Prosecution Insights
Last updated: April 19, 2026
Application No. 18/331,731

ONE-COMPONENT SYSTEM COMPRISING BLOCKED POLYURETHANE PREPOLYMERS

Non-Final OA §101§102§103§112
Filed
Jun 08, 2023
Examiner
STONEHOCKER, VIRGINIA LEE
Art Unit
1766
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Evonik Operations GmbH
OA Round
1 (Non-Final)
86%
Grant Probability
Favorable
1-2
OA Rounds
3y 3m
To Grant
99%
With Interview

Examiner Intelligence

Grants 86% — above average
86%
Career Allow Rate
25 granted / 29 resolved
+21.2% vs TC avg
Strong +17% interview lift
Without
With
+17.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
40 currently pending
Career history
69
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
42.5%
+2.5% vs TC avg
§102
26.5%
-13.5% vs TC avg
§112
26.8%
-13.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 29 resolved cases

Office Action

§101 §102 §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 . Priority Acknowledgment is made of applicant's claim for foreign priority based on an application filed in Europe on 6/08/2022. It is noted, however, that applicant has not filed a certified copy of the EP22177717 application as required by 37 CFR 1.55. Specification Applicant is reminded of the proper language and format for an abstract of the disclosure. The abstract should be in narrative form and generally limited to a single paragraph on a separate sheet within the range of 50 to 150 words in length. The abstract should describe the disclosure sufficiently to assist readers in deciding whether there is a need for consulting the full patent text for details. The language should be clear and concise and should not repeat information given in the title. It should avoid using phrases which can be implied, such as, “The disclosure concerns,” “The disclosure defined by this invention,” “The disclosure describes,” etc. In addition, the form and legal phraseology often used in patent claims, such as “means” and “said,” should be avoided. The abstract is objected to because it includes the implied phrase “The present invention relates to” in line 3. Claim Rejections - 35 USC § 101/112 35 U.S.C. 101 reads as follows: Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title. 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 15 is rejected under 35 U.S.C. 101 because the claimed recitation of a use, without setting forth any steps involved in the process, results in an improper definition of a process, i.e., results in a claim which is not a proper process claim under 35 U.S.C. 101. See, for example, Ex parte Dunki, 153 USPQ 678 (Bd.App. 1967) and Clinical Products, Ltd. v. Brenner, 255 F. Supp. 131, 149 USPQ 475 (D.D.C. 1966). The claimed invention which recited ‘use’ is directed to non-statutory subject matter. Claims 15 is rejected under 35 U.S.C. 112, second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which applicant regards as the invention. A claim is indefinite where it merely recites a use without any active, positive steps delimiting how this use is actually practiced. Claim Rejections - 35 USC § 102 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claims 1-2, 4, 6-7, 10-14, 16-17 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kelso et al, US4439593. Regarding claims 1-2, 4, 6, 10-14, 16, Kelso teaches a one-component system comprising the polyurethane composition in example 5, Col. 13 line 25, where a prepolymer is made by reacting polypropylene glycol with a molecular weight of 1000 g/mol, diethylene glycol (reads on claims 1, 6, 10, 11) and trimethylolpropane with a mixture of 2,4- and 2,6-diisocyanatotoluene (reads on claims 1, 2, and 4). The remaining isocyanate groups are blocked with diethyl malonate (reads on claims 12-13). Then this mixture is mixed with bis-(4-amino-3-methyl-cyclohexyl)-methane, which reads on the diamine of claim 1, and is another name for the claimed diamine 4,4’-methylenebis(2-methylcyclohexanamine) of claim 14. Kelso teaches the prepolymer process in Col. 8 lines 9-18, and teaches the diethyl malonate is for blocking the isocyanate groups, Col. 3 lines 45-46. The process of making the polyurethane in example 5 anticipates the process of claim 16. Kelso teaches making the prepolymer based on the polypropylene glycol with a molecular weight of 1000 g/mol and the diisocyanate, where the unreacted NCO groups are blocked with diethyl malonate, and then mixing the prepolymer with a diamine, Col. 13 lines 25-49. Regarding claim 7, Kelso teaches in example 5 that the prepolymer comprises 14.1 g DEG and 132.5 g PPG which totals 146.6 g. Therefore the PPG, which is the first diol, is 90.4 wt.% based on the total mass of the diols. Regarding claim 17, Kelso teaches a process wherein the polyurethane composition is coated onto a substrate (reads on carrier) and thermally cured, Col. 10 lines 42-55. Kelso does not state the process is for producing an artificial leatherbut insofar as Kelso discloses the application of anticipatory polyurethanes to a substrate, they will inherently be leather-like based on applicant’s meaning of artificial leather on page 1 lines 15-16 of the instant specification. Furthermore, Kelso teaches the coating is suitable for a variety of substrates, Col 10 line 52, which includes flexible substrates for leather-like material. 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. 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. Claims 3, 5, and 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Kelso et al, US4439593. Regarding claims 3 and 5, Kelso teaches the invention according to claim 1, explained above. Kelso does not use isophorone diisocyanate (IPDI) in example 5, but it is taught in the broader disclosure as 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane, Col. 2 line 51-52, which is a cycloaliphatic diisocyanate. It is prima facie obvious to substitute one material for another to obtain predictable results when the materials fulfill the same use and function. “[I]t is prima facie obvious to substitute equivalents, motivated by the reasonable expectation that the respective species will behave in a comparable manner or give comparable results in comparable circumstances.” In re Ruff 118 USPQ 343; In re Jezel 158 USPQ 99; “the express suggestion to substitute one equivalent for another need not be present to render the substitution obvious.” In re Font, 213 USPQ 532. Therefore, it would be obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to substitute the TDI in Kelso’s example 5 with IPDI to obtain another permutation of a blocked isocyanate stable under ambient conditions but capable of being de-blocked at more moderate temperatures (column 1, lines 43-47). Regarding claims 8-9, Kelso teaches the invention according to claim 1, as explained above. Kelso does not use polytetramethylene ether glycol in example 5, but it is taught in the broader disclosure. Where Kelso describes the high molecular weight polyether polyols, it is disclosed that they can be made by the known reactions using starting compounds such as 1,4-butanediol and tetrahydrofuran, Col. 5 lines 31-36, both of which are known to produce PTMEG, also known as polyTHF, and therefore renders obvious the use of PTMEG for the polyurethane composition. Furthermore, Kelso teaches that the molecular weight for the polyols is 400-10,000 g/mol, which encompasses the claimed range of claim 9. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) Alternatively, Kelso teaches in example 5 that the polypropylene glycol has a molecular weight of 1,000 g/mol, Col. 13, which falls within the claimed range and it is obvious to substitute one material for another to obtain predictable results when the materials provide the same use and function. Therefore it would be obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to substitute the PPG with a molecular weight of 1,000 g/mol in Kelso’s example 5 with a PTMEG that also has a molecular weight of 1,000 g/mol to obtain another permutation of a blocked isocyanate stable under ambient conditions but capable of being de-blocked at more moderate temperatures. Claims 1-6, 8, 10-18 are rejected under 35 U.S.C. 103 as being unpatentable over Irnich et al, US20190017221. Regarding claims 1-5, and 12-14, Irnich teaches a coating system comprising a blocked polyisocyanate prepolymer, the prepolymer is prepared from a polyol and an isocyanate, the isocyanate groups are blocked with dialkyl malonate, and further comprises a polyamine, abstract. Irnich teaches the suitable polyols have a molecular weight, Mn, of 2,000-8,000 g/mol, ¶[0014], and preferably comprises at least one polyether polyol ¶[0016,0026]. The molecular weight range overlaps with the range of claim 1. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). The isocyanate(s) used for the prepolymers include HDI, IPDI, XDI, TMXDI, and TDI, which reads on the diisocyanate(s) of claims 1-5, ¶¶[0029-0030]. The dialkyl malonate for blocking the isocyanate groups is preferably diethyl malonate, ¶[0043], which reads on the malonic ester of claims 1, 12 and 13. The prepolymer is reacted with a polyamine comprising at least one diamine, ¶[0049]. Irnich further lists isophoronediamine and 4,4’-diaminodicyclohexylmethane, ¶[0049] which reads on the diamines of claims 1 and 14. Irnich does not state that the system is a one-component system and describes keeping the prepolymer with block NCO groups separate from the diamine until use, but then states that after mixing, the composition is workable for at least 4 hours, ¶¶[0064-0066], which during this time, the composition would then be considered one-component. Regarding claims 6, 10-11, Irnich teaches the prepolymer can further comprise low molecular weight polyols, ¶¶[0034-0035]. These low molecular weight polyols can be selected as short chain diols with 2-10 carbons, such as ethylene glycol and diethylene glycol, among others, ¶[0035], which reads on claims 6, and 10-11. Regarding claim 8, Irnich teaches the high molecular weight polyether polyols are made by known methods and can be made from 1,4-butanediol and tetrahydrofuran ¶[0018], both of which are known to produce PTMEG, also known as polyTHF, and therefore renders obvious the use of PTMEG for the polyurethane composition. Regarding claims 15, 17-18, Irnich teaches using the composition as a coating for substrates such as leather, plastics, ¶[0072], and other textile materials, ¶[0073], and for the production of artificial leather articles, ¶[0079], which reads on claims 15 and 18. The coating can be applied as a topcoat to textiles, ¶[0076], which would read on the carrier of claim 17. The coating can also be applied to other substrates (carriers) such as metal, glass, PVC, polyurethanes, ¶[0072, 0079], the coatings are heat cured after application, ¶[0069, 0109]. Regarding claim 16, Irnich teaches a process of making the polyurethane composition comprising making a prepolymer by mixing the polyol(s) with the diisocyanates, then the free NCO groups are reacted with diethyl malonate to block them, ¶¶[0101-0102]. Then, the prepolymer is mixed with a diamine, ¶[0109]. Irnich teaches the polyols preferably comprise polyether polyols, ¶[0016,0026], and teaches the suitable polyols have a molecular weight, Mn, of 2,000-8,000 g/mol, ¶[0014], which encompasses the claimed range. Irnich does not state that the system is a one-component system and describes keeping the prepolymer with block NCO groups separate from the diamine until use, but then states that after mixing, the composition is workable for at least 4 hours, ¶¶[0064-0066], which during this time, the composition would then be considered one-component. Additionally, the process of Irnich mirrors the same process applicant uses in the examples in that applicant only mixes the diamine to the prepolymer just before application. Therefore, the system of Irnich reads on the one-component system of claims 1 and 16. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to VIRGINIA L STONEHOCKER whose telephone number is (571)272-3431. The examiner can normally be reached Monday-Friday 7:00AM-4:00PM EST. 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, Randy Gulakowski can be reached at 571-272-1302. 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. /V.L.S./Examiner, Art Unit 1766 /MARC S ZIMMER/Primary Patent Examiner, Art Unit 1765
Read full office action

Prosecution Timeline

Jun 08, 2023
Application Filed
Feb 11, 2026
Non-Final Rejection — §101, §102, §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
86%
Grant Probability
99%
With Interview (+17.4%)
3y 3m
Median Time to Grant
Low
PTA Risk
Based on 29 resolved cases by this examiner. Grant probability derived from career allow rate.

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