Prosecution Insights
Last updated: April 19, 2026
Application No. 18/567,272

CONTINUOUS RECTIFICATION APPARATUS FOR PRODUCING ELECTRONIC-GRADE PROPYLENE CARBONATE

Non-Final OA §103§112
Filed
Dec 05, 2023
Examiner
PILCHER, JONATHAN L
Art Unit
1772
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Shandong Lixing Advanced Material Technology Co. Ltd.
OA Round
1 (Non-Final)
64%
Grant Probability
Moderate
1-2
OA Rounds
2y 9m
To Grant
99%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
380 granted / 597 resolved
-1.3% vs TC avg
Strong +46% interview lift
Without
With
+46.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
37 currently pending
Career history
634
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
36.9%
-3.1% vs TC avg
§102
14.5%
-25.5% vs TC avg
§112
32.5%
-7.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 597 resolved cases

Office Action

§103 §112
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 § 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 1-3 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 “electronic-grade propylene carbonate” in lines 1-2. The scope of “electronic-grade propylene carbonate” is unclear, i.e. it is unclear exactly what requirements must be met for a propylene carbonate to qualify as “electronic-grade”. For the purposes of examination, the term “electronic-grade” has been interpreted broadly. Claims 2 and 3 are rejected due to their dependency on indefinite claim 1. Claim 3 recites the limitation "the first extraction pipe" in lines 3-4. There is insufficient antecedent basis for this limitation in the claim. 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. 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) 1-3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 2021/0387937), hereafter referred to as Chen, in view of Ii et al. (US 2017/0342017), hereafter referred to as Ii. With regard to claim 1: Chen teaches continuous rectification apparatus for producing a purified solvent (Figure 1, paragraphs [0009], [0026], [0042]-[0044], [0057]-[0062]), wherein said solvent may be propylene carbonate (paragraphs [0019] and [0030]), the apparatus comprising: A light component removal column 6 and a heavy component removal column 8 (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]). Wherein: One side of the light component removal column 6 is connected to a first feeding pipe (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]), A top of the light component removal column 6 is connected to a first condensing box (condenser) 6a via a first pipeline (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]). One side of the first condensing box 6a is connected to a first reflux pipe (12) (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]). A bottom of the light component removal column 6 is connected to a feeding pump 7 via a fourth pipeline (Figure 1, paragraph s[0042]-[0044], [0057]-[0062]). One end of the feeding pump 7 is connected to a second feeding pipe (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]). One end of the second feeding pipe is connected to one side of the heavy component removal column 8 (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]). A top of the heavy component removal column 8 is connected to a second condensing box (condenser) 8a via a fifth pipeline (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]). One side of the second condensing box 8a is connected to a second reflux pipe (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]). One end of the second reflux pipe is connected to the other side of the heavy component removal column (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]). And the second reflux pipe is connected to a second extraction pipe (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]; see annotated Figure 1 below). PNG media_image1.png 732 968 media_image1.png Greyscale Chen does not explicitly teach that the system is for producing propylene carbonate which is specifically “electronic-grade”. However, the system of Chen, as discussed above, is capable of producing a purified propylene carbonate (paragraphs [0019] and [0030]). Furthermore, the distillation sequence in Chen is substantially identical to the distillation sequence of the claimed system, i.e. the distillation columns in Chen are arranged in a manner substantially identical to the distillation columns in the claim. The claimed reflux tanks, reflux pumps, and associated pipes are merely auxiliary systems which do not have a substantial effect on the actual distillations performed by the system. For the forgoing reasons, the system of Chen is necessarily capable of producing purified propylene carbonate that is specifically “electronic-grade” (See MPEP 2114 for guidance). Chen is silent to one side of the first condensing box being connected to a first reflux tank via a second pipeline, one side of the first reflux tank being connected to a first conveying pump via a third pipeline, and one end of the first conveying pump being connected to the first reflux pipe. Chen is also silent to one side of the second condensing box being connected to one side of a second reflux tank via a sixth pipeline, another side of the second reflux tank being connected to one end of a second conveying pump via a seventh pipeline, and another end of the second conveying pump being connected to the second reflux pipe. However, it is well-known in the art to provide distillation columns with such arrangements of reflux tanks, reflux pumps, and associated pipes. For example, Ii teaches a distillation system similar to that of Chen at least in terms of structure/layout (Figure 1). The system of Ii comprises reflux tanks 24 and 44 and reflux pumps 27 and 47 arranged in the claimed manner (Figure 1, paragraphs [0041], [0045], [0047], [0053], [0061], and [0110]). The reflux tanks 24 and 44 store liquid condensed by condensers 22 and 42 (Figure 1, paragraphs [0041] and [0053]). A person having ordinary skill in the art would recognize that the reflux tanks 24 and 44, by storing condensed liquids, act as surge drums. The reflux pumps 27 and 47 serve to discharge liquid from the respective tanks 24 and 44 and supply said liquid to respective reflux pipes (Figure 1, paragraphs [0041], [0047], [0053], and [0061]). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Chen in view of Ii by configuring the system such that: 1) one side of the first condensing box is connected to a first reflux tank via a second pipeline, one side of the first reflux tank is connected to a first conveying pump via a third pipeline, and one end of the first conveying pump is connected to the first reflux pipe; and 2) one side of the second condensing box is connected to one side of a second reflux tank via a sixth pipeline, another side of the second reflux tank is connected to one end of a second conveying pump via a seventh pipeline, and another end of the second conveying pump is connected to the second reflux pipe, in order to provide the system of Chen with reflux tanks which serve as surge tanks storing liquid condensed by the condensing boxes, and in order to provide the system of Chen with reflux pumps for discharging liquid from the reflux tanks and supplying said liquid to respective reflux pipes. The system of Chen modified in view of Ii as discussed above is structurally identical to the claimed system. Thus, for the sake of argument, if the system of Chen prior to said modification were not necessarily capable of producing “electronic grade” propylene carbonate, the system of modified Chen is on account of said system being identical to the claimed system (see MPEP 2114 for guidance). With regard to claim 2: The first reflux pipe is connected to a first extraction pipe (Figure 1, paragraphs [0042]-[0044], [0057]-[0062]; see annotated Figure 1 above), and one end of the first extraction pipe is connected to a first collecting tank (waste container; not shown in Figure 1). (Chen: Figure 1, paragraph [0059]). With regard to claim 3: One end of the second extraction pipe is connected to a second collecting tank (distilled solvent tank) 9 (Chen: Figure 1, paragraphs [0042]). Modified Chen is silent to the first and second extraction pipes each being provided with valves. However, Chen teaches that the distillation system 100 may be provided with a valves that are not shown in the Figure (paragraph [0042]). A person having ordinary skill in the art would recognize that it is desirable to provide flow lines in distillation systems with valves, as valves can be used to control the flow of a liquid through a flow line and/or cut off said flow of liquid if necessary. Indeed, the disclosure of Chen acknowledges that valves can be used to control fluid flow (paragraph [0043]). It would have been obvious to one of ordinary skill in the art before the effective filing date to further modify Chen by adding valves to the first and second extraction pipes, in order to provide a means of controlling fluid flow through said pipes and/or shutting off said fluid flow if necessary. Citation of Pertinent Prior Art The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Ii et al. (US 10,351,507) is the granted patent corresponding to the Ii PG Pub relied upon in the 103 rejections above. Chen et al. (US 11,440,866) is the granted patent corresponding to the Chen PG Pub relied upon in the 103 rejections above. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to JONATHAN "LUKE" PILCHER whose telephone number is (571)272-2691. The examiner can normally be reached Monday-Friday 9am-5pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, In Suk Bullock can be reached at 5712725954. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /JONATHAN LUKE PILCHER/ Examiner, Art Unit 1772
Read full office action

Prosecution Timeline

Dec 05, 2023
Application Filed
Feb 03, 2026
Non-Final Rejection — §103, §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
64%
Grant Probability
99%
With Interview (+46.1%)
2y 9m
Median Time to Grant
Low
PTA Risk
Based on 597 resolved cases by this examiner. Grant probability derived from career allow rate.

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