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 .
Election/Restrictions
Claims 19 and 20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 12/19/25.
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) 1-7 and 10-18 are rejected under 35 U.S.C. 103 as being unpatentable over Ansorge et al (US 2008/0197072) in view of Hu et al (US 5,178,765.)
Ansorge teaches a microporous membrane substantially as claimed, except for blending poly(2-oxazoline) with the polyethersulfone.
Ansorge teaches a flat sheet membrane having two asymmetric regions and a separating layer there between. See the abstract and [0011]-[0016]. The membrane is formed from polyether sulfone and can be without any PVP. See the working [0038].
Regarding polyoxazoline, see Hu, which teaches blending poly (2-oxazoline) with polysulfone (abstract) for obtaining exceedingly high strength microfiltration membrane: see example 1. High strength even after alcohol extraction – see Hu, col. 2, lines 34-39. Therefore, it would have been obvious to one of ordinary skill in the art to have polyoxazoline blended with polysulfone for making the Ansorge membrane. Hu teaches this as also known in the art - see col. 2 lines 16-30.
Regarding the polymeric blend not having PVP, see [0038] of Ansorge, which teaches other candidates for imparting hydrophilicity. This list significantly overlaps applicant’s list of the hydrophilic polymer additives in page 8, lines 10-15.
Regarding claim 4, since the separating layer is between the two asymmetric regions, it can be considered as being either on the first or on the second layer.
Claim 5: pore size on the first layer is larger than that of the second layer – see [0014]-[0015].
Claim 6: see [0038] or Ansorge; also, the blend further has PEG – examples.
Claim 7: hydrophilic polymer is within the range claimed – examples.
Claim 10: while the solvents are not patentable elements for the product claim, Ansorge does teach them in the examples.
Claim 11: polymer blend is hydrophobic – this would be inherent because Ansorge in view of Hu has the same blend of PES and polyoxazoline.
Claim 12: “essentially isotropic region” – see [0013]
Claims 13, 14: isotropic region is the separating layer – [0011]: interior of the membrane with minimal pore size, though very thin, would be isotropic as well.
Claim 15 – see [0013]-[0014]: pore size pass through maximum on isotropic region and then decreases towards second surface.
Notes on claims 13-15: Ansorge membrane structure has an asymmetric region near the first surface, then a narrow pore (separation) region, then pores widens to a larger isotropic region and to the second asymmetric region as seen in [0011]-[0016]
Claim 16: elongated pores – while Ansorge is silent on this, it is well-known that the asymmetric membranes have a sponge-like structure with finger-shaped pores formed by phase inversion. See the examples: after casting, the membrane is introduced into a coagulation bath to remove solvents and PVP. Also, pores are elongated by their nature – cylindrical or tubular.
Claim 17, pore size ratio – see [0015]
Claim 18: two membranes stacked in series – while the references are silent on this, having multiple layers of filters in series is commonly practiced to improve filtration efficiency, and is not patentable, unless otherwise shown.
Allowable Subject Matter
Claim 30 is allowable with the following rewrite as new claim 31 to correct for clarity (the throughput and LRV are for the stack), correct a typo, and add the units for throughput:
31. (New) An asymmetric membrane comprising:
a stack of at least two asymmetric membrane sheets stacked adjacent to each other in series, each asymmetric membrane sheet comprising
a membrane wall with a first and a second porous surface and an interior situated between the surfaces;
a first asymmetrical region towards the first surface,
a second asymmetrical region towards the second surface;
wherein the asymmetric membrane sheet is made from a polymeric blend comprising polyethersulfone, sulfonated polyether sulfone, and a poly(2-oxazoline); and
wherein said asymmetric membrane provides an LRV in L. brevis CFU count in the range of about 5 to about 8; and
wherein said asymmetric membrane provides a throughput in the range of about 1500 to about 5800 L/(m2.bar) when filtering a beer.
Response to Arguments
Applicant's arguments filed 4/29/26 have been fully considered but they are not persuasive. Ansorge teaches other hydrophilic polymers as disclosed by the applicant, which are alternates to PVP.
The argument that Ansorge teaches PVP as especially preferred does not negate the cited general teaching and preferred additives in Ansorge.
The argument that Hu teaches away from the combination is also unpersuasive. First of all, the claims do not require that the membrane is hydrophilic, the reason why PVP or other hydrophilic polymers are added to the membrane formulations. Hu was cited only to show that adding the polyoxazoline results in higher mechanical strength. Hu example 1 has no PVP Therefore, this argument is not commensurate in scope with claims and the rejection. Secondly, the argument that Hu teaches away is also otherwise unpersuasive. Hu has specific examples, which all show that the claimed invention is known or obvious. Hu does teach that PVP retains the hydrophilicity even after hours of Soxhlet extraction in boiling alcohol for many hours, very extreme conditions of extraction. However, this does not constitute a disparaging teaching, or “teaching away.” Hu does not teach that any membrane that does not have PVP is no good.
For applicant to overcome this strong case of obviousness, applicant must show secondary evidences in support, which are not forthcoming in the arguments or in the disclosure.
Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971). "A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use." In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994) (The invention was directed to an epoxy impregnated fiber-reinforced printed circuit material. The applied prior art reference taught a printed circuit material similar to that of the claims but impregnated with polyester-imide resin instead of epoxy. The reference, however, disclosed that epoxy was known for this use, but that epoxy impregnated circuit boards have "relatively acceptable dimensional stability" and "some degree of flexibility," but are inferior to circuit boards impregnated with polyester-imide resins. The court upheld the rejection concluding that applicant’s argument that the reference teaches away from using epoxy was insufficient to overcome the rejection since "Gurley asserted no discovery beyond what was known in the art." Id. at 554, 31 USPQ2d at 1132.). Furthermore, "[t]he prior art’s mere disclosure of more than one alternative does not constitute a teaching away from any of these alternatives because such disclosure does not criticize, discredit, or otherwise discourage the solution claimed…." In re Fulton, 391 F.3d 1195, 1201, 73 USPQ2d 1141, 1146 (Fed. Cir. 2004).In honoring applicant’s request for an interview, such an interview was conducted as detailed in the attached interview summary.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KRISHNAN S MENON whose telephone number is (571)272-1143. The examiner can normally be reached Flexible, but generally Monday-Friday: 8:00AM-4:30PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Prem Singh, 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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/KRISHNAN S MENON/ Primary Examiner, Art Unit 1771
