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
Applicant’s claim for the benefit of a prior-filed application (has PRO 63/314,648, 63/314,663, 63/314,661, filed on February 28, 2022) under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged.
Claim Objections
Claim 1 objected to because of the following informalities:
Steps (c) and (f) should be indented consistently with the other method steps to improve claim formatting and readability.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION. —The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 5, 7, and 13-16 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 5 recites the limitation “the polymer solution.” There is insufficient antecedent basis for this limitation in the claim. Claim 1 introduces “a spinning solution,” and Claim 5, as a dependent claim, should refer back to the previously introduced “spinning solution” for consistency.
Claim 7 recites the limitation “SBS system.” This limitation lacks clear antecedent basis for this limitation in the claim.
Claim 13 recites the limitation “m-phenylenediamine in step (h).” This limitation is unclear because Claim 1 prepares the m-phenylenediamine solution in step (g). Claims 14–16, which depend on Claim 13, are similarly rejected by virtue of dependency.
Claim 14 recites the limitation “trimesoyl chloride in step (h).” This limitation is unclear because Claim 1 prepares the trimesoyl chloride solution in step (g). Claim 15-16, which depend on Claim 14, are similarly rejected by virtue of dependency.
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:
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.
Claims 1-16 are rejected under 35 U.S.C. 103 as being unpatentable over LIU et al. (“Solution Blown Nylon 6 Nanofibrous Membrane as Scaffold for Nanofiltration” 2019, hereinafter LIU) in view of MCCUTCHEON et al. (US20130105395A1, hereinafter MCCUTCHEON).
Regarding Claim 1, LIU discloses a preparation method for a nanofiltration membrane, including preparing a nylon 6 nanofibrous membrane by solution blowing, hot pressing the solution-blown nanofibrous membrane as a scaffold, and preparing an ultra-thin polyamide active layer on the scaffold by interfacial polymerization (Abstract, Pg. 1).
In §2.2, a nanofibrous membrane is obtained using a solution blowing apparatus, as shown in FIG. 1. The apparatus includes a high-pressure gas source, suction system, porous spinning die, metering pump device, receiving system, and spinning box. Each single hole in the multi-hole spinneret has two concentric channels, and the spinning solution is extruded through the internal passage while high-pressure gas flow is ejected through the external passage. The droplet is stretched to form solution jets under shearing and drawing action caused by the high-pressure gas flow at the spinneret, and nylon 6 nanofibers are formed after solvent evaporation (Pg. 3).
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FIG. 1 of LIU et al.
FIG. 1 illustrates the solution blowing device, including a motor-driven receiving/convey belt and suction fan below the collection region. The motor-driven receiving/convey belt and suction fan reasonably correspond to the claimed rotating vacuum collector.
In §2.3, the solution-blown nanofibers are hot pressed with PET spunbond nonwoven fabric having 40 g/m² as backing material to form a thin and dense porous layer. The hot pressing conditions are 180 °C for 10 s under pressures of 0, 5, 10, and 15 MPa (Pg. 4).
In §2.4, an ultra-thin polyamide barrier layer is prepared by interfacial polymerization on the hot-pressed nanofibrous membrane. The process includes preparing a 2.0% m-phenylenediamine solution and a 0.2% (w/v) trimesoyl chloride solution, immersing the membrane in the m-phenylenediamine solution for 1 min, drying in air for 5 min, dipping in the trimesoyl chloride solution for 30 s, curing at 100 °C for 10 min, and rinsing with DI water (Pg. 4).
Regarding the limitation “at 150 °C for 10 minutes or 175 °C for 6 minutes under a low loading of 0.5 tons/m²,” the recited hot-pressing temperature, dwell time, and loading are result-effective variables for consolidating a nanofiber mat into a scaffold. LIU discloses that hot pressing converts loose nanofibers into a close-packed scaffold, reducing pore size and narrowing pore-size distribution, with higher pressure causing fiber deformation or partial melting (§3.2, Pg. 6–7). A person skilled in the art would have adjusted temperature, dwell time, and loading to obtain the desired scaffold consolidation without excessive deformation.
Regarding step (c), LIU’s collector would have evenly collected the nanofibers to form a uniform nanofiber mat, and a person skilled in the art would have recognized that uneven collection would predictably produce nonuniform scaffold thickness and inconsistent scaffold properties.
Regarding step (e), “removing the steel plates from the hot-press and cooling the steel plates,” heated steel plates must be handled after the hot-press cycle is completed, and removing and cooling the plates is a routine post-press handling step.
However, LIU does not explicitly disclose (a) preparing the spinning solution by mixing a polymer with a solvent, wherein the polymer and solvent are selected from either polysulfone with N,N-dimethylformamide or polyethersulfone with a solvent mixture of N-methyl-2-pyrrolidone and toluene in a 2:1 ratio by weight, and (b) producing the membrane for a forward osmosis process.
MCCUTCHEON discloses thin film composite membranes for engineered osmosis applications, including forward osmosis, wherein the membrane includes a porous nanofiber support and a polyamide layer produced by interfacial polymerization of a polyfunctional amine monomer with a polyfunctional acyl halide monomer (¶¶[0010]–[0014]; ¶¶[0057]–[0060]).
The materials used in the experiments include polyethersulfone (PES), polysulfone (PSu), polyester nonwoven fabric (PET), N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), trimesoyl chloride (TMC), and m-phenylenediamine (MPD) (¶[0107]).
The fabrication process includes preparing a homogeneous spinning solution of 25 wt% PSu in a bi-solvent system of DMF and NMP, and stirring at 60 °C for 8 hours followed by stirring at room temperature overnight. The polymeric solution is deposited onto a PET backing layer and dried. The dried support membrane is immersed in an aqueous solution of 3.4 wt% MPD for 120 s, and then dipped into a solution of 0.15 wt% TMC in isopar for 60 s to form an ultrathin polyamide layer, followed by post-process washing (¶¶[0109]–[0112]). The disclosed 25 wt% PSu in a bi-solvent system of DMF and NMP reads upon the claimed limitation “the polymer is present in an amount of 5 wt % to 30 wt % by weight of the solvent.”
The DMF to NMP solvent ratio is adjusted to obtain adhesion between the PSu nonwoven layer and the PET backing layer, while achieving a desired nanofiber structure. A DMF fraction of 100% is shown to produce smooth, continuous fibers with decreased beads and defects (¶¶[0121]–[0122]).
The nanofiber-supported TFC polyamide membranes disclosed by MCCUTCHEON, including PSu/PES support materials, DMF/NMP solvent systems, PET backing, and MPD/TMC interfacial polymerization chemistry, provide a compatible polymer-support and interfacial-polymerization material system for forming an ultrathin polyamide active layer on a nanofiber scaffold for engineered osmosis applications, including forward osmosis (¶¶[0002]–[0006]; ¶¶[0107]–[0112]). In view of LIU’s solution-blown, hot-pressed nanofibrous scaffold process, a person skilled in the art would have used this material system in the solution-blowing process to form the nanofiber scaffold, predictably controlling nanofiber formation, scaffold morphology, and compatibility with the subsequently formed polyamide active layer.
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 use the compatible polymer-support, solvent, and interfacial-polymerization materials, as disclosed by MCCUTCHEON, in the solution-blown, hot-pressed nanofibrous scaffold preparation method by LIU.
Regarding Claim 2, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. MCCUTCHEON discloses a homogeneous spinning solution having a polymer concentration of 25% by weight of PSu in a bi-solvent system of DMF and NMP (¶[0109]).
Regarding the limitation “in (a)(1) is 10 wt % by weight of the solvent,” polymer concentration is a result-effective variable for controlling spinning-solution viscosity, fiber formation, and nanofiber mat integrity. A person skilled in the art would have adjusted the polymer concentration as a matter of routine optimization to obtain a spinnable solution and desired nanofiber morphology (In re Aller, 220 F.2d 454, 456–57 (CCPA 1955)).
Regarding Claim 3, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. LIU discloses a solution-blowing apparatus including a high-pressure gas source that ejects a gas flow through the external passage of the spinneret to draw the spinning solution into jets (Pg. 3). It is reasonable to interpret the high-pressure gas as compressed air or nitrogen because both are common gases used for high-pressure gas flow in solution-blowing fiber formation.
Regarding Claim 4, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. FIG. 1 of LIU illustrates a collection system for obtaining the nanofibrous membrane (Pg. 3).
Regarding the limitation “for up to 60 minutes,” the collection duration is a result-effective variable for controlling nanofiber areal density and mat thickness. A person skilled in the art would have selected a collection time up to 60 minutes as a matter of routine optimization to obtain a desired nanofiber mat (In re Aller, 220 F.2d 454, 456–57 (CCPA 1955)).
Regarding Claim 5, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. MCCUTCHEON discloses a polymer-solution flow rate of 0.9 mL/h (¶[0110]). Table 1 of LIU includes a metering-pump rotation rate of 17.5 r/min and a step size of 0.6 mL/r (Pg. 4). These values correspond to a volumetric feed rate of 630 mL/h.
Regarding the limitation “fed into the SBS apparatus at a rate from about 5 mL/h to 25 mL/h,” the polymer-solution feed rate is a result-effective variable for controlling solution delivery, jet formation, and nanofiber deposition. A person skilled in the art would have adjusted the feed rate as a matter of routine optimization to obtain stable fiber formation and a desired nanofiber mat (In re Aller, 220 F.2d 454, 456–57 (CCPA 1955)).
Regarding Claim 6, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. Table 1 of LIU includes a drafting wind pressure of 2 bar, which reads upon the claimed range “about 1.5 to 2.0 bar” (Pg. 4).
Regarding Claim 7, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. Table 1 of LIU includes a drafting wind pressure of 2 bar (Pg. 4).
Regarding the limitation “is higher than 2.0 bars,” gas pressure is a result-effective variable for controlling solution-jet formation and nanofiber morphology during solution blowing. A person skilled in the art would have selected a pressure higher than 2.0 bars as a matter of routine optimization to obtain stable jet formation for a given spinning solution (In re Aller, 220 F.2d 454, 456–57 (CCPA 1955)).
Regarding Claim 8, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. Table 1 of LIU includes an auxiliary voltage of 4 kV, which reads upon the claimed range “about 0 to 20 kV” (Pg. 4).
Regarding Claim 9, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. MCCUTCHEON discloses electrospinning under a high-voltage field of 27.5 kV (¶[0110]). The disclosed 27.5 kV reads upon the claimed limitation “higher than 20 kV.”
Regarding Claim 10, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. LIU discloses hot pressing at 180 °C, which reads upon the claimed range “about 80 °C to 200 °C” (Pg. 4).
Regarding Claim 11, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. LIU discloses hot pressing for 10 s (Pg. 4).
Regarding the limitation “for about 5 to 20 minutes,” hot-pressing duration is a result-effective variable for controlling scaffold consolidation, density, and mechanical integrity. A person skilled in the art would have selected a dwell time of about 5 to 20 minutes as a matter of routine optimization to obtain a desired scaffold structure for a given scaffold material (In re Aller, 220 F.2d 454, 456–57 (CCPA 1955)).
Regarding Claim 12, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. LIU discloses hot pressing pressures of 0 MPa to 15 MPa (Pg. 4). The disclosed pressure range corresponds to about 0 to 1686 tons/m², which encompasses the claimed range “about 0.5 to 2.0 tons/m².”
Regarding Claim 13, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 1. MCCUTCHEON discloses immersing the support membrane in an aqueous solution of 3.4 wt% m-phenylenediamine for 120 s (¶[0112]). The disclosed 3.4 wt% m-phenylenediamine reads upon the claimed concentration range “from about 1 wt.% to 5 wt.%,” and the disclosed 120 s reads upon the claimed immersion time “about 2 to 5 minutes.”
Regarding the limitation “dissolving m-phenylenediamine in DI water,” DI water is a well-known aqueous solvent for preparing m-phenylenediamine solutions used in interfacial polymerization, because DI water avoids impurities and ions that can interfere with polyamide formation and membrane performance.
Regarding Claim 14, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 13. MCCUTCHEON discloses dipping the membrane into a 0.15 wt% trimesoyl chloride organic solution for 60 s (¶[0112]). The disclosed 0.15 wt% trimesoyl chloride reads upon the claimed concentration range “about 0.1 wt.% to 0.15 wt.%.”
Regarding the limitation “dissolving trimesoyl chloride in n-hexane,” LIU discloses preparing a trimesoyl chloride solution for interfacial polymerization and identifies n-hexane as a chemical used in the membrane-preparation process (Pg. 3–4). It would have been obvious to use n-hexane as the solvent for the trimesoyl chloride solution because n-hexane is a nonpolar, aprotic solvent that is compatible with acyl chloride monomers and poorly miscible with the aqueous m-phenylenediamine phase, allowing the trimesoyl chloride to remain in the organic phase during polyamide film formation.
Regarding Claim 15, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 14. MCCUTCHEON discloses immersing the support membrane in the m-phenylenediamine solution for 120 s, and then dipping the membrane into the trimesoyl chloride organic solution for 60 s (¶[0112]). The disclosed 120 s and 60 s read upon the claimed immersion times “about 2 to 5 minutes” and “10 seconds to 60 seconds.”
Regarding Claim 16, modified LIU makes obvious a method of producing polymer nanofiber supported thin film composite membranes of Claim 15. LIU discloses curing the membrane at 100 °C for 10 min, which reads upon the claimed temperature range “about 60 to 110 °C” (Pg. 4).
Regarding the limitation “for 90 seconds to 8 minutes,” curing time is a result-effective variable for controlling polyamide layer formation and membrane performance. A person skilled in the art would have adjusted curing time as a matter of routine optimization based on the scaffold material and curing temperature to obtain a desired polyamide layer (In re Aller, 220 F.2d 454, 456–57 (CCPA 1955)).
Response to Arguments
Applicant’s arguments, see Remarks, filed on March 31, 2026, with respect to the rejection(s) of claims 1–16 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 is made in view of LIU and MCCUTCHEON. The current rejection relies on LIU as the primary reference for the membrane-production process recited in amended Claim 1, and MCCUTCHEON for the polymer-support, solvent, and interfacial-polymerization materials.
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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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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