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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 02/26/2026 has been entered.
Status of the Claims
The amendment/remarks submitted 02/26/2026 has been entered and fully considered. Claims 1-2, 4-5, 8-11, and 15-17 are pending. Claims 3, 6-7, and 12-14 are cancelled. Claims 1-2 are amended. Claims 1-2, 4-5, 8-11, and 15-17 are examined herein.
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.
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 1-2, 4-5, 8-12, and 15-17 are rejected under 35 U.S.C. 103 as being unpatentable over WO 2018/055882 A1 (“Nakahiro” – machine translation dated 03/15/2024 cited herein).
Regarding claim 1, Nakahiro discloses a separator for a lithium secondary battery (Abstract; [0185]). The separator comprises a porous polymer substrate and an adhesive porous layer (“porous coating layer”) provided on one or both sides of the porous substrate ([0116]). The adhesive porous layer comprises a polyvinylidene fluoride resin comprising vinylidene fluoride monomer units and hexafluoropropylene monomer units (“fluorine-based binder”) ([0117]-[0118]); a resin having a glass transition temperature of 30°C to 120°C, examples of which include acrylic resins such as polyvinyl acetate (PVAc) ([0120], [0126], [0140], [0144]); and an inorganic filler ([0155]).
The amount of the resin having a glass transition temperature of 30°C to 120°C (i.e. PVAc) is 15% by mass or more and 50% by mass or less of the total amount of all resins contained in the adhesive porous layer ([0149]). This is deemed to disclose the claimed range with sufficiently specificity so as to anticipate the claimed range. Alternatively, Nakahiro discloses motivation to optimize the claimed amount: the amount balances increasing peel strength and suppressing cohesive failure of the porous layer ([0149]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to increase peel strength while suppressing cohesive failure of the porous layer.
Nakahiro discloses the content of the inorganic filler (“inorganic particles”), in the form of particles, in the adhesive porous layer is 5% by mass to 75% by mass of the total amount of all resins and inorganic filler contained in the adhesive porous layer ([0155]-[0160]). When the content of the inorganic filler is 5% by mass or more, thermal shrinkage of the separator when heat is applied is suppressed, which is preferable from the viewpoint of dimensional stability. On the other hand, if the content of the inorganic filler is 75% by mass or less, it is preferable from the viewpoint of ensuring adhesion of the adhesive porous layer to the electrode ([0160]). For these reasons it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention top optimize the amount of the inorganic filler.
The adhesive porous layer has a structure wherein the inorganic filler is dispersed within a matrix formed by the polyvinylidene fluoride resin and the PVAc ([0150], [0174]). Given the method of formation of the adhesive porous layer disclosed by Nakahiro ([0174]), the limitation regarding the claimed thickness-direction homogeneity of the fluorine-based binder polymer, the polyvinyl acetate binder polymer and the inorganic particles is inherently present.
Nakahiro further discloses the weight average molecular weight of the polyvinylidene fluoride resin is 100,000 to 1,500,000 ([0137]).
Nakahiro further discloses the weight average molecular weight (Mw) of the polyvinyl acetate resin is 50,000 to 500,000. When the Mw of the vinyl acetate resin is 50,000 or more, the film-forming property is good, and the adhesive porous layer has excellent properties. On the other hand, when the Mw of the vinyl acetate resin is 500,000 or less, the viscosity of the coating liquid used in coating and molding the adhesive porous layer does not become too high, and the productivity of the separator is improved ([0145]). For these reasons, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to optimize the molecular weight of the polyvinyl acetate as taught by Nakahiro.
Regarding claim 2, Nakahiro discloses a separator for a lithium secondary battery (Abstract; [0185]). The separator comprises a porous polymer substrate and an adhesive porous layer (“porous coating layer”) provided on one or both sides of the porous substrate ([0116]). The adhesive porous layer comprises a polyvinylidene fluoride resin comprising vinylidene fluoride monomer units and hexafluoropropylene monomer units (“fluorine-based binder”) ([0117]-[0118]); a resin having a glass transition temperature of 30°C to 120°C, examples of which include acrylic resins such as polyvinyl acetate (PVAc) ([0120], [0126], [0140], [0144]); and an inorganic filler ([0155]).
The amount of the resin having a glass transition temperature of 30°C to 120°C (i.e. PVAc) is 15% by mass or more and 50% by mass or less of the total amount of all resins contained in the adhesive porous layer ([0149]). This is deemed to disclose the claimed range with sufficiently specificity so as to anticipate the claimed range. Alternatively, Nakahiro discloses motivation to optimize the claimed amount: the amount balances increasing peel strength and suppressing cohesive failure of the porous layer ([0149]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to increase peel strength while suppressing cohesive failure of the porous layer.
Nakahiro discloses the content of the inorganic filler (“inorganic particles”), in the form of particles, in the adhesive porous layer is 5% by mass to 75% by mass of the total amount of all resins and inorganic filler contained in the adhesive porous layer ([0155]-[0160]). When the content of the inorganic filler is 5% by mass or more, thermal shrinkage of the separator when heat is applied is suppressed, which is preferable from the viewpoint of dimensional stability. On the other hand, if the content of the inorganic filler is 75% by mass or less, it is preferable from the viewpoint of ensuring adhesion of the adhesive porous layer to the electrode ([0160]). For these reasons it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention top optimize the amount of the inorganic filler.
Nakahiro further discloses the weight average molecular weight of the polyvinylidene fluoride resin is 100,000 to 1,500,000 ([0137]).
Nakahiro further discloses the weight average molecular weight (Mw) of the polyvinyl acetate resin is 50,000 to 500,000. When the Mw of the vinyl acetate resin is 50,000 or more, the film-forming property is good, and the adhesive porous layer has excellent properties. On the other hand, when the Mw of the vinyl acetate resin is 500,000 or less, the viscosity of the coating liquid used in coating and molding the adhesive porous layer does not become too high, and the productivity of the separator is improved ([0145]). For these reasons, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to optimize the molecular weight of the polyvinyl acetate as taught by Nakahiro.
The instant claim recites a result of a product-by-process limitation (i.e. “wherein pores in the porous coating layer are formed by mass interchange between a solvent and a non-solvent for the fluorine-based binder polymer and the polyvinyl acetate binder polymer”). In this regard, MPEP 2113 sets forth the following: "[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985). In this case, the structure disclosed by Nakahiro meets the structure implied by the claim limitation. See, for example, [0132] and [0150]. Moreover, Nakahiro discloses the adhesive porous layer is formed by a process of immersing the porous substrate on which the coating layer has been formed in a coagulation liquid to solidify the polyvinylidene fluoride resin while inducing phase separation in the coating layer, thereby forming a porous layer on the porous substrate and obtaining a composite membrane ([0174]).
Regarding claims 4-5, modified Nakahiro discloses the separator of claim 2. The instant claims specify a solvent and a non-solvent used in the process of forming the pores. As such, these are interpreted as part of the product-by-process limitation. See the sections of MPEP 2113 cited above. In this case, the structure disclosed by the product-by-process limitation does not differ from the structure of Nakahiro. Moreover, Nakahiro discloses a good solvent used in preparing the coating liquid is a solvent that dissolves polyvinylidene fluoride resin. Examples of the good solvent include polar amide solvents such as N-methylpyrrolidone, dimethylacetamide, and dimethylformamide ([0176]). Nakahiro further discloses the solvent used in preparing the coating liquid preferably contains a phase separation agent that induces phase separation. The phase separation agent may include water ([0177]).
Regarding claims 9 and 16, modified Nakahiro discloses the separator of claims 1-2. It is deemed that the heat shrinkage is an inherent characteristic and/or property of the specifically disclosed separator. See the sections of MPEP 2112 cited above. However, even if the heat shrinkage is not inherent, it would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention in view of the teachings regarding the amount of the inorganic filler. When the content of the inorganic filler is 5% by mass or more, thermal shrinkage of the separator when heat is applied is suppressed, which is preferable from the viewpoint of dimensional stability. On the other hand, if the content of the inorganic filler is 75% by mass or less, it is preferable from the viewpoint of ensuring adhesion of the adhesive porous layer to the electrode ([0160]).
Regarding claims 10 and 17, modified Nakahiro discloses the separator of claims 1-2. Nakahiro further discloses a non-aqueous secondary battery a positive electrode, a negative electrode, and the separator ([0184]).
Regarding claims 8 and 15, modified Nakahiro discloses the electrochemical device of claims 10 and 17. It is deemed that the adhesion to an electrode (Lami strength) is an inherent characteristic and/or property of the specifically disclosed separator. In this respect, MPEP 2112 sets forth the following:
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).
“When the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not.” In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990).
“Products of identical chemical composition cannot have mutually exclusive properties.” In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. Id.
It is noted that Nakahiro discloses the positive electrode, the separator, and the negative are dry bonded ([0198]-[0201]).
Response to Arguments
Applicant's arguments filed 09/12/2025 have been fully considered but they are not persuasive.
Applicant’s primary argument is the presence of unexpected results in the claimed invention. Applicant cites the data presented in Table 2 in support. The Office respectfully disagrees. Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980). The data presented are narrower in scope than the claims. For example, in the data presented only a particular fluorine-based polymer (polyvinylidene fluoride-co-hexafluoropropylene) is used and the inorganic particles are present in an amount of 70% to 80%, while the independent claims recite a fluorine-based binder and the amount of inorganic particles is 70 parts by weight or more. It is not clear that the entire claimed range would appreciate the benefits discussed by applicant.
Applicant’s arguments to the adhesion mechanism in Nakahiro are not persuasive. Applicant is reminded the instant claims are product claims and patentability is based on the structure of the claims. It is noted that the dry heat pressing described by applicant is part of a process of adhering the separator to an electrode and does not distinguish over the separator itself. Moreover, the separator of Nakahiro is formed by a substantially similar process to the instant separator. Nakahiro discloses the adhesive porous layer is formed by a process of immersing the porous substrate on which the coating layer has been formed in a coagulation liquid to solidify the polyvinylidene fluoride resin while inducing phase separation in the coating layer, thereby forming a porous layer on the porous substrate and obtaining a composite membrane ([0174]).
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Robert Scott Carrico whose telephone number is (571)270-5504. The examiner can normally be reached Monday-Friday 9:15AM-6PM ET.
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Robert Scott Carrico
Primary Examiner
Art Unit 1727
/Robert S Carrico/Primary Examiner, Art Unit 1727
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