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 and 11-15 are pending as amended on 8/3/2026.
Claims 14 and 15 stand withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim.
No new grounds of rejection have been made. Therefore, this action is properly made final.
Any rejections and/or objections made in the previous Office action and not repeated below are hereby withdrawn. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office Action.
Claim Rejections - 35 USC § 103
Claim(s) 1 and 11-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Christensen et al (WO 2023/212648) in view of in view of Nowak et al (Visually and Infrared Transparent Poly(oxalamide) Films with Mechanical Toughness, ACS Appl. Polym. Mater. 2022, 4, 5027−5034) and Ascend Performance Materials (HexatranTM Product Profile brochure, pp 1-4, Rev 04/2022; downloaded from: https://ascendmaterials-files.sfo2.cdn.digitaloceanspaces.com/files/Brochures/Hexatran_Brochure.pdf on 5/2/2025.
Christensen discloses a polydiketoenamine (PDK) based renewable plastic [0002]. Christensen teaches that the composition for PDK comprises at least one triketone and at least one polyamine. The triketones and polyamines are bound using dynamic covalent diketoenamine bonds, thereby allowing recovery of the monomeric compounds [0027]. Christensen teaches that the system for a PDK which comprises at least one triketone and at least one polyamine functions as a renewable, customizable plastic system with desired functional properties [0027].
Christensen teaches that triketones may be obtained from the condensation of 1,3-diketones (with dimedone named as an example thereof) with dicarboxylic acids (with sebacic acid, forming TK10, named as an example thereof). Christensen teaches that triketones with heteroatoms may change the rate of hydrolysis and depolymerization conditions such as time and temperature [0029-31].
As shown in figure 6 (copied below):
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the triketone formed from reaction of diketone with dicarboxylic acid, as taught by Christensen, is a triketone dimer and therefore corresponds to (a) as presently recited.
[As to the presently elected triketone dimer species, DK10, a triketone TK10 obtained from dimedone as the 1,3-diketone, as taught by Christensen, has a structure according to the instant elected (a) species DK-10, as recited in instant claims 12 and 13, wherein R’ is a 10-carbon linear hydrocarbon group. It would have been obvious to the person having ordinary skill in the art to have formed PDK from TK10 as the triketone monomer, as taught by Christensen, by selecting any 1,3-diketone for the reaction with sebacic acid to form the triketone, including dimedone, in order to obtain a PDK with a desired rate of hydrolysis and depolymerization.]
Christensen further teaches that the polyamine building block may comprise any polyamine that can form a diketoenamine bond with triketone, and that examples of possible polyamines include linear and/or branched diamines, also polyamines such as triamine [0032]. Christensen teaches that diamines act as chain extenders to the triamine crosslinkers, and that chain extenders increase elongation to break and toughness of the network [0081] (see also [00142] teaching an embodiment of PDK comprising a triamine that acts as a crosslinking agent). The polyamine formulation (various functionality, di and tri series, molecular weight) can increase toughness and elongation to break, create tunable Tg, tunable rheology, and increase thermal stability [0083]. Christensen names several examples of polyamines with various chemical structure, including diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), which are polyamines containing primary and secondary amine groups, and including tris(aminomethyl)ethane (TAME), which is a triamine containing three primary amine groups and no secondary or tertiary amine groups [0032].
While the TAME named by Christensen meets the presently claimed requirement regarding the absence of secondary or tertiary amine groups, TAME has a quaternary (not a tertiary) carbon within the hydrocarbon group, and, TAME has five carbons (which is not within the claimed range of 8 to 20). Christensen fails to name a triamine crosslinker meeting all of the requirements of the presently recited multifunctional amine species. Christensen further fails to teach PDK formed from 4-(aminomethyl)octane-1,8-diamine (the elected multifunctional amine species, recited in instant claim 11) as the crosslinking triamine.
As set forth in the Ascend product brochure, 4-(aminomethyl)octane-1,8-diamine), “Hexatran,” was known in the art as a trifunctional primary amine with equal or better performance compared to other amines (TEPA, TETA and DETA) typically used in high-performance applications. Ascend teaches that Hexatran has a high boiling point, low vapor pressure and low to no smell and color, and that its unique trifunctional structure provides toughness, flexibility and high cross-linking density (p 2). Ascend shows that a coating made with Hexatran has superior flexibility with no cracking compared to products made with DETA or TETA (p 3). Nowak also discloses the use of Hexatran, a commercially available trifunctional primary amine with aliphatic interior, as a crosslinker for preparing poly(oxalamide) from aliphatic amine monomers and dioxalate. See p 5029 and abstract on p 5027.
Considering Christensen’s teachings in [0081-83], particularly that the polyamine formulation (various functionality, di and tri series, molecular weight) can increase toughness and elongation to break, create tunable Tg, tunable rheology, and increase thermal stability, the person having ordinary skill in the art would have recognized that several properties of a PDK depend on its chemical structure. Additionally, considering that Christensen’s disclosed list in [0032] of example polyamine building blocks for PDK includes a variety of types of chemical structures, one having ordinary skill in the art would have had a reasonable expectation of success in varying the structure of the polyamine reactant in order to tune the properties of a PDK product. Therefore, when forming a PDK from TK10 and a triamine as a cross-linker, as taught by Christensen, the person having ordinary skill in the art would have been motivated to select a known triamine crosslinker having any appropriate structure in order to tune the properties of the PDK for a specific application, with a reasonable expectation of success.
Considering the disclosures regarding Hexatran in Nowak and Ascend, the person having ordinary skill in the art would have been motivated to select 4-(aminomethyl)octane-1,8-diamine) as a triamine crosslinker in order to provide a material having toughness, flexibility and high cross-linking density, and, in order to provide equal to or better performance compared to the typically used amines (e.g., DETA, TETA, TEPA). One would have been further motivated to select Hexatran as a polyamine crosslinker in view of Ascend’s teaching that it has low/no smell and color. It would have been obvious to the person having ordinary skill in the art, therefore, to have formed a PDK network from TK10 and triamine crosslinker, as taught by Christensen, by utilizing 4-(aminomethyl)octane-1,8-diamine) (i.e., Hexatran, as described in both Nowak and Ascend) instead of a typically used amine as taught by Christensen (e.g., DETA, TETA, TEPA), thereby arriving at a vitrimeric PDK network as presently recited.
Response to Arguments
Applicant's arguments and Declaration filed 8/3/2026 have been fully considered.
Applicant’s arguments on pp 5-6 refer to a discussion of a disclosure in Helms in the specification as originally filed. Note, however, that Helms is not cited as prior art in the rejection of the claims. Arguments which are applicable to the rejection of record citing Christensen as a primary reference are addressed below.
Applicant argues (p 6) that the presently claimed subject matter improves upon known networks by replacing the TREN monomer (which has a tertiary amine group, resulting in a hygroscopic material which rapidly breaks down due to water penetration) with an aliphatic polyamine such as Hexatran (which is more hydrophobic because it lacks the tertiary amine), the obtained network material is more robust to natural operating requirements and selective to depolymerization. Applicant argues (p 7) that the prior art did not recognize the problems associated with the hygroscopicity of TREN, and therefore, the person having ordinary skill in the art would not have been motivated to combine the cited references to create the new material recited in claim 1.
However, primary reference Christensen does not limit the disclosure of a primary amine building block for the PDK to TREN, as might be inferred from Applicant’s argument. Rather, as set forth in the rejection of record, Christensen’s disclosed list in [0032] of example polyamine building blocks for PDK includes a variety of types of chemical structures (including triamines with primary and secondary amine groups, and a triamine with only primary amine groups and no secondary/tertiary amine groups); Christensen’s teaching in [0081-83] associates polyamine structure with material properties (see paragraph 15 of the previous action). The existence of structure-property relationships within PDK materials, including a dependence of hydrolysis/depolymerization on heteroatoms, is also recognized by Christensen (see, e.g., [0029-31]: Christensen teaches that triketones with heteroatoms may change the rate of hydrolysis and depolymerization conditions such as time and temperature). Therefore, Christensen’s disclosure guides the person having ordinary skill in the art toward tuning properties (including a rate of hydrolysis) of a PDK by selecting an appropriate structure for the primary amine building block. [Note that Applicant has acknowledged (see arguments filed on 11/19/2025, p 6) that the expected properties of a material based on its chemical structure can be determined based on, e.g., known-structure property relationships and chemistry modeling software.]
Applicant argues (remarks p 8 and Declaration section 6) that secondary reference Nowak uses Hexatran to provide mechanical toughness and fluid imperviousness in a vehicle exterior which is not designed to degrade, while the PDK networks of primary reference Christensen are designed to break down under environmental exposure. However, Applicant has not pointed to any particular teaching in Christensen with regard to degradation under environmental exposure, and therefore, Applicant has not sufficiently established that there are teachings in Christensen which conflict or are non-combinable with the teachings in Nowak. Additionally, Christensen teaches selecting appropriate crosslinkers in order to achieve desired properties, including a tough material [0082-83], which is consistent with Applicant’s cited teachings regarding the use of Hexatran in Nowak.
Applicant argues (p 8) that Nowak fails to motivate the use of Hexatran in the claimed invention because the Nowak Declaration is executed by the same first author in the Nowak reference itself. Applicant has not provided reasoning to support this conclusion, and therefore, the fact that the Declaration is executed by the first author in the Nowak reference fails to establish that there is no motivation to use Hexatran in the claimed invention.
Conclusion
THIS ACTION IS MADE FINAL. 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.
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.
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/RACHEL KAHN/Primary Examiner, Art Unit 1766
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