Prosecution Insights
Last updated: April 19, 2026
Application No. 18/296,830

CERAMIC FILTRATION ELEMENT

Non-Final OA §103
Filed
Apr 06, 2023
Examiner
HUANG, RYAN
Art Unit
1777
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Mann+Hummel Life Sciences & Environment Holding Singapore Pte. Ltd.
OA Round
1 (Non-Final)
52%
Grant Probability
Moderate
1-2
OA Rounds
3y 5m
To Grant
84%
With Interview

Examiner Intelligence

Grants 52% of resolved cases
52%
Career Allow Rate
283 granted / 544 resolved
-13.0% vs TC avg
Strong +32% interview lift
Without
With
+31.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 5m
Avg Prosecution
62 currently pending
Career history
606
Total Applications
across all art units

Statute-Specific Performance

§101
2.1%
-37.9% vs TC avg
§103
47.3%
+7.3% vs TC avg
§102
17.6%
-22.4% vs TC avg
§112
24.3%
-15.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 544 resolved cases

Office Action

§103
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 (EP20202296.8, filed 16 October 2020) under 35 U.S.C. 119 (a)-(d). Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Applicant’s claim for the benefit of a prior-filed application (CON of PCT/IB2021/059493, filed 15 October 2021) under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged. Election/Restrictions Applicant’s election without traverse of Invention I, Claims 1 and 3-11, in the reply filed on 12 November 2025 is acknowledged. Claims 12-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 12 November 2025. Applicant is reminded that upon the cancelation of claims to a non-elected invention, the inventorship must be corrected in compliance with 37 CFR 1.48(a) if one or more of the currently named inventors is no longer an inventor of at least one claim remaining in the application. A request to correct inventorship under 37 CFR 1.48(a) must be accompanied by an application data sheet in accordance with 37 CFR 1.76 that identifies each inventor by his or her legal name and by the processing fee required under 37 CFR 1.17(i). Claim Interpretation The claims recite “Z-ratio” and the related terms “D90” and “D10”. As defined in the Specification p0034: “the Z-[ratio] of layer x, i.e., Zx, is the quotient of the particle size D90 of the particles composing the layer and the particle size D10 of the same particles composing the layer”. Further, the terms “D90” and “D10” or more broadly, “Dx”, are each defined in the context of a sample of particles having disparate sizes; Dx represents the diameter of particles at which x% of all particles in the sample have diameters smaller than or equal to that diameter Dx (see p0028). The disclosure further states that the Dx value is “a number distribution of the particles” and indicates that the values of D10, D50, and D90 are determined by dynamic light scattering (p0028). Even further, the disclosure states that “[b]y approximation, it is understood that the pore size of a layer is about one fifth (i.e., 1/5 or 20%) of the mean particle size D50 of the primary particles forming the layer” (p0030). Thus, it is interpreted that if a prior art discloses a layer comprising inorganic particles as claimed and further discloses a pore size of the layer, a mean particle size D50 of the particles forming that layer is inherently approximately five times the disclosed pore size. Finally, it is noted that Claim 11 requires that the membrane layer (i.e., the separating layer or the discriminating layer) consists of either TiO2 particles or ZrO2 particles. Claim Objections Claim 1 is objected to because of the following informalities: “a ceramic support structure, wherein the ceramic support structure has a mean pore size”. Appropriate correction is required. 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 (i.e., changing from AIA to pre-AIA ) 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. Claim(s) 1 and 3-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over OYAMA et al. (US 2005/0172811 A1) in view of ONOZUKA et al. (US 2017/0259214 A1). Regarding Claim 1, OYAMA discloses a permselective asymmetric membrane comprising a set of graded porous intermediate layers between a porous support and a membrane material (p0035), wherein the porous intermediate layers are produced from a plurality of graded ceramic sol solutions with narrow, well-defined particle size distributions and are overlaid with a selective silica layer (i.e., a multilayered ceramic filtration element comprising a ceramic support structure…, a membrane layer and at least one intermediate layer between the ceramic support structure and the membrane layer; p0016). Although the prior art preferentially discloses silica and alumina layers, alternative materials taught by the art include zirconia, titania, silicon nitride, silicon carbide, and boron nitride (i.e., wherein all layers comprise particles of at least one ceramic compound selected from the group consisting of metal oxides, metal carbides and metal nitrides; p0052). As further shown in FIGs. 2-4, OYAMA discloses the intermediate layer being produced from ceramic sols having median particle sizes of 630, 200, 55, and 40 nm (p0048), which reads on the limitation requiring that wherein the at least one intermediate layer comprises particles with a particle size of D10 in the range of from 70 to 250 nm. As also further shown in FIGs. 3 and 4, the particle size distribution of each sol layer satisfies the limitation requiring the at least one intermediate layer comprises particles of the at least one ceramic compound with a Z-ratio D90/D10 of up to 4. PNG media_image1.png 200 372 media_image1.png Greyscale PNG media_image2.png 200 400 media_image2.png Greyscale OYAMA further discloses the porous intermediate layers are formed on an alumina porous support having a nominal pore size of 100 nm (p0045). Thus, OYAMA is deficient in disclosing the ceramic support structure having a mean pore size of from 0.5 to 1.5 µm. ONOZUKA discloses a porous support-zeolite membrane composite (abstract). The porous support is an inorganic porous support comprising a ceramic, including silica, alumina, zirconia, titania, etc. (p0036). Further, the prior art discloses the average pore size of the porous support is 0.5 µm or more and 1.5 µm or less (p0039), which reads upon the claimed range of a mean pore size of from 0.5 to 1.5 µm. ONOZUKA discloses that the average pore size is preferably within the disclosed ranges to increase permeation while maintaining strength (p0039). Thus, prior to the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to provide a ceramic support structure having a mean pore size of from 0.5 to 1.5 µm as taught by ONOZUKA for the ceramic porous support taught by OYAMA. Regarding Claim 3, modified OYAMA makes obvious the multilayered ceramic filtration element of Claim 1. OYAMA further discloses ceramic materials include zirconia, titania, silicon nitride, silicon carbide, and boron nitride (p0052). Regarding Claim 4, modified OYAMA makes obvious the multilayered ceramic filtration element of Claim 1. OYAMA further discloses the intermediate layer being produced from ceramic sols having median particle sizes of 630, 200, 55, and 40 nm (p0048) having the particle distributions shown in FIGs. 2-4 (circle line CH3COOH in FIG. 2, triangle line 0.07 in FIG. 3, and upside down triangle line 72 h in FIG. 4), which reads on the limitation requiring that wherein the at least one intermediate layer comprises particles with a particle size of D90 in the range of from 200 to 500 nm. Regarding Claim 5, modified OYAMA makes obvious the multilayered ceramic filtration element of Claim 1. OYAMA further describes that the intermediate sol layer was prepared by sequentially dipping the support in successive sol solutions having sequentially smaller particle diameters (p0047, p0049). Such a process would result in the claimed limitations of at least two intermediate layers, wherein a first intermediate layer is directly supported on the ceramic support structure and a second intermediate layer is directly supported on the first intermediate layer; or at least three intermediate layers, wherein a first intermediate layer is directly supported on the ceramic support structure, a second intermediate layer is directly supported on the first intermediate layer, and a third intermediate layer is directly supported on the second intermediate layer. Regarding Claims 6, 8, and 10, modified OYAMA makes obvious the multilayered ceramic filtration element of Claims 5 and 1. OYAMA further discloses all sol solutions include ceramic materials including zirconia, titania, silicon nitride, silicon carbide, and boron nitride (p0052). Regarding Claim 7, modified OYAMA makes obvious the multilayered ceramic filtration element of Claim 5. OYAMA further discloses the intermediate layer being produced from ceramic sols having median particle sizes of 630, 200, 55, and 40 nm (p0048) having the particle distributions shown in FIGs. 2-4 (circle line 1.5 in FIG. 3, circle line 24 hr in FIG. 4), which reads on the limitation requiring that wherein the second intermediate layer comprises particles with a Z-ratio D90/D10 of up to 3, a particle size of D10 in a range of from 50 to 170 nm and a particle size D90 in the range of from 150 to 350 nm. Regarding Claim 9, modified OYAMA makes obvious the multilayered ceramic filtration element of Claim 5. OYAMA further discloses the intermediate layer being produced from ceramic sols having median particle sizes of 630, 200, 55, and 40 nm (p0048) having the particle distributions shown in FIG. 4 (square line 0.5 h in FIG. 4), which reads on the limitation requiring that wherein the second intermediate layer comprises particles with a Z-ratio D90/D10 of up to 3, a particle size of D10 in a range of from 50 to 170 nm and a particle size D90 in the range of from 150 to 350 nm. Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over OYAMA et al. (US 2005/0172811 A1) in view of ONOZUKA et al. (US 2017/0259214 A1) as applied to Claim 1 above, and further in view of BENFER et al. (Separation and Purification Technology, 2001, 22-23, pg. 231-237). Regarding Claim 11, modified OYAMA makes obvious the multilayered ceramic filtration element of Claim 1. OYAMA further discloses all sol solutions include ceramic materials including zirconia, titania, silicon nitride, silicon carbide, and boron nitride (p0052). OYAMA further shows in FIG. 6 that the pore sizes of each successive layer of ceramic sol decreases from 5.1 nm to 4.6 nm to 3.7 nm, and thus, the expected pore size of the discriminating membrane layer would at least be less than 3.7 nm. Nevertheless, the prior art is explicitly deficient in disclosing the membrane layer consists of TiO2 particles with a Z-ratio D90/D10 of less than 3, a particle size D10 being in a range of from 5 to 9 nm, and a particle size D90 being in a range of from 9 to 15 nm or the membrane layer consists of ZrO2 particles with a Z-ratio D90/D10 of less than 5, a particle size D10 being in a range of from 1 to 3 nm, and a particle size D90 being in a range of from 3 to 5 nm. However, such TiO2 and ZrO2 membrane layers have long been known in the art as taught by BENFER. Utilizing a polymeric sol-gel process, BENFER produced composite membranes having a nanofiltration active separating layer supported on zirconia or titania ultrafiltration membranes (§2.1, par. 2). The prior art further determined the pore size distribution of a TiO2 and a ZrO2 nanofiltration membrane as shown in FIG. 7 (annotations added): [AltContent: textbox (D90)][AltContent: arrow][AltContent: arrow][AltContent: textbox (D10)] PNG media_image3.png 200 400 media_image3.png Greyscale While the prior art did not explicitly disclose the zirconia or titania particle sizes, based on Applicant’s disclosure, the approximate particle sizes for these two membranes would be about five times (i.e., 5x) the reported pore diameter, i.e., the titania membrane would have a peak diameter D50 at about 7.3 nm with a distribution range from as low as 2.5 nm to as high as 12 nm, and the zirconia membrane would have a peak diameter D50 at about 6 nm with a distribution range from as low as 1.5 nm to as high as 10.5 nm. Furthermore, based on FIG. 7 (see annotations), the TiO2 membrane D10 and D90 values conservatively seem to be at about 5.8 nm (1.15 in FIG. 7) and 9.0 nm (1.8 in FIG. 7), respectively, i.e., a Z-ratio D90/D10 would be less than 3, a particle size D10 being in a range of from 5 to 9 nm, and a particle size D90 being in a range of from 9 to 15 nm as claimed. All claimed elements were known in the prior art and one of ordinary skill in the art could have combined the elements as claimed by known methods with no change in their respective, individual functions, and the combination would have yielded nothing more than predictable results (MPEP §2143.01 A). Thus, one of ordinary skill in the art prior to the effective filing date of the claimed invention would have found it obvious to adapt BENFER’s taught titania membrane having the claimed particle sizes and Z-ratio to modified OYAMA’s membrane as both disclosures are directed toward nano-sized pores in ceramic composite membranes. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to RYAN B HUANG whose telephone number is (571)270-0327. The examiner can normally be reached 9 am-5 pm EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, In Suk Bullock can be reached at 571-272-5954. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /Ryan B Huang/Primary Examiner, Art Unit 1777
Read full office action

Prosecution Timeline

Apr 06, 2023
Application Filed
Apr 18, 2023
Response after Non-Final Action
Feb 18, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
52%
Grant Probability
84%
With Interview (+31.9%)
3y 5m
Median Time to Grant
Low
PTA Risk
Based on 544 resolved cases by this examiner. Grant probability derived from career allow rate.

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