Prosecution Insights
Last updated: April 19, 2026
Application No. 18/151,212

MANUFACTURING METHOD FOR HOLLOW FINE PARTICLES, AND HOLLOW FINE PARTICLES

Final Rejection §102§103§DP
Filed
Jan 06, 2023
Examiner
KRYLOVA, IRINA
Art Unit
1764
Tech Center
1700 — Chemical & Materials Engineering
Assignee
National University Corporation Kobe University
OA Round
2 (Final)
36%
Grant Probability
At Risk
3-4
OA Rounds
4y 4m
To Grant
84%
With Interview

Examiner Intelligence

Grants only 36% of cases
36%
Career Allow Rate
274 granted / 753 resolved
-28.6% vs TC avg
Strong +48% interview lift
Without
With
+48.1%
Interview Lift
resolved cases with interview
Typical timeline
4y 4m
Avg Prosecution
68 currently pending
Career history
821
Total Applications
across all art units

Statute-Specific Performance

§103
50.6%
+10.6% vs TC avg
§102
11.9%
-28.1% vs TC avg
§112
19.4%
-20.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 753 resolved cases

Office Action

§102 §103 §DP
DETAILED ACTION Notice of Pre-AIA or AIA Status 1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Response to Amendment 2. The amendment filed by Applicant on November 19, 2025 has been fully considered. The amendment to instant claim 1 is acknowledged. Specifically, claim 1 has been amended to recite the hollow fine particulate having particle size of 2 micro or higher. This limitation was not previously presented and was taken from instant specification (see [0096] of instant specification). In light of the amendment filed by Applicant, all previous rejections are withdrawn. The new grounds of rejections necessitated by Applicant’s amendment are set forth below. Thus, the following action is properly made final. 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. 3. Claims 1-2, 7-12 are rejected under 35 U.S.C. 103 as being unpatentable over Minaki (JP 2008/184473, based on machine translation). 4. Minaki discloses a method for producing hollow resin particles comprising: 1) dissolving a precursor of a resin (A), specifically fluororesin, and a phase separation promoting agent (C) in a volatile solvent (B) to prepare a solution (E); 2) suspending said solution (E) in a solvent (D); 3) polymerizing the precursor of the resin (A) in the presence of an initiator (Abstract, claim 1, also as to instant claim 11), 4) removing the liquid after washing the particles ([0045], as to instant claim 12), wherein the produced hollow particles are having an average size of 20-250 micron ([0043]). 5. The precursor of the resin (A) includes a fluororesin, specifically tetrafluorostyrene ([0020], as to instant claim 2). Since molar mass of tetrafluorostyrene is 176 and the molar mass of fluorine is 19, therefore, the fluorine content in said tetrafluorostyrene will be 43%mass (as to instant claim 7). 6. The precursor monomers also include cyclopentadiene and divinylbenzene ([0013], which monomers are cross-linkable monomers (as to instant claim 8). 7. The solvent (B) comprises pentane or hexane or toluene ([0028], as to instant claim 9); the solvent (D) comprises water ([0029], [0032], as to instant claim 1). The specific combination of (D), (A) and (B) include a combination of water, hexane and hydrophobic precursor ([0032]). 8. Based on the teachings of Minaki, it would have been obvious to a one of ordinary skill in the art to choose and use tetrafluorostyrene and a cross-linkable divinylbenzene as the comonomers for preparing the resin (A), hexane as the solvent (B) and water as the solvent (D) to prepare the hollow particles, since it would have been obvious to choose material based on its suitability. Case law holds that the selection of a known material based on its suitability for its intended use supports prima facie obviousness. Sinclair & Carroll Co vs. Interchemical Corp., 325 US 327, 65 USPQ 297 (1045). 9. As to instant claim 11, given the initiator is required for polymerization, but may cause premature polymerization if added before dispersing step, it would have been obvious to a one of ordinary skill in the art to add the initiator after the dispersion is made, so to prevent premature polymerization as well. Ex parte Rubin, 128 USPQ 440 (Bd. App. 1959) (Prior art reference disclosing a process of making a laminated sheet wherein a base sheet is first coated with a metallic film and thereafter impregnated with a thermosetting material was held to render prima facie obvious claims directed to a process of making a laminated sheet by reversing the order of the prior art process steps.). See also In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946) (selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results). 10. The specifically exemplified polymerization temperature was 70-250⁰C (Table 1). Since polymerization is conducted at a temperature of more than 50⁰C, therefore, it would have been obvious to a one of ordinary skill in the art to suspend the solution (E) at any temperature below 50⁰C, such as room temperature, followed by heating said dispersion to a temperature higher than 50⁰C, i.e. to 70-250⁰C to conduct polymerization as well (as to instant claim 10). 11. Claims 1-2, 4-12 are rejected under 35 U.S.C. 103 as being unpatentable over Minaki (JP 2008/184473, based on machine translation) in view of Kiyohara et al (JP 2016-068037, based on machine translation). 12. The discussion with respect to Minaki (JP 2008/184473, based on machine translation) set forth in paragraphs 3-10 above, is incorporated here by reference. 13. Minaki does not recite the phase separation promoter being aromatic vinyl polymer or polyalkyl (meth)acrylate. 14. However, Kiyohara et al discloses a method for producing hollow resin particles comprising: 1) dispersing a mixed solution containing: a) a monomer mixture of a polyfunctional monomer having two or more ethylenically unsaturated groups ([0012]) and a monofunctional monomer ([0016]); b) a non-reactive solvent, specifically toluene or ethyl acetate ([0026], as to instant claim 9), and c) a non-crosslinkable polymer, specifically polystyrene or polymethyl methacrylate (PMMA) ([0019]), acting as a phase separation agent ([0021], as to instant claims 5, 6), in an aqueous solution ([0026]) and 2) heating the dispersion at a temperature of 70⁰C and polymerizing the monomer mixture ([0033], [0051], as to instant claim 10); 3) isolating the hollow particles and removing the non-reactive organic solvent ([0042], as to instant claim 12). The mixed solution may contain a polymerization initiator such as azobisisobutylenitrile ([0036], as to instant claim 11). 15. Since a) the phase separation agent, specifically polystyrene or PMMA, is the same as that claimed (instant claim 6) and disclosed in instant invention, b) the non-reactive solvent, specifically toluene or ethyl acetate, is the same as that disclosed in instant invention ([0069] of instant specification), therefore, the relationship cited in instant claim 4 will intrinsically and necessarily be fulfilled (as to instant claim 4). Since PTO cannot conduct experiments the proof of burden is shifted to the applicants to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977). See MPEP § 2112.01. 16. As to instant claims 10-11, given the mixed solution is cited as being polymerized at 70⁰C, therefore, it would have been obvious to a one of ordinary skill in the art, to either i) conduct both the steps of dispersing the mixed solution into water and polymerizing at 70⁰C, or ii) disperse the mixed solution into water at ambient temperature, and further heat said dispersion to 70⁰C to conduct polymerization, as well, since selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results. Ex parte Rubin, 128 USPQ 440 (Bd. App. 1959) (Prior art reference disclosing a process of making a laminated sheet wherein a base sheet is first coated with a metallic film and thereafter impregnated with a thermosetting material was held to render prima facie obvious claims directed to a process of making a laminated sheet by reversing the order of the prior art process steps.). See also In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946) (selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results). 17. Since both Kiyohara et al and Minaki are related to methods for making hollow resin particles in the presence of a phase separation promoter, and thus belong to the same field of endeavor, wherein Kiyohara et al teaches that phase separation promoters for such methods include polystyrene or polymethyl methacrylate (PMMA), therefore, it would have been obvious to a one of ordinary skill in the art to combine the teachings of Minaki and Kiyohara et al, and to include, or obvious to try to use, at least partially, polystyrene or polymethyl methacrylate as the phase separation promoter in the method of Minaki, either in addition to or as at least partial substitution of the phase separation promoter used by Minaki as well, since it would have been obvious to choose material based on its suitability, thereby arriving at the present invention. Case law holds that the selection of a known material based on its suitability for its intended use supports prima facie obviousness. Sinclair & Carroll Co vs. Interchemical Corp., 325 US 327, 65 USPQ 297 (1045). Case law holds that the mere substitution of an equivalent (something equal in value or meaning, as taught by analogous prior art) is not an act of invention; where equivalency is known to the prior art, the substitution of one equivalent for another is not patentable. See In re Ruff 118 USPQ 343 (CCPA 1958). 18. Claims 1-3, 7-12 are rejected under 35 U.S.C. 103 as being unpatentable over Minaki (JP 2008/184473, based on machine translation) in view of Tanaka et al (WO 2020/226010, submitted in IDS on 01/06/23). It is noted that while the rejection is made over WO 2020/226010 for date purposes, in order to elucidate the examiner's position the corresponding US equivalent viz. US 2022/0056178 is relied upon. All citations to paragraph numbers, etc., below refer to US 2022/0056178. 19. The discussion with respect to Minaki (JP 2008/184473, based on machine translation) set forth in paragraphs 3-10 above, is incorporated here by reference. 20. Minaki does not recite the precursor for the fluororesin being fluorinated alkyl (meth)acrylates. 21. However, Tanaka et al discloses a method for producing hollow fine particles comprising: 1) dispersing a solution containing: a fluorine-containing monomer, a multifunctional monomer ([0026]), an oil-soluble initiator, a non-polymerizable solvent, including toluene or ethyl acetate ([0036]), in water and polymerizing the dispersion (Abstract), wherein the fluorine-containing monomers includes a fluoroalkyl methacrylate such as ([0019]-[0024], as to instant claims 1-3): PNG media_image1.png 53 351 media_image1.png Greyscale Given the fluorinated acrylic monomer of Tanaka et al is the same as claimed and exemplified in instant invention, therefore, the fluorinated acrylic monomer of Tanaka et al will intrinsically and necessarily have a fluorine content of at least 30% by mass (as to instant claim 7). Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). MPEP 2112.01(I). Since PTO cannot conduct experiments the proof of burden is shifted to the applicants to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977). See MPEP § 2112.01. 22. Since both Minaki and Tanaka et al are related to processes for making hollow fine particles by dispersing monofunctional monomers, polyfunctional monomers, toluene solvent and oil-soluble initiator into water, followed by polymerizing the monomers, and thereby belong to the same field of endeavor, wherein Tanaka et al specifies the used monofunctional monomers being fluoroalkyl methacrylates, therefore, it would have been obvious to a one of ordinary skill in the art to combine the teachings of Tanaka et al and Minaki, and to include, at least partially, fluoroalkyl methacrylate monomers of Tanaka et al as the monofunctional alkyl methacrylate monomers component in the process of Minaki, since it would have been obvious to choose material based on its suitability, depending on the specific end-use of said hollow particles, especially since Tanaka et al recites said fluoropolymer containing hollow particles being used in various electric material applications ([0140] of Tanaka et al). Case law holds that the selection of a known material based on its suitability for its intended use supports prima facie obviousness. Sinclair & Carroll Co vs. Interchemical Corp., 325 US 327, 65 USPQ 297 (1045). Case law holds that the mere substitution of an equivalent (something equal in value or meaning, as taught by analogous prior art) is not an act of invention; where equivalency is known to the prior art, the substitution of one equivalent for another is not patentable. See In re Ruff 118 USPQ 343 (CCPA 1958). The key to supporting any rejection under 35 USC 103 is the clear articulation of the reason(s) why the claimed invention would have been obvious. The Supreme Court in KSR noted that the analysis supporting a rejection under 35 USC 103 should be made explicit. The Court quoting In re Kahn, 441 F.3d 977, 988, 78 USPQ2d 1329, 1336 (Fed. Cir. 2006), stated that "‘[R]ejections on obviousness cannot be sustained by mere conclusory statements; instead, there must be some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness.’" KSR, 550 U.S. at 418, 82 USPQ2d at 1396. Exemplary rationales that may support a conclusion of obviousness include: PNG media_image2.png 18 19 media_image2.png Greyscale (A) Combining prior art elements according to known methods to yield predictable results; PNG media_image2.png 18 19 media_image2.png Greyscale (B) Simple substitution of one known element for another to obtain predictable results; PNG media_image2.png 18 19 media_image2.png Greyscale (C) Use of known technique to improve similar devices (methods, or products) in the same way; PNG media_image2.png 18 19 media_image2.png Greyscale (D) Applying a known technique to a known device (method, or product) ready for improvement to yield predictable results; PNG media_image2.png 18 19 media_image2.png Greyscale (E) "Obvious to try" – choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success; PNG media_image2.png 18 19 media_image2.png Greyscale (F) Known work in one field of endeavor may prompt variations of it for use in either the same field or a different one based on design incentives or other market forces if the variations are predictable to one of ordinary skill in the art; (G) Some teaching, suggestion, or motivation in the prior art that would have led one of ordinary skill to modify the prior art reference or to combine prior art reference teachings to arrive at the claimed invention. MPEP 2141 23. Claims 1-3, 7-12 are rejected under 35 U.S.C. 103 as being unpatentable over Minaki (JP 2008/184473, based on machine translation) in view of Lee et al (WO 2015/138163, submitted in IDS on 03/04/25). 24. The discussion with respect to Minaki (JP 2008/184473, based on machine translation) set forth in paragraphs 3-10 above, is incorporated here by reference. 25. Minaki does not recite the precursor for the fluororesin being fluorinated alkyl (meth)acrylates. 26. However, Lee et al discloses a method for producing hollow particles comprising: providing a mixture of water, a non-reactant solvent, at least one acrylic monomer including ethyl glycol dimethacrylate (p. 4, lines 20-22, i.e. polyfunctional methacrylate), at least one fluorinated acrylic monomer, an initiator, followed by shearing the components to form a mini-emulsion and further heating to at least 50⁰C to form said hollow particles (Abstract, p. 2, lines 5-20), wherein the fluorinated acrylic monomers are having the formula PNG media_image3.png 31 224 media_image3.png Greyscale Wherein Rf is a linear or branched perfluoroalkyl group containing 1-10 carbon atoms and A is O (p. 4, lines 25-30, as to instant claims 1-3). 27. Given the fluorinated acrylic monomer of Lee et al is the same as claimed in instant invention, therefore, the fluorinated acrylic monomer of Lee et al will intrinsically and necessarily have a fluorine content of at least 30% by mass (as to instant claim 7). Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). MPEP 2112.01(I). Since PTO cannot conduct experiments the proof of burden is shifted to the applicants to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977). See MPEP § 2112.01. 28. Since both Minaki and Lee et al are related to processes for making hollow particles by dispersing monofunctional monomers, polyfunctional monomers, an organic solvent and oil-soluble initiator into water, followed by polymerizing, and thereby belong to the same field of endeavor, wherein Lee et al specifies the used monofunctional monomers being fluoroalkyl methacrylates, therefore, it would have been obvious to a one of ordinary skill in the art to combine the teachings of Lee et al and Minaki, and to include, or obvious to try to include, at least partially, fluoroalkyl (meth)acrylate monomers of Lee et al as the monofunctional monomers in the process of Minaki, since it would have been obvious to choose material based on its suitability, depending on the specific end-use of said hollow particles, especially since Lee et al teaches such fluoropolymer-based hollow particles being used in coating, molding applications and as drug delivery systems (p. 3, lines 20-25 of Lee et al). Case law holds that the selection of a known material based on its suitability for its intended use supports prima facie obviousness. Sinclair & Carroll Co vs. Interchemical Corp., 325 US 327, 65 USPQ 297 (1045). Case law holds that the mere substitution of an equivalent (something equal in value or meaning, as taught by analogous prior art) is not an act of invention; where equivalency is known to the prior art, the substitution of one equivalent for another is not patentable. See In re Ruff 118 USPQ 343 (CCPA 1958). The key to supporting any rejection under 35 USC 103 is the clear articulation of the reason(s) why the claimed invention would have been obvious. The Supreme Court in KSR noted that the analysis supporting a rejection under 35 USC 103 should be made explicit. The Court quoting In re Kahn, 441 F.3d 977, 988, 78 USPQ2d 1329, 1336 (Fed. Cir. 2006), stated that "‘[R]ejections on obviousness cannot be sustained by mere conclusory statements; instead, there must be some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness.’" KSR, 550 U.S. at 418, 82 USPQ2d at 1396. Exemplary rationales that may support a conclusion of obviousness include: PNG media_image2.png 18 19 media_image2.png Greyscale (A) Combining prior art elements according to known methods to yield predictable results; PNG media_image2.png 18 19 media_image2.png Greyscale (B) Simple substitution of one known element for another to obtain predictable results; PNG media_image2.png 18 19 media_image2.png Greyscale (C) Use of known technique to improve similar devices (methods, or products) in the same way; PNG media_image2.png 18 19 media_image2.png Greyscale (D) Applying a known technique to a known device (method, or product) ready for improvement to yield predictable results; PNG media_image2.png 18 19 media_image2.png Greyscale (E) "Obvious to try" – choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success; PNG media_image2.png 18 19 media_image2.png Greyscale (F) Known work in one field of endeavor may prompt variations of it for use in either the same field or a different one based on design incentives or other market forces if the variations are predictable to one of ordinary skill in the art; (G) Some teaching, suggestion, or motivation in the prior art that would have led one of ordinary skill to modify the prior art reference or to combine prior art reference teachings to arrive at the claimed invention. MPEP 2141 Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory obviousness-type double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); and In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on a nonstatutory double patenting ground provided the conflicting application or patent either is shown to be commonly owned with this application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. Effective January 1, 1994, a registered attorney or agent of record may sign a terminal disclaimer. A terminal disclaimer signed by the assignee must fully comply with 37 CFR 3.73(b). 29. Claims 1-12 are provisionally rejected on the ground of nonstatutory obviousness-type double patenting as being unpatentable over claims 1-12 of a copending application 18/619,369 (published US 2024/0269638) in view of Kiyohara et al (JP 2016-068037, based on machine translation) and Minaki (JP 2008/184473, based on machine translation). Although the conflicting claims are not identical, they are not patentably distinct from each other because of the following reasons. 30. The copending application 18/619,369 claims a method for producing a hollow fine particulate comprising: a step A of dispersing a solution containing a fluorinated monomer and a non-polymerizable solvent into water to provide a dispersion; a step B of polymerizing the fluorinated monomer to provide a phase-separated fine particulate containing a fluorine-containing resin, the phase-separated fine particulate including a monolayer structured shell and a core including the non-polymerizable solvent therein; and a step C of removing the non-polymerizable solvent in the phase-separated fine particulate to provide a hollow fine particulate having an average particle size of 1.0 μm or greater. In the step A, the dispersion contains at least one particulate dispersion stabilizer selected from the group consisting of the following (A), (B) and (C); (A) at least one high molecular weight dispersion stabilizers selected from the group consisting of polyvinyl alcohol, methyl cellulose, ethyl cellulose, polyacrylic acid, polymethacrylic acid, polyacrylimide, polyethylene oxide, polyvinyl pyrrolidone, and a poly(hydroxystearic acid-g-methyl methacrylate-co-methacrylic acid) copolymer; (B) a fluoropolymer (α) of at least one monomer (α) selected from the formula (1a): CF2=CF-O-Rf-A and the formula (2a): CH2=CF-CF2-O-Rf-A wherein Rf is a C1-C40 fluorine-containing alkylene group, a C2-C100 fluorine-containing alkylene group containing an ether bond, or a C2-C100 fluorine-containing alkylene group containing a keto group; A is -COOM, -SO3M, -OSO3M, or -C(CF3)2OM (wherein M is H, a metal atom, NR74, an optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium; and R7 is H or an organic group; (C) an anionic fluorine-containing surfactant represented by the formula (1): Rf§(X-)j(M+)j formula (1) wherein Rf§ is a C1-C30 (per)fluoroalkyl chain or a (per)fluoro(poly)oxyalkylene chain; X- is-COO-, -PO3-, or -SO3-; M+ is selected from H+, NH4+, and an alkali metal ion; and j may be 1 or 2. The fluorinated monomer is a high-fluorine-conversion monomer having a fluorine conversion FC of 70% or higher, the fluorine conversion FC being calculated by the following formula: Fluorine conversion FC (%) = (the number of C-F bonds in a monomer molecule)/{(the number of C-F bonds in a monomer molecule) + (the number of C-H bonds in a monomer molecule)} × 100, and wherein the high-fluorine-conversion monomer is a high-fluorine-conversion cyclic olefin or a monomer represented by the following formula (b), (d), or (e): CF2=CF-Q1-CF=CF2 (b) wherein Q1 is a C1-C5 linear or optionally branched perfluoroalkylene group optionally containing an ether bond; CR20R21=CR22R23 (d) wherein R20 to R23 are each independently a fluorine atom, a C1-C5 perfluoroalkyl group, or a C1-C5 perfluoroalkoxy group; or PNG media_image4.png 105 721 media_image4.png Greyscale wherein R30 and R31 are each independently H or F; R32 is H, F, or CF3; R33 is H, F, or CF3; h1 to h3 are each independently 0 or 1; Z is H, F, Cl, -OH, CH2OH, -COOH, -COF, a carboxylic acid derivative, -SO3H, a sulfonic acid derivative, an epoxy group, or a cyano group; and Rf is a C1-C20 linear or branched fluorine-containing alkylene group or a C2-C100 linear or branched fluorine-containing alkylene group containing an ether bond. The solution further contains a crosslinkable monomer, wherein the crosslinkable monomer is a multifunctional monomer containing two or more polymerizable reactive groups. 31. Though the application 18/619,369 does not recite the solution of step A comprising a phase separation promoter such as polystyrene, the polymerization taking place at a temperature of above 50⁰C, and the particle size being more than 2 micron, 1) Kiyohara et al discloses a method for producing hollow resin particles comprising: i) dispersing a mixed solution containing: a) a monomer mixture of: a1) a polyfunctional monomer having two or more ethylenically unsaturated groups ([0012], as to instant claim 8) and a2) a monofunctional monomer including esters of (meth)acrylic acid ([0015]- [0016]); b) a non-reactive solvent, specifically toluene or ethyl acetate ([0026], as to instant claim 9), and c) a non-crosslinkable polymer, specifically polystyrene or polymethyl methacrylate (PMMA) ([0019]), acting as a phase separation agent ([0021], as to instant claims 5, 6), in an aqueous solution ([0026]) and ii) heating the dispersion at a temperature of 70⁰C and polymerizing the monomer mixture ([0033], [0051], as to instant claim 10); iii) isolating the hollow particles and removing the non-reactive organic solvent ([0042], as to instant claim 12). The mixed solution may contain a polymerization initiator such as azobisisobutylenitrile ([0036], as to instant claim 11). Kiyohara et al teaches that phase separation agent promotes migration to the interface when the monomer components are polymerized to form a polymer and adsorbed at the interface with water ([0021]). Since a) the phase separation agent, specifically polystyrene or PMMA, is the same as that claimed (instant claim 6) and disclosed in instant invention, b) the non-reactive solvent, specifically toluene or ethyl acetate, is the same as that disclosed in instant invention ([0069] of instant specification), therefore, the relationship cited in instant claim 4 will intrinsically and necessarily be fulfilled (as to instant claim 4). Since PTO cannot conduct experiments the proof of burden is shifted to the applicants to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977). See MPEP § 2112.01. As to instant claims 10-11, given the mixed solution is cited as being polymerized at 70⁰C, therefore, it would have been obvious to a one of ordinary skill in the art, to either i) conduct both the steps of dispersing the mixed solution into water and polymerizing at 70⁰C, or ii) disperse the mixed solution into water at ambient temperature, and further heat said dispersion to 70⁰C to conduct polymerization, as well, since selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results. Further, given a) the mixed solution may contain the initiator, but is not required and b) said initiator is required for polymerization, it would have been further obvious to a one of ordinary skill in the art to add the initiator after the dispersion is made, so to prevent premature polymerization as well. Ex parte Rubin, 128 USPQ 440 (Bd. App. 1959) (Prior art reference disclosing a process of making a laminated sheet wherein a base sheet is first coated with a metallic film and thereafter impregnated with a thermosetting material was held to render prima facie obvious claims directed to a process of making a laminated sheet by reversing the order of the prior art process steps.). See also In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946) (selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results). 2) Minaki discloses a method for producing hollow resin particles comprising: i) dissolving a precursor of a resin (A), specifically fluororesin, and a phase separation promoting agent (C) in a volatile solvent (B) to prepare a solution (E); further dissolving a peroxide or pedox initiator into the solution (E) ([0036], as to instant claim 11); ii) suspending said solution (E) in a solvent (D); iii polymerizing the precursor of the resin (A) in the presence of an initiator (Abstract, claim 1), iv) removing the liquid after washing the particles ([0045], as to instant claim 12), wherein the produced hollow particles are having an average size of 20-250 micron ([0043]). 32. Since the application 18/619,369, Minaki and Kiyohara et al are related to methods for forming hollow fine particles by preparing a solution of mono- and poly-functional monomers, solvent, dispersing the solution into water, followed by polymerizing said monomers, and thereby belong to the same field of endeavor, wherein i) Kiyohara et al teaches the solution further comprising a phase separation agent, which phase separation agent promotes migration to the interface when the monomer components are polymerized to form a polymer and adsorbed at the interface with water ([0021]), and ii) Minaki discloses such method leading to producing hollow resin particles having size of 20 micron or more, therefore, it would have been obvious to a one of ordinary skill in the art to combine the teachings of Kiyohara et al, Minaki and application 18/619,369, and to include, at least partially, the phase separation agent such as polystyrene, into the solution of the step A of the method of application 18/619,369, so to further promote phase separation and migration to the interface when the monomers are polymerized, as taught by Kiyohara et al, and since it would have been obvious to choose material based on its suitability, and prepare the hollow particles having the size of 2 micron or more as well, as taught by Minaki, thereby arriving at the present invention. Case law holds that the selection of a known material based on its suitability for its intended use supports prima facie obviousness. Sinclair & Carroll Co vs. Interchemical Corp., 325 US 327, 65 USPQ 297 (1045). 33. Thus, the limitations claimed in instant invention are obvious variants of the limitations claimed in application 18/619,369 in view of Kiyohara et al and Minaki. 34. Claims 1-12 are directed to an invention not patentably distinct from claims 1-12 of a copending application 18/619,369 (published US 2024/0269638) in view of Kiyohara et al (JP 2016-068037, based on machine translation) and Minaki (JP 2008/184473, based on machine translation). Specifically, see the discussion in paragraphs 29-33 above. The U.S. Patent and Trademark Office normally will not institute an interference between applications or a patent and an application of com-mon ownership (see MPEP Chapter 2300). The copending application 18/619,369, discussed above, would form the basis for a rejection of the noted claims under 35 U.S.C. 103(a) if the commonly assigned case qualifies as prior art under 35 U.S.C. 102(e), (f) or (g) and the conflicting inventions were not commonly owned at the time the invention in this application was made. In order for the examiner to resolve this issue, the assignee can, under 35 U.S.C. 103(c) and 37 CFR 1.78(c), either show that the conflicting inventions were commonly owned at the time the invention in this application was made, or name the prior inventor of the conflicting subject matter. A showing that the inventions were commonly owned at the time the invention in this application was made will preclude a rejection under 35 U.S.C. 103(a) based upon the commonly assigned case as a reference under 35 U.S.C. 102(f) or (g), or 35 U.S.C. 102(e) for applications pending on or after December 10, 2004. Response to Arguments 35. Applicant's arguments filed on November 19, 2025 have been fully considered but they are moot in light of new grounds of rejections and discussion set forth above. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to IRINA KRYLOVA whose telephone number is (571)270-7349. The examiner can normally be reached 9am-5pm EST M-F. 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, Arrie Lanee Reuther can be reached at 571-270-7026. 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. /IRINA KRYLOVA/Primary Examiner, Art Unit 1764
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Prosecution Timeline

Jan 06, 2023
Application Filed
Aug 15, 2025
Non-Final Rejection — §102, §103, §DP
Nov 19, 2025
Response Filed
Jan 28, 2026
Final Rejection — §102, §103, §DP (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

3-4
Expected OA Rounds
36%
Grant Probability
84%
With Interview (+48.1%)
4y 4m
Median Time to Grant
Moderate
PTA Risk
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