Prosecution Insights
Last updated: April 19, 2026
Application No. 18/287,720

Process for Preparing Carbodiimides

Non-Final OA §103
Filed
Oct 20, 2023
Examiner
LEONARD, MICHAEL L
Art Unit
1763
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Lanxess Deutschland GmbH
OA Round
1 (Non-Final)
64%
Grant Probability
Moderate
1-2
OA Rounds
3y 3m
To Grant
72%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
839 granted / 1319 resolved
-1.4% vs TC avg
Moderate +8% lift
Without
With
+8.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
64 currently pending
Career history
1383
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
50.5%
+10.5% vs TC avg
§102
19.2%
-20.8% vs TC avg
§112
18.7%
-21.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1319 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 . 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. Claims 1, 4-6, 8-12, and 15 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Pub. No. 2015/0225336 to Haeberle et al. As to claims 1, 4-6, 8, 11-12, Haeberle discloses a process for the preparation of polycarbodiimides comprising carbodiimization of diisocyanates in the presence of phospholene oxide catalysts, separating the catalyst by distillation to obtain a mixture comprising carbodiimide and diisocyanate (0043), followed by a further distillation step (0072-0078) to obtain a mixture comprising polycarbodiimide, catalyst, and diisocyanate (0055, 0078). Haeberle further discloses the addition of an alcohol to the obtained mixture and reaction either completely or partially with the polycarbodiimide and diisocyanate with the alcohols such as methanol, ethanol, dodecanol, etc. (0085-0087). At the time of filing it would have been obvious to react the alcohol component with the polycarbodiimide mixture to covalently modify the product which allows for better compatibility with ester resins when the polycarbodiimide is used as a crosslinker (0084). With regards to the claimed structure, the structures represented by the claimed formulas are be generated by carbodiimization reaction of diisocyanates, distillation of remaining residues and reaction of the carbodiimide and monomeric diisocyanate with an alcohol component. This process is substantially identical to the process taught in Haeberle Because Haeberle teaches a substantially identical process using identical amounts of analogous components as required by the instantly claimed invention, the claimed formulas would be formed in the invention of Haeberle. As to claims 9-10, Haeberle discloses a distillation step at temperatures and pressures of 150 to 200°C and 0.1 to 10mbar (0073). As to claim 15, Haeberle discloses a content of monomeric diisocyanate of 1 wppm to 100 wppm (0079). Claims 2-3 and 12-14 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Pub. No. 2015/0225336 to Haeberle et al. in view of U.S. Patent No. 5,246,993 to Scherzer et al. As to claims 2-3 and 14, Haeberle discloses a process for the preparation of polycarbodiimides comprising carbodiimization of diisocyanates in the presence of phospholene oxide catalysts, separating the catalyst by distillation to obtain a mixture comprising carbodiimide and diisocyanate (0043), followed by a further distillation step (0072-0078) to obtain a mixture comprising polycarbodiimide, catalyst, and diisocyanate (0055, 0078). Haeberle further discloses the addition of an alcohol to the obtained mixture and reaction either completely or partially with the polycarbodiimide and diisocyanate with the alcohols such as methanol, ethanol, dodecanol, etc. (0085-0087). At the time of filing it would have been obvious to react the alcohol component with the polycarbodiimide mixture to covalently modify the product which allows for better compatibility with ester resins when the polycarbodiimide is used as a crosslinker (0084). Haeberle does not expressly disclose the amount of alcohol component. However, Scherzer within the same field of endeavor discloses a process for preparing polycarbodiimides that are further modified with less than 20 mol% of alcohol component (3:22-30) at temperatures of 50 to 200°C (2:64-65) wherein excess alcohol is distilled off (Example 5). At the time of filing it would have been obvious to a person of ordinary skill in the art to add the alcohol taught in Haeberle within the amounts taught in Scherzer to establish a relatively uniform degree of condensation and allow for desirable facilitation of the carbodiimides into plastic materials during crosslinking (3:32-47). Claims 7 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Pub. No. 2015/0225336 to Haeberle et al. in view of U.S. Patent Pub. No. 2012/0123062 to Laufer et al. As to claims 7 and 13, Haeberle discloses a process for the preparation of polycarbodiimides comprising carbodiimization of diisocyanates in the presence of phospholene oxide catalysts, separating the catalyst by distillation to obtain a mixture comprising carbodiimide and diisocyanate (0043), followed by a further distillation step (0072-0078) to obtain a mixture comprising polycarbodiimide, catalyst, and diisocyanate (0055, 0078). Haeberle further discloses the addition of an alcohol to the obtained mixture and reaction either completely or partially with the polycarbodiimide and diisocyanate with the alcohols such as methanol, ethanol, dodecanol, etc. (0085-0087). At the time of filing it would have been obvious to react the alcohol component with the polycarbodiimide mixture to covalently modify the product which allows for better compatibility with ester resins when the polycarbodiimide is used as a crosslinker (0084). Haeberle does not expressly disclose the claimed diisocyanates. However, within the same field of endeavor Laufer discloses carbodiimization of 1,3,5-triisopropyl-2,4-diisocyanatobenzene (0037). At the time of filing it would have been obvious to a person of ordinary skill in the art to substitute the diisocyanates used in the process of Haeberle with the diisocyanate of Laufer to prepare polycarbodiimides to prepare products that have higher molecular weights, lower polydispersities, and higher compatibility with plastics when used as stabilizers (0076). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHAEL L LEONARD whose telephone number is (571)270-7450. The examiner can normally be reached M - F 7:00-4:00. 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, Joseph Del Sole can be reached at 571-272-1130. 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. /MICHAEL L LEONARD/ Primary Examiner, Art Unit 1763
Read full office action

Prosecution Timeline

Oct 20, 2023
Application Filed
Jan 28, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
64%
Grant Probability
72%
With Interview (+8.0%)
3y 3m
Median Time to Grant
Low
PTA Risk
Based on 1319 resolved cases by this examiner. Grant probability derived from career allow rate.

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