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 Status
Claims 1-18 were filed on 4/23/2024 and are pending.
Priority
The application was filed on 4/23/2024 and claims benefit of priority to:
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See filing receipt dated 9/25/2024.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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) 1-12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mori (JP2011207823A, published on 10/20/2011, including a machine generated English translation) as evidenced by Methanol (downloaded from https://pubchem.ncbi.nlm.nih.gov/compound/Methanol#section=Boiling-Point&fullscreen=true on 8/19/2026).
Applicants claim a low temperature (75°C and below) process for the C1-C3 alcoholysis of BHET (bis(hydroxyethyl)terephthalate) and derivatives thereof.
Mori teaches a method for producing dimethyl terephthalate (DMT) from polyesters, in particular polyethylene terephthalate (PET) having an average water content of 0.5 to 3.0 wt%. Mori teaches the process comprises subjecting the PET to glycolysis with ethylene glycol (EG) (step a) with distillation of excess EG from the reaction (step b) and subjecting the glycolysis product to a transesterification reaction with methanol, a C1 alcohol (step c). See abstract and claims. Mori teaches that transesterification reaction comprises a catalyst, including alkali and alkaline earth metal carbonates, acetates, alkoxides, hydroxides, and oxides. See [0011] and claim 3.
Mori teaches examples 1-2 in [0012-0015]. In both examples, the PET is depolymerized with EG to provide an intermediate product of BHET. The BHET (claim 10) is subjected to transesterification with methanol (C1 alcohol, claim 2) in the presence of a potassium carbonate catalyst (alkali metal carbonate). In the examples, Mori teaches that the methanol and potassium carbonate are added to the BHET and that the reaction mixture is heated under normal pressure to the reflux temperature of MeOH for 1 hour (a first time period). As evidenced by Methanol, the boiling point (reflux temperature) of methanol is about 65°C, which falls within the range of step (b) in claims 1 and 5. The methanolysis reaction mixture is then cooled over a second time period to about 35°C (35-40°C), which falls within the temperature range of step (c) in claim 1. Once at about 35°C, the reaction mixture was immediately (thus the third time period is about 0 minutes, which falls within the range of step (d) in claims 1 and 8) either filtered (example 1) or centrifuged (example 2-claim 9) to separate the cake component and the filtrate component. The procedure indicates that the pre-filtration/centrifugation mixture existed as a slurry and that methanol and/or ethylene glycol are isolated from the DMT cake in the filtrate (claim 12). The cake was further washed with methanol (which is again isolated from the DMT cake by filtration as the filtrate-claim 12), dried, and the solvent was evaporated and separated to produce crude crystals of DMT (claim 11). Further regarding claim 12, Mori teaches that EG is also recovered and isolated by distillation in the preliminary glycolysis step to prepare BHET and that the methanol and EG recovered from the process are recycled to the depolymerization step. See steps a) and b) in claim 1 and [0010].
Mori does not explicitly the order of addition in instant steps (a) and (b) in claim 1. Mori indicates that methanol and potassium carbonate were added to the BHET and heated for 1 hour under normal pressure and reflux conditions.
It would have been prima facie obvious to arrive at the claimed invention based on the teachings of Mori with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill would have been motivated to modify the process of Mori to arrive at that claimed because the selection of any order of performing process steps and/or mixing ingredients is prima facie obvious in the absence of new or unexpected results. See MPEP 2144.04(IV)(C). Mori teaches that the transesterification requires heat. Therefore, regardless of the order of adding the reactants, the reaction will predictably produce DMT from BHET when heat is applied.
Regarding claims 3 and 4, Mori teaches that transesterification reaction comprises a catalyst, including alkali (including lithium, sodium, potassium) and alkaline earth metal carbonates, acetates, alkoxides, hydroxides, and oxides. See [0011] and claim 3. Therefore, it would have been obvious to use sodium, potassium, lithium hydroxide or C1-3 alkoxide thereof as the transesterification catalyst because Mori expressly teaches that these are alternatives for the potassium carbonate used in the examples.
Regarding claim 6, a person of ordinary skill would have been motivated to arrive at first time period for transesterification step (b) falling within the range of 10-20 minutes through routine optimization of the process of Mori. Mori teaches that both examples are run under reflux for 60 minutes, however, the time period does not appear to be critical to the success of the reaction. The skilled artisan would be motivated to decrease the reaction time in order to make the process more efficient. A process carried out for a shorter reaction time will still predictably produce the DMT product. Also see MPEP 2144.05. Additionally, Mori teaches that a selection of different catalysts may be used, which may require minor optimization of reaction time for each selection.
Regarding claim 7, Mori teaches that the mixture is cooled from 65 to about 35°C in example 1 (35- 40°C). A person of ordinary skill would have been motivated to arrive at the second time period for cooling step (c) of 15-45 minutes through routine optimization of the process of Mori. Mori does not teach the time it takes to cool the mixture from 65-35°C, however, the time period does not appear to be critical as long as the mixture reaches about 35°C before the filtration is carried out (claim 7). Also see MPEP 2144.05.
Claim(s) 13-15 and 17-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pham (“Low-energy catalytic methanolysis of poly(ethyleneterephthalate)” Green Chem., 2021, p. 511, first published online 12/8/2020, including Supporting Information (SI) p. S1-S11).
Applicants claim a low temperature (35°C and below) process for the C1-C3 alcoholysis of BHET (bis(hydroxyethyl)terephthalate) and derivatives thereof.
Pham is directed toward low-energy catalyst methanolysis of polye(ethyleneterephthalate). Pham teaches carrying out a methanolysis (using methanol-claim 14) at 25°C for 24 hours (a time period) over a variety of feedstocks, including BHET monomer (claim 14) and BHET dimer, to produce DMT (claim 17):
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. See Table 1 on p. 519 and discussion thereof. The temperature of 25°C is “less than about 35°C”. At the top of col. 2 on p. 519, Pham teaches: “Table 1 shows the methanolysis results for various feedstock materials possessing ester bonds connecting terephthalate and EG. Methanolysis was carried out under identical conditions described in the Experimental section (see section 2.2).”.
Experimental section 2.2 on p. 516 recites:
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Thus, the process also includes a potassium carbonate (K2CO3, an alkali metal carbonate) transesterification catalyst. In Fig. S5 on p. S5, Pham teaches that potassium methoxide (CH3OK, an alkali metal alkoxide), also promotes the reaction (claim 15). Also see list of bases tested in section 2.1 on p. 512-513.
Pham teaches that the product is isolated from a liquid filtrate, obtained by subjecting the reaction mixture to filtration to remove insoluble solids. Pham teaches that the liquid solvents and EG are removed from the filtrate by evaporation using a rotary evaporator (thus isolating the by-product EG and methanol from the mixture-claim 18). Pham teaches that the rest of the mixture, comprising non-distillable products, were mixed with water and DMT was recrystallized from the water as almost pure white needle-like crystals. See section 2.3 on p. 513. Thus, Pham teaches instant step c).
Though Pham teaches all of the required reactants and temperature of instant steps a) and b) in the experimental procedure, Pham fails to teach the claimed order of addition, wherein the BHET is mixed with methanol, before the catalyst is added thereto.
It would have been prima facie obvious to arrive at the instantly claimed process based on the teachings of Pham with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill would have been motivated to arrive at the claimed process based on the teachings of Pham because the selection of any order of performing process steps and/or mixing ingredients is prima facie obvious in the absence of new or unexpected results. See MPEP 2144.04(IV)(C). Regardless of the order of adding the reactants, the reaction will predictably produce DMT from BHET.
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pham (“Low-energy catalytic methanolysis of poly(ethyleneterephthalate)” Green Chem., 2021, p. 511, first published online 12/8/2020, including Supporting Information (SI) p. S1-S11), as applied to claims 13-15 and 17-18 above, and further in view of Mori (JP2011207823A, published on 10/20/2011, including a machine generated English translation).
Pham does not explicitly teach that the potassium carbonate transesterification catalyst can be replaced by one of the claimed alkali hydroxides. The teachings of Mori were discussed in a previous rejection and are incorporated by reference herein. Mori teaches an analogous process to that of Pham which is carried out at the reflux temperature of MeOH (about 65°C) for a shorter period of time (1 hour). Mori teaches that transesterification reaction comprises a catalyst, including alkali (including lithium, sodium, potassium) and alkaline earth metal carbonates, acetates, alkoxides, hydroxides, and oxides. See [0011] and claim 3.
It would have been prima facie obvious to combine the teachings of Pham and Mori to arrive at the instantly claimed process with a reasonable expectation of success before the effective filing of the claimed invention. A person of ordinary skill would have been motivated to replace the carbonate base of Pham with the claimed hydroxide base because Mori teaches that alkali hydroxide bases are known substitutes for alkali carbonates in the low temperature methanolysis of BHET. Therefore, replacing one known catalyst with another will predictably produce DMT from BHET in the combined process of Pham and Mori. Also see MPEP 2143(I)(B).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AMY C BONAPARTE whose telephone number is (571)272-7307. The examiner can normally be reached 11-7.
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/AMY C BONAPARTE/
Primary Examiner, Art Unit 1692
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