Prosecution Insights
Last updated: April 19, 2026
Application No. 18/260,791

METHOD FOR DECOLORIZING POLYESTER AND METHOD FOR DEPOLYMERISING POLYESTER COMPRISING THE SAME

Non-Final OA §103§DP
Filed
Jul 10, 2023
Examiner
BOYKIN, TERRESSA M
Art Unit
1765
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Kolon Industries Inc.
OA Round
1 (Non-Final)
90%
Grant Probability
Favorable
1-2
OA Rounds
2y 1m
To Grant
98%
With Interview

Examiner Intelligence

Grants 90% — above average
90%
Career Allow Rate
1662 granted / 1855 resolved
+24.6% vs TC avg
Moderate +8% lift
Without
With
+8.2%
Interview Lift
resolved cases with interview
Fast prosecutor
2y 1m
Avg Prosecution
35 currently pending
Career history
1890
Total Applications
across all art units

Statute-Specific Performance

§101
1.6%
-38.4% vs TC avg
§103
40.9%
+0.9% vs TC avg
§102
17.9%
-22.1% vs TC avg
§112
17.6%
-22.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1855 resolved cases

Office Action

§103 §DP
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 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. Claim(s) 1-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over USP5473102 see ; in view of CS256748B1 see abstract and pages 1-3 ; further in view of JP2003260425A See abstract and examples and paragraphs [0003] and [0004] . Claim 1 is directed to a method of decolorizing a polyester, comprising adding a degradation agent including an alkali, an acid, a salt thereof, a mono-alcohol, a polyhydric alcohol, or a mixture thereof to the polyester, and contacting the polyester with superheated water vapor. USP5473102 discloses a method applied to polyester materials involving hydrolysis degradation using superheated water vapor. The reference discloses contacting polyester with superheated steam to affect hydrolysis, remove impurities including color and recover purified polyester components. The reference does not expressly discloses the specific agents that would chemically remove color. CS256748B1 discloses treating polyester with chemical degradation agents, specifically alkaline agents, to cause hydrolysis. The reference discloses impregnating polyester with aqueous alkali metal hydroxides and subjecting the polyester to thermal treatment, thereby modifying surface properties and improving color removal. See abstract, pages 1-3. Thus CS256748B1 teaches chemical degradation agents suitable for hydrolytic polyester treatment of the type used in USP5473102. JP2003260425A discloses the use of superheated steam in combination with chemical degradation processes to hydrolyze and decompose thermoplastic resins which shows that combining superheated steam and chemical degradation agents was known and predictable in the art and that such combination enhance the removal of residual contaminants and degraded polymer residues which would include colorants or dyes. See abstract and examples and paragraphs [0003] and [0004] It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of USP5473102 to include the chemical degradation agents taught by CS256748B1 because both references address hydrolytic degradation of polyester and removal of color-causing impurities. The addition of alkali, acid salt or alcohol degradation agents represents a known modification intended to enhance hydrolysis efficiency and decolorization outcomes. JP2003260425A further supports the predictability of combing superheated steam with chemical degradation agents. The combination shows routine techniques to achieve expected results. Claim 2 is directed to the method of decolorizing the polyester of claim 1, wherein a temperature of the superheated water vapor is 250 0C to 450 *C. USP5473102 discloses contacting polyester with superheated water vapor at elevated temperatures sufficient to effect hydrolysis and depolymerization. JP2003260425A discloses superheated steam temperatures of approximately 350C to 45C. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to select a temperature within the recited range to ensure effective hydrolysis and impurity removal. Claim 3 is directed to the method of decolorizing the polyester of claim 1, wherein the superheated water vapor is applied with an injection pressure of 0.1 bar to2bar. USP5473102 discloses contacting polyester with superheated water vapor at controlled processing sufficient to effect hydrolysis and depolymerization. JP2003260425A discloses supplying superheated steam under controlled pressure conditions sufficient to effect hydrolysis and depolymerization. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to select pressure conditions within the recited range to ensure effective hydrolysis and impurity removal. Claim 4 is directed to the method of decolorizing the polyester of claim 1, wherein the decolorizing is performed for 1 minute to 60 minutes. USP5473102 discloses contacting polyester with superheated water vapor at controlled processing sufficient to effect hydrolysis and depolymerization. JP2003260425A discloses supplying superheated steam under controlled conditions sufficient to effect hydrolysis and depolymerization. See abstract and examples and paragraphs [0003] and [0004]. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to select processing conditions within the recited range to ensure effective hydrolysis and impurity removal. Claim 5 is directed to the method of decolorizing the polyester of claim 1, wherein the alkali includes sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonia, or a mixture thereof. CS256748B1 discloses treating polyester with chemical degradation agents, specifically alkaline agents, to cause hydrolysis. The reference discloses impregnating polyester with aqueous alkali metal hydroxides and subjecting the polyester to thermal treatment, thereby modifying surface properties and improving color removal. See abstract, pages 1-3. Claim 6 is directed to the method of decolorizing the polyester of claim 1, wherein the acid includes hydrochloric acid, nitric acid, sulfuric acid, carbonic acid, phosphoric acid, acetic acid, hypochlorous acid (HCIO), or a mixture thereof. USP5473102 discloses a method applied to polyester materials involving hydrolysis degradation using superheated water vapor. The reference discloses contacting polyester with superheated steam to affect hydrolysis, remove impurities including color and recover purified polyester components and the claimed acids are conventional and used in polyester hydrolysis and their selection would have thus been obvious. Claim 7 is directed to the e method of decolorizing the polyester of claim 1, wherein the salt includes carbonate, hydrogen carbonate, phosphate, sulfate, sulfite, nitrate, silicate, hypochlorites, format, acetate, citrate, oxalate, or a mixture thereof. USP5473102 discloses a method applied to polyester materials involving hydrolysis degradation using superheated water vapor. The reference discloses contacting polyester with superheated steam to affect hydrolysis, remove impurities including color and recover purified polyester components and the claimed acids are conventional and used in polyester hydrolysis and their selection would have thus been obvious. Claim 8 is directed to the method of decolorizing the polyester of claim 1, wherein the mono-alcohol includes methanol, ethanol, propanol, butanol, or a mixture thereof. USP5473102 discloses a method applied to polyester materials involving hydrolysis degradation using superheated water vapor. The reference discloses contacting polyester with superheated steam to affect hydrolysis, remove impurities including color and recover purified polyester components and the claimed mono-alcohols are conventional and used in polyester hydrolysis and their selection would have thus been obvious. Generally, it is prima facie obvious to select a known material for incorporation into a composition, based on its recognized suitability for its intended purpose. See Sinclair & Carroll Co. v. Interchemical Corp., 325 US 327, 65 USPQ 297 (1945). (Selection of solvent having boiling point and vapor pressure properties recognized as being ideal for printing inks into printing ink compositions found obvious on its face). See also In re Leshin, 227 F.2d 197, 125 USPQ 416 (CCPA 1960). (Selection of a known plastic to make a plastic container found obvious on its face). Claim 9 is directed to the method of decolorizing the polyester of claim 1, wherein the polyhydric alcohol includes ethylene glycol, n-propylene glycol, isopropylene glycol, diethylene glycol, polyethylene glycol, triethylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, glycerin, benzyl alcohol, polypropylene glycol, pentaerythritol, trimethylolpropane, or a mixture thereof. USP5473102 discloses a method applied to polyester materials involving hydrolysis degradation using superheated water vapor. The reference discloses contacting polyester with superheated steam to affect hydrolysis, remove impurities including color and recover purified polyester components. In the abstract the reference discloses the use of various glycols and their selection would have thus been obvious. Note also that various glycols are disclosed in the abstract. Claim 10 is directed to the method of decolorizing the polyester of claim 1, wherein the decoloring agent is added at 0.05 mol to 1.5 mol per 1.0 mol of dibasic acid in the polyester. USP5473102 discloses controlled processing sufficient to effect hydrolysis and depolymerization. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to select processing conditions within the recited range to ensure effective hydrolysis and impurity removal. Claim 11 is directed to a method of depolymerizing a polyester. comprising adding a decoloring agent including an alkali, an acid, a salt thereof, a mono-alcohol, a polyhydric alcohol, or a mixture thereof to polyester, and then contacting the polyester with superheated water vapor to decolorize the polyester, depolymerizing the decolorized polyester to obtain a depolymerization product including an alkylene glycol and a dibasic salt, performing solid-liquid separation of liquid-phase alkylene glycol and a solid-phase dibasic salt from the depolymerization product, dissolving the solid-phase dibasic salt in water, neutralizing an aqueous solution of the dibasic salt with an acid to precipitate a dibasic acid crystal, and performing solid-liquid separation of the dibasic acid crystal from a precipitation product. In addition to the discussion for claim 1 above, note USP5473102 discloses a method applied to polyester materials involving hydrolysis degradation using superheated water vapor. The reference discloses contacting polyester with superheated steam to affect hydrolysis, remove impurities including color and recover purified polyester components. The reference does not expressly discloses the specific agents that would chemically remove color. Although the reference does not expressly recite each individual separation and neutralization step as claimed, these steps are routine and conventional post depolymerization processing steps commonly employed to recover glycols and dibasic acids from polyester hydrolysis products. Claim 12 is directed to the method of depolymerizing the polyester of claim 11, wherein the method of depolymerizing the polyester further includes removing impurities from the aqueous solution of the dibasic salt. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the remove impurities for the aqueous solution of the dibasic salt as recited in claim 12 as a routine optimization of claim 11. Claim 13 is directed to the method of depolymerizing the polyester of claim 11, wherein the method of depolymerizing the polyester further includes recrystallizing the dibasic acid crystal. Although the references do not expressly disclose recrystallizing the dibasic acid, recrystallization is a well-known and convention purification step to improve the purity of recovered moieties from polymer depolymerization process. it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to select processing steps to ensure effective hydrolysis and impurity removal. Claim 14 is directed to a composition for polymerizing recycled polyester, comprising a dibasic acid and an alkylene glycol, obtained by the method of depolymerizing the polyester of claim 11. USP5473102 discloses recovering the alkylene glycols and dibasic acids suitable for repolymerization. Using recovered monomers to polymerize polyester is explicitly taught and thus obvious. Claim 15 is directed to a recycled polyester prepared using the composition for polymerizing polyester of claim 14. In addition to the discussion in claims 1 and 14, claim 15 is a product-by-process and thus the claim is not limited to the manipulations of the recited steps of claims 1 and 14only the structure of the implied by the steps. The claim dos not recite any structural, composition or physical characteristics of the recycled polyester that distinguishes it from recycled polyesters produced by conventional depolymerization and repolymerization processes as taught by USP 5473102 above. Claim 16 is directed to the recycled polyester of claim 15, wherein a color of the recycled polyester has an L-value of 60or higher. USP5473102 discloses a controlled processing sufficient to effect hydrolysis and depolymerization. Achieving a particular color metric is an inherent result of effective purification and is this obvious. In conclusion, in view of the above, there appears to be no significant difference between the reference(s) and that which is claimed by applicant(s). Any differences not specifically mentioned appear to be conventional. Consequently, the claimed invention cannot be deemed as unobvious and accordingly is unpatentable. Obviousness-Type Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1-16 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims of copending Application No. 18260292. Although the claims at issue are not identical, they are not patentably distinct from each other because both methods, although claiming a specific goal whether in decolorizing or depolymerizing, recited the same process steps and substantially the same conditions accomplish that goal, i.e. adding a degradation agent including an alkali, an acid a salt thereof, a mono alcohol, a polyhydric alcohol. The end result is polyester which has been both depolymerized and decolored and does not result in a structurally distinct product. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Information Disclosure Statement Note that any future and/or present information disclosure statements must comply with 37 CFR § 1.98(b), which requires a list of the publications to include: the author (if any), title, relevant pages of the publication, date and place of publication to be submitted for consideration by the Office. Improper Claim Dependency Prior to allowance, any dependent claims should be rechecked for proper dependency if independent claims are cancelled. Correspondence Any inquiry concerning this communication or earlier communications from the examiner should be directed to TERRESSA M BOYKIN whose telephone number is (571)272-1069. The examiner can normally be reached M-F 7-5:30. 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, Heidi Kelley can be reached at 571 270-1831. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /Terressa Boykin/Primary Examiner, Art Unit 1765
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Prosecution Timeline

Jul 10, 2023
Application Filed
Feb 08, 2026
Non-Final Rejection — §103, §DP (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
90%
Grant Probability
98%
With Interview (+8.2%)
2y 1m
Median Time to Grant
Low
PTA Risk
Based on 1855 resolved cases by this examiner. Grant probability derived from career allow rate.

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