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 1-18 are pending as amended on 10/28/2025.
Claims 14-18 stand withdrawn from consideration as being drawn to a non-elected invention.
The new ground of rejection below was necessitated by Applicant’s amendment to claim 1 reciting process steps by which the recited copolycarbonate product must be 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Any rejections and/or objections made in the previous Office action and not repeated below are hereby withdrawn.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.
Dependent claims 2-6, 8, 9, 12 and 13 are presented in the amendment filed on 10/28/2025 with the status identifier “(Withdrawn)”. Applicant has not provided any remarks which explain why these claims were identified as “withdrawn.” Note that the claims were NOT withdrawn by the examiner. Claim 2, for example, no longer further limits claim 1 in view of the amendment to claim 1 (because claim 1 no longer recites a formula 1 or group R1, claim 2 no longer properly further limits claim 1). Therefore, Applicant may have intended to cancel claims 2-6, 8, 9, 12 and 13.
In the remarks filed on 10/28/2025, Applicant states that “claims 1, 7, 10 and 11 are pending…”, and therefore, claims 1, 7, 10 and 11 have been examined. In any subsequent response, Applicant must either cancel claims 2-6, 8, 9, 12 and 13, or, amend the claims so that they comply with 35 USC 112(d). Only claims drawn to a non-elected invention may be presented with the status identifier “withdrawn.”
Claim Rejections - 35 USC § 103
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.
Claim(s) 1, 7, 10 and 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cai et al (Modification of biodegradable poly(butylene carbonate) with 1,4-cyclohexanedimethylene to enhance the thermal and mechanical properties, Polymer Degradation and Stability 143 (2017) pp 35-41) in view of Wang et al (Synthesis of high-molecular-weight aliphatic polycarbonates from diphenyl carbonate and aliphatic diols by solid base, Journal of Molecular Catalysis A: Chemical 424 (2016) 77–84).
Cai discloses a copolycarbonate having repeating units derived from reaction of diphenyl carbonate (DPC), butanediol (BD) and cyclohexanedimethanol CHDM). See p 36, last paragraph.
Cai discloses a polycarbonate synthesis wherein CaO (calcium oxide) is utilized as a catalyst (p 36 section 2.2). Cai fails to disclose a polycarbonate obtained by a method comprising adding magnesium oxide as a catalyst.
Wang discloses that MgO exhibited remarkably higher activity than other solid bases for direct transesterification of DPC with aliphatic diols to synthesize aliphatic polycarbonates (p 78, left column, middle). Wang teaches that MgO prepared via simple coprecipitation route (MgO-P) showed the best performance among the solid bases and magnesium compounds investigated (conclusion). See also Table 1 on p 79 showing that polycarbonate formed using MgO-P has a higher molecular weight and yield compared to polycarbonate formed using CaO, and Figure 6 (p 81) showing superior performance of MgO compared to CaO (based on the effect of reaction time on molecular weight and yield). Considering Wang’s disclosure, it would have been obvious to the person having ordinary skill in the art to have substituted the CaO catalyst taught by Cai for the magnesium oxide catalyst taught by Wang in order to improve catalytic performance (and, e.g., improve molecular weight and/or yield) in Cai’s polymerization.
As to the presently recited polymerization conditions (heat, pressure, duration):
Cai’s polycarbonate is made by a method as set forth in section 2.2 of p 36, comprising placing CHDM, DPC, BD and catalyst in a flask (corresponding to a reactor as presently recited). The flask is then stirred under nitrogen atmosphere and heated at 200 C for 2 hours, substantially corresponding to the presently recited step of heating, melting and mixing uniformly under high purity nitrogen atmosphere at 210 C for 2 hours to obtain an oligomerized byproduct. Cai subsequently teaches applying a vacuum of 100 Pa over 0.5 hours to avoid foaming and oligomer sublimation, and then maintaining the state (i.e. 100 Pa and 200 C) for another 2 hours, substantially corresponding to the presently recited step of reducing the pressure to below 200 Pa for 2 hours. Note that Cai also teaches removing volatile byproducts, substantially corresponding to the instant step of distilling off byproducts under reduced pressure.
Claim 1 is a product-by-process claim. Case law has established that the patentability of a product-by-process is determined by the patentability of the product itself, i.e., that the patentability of a product does not depend upon its method of production (MPEP 2113). The process limitations are only given consideration regarding patentability if there is criticality to the structure implied by the steps of the process. No criticality has been demonstrated to the presently recited oligomerization temperature of 210 C compared to Cai’s disclosed temperature of 200 C, nor to the presently recited polycondensation temperature of 220 C compared to Cai’s disclosed temperature of 200 C.
As established above, modified Cai suggests a polycarbonate formed from the same monomers as presently recited (DPC, CHDM, BD), utilizing the same catalyst as presently recited (MgO), and utilizing polymerization conditions which are substantially similar to those recited in the instant product-by-process claim (both Cai’s process and the instant process have a first oligomerization step with heating under nitrogen for 2 hours and a second polycondensation step with heating under vacuum for 2 hours). There is reasonable basis to conclude, therefore, that modified Cai suggests a polycarbonate which is encompassed by instant claim 1, notwithstanding any minor differences in the polymerization conditions under which the polycarbonate of modified Cai is obtained.
As to claim 7, the Mw values for PBCC10, PBCC30, PBCC50 and PBCC90 in Cai’s table 1 on p 38 fall within the presently recited Mw range. Note that the molecular weights of polycarbonates produced from MgO taught by Wang in Table 1 also fall within the presently claimed range.
As to claims 10 and 11, the PDI values in Cai’s table 1 fall within the presently recited ranges. The PDI values in Wang’s table 1 also fall within the presently recited ranges.
Response to Arguments
Applicant's arguments filed 10/28/2025 have been fully considered.
To the extent that Applicant’s arguments regarding the (withdrawn) rejection under 35 USC 102 over Cai may be considered applicable to the new rejection above over Cai in view of Wang, they have been addressed below.
Applicant argues that Cai uses the trans form of CHDM monomer, while the CHDM used in the present application is a mixture of trans and cis forms. Applicant argues that Cai does not disclose using a mixture of trans and cis forms of CHDM, and that the Tg of polycarbonate obtained using the trans form is lower than polycarbonate obtained using a mixture of cis and trans. However:
there is no evidence in the instant specification or in Applicant’s remarks that the CHDM disclosed in the instant specification is a mixture of trans and cis forms (and the arguments of counsel cannot take the place of evidence in the record),
the claims are not limited to any particular geometric isomer(s) of CHDM (and therefore encompass polycarbonates made from trans-CHDM as taught by Cai), and,
the claims are not limited to any particular Tg values (and therefore do not exclude polycarbonates having different Tg values than those in the instant examples).
For at least the above reasons, Applicant’s argument that Cai does not disclose using a mixture of trans and cis forms of CHDM is not sufficient to overcome a rejection over Cai in view of Wang.
[Additionally, it is not possible to know whether the cited ~8 degree difference between the Tg values measured in the instant specification and in Cai is actually due to a difference in CHDM isomerism, as alleged by Applicant. Differences in measurement procedures/equipment between those used in the instant specification and those used in Cai have not been ruled out, and such differences could result in differences in Tg values. Furthermore, while both Cai and the instant application describe polycarbonate formed from a 50:50 ratio of the BD and CHDM diols, there could be differences in the ratio of the diol monomer units in the polymers which are ultimately obtained, which would result in differences in the Tg values of the ultimately obtained polymers. See, e.g., Cai’s Table 1 showing that a 50/50 ratio of monomers in the feed results in a polymer having a 46/54 ratio of monomers, and, Table 2 showing that Tg varies substantially as diol ratio varies.]
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.
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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