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 Objections
The limitation of “the step of allowing gas containing moisture to pass through the wall-flow type filter” in claim 14 should be “the step of allowing the gas containing moisture to pass through the wall-flow type filter”.
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.
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.
The claims are rejected as follows:
Claims 7, 9, 13–14, 16–20 are rejected under 35 U.S.C. 103 as being unpatentable over Sakon et al., JP 10249124 A (“Sakon”)1 in view of Murasaki et al., US 2012/0285148 A1 (“Murasaki”).
Regarding claim 7:
Sakon discloses that a method for producing a fine particle filter (Sakon’s step of producing a filter with a filter layer, Sakon Fig. 1a, p. 2),
comprising: a step of preparing an aerosol by mixing ceramic particles and air (Sakon’s step where air A and ceramic fine particles B are mixed, Sakon Fig. 1a, p. 2);
a step of allowing the aerosol to pass through the inside of a flow channel of a wall-flow type filter having a porous wall (Sakon’s step where mixed air A and ceramic fine particles B are supplied via supply pipe 24 into the porous support 11, which is a honeycomb structure, Sakon Fig. 1a, p. 2);
a step of supplying water in an amount of 30 g/L or more and 300 g/L or less with respect to the volume of the wall-flow type filter to the ceramic particles and the wall-flow type filter (Sakon’s step of supply steam C, which Sakon discloses could also be water, to the porous support 11, Sakon Fig. 1b, ps. 2–3);
and a step of drying the wall-flow type filter (Sakon discloses that the porous support 11 having the layered body adsorbed thereon is then dried and fired, Sakon Fig. 1, p. 2) to produce a ceramic layer on the porous wall of the wall-flow type filter (Sakon discloses a ceramic layer constituting the filter layer are formed on one side of the porous support, Sakon, [0007]).
Sakon does not explicitly disclose that the water is supplied in an amount of 30 g/L or more and 300 g/L or less with respect to the volume of the wall-flow type filter to the ceramic particles and the wall-flow type filter.
However, Sakon discloses in the step where water is used, a water injector 33 is attached to porous support 11 and water is supplied through water pipe 36 to the interior of the porous support 11. Sakon Fig. 1(c), p. 2. Sakon also discloses that introduced water is observed by a liquid level gauge 37, and when the liquid level reaches a predetermined height, the supply of water is stopped, and the water in the porous support 11 is quickly discharged, Sakon Fig. 1(c), p. 2. It is therefore concluded that the water supplied would be less than the porous support entire volume, i.e., the predetermined height has to be equal to or less than the height of the monolith structure as shown in Sakon’s Fig. 1(c). Assuming a honeycomb bulk volume (including partition wall is
V
h
), the maximum amount of water the honeycomb structure could accommodate would be less than
V
h
, denote as (
V
h
'
), because the solid portion of the partition wall of the honeycomb structure has to be excluded. Water load could be calculated by
V
h
'
×
(
w
a
t
e
r
d
e
n
s
i
t
y
)
V
h
, which would give a value less than water density, because
V
h
'
V
h
gives a value less than 1. Water density2 is 1000 g/L. Sakon’s water load is therefore less than water density of 1000 g/L, such range overlaps with the claimed range of 30 g/L or more and 300 g/L or less, and therefore support a prima facie case of obviousness. MPEP 2144.05(I). Additionally, it is understood that during the water injection process, water would gradually accumulate in the honeycomb structure before a predetermined height is reached, water supply would therefore accumulate from 0 g/L inside the wall-flow type filter to the calculated maximum of less than 1000 g/L. There would necessarily be a period of time, where water supply overlaps with the claimed range of 30 g/L and 300 g/L before it reaches the calculated maximum water supply.
Furthermore, the instant disclosure does not teach the claimed water load range is critical to the operation of the claimed invention, i.e., as evidenced by multiple claimed ranges in claims 7, 16–17. Therefore, absent evidence of criticality, this difference fails to patentably distinguish over prior art because it produces a different in degree rather than in kind. MPEP 2044.05 (III)(A).
Sakon also does not disclose that the ceramic layer having a porosity of 20% or more and 41% or less.
In the analogous art of wall-flow type filters comprising ceramic filtration layer, Murasaki discloses a substrate 14 including a porous base material 11 and a trapping layer 12, Murasaki Fig. 2, [0012]. Murasaki discloses its trapping layer could be made of ceramic materials, Id. Murasaki discloses its trapping layer 12 could have a porosity range preferably from 20% to less than 55%, Murasaki [0015]. Murasaki discloses its invention display high PM trapping (low pressure loss), Murasaki [0031]. It would therefore have been obvious for one ordinary skill in the art at the time of filing to modify Sakon’s ceramic layer to have a porosity similar to that disclosed by Murasaki realize high PM trapping and low pressure loss performance. With such modification, modified Sakon’s ceramic layer would have a porosity range overlaps with the claimed range and support a prima facie case of obviousness. MPEP 2144.05(I).
Additionally, the instant disclosure does not teach the claimed porosity range is critical to the operation of the claimed invention. Therefore, absent evidence of criticality, this difference fails to patentably distinguish over prior art because it produces a different in degree rather than in kind. MPEP 2044.05 (III)(A).
Regarding claim 9:
Modified Sakon discloses that the method for producing a fine particle filter according to claim 7, wherein the step of supplying water includes a step of allowing a gas containing moisture to pass through the wall-flow type filter (Sakon discloses that the step of suppling water could alternatively be supplying steam, which is essentially gas containing moisture to pass through the wall-flow type filter, Sakon Fig. 1(b), p. 2).
Regarding claim 13:
While modified Sakon does not explicitly disclose that the method for producing a fine particle filter according to claim 7, wherein an air stream passes through the porous wall of the wall-flow type filter during the step of allowing the aerosol to pass through the inside of the flow channel and also during the subsequent step of supplying water to the ceramic particles and the wall-flow type filter, Sakon does not disclose its steps are performed in vacuum, which means there would necessary be air flow accompanying the entire manufacturing process, and the suction device would cause air to flow through the inside of flow channel, Sakon Fig. 1(b), p. 2.
Regarding claim 14:
Modified Sakon disclose that the method for producing a fine particle filter according to claim 9, wherein the step of drying is by heating that is initiated following stoppage of the step of allowing gas containing moisture to pass through the wall-flow type filter (Sakon discloses that when the step of supply steam C is stopped, the layered body is “then dried and fired”, the fired process would necessarily involve heating, and such step is initiated following stopping of the supplying steam C, Sakon Fig. 1(b), p. 2).
Regarding claim 16:
As stated in claim 7, Sakon discloses in the step where water is used, a water injector 33 is attached to porous support 11 and water is supplied through water pipe 36 to the interior of the porous support 11. Sakon Fig. 1(c), p. 2. Sakon also discloses that introduced water is observed by a liquid level gauge 37, and when the liquid level reaches a predetermined height, the supply of water is stopped, and the water in the porous support 11 is quickly discharged, Sakon Fig. 1(c), p. 2. It is therefore concluded that the water supplied would be less than the porous support entire volume, i.e., the predetermined height has to be equal to or less than the height of the monolith structure as shown in Sakon’s Fig. 1(c). Assuming a honeycomb volume (including partition wall) is Vh, the maximum amount of water the honeycomb structure could accommodate would be less than Vh, denote as Vh’, because some of volume is occupied by the partition wall portion of the honeycomb structure. Water load could therefore be calculated by Vh’ multiply water density (1000g/L) and then divide the value by Vh, which would give a value less than 1000 g/L, such range overlaps with the claimed range of 40 g/L or more and 200 g/L or less, and therefore support a prima facie case of obviousness. MPEP 2144.05(I).
Additionally, the instant disclosure does not teach the claimed water load range is critical to the operation of the claimed invention, i.e., as evidenced by multiple claimed ranges in claim 1, claims 16–17. Therefore, absent evidence of criticality, this difference fails to patentably distinguish over prior art because it produces a different in degree rather than in kind. MPEP 2044.05 (III)(A).
Regarding claim 17:
As stated in claim 7, Sakon discloses in the step where water is used, a water injector 33 is attached to porous support 11 and water is supplied through water pipe 36 to the interior of the porous support 11. Sakon Fig. 1(c), p. 2. Sakon also discloses that introduced water is observed by a liquid level gauge 37, and when the liquid level reaches a predetermined height, the supply of water is stopped, and the water in the porous support 11 is quickly discharged, Sakon Fig. 1(c), p. 2. It is therefore concluded that the water supplied would be less than the porous support entire volume, i.e., the predetermined height has to be equal to or less than the height of the monolith structure as shown in Sakon’s Fig. 1(c). Assuming a honeycomb volume (including partition wall) is Vh, the maximum amount of water the honeycomb structure could accommodate would be less than Vh, denote as Vh’, because some of volume is occupied by the partition wall portion of the honeycomb structure. Water load could therefore be calculated by Vh’ multiply water density (1000g/L) and then divide the value by Vh, which would give a value less than 1000 g/L, such range overlaps with the claimed range of 50 g/L or more and 100 g/L or less, and therefore support a prima facie case of obviousness. MPEP 2144.05(I).
Additionally, the instant disclosure does not teach the claimed water load range is critical to the operation of the claimed invention, i.e., as evidenced by multiple claimed ranges in claim 1, claims 16–17. Therefore, absent evidence of criticality, this difference fails to patentably distinguish over prior art because it produces a different in degree rather than in kind. MPEP 2044.05 (III)(A).
Regarding claim 18:
Modified Sakon discloses that the method for producing a fine particle filter according to claim 7, wherein the step of drying is initiated after stoppage of the step of supplying water (Sakon discloses after water is supplied to its porous support 11, the layered body is then dried and fired, Sakon Fig. 1(c), ps. 2–3).
Regarding claim 19:
While modified Sakon does not explicitly disclose that the method for producing a fine particle filter according to claim 7, wherein the step of supplying water is carried out at a temperature of 0 to 100°C, it would have been obvious for one ordinary skill in the art at the time of filing to understand such water supplying step has to be less than 100 °C, because at 100 °C, water turns into steam. Sakon therefore discloses a range overlaps with the claimed temperature range and support a prima facie case of obviousness. MPEP 2144.05(I).
Additionally, the instant disclosure does not teach the claimed temperature range is critical to the operation of the claimed invention, i.e., as evidenced by multiple claimed ranges in claims 19–20. Therefore, absent evidence of criticality, this difference fails to patentably distinguish over prior art because it produces a different in degree rather than in kind. MPEP 2044.05 (III)(A).
Regarding claim 20:
While Sakon does not explicitly disclose that the method for producing a fine particle filter according to claim 7, wherein the step of supplying water is carried out at a temperature of 0 to 50°C, it would have been obvious for one ordinary skill in the art at the time of filing to understand such water supplying step has to be less than 100 °C, because at 100 °C, water turns into steam. Sakon therefore discloses a range overlaps with the claimed temperature range and support a prima facie case of obviousness. MPEP 2144.05(I).
Additionally, the instant disclosure does not teach the claimed temperature range is critical to the operation of the claimed invention, i.e., as evidenced by multiple claimed ranges in claims 19–20. Therefore, absent evidence of criticality, this difference fails to patentably distinguish over prior art because it produces a different in degree rather than in kind. MPEP 2044.05 (III)(A).
Claims 8, 15 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Sakon in view of Murasaki and Sato et al., US 2011/0262639 A1 (“Sato”).
Regarding claim 8:
Modified Sakon does not disclose that the method for producing a fine particle filter according to claim 7, wherein the aerosol has a density of 0.001 g/m3 or more and 1 g/m3 or less.
In the analogous art of honeycomb structure manufacturing, Sato discloses a similar step of supplying gas containing ceramic particles to honeycomb cell to allow ceramic particles to adhere to the surfaces of the cells, Sato Fig. 3, [0009]. Sato discloses it is preferred to have an aerosol density to be 1 g/m3 or more, Sato [0014]. It would therefore have been obvious for one ordinary skill in the art at the time of filing for Sakon to have an aerosol density of 1 g/m3 as disclosed by Sato because Sato discloses an aerosol density of 1 g/m3 allows ceramics particles to form bridges and therefore save time spent for the membrane formation, Sato [0024]. With such modification, modified Sakon would have an aerosol range overlap with the claimed aerosol density and support a prima facie case of obviousness. MPEP 2144.05(I).
Additionally, the instant disclosure does not teach the claimed aerosol density is critical to the operation of the claimed invention. Therefore, absent evidence of criticality, this difference fails to patentably distinguish over prior art because it produces a different in degree rather than in kind. MPEP 2044.05 (III)(A).
Regarding claim 15:
Modified Sakon does not explicitly disclose that the method for producing a fine particle filter according to claim 13, wherein the passage of the air stream through the wall-flow type filter includes sucking air from an end of the wall-flow type filter that is opposite to an inlet end of the wall-flow type filter to which the aerosol and water are supplied.
In the analogous art of honeycomb structure manufacturing, Sato discloses a similar step of supplying gas containing ceramic particles to honeycomb cell to allow ceramic particles to adhere to the surfaces of the cells, Sato Fig. 3, [0009]. Sato discloses a fan structure 34 configured to suck air current through the cells of the plugged honeycomb filter and Sato’s fan 34 is located opposite to an inlet end of the wall-flow type filter 30 to which the aerosol is supplied, Sato Fig. 3, [0097]. Sato discloses its design suppress scattering of particles to reduce waste and improves manufacturing environment, Sato Fig. 3, [0016]. It would therefore have been obvious for one ordinary skill in the art at the time of filing for Sakon to have a similar design for the benefits disclosed. Such design involves locating the fan at an opposite side of inlet of aerosol.
Regarding claim 21:
Modified Sakon does not disclose that the method for producing a fine particle filter according to claim 7, wherein the ceramic particles have an average particle diameter (d50) of 1.5 µm or more or and less than 5 µm.
In the analogous art of honeycomb structure manufacturing, Sato discloses a similar step of supplying gas containing ceramic particles to honeycomb cell to allow ceramic particles to adhere to the surfaces of the cells, Sato Fig. 3, [0009]. Sato discloses the average particle diameter of the ceramic particles forming the trapping layer is preferably about 1 to 15 µm, Sato [0065]. Sato discloses such ceramic particle average diameter is preferable for the formation of trapping layer with an optimized pressure loss, Sato [0065]. It would therefore have been obvious for one ordinary skill in the art at the time of filing to modify Sakon’s ceramic particles to have an average diameter as disclosed by Sato for the benefits disclosed by Sato. With such modification, Sakon would have an average particle diameter overlapping the claimed range and therefore support a prima facie case of obviousness. MPEP 2144.05(I).
Additionally, the instant disclosure does not teach the claimed average particle size is critical to the operation of the claimed invention. Therefore, absent evidence of criticality, this difference fails to patentably distinguish over prior art because it produces a different in degree rather than in kind. MPEP 2044.05 (III)(A).
Claims 10–12 are rejected under 35 U.S.C. 103 as being unpatentable over Sakon in view of Murasaki, and in further view of Foerster et al., US 2021/0396167 A1 (“Foerster”).
Regarding claim 10:
Modified Sakon does not disclose that the method for producing a fine particle filter according to claim 7, including a step of washcoating an exhaust gas purification catalyst into the flow channel of the wall-flow type filter before the step of allowing the aerosol to pass through the inside of the flow channel of the wall-flow type filter.
Similar to modified Sakon, Foerster discloses a method of making wall-flow particulate filter. Foerster discloses a step of applying active coating made of catalytically active component in the channels, Foerster discloses the active coating is washcoat. Foerster Abstract and [0020]. Foerster discloses an additional step of applying dry powder-gas aerosol. Foerster Abstract. Foerster discloses such step simultaneously improve the catalytic activity and the degree of filtration efficiency with respect to the exhaust gas back-pressure. Id. It would have been obvious for one ordinary skilled in the art at the time of filing to include Foerster’s step of applying a washcoat made of catalytically active components, a step of washcoating an exhaust gas purification catalyst into the flow channel of the wall-flow type filter before the step of allowing the aerosol to pass through the inside of the flow channel of the wall-flow type filter for the benefits disclosed above.
Regarding claim 11:
Modified Sakon discloses that the method for producing a fine particle filter according to claim 10, wherein the step of washcoating produces an in-wall coating in the fine particle filter because Foerster discloses its catalytic coating could be a combination of on-wall coating and in-wall coating, Foerster [0004].
Regarding claim 12:
Modified Sakon discloses that the method for producing a fine particle filter according to claim 10, wherein the step of washcoating produces an on-wall coating in the fine particle filter because Foerster discloses its catalytic coating could be a combination of on-wall coating and in-wall coating, Foerster [0004].
Response to Arguments
Prior Art Rejections
The applicant argues that Sakon does not teach a step of supply water in an amount of 30 g/L or more and 300 g/L or less with respect to the volume of the water-flow type filter to the ceramic particles and the wall-flow type filter, Applicant Rem. dated Apr. 24, 2026 (“Applicant Rem.”) p. 5. The applicant argues that it is improper to invoke per se rules and the applicant reminds the examiner that rejections based on legal precedent must be explained and shown to apply facts at hands, and simply invoking a general principle without a fact specific explanation is insufficient to establish a prima facie case of obviousness. Id. The applicant further argues that Sakon does not disclose any range for a water load, let alone an overlapping range, Id. The applicant argues that the office calculates a presumed maximum water load range and uses the maximum value to establish a range covering all presumable workable values, which is improper. The applicant states that the rejection fails to identify a prior art teaching with an overlapping range as required and that the office cannot reply on reference that is silent with respect to the variable. The applicant argus that the reasoning amounts to per se rule of obviousness, and that the maximum value is presumed, and such reasoning would bar patentability to any variable that can be identified as having a maximum value and thus cannot be accepted as a sufficiently reasoned rationale in support of the obviousness, Id.
The examiner disagrees with the applicant regarding the water load range. First of all, the examiner points out that the maximum water load of 1000 g/L is not based on presumption. As clearly stated in the rejection section, it was carefully calculated based on the information provided by Sakon. Sakon clearly states in the step where water is used, a water injector 33 is attached to porous support 11 and water is supplied through water pipe 36 to the interior of the porous support 11, Sakon Fig. 1(c), p. 2. Sakon also teaches that introduced water is observed by a liquid level gauge 37, and when the liquid level reaches a predetermined height, the supply of water is stopped, and the water in the porous support 11 is quickly discharged, Sakon Fig. 1(c), p. 2. Based on the information provided by Sakon, the examiner concludes that the water supplied would be less than the porous support entire open volume, i.e., the predetermined height has to be equal to or less than the height of the monolith structure as shown in Sakon’s Fig. 1(c). Assuming a honeycomb bulk volume (including partition wall is
V
h
), the maximum amount of water the honeycomb structure could accommodate would be less than
V
h
, denote as (
V
h
'
), because the solid portion of the partition wall of the honeycomb structure has to be excluded. Water load could be calculated by
V
h
'
×
(
w
a
t
e
r
d
e
n
s
i
t
y
)
V
h
, which would give a value less than water density, because
V
h
'
V
h
gives a value less than 1. The only piece of information that is not directly obtained from Sakon is water density of 1000 g/L, which is basic science concept that a person or ordinary skill in the art is expected to understood. The examiner therefore provides detailed explanation of applicability to the facts of the case, which is sufficient to establish a prima facie case of obviousness, MPEP 2144. Additionally, it is understood that during the water injection process, water would gradually accumulate in the honeycomb structure before a predetermined height is reached, water supply would therefore accumulate from 0 g/L inside the wall-flow type filter to the calculated maximum of less than 1000 g/L. There would necessarily be a period of time, where water supply overlaps with the claimed range of 30 g/L and 300 g/L, which reads on the claimed step.
The applicant is also reminded that there is a second set of rejection reasoning regarding the criticality of the claimed water supply range, which the applicant fails to respond. The applicant is encouraged to show criticality of the claimed range for the examiner to reconsider the patentability of such range. “T[t]he law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims…In such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative the prior art range.” MPEP 2144.05(III)(A).
The applicant includes a further limitation of porosity and argues that Sakon fails to teach such limitation, Applicant Rem. p. 7.
In view of the amendment, the examiner relies on Murasaki to teach the claimed porosity range. Please see details in the claim rejection section.
New claim
New claim is rejected, please see details in the claim rejection section.
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 QIANPING HE whose telephone number is (571)272-8385. The examiner can normally be reached on 7:30-5:00 M-F.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jennifer Dieterle can be reached on (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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/Qianping He/Examiner, Art Unit 1776
1 Sakon is the 6-page FOR dated May. 31, 2023. A copy of machine translation is provided with the previous non-final office action. The examiner relies on the original document for the figure and machine translation for the text.
2 water density g/l - Google Search
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