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 .
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). The certified copy has been filed in parent Application No. 2023-051824, filed on 03/28/2023.
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.
Claim 1 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, 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.
Claim 1 recites the limitation “a porosity of the partition wall measured by the mercury press-in method is 55 to 70%.” There is insufficient antecedent basis for this limitation in the claim.
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 non-obviousness.
Claims 1-5 are rejected under 35 U.S.C. 103 as being unpatentable over Kishine et al. U.S. Pub. No. 20200306680 A1, October 01, 2020 (hereinafter “Kishine”) in view of Yoshiyama JP 7024698 B2, February 24, 2022 (hereinafter “Yoshiyama”).
Regarding claim 1, Kishine discloses a honeycomb filter (paragraph 0014) comprising: a pillar-shaped honeycomb structure (fig. 1, honeycomb structure 10) having a porous partition wall (fig. 1, partition wall 1) disposed so as to surround a plurality of cells (fig. 1, cells 2) which serve as a fluid through channel extending from a first end face to a second end face (paragraphs 0015 and 0034); and a plugging portion (fig. 1, plugging portion 5) provided at either an end on the first end face side or the second end face side of the cell (paragraphs 0034-0035); wherein a thickness of the partition wall is 190 to 240µm (see Table 1, 0.19mm to 0.24mm), a porosity of the partition wall measured by the mercury press-in method (paragraph 0048) is 50 to 70% (paragraph 0048).
However, Kishine fails to disclose that the honeycomb filter has an average pore diameter of the partition wall measured by the mercury press-in method is 20 to 25µm, and the partition wall has an average base material neck diameter of 11 to 18µm for a base material neck part in which an actual part of a porous base material constituting the partition wall is locally narrowed. Yoshiyama discloses the average pore diameter of the partition wall can be adjusted in the range of 12 to 30 µm (paragraph 0017), Yoshiyama further discloses a relationship between the average pore diameter and the average neck diameter, as the ratio of the average neck diameter to the average pore diameter of the partition wall is 0.2 or more (paragraph 0039). A POSITA would understand that controlling pore size and neck size is conventional practice and the neck diameter within the claimed range fall within normal design parameters when average pore diameter is in the claimed range.
Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the honeycomb filter by selecting a partition wall pore structure having diameters of about 20 to 25µm and corresponding neck diameters of about 11 to 18µm, because Yoshiyama discloses that such pore and neck dimensions are within the routine design space for cordierite porous walls measured by mercury press-in porosimetry (paragraph 0045).
Regarding claim 2, Kishine disclose a cordierite wall-flow honeycomb filter having partition walls with porosity measured by the mercury press in method and porosity values within the claimed range (table 1, paragraphs 0048 and 0055). Yoshiyama discloses control of pore size distribution within the porous partition wall of a honeycomb filter, including discussion of pore diameter distributions measured by mercury intrusion. Yoshiyama further discloses average pore diameter and discusses controlling pore neck structure to optimize filtration and pressure loss characteristics. Mercury intrusion provide cumulative pore volume distribution data, including volume percentages associated with pore diameters below specified thresholds (paragraphs 0069-0071). Controlling the proportion of fine pores to a small fraction of the total pore volume is a recognized result effective variable affecting filtration efficiency and pressure drop. Optimization of this lower diameter pore fraction to a value within 0.1-3.0% would have been a matter of routine design adjustment through control of raw materials particle size and pore former loading. MPEP 2144.05.
Regarding claim 3, Kishine disclose a cell density of the cells in the honeycomb structure, defined by the partition walls preferable ranges from 27 to 51 cells/cm.sup.2 and more preferably ranges from 31 to 47 cells/cm.sup.2 (Table 1, paragraph 0051). Because the claimed range corresponds to standard commercial cell densities known in the art, selection of a specific value within that known range constitute routine optimization of a result effective variable. It would have been obvious to one or ordinary skill in the art at the time of invention to select a cell density within the claimed range based on desired filtration and backpressure characteristics.
Regarding claim 4, Kishine discloses the material of the partition wall preferable includes at least one selected from a group composed of silicon carbide, cordierite, a silicon-silicon carbide composite material, cordierite-silicon carbide composite material (paragraph 0055). Yoshiyama discloses that the main component of the filter contains cordierite (paragraphs 0048-0050). Cordierite has long been recognized in the art as the conventional material for wall-flow diesel particulate filter due to its low thermal expansion coefficient, high thermal shock resistance, and suitability for forming porous honeycomb structures. It would have been obvious to a person or ordinary skill in the art at the time of the invention to form the partition wall of the honey comb filter from cordierite because cordierite is well-known and commonly used material for wall-flow exhaust filters and provides predictable advantages in thermal durability and manufacturability.
Regarding claim 5, Yoshiyama discloses a mercury intrusion porosimetry which provides percentile diameters, including D10, D50, and D90 values. When the average pore diameter is controlled within 20-25 µm, as recited in claim 1, the D10 value will necessarily fall below the average diameter and within a predictable proportional range of the distribution. A D10 value of 16-19 µm represents a typical lower percentile within a moderately narrow pore size distribution width centered at 20-25 µm (paragraph 0069-0071). Adjusting the distribution width through conventional control of the pore characteristics would have been obvious to one skilled in the art for routine optimization. The claimed D10 range does not represent a critical departure from the distribution expected from the pore structure taught by Yoshiyama.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MIRIAM N EZELUOMBA whose telephone number is (571)272-0110. The examiner can normally be reached Monday-Friday 8:00am-4:30pm.
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/M.N.E./Examiner, Art Unit 1776
/Jennifer Dieterle/Supervisory Patent Examiner, Art Unit 1776