Prosecution Insights
Last updated: April 19, 2026
Application No. 18/663,443

ANTIFOULING AGENTS FOR PLASTIC-DERIVED SYNTHETIC FEEDSTOCKS

Non-Final OA §103
Filed
May 14, 2024
Examiner
GRAHAM, CHANTEL LORAN
Art Unit
1771
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Ecolab Usa Inc.
OA Round
1 (Non-Final)
72%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
83%
With Interview

Examiner Intelligence

Grants 72% — above average
72%
Career Allow Rate
771 granted / 1079 resolved
+6.5% vs TC avg
Moderate +12% lift
Without
With
+11.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
23 currently pending
Career history
1102
Total Applications
across all art units

Statute-Specific Performance

§101
0.9%
-39.1% vs TC avg
§103
66.4%
+26.4% vs TC avg
§102
5.6%
-34.4% vs TC avg
§112
15.8%
-24.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1079 resolved cases

Office Action

§103
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 . Summary This is the initial Office action based on application 18663443 filed 5/14/24. Claims 1-16 are pending and have been fully considered. Information Disclosure Statement IDS filed on 1/7/26, 12/31/25, 10/8/25, 9/5/25, 5/30/25, 4/3/25, 3/20/25, 11/5/24, and 8/13/24 have been considered by the examiner and copies of the Form PTO/SB/08 are attached to the office action. Drawings The Drawings filed on 5/14/24 are acknowledged and accepted by the examiner. Specification The Specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant's cooperation is requested in correcting any errors of which applicant may become aware in the specification. MPEP § 608.01 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 1-16 are rejected under 103(a) as being obvious over STARK ET AL. (US PG PUB 20110042268; 8/2010) in view of DERKS (WO2018104443; 6/2018) and as evidence by WU ET AL. (US PG PUB 20220396735; 10/2019) in their entirety. Hereby referred to as STARK, DERKS and WU. Regarding claims 1-16: STARK teaches in the abstract fouling of hot furnace surfaces in selected refinery processes can be stopped or at least mitigated using an antifouling agent. STARK teaches in para [0019] the antifouling agents useful with the disclosure may also include a dispersant. Suitable dispersants include, but are not necessarily limited to, copolymers of carboxylic anhydride and alpha-olefins, particularly alpha-olefins having from 2 to 70 carbon atoms. Suitable carboxylic anhydrides include aliphatic, cyclic and aromatic anhydrides, and may include, but are not necessarily limited to maleic anhydride, succinic anhydride, glutaric anhydride, tetrapropylene succinic anhydride, phthalic anhydride, trimellitic anhydride (oil soluble, non-basic), and mixtures thereof. Typical copolymers include reaction products between these anhydrides and alpha-olefins to produce oil-soluble products. Suitable alpha olefins include, but are not necessarily limited to ethylene, propylene, butylene (such as n-butylene and isobutylene), C2-C70 alpha olefins, polyisobutylene, and mixtures thereof. STARK teaches in para [0020] a typical copolymer is a reaction product between maleic anhydride and an alpha olefin to produce an oil soluble dispersant. A useful copolymer reaction product is formed by a 1:1 stoichiometric addition of maleic anhydride and polyisobutylene. The resulting product has a molecular weight range from about 5,000 to 10,000, in another non-limiting embodiment. STARK teaches in para [0026] the antifouling agents may be used in any amount that is effective to stop or mitigate fouling. The amount that is necessary will be, to some extent, dependent upon the properties of the hydrocarbon feed in which it will be used. In most cases, the hydrocarbon feed will be a very heavy hydrocarbon feed with a significant tendency to produce fouling. The amount of antifouling agent useful with method of the invention will range, as a weight percent of the hydrocarbon feed (furnace feed stream), of from about 50 ppm to about 10,000 ppm. In one embodiment, the range is from about 100 ppm to about 600 ppm. In another embodiment, the range is from about 250 ppm to about 500 ppm. STARK teaches in para [0025] the anti-fouling agent of the invention may be used with other refinery process as well. For example, the method of the invention may be used with vacuum distillation tower furnaces. The process of the invention may be used in any circumstance where a hydrocarbon feed is being fed through a furnace at temperatures that would induce fouling of the heat exchanging surfaces of the furnace. For the purposes of the invention, these temperatures are those from about 260 C. to about 870 C. Further, also for the purposes of the invention, the term "furnace feed stream" means not just feeds going into a furnace, but rather any circumstances wherein a hydrocarbon is brought into contact with a surface, especially the surface of a heat exchanger, at a temperature of from 260 C. to about 870 C. Although STARK does not explicitly teach that the hydrocarbon stream is plastic, it is within the scope of STARK as the reference discloses compounds that make up plastic as the feedstock; as evident by WU teachings in para [0232] recycled waste plastics can be isolated as one type of polymer stream or may be a stream of mixed recycled waste plastics. The plastics can be any organic synthetic polymer that is solid at 25° C. at 1 atm. The plastics can be thermosetting, thermoplastic, or elastomeric plastics. Examples of plastics include high density polyethylene and copolymers thereof, low density polyethylene and copolymers thereof, polypropylene and copolymers thereof, other polyolefins, polystyrene, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyesters including polyethylene terephthalate, copolyesters and terephthalate copolyesters (e.g. containing residues of TMCD, CHDM, propylene glycol, or NPG monomers), polyethylene terephthalate, polyamides, poly(methyl methacrylate), polytetrafluoroethylene, acrylobutadienestyrene (ABS), polyurethanes, cellulosics and derivates thereof such as cellulose acetate, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate; regenerated cellulosics such as viscose and rayons, epoxy, polyamides, phenolic resins, polyacetal, polycarbonates, polyphenylene-based alloys, polypropylene and copolymers thereof, polystyrene, styrenic compounds, vinyl based compounds, styrene acrylonitrile, thermoplastic elastomers, and urea based polymers and melamine containing polymers. Para [0277] the pyrolysis oil fed to a cracker furnace is a C5 to C 25 hydrocarbon stream containing at least 1 wt. %. Para [0055] such cracking can be conducted by a thermal cracker, or a thermal steam cracker, in a liquid fed furnace, or in a gas fed furnace, or in any cracking process. In addition, DERKS further teaches said limitations. DERKS teaches that the hydrocarbon steam cracker feed may comprise pyrolysis oil from plastic waste (pg 2 ln 18-19) DERKS teaches that the products from the steam cracker are cooled (pg 2 ln 26-27) DERKS teaches products stream is removed from the coil/reactor and cooled in a transfer line exchanger (TLE) from a temperature of about 600 ° C (pg 4 ln 14-15) DERKS teaches that the TLE is further cooled to about 40 ° C in a separate quench vessel (pg 4 ln 18-19) DERKS teaches that these contaminants may also be removed from the hydrocarbon steam cracker feed by contact with the solvent. The hydrocarbon steam cracker feed is pretreated by contacting the feed with a solvent. The feed may be contacted with the solvent in a vessel, in a conduit or in another means known to one of ordinary skill in the art for carrying out a solvent extraction step. (pg 2 ln 31-pg 3 ln 3) DERKS teaches that the pretreated feed is typically preheated. The feed can be heated using heat exchangers, a furnace or any other combination of heat transfer and/or heating devices (pg 3 ln 19-20) DERKS teaches that the cracking step is performed at elevated temperatures, preferably in the range of from 650 to 1000 °C (pg 3 ln 26-27) Therefore, before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to recognize STARK and DERKS processes for upgrading hydrocarbons to operate and function as the claimed invention, and the motivation to combine is that both STARK and DERKS are from the same endeavor wherein anti-fouling agent of the invention may be used with other refinery process as well. For example, the method of the invention may be used with vacuum distillation tower furnaces. The process of the invention may be used in any circumstance where a hydrocarbon feed is being fed through a furnace at temperatures that would induce fouling of the heat exchanging surfaces of the furnace. For the purposes of the invention, these temperatures are those from about 260 C. to about 870 C. Further, also for the purposes of the invention, the term "furnace feed stream" means not just feeds going into a furnace, but rather any circumstances wherein a hydrocarbon is brought into contact with a surface, especially the surface of a heat exchanger, at a temperature of from 260 C. to about 870 C, as taught by STARK. Therefore, from the teachings of the references it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art before the effective filing date, as evidenced by the references, especially in the absence of evidence to the contrary. Furthermore, "The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results." KSR Int'! Co. v. Teleflex Inc., 550 U.S. 398,416 (2007). "If a person of ordinary skill can implement a predictable variation, § 103 likely bars its patentability." Id. at 417. In addition, one of ordinary skilled in the art would recognize that adding duplicate / repeating process steps or recognizing additional instrumentation for analysis or additional analysis would not have been expected to confer any particular desirable property on the final product. Rather, the final product obtained according to the claim limitations would merely have been expected to have the same functional properties as the prior art product. “Products of identical chemical composition cannot have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical product, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). Also see in re Papesch, 315 F.2d 381, 391, 137 USPQ 43, 51 (CCPA 1963) (“From the standpoint of patent law, a compound and all its properties are inseparable.”). In conclusion, an intended result of a process being claimed does not impart patentability to the claims when the general conditions of a claim are disclosed in the prior art. Furthermore, it has been held that obviousness is not rebutted by merely recognizing additional advantages or latent properties present in the prior art process and composition. Further, the fact that applicant has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. Ex parte Obiaya, 227 USPQ 58, 60 (Bd.Pat. App. & Inter. 1985). Therefore, it would have been obvious to the person having ordinary skill in the art to have selected appropriate conditions, as guided by the prior art, in order to obtain the desired products. It is not seen where such selections would result in any new or unexpected results. Please see MPEP 2144.05, II: noting obviousness within prior art conditions or through routine experimentation. Again, WU is considered a teaching reference, not a modifying reference. See MPEP 2112. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHANTEL GRAHAM whose telephone number is (571)270-5563. The examiner can normally be reached on M-TH 9:00 am - 7:00 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, Prem Singh can be reached on 571-272-6381. 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. /CHANTEL L GRAHAM/ Examiner, Art Unit 1771 /ELLEN M MCAVOY/Primary Examiner, Art Unit 1771
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Prosecution Timeline

May 14, 2024
Application Filed
Jan 24, 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
72%
Grant Probability
83%
With Interview (+11.9%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 1079 resolved cases by this examiner. Grant probability derived from career allow rate.

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