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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Taube (US Pat. 10,858,311, hereafter US’311) in view of Kaibel (US Pat. 7,264,696, hereafter US’696).
US’311 discloses producing isocyanates by reacting an amine with phosgene, quenching the reaction product, and separating the mixture into a vapor phase containing unreacted phosgene and a liquid phase containing isocyanate and solvent (Abstract; col. 1, ll. 15–26; col. 17, ll. 124–135).
US’696 discloses a dividing-wall distillation column having feed, take-off, and shared regions that separate a multicomponent feed into overhead, side-draw, and bottoms streams (Abstract; col. 1, ll. 1–17).
It would have been obvious to replace the separation of US’311 with the dividing-wall distillation column of US’696 to separate phosgene, solvent, and isocyanate in a single column, motivated by reduced equipment and energy requirements and with predictable results.
The limitation that the bottom temperature is 165 °C or less represents routine optimization to protect thermally sensitive isocyanates and to achieve effective separation, which would have been obvious (In re Aller; In re Peterson).
With respect to claims 2–4, US’696 teaches that column pressure, reboiler temperature, and liquid split ratios are selected to optimize dividing-wall column separations (col. 1, ll. 1–17). Accordingly, specifying a top pressure of 20 torr or less, a liquid split ratio of 15% or less, and a reboiler temperature of 100–165 °C constitutes routine optimization of known operating parameters.
With respect to claims 5–9, US’311 teaches phosgenation of primary aliphatic and aromatic amines to form isocyanates (col. 17, ll. 124–135). The recited amines represent known alternatives and their selection would have been obvious.
With respect to claim 10, US’311 applies to amine feedstocks generally. Use of amine salts, including hydrochloride or carbonate salts, is a known equivalent for handling and feeding amines and would have been obvious.
With respect to claims 11–12, US’311 teaches use of organic quench liquids and solvents in forming and separating the reaction mixture (col. 1, ll. 15–26). The claimed aromatic and ester solvents are conventional solvent choices and would have been obvious.
With respect to claims 13–14, US’311 inherently separates a low-boiling vapor phase containing phosgene from a higher-boiling liquid product stream containing isocyanate and solvent, corresponding to removal of low-boiling and high-boiling components during purification (col. 1, ll. 15–26; col. 17, ll. 124–135).
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 3, 6, 13-14 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 3 recites: “the liquid split ratio divided from the rectifying section of the dividing-wall distillation column to a pre-fractionator side is 15% or less.” This limitation is indefinite because the claim does not clearly define what constitutes the “liquid split ratio.” Specifically, the claim does not identify the numerator and denominator of the ratio, whether the ratio is based on mass flow, molar flow, or volumetric flow, or the specific locations in the column at which the flows are measured. Further, the phrase “divided from the rectifying section … to a pre-fractionator side” does not clearly identify the flow path or reference points within the dividing-wall column. Accordingly, one of ordinary skill in the art would not be able to determine the metes and bounds of this claim with reasonable certainty.
Claim 6 recites “higher chain-like or cyclic aliphatic amines.” The term “higher” does not have a recognized meaning in the art and is not defined in the specification. The claim does not specify any objective boundary, such as a minimum number of carbon atoms, molecular weight range, or structural limitation, by which one of ordinary skill in the art could determine whether a given amine falls within the scope of “higher chain-like or cyclic aliphatic amines.”
Claims 13 and 14 recite removal of “low-boiling substances” and “high-boiling substances,” respectively. These terms do not have a definite meaning in the absence of reference temperatures, boiling point ranges, or identification of specific components relative to the process conditions. Without objective criteria for determining which substances are “low-boiling” or “high-boiling,” one of ordinary skill in the art cannot determine the metes and bounds of these claims with reasonable certainty.
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 7-9, 12 rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claims 7–9 recite broad and structurally diverse classes of amine compounds, including linear and branched aliphatic diamines, bicyclic and tricyclic diamines, aromatic diamines, and sulfur-containing amines. The specification does not provide representative species across these classes, nor does it identify common structural features that correlate with successful phosgenation and separation in a dividing-wall distillation column. In view of the substantial differences in volatility, reactivity with phosgene, and separation behavior among the recited compounds, the specification does not reasonably convey to one of ordinary skill in the art that the inventor had possession of the full scope of the claimed amine genera at the time of filing.
Claim 12 recites a broad genus of solvents including chlorinated aromatics, acetate esters, lactates, salicylates, phthalates, and benzoates. These solvents differ significantly in boiling point, polarity, and chemical compatibility with phosgene and isocyanates. The specification does not provide representative examples or technical guidance demonstrating possession of the claimed process across all recited solvent classes in combination with the claimed distillation conditions.
Claims 1-2, 4, 13-14 rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
Claims 1, 2, and 4 require specific temperature and pressure conditions for operating a dividing-wall distillation column on reaction mixtures derived from numerous amines and solvents. The specification does not teach how to select column configurations, tray or packing designs, reflux ratios, pressure profiles, or residence times necessary to achieve the claimed separations across the full scope of the claimed chemical systems. Phosgene–isocyanate systems are highly sensitive to temperature, pressure, and solvent choice, and variations in these parameters materially affect reaction kinetics, vapor-liquid equilibria, and product stability.
Considering the factors set forth in In re Wands, including the breadth of the claims, the unpredictability of phosgene chemistry and multicomponent distillation behavior, the limited number of working examples, and the lack of specific guidance for adapting the process to different amine and solvent combinations, undue experimentation would be required to practice the claimed invention across its full scope.
Claims 13 and 14 recite additional removal steps for low-boiling and high-boiling materials from streams containing isocyanate. The specification does not provide sufficient guidance on how such steps are implemented across the wide range of solvents and products encompassed by the claims, nor does it describe how these steps are integrated with the dividing-wall distillation process without causing product degradation or unsafe operating conditions. For the same reasons discussed above under the In re Wands factors, undue experimentation would be required to practice the full scope of claims 13 and 14.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DEBORAH D CARR whose telephone number is (571)272-0637. The examiner can normally be reached Monday-Friday (10:30 am -7:00 pm).
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Renee Claytor can be reached at 572-272-8394. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/DEBORAH D CARR/ Primary Examiner, Art Unit 1691