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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 December 29, 2025 has been entered.
Priority
Acknowledgment is made of applicant’s claim for foreign priority (JP2020-060684, Filed on 30 March 2020) under 35 U.S.C. 119 (a)-(d). Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, and 3-5 are rejected under 35 U.S.C. 103 as being unpatentable over OHKAME et al. (WO2018066631A1, hereinafter OHKAME) in view of FUJIMOTO et al. (US8110636B1, hereinafter FUJIMOTO).
Regarding Claim 1, OHKAME discloses a polyphenylene-based semipermeable membrane comprising a porous polyphenylene ether (PPE) hollow fiber support (¶[0026]) with a first surface formed by a sulfonated polymer layer containing sulfonic acid groups, including sulfonated polyphenylene ether (¶[0020]). The first separation layer is provided on one surface of the porous support (¶[0016]). The sulfonated polymer layer, identified as the first separation layer, has a thickness in the range of 50 nm to 10 µm, preferably 100 nm to 1 µm (¶[0029]).
In a specific embodiment, the sulfonated polymer layer has a thickness of 300 nm applied to a PPE hollow fiber support with a support wall thickness of 50 µm (¶[0055]–[0061]). The membrane includes a second separation layer formed by layer-by-layer adsorption of CPVA and APVA (¶[0035]), where each adsorption cycle is estimated to deposit a layer approximately 1–10 nm thick (¶¶[0031]–[0039]).
Based on the numerical values disclosed and the equation provided in the instant application, the sulfonated-region ratio is calculated using OHKAME’s disclosed first-layer thickness range of 50 nm to 10 µm (¶[0029]) and a PPE hollow fiber support wall thickness of 50 µm (¶[0055]), resulting in a computed range of approximately 0.1% to 20%, which overlaps with the claimed range of 5% to 40%, and therefore establishes a case of prima facie obviousness (MPEP § 2144.05).
However, OHKAME does not explicitly disclose that “the sulfonated region is formed by sulfonating the first surface of the semipermeable membrane.”
FUJIMOTO discloses sulfonated polymer compositions suitable for producing polymer membranes and for use in dialysis equipment and ultrafiltration, and methods of synthesizing sulfonated poly(phenylene) copolymers (Col. 1, Lns. 18–28).
The degree of sulfonation and the homogeneity of sulfonation between repeat units are controlled by varying the concentration of the sulfonating agent, varying the temperature of the reaction, and whether the poly(phenylene) polymer is dissolved at the time of sulfonation (Col. 7, Lns. 31–37).
In particular, the sulfonating agent can be added to solid polyphenylene polymer to yield polymers with various ion exchange capacities. The sulfonating agents include sulfuric acid, fuming sulfuric acid, and sulfur trioxide, and the method can result in inhomogeneous sulfonation because only the surface of the solid polymer contacts the sulfonating agent (Col. 7, Lns. 41–49). The membranes can also be sulfonated in the solid state by immersion in a TMSCS/dichloromethane solution, with suitable TMSCS concentrations in dichloromethane including 0.25 to 1.5 wt.% (Col. 8, Lns. 17–20).
Advantageously, the surface-contact sulfonation of solid polyphenylene polymer disclosed by FUJIMOTO provides controlled sulfonated polyphenylene morphology by varying sulfonation conditions such as sulfonating-agent concentration and temperature (Col. 8, Lns. 8–16). In view of OHKAME’s polyphenylene-based semipermeable membrane having a sulfonated polymer region on one surface, a person skilled in the art would have applied the surface-contact sulfonation technique to form the sulfonated region directly at the first surface of the semipermeable membrane with predictable results.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to apply the surface-contact sulfonation technique, as disclosed by FUJIMOTO, to form the sulfonated region on one surface of the polyphenylene-based semipermeable membrane disclosed by OHKAME.
Regarding Claims 3 and 4, modified OHKAME makes obvious the polyphenylene-based semipermeable membrane of Claim 1. OHKAME discloses that the first separation layer is provided on the outer surface of the porous support membrane (¶[0020]), and the sequential contacting and crosslinking steps are performed on the separation-layer side (¶[0016]). The porous support is composed of polyphenylene ether (¶[0026]). It is reasonably interpreted that the second surface of the semipermeable membrane is not exposed to the sulfonated first separation layer and is not sulfonated, and therefore has an elemental sulfur ratio of less than 0.1 atm. %.
Regarding Claim 5, modified OHKAME makes obvious the polyphenylene-based semipermeable membrane of Claim 1. OHKAME discloses that the preferred ion exchange capacity is 0.7 meq./g (¶[0024]). Using a standard density for sulfonated polyphenylene ether of 1.06 g/cm³, this corresponds to approximately 7.4 × 10⁴ meq./m³, which falls within the claimed sulfonation degree range of 0.1 × 10⁴ to 9.0 × 10⁴ meq./m³.
Response to Arguments
Applicant’s arguments, see Remarks filed December 29, 2025, with respect to the rejection of claims 1 and 3–5 under 35 U.S.C. § 103 have been fully considered. The rejection is updated and maintained under 35 U.S.C. § 103 over OHKAME in view of FUJIMOTO. Applicant’s amendment recites how the sulfonated region is formed, and FUJIMOTO accounts for the added formation limitation by disclosing a known surface-contact sulfonation technique for solid polyphenylene polymer.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAK L. CHIU whose telephone number is (703)756-1059. The examiner can normally be reached M-F: 9:00am - 6:00pm (CST).
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, PREM C. SINGH can be reached at (571)272-6381. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TAK L. CHIU/Examiner, Art Unit 1777
/KRISHNAN S MENON/Primary Examiner, Art Unit 1777
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