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 Objections
Claims 1, 6, and 10 are objected to because of the following informalities:
In claim 1, line 2, the examiner suggests deleting both instances of “undesired” because they are redundant and do not help clarify the claim.
In claim 1, line 3, the examiner suggests inserting “(PLA)” after “polylactic acid” for the utmost clarity that the PLA recited in line 4 is polylactic acid.
In claim 1, line 10, the examiner suggests deleting “under operating condition” because it is redundant and does not help clarify the claim.
In claim 6, line 2, “separate” should read “separated.”
In claim 10, line 2, the examiner suggests deleting both instances of “undesired” because they are redundant and do not help clarify the claim.
In claim 10, line 3, the examiner suggests inserting “(L-PLA)” after “L-polylactic acid” for the utmost clarity that the L-PLA recited in line 5 is L-polylactic acid.
Appropriate correction is required.
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.
Claims 1-12 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 1 recites the limitation "the production process of polylactic acid” in lines 2-3 and the limitation “the production of PLA” in line 4. There is insufficient antecedent basis for these limitations in the claim. As a result, it is not clear if a step of producing polylactic acid is required as a part of the method.
Claim 1 recites the limitation "the various stage” in line 4. There is insufficient antecedent basis for this limitation in the claim. Claim 1 does not recite a various stage. The examiner suggests deleting the phrase “the various stage of.”
Claim 1 recites “a flux containing undesired lactic acid and/or one or more undesired lactic acid esters” in lines 1-2. In step (i), claim 1 further recites “a concentrated lactic acid solution” and “monomeric lactic acid” in step (i). It is unclear how one can achieve a concentrated lactic acid solution with the claimed monomeric lactic acid content when the flux contains no lactic acid (species with lactic acid esters).
Claim 1 recites the limitation “higher chiral purity” in step (ii). This limitation is unclear because one would not know what the chiral purity is higher than. For the purposes of examination, higher chiral purity is interpreted as being higher than the chiral purity of the concentrated lactic acid solution produced in step (i).
Claim 1 recites “using some or all of said recycle stream as a base” in the 5th to last line. This limitation is indefinite because it is unclear how one can perform steps (i) and (ii) when all of the recycle stream (recited in line 5) is used as a base.
Claims 2-9 and 11-12 are rejected along with claim 1 because they depend from claim 1 and incorporate all of the limitations of claim 1, including those that are indefinite.
Claim 7 recites the limitation “the obtained chiral purified lactic acid or lactic acid solution.” There is insufficient antecedent basis for the chiral purified lactic acid solution. Claim 7 depends from claim 1, but the method of claim 1 produces a crystallized lactic acid, not a lactic acid solution.
Claim 10 recites the limitation “the production process of L-polylactic acid” in line 3 and the limitation “the production of L-PLA” in lines 4-5. There is insufficient antecedent basis for these limitations in the claim. As a result, it is not clear if a step of producing L-polylactic acid is required as a part of the method.
Claim 10 recites the limitation "the various stage” in line 4. There is insufficient antecedent basis for this limitation in the claim. Claim 10 does not recite a various stage. The examiner suggests deleting the phrase “the various stage of.”
Claim 10 recites “a flux containing undesired D-lactic acid and/or one or more undesired D-lactic acid esters” in lines 1-2. In step (i), claim 1 recites “a concentrated lactic acid solution” and “monomeric lactic acid” in step (i). It is unclear how one can achieve a concentrated lactic acid solution with the claimed monomeric lactic acid content when the flux contains no lactic acid (species with D-lactic acid esters).
Claim 10 recites the limitation “higher chiral purity” in step (ii). This limitation is unclear because one would not know what the chiral purity is higher than. For the purposes of examination, higher chiral purity is interpreted as being higher than the chiral purity of the concentrated lactic acid solution produced in step (i).
Claim 10 recites “wherein some or all of said recycle stream is used as a base” in the 5th to last line. This limitation is indefinite because it is unclear how one can perform steps (i) and (ii) when all of the recycle stream is used as a base.
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 1-12 are rejected under 35 U.S.C. 103 as being unpatentable over Van Breugel (US 6,630,603 B1) in view of Albert (WO 2018/165283 A1).
Regarding claims 1, 7, and 10-12, Van Breugel discloses a method of purification of lactic acid (title). Van Breugel’s method includes concentrating a dilute lactic acid containing stream in one or more of a falling-film evaporator, thin-film evaporator, and/or lubricated film evaporator (col. 6, lines 11-22). The stream then undergoes steps of (a) reduced-pressure distillation of a concentrated lactic acid solution having a total acid content of at least 95 wt % and a content of monomeric lactic acid of at least 80 wt %, based on the concentrated lactic acid solution and (b) subjecting the concentrated lactic acid solution to crystallization to form a pure lactic acid (abstract and col. 6, lines 33-35). The feed has a chiral purity of at least 90% of (R)- or (S)-lactic acid (col. 5, lines 49-55). Van Breugel’s (R)- and (S)-lactic acid are the same compounds as instant L- and D-lactic acid, respectively. After the concentration step, the bottom product (lactic acid concentrate) has a chiral purity of at least 90% (col. 6, lines 49-52). The lactic acid product of Van Breugel’s method is optically pure (col. 4, lines 64-66). In Example 1, Van Breugel demonstrates that lactic acid solution before and after concentrating and distilling has a chiral purity of 97.1%, but that the crystallized lactic acid has a chiral purity of 99.93% (Table 1). This demonstrates that the chiral purity of the crystallized product is higher than the chiral purity during previous stages. Van Breugel further teaches using the chirally pure lactic acid in the production of poly(lactic acid) (PLA) (col. 5, 29-32).
Van Breugel’s method of purification reads on a method of valorization. The dilute lactic acid containing stream reads on a flux containing D-lactic acid and L-lactic acid. While Van Breugel’s dilute lactic acid containing stream is not explicitly a recycle stream obtained by recycling during the production of PLA or L-PLA, the stream could be obtained by recycling and reads on the generic recycle stream, which is considered to be a product by process limitation in claim 1. Concentrating the flux with a falling-film evaporator, thin-film evaporator, and/or lubricated film evaporator followed by step (a)’s distillation reads on the concentrating steps performed in instant step (i) (claim 11). Step (b) reads on instant step (ii). Because Van Breugel teaches that feed has both L- and D- lactic acid while the product is chirally pure, Van Breugel teaches separating a fraction rich in L-lactic acid from a fraction containing most of the D-lactic acid (claim 10). Using the chirally purified lactic acid in the production of PLA reads on claim 7.
It is noted that while claim 1 and claim 10 claim a recycle stream obtained by recycling during the production of PLA (claim 1) or L-PLA (claim 10), case law holds that:
Even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process. See In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985).
To the extent that the process limitations in a product-by-process claim do not carry weight absent a showing of criticality, the reference discloses the claimed product in the sense that the prior art product structure is seen to be no different from that indicated by the claims. The prior art teaches the same product as the instant claims, regardless of the process by which the prior art product has been produced. The burden is shifted to Applicant to provide factually supported evidence which demonstrates the contrary.
Van Breugel does not teach using some of the recycle stream as a base for the synthesis of molecules insensitive to the optical isometry D or L of lactic and/or of lactic acid esters (claim 1) or as a base for the synthesis of acrylic acid (claims 10 and 12). Instead, Van Breugel processes the entire dilute lactic acid containing stream by a process comprising condensation and crystallization.
However, prior to the effective filing date, lactic acid streams were known to be useful for producing acrylic acid, as taught by Albert. Albert teaches a method of making acrylic acid from a feed stream containing lactic acid, lactide, or mixtures thereof (Albert, abstract). Albert’s lactic acid in the feed stream can be in monomeric or oligomeric form (Albert, page 11, line 23). In addition, the lactic acid can be D-lactic acid, L-lactic acid, or a mixture thereof (Albert, page 11, line 12). Albert teaches that acrylic acid is typically produced from fossil resources and that these resources are not renewable and take hundreds of thousands of years to form naturally (Albert, page 1, lines 21-29). On the other hand, renewable resources can be replenished at a rate comparable with their consumption and can be replenished naturally or via agricultural techniques (Albert, page 2, lines 29-32). Albert goes on to teach that lactic acid presents an opportunity of serving as a feedstock for bio-based acrylic acid (Albert, page 2, lines 10-12).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date to have combined the method of Van Breugel with the method of Albert in order to produce acrylic acid from a bio-based feedstock. In particular, it would have been obvious to use some of Van Bruegel’s dilute lactic acid containing stream (reading on instant recycle stream) to prepare acrylic acid using the method of Albert (claims 1, 10, and 12). One would have been motivated to make this combination in order to prepare acrylic acid from a renewable resource.
Regarding claim 2, Van Breugel teaches the method of claim 1 and further teaches wherein the evaporators comprise a falling-film evaporator and/or a thin-film evaporator (col. 6, lines 19-22).
Regarding claim 3, Van Breugel teaches the method of claim 1. Van Breugel teaches evaporator conditions of 100-500 mbar and 25-140 °C (col. 6, lines 19-25). Van Breugel also teaches a second concentration step at 50-250 mbar and 100-140 °C (col. 6, lines 35-39). Temperatures in the range of 25-140 °C read on low temperature.
Regarding claim 4, Van Breugel teaches the method of claim 1 wherein the distillation step is performed at 0.1-20 mbar and 100-200 °C (col. 4, lines 8-23).
Regarding claim 5, Van Breugel teaches the method of claim 1 wherein the crystallization is carried out in one or more cooling crystallizers, evaporation crystallizers, or adiabatic crystallizers (Van Breugel, claim 10).
Regarding claim 6 and 8-9, Van Breugel teaches the method of claim 1 wherein the crystallized lactic acid is separated from the mother liquor using a solid-liquid separation (claim 6) (col. 8, lines 16-18). Van Breugel further that the mother liquor from the crystallization stage contains considerable amounts of lactic acid and it is therefore preferable to recycle said mother liquor into the production process (col. 8, lines 26-28).
Van Breugel does not teach a specific recycle point in the production process.
However, it would have been obvious to one of ordinary skill in the art prior to the effective filing date to have recycled the mother liquor at any point in the production process because Van Breugel teaches recycling the mother liquor in the production process. Furthermore, it would have been obvious to recycle the mother liquor at the condensation stage (claim 8) in order to ensure that the feed to the crystallization step has the monomer content and chiral purity taught by Van Breugel. Separating the mother liquor from the crystallized lactic acid reads on purifying the mother liquor before recycling (claim 9).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AUDRA DESTEFANO whose telephone number is (703)756-1404. The examiner can normally be reached Monday-Friday 9-5.
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/AUDRA J DESTEFANO/Examiner, Art Unit 1766
/RANDY P GULAKOWSKI/Supervisory Patent Examiner, Art Unit 1766
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