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 .
Applicant’s Submission of a Response
Applicant’s submission of a response was received on 7/31/2026.
Claim Rejections - 35 USC § 103
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.
Claim(s) 1-17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Krause et al. (US 2006/0138044 in IDS) in view of Herczeg (US 2003/0141238).
Regarding claim 1, Krause teaches a hollow-fiber membrane; the hollow-fiber membrane made from a polymeric blend comprising an aromatic sulfone polymer and a polyoxazoline; wherein the hollow-fiber membrane comprises an inner surface facing towards its lumen, an outer surface facing outwards and an intermediate wall having a wall thickness ([0020]-[0021]).
It is noted that Krause is silent on whether the membrane produced is symmetric or asymmetric. However, there are only 2 options when classifying a membrane as symmetric or asymmetric. As such, one skilled in the art would consider that that Krause membrane would be either one of the types (see MPEP 2144.08 for when the genus (hollow fiber membranes) has limited predictable options (2 options)). Further, many prior art detail that hollow fiber membranes could be chosen from either configuration with a reasonable expectation of success (see Herczeg [0054]-[0067]). Therefore, one skilled in the art would have found that Krause encompasses asymmetric membranes, or it would have been obvious to choose an asymmetric style membrane as such membranes are known and used in the art and provide efficiency and flow rate benefits.
Regarding claims 2-3, Krause teaches the membranes are formed from preferred polymers of polyethersulfones and polyethyloxazolines (poly(2-ethyl-2-oxazoline) ([0021] and [0084]).
Regarding claim 4, Krause teaches the molecular weight of the polyoxazoline is 500,000 (500 kg/mol) ([0084]).
Regarding claims 5-8, Krause does not detail the pore structures as claimed. However, Herczeg teaches that there are many options for asymmetric membranes depending on the desired flow pattern, such as larger pores on the inner surface and smaller pores on the outer surface, or smaller pores on the inner surface and larger pores on the outer surface, or smaller pores on both surfaces with macrovoids between the pores ([0050]-[0067]). Therefore, one skilled in the art would have found it obvious to provide the Krause membrane in a variety of different configurations as taught in Herczeg as such configurations are known and used in the art and one skilled in the art would have a reasonable expectation of success in doing so.
Regarding claims 9-10, Krause teaches the membrane is employed for various uses (hemofiltration, ultrafiltration) (abstract) but fails to teach the pore size associated with said uses. Herczeg teaches that ultrafiltration hollow fiber membranes typically have a size of 0.05 microns (50 nm) ([0063]). Therefore, one skilled in the art would have found it obvious for the membrane to have pores in the range claimed in order to achieve the ultrafiltration use.
Regarding claims 11-14, Krause teaches that the polymeric blend also includes hydrophilic polymers, such as polyvinylpyrrolidone or polyacrylic acid ([0021]) and a solvent, such as 1-methyl-2-pyrrolidone (NMP) ([0084]), which is considered to be polar and aprotic.
Regarding claims 15-16, Krause teaches that the polymeric blend does not include polyvinylpyrrolidone, which would be considered less than 3 wt % ([0084]).
Regarding claim 17, Krause merely teaches that the hollow fiber membrane has pores but fails to teach the specifics of the pores structure, such as tortuous structures extending from the inner to outer surfaces. Herczeg teaches that hollow fiber membranes of the asymmetric or can have a variety of structure and sizes where large intrusions or macrovoids are formed ([0034] and [0053]). It is submitted that the tortuous structures claimed would be considered under the broad teachings in Herczeg about any variety of pore structure and the intrusions/macrovoids formed.
Claim(s) 1 and 28 is/are rejected under 35 U.S.C. 103 as being unpatentable over Krause et al. (US 2006/0138044 in IDS) in view of Kools (US 2003/0209486).
Regarding claims 1 and 28, Krause teaches a hollow-fiber membrane; the hollow-fiber membrane made from a polymeric blend comprising an aromatic sulfone polymer and a polyoxazoline; wherein the hollow-fiber membrane comprises an inner surface facing towards its lumen, an outer surface facing outwards and an intermediate wall having a wall thickness ([0020]-[0021]).
Krause is silent on whether the membrane produced is symmetric or asymmetric. However, there are only 2 options when classifying a membrane as symmetric or asymmetric. As such, one skilled in the art would consider that that Krause membrane would be either one of the types (see MPEP 2144.08 for when the genus (hollow fiber membranes) has limited predictable options (2 options)). Further, many prior art detail that hollow fiber membranes could be chosen from either configuration with a reasonable expectation of success (see Kools abstract, [0019], [0040]) and that asymmetric membranes provide better flux and flow rates than symmetrical membranes ([0004], [0040], [0046], and [0053]). Therefore, one skilled in the art would have found that Krause encompasses asymmetric membranes, or it would have been obvious to choose an asymmetric style membrane as such membranes are known and used in the art and provide efficiency, flux, and flow rate benefits.
Krause does not teach the pore shape being such that the intermediate wall comprises a first cross-section zone that begins at the inner surface and terminates at an internal distance within the intermediate wall, and a second cross-section zone that begins where the first cross- section zone terminates and extends to the outer surface, wherein in the first cross-section zone the pore size progressively decreases in a direction from the inner surface toward the outer surface, wherein in the second cross-section zone the pore size progressively increases in a direction toward the outer surface, and wherein a pore size transition location at which the first cross-section zone terminates and the second cross-section zone begins forms at least a portion of a retention layer (essentially an hourglass pore shape). Kools teaches that known shapes for asymmetric membranes include a shape as claimed (essentially hourglass shape) ([0028]-[0037]). Therefore, it would have been obvious to provide known and used pore shapes for asymmetric membranes, such as hourglass shapes, as such pore shapes are known and used in the art at the time of invention and one skilled in the art would have a reasonable expectation of success in doing so.
Response to Arguments
Applicant's arguments filed 7/31/2026 have been fully considered but they are not persuasive.
Applicant argues that Examiner improperly reduces integrally asymmetric permeable hollow fiber membrane limitation to a binary choice. It is noted that the prior art cited by Examiner above (Herczeg and Kools) does in fact teach that membranes would be classified as either symmetrical or asymmetrical and the making of the membranes would be modified to ensure the desired choice between symmetric and asymmetric. Applicant has not provided any factual support that there is a third option for membranes besides symmetric and asymmetric. As such, any membrane made would have to be either symmetric or asymmetric. Further, Herczeg and Kools both teach that makers of membranes would in fact choose to make theirs either symmetrical or asymmetrical with both teaching the preferred embodiment is asymmetric. Lastly, the prior art teaches that asymmetric membranes provide certain flow, efficiency, and flux benefits when compared with symmetrical membranes providing a motivation to modify membranes to asymmetrical if flow, flux, and certain efficiency properties are desired. As mentioned in the rejection above, Krause is silent on the symmetric and asymmetric membrane configuration of their membranes, but based on the teachings in the art (Herczeg and Kools), choosing asymmetrical membranes would have been selecting one of the two choices given the small amount of options, and/or it would have been obvious to choose asymmetric membrane configurations based on the benefits taught in Herczeg and Kools.
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
It is noted that the argued shape being different between the asymmetric Herczeg membrane and the claimed membrane are not present in claim 1 as argued. 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). New claim 28 does recite the argued limitations but the claim is not rejected based on Herczeg.
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.
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/PETER KEYWORTH/Primary Examiner, Art Unit 1776
