1 are formed around each of the holes a2 and a3 in the separator 33a, and protrude toward separator 33c ([0032], Fig 2). Protruding portion 36c is formed around each of the holes c2 and c3 in the separator 33c, and protrudes from the periphery toward the separator 33a ([0033], Fig 3). Protruding portions 36a1 and 36a2 of separator 33a contact the protruding portions 36c of separator 33c ([0042], Figs 4-5B). In addition, as seen in Figure 5B, protruding portions 36a1 and 36a2 of separator 33a and protruding portion 36c of separator 33c are spaced away from the insulating member 40 (Fig 5B). As protruding portions 36a3 and 36a4 of separator 33a and protruding portion 36c of separator 33c extend around the respective holes a2,a3,c2,c5, the portion away from the lead-in/lead-out region has an uneven shape and is at least partially out of contact with the insulating sheet [insulating member 40] (Figs 4-6B). Kajiwara teaches with the structures [protruding portions] around the holes, it is possible to receive the reaction force of the gaskets 55 and 55 by the separators 33a and 33c, thereby suppressing the deterioration of the sealing property and suppressing the increase in the number of parts ([0055]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the protruding portions toward the other separator and away from the insulating member as taught by Kajiwara with the separators and manifolds of Yoshimura for the purpose of receiving the reaction force of the gaskets, and suppressing deterioration of the sealing property and suppressing the increase in the number of parts.
In addition, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use stainless steel, as taught by Kajiwara, as the material for the separators in Yoshimura because Kajiwara recognizes the material as suitable for separators in a fuel cell stack, and would amount to a simple substitution of one known element for another to obtain predictable results.
While the protrusions 52,52’ [sacrificial electrolytic corrosion region] have a width in the planar direction (see Fig 2A-5B) from an end portion of the coolant manifold on a coolant inlet or outlet side, and therefore has a sacrificial electrolytic corrosion distance W, and also has a thickness [D], and further teaches that the current corrosion can be controlled by adjusting the parameters of the protrusion ([0086]-[0087], [0091]-[0093]), modified Yoshimura does not explicitly disclose that a sacrificial electrolyte corrosion surface area W x D that is a product of the sacrificial electrolytic corrosion distance W and a thickness D of the separator, is 0.25 mm2 or more.
However, as the amount of protection and suppression of electrolytic corrosion is dependent on the size of the protrusion (as taught and acknowledged by Yoshimura), as an increased size or area provides more material for suppression while increasing the weight and manufacturing costs, the size and area of the sacrificial electrolytic corrosion region [projected/protrusion part] would have been considered a result effective variable by one of ordinary skill in the art.
As such, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize, by routine experimentation, the area (W x D, including the amount of 0.25 mm2 or more) of the sacrificial electrolytic corrosion region [protrusions] of modified Yoshimura for the purpose of obtaining the desired balance between electrolytic corrosion suppression and added weight and/or manufacturing costs.
Regarding claims 5 and 7-8, modified Yoshimura discloses all of the claim limitations as set forth above. While the protrusions 52,52’ [sacrificial electrolytic corrosion region] have a width in the planar direction (see Fig 2A-5B) from an end portion of the coolant manifold on a coolant inlet or outlet side, and therefore has a sacrificial electrolytic corrosion distance W, and also has a thickness [D], and further teaches that the current corrosion can be controlled by adjusting the parameters of the protrusion ([0086]-[0087], [0091]-[0093]), modified Yoshimura does not explicitly disclose wherein (claim 5) the sacrificial electrolytic corrosion distance W is 2.1 mm to 13 mm; and the thickness D of the separator is 0.08 mm to 0.12 mm; (claim 7) the sacrificial electrolytic corrosion surface area W x D is 1.00 mm2 or less; or (claim 8) the sacrificial electrolytic corrosion distance W is 2.5 mm or more.
However, as the amount of protection and suppression of electrolytic corrosion is dependent on the size of the protrusion (as taught and acknowledged by Yoshimura), as an increased size or area provides more material for suppression while increasing the weight and manufacturing costs, the size and area of the sacrificial electrolytic corrosion region [projected/protrusion part] would have been considered a result effective variable by one of ordinary skill in the art.
As such, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize, by routine experimentation, the area (W x D, including the amount of 1.00 mm2 or less), the distance W (including the amount of 2.1-13 mm, or the amount of 2.5 mm or more), and/or the thickness D (including the amount of 0.08 to 0.12 mm) of the sacrificial electrolytic corrosion region [protrusions] of modified Yoshimura for the purpose of obtaining the desired balance between electrolytic corrosion suppression and added weight and/or manufacturing costs.
Regarding claim 6, modified Yoshimura discloses all of the claim limitations as set forth above. As seen in Figures 4A, 4C, and 8, the protrusions in the cathode separator and anode separator are spaced apart from each other in a laminating direction. Further, Yoshimura teaches that the penetration holes are preferably formed with identical sectional configurations so that the configurations coincide with another as seen looking in the direction of stacking of the cells 12 ([0065, Figs 2A-B and 8). Thus, Yoshimura suggests having identical cross sections (protrusions formed on the cathode separator and the anode separator are formed at a same position in a planar direction) in order to minimize pressure loss.
Regarding claim 10, modified Yoshimura discloses all of the claim limitations as set forth above. Yoshimura further teaches that the protrusions 52,52’ [sacrificial electrolytic corrosion region] is provided in all of the unit cells (see Figs 2A-B and 8).
Claim(s) 3-4 and 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshimura et al. (US 2013/0157160) in view of Kajiwara et al. (US 2019/0288321), as applied to claim 1 above, and further in view of Bisaka (US 2006/0093889).
Regarding claims 3-4, modified Yoshimura discloses all of the claim limitations as set forth above. While Yoshimura discloses the protrusions 52,52’ [sacrificial electrolytic corrosion regions] protrude further in the planar direction toward a partial region of the coolant manifold than the insulating sheet adjacent to the separator (Figs 2A-B and 8), modified Yoshimura does not explicitly disclose (claim 3) the type of separator being selected from a group consisting of: a cathode separator of a highest-potential unit cell that contributes to power generation and has a highest electrical potential among the unit cells, a cathode separator of an end portion unit cell that is adjacent to the highest-potential unit cell and does not contribute to power generation, and an anode separator of the end portion unit cell, nor (claim 4) wherein the cathode separator of the highest-potential unit cell includes the sacrificial electrolytic corrosion region protruding portion.
Bisaka discloses a fuel cell stack 10 with improved corrosion resistance of metal separators (abstract). The cell stack 10 is constituted by stacking a number of unit cells 20 obtained by sandwiching both surfaces of an electrolyte membrane between an anode and a cathode and sandwiching the outer sides thereof with a pair of metal separators, wherein the metal separators positioned on the plus side (cathode side) of the cell stack is subjected to surface treatment providing for relatively higher corrosion resistance (abstract). That is, Bisaka teaches by having corrosion resistant improvements at the end of the stack on the plus/cathode side that has the highest potential unit cell ([0024], see Fig 1B where the highest oxidation occurs at the plus/cathode side), the corrosion resistance can be improved with reduced cost.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to add the corrosion resistance to the end cell of the cell stack at the plus/cathode side as taught by Bisaka with the corrosion resistance protrusions of Yoshimura for the purpose of adding corrosion resistance with reduced cost.
Regarding claim 11, modified Yoshimura discloses all of the claim limitations as set forth above. As seen in Figures 2A-B, the protrusions [sacrificial electrolytic corrosion region protruding portion] protrudes so as not to block the coolant manifold, because the manifold is still open.
Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshimura et al. (US 2013/0157160) in view of Kajiwara et al. (US 2019/0288321), as applied to claim 1 above, and further in view of Yasuo et al. (JP 2002-151110, see machine translation).
Regarding claim 9, modified Yoshimura discloses all of the claim limitations as set forth above. However, Yoshimura does not explicitly disclose wherein an ionic conductivity of the separator is 1 µS/cm2 to 8 1 µS/cm2. It is noted that ionic conductivity is usually measured in siemens per meter (S/m) as the measurement is a movement of ions through a material, and not in siemens per meter-squared (S/m2). Therefore, it is interpreted that the correct units are µS/cm.
Yasuo discloses a separator that can be made of stainless steel ([0015], [0025]) that has an ionic conductivity of 1 µS/cm ([0056]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the ionic conductivity of the stainless steel separator of the fuel cell as taught by Yasuo with the stainless steel separator of modified Yoshimura for the purpose of having a separator have a known ionic conductivity.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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 JACOB BUCHANAN whose telephone number is (571)270-1186. The examiner can normally be reached M-F 8:00-5:00 PM (ET).
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nicole Buie-Hatcher can be reached at 571-270-3879. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JACOB BUCHANAN/ Examiner, Art Unit 1725
/NICOLE M. BUIE-HATCHER/ Supervisory Patent Examiner, Art Unit 1725
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