Prosecution Insights
Last updated: April 19, 2026
Application No. 17/757,389

METHOD FOR PRODUCING DIMETHYL TEREPHTHALATE FROM POLYESTER METHANOLYSIS DEPOLYMERIZATION SYSTEMS

Final Rejection §103§112
Filed
Jun 15, 2022
Examiner
O DELL, DAVID K
Art Unit
1621
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Eastman Chemical Company
OA Round
2 (Final)
58%
Grant Probability
Moderate
3-4
OA Rounds
2y 10m
To Grant
94%
With Interview

Examiner Intelligence

Grants 58% of resolved cases
58%
Career Allow Rate
768 granted / 1333 resolved
-2.4% vs TC avg
Strong +36% interview lift
Without
With
+35.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
43 currently pending
Career history
1376
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
32.9%
-7.1% vs TC avg
§102
15.8%
-24.2% vs TC avg
§112
28.2%
-11.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1333 resolved cases

Office Action

§103 §112
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 1. Claims 1-10, 12-20 are pending in the current application. 2. This application is a 371 of PCT/US2020/065257 12/16/2020; PCT/US2020/065257 has PRO 62/950,611 12/19/2019. Response to Amendments/Arguments 3. The rejections of canceled claim 11 are withdrawn. The rejection of claim 20 under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement is withdrawn. The rejection of claim(s) 1-10, 13-19 under 35 U.S.C. 103 as being unpatentable over Cudmore 4,578,502 and Jung, K. W.; et al “Acyclic and cyclic carbonic acids and esters, and their sulfur, selenium, and tellurium analogues” Science of Synthesis (2005), 18, 379-450 is withdrawn in view of the amendments. The rejection claim 1-3, 10, 12, 15-17, 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 is maintained. Applicant's arguments filed December 22, 2025 have been fully considered but they are not persuasive. The rejection of claim(s) 1-10, 12-19 under 35 U.S.C. 103 as being unpatentable over Cudmore 4,578,502 and Jung, is withdrawn based upon the amendments. The rejection of claim 20 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement is withdrawn based upon the amendments. The rejection of claim(s) 11-12 under 35 U.S.C. 103 as being unpatentable over Cudmore 4,578,502 and Jung, further in view of GB 1,061542 Ishihara U.S. 6,706,843 and Risse US 8,338,631 is withdrawn and now made for claims 1-10, 12-19 since the limitations of claim 11 (now canceled) were imported into claim 1. Applicant's arguments filed December 22, 2025 have been fully considered but they are not persuasive. According to the arguments, applicant has discovered a synergistic system, where removing a product enhances the equilibrium in a combined system. This is the expected result, consistent with Le Chatleier’s principle. According to Le Chatelier's principle, removing a product from a system at equilibrium causes the reaction to shift to the right (forward direction) producing more product. This action reduces the product concentration, prompting the system to consume more reactants to reestablish equilibrium. Assuming this basic chemical principle led to unexpected results, the specification does not appear to contain any results. The arguments are limited to a process where PET is depolymerized with methanol, with ethylene glycol reacting with dimethyl carbonate to give 1,3-dioxolan2-one. Nothing has been cited in terms of actual results by discussing examples in the specification with certain catalysts or reaction conditions such as temperature, pressure etc. Evidence of unexpected results "must be reasonably commensurate with the scope of the claims," although every claimed embodiment need not be tested. In re Huai-Hung Kao, 639 F.3d 1057, 1068 (Fed. Cir. 2011); see also Allergan, Inc. v. Apotex, Inc., 754 F.3d 952, 965 (Fed. Cir. 2014). "Appellant bears the burden of establishing a nexus between the full scope of the claimed invention and the proffered evidence of nonobviousness." Demaco Corp. v. F. Von Langsdorff Licensing Ltd., 851 F.2d 1387, 1392 (Fed. Cir. 1988). Unexpected results must be “commensurate in scope with the degree of protection sought by the claimed subject matter.” In re Harris, 409 F.3d 1339, 1344 (Fed. Cir. 2005). Since there are no results in the specification they cannot be unexpected. Claim 20 was amended to overcome a 112 rejection and is rejected under 103 below. 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. 4. Claim 1-3, 10, 12, 15-17 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 1 is drawn to converting a diol to “a compound substantially non-reactive with said dimethyl terephthalate and said polyester”. It is unclear what the compound is since it is only defined by what it substantially will not do chemically. 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. 6. Claim(s) 1-10, 12-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cudmore 4,578,502 and Jung, K. W.; et al “Acyclic and cyclic carbonic acids and esters, and their sulfur, selenium, and tellurium analogues” Science of Synthesis (2005), 18, 379-450 further in view of GB 1,061542 Ishihara U.S. 6,706,843 and Risse US 8,338,631. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: Determination of the scope and content of the prior art (MPEP 2141.01) Cudmore teaches the depolymerization methanolysis of polyethylene terephthalate (PET) to dimethyl terephthalate, (DMT), reaction which is the step (a) of claim 1 and the steps (a) and (b) of claim 18. The process id described generally at column 2 lines 58ff: 1. Granulating said scrap resin into resin particles sufficiently minute to be readily slurried. 2. Slurrying said resin particles with sufficient solvent such as water or methanol to prepare a readly pumpable slurry. 3. Depolymerizing said slurried resin by application of heat and pressure for a time sufficient to convert substantially all of said resin into its monmeric components in liquid form as a mixture of a monomeric poly carboxylic acid or a dimethyl ester thereof, and a polyol, typically a lower alkylene diol such as ethylene glycol, dissolved in said solvent. Such a depolymerization reaction is occasionally referred to as hydrolysis whenever water is the solvent. It may also be referred to as methanolysis whenever methanol is the solvent. Besides the DMT, which is the product in claim 15, the reaction also produces as “a mixture of a monomeric poly carboxylic acid or a dimethyl ester thereof, and a polyol, typically a lower alkylene diol such as ethylene glycol”. “Step 5. Recovering said crystallized monomeric polycarboxylic acid by filtration or centrifugation.” is the step in claim 15-16. 11. “The process of claim 10 where said pressure is at least 350 psig,” which is that in claim 14. Jung discloses all of the reactions of step (b) claim 1 and those of claim 18 step (c) and all the specific carbonate forming reactions of claims 4-7, 18-19. Jung discloses the reactions of claim 5-7, with dimethyl carbonate and other alkyl carbonates on page 389, “18.4.3.1.2.2 Variation 2: Transcarbonylation Using Dimethyl or Diethyl Carbonate” and on page 398 where cyclic carbonates are formed, “18.4.4.1.1.2 Variation 2: Transcarbonylation Using Dimethyl or Diethyl Carbonate”. Reactions with phosgene are disclosed on page 397, “18.4.4.1.1 Method 1: Transfer of the Carbonyl Group to Diols” While reactions with urea are disclosed on page 393 “18.4.3.1.6 Method 6: Coupling Using Urea as a Carbonyl Source”. Claims 1 and 12 use additional catalysts in the depolymerization with methanol. These are known additives in these reactions as shown by GB 1061542 A on page 3, “The depolymerization process of the invention can be carried out without the addition of catalyst but the presence of the usual ester interchange catalysts shortens the duration of the ester interchange reaction. Suitable catalysts are, for example, zinc acetate, manganese acetate, manganese phosphate, calcium phosphate, alkali metal oxides, alkaline earth metal oxides, alkali metal hydroxides, alkaline earth metal hydroxides, sodium silicate and lead oxide.” At least alkali metal oxides, alkaline earth metal oxides, alkali metal hydroxides, alkaline earth metal hydroxides are in claim 12. Ishihara also uses a catalyst as discussed on column 4 line 16 ff. “In the separation and recovery process of the present invention, the depolymerization catalyst for step (a) preferably contains at least one metal compound selected from the group consisting of metal carbonates, metal carboxylates, metal oxides and metal alkoxides, and the amount of the catalyst is preferably controlled to 0.1 to 10% based on the weight of the polyester waste. In the separation and recovery process of the present invention, the metal compound for the depolymerization catalyst preferably selected from the group consisting of sodium carbonate, sodium carboxylates, manganese acetate and zinc acetate…..In the transesterification reaction of step ( d), the methanol is preferably charged in an amount of 150 to 400 wt % based on the weight of the charged polyester waste, and the transesterification reaction catalyst is preferably charged simultaneously in an amount of 0.3 to 10 wt % based on the weight of the charged polyester waste.” These same catalysts also promote the formation of cyclic carbonates from the diols as disclosed in Risse US 8,338,631 column 5-8. Ascertainment of the difference between the prior art and the claims The prior art differs only by the source of the diol in the reactions of Jung. Cudmore does not elaborate on what additional processes the ethylene glycol was destined for. Finding of prima facie obviousness Rationale and Motivation (MPEP 2142-2143) It would have been obvious to one of ordinary skill in the art at the time the claimed invention was made to conduct the reactions of Jung on the depolymerized methanolysis of polyethylene terephthalate (PET) containing glycols to make cyclic carbonates. Line 24 ff. explains that diols would interfere with subsequent processing. “Diols and polyols are not utilized as a solvent in the recovery process of the instant invention inasmuch as their use would result in extraneous esterification reactions in the latter steps of the process or in difficult separation steps”. Reacting the glycols would make the process more efficient and create a further value added product, carbonates, through the known reactions of Jung. A reference is good not only for what it teaches by direct anticipation but also for what one of ordinary skill in the art might reasonably infer from the teachings. (In re Opprecht 12 USPQ 2d 1235, 1236 (Fed Cir. 1989); In re Bode 193 USPQ 12 (CCPA) 1976). In light of the forgoing discussion, the Examiner concludes that the subject matter defined by the instant claims would have been obvious within the meaning of 35 USC 103. From the teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary. 7. Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Cudmore 4,578,502 and Jung, GB 1,061542, Ishihara U.S. ‘843 and Risse US ‘631 as applied to claims 1-10, 12-19 above and further in view of Okano “Acetalization of Ketones and Aldehydes Catalyzed by Lanthanoid Trisulfonates” APPLIED ORGANOMETALLIC CHEMISTRY, VOL. 9, 473-478 (1995). Claim 20 is drawn to an additional step of converting ethylene glycol and 2,2-dimethoxy propane to 2,2-dimethyl-1,3-dixoane. This reaction is known to give the dioxolane, as described in Okano Page 476, Table 5: PNG media_image1.png 90 638 media_image1.png Greyscale PNG media_image2.png 43 630 media_image2.png Greyscale Reacting the ethyleneglycol with 2,2-dimethoxypropane would create a further value added product, 2,2-dimethyl-1,3-dioxolane, through the known reactions of Jung. Conclusion 8. 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 DAVID K O'DELL whose telephone number is (571)272-9071. The examiner can normally be reached on Monday - Friday 9:30 - 7:00 PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Clinton Brooks can be reached on 571-270-7682. 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 Patent Center. Status information for published applications may be obtained from Patent Center. Status information for unpublished applications is available through Patent Center for authorized users only. Should you have questions about access to Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). 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) Form at https://www.uspto.gov/patents/uspto-automated- interview-request-air-form. /DAVID K O'DELL/Primary Examiner, Art Unit 1621
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Prosecution Timeline

Jun 15, 2022
Application Filed
Jun 27, 2025
Non-Final Rejection — §103, §112
Dec 22, 2025
Response Filed
Feb 09, 2026
Final Rejection — §103, §112 (current)

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Prosecution Projections

3-4
Expected OA Rounds
58%
Grant Probability
94%
With Interview (+35.9%)
2y 10m
Median Time to Grant
Moderate
PTA Risk
Based on 1333 resolved cases by this examiner. Grant probability derived from career allow rate.

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