Prosecution Insights
Last updated: April 19, 2026
Application No. 18/004,985

METHOD AND SYSTEM FOR PREPARING EPOXYPROPANE BY DIRECTLY EPOXIDIZING PROPYLENE

Non-Final OA §103
Filed
Jan 10, 2023
Examiner
MURESAN, ANA Z
Art Unit
1692
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Sinopec Research Institute Of Safety Engineering Co. Ltd.
OA Round
1 (Non-Final)
76%
Grant Probability
Favorable
1-2
OA Rounds
2y 4m
To Grant
99%
With Interview

Examiner Intelligence

Grants 76% — above average
76%
Career Allow Rate
530 granted / 702 resolved
+15.5% vs TC avg
Strong +30% interview lift
Without
With
+30.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 4m
Avg Prosecution
38 currently pending
Career history
740
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
39.6%
-0.4% vs TC avg
§102
20.1%
-19.9% vs TC avg
§112
26.3%
-13.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 702 resolved cases

Office Action

§103
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 . DETAILED ACTION This Office action is responsive to Applicant's response to restriction requirement filed Nov. 17, 2025. As filed, claims 1-18 are pending. Priority This application, filed 01/10/2023 is a National Stage entry of PCT/CN2021/073744 , International Filing Date: 01/26/2021 claims foreign priority to 202010662746.4, filed 07/10/2020 claims foreign priority to 202010662738.X, filed 07/10/2020 claims foreign priority to 202010662744.5, filed 07/10/2020. Information Disclosure StatementApplicants' information disclosure statements (IDS) filed on 01/10/2023,01/26/2024,4/21/2025 have been considered except where lined through. Please refer to Applicants' copy of the 1449 submitted herewith. Election/Restrictions Applicant's election without traverse of Group I, claims 1-12, 16-18, drawn to process for preparing epoxypropane. in the reply filed on 11/17/2025 is acknowledged. Claims 13-15 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Claims 1-12, 16-18 will be examined on the merits herein. Claim Objection Claim 2 is objected to because of the following informalities: the equation in claim 2 is blurred PNG media_image1.png 200 400 media_image1.png Greyscale and it should be replaced. Appropriate correction is required. 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 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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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. Claims 1-13, 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over CN 1268072 (“the 072 publication “; cited by Applicants in IDS; machine translation attached) and further in view of US 2010/10197947 Aug. 2010 by Narahara et al. (the “947 publication “; cited by Applicants in IDS). Instant claims are drawn to a method for preparing epoxypropane by direct epoxidation of propylene comprising: subjecting a mixed gas of a first feed gas and a second feed gas to a contact reaction with a catalyst under reaction conditions of propylene epoxidation to prepare epoxypropane; wherein the first feed gas contains oxygen gas and is free or substantially free of hydrogen gas, the second feed gas contains hydrogen gas and is free or substantially free of oxygen gas, the first feed gas and/or the second feed gas contain propylene, at least one of the first feed gas and the second feed gas further comprises a diluent gas. Regarding instant claim 1, the ‘072 publication discloses a process for the preparation of propylene oxide (aka epoxypropane), by direct oxidation of propylene in gas phase in the presence of hydrogen and a dispensable diluent, the epoxidation reaction is mediated by catalyst comprising titanium, silver, gold, and optionally one promoter (abstract; see claim 39 of the ‘072 publication). Regarding the amount of oxygen in gas mixture calculated by equation of instant claim 2, the ’072 publication teaches that oxygen amount is higher than about 0.01-5mol%, based on the total mole number of propylene, oxygen, hydrogen and optional diluent; the amount of oxygen is lower than about 20mol%, because higher than about 20mol%, concentration of oxygen is in the flammable range of propylene -hydrogen gas-oxygen mixture (page 8). Therefore, the prior art relied upon, and knowledge generally available in the art before the effective filing date provide the suggestion that would have motivated the skilled artisan to adjust and optimize the amount of oxygen, hydrogen and propylene of the gas mixture feed. Additionally, pertaining to the concentration, it is noted that generally, differences in such parameters will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such parameter is critical. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) See MPEP 2144.5. Regarding instant claims 3 and 4, the ‘072 publication teaches that suitable gaseous diluent includes, but not limited to helium, argon gas, and methane, carbon dioxide, steam, and composition thereof (page 7 of translation; claim 9 of the ‘072 publication). Regarding instant claims 8 and 16 the ‘072 publication teaches a supported metal catalyst comprising a carrier and an active metal component, the active metal component comprise silver, gold contains one or more promoter element with the catalyst that contains as silica, aluminum oxide, alumino-silicate, magnesia, titanium oxide or carbon as carrier; thee loading of gold is greater than 0 wt% but less than 20 wt%, based on the total weight of the catalyst; e.g. TiO 2On 4%Ag and 0.9%Au and Na; (page 14, 31, claim 18). Regarding instant claims 7, 9 and 17, the ‘072 publication teaches the reactors contain a plurality of catalyst beds structures parallel connected and that use in an alternating manner (page 16). Regarding instant claims 10 and 18, the ’072 publication teaches reaction temperature of 20°C but lower than 250°C (see claim 39 of the reference) which is within the claimed range of 20-300 °C, about normal pressure to about 400psig (2758kP); in a flow reactor, the mol ratio of the time of staying of reactant and reactant and catalyst determined by space velocity; for gas phase process, the gas space-time speed (GHSV) of alkene typically is higher than about 10ml alkene/ml catalyst/hour (h -1), higher than about 1,000h -1h; the GHSV typical case of alkene is lower than, 1000h -1h (page 16, claims 32-35), Regarding instant claims 11-12, the ’072 publication teaches oxidation process in gas phase without solvent and with separation of product ( example on page 19-20). The difference between the process of the ‘072 publication and the instantly claimed process for preparing epoxypropane by direct epoxidation of propylene is that the process of prior art does not teach the oxygen provided as first feed gas and a second feed gas contains hydrogen gas and is free or substantially free of oxygen gas, the first feed gas and/or the second feed gas contain propylene; instead the prior art teaches a different mixing of staring materials, mixed gas comprising both hydrogen and oxygen and propene. Regarding the reaction feed gas mixing to reduce the risk of explosion by adjusting the amount of oxygen in gas mixture, the ’072 publication specifically teaches that oxygen amount is higher than about 0.01-5mol%, and lower than about 20mol%, since higher than about 20mol%, concentration of oxygen are in the flammable range of propylene -hydrogen gas-oxygen mixture. Therefore, the prior art relied upon, and knowledge generally available in the art before the effective filing date provide the suggestion that would have motivated the skilled artisan to adjust and optimize the amount of oxygen, hydrogen and propylene of the mixture feed. Furthermore, the ‘947 publication, analogous prior art which discloses a method for producing an epoxy compound e.g. propylene oxide (aka epoxypropane), derived from an olefin such as propylene by epoxidation reaction of hydrogen, oxygen and the olefin in the presence of a catalyst in a reactor is characterized in that the process comprises a step of continuously supplying hydrogen, an oxygen-containing gas with an oxygen concentration of at least 90% by volume and the olefin to the vapor phase and/or liquid phase of the reactor. With respect to gas feed containing oxygen gas and hydrogen gas, the explosion range is very wide and direct mixing of them is very dangerous. Accordingly, in terms of the safety, as a mixture gas containing oxygen, an olefin, and hydrogen to be used for epoxidation reaction, oxygen diluted with nitrogen gas, an inert gas, is used and hydrogen and propylene are mixed with the diluted oxygen to produce the mixture gas; wherein the process comprises a first mixing step of preparing an oxygen/steam/olefin-containing gas by mixing oxygen/steam-containing gas containing oxygen and steam with an olefin (which reads on claims 1, 5 and preheating gas mixture of claim 7); (abstract; [0002], [0085]; Fig 1, claims 26, 28). PNG media_image2.png 200 400 media_image2.png Greyscale Therefore, the ‘947 publication specifically teaches that separate premix treatment of oxygen and hydrogen feed gas can be performed using a diluent gas in a process for the epoxidation of propylene to prepare alkylene oxides, and by adding separate premix to the epoxidation reaction the process is safer, with lower the possibility of explosion of the gas mixture [0080]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to combine the teachings of cited references to arrive at instant invention with reasonable expectation of success, because the prior art by the ‘072 publication teaches the process for preparation of propylene oxide (aka epoxypropane) by epoxidation of propylene with oxygen and hydrogen gas feed mediated by catalyst, while aspects of utilizing the reaction feed gas mixing as claimed are discussed in the ‘947 publication. One would be motivated to combined the teaches of the cited references because the prior art specifically teaches that adding separate premix to the epoxidation reaction the process is safer, with lower the possibility of explosion of the gas mixture. The rationale to support a conclusion that the claim would have been obvious is that teaching, suggestion, or motivation in the prior art that would have led one of ordinary skill to modify the prior art reference or to combine prior art reference teachings to arrive at the claimed invention. KSR, 550 U.S. at_, 82 USPQ2d at 1395. Therefore, the claimed invention as a whole is prima facie obvious over the teachings of the prior art. Conclusion Claims 1-12, 16-18 are rejected. Claims 13-15 are withdrawn from further consideration. Telephone Inquiry Any inquiry concerning this communication or earlier communications from the examiner should be directed to: Ana Muresan (571) 270-7587 (phone) (571)270-8587 (fax) Ana.Muresan@uspto.gov The examiner can normally be reached Monday - Friday (9:00AM - 5:30PM). 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, Scarlett Goon can be reached at 571-270-5241. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see https://ppair-my.uspto.gov/pair/PrivatePair. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /ANA Z MURESAN/Primary Examiner, Art Unit 1692
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Prosecution Timeline

Jan 10, 2023
Application Filed
Mar 03, 2026
Non-Final Rejection — §103 (current)

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Prosecution Projections

1-2
Expected OA Rounds
76%
Grant Probability
99%
With Interview (+30.3%)
2y 4m
Median Time to Grant
Low
PTA Risk
Based on 702 resolved cases by this examiner. Grant probability derived from career allow rate.

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