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
This office action is in response to applicant’s communication filed on 6/25/26.
Claims 1-17 are pending in this application and are being examined in this Office Action.
Applicant's election with traverse of Group 1, claims 1-3, in the reply filed on 6/24/26 is acknowledged. The traversal is on the ground(s) that the examiner did not explain why the group lacks unity. This is not found persuasive because the claims of the various groups do not relate to a single general inventive concept under PCT Rule 13.1 because, under PCT Rule 13.2, they lack the same or corresponding special technical feature due to the art found on applicant’s claims, as discussed within this Office Action (see the 103 rejection below over Guo (US 2021/0309825 is used herein as the US equivalent of WO 2020/035590 A1, pub. date Feb. 20, 2020), in view of Oku et al. (“Alkali Decomposition of Poly(ethylene terephthalate) with Sodium Hydroxide in Nonaqueous Ethylene Glycol: A Study on Recycling of Terephthalic Acid and Ethylene Glycol,” J. Appl. Polym. Sci. 1997, 63, 595-601), and further in view of Essaddam (US 2017/0008826 A1, pub. date Jan. 12, 2017).
Thus claims 4-17 are withdrawn from consideration being drawn to the non-elected invention.
As a result, claims 1-3 are being examined in this Office Action.
Priority
The applicant claims benefit as follows:
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Objections
Specification
The disclosure is objected to because of the following informalities:
The Abstract designates the initial solid phase as “(ESI),” the initial liquid phase as “(ELI),” and the solid purified phase as “(ESP),” whereas the description and claims designate these same elements as “(FSI),” “(FLI),” and “(FSP),” respectively. The reference characters used in the Abstract are inconsistent with those used in the description and the claims.
The Abstract further recites in the last two lines “obtaining, by the removal of the later, a final solid phase (FSF).” The word “later” appears to be a typographical error for “the latter.” Appropriate correction is required.
Claims
Claims 1-3 are objected to because of the following informalities:
Claims 1-3 are objected to because each claim is numbered with a closing parenthesis, for example “1),” rather than with a period. Claim numbers should be followed by a period.
Claim 1 is objected to because the preamble recites “Method for the recycling of a textile waste (ST)” without an introductory article. The preamble should read “A method for the recycling of a textile waste (ST).”
Claim 1 is further objected to because it recites in line 5 “an alkali metal hydroxide (IMA) and at least a water-soluble organic reaction solvent (SOIR).” The phrase “at least a” is grammatically incorrect. The examiner suggests “at least one water-soluble organic reaction solvent (SOIR).”
Claim 1 is further objected to because of extraneous spaces in the following:
“a depolymerization step , comprising,”
“a step of treatment with organic solvent , wherein,” and
“said first step of solid-liquid separation , is treated.”
Claim 2 is objected to because it recites “The Method, as in claim 1.” The word “Method” should not be capitalized.
Claims 2 and 3 are objected because they recite “as in claim 1” which should read “of claim 1.”
Claims 2 and 3 are objected to because the alternative substances are not set forth in proper alternative form. For example, claim 2 recites that the organic washing solvent “is or comprises at least one of the following substances,” followed by a list. The alternatives should be presented as a Markush group, for example “wherein said organic washing solvent (SOL) comprises at least one substance selected from the group consisting of….”
Claim 3 is objected because of the formatting of the claim. The claim appears to be indented incorrectly and not aligned with claims 1 and 2.
Appropriate correction is required.
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.
Claims 1-3 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112, second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 1 is indefinite because the claim recites, in the step of treatment with organic solvent, that the initial solid phase (FSI) “is treated with an organic washing solvent (SOL) until removing from said initial solid phase (FSI) one or more possible contaminants present therein.”
The recitation of “possible” contaminants renders the claim indefinite. It is unclear whether the claim requires that one or more contaminants actually be present in the initial solid phase (FSI) and actually be removed by the organic washing solvent (SOL), or whether the step is instead satisfied by any treatment with an organic washing solvent regardless of whether any contaminant is present or removed. The claim recites the endpoint of the step as “until removing” the contaminants, which suggests that removal is required, while simultaneously reciting those contaminants as merely “possible,” which suggests that removal is optional and may not occur at all. This is confusing.
The same problem appears in the second step of solid-liquid separation, which recites that the solid purified phase (FSP) “is separated from said organic washing solvent (SOL) and from said one or more possible contaminants dissolved therein.” A claim step cannot be definite when it recites separation from an element that may or may not exist.
Because the claim does not make clear whether contaminant removal is a required result of the recited steps, the metes and bounds of claim 1 are unclear. Claims 2 and 3 are rejected as being dependent on claim 1.
Appropriate correction is required.
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 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 of this title, 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.
Claims 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over Guo (US 2021/0309825 is used herein as the US equivalent of WO 2020/035590 A1, pub. date Feb. 20, 2020), in view of Oku et al. (“Alkali Decomposition of Poly(ethylene terephthalate) with Sodium Hydroxide in Nonaqueous Ethylene Glycol: A Study on Recycling of Terephthalic Acid and Ethylene Glycol,” J. Appl. Polym. Sci. 1997, 63, 595-601), and further in view of Essaddam (US 2017/0008826 A1, pub. date Jan. 12, 2017).
Determination of the Scope and Content of the Prior Art
(MPEP §2141.01)
Guo teaches a method for recycling polyester from a polyester textile, comprising providing the polyester textile soaked in a mixture comprising a solvent and a catalyst, and providing and maintaining a temperature of the mixture within a range of 80-240° C. during depolymerization of the polyester, wherein the catalyst of the mixture comprises calcium hydroxide. (Guo, claim 1; Abstract; paragraphs [0010], [0016])
Guo teaches that at least a part of the depolymerization products will be dissolved in the solvent, this solution being referred to as the liquid fraction, and that the catalyst and any undepolymerized polyester or further solid material is referred to as the solid fraction. (Guo, paragraph [0020])
Guo teaches that the polyester textile further comprises natural fibers and/or additional synthetic fibers, wherein the natural fibers are, for example, cotton fibers, viscose fibers, cellulose fiber or regenerated cotton fibers. Guo teaches that the disclosed method allows for recovering the natural fiber from the polyester fabric, and that maintaining the mixture at as low a temperature as possible is advantageous because it does not degrade the natural fiber, e.g. a cotton fiber, as much as it may degrade at higher temperatures. (Guo, paragraphs [0043]-[0044])
Guo teaches that the solvent comprises an alcohol or a diol, wherein the alcohol may be chosen from methanol, ethanol, propanol, butanol, pentanol, hexanol or heptanol, and teaches that methanol is the most reactive alcohol among those listed. (Guo, paragraphs [0035], [0037])
Guo teaches that the recovering of the depolymerization products may be done via extraction and/or soxhlet extraction of the solid fraction using methanol, and that, additionally or alternatively, the ethylene glycol reaction product may be separated from the solvent by distillation if the solvent used is a different alcohol or diol than ethylene glycol – but that if ethylene glycol is itself used as the solvent of the depolymerization reaction, this separate recovery step is unnecessary. (Guo, paragraph [0060])
Guo teaches that the dye of the polyester textile may be fully or partially soluble in the solvent used in the mixture in which the polyester textile is soaked, and that if so, the solid fraction is removed by filtration and the dye is thereafter recovered by removing the solvent by distillation; and that, additionally or alternatively, the dye may be insoluble in the solvent, in which case the dye forms part of the solid fraction and is collected by filtration, and a solvent in which the dye is soluble may then be used to separate the dye from the rest of the solid fraction. (Guo, paragraph [0064])
Guo exemplifies the treatment of a cellulose-and-polyester textile waste in Example 7. Guo teaches soaking 10 g of white PET/cotton mixed textile waste, having a weight ratio of 1:1, in 100 ml methanol together with a mixed-oxide catalyst, heating and maintaining the mixture at 165° C. during the depolymerization, separating the liquid fraction from the solid fraction by filtration, wherein the solid fraction mainly contains the depolymerization product and cotton, extracting the depolymerization product from the solid fraction by methanol, and drying and reusing the remaining cotton through a wet-spinning process to produce regenerated cellulose fiber. (Guo, paragraph [0090])
Ascertainment of the Difference Between Scope the Prior Art and the Claims
(MPEP §2141.012)
Guo teaches the recycling of a textile waste comprising a cellulosic component and a polyester component by solvolytic depolymerization in a water-soluble organic reaction solvent within the 80-240° C. range recited in claim 1, a solid-liquid separation of the resulting biphasic mixture by filtration, treatment of the resulting solid fraction with an organic solvent to remove a contaminant such as a dye, and recovery of the cellulosic fibres.
However, Guo is deficient in two respects.
First, the catalyst of Guo is calcium hydroxide, which is an alkaline-earth metal hydroxide rather than an alkali metal hydroxide, so that the depolymerization product taught by Guo is dimethyl terephthalate rather than a terephthalic acid salt. Guo therefore does not expressly teach that the initial solid phase contains a terephthalic acid salt as recited in claim 1.
Second, because the depolymerization product of Guo is dimethyl terephthalate rather than a terephthalic acid salt, Guo separates that product from the cellulosic fibres by methanol extraction rather than by a step of treatment with water. Guo therefore does not expressly teach bringing the solid purified phase into contact with washing water until solubilizing a terephthalic acid salt contained therein and obtaining, by removal of that salt, a final solid phase comprising the cellulosic fibres.
Oku et al. cures the first deficiency. Oku et al. teaches heating pellets of poly(ethylene terephthalate) in anhydrous ethylene glycol with two equivalents of sodium hydroxide at 150° C. for 80 minutes or at 180° C. for 15 minutes to convert them quantitatively to disodium terephthalate and ethylene glycol, and depicts the corresponding reaction equation, in which the polyester and two equivalents of sodium hydroxide yield ethylene glycol and the disodium salt of terephthalic acid. Thus, Oku et al. teaches a depolymerization reaction of a polyester component by basic hydrolysis by means of a solvolytic mixture comprising an alkali metal hydroxide and a water-soluble organic reaction solvent, yielding a terephthalic acid salt. (Oku et al., Abstract, page 595; page 596, equation 1)
Oku et al. further teaches that the disodium terephthalate so formed precipitates quantitatively in pure state from the ethylene glycol solution and is separated readily, while the ethylene glycol product remains in the solution; that the alkali decomposition takes place on the surface of the pellets and not in solution; and that the concentration of the disodium terephthalate in solution can be considered zero because it is insoluble and precipitates. Oku et al. therefore teaches obtaining a biphasic mixture comprising a solid phase containing a terephthalic acid salt and a liquid phase containing the water-soluble organic reaction solvent. (Oku et al., Abstract, page 595; pages 597-598)
Oku et al. also teaches that the white powder of disodium terephthalate was separated, dissolved in water, and acidified with hydrochloric acid to obtain terephthalic acid, and depicts a recycling scheme in which the reaction mixture is filtered, the filtrate is distilled to recover the ethylene glycol, and the recovered disodium terephthalate is converted to terephthalic acid by addition of acid. Oku et al. thereby teaches bringing the recovered solid terephthalic acid salt into contact with water in order to solubilize it. (Oku et al., page 597; page 601, Scheme I)
Oku et al. teaches the advantages of this reaction system: that the reaction conditions are mild, at 150-180° C. under atmospheric pressure; that the system is simple in that no water and no extra reagent other than sodium hydroxide and ethylene glycol are used; and that the efficiency of monomer reproducibility and separation is remarkably high because the disodium terephthalate precipitates quantitatively in pure state and is separated readily. (Oku et al., Abstract, page 595; page 596; Conclusions, page 601)
Essaddam independently confirms that the modification proposed above is the substitution of one art-recognized functional equivalent for another. Essaddam teaches a process for depolymerizing a polymer comprising an ester functionality by admixing the polymer with an agent for breaking the ester functionality consisting of a mixture of an alcohol and a hydroxide, wherein the hydroxide is selected from a group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, an ammonium hydroxide, and a combination thereof. (Essaddam, claim 9; paragraph [0011])
Essaddam thereby expressly groups alkali metal hydroxides and alkaline-earth metal hydroxides together as recognized, interchangeable choices for the identical purpose of breaking the ester functionality of a polyester such as polyethylene terephthalate. (Essaddam, paragraphs [0011], [0015])
Essaddam cures the second deficiency of Guo.
Essaddam teaches that after completion of the depolymerization reaction a solid is obtained containing terephthalic acid salts, terephthalic acid derivatives, unreacted polymers and debris, and that the reaction mixture is filtered to obtain a filter cake and a filtrate. Essaddam teaches that the filter cake so obtained is washed with some additional alcohol, or with some deionized water. (Essaddam, paragraphs [0105], [0109]-[0110])
Essaddam further teaches that the filter cake is thereafter added to an aqueous solution, that the solution is filtered to remove non-soluble unreacted polymers, non-soluble oligomers and debris, and that the filtrate obtained contains the solubilized terephthalic acid salts. (Essaddam, paragraph [0112])
Essaddam exemplifies this operation in Example 5, in which water was added to a polyethylene-terephthalate reaction product to dissolve all of the terephthalic acid salts, and the solution was filtered to yield the unreacted starting material or insoluble oligomers. (Essaddam, paragraph [0151])
Essaddam thereby teaches bringing a solid phase containing a terephthalic acid salt into contact with washing water until solubilizing that salt, and obtaining, by the removal of the salt, a remaining solid phase of the water-insoluble constituents.
Finding of Prima Facie Obviousness Rationale and Motivation
(MPEP §2142-2143)
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute an alkali metal hydroxide, such as the sodium hydroxide of Oku et al., for the calcium hydroxide catalyst of Guo in the recycling of a cotton/polyester textile waste. Because the catalyst of Guo is already a metal hydroxide, this substitution is an obvious substitution. It is the selection of an alkali metal hydroxide in place of an alkaline-earth metal hydroxide, both being hydroxides of the type Essaddam itself groups together in a single Markush recitation as recognized functional equivalents for breaking the ester bonds of a polyester. The selection of any one member of a group of art-recognized functional equivalents for its known purpose is prima facie obvious. It is likewise the simple substitution of one known element for another to obtain predictable results.
One of ordinary skill in the art would have been motivated to make this substitution because Oku et al. expressly teaches the benefits obtained, namely mild reaction conditions at atmospheric pressure, a simple reagent system requiring no water and no reagent other than sodium hydroxide and ethylene glycol, and remarkably high efficiency of monomer reproducibility and separation because the disodium terephthalate precipitates quantitatively in pure state and is separated readily. Guo’s own solvent teaching supports the combination directly, since Guo teaches that the solvent may be a diol, and that the diol may be chosen from ethylene glycol, propanediol or butanediol, ethylene glycol being the very solvent taught by Oku et al.; and Oku et al.’s 150-180° C. reaction temperature falls within the 80-240° C. range recited in claim 1 and taught by Guo.
Upon making this substitution, the initial solid phase obtained in the Guo process would contain the terephthalic acid salt taught by Oku et al. together with the cotton fibres taught by Guo, and the initial liquid phase would contain the water-soluble organic reaction solvent, as recited in claim 1.
It would then have been prima facie obvious to one of ordinary skill in the art to separate that terephthalic acid salt from the cellulosic fibres by treatment with water, as taught by both Oku et al. and Essaddam, because a terephthalic acid salt is readily soluble in water whereas cellulosic fibres are not. Applying this known water-dissolution technique to the modified solid phase of Guo would predictably liberate the water-insoluble cellulosic fibres as a final solid phase. This is the use of a known technique to improve a similar method in the same way.
It would further have been prima facie obvious to one of ordinary skill in the art to retain, in the modified process, the treatment of the solid phase with an organic washing solvent prior to the water treatment. Guo expressly teaches that a solvent in which the dye is soluble may be used to separate the dye from the rest of the solid fraction, and Essaddam likewise teaches washing the filter cake obtained after depolymerization with additional alcohol. One of ordinary skill would therefore have washed the solid phase with an organic solvent for the purpose of removing dye and other contaminants before recovering the terephthalic acid salt and the cellulosic fibres.
Note that an express suggestion to substitute one equivalent component for another is not necessary to render such substitution obvious. In re Fout, 675 F.2d 297, 213 USPQ 532 (CCPA 1982). The substitution of a known alkali metal hydroxide for a known alkaline-earth metal hydroxide in a known solvolytic depolymerization of polyester, and the recovery of the resulting water-soluble terephthalate salt by dissolution in water, represent predictable process modifications of a known polyester recycling reaction.
With regard to claim 2, Guo teaches extracting the solid fraction with methanol, methanol being an alcohol C1-C6 as recited in claim 2, and Oku et al. teaches ethylene glycol as the reaction solvent, ethylene glycol being a glycol C2-C8 as also recited in claim 2. Essaddam further teaches washing the filter cake with additional alcohol, wherein the alcohol is a linear C1-C4 alcohol such as methanol. Therefore, the recitation that the organic washing solvent is or comprises a glycol C2-C8 or an alcohol C1-C6 would have been obvious to one of ordinary skill in the art.
With regard to claim 3, Guo teaches in Example 7 that the same methanol serves both as the medium in which the textile waste is soaked during the depolymerization and as the solvent with which the resulting solid fraction is subsequently extracted. Guo separately teaches that when ethylene glycol is used as the solvent of the depolymerization reaction, the step of recovering the reaction products by a different solvent is unnecessary. In other words, the reaction solvent and the recovery solvent may be the same substance. Therefore, the recitation that the water-soluble organic reaction solvent and the organic washing solvent are or comprise the same substance would have been obvious to one of ordinary skill in the art in view of Guo alone, and would additionally have been an obvious matter of process economy in avoiding the handling and recovery of a second solvent.
Response to Arguments
Applicant’s arguments have been considered but are not persuasive for the following reasons:
The examiner acknowledges applicant's argument that the claimed method differs from EP 3363852, the European family member of Guo (US 2020/0157307).
The examiner does not agree with the applicant. Guo (US 2021/0309825, the US equivalent of WO 2020/035590) was used in the 103 within this office action and not EP 3363852, the European family member of Guo (US 2020/0157307.
Nevertheless, applicant’s arguments are not persuasive as to either reference because the present rejections do not rely upon Guo for the alkali metal hydroxide. Oku et al. was relied upon to teach this limitation.
The examiner acknowledges applicant's argument that the claimed method provides a purification phase in which the solid phase is washed with a solvent that only removes impurities such as dyes without extracting the polymeric component, in contrast to the treatment of dimethyl terephthalate with methanol described in the reference.
The examiner does not agree with the applicant. Applicant’s argument is not commensurate in scope with the claim. Claim 1 does not recite that the organic washing solvent (SOL) is incapable of dissolving or does not dissolve the terephthalic acid salt (SAT). Claim 1 recites only that the initial solid phase is treated with an organic washing solvent until removing one or more possible contaminants, and that the resulting solid purified phase contains the terephthalic acid salt and the cellulosic fibres.
The examiner acknowledges applicant's argument that neither reference describes or suggests the separation of the cellulose component from the terephthalic component by dissolving the latter in water.
The examiner does not agree with the applicant. Oku et al. teaches that the separated disodium terephthalate is dissolved in water.
The examiner acknowledges applicant's argument that EP 3 320 033 B1, the European family member of Essaddam, does not describe the treatment of textile waste containing high quantities of a cellulose component.
The examiner does not agree with the applicant. Essaddam is not relied upon for the textile feedstock. Guo supplies the recycling of a cotton and polyester blended textile waste.
The examiner acknowledges applicant's argument that the claimed method allows recovery of both components at a higher degree of purity and with reduced environmental impact compared to prior art methods.
To the extent this argument is offered as evidence of unexpected results, it is not persuasive because no comparative data has been made of record.
Conclusion
No claim is allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jennifer Cho Sawyer whose telephone number is (571) 270 1690. The examiner can normally be reached on Monday-Friday 9 AM - 6 PM PST.
If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Renee Claytor can be reached on (571) 272-8394. The fax phone number for the organization where this application or proceeding is assigned is 571-274-1690.
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Jennifer Cho Sawyer
Patent Examiner
Art Unit: 1691
/RENEE CLAYTOR/Supervisory Patent Examiner, Art Unit 1691
Prosecution Insights