Prosecution Insights
Last updated: April 19, 2026
Application No. 18/076,463

SEPARATOR FOR ELECTRIC STORAGE DEVICE AND ELECTRIC STORAGE DEVICE

Final Rejection §103§DP
Filed
Dec 07, 2022
Examiner
DIETERLE, JENNIFER M
Art Unit
1776
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Asahi Kasei Kabushiki Kaisha
OA Round
2 (Final)
65%
Grant Probability
Favorable
3-4
OA Rounds
3y 2m
To Grant
93%
With Interview

Examiner Intelligence

Grants 65% — above average
65%
Career Allow Rate
383 granted / 586 resolved
At TC average
Strong +27% interview lift
Without
With
+27.3%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
15 currently pending
Career history
601
Total Applications
across all art units

Statute-Specific Performance

§101
2.0%
-38.0% vs TC avg
§103
43.8%
+3.8% vs TC avg
§102
24.3%
-15.7% vs TC avg
§112
20.8%
-19.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 586 resolved cases

Office Action

§103 §DP
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 . Response to Amendment Applicant’s arguments regarding the double patenting are persuasive. Given the amendments to the independent claim, the double patenting rejection is withdrawn; however, a new ground of rejection is set forth below to address the amendments. Applicant appears to argue that the secondary reference Takahashi was utilized to show the layered structure; however, Takahashi was used to show the positive electrode material lithium iron phosphate is a known material. Applicant also argues unexpected effects; however, these effects have additional specific unclaimed parameters such as thickness and percentage of styrene, etc. to arrive at the results. Upon further search and consideration, prior art Masaki (WO 2020196120) was identified that appears to teach a variety of layering of a separator comprising polyolefins. 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. Claims 1 and 5-8 are rejected under 35 U.S.C. 103 as being unpatentable over Hamasaki et al. (PCT/JP2021/034173, citing to US 20230282933 as translation) in view of Masaki (WO 2020196120, citing to translation). Regarding claim 1, Hamasaki et al. teaches a microporous membrane that can comprise at least two layers wherein the first layer can be a polypropylene [0088- 95] and a second layer can be a polyolefin (see claims 1 and 14). The second layer can be a copolymer of polyethylene and polypropylene, or individually polypropylene or polyethylene [0119-120]. Hamasaki et al. teaches the use of SEM in either the MD-TD or ND-MD directions to analyze the long pore diameter of the second layer material can be 100nm or more and 400nm or less [0056]. Hamasaki et al. also teaches that a filler thermoplastic such as styrene [0169] can be utilized. While Hamasaki does not specifically teach the use of a separator with a three-layer structure of microporous layer (A)/microporous layer (B)/microporous layer (A), it is noted that Hamasaki does teach lists of thermoplastics that can be utilized and variations for what can be utilized for the first and second layers. It teaches that there can even be more than two layers [0132-33]. However, Masaki also teaches a separator for a battery (see abstract; [0011]). Masaki, like Hamasaki, teaches its structure can be two or more layers including the microporous membrane mainly composed of the polyolefins and a multilayer structure in which three or more microporous membranes are laminated. Masaki teaches the multilayer structure can comprise at least two layers of the microporous membrane (PP microporous layer) mainly composed of polypropylene of this embodiment and at least one further microporous membrane (PE microporous layer) mainly composed of polyethylene (see [0046]). Masaki teaches that the benefits can be achieved regardless of the order in which the layers are laminated in the multilayer structure, but a three-layer structure in which the layers are laminated in the order of PP microporous layer/PE microporous layer/PP microporous layer is particularly preferred as it allows the PE microporous layer to provide shutdown properties, while the PP microporous layer can maintain mechanical strength. Makasi also teaches [0047] the multilayer structure does not necessarily contain both a PP microporous layer and a PE microporous layer, and may be a structure in which only the PP microporous layer is laminated, such as, for example, PP microporous layer (A)/PP microporous layer (B)/PP microporous layer (C). Masaki also teaches the use of pore formers, plasticizers, and styrene is a plasticizer [0059]. Thus, it would have been obvious to one skilled in the art before the effective file date of the present invention to have selected the claimed combinations from the materials from the limited lists set forth in Hamasaki with the reasonable expectation of providing a microporous membrane which has thermal stability and will work to prevent dendrite clogging (abstract) or to utilize a PP/PP or PE (styrene)/PP layering as taught by Masaki in the device of Hamasaki who already teaches the use of a PP/PP/PE styrene and possible additional layers to arrive at a separator that has mechanical strength and minimizes shutdown. Regarding claim 5, Hamasaki teaches a permeability in the claimed range of 10-300 sec/100 cm3 [0138-139]. Regarding claim 6, Hamasaki teaches a melt flow rate for the first polypropylene layer of less than or equal to 0.9 g/10 min [0066; abstract]. Regarding claim 7, Hamasaki teaches a melt flow rate for the second polyolefin layer of less than or equal to 0.7 g/10 min [0069]. Regarding claim 8, Hamasaki teaches that the separator can be utilized in a cell between a positive and negative electrode [0171]. Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Hamasaki and Masaki, as applied to claim 1 above, in further view of JP6103921 (citing to translation). Regarding claim 4, Hamasaki and Masaki are silent as to the styrene weight content. However, JP'921 also teaches a lithium battery and teaches the use of fillers such as styrene elastomer from 10-70% mass in the separator/microporous film that is comprised of a polyolefin. It helps with dimensional stability and helps to prevent accidents such as ignition due to abnormal battery heat generation (see page 4/23 of translation). Therefore, it would have been obvious to one skilled in the art before the effective file date of the present invention to have added styrene to the second layer as taught by JP'921 in order to help reduce dendrite clogging and thermal instability. Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Hamasaki et al. and Masaki, as applied to claim 8 above, in further view of Takahashi et al. (US 2015/0380777). Regarding claim 9, While Hamasaki and Masaki teach a battery, they do not specifically teach the material of the positive electrode. However, Takahaski et al. also in the battery art teaches that positive electrodes are known to be made from lithium iron phosphate [0041] and that polypropylene is utilized as a separator. Therefore, it would have been obvious to one skilled in the art before the effective file date of the present invention to have utilized lithium iron phosphate as the positive electrode material in Hamasaki as taught by Takahaski as lithium iron phosphate is a known material in the battery art to produce electrodes. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Shi (US202000219796) teaches a multilayer battery separator. 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 JENNIFER M DIETERLE whose telephone number is (571)270-7872. The examiner can normally be reached M-Th 9:30-5:30 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, Yvonne Eyler can be reached at 571-272-1200. 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. /Jennifer Dieterle/Supervisory Patent Examiner, Art Unit 1776
Read full office action

Prosecution Timeline

Dec 07, 2022
Application Filed
Jun 15, 2025
Non-Final Rejection — §103, §DP
Oct 16, 2025
Response Filed
Mar 18, 2026
Final Rejection — §103, §DP (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

3-4
Expected OA Rounds
65%
Grant Probability
93%
With Interview (+27.3%)
3y 2m
Median Time to Grant
Moderate
PTA Risk
Based on 586 resolved cases by this examiner. Grant probability derived from career allow rate.

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