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 Status
Claims 1, 4, and 7 were amended in the response filed 2/19/2026. Claims 1-12 are pending.
Claim Objections
The amendments are persuasive to overcome the objections of record on p. 7-8 of the OA dated 11/20/2025. Therefore, the objections are withdrawn.
Claim Rejections - 35 USC § 112(b)
The Applicant’s arguments on p. 4-5 of the 2/19/2026 response are persuasive to overcome the 35 USC 112(b) rejection of record on p. 3-4 of the OA dated 11/20/2025; therefore, the rejection is withdrawn.
Claim Rejections - 35 USC § 103
See p. 4-14 of the OA dated 11/20/2025 for rejection of record.
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.
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.
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) 1-10 and 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nakahara (US6348135B1, published on 2/19/2002, of record) in combination with Mosler (US2008/0197086 A1, published on 8/21/2008, of record).
Applicant Claims
Applicant claims a method for producing an easily polymerizable compound comprising a step of introducing a liquid comprising said compound into a vaporization separation column for purification wherein the column is provided with a circulation path for returning a drawn liquid from bottom of the column. The circulation path comprises a supply port for supplying an oxygen-containing gas, and a reboiler having a heating part, in order, to form upstream side, wherein the supply port is located below an inlet of the heating part with a height difference of 1.0 m or more; and an oxygen containing gas is supplied to the drawn liquid from the supply port.
Determining the Scope and Content of the Prior Art (MPEP §2141.01)
Nakahara discloses a process for the purification of (meth)acrylic acid, a readily polymerizable compound according to [0011] of the specification as filed and claim 12, using a distillation unit containing a distillation column (vaporization separation column), a multi-tubular reboiler, and a pipe connecting the elements in a circulation loop, wherein an oxygen containing gas is supplied to the circulation loop at a point between the distillation column and an inlet of the reboiler. See abstract and claims. The process is exemplified by Fig. 1 of Nakahara:
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Nakahara teaches that the process comprises introducing a liquid containing an easily polymerizable compound (methacrylic acid or an ester thereof, line 7) into a vaporization separation (distillation column-1). The column is provided with a circulation path for returning a drawn liquid from the bottom of the column (via pipe 3) back to the column (1) after passing through a reboiler (2) via line (13). See claims and col. 2, line 56-col. 3, line 17. The circulation path is further equipped with an oxygen supply port which can be installed at least in one point between the bottom of column (1) and the inlet of reboiler (2) and/or in regions between an inlet of the reboiler and an inlet side tube sheet of the reboiler (2). Nakahara teaches that when a circulation pump (4) is installed the oxygen gas supply port is preferably located between an outlet of the circulation pump (4) and the inlet of the reboiler (2). Nakamura also teaches that when liquid exit pipe (12) is connected to the pipe (3) and the oxygen containing gas is supplied from the upstream of a branch point (30 in Fig. 8), that a part of the oxygen containing gas is preferably supplied through exit pipe (12). See col. 3, lines 17-61.
Nakamura teaches that the oxygen gas is used to prevent formation of polymerization products inside the tubes of the reboiler, such that the easily polymerizable methacrylic acid and esters thereof can be stably and effectively purified. See col. 1, lines 20-50 and col. 3, lines 26-29. Figures 2-7 of Nakamura further describe nozzles that can be used to introduce oxygen into the circulation path. See col. 2, lines 1-22 and col. 3, line 62-col. 4, line 14. The examples of Nakamura teach that if oxygen is present in the reboiler in the recited concentration in col. 3, lines 49-60 and claims 2 and 9, then polymerization is suppressed. If oxygen is supplied to the circulation loop downstream of an outlet side tube sheet of the reboiler (comparative example 1) or directly to the bottom of the column (comparative example 2), polymerization is not effectively suppressed. See col. 5, line 1 to col. 6, line 26.
Mosler teaches an arrangement (1) for treatment of a polymerizable material (12) comprising at least one gassing device (2) to feed a gas (11) into the polymerizable material (12) and a heating device (3) to heat the polymerizable material (12) provided with gas (11). See abstract, Fig. 1 and [0078-0080]:
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Mosler teaches that the heating device (3) is arranged such that the polymerizable material (12) flows through the heating device (3) via an inlet (4) against gravity (9) and a means for even distribution of the gas (11) over the inlet (4) is provided. See [00777-0080]. Mosler further teaches that the at least one gassing device (2) is arranged at a distance (16) to the inlet (4) of heating device (3) from about 300 to about 1000 mm (0.3-1.0 m), which overlaps with the claimed range of “1.0 m or more”. See [0027], claim 3, and MPEP 2144.05. Mosler teaches that in this way a particularly compact arrangement is created and in interplay with the means for even distribution of the gas, a very good distribution of the gas may be achieved. Mosler also teaches that the gassing device leads into a type of mixing chamber in the transition region from the pipe to the heating device. See [0027].
Mosler teaches that the disclosed arrangement, wherein the polymerizable material may flow against gravity or substantially parallel against gravity, is advantageous when the flow paths for the polymerizable material through the heating device also run parallel to gravity. In this way, regions within the flow paths in which an increased accumulation of the supplied gas occurs are avoided and the even distribution of gas in the polymerizable material remains over the total duration of the flowing through the heating device. In this way, polymerization in the heating device is considerably reduced and partially even durably prevented. See [0023].
Mosler teaches that the polymerizable material includes methacrylic acid and esters thereof. See abstract, [0002-0004, 0033]. Mosler teaches that the polymerizable material can be obtained as a bottom product from a distillation. See Fig. 6 [0050-0061, 0065-0066, and 0085]. Mosler teaches that the gas is oxygen or contains oxygen and functions as a polymerization inhibitor. See [0004 and 0049].
Ascertainment of the Difference Between Scope of the Prior Art and the Claims (MPEP §2141.02-03)
Nakahara does not explicitly teach that the oxygen gas supply port is located below an inlet of the heating part with a height difference of 1.0 meters or more.
Finding of Prima Facie Obviousness Rationale and Motivation (MPEP §2142-2143)
It would have been prima facie obvious to one of ordinary skill in the art to combine the teachings of Nakahara and Mosler to arrive at the instantly claimed process with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill in the art would have been motivated to carry out the purification process for easily polymerizable methacrylic acid/ester of Nakahara using a circulation loop wherein the oxygen supply port is located below an inlet of the heating part with a height difference of 1.0 m or more because changes in size and/or proportion of a known apparatus, such as that of Nakahara, are prima facie obvious in the absence of criticality. See MPEP 2144.04(IV)(A). Furthermore, Mosler teaches an analogous heating device arrangement to that of Nakahara for heating easily polymerizable compounds, including the methacrylic acid/esters of Nakahara in the presence of oxygen gas, which explicitly teaches a range which includes that claimed. See MPEP 2144.05. Mosler teaches that polymerization is suppressed when heating the mixture of the polymerizable compound and oxygen gas in the disclosed apparatus provided that there is even and sufficient distribution of the gas in the heating device. Therefore, it would have been prima facie obviously to carry out the known process of Nakahara in the known apparatus of Mosler to predictably obtain a process for purification of methacrylic acid/esters with reduced polymerization in the purification device. Also see MPEP 2143(I)(B).
Regarding claims 2-4, Nakamura teaches that the distillation can be carried out at standard (normal) pressure or reduced pressure. See col. 3, lines 50-61. The examples teach that the distillation occurs under reduced pressure (70 hPa and 150 hPa, or 0.07 to 0.15 atm). See col. 5-6. Therefore, the ranges taught by Nakamura overlap with those claimed. See MPEP 2144.05. Further regarding claim 4, both Nakamura and Mosler teach that the withdrawn stream from the bottom of the column is subjected to a pressure increase before being sent to the reboiler/heating device. See pump (4) in fig. 1 of Nakamura and pump (34) in Fig. 6 of Mosler. Mosler further teaches that when the withdrawn liquid is fed back to the column (via line 6), that the fluid pressure reduces. See [0085]. Mosler also teaches embodiments wherein the oxygen gas is mixed with the withdrawn liquid at an overpressure of at least 2 bar (200 kPa). See [0028 and 0081]. Therefore, though neither reference explicitly teaches that the claimed pressure of the withdrawn liquid at the supply port is 30 kPa or more higher than a gas pressure on the upper surface of the bottom liquid, both references teach that the pressure of the withdrawn liquid at the supply port is higher than that of the gas pressure on the upper surface of the bottom liquid. The exact difference in pressures would be optimizable and depend upon the conditions in the column and reboiler. Thus, the skilled artisan could reasonable to arrive at the claimed range with a reasonable expectation of success through routine optimization. Also see MPEP 2144.05.
Regarding claim 5 and the retention time of claim 8, neither Nakamura nor Mosler explicitly teach the residence/retention time of the drawn liquid from the oxygen gas supply port to the inlet of the heating part. However, Nakamura teaches the concentration of oxygen that should be present to prevent polymerization in the reboiler and Mosler teaches that effective even mixing of oxygen, or another gas, also prevents polymerization. Further, Mosler teaches that height between the oxygen supply port and the inlet of the heating part is variable, as are the pressures, temperatures, and flow rates of the reactants. Therefore, the retention time of the polymerizable compound containing liquid and the oxygen gas introduced into the supply port can be routinely optimized depending upon the conditions in the distillation column, the conditions in the reboiler, the relative distances between all the apparatus components, and the efficiency of the mixing between the oxygen and liquid. Based on the teachings of Nakamura and Mosler, as long as a sufficient concentration of oxygen and/or the efficiency of the mixing of the oxygen with the liquid is sufficient, then the result would predictably be less risk of polymerization in the reboiler. Also see MPEP 2144.05.
Regarding claims 6, 7, and 9, Nakamura teaches that the circulation path can have a bent portion between the oxygen supply port and the heating part. See Fig. 7. Nakamura also teaches that the circulation path can be horizontal with respect to the distillation column and/or reboiler and that the supply port can be placed on a horizontal or vertical portion as long as it is supplied to a point between the distillation column and an inlet of the reboiler and/or in regions between the inlet and an inlet side tube sheet of the multi-tubular reboiler. See Figures and col. 3, lines 18-61. The embodiment wherein the oxygen is fed to a point between the inlet of the reboiler and the inlet side tube sheet of a multi-tubular reboiler also corresponds to a circulation path having a “widened portion” as the inlet of the reboiler is depicted as being wider than the rest of the circulation path in Fig. 1. Mosler also teaches that the circulation path can comprise a horizontal, bent, and/or widened portion between the supply port of the oxygen gas (2) and the inlet (4) of the reboiler/heating device (3) in order to facilitate the mixing between the oxygen and the bottoms liquid comprising the polymerizable compound. See Figures and [0081].
Regarding claim 10, Nakamura teaches that the reboiler is a multi-tubular reboiler which can also comprise a shell (a shell-and-tube heat exchanger). See reboiler (2) in Figure 1 and col. 2, line 42-col. 3, line 10. Mosler also discusses shell-and-tube heat exchangers in [0026].
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nakahara (US6348135B1, published on 2/19/2002, of record) in view of Mosler (US2008/0197086 A1, published on 8/21/2008, of record), as applied to claims 1-10 and 12 above, and further in view of Ogawa (JP2014162783, published on 9/8/2014, including a machine generated English translation thereof, of record).
The Applicant claims the method of claim 1, wherein the oxygen-containing gas is supplied as microbubbles. Neither Nakamura nor Mosler explicitly teach this limitation.
Ogawa is directed to an analogous process to that of Nakamura/Mosler comprising a step of purifying a process liquid containing methacrylic acid/ester from the bottom of a distillation column. Ogawa teaches that the process liquid is fed through circulation loop comprising a reboiler and that oxygen is added to the circulation loop in order to inhibit polymerization. See abstract and claims. Ogawa teaches that the oxygen is mixed with the process fluid in a static mixer to form microbubbles. See discussion of “(5) Oxygen containing- gas” in lines 253-274 of the translation of the specification”. Ogawa speculates that the microbubbles may have a polymerization preventing effect different from that of forming from a sintered metal. See lines 564-571 and lines 266-274 of the translation of the specification.
It would have been prima facie obvious to combine the teachings of Nakamura, Mosler, and Ogawa to arrive at the instantly claimed process with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill would have been motivated to introduce oxygen into the combined process of Nakamura/Mosler because both Nakamura and Mosler, especially Mosler, teach the importance of efficient mixing to efficiently distribute oxygen to the process liquid before it is fed to the reboiler, and Ogawa teaches that when the oxygen is supplied as microbubbles that additional advantages can occur through a different mechanism. Therefore, including the microbubbles of Ogawa in the combined process of Nakamura/Mosler will predictably inhibit polymerization more effectively because more than one mechanism is being utilized. Also see MPEP 2143(I)(A).
Response to Arguments on p. 6-9 of the response filed 2/19/2026
Applicant argues Nakahara does not teach the limitation of “the supply port is located below an inlet of the heating part with a height difference of 1.0 m or more”. Applicant argues that the application of Mosler to the teachings of Nakahara fails to cure this deficiency. Applicant argues that:
“ the above findings establish that uniform gas distribution is not merely an incidental benefit in Mosler, but a fundamental design objective. Mosler therefore intendedly limits the distance between the gassing device and the inlet of the heating device to a relatively short range, about 300-1000 mm, so that the gas is dispersed across the pipe cross-section and introduced into the heating device before the gas distribution deteriorates.
Importantly, extending the distance between the gas supply port and the heating device - particularly in a vertically downward direction - would be contrary to this teaching. In a vertical pipe, gas bubbles tend to rise relative to the liquid phase due to buoyancy, and as the travel distance increases, bubble coalescence is likely to increase. Such coalescence leads to larger bubbles, reduced interfacial area, and non-uniform gas distribution. Accordingly, increasing the distance beyond the compact range disclosed in Mosler would undermine the very objective emphasized by Mosler, namely, maintaining an even distribution of gas at the inlet of the heating device.
Thus, Mosler teaches away from increasing the vertical distance between the gas supply port and the heating device, because a person having ordinary skill in the art, seeking to achieve uniform gas dispersion as taught by Mosler, would have avoided design modifications that promote bubble coalescence and gas maldistribution.
In contrast, the claimed method does not determine the position of the gas supply port for the purpose of achieving uniform gas dispersion at the inlet of the heating part. Rather, the claimed method requires the gas supply port is located below the inlet of the heating part within a height difference of 1.0 m or more in order to promote dissolution of oxygen into the circulating liquid. See paragraphs [0008] and [0032] of the specification. That is, the claimed method is designed such that a greater amount of oxygen-containing gas dissolves into the circulating liquid before the liquid reaches the reboiler.
Accordingly, unlike Mosler, the claimed method does not recommend that the oxygen- containing gas be present in the form of gas bubbles at the inlet of the heating part. Instead, the claimed method aims to introduce oxygen into the reboiler predominantly in a dissolved state within the circulating liquid. This technical objective is fundamentally different from that of Mosler, which seeks to introduce gas into the heating device while maintaining gas bubbles in a Because of this difference in objectives, the design principles of Mosler and the claimed method diverge significantly. Mosler adopts a compact arrangement and a short distance between the gas supply port and the heating device, in order to disperse gas rapidly while avoiding deterioration of gas distribution. Extending the distance between the gas supply port and the heating device - particularly in a vertically downward direction - would increase the likelihood of bubble coalescence and gas maldistribution, thereby undermining the uniform gas distribution emphasized by Mosler. For this reason, Mosler teaches away from increasing the distance beyond the disclosed range.
Accordingly, even accepting the Examiner's characterization of Mosler, the teachings of Mosler would not have motivated a person having ordinary skill in the art to increase the height difference to 1.0 m or more, but instead discourages such modification.
In addition, since claim 1 as amended requires that "the supply port is located below an inlet of the heating part, with a height difference of 1.0 m or more," in order to arrive at the claimed method, it is necessary to further modify Mosler's teaching, the distance between the gassing device and the inlet of the heating device of 300 to 1000 mm. As noted above, however, a person skilled in the art would find that increasing the distance between the gassing device and the inlet of the heating device results in bubble coalescence and gas maldistribution thereby increasing the tendency to polymerize. Therefore, there would have been no reasonable expectation of success to modify Nakahara's process in view of Mosler by increasing the distance between the gassing device and the inlet of the heating device (MPEP 2143.02)”.
These arguments have been fully considered but are not persuasive. Regarding the range of Mosler, a range of 300 to 1000 mm or 0.3 to 1.0 m, still overlaps with the claimed range of “1.0 m or more”. Therefore, there is no further motivation required to set the distance at 1.0 m, because Mosler explicitly includes this height in the range. Though it is in the top of the end of the range, it is still within the range. Also see MPEP 2144.05.
Further, regarding the “technical objective” difference between the claimed process and Mosler, in response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). The combination of Nakahara and Mosler teach all of the limitations of the claimed invention. As recited in the rejection:
“Mosler teaches that polymerization is suppressed when heating the mixture of the polymerizable compound and oxygen gas in the disclosed apparatus provided that there is even and sufficient distribution of the gas in the heating device. Therefore, it would have been prima facie obviously to carry out the known process of Nakahara in the known apparatus of Mosler to predictably obtain a process for purification of methacrylic acid/esters with reduced polymerization in the purification device. Also see MPEP 2143(I)(B).”
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., the state of the oxygen in the supply port) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). The Applicant’s arguments regarding the “bubbles in a uniformly dispersed state” of Mosler vs. “predominantly in a dissolved state” as claimed are not persuasive because there are no limitations regarding the degree of “dispersion” or “dissolution” of the oxygen in the drawn liquid. Further, even if it were in the claim, the Applicant has not provided an objective standard for determining “oxygen predominantly in a dissolved state”. The relative term “predominantly” is not in the specification as filed. Further, the Office notes that claim 11, requires “microbubbles” of oxygen and this limitation is taught by the combination of Nakahara, Mosler, and Ogawa in a separate rejection. It is additionally noted that the Applicant does not point to any objective results which are commensurate in scope of the claimed invention which might distinguish the claimed process from the prior art.
In response to applicant's argument that Mosler has a different motivation to set the height at 1.0 m than the intended use of said height in the claimed method, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
Therefore, because claim 1 still recites a range which overlaps with that of Mosler, the Applicant’s arguments are not persuasive.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AMY C BONAPARTE whose telephone number is (571)272-7307. The examiner can normally be reached 11-7.
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/AMY C BONAPARTE/ Primary Examiner, Art Unit 1692
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