Prosecution Insights
Last updated: April 19, 2026
Application No. 18/023,671

CONTINUOUS POLYMERIZATION REACTOR FOR SUPER ABSORBENT POLYMER AND CONTINUOUS POLYMERIZATION REACTION SYSTEM

Non-Final OA §103
Filed
Feb 27, 2023
Examiner
TESKIN, FRED M
Art Unit
1762
Tech Center
1700 — Chemical & Materials Engineering
Assignee
LG Chem, Ltd.
OA Round
1 (Non-Final)
90%
Grant Probability
Favorable
1-2
OA Rounds
2y 3m
To Grant
97%
With Interview

Examiner Intelligence

Grants 90% — above average
90%
Career Allow Rate
1176 granted / 1313 resolved
+24.6% vs TC avg
Moderate +8% lift
Without
With
+7.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 3m
Avg Prosecution
34 currently pending
Career history
1347
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
38.7%
-1.3% vs TC avg
§102
17.0%
-23.0% vs TC avg
§112
27.6%
-12.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1313 resolved cases

Office Action

§103
DETAILED ACTION Status of Application This action is responsive to national-stage application filed 02/27/2023. The concurrently filed preliminary amendment is acknowledged. Amended claims 1-3 and 5-9, and original claim 4, are currently pending and under examination herein. 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 . However, 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 a 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. Information Disclosure Statement(s) The information disclosure statement(s) (IDS) filed on 02/27/2023, 03/02/2023, 03/06/2023, 04/21/2023, 01/14/2024, 02/13/2024, 04/16/2024, 06/04/2024, 08/07/2024, 10/21/2024, 12/12/2024, 02/03/2025, 02/10/2025, 07/22/2025 and 11/23/2025 are in compliance with the provisions of 37 CFR 1.97, 1.98 and MPEP § 609, and therefore the information referred to therein has been considered as to the merits. Initialed copies of the IDS are included with the mailing/transmittal of this Office action. Foreign Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Objection – Specification The disclosure is objected to because of the following informalities: a typographical error is noted at page 7, line 16: “BREIF” should read –BRIEF--. Appropriate correction is required. Claim Interpretation With respect to claims 1-4, the Office considers the preamble recitation "for super absorbent polymer” to be non-limiting for purposes of claim construction because the body of base claim 1 fully sets forth all the structural features of the claimed reactor, and the preamble merely states the purpose or intended use of the claimed reactor. See MPEP 2111.02(II). Common Ownership Notice 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 Rejections – 35 U.S.C. 103 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. Claims 1-4 are rejected under 35 U.S.C. 103 as being unpatentable over El-Toufaili et al (US 2021/0347924 A1) (‘El-Toufaili’) in view of Langlotz (US 2017/0029546 A1). Regarding Claim 1, reference to El-Toufaili discloses a continuous polymerization unit P1 (i.e., reactor) comprising: a cylindrical body (Fig. 5: cylindrical upper part (30) and ¶¶ [0249]-[0250]); a discharge part having an inverted circular cone shape with a diameter decreasing downward, located at a lower part of the cylindrical body (Fig. 5: conical part (31) and ¶ [0250]); an inlet connected to the cylindrical body, through which a monomer composition is introduced into the cylindrical body (¶ [0250] – After polymerization, the polyacrylamide gel is removed through the opening (32) (implicitly, an inlet for introducing the precursor monomer composition must be connected to the polymerization unit P1); an outlet located at a lower part of the discharge part (Fig. 5: opening (32)), through which hydrogel super absorbent polymer produced by polymerization of the monomer composition (¶ [0250] - polyacrylamide gel is removed through the opening (32)); and a discharge valve for opening or closing the outlet (¶ [0250] – At the bottom end, there is a bottom opening (32) which may be opened and closed. After polymerization, the polyacrylamide gel is removed through the opening (32)). Claim 1 further recites wherein a ratio (H1/D1) of a sum (H1) of a height of the body and a height of the discharge part to a diameter (D1) of the cylindrical body is 2 to 4. As to the claimed ratio, El-Toufaili describes (¶ [0252]) embodiments that comprise polymerization units P1 having basically the same shape, i.e. a cylindrical upper part and a conical part at its lower end and a bottom opening, however having a diameter from about 3 m to 4.5 m, a length of the cylindrical section from 10 m to 12 m and a length of the conical section from 1.5 to 2.5 m. As such, El-Toufaili implicitly describes polymerization units P1 wherein the sum of the length (height) of the cylindrical section and length (height) of the conical section is 11.5 m to 14.5 m, and the diameter of the cylindrical section is from about 3 m to 4.5 m, which equates to a ratio (H1/D1) of 3.8 (11.5 m : 3 m) to 3.2 (14.5 m : 4.5 m), as claimed. El-Toufaili arguably differs from the claimed subject matter only in failing to explicitly disclose that the aforementioned inlet is located at the upper part of and connected to the cylindrical body. However, when producing (co)polymers of (meth)acrylamide by gel polymerization as in El-Toufaili (cf., ¶ [0244]) in a conical reactor having a cylindrical upper part and a conical part at its lower end, it is common practice to introduce a monomer composition to the reactor through an inlet located at the upper part of and connected to the cylindrical body as taught by Langlotz (see Fig. 1 – feed (4) and ¶ [0143] – Through this feed (4), the aqueous monomer solution and/or gases and/or further components can be passed into the reactor). It would have been obvious to one of ordinary skill in the art at the time of effective filing to modify the continuous polymerization unit P1 of El-Toufaili by locating the inlet for introducing the monomer composition at the upper part of and connected to the cylindrical upper part (30) of P1 as per Langlotz, as a routine matter of reactor design and with the expectation of realizing equivalent results when conducting gel polymerization reactions. Regarding Claims 2-4, it is acknowledged that the recitation specifying that the monomer composition is continuously introduced into the continuous polymerization reactor through the inlet with a predetermined flow rate, and the discharge valve controls an open rate of the outlet such that the hydrogel super absorbent polymer is continuously discharged from-through the outlet with the same flow rate as the predetermined flow rate (Cl. 2), that the recited manner of operating the discharge valve (Cl. 3), and the recited constituents of the monomer composition (Cl. 4) are not directly disclosed by El-Toufaili or Langlotz; however, such recitations are directed to intended manners of using the claimed reactor (i.e., apparatus) or to the contents thereof during an intended operation (continuous polymerization), neither of which is germane to the patentability of the apparatus itself. That is, such recitations do not expressly or impliedly require any reactor structure in addition to that described in the applied art. Thus, the polymerization unit P1 of El-Toufaili as modified as per Langlotz possesses all the structural elements of the Applicant’s reactor as claimed, any difference resides in the manner in which the reactor is to be used, and the manner in which an apparatus is to be utilized is not germane to the issue of patentability of the apparatus itself. See, MPEP § 2115 and In re Casey, 152 USPQ 235 (CCPA 1967). Pertinent Art The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Patents to Funk et al (US 8829135 B2; US 8785583 B2) are cited as of interest concerning continuous processes for producing water-absorbing polymer particles. Neither citation teaches the present invention. Allowable Subject Matter Claims 5-9 are allowed. The following is a statement of reasons for the indication of allowable subject matter: The closest prior art to El-Toufaili et al and Langlotz, discussed above, and Zaquen Neomy et al (“Polymer Synthesis in Continuous Flow Reactors”) (cited in supplemental ESR, of record) does not describe the invention of instant claims 5-9, especially claimed features of: first vessel to third vessels, a continuous polymerization reactor, respective first to third supply valves, and a controller, wherein the controller controls the first to third supply valves such that a monomer composition is continuously introduced at a predetermined flow rate through an inlet (of the reactor), and controls a discharge valve such that a hydrogel polymer is continuously discharged at the same flow rate as the predetermined flow rate (cf., independent claim 5). Nor is the closest prior art seen to provide proper rationale to modify any of their respective disclosures to arrive at the invention of instant claims 5-9. Correspondence Any inquiry concerning this communication should be directed to Examiner F. M. Teskin whose telephone number is (571) 272-1116. The examiner can normally be reached on Monday through Friday from 9:00 AM - 5:30 PM. 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, Robert Jones, can be reached at (571) 270-7733. The appropriate 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 Patent Center. Status information for published applications may be obtained from Patent Center. Status information for unpublished applications is available through Patent Center for authorized users only. Should you have questions about access to Patent Center, 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. 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) Form at https://www.uspto.gov/patents/uspto-automated- interview-request-air-form. /FRED M TESKIN/Primary Examiner, Art Unit 1762 /FMTeskin/01-05-26
Read full office action

Prosecution Timeline

Feb 27, 2023
Application Filed
Jan 05, 2026
Non-Final Rejection — §103 (current)

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Prosecution Projections

1-2
Expected OA Rounds
90%
Grant Probability
97%
With Interview (+7.8%)
2y 3m
Median Time to Grant
Low
PTA Risk
Based on 1313 resolved cases by this examiner. Grant probability derived from career allow rate.

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