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 Amendments
This is a final office action in response to applicant's arguments and remarks filed on 05/14/2026.
Status of Rejections
The objection to claim 2 is withdrawn in view of the Applicant’s amendment.
The rejection of claim 5 is obviated by Applicant’s cancellation.
The rejections of claims 1 and 25 are updated in response to the Applicant’s new amendments. No new art is cited.
All other previous rejections are maintained.
Claims 1-4, 6-15, 25, and 28-31 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.
Claim(s) 1-4, 6-13, 15, 25, 30 and 31 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al (US 20240368784 A1) in view of Bushong et al (WO 02095847 A1). Zou et al (“Boric acid-loosened polyvinyl alcohol/glutaraldehyde membrane with high flux and selectivity for monovalent/divalent salt separation”, Journal of Membrane Science, Volume 662, 15 October 2022, 120954) cited as evidence for claims 12 and 13.
Claim 1: Lee discloses a separator for an electrolyzer cell (see e.g. abstract) comprising:
a porous substrate (“porous support”, see e.g. [0029] and Fig 1) having pores which provide a fluid path through the porous substrate from a first side of the porous substrate to an opposite side of the porous substrate (see e.g. “porous support” on Fig 1) and formed of one or more hydrophobic polymers or copolymers (see e.g. [0029] and [0040]); and
a coating that coats the surfaces the pores of the porous substrate while maintaining the fluid path (see e.g. [0011] and [0041]-[0042]),
Lee discloses that the coating can be formed of an alcohol-containing polymer like polyvinyl alcohol (see e.g. [0043]). KSR rationale E states that is obvious to choose “from a finite number of identified, predictable solutions, with a reasonable expectation of success” and MPEP § 2144.07 states “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)”. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to select polyvinyl alcohol from the list of Lee.
Lee discloses that the coating can further include a boron-containing species, like boric acid, that is reacted with the alcohol-containing polymer (see e.g. [0045]). KSR rationale E states that is obvious to choose “from a finite number of identified, predictable solutions, with a reasonable expectation of success” and MPEP § 2144.07 states “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)”. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to select boric acid from the list of crosslinkers disclosed in Lee.
Lee does not explicitly teach that the boron-containing species is formed of the boric acid and a base are simultaneously present within the same crosslinking step. However, Lee does teach that the boron-containing is used to cross-link with the polymer (see e.g. [0043]-[0045]). According to Bushong, KOH can be added to a solution of boric acid and PVA to trigger the crosslinking reaction (see e.g. [0029]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the separator of Lee by having the boron-containing species is formed of the boric acid and a base (KOH) simultaneously present as taught in Bushong to trigger the crosslinking reaction between the boric acid and PVA.
Lee view of Bushong teaches that coating can be applied onto the support or only into the pores (see e.g. [0010] and [0041] of Lee). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention that for the embodiments where the coating is only applied to the pores, an extent of the porous substrate measured from the first side to the opposite side is not substantially increased by the alcohol-containing polymer coating.
Claim 25: Lee discloses an electrolysis reactor (see e.g. [0002] and [0106]) comprising:
an aqueous or gaseous anode area with an aqueous or gaseous oxidation substrate (see e.g. [0106]);
an aqueous or gaseous cathode area with an aqueous species or a gaseous species as a reduction substrate (see e.g. [0106]); and
a separator separating the anode area and the cathode area while allowing ionic migration between the anode area and cathode area (see e.g. [0106]);
wherein: (i) the separator is a polymer (“porous support”, see e.g. [0029] and Fig 1) having a coating (see e.g. [0011] and [0041]-[0042]) and (iv) the coating coats the surfaces of pores of the separator while maintaining a fluid path through the separator (see e.g. [0011] and [0041]-[0042]).
Lee discloses that the coating can be formed of an alcohol-containing polymer like polyvinyl alcohol (see e.g. [0043]). KSR rationale E states that is obvious to choose “from a finite number of identified, predictable solutions, with a reasonable expectation of success” and MPEP § 2144.07 states “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)”. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to select polyvinyl alcohol from the list of Lee.
Lee discloses that the coating can further include a boron-containing species, like boric acid, that is reacted with the alcohol-containing polymer (see e.g. [0045]). KSR rationale E states that is obvious to choose “from a finite number of identified, predictable solutions, with a reasonable expectation of success” and MPEP § 2144.07 states “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)”. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to select boric acid from the list of crosslinkers disclosed in Lee.
Lee does not explicitly teach that the boron-containing species is formed of the boric acid and a base are simultaneously present within the same crosslinking step. However, Lee does teach that the boron-containing is used to cross-link with the polymer (see e.g. [0043]-[0045]). According to Bushong, KOH can be added to a solution of boric aicid and PVA to trigger the crosslinking reaction (see e.g. [0029]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the separator of Lee by having the boron-containing species is formed of the boric acid and a base (KOH) simultaneously present as taught in Bushong to trigger the crosslinking reaction between the boric acid and PVA.
Lee view of Bushong teaches that coating can be applied onto the support or only into the pores (see e.g. [0010] and [0041] of Lee). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention that for the embodiments where the coating is only applied to the pores, an extent of the separator measured from a first side to an opposite side is not substantially increased by the coating.
Response to Arguments
Applicant's arguments filed 05/14/2026 have been fully considered but they are not persuasive.
On page(s) 9, the Applicant argues that the rejection “does not clearly identify which embodiment of Lee is being relied upon as the starting point”. This is not considered persuasive. The citations for claim 1 are all based on the best mode described in Lee (see e.g. [0029], [0041]-[0045]). The Applicant argues that the hydrophilized porous supports, the functionalized membranes, and crosslinkers are all separate embodiments. However, there is nothing in Lee that says these are separate embodiments. The disclosure of Lee makes it clear these three features can all be used together.
On page(s) 10, the Applicant argues that Lee never tests a boron-crosslinked hydrophilizing layer as a standalone separator. This is not considered persuasive. Although Lee does not test a boron-crosslinked layer, the disclosure makes it clear the use of this crosslinker is acceptable for their invention (see e.g. [0045]). “Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971). "A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use." In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994)”. See MPEP § 2123 II.
On page(s) 10, the Applicant argues that the disclosure of Lee does not disclose that the hydrophilizing layer would remain a thin, pore-surface coating preserving an open fluid path. This is not considered persuasive. It is noted that the features upon which applicant relies (i.e. a thin coating) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Additionally, Lee does discloses a pore-surface coating preserving a fluid path (see e.g. [0011]; [0041]-[0042]; [0094]).
On page(s) 10-11, the Applicant argues that Lee focuses on reducing gas permeability and does not retain the open pore network and thus does not read on claim 1. This is not considered persuasive. While it is true that Lee discloses reducing gas permeability, the fluid path is still maintained open (see e.g. [0094]: “it can be confirmed that the porous structure of the polyethylene support was maintained even after the hydrophilic coating”).
On page(s) 11, the Applicant argues that Bushong does not disclose the limitations discussed above. This not considered persuasive because it was not argued that Bushong did.
On page(s) 11, the Applicant argues that there is not reasonable expectation of success in combining Lee with Bushong because neither reference states that the coating of Lee would be preserved. This is not considered persuasive. Lee already explicitly discloses using boric acid as a crosslinker (see e.g. [0045]). Bushong teaches KOH can be added to a solution of boric acid and PVA to trigger the crosslinking reaction (see e.g. [0029]). It would be well within the skill of a person having ordinary skill in the art before the effective filing date of the instant invention to incorporate KOH into the boric acid. Although Lee may not have a specific example using boric acid, ‘Obviousness does not require absolute predictability, but at least some degree of predictability is required’ (see MPEP § 2143.02 II). There is sufficient disclosure within both references that a person having ordinary skill in the art before the effective filing date of the instant invention would have a reasonable expectation of success.
On page(s) 11-12, the Applicant argues that the combination of Lee with Bushong is non-obvious because the Applicant tested the membrane of Lee using boric acid with hydroxide and the membrane was inoperable. This is not considered persuasive. Reviewing the arguments provided on 05/14/2026 and 09/04/2025, it appears that the Applicant is arguing that Lee’s own invention does not work. Lee explicitly discloses that boric acid is suitable to form the invention. The Applicant concludes, based on their tests, and that boric acid would yield a membrane that inoperable. However, the data provided on 09/04/2025 is inconclusive. The Figure on page 10 is hard to read and it is not clear what the units are or what is being shown. Additionally, the method steps at the bottom of page 10 do not mention boric acid at all. There is no discussion on how the boric acid is added or how much is added. It could be the membrane was not formed correctly. It does not seem reasonable that a person having ordinary skill in the art before the effective filing date of the instant invention would simply take an example that does not use boric acid and just add boric acid to it without any consideration for how that would be done. Furthermore, despite the Applicant’s findings, none of what is discussed has been explicitly claimed in the claims.
On page(s) 12, the Applicant argues that Lee teaches away from the proposed combination because Lee wants to reduce gas permeability. This is not considered persuasive. Lee states “it can be confirmed that the porous structure of the polyethylene support was maintained even after the hydrophilic coating” (see e.g. [0094]).
On page(s) 12-13, the Applicant argues that a person having ordinary skill in the art before the effective filing date would not be motivated to combine Lee with Bushong because Lee already discloses crosslinking the alcohol-containing polymer and would not need the KOH of Bushong. This is not considered persuasive. The inclusion of KOH in Bushong helps initiate the reaction. It would be obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to include compounds that can help initiate the desired reaction. Additionally, Bushong qualifies as analogous art because “the reference is reasonably pertinent to the problem faced by the inventor” (crosslinking the polymer using boric acid) (see MPEP § 2141.01(a)I).
On page(s) 13, the Applicant argues that the combination of Lee with Bushong is based on hindsight reconstruction requiring a series of selections “connected only by the roadmap of the Applicant’s specification”. This is not considered persuasive. Lee explicitly discloses that PVA is a suitable polymer for the coating, the crosslinker can be boric acid, and that the fluid path is maintained, as discussed above. The selection of a material explicitly disclosed in the primary reference itself is not a hindsight reconstruction and conforms with KSR rationale E and MPEP § 2144.07. The inclusion of KOH from Bushong also relied on rationale supported by KSR.
On page(s) 14, the Applicant argues that claims 30 and 31 are allowable over the prior art because Lee does not discuss the conductivity before or after the crosslinking. This is not considered persuasive. As explained in the rejections, the limitations are describing the state of a claimed product before it is formed and after. Product claims are limited by structure of the product itself and not prior states. MPEP § 2113 states that “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)”. Therefore, the limiting structure of this claim is that the separator is ionically conductive. Lee view of Bushong teaches that the separator is ionically conductive (see e.g. [0066] of Lee).
The arguments on pages 15-16 are substantially similar to arguments addressed above.
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 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 ALEXANDER W KEELING whose telephone number is (571)272-9961. The examiner can normally be reached 7:30 AM - 4:00 PM. 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, Luan Van can be reached at 571-272-8521. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ALEXANDER W KEELING/Primary Examiner, Art Unit 1795
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