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 .
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.
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, 6, 9 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Burkholder et al., US 2019/0201831 A1 in view of Walls et al., US 2011/0174158 A1.
Regarding claim 1, Burkholder teaches a filtration media comprising nanofiber layers, which reads on the “nanofiber filter.” See Burkholder [0002]. The filtration media can comprise three nanofiber layers attached to each other, with the nanofiber layers sandwiched between a substrate layer and a pre-filter nonwoven layer, and with the upstream-most nanofiber layer attached to the downstream surface (the effluent surface) of the pre-filter layer and with the downstream-most nanofiber layer attached to the upstream surface (the influent surface) of the substrate layer. See Burkholder [0024], [0026].
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The pre-filter layer reads on the “first support.” The upstream surface of the pre-filter layer reads on the “front surface” and the downstream surface of the pre-filter layer reads on the “rear surface opposite to the front surface.”
The first nanofiber layer reads on the “first nanofiber filter layer disposed on the rear surface of the first support.”
The second nanofiber filter layer reads on the “second nanofiber filter layer disposed on a rear surface of the first nanofiber filter layer.” Note that the downstream surface of the first nanofiber layer is its “rear surface.”
The third nanofiber filter layer reads on the “third nanofiber filter layer disposed on a rear surface of the second nanofiber filter layer.” Note that the downstream surface of the second nanofiber layer is its “rear surface.”
The substrate layer reads on the “second support disposed on a rear surface of the third nanofiber filter layer.” Note that the downstream surface of the third nanofiber layer is its “rear surface.”
The third nanofiber layer (indeed all of the nanofiber layers) can be manufactured from an electrospun mixture comprising nylon. See Burkholder [0039]. This mixture reads on an “electrospun hygroscopic nanomaterial mixture” because nylon is hygroscopic. See Park, US 2016/0175748 A1, [0119].
The second nanofiber layer (indeed all of the nanofiber layers) comprises an electrospun material made of a mixture of a polymer in a solvent with optional additives. See Burkholder [0039], [0040]. This mixture reads on the “electrospun gas suction material mixture.” Note that the mixture is capable of performing the function of being used in “gas suction” because a vacuum could be pulled across the second nanofiber layer as the nanofiber layer is incorporated into an air filter material. Id. at [0015]; MPEP 2114, subsection IV (functional claim language that is not limited to a specific structure covers all devices that are capable of performing the recited function).
Burkholder differs from claim 1 because it is silent as to the first nanofiber filter layer comprising an electrospun photocatalytic nanomaterial mixture.
But the nanofibers of all of the nanofiber layers (including the first nanofiber layer) are made using an electrospinning process where a polymer spinning solution is spun to form the fibers. See Burkholder [0039]. The base polymer of the polymer spinning solution is selected from various polymers, including nylon. Id. Also, various additives can be applied to the polymer spinning solution to enhance certain attributes of the nanofibers, such as odor absorption or to improve mold resistance of the nanofibers. Id. at [0040].
With this in mind, Walls teaches an air filter material comprising electrospun nanofibers, made from a polymer such as nylon, where the nanofibers comprise photocatalytic nanoparticles included in the nanofibers. See Walls [0080], [0120], [0153]. The nanoparticles are an additive that can be incorporated into the fibers during electrospinning. Id. at [0145]. The photocatalytic nanoparticles are beneficial because they provide biocidal properties to the nanofibers. Id. at [0153].
It would have been obvious for the nanofibers of at least the first layer of Burkholder to comprise the photocatalytic nanoparticles of Walls to provide a biocidal additive to the nanofibers, because Burkholder teaches that the nanofibers can comprise various additives to perform functions such as reduce odor or mold and Walls teaches photocatalytic nanoparticles that can be added to electrospun nanofibers to act as a biocide (which could reduce odor and mold, as well as eliminate other microbes). With this modification, the electrospun nanofibers of the first layer of Burkholder comprise an “electrospun photocatalytic nanomaterial mixture,” as claimed.
Regarding claim 6, Burkholder in view of Walls teaches that the “photocatalytic nanomaterial mixture” comprises titania nanoparticles, which are “visible light-sensitive photocatalytic nanoparticles,” as claimed. because exposure to light produces free radicals. See Walls [0153].
Regarding claim 9, Burkholder teaches that the filtration media (the “nanofiber filter”) is configured to filter odor. See Burkholder [0040].
Regarding claim 16, Burkholder teaches a filtration media comprising nanofiber layers, which reads on the “nanofiber filter.” See Burkholder [0002]. The filtration media can comprise three nanofiber layers attached to each other on the upstream (influent) surface of a substrate, and four nanofiber layers attached to each other on the downstream (effluent) surface of a substrate. Id. at [0024] (1 to 8 additional nanofiber layers may be coated on top of the two nanofiber layers and/or on the other side of the filtration media substrate). Also, a prefilter layer can be provided on the upstream surface the upstream-most nanofiber layer. Id. at [0026].
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The pre-filter layer reads on the “first support.” The upstream surface of the pre-filter layer reads on the “front surface” and the downstream surface of the pre-filter layer reads on the “rear surface opposite to the front surface.”
The first, second and third nanofiber layers collectively read on the “first nanofiber filter including first, second, and third nanofiber filter layers disposed on the rear surface of the first support.”
The substrate layer reads on the “second support disposed on a rear surface of the first nanofiber filter.” Note that the downstream surface of the third nanofiber layer is the “rear surface of the first nanofiber filter.”
The fourth, fifth and six nanofiber layers read on the “second nanofiber filter including fourth, fifth and sixth nanofiber filter layers disposed on a rear surface of the second support.” Note that the downstream surface of the substrate layer is the “rear surface of the second support.”
The seventh nanofiber layer reads on the “third support disposed on a rear surface of the second nanofiber layer.” Note that the downstream surface of the sixth nanofiber layer is the “rear surface of the second nanofiber filter.” Note also that the seventh nanofiber layer will provide at least some support to the filtration media because it is a piece of material that is attached to the filtration media.
The third and sixth nanofiber layers (indeed all of the nanofibers layers) can be manufactured from an electrospun mixture comprising nylon. See Burkholder [0039]. This mixture reads on an “electrospun hygroscopic nanomaterial mixture” because nylon is hygroscopic. See Park, US 2016/0175748 A1, [0119].
The second and fifth nanofiber layers (indeed all of the nanofiber layers) comprises an electrospun material made of a mixture of a polymer in a solvent with optional additives. See Burkholder [0039], [0040]. This mixture reads on the “electrospun gas suction material mixture.” Note that the mixture is capable of performing the function of being used in “gas suction” because a vacuum could be pulled across the second and fifth nanofiber layers as the nanofiber layer is incorporated into an air filter material. Id. at [0015]; MPEP 2114, subsection IV (functional claim language that is not limited to a specific structure covers all devices that are capable of performing the recited function).
Burkholder differs from claim 16 because it is silent as to the first and fourth nanofiber filter layers comprising an electrospun photocatalytic nanomaterial mixture.
But the nanofibers of all of the nanofiber layers (including the first and fourth nanofiber layers) are made using an electrospinning process where a polymer spinning solution is spun to form the fibers. See Burkholder [0039]. The base polymer of the polymer spinning solution is selected from various polymers, including nylon. Id. Also, various additives can be applied to the polymer spinning solution to enhance certain attributes of the nanofibers, such as odor absorption or to improve mold resistance of the nanofibers. Id. at [0040].
With this in mind, Walls teaches an air filter material comprising electrospun nanofibers, made from a polymer such as nylon, where the nanofibers comprise photocatalytic nanoparticles included in the nanofibers. See Walls [0080], [0120], [0153]. The nanoparticles are an additive that can be incorporated into the fibers during electrospinning. Id. at [0145]. The photocatalytic nanoparticles are beneficial because they provide biocidal properties to the nanofibers. Id. at [0153].
It would have been obvious for the nanofibers of at least the first layer of Burkholder to comprise the photocatalytic nanoparticles of Walls to provide a biocidal additive to the nanofibers, because Burkholder teaches that the nanofibers can comprise various additives to perform functions such as reduce odor or mold and Walls teaches photocatalytic nanoparticles that can be added to electrospun nanofibers to act as a biocide (which could reduce odor or mold, as well as eliminate other microbes). With this modification, the electrospun nanofibers of the first and fourth layers of Burkholder comprise an “electrospun photocatalytic nanomaterial mixture,” as claimed.
Claims 2 and 3 are rejected under 35 U.S.C. 103 as being unpatentable over Burkholder et al., US 2019/0201831 A1 in view of Walls et al., US 2011/0174158 A1 and in further view of Braeunling et al., US 2006/0016340 A1.
Regarding claims 2 and 3, Burkholder teaches that the pre-filter layer (the “first support”) and the substrate layer (the “second support”) each comprise a breathable material. See Burkholder [0027], [0037].
Burkholder as modified differs from claim 2 because it is silent as to the substrate and prefilter layers being transparent or translucent. Burkholder differs from claim 3 because it is silent as to the substrate and prefilter layers each comprising at least one of a hydrophilic polymer material, a hydrophobic polymer material or a decomposable polymer material.
But Burkholder teaches that the prefilter and substrate layers can be made from synthetic nonwoven materials. See Burkholder [0027], [0037]. Burkholder also teaches that the substrate layer can be made from various polymers, including polyolefin or polysulfone. Id. at [0037].
With this in mind, Braeuling teaches a filtration media comprising a prefilter made of PES (polyethersulfone). See Braeuling [0018]. It would have been obvious for the prefilter and substrate layers to be manufactured from polyethersulfone because this would merely represent the selection of a known material based on the suitability of its intended use. See MPEP 2144.07.
With this modification, the substrate and prefilter layers would be transparent because polyethersulfone is a transparent resin (claim 2). See Park, US 2016/0193555 A1, [0075]. The substrate and prefilter layers would also comprise a hydrophobic polymer material because polyethersulfone is hydrophobic (claim 3). See Nazir et al., US 2013/0323383 A1, [0016].
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Burkholder et al., US 2019/0201831 A1 in view of Walls et al., US 2011/0174158 A1 and in further view of Taylor et al., US 2013/0125748 A1.
Regarding claim 4, Burkholder teaches the limitations of claim 1, as explained above.
Burkholder differs from claim 4 because it is silent as to the pre-filter layer (the “first support”) and the substrate layer (the “second support”) each comprising at least one of a metal mesh member or a breathable transparent film.
But Taylor describes an air filter medium comprising a support layer on either side of the air filter medium. See Taylor [0023]. The support layer is made of a metallic wire mesh. Id. The support layer is beneficial because it allows the filter medium to retain its desired shape. Id.
It would have been obvious for the filtration media of Burkholder to comprise a support layer of Taylor on the upstream surface of the prefilter layer and the downstream surface of the substrate layer to allow the filtration media to retain its desired shape.
With this modification, the substrate layer and its support layer collectively read on the “first support” and the prefilter layer and its support layer collectively read on the “second support.” Therefore, this combination reads on “each of the first support and the second support comprises at least one of a metal mesh member” because the support layer of Taylor comprises a metallic wire mesh.
Response to Arguments
The Applicant argues that it would not have been obvious to modify the nanofibers of Burkholder to include the photocatalytic nanoparticles of Walls, asserting that this combination is impermissible hindsight. See Applicant Rem. filed November 26, 2025 (“Applicant Rem.”) 7. The Applicant argues that the rejection selectively extracts features from Walls and retrofits them into only the first nanofiber layer of the multi-layer structure of Burkholder, with arguing that there is no motivation to apply a photocatalytic material specifically to that layer. Id. The Applicant acknowledges that Burkholder teaches that additives may be introduced during electrospinning, and that the nanofiber layers may differ in diameter or polymer composition. Id. But the Applicant argues that there is no rationale for applying different functional materials to different layers. Id. The Applicant also argues that Burkholder teaches that the nanofiber layers are made of thermoplastic polymers whereas the titania photocatalyst of Walls is not a thermoplastic. Id.
The Examiner respectfully disagrees. Burkholder teaches that the polymer spinning solution used to make the electrospun nanofibers can include various additives, to perform functions such as reduce odor and improve mold resistance of the nanofibers. See Burkholder [0040]. The photocatalytic nanoparticles of Walls can be added to electrospun nanofibers during the electrospinning process, and provide biocidal function to the nanofibers. See Walls [0145], [0153]. Also, the growth of microbes are known to cause bad odors on fibers used in filtration (see e.g., Ito, US 2018/0080149 A1, [0003]) and biocides are conventionally applied to filter materials to protect against mold (see e.g., Scope et al., US 2016/0296871 A1, [0013]). Therefore, it is not impermissible hindsight to use the photocatalytic nanoparticles of Walls with the electrospun nanofibers of Burkholder, because Burkholder teaches that the nanofibers can include additives to perform functions such as reduce odor or mold growth, while the photocatalytic nanoparticles of Walls can be incorporated into electrospun fibers to provide biocidal function (which could reduce odor or mold growth).
The Examiner also respectfully disagrees with the Applicant’s argument that the rejection “selectively extracts features from Walls and retrofits them into only the first nanofiber layer of Burkholder.” See Applicant Rem. 7. Claims 1 and 16 are written with the open-ended transitional phrase “comprising” and there is nothing in the claim to prevent the second, third, fifth or sixth layers from also comprising photocatalytic nanomaterial. Also, the rejection acknowledges that it would have been obvious to include the photocatalytic nanoparticles of Walls with at least the first and fourth layers of Burkholder, indicating that the other nanofiber layers could include the photocatalytic nanoparticles as well.
Also, with respect to the Applicant’s argument that it would have been non-obvious to use the photocatalytic nanoparticles of Walls with the nanofibers of Burkholder because the titania photocatalyst particles are not polymeric—the Examiner respectfully disagrees. The electrospun nanofibers of Walls are made of a polymer, such as nylon (see Walls [0080], [0153]) with the nanoparticle catalyst (e.g., titania) being incorporated into the fibers during formation (id. at [0145]). Likewise, the electrospun fibers of Burkholder are made of a polymer, such as nylon, and the additive can be added to the polymeric spinning solution so that the additive is incorporated into the fiber. See Burkholder [0039]–[0040]. Therefore, incorporating the nanoparticles of Walls into the fibers of Burkholder would not involve replacing a polymer-based nanofiber with a non-polymeric photocatalytic compound, as proposed by the Applicant. Instead, the modification would involve incorporating the nanoparticles of Walls into the polymeric nanofibers of Burkholder, in a manner consistent with the teachings of Burkholder and Walls.
The Applicant further argues that the amendment to claim 1 now further recites a third nanofiber layer comprising an electrospun hygroscopic nanomaterial mixture and a second nanofiber layer comprising an electrospun gas-suction material mixtures. See Applicant Rem. 7. The Applicant argues that the amended claim requires a specific multi-layer arrangement where each nanofiber layer has distinct material properties. Id. The Applicant asserts that the rationale for applying the teaching of Walls to the first nanofiber layer of Burkholder, rather than to the second or third nanofiber layers, finds no support in either reference and therefore is impermissible hindsight. Id. at 7–8.
The Examiner respectfully disagrees. There is nothing in claim 1 to specify that the first, second and third nanofiber layers each have distinct material properties. Instead, each of the first, second and third nanofiber layers could comprise an electrospun photocatalytic nanomaterial mixture, a hygroscopic nanomaterial mixture and an electrospun gas suction material mixture, because the claim is written with the open-ended transitional phrase “comprising” and there is nothing to prevent all three layers from having these characteristics. Therefore, for instance, the electrospun nanofibers of each of the three nanofiber layers of Burkholder could be made of a base polymer of nylon—which reads on “the third nanofiber layer comprises an electrospun hygroscopic nanomaterial mixture” (as nylon is hygroscopic)—even though the other two layers are also made of nylon.
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 T. BENNETT MCKENZIE whose telephone number is (571)270-5327. The examiner can normally be reached Mon-Thurs 7:30AM-6:00PM.
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T. BENNETT MCKENZIE
Primary Examiner
Art Unit 1776
/T. BENNETT MCKENZIE/Primary Examiner, Art Unit 1776
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