DETAILED ACTION
Response to Amendment
This is a final office action in response to a communication filed on April 28, 2025. Claims 1-17 are pending in the application.
Status of Objections and Rejections
All rejections under 35 U.S.C. §103 are maintained.
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 and 3-17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Gambert (US 2007/0272553) in view of Kitazawa (US 2010/0252432), and further in view of Liao (B. Liao, Effect of citrate ions on the electrochemical migration of tin in thin electrolyte layer containing chloride ions, Corrosion Science 2016(112), pp. 393-401).
Regarding claims 1, 4, and 14, Gambert teaches an electrochemical oxygen sensor (for claim 1; Fig. 1; [0042] line 2: a galvanic, electrochemical sensor for O2) or equipment comprising the electrochemical oxygen sensor of claim 1 (for claim 14; Fig. 1; [0042] line 2: a galvanic, electrochemical sensor for O2) comprising:
a holder (Fig. 1; [0042] line 3: a housing 1);
a positive electrode (Fig. 1; [0042] line 7: a cathode 4);
a negative electrode (Fig. 1; [0042] line 3: an anode 2); and
an electrolyte solution (Fig. 1; [0042] line 10: electrolyte 5),
the positive electrode, the negative electrode, and the electrolyte solution being contained in the holder (Fig. 1: showing the cathode 4, the anode 2, and the electrolyte 5 are contained in the housing 1),
wherein the negative electrode contains an alloy of Sn ([0042] lines 3-4: an anode being made of an alloy of tin with a silver and a copper).
Gambert does not teach wherein the electrolyte solution contains a chelating agent and a molar concentration of the chelating agent is 1.4 mol/L or higher.
However, Kitazawa teaches an electrochemical oxygen sensor ([0014] lines 1-2), including a cathode, an anode, and an electrolyte solution, wherein the electrolyte solution contains a chelating agent ([0014] lines 2-4). The concentration of the chelating agent in the electrolyte solution is particularly preferably not less than 1.0 mol/liter ([0079] lines 2-5), which overlaps the claimed range.
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 Gambert by adjusting the concentration of the chelating agent within the claimed range as suggested by Kitazawa because the chelating agent would increase the response speed of the sensor ([0078] lines 1-3). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP 2144.05(I).
Gambert and Kitazawa do not explicitly disclose the chelating agent contains at least one of citric acid and citrates (claim 1) or wherein the electrolyte solution contains trisodium citrate (claim 4).
However, Liao teaches tri-sodium citrate acts as an inhibitor by suppressing anodic dissolution and metallic ion transfer through the formation of tin citrate complexes ([Abstract]), and the dissolution rate of anode decreases with the increase of citrate ion concentration (Fig. 11: various citrate ion concentration, e.g., from 10 to 500 mM; p. 400, col. 1, para. 1). The disclosed tri-sodium citrate is a chelating agent because, as evidenced by Kitazawa, the chelating agent present in the electrolyte solution diffuses or partially dissolves the reaction inhibition production in the electrolyte solution, or catches an intermediate originating the reaction inhibition production to prevent the generation of the reaction inhibition production itself, thereby increasing the response speed of the oxygen sensor (Kitazawa, ¶77).
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 Gambert and Kitazawa by selecting tri-sodium citrate to be the chelating agent as taught by Liao because it acts as an inhibitor by suppressing anodic dissolution and metallic ion transfer through the formation of tin citrate complexes ([Abstract]), and the increase of the citrate ion concentration would decrease the dissolution rate of the anode (Fig. 11; p. 400, col. 1, para. 1). The suggestion for doing so would have been that tri-sodium citrate is a suitable material for the chelating agent and 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.
Gambert does not explicitly disclose the electrolyte solution has a pH of not less than 2.09 and not more than 7.40.
However, Gambert teaches the composition of the electrolyte influences the function of the sensor ([0036] lines 1-2) and the best results can be obtained with strong phosphoric acid solutions ([0036] lines 3-4). The phosphoric acid solutions buffered with their salts that is used as electrolyte with a pH up to 7 gave good results ([0037] lines 3-5), which overlaps the claimed pH range from 2.09 to 7.40.
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 Gambert by setting the pH value of the electrolyte solution as claimed because in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP 2144.05(I).
Regarding claim 3, Gambert, Kitazawa, and Liao disclose all limitations of claim 1, including the electrolyte solution containing a chelating agent that contains citrate (Liao: tri-sodium citrate). Since Gambert teaches the electrolyte solution is acidic (¶37: a pH up to 7), the combined Gambert and Liao containing tri-sodium citrate as a chelating agent would necessarily result in citric acid in the electrolyte solution.
Regarding claim 5, Gambert, Kitazawa, and Liao disclose all limitations of claim 1 as applied to claim 1. Gambert, Kitazawa, and Liao do not explicitly disclose the electrolyte solution has a pH of not less than 3.75 and not more than 5.75.
However, Gambert teaches the composition of the electrolyte influences the function of the sensor ([0036] lines 1-2) and the best results can be obtained with strong phosphoric acid solutions ([0036] lines 3-4). The phosphoric acid solutions buffered with their salts that is used as electrolyte with a pH up to 7 gave good results ([0037] lines 3-5), which overlaps the recited pH range.
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 Gambert, Kitazawa, and Liao by setting the pH value of the electrolyte solution as claimed because in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP 2144.05(I).
Regarding claim 6, Gambert teaches the electrolyte solution further contains phosphoric acid and salts of the compound ([0037] line 3: phosphoric acid solutions buffered with their salts).
Regarding claim 7, Gambert, Kitazawa, and Liao disclose all limitations of claim 1. Gambert and Liao do not explicitly disclose the negative electrode is substantially lead free.
However, Kitazawa teaches the negative electrode is substantially lead free ([0060] lines 8-10: electrochemical oxygen sensors have been demanded which are low in environmental load without the use of lead or the like; [0061] lines 1-4: Accordingly, the material for the anode 8 is preferably tin in that no hydrogen generation due to local corrosion is caused in the electrolyte solution 7 containing the chelating agent, resulting in low environmental loads; thus the material of the anode, i.e., the negative electrode, is deemed to be substantially lead free).
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 Gambert and Liao by utilizing substantially lead free negative electrode as taught by Kitazawa because the electrochemical oxygen sensors have low environmental loads without the use of lead (0060] lines 8-10; [0061] lines 1-4).
Regarding claim 8, 10, and 15, Gambert teaches an electrochemical oxygen sensor (for claim 8; Fig. 1; [0042] line 2: a galvanic, electrochemical sensor for O2) or equipment comprising the electrochemical oxygen sensor of claim 8 (for claim 15; Fig. 1; [0042]) comprising:
a holder (Fig. 1; [0042] line 3: a housing 1);
a positive electrode (Fig. 1; [0042] line 7: a cathode 4);
a negative electrode (Fig. 1; [0042] line 3: an anode 2); and
an electrolyte solution (Fig. 1; [0042] line 10: electrolyte 5),
the positive electrode, the negative electrode, and the electrolyte solution being contained in the holder (Fig. 1: showing the cathode 4, the anode 2, and the electrolyte 5 are contained in the housing 1).
Gambert does not teach wherein the electrolyte solution contains a chelating agent and a molar concentration of the chelating agent is 1.4 mol/L or higher.
However, Kitazawa teaches an electrochemical oxygen sensor ([0014] lines 1-2), including a cathode, an anode, and an electrolyte solution, wherein the electrolyte solution contains a chelating agent ([0014] lines 2-4). The concentration of the chelating agent in the electrolyte solution is particularly preferably not less than 1.0 mol/liter ([0079] lines 2-5) , which overlaps the claimed range.
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 Gambert by adjusting the concentration of the chelating agent within the claimed range as suggested by Kitazawa because the chelating agent would increase the response speed of the sensor ([0078] lines 1-3). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP 2144.05(I).
Gambert and Kitazawa do not disclose the chelating agent contains citrate (claim 8) or wherein the electrolyte solution contains trisodium citrate (claim 10).
However, Liao teaches tri-sodium citrate acts as an inhibitor by suppressing anodic dissolution and metallic ion transfer through the formation of tin citrate complexes ([Abstract]), and the dissolution rate of anode decreases with the increase of citrate ion concentration (Fig. 11: various citrate ion concentration, e.g., from 10 to 500 mM; p. 400, col. 1, para. 1). The disclosed tri-sodium citrate is a chelating agent because, as evidenced by Kitazawa, the chelating agent present in the electrolyte solution diffuses or partially dissolves the reaction inhibition production in the electrolyte solution, or catches an intermediate originating the reaction inhibition production to prevent the generation of the reaction inhibition production itself, thereby increasing the response speed of the oxygen sensor (Kitazawa, ¶77).
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 Gambert and Kitazawa by selecting tri-sodium citrate to be the chelating agent as taught by Liao because it acts as an inhibitor by suppressing anodic dissolution and metallic ion transfer through the formation of tin citrate complexes ([Abstract]), and the increase of the citrate ion concentration would decrease the dissolution rate of the anode (Fig. 11; p. 400, col. 1, para. 1). The suggestion for doing so would have been that tri-sodium citrate is a suitable material for the chelating agent and 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.
Gambert does not explicitly disclose the electrolyte solution has a pH of not less than 2.09 and not more than 7.40.
However, Gambert teaches the composition of the electrolyte influences the function of the sensor ([0036] lines 1-2) and the best results can be obtained with strong phosphoric acid solutions ([0036] lines 3-4). The phosphoric acid solutions buffered with their salts that is used as electrolyte with a pH up to 7 gave good results ([0037] lines 3-5), which overlaps the claimed pH range from 2.09 to 7.40.
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 Gambert by setting the pH value of the electrolyte solution as claimed because in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP 2144.05(I).
Regarding claim 9, Gambert, Kitazawa, and Liao disclose all limitations of claim 8, including the electrolyte solution containing a chelating agent that contains citrate. Since Gambert teaches the electrolyte solution is acidic (¶37: a pH up to 7), the combined Gambert and Liao containing tri-sodium citrate as a chelating agent would necessarily result in citric acid in the electrolyte solution.
Regarding claim 11, Gambert, Kitazawa, and Liao disclose all limitations of claim 8. Gambert, Kitazawa, and Liao do not explicitly disclose the electrolyte solution has a pH of not less than 3.75 and not more than 5.75.
However, Gambert teaches the composition of the electrolyte influences the function of the sensor ([0036] lines 1-2) and the best results can be obtained with strong phosphoric acid solutions ([0036] lines 3-4). The phosphoric acid solutions buffered with their salts that is used as electrolyte with a pH up to 7 gave good results ([0037] lines 3-5), which overlaps the recited pH range.
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 Gambert, Kitazawa, and Liao by setting the pH value of the electrolyte solution as claimed because in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP 2144.05(I).
Regarding claim 12, Gambert teaches the electrolyte solution further contains phosphoric acid and salts of the compound ([0037] line 3: phosphoric acid solutions buffered with their salts).
Regarding claim 13, Gambert, Kitazawa, and Liao disclose all limitations of claim 8. Gambert and Liao do not explicitly disclose the negative electrode is substantially lead free.
However, Kitazawa teaches the negative electrode is substantially lead free ([0060] lines 8-10: electrochemical oxygen sensors have been demanded which are low in environmental load without the use of lead or the like; [0061] lines 1-4: Accordingly, the material for the anode 8 is preferably tin in that no hydrogen generation due to local corrosion is caused in the electrolyte solution 7 containing the chelating agent, resulting in low environmental loads; thus the material of the anode, i.e., the negative electrode, is deemed to be substantially lead free).
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 Gambert and Liao by utilizing substantially lead free negative electrode as taught by Kitazawa because the electrochemical oxygen sensors have low environmental loads without the use of lead (0060] lines 8-10; [0061] lines 1-4).
Regarding claims 16-17, Gambert, Kitazawa, and Liao disclose all limitations of claims 1 and 8, respectively. Gambert, Kitazawa, and Liao do not explicitly disclose the molar concentration of the chelating agent is 2.2 mol/L or higher.
However, Kitazawa teaches an electrochemical oxygen sensor ([0014] lines 1-2), including a cathode, an anode, and an electrolyte solution, wherein the electrolyte solution contains a chelating agent ([0014] lines 2-4). The concentration of the chelating agent in the electrolyte solution is particularly preferably not less than 1.0 mol/liter ([0079] lines 2-5), which overlaps with the claimed range.
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 Gambert, Kitazawa, and Liao adjusting the concentration of the chelating agent within the claimed range as suggested because the chelating agent would increase the response speed of the sensor ([0078] lines 1-3). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP 2144.05(I).
Claim(s) 2 is/are rejected under 35 U.S.C. 103 as being unpatentable over Gambert in view of Kitazawa and Liao, and further in view of Tao (U.S. Patent Pub. 2003/0143440).
Regarding claim 2, Gambert, Kitazawa, and Liao disclose all limitations of claim 1 as applied to claim 1. Gambert, Kitazawa, and Liao do not explicitly disclose the negative electrode contains a Sn-Sb alloy.
However, Tao teaches an electrochemical devices capable of operation as either as fuel cells or batteries ([0002] lines 2-3). The anode comprises a metal or alloy ([0059] lines 1-2), such as antimony, tin, or combinations thereof ([0059] lines 5-10). An example of anode comprised antimony alloy with 10% tin ([0125] lines 9-11). Thus, Tao teaches the negative electrode contains a Sn-Sb alloy ([0125] lines 9-11).
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 Gambert, Kitazawa, and Liao by utilizing a Sn-Sb alloy for the negative electrode as taught by Tao. The suggestion for doing so would have been that Sn-Sb alloy is a suitable material for the anode of an electrochemical device and 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.
Response to Arguments
Applicant’s arguments have been considered but are unpersuasive.
Applicant argues Liao does not teach that trisodium citrate would improve oxygen-sensor response speed in Kitazawa’s sensor, but inhibit electrochemical migration of tin by suppressing anodic dissolution and metallic ion transfer through formation of tin citrate complexes (Response, p. 3, para. 2). This argument is unpersuasive. Examiner notes the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). Further, Kitazawa explicitly discloses the chelating agent present in the electrolyte solution diffuses or partially dissolves the reaction inhibition production in the electrolyte solution, or catches an intermediate originating the reaction inhibition production to prevent the generation of the reaction inhibition production itself, thereby increasing the response speed of the oxygen sensor (Kitazawa, ¶77). The response speed of the sensor can be increased with the presence of the chelating agent, and the increase in the concentration of the chelating agent would increase its service life till seven months with good response speed (e.g., Table 1: Ex. 11-13). Thus, the increase in the service life of the sensor is not unexpected results that support nonobviousness of the claim.
Applicant argues Kitazawa’s pH teachings undermine the proposed combination (p. 4, last para.) by citing the Safety Data Sheet for Trisodium Citrate (p. 5, para. 2-3) that does not direct a person of ordinary skill in the art toward Kitazawa’s strongly alkaline electrolyte regime (p. 5, para. 4). This argument is unpersuasive. The Safety Data Sheet for Trisodium Citrate merely indicates that a pH of 7.6 – 9.0 when 1.0g of trisodium citrate is dissolved in water (20 mL), and it does not teach away using trisodium citrate in an alkaline solution. Here, Applicant’s arguments against the references individually would not 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). The rationale of the instant rejection is based on Gambert, as a primary reference, which would be modified by Kitazawa and Liao by incorporating a chelating agent with a molar concentration of 1.4 mol/L or higher (Kitazawa, ¶79) that is trisodium citrate (Liao, Fig. 11; [Abstract]).
Applicant argues the present application is different from the combination of the prior reference because Kitazawa teaches EDTA-type chelating agents in alkaline pH to maintain increased response speed, while Liao teaches a tin electrochemical migration inhibition mechanism (p. 8). This argument is unpersuasive. The primary reference, Gambert, teaches an electrochemical sensor, which has an electrolyte solution. Kitazawa teaches a chelating agent would increase the response speed of the sensor, rendering it obvious to one of ordinary skill in the art to incorporating the chelating agent for improved sensor performance. Here, Kitazawa teaches an EDTA-type chelating agent, and the chelating agent present in the electrolyte solution diffuses or partially dissolves the reaction inhibition production in the electrolyte solution, or catches an intermediate originating the reaction inhibition production to prevent the generation of the reaction inhibition production itself, thereby increasing the response speed of the oxygen sensor (Kitazawa, ¶77). Liao teaches a chelating agent, trisodium citrate, to inhibit anodic dissolution, which acts as an inhibitor by suppressing anodic dissolution and metallic ion transfer through the formation of tin citrate complexes ([Abstract]), and the dissolution rate of anode decreases with the increase of citrate ion concentration (Fig. 11: various citrate ion concentration, e.g., from 10 to 500 mM; p. 400, col. 1, para. 1), which functions as an chelating agent as defined by Kitazawa (¶77). Thus, it would be obvious to one of ordinary skill in the art to substitute the EDTA-type chelating agent with trisodium citrate as taught by Liao to prevent the generation of the reaction inhibition product for further improvement of the sensor performance.
Further, differences in concentration or pH range will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or pH value is critical. "[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). MPEP 2144.05(II)(A).
Conclusion
THIS ACTION IS MADE FINAL. 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 extension fee 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 CAITLYN M SUN whose telephone number is (571)272-6788. The examiner can normally be reached M-F: 8:30am - 5:30pm.
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/C. SUN/Primary Examiner, Art Unit 1795
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