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 1-20 are pending as filed on 5/19/2023.
Election/Restrictions
Applicant’s election without traverse of species wherein the polyester is PBAT formed according to instant example 15, i.e., without utilizing metal salt, branching agent, CNC, ester polyol diol/PCL or chain extender in the reply filed on 1/6/2026 is acknowledged.
Claims 2, 3, 7, 10, 11 and 19 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim.
Specification
The disclosure is objected to because of the following informalities:
Tables 20 and 21 of the instant specification appear to be identical. One of the tables should be removed.
Additionally: according to Table 2 and Table 5, Comparative Example 1 and Inventive Example 15 were prepared utilizing different amounts of first reaction slurry, and therefore there is reasonable basis to conclude that the PBAT polymers resulting from these two examples are not identical. However, all of the properties reported for Comparative Example 1 and Inventive Example 15 are identical. Compare data in:
Table 7 to Table 8
Table 9 to Table 10
Table 11 to Table 12
The number of identical properties between the two examples raises the question as to whether there is an error in the Tables reporting the amounts of slurry utilized in the preparation of each example, or, whether there is an error in the reporting of data for one or both of the examples. Applicant is requested to clarify/confirm whether the data in the Tables is accurate.
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 13 and 14 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 13 recites a difference between wet hardness after a 1 hr immersion and wet hardness after a 20 hour immersion of 10% or less “based on the initial hardness.” It is not clear how a difference between two wet hardness values should be based on an initial hardness (i.e., the hardness prior to any immersion). Because one would not how the initial hardness value should be included in the calculation of the percentage difference between the two wet hardness values, the scope of claim 13 is unclear. Claim 14 is similarly unclear because it recites a difference between two wet hardness values which is “based on the initial hardness.”
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, 4-6, 8, 9, 12-18 and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al (US 2006/0155099) in view of Mahata (Poly(butylene adipate-co-terephthalate) Polyester Synthesis Process and Product Development, Polymer Science, Series C, 2021, Vol. 63, No. 1, pp. 102–111) and Antheunis et al (Autocatalytic Equation Describing the Change in Molecular Weight during Hydrolytic Degradation of Aliphatic Polyesters, Biomacromolecules 2010, 11, 1118–1124).
As to claims 1, 4-6, 12-18 and 20, Wu discloses biodegradable copolyester products which can be directly utilized in any application that requires biodegradable materials, including disposable tableware [0031] (corresponding to a biodegradable molded article, as presently recited). Wu discloses that the biodegradable polyester is a reaction product of an aromatic dicarboxylic acid, an aliphatic diol and an aliphatic dicarboxylic acid [0026], and exemplifies polyester formed from a reaction of 1,4-terephthalic acid (TA), 1,4-butyleneglycol (BDO) and adipic acid (AA) [0041] (i.e., the same monomers which form the presently elected species, PBAT; note that the polyester in Wu’s example 2 [0041] is formed without utilizing metal salt, branching agent, CNC, ester polyol diol/PCL or chain extender).
Wu fails to teach a hydrolysis degree after one or three weeks (as recited in claim 12), an initial hardness and wet hardness (as recited in claim 5), wet hardness reduction rates or differences (as recited in claims 1, 4, 6, 13 and 14), and weight and volume swelling rates (as recited in claims 15-18 and 20).
However:
As established above, Wu discloses PBAT formed without utilizing metal salt, branching agent, CNC, ester polyol diol or chain extender, and which therefore has a polymeric structure which is the same as structure of the PBAT described in the instant specification, and particularly, the presently elected species according to instant example 15. Wu teaches that aliphatic polyesters are biodegradable and will not pollute the environment, but have low heat resistance and unsatisfactory mechanical properties. Aryl groups improve physical properties and processability, but the biodegradable rate of the aliphatic polyesters decreases with an increase in the amount of the aryl group introduced [0006].
Consistent with Wu’s disclosure, Mahata teaches that the biodegradation rate of PBAT depends on the aromatic segment of terephthalic acid content in the polymer. The rate of biodegradation increases with the decrease of terephthalic acid content because of the higher rate of hydrolytic degradation in the presence of microbial population. Mahata further teaches that a hard terephthalic acid segment imparts crystallinity, rigidity, heat resistance and melt strength in the PBAT copolyester, while the adipic acid segment improves flexibility and biodegradation properties in PBAT. See paragraph bridging pp 104-105, as well as Scheme 3 at the top of p 105.
Antheunis similarly teaches that water will only penetrate into the amorphous domains of an aliphatic polyester, and cannot enter crystalline domains if present. Antheunis further teaches that hydrolysis of an ester bond under mild conditions can only occur when acid or base catalyzed. Carboxylic end groups in the polymer matrix catalyze hydrolysis, and when a polymer initially has a high amount of carboxylic end groups, the hydrolysis is accelerated from the very beginning of the degradation process (p 1118, paragraph bridging columns).
As evidenced by the disclosures in Wu, Mahata and Atheunis discussed above, the ratio of terephthalic acid to adipic acid in PBAT was known in the art as a result effective variable which can be optimized depending on demands of a given application to achieve a desired balance between properties associated with terephthalic segments (e.g., increased crystallinity, rigidity, heat resistance, melt strength) and properties associated with adipic segments (e.g., increased flexibility, swelling and biodegradation). Additionally, as evidenced by Atheunis’ disclosure, the carboxylic end group concentration in an aliphatic polyester was known in the art as a result effective variable which can be optimized in order to achieve a desired rate of hydrolysis from the beginning of the degradation process (i.e., as carboxyl concentration increases, hydrolysis rate increases).
The person having ordinary skill in the art would have recognized that for some applications, biodegradability and/or fast hydrolysis is of higher importance than mechanical properties such as rigidity and heat resistance, while for other applications, improved mechanical properties (such as rigidity/hardness, crystallinity, heat resistance) are a higher priority than faster biodegradation/hydrolysis. Therefore, when synthesizing a PBAT for a molded article, the person having ordinary skill in the art would been motivated to select both an appropriate terephthalic/adipic ratio and an appropriate carboxylic end group content, in order to achieve a desired balance between mechanical properties and biodegradability/hydrolysis, depending on the priorities and demands of a given application. It would have been obvious to the person having ordinary skill in the art, therefore, to have produced a PBAT (composition and molded article), as taught by Wu, by selecting any appropriate ratio of adipic acid and terephthalic acid segments, as well as any appropriate carboxyl end group content, in order to achieve desired mechanical properties balanced with desired rates of biodegradation and hydrolysis, including an adipic/terephthalic ratio and carboxyl end group content which results in a hydrolysis degree after one or three weeks, an initial hardness and wet hardness, wet hardness reduction rates or differences, and weight and volume swelling rates within the presently claimed ranges.
As to claims 8 and 9, modified Wu suggests a PBAT resin composition according to claims 1 and 4, as set forth above. Wu is silent as to the water contact angle and surface polarity of a block formed from the PBAT resin. However, as established above, the carboxylic acid concentration of PBAT was known in the art to be a result effective variable and obvious to optimize. Given that carboxylic acid groups are polar and hydrophilic, there is reasonable basis to conclude that increasing the concentration of carboxylic groups increases the surface polarity and decreases water contact angle of PBAT. For the reasons established above, it would have been obvious to the person having ordinary skill in the art to have produced Wu’s PBAT composition by selecting any appropriate carboxyl end group content in order to achieve desired rates of biodegradation and hydrolysis, including a carboxyl end group content corresponding to a water contact angle and a surface polarity within the presently claimed ranges.
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.
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/RACHEL KAHN/ Primary Examiner, Art Unit 1766