Prosecution Insights
Last updated: April 19, 2026
Application No. 18/580,191

METHODS FOR MANUFACTURING HOLLOW FIBER CARBON MEMBRANES

Non-Final OA §102§103§112
Filed
Jan 18, 2024
Examiner
JONES, CHRISTOPHER P
Art Unit
1776
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Dow Global Technologies LLC
OA Round
1 (Non-Final)
76%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
99%
With Interview

Examiner Intelligence

Grants 76% — above average
76%
Career Allow Rate
1023 granted / 1346 resolved
+11.0% vs TC avg
Strong +25% interview lift
Without
With
+24.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
39 currently pending
Career history
1385
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
41.6%
+1.6% vs TC avg
§102
30.9%
-9.1% vs TC avg
§112
20.4%
-19.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1346 resolved cases

Office Action

§102 §103 §112
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 § 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. Claims 12 and 13 are 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. Regarding claim 12, it is first noted that the claim should only be one sentence. Furthermore, it is unclear whether or not the second sentence is optional. The language “in embodiments, polyamides may” appears to be optional language. Claim 13 is rejected for depending from an indefinite claim. Claim Rejections - 35 USC § 102 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. Claims 1-12, 14 and 15 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kiyono USPA 2013/0305921 A1. Regarding claim 1, Kiyono discloses a method of manufacturing a hollow fiber carbon membrane (Abstract; paragraph 5), the method comprising: heating a polymeric precursor to a pyrolysis temperature that is greater than or equal to 900 degrees C and less than or equal to 1200 degrees C (paragraph 54); and pyrolyzing the polymeric precursor at the pyrolysis temperature in a pyrolysis atmosphere that comprises oxygen in an amount that is greater than 0 ppm and less than 200 ppm (paragraph 54). Regarding claim 2, Kiyono discloses that the hollow fiber carbon membrane is asymmetric (paragraph 12). Regarding claim 3, Kiyono discloses that the pyrolysis temperature is greater than or equal to 900 C and less than or equal to 1000 C (paragraph 54). Regarding claim 4, Kiyono discloses that the pyrolysis temperature is greater than or equal to 925 C and less than or equal to 975 C (paragraph 54). Regarding claim 5, Kiyono discloses that the pyrolysis atmosphere comprises oxygen in an amount that is greater than 0 ppm and less than 150 ppm oxygen (paragraph 54). Regarding claim 6, Kiyono discloses that the pyrolysis atmosphere comprises oxygen in an amount that is greater than 5 ppm and less than 150 ppm oxygen (paragraph 54). Regarding claim 7, Kiyono discloses that the pyrolysis atmosphere comprises oxygen in an amount that is greater than 0 ppm and less than 100 ppm oxygen (paragraph 54). Regarding claim 8, Kiyono discloses that the pyrolysis atmosphere comprises an inert gas and oxygen (paragraph 54). Regarding claim 9, Kiyono discloses that the pyrolysis atmosphere comprises argon and oxygen (paragraphs 40 and 54). Regarding claim 10, Kiyono discloses that the polymeric precursor comprises a polyimide (paragraph 54). Regarding claim 11, Kiyono discloses that the polymeric precursor comprises a polymer formed from one or more monomers selected from the group consisting of 2,4,6-trimethyl-1,3-phenylene diamine (DAM); oxydianaline (ODA);dimethyl-3 ,7-diaminodiphenyl-thiophene-5,5 '-dioxide (DDBT); 3,5 -diaminobenzoic acid (DABA); 2.3 ,5,6-tetramethyl- 1,4-phenylene diamine (durene); meta-phenylenediamine (in- PDA); 2,4-diaminotolune (2,4-DAT); tetramethylmethylenedianaline (TMMDA); 4,4 '-diamino- 2,2 '-biphenyl disulfonic acid (BDSA); 5,5 '- [2,2,2-trifluoro- 1-(trifluoromethyl)ethylidene] -1,3 - isobenzofurandion (6FDA); 3,3 ',4,4'-biphenyl tetracarboxylic dianhydride (BPDA); pyromellitic dianhydride (PMDA); 4,5,8-naphthalene tetracarboxylic dianhydride (NTDA); 4,4'- Oxydiphthalic anhydride (ODPA); and benzophenone tetracarboxylic dianhydride (BTDA) (paragraph 58). Regarding claim 12, Kiyono discloses that the polymeric precursor comprises a polymer comprising monomers Ax, By, and Cz, wherein X, Y, and Z are a mole fraction of each of A, B, and C,a sum of X + Y + Z is greater than or equal to 1, and A, B, and C are individually 2,4,6- trimethyl- 1,3 -phenylene diamine (DAM) (paragraph 31). Regarding claims 14 and 15, Kiyono does not explicitly disclose a hydrogen to ethylene (H2/C2H4) selectivity that is less than 50, or less than or equal to 30, when treating a stream containing an equal amount of hydrogen and ethylene. Nevertheless, Kiyono discloses a hollow fiber carbon membrane with the same structure and made by the same method as that disclosed and claimed by Applicant (see claims 1-11); therefore, it is inherent that the hollow fiber carbon membrane of Kiyono has a hydrogen to ethylene (H2/C2H4) selectivity that is less than 50, or less than or equal to 30, when treating a stream containing an equal amount of hydrogen and ethylene. See MPEP 2112. 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. Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Kiyono USPA 2013/0305921 A1 in view of Zhang USPA 2019/0054427 A1. Kiyono is relied upon as above. Regarding claim 13, Kiyono does not disclose that A is a monomer selected from the group consisting of 6FDA, ODPA, and BTDA;B is DAM; and C is a monomer selected from the group consisting of BPDA and PMDA. However, this combination of precursor is a known effective precursor for such hollow fiber membranes (see Zhang paragraph 36). It would have been obvious to one having ordinary skill in the art before the filing date of the claimed invention to modify Kiyono to have the claimed precursor, as taught by Zhang, since it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER P JONES whose telephone number is (571)270-7383. The examiner can normally be reached 9AM-6PM EST M-F. 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, Jennifer Dieterle can be reached at (571)270-7872. 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. /CHRISTOPHER P JONES/Primary Examiner, Art Unit 1776
Read full office action

Prosecution Timeline

Jan 18, 2024
Application Filed
Feb 05, 2026
Non-Final Rejection — §102, §103, §112 (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
76%
Grant Probability
99%
With Interview (+24.8%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 1346 resolved cases by this examiner. Grant probability derived from career allow rate.

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