Prosecution Insights
Last updated: April 19, 2026
Application No. 17/923,966

POROUS MEMBRANE OF POLYTETRAFLUOROETHYLENE AND/OR MODIFIED POLYTETRAFLUOROETHYLENE HAVING HIGH STRENGTH AND SMALL PORE DIAMETER

Non-Final OA §102§103§DP
Filed
Nov 08, 2022
Examiner
KHATRI, PRASHANT J
Art Unit
1783
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Chemours-Mitsui Fluoroproducts Co. Ltd.
OA Round
3 (Non-Final)
61%
Grant Probability
Moderate
3-4
OA Rounds
3y 6m
To Grant
90%
With Interview

Examiner Intelligence

Grants 61% of resolved cases
61%
Career Allow Rate
515 granted / 849 resolved
-4.3% vs TC avg
Strong +29% interview lift
Without
With
+28.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 6m
Avg Prosecution
39 currently pending
Career history
888
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
46.7%
+6.7% vs TC avg
§102
21.1%
-18.9% vs TC avg
§112
21.7%
-18.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 849 resolved cases

Office Action

§102 §103 §DP
DETAILED ACTION In response to RCE filed 12/22/2025. Claims 1 and 3-11 are pending. Claims 9-11 are withdrawn. Claims 1 and 3-8 are examined thusly. Claim 1 was amended. Claim 2 was cancelled. Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12/22/2025 has been entered. Claim Rejections - 35 USC § 102 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claims 1, 3-4, and 6-7 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Bacino et al. (US 7306729) with evidence from ASTM F316-03. Bacino discloses a porous PTFE material. Concerning claims 1 and 6, Bacino discloses the porous PTFE material has a tensile strength in the longitudinal direction (or MD) of 217 MPa and transverse direction (or CD) of at least 214 MPa and has a thickness of at most 20 microns, wherein such materials also have a bubble point of at least 564 kPa (Tables 1 and 2, Examples 1-5; cols. 12-21). The resulting ratio is at least 1.01 which is within the claimed range. While it is noted that the bubble point is determined using ASTM 316-03 with a mineral oil (SilWick Silicone Fluid), as shown in the standard, isopropyl alcohols (i.e. denatured alcohols) are one of the fluids used to determine bubble point; given that Bacino discloses a porous PTFE material having the claimed tensile strength and thickness, Examiner takes the position that the bubble point of the porous PTFE materials of Bacino would have the claimed bubble point when measured using isopropyl alcohol. Further, given that the materials, thicknesses, and mechanical properties are the same, the heat of fusion and properties as claimed in claims 3, 4 and 7 would be met by the disclosure of Bacino. Examiner notes that Examples 3-5 as shown in Table 2 are heated at a temperature of 380°C to 390°C which would lead to calcined porous PTFE materials (Tables 1 and 2). As stated in In re Best, 562 F.2d 1252, 1255 (CCPA 1977): Where, as here, the claimed and prior art products are identical or substantially identical, or are produced by identical or substantially identical processes, the PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of his claimed product. Whether the rejection is based on "inherency" under 35 U.S.C. § 102, on “prima facie obviousness” under 35 U.S.C. § 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO’s inability to manufacture products or to obtain and compare prior art products. Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Bacino et al. (US 7306729) with evidence from ASTM F316-03. Bacino discloses the above, including the porosity is at least 50%, which overlaps and includes the claimed range (col. 7, lines 28-40). Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Bacino et al. (US 7306729) in view of Xu et al. (US 8557883) with evidence from ASTM F316-03. Bacino discloses the above but is silent to the PTFE being a copolymer with the comonomer at the amount as claimed and identity thereof. Xu discloses an expandable TFE copolymer product. The TFE copolymer comprises tetrafluoroethylene and a comonomer at a content of less than 1 mol%, wherein the comonomer can be a perfluoro(alkyl vinyl ether) as claimed (cols. 5-7; Tables 3-5; e.g. Example 9). The addition of a comonomer at the amount as claimed allows for imparting different chemical or physical properties to the expanded article (cols. 9-12). As such, it would have been obvious to one of ordinary skill in the art to use a TFE copolymer in order to provide an article with different chemical and physical properties. Double Patenting Claims 1 and 3-8 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-7 of U.S. Patent No. 12138842 in view of Xu et al. (US 8557883). Although the claims at issue are not identical, they are not patentably distinct from each other because both sets of claims are directed to at least a PTFE porous film having overlapping bubble points and further properties that are the same. While it is noted that the ‘842 claims recite a tensile strength but is silent to whether this is in the machine or cross direction and the ratio thereof, since the further properties are the same and the materials are the same, the CD and MD when measured would overlap and in scope as well, resulting in a ratio that also would overlap in scope. The ‘842 claims are silent to the use of a PTFE copolymer. Xu discloses an expandable TFE copolymer product. The TFE copolymer comprises tetrafluoroethylene and a comonomer at a content of less than 1 mol%, wherein the comonomer can be a perfluoro(alkyl vinyl ether) as claimed (cols. 5-7; Tables 3-5; e.g. Example 9). The addition of a comonomer at the amount as claimed allows for imparting different chemical or physical properties to the expanded article (cols. 9-12). As such, it would have been obvious to one of ordinary skill in the art to use a TFE copolymer in order to provide an article with different chemical and physical properties. Response to Arguments Applicant's arguments filed 12/22/2025 regarding the 35 USC 102(a)(1) and 103 rejections under Bacino and in view of Xu have been fully considered but they are not persuasive. Applicant asserts the test method JIS 6251 is only for single layers. Examiner respectfully disagrees and notes that Applicant has provided no evidence that the test method is only for single layers. Generally, one of the requirements for testing tensile strength is the sample size which is a dog bone shaped sample. Examiner further notes that the instant claims are not limited to single layers but can include embodiments of multilayer membranes. Applicant further asserts that the stretching temperature affects the resulting heat of fusion and since Bacino discloses a higher temperature at which the membrane is stretched, Bacino cannot have the claimed heat of fusion. Examiner respectfully disagrees and notes that the specification does not necessarily correlate the fibril sizes and stretching temperature to the resulting heat of fusion. The specification does, however, positively recites that the tensile strength is related to the heat of fusion in paragraph 0078 of the Application PG-Pub US20230211296, wherein if the heat of fusion is less than 5.0 J/g, a tensile strength of greater than 90 MPa cannot be achieved. Based on this correlation, the membrane of Bacino has a tensile strength greater than 90 MPa and as such, the heat of fusion for the membranes of Bacino should be greater than 5.0 J/g. Examiner notes that “the arguments of counsel cannot take the place of evidence in the record”, In re Schulze, 346 F.2d 600, 602, 145 USPQ 716, 718 (CCPA 1965). It is the examiner’s position that the arguments provided by the applicant regarding the heat of fusion for the membrane of Bacino must be supported by a declaration or affidavit. As set forth in MPEP 716.02(g), “the reason for requiring evidence in a declaration or affidavit form is to obtain the assurances that any statements or representations made are correct, as provided by 35 U.S.C. 24 and 18 U.S.C. 1001”. Applicant's arguments filed 12/22/2025 regarding the double patenting rejection have been fully considered but they are not persuasive. The double patenting rejection is still applicable as shown above and is held in abeyance. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to PRASHANT J KHATRI whose telephone number is (571)270-3470. The examiner can normally be reached M-F 10AM-6:30PM. 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, Veronica Ewald can be reached at (571) 272-8519. 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. PRASHANT J. KHATRI Primary Examiner Art Unit 1783 /PRASHANT J KHATRI/Primary Examiner, Art Unit 1783
Read full office action

Prosecution Timeline

Nov 08, 2022
Application Filed
Jan 08, 2025
Non-Final Rejection — §102, §103, §DP
Jun 13, 2025
Response Filed
Sep 19, 2025
Final Rejection — §102, §103, §DP
Dec 22, 2025
Request for Continued Examination
Dec 27, 2025
Response after Non-Final Action
Jan 22, 2026
Non-Final Rejection — §102, §103, §DP (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12604426
COVER PLATE AND DISPLAY DEVICE
2y 5m to grant Granted Apr 14, 2026
Patent 12604654
DISPLAY DEVICE
2y 5m to grant Granted Apr 14, 2026
Patent 12599971
COATED CUTTING TOOL
2y 5m to grant Granted Apr 14, 2026
Patent 12594743
ANTI-GLARE FILM, METHOD FOR PRODUCING SAME, AND USE OF SAME
2y 5m to grant Granted Apr 07, 2026
Patent 12595268
ACID ANHYDRIDE COMPOUND, AND POLYAMIDEIMIDE RESIN AND FILM USING THE SAME
2y 5m to grant Granted Apr 07, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

3-4
Expected OA Rounds
61%
Grant Probability
90%
With Interview (+28.9%)
3y 6m
Median Time to Grant
High
PTA Risk
Based on 849 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month