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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Any rejections and/or objections made in the previous Office action and not repeated below are hereby withdrawn.
New grounds of rejection not necessitated by Applicant’s amendment is presented below. Accordingly, the following action is non-final.
A Declaration from the inventor of the present application, Raouf Medimagh, has been received on 4/13/2026. The Declaration is addressed within the “Response to Arguments” section below.
Priority
Applicant’s foreign priority claim to FR2012085 is acknowledged. A certified English translation was received on 4/30/2026. However, written support for the subject matter claimed is not found within the priority document. Specifically, the priority document only describes depolymerizing PET into DMT with methanol whereas claims 1 and 16 use “ester of terephthalate” and “monoalcohol” generically. The priority document only describes organic bases with a guanidine unit and DBU whereas claims 1 and 16 of the present application is open to those with amidine units generically. The full scope of claims 3, 4, 6, 8-10, 18, and 19 is also not supported.
Therefore, the claims as currently presented are not entitled to the foreign priority date and claims 1-19 are construed as having a filing date of 11/24/2021 (corresponding with PCT/FR2021/052085).
Claim Interpretation
Claims 1 and 16 require a “catalytic amount” of bases be used. Per ¶ 25 of the specification and Applicant’s arguments of 4/13/2026, a “catalytic amount” equates to a molar ratio of 1% to 49% relative to the amount of PET.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 3, 11, and 16-19 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 3 has been amended to recite “X = C-R3, N-R2 with R = H, alkyl”. The limitation at issue is not found within the specification as originally filed. Therefore, claim 3 fails to comply with the written description requirement.
Claim 11 has been amended to recite “wherein the weight amount of the bases is less than 5% with respect to a weight of the PET”. Written support is only found for the 5% figure to be a molar ratio. Therefore, claim 11 fails to comply with the written description requirement.
Claim 16 has been amended to recite “the organic base and the etheroxide or inorganic base are present in catalytic amount”. Written support is only found for all bases to be present in catalytic amount. Therefore, claim 16 fails to comply with the written description requirement.
As claims 17-19 depend from claim 16, they are rejected for the same issue discussed above.
Claim 18 has been amended to recite “X = C-R3, N-R2 with R = H, alkyl”. The limitation at issue is not found within the specification as originally filed. Therefore, claim 3 fails to comply with the written description requirement.
Claims 3 and 16-19 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 3 presents two definitions of X (either X = “C, N” or X = C-R3, N-R2). Accordingly, the intended scope of the claim is unclear.
Further with respect to claim 3, the variables R2 and R3 are undefined. It is also unclear whether the second recitation of “R = H, alkyl” is meant to refer to R2/R3 or not. Therefore, the intended scope of the claim is unclear.
Claim 16 refers to “the organic base and the etheroxide or inorganic base”. The terminology “the inorganic base” lacks antecedent basis. Therefore, the intended scope of the claim is unclear.
As claims 17-19 depend from claim 16, they are rejected for the same issue discussed above.
Claim 18 presents two definitions of X (either X = “C, N” or X = C-R3, N-R2). It is also unclear whether the second recitation of “R = H, alkyl” is meant to refer to R2/R3 or not. Accordingly, the intended scope of the claim is unclear.
Further with respect to claim 18, the variables R2 and R3 are undefined. Therefore, the intended scope of the claim is unclear.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 5 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 5 recites “wherein the etheroxide base is selected from sodium or potassium methoxide, or the inorganic base is selected from sodium hydroxide or potassium hydroxide”. Claim 1 already requires such. Therefore, claim 5 fails to further limit the subject matter of claim upon which it depends.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 103
Claim(s) 1-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Medimagh (WO 2020/128218 A1) in view of Sharpe (US 2023/0030777 A1). As the cited WO publication is in a non-English language, a machine-translated version of the publication will be cited to.
The examiner has reviewed priority application 62/951,425 of Sharpe finds written support for the citations below.
Regarding Claims 1, 3-7, 16, 18, and 19, Medimagh teaches methods of recycling PET comprising milling/grinding the PET into fragmented pieces, pretreating the fragmented pieces with solvent to facilitate depolymerization, and depolymerizing the PET into terephthalate ester and monoethylene glycol with monoalcohol and base such as sodium/potassium methoxide (¶ 26-30, 35). Embodiments are taught with 2 g PET relative to 15 mL (~ 12 g) of methanol and 560 mg of sodium methoxide to provide dimethyl terephthalate and ethylene glycol (¶ 76), construed as depolymerization with excess monoalcohol. White solid terephthalate ester is isolated via filtration (¶ 76), construed as powder.
Medimagh teaches depolymerizations at temperatures below 50 degrees C (¶ 29) and timeframes on the order of 30 minutes to 5 hours (Examples spanning ¶ 69-77). The disclosed temperature range overlaps that claimed. It would have been obvious to one of ordinary skill in the art to use a range within the claimed range because a reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill the art and Medimagh suggests the claimed range. A person of ordinary skill would be motivated to use the claimed amount, based on the teachings of Medimagh. See MPEP 2123.
Medimagh differs from the subject matter claimed in that a combination of organic amidine/guanidine base with etheroxide/inorganic base in catalytic amounts (i.e. a molar ratio of 1% to 49% relative to the amount of PET) is not described. Sharpe also pertains to the depolymerization of polyalkylene terephthalates with monoalcohol in the presence of base catalyst (Abstract). Sharpe teaches sodium methoxide, diazabicyclo[5.4.0]undec-7-ene (DBU), and triazabicyclodecene (TBD) were all known catalysts of the art that exhibit excellent depolymerization ability at reasonable catalyst loadings (¶ 29), such as 0.5-10 mol% (¶ 12; Table 2). It is well settled that it is prima facie obvious to combine two ingredients, each of which is targeted by the prior art to be useful for the same purpose. In re Crockett, 279 F.2d 274, 126 USPQ 186 (CCPA 1960). Ex parte Quadranti, 25 USPQ2d 1071 (Bd. Pat. App. & Inter. 1992). Also, case law holds that “it is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.... [T]he idea of combining them flows logically from their having been individually taught in the prior art.” In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980). As Sharpe indicates it was known in the art all of sodium methoxide, diazabicyclo[5.4.0]undec-7-ene (DBU), and triazabicyclodecene (TBD) are effective depolymerization catalysts, it would have been obvious to one of ordinary skill in the art to utilize combinations of suitable catalysts, inclusive of a combination of sodium methoxide with diazabicyclo[5.4.0]undec-7-ene (DBU) and/or triazabicyclodecene (TBD) to afford the predictable result of depolymerization ability at reasonable catalyst loadings, inclusive of 0.5-10 mol%.
Regarding Claims 2 and 17, Medimagh teaches pretreating with solvents such as DMAC, DMF, and/or MEK (¶ 47).
Regarding Claim 8, Medimagh teaches ethanol can be used as monoalcohol (¶ 53). As monoalcohol solvent is used in excess, a diethyl terephthalate product would naturally arise over the course of depolymerization.
Regarding Claims 9 and 10, Medimagh teaches monoalcohols such as methanol, ethanol, or any linear/branched alcohol with a hydrocarbon chain can be used (¶ 53). Although Medimagh does not explicitly state the species propanol and butanol, Medimagh makes clear any linear alcohol with a hydrocarbon chain can be used. It is the examiner’s position that one would expect similar beneficial results with compounds having only additional one or two –CH2– groups in view of the teachings of Medimagh. Case laws holds that homologs (compounds differing regularly by the successive addition of the same chemical group, e.g,. by –CH2– groups) are generally of sufficiently close structural similarity that there is a presumed expectation that such compounds possess similar properties. In re Wilder, 563 F.2d 457, 195 USPQ 426 (CCPA 1977). In view of such, it would have been obvious to one of ordinary skill in the art that linear homologues such as propanol or butanol can be used within the protocols of Medimagh with a reasonable expectation of similar characteristics, namely the ability to arrive at terephthalate and monoethylene glycol depolymerization products. As Medimagh teaches excess of mono-alcohol is used, the formation of either dipropyl terephthalate or dibutyl terephthalate would naturally arise.
Regarding Claim 11, Sharpe teaches reasonable catalyst loadings (¶ 29), such as 0.5-10 mol% (¶ 12; Table 2). The range of Sharpe suggests base contents that overlap the concentrations claimed. It would have been obvious to one of ordinary skill in the art to use a range within the claimed range because a reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill the art and Sharpe suggests the claimed range. A person of ordinary skill would be motivated to use the claimed amount, based on the teachings of Sharpe. See MPEP 2123.
Regarding Claim 12, Medimagh teaches embodiments with 2 g PET (~ 0.01 mol) relative to 15 mL (~ 12 g; ~ 0.37 mol) of methanol is used (¶ 76), which is in excess of 5x greater in molar ratio.
Regarding Claim 13, Medimagh teaches depolymerizations timeframes such as 1 hr 30 min (¶ 76). Medimagh teaches temperatures below 50 degrees C (¶ 29). While just outside the range claimed, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. MPEP 2144.05(I). In view of the cited case law therein, it would have been obvious to one of ordinary skill in the arts that temperatures just outside the range of Medimagh (e.g. 50 degrees C) can be used since the value is so close that there would be expectation that the reaction would still afford the predictable result of depolymerized PET.
Alternatively, to the extent Medimagh differs from the subject matter claimed with respect to depolymerization temperature used, Sharpe teaches it was known in the art the temperature used for depolymerization should be high enough in order to effect depolymerization while also low reaction temperatures at which the catalyst is active is generally preferable (¶ 35; Claim 1). Case law holds that “discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art.” See In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). In view of this, it would have been obvious to one of ordinary skill in the art to discover optimal or workable depolymerization temperatures within the scope of the present claims so as to produce desirable reaction rates/catalysis while avoiding costs associated with excessive heating.
Regarding Claim 14, Medimagh teaches washing the pretreated pieces with alcohol and drying prior to depolymerizing (¶ 76).
Regarding Claim 15, Medimagh teaches recovering DMT via filtration of the reaction medium and washing a cake obtained (¶ 76).
Claim(s) 1-10 and 12-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Medimagh (WO 2020/128218 A1) in view of Pham (Green Chem. 2021, 23, 511). As the cited WO publication is in a non-English language, a machine-translated version of the publication will be cited to.
Pham has a publication date of 12/8/2020. Therefore, Pham is prior art under 35 USC 102(a)(1) for reasons set forth within the “Priority” section above.
Regarding Claims 1, 3-7, 16, and 18-20, Medimagh teaches methods of recycling PET comprising milling/grinding the PET into fragmented pieces, pretreating the fragmented pieces with solvent to facilitate depolymerization, and depolymerizing the PET into terephthalate ester and monoethylene glycol with monoalcohol and base such as sodium/potassium methoxide (¶ 26-30, 35). Embodiments are taught with 2 g PET relative to 15 mL (~ 12 g) of methanol and 560 mg of sodium methoxide to provide dimethyl terephthalate and ethylene glycol (¶ 76), construed as depolymerization with excess monoalcohol. White solid terephthalate ester is isolated via filtration (¶ 76), construed as powder.
Medimagh teaches depolymerizations at temperatures below 50 degrees C (¶ 29) and timeframes on the order of 30 minutes to 5 hours (Examples spanning ¶ 69-77). The disclosed temperature range overlaps that claimed. It would have been obvious to one of ordinary skill in the art to use a range within the claimed range because a reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill the art and Medimagh suggests the claimed range. A person of ordinary skill would be motivated to use the claimed amount, based on the teachings of Medimagh. See MPEP 2123.
Medimagh differs from the subject matter claimed in that a combination of organic amidine/guanidine base with etheroxide/inorganic base in catalytic amounts (i.e. a molar ratio of 1% to 49% relative to the amount of PET) is not described. Pham teaches potassium methoxide and triazabicyclodecene (TBD) were both known catalysts of the art that exhibit excellent depolymerization ability (Figure 2; Section 3.2). Catalyst levels of 20 mol% are applicable (Conclusion section of page 524). It is well settled that it is prima facie obvious to combine two ingredients, each of which is targeted by the prior art to be useful for the same purpose. In re Crockett, 279 F.2d 274, 126 USPQ 186 (CCPA 1960). Ex parte Quadranti, 25 USPQ2d 1071 (Bd. Pat. App. & Inter. 1992). Also, case law holds that “it is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.... [T]he idea of combining them flows logically from their having been individually taught in the prior art.” In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980). As Pham indicates it was known in the art all of potassium methoxide and triazabicyclodecene (TBD) are effective catalysts at catalyst levels such as 20 mol%, it would have been obvious to one of ordinary skill in the art to utilize combinations of suitable catalysts, inclusive of a combination of potassium methoxide and triazabicyclodecene (TBD) to afford the predictable result of depolymerization ability.
Regarding Claims 2 and 17, Medimagh teaches pretreating with solvents such as DMAC, DMF, and MEK (¶ 47).
Regarding Claim 8, Medimagh teaches ethanol can be used as monoalcohol (¶ 53). As monoalcohol solvent is used in excess, a diethyl terephthalate product would naturally arise over the course of depolymerization.
Regarding Claims 9 and 10, Medimagh teaches monoalcohols such as methanol, ethanol, or any linear/branched alcohol with a hydrocarbon chain can be used (¶ 53). Although Medimagh does not explicitly state the species propanol and butanol, Medimagh makes clear any linear alcohol with a hydrocarbon chain can be used. It is the examiner’s position that one would expect similar beneficial results with compounds having only additional one or two –CH2– groups in view of the teachings of Medimagh. Case laws holds that homologs (compounds differing regularly by the successive addition of the same chemical group, e.g,. by –CH2– groups) are generally of sufficiently close structural similarity that there is a presumed expectation that such compounds possess similar properties. In re Wilder, 563 F.2d 457, 195 USPQ 426 (CCPA 1977). In view of such, it would have been obvious to one of ordinary skill in the art that linear homologues such as propanol or butanol can be used within the protocols of Medimagh with a reasonable expectation of similar characteristics, namely the ability to arrive at terephthalate and monoethylene glycol depolymerization products. As Medimagh teaches excess of mono-alcohol is used, the formation of either dipropyl terephthalate or dibutyl terephthalate would naturally arise.
Regarding Claim 12, Medimagh teaches embodiments with 2 g PET (~ 0.01 mol) relative to 15 mL (~ 12 g; ~ 0.37 mol) of methanol is used (¶ 76), which is in excess of 5x greater in molar ratio.
Regarding Claim 13, Medimagh teaches depolymerizations timeframes such as 1 hr 30 min (¶ 76). Medimagh teaches temperatures below 50 degrees C (¶ 29). While just outside the range claimed, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. MPEP 2144.05(I). In view of the cited case law therein, it would have been obvious to one of ordinary skill in the arts that temperatures just outside the range of Medimagh (e.g. 50 degrees C) can be used since the value is so close that there would be expectation that the reaction would still afford the predictable result of depolymerized PET.
Alternatively, to the extent Medimagh differs from the subject matter claimed with respect to depolymerization temperature used, Pham teaches it was known in the art the temperature used for depolymerization should be high enough in order to effect depolymerization while also low reaction temperatures at which the catalyst is active is generally preferable (Abstract). Case law holds that “discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art.” See In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). In view of this, it would have been obvious to one of ordinary skill in the art to discover optimal or workable depolymerization temperatures within the scope of the present claims so as to produce desirable reaction rates/catalysis while avoiding costs associated with excessive heating.
Regarding Claim 14, Medimagh teaches washing the pretreated pieces with alcohol and drying prior to depolymerizing (¶ 76).
Regarding Claim 15, Medimagh teaches recovering DMT via filtration of the reaction medium and washing a cake obtained (¶ 76).
Response to Arguments
Applicant's arguments filed 4/13/2026 have been fully considered but they are not persuasive.
With respect to Medimagh/Sharpe, Applicant generally argues the examples of Medimagh use roughly stoichiometric quantities of PET and base. While it is acknowledged most examples of Medimagh use stoichiometric quantities of base (although it is noted Example 7 uses sub-stoichiometric quantities), Medimagh imposes no particular requirement that this be the case. As set forth by Sharpe, the base catalysts at issue may predictably be used in catalytic quantities.
Applicant also argues Sharpe generally describes temperatures of 100-180 degrees C, which exceed the range claimed. In response, Sharpe does not require, nor is limited to the stated range (see “In general” of ¶ 10-11). Medimagh expressly teaches the PET pre-treatment protocol renders it possible to perform depolymerization under mild conditions (¶ 44). Thus, in view of the references, one of ordinary skill would ascertain the mild depolymerization conditions of Medimagh are applicable where pre-treatment is conducted.
Applicant argues the Medimagh Declaration illustrates that DBU is not expected to be successful in depolymerizing PET in the timeframes/temperatures specified. This is not found persuasive. Medimagh expressly teaches pre-treating PET facilitates depolymerization under relatively mild conditions. Medimagh ascribes such to the solvent altering the polymer chains so as to make ester functionalities more accessible (¶ 49). Sharpe expressly teaches both DBU and methoxide were known base depolymerization catalysts at the time of filing. It is unclear why one of ordinary skill would lack a reasonable expectation of success in using a catalyst such as DBU under milder conditions since the pre-treatment protocol would nevertheless result in PET functionalities being more accessible. Table 2 of the Declaration appears to confirm such; Ex F (NaOMe alone) and Ex C (DBU alone) both result in successful depolymerizations under the conditions at issue.
With respect to Madimagh/Pham, Applicant argues Pham is not prior art in view of the submitted translation of the FR foreign priority document. This is not found persuasive for reasons set forth within the “Priority” section above.
In light of the discussion above, it is maintained a prima facie case of obviousness exists. The inventor’s emphasis that the combination of DBU and methoxide procures unexpectedly synergistic improvements in efficiency/conversions within the Declaration is acknowledged, but is unpersuasive as the claims at issue are not commensurate in scope with the evidence relied upon in support of the unexpected results allegation. The claims broadly recite any organic base with an amidine or guanidine unit, but only DBU or DBN is illustrated. The formation of PET into terephthalate ester from monoalcohol is claimed, but only the formation of DMT from PET and methanol is illustrated. The evidence fails to establish the results alleged to be unexpected occurs throughout the scope claimed and one of ordinary skill would be unable to ascertain a trend within the data to reasonably extend the probative value thereof.
Conclusion
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/STEPHEN E RIETH/Primary Examiner, Art Unit 1759
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