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 § 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 1-11 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as failing to set forth 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.
Regarding claim 1, the terms “improved” and “partial” are subjective terms and render the claim indefinite, since it is difficult to determine from the specification the scope of the claimed terms.
The recitation "the gas stream” does not have a proper antecedent basis since the claim introduces “a plurality of gas streams”.
The recitation “the fluid” does not have a proper antecedent basis since the claim introduces “a wetting fluid”.
The recitation “the present treatment circuit”, “the precipitated lactide”, and “the aqueous solution” lack antecedent basis in the claim.
The claim recites: heating “this aqueous solution”, from which solid lactide…. and sending “this acid aqueous solution” into a feed tank….., the language is unclear, since it cannot be ascertained if “the aqueous solution” or “the acid aqueous solution” is the same as the wetting fluid as defined earlier in the claim. Appropriate clarification or correction is required.
The claim language with respect to “gas stream” is unclear. The claim introduces “a plurality of gas streams”, but further recites “the gas stream”, and therefore it is difficult to understand if there are multiple gas streams or one gas stream or multiple gas streams were combined to make one gas stream. Appropriate clarification or correction is required.
The claim language with respect to “an assembly of packed columns” in unclear. In the beginning the claim defines that an assembly of packed columns comprises at least one column, however the claim further recites “the assembly of packed columns”, suggesting the requirement of plurality of columns. Applicant is suggested to revise the term columns as column(s), to encompass the presence of single and multiple columns.
The claim language is also unclear on the form of lactide, is the precipitated lactide the same as the lactide in solid form? If the precipitated and lactide in solid form are the same, applicant is encouraged to utilize one term either solid or precipitated in the claim.
Regarding claim 4, it is unclear if the precipitated lactide the same as the lactide in solid form.
Regarding claim 6, “the fluid”, does not have a proper antecedent basis, since “a fluid” is not introduced in claim 1.
Regarding claim 7, the term “partially” is a subjective term and renders the claim indefinite, since it is difficult to determine from the specification the scope of the claimed term. Additionally, it is unclear if a precipitated lactide and solid lactide (in the fluid) are the same, if they are same, applicant is encouraged to utilize one term either solid or precipitated in the claim (as well as instant claims 8-10).
Regarding claim 9, which is dependent of claim 8, it is unclear what aqueous solution is required. Claim 9 requires “the aqueous solution”, but claim has the limitation “the acid aqueous solution”.
Regarding claim 10, the term “polymer grade quality” is a subjective and renders the claim indefinite, since it is difficult to determine from the specification the scope of the claimed term.
Regarding claim 11, “the aqueous solution”, there is insufficient antecedent basis for this limitation in the claim. The term “partially” is a subjective term and renders the claim indefinite, since it is difficult to determine from the specification the scope of the claimed term.
Claim Interpretation
Regarding claim 1, in the absence of definition of “the present treatment circuit” in the specification, the packed column(s) which brings the gas stream in contact with the wetting fluid, is considered as the “the present treatment circuit”.
Regarding claim 9, the requirement of “the aqueous solution” is understood to be “the acid aqueous solution” due to dependence of claim 9 on claim 8.
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.
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.
Claim(s) 1-11 are rejected under 35 U.S.C. 103 as being unpatentable over Dünnenberger et al. US 2015/0151247 A1, in view of Hagen et al. US2010/0252076 A1 (cited within Dünnenberger).
Regarding claims 1 and 5-6, Dünnenberger teaches a method to remove lactide from a vapor mixture in the process of making polylactic acid polymer (abstract).
Dünnenberger notes (paras [0003] and [0004]) that the vapor mixtures of lactide originate from a vacuum overhead system of a reactor system or from distillates of the crude lactide product stream or byproduct stream in the production of polylactic acid, and which contain lactide, water, lactic acid and oligomer, and corresponds to applicant’s plurality of gas streams.
Dünnenberger discloses (paras [0061]-[0063]) that the vapor mixture (containing lactide, water and lactic acid) is introduced into a packed column (2’ in Fig. 5) assembly via first inlet (211’, Fig. 5) and where the aqueous solution containing lactic acid is introduced into the same column via second inlet (212’, Fig. 5). The packed column serves as a condensation device, and where the vapor mixture and the aqueous (acid) solution contact each other.
Dünnenberger adds that the portion of the ester is dissolved in the aqueous solution, thereby generating a fluid comprising water, lactic acid and dissolved lactide (reference claim 35). Dünnenberger (para [0062]) incorporates reference Hagen.
Hagen (reference claim 19) recommends the temperature of washing liquid (corresponding to wetting liquid) to be adjusted to 10 to 80 oC, overlapping the claimed requirement (instant claim 5). Hagen (claim 19), recommends the column temperature of 30 oC (Hagen para [0042]), thus implying the wetting fluid exiting the column would also achieve the temperature of 30 oC (instant claim 6). Hagen also discloses (reference claim 22) the concentration of lactide in the condensation and washing liquid to be at most 5 wt%. Owing to the low solubility of lactide in water, the required weight % of lactide in solid form would be reasonably expected in the exiting fluid (or the aqueous solution).
Dünnenberger includes a heat exchanger (8, Fig. 5), for carrying out a heating step (para [0060]). The outlet of the heat exchanger remains in fluid communication with the inlet of the reactor tank and therefore in order to avoid any hot spots a person of ordinary skill in the art would maintain the temperature of the heat exchanger to be the same as the reactor tank of 50 to 75 oC (reference claims 31 and 35).
Dünnenberger teaches a reactor tank (9, Fig. 5) which is a stirred vessel (para [0070]), which corresponds to applicant’s feed tank, where the aqueous solution undergoes a hydrolysis reaction to convert the lactide to lactic acid, where the temperature of the reactor tank is 50 to 75 oC (reference claim 31).
Dünnenberger does not provide explicit presence of a second inlet at the reactor tank where the acid aqueous solution is continuously fed, present upstream of the packed column. However, Dünnenberger teaches (para [0073]) the inclusion of additional inlets in circuit 7 (which houses reactor tank 9) where water and lactic acid can be added, and notes supply a mixture of water and lactic acid continuously to prevent viscosity increases in the circulating liquid (para [0007]).
It is noted that there is a finite list of immediately recognizable options available to one of ordinary skill in the art, including a) additional inlet continuously feeding acid aqueous solution to reactor tank present downstream of the packed column b) additional inlet continuously feeding acid aqueous solution to reactor tank present upstream of the packed column. With the presence of a finite number of options which are immediately recognizable to a person having ordinary skill in the art, and the options do not produce new or unexpected results, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to try any of the immediately recognizable and finite options of integrating additional inlet providing acid aqueous solution to the reactor tank positioned upstream of the packed column, with reasonable expectation of success of achieving, as taught above by Dünnenberger (see MPEP 2143 I. E.).
Regarding claims 2-3, Dünnenberger teaches more than one column packed column (para [0061] and para [0062]). Since multiple columns can be connected in finite options of either series or parallel, the limitations are rendered obvious.
Regarding claim 4, since the filtration and extraction of precipitated lactide is optional, the claimed requirement is met by Dünnenberger’s disclosure.
Regarding claims 7 and 11, Dünnenberger is silent on filtration of lactide, however teaches (para [0007]) that precipitation of solid lactide in the circulation liquid causes blockages in the circulation. It would have been obvious to one of ordinary skilled in the art before the effective filing date of the invention to have modified Dünnenberger so as to remove the solid lactide precipitate via known techniques such as filtration, thereby removing the blockage caused by the precipitated solids. Dünnenberger discloses (claim 31) the temperature of the reactor tank to be 50 to 75° C. In order to prevent any pressure differences in the circulation channels or increase the solubility of lactide, one of ordinary skill in the art would have maintained similar temperature profile for the aqueous solution, overlapping the claimed requirement.
Regarding claims 8-9, as discussed when addressing claim 1, the circulation of acid aqueous solution between reaction tank (applicant’s feed tank) and the packed column is rendered obvious by Dünnenberger. The low solubility of lactide in precipitated form would assure the concentration of lactide as required.
Regarding claim 10, Dünnenberger teaches (para [0003]) recovering of lactic acid, recycling back into the production process and distillation of the crude lactide product. Dünnenberger also discusses thin film evaporators as part of the recycling process (para [0005]). It would have been obvious to one of ordinary skilled in the art before the effective filing date of the invention to have modified Dünnenberger to have concentrated and purified lactic acid by the processes as disclosed after the hydrolysis step conducted in the reactor tank to optimize the recycling process and reduce waste.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Surbhi M Du whose telephone number is (571)272-9960. The examiner can normally be reached M-F 9:00 am to 5:00pm.
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/S.M.D./
Examiner
Art Unit 1765
/JOHN M COONEY/Primary Examiner, Art Unit 1765
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