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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 06/02/2025 has been entered.
Status of Rejections
The rejection(s) of claim(s) 16 is/are obviated by applicant’s cancellation.
All other previous rejections are maintained and modified only in response to the amendments to the claims.
Claims 1-12 and 14-15 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 1-2, 4, 6 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida et al. (U.S. Patent No. 4,354,905).
Regarding claim 1, Yoshida teaches an electrode for electrolysis (see e.g. Col. 3, lines 39-41 and 49-52, anode for electrolysis method), comprising:
a conductive substrate formed of a porous metal plate, wherein the conductive substrate is a titanium expanded metal (see e.g. Col. 4, lines 1-10, and Col. 6, lines 28-33, substrate for perforated, i.e. porous, plate formed from expanded metal comprising material including titanium), and
a catalyst layer formed on a surface of the conductive substrate, wherein the catalyst layer comprises ruthenium (see e.g. Col. 6, lines 33-38, anode active coating material comprising ruthenium oxide), and
a thickness of the electrode for electrolysis is 0.8 to 3 mm (see e.g. Col. 6, lines 26-27), overlapping the claimed range of the present invention.
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.”.
Regarding value C, Yoshida teaches the electrode having a total of circumferential lengths of openings per area of 4 to 20 m/dm2 (see e.g. Col. 5, lines 16-27 and 38-47, and Claim 13), with an opening rate of preferably 15-60% (see e.g. Col. 5, lines 59-60), which, for the specified area of 8.0 x 5.3 mm, i.e. 42.4 mm2, equates to C values ranging from 0.28-1.13 mm at 4 m/dm2 to 1.41-5.65 mm at 20 m/dm2, encompassing the claimed range of the present invention (see MPEP § 2144.05 I as cited above). Though Yoshida does not teach the exact C value range, it does teach the total of circumferential lengths of openings, which is proportional to value C, being 4 m/dm2 or more to decrease voltage drop at a membrane (see e.g. Col. 5, lines 13-27) but 20 m/dm2 or less so that mechanical strength for the electrode doesn’t become low and practical disadvantages coming from the difficulty of obtaining such a large value are avoided (see e.g. Col. 5, lines 38-47), as well as the opening ratio, which is inversely proportional to value C, having an influence on the voltage drop (see e.g. Col. 5, lines 50-65). Paragraphs 0018 to 0019 of the instant specification similarly describe the value C being provided within a specific range resulting in a decrease in electrolysis voltage.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized the total circumferential lengths of openings and opening rate of the electrode of Yoshida, and with them the C value, to achieve a desired balance between decreased membrane voltage drop and electrode mechanical strength and production difficulty. MPEP § 2144.05 II states “"[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955)”. The total circumferential lengths of openings and the opening rate, which are the variables upon which value C is calculated, are results-effective variables influencing membrane voltage drop, mechanical strength and production difficulty as taught by Yoshida above.
Regarding claim 2, Yoshida teaches the opening ratio A being 10 to 70%, preferably 15 to 60% (see e.g. Col. 5, lines 59-60), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 4, Yoshida teaches the thickness for the electrode for electrolysis being from 0.8 mm to 3 mm (see e.g. Col. 6, lines 26-27), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 6, Yoshida teaches an electrolyzer, comprising: an anode chamber comprising, as an anode, the electrode for electrolysis according to claim 1, a cathode chamber comprising a cathode, and an ion exchange membrane isolating the anode chamber from the cathode chamber (see e.g. Col. 7, lines 1-7, electrolytic cell with inventive anode in anode chamber and cathode in cathode chamber partitioned by cation exchange membrane).
Regarding claim 15, Yoshida teaches each of the openings opening on opposing outer surfaces of the electrode for electrolysis (see e.g. Col. 5, lines 66-67, perforated plate produced by punching, i.e. creating holes passing through the electrode).
Claims 3 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida in view of Hashimoto et al. (U.S. 2016/0333488); claim 3 evidenced by Brown, Jr. et al. (U.S. Patent No. 6,139,705, hereinafter Brown).
Regarding claim 3, Yoshida teaches all the elements of the electrode of claim 1 as stated above. Yoshida further teaches the porous metal plate comprising a mesh (see e.g. Yoshida Col. 5, lines 66-67, perforated plate produced by punching; thereby forming a mesh as evidenced by Brown, see e.g. Brown Col. 10, lines 13-16). Yoshida does not explicitly teach the center-to-center distance of the openings in a minor-axis direction of the mesh electrode being 1.5mm-3mm and the center-to center distance in a major-axis direction of the electrode being 2.5mm-5mm.
Hashimoto teaches an anode (Fig.1, plate 1) for electrolysis comprising a perforated flat metal plate (Paragraph 0019, lines 7-13). The anode comprising openings (perforations 1a) which have a center-to-center distance in a minor axis direction of 0.5mm-3mm (Fig. 1, “short way SW”; Paragraph 0021, lines 5-7, and Paragraph 0022, lines 2-4 and 8), overlapping the claimed range of the present invention. The center-to-center distance in a major axis direction of the electrode (“long way LW”; Paragraph 0021, lines 7-9) is taught to be the value of “SW” divided by 0.48-0.50 (Paragraph 0021, lines 16-17), resulting in a “LW” distance of about 1.0mm-6mm, which is closely comparable to the claimed range of the present invention. This “SW” distance provides more uniform current distribution while maintaining sufficient mechanical strength (Paragraph 0022, lines 4-9), and the provided ratio for the resultant “LW” distance can reduce the impurity gas produced on the anode (Paragraph 0021, lines 11-16).
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 electrode taught by Yoshida to include the opening spacing dimensions taught by Hashimoto in order to provide the benefits of increased current distribution, mechanical strength, and reduced impurity production.
Regarding claim 5, combining the B and A values taught by Yoshida with the SW and LW values taught by Hashimoto as stated above, value E can be calculated to range from 0.042 to 5.06, overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshida in view of Kashiwada et al. (U.S. 20090120788).
Regarding claim 7, Yoshida teaches all the elements of the electrolyzer of claim 6 as stated above. Yoshida does not teach the ion exchange membrane having a projection formed of a polymer constituting the ion exchange membrane on a surface facing the anode.
Kashiwada teaches a cation-exchange membrane for electrolysis comprising a fluorine-containing polymer that has “projecting parts” on the surface of the anode side of the membrane (Paragraph 0021, lines 3-8). This membrane reduces impurities in produced alkali hydroxide, especially during the electrolysis of an alkali chloride, while maintaining electrochemical performance and mechanical strength over a long period of time (Paragraph 0017, lines 1-7).
Yoshida similarly teaches the ion exchange membrane being a cation-exchange membrane (see e.g. Yoshida Col. 7, lines 4-5), and further teaches the production of an alkali hydroxide at an electrode of the electrolytic cell (see e.g. Yoshida Col. 1, lines 31-35).
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 electrolyzer taught by Yoshida with the anode-side ion exchange membrane projections taught by Kashiwada in order to reduce impurities of the alkali hydroxide products of the electrolyzer while maintaining desirable electrochemical ion-exchange and mechanical qualities. 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.
Claims 8 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida in view of Müller (U.S. 20160049677).
Regarding claim 8, Yoshida teaches all the elements of the electrode of claim 1 as stated above. Yoshida does not teach this electrode forming an electrode laminate with a base electrode different from the electrode.
Müller teaches an electrode laminate (Fig. 4, electrode 4 with layer groups 6, 7 and 8; Paragraph 0043, lines 1-4) in which different layers are formed of expanded metal plate with different mesh sizes and different orientations (Paragraph 0043, lines 4-8, and Paragraph 0045, lines 4-11). This layered electrode configuration contributes to the overall mechanical stability of the electrode and the entire electrolytic assembly (Paragraph 0013, lines 1-44).
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 electrode taught by Yoshida to utilize the configuration of the electrode laminate taught by Müller in order to provide a more mechanically and dimensionally stable electrode electrolytic apparatus. 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 9, modified Yoshida teaches the thickness of the electrode for electrolysis being from 0.8 mm to 3 mm (see e.g. Yoshida Col. 6, lines 26-27), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshida in view of Fabian et al. (U.S. Patent No. 5,824,202).
Regarding claim 10, Yoshida teaches all the elements of the electrode of claim 1 as stated above. Yoshida does not teach a method for renewing the electrode comprising welding the electrode onto an existing electrode in an electrolyzer.
Fabian teaches a mesh electrode with an electrocatalytic coating (Abstract), and further teaches a method of renewing the electrode by welding (“spot-welding”) a new electrode to the surface of the exhausted electrode (Col. 2, lines 43-45 and 51-53). This provides a time and cost saving alternative to complete removal and replacement of the anode (Col. 2, lines 45-51).
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 electrode taught by Yoshida to utilize the electrode renewal method taught by Fabian in order to overcome electrode degradation in a cost and time efficient way.
Claims 11-12 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida et al. (U.S. Patent No. 4,354,905) in view of De Nora et al. (U.S. Patent No. 3,930,981), and further in view of Brown; claim 11 also evidenced by Brown.
Regarding claim 11, Yoshida teaches all the elements of the electrode of claim 1 as stated above. Yoshida further teaches the porous metal plate comprising a mesh (see e.g. Yoshida Col. 5, lines 66-67, perforated plate produced by punching; thereby forming a mesh as evidenced by Brown, see e.g. Brown Col. 10, lines 13-16).
Yoshida does not explicitly teach a shape of the openings of the electrode for electrolysis being right-and-left symmetric about a first imaginary center line in a minor-axis of direction of a mesh with respect to a top plan view of the surface of the conductive substrate and up-and-own asymmetric about a second imaginary center line extending in a major-axis direction of the mesh with respect to the top plan view of the surface of the conductive substrate, wherein the shape has more than three sides. Yoshida does however teach that the openings may have any shape, as long as the required total of circumferential lengths can be given and punching to form the shape can be performed easily (see e.g. Yoshida Col. 6, lines 2-6).
De Nora teaches an electrode for electrolysis (see e.g. Abstract), comprising a conductive substrate formed of a porous metal plate (see e.g. Fig. 10, expanded metal sheet type anode 130 with diamond-shaped openings 131; Col. 8, lines 23-25 and 29-30) and a catalyst layer formed on a surface of the conductive substrate (see e.g. Col. 8, lines 25-27), wherein, a shape of openings of the electrode for electrolysis is right-and-left symmetric about a first imaginary center line extending in a minor-axis direction of a mesh with respect to a top plan view of the surface of the conductive substrate and up-and-down asymmetric about a second imaginary center line extending in a major-axis direction of the mesh with respect to the top plan view of the surface of the conductive substrate (see e.g. Fig. 10, diamond-shaped openings 131 are symmetric about a vertical axis and asymmetric about a horizontal axis, as shown below), wherein the shape has four sides (see e.g. Fig. 10, openings 131 have three sides on the lower half and a fourth upper curved side).
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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 openings of the electrode of Yoshida to comprise the right-left symmetric, up-down asymmetric as taught by De Nora as a suitable opening shape for a porous metal plate substrate of an electrode for electrolysis. 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.
Yoshida in view of De Nora does not explicitly teach a value obtained by dividing a value (St), which is obtained by subtracting a maximum size of the openings in the minor-axis direction of a mesh from a center-to-center distance (SW) of the openings in the minor-axis direction of the mesh, by the (SW) is 0.4 or more.
Brown teaches an electrode for an electrolytic cell (see e.g. Col. 1, lines 11-14) comprising an expanded metal mesh with a pattern of long and narrow voids comprising a network of wide metal strands which merge into double-strand-width nodes (see e.g. Fig. 3, expanded mesh 2 with voids 7, strands 8 and nodes 9; Col. 8, lines 24-27 and 30-36). The somewhat oval-shaped voids of the mesh have a short way of design (SWD) dimension, i.e. minor-axis center-to-center distance, within a range of 0.2 to 0.25 inches (see e.g. Col. 8, lines 38-40). The nodes, which are equivalent to the claimed St value that subtracts the max minor-axis opening width from the minor-axis center-to-center distance, have a width of 0.08 to 0.2 inches (see e.g. Col. 8, lines 36-38). This results in a St/SW value ranging from 0.32 to 1, overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above). The expanded metal of De Nora is shown similarly with elongated openings and a network of wide strands forming approximately double-strand-width nodes (see e.g. De Nora Fig. 10, anode 130 with openings 131 is shown with relatively wide strands and approximately double-width nodes), but the specific dimensions are not disclosed.
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 expanded metal anode of Yoshida in view of De Nora to have the 0.08 to 0.2 inch nodes and 0.2 to 0.25 inch SWD, resulting in a St/SW value of 0.32 to 1, as taught by Brown as suitable dimensions for a wide-stranded expanded metal mesh for an electrode. 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 12, modified Yoshida does not explicitly teach, when the openings each are partitioned in a first portion (a) and a second portion (b) by the secondary imaginary center line, a value obtained by dividing an area (Sa) of the portion (a) by an area (Sb) of the second portion (b) is 1.15 or more and 2.0 or less.
De Nora does however teach that the openings may have different shapes (see e.g. De Nora Col. 8, lines 61-64), as well as the positioning of upper and lower portions of the openings being used to pass and deflect gases released from the anode (see e.g. De Nora Col. 8, line 64-Col. 9, line 3). The instant specification similarly describes the shape of the openings and particularly the Sa/Sb ratio contributing to release and passage of the generated gases (see instant paragraph 0026, lines 34-40, and paragraph 0028, lines 11-15).
However, the claimed range of ratio of the area of an upper half of the opening to the area of the lower half of the opening does not appear to have critical significance and would be a matter of choice. Paragraph 0028, lines 11-16, instant specification states that, with this Sa/Sb value range, generated gas “tends” to be successfully and effectively desorbed without affecting circulation and electrolysis voltage “tends” to be successfully decreased. The term “tend” is not conclusive, and there is no evidence in the specification for this ratio range being critical for the successful/effective gas desorption. Additionally, there appears to be more affecting the electrolysis voltage than the Sa/Sb value. For example, instant Examples 1 and 4 have the same opening shape and same Sa/Sb value of 1.28, but very different ΔV values shown in Table 1. Furthermore, the instant specification explicitly states, in paragraph 0026, lines 1-4, that the reason the electrode results in low voltage is “not known” and only provides presumption of the influencing factors.
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 shape of the opening of modified Yoshida to have a ratio of the upper half area to the lower half area of between 1.15 and 2.0 as a matter of choice. MPEP § 2144.04 IV B cites “In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966) (The court held that the configuration of the claimed disposable plastic nursing container was a matter of choice which a person of ordinary skill in the art would have found obvious absent persuasive evidence that the particular configuration of the claimed container was significant.)”.
Regarding claim 14, modified Yoshida teaches the thickness for the electrode for electrolysis being from 0.8 mm to 3 mm (see e.g. Yoshida Col. 6, lines 26-27), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Affidavit/Declaration
The declarations under 37 CFR 1.132 filed 06/02/2025 are insufficient to overcome the rejection of claim 1 based upon 35 USC 103 over Yoshida as set forth in the last Office action because: though the Yamashita Declaration shows improved results in the claimed value C range, there is still insufficient evidence that such improvements are unexpected; and the Kotaki Declaration establishes a relationship between opening ratio/single opening perimeter and production difficulty, but this does not necessarily directly translate to the relationship between value C and the production difficulty.
Response to Arguments
Applicant's arguments filed 06/02/2025 have been fully considered but they are not persuasive.
On pages 8-13, Applicant argues that the cited art does not recognize the criticality of the “narrow” claimed range and that the claimed range is not an obvious optimization but instead a critical structural parameter essential to the invention’s superior performance, as exemplified by several examples from the Yamashita Declaration. This is not considered persuasive. Though the examples from the Yamashita Declaration show superior performance, as indicated by lower electrolysis voltage, for a C value within the claimed range vs lower than the claimed range, these results cannot necessarily be said to be unexpected in view of Yoshida. The value C is an inherent calculated parameter dependent wholly on the measured parameters B and A in the C=B/A relationship. Yoshida teaches both the total circumferential lengths per area (parameter B) and the opening rate (parameter A) being results effective variables that have an influence on the voltage drop at the membrane and thereby electrolysis voltage (see e.g. Yoshida Col. 5, lines 13-27, 35-37 and 59-65). It would therefore not necessarily be unexpected for simultaneous optimization of both these variables, and thereby a variable based on the two, to have a positive influence on electrolysis voltage.
On pages 13-16, Applicant argues that the upper limit of 5 mm for value C is critical in terms of production difficulty, as evaluated in the Kotaki Declaration based on the relationship of opening ratio and perimeter of a single opening to the production difficulty. This is not considered persuasive. The method of evaluating production difficulty does not directly relate value C to the production difficulty, only the opening ratio and the perimeter of a single opening. As value C depends on the opening ratio (A) and a sum of perimeters in an area (B), not the perimeter of a single opening, there cannot be said to be a direct correlation between value C and the production difficulty. For example, the sum of perimeters in an area and with it opening ratio could proportionally increase without necessarily changing the perimeter of a single opening, resulting in an increased production difficulty without an equivalent change in value C. Thus the conclusion to be drawn from the Kotaki Declaration is not necessarily that the value C should have an upper limit of 5 mm, but that the opening ratio and the perimeter of a single opening should be in a certain range. On that note, Applicant states that the opening ratio being too small would result in increased production difficulty, but Yoshida teaches the opening ratio preferably being at least 10% (see e.g. Yoshida Col. 5, lines 51-52), which overlaps and is greater than the lower limit of the preferable range described for the opening ratio in paragraph 0021 of the instant specification. Yoshida further teaches the total circumferential lengths per area having an effect on the difficulty of producing the electrode (see e.g. Yoshida Col. 5, lines 41-47).
Conclusion
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/M.S.J./Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795