Prosecution Insights
Last updated: April 19, 2026
Application No. 17/913,447

PROCESS FOR INHIBITING THE UNDESIRED FREE-RADICAL POLYMERIZATION OF ACRYLIC ACID PRESENT IN A LIQUID PHASE P

Final Rejection §103
Filed
Sep 22, 2022
Examiner
DOLETSKI, BLAINE G
Art Unit
1692
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
BASF Corporation
OA Round
2 (Final)
76%
Grant Probability
Favorable
3-4
OA Rounds
2y 2m
To Grant
83%
With Interview

Examiner Intelligence

Grants 76% — above average
76%
Career Allow Rate
415 granted / 548 resolved
+15.7% vs TC avg
Moderate +7% lift
Without
With
+7.2%
Interview Lift
resolved cases with interview
Typical timeline
2y 2m
Avg Prosecution
26 currently pending
Career history
574
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
41.1%
+1.1% vs TC avg
§102
15.7%
-24.3% vs TC avg
§112
26.3%
-13.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 548 resolved cases

Office Action

§103
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 . DETAILED ACTION Claim Status Claims 16-30 are pending. Claims 16-23 are under examination. Claims 16-23 are rejected. No claims allowed. Election/Restrictions Claims 24-30 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made with traverse in the reply filed on 06/11/2025. Filing Receipt PNG media_image1.png 146 1014 media_image1.png Greyscale PNG media_image2.png 164 1014 media_image2.png Greyscale Response to Amendments/Arguments Applicant's amendments and arguments filed 09/05/2025 are acknowledged and have been fully considered. Applicant's arguments filed 09/05/2025 have been fully considered but they are not persuasive. Applicant argues PNG media_image3.png 222 1086 media_image3.png Greyscale PNG media_image4.png 250 1072 media_image4.png Greyscale Examiner’s response The claims are directed to acrylic acid of at least 10% by weight of a liquid phase. The claims are not directed to “substantially pure (≥98% by weight) acrylic acid”. Concerning the purported “entirely different” “conditions” when working with sub. pure acrylic acid, These conditions are associated with sub. pure acrylic acid. The claims are not directed towards “substantially pure (≥98% by weight) acrylic acid”. Applicant argues PNG media_image5.png 30 1080 media_image5.png Greyscale PNG media_image6.png 168 1074 media_image6.png Greyscale Examiner’s response The above 2-30 ppm may be from Table 3 of the specification which only has an entry of 2 ppm. Moreover, the results in Table 3 were ascertained using sub. pure acrylic acid. The claims are not commensurate in scope with the purported critical content of the protoanemonin/anemonine. The reason being the claims allow for acrylic acid concentrations of least 10% by weight of a liquid phase. Concerning the “dramatic, dose-dependent inhibition effect observed in the present application”, the claims are not commensurate in scope with the “dramatic, dose-dependent inhibition effect”. Applicant argues PNG media_image7.png 280 1072 media_image7.png Greyscale Examiner’s response The above “additional experiments” are in the affidavit filed 09/05/2025. The experiments were conducted using “unstabilized” acrylic acid, i.e., in the absence of MEHQ and PTZ. The experimental procedures were otherwise identical to those described in the examples of the application. The examples in the application, specification pages 18-20 are conducted with “100.0g of acrylic acid (with appropriate additives)” (p. 18) at “>98% by weight” (p. 19). These experiments are not conducted with the claimed concentration of acrylic acid of at least 10% by weight of the liquid phase. Additionally, as written in the non-final mailed 08/14/2025 page 7, the prior art reference Wataaki teach 100ppm of protoanemonin in a 10% aqueous solution of purified acrylic acid (Table 2 page 84, right column Examples 3-6). This range overlaps the current range. Wataaki teach the following broader range (p. 84). The amount of protoanemonin used in the present invention is s to 5,000 ppm, preferably 10 to 2000 ppm, based on the amount of the monomer. Wataaki teach the following benefits of protoanemonin with aqueous acrylic acid (p. 83). “The present inventors have conducted extensive research into many organic compounds and have found that protoanemonin exhibits excellent effects as a polymerization inhibitor for an aqueous acrylic acid solution”. “Another feature of tile present invention is that, although protoanemonin has a large polymerization inhibitory effect. When acrylic acid is polymerized in an aqueous solution in the presence of a polymerization initiator, the polymerization initiation time is slightly longer, but the viscosity of the aqueous solution polymer is remarkably higher than that in the presence of a known polymerization inhibitor, and a polymer with a high degree of polymerization can be obtained”. Any purported “significant inhibition” would have been expected by the ordinary artisan per Wataaki above. Concerning the affidavit, The “additional experiments” in the affidavit filed 09/05/2025 were conducted using “unstabilized” acrylic acid, i.e., in the absence of MEHQ and PTZ. The experimental procedures were otherwise identical to those described in the examples of the application. The examples in the application, specification pages 18-20 are conducted with “100.0g of acrylic acid (with appropriate additives)” (p. 18) at “>98% by weight” (p. 19). These experiments are not conducted with the claimed concentration of acrylic acid of at least 10% by weight of the liquid phase. Additionally, as written in the non-final mailed 08/14/2025 page 7, the prior art reference Wataaki teach 100ppm of protoanemonin in a 10% aqueous solution of purified acrylic acid (Table 2 page 84, right column Examples 3-6). This range overlaps the current range. Wataaki teach the following broader range (p. 84). The amount of protoanemonin used in the present invention is s to 5,000 ppm, preferably 10 to 2000 ppm, based on the amount of the monomer. Wataaki teach the following benefits of protoanemonin with aqueous acrylic acid (p. 83). “The present inventors have conducted extensive research into many organic compounds and have found that protoanemonin exhibits excellent effects as a polymerization inhibitor for an aqueous acrylic acid solution”. “Another feature of tile present invention is that, although protoanemonin has a large polymerization inhibitory effect. When acrylic acid is polymerized in an aqueous solution in the presence of a polymerization initiator, the polymerization initiation time is slightly longer, but the viscosity of the aqueous solution polymer is remarkably higher than that in the presence of a known polymerization inhibitor, and a polymer with a high degree of polymerization can be obtained”. Any purported “inhibiting effect even in the absence of any other polymerization inhibitor” would have been expected by the ordinary artisan per Wataaki above. For the reasons stated above the rejections are being maintained/modified as set forth below. 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. Claim(s) 16-19 and 21-23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Blum et al. (USPGPub20120085969, Published 04-2012) and Wataaki (JP1972017714, Published 09-1972, Google translation attached) as evidence by Fauconet et al. (US Patent 5,734,075, Patented 03-1998). Interpretation of the Claims PNG media_image8.png 238 994 media_image8.png Greyscale Note: the spelling of protoanemonin as currently claimed is conventional. The use of a more conventional spelling is suggested. Below is a screen shot of the different names for the claimed substance in STN. PNG media_image9.png 162 802 media_image9.png Greyscale PNG media_image10.png 140 802 media_image10.png Greyscale Scope of the Prior Art Blum et al. teach the following. PNG media_image11.png 178 456 media_image11.png Greyscale The above ranges overlap the currently claimed ranges (claims 17-19). Concerning claim 17, Blum et al. teach the following. PNG media_image12.png 94 454 media_image12.png Greyscale PNG media_image13.png 66 452 media_image13.png Greyscale The above ranges overlap the currently claimed ranges (claims 17). Concerning the distillation of claims 21-22, Blum et al. teach the following. PNG media_image14.png 120 456 media_image14.png Greyscale The above ranges overlap the currently claimed ranges (claim 21). Blum et al. goes on to teach in paragraph 93 the following. PNG media_image15.png 138 456 media_image15.png Greyscale PNG media_image16.png 74 460 media_image16.png Greyscale Distillations have columns as evidence by Fauconet et al. (Figure 1, item C1). Concerning claim 23, Blum et al. teach the following. PNG media_image17.png 114 464 media_image17.png Greyscale PNG media_image18.png 116 454 media_image18.png Greyscale The above ranges overlap the currently claimed ranges (claim 23). Ascertain the Differences Blum et al. does not teach the protoanemonine content being 0.5 to 100 ppmw. Secondary References Wataaki teach 100ppm of protoanemonin in a 10% aqueous solution of purified acrylic acid (Table 2 page 84, right column Examples 3-6). This range overlaps the current range. Wataaki teach the following broader range (p. 84). The amount of protoanemonin used in the present invention is s to 5,000 ppm, preferably 10 to 2000 ppm, based on the amount of the monomer. Wataaki teach the following benefits of protoanemonin with aqueous acrylic acid (p. 83). “The present inventors have conducted extensive research into many organic compounds and have found that protoanemonin exhibits excellent effects as a polymerization inhibitor for an aqueous acrylic acid solution”. “Another feature of tile present invention is that, although protoanemonin has a large polymerization inhibitory effect. When acrylic acid is polymerized in an aqueous solution in the presence of a polymerization initiator, the polymerization initiation time is slightly longer, but the viscosity of the aqueous solution polymer is remarkably higher than that in the presence of a known polymerization inhibitor, and a polymer with a high degree of polymerization can be obtained”. Wataaki teach the following with regards to utilizing other inhibitors with protoanemonin (p. 84). “Furthermore, it is possible to use protoanemonin not only alone but also in combination with other known polymerization inhibitors depending on the application, and this does not impede the present invention in any way”. Concerning claim 22 and distillation, Wataaki teach the following (p. 83 left column). “Acrylic acid is a vinyl polymer that is highly polymerizable, particularly in an aqueous solution, and therefore the prevention of polymerization during distillation and storage of an aqueous acrylic acid solution is a major problem”. The above teachings overlap with the teachings of Blum et al. with respect to inhibitors of the polymerization of aqueous compositions of acrylic acid and render Wataaki analogous art to the invention. Obviousness It would have been prima facie obvious for an ordinary artisan before the effective filing date of the claimed invention to have added the protoanemonin taught by Wataaki to the composition taught by Blum et al. to arrive at the current invention of PNG media_image19.png 182 702 media_image19.png Greyscale The ordinary artisan would have done so to prevent polymerization of acrylic acid during the purification of the acrylic acid by distillation and acquire all the benefits associated with protoanemonin taught by Wataaki. The ordinary artisan would have had a reasonable expectation of success because Wataaki taught “it is possible to use protoanemonin not only alone but also in combination with other known polymerization inhibitors depending on the application, and this does not impede the present invention in any way”. (Wataaki, p. 84). The ordinary artisan would have looked to Wataaki because Wataaki taught overlapping subject matter and was determined to be analogous art to the invention. Concerning the claimed ranges/numerical values etc., MPEP 2144.05 I.: “In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976).” Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Blum et al. (USPGPub20120085969, Published 04-2012) and Wataaki (JP1972017714, Published 09-1972, Google translation attached) as evidence by Fauconet et al. (US Patent 5,734,075, Patented 03-1998) as applied to claims 16-19 and 21-23 and in further view of Imaizumi et al. (USPGPub 2008/0305707, Published 12-2008). Scope of the Prior Art The combinational teachings of the prior art are written in the above 103 rejection and are incorporated by reference. Concerning claim 20, Wataaki does not teach phenothiazine and/or methylhydroquinone but teach comparable inhibitors hydroquinone at 100 to 200ppm (Table 1). The above ranges overlap the currently claimed ranges (claim 20). Additionally, as a reminder, Wataaki teach the following with regards to utilizing other inhibitors with protoanemonin (p. 84). “Furthermore, it is possible to use protoanemonin not only alone but also in combination with other known polymerization inhibitors depending on the application, and this does not impede the present invention in any way”. Ascertain the Differences The prior art does not teach the addition of phenothiazine and/or methylhydroquinone. Secondary References Imaizumi et al. teach the following inhibitors methoquinone, hydroquinone, methylhydroquinone, phenothiazine, dibutyl hydroxytoluene in association with (meth)acrylic acid (par. 43). The above teachings overlap with the teachings of Wataaki with respect to inhibitors and render Imaizumi et al. analogous art to the invention. Obviousness It would have been prima facie obvious for an ordinary artisan before the effective filing date of the claimed invention to have added the inhibitors taught by Imaizumi et al. to the claimed composition arrived at by the combinational teachings of Blum et al. and Wataaki utilizing the claimed ppmw ranges. The ordinary artisan would have done so with a reasonable expectation of success because Wataaki taught “Furthermore, it is possible to use protoanemonin not only alone but also in combination with other known polymerization inhibitors depending on the application, and this does not impede the present invention in any way” and because Imaizumi et al. teach overlapping inhibitors taught by Wataaki. Concerning the claimed ranges/numerical values etc., MPEP 2144.05 I.: “In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976).” 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to BLAINE G DOLETSKI whose telephone number is (571)272-2766. The examiner can normally be reached M-F 7-4 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, Scarlett Goon can be reached at (571)270-5241. 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. /B.G.D/Examiner, Art Unit 1692 /Andrew D Kosar/Supervisory Patent Examiner, Art Unit 1625
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Prosecution Timeline

Sep 22, 2022
Application Filed
Jul 25, 2025
Non-Final Rejection — §103
Sep 05, 2025
Response Filed
Sep 05, 2025
Response after Non-Final Action
Nov 19, 2025
Final Rejection — §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
76%
Grant Probability
83%
With Interview (+7.2%)
2y 2m
Median Time to Grant
Moderate
PTA Risk
Based on 548 resolved cases by this examiner. Grant probability derived from career allow rate.

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