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, 4, 7, 8 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Zinn et al., WO 2021/158726 A11.
Regarding claim 1, Zinn teaches an air filtration media, which reads on the claimed “filter media.” See Zinn [0013].
The filtration media comprises a “fiber substrate” made of a plurality of fibers. See Zinn [0017]. The substrate has at least two opposing surfaces because the filter media is interpreted as a substantially flat piece of material, with the reference describing the filtration media having “surfaces.” Id. at [0018]. One of the surfaces reads on the “first surface” and the opposing surface reads on the “opposing second surface.”
The filtration media also comprises metal oxide nanoparticles, made from oxides such as ZnO, TiO2, NiO, or oxides of copper, disposed within the substrate between the two surfaces. See Zinn [0017]–[0018], [0034], [0069]. The nanoparticles read on the claimed “nanoparticles.” See Zinn [0018].
Zinn teaches that the nanoparticles can be disposed within the substrate from the first surface to the second surface, as claimed, because the nanoparticles can be loaded “substantially uniform throughout” the air filtration medium (as opposed to being localized at or on the outer surface, e.g., within the top 3–4 layers). See Zinn [0078].
Zinn also teaches that an area density of the nanoparticles can decrease from the first surface towards the second surface, as claimed, because the nanoparticles can be distributed in a gradient fashion. See Zinn [0018].
Zinn further teaches that nanoparticles have a coverage density within the filtration media of 0.1 to 10 mg/in2, which converts to 0.155 to 15.5 g/m2. See Zinn [0065]. The prior art range of 0.155 to 15.5 g/m2 overlaps with the claimed range of “an add-on amount of the nanoparticles within the fiber substrate between the first surface and the second surface is about 2.0 grams/m2 (gsm) to about 20 grams/m2 (gsm),” establishing a prima facie case of obviousness.
It is noted that Zinn is silent as to an example where the nanoparticles are both distributed in a gradient and with the gradient extending from the first surface through the midpoint to the second surface. But it would have been obvious to combine the loading techniques such that the nanoparticles are distributed in a gradient fashion from the first surface through the midpoint to the second surface because Zinn teaches that the nanoparticles can be distributed in a gradient and can be extend from the first surface to the second surface. This reads on “nanoparticles disposed within the fiber substrate from the first surface to the second surface, wherein an area density of the nanoparticles decreases from the first surface towards the second surface.”
As noted, the metal oxide nanoparticles can be made of ZnO, TiO2, NiO, or oxides of copper. See Zinn [0017], [0034], [0069]. ZnO, TiO2, NiO, or oxides of copper are ceramic materials. See Oh et al., US 2020/0152907 A1 [0064], (“a ceramic material, for example TiO2 or ZnO”); Jin et al., US 5,725,938 col. 3, ll. 48–54 (ceramic powder includes copper oxides and NiO). This reads on “the nanoparticles comprise a material selected from…ceramic materials.”
Regarding claim 4, Zinn teaches that the metal nanoparticles are disposed adjacent to or near one of the surfaces (the “first surface”) in a greater number than the nanoparticles disposed adjacent to or near the other surface (“the “second surface”) because the nanoparticles are distributed in a gradient fashion near one of the surfaces. See Zinn [0018].
Regarding claims 7 and 8, Zinn teaches the limitations of claim 1, as explained above.
Zinn differs from claim 7 because it is silent as to the area density of the metal nanoparticles at the midpoint being about 25% of the area density of the nanoparticles at the first surface. Zinn differs from claim 8 because it is silent as to the area density of the metal nanoparticles at the second surface being about 50% of the area density of the nanoparticles at the first surface.
But the metal nanoparticles can be evenly distributed throughout the entire thickness of the filtration media, or can be distributed in a gradient fashion upon or near one or more surfaces of the filtration media. See Zinn [0018]. Also, the metal nanoparticles are provided in the filtration media to provide biocidal properties to the filtration media. Id. at [0017]. It would have been obvious to use routine experimentation to determine the optimal area density of the metal nanoparticles at the midpoint or the second surface of the filtration media in order to optimize the biocidal activity provided to the media (claims 7 and 8). See MPEP 2144.05, subsection II (where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation).
Regarding claim 10, the claim recites the limitations of—“the nanoparticles are entrained within a gas, individualized, and dispersed through the first surface of the fibrous substrate.” This limitation describes the process of manufacturing the filter media instead of its structure. Therefore, the limitations of claim 10 fail to patentability distinguish over the prior art. See MPEP 2113, subsection I (the patentability of a product does not depend on its method of production).
Claims 9, 12–14, 16, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Zinn et al., WO 2021/158726 A1 in view of Bruan et al., US 5,656,368.
Regarding claim 9, Zinn teaches the limitations of claim 1, as explained above.
Zinn differs from claim 9 because it is silent as to the substrate comprising fibers having a linear density of 3 denier or greater.
But Zinn teaches that the filtration media can be a face mask and can comprise polyester fibers. See Zinn [0136]. Zinn also teaches that the filtration media can be any porous construct through which air or gas may traverse, with the filtration media being loaded with nanoparticles. Id. at [0024].
With this in mind, Braun teaches a facemask comprising a nonwoven web of polymeric microfiber (referenced in Braun as the “NWPM”) comprising a mixture of 65 weight percent polypropylene microfibers and 35 weight percent of 6 denier polyester staple fibers polymer microfiber comprising 6 denier polyester fibers. See Braun col. 25, ll. 8–25. The web can be loaded with solid particles capable of interacting with the fluid being exposed (id. at col. 9, ll. 26–30) and the web is beneficial because it provides good filtration performance when incorporated into a filter, such as a facemask (id. at abstract). It would have been obvious to use the nonwoven web of Braun as the air filtration medium of Zinn to provide a filtration material usable in a facemask that provides good filtration performance. It also would have been obvious to use the nonwoven web of Braun as the air filtration medium of Zinn because this would merely represent the selection of a known material based on the suitability of its intended use. See MPEP 2144.07. This is because Zinn requires that the filtration media can be any porous construct through which air or gas may traverse that can be loaded with nanoparticles, while the nonwoven web of Braun is a porous material that gas can traverse and that can be loaded with solid particles. With this modification, the 6 denier polyester staple fibers reads on the “fibers having a linear density of 3 denier or greater.”
Regarding claims 12, 16 and 17, Zinn teaches a mask comprising air filtration media. See Zinn [0013]. The mask reads on the claimed “filter” and the air filtration media reads on the “filter media.”
The filtration media comprises a “substrate” made of a plurality of fibers having a diameter of about 10 microns, which reads on fibers having a diameter of greater than 1 micron. See Zinn [0017], [0136]. The substrate has at least two opposing surfaces because the filter media is interpreted as a substantially flat piece of material, with the reference describing the filtration media having “surfaces.” Id. at [0018]. One of the surfaces reads on the “first surface” and the opposing surface reads on the “opposing second surface.”
The filtration media also comprises metal oxide nanoparticles, made from oxides such as ZnO, TiO2, NiO, or oxides of copper, disposed within an internal structure of the substrate. See Zinn [0018]. The nanoparticles read on the claimed “nanoparticles.” The nanoparticles are distributed in a gradient fashion within the substrate. Id. at [0018]. This reads on “an add-on amount of the nanoparticles decreases from the first surface towards the second surface.”
The substrate has a “first area density in grams/m2, which is the basis weight of the filtration medium (not disclosed).
The nanoparticles in the substrate between the first and second surfaces have a “second area density in grams/m2” of 0.1 to 10 mg/in2, which converts to 0.155 to 15.5 g/m2. See Zinn [0065]. Note that this is the area density of the nanoparticles “between” the first and second surfaces, as claimed, at least because the nanoparticles extend to a depth of about 3–4 layers within the filtration medium. Id. at [0064].
As noted, the metal oxide nanoparticles can be made of ZnO, TiO2, NiO, or oxides of copper. See Zinn [0017], [0034], [0069]. ZnO, TiO2, NiO, or oxides of copper are ceramic materials. See Oh et al., US 2020/0152907 A1 [0064], (“a ceramic material, for example TiO2 or ZnO”); Jin et al., US 5,725,938 col. 3, ll. 48–54 (ceramic powder includes copper oxides and NiO). This reads on “the nanoparticles comprise a material selected from…ceramic materials.”
Zinn differs from claims 12, 16 and 17 because it is silent as to the basis weight of the air filtration medium. Therefore, the reference fails to provide enough information to teach the ratio of “first area density” (of the substrate) to the “second area density” (of the nanoparticles) being less than or equal to about 100, as claimed.
But Zinn teaches that the filtration media can be any porous construct through which air or gas may traverse, with the porous construct preferably comprising fibers. See Zinn [0024]. Also, as noted, the filtration media can be part of a facemask. Id. at [0013].
With this in mind, Braun teaches a facemask comprising a nonwoven web of polymeric microfiber (referenced in Braun as the “NWPM”). See Braun col. 25, ll. 8–25. The nonwoven web can be loaded with solid particles capable of interacting with the fluid being exposed. Id. at col. 9, ll. 26–30. The nonwoven web is beneficial because it provides good filtration performance when incorporated into a filter, such as a facemask. Id. at abstract. It would have been obvious to use the nonwoven web of Braun as the air filtration medium of Zinn to provide a filtration material usable in a facemask that provides good filtration performance. It also would have been obvious to use the nonwoven web of Braun as the air filtration medium of Zinn because this would merely represent the selection of a known material based on the suitability of its intended use. See MPEP 2144.07. This is because Zinn requires that the filtration media can be any porous construct through which air or gas may traverse that can be loaded with nanoparticles, while the nonwoven web of Braun is a porous material that gas can traverse and that can be loaded with solid particles.
With this modification, the nonwoven web of Braun has a basis weight of 100 g/m2. See Braun, Table 10, Example 11, col. 25, ll. 27–44. This basis weight of the nonwoven web reads on the “first area density” of the “fibers in the substrate.” Also, as noted, the nanoparticles of Zinn can be loaded within the filtration media in an amount of 0.1 to 10 mg/in2, which converts to 0.155 to 15.5 g/m2. See Zinn [0065]. This basis weight of the nanoparticles reads on the “second area density” of the “nanoparticles.” Therefore, the ratio of the density of the nonwoven media (the “first area density”) to the density of the nanoparticles (the “second area density”) ranges from 6 to 645. The range of 6 to 645 overlaps with the claimed ranges of less than or equal to about 100 (claim 12), less than or equal to about 67 (claim 16) and less than or equal to about 33.5 (claim 17), establishing a prima facie case of obviousness.
Regarding claims 13 and 14, Zinn teaches that the nanoparticles can be loaded in an amount of 0.1 to 10 mg/in2, which converts to 0.155 to 15.5 g/m2. See Zinn [0065]. The prior art range of 0.155 to 15.5 g/m2 is within the claimed range “the add-on amount of the nanoparticles within the fiber substrate is about 1 grams/m2 (gsm) to about 20 grams/m2 (gsm)” (claim 13) and overlaps with the claimed range of “the add-on amount is 2 grams/m2 (gsm) or greater,” establishing a prima facie case of obviousness (claim 14).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Zinn et al., WO 2021/158726 A1 in view of Smithies et al., US 2021/0121804 A1.
Regarding claim 11, Zinn teaches the limitations of claim 1, as explained above.
Zinn differs from claim 11 because it is silent as to the MERV rating and pressure drop of the filtration media. Therefore, the reference fails to provide enough information to teach the filtration media having a MERV rating of greater than about 10 and a pressure drop of less than about 0.5 inches of water.
But Smithies teaches a filtration media that can be used for various applications, including protective masks. See Smithies [0056]. The filtration media has a MERV rating from 9 to 18 and a pressure drop of 20 to 80 Pa (0.080 to 0.3 inches of water). Id. at [0049], [0055]. The filtration media of Smithies is beneficial because it meets the international test standards of 2018. It would have been obvious to use the filtration media of Smithies as the substrate of Zinn to provide a filter material that meets the international test standards of 2018.
Claims 18–20 are rejected under 35 U.S.C. 103 as being unpatentable over Zinn et al., WO 2021/158726 A1 in view of Bruan et al., US 5,656,368 in view of Smithies et al., US 2021/0121804 A1.
Regarding claims 18–20, Zinn teaches the limitations of claim 12, as explained above.
Zinn differs from claims 18–20 because it is silent as to the MERV rating and pressure drop of the filtration media. Therefore, the reference fails to provide enough information to teach the filtration media having a MERV rating of greater than about 10 and a pressure drop of less than about 0.5 inches of water (claim 18), a MERV rating of about 13 and a pressure drop of less than or equal to about 0.36 inches of water (claim 19) or a MERV rating of about 14 and a pressure drop of less than or equal to about 0.5 inches of water (claim 20).
But Smithies teaches a filtration media that can be used for various applications, including protective masks. See Smithies [0056]. The filtration media has a MERV rating from 9 to 18 and a pressure drop of 20 to 80 Pa (0.080 to 0.3 inches of water). Id. at [0049], [0055]. The filtration media of Smithies is beneficial because it meets the international test standards of 2018. It would have been obvious to use the filtration media of Smithies as the substrate of Zinn to provide a filter material that meets the international test standards of 2018.
Response to Arguments
35 U.S.C. 103 Rejections
The Applicant argues that Zinn does not teach nanoparticles comprising a material selected from the claimed group, which includes “ceramic materials.” See Applicant Rem. filed May 14, 2026 (“Applicant Rem.”) 5. Instead, it is argued that the air filtration media of Zinn comprises metal nanoparticles. Id.
The Examiner respectfully disagrees. Zinn teaches that the nanoparticles can be made from metal oxides, including ZnO, TiO2, NiO, or oxides of copper. See Zinn [0017], [0034], [0069]. ZnO, TiO2, NiO, or oxides of copper are ceramic materials. See Oh et al., US 2020/0152907 A1 [0064], (a ceramic material, for example TiO2 or ZnO); Jin et al., US 5,725,938 col. 3, ll. 48–54 (ceramic powder includes copper oxides and NiO).
The Applicant further argues that Zinn fails to describe dispersing nanoparticles through the depth of a substrate. See Applicant Rem. 7.
The Examiner respectfully disagrees. Zinn teaches that the filter medium can have nanoparticles either distributed throughout the air filtration medium (interpreted as from one surface to another) or the nanoparticles can be localized at or an outer surface of the filter medium. This is because paragraph [0078] says:
“Loading of metal nanoparticle agglomerates may be substantially uniform throughout an air filtration medium, or the metal nanoparticle agglomerates may be localized at or an outer surface of the air filtration medium (e.g., within the top 3-4 layers of a multilayer fabric).”
Therefore, because the nanoparticles can be loaded “throughout an air filtration medium” (and not merely at an outer surface), the Examiner maintains that the nanoparticles can be distributed within the filtration medium from the first surface and the second surface.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Hasan et al., US 2023/0292860 A1 (filter material with nanoparticles incorporated into nanofiber membrane); Choi et al., US 2022/0370937 A1 (air purifier comprising nanoparticles in inorganic particle layer 11 existing on top region A and side regions B of a substrate).
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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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jennifer Dieterle can be reached at 571-270-7872. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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T. BENNETT MCKENZIE
Primary Examiner
Art Unit 1776
/T. BENNETT MCKENZIE/Primary Examiner, Art Unit 1776
1 Zinn is in the record as the 59-page Foreign Reference filed August 15, 2023.
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