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
The Applicant’s arguments and claim amendments received November 20, 2025 have been entered into the file. Currently, claims 1, 3, 5-8, and 10-11 are amended; claims 2 and 4 are cancelled; and claims 15-19 are new; resulting in claims 1, 3, and 5-19 pending for examination.
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 (i.e., changing from AIA to pre-AIA ) 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, 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 1, 3, 5, 7-10, and 12-14 are rejected under 35 U.S.C. 103 as being unpatentable over Suminosuke, et al. (JP 2015/088253 A), cited on IDS.
Regarding claims 1 and 9, Suminosuke teaches a separator for a lithium ion secondary battery, comprising a separator substrate and an adhesive layer (coating layer), wherein the adhesive layer contains a particulate polymer, and the particulate polymer has a core-shell structure (¶ [0010], Ln. 14-16). Examples of separator substrates include porous substrates made of resins containing polyolefins such as polyethylene, polypropylene, polybutene, and polyvinyl chloride, mixtures thereof, and copolymers thereof (porous polymer substrate having a plurality of pores) (¶ [0135], Ln. 1-3). Suminosuke teaches that pores are provided in the adhesive layer to increase ion diffusibility (porous coating layer) (¶ [0102], Ln. 2-3).
Suminosuke teaches that the core portion of the particulate polymer is made of a polymer having a swelling degree in an electrolytic solution of 5 to 30 times (first polymer absorbs an electrolyte in an amount corresponding to 2-50 times a weight of the first polymer) and the shell portion is made of a polymer having a swelling degree in an electrolytic solution of more than 1 to 4 times (second polymer) (¶ [0010], Ln. 4-6). Additionally, Suminosuke teaches that the glass transition temperature of the shell polymer is preferably 70 °C or higher (¶ [0067], Ln. 1-3). The melting point temperature is higher than the glass transition temperature. A general rule of thumb is that the glass transition temperature of a polymer is 2/3 the melting point temperature, resulting in a general melting point temperature of 104 °C for the shell polymer of Suminosuke (melting point of 80 °C or higher).
Suminosuke further teaches that the swelling degree of the shell portion (low-absorbent polymer) is preferably 1.2 to 3 times (¶ [0055], Ln. 4-6), overlapping the claimed range of 2 times or less. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (MPEP 2144.05 (I)).
Regarding claims 3, 5, and 7, Suminosuke teaches all of the limitations of claim 1 above and further teaches that the core polymer preferably contains a crosslinkable monomer unit (¶ [0047], Ln. 1). Specifically, in example 1, the core polymer includes 74.5 parts methyl methacrylate, 4 parts methacrylic acid, 1 part ethylene dimethacrylate, and 0.5 parts acrylamide (crosslinked polymer selected from the group including acrylic polymer) (¶ [0223], Ln. 1-3). The shell polymer of example 1 includes 19.5 parts styrene and 0.5 parts acrylamide (crosslinked polymer comprising a styrene-containing polymer, an olefin-containing polymer, and an amide-containing polymer) (¶ [0224], Ln. 1). The core-shell particles of example 1 have a weight ratio of the core portion to the shell portion of 80:20, within the claimed range of 84:16 to 40:60.
Regarding claim 8, Suminosuke teaches all of the limitations of claim 1 above and further teaches that diameter of the core portion is particularly preferably 70% or more and 98% or less, relative to 100% of the volume average particle diameter of the particulate polymer (¶ [0053], Ln. 1-4), overlapping the claimed range of 10% to 90%. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (MPEP 2144.05 (I)).
Regarding claim 10, Suminosuke teaches all of the limitations of claim 1 above and further teaches that the adhesive preferably further contains a binder for the adhesive layer in addition to the particulate polymer (¶ [0087], Ln. 1-2). Suminosuke teaches that by using the binder, the particulate polymer can be bonded to each other both in a state where it is swollen in the electrolytic solution and in a state where it is not swollen (binder polymer disposed partially or totally on a surface of the core-shell polymer particles and core-shell polymer particles are interconnected and fixed) (¶ [0087], Ln. 3-5).
Regarding claim 12, Suminosuke teaches all of the limitations of claim 10 above and, as the adhesive layer further contains a binder that is partially or totally on a surface of the core-shell polymer particles wherein the core-shell polymer particles are interconnected and fixed, necessarily meets the limitations of claim 12.
Regarding claims 13-14, Suminosuke teaches a lithium-ion secondary battery including a positive electrode, a negative electrode, an electrolyte, and the separator described above (meeting the limitations of claim 1) (¶ [0163], Ln. 1-4). The lithium-ion secondary battery is manufactured by stacking a positive electrode, a separator, and a negative electrode in this order (separator interposed between the cathode and anode) (¶ [0165], Ln. 1-3).
Claims 6, 11, and 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Suminosuke, et al. (JP 2015/088253 A), as applied to claims 1, 5, and 10 above, and further in view of Fan (US 2021/0234233 A1).
Regarding claim 6, Suminosuke teaches all of the limitations of claim 5 above. Suminosuke does not expressly teach that the shell polymer is a non-crosslinked or crosslinked polymer comprising at
least one of the monomers included in claim 6.
Fan teaches a separator including a porous substrate and a first coating disposed on at least a surface of the porous substrate, wherein the first coating includes a first polymer binder and first inorganic particles, further teaching that the first polymer binder includes core-shell structured particles (¶ [0005], Ln. 1-6). The porous substrate includes a polymer film, multilayer polymer film, or a non-woven fabric formed of polymers (porous polymer substrate) (¶ [0023], Ln. 1-3). Fan teaches that the core of the first polymer binder is formed by polymerizing of monomers selected from a group consisting of ethyl acrylate, butyl acrylate, ethyl methacrylate, styrene, chlorostyrene, fluorobenzene ethylene, methylstyrene, acrylic acid, methacrylic acid, maleic acid, and any combination thereof, and that the shell of the first polymer binder is formed by polymerizing of monomers selected from a group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene, chlorostyrene, fluorostyrene, methylstyrene, acrylonitrile, methyl acrylonitrile, and any combination thereof (¶ [0024], Ln. 1-15). Fan teaches that by adopting the core-shell particle structure, the uniformity of the particles is improved and, in the post-heating process, the shell of the first polymer binder may be softened first, and then the core of the first polymer binder may have bonding function (¶ [0024], Ln. 15-21).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the shell polymer of Suminosuke to include a polymer taught by Fan, such as methyl methacrylate. In polymerizing methyl methacrylate, a polymethyl methacrylate shell polymer would be formed. One of ordinary skill in the art would be motivated to modify the shell polymer based on the teachings of Fan such that the shell of the first polymer binder may be softened first, and then the core of the first polymer binder may have bonding function.
Regarding claim 11, Suminosuke teaches all of the limitations of claim 10 above. Suminosuke does not expressly teach that the binder polymer comprises at least one of the polymers listed in claim 11.
Fan teaches that the first coating further includes an auxiliary binder, which may be selected from the group consisting of copolymer of vinylidene fluoride-hexafluoropropylene, copolymer of vinylidene fluoride-trichloroethylene, polystyrene, polyacrylate, polyacrylic acid, polyacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyacetic acid vinyl ester, copolymer of ethylene-vinyl acetate, polyimide, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl amylopectin, cyanoethyl poly copolymerization of vinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, amylopectin, carboxymethyl cellulose, sodium carboxymethyl cellulose, lithium carboxymethyl cellulose, acrylonitrile-styrene-butadiene polymers, polyphthalamide, polyvinyl alcohol, styrene-butadiene copolymers, polyvinylidene fluoride, and any combination thereof (¶ [0028], Ln. 4-19). Fan teaches that the auxiliary binder helps to improve a bonding performance of the first coating (¶ [0028], Ln. 26-27).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the binder polymer of Suminosuke to comprise one of the auxiliary binder polymers taught by Fan. One of ordinary skill in the art would find it obvious to select any polymer taught by Fan, including a copolymer of vinylidene fluoride-hexafluoropropylene, a copolymer of vinylidene fluoride-trichloroethylene, a polyacrylate, polyacrylonitrile, polyvinylpyrrolidone, a copolymer of ethylene-vinyl acetate, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl poly copolymerization of vinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, or carboxymethyl cellulose. One of ordinary skill in the art would be motivated to include one of these polymers in the adhesive layer of Suminosuke in order to improve the bonding performance of the adhesive layer and the separator.
Regarding claim 15, Suminosuke teaches all of the limitations of claim 1 above. Suminosuke does not expressly teach that the shell polymer comprises polymethyl methacrylate-co-n-butyl acrylate.
Fan teaches a separator including a porous substrate and a first coating disposed on at least a surface of the porous substrate, wherein the first coating includes a first polymer binder and first inorganic particles, further teaching that the first polymer binder includes core-shell structured particles (¶ [0005], Ln. 1-6). The porous substrate includes a polymer film, multilayer polymer film, or a non-woven fabric formed of polymers (porous polymer substrate) (¶ [0023], Ln. 1-3). Fan teaches that the core of the first polymer binder is formed by polymerizing of monomers selected from a group consisting of ethyl acrylate, butyl acrylate, ethyl methacrylate, styrene, chlorostyrene, fluorobenzene ethylene, methylstyrene, acrylic acid, methacrylic acid, maleic acid, and any combination thereof, and that the shell of the first polymer binder is formed by polymerizing of monomers selected from a group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene, chlorostyrene, fluorostyrene, methylstyrene, acrylonitrile, methyl acrylonitrile, and any combination thereof (¶ [0024], Ln. 1-15). In the first polymer binder of Example 1, Fan teaches that the shell includes a copolymer of methyl methacrylate and methyl styrene (¶ [0079], Ln. 1-3). Fan teaches that by adopting the core-shell particle structure, the uniformity of the particles is improved and, in the post-heating process, the shell of the first polymer binder may be softened first, and then the core of the first polymer binder may have bonding function (¶ [0024], Ln. 15-21).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the shell polymer of Suminosuke to include a polymer taught by Fan. As Fan teaches methyl methacrylate in the list of possible monomers and in the example, one of ordinary skill in the art would find it obvious to include methyl methacrylate in the shell polymer. Additionally, as Fan teaches butyl acrylate as a monomer that can be used to form the shell of the first polymer binder, one of ordinary skill in the art would find it obvious to include butyl acrylate in the shell polymer. In polymerizing methyl methacrylate and butyl acrylate, the resulting shell polymer would comprise polymethyl methacrylate-co-n-butyl acrylate. One of ordinary skill in the art would be motivated to modify the shell polymer based on the teachings of Fan such that the shell of the first polymer binder may be softened first, and then the core of the first polymer binder may have bonding function.
Regarding claim 16, Suminosuke in view of Fan teaches all of the limitations of claim 15 above. Suminosuke further teaches that the core polymer preferably contains a crosslinkable monomer unit so that the swelling degree can be easily controlled (¶ [0047], Ln. 1-7) and that acrylic acid is included in the list of possible monomers used to produce a core polymer with the desired swelling degree (¶ [0044], Ln. 1-7). Suminosuke does not expressly teach that the core polymer comprises polyacrylic acid crosslinked polymer.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the core polymer of Suminosuke to crosslink acrylic acid, forming a crosslinked polyacrylic acid, based on the teachings of Suminosuke. As the reference teaches that it is preferred to include crosslinkable monomers in the core portion and provides acrylic acid in the list of possible monomers, one of ordinary skill in the art would find it obvious to include polyacrylic acid crosslinked polymer in the core polymer. One would be motivated to include crosslinked acrylic acid monomers in order to control the swelling degree.
Claims 17-19 are rejected under 35 U.S.C. 103 as being unpatentable over Suminosuke, et al. (JP 2015/088253 A) in view of Fan (US 2021/0234233 A1).
Regarding claim 17, Suminosuke teaches a separator for a lithium ion secondary battery, comprising a separator substrate and an adhesive layer (coating layer), wherein the adhesive layer contains a particulate polymer, and the particulate polymer has a core-shell structure (¶ [0010], Ln. 14-16). Examples of separator substrates include porous substrates made of resins containing polyolefins such as polyethylene, polypropylene, polybutene, and polyvinyl chloride, mixtures thereof, and copolymers thereof (porous polymer substrate having a plurality of pores) (¶ [0135], Ln. 1-3). Suminosuke teaches that pores are provided in the adhesive layer to increase ion diffusibility (porous coating layer) (¶ [0102], Ln. 2-3).
Suminosuke teaches that the core portion of the particulate polymer is made of a polymer having a swelling degree in an electrolytic solution of 5 to 30 times (first polymer absorbs an electrolyte in an amount corresponding to 2-50 times a weight of the first polymer) and the shell portion is made of a polymer having a swelling degree in an electrolytic solution of more than 1 to 4 times (second polymer) (¶ [0010], Ln. 4-6). Additionally, Suminosuke teaches that the glass transition temperature of the shell polymer is preferably 70 °C or higher (¶ [0067], Ln. 1-3). The melting point temperature is higher than the glass transition temperature. A general rule of thumb is that the glass transition temperature of a polymer is 2/3 the melting point temperature, resulting in a general melting point temperature of 104 °C for the shell polymer of Suminosuke (melting point of 80 °C or higher).
Suminosuke does not expressly teach that the shell polymer is a non-crosslinked or crosslinked polymer comprising at least one of the monomers included in claim 17.
Fan teaches a separator including a porous substrate and a first coating disposed on at least a surface of the porous substrate, wherein the first coating includes a first polymer binder and first inorganic particles, further teaching that the first polymer binder includes core-shell structured particles (¶ [0005], Ln. 1-6). The porous substrate includes a polymer film, multilayer polymer film, or a non-woven fabric formed of polymers (porous polymer substrate) (¶ [0023], Ln. 1-3). Fan teaches that the core of the first polymer binder is formed by polymerizing of monomers selected from a group consisting of ethyl acrylate, butyl acrylate, ethyl methacrylate, styrene, chlorostyrene, fluorobenzene ethylene, methylstyrene, acrylic acid, methacrylic acid, maleic acid, and any combination thereof, and that the shell of the first polymer binder is formed by polymerizing of monomers selected from a group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene, chlorostyrene, fluorostyrene, methylstyrene, acrylonitrile, methyl acrylonitrile, and any combination thereof (¶ [0024], Ln. 1-15). Fan teaches that by adopting the core-shell particle structure, the uniformity of the particles is improved and, in the post-heating process, the shell of the first polymer binder may be softened first, and then the core of the first polymer binder may have bonding function (¶ [0024], Ln. 15-21).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the shell polymer of Suminosuke to include a polymer taught by Fan, such as methyl methacrylate. In polymerizing methyl methacrylate, a polymethyl methacrylate shell polymer would be formed. One of ordinary skill in the art would be motivated to modify the shell polymer based on the teachings of Fan such that the shell of the first polymer binder may be softened first, and then the core of the first polymer binder may have bonding function.
Regarding claim 18, Suminosuke teaches a separator for a lithium ion secondary battery, comprising a separator substrate and an adhesive layer (coating layer), wherein the adhesive layer contains a particulate polymer, and the particulate polymer has a core-shell structure (¶ [0010], Ln. 14-16). Examples of separator substrates include porous substrates made of resins containing polyolefins such as polyethylene, polypropylene, polybutene, and polyvinyl chloride, mixtures thereof, and copolymers thereof (porous polymer substrate having a plurality of pores) (¶ [0135], Ln. 1-3). Suminosuke teaches that pores are provided in the adhesive layer to increase ion diffusibility (porous coating layer) (¶ [0102], Ln. 2-3).
Suminosuke teaches that the core portion of the particulate polymer is made of a polymer having a swelling degree in an electrolytic solution of 5 to 30 times (first polymer) and the shell portion is made of a polymer having a swelling degree in an electrolytic solution of more than 1 to 4 times (second polymer) (¶ [0010], Ln. 4-6). Additionally, Suminosuke teaches that the glass transition temperature of the shell polymer is preferably 70 °C or higher (¶ [0067], Ln. 1-3). The melting point temperature is higher than the glass transition temperature. A general rule of thumb is that the glass transition temperature of a polymer is 2/3 the melting point temperature, resulting in a general melting point temperature of 104 °C for the shell polymer of Suminosuke (melting point of 80 °C or higher).
Suminosuke does not expressly teach that the shell polymer comprises polymethyl methacrylate-co-n-butyl acrylate.
Fan teaches a separator including a porous substrate and a first coating disposed on at least a surface of the porous substrate, wherein the first coating includes a first polymer binder and first inorganic particles, further teaching that the first polymer binder includes core-shell structured particles (¶ [0005], Ln. 1-6). The porous substrate includes a polymer film, multilayer polymer film, or a non-woven fabric formed of polymers (porous polymer substrate) (¶ [0023], Ln. 1-3). Fan teaches that the core of the first polymer binder is formed by polymerizing of monomers selected from a group consisting of ethyl acrylate, butyl acrylate, ethyl methacrylate, styrene, chlorostyrene, fluorobenzene ethylene, methylstyrene, acrylic acid, methacrylic acid, maleic acid, and any combination thereof, and that the shell of the first polymer binder is formed by polymerizing of monomers selected from a group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene, chlorostyrene, fluorostyrene, methylstyrene, acrylonitrile, methyl acrylonitrile, and any combination thereof (¶ [0024], Ln. 1-15). In the first polymer binder of Example 1, Fan teaches that the shell includes a copolymer of methyl methacrylate and methyl styrene (¶ [0079], Ln. 1-3). Fan teaches that by adopting the core-shell particle structure, the uniformity of the particles is improved and, in the post-heating process, the shell of the first polymer binder may be softened first, and then the core of the first polymer binder may have bonding function (¶ [0024], Ln. 15-21).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the shell polymer of Suminosuke to include a polymer taught by Fan. As Fan teaches methyl methacrylate in the list of possible monomers and in the example, one of ordinary skill in the art would find it obvious to include methyl methacrylate in the shell polymer. Additionally, as Fan teaches butyl acrylate as a monomer that can be used to form the shell of the first polymer binder, one of ordinary skill in the art would find it obvious to include butyl acrylate in the shell polymer. In polymerizing methyl methacrylate and butyl acrylate, the resulting shell polymer would comprise polymethyl methacrylate-co-n-butyl acrylate. One of ordinary skill in the art would be motivated to modify the shell polymer based on the teachings of Fan such that the shell of the first polymer binder may be softened first, and then the core of the first polymer binder may have bonding function.
Regarding claim 19, Suminosuke teaches a separator for a lithium ion secondary battery, comprising a separator substrate and an adhesive layer (coating layer), wherein the adhesive layer contains a particulate polymer, and the particulate polymer has a core-shell structure (¶ [0010], Ln. 14-16). Examples of separator substrates include porous substrates made of resins containing polyolefins such as polyethylene, polypropylene, polybutene, and polyvinyl chloride, mixtures thereof, and copolymers thereof (porous polymer substrate having a plurality of pores) (¶ [0135], Ln. 1-3). Suminosuke teaches that pores are provided in the adhesive layer to increase ion diffusibility (porous coating layer) (¶ [0102], Ln. 2-3).
Suminosuke teaches that the core portion of the particulate polymer is made of a polymer having a swelling degree in an electrolytic solution of 5 to 30 times (first polymer) and the shell portion is made of a polymer having a swelling degree in an electrolytic solution of more than 1 to 4 times (second polymer) (¶ [0010], Ln. 4-6). Additionally, Suminosuke teaches that the glass transition temperature of the shell polymer is preferably 70 °C or higher (¶ [0067], Ln. 1-3). The melting point temperature is higher than the glass transition temperature. A general rule of thumb is that the glass transition temperature of a polymer is 2/3 the melting point temperature, resulting in a general melting point temperature of 104 °C for the shell polymer of Suminosuke (melting point of 80 °C or higher). Suminosuke further teaches that the core polymer preferably contains a crosslinkable monomer unit so that the swelling degree can be easily controlled (¶ [0047], Ln. 1-7) and that acrylic acid is included in the list of possible monomers used to produce a core polymer with the desired swelling degree (¶ [0044], Ln. 1-7). Suminosuke does not expressly teach that the core polymer comprises polyacrylic acid crosslinked polymer.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the core polymer of Suminosuke to crosslink acrylic acid, forming a crosslinked polyacrylic acid, based on the teachings of Suminosuke. As the reference teaches that it is preferred to include crosslinkable monomers in the core portion and provides acrylic acid in the list of possible monomers, one of ordinary skill in the art would find it obvious to include polyacrylic acid crosslinked polymer in the core polymer. One would be motivated to include crosslinked acrylic acid monomers in order to control the swelling degree.
Suminosuke does not expressly teach that the shell polymer comprises polymethyl methacrylate-co-n-butyl acrylate.
Fan teaches a separator including a porous substrate and a first coating disposed on at least a surface of the porous substrate, wherein the first coating includes a first polymer binder and first inorganic particles, further teaching that the first polymer binder includes core-shell structured particles (¶ [0005], Ln. 1-6). The porous substrate includes a polymer film, multilayer polymer film, or a non-woven fabric formed of polymers (porous polymer substrate) (¶ [0023], Ln. 1-3). Fan teaches that the core of the first polymer binder is formed by polymerizing of monomers selected from a group consisting of ethyl acrylate, butyl acrylate, ethyl methacrylate, styrene, chlorostyrene, fluorobenzene ethylene, methylstyrene, acrylic acid, methacrylic acid, maleic acid, and any combination thereof, and that the shell of the first polymer binder is formed by polymerizing of monomers selected from a group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene, chlorostyrene, fluorostyrene, methylstyrene, acrylonitrile, methyl acrylonitrile, and any combination thereof (¶ [0024], Ln. 1-15). In the first polymer binder of Example 1, Fan teaches that the shell includes a copolymer of methyl methacrylate and methyl styrene (¶ [0079], Ln. 1-3). Fan teaches that by adopting the core-shell particle structure, the uniformity of the particles is improved and, in the post-heating process, the shell of the first polymer binder may be softened first, and then the core of the first polymer binder may have bonding function (¶ [0024], Ln. 15-21).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the shell polymer of Suminosuke to include a polymer taught by Fan. As Fan teaches methyl methacrylate in the list of possible monomers and in the example, one of ordinary skill in the art would find it obvious to include methyl methacrylate in the shell polymer. Additionally, as Fan teaches butyl acrylate as a monomer that can be used to form the shell of the first polymer binder, one of ordinary skill in the art would find it obvious to include butyl acrylate in the shell polymer. In polymerizing methyl methacrylate and butyl acrylate, the resulting shell polymer would comprise polymethyl methacrylate-co-n-butyl acrylate. One of ordinary skill in the art would be motivated to modify the shell polymer based on the teachings of Fan such that the shell of the first polymer binder may be softened first, and then the core of the first polymer binder may have bonding function.
Response to Arguments
Response-Specification Objections
The previous objection to the specification for informalities regarding the definition of the low-
absorbent polymer is overcome by the Applicant’s amendment to the specification filed November 20, 2025.
Response-Claim Objections
The previous objections to claims 4 and 8 for informalities regarding the definition of the low-absorbent polymer and the ratio of the average diameter of the core portion to the average diameter of the core-shell type polymer particle are overcome by the Applicant’s cancellation of claim 4, and amendments to claims 1 and 8 in the response filed November 20, 2025.
Response-Claim Rejections – 35 U.S.C. 112
The previous rejections of claims 1, 3, 5-8, 10, and by dependency claims 2-14 under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention are overcome by the Applicant’s amendments to claims 1, 3, 5-8, and 10, and cancellation of claims 2 and 4 in the response filed November 20, 2025.
Response-Claim Rejections – 35 U.S.C. 102 and 103
In light of the Applicant’s amendments to claim 1 to incorporate the limitations of claims 2 and 4, the previous rejections of claims 1, 3, 5-7, and 9-14 under 35 U.S.C. 102(a)(1) and 102(a)(2) over Lee, et al. (US 2019/0237734 A1) and claims 1-3, 5, 7, 9-10, and 12-14 under 35 U.S.C. 102(a)(1) over Suminosuke, et al. (JP 2015/088253 A) are overcome, however, upon further consideration, Suminosuke is still applicable under 35 U.S.C. 103 and used in the rejections above. Any arguments with respect to the reference that are still deemed valid will be addressed herein.
The Applicant argues, see page 9 of the remarks, that the claimed separator would not be obvious over Suminosuke because the claimed separator produces unexpected results in terms of shutdown prevention. It is noted that the feature which the Applicant relies upon, the core-shell structure of the polymer particles, is taught by the reference applied. Further, the reference teaches a core-shell structure meeting the melting point limitations of the claimed separator. In response to applicant's argument that the claimed separator delays or suppresses ignition of electrolyte at elevated temperatures, the fact that the inventor 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. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
In the event that the Applicant intends to present a showing of unexpected results, a detailed description of the reasons and evidence supporting Applicant’s position is necessary. See MPEP 716.02(b). Applicants may compare the claimed invention with prior art that is more closely related to the invention than the prior art relied upon by the examiner. See MPEP 716.02(e).
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 SARAH J JACOBSON whose telephone number is (703)756-1647. The examiner can normally be reached Monday - Friday 8:00am - 5:00pm.
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/SARAH J JACOBSON/Examiner, Art Unit 1785
/MARK RUTHKOSKY/Supervisory Patent Examiner, Art Unit 1785