DETAILED ACTION
This action is in response to the RCE with amendments and remarks filed 06/08/2026, in which claims 1, 14 and 16 have been amended, claims 21-26 have been newly added and claims 1-10, 14 and 16-26 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 06/08/2026 has been entered.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-10 and 14-20 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claims 1 and 14 recite the limitation “a second layer having many pores with a diameter of pores 4-13 μm as measured according to DIN ISO 4003:1990 at a pressure at which air passes across an entire surface of the second laver with an even distribution of bubbles without foaming”. However, the described process is seen to be indefinite, it recites "a pressure at which air passes across an entire surface of the second layer with an even distribution of bubbles without foaming", it is not clear what constitutes an "even distribution of bubbles", as even is a term of degree which is not further defined, it is further unclear whether the measured value is taken as soon as the "even distribution" of bubbles in achieved or if the flow is increased until just before foaming occurs. Foaming itself is confusing as the process produces bubbles, so what amount of bubbles is considered "foam". Further, the 4003:1990 process appears to be one where the bubble point is measured to be when the first bubbles form, thus this process claimed appears not to be in accordance with DIN ISO 4003:1990. It is further not clear if the second layer must haves pores spanning the full range 4-13 µm, or if the valve measured is a single number which must merely be in the range claimed. For purposes of examination it will be interpreted to read “a second layer having many pores with an average diameter of pores in the range of 4-13 μm as measured according to a bubble point method
Claims 2-10 and 16-20 are rejected for depending from an indefinite claim.
Claim Objections
Claim 21 is objected to because of the following informalities: “pore” in line 4 should be “pores”. Appropriate correction is required.
Claim Interpretation
“Densified meltblown” as claimed is seen to be defined by the instant specification to mean that it is “produced by calendaring using flat rolls such that the entire surface, i.e. all the fibers on the surface, of the meltblown nonwoven are partially melted to achieve the desired diameter of many pores”, and is specifically differentiated from calendaring where the calendar roll has a pattern of protrusions on its surface so that only discrete portions of the surface are melted, i.e. not the entire surface; P10/L24-P11/L2.
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 1-8, 14 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over US 2021/0077930 Al (hereinafter “Iiba”) in view of US 2012/0048115 Al (hereinafter “Crabtree”) and US 2020/0070075 A1 (hereinafter “Koppi”).
Regarding Claim 1 Iiba discloses a filter medium, comprising
a first layer (which may be a substrate [0143], [0180]); and
a second layer having a densified [0201] meltblown [0143]-[0144], [0167] layer having many pores,
wherein the pores have an average size (i.e. diameter) of 10.0 µm or less and 0.01 µm or more [0153]-[0154], and
where the average pore sizes can be measured by bubble point method (JIS Z 8703:1983) [0157].
Iiba does not disclose many pores with a diameter of 4-13 µm as measured according to DIN ISO 4003:1990 at a pressure at which air passes across an entire surface of the second layer with an even distribution of bubbles without foaming.
However, Crabtree discloses an air filter made from melt blown nonwoven, wherein “a very tight pore size distribution is provided for air flow” such that “more than 50 percent of the pores are from 4 to 8 microns in diameter”; [0042], [0053]-[0054].
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter medium of Iiba by using a very tight pore size distribution with more than 50 percent of the pores from 4 to 8 microns in diameter as disclosed by Crabtree because this diameter range is known to provide desirable filtration properties for a similar meltblown non-woven air filter.
The pore sizes of Iiba, and thus obviously in the combined invention, are determined by bubble point, and while not specifically DIN ISO 4003:1990, the values obtained would be expected to be the same as they are both bubble point methods for determining pore size. Further as more than 50 percent of the pores are from 4 to 8 microns in diameter, it is expected that the second layer inherently has many pores in the range 4-13 µm as measured according to DIN ISO 4003:1990 at a pressure at which air passes across an entire surface of the second layer with an even distribution of bubbles without foaming.
Further, Koppi discloses it is known to use DIN ISO 4003 to measure pore sizes by bubble point for a similar filter comprising a meltblown layer; [0009], [0013], [0033], [0034]
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to use pore sizes as measured by DIN ISO 4003 in the invention of Iiba in view of Crabtree, because they are known alternative means of measuring pore diameter by bubble point method. And while specifically DIN ISO 4003:1990 is not disclosed, it would have been obvious to use any version of DIN ISO 4003 including DIN ISO 4003:1990.
This is seen to result in a structure equivalent to a second layer having many pores with a diameter of pores 4-8 µm as measured according to DIN ISO 4003:1990 at a pressure at which air passes across an entire surface of the second layer with an even distribution of bubbles without foaming, as claimed.
Regarding Claim 2-3 Iiba in view of Crabtree and Koppi discloses the filter medium according to claim 1, wherein the second layer is a nonwoven and may be made by a dry laid process, including meltblown process; Iiba [0143]-[0144], [0167].
Regarding Claim 4 Iiba in view of Crabtree and Koppi discloses the filter medium according to claim 1, wherein the first layer may comprise cellulose [0143].
Regarding Claim 5 Iiba in view of Crabtree and Koppi discloses the filter medium according to claim 1, wherein the filter may be formed of a layered body having two or more layers of nonwoven fabrics [0199], and thus discloses at least three layers
Regarding Claim 6 Iiba in view of Crabtree and Koppi discloses the filter medium according to claim 1, wherein the second layer is a calendered/densified layer; Iiba [0201].
Regarding Claim 7 Iiba in view of Crabtree and Koppi discloses the filter medium according to claim 1, wherein the second layer comprises polyester fibers; Iiba [0131].
Regarding Claim 8 Iiba in view of Crabtree and Koppi discloses the filter medium according to claim 1, wherein the second layer comprises a calendered/densified meltblown layer; Iiba [0143]-[0144], [0167], [0201].
Regarding Claim 14 Iiba discloses a filter medium, comprising
a first layer (which may be a substrate [0143], [0180]); and
a second layer having a densified [0201] meltblown [0143]-[0144], [0167] layer having many pores,
wherein the pores have an average size (i.e. diameter) of 10.0 µm or less and 0.01 µm or more [0153]-[0154],
wherein the maximum pore size is 20.0 µm or less [0155],
and where the average and maximum pore sizes can be measured by bubble point method (JIS Z 8703:1983) [0157].
Iiba does not disclose many pores with a diameter of 4-13 µm as measured according to DIN ISO 4003:1990 at a pressure at which air passes across an entire surface of the second layer with an even distribution of bubbles without foaming, or that the maximum pore diameter is determined according to DIN ISO 4003:1990 at a pressure at which a first air bubble is visible.
However, Crabtree discloses an air filter made from melt blown nonwoven, wherein “a very tight pore size distribution is provided for air flow” such that “more than 50 percent of the pores are from 4 to 8 microns in diameter”; [0042], [0053]-[0054].
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter medium of Iiba by using a very tight pore size distribution with more than 50 percent of the pores from 4 to 8 microns in diameter as disclosed by Crabtree because this diameter range is known to provide desirable filtration properties for a similar meltblown non-woven air filter.
The pore sizes of Iiba, and thus obviously in the combined invention, are determined by bubble point, and while not specifically DIN ISO 4003:1990, the values obtained would be expected to be the same as they are both bubble point methods for determining pore size. Further as more than 50 percent of the pores are from 4 to 8 microns in diameter, it is expected that the second layer inherently has many pores in the range 4-13 µm as measured according to DIN ISO 4003:1990 at a pressure at which air passes across an entire surface of the second layer with an even distribution of bubbles without foaming.
Further, Koppi discloses it is known to use DIN ISO 4003 to measure pore sizes by bubble point for a similar filter comprising a meltblown layer; [0009], [0013], [0033], [0034]
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to use pore sizes as measured by DIN ISO 4003 in the invention of Iiba in view of Crabtree, because they are known alternative means of measuring pore diameter by bubble point method. And while specifically DIN ISO 4003:1990 is not disclosed, it would have been obvious to use any version of DIN ISO 4003 including DIN ISO 4003:1990.
This is seen to result in a structure equivalent to a second layer having many pores with a diameter of pores 4-8 µm as measured according to DIN ISO 4003:1990 at a pressure at which air passes across an entire surface of the second layer with an even distribution of bubbles without foaming; and a maximum pore diameter of 20 µm or less, wherein the maximum pore diameter is determined according to DIN ISO 4003:1990 at a pressure at which a first air bubble is visible, as claimed.
Regarding Claim 16 Iiba in view of Crabtree and Koppi discloses the filter medium of claim 14, wherein the second layer comprises fibers having an average diameter of 2.7 µm or less and 0.3 µm and more; Iiba [0133]-[0134]. 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).
Claims 9-10 and 17-20 are rejected under 35 U.S.C. 103 as being unpatentable over Iiba in view of Crabtree and Koppi further in view of US 2014/0130469 A1 (hereinafter “Nagy”).
Regarding Claims 9-10 and 17-20 Iiba in view of Crabtree and Koppi discloses the filter medium according to claims 1 and 14, wherein the filter may be formed of a layered body having two or more layers of nonwoven fabrics [0199], and thus discloses at least a third layer, and wherein the first, second and third layers each inherently have an air permeability and basis weight, but Iiba is silent to any specific value thereof, and thus does not disclose (claims 9 and 17) wherein the first layer has a first air permeability and the second layer has a second air permeability greater than the first air permeability, (claims 10 and 19) wherein the first layer has a first basis weight and the second layer has a second basis weight less than the first basis weight, (claim 18) wherein the third layer has a third air permeability greater than the second air permeability, or (claim 20) wherein the third layer has a third basis weight less than the second basis weight.
However Nagy discloses a similar multilayer nonwoven, wherein it is disclosed that a gradient in one or more properties may be formed across the thickness of layers/sublayers of the filter, those properties including air permeability and/or basis weight, [0089]-[0092]; and thus before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to form a gradient of air permeability and/or basis weight across all the layers of the filter of Iiba in view of Crabtree and Koppi because this is known to provide desirable filtration properties in a similar multilayer nonwoven filter.
Thus each layer will have different air permeabilities and/or basis weights then each of the other layers, where choosing which has the lower or higher air permeability or basis weight would be an obvious choice amongst a finite number of solutions.
Claims 21-26 are rejected under 35 U.S.C. 103 as being unpatentable over US 2021/0077930 Al (hereinafter “Iiba”) in view of US 2012/0048115 Al (hereinafter “Crabtree”).
Regarding Claim 21 Iiba discloses a filter medium (an air of liquid filter [0196]), comprising
a first layer comprising cellulose (where the filter may comprise a layer of cellulose spunbond nonwovens [0143], [0180]); and
a second layer having a densified [0201] meltblown [0143]-[0144], [0167] layer comprising polyester fibers [0131] and pores;
wherein the pores have an average size (i.e. diameter) of 10.0 µm or less and 0.01 µm or more [0153]-[0154].
Iiba does not disclose (1) wherein greater than 50% of the pores have a diameter of 4-13 μm.
However, with regard to (1) greater than 50% of the pores having a diameter of 4-13 μm, Crabtree discloses an air filter made from melt blown nonwoven, wherein “a very tight pore size distribution is provided for air flow” such that “more than 50 percent of the pores are from 4 to 8 microns in diameter”; [0042], [0053]-[0054].
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter medium of Iiba by using a very tight pore size distribution with more than 50 percent of the pores from 4 to 8 microns in diameter as disclosed by Crabtree because this diameter range is known to provide desirable filtration properties for a similar meltblown non-woven air filter.
Regarding Claim 22 Iiba in view of Crabtree discloses the filter medium of claim 21, wherein the polyester fibers comprise polybutylene terephthalate (PBT); Iiba [0131].
Regarding Claim 23 Iiba in view of Crabtree discloses the filter medium of claim 21, wherein the filter may be formed of a layered body having two or more layers of nonwoven fabrics [0199], and thus discloses at least three layers, but does not provide to details as to what the third layer would be, therefore it would have been obvious to include another of the layers as disclosed, i.e. such as a second spunbonded substrate layer. Further it is disclosed that the whole filter, i.e. all layers, may be subjected to densification/flat calendaring to regulate pore size[0201], and it is not required that the different layer have different pore sizes, and thus it would have been obvious to provide the same pore sizes for all the layers. Thus one of the spunbonded layers, i.e. which is a densified spunbond layer comprising fibers and pores, wherein more than 50 percent of the pores are from 4 to 8 microns in diameter, is in contact with the meltblown layer and may be considered part of the second layer as claimed.
Regarding Claim 24 Iiba in view of Crabtree discloses the filter medium of claim 23, wherein the fibers of the nonwoven fabric of the disclosure (i.e. seen to obviously include all the layers i.e. the densified spunbond layer and the densified meltblown layer) have an average diameter 2.7 µm or less and 0.3 µm and more; Iiba [0133]-[0134]. 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 25 Iiba in view of Crabtree discloses the filter medium of claim 24, wherein the fibers of the nonwoven fabric of the disclosure (i.e. seen to obviously include all the layers i.e. the densified spunbond layer and the densified meltblown layer and all of the fibers, i.e. more than 30%) have an average diameter 2.7 µm or less and 0.3 µm and more; Iiba [0133]-[0134]. 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 26 Iiba in view of Crabtree discloses the filter medium of claim 23, but does not disclose wherein the second layer has a thickness of greater than or equal to about 0.10 mm and less than or equal to about 0.5 mm.
However Crabtree discloses a composite air filter comprising a melt blown nonwoven, wherein the meltblown layer in combination with another layer (i.e. the meltblown polymeric fiber entanglement) has a thickness of at least about 0.25 mm to less than about 1 mm [0042], [0054].
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter medium of Iiba by using a thickness of 0.25-1mm for the second meltblown layer as disclosed by Crabtree because this thickness range is known to provide desirable filtration properties for a similar meltblown non-woven air filter.
Response to Arguments
Applicant's arguments filed 06/08/2026 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.
Regarding Applicants’ arguments directed to the 112(b) rejection of the term “many pores”, while the Examiner agrees that the new limitations are clearer than simply “many pores”, the process of pore diameter measurement as recited in the claims is still considered indefinite, see the above updated 112(b) rejections above.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Eric J. McCullough whose telephone number is (571)272-8885. The examiner can normally be reached Monday-Friday 10:00-6:00.
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/ERIC J MCCULLOUGH/ Examiner, Art Unit 1773
/BENJAMIN L LEBRON/ Supervisory Patent Examiner, Art Unit 1773
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