Prosecution Insights
Last updated: April 19, 2026
Application No. 18/267,792

METHOD FOR RECOVERING RESIDUAL MONOMERS IN THE PREPARATION OF VINYL ESTER-ETHYLENE COPOLYMERS

Non-Final OA §103§112
Filed
Jun 16, 2023
Examiner
LEE, RIP A
Art Unit
1762
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Wacker Chemie AG
OA Round
1 (Non-Final)
83%
Grant Probability
Favorable
1-2
OA Rounds
2y 8m
To Grant
78%
With Interview

Examiner Intelligence

Grants 83% — above average
83%
Career Allow Rate
1119 granted / 1345 resolved
+18.2% vs TC avg
Minimal -5% lift
Without
With
+-4.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
36 currently pending
Career history
1381
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
31.8%
-8.2% vs TC avg
§102
25.5%
-14.5% vs TC avg
§112
24.4%
-15.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1345 resolved cases

Office Action

§103 §112
DETAILED ACTION Claim Objections Claim 12 is objected to because of the following informalities: In line 9, please replace “the mixture” with “a mixture”. Claim 13 is objected to because of the following informalities: In line 2, please replace “the weight” with “a weight”. Claim 14 is objected to because of the following informalities: In line 2, please insert “ethylene-containing” prior to “gas phase”. Claim 14 is objected to because of the following informalities: In line 2, please replace “the total” with “a total”. Claim 15 is objected to because of the following informalities: In line 1, delete “the” which precedes “depressurization”. Claim 17 is objected to because of the following informalities: In line 1, delete “the” which precedes “condensation”. Claim 18 is objected to because of the following informalities: In line 1, delete “the” which precedes “condensation”. Claim 18 is objected to because of the following informalities: In line 3, please replace “the first” with “a first”. Claim 18 is objected to because of the following informalities: In line 3, please replace “the second” with “a second”. Claim 19 is objected to because of the following informalities: In line 1, please replace “the condensate” with “a condensate”. Claim 19 is objected to because of the following informalities: In line 2, please replace “the total” with “a total”. Claim 20 is objected to because of the following informalities: In line 1, please replace “the condensate” with “a condensate”. Claim 20 is objected to because of the following informalities: In line 2, please replace “the total” with “a total”. Claim 21 is objected to because of the following informalities: In line 2, please replace “the condensate” with “a condensate”. Claim 21 is objected to because of the following informalities: In line 3, please replace “the total” with “a total”. 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. Claims 12-22 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. Claim 12 recites a process whereby in performing stage b), an ethylene-containing gas phase is absorbed into vinyl esters. Claim describes an initial step of polymerizing vinyl esters, ethylene and optionally further ethylenically unsaturated monomers. Presumably, these vinyl esters originate from some unrecited source or feed in communication with a polymerization reactor. After performing depressurization in stage a), an aqueous phase that contains vinyl esters is formed. It is unclear with which batch of vinyl esters (vinyl esters from unrecited source or feed or vinyl esters in aqueous phase) the ethylene-containing gas phase is to be contacted, and it is not evident where in a polymerization apparatus or how such contacting is carried out. Furthermore, it is not understood how the ethylene-containing gas phase is “absorbed” into vinyl esters as described. Depending on pressure and temperature, the ethylene-containing gas phase may be an entrained mixture with vinyl esters or the ethylene-containing gas may be dissolved in the vinyl esters. Finally, it not definitive if the ethylene alone is absorbed into vinyl esters or the entirety of the gas phase, which contains unrecited materials in addition to ethylene, is absorbed into vinyl esters. Elucidation is required, for without further clarification, one of ordinary skill in the art would not be apprised of how to carry out claimed steps. Based on these considerations, claim 12 is deemed being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. Dependent claims 13-22 are subsumed under the rejection. Claim 12 is rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. Claim recites a process in which a gas phase has a temperature of 50 ºC to less than 80 ºC. Claim is indefinite because it is unclear where the upper bound lies exactly. For instance, it is not clear if the temperature lies in a range of 50 ºC to 55ºC or in a range of 50 ºC to 77 ºC. Without further qualification, one of ordinary skill in the art would not be apprised of the actual working range and scope of the invention. Claim 16 is rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. Claim recites a process in which a gas phase has a temperature of 50 ºC to less than 75 ºC. Claim is indefinite because it is unclear where the upper bound lies exactly. For instance, it is not clear if the temperature lies in a range of 50 ºC to 55ºC or in a range of 50 ºC to 74 ºC. Without further qualification, one of ordinary skill in the art would not be apprised of the actual working range and scope of the invention. Claim 18 is rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. Claim recites a process of carrying out a second stage a temperature of 0 ºC to less than 15 ºC. Claim is indefinite because it is unclear where the upper bound lies exactly. For instance, it is not clear if the temperature lies in a range of 0 ºC to 2ºC or in a range of 0 ºC to 13 ºC. Without further qualification, one of ordinary skill in the art would not be apprised of the actual working range and scope of the invention. Claim Rejections - 35 USC § 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 12, 16, and 22 are rejected under 35 U.S.C. 103 as being unpatentable over Babar et al. (WO 2021/013354; equivalent US 12,018,101 relied upon for translation) in view of Weitzel et al. (US 6,809,174). Babar et al. teaches a process of preparing ethylene vinyl acetate copolymer in an aqueous medium using a free radical initiator in a polymerization reactor operating at a pressure between 10 to 80 bar (col. 6, line 47). In a first phase of post-treatment, the polymerization mixture is depressurized to a pressure of approximately 0.1 to approximately 5.0 bar (col. 8, line 37). During depressurization, phase separation occurs between a polymer dispersion (liquid phase) and a gaseous phase which may include inert gas and unreacted monomer(s) from the polymerization reation (col. 8, lines 59-64). The gaseous phase obtained during depressurization is withdrawn in a second phase of post-treatment comprising degassing, and the gaseous phase contents are fed to monomer recovery (col. 8, lines 63-66). A final stage of post-treatment involves a stripping stage to remove all impurities from the ethylene vinyl acetate copolymer. This process is carried out under vacuum at 0.1 to 0.5 bar at a temperature of 50 ºC to 80 ºC (col. 9, lines 25-28). Reference is silent with respect to the conditions used for the second phase of post-treatment comprising degassing, however, it would have been obvious to use the same conditions disclosed for depressurizing or stripping. Babar et al. does not disclose details regarding monomer recovery. Weitzel et al. discloses a typical polymerization system for preparation of ethylene vinyl acetate copolymer. The reference teaches a use of a recovery line 4, compressor 5, and pump 10 to return unreacted monomer to the polymerization reactor 1. The person of ordinary skill in the art would have found it obvious that the gaseous phase under same temperature and reduced pressure would include unreacted monomer ethylene and vinyl acetate, as well as residual water vapor. These components would be condensed when introduced into compressor 5. One learns from Weitzel et al. that the returned gaseous phase components are combined with vinyl acetate supply 7 in mixing unit 6 prior to reintroduction into reactor 1; see Figure 1. One of ordinary skill in the art would have found it obvious that Babar et al. contemplates a recovery system similar to that disclosed in Weitzel et al. The person of ordinary skill in the art would have found it obvious to modify the process of Babar et al. to include a recovery system in order to recycle unreacted components. Since these processes are well-established in the art, the person of ordinary skill in the art would have expected the combination of teaching to work with a reasonable expectation of success. Neither of cited references teaches the subject of claims 13-15 and 21, which are characteristics specific to inventive process. Neither of cited references teaches the particulars of the condensation process described in claims 17-20. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Rip A. Lee whose telephone number is (571)272-1104. The examiner can be reached on Monday through Friday from 9:00 AM - 5:00 PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Robert Jones, can be reached at (571)270-7733. 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 http://pair-direct.uspto.gov. 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. /RIP A LEE/Primary Examiner, Art Unit 1762 February 7, 2026
Read full office action

Prosecution Timeline

Jun 16, 2023
Application Filed
Feb 07, 2026
Non-Final Rejection — §103, §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
83%
Grant Probability
78%
With Interview (-4.7%)
2y 8m
Median Time to Grant
Low
PTA Risk
Based on 1345 resolved cases by this examiner. Grant probability derived from career allow rate.

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