DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. 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
2. 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 20 July 2026 has been entered.
Response to Amendments
3. The applicant’s response filed 20 July 2026 has been entered into the record and is considered fully responsive. The applicant has previously cancelled Claims 1-19, 22, and 23. Claims 20, 31, 33, and 41 have been amended with no new matter being added. The independent claims are presently Claim 20 and Claim 33. Claims 20, 21, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, and 41 are pending and under examination.
Claim Rejections - 35 USC § 103
4. 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.
5. 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.
6. Claims 33, 34, 35, 36, 37, 38, 39, and 40 are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. and Jesswein.
Liu et al. (CN111420676A – EPO Translation; previously presented) is directed at inorganic-organic hybrid metal particles for water splitting (title and abstract). Jesswein (DE102012223556A1 – EPO translation) is directed toward application of a conductive paste and subsequent sintering (title).
Based on the applicant’s amendments, Claim 33 is an independent claim.
Regarding Claim 33, the limitations written as “an electrode made by a process comprising: thermal depositing an electrode material comprising a plurality of polyacrylic acid (PAA) coated silver nanoparticles over a substrate” is a product-by-process limitation wherein the electrode is a product of a thermal depositing process (among other steps). MPEP § 2113 I states: "[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted). The result of the product-by-process procedure is a silver-based electrode for HER.
Regarding Claim 33, Liu et al. discloses a silver-based electrode made by a process comprising: depositing a formulation onto a substrate where the substrate is nickel foam and the formulation is polyacrylic acid (PAA) coated silver nanoparticles (synthesis of PAA-AgNPs disclosed in ¶11-23) as described in examples in ¶44, 48, and 57 used to form the electrode material. The general procedure disclosed by Liu et al. indicates that the nickel foam immersed in the PAA-AgNPs dispersion and then removed followed by drying at 60 to 80 °C for 4 to 8 hours, and then calcining at 300 to 600 °C for 2 to 3 hours under argon protection to obtain an electrocatalytic water splitting catalyst (¶27). The resultant catalyst is composed of a carbonized layer embedded with silver metallic particles loaded on the surface of the nickel foam (¶27). Argon is explicitly used to protect the electrocatalytic water splitting catalyst by excluding oxygen and allowing carbonization of the organic species (i.e.: PAA) during sintering at temperatures above 300 °C. A prima facie case of obviousness exists when the sintering temperature range disclosed in the prior art (300 to 600 °C) overlaps with the claimed sintering temperature range (150 to 700 °C) as in Claim 33. See MPEP 2144.05(I) – OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS
However, Liu et al. does not expressly indicate whether the application/depositing of the silver paste to the substrate occurs under an inert or reducing atmosphere (i.e.: hydrogen). Jesswein discloses the application of a conductive paste with (Ag) nanoparticles in the submicron range with a range of 10-50 nm (¶9) meaning Jesswein is analogous art to Liu et al. Jesswein further discloses that application and optionally drying of oxidation prone metallic nanoparticle pastes (i.e.: silver and copper) takes place under an inert (or reducing atmosphere) to prevent the surface oxidation of the conductive paste (¶12).
Therefore, the use of an inert atmosphere during the application process as per Jesswein and the use of an argon atmosphere during the sintering process of Liu et al. serve the same purpose of preventing oxidation of the silver nanoparticles at the surface of the deposited/annealing conductive ink. Combination of these two references would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention with the reasonable expectation of preventing Ag surface oxidation during the entire Ag-electrode formation process.
Moreover, the present application indicates on pg. 10 in ¶47 of the disclosure that: “by maintaining a hydrogen atmosphere, oxidation of the top surface of the substrate is avoided. In embodiments, the ink or paste may be deposited or printed atop or directly atop various substrates to form an electrode.” Thus, showing the use of argon/inert atmosphere in Jesswein/Liu et al. serves the same purpose as the use of hydrogen in the present application during the deposition and annealing processes, that is, removal of oxygen exposure.
It would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention that an inert atmosphere (e.g.: art) as taught by Liu et al. and Jesswein and a hydrogen atmosphere as in the instant application maintained during the depositing and annealing steps protect the silver from oxidizing in the presence of oxygen indicating they are equivalent steps in the art known for the same process. See MPEP 2144.06(II) – Art Recognized Equivalence for the Same Purpose: Substituting Equivalent Known for the Same Purpose.
Given the final product in both Claim 33 and the combination of Liu et al. and Jesswein is a silver-based electrode (for HER) that has been subjected to (a) deposition processing using PAA-coated silver-nanoparticle ink or composition, removal of the solvent, and annealing under an inert or reducing atmosphere, the electrodes produced by either method will have a substantially identical structure. Therefore, the Claim 33 having a product-by-process structure is rendered obvious by the electrode described by the combination for Liu et al. in view of Jesswein.
Regarding Claim 34, Liu et al. in view of Jesswein discloses the electrode of Claim 33, wherein the electrode material comprising a plurality of PAA coated silver nanoparticles is provided in an amount sufficient to form a continuous layer as evidenced by immersing the nickel foam into the PAA-AgNPs dispersion, subsequently drying and carbonizing the film under argon atmosphere to make the supported catalyst cathode made of silver particles embedded in a carbon layer loaded onto nickel foam (Liu et al. in ¶26-27, ¶42-44, ¶47-48, and ¶56-57).
Regarding Claim 35, Liu et al. in view of Jesswein discloses the electrode of Claim 33, wherein the plurality of PAA coated silver nanoparticles (“AgNPs@PAA”) are characterized as substantially mono-disperse nanoparticles having an average diameter of about 1.0 to 30 nm as indicated in ¶24 and 27 of Liu et al. where the average diameter of the AgNPs is ~2-5 nm. It has been held that a prima facie case of obviousness exists when the range disclosed in the prior art overlaps with the claimed range. See MPEP 2144.05(I) – OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS.
Regarding Claim 36, Liu et al. in view of Jesswein discloses the electrode of Claim 33, wherein the plurality of PAA coated silver nanoparticles (“AgNPs@PAA”) are characterized as substantially mono-disperse nanoparticles having an average diameter of about 1.0 to 10 nm as indicated in ¶24 and 27 of Liu et al. where the average diameter of the AgNPs is ~2-5 nm. It has been held that a prima facie case of obviousness exists when the range disclosed in the prior art overlaps with the claimed range. See MPEP 2144.05(I) – OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS.
Regarding Claim 37, Liu et al. in view of Jesswein discloses the electrode of Claim 33, wherein the plurality of PAA coated silver nanoparticles (“AgNPs@PAA”) are characterized as electrocatalysts toward hydrogen evolution in acidic media as indicated in ¶31 and 32 of Liu et al. where the catalytic HER performance is termed “excellent.” During the evaluation of HER activity, Liu et al. uses a 0.5 M H2SO4 electrolyte, which is acidic media (¶50 and 59).
Regarding Claim 38, Liu et al. in view of Jesswein discloses the electrode of Claim 33, but is silent on the altered crystal structure featuring a lower surface of atomic coordination number nor a lattice strain of about 0.5% to about 1% of the plurality of particles. The specification of the instant application indicates that in certain embodiments, the plurality of particles have a lower surface atomic coordination number on page 8 in ¶39 and that increasing the surface area of Ag results in more unsaturated coordination atoms on page 2 thereby improving the HER activity of said catalyst. Liu et al. discloses the electrode material Claim 33 which comprises PAA-coated silver nanoparticles which have increased surface area from the small particle size (2-5 nm diameter) and catalyze the HER reaction. Therefore, the electrode material of Claim 33 would inherently have an altered crystal structure featuring a lower surface of atomic coordination number as evidenced by, at least, the Applicant’s own disclosure (pg. 2 in ¶6 and pg. 8 ¶39). See MPEP 2112-III.
Regarding Claim 39, Liu et al. in view of Jesswein discloses the electrode of Claim 33, wherein the electrode material is characterized as a catalyst (toward hydrogen evolution reaction) as per ¶31 and 32 in Liu et el.
Regarding Claim 40, Liu et al. in view of Jesswein discloses the electrode of Claim 33, comprising a capping agent which is analogous to the aqueous polymer of Liu et al. (¶15 and 16). The aqueous polymer controls the size of the Ag particles, provides stability to the silver particles, coats the nanoparticles, and binds them into super particles (¶22, 24, 27, and 29).
7. Claim 41 is rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. in view of Jesswein as applied to Claim 33 above, and further in view of Milardović et al.
Liu et al. (CN111420676A – EPO Translation; previously presented) is directed at inorganic-organic hybrid metal particles for water splitting (title and abstract). Jesswein (DE102012223556A1 – EPO translation) is directed toward application of a conductive paste and subsequent sintering (title). Milardović et al. (“Synthesis and Electrochemical Characterization of AgNP Ink Suitable for Inkjet Printing,” Int. J. Electrochem. Sci. 2018, 13, 11136 – 11149) is directed toward the preparation of silver nanoparticles (pg. 11136: title).
Regarding Claim 41, Liu et al. in view of Jesswein discloses the electrode of Claim 33, but does not explicitly disclose the use of ethylene glycol in the electrode material rather but only discloses the use of water as a dispersing solvent for the PAA-coated silver nanoparticles. Milardović et al. is directed toward the synthesis of Ag nanoparticle suspension for ink jetting (pg. 11136: Title and Abstract). Milardović et al. discloses the formation of PAA-AgNPs in a manner similar to Liu et al. using silver nitrate, PAA as a capping agent, and a reducing agent (e.g.: hydrazine) to form 2.5 nm diameter nanoparticles (pg. 11136: Title and Abstract). This material was precipitated, washed, and dried (pg. 11138-9: 2.3 Synthesis of silver nanoparticles). The resultant material was dispersed with 2-AMP into a mixture of water and ethylene glycol (pg. 11139: 2.4. Preparation of the stable silver nanoparticle ink suspension). UV-Vis analysis of the resultant dispersion showed stability over a seven month storage period (pg. 11144: FIG 7). It would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the water-based electrode paste composition taught by Liu et al. and Jesswein with the binary solvent system of water and ethylene glycol as disclosed in Milardović et al. with the reasonable expectation of forming an electrode paste with enhanced storage stability more suitable for inkjet printing (pg. 11136: abstract of Milardović et al).
Allowable Subject Matter
8. Claims 20, 21, 24, 25, 26, 26, 27, 28, 29, 30, 31, and 32 are allowed.
9. The formation of silver particles coated with polyacrylic acid is from the in-situ reduction of soluble silver salts (i.e.: silver nitrate) using reducing agents (e.g.: monethanolamine, NaBH4, hydrazine, sodium citrate, or ascorbic acid) in the presence of polyacrylic acid as a chelating agent or stabilizing agent is well represented in the prior art.
10. The following references are being analyzed with respect to the limitations of amended Claim 20 pertaining to the specific processing steps of the method of forming an electrode. All subsequent dependent claims are allowable because Claim 20 is allowable.
Reference
Author
Citation
1.
Liu et al.
CN111420676A – EPO Translation: previously presented as the primary reference
2.
Jesswein.
DE102012223556A1 – EPO translation: previously presented as the secondary reference
3.
Mavuri et al.
“Inkjet printing of polyacrylic acid-coated silver nanoparticle ink onto paper with sub-100-micron pixel size,” Materials, 2019, 12(14), article 2277, pg. 1-10.
4.
Evanoff et al.
“Size-controlled Synthesis of Nanoparticles. 1. ‘Silver-Only’ Aqueous Suspension via Hydrogen Reduction,” J. Phys. Chem. B 2004, 108, 13498-13956.
5.
Hartlieb et al.
“Continuous flow synthesis of small silver nanoparticles involving hydrogen as the reducing agent,” Green Chem, 2010, 12(6), 1012-1017.
6.
Li et al.
US Pub. No. 2006/0073667 A1 (“Stabilized silver nanoparticles and their use)
11. Regarding Claim 20, Liu et al. disclose contacting a substrate (e.g.: nickel foam) with a formulation comprising an electrode material comprised of polyacrylic acid (PAA) coated silver nanoparticles (synthesis of PAA-AgNPs disclosed in ¶11-23) as described in examples in ¶44, 48, and 57. The general procedure disclosed by Liu et al. indicates that the nickel foam immersed in the PAA-AgNPs dispersion (at room temperature), removed, dried at 60 to 80 °C for 4 to 8 hours, and then calcined at 300 to 600 °C for 2 to 3 hours under argon protection to obtain an electrocatalytic water splitting catalyst (¶27). The resultant catalyst was composed of a carbonized layer embedded with silver metallic particles loaded on the surface of the nickel foam (¶27). Argon is explicitly used to protect the electrocatalytic water splitting catalyst by excluding oxygen and allowing carbonization of the organic species (i.e.: PAA) during sintering at temperatures above 300 °C. However, Liu et al. does not expressly indicate whether the depositing of the silver paste onto the substrate occurs under an inert or reducing atmosphere (i.e.: hydrogen). Jesswein discloses the application of a conductive paste with (Ag) nanoparticles in the submicron range with a range of 10-50 nm (¶9) meaning Jesswein is analogous art to Liu et al. Jesswein et al. further discloses that application (i.e.: depositing) and optionally drying of oxidation prone metallic nanoparticle pastes (i.e.: silver and copper) takes place under an inert (or reducing atmosphere) to prevent the surface oxidation of the conductive paste (¶12). Therefore, two required elements of amended Claim 20 missing from Liu et al. in view of Jesswein, are the deposition of the electrode formulation on the substrate at an elevated temperature (i.e.: 120 °C) and the deposition occurring specifically under a hydrogen atmosphere.
Mavuri et al. is analogous art to Liu et al. and Jesswein since it is directed toward the formation of silver films from PAA-coated silver nanoparticles (pg. 1: abstract and introduction). The silver nanoparticles were prepared from the reduction of silver nitrate in the present of PAA and triethanolamine and dispersed into a mixture of ethylene glycol, water, and alcohol to prepare the ink (pg. 8: 3.2. Synthesis of Ag Nanoparticles and Inkjet Formulation). Of particular relevance to the limitations of Claim 20, Mavuri et al. teaches the deposition of the PAA-silver nanoparticle ink at different temperatures (i.e.: the substrate is held at a specific temperature during the ink jetting of the ink) on pg. 8-9 in the materials and methods section. Mavuri et al. found that the thermal deposition of the ink at a moderate temperature of 50 °C improved the resistivity over a room temperature application (pg. 7: Figure 7 and Figure 8). While Mavuri et al. discusses that high temperature post processing will further reduce the resistivity of the inkjetted silver lines, the reference does not suggest using higher temperatures (e.g.: above 120 °C as per Claim 20) during the thermal deposition step. Moreover, Mavuri et al. does not suggest using an inert atmosphere or a hydrogen atmosphere during the thermal deposition process and actually indicates that silver is relatively oxidation resistant in air (pg. 2: introduction) making a protective atmosphere unnecessary. Therefore, Mavuri et al. does not suggest or teach the missing limitations of amended Claim 20.
12. Evanoff et al. and Hartlieb et al. are both directed toward the use of hydrogen as a reducing agent for the formation of silver nanoparticles in a reactor (batch or continuous). Evanoff et al. discloses the use of hydrogen to form silver nanoparticles with PVP as a stabilizing agent (pg. 13952: Electron Microscopy Section) showing the ability to control the particle size depending on the processing conditions (Figure 3 and Figure 4). Evanoff et al. did use the nanoparticles to form a silver mirror on ITO glass after exposing the ITO slide to the suspension of nanoparticles for 24 hours. Subsequent processing included: rinsing the slide to remove PVP and drying the deposited Ag mirror under a stream of nitrogen at 110 °C (pg. 13952: Electron Microscopy Section). Like Evanoff et al., Hartlieb et al. discloses the formation of silver-stabilized nanoparticles in a reactor using polyphosphates as the stabilizer and hydrogen gas as the reducing agent (see Fig. 1 for a schematic on pg. 1013). Moreover, Hartlieb et al. found that elevated reaction temperatures (i.e.: 70 or 120 °C) resulted in smaller silver nanoparticles requiring lower concentrations of stabilizing ligands. Hartlieb et al. did not use the nanoparticles for preparation of any silver-based films. Therefore, neither Evanoff et al. nor Hartlieb et al. suggest or teach the missing limitations of amended Claim 20.
13. Li et al. is directed toward production of stabilized silver particles and their use (title and abstract). Li et al. expressly discloses a process for preparing a reaction mixture comprising a silver compound, a reducing agent, and the stabilizer to silver-containing nanoparticles surface stabilizer with molecules of the stabilizer (abstract). Various silver compounds include silver acetate, silver carbonate, silver nitrate, silver perchlorate, silver phosphate, silver trifluoroacetate, silver benzoate, silver lactate (¶42) and the reducing agent includes substituted and unsubstituted hydrazine salts and free bases (¶43-54). The stabilizing agent is selected from organic stabilizers including: thiols, amines, carboxylic acids, carboxylates, polyethylene glycols, and other surfactants (¶56). In Ex. 1, Ex. 2, and Ex. 3, silver acetate and different alkylamine were combined in the presence of a hydrazine to form the stabilized AgNPs (¶98-102). The AgNPs were then purified and dispersed into cyclohexanone with deposition of a brown film being achieved using spin coating. The deposited brown material was then heated on a hot plate to temperatures greater than 120 °C under ambient conditions (¶98-102). The heating of the deposited film may occur in air, under inert gas (argon or nitrogen), or in a reducing atmosphere (e.g.: 20 vol% H2 in N2) as per ¶79 of Li et al. Additionally, Li et al. discusses heating the film to sufficiently high temperatures to thermally decompose the stabilizer (¶79-82). However, Li et al. does not suggest using an inert atmosphere or a hydrogen atmosphere during the thermal deposition process, nor heating during the deposition process of the brown film (i.e.: silver-containing film). Therefore, Li et al. does not suggest or teach the missing limitations of amended Claim 20.
Response to Arguments
14. Applicant’s arguments, see pg. 5-8, filed 20 July 2026, with respect to the rejection of Claim 20 and subsequent dependent claims have been fully considered and are persuasive. The reasons for the withdrawal of the rejection and subsequent allowance are explained in detail above.
15. Applicant's arguments filed 20 July 2026 have been fully considered but they are not persuasive with respect to the rejection of amended Claim 33 and all subsequent dependent claims. In summary, Claim 33 is directed toward an electrode made by a specific process, making it a product-by-process type claim. As explained above, MPEP § 2113 I states: "[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted). The result of the product-by-process procedure is a silver-based electrode for HER. Given the final product in both Claim 33 and the combination of Liu et al. and Jesswein is a silver-based electrode (for HER) that has been subjected to (a) deposition processing using PAA-coated silver-nanoparticle ink or composition, removal of the solvent, and annealing under an inert or reducing atmosphere, the electrode produced by either method will have a substantially identical structure. Therefore, the Claim 33 having a product-by-process structure is rendered obvious by the electrode described by the combination for Liu et al. in view of Jesswein.
Conclusion
16. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Shen et al. (“Preparation of solid silver nanoparticles for inkjet printed flexible electronics with high conductivity,” Nanoscale 2013, 6, 1622-1628) is directed toward the inkjet deposition of highly conductive traces from silver nanoparticles.
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/KEVIN SYLVESTER/Examiner, Art Unit 1794
/CIEL P CONTRERAS/Primary Examiner, Art Unit 1794
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