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 .
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.
Claims 1, and 3-5 are rejected under 35 U.S.C. 103 as being unpatentable over OHKAME et al. (WO2018066631A1, hereinafter OHKAME).
Regarding Claim 1, OHKAME discloses a polyphenylene-based semipermeable membrane comprising a porous polyphenylene ether (PPE) support (¶¶[0025]–[0026]) with a sulfonated polymer first separation layer containing sulfonic acid groups, including sulfonated polyphenylene ether, provided on the outer surface of the porous support (¶[0020]). The first separation layer is provided on one surface of the porous support (¶[0016]). The sulfonated polymer can be obtained by sulfonating a known polymer, including polyphenylene ether, using chlorosulfuric acid or concentrated sulfuric acid (¶[0021]). 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 PPE support is formed as a hollow fiber membrane by extruding a PPE-containing film-forming solution through a double cylindrical nozzle, coagulating the extruded hollow fiber, and washing the resulting membrane, which has a membrane thickness of 50 µm (¶¶[0055]–[0057]). A sulfonated polyarylene ether (SPAE) coating solution is then applied to the PPE hollow fiber support by dip coating and dried to form the first separation layer, which has a measured thickness of 300 nm (¶¶[0058]–[0061]).
Based on the disclosure, it is reasonable to interpret that the sulfonated SPAE coating solution penetrates into the porous PPE support from the outer surface during dip coating, with the extent of penetration depending on the pore structure, including the pore size and porosity of the support, resulting in a sulfonated region extending from the outer surface into only a portion of the membrane thickness.
Regarding the recitation that the sulfonated region is formed by sulfonating the first surface of the semipermeable membrane, the recitation defines the claimed product in terms of the process by which the sulfonated region is formed. Patentability is based on the product itself rather than the process by which it is made. As discussed above, OHKAME provides a membrane structure having a sulfonated region extending from the outer surface into only a portion of the membrane thickness (In re Thorpe, 777 F.2d 695, 698; Fed. Cir. 1985).
Regarding the limitation that the ratio of the sulfonated region is 5% or more and 40% or less, the sulfonated-region ratio is considered a result-effective variable dependent on the pore structure of the porous PPE support, including pore size and porosity. A person skilled in the art would have routinely optimized these known parameters to control the penetration depth of the sulfonated coating solution and obtain a sulfonated-region ratio within the claimed range (In re Aller, 220 F.2d 454, 456–57; 1955).
Regarding Claim 3, OHKAME makes obvious the polyphenylene-based semipermeable membrane of Claim 1. OHKAME discloses preparing a sulfonated polyarylene ether (SPAE) coating solution and applying the SPAE coating solution to the PPE hollow fiber support by dip coating and drying to form the first separation layer (¶¶[0058]–[0061]).
Based on the disclosure, it is reasonable to interpret that the coating solution penetrates inward from the outer surface during dip coating but is not driven completely through the 50 µm membrane wall to the lumen side, particularly due to resistance from the air within the hollow fiber, while the resulting first separation layer has a measured thickness of only 300 nm. Accordingly, the lumen-side surface, which corresponds to the recited second surface, is not sulfonated.
Regarding Claim 4, OHKAME makes obvious the polyphenylene-based semipermeable membrane of Claim 1. OHKAME discloses preparing a sulfonated polyarylene ether (SPAE) coating solution and applying the SPAE coating solution to the PPE hollow fiber support by dip coating and drying to form the first separation layer (¶¶[0058]–[0061]).
Regarding the limitation that the second surface has an elemental sulfur ratio of less than 0.1 atm. %, the XPS-measured sulfur ratio at the second surface is considered a result-effective variable reflecting sulfonic acid groups present at that surface. During exterior dip coating of the hollow fiber, resistance from the air within the hollow fiber limits penetration of the sulfonated coating solution through the membrane wall to the lumen side. A person skilled in the art would have routinely optimized known membrane parameters, including pore size and porosity, to further control penetration of the coating solution such that the sulfonation does not reach the lumen-side surface, resulting in a measured elemental sulfur ratio of less than 0.1 atm. % at the second surface (In re Aller, 220 F.2d 454, 456–57; 1955).
Regarding Claim 5, OHKAME makes obvious the polyphenylene-based semipermeable membrane of Claim 1. OHKAME discloses that the more preferred ion exchange capacity of the sulfonated polymer is 0.7 to 2.9 meq./g, with lower IEC and sulfonation degree resulting in insufficient anionic charge density and higher IEC and sulfonation degree resulting in excessive hydrophilicity and swelling (¶[0024]).
Regarding the limitation that the sulfonation degree is 0.1 × 10⁴ meq./m³ to 9.0 × 10⁴ meq./m³, the sulfonation degree is considered a result-effective variable. A person skilled in the art would have routinely optimized the degree of sulfonation to balance anionic charge density and hydrophilicity of the membrane, including a sulfonation degree within the claimed range (In re Aller, 220 F.2d 454, 456–57; 1955).
Response to Arguments
Applicant’s arguments, see Remarks filed July 27, 2026, with respect to the rejection under 35 U.S.C. § 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground of rejection under 35 U.S.C. § 103 is made over OHKAME.
Regarding Applicant’s argument that OHKAME merely applies a sulfonated polymer coating to the PPE support and does not disclose sulfonation extending only through a portion of the membrane thickness, OHKAME discloses dip coating a porous PPE hollow fiber support with a sulfonated SPAE coating solution (¶¶[0058]–[0061]). As discussed in the rejection, the coating solution penetrates inward from the outer surface of the porous support, with the extent of penetration dependent on the pore structure, including pore size and porosity. Applicant’s argument is therefore not persuasive.
Conclusion
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.
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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/TAK L. CHIU/Examiner, Art Unit 1771
/KRISHNAN S MENON/Primary Examiner, Art Unit 1771
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