DETAILED ACTION
Note
The amendments filed December 23, 2025 do not consistently underline the added limitations and strike-through (or put brackets around) the deleted limitations. For example, in claim 13 “per metric ton of material, of” has been added with no underline. Not properly indicating the status of limitations in the amendments can result in a Notice of Non-Compliant Amendment.
Drawings
The drawings were received on December 23, 2025. These drawings are acceptable.
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 1-16 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 1: BHET is undefined. For the purpose of further examination, BHET is taken to mean bis-hydroxylethylterephthalate.
Regarding claim 2: The term rBHET is undefined. For the purpose of further examination, it is taken to mean recycled bis-hydroxylethylterephthalate.
Regarding claim 3: The term rBHET is undefined. For the purpose of further examination, it is taken to mean recycled bis-hydroxylethylterephthalate.
A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 3 recites the broad recitation “a carboxyl end group concentration (CEG), measured as mols acid ends per metric ton of material of from 300 to 1500”, and the claim also recites preferably from 500 to 1200, more preferably from 700 to 1100”, which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
Regarding claim 5: The term rBHET is undefined. For the purpose of further examination, it is taken to mean recycled bis-hydroxylethylterephthalate.
Regarding claim 6: The term rBHET is undefined. For the purpose of further examination, it is taken to mean recycled bis-hydroxylethylterephthalate.
Claim 6, which depends on claim 1, requires the temperature to be either 120 C to 300 C or 270 C to 300 C, yet claim 1 requires the temperature to be 150 °C to 270 °C. Therefore, the limitations of claim 6 are broader than claim 1, from which they depend.
Regarding claim 8: The term rBHET is undefined. For the purpose of further examination, it is taken to mean recycled bis-hydroxylethylterephthalate.
Regarding claim 9: The term rBHET is undefined. For the purpose of further examination, it is taken to mean recycled bis-hydroxylethylterephthalate.
Regarding claim 14: The limitations “carboxyl end group concentration (CEG)” is defined in claim 14 as “measured as mols acid endsof between 40 to 200”, which in indefinite. For the purpose of further examination, it is taken to mean “measured as mols acid ends per metric ton of material”, as in claim 13.
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.
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 1-6 and 11-16 are rejected under 35 U.S.C. 103 as being unpatentable over Joshi et al. (US 2023/0092075).
Regarding claims 1-4, 6, and 12-16: Joshi et al. teaches a method for using recycled PET to form an oligomeric polyethylene terephthalate (para. 55, 62) comprising reacting bis-hydroxyethyl terephthalate (para. 5, 62) which has been recycled by depolymerizing polyester with water in a reaction vessel (para. 5, 24) to form small PET polymers that react with each other to make longer and longer PET chains/oligomers (para. 62). The temperature is 325 °C or lower (para. 74), which overlaps with the claimed range. Joshi et al. also teaches the oligomeric PET structure (para. 77, 3) having carboxylic acid or hydroxy end groups (fig. 5). Joshi et al. teaches the recycled PET polymer is added back into the feed stream of a PET reactor (para. 55) meaning that some percentage between 0-100% is recycled.
Joshi et al. does not explicitly teach the degree of polymerization, the CEG, or the ratio of hydroxyl end group to carboxyl end group in the ranges claimed. However, since the prior art teaches the same reactants (bis-hydroxylethylene terephthalate and water) and the same reaction (synthesizing a polyethylene terephthalate) in a reactor at an overlapping temperature, the product would have the same properties. Mere recognition of latent properties or additional advantages in the prior art does not render nonobvious an otherwise known invention (MPEP 2145 II). Products of identical chemical composition cannot have mutually exclusive properties; a chemical composition and its properties are inseparable (MPEP 2112.01 II).
Regarding claim 5: Joshi et al. teaches the water is in an amount of less than 5% (para. 113), which overlaps the claimed ranges.
Regarding claim 11: Joshi et al. teaches adding the recycled PET polymer back into the feed stream of a PET reactor (para. 55).
Claims 7-10 are rejected under 35 U.S.C. 103 as being unpatentable over Joshi et al. (US 2023/0092075) as applied to claim 1 set forth above and in view of Nakao et al. (US 2005/0004390).
Regarding claim 7: Joshi et al. teaches the basic claimed method as set forth above. Not disclosed is the residence time. However, Nakao et al. teaches a similar reaction with a residence/retention time of 1-5 hours (para. 67). Joshi et al. and Nakao et al. are analogous art since they are both concerned with the same field of endeavor, namely recycling PET polymers with a reaction with water. Before the effective filing date of the claimed invention a person having ordinary skill in the art would have found it obvious to use the retention time of Nakao et al. in the method of Joshi et al. and would have been motivated to do so since Joshi et al. does not teach a retention time so a person having ordinary skill in the art would have to look to a similar reaction to deduce what the retention time should be.
Regarding claim 8: Joshi et al. teaches the basic claimed method as set forth above. Not disclosed is the pressure. However, Nakao et al. teaches a gauge pressure of 2.9-4.0 MPa (para. 67), which is 29-40 barG, which overlaps the claimed range. Before the effective filing date of the claimed invention a person having ordinary skill in the art would have found it obvious to use the pressure of Nakao et al. in the method of Joshi et al. and would have been motivated to do so since Joshi et al. does not teach a reaction pressure so a person having ordinary skill in the art would have to look to a similar reaction to deduce what the pressure should be.
Regarding claims 9 and 10: Joshi et al. teaches the basic claimed method as set forth above. Not disclosed is what type of catalyst should be used. However, Nakao et al. teaches antimony trioxide (claim 12). Before the effective filing date of the claimed invention a person having ordinary skill in the art would have found it obvious to use the catalyst of Nakao et al. in the method of Joshi et al. and would have been motivated to do so since Joshi et al. does not teach which catalyst can be used so a person having ordinary skill in the art would have to look to a similar reaction to deduce what the catalyst should be.
Response to Arguments
Applicant’s arguments filed December 23, 2025 have been considered but are moot because of the new ground of rejection.
Applicants argue that “official notice” was taken without factual support. However, factual support is supplied, namely that products of identical chemical composition cannot have mutually exclusive properties; a chemical composition and its properties are inseparable (MPEP 2112.01 II). Since the prior art teaches the same reactants and the same reaction, it is implicit that the composition would have these properties. If it is applicants’ position that this would not be the case: (1) evidence would need to be presented to support applicants’ position; and (2) it would be the Office’s position that the application contains inadequate disclosure that there is no teaching as to how to obtain a composition with these properties.
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.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Megan McCulley whose telephone number is (571)270-3292. The examiner can normally be reached Monday - Friday 9-5:30.
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, Mark Eashoo can be reached at 571-272-1197. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/MEGAN MCCULLEY/Primary Examiner, Art Unit 1767
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