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 30 August 2025 have been fully considered but they are not persuasive. Applicant has argued that (1) Katayama et al do not teach that the protrusions are disposed only on one surface with a conductive elastic body used on the opposite side and (2) Revill et al utilized conductive posts connected to the protrusions and also placed insulating cushions between the posts and the electrode plates thus failing to teach using a conductive elastic body.
In response to (1), while Katayama et al do indeed fail to teach using a conductive elastic body between an electrode and the protrusions, it is noted that the primary reference, Tanaka et al, teach using an elastic conductive body between both electrodes (anode and cathode) and the corresponding protrusions of the bipolar wall. Thus, the noted deficiency of the secondary reference Katayama et al does not overcome the rejection grounds since the deficiency is accounted for by the primary reference.
In response to (2), while Revill et al do indeed fail to teach using a conductive elastic body between an electrode and the protrusions, it is noted that the primary reference, Tanaka et al, teach using an elastic conductive body between both electrodes (anode and cathode) and the corresponding protrusions of the bipolar wall. Thus, the noted deficiency of the secondary reference Katayama et al does not overcome the rejection grounds since the deficiency is accounted for by the primary reference. Further, the claims do not exclude the inclusion of additional elements, such as the conductive posts taught by Revill et al.
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
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.
Claims 1, 2, 4, 6-13, and 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over Tanaka et al (US 2020/034130) in view of Katayama et al (US 5,314,591) and Revill et al (US 6,761,808).
Tanaka et al teach (see title, abstract, figs. 1, 7, 8, and 11-14, and paragraphs [0098]-[0099], [0107], and [0116]-[0117]) a bipolar zero-gap electrolyzer for water electrolysis comprising a plurality of bipolar elements (910) stacked so as to sandwich a gasket (930) and a membrane (920), each of the bipolar elements comprising an anode chamber (A) with an anode (940), a cathode chamber (C) with a cathode (970), a conductive partition wall (911) provided between the anode chamber and the cathode chamber, and an out frame (912) framing the conductive partition wall, wherein surface pressure was applied between the gasket and the partition wall/outer frame to achieve sealing of the cell chambers. The conductive partition wall (911) included ribs (913) on at least one surface. A conductive elastic body (960) is disposed between a surface of the conductive partition wall opposite the one surface and one of the electrodes (in fig. 1, between cathode 970 and partition wall 911). The two electrodes, anode and cathode, form conduction with the conductive partition wall at least through the ribs and the conductive elastic body. The membrane was sandwiched between the cathode and the anode of adjacent bipolar elements by elastic stress of the conductive elastic body.
While the “ribs” of Tanaka et al would normally be considered “protrusions” as claimed, it is noted that the specification explicitly excludes “ribs” from the scope of the claim term “protrusions”.
Therefore, Tanaka et al fail to teach that the conductive partition wall has “protrusions” as limited by the definition in the instant specification on at least one surface.
Katayama et al teach (see figs. 5(A), 5(B), and 6) a bipolar electrolyzer comprising a plurality of bipolar elements (1) stacked so as to sandwich a membrane (22), wherein the bipolar elements included anode chamber, cathode chamber, conductive partition wall and outer frame similar to Tanaka et al. Instead of ribs, Katayama et al show a plurality of truncated-cone shaped protrusions on at least one surface of the conductive partition wall, which may be used in place of ribs (col. 6, lines 34-39). Further, Katayama et al teach (see col. 2, lines 21-36) that there was a recognized problem in the prior art when ribs were used to support electrodes in that the welding of the ribs to the electrodes caused unavoidable voltage drops, and that the use of the recesses and projections that engaged with each other avoided this problems.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified the bipolar electrolyzer of Tanaka et al according to the suggestion of Katayama et al by replacing the ribs with truncated-cone projections to avoid the unavoidable voltage drop associated with using the ribs as taught by Katayama et al.
Katayama et al show (see figs 5(A) and 5(B)) that the conductive partition wall included the protrusions, concavities, and flat portions on the surfaces. The protrusions and corresponding cavities were provided on both surfaces of the conductive partition wall.
Thus, Katayama et al fail to teach providing the projections only on one surface and the concavities only on the other surface.
Revill et al teach (see fig. 5 and col. 2, line 26 to col. 3, line 17) as an improvement over Katayama et al (EP 0521386 cited by Revill is the EPO equivalent of US 6,761,808) by having the projections that only extend from one surface of the conductive partition wall and the concavities are only provided on the opposing surface of the conductive partition wall. Revill et al teach that the design is of simple construction that was easier to fabricate.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have formed the projections of Katayama et al only on one surface of the conductive partition wall as taught by Revill et al for the purpose of making the bipolar electrolyzer easier to fabricate.
Regarding claim 2, Katayama et al show that concavities were formed on the opposite side of the conductive partition wall corresponding to the protrusions.
Regarding claim 4, in at least one embodiment (fig. 7), Tanaka et al show disposing a second conductive elastic body (81, 82) such that a conductive elastic body is disposed between each electrode and the respective electrode chambers.
Regarding claim 6, Tanaka et al show (fig. 1) the conductive elastic body being in the cathode chamber (C).
Regarding claims 7 and 8, absent a showing of unexpected results, it would have been well within the ordinary level of skill in the art at the time of filing to have performed routine experimentation to determine workable or optimal spacing, diameter and height of the protrusions taught by Katayama et al.
Regarding claim 9, Tanaka et al teach (see paragraph [0098]) that the membrane (10) may be a porous membrane.
Regarding claim 10, Tanaka et al provided current collectors (950 in fig. 1, 71 and 72 in fig. 7) between the conductive elastic bodies and the conductive partition wall. Absent a showing of unexpected results, it would have been obvious to one of ordinary skill in the art at the time of filing to have performed routine experimentation to determine workable or optimal contact resistance of the current collector based on the understanding that higher contact resistance caused efficiency losses.
Regarding claims 11 and 12, absent a showing of unexpected results, it would have been well within the ordinary level of skill in the art at the time of filing to have performed routine experimentation to determine workable or optimal elastic modulus (i.e. strength) ranges of the electrodes.
Regarding claim 13, the conductive elastic body of Tanaka et al was taught (see paragraph [0120]) using an elastic mat made of metal wires. Absent a showing of unexpected results, it would have been well within the ordinary level of skill in the art at the time of filing to have performed routine experimentation to determine workable or optimal properties of the elastic mat to achieve appropriate strength and elasticity properties to adequately hold the electrode surfaces against the membrane (i.e. achieve the zero-gap feature) without damaging the membrane.
Regarding claim 16, the electrolyzer of Tanaka et al would have been understood by one of ordinary skill in the art at the time of filing as inherently being capable of operating under pressure, including pressures within the claimed range.
Regarding claim 17, Tanaka et al, as modified by Katayama et al, teach the electrolyzer of claim 1 as noted above. The electrolyzer was used to produce hydrogen gas via water electrolysis.
Regarding claim 18, it would have been obvious to one of ordinary skill in the art at the time of filing to have operated the electrolyzer of Tanaka et al at a desired hydrogen production pressure.
Claims 14 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Tanaka et al (US 2020/034130) in view of Katayama et al (US 5,314,591) and Revill (US 6,761,808) as applied to claim 1 above, and further in view of Funakawa et al (US 2015/0027878).
Regarding claim 14, Tanaka et al suggests that the anode and cathode may be made from nickel, but fails to teach that the conductive partition wall has a nickel plating layer.
Funakawa et al teach (see abstract, paragraphs [0008]-[0011], [0014] and [0019]) providing a reverse current absorbing body in a bipolar water electrolyzer. The reverse current absorbing body was effective at reducing or even preventing damage to the cathode when the electrolyzer was turned off. In at least one embodiment, Funakawa et al teach (see paragraph [0100]) plating the reverse current absorbing body onto the partition wall of the bipolar element.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have added a nickel plating on the conductive partition wall as suggested by Funakawa et al for reducing or preventing damage to the cathode when the electrolyzer was turned off.
Regarding claim 15, Tanaka et al suggests that the anode and cathode may be made from nickel.
However, Tanaka et al and Katayama et al fail to teach a porous body being disposed on the conductive elastic body.
Funakawa et al teach (see abstract, paragraphs [0008]-[0011], [0014] and [0019]) providing a reverse current absorbing porous body adjacent to a conductive elastic mat in a bipolar water electrolyzer. The reverse current absorbing porous body was effective at reducing or even preventing damage to the cathode when the electrolyzer was turned off.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have added a porous body on the conductive elastic body as suggested by Funakawa et al for reducing or preventing damage to the cathode when the electrolyzer was turned off.
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 HARRY D WILKINS III whose telephone number is (571)272-1251. The examiner can normally be reached M-F 9:30am -6:00pm.
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/HARRY D WILKINS III/Primary Examiner, Art Unit 1794