Prosecution Insights
Last updated: April 19, 2026
Application No. 17/872,711

HALOGEN-SUBSTITUTED 9,9-BIS(4-AMINOPHENYL)FLUORENE BASED POLYIMIDE MEMBRANES FOR GAS SEPARATION APPLICATIONS

Final Rejection §102§103§112
Filed
Jul 25, 2022
Examiner
HE, QIANPING
Art Unit
1776
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Saudi Arabian Oil Company
OA Round
3 (Final)
68%
Grant Probability
Favorable
4-5
OA Rounds
3y 2m
To Grant
80%
With Interview

Examiner Intelligence

Grants 68% — above average
68%
Career Allow Rate
169 granted / 248 resolved
+3.1% vs TC avg
Moderate +12% lift
Without
With
+11.7%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
62 currently pending
Career history
310
Total Applications
across all art units

Statute-Specific Performance

§101
1.4%
-38.6% vs TC avg
§103
43.2%
+3.2% vs TC avg
§102
17.6%
-22.4% vs TC avg
§112
34.0%
-6.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 248 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(b) 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 8–10 and 15 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. Claim 8 is indefinite because the monomer structure as reproduced below is lacking a bond at the circled location. It is unclear if this is a typo or the applicant meant to claim such structure. For the purpose of examination, the structure below is interpreted as the same as what is shown in Claim 7, which is consistent with what is disclosed in the instant disclosure. PNG media_image1.png 116 234 media_image1.png Greyscale i Claims 9–10 are indefinite because they depend on claim 8. Claim 15 is indefinite for the same reason as claim 8. Additionally, the PNG media_image2.png 86 52 media_image2.png Greyscale is also missing a bond. Claim Rejections - 35 USC § 102(a)(1) 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 claims are rejected as follows: Claims 1, 2 and 14 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kai et al., JP 2009–82850 A (“Kai”). Regarding claim 1: Kai discloses a gas separation membrane (Kai’s coating layer formed on the outer surface of the porous support film by dipping coating of a solution containing cardo type polyimide would be the claimed “gas separation membrane”, Kai p. 4, Kai specifically points out that the cardo type polyimide is a materially before carbonization into carbon, and Kai discloses its cardo type polyimide comprising formula “A-1”, Kai p. 4, noted here that the term “gas separation” describes intended use, and the only structure required by the claim is a structure met by Kai’s membrane with formular “A-1”; additionally, Kai discloses its cardo type polyimide forms a coating layer by dip coating on a porous support, Kai p. 4, Kai coating layer made of cardo type polyimide therefore read on the term “membrane”) comprising a polyimide polymer comprising a monomer (Kai’s formular “A-1”, Kai p. 4) having a structure comprising: PNG media_image3.png 250 326 media_image3.png Greyscale wherein when X1 = X2, X1 and X2 are selected from F, Cl, Br, or I and wherein when X1 and X2 are different elements, X1 and X2 are independently selected from H, F, Cl, Br, or I, and at least one of X1 and X2 are a halogen (Kai discloses its formular (A-1), wherein R1 to R12 are the same as formular (A), where Kai discloses R1 to R12 in Kai’s formular A are the same of different and each represents a hydrogen atom…or a halogen atom, Kai’s formular A-1 would read on the claimed monomer structure, for example, when R11 being a halogen atoms and all others being a hydrogen atom, Kai Formular [A-1], ps. 3–4). Regarding claim 2: Kai discloses that the gas separation membrane of claim 1, comprising a homopolymer of the structure: PNG media_image4.png 268 506 media_image4.png Greyscale wherein Art comprises an aromatic moiety or a bridging moiety. Because Kai discloses a general formular (I): PNG media_image5.png 142 354 media_image5.png Greyscale , where X could be represented by formular (A-1) and the rest part has the structure of left part of the claimed homopolymer. Kai discloses its component Y is a moiety, Kai’s Y connects two or more atoms and therefore, it is a bridging moiety. Kai Formula I, p. 4. Regarding claim 14: Modified Kai discloses that the claimed monomer, which is known as 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride. Kai p. 4. 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. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. 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. The claims are rejected as follows: Claim 3–5 and 8–13 are rejected under 35 U.S.C. 103 as being unpatentable over Kai in view of Hayek et al., US 2021/0309803 A1 (“Hayek”). Regarding claim 3: Kai does not disclose the claimed structure. However, similar to Kai, Hayek discloses a gas separation membrane comprising polyimide and CARDO. Hayek Fig. 2A, [0015]. Hayek discloses a very similar polymer structure as that shown in claim 3. Hayek’s polymer structure of Fig. 2a differs from the claimed structure in that the fluorene skeleton does not comprise halogen ion. However, it would have been obvious for one ordinary skill in the art at the time of filing to replace Hayek’s fluorene skeleton with a fluorene skeleton comprising halogen ions because Kai discloses a fluorene skeleton suitable for use as a gas separation membrane could comprise a hydrogen atom, a C1-4 alkyl, a C1-4 alkoxy group, a carboxyl group, a C2-C5 alkoxycarbonyl group, or a halogen atom. And a person of ordinary skill in the art would be motivated to try those disclosed alternative structure and test the separation efficiency to improve the polyimide gas separation membrane. Hayek also discloses that its 6FDA-durene/CARDO copolymer could have a ratio of 3:1, which read on the claimed ratio. Hayek [0044]. Regarding claim 4: Modified Kai discloses that the gas separation membrane of claim 3, comprising a random copolymer. Hayek [0091]. Regarding claim 5: Modified Kai discloses that the gas separation membrane of claim 3, comprising a block copolymer. Hayek [0091]. Regarding claim 8: Kai does not disclose the claimed structure. However, similar to Kai, Hayek discloses a gas separation membrane comprising polyimide and CARDO. Hayek Fig. 2A, [0015]. Hayek discloses a very similar polymer structure as that shown in claim 8. Hayek’s polymer structure of Fig. 2a differs from the claimed structure in that the fluorene skeleton does not comprise bromide ion. However, it would have been obvious for one ordinary skill in the art at the time of filing to replace Hayek’s fluorene skeleton with a fluorene skeleton comprising bromide ions because Kai discloses a fluorene skeleton suitable for use as a gas separation membrane could comprise a hydrogen atom, a C1-4 alkyl, a C1-4 alkoxy group, a carboxyl group, a C2-C5 alkoxycarbonyl group, or a halogen atom. And a person of ordinary skill in the art would be motivated to try those disclosed alternative structure and test the separation efficiency to improve the polyimide gas separation membrane. Hayek also discloses that its 6FDA-durene/CARDO copolymer could have a ratio of 3:1, which read on the claimed ratio. Hayek [0044]. Regarding claim 9: Modified Kai discloses that the gas separation membrane of claim 8, comprising a random copolymer. Hayek [0091]. Regarding claim 10: Modified Kai discloses that the gas separation membrane of claim 8, comprising a block copolymer. Hayek [0091]. Regarding claim 11: While modified Kai does not disclose the claimed monomer. Hayek discloses 2,3,5,6-tetramethyl-1,4-phenylenediamine, which could be used as monomer for a polyimide gas separation membrane. Hayek [0041]. The Benzene ring is an aromatic moiety. It would therefore have been obvious for one ordinary skill in the art at the time of filing to use Hayek’s 2,3,5,6-tetramethyl-1,4-phenylenediamine as a monomer in modified Kai’s gas separation membrane because Hayek discloses such monomers could be used in polyimide CARDO gas separation membranes. Regarding claim 12: Modified Kai does not disclose the claimed monomer. However, Hayek discloses 2,3,5,6-tetramethyl-1,4-phenylenediamine, which could be used as monomer for a polyimide gas separation membrane. Hayek [0041]. It would therefore have been obvious for one ordinary skill in the art at the time of filing to use Hayek’s 2,3,5,6-tetramethyl-1,4-phenylenediamine as a monomer in modified Kai’s gas separation membrane because Hayek discloses such monomers could be used in polyimide CARDO gas separation membranes. Regarding claim 13: Modified Kai does not disclose the claimed monomer. However, Hayek discloses 1,3-phenylenediamine, which could be used as monomer for a polyimide gas separation membrane. Hayek [0041]. It would therefore have been obvious for one ordinary skill in the art at the time of filing to use Hayek’s 1,3-phenylenediamine as a monomer in modified Kai’s gas separation membrane because Hayek discloses such monomers could be used in polyimide CARDO gas separation membranes. Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Kai in view of Inomata et al., US 2018/0290111 A1 (“Inomata”). Regarding claim 6: Kai discloses a structure as claimed. Kai Formula I, p. 4. Kai does not disclose such structure is an oligomer. Similar to Kai, Inomata discloses a similar CARDO type polyimide. Inomata Formula (I), [0004]. Inomota formula (I). Inomota discloses the monomer represented by formula (IV) and (V) may be used as oligomer or prepolymer in advance. Inomota [0111], [0114] and [0126]. It would therefore have been obvious for one ordinary skill in the art at the time of filing for Kai’s formula I to be an oligomer as disclosed by Inomata because oligomer comprising the disclosed structure is known as suitable to be used as an oligomer in polyimide-cardo gas separation membranes. Claim 7 are rejected under 35 U.S.C. 103 as being unpatentable over Kai. Regarding claim 7: Kai discloses an example of formula (7) which is reproduced below: PNG media_image6.png 134 278 media_image6.png Greyscale Kai’s Formula (7) is very similar to the claimed structure expect Kai’s fluorene skeleton does not include bromide ions. However, Kai discloses in its general formula of formular A-1, where R1 to R12 could be hydrogen or halogen. It would therefore have been obvious for one ordinary skill in the art at the time of filing for Kai’s fluorene skeleton in formular (7) to comprise a bromide ion at the claimed position because Kai discloses halogen could substitute R11 or R6 or both. Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Kai in view of Hayek, and in further view of Inomata. Regarding claim 15: Modified Kai does not disclose the claimed oligomer. However, Hayek discloses the claimed monomer. Kai Fig. 4. It would therefore have been obvious for one ordinary skill in the art at the time of filing to use the monomer disclosed by Hayek because Hayek discloses such monomers as being suitable for polyimide/CARDO gas separation membrane. Such modification does not disclose the claimed structure forms oligomer. However, Inomota discloses the monomer represented by Formula (IV) and the monomer represented by Formula (V), (VII-a), or (VII-b) may be used as oligomers or prepolymers in advance. Inomota [0111], [0114], [0126], [0122] and [0125]. It would therefore have been obvious for one ordinary skill in the art at the time of filing for modified Kai’s formula to be an oligomer as disclosed by Inomata because oligomer comprising the disclosed structure is known as suitable to be used as an oligomer in polyimide-cardo gas separation membranes. Response to Arguments Claim Rejections - 35 USC § 102(a)(1) and § 103 The applicant amends claim 1 to further limit that at least one of X1 or X2 is a halogen, and argues that Kai does not anticipate claim 1 because Kai does not disclose a polyimide separation membrane as claimed, Applicant Rem. dated Jan. 06, 2026 (hereinafter “Applicant Rem.”) ps. 12. The applicant argues that Kai focuses on a gas separation membrane comprising alkali metal, alkaline earth metal and /or amine compounds supported on a carbon membrane that is produced by carbonizing a cardo type polyimide precursor on a porous support, resulting in an inorganic carbon film, rather than a polyimide polymer structure. Id. The applicant argues that Kai’s cardo-typo polyimides only exist as precursors that undergo carbonization step at temperatures of 300-2000 degree C in an anaerobic atmosphere, Id. The applicant argues that the carbonization step fundamentally transforms the precursor’s chemical structure into an inorganic carbon film, which is the primary membrane material of Kai. Id. Therefore, Kai does not teach or suggest any retention of the imide functionality and original polymer architecture in the precursor, thereby failing to teach or suggest a polyimide polymer as a separation membrane. Id. In response, the examiner first points out that claim 1 requires a “gas separation membrane”. The invention is therefore directed to a membrane. The term of “gas separation” is an intended use and are given patentable weight only insofar as it affects the structure of the claimed membrane. Here, Kai’s coating layer of cardo polyimide reads on the claimed “gas separation membrane” because it has all the structure required by the claim. Kai therefore teaches the claimed gas separation membrane. Noted here that while Kai discloses a process where its alumina support membrane coated with the precursor undergoes carbonization, the examiner maps Kai’s cardo polyimide coating layer to the claimed “gas separation membrane”. And therefore, applicant’s arguments relying on the carbonized gas separation membrane is moot because the rejection is not relied upon that the carbonized membrane. Claim Rejections - 35 USC § 112(b) The applicant states that there is no missing bond observed in the claimed monomer structure. The structure submitted is complete and consistent with the chemical description provided in the spec. Applicant Rem. p. 13. The examiner does not agree, Applicant’s Spec. shows a different formular compared with what is presented in the claim. For example, the instant disclosure dated Jul. 25, 2022 (hereinafter “Spec.”) para. [0135] shows the copolymer, which the examiner believes is what is claimed in claim 8, however, the formula presented in claim 8 is missing a bond as highlighted in the claim rejection section above. Applicant’s Spec. para. [0142] presents an oligomer, which is the only oligomer disclosed by the applicant comprising CF bond, and it is different from what is claimed in claim 15 as highlighted in the claim rejection section. Clarification is needed. Also noted here that if the applicant believes there is no missing bond in the claimed structure in claim 8 and claim 15, a potential 35 U.S.C. 112(a) rejection based on lack of written support would be appropriate. Conclusion 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 QIANPING HE whose telephone number is (571)272-8385. The examiner can normally be reached on 7:30-5:00 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 on (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 an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see https://ppair-my.uspto.gov/pair/PrivatePair. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /Qianping He/Examiner, Art Unit 1776
Read full office action

Prosecution Timeline

Jul 25, 2022
Application Filed
Apr 03, 2025
Non-Final Rejection — §102, §103, §112
Jul 02, 2025
Response Filed
Oct 06, 2025
Non-Final Rejection — §102, §103, §112
Jan 06, 2026
Response Filed
Mar 12, 2026
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

4-5
Expected OA Rounds
68%
Grant Probability
80%
With Interview (+11.7%)
3y 2m
Median Time to Grant
High
PTA Risk
Based on 248 resolved cases by this examiner. Grant probability derived from career allow rate.

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