DETAILED ACTION
This action is in response to the RCE amendments and remarks filed 05/21/2026, in which claims 1, 6-7 and 12 have been amended and claims 1-4 and 6-15 are pending and ready for examination.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 05/21/2026 has been entered.
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 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 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-4, 6 and 10-12 are rejected under 35 U.S.C. 103 as being unpatentable over S.Sh. Homaeigohar, K. Buhr, K. Ebert, Polyethersulfone electrospun nanofibrous composite membrane for liquid filtration, Journal of Membrane Science, Volume 365, Issues 1–2, 2010, Pages 68-77 (hereinafter “Homaeigohar”) in view of X. Tang et al., "Development and characterisation of nanofiber films with high adhesion," 2011 IEEE 61st Electronic Components and Technology Conference (ECTC), Lake Buena Vista, FL, USA, 2011, pp. 673-677 (hereinafter “Tang”).
Regarding Claim 1 Homaeigohar discloses a filter element (Fig. 2) comprising a filtration media for use in fluid filtration applications, wherein the filtration media comprises:
a first layer on an upstream side of the self-cleaning filtration media, the first layer comprising polyethersulfone nanofibers having a diameter of 260±110 nm (i.e. 150-370 nm); and
a second layer (see Sec. 3.2. and 4) on a downstream side of the self-cleaning filtration media, the second layer comprising a PET nonwoven substrate; and
wherein the first layer is coated onto the second layer (electrospun directly onto), and an upstream surface of the filter element is a surface of the first layer; Abstract, Introduction, Sec. 2.2., Table 2.
With specific regard to the PES nanofiber first layer being on the upstream side of the second supporting layer, it is disclosed that the PET nonwoven is disclosed as a “sub-layer” and the particles when filtered accumulate on the surface of the nanofibers as the uppermost layer (see Fig. 13 and 3.3.3. Retention tests with particle suspensions ), and therefore the nanofiber layer must be the upstream layer and/or would have been obvious to make the upstream layer.
Homaeigohar does not disclose the first layer further comprising an adhesive with the adhesive and the polyethersulfone nanofibers electrospun simultaneously such that the adhesive is applied at the same time the polyethersulfone nanofibers are being formed.
However Tang discloses electrospinning a nanofiber mat wherein hotmelt was added into the electrospinning solution, in addition to the fiber polymer, to improve the adhesion properties of the film, and resulted in films having a shear strength 2 times better than the case without the hotmelt addition (Abstract, Experimental Procedure).
Therefore, at the time of filing, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter media of Homaeigohar by adding hotmelt adhesive into the electrospinning solution with the polyethersulfone as disclosed by Tang in order to improve the adhesion properties of the nanofiber film including shear stress.
The hotmelt adhesive in the electrospinning solution with the polyethersulfone thus results in the adhesive and the polyethersulfone nanofibers electrospun simultaneously such that the adhesive is applied at the same time the polyethersulfone nanofibers are being formed, as claimed.
Note: With regard to the filtration media being “self-cleaning” or “for use in hydrocarbon fluid filtration applications” this is a functional limitation which is not limiting because the structure disclosed by Homaeigohar in view of Tang would be capable of “self-cleaning” or “for use in hydrocarbon fluid filtration applications”; Claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function (see MPEP 2114).
Regarding Claims 2-3 Homaeigohar in view of Tang discloses the filter element of claim 1, wherein the polyethersulfone nanofibers have a diameter of 260±110 nm (i.e. 150-370 nm); Homaeigohar Table 2.
Since the range disclosed overlaps the range claimed, the range recited in the claim is considered prima facie obvious. Overlapping ranges are prima facie evidence of obviousness. It would have been obvious to one having ordinary skill in the art to have selected the portion of the disclosed range that corresponds to the claimed range. See MPEP 2144.05(I).
Regarding Claim 4 Homaeigohar in view of Tang discloses the filter element of claim 1, wherein the polyethersulfone nanofibers of the first layer are electrospun onto the second layer, Homaeigohar Introduction, Sec. 2.2.
Regarding Claim 6 Homaeigohar in view of Tang discloses the filter element of claim 1, wherein the adhesive is electrospun with the polyethersulfone in an amount of 0 to 5 wt% (Tang pg. 674, left column, bottom paragraph).
Regarding Claim 10 Homaeigohar in view of Tang discloses the filter element of claim 1, which is inherently chemically resistant to gasoline, petroleum, alcohols, engine oil, and transmission oil due to the PES and PET polymer materials inherent properties; see MPEP 2112.02.
Regarding Claim 11 Homaeigohar in view of Tang discloses the filter element of claim 1, wherein the nonwoven substrate of the second layer is disclosed to only be composed of PET and thus is expected to be free of glass fibers.
Regarding Claim 12 Homaeigohar in view of Tang discloses the filter element of claim 1, wherein the nonwoven substrate of the second layer comprises PET, i.e. synthetic fibers.
Claims 7-9 and 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over Homaeigohar in view of Tang further in view of US 2012/0061332 Al (hereinafter “Kas”) and US 2011/0079553 A1 (hereinafter “Thompson”).
Regarding claims 7-9 and 13-14 Homaeigohar in view of Tang discloses the filter element of claims 1 and 12, but does not disclose (claim 7) wherein the nonwoven substrate of the second layer comprises up to 20% by weight glass microfibers, (claim 8) wherein the wet laid nonwoven further comprises a resin applied to a weight of 10 % to 25 % of the weight of the wet laid nonwoven, or (claim 9) wherein the second layer comprises 3 % to 20 % glass microfibers, or (claim 13) wherein the nonwoven substrate of the second layer has a basis weight in a range of between 75 gsm and 200 gsm, or (claim 14) wherein the nonwoven substrate of the second layer comprises a resin applied to a weight of 10 % to 25 % of the weight of the nonwoven substrate.
However, with regard to the supporting layer, it is disclosed that the nanofibers are spun directly onto a stronger more rigid support in order to reduce problems with handling the nanofiber mats due to electrostatic charges during the electrospinning and uses a PET nonwoven, but does not disclose as specific reason for choosing the PET nonwoven, or the details of said PET nonwoven and therefore it is seen as obvious to substitute other nonwovens as there is no criticality to the PET nonwoven chosen (1. Introduction),
Further Kas discloses a similar composite nanofiber layer filter medium (Abstract), wherein the nanofibers may be made of polyether sulfone [0054]-[0055], and the porous supporting substrate may be made of various materials including nonwovens or paper [0061], wherein the nanofibers and the substrate are bonded to each other via heated means [0062]-[0068]. Thus the nanofibers would be expected to bond to paper in the heat treatment, such as disclosed by Homaeigohar.
Therefore, at the time of filing, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter media of Homaeigohar in view of Tang by substituting for the supporting layer a porous paper substrate as disclosed by Kas because this involves the simple substitution of known porous supporting layers for a PES nanofiber layer to obtain the predictable result of forming a successful supported PES nanofiber layer filtration media.
Kas is silent to the composition of the paper.
However, Thomson discloses a nonwoven filtration media which may include a mixture of microglass fibers with synthetic fibers, where the synthetic fibers may be “at least about 50 wt%” to and including 100% of the mixture [0055] with the reminder microglass and wherein the synthetic fibers including regenerated cellulose [0056], and may additionally include wood pulp cellulose [0058], and which may include a binder resin in the nonwoven filter media in an amount of less than about 10 wt% binder [0059]-[0060] and wherein the nonwoven may be formed by wetlaid processes , [0089],[0096]. Thus the media may comprise a wetlaid non-woven of 100 wt% cellulose fibers.
Therefore, at the time of filing, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter media of Homaeigohar in view of Tang and Kas by substituting for the paper supporting layer the cellulose wet laid nonwoven media as disclosed by Thomson because this involves the simple substitution of known porous paper filtration material for another to obtain the predictable result of successful paper supported filtration media formation.
Thus:
Regarding Claims 7 and 9 the second layer may comprise 0 to 50 wt% glass microfibers; Thomson [0055].
Regarding Claim 8 the wet laid nonwoven may further comprise a binder resin in an amount of less than about 10 wt% of the nonwoven Thomson [0059]-[0060]. The range of “less than about 10 wt%” is seen to overlap with the range claimed that stars at 10 wt% because “about 10 wt%” is seen to include values slightly over 10 wt%.
Regarding Claim 13 the nonwoven substrate of the second layer is that disclosed by Thomson which is disclosed to have a basis weight of from 20-200 gsm, [0064].
Regarding Claim 14 wherein the wet laid nonwoven may further comprise a binder resin a binder resin in an amount of less than about 10 wt% of the nonwoven Thomson [0059]-[0060]. The range of “less than about 10 wt%” is seen to overlap with the range claimed that stars at 10 wt% because “about 10 wt%” is seen to include values slightly over 10 wt%.
Since the range(s) disclosed overlaps the range(s) claimed, the range(s) recited in the claim is/are considered prima facie obvious. Overlapping ranges are prima facie evidence of obviousness. It would have been obvious to one having ordinary skill in the art to have selected the portion of the disclosed range(s) that corresponds to the claimed range. See MPEP 2144.05(I).
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Homaeigohar in view of Tang further in view of US 2004/0203306 A1 (hereinafter “Grafe”).
Regarding Claim 15 Homaeigohar in view of Tang discloses the filter element of claim 1, wherein the self-cleaning filtration media has a stiffness of at least 7,000 mg when measured according to TAPPI T489 om-92.
However Grafe discloses that typical stiffness values for filter media are about 350-12,000 mg according to TAPPI T-543 om-00; [0062], [0065].
Therefore, at the time of filing, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter media of Homaeigohar in view of Tang by forming the media to have a stiffness of from 350-12,000 mg according to TAPPI T-543 om-00 as disclosed by Grafe because this is a stiffness known to make functional filtration media.
While the testing standard is “TAPPI T-543 om-00” and not the “TAPPI T489 om-92”, they are similar test for the same stiffness values and are thus seen to be equivalent and/or close enough that the range disclosed would still overlap the range claimed. Since the range disclosed overlaps the range claimed, the range recited in the claim is considered prima facie obvious. Overlapping ranges are prima facie evidence of obviousness. It would have been obvious to one having ordinary skill in the art to have selected the portion of the disclosed range that corresponds to the claimed range. See MPEP 2144.05(I).
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1-12 and 14 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-18 of U.S. Patent No. 12,023,610 B2 in view of Tang. Although the claims at issue are not identical, they are not patentably distinct from each other because the claims of US‘610 largely anticipate the instant claims 1-12 and 14 as they contain all of the noted limitations except that it is not disclosed (with regard to claim 1) that the first layer further comprising an adhesive with the adhesive and the polyethersulfone nanofibers electrospun simultaneously such that the adhesive is applied at the same time the polyethersulfone nanofibers are being formed.
However Tang discloses electrospinning a nanofiber mat wherein hotmelt was added into the electrospinning solution, in addition to the fiber polymer, to improve the adhesion properties of the film, and resulted in films having a shear strength 2 times better than the case without the hotmelt addition (Abstract, Experimental Procedure).
Therefore, at the time of filing, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter media of US’610 by adding hotmelt adhesive into the electrospinning solution with the polyethersulfone as disclosed by Tang in order to improve the adhesion properties of the nanofiber film including shear stress.
The hotmelt adhesive in the electrospinning solution with the polyethersulfone thus results in the adhesive and the polyethersulfone nanofibers electrospun simultaneously such that the adhesive is applied at the same time the polyethersulfone nanofibers are being formed, as claimed.
Claim 13 is rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-18 of U.S. Patent No. 12,023,610 B2 in view of Tang and Thompson.
Claims 13 additionally recites wherein the nonwoven substrate of the second layer has a basis weight in a range of between 75 gsm and 200, which is not disclosed by the claims of US’610.
However Thomson discloses it is known to uses a basis weight of from 20-200 gsm [0064] in nonwoven filters, i.e. which may be used to support.
Therefore, at the time of filing, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter media of US’610 by using a basis weight of from 20-200 gsm as disclosed by Thomson because this involves the use of known functional basis weight for a nonwoven filter to obtain the predictable result of a functional filter.
Claim 15 is rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-18 of U.S. Patent No. 12,023,610 B2 in view of Tang and Grafe.
Claim 15 wherein the self-cleaning filtration media has a stiffness of at least 7,000 mg when measured according to TAPPI T489 om-92, which is not disclosed by the claims of US’610.
However Grafe discloses that typical stiffness values for filter media are about 350-12,000 mg according to TAPPI T-543 om-00; [0062], [0065].
Therefore, at the time of filing, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter media of US’610 by forming the media to have a stiffness of from 350-12,000 mg according to TAPPI T-543 om-00 as disclosed by Thomson because this is a stiffness known to make functional filtration media.
Response to Amendment
The previous 35 U.S.C. 112(b) rejections of claim 7-9 and 12-14 are withdrawn in view of the Applicants’ arguments and amendments.
Response to Arguments
Applicant's arguments filed 05/21/2026 have been fully considered and they are persuasive with regard to the previous combination of references as they would apply to the amended claims, but they are now moot because they are directed in their entirety to grounds of rejection which are no longer cited in the current action and the new limitations of the amended claims which had not been previously addressed. See the updated rejection above citing a new combination of references to address the amended claims.
Terminal Disclaimer
The terminal disclaimer filed 05/21/2026 is noted but has not been reviewed or approved and thus the Double Patent Rejections are maintained until the terminal disclaimer is approved.
Conclusion
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/ERIC J MCCULLOUGH/ Examiner, Art Unit 1773
/BENJAMIN L LEBRON/ Supervisory Patent Examiner, Art Unit 1773
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