Prosecution Insights
Last updated: April 19, 2026
Application No. 18/256,488

BIODEGRADABLE POLYESTER RESIN PREPARED BY ADDING REACTION RATE CONTROL AGENT AND MOLECULAR WEIGHT INCREASING AGENT DERIVED FROM BIOMASS AND METHOD FOR PREPARING SAME

Non-Final OA §112
Filed
Jun 08, 2023
Examiner
KAHN, RACHEL
Art Unit
1766
Tech Center
1700 — Chemical & Materials Engineering
Assignee
BIOPLASTICS INNOVATIONS LIMITED
OA Round
1 (Non-Final)
28%
Grant Probability
At Risk
1-2
OA Rounds
3y 9m
To Grant
44%
With Interview

Examiner Intelligence

Grants only 28% of cases
28%
Career Allow Rate
179 granted / 649 resolved
-37.4% vs TC avg
Strong +16% interview lift
Without
With
+15.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
65 currently pending
Career history
714
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
48.5%
+8.5% vs TC avg
§102
15.5%
-24.5% vs TC avg
§112
23.7%
-16.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 649 resolved cases

Office Action

§112
DETAILED ACTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Claims 1-9 are pending as filed on 6/8/2023. Specification The disclosure is objected to because of the following informalities: The specification contains reaction formulas 1 and 2 (see pp 8, 12 and 13) which include chemical structures of insufficient clarity. The specification must be amended to provide chemical structures and subscripts with improved resolution. Claim Objections Claims 3 and 4 are objected to because of the following informalities: Claims 3 and 4 recite reaction formulas 1 and 2, which include chemical structures of insufficient clarity. The claims must be amended to provide chemical structures and subscripts with improved resolution. 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. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1-9 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 1 recites a biodegradable polyester resin. Due to the absence of formatting, unclear punctuation, and the recitation of “an esterification and condensation polymerization reaction by adding…” (emphasis added), it is not clear: what process is being recited in the product-by-process claim (i.e., it is not clear what component(s) are being added to what other component(s), and what further step(s) beyond “adding” must be performed to prepare the recited resin), which recited reactant(s) are considered part of the recited “glycol component” (i.e., just the recited 1,4-butanediol, or, the recited 1,4-butanediol in combination with the recited polyglycerol succinate and/or the recited polyglycerol furanoate), and, which component, reactant or product must exhibit the properties recited in the last three lines of the claim (i.e., are the properties limiting the biodegradable polyester resin, or, are the properties limiting the polyglycerol furanoate). For examination purposes, claim 1 has been interpreted as set forth below. Applicant is not limited to amending claim 1 according to the below interpretation, however, the interpretation provides an example of how the claim could be amended to improve clarity: 1. A biodegradable polyester resin prepared by a method comprising an esterification reaction and condensation polymerization reaction of: dimethyl terephthalate and adipic acid in a weight ratio of 40:60 to 60:40 as an acid component, 1,4-butanediol as a glycol component, polyglycerol succinate as a reaction rate control agent, and polyglycerol furanoate as a molecular weight increasing agent, wherein the biodegradable polyester resin has: a number average molecular weight of 70,000 or more, a weight average molecular weight of 150,000 or more, an acid value of 0.4 to 0.8 mgKOH/g, and a tensile strength of 400 kgf/cm2 or more. Claims 2-9 are similarly rejected as being indefinite due to their dependence from claim 1. The formatting, punctuation and language in the dependent claims should be reviewed and amended to be consistent with any amendments made to claim 1. Additionally: Claim 5 depends from claim 1 and recites that “the catalyst” is added in an amount based on the total weight of “the reactant.” There is no prior recitation of “a catalyst” in claim 5 or in independent claim 1, and therefore, “the catalyst” recited in line 3 of claim 5 lacks antecedent basis. Additionally, claim 1 recites multiple elements which can be considered reactants, and therefore, it is not clear which element or elements is being referred by “the reactant” recited in line 4 of claim 5. Additionally, claim 5 recites that the catalyst is added “at the beginning or end of the esterification reaction and condensation polymerization reaction…” (emphasis added). It is not clear whether claim 5 requires two additions of catalyst (i.e., a first addition at the beginning or end of the esterification reaction and a second addition at the beginning or end of the condensation polymerization reaction), or, whether the recitations of claim 5 could be met by a single catalyst addition which is either at the beginning or end of the entire duration of both recited reactions. Claim 6 recites that “the catalyst is used with one or a mixture of two or more selected from…” (emphasis added). It is not clear what the words “used with” mean in the context of this claim. For examination purposes, the claim has been interpreted as if “used with” were deleted. Additionally, claim 6 recites “etc.” at the end of the recited list of alternatively useable members. Claim language defined by a Markush grouping requires selection from a closed group of alternative members. See MPEP 2117(I) and 2173.05(h). Because the list of alternatives in claim 6 is not a closed grouping, it is unclear what other alternatives are intended to be encompassed by the claim. Claim 7 depends from claim 1 and recites that “the stabilizer” is added in an amount based on the total weight of “the reactant.” There is no prior recitation of “a stabilizer” in claim 7 or in independent claim 1, and therefore, “the stabilizer” recited in line 3 of claim 7 lacks antecedent basis. Additionally, claim 1 recites multiple elements which can be considered reactants, and therefore, it is not clear which element or elements is being referred by “the reactant” recited in line 4 of claim 7. Additionally, claim 7 recites that the stabilizer is added “at the beginning or end of the esterification reaction and condensation polymerization reaction…” (emphasis added). It is not clear whether claim 7 requires two additions of stabilizer (i.e., a first addition at the beginning or end of the esterification reaction and a second addition at the beginning or end of the condensation polymerization reaction), or, whether the recitations of claim 7 could be met by a single stabilizer addition which is either at the beginning or end of the entire duration of both recited reactions. Claim 8 recites that “the stabilizer is used with one or a mixture of two or more selected from…” (emphasis added). It is not clear what the words “used with” mean in the context of this claim. For examination purposes, the claim has been interpreted as if “used with” were deleted. Citation of Pertinent Prior Art Claims 1-9 are not in condition for allowance in view of the rejection above under 35 USC 112(b). However, the claims are free of prior art. As acknowledged by Applicant in the specification as filed (see, e.g., [7]), polyester which is formed from reaction of dimethyl terephthalate, adipic acid and butanediol (i.e., PBAT) is well known in the art. However, the examiner is unaware of prior art which discloses or suggests forming PBAT by including polyglycerol succinate and polyglycerol furanoate as additional reactants in combination with the conventionally utilized PBAT monomers (dimethyl terephthalate, adipic acid and butanediol). The following is considered the closest prior art: Zhao et al (WO 2014/019459) discloses a biodegradable copolyester containing 2,5-furandicarboxylate (abstract). The polyester additionally contains units derived from an aliphatic dibasic acid (monomer a), aromatic dibasic acid (monomer b) and aliphatic diol (monomer c). See translation p 4. The aliphatic dibasic acid is preferably dimethyl succinate or dimethyl adipate (p 4), the aromatic dibasic ester is preferably dimethyl terephthalate (p 4), and butanediol is named as a preferred diol (p 5). However, Zhao fails to name glycerol as a monomer. Zhao further teaches that the copolyester has random repeating structural units (p 6), and, does not disclose a method wherein any of the diol or diacid reactants are prepolymerized (such as would be necessary to provide the presently recited polyglycerol succinate and polyglycerol furanoate reactants). Therefore, Zhao fails to disclose or suggest a polyester formed from reaction of a glycol component which includes polyglycerol succinate and a polyglycerol furanoate as presently recited. Faiella et al (US 2018/0237583) discloses a polyester comprising a diacid component which comprises aromatic and aliphatic diacids [0012-14] and a diol component comprising at least one aliphatic diol [0015]. Faiella names butanediol as an aliphatic diol [0017-18], names terephthalic acid/esters and 2,5-furandicarboyxlic acid/esters as aromatic dicarboxylic acids [0020-22], and names succinic and adipic acids as aliphatic dicarboxylic acids [0024]. Faiella further teaches including glycerol in order to obtain branched products [0033]. Therefore, Faiella reasonably suggests a polyester which comprises units derived from glycerol, succinic acid and furandicarboxylic acid as monomers, along with units derived from dimethyl terephthalate, adipic acid and butanediol as monomers. However, Faiella fails to teach a polyester which is formed from a reaction of dimethyl terephthalate, adipic acid and butanediol with polyglycerol succinate (such as formed from a pre-reaction of glycerol and succinic acid) and polyglycerol furanoate (such as formed from a pre-reaction of glycerol and furandicarboxylic acid). Therefore, a rejection of the present product-by-process claims citing Faiella has not been made, because the examiner has no basis to conclude that a polyester formed from the reaction of a mixture of glycerol, succinic acid, furandicarboxylic acid, dimethyl terephthalate, adipic acid and butanediol, as reasonably suggested by Faiella, would be indistinguishable (e.g., in terms of properties and randomness of repeating units) from a polyester as presently claimed, which is formed from a mixture of polyglycerol succinate, polyglycerol furanoate, dimethyl terephthalate, adipic acid and butanediol. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to RACHEL KAHN whose telephone number is (571)270-7346. The examiner can normally be reached Monday to Friday, 8-5. 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, Randy Gulakowski can be reached at 571-272-1302. 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. /RACHEL KAHN/ Primary Examiner, Art Unit 1766
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Prosecution Timeline

Jun 08, 2023
Application Filed
Jan 12, 2026
Non-Final Rejection — §112 (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
28%
Grant Probability
44%
With Interview (+15.9%)
3y 9m
Median Time to Grant
Low
PTA Risk
Based on 649 resolved cases by this examiner. Grant probability derived from career allow rate.

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