Prosecution Insights
Last updated: April 19, 2026
Application No. 18/006,289

METHOD FOR PURIFYING A VINYLIDENE FLUORIDE POLYMER

Final Rejection §102§103
Filed
Jan 20, 2023
Examiner
BUIE-HATCHER, NICOLE M
Art Unit
1725
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Arkema France
OA Round
2 (Final)
64%
Grant Probability
Moderate
3-4
OA Rounds
3y 3m
To Grant
91%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
615 granted / 963 resolved
-1.1% vs TC avg
Strong +27% interview lift
Without
With
+26.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
4 currently pending
Career history
967
Total Applications
across all art units

Statute-Specific Performance

§101
1.1%
-38.9% vs TC avg
§103
48.8%
+8.8% vs TC avg
§102
15.0%
-25.0% vs TC avg
§112
19.2%
-20.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 963 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 . Response to Amendment The amendment filed 01/20/2023 has been entered. Claims 1-13 and 15-21 are pending. Election/Restriction Applicant's election with traverse of Group I, claims 1-12 and 18-20 in the reply filed on 10/23/2025 is acknowledged. The traversal is on the ground(s) that the three groups of inventions share the technical feature of vinylidene fluoride polymer having reduced content of fluoride anions and of organic compounds (page 7) is not persuasive. This is not found persuasive because the special technical feature is based on what is claimed. The special technical feature is a vinylidene fluoride polymer having a reduce content level of impurities. Claim 1 does not claim the amount of organic compounds or fluoride content. The requirement is still deemed proper and is therefore made FINAL. Claims 13, 15-17, and 24 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 10/23/2025. 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 1-5, 7- 9, 11-12, and 18-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Bohnert (US 2006/0223981 A1). Regarding claims 1-3, 12, and 18, Bohnert discloses the particulate synthetic resin material is transferred from storage silo to extraction vessel 13 [0050]. The desired temperature and pressure for solvency of the solvent in supercritical carbon dioxide [0051]. The synthetic resin material includes polyvinylidene fluoride (PVDF) [0048]. The carbon dioxide enters as a gas (a stream of inert gas) and then converted to supercritical carbon dioxide. The recirculation of the carbon dioxide is continued until all of the solvent has been removed from the synthetic resin material (therefore the extracting step with a stream of inert gas is continually being performed after washing) [0052]. Bohnert also discloses the solvent-free synthetic resin material is removed from the extraction vessel 132 preferably by a vacuum system [0053]. Regarding claim 4, as shown in Fig. 1 there is a reactor. Regarding claims 5 and 9, the pressure is from about 600 psia to 5000 psia (about 4 to 34 MPa) which overlaps the claimed range) and the temperature is from about 20 to 100℃ which is within the claimed range [0051]. Regarding claim 8, since the step of washing with a stream of inert gas is optional. The claimed limitations are met. Regarding claims 7 and 19, Bohnert discloses a first organic solvent wherein the first organic solvent remains when the carbon dioxide is added and includes alcohols or alkyl lactates such as ethanol (polar cosolvent) (Abstract, [0019], [0030], [0047]). Regarding claim 11, the first organic solvent is considered a contaminant as well as other contaminants such as oil [0014]. Regarding claim 20, the anions are optional. Therefore, the claimed limitations are met. 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 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. Claims 6 and 10 is rejected under 35 U.S.C. 103 as being unpatentable over Bohnert (US 2006/0223981 A1) as applied to claim 1 above. Regarding claims 6 and 10, Bohnert dislcoes the purification method as shown above in claim 1. However, Bohnert does not disclose a quantity of supercritical fluid used for the washing of the vinylidene fluoride polymer amounts to from 1 1 to 30 kg per kg of vinylidene fluoride polymer and per hour or the washing of PVDF with a stream of supercritical fluid takes place for a period of 1 to 12 hours and/or the extraction of residual supercritical fluid takes place for a period of 1 to 40 hours. As the amount of contaminant removed is variable that can be modified by adjusting said amount of supercritical fluid and amount of time of washing of the supercritical carbon dioxide, the precise amount of washing with the supercritical fluid would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, amount of time for washing, and the motivation to do so would have been to obtain desired purified material, since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05. Response to Arguments Applicant's arguments filed 10/23/2025 have been fully considered but they are not persuasive. The following comment(s) apply: Applicant’s argument that the recirculation of carbon dioxide is still part of the washing step of the resin with carbon dioxide (page 10) is not persuasive. The recirculation of the carbon dioxide is being treat as a step after the initial washing step and still reads on the claimed limitations of after washing, a stream of inert gas is still applied. Applicant’s argument that in Bohnert, the recycled carbon dioxide that is again brought into contact with the resin particles is in a liquid or supercritical form and is not a gas (page 10) is not persuasive. Bohnert teaches the expansion device 148 and heat exchanger 150 are set such that the carbon dioxide entering the separator vessel 152 is in the gaseous phase [0052]. As shonw in Fig 1, 132 and 154 are in the same componenent 132. Therefore, it would be expected at least some carbon dioxide gas would be present in the contact with the polyvinylidene fluoride. Furthermore, Bohnert discloses the polyvinylidene fluoride is contacted with a vacuum system as discussed above. Applicant’s allegation of unexpected results (page 5) is not persuasive. Instant claim 1 recites “said extraction of residual supercritical fluid being carried out by bringing the vinylidene fluoride polymer into contact, after washing, with a stream of inert gas and/or by placing the vinylidene fluoride polymer after washing under vacuum. Instant claim 1 does not recite amount of organic compounds. The reduction of the content of organic compounds is not claimed. Instant claim 1 is not limited to contacting the vinylidene fluoride with a stream of inert gas. A vacuum may may also be applied which is taught by Bohnert. The evidence is not commensurate in scope with the claims. Conclusion THIS ACTION IS MADE FINAL. 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. Correspondence Any inquiry concerning this communication or earlier communications from the examiner should be directed to NICOLE M. BUIE-HATCHER whose telephone number is (571)270-3879. The examiner can normally be reached M-F, 9:00 am - 6:00 pm. 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, Srilakshmi K Kumar can be reached at (571)272-7769. 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. /NICOLE M. BUIE-HATCHER/Supervisory Patent Examiner, Art Unit 1725
Read full office action

Prosecution Timeline

Jan 20, 2023
Application Filed
Jul 21, 2025
Non-Final Rejection — §102, §103
Oct 23, 2025
Response Filed
Jan 10, 2026
Final Rejection — §102, §103 (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
64%
Grant Probability
91%
With Interview (+26.9%)
3y 3m
Median Time to Grant
Moderate
PTA Risk
Based on 963 resolved cases by this examiner. Grant probability derived from career allow rate.

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