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) 1-15 is/are rejected under 35 U.S.C. 103 as being unpatentable over KR 10-2019-0142642 (hereafter KR’642) in view of KR 10-2018-0127517 (hereafter KR’517) in further view of KR 10-2014-0136456 (hereafter KR’456).
Claim 1 recites:
(a) a phosgene reaction step of reacting a salt of an amine compound with phosgene in the presence of a solvent to obtain a reaction product containing an isocyanate compound;
(b) a degassing step of removing a gas phase from the reaction product;
(c) a gas compression step of compressing the gas phase obtained in the degassing step to obtain a gas phase condensate; and
(d) a distillation step of distilling the condensate to separate phosgene from the condensate.
KR’642 discloses reacting an aliphatic amine salt with phosgene in a solvent to produce an aliphatic isocyanate (see KR’642, claims 1 and 8; paragraphs [0024] – [0030]), corresponding to limitation (a).
KR’642 further discloses separating the isocyanate product from the reaction mixture and sending a mixture containing hydrogen chloride, unreacted phosgene, and solvent to a condenser (see paragraph [0051]). KR’642 also discloses distilling separated liquid streams to recover unreacted phosgene and recycling the recovered phosgene to the phosgenation step (see paragraphs [0054] – [0055]). However, KR’642 does not expressly disclose removing gas from the reaction product prior to condensation, nor compressing degassed gas to form condensate.
KR’517 discloses a degassing step in which gas containing phosgene and hydrogen chloride is removed from the reaction solution using a degassing column (see KR’517, paragraphs [0071] – [0076], [0154], [0155], and Fig. 1), corresponding to limitation (b).
KR’517 further discloses that phosgene separated in the degassing column is directed to a recovery device (see paragraph [0104]). KR’517 does not expressly disclose compressing the degassed gas to form condensate or distilling condensate derived from compressed gas.
KR’642 teaches recovery and recycle of unreacted phosgene from process streams, and KR’517 teaches removal of gaseous phosgene and hydrogen chloride from reaction mixtures using degassing columns and directing recovered phosgene to recovery units. Because both references are directed to recovery and reuse of phosgene in isocyanate production, it would have been obvious to incorporate the degassing technique of KR’517 into the recovery scheme of KR’642 in order to remove gaseous phosgene and hydrogen chloride prior to downstream recovery and purification, with a reasonable expectation of recovering phosgene for reuse.
Once gas is separated, compressing the separated gas to facilitate condensation and downstream separation by distillation is a conventional technique for handling condensable reactive gases.
Claim 2 recites degassing temperature and pressure. KR’517 discloses regulating temperature of the degassing column using a reboiler (see paragraph [0161]). Selection of operating temperature and pressure would have been a matter of routine optimization based on vapor–liquid equilibrium and gas composition.
Claim 3 recites compressing the gas phase to a pressure of 16 bar or more. KR’642 discloses condensers used for recovery of phosgene-containing streams (see paragraph [0051]). Selection of compression pressure sufficient to condense phosgene would have been an obvious engineering choice based on known vapor pressure behavior of phosgene.
Claim 4 recites using three or more compressors. Use of multiple compressors in series to achieve higher compression ratios while controlling temperature rise is conventional in gas processing systems and would have been an obvious design choice.
Claim 5 recites a column top temperature of −15°C or more. KR’642 discloses recovery of phosgene in distillation columns (see paragraph [0054]). Column top temperature is an inherent operating parameter dependent on pressure and composition, and selection of an appropriate temperature would have been routine process optimization.
Claim 6 recites supplying recovered phosgene to the phosgene reaction step. KR’642 explicitly discloses recycling recovered phosgene to the phosgenation step (see paragraph [0055]).
Claim 7 recites compressing gas obtained from the phosgene reaction step together with gas obtained from the degassing step. KR’642 discloses that gas from the reactor is sent to condenser units (see paragraph [0051]). Combining gas streams from different process stages for joint recovery is a routine plant design choice.
Claim 8 recites a salt formation reaction step, compressing gas from multiple steps, separating phosgene and hydrogen chloride by distillation, and supplying hydrochloric acid to the salt formation step and phosgene to the phosgene reaction step. KR’642 discloses salt formation and subsequent phosgenation (see claim 8), and discharge and handling of hydrogen chloride (see claim 1). Routing recovered hydrogen chloride back to salt formation and phosgene back to phosgenation would have been an obvious closed-loop modification to reduce raw material consumption.
Claim 9 recites desolvation, low-boiling material removal, and high-boiling material removal. KR’517 discloses desolvation and removal of low-boiling substances during purification (see paragraphs [0071]–[0076], [0154], [0155], Fig. 1). KR’456 discloses removal of solvent, low-boiling substances, and high-boiling substances during post-treatment of isocyanate reaction products (see KR’456, claim 1). It would have been obvious to apply the purification steps of KR’456 to the reaction mixture of KR’642 and KR’517 to improve product purity.
Claim 10 recites that the degassing, desolvation, low-boiling removal, and high-boiling removal steps are each performed at 165°C or less. KR’456 discloses post-treatment of reaction liquids at temperatures of 120–230°C (see paragraphs [0041], [0063], and [0075]). Selecting a temperature of 165°C or less would have been an obvious choice within the disclosed operating range to balance volatility and thermal stability of the product.
Claims 11–15 recite specific types of amine compounds. KR’642 discloses that the aliphatic amine may be chain or cyclic aliphatic amines, diamines and polyamines, sulfur-containing amines, and xylylenediamine isomers (see paragraphs [0026]–[0028]). Therefore, the amine species recited in Claims 11–15 are expressly disclosed by KR’642.
The claimed invention represents a combination of known recovery, degassing, compression, and purification techniques applied to a known isocyanate production process, yielding predictable results and involving routine engineering optimization.
Therefore, all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would have yielded predictable results to one of ordinary skill in the art at the time of the invention. KSR International Co. v. Teleflex Inc., 550 U.S. 902, 82 USPQ2d 1385 (U.S. 2007).
A reference is good not only for what it teaches by direct anticipation but also for what one of ordinary skill in the art might reasonably infer from the teachings. (In re Opprecht 12 USPQ 2d 1235, 1236 (Fed Cir. 1989); In re Bode 193 USPQ 12 (CCPA) 1976). In light of the forgoing discussion, the Examiner concludes that the subject matter defined by the instant claims would have been obvious within the meaning of 35USC 103(a). From the teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention.
Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary.
Claim Rejections - 35 USC § 112
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 1-15 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.
The specification states that the invention is directed to a method for producing an isocyanate compound that enables recovery and reuse of reaction substances while minimizing thermal degradation of the product and formation of by-products during phosgenation (see paragraph [0010]).
The specification further explains that proper control of gas compression pressure and distillation column top temperature is necessary to achieve these results, and specifically teaches that setting the gas compression pressure to 16 bar or more allows the top temperature of the distillation column to be maintained at −15°C or higher, which improves energy efficiency and reduces thermal degradation (see paragraphs [0074] – [0075]).
The specification also describes that when these conditions are not satisfied, the process suffers from excessive energy consumption and poor economic performance compared with the working examples (see paragraphs [0107] – [0149]).
However, claim 1 and several dependent claims do not recite any limitation on gas compression pressure or distillation column top temperature. As a result, claims 1–15 encompass processes that do not include the operating conditions that the specification describes as necessary to achieve the stated objectives of the invention.
Because the specification consistently describes the invention as requiring specific pressure and temperature conditions to solve the stated technical problem, but claims 1–15 is not limited to those conditions, the claims are broader than what is described as the invention in the specification.
Accordingly, the specification does not reasonably convey to a person skilled in the art that the inventor had possession of the full scope of the subject matter now claimed.
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 8-9 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 8 recites, in part, “a step of supplying hydrochloric acid obtained in the distillation step to a reaction product of the salt formation reaction step, and supplying the phosgene to a reaction product of the phosgene reaction step.”
It is unclear what is meant by “supplying hydrochloric acid obtained in the distillation step to a reaction product of the salt formation reaction step.” The salt formation reaction step produces a salt of the amine compound, and the claim does not clearly identify whether the hydrochloric acid is supplied to a salt formation reactor, to a stream after salt formation is complete, or to another process location. The destination and function of the recycled hydrochloric acid are not clearly defined.
Likewise, the phrase “supplying the phosgene to a reaction product of the phosgene reaction step” is unclear, because supplying phosgene to a reaction product does not clearly indicate supply to a reaction zone or reactor, and does not clearly describe how further phosgenation would occur.
Because the routing and purpose of the recycled hydrochloric acid and phosgene are unclear, the scope of the claimed process cannot be determined with reasonable certainty.
Claim 9 recites “a low boiling material-removing step of removing low boiling materials” and “a high boiling material-removing step of removing high boiling materials.”
The claim does not define what constitutes “low boiling materials” or “high boiling materials,” and does not specify the reference point relative to which boiling points are determined, such as relative to the solvent, the isocyanate product, or other components of the reaction mixture. Because the reaction mixture contains multiple components with different boiling points, it is unclear which materials are included in each category.
As a result, claim 9 does not clearly define the subject matter being removed in these steps, and the boundaries of the claim are unclear.
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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/DEBORAH D CARR/ Primary Examiner, Art Unit 1691