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 .
Response to Amendments
2. Applicant’s election response dated 10 April 2026 has been entered into the record and is considered fully responsive. The applicant amended Claim 1 and the examiner agrees that the basis for the amendment can be found in ¶28 of the instant application cited as US Pub. No. 2024/0128470 A1. Claims 1, 2, 3, 4, 5, 6, 7, and 8 are currently pending and under examination.
Claim Rejections - 35 USC § 103
3. 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.
4. 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.
5. Claims 1, 2, 3 4, 5, 6, 7, and 8 are rejected under 35 U.S.C. 103 as being obvious over Wada et al. further in view of Kazufumi et al. and Riley et al.
Wada et al. (US Pub. No. 2008/0090719 A – previously presented) is directed toward a spongy sintered article of titanium (title). Kazufumi et al. (JP2017050185A – previously presented) is directed toward a gas diffusion layer for membrane electrode assemblies (title). Riley et al. (US3321413A) is directed toward activated azodicarbonamide blowing agent compositions (title).
Regarding Claim 1, Wada et al. discloses a composition for a porous transport layer (analogous to spongy sintered article useful in fuel cells on water electrolyzers in ¶2), the composition comprising:
(i) a titanium group element (powdered titanium in Ex. 4-6 in Table 1);
(ii) a solvent (water in Ex. 4-6 in Table 1);
(iii) a foaming agent (e.g.: neopentane in Ex. 4-6 in Table 1).
Pertaining to the new limitations of amended to Claim 1, Wada et al. does not contemplate the treatment of the foaming agent with a hydrophilic resin nor that the foaming agent is a solid material (since the surface treated).
Kazufumi et al. teaches the composition for forming a conductive porous layer (11) in ¶78 comprising a conductive carbon material, high molecular weight polymer (i.e.: a binder), a dispersant, a dispersion medium (i.e.: solvent) and a foaming agent. Since both Wada et al. and Kazufumi et al. are directed toward conductive porous layers useful for electrochemical process and are formed using a foaming agent, they are deemed analogous art. The conductive carbon material is analogous to the titanium element in the present application as both materials make the porous layer conductive. In ¶83, Kazufumi et al. discloses two preferred organic foaming agents (analogous to pyrolytic foaming agents of the instant application), which are azodicarbonamide (ADCA) and 4,4'-oxybisbenzenesulfonylhydrazide (OBSH). The foaming agents in Kazufumi et al. are defined to have an average particle size of 1 micron to 50 microns in ¶82. The advantage of having a well-defined particle size for the foaming agent ensure more predictable results as the particle size of the foaming agent will dictate the void size in the sintered conductive foam. 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 metallic foam forming composition of Wada et al. by using the organic foaming agents taught in Kazufumi et al. with the reasonable expectation of controlling the void size of the pores in the prepared titanium foam.
The combination of Wada et al. and Kazufumi et al. do not disclose the use of a hydrophilic resin to treat the surface of the solid foaming agent as required by amended Claim 1. Riley et al. is directed toward activated azodicarbonamide blowing agent compositions make it analogous art to Wada et al. and Kazufumi et al. since all three references are designed at making porous materials through the emission and release of gas during a heating process. Like Kazufumi et al., Riley et al. discloses the use of azodicarbonamide (ADCA) as a foaming agent (abstract). Riley et al. further discloses the need to change or lower the decomposition temperature of ADCA (Col. 1 lines 69-72 to Col. 2 lines 1-6). Riley et al. indicates that the decomposition temperature of ADCA can be altered by the use of aliphatic hydroxylamine compounds (and metal salts) as per Col. 2 lines 49-59. In Col. 3 lines 1-20, Riley et al. indicates that the hydroxy amine compound can be poly(glycol) amines that are derived from an amine with chain extension occurring using ethylene oxide, propylene oxide, and/or epichlorohydrin. The resultant species can be rendered more hydrophilic by using a higher concentration of ethylene oxide over propylene oxide. The poly(glycol) amine is analogous to the hydrophilic resin of amended Claim 1 and the poly(glycol) amine would be attracted to the surface of a foaming agent (i.e.: ADCA) through hydrogen bonding interactions. 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 composition of Wada et al. and Kazufumi et al. with a poly(glycol) amine (i.e.: hydrophilic resin) as taught by Riley et al. with the reasonable expectation of being able to control the decomposition temperature of the green body that is heated to form the porous conductive material as the poly(glycol) amine facilitates control of the decomposition temperature of the foaming agent.
Regarding Claim 2, Wada et al. in view of Kazufumi et al. and Riley et al. disclose the composition of Claim 1, where in the titanium group element is titanium (Ex. 4-6 in Table 1).
Regarding Claim 3, Wada et al. in view of Kazufumi et al. and Riley et al. disclose the composition of Claim 1, wherein the foaming agent is a pyrolytic chemical foaming agent as supported by the use of azodicarbonamide (ADCA) and 4,4'-oxybisbenzenesulfonylhydrazide (OBSH) (Kazufumi et al. in ¶82 and ¶83).
Regarding Claim 4, Wada et al. in view of Kazufumi et al. and Riley et al. disclose the composition of Claim 3, wherein the pyrolytic foaming agent comprises 4,4'-oxybisbenzene- sulfonylhydrazide (OBSH) as supported the preferred organic (pyrolytic) foaming agent (Kazufumi et al. in ¶83).
Regarding Claim 5, Wada et al. in view of Kazufumi et al. and Riley et al. disclose the composition of Claim 1, wherein the foaming agent is in a granular form and has an average diameter in a range from 50 micrometers (pm) to 1 millimeter (mm) as Kazufumi et al. discloses foaming agent that are defined to have an average particle size of 1 micron to 50 microns in ¶82, meaning the materials are granular. It has been held that a prima facie case of obviousness exists when the prior art discloses a range that overlaps, approaches, or is similar to the claimed range. See MPEP 2144.05(I).
Regarding Claim 6, Wada et al., discloses the composition of Claim 1 and the combination of reference further render the composition of Claim 6 obvious. The composition of Claim 6 requires the composition comprises 40 to 90 parts by weight of the titanium group element, 2 to 10 parts by weight of the solvent, and 5 to 40 parts by weight of the blowing agent (i.e.: foaming agent). In Ex. 4-6, Wada et al. explicitly discloses a concentration of 60 wt.% for the titanium powder. Wada et al., in particular, discloses the composition is applied to a substrate prior to foaming using a doctor blade (¶22) meaning that the viscosity of the slurry will dictate the thickness of the wet film and the thickness of the final film. Wada et al. evaluated different concentrations of blowing agent (i.e.: foaming agent) and water (solvent) with both of these species expected to modify the viscosity of the slurry. Moreover, Wada et al. teaches in the Table 1 (by Ex. 4-6) that the increased the concentration of the blowing agent will increase the porosity of the sintered titanium foam.
Given the effect of the concentrations of both the blowing agent and the solvent as taught by Wada et al. on the resultant sintered foam, it would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to optimize the levels of these two additives in the composition, including the levels of the claimed range, as part of routine experimentation. See MPEP 2144.05(II) – routine optimization
Regarding Claim 7, Wada et al., Kazufumi et al., and Riley et al. disclose the composition of Claim 1, further comprising a dispersant (surfactant such as alkylbenzene sulfonate in Ex. 4-6 in Table 1 in Wada et al.) and a binder (methylcellulose in Ex. 4-6 in Table 1 of Wada et al.).
Regarding Claim 8, Wada et al., Kazufumi et al., and Riley et al. render the composition of Claim 6 obvious as explained above; moreover, the composition of Claim 8 can also be derived from the combination of references. The limitations of Claim 8 require a composition of: 0.1 to 3.0 by weight of a dispersant; and 0.1 to 4 parts by weight of a binder with respect to 40 to 90 parts by weight of the titanium group element. In Ex. 4, 5, and 6 of Wada et al., there different composition are disclosed that comprise 60 wt.% titanium powder, 2.0-2.9 wt.% methylcellulose (i.e.: a binder), 0.4-3.0 wt.% blowing agent (i.e.: foaming agent), 4.0 wt.% alkylbenzene sulfonate (i.e.: surfactant), and other additives. Given the examples in the prior art (i.e.: Wada et al.), a prima facie case of obviousness exists as the concentrations of the titanium group (i.e.: titanium powder), the dispersant (i.e.: alkyl benzenesulfonate), and the binder (i.e.: methyl cellulose) overlap, approach, or are similar to the concentrations of the claimed range. See MPEP 2144.05(I).
Response to Arguments
6. Applicant’s arguments, see pg. 6-7, filed 10 April 2026, with respect to the rejection of Claim 1 (and dependent claims) under 35 USC 102/103 have been fully considered and are persuasive given the amendment to Claim 1. The examiner agrees that Wada et al. does not disclose the use of a hydrophilic resins for treating the foaming agent as per the applicant’s response. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground of rejection is made in view of Wada et al. in view of Kazufumi et al. and Riley et al. The new reasons for rejections are discussed in detail above.
Conclusion
7. 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.
8. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KEVIN SYLVESTER whose telephone number is 703-756-5536. The examiner can normally be reached Mon - Fri 8:15 AM to 4:30 PM EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, James Lin can be reached at 571-272-8902. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/KEVIN SYLVESTER/Examiner, Art Unit 1794
/JAMES LIN/Supervisory Patent Examiner, Art Unit 1794
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