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 Objections
‘Molecular weight distribution” and “polydispersity index” are two ways of labeling the same property of a polymer and, hence, their simultaneous mention in claim 17 is redundant.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-4, 6, 8, 29, and 31 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by GB 1599530.
GB ‘530 is directed to the copolymerization of a mixture of cyclic organic monomers, one of which would provide a primary alcohol residue as the terminating unit and the other of which would provide a secondary alcohol residue as the terminating unit. A primary stated objective is to identify an approach that allows the ratio of primary- and secondary hydroxyl groups to be regulated independently of the compositional content of the remainder of the copolymer chain. One aspect of the approach involves the provision of a “main” feed source that contains a mixture of the two aforementioned cyclic monomers. The composition of the main feed source is fixed and is continuously introduced into the polymerization chamber. Although the composition of the main feed is fixed, the mol ratio of the monomers introduced into the polymerization chamber is varied by the introduction of a second “auxillary feed source” that differs from the main feed source in the relative mol contributions of the primary- and secondary alcohol-providing monomers. The makeup of the monomer mixture entering the polymerization chamber at a given time can be constantly evolved by altering the relative quantities of the main- and auxillary feed source being combined. See page 2, lines 30-44 and page 3, lines 55-59. Relevant to the present discussion, among the monomers that can be used to furnish primary- and secondary alcohol end groups are lactones, such as caprolactone, and lactides respectively (page 2, lines 59-63).
Page 3, lines 11-22 reiterate that the makeup of the main- and auxillary feed compositions must be different but, otherwise, the concentrations of the two monomers in each can be any that is desired. Recognizing that the two monomers react at different rates, it is mandated that the feed solutions be introduced at a rate that establishes a “monomer starvation” condition. This, it is the Examiner’s interpretation, is a different way of stating that the feed rate is controlled such that it is slower than the polymerization rate as claim 29 requires. See page 5, lines 27 to 39 and also page 6, lines 59 to 64 for further development of the concept of a monomer-starved system. (The latter passage actually makes reference to an ethylene oxide/propylene oxide mixture, a favored embodiment of the disclosure, but the skilled artisan will appreciate that the same benefits apply to other monomer mixtures with a documented large difference in their individual polymerization rates.)
As for claim 4, the provision of the two monomers making up the main feed source and auxillary feed source can be done from a plurality of tanks in fluid connection with the feed lines according to page 4, lines 15-21.
Regarding claim 8, page 7, lines 16-17 state that any active hydrogen compound including alcohols may be used as the initiating species. (The Examiner appreciates that much of the disclosure is devoted to the employment of ethylene oxide/propylene oxide but takes notice of the fact that one having ordinary skill in the polymerization of cyclic esters will recognize alcohols as being suited to initiate polymerization of this class of monomers as well.)
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 5, 14-15, 18, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over GB 1599530.
It is acknowledged that the reference is silent as to the employment of glycolide as a cyclic monomer candidate. However, the Examiner takes notice of the fact that lactide/glycolide copolymers have achieved recognition as having broad utility in the production of biomedical materials. Additionally, lactides furnish secondary hydroxy groups and glycolide primary alcohol groups so this combination would be among those of interest in the practice of the prior art invention given that its focus is on copolymers mixtures with primary- and secondary alcohol moieties alike.
Concerning claims 14 and 15, page 3 stipulates only that the mixtures funneled into the main and auxillary feeds are compositionally distinct, there being a suggestion that each will contain a primary hydroxy-forming monomer and a secondary hydroxyl-forming monomer. There is no directive that each feed will only contain one of these and, thus, one of ordinary skill will understand that the two feeds may contain another monomer of either the primary hydroxy-forming type or the secondary hydroxyl-forming type. To reiterate, GB ‘530 aims for a monomer starvation condition meaning that feed rates lower than reaction rates will be established.
As for claim 21, GB ‘530, once more, like the instant invention endeavors to establish a condition where the feed rate is slower than the polymerization rate. (It is acknowledged that claim 1 has now been broadened out to also embrace a condition where the feed rate may be faster than the polymerization rate but, prior to the preliminary amendment it was confined to the former and, thus, it may be assumed that the feed rate disclosed in original claim 21 represents a rate slower than the reaction rate.) To the extent that the same process condition is prioritized by both, it is the Examiner’s position that, in the act of optimizing the feed rate for a mixture of either caprolactone or glycolide, and lactide (and in the presence of guanidine/amidine catalysts which the Examiner considers to be prima facie obvious for reasons delineated supra), to maintain monomer starvation, a skilled practitioner of the prior art invention will make the determination through routine experimentation that the feed rate of claim 21 is operable/idealized.
Claims 10-12 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over GB 1599530 in view of the article entitled “Guanidine and Amidine Organocatalysts for Ring-opening Polymerization of Cyclic Esters” authored by Lohmeijer et al., and published in Macromolecules (2006) 39, 8574-8583.
As before, GB ‘530 is primarily focused on the polymerization conditions of EO and PO but still embraces the polymerization of mixtures of caprolactone/valerolactone and lactide as combinations of monomers that furnish primary- and secondary alcohol groups as the last unit polymerized under monomer starvation conditions. Because the reference is not forthcoming as to the catalysts that might be employed in their polymerization, the skilled artisan will consult related disclosures to ascertain what is useful in that regard. The article entitled “Guanidine and Amidine Organocatalysts for Ring-opening Polymerization of Cyclic Esters” is representative of these disclosures and advocates using the same classes of materials as are outlined in claims 10-12 for the reason that their metal catalyst counterparts leave behind contamination that can be a detriment to the properties sought in, for instance, microelectronic and drug delivery applications. See the subject matter on page 8574 under the heading Introduction. Applicant is referred to the abstract and to the teachings under the heading Synthesis of Block Copolymers where the use of these same catalysts is mentioned.
As for claim 17, the copolymerization of the caprolactone/valerolactone and lactide in the presence of the same initiator/catalyst combinations will inherently yield copolymers of a comparable polydispersity.
Allowable Subject Matter
Claims 7, 24, 26, 30, and 32 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Both caprolactone and glycolide are primary hydroxyl-forming compounds so their use together in the practice of the prior art invention would be unobvious. There is no expressed desired to provide the polymer products as micro/nano particles nor could the Examiner ascertain from this reference why it would be obvious to do so inasmuch as the applications of the copolymers are not discussed. As for claims 30 and 32, the intent of the prior art is to establish exactly the opposite feed condition.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MARC S ZIMMER whose telephone number is (571)272-1096. The examiner can normally be reached M-F 8:30-5:00.
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August 7, 2026
/MARC S ZIMMER/Primary Patent Examiner, Art Unit 1765
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