DETAILED ACTION
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.
Claims 1-16 are rejected under 35 U.S.C. 103 as being unpatentable over Seppala (US 5,925,726, US Reference # 1 from IDS dated 3/7/2024) in view of de Silva (Polymer Testing volume 93, 106889 (2021), Non-Patent Reference #2 from IDS dated 3/5/2024).
Regarding Claims 1, 6, and 12,
Seppala teaches a lactic acid-based polymer (Column 2, Lines 3-8) where all terminal groups are carboxyl groups (Column 2, Lines 49-55) and which is subsequently reacted with a diepoxy compound ((Column 2, Lines 6-8) which results in branching (Column 3, Lines 25-29). Seppala further teaches a method for preparing this polymer (Column 4, Lines 47-67, Column 5, Lines 15-26, Column 6, Lines 2-9). Seppala further teaches that the carboxyl termination is accomplished by reacting the poly(lactic acid) polymer with a diacid or anhydride in amounts of 0.1 to 10% by molar ratio (Column 5, Lines 15-26) which overlaps with the range of the instant claim. Seppala also teaches that this carboxyl-terminated polymer is then reacted with a diepoxide (Column 6, Lines 5-9) where the reaction is promoted by a catalyst (Column 6, Lines 16-17) and where the number of epoxide groups to carboxyl groups is between 0.5 and 1.5 (Column 6, Lines 35-38), which would overlap with the range of the instant claims. Seppala teaches that reactivity of the polymer with the diepoxide proceeds best when both chain ends are terminated with an acid (Column 5, Lines 6-14) and as such, the ordinarily skilled artisan would recognize that because Seppala teaches the addition of the anhydride to make sure all end groups are carboxyl groups, that the amount of the anhydride needed is the amount that results in a polymer with only acid end groups. As such, it would have been obvious prior to the effective filing date of the instant application to have used the anhydride in any amount that resulted in only acid end groups. Additionally, because Seppala teaches that the diepoxide is used to increase the molecular weight of the polymer (Column 2, Lines 3-8) and to introduce branching (Column 3, Lines 25-29), one of ordinary skill in the art would recognize that the amount of diepoxide used would be correlated with the amount of branching desired as well as the chosen molecular weight of the final polymer. As such, it would have been obvious prior to the effective filing date of the instant application to have used any amount of diepoxide that achieved the desired molecular weight and amount of branching.
While Seppala teaches the use of diepoxides and of catalysts to promote the reaction, Seppala does not teach the specific diepoxide or a phosphorus catalyst. de Silva teaches the use of epoxidized cardanol (ECP) (Figure 1) and further teaches that the catalyst to promote the reaction is triphenylphosphine (Page 2, right column, Section 2.2), meeting the requirements of the instant claims. de Silva further teaches that ECP can be used as an eco-friendlier replacement for other epoxides (Page 2, left column, fourth Paragraph), one of ordinary skill in the art would be motivated to use it in the polymer taught by Seppala, who teaches that the polymer is biodegradable (Column 3, Lines 1-3). As such, it would have been obvious prior to the effective filing date of the instant application to have substituted the catalyst and diepoxide of de Silva into the composition taught by Seppala to obtain the predictable result of a biodegradable branched lactic acid-based polymer with a reasonable expectation of success.
With regard to the method, Seppala teaches that the polylactide polymer can be terminated with an acid anhydride (Column 5, lines 15-26) and notes reaction temperatures between 160 and 210 °C (Column 4, Lines 58-60), which overlaps with the range of the instant claims and teaches that this acid-terminated polymer is then reacted with the diepoxide (Column 6, Lines 2-9), meeting the requirement of the instant claims. One of ordinary skill in the art would recognize that the reaction rate is affected by the reaction temperature and would further note that Seppala teaches that at temperatures above 210 °C polymer chain degradation can occur (Column 4, Lines 47-51). As such, it would have been obvious prior to the effective filing date of the instant application to have selected the overlapping portion of the ranges because the selection of overlapping portions of ranges has been held to be a prima facie case of obviousness. See MPEP 2144.05.I.
Regarding Claims 2-3 and 16,
Seppala teaches the use of anhydrides such as succinic and phthalic anhydride (Column 5, Lines 24-26) in amounts of 0.1 to 10% by molar ratio (Column 5, Lines 15-26) which overlaps with the range of the instant claim and it would have been obvious prior to the effective filing date of the instant application to have selected the overlapping portion of the ranges for the reasons listed above in regard to claim 1.
Regarding Claims 4-5 and 15,
Seppala in view of de Silva teaches the use of triphenylphosphine (Page 2, right column, Section 2.2) as described above in regard to claims 1 and 12 and it would have been obvious prior to the effective filing date of the instant application to have combined the catalyst and diepoxide of de Silva with the polymer of Seppala for the reasons stated above in regard to claims 1 and 12.
Regarding Claims 7 and 9-11,
Seppala teaches that the number average molecular weight of the polymer is from 10,000 to 200,000 (Column 6, Lines 61-62) and that the molecular weight distribution is preferred to be at least 2 (Column 6, Lines 48-51). While Seppala does not teach the weight average or Z average molecular weights, as these weights are by definition higher than the number average molecular weight and particularly with a preferred molecular weight distribution (Mw/Mn) of 2 or more, the weight average molecular weight would then have a range of 20,000-400,000 if the distribution was 2 with the Z average being similar, which would overlap with the ranges of the instant claims. One of ordinarily skill in the art would recognize that increased molecular weight alters the physical properties of the polymer and would adjust the molecular weight to obtain the desired physical properties of the final polymer. As such, it would have been obvious prior to the effective filing date of the instant application to have selected any molecular weight that gives the desired physical properties and it would have been obvious prior to the effective filing date of the instant application to have selected the overlapping portion of the ranges because the selection of overlapping portions of ranges has been held to be a prima facie case of obviousness. See MPEP 2144.05.I.
Regarding Claim 8,
Seppala teaches that the reaction between the lactide polymer and the diepoxide preferably takes place between 130 and 200 °C (Column 45-48), meeting the requirement of the instant claim.
Regarding Claim 13,
Seppala does not teach a specific reaction time. However, Seppala teaches that reactivity of the polymer with the diepoxide proceeds best when both chain ends are terminated with an acid (Column 5, Lines 6-14) and as such, the ordinarily skilled artisan would recognize that because Seppala teaches the addition of the anhydride to make sure all end groups are acid groups. As such, the ordinarily skilled artisan would be motivated to have run the reaction between the anhydride and the polymer for a length of time required to have all end groups be acids. It would therefore have been obvious prior to the effective filing date of the instant application to have run the reaction for any length of time that affords polymer with only acid end groups.
Regarding Claim 14,
Seppala teaches that the reaction of the diepoxide and the polymer (equivalent to step 2 of the instant claim) is preferred to be from 1 min to 100 h (Column 6, Lines 58-59). One of ordinary skill in the art would recognize that the reaction should be run to completion to avoid side reactions or unreacted starting materials in the final polymer and would naturally let the reaction run for the length of time required to reach completion. As such, it would have been obvious to have run the reaction for any length of time required to reach completion.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ADAM J BERRO whose telephone number is (703)756-1283. The examiner can normally be reached M-F 8:30-5.
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/A.J.B./Examiner, Art Unit 1765
/JOHN M COONEY/Primary Examiner, Art Unit 1765
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