Prosecution Insights
Last updated: April 19, 2026
Application No. 18/490,621

MICROPOROUS POLYOLEFIN MEMBRANES FROM BESPOKE SOLVENTS

Non-Final OA §102§103
Filed
Oct 19, 2023
Examiner
MENON, KRISHNAN S
Art Unit
1777
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Amtek Research International LLC
OA Round
6 (Non-Final)
60%
Grant Probability
Moderate
6-7
OA Rounds
3y 2m
To Grant
71%
With Interview

Examiner Intelligence

Grants 60% of resolved cases
60%
Career Allow Rate
879 granted / 1475 resolved
-5.4% vs TC avg
Moderate +12% lift
Without
With
+11.7%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
72 currently pending
Career history
1547
Total Applications
across all art units

Statute-Specific Performance

§101
1.7%
-38.3% vs TC avg
§103
31.5%
-8.5% vs TC avg
§102
29.4%
-10.6% vs TC avg
§112
26.4%
-13.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1475 resolved cases

Office Action

§102 §103
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 § 102/103 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. 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. Claims 1-4, 6-9, 12, 14-16, 38-41, 43 and 46 (all pending claims) are rejected under 35 U.S.C. 102(a1) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over JP-(4139178B2), submitted by applicant in an IDS, with evidence from ENTEK ppt brochure and Miller et al (US 2017/0072610.) Claims are generally in the product-by-process format, directed at a self-supporting polyolefin/polyethylene microporous membrane. The membrane is also biaxially stretched. Additional elements in the dependent claims include web thickness. Product-by-process claims, MPEP 2113: "[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985). A rejection based alternatively on 35 U.S.C. 102 or 103 for product-by-process claims has been approved by the courts. Therefore, all the process steps in these claims are given no patentable weight. Only structural elements and any process step that appears to influence the structure are only considered in the following analysis. JP teaches microporous battery separators [0001] of high density polyethylene of Mol. Wt. 500,000 or more [0008]; and 2 million in examples. It uses mineral oils of flash point about 250C (240C or greater: [0005], examples.) Extracting solvent, isoparaffin, has flash point 46-50C (examples.) The microporous structure would be inherently having interconnected pores. JP also teaches that biaxial stretching is well-known in the art of battery separators [0002.] Isoparaffin is halogen-free. The JP battery separator also has silica in similar proportions as in the disclosed and claimed invention. See the Examples. Characteristics such as aniline point, and the boiling point difference inherently follows the flash point and the type of oils used, unless otherwise shown. Residual solvent and plasticizer would be inherent, depending on the process and the stage of the process, unless otherwise shown. JP, [0025] teaches residuals as 1% or less, though it can also be 1-20%. Thickness: JP teaches 100 microns in examples. The 25 microns or less, or 150-300 microns of thickness is not patentable unless otherwise shown, because this can be engineered based on the separator thickness required for the desired application. Applicant uses ENTEK 800 oil: Calumet in the examples, which appear to be a commercially available mineral oil used for the purpose of making battery separators. Entek is known for its battery separators (source: internet: << https://entek.com/wp-content/uploads/2021/05/150909_ENTEK_-16ABCWeb.pdf >>). Copy attached in an 892. Additional evidence that the battery separators are biaxially stretched is available from Miller, the previously applied prior art. Miller teaches free-standing UHMWPE microporous polyethylene membrane (abstract) that can be used for battery separator (claim 25) having TiO2, silica, etc., as filler [0008], [0021], and biaxially stretched [0044]. The molecular weight, by applicant’s own disclosure, of UHMWPE >> 0.5 million g/mol. Microporous matrix having Interconnecting pores: [0008]. Miller also teaches thickness 25 microns or less and 150-300 microns – see Table 3 which shows examples that have thickness within this thickness range. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to KRISHNAN S MENON whose telephone number is (571)272-1143. The examiner can normally be reached Flexible, but generally Monday-Friday: 8:00AM-4:30PM. 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, Prem C Singh can be reached on 571-272-6381. 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. /KRISHNAN S MENON/Primary Examiner, Art Unit 1777
Read full office action

Prosecution Timeline

Oct 19, 2023
Application Filed
Mar 14, 2024
Non-Final Rejection — §102, §103
Apr 22, 2024
Interview Requested
Apr 30, 2024
Examiner Interview Summary
Apr 30, 2024
Applicant Interview (Telephonic)
Jul 08, 2024
Response Filed
Aug 13, 2024
Final Rejection — §102, §103
Oct 21, 2024
Interview Requested
Oct 28, 2024
Examiner Interview Summary
Oct 28, 2024
Applicant Interview (Telephonic)
Nov 13, 2024
Request for Continued Examination
Nov 17, 2024
Response after Non-Final Action
Jan 10, 2025
Non-Final Rejection — §102, §103
Apr 15, 2025
Response Filed
Apr 21, 2025
Final Rejection — §102, §103
Aug 25, 2025
Request for Continued Examination
Aug 29, 2025
Response after Non-Final Action
Sep 08, 2025
Non-Final Rejection — §102, §103
Dec 11, 2025
Response Filed
Jan 16, 2026
Request for Continued Examination
Jan 20, 2026
Response after Non-Final Action
Mar 06, 2026
Non-Final Rejection — §102, §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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TECHNIQUES FOR DIALYSIS BASED ON RELATIVE BLOOD VOLUME
2y 5m to grant Granted Apr 07, 2026
Patent 12582944
METHODS FOR TREATING POROUS MEMBRANES
2y 5m to grant Granted Mar 24, 2026
Patent 12577705
ASSEMBLY COMPRISING A CENTER-FLUID DISTRIBUTOR AND A MULTI-FIBER SPINNERET
2y 5m to grant Granted Mar 17, 2026
Patent 12577130
DRINKING WATER DISPENSER WITH ULTRAVIOLET DISINFECTION DEVICE
2y 5m to grant Granted Mar 17, 2026
Patent 12566160
PILLAR STRUCTURES
2y 5m to grant Granted Mar 03, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

6-7
Expected OA Rounds
60%
Grant Probability
71%
With Interview (+11.7%)
3y 2m
Median Time to Grant
High
PTA Risk
Based on 1475 resolved cases by this examiner. Grant probability derived from career allow rate.

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