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Any rejections and/or objections made in the previous Office action and not repeated below are hereby withdrawn.
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).
Information Disclosure Statement
The provided NPL document has been considered and is cited in the attached PTO-892.
Claim Rejections - 35 USC § 112
Claims 22, 23, and 25-41 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 22 recites “wherein said process is catalyst-free”, but the specification appears to indicate “ionic liquids” are materials that seemingly fall outside the scope of catalysts (see Page 13, Lines 13-14) despite such materials being well known catalytic materials for the glycolysis of polyesters (see Liao below). In view of such, the metes and bounds of the claim is unclear as it is uncertain whether ionic liquids are intended to be excluded by the claim in light of the specification. This issue can be resolved by reciting “wherein said process is free of ionic liquids or catalysts” within claim 1.
As claims 23 and 25-41 depend from claim 1, they are rejected for the same issue discussed above.
Claim Rejections - 35 USC § 103
Claim(s) 22, 23, 25, 26, 29, 31-35, 38, and 39 is/are rejected under 35 U.S.C. 103 as being unpatentable over Liao (US 2023/0085243 A1) in view of Sheel (Chemical Depolymerization of PET Bottles via Glycolysis) and Inada (JP2008-088096A) as evidenced by Pilati (EP 0723951 A1). As the cited JP publication is in a non-English language, a machine-translated version of the publication will be cited to.
Regarding Claims 22, 25, 26, 33, 34, and 38, Liao teaches methods of depolymerizing PET to form BHET (Abstract) and describes examples where:a) PET and ethylene glycol solvent are mixed in a predetermined weight ratio to obtain first mixture,b) the first mixture is heated to roughly 190 degrees C at a pressure of 1-3 bar under stirring for a time period for depolymerization, obtaining crude BHET,c) ethylene glycol solvent is separated from crude BHET via distillation,d) water is added and then heated to dissolve BHET with stirring for a time period,e) the solids present in water are filtered to form a cake, the filtrate containing water and BHET, andf) the BHET is isolated from water via precipitation/crystallization induced by cooling (¶ 46, 61 67-69).
Liao teaches the depolymerization process yields oligomeric impurities (¶ 39-40), indicating the obtained crude has BHET monomers and oligomers. As evidenced by Pilati, it is known in the art BHET is solubilized in hot water while oligomers remain suspended in solution (Page 3, Lines 40-49), construed as floccules. Therefore, the protocol of Liao necessarily involves obtaining floccules of oligomers and separation of said floccules during filtration.
With respect to the process being “catalyst-free”, the instant specification indicates the procedure is performed without the use of “ionic liquids or catalysts” (Page 13, Lines 13-14), thus seemingly suggesting ionic liquids are a separate material from catalysts within the confines of the claims. Liao teaches ionic liquids can be used to facilitate the reactions (¶ 44), which appears to meet the criteria of a “catalyst-free” process in light of the specification. In the alternative, Liao indicates a catalyst is used “in certain embodiments” and “is not limited thereto” (¶ 13, 42), thus implying non-preferred embodiments where catalyst is not used.
Liao differs from the subject matter claimed with respect to 1) the use of flakes and inert solvent is not indicated and 2) the use of co-solvent during depolymerization is not indicated.
With respect to flakes, Sheel teaches it was known the particle size influences the glycolysis of PET, where smaller particle sizes lead to better PET decomposition (Section 4.3.3). Therefore, it would have been obvious to one of ordinary skill in the art to pulverize the PET fabrics of Liao into flakes, because doing so would give better PET decomposition rates as taught by Sheel.
With respect to inert atmosphere, Inada teaches it was known in the art oxygen gas during glycolysis of PET creates colored side products, of which use of an inert atmosphere prevents (¶ 81-85). It would have been obvious to one of ordinary skill in the art to perform the depolymerization reactions of Liao within an inert atmosphere, thereby preventing the formation of colored impurities as taught by Inada.
With respect to co-solvent, Sheel teaches it was known in the art sufficient glycolysis is achieved with various techniques, inclusive of catalyzed glycolysis and/or solvent-assisted glycolysis (Page 68). In the case of solvent-assisted glycolysis, additional solvent is further included with PET and EG so as to solubilize glycolyzed products and improve yields/conversion (Section 4.2.2). It would have been obvious to one of ordinary skill in the art to further include co-solvent within the reactions of Liao thereby solubilizing glycolyzed products and improving yields/conversion as taught by Sheel.
Example 1 of Liao utilizes a PET:EG ratio of 1:6 (¶ 67). While not indicating a specific PET:EG:Co-solvent ratio, Sheel makes clear the solvent ratio used is the most important factor affecting PET glycolysis, where the content of EG directly impacts the rate of depolymerization and the content of co-solvent increases mixability (Section 4.3.4). Accordingly, the relative solvent content is a known result effective variable subject to routine optimization by one of ordinary skill in the art. See MPEP 2144.05(II). 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/workable solvent and co-solvent ratios within the scope of the present claims so as to produce desirable reaction rates and mixability characteristics.
Regarding Claim 23, Example 1 of Liao is seen to set forth a batch process.
Regarding Claim 29, Liao teaches reaction times spanning 1-6 hours, which overlaps the range 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 Liao suggests the claimed range. A person of ordinary skill would be motivated to use the claimed amount, based on the teachings of Liao. See MPEP 2123.
Although Liao does not specify an exact stir rate, Sheel teaches stirring speed is a known result effective variable for glycolysis reactions whereby reaction efficiency changes depending on speed (Section 4.3.2). See MPEP 2144.05(II). 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/workable stirring speeds within the scope of the present claims so as to produce desirable reaction efficiencies.
Regarding Claims 31 and 32, Liao teaches distilling ethylene glycol at temperatures spanning 150-250 degrees C (¶ 48), noting the boiling point of the depolymerization liquid spans roughly 180-220 degrees C (¶ 49). As a pressure is not specified, ambient pressure (roughly 1000 mbar) is implied. The disclosed temperatures overlap those instantly claimed.
While not specifying a pressure of 800 mbar with respect to claim 32, it is well known the boiling point of a given liquid is pressure dependent, whereby lower pressures effectively lowers boiling points. 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/workable pressures/temperatures within the scope of the present claims so as to facilitate solvent removal while avoiding excessive costs associated with heating at higher temperatures.
Regarding Claim 35, Liao teaches the weight ratio of water to crude BHET spans 3:1 to 20:1 (¶ 54), which overlaps the claimed range. 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 Liao suggests the claimed range. A person of ordinary skill would be motivated to use the claimed amount, based on the teachings of Liao. See MPEP 2123.
Regarding Claim 39, Liao teaches embodiments where the aqueous solution is cooled to 5 degrees C for crystallization (¶ 62-63, 68).
Claim(s) 27, 29, and 30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Liao (US 2023/0085243 A1) in view of Sheel (Chemical Depolymerization of PET Bottles via Glycolysis), Inada (JP2008-088096A), and Liu (Ind. Eng. Chem. Res. 2018, 57, 16239-16245) as evidenced by Pilati (EP 0723951 A1). As the cited JP publication is in a non-English language, a machine-translated version of the publication will be cited to.
The discussion regarding Liao, Sheel, Inada, and Pilati within ¶ 10-24 is incorporated herein by reference.
Regarding Claim 27, Sheel differs from the subject matter claimed in that the listed co-solvents are not described. Liu teaches it was known in the art various polar co-solvents can be used for the glycolysis of PET to BHET (Abstract) whereby the co-solvent procures a more homogenous reaction blend owing to the co-solvent effecting PET dissolution , thereby achieving higher yields and shorter reaction times (Section 3.1; Figure 1; Table 1). It would have been obvious to one of ordinary skill in the art to utilize polar co-solvents with high PET solvating ability, thereby achieving higher yields and shorter reaction times as taught by Liu. Liu teaches the use of NMP and DMSO (Section 3.1).
Regarding Claims 29 and 30, Although Liao does not specify an exact stir rate, Sheel teaches stirring speed is a known result effective variable for glycolysis reactions whereby reaction efficiency changes depending on speed (Section 4.3.2). See MPEP 2144.05(II). 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/workable stirring speeds within the scope of the present claims so as to produce desirable reaction efficiencies.
With respect to reaction time, Liao teaches reaction times spanning 1-6 hours. As the teachings of Liu make clear, the further incorporation of co-solvent is expected to lower reaction times (Figure 1; Table 1). Thus, the interplay between co-solvent quantity, reaction time, and yield of BHET is a known result effective variable subject to routine optimization by one of ordinary skill in the art. See MPEP 2144.05(II). 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/workable reaction times and co-solvent quantities within the scope of the present claims so as to produce desirable yields in suitable timeframes.
Claim(s) 28 is/are rejected under 35 U.S.C. 103 as being unpatentable over Liao (US 2023/0085243 A1) in view of Sheel (Chemical Depolymerization of PET Bottles via Glycolysis), Inada (JP2008-088096A), Liu (Ind. Eng. Chem. Res. 2018, 57, 16239-16245), and Huang (Polymer Degradation and Stability 2023, 208, 110245) as evidenced by Pilati (EP 0723951 A1). As the cited JP publication is in a non-English language, a machine-translated version of the publication will be cited to.
The discussion regarding Liao, Sheel, Inada, Pilati, and Liu within ¶ 26-29 is incorporated herein by reference.
Regarding Claim 28, Liu teaches the use of NMP and DMSO for cosolvent-assisted glycolysis of PET (Section 3.1). Thus, the combination of references differs from the subject matter claimed with respect to the use of DMF, DMAc, or DMC.
Huang also pertains to the cosolvent-assisted glycolysis of PET (Abstract; Section 2.3) and notes various solvents are known to be effective relative to EG alone, inclusive of DMF, DMC, and DMSO (Figure 3). In view of Huang’s teachings of known suitable co-solvents for glycolysis, it would have been obvious to one of ordinary skill in the art to substitute DMSO with either DMF or DMC thereby predictably affording cosolvent-assisted glycolysis of PET.
Claim(s) 36 and 37 is/are rejected under 35 U.S.C. 103 as being unpatentable over Liao (US 2023/0085243 A1) in view of Sheel (Chemical Depolymerization of PET Bottles via Glycolysis), Inada (JP2008-088096A), and Hwang (US 2023/0399462 A1) as evidenced by Pilati (EP 0723951 A1). As the cited JP publication is in a non-English language, a machine-translated version of the publication will be cited to.
The discussion regarding Liao, Sheel, Inada, and Pilati within ¶ 10-24 is incorporated herein by reference.
Regarding Claims 36 and 37, while not describing particular stirring speeds or time frames with respect to mixing with water, Hwang also pertains to the purification of BHET via water dissolution/filtration (Abstract; ¶ Examples). Hwang teaches the overall stirring time / stirring speed can be controlled with respect to the desired degree of impurity removal (¶ 24). Thus, the stirring speed / stirring time is a known result effective variable subject to routine optimization by one of ordinary skill in the art. See MPEP 2144.05(II). 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/workable stirring speeds and times so as to achieve desirable degrees of purification and BHET dissolution.
Claim(s) 40 and 41 is/are rejected under 35 U.S.C. 103 as being unpatentable over Liao (US 2023/0085243 A1) in view of Sheel (Chemical Depolymerization of PET Bottles via Glycolysis), Inada (JP2008-088096A), and Yuan (Cryst. Res. Technol. 2021, 56, 2100025) as evidenced by Pilati (EP 0723951 A1). As the cited JP publication is in a non-English language, a machine-translated version of the publication will be cited to.
The discussion regarding Liao, Sheel, Inada, and Pilati within ¶ 10-24 is incorporated herein by reference.
Regarding Claims 40 and 41, Liao teaches the processes removes impurities within the obtained BHETs and also crystallizes the BHET from water (¶ 81). While Liao does not specify certain degrees of purity, crystallinity, and particle size, it was known in the art that such characteristics may be adjusted/optimized depending on the recrystallization conditions. See Section 3 of Yuan where temperature/stirring speed during nucleation, crystal seeds, and time all effect the achieved BHET particle size and in 3.1.6 where it is noted purity and crystal yield can also be optimized. Thus, Yuan indicates achieved purity, crystallinity, and particle size are all optimizable aspects known to one of ordinary skill in the art. See MPEP 2144.05(II). 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/workable crystallization conditions so as to achieve desired purity/crystallinity/particle sizes, such as those claimed.
Alternatively with respect to purity / crystallinity, the mere purity of a product, by itself, does not render a product nonobvious. Factors to be considered in determining whether a purified form of an old product is obvious over the prior art include whether the claimed chemical compound or composition has the same utility as closely related materials in the prior art, and whether the prior art suggests the particular form or structure of the claimed material or suitable methods of obtaining that form or structure. In re Cofer, 354 F.2d 664, 148 USPQ 268 (CCPA 1966). In the particular case, both Liao and the present specification describes the same particular form or structure of the claimed material (purified recycled BHET via crystallization from water) and the same utility (re-use for the creation of new polyesters). Both Liao and the present specification suggest substantially similar methods by which the form or structure is obtained (distillation, water solubilization/filtration, recrystallization in water). In view of such, it would have been obvious to one of ordinary skill in the art to utilize the protocols of Liao is provide BHET in given/desirable degrees of purification/crystallinity.
Related Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Charra (US 2019/0161595 A1) describes known glycolysis protocols of PET. Charra teaches it was known glycolysis can be performed with or without catalyst, whereby in the presence of high pressure, a catalyst is not present (¶ 23, 52-55, 88).
Response to Arguments
Applicant's arguments filed 7/20/2026 have been fully considered but they are not persuasive.
Applicant argues the rejections rely on a combination of 8 different references. This is not found persuasive. The Examiner counts only three for independent claim 1 (excluding evidentiary reference Pilati). Moreover, reliance on a large number of references in a rejection does not, without more, weigh against the obviousness of the claimed invention. See In re Gorman, 933 F.2d 982, 18 USPQ2d 1885 (Fed. Cir. 1991).
Applicant argues Liao has a different purpose than what is set forth within the specification. This is not found persuasive as it is not necessary that the prior art suggest the combination to achieve the same advantage or result discovered by applicant. See MPEP 2144(IV). The combination of references meets all limitations claimed and proper rationale supporting the combination of references was presented. Thus, a prima facie case of obviousness is established.
Applicant further argues the examples of Liao differ with respect to the subject matter claimed such as reaction time, use of catalyst, and/or the inclusion of various other processing steps. This is not found persuasive. The rejections at issue are obviousness rejections and not anticipation rejections relying on Liao’s examples. The reactions times and non-use of catalyst would have been obvious in view of Liao for reasons set forth above. Any additional steps described by Liao are not excluded owing to the transitional phrase “comprising” within the claims.
Applicant presents numerous arguments that essentially urge each reference in isolation fails to disclose all of the limitations present within claim 1. Such arguments are not persuasive as one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Applicant admits Liu describes aniline, NMP, DMSO, and nitrobenzene as co-solvents, but urges only aniline was studied. This is not found persuasive. Liu unambiguously teaches NMP, DMSO, and/or nitrobenzene can be used as co-solvent and thus, the use of such would have been obvious in view of Liu. A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill the art, including nonpreferred embodiments. Merck & Co. v. Biocraft Laboratories, 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. denied, 493 U.S. 975 (1989). The same can also be said in response to applicant’s argumentation concerning acetonitrile vs. the DMF/DMC/DMSO of Huang. While acetonitrile may be the most preferred co-solvent disclosed, this does not render other co-solvents of Huang any more or less obvious. Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971). "A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use." In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994)
Applicant generally argues Yuan described BHET crystal sizes of about 1300 microns, which teaches away from less than 10 microns. This is not found persuasive. Yuan is merely relied upon to establish it was known in the art degrees of purity, crystallinity, and particle size can be adjusted/optimized depending on the recrystallization conditions such as temperature/stirring speed during nucleation, crystal seeds, and time. Thus, given a crude BHET mixture, achieving a desired degree of purity, crystallinity, and/or particle size is matter of optimization via routine experimentation by one of ordinary skill in the art. The fact that Yuan is able to achieve a larger crystal size under certain circumstances does not render such parameters non-result effective.
Conclusion
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.
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/STEPHEN E RIETH/Primary Examiner, Art Unit 1759
