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
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.
Claims 1,2,4,5,8-10,12 and 16-19 rejected under 35 U.S.C. 103 as being unpatentable over Nemoto 2015/0018513.
Nemoto exemplifies (#4) polymerizing 99 parts of a 90/10 L-lactide/ D-lactide mixture (“Nemoto’s 1st monomer” or applicant’s “monomer I”) with 1 mol% lauryl alcohol initiator (paragraph 124) and DBU catalyst (paragraph 128). This is applicant’s step (1). Nemoto (paragraph 126) then polymerizes additional 90/10 L-lactide/ D-lactide mixture (“Nemoto’s 2nd monomer” or applicant’s “monomer II”) in the presence of the first step’s product. This qualifies as applicant’s step (2). The result is a polylactide of 135,000g/mol Mn (table 1).
The 1 mole of lauryl alcohol and 100 moles of lactides provides an initiator:monomer ratio of:
1 x 186g/mol initiator
------------------------------- = 0.0127 g init/g lactides or 1.3:98.7
100 x 146g/mol lactides
This ratio is below applicant’s 5:95 minimum.
However, Nemoto (paragraph 43) suggests up to 5mol initiator per 100 mol lactide. Anywhere from 4.1 to 5 mol of lauryl alcohol per 100 mol lactide provides amounts within applicants initiator:monomer weight ratio range.
Nemoto does not measure/report the hydroxyl value of polylactic acid stage (I) polymer in order to make applicant’s theoretical Mn calculation for the stage (I) prepolymer.
The hydroxyl value can be estimated from the knowledge that each mol of lauryl alcohol initiator provides 1 mol of hydroxyl groups to 100mol of monomer. For example, at 4.1 mol lauryl alcohol per 100 mol lactide, the hydroxyl value would be:
4.1 mol -OH mol lactide 1000mmol KOH 56.1mg KOH
------------------ X ---------------- X ----------------------- X --------------- = 16.0mgKOH/g 100mol lactide 144g lactide mol -OH mmol KOH
According to applicant’s formula of page 12 line 22,
Mn = 56.1 x functionality of initiator x 1000/ hydroxyl value
56.1 x 1 x 1000 /16.0 = 3,500 theoretical Mn
Anywhere from 4.1 to 5 mol of lauryl alcohol per 100 mol lactide provides theoretical Mn within applicant’s range and would have been obvious based on paragraph 43’s teachings.
To summarize, a choice of 4.1 to 5mol% lauryl alcohol initiator instead of the cited example’s 1mol% would result in a hydroxyl value that provides a Mn of stage 1 prepolymer within applicant’s range as well as applicant’s claimed weight ratio of initiator:monomer.
In regards to applicant’s dependent claims:
The ratio of the first step polymer to the final polymer (table 1) is 0.5:7.5 or 6:94 – meeting applicant’s claim 4.
The DBU catalyst does not qualify as one of applicant’s claim 5 catalysts. However, Nemoto (paragraph 33) does suggest such alternative catalysts.
The cited example has a 99% conversion (table 1) which is higher than applicant’s claimed 90-98% conversion of claim 10. However, Nemoto (paragraph 102) suggests 2% residual monomer (ie 98% conversion).
Step (1) feed (paragraph 141) was carried out continuously – meeting applicant’s claim 12.
Claims 6 and 7 rejected under 35 U.S.C. 103 as being unpatentable over Nemoto 2015/0018513 in view of Komazawa 2010/0324229.
Nemoto applies as explained above.
Nemoto (paragraph 33) suggests metal catalysts such as tin octylate as an alternative to DBU, but does not teach particular amounts thereof.
Komazawa similarly produces polylactic acid. Komazawa (paragraph 50) teaches metal catalysts such as tin octylate are to be used in amounts of 0.001-0.5mol% relative to the lactide monomer. Given tin octylate’s Mw of 405g/mol and lactide Mw of 144g/mol, the above mol ratio would be 0.0028 – 1.41wt% tin octylate relative to the lactide monomer. This overlaps applicant’s claim 6 and 7’s catalyst amounts.
The tin octylate is 29wt% tin. Therefore, weight % of tin relative to lactide is 0.00081- 0.41wt%. This is 0.8-4100ppm which overlaps applicant’s amount of metal.
It would have been obvious to employ typical amounts of tin octylate to catalyze Nemoto’s polylactide.
Claim 11 rejected under 35 U.S.C. 103 as being unpatentable over Nemoto 2015/0018513 in view of Komazawa 2010/0324229.
Nemoto applies as explained above.
The cited example of Nemoto uses lower polymerization temperatures than applicant and DBU as catalyst. However, Nemoto (paragraph 33) suggests metal catalysts such as tin octylate as an alternative to DBU.
Komazawa demonstrates (paragraph 117,119,129,130) 1900C polymerization temperatures for two step lactide polymerizations catalyzed by tin octylate.
It would have been obvious to conduct both polymerization steps at 1900C especially when using tin octylate catalyst.
Applicant's arguments filed 2/12/26 have been fully considered but they are not persuasive.
Applicant argues that Nemoto’s examples only have an initiator/lactide ratio of 1.28:98.8 instead of 5:95 minimum now required.
This is true, but ignores the broader teachings of Nemoto (paragraph 43) suggesting up to 5mol initiator per 100 mol lactide. A reference is not limited to its preferred embodiments (MPEP2123).
Applicant argues that this high initiator:lactide ratio improves properties but fails to point out which examples and comparisons illustrate the point. It is also noted that applicant’s original claim 3 considered a ratio of 1.2:98.8 to be acceptable.
Arguments regarding the importance of a two-step polymerization are irrelevant to the Nemoto rejection as Nemoto also conducts a two-step polymerization.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DAVID J BUTTNER whose telephone number is (571)272-1084. The examiner can normally be reached M-F 9-3pm.
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/DAVID J BUTTNER/Primary Examiner, Art Unit 1765 3/3/26