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 Amendment
Claims 1-15 are pending. Claim 1 is currently amended.
In view of the amendment, filed 08/06/2025, claim rejections under 35 U.S.C. 103 are withdrawn from the previous Office Action mailed 05/06/2025.
New grounds of rejection are necessitated by claim amendments.
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) 1-5 and 9-15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al., US 20210154621 A1 (of record), in view of Zhao et al., Fabrication of antifouling polyethersulfone ultrafiltration membranes using Pluronic F127 as both surface modifier and pore-forming agent (2008), and Ikeyama, WO 2020111211 A1 (citations to English equivalent US 20210260538 A1, of record).
Regarding claim 1, Wang discloses a method for producing an asymmetric porous membrane (preparing asymmetric membranes, [0044], the asymmetric membranes being porous, [0049]-[0050], [0061]), comprising:
Forming a first casting film (casting a thin film, [0048], [0056]) from a casting solution (from a polymer/casting solution, [0045]-[0046], [0056]) on a carrier (on a support paper or belt, [0050]), the casting solution containing a hydrophobic polymer (a hydrophobic polymer, such as a sulfone polymer, [0044]), a hydrophilic polymer selected from the group consisting of polyvinylpyrrolidone, polyalkylene glycol, and a combination thereof (polyvinylpyrrolidone, polyethylene glycol, [0046]), and a solvent (solvent, [0046]);
Placing the first casting film in an environment containing water vapor to contact the first casting film with the water vapor (exposing the cast membrane to humid air, [0048], [0059]), thereby obtaining a second casting film (a result of the “exposing” step), the environment having a relative humidity of 30% to 80% (having a relative humidity of preferably 55-80%, [0048]); and
Contacting the second casting film with a coagulating agent (quenching the membrane, [0048], [0056], in a quenching liquid, such as water, [0056]) to perform a wet-phase inversion (the quench operation precipitates or coagulates the polymer, produces a microporous structure, [0056]) so as to obtain a coagulating film (producing a resulting membrane, [0056]).
In the illustrative casting formulation, Wang discloses the casting solution contains another nonsolvent (other nonsolvent, such as water, [0046], [0055]). Wang further discloses a different nonsolvent can be used to replace or supplement water as the nonsolvent, e.g., to prepare casting dopes with particular qualities ([0055]). Wang does not disclose the casting solution contains a water-soluble polymer selected from the claimed group.
In the analogous art, Zhao discloses techniques for fabrication of asymmetric porous membranes based on polyethersulfone (Title, Abstract). Zhao teaches introducing an additive to the casting solution to endow the membrane with superior antifouling properties and high separation performance (p. 405, Introduction, first paragraph), where the additive is an ethylene glycol/propylene glycol based copolymer (Pluronic F127, pp. 405-406, Introduction; as presently exemplified in the filed specification, [0030]). Zhao teaches incorporation of the Pluronic F127 additive to the casting solution produced membranes having excellent antifouling properties and enabled control of the water permeation flux by adjusting the content of the additive in the casting solution (p. 406, Introduction; p. 410, Section 3.3 The role of Pluronic F127 as the pore-forming agent; p. 411, Conclusions).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the casting solution of Wang to replace the nonsolvent of water with a nonsolvent for achieving a particular quality, as taught by Wang, the replacement nonsolvent being a water soluble polymer that is an ethylene glycol/propylene glycol based copolymer in order to achieve a cast membrane with improved antifouling properties and/or for enhanced control over the water permeation flux of the membrane, as taught by Zhao.
Wang discloses the casting solution or dispersion temperature is between about 20°C and 35°C ([0058]). However, Wang is silent as to a specific temperature for the environment and therefore does not disclose a temperature ranging from 20°C to 33°C.
In the analogous art, Ikeyama discloses a method for manufacturing a porous membrane (Abstract). Ikeyama discloses casting a solution including a water-insoluble resin and a water-soluble resin on a support to form the porous membrane ([0030]), the casting solution utilizing similar materials to those of Wang (e.g., water-insoluble resin including sulfone polymers, [0055]-[0057], water-soluble materials including polyvinylpyrrolidone, or a copolymer obtained from N-vinylpyrrolidone and optionally vinyl acetate, [0063]-[0064], including additives/non-solvents such as polyethylene glycol, [0069], [0107], solvent, [0106]). Ikeyama teaches a similar process of casting the solution on a support and exposing the cast membrane to temperature-controlled humid air prior to immersing the membrane in a coagulation liquid ([0095]-[0097]), where the temperature-controlled humid air is preferably 10-40°C ([0099]). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. MPEP 2144.05 (I). Ikeyama teaches that application of the temperature-controlled humid air enables coacervation from the surface of the liquid membrane toward the inside of the membrane by controlling evaporation of a solvent, which facilitates the formation of fine pores ([0102]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further specify in the process of Wang that the environment had a temperature ranging from 20°C to 33°C in order to provide a sufficient temperature of the humid air environment to facilitate pore formation, as desired by Wang and taught by Ikeyama. In the absence of a specific temperature instruction from Wang, one of ordinary skill would have been motivated to select the overlapping temperature range from Ikeyama in order to specify a suitable working temperature for the same process step performed under otherwise similar conditions with a reasonable expectation of success.
Regarding claim 2, modified Wang discloses the method of claim 1, and Wang further discloses the other nonsolvent, the water-soluble polymer per the combination, being present in an amount ranging from 0.5 wt% to 20 wt% based on 100 wt% of the casting solution (the other nonsolvent being present at about 0.5% to about 5%, [0046]). The example in the prior art is entirely within the claimed range. MPEP 2131.03 (I). The examiner notes that although Wang does not specify the percentage amount is a weight percentage in the referenced table, this is understood to be the intent of the disclosure, as Wang generally refers to constituent percentages of a casting solution as weight percentages (e.g., [0043]).
Regarding claim 3, modified Wang discloses the method of claim 2. Wang discloses the other nonsolvent, the water-soluble polymer per the combination, being present in an amount ranging from 0.5 wt% to 5 wt% based on 100 wt% of the casting solution (the other nonsolvent being present at about 0.5% to about 5%, [0046]). The example in the prior art is entirely within the claimed range. MPEP 2131.03 (I).
Regarding claim 4, modified Wang discloses the method of claim 1, and Wang discloses the hydrophilic polymer being present in an amount ranging from about 18 to 40% based on 100 wt% of the casting solution (polyvinylpyrrolidone from about 3% to about 15%, polyethylene glycol from about 15% to about 25%, [0046], such that the total amount can range from about 18 to 40%). Wang does not explicitly disclose the claimed range. However, the claimed range of the hydrophilic polymer being present in an amount ranging from 5 to 30 wt% based on 100 wt% of the casting solution overlaps the prior art range of about 18 to 40%. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. MPEP 2144.05 (I). As such, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to select at least the overlapping portion of the range in specifying a suitable concentration for the hydrophilic polymer in the casting solution, as taught by Wang. The examiner notes that although Wang does not specify the percentage amount is a weight percentage in the referenced table, this is understood to be the intent of the disclosure, as Wang generally refers to constituent percentages of a casting solution as weight percentages (e.g., [0043]).
Regarding claim 5, modified Wang discloses the method of claim 4. Wang discloses the hydrophilic polymer being present in an amount ranging from about 18 to 40% based on 100 wt% of the casting solution (polyvinylpyrrolidone from about 3% to about 15%, polyethylene glycol from about 15% to about 25%, [0046], such that the total amount can range from about 18 to 40%). Wang does not explicitly disclose the claimed range. However, the claimed range of the hydrophilic polymer being present in an amount ranging from 5 to 22 wt% based on 100 wt% of the casting solution overlaps the prior art range of about 18 to 40%. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. MPEP 2144.05 (I). As such, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to select at least the overlapping portion of the range in specifying a suitable concentration for the hydrophilic polymer in the casting solution, as taught by Wang.
Regarding claim 9, modified Wang discloses the method of claim 1, and Wang discloses a contacting time of the first casting film and the water vapor ranges from 0.1 seconds to 60 seconds (about 2 to about 20 seconds, [0048], [0060], entirely within the claimed range).
Regarding claim 10, modified Wang discloses the method of claim 1, and Wang discloses the coagulating agent is one of water, alcohol, and a combination thereof (water, [0056]).
Regarding claim 11, modified Wang discloses the method of claim 1. Wang discloses the hydrophobic polymer (sulfone polymer) is present at about 9% to about 12% ([0046]; see also [0052]). Wang does not explicitly disclose the claimed range. However, the claimed range of the hydrophobic polymer being present in an amount ranging from 10 wt% to 25 wt% based on 100 wt% of the casting solution overlaps the prior art range of about 9% to about 12%. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. MPEP 2144.05 (I). As such, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to select at least the overlapping portion of the range in specifying a suitable concentration for the hydrophobic polymer in the casting solution, as taught by Wang.
Regarding claim 12, modified Wang discloses the method of claim 1, and Wang further discloses the hydrophobic polymer is polysulfone or poly(vinylidene fluoride) (polysulfone, [0044], [0052]).
Regarding claim 13, modified Wang discloses the method of claim 1, and Wang further discloses the solvent being dimethyl acetamide ([0054]).
Regarding claim 14, modified Wang discloses the method of claim 1. Wang discloses the environment has a relative humidity of preferably 55% to 80% ([0048]). Wang does not explicitly disclose the claimed range. However, the claimed range of the relative humidity of 70% to 80% overlaps the preferred prior art range of 55% to 80%. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. MPEP 2144.05 (I). As such, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to select at least the overlapping portion of the range in specifying a suitable relative humidity range for the disclosed exposure step, as taught by Wang.
Regarding claim 15, modified Wang discloses the method of claim 1. Wang does not explicitly recite a step of detaching the coagulating film from the carrier. However, Wang does not disclose or suggest that the carrier/support is intended to form part of the membrane product, and therefore it would likely have been apparent to one of ordinary skill in the art in view of the reference that the produced coagulating film would require separation from the carrier in order to fulfill its ultimate intended use of functioning as a filtering structure in a filter device ([0004], [0073], Fig. 4).
Furthermore, in the similar film casting process ([0094]-[0098]), Ikeyama additionally teaches a step of detaching the coagulating film from the carrier after the contacting with a coagulating agent (the support is peeled off, [0098]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further specify in the method of Wang a step of detaching the coagulating film from the carrier, as taught by Ikeyama, in order to enable subsequent processing and/or use of the entirety of the produced coagulated film as the asymmetric membrane, as intended by Wang.
Claim(s) 6-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al., US 20210154621 A1, in view of Zhao et al., Fabrication of antifouling polyethersulfone ultrafiltration membranes using Pluronic F127 as both surface modifier and pore-forming agent, and Ikeyama, WO 2020111211 A1 (citations to US 20210260538 A1), as applied to claim 1 above, and further in view of Wrasidlo, US 4629563 A.
Regarding claim 6, modified Wang discloses the method of claim 1, wherein the casting solution has a first temperature (casting solution temperature of between about 20°C and 35°C, [0058]). The carrier of Wang necessarily has a temperature and therefore has an undefined second temperature. Wang does not disclose or suggest that a temperature of the carrier should contribute to a specific effect on the film. However, Wang is silent as to a temperature difference between the first temperature and the carrier temperature and therefore is silent as to a difference equal to or smaller than 15°C.
In the analogous art (col. 1, lines 13-17), Wrasidlo discloses forming asymmetric porous membranes from similar materials (polysulfone, solvents, non-solvents, col. 8, lines 26-65). In the membrane production, Wrasidlo discloses casting a polymer solution provided at 30°C onto a glass plate preheated to 30°C prior to subsequent transfer to a water bath and coagulation to produce a microporous structure (polysulfone example, Example V, col. 12, lines 10-18, casted as described in Example I, col. 10, line 66-col. 11, line 9).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further specify in the method of Wang the first temperature and the second temperature having a difference equal to or smaller than 15°C in order to provide the casting solution and the carrier at essentially the same temperature during casting, as taught by Wrasidlo. Since Wang is silent as to a specific temperature of the carrier, one of ordinary skill in the art would have looked to a relevant known process for specifying a carrier temperature relative to the casting solution and would have had a reasonable expectation of success in implementing the prior art temperature relationship given the similarities between the process steps, materials, and intended result. Particularly since Wang does not disclose or suggest influencing any properties of the film/membrane via a temperature effect from the carrier, setting the carrier temperature similar to or the same as the casting solution, as taught by Wrasidlo, would have been expected to be appropriate for achieving the intended result of providing a film support without undue influence from the carrier.
Regarding claim 7, modified Wang discloses the method of claim 6, and Wang discloses the first temperature ranges from 20°C to 45°C (casting solution temperature of between about 20°C and 35°C, [0058], entirely within the claimed range).
Regarding claim 8, modified Wang discloses the method of claim 6, and the combination discloses the second temperature ranges from 20°C to 45°C (Wrasidlo as applied above teaches a second temperature of 30°C when the casting solution is 30°C, as well as the second temperature being the same as the first temperature; in either case, the second temperature is entirely within the claimed range).
Response to Arguments
Applicant’s arguments with respect to the prior art rejection of claim(s) 1 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument (i.e., the teaching of the specific water-soluble polymers recited in amended claim 1).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 20170056835 A1, Berzinis et al. disclose the addition of amphiphilic polymer to a porous asymmetric membrane forming composition and a membrane made from a hydrophobic polymer and a polymer additive comprising poly(vinyl pyrrolidone), poly(ethylene glycol), a block copolymer of poly(ethylene oxide) and poly(propylene oxide), or a combination thereof.
Zhang et al., Fabrication of novel anti-fouling poly(m-phenylene isophthalamide) ultrafiltration membrane modified with Pluronic F127 via coupling phase inversion and surface segregation (2022), discuss existing research related to the use of Pluronic, especially Pluronic F127, as an additive in membrane fabrication (e.g., p. 2).
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.
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/J.L.G./Examiner, Art Unit 1754
/SUSAN D LEONG/Supervisory Patent Examiner, Art Unit 1754