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 .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1 – 2, 4, 7-9, 12, 14-17, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Seong Dong-wook, et. al. (KR101689752B1, hereinafter Seong), and in view of Zhang, et. al. (US2016164060A1) and further in view of Wiley, et. al., N-vinylamide Polymers, Encyclopedia of Polymer Science and Technology, 1-29, 2005, and Nakajima, et. al. (US2004166407A1).
Regarding Claim 1, Seong teaches a separator for a lithium secondary battery, comprising: a porous polymer substrate (“[0007] According to an aspect of the invention, the separation membrane by applying a first binder polymer on at least one surface of a porous substrate”); and a porous coating layer formed on at least one surface of the porous polymer substrate (“and the inorganic particles are dispersed second binder polymer to form a porous coating layer”), wherein the porous coating layer comprises inorganic particles, a polyvinylidene fluoride-based binder polymer (“a first binder polymer of the non-limiting examples include polyvinylidene fluoride”), a polyvinylpyrrolidone binder polymer (“[0030] Non-limiting examples of the dispersion binder, to enhance the binding property between the inorganic particles constituting the porous coating layer as a binder to improve the durability of the coating layer itself, [including] . . . polyvinylpyrrolidone”) and a dispersant (“In step S2, a slurry is prepared by first dissolving a second binder polymer in a solvent to disperse the inorganic particles thereto.”), wherein the polyvinylidene fluoride-based binder polymer and the polyvinylpyrrolidone binder polymer are not particles and coat part or all of a surface of the inorganic particles (“to thereby prepare a slurry containing the inorganic particles are dispersed by the addition of inorganic particles in the coating liquid is prepared,”). Seong at [0007, 22-29, 30, 41].
Seong teaches the first binder is 0.1 – 10 parts by weight, and Seong teaches a second binder is 0.1 to 20 parts by weight. Id. As such, Seong teaches a weight (A) of the polyvinylpyrrolidone binder polymer (“second binder”) and a weight (B) of the polyvinylidene fluoride-based binder (“first binder”) polymer satisfy a ratio of A/B < 1 (for example, if the second binder is 1 part by weight and the first binder is 2 parts by weight). Id.
While modified Seong teaches a porous polymer substrate, and a porous coating layer comprising inorganic particles disposed upon this substrate, as well as the two binder polymers and a dispersant, modified Seong is silent as to whether these polymers constitute a separate polymer coating layer coated upon the surface of the inorganic particles.
Zhang teaches a separator “[0009] (a) a porous or microporous substrate (having single or multiple layers or plies of the same or different materials), and (b) a coating layer formed on at least one surface of the substrate, wherein the coating layer comprises or is formed from at least one aqueous or water-based polymeric binder or matrix. The aqueous or water-based polymeric binder or matrix may include one or more typically water-insoluble polymers (such as PVDF), and in some embodiments, the aqueous or water-based polymeric binder or matrix may further include one or more typically water-soluble polymers (such as, by way of example, polyvinyl alcohol (PVA) or polyacrylic acid (PAA)).” Zhang at [0009]. Further, Zhang teaches “[0077] An aqueous-based PVDF/ceramic coating slurry was prepared by uniformly dispersing 25 grams of high purity alumina particles having a D50 average particle diameter of 0.65 μm, a bulk tapped density of 0.8 g/cm3 and a BET surface area of 4.6 m2 /g with 18.7 grams of Formulation #1, a 50:50 blend of Formulation #2 and Formulation #3, two aqueous solutions or suspensions of PVDF:HFP (available from Arkema Inc. of King of Prussia, Pa., under the product line Kynar® Latex) which differ by content of HFP and are described in more detail below. Improved mixing was achieved by first pre-wetting the alumina particles with the Formulation #1 solution or suspension. Dispersion was accomplished using a Silverson High Shear L4M-5 mixer at 5000 rpm for 12 minutes at room temperature. The slurry was applied to the surface of a Celgard®2400 PP microporous membrane.” Id. at [0077 – 81]. Zhang teaches it is known to dissolve PVDF homopolymer and copolymer in organic solvents such as acetone. Id. at [0061]. Zhang teaches or suggests its invention improves “adhesion of the coating to the porous base membrane,” and this “good contact between separator and electrodes may be important for optimal cycle life in a lithium battery.” Id. at [0004].
By “pre-wetting” the alumina particles (i.e. inorganic particles) with Formulation 1, this is coating a polymer onto inorganic particles. Further, the instant specification at page 8 describes “[p.8] the polyvinylidene fluoride-based binder polymer and the polyvinylpyrrolidone binder polymer dissolved in a solvent, so that the polymers are coated on the surface of inorganic particles.” This taken together with “[p. 23] a polyvinylpyrrolidone binder polymer . . . is added to a first organic solvent, isopropylalcohol, and dissolved at 50°C for about 4 hours to prepare a binder polymer solution. Subsequently, Al2O3 inorganic particles . . . and boehmite inorganic particles are added to the binder polymer solution.” Under the broadest reasonable interpretation in light of the specification, this “pre-wetting” reads upon “the porous coating layer further comprises a polymer coating layer on a surface of the inorganic particles.”
One of ordinary skill in the art before the effective filing date of the claimed invention would find it obvious to further modify Seong with the coating method of Zhang, because Zhang teaches a benefit to adhesion which may improve cycle life.
Regarding the amendments, modified Seong is silent as to “a k value of the polyvinylpyrrolidone binder polymer is 90 to 120.”
However, modified Seong is silent as to the K-value. Wiley teaches a table of K-values for PVP, wherein the k value is related to weight-average molecular weight, with a k-value of 120 corresponding to 2,866,000, and k-95 corresponding to 1,483,000. Wiley at p. 13. Wiley teaches that PVP complexes with other polymers, such as PVP and polysulfones, and is usable within applications such as an “adhesive, binder, complexant, or stabilizer.” Wiley at p. 21, 25 (Table 16). This table lists “homopolymers,” followed by the second line “K-15 to K-120” and the third line “K-12 to K-90,” which taken with the neighboring column refer to the relative grades the trade named materials correspond to. This indicates that K-90 to K-120 PVP is well suited to film forming, adhesives, and binders. Id. Wiley teaches a value of k-95 corresponds to higher relative viscosity. Id. at p.24. Finally, Wiley teaches “in addition to the ability to complex, PVP and its analogues along with a large assortment of copolymers are excellent film formers.” Id. at p.1
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An excerpt of p. 25 of Wiley, showing the referenced table.
Taken together with modified Seong, Wiley at least suggests that a PVP binder polymer in the PVP weight average MW range as claimed would fall within the k-value range. Wiley presents a benefit to adhesive performance of the overall polymer layer when utilizing PVP in the cited range, because Wiley also teaches PVP is beneficial as a copolymer, indicating or at least suggesting that a PVDF / PVP k-90 to 120 layer would capture benefits to binder performance. Wiley at p. 25.
A reference is analogous art to the invention if the reference is from the same field of endeavor as the claimed invention or if the reference is reasonably pertinent to the problem faced by the inventor. MPEP 2141.01 (a). Here, Wiley is analogous art because the known properties of polyvinylpyrrolidone and its use as a binder is in the same field of endeavor, and because it is reasonably pertinent to the problem of forming a polymer coating layer utilizing binder polymers. Wiley at p. 25.
One of ordinary skill in the art before the effective filing date of the claimed invention would find it obvious to further modify the polymer coating layer of modified Seong, such that the k-value of the polyvinylpyrrolidone binder polymer is 90 to 120, because Wiley teaches a benefit to binder performance, and because Wiley at least suggests that PVP within the previously claimed weight average MW range would have the requisite k-value.
As amended, Claim 1 now requires a weight average molecular weight of the polyvinylpyrrolidone binder to be more than 2,000,000 to 3,500,000. Modified Seong does not teach a weight average molecular weight of the polyvinylpyrrolidone binder is more than 2,000,000 to 3,500,000.
Nakajima teaches a primary binder and a “secondary binder” which comprises polyvinylpyrrolidone, wherein “[0019] The secondary binder comprising polyvinylpyrrolidone serves to . . . enhance the binding property of the composite binder with the surface of basic solid particles. Polyvinylpyrrolidone has a good binding property with the surface of basic solid particles . . . Additionally, polyvinylpyrrolidone is flexible so that the workability during the construction process of an electrode assembly, which involves spiral winding and/or stacking, is improved.” Nakajima at [0019]. Nakajima teaches “[0017] Likewise, the weight average molecular weight of polyvinylpyrrolidone is not specifically limited, but preferably 10,000 to 10,000,000.”
One of ordinary skill in the art before the effective filing date of the claimed invention would find it obvious to modify the separator of modified Seong, such that the polyvinyl binder polymer is more than 2,000,000 to 3,500,000, because Nakajima teaches a benefit to workability and binding property within this range, and because an overlapping range presents a prima facie case of obviousness. MPEP 2144.05 (I).
Claim 1 is obvious over Seong, in view of Zhang, Wiley and Nakajima.
Regarding Claim 2, Claim 2 relies upon Claim 1. Claim 1 is taught by the modification of Seong. Seong teaches the first binder is 0.1 – 10 parts by weight, and Seong teaches a second binder is 0.1 to 20 parts by weight. Seong at [0007, 22-29, 30, 41]. As such, Seong teaches the separator for a lithium secondary battery according to claim 1, wherein the weight (A) of the polyvinylpyrrolidone binder polymer and the weight (B) of the polyvinylidene fluoride-based binder polymer satisfy the ratio of 0.1 < A/B < 1.
Claim 2 is obvious over Seong, in view of Zhang, Wiley and Nakajima.
Regarding Claim 4, Claim 4 relies upon Claim 1. Claim 1 is taught by the modification of Seong.
Zhang teaches “[0063] In other particular embodiments, the coating described herein includes the typically water-insoluble polymer described just above, but further includes one or more typically water-soluble binders or components or polymers. . . . examples of water-soluble polymers or binders useful herein may include, but are not limited to, polyvinyl alcohols, carboxymethyl cellulose, polylactams, polyacrylic acid, polyacrylates, and polyvinyl acetate.” Zhang at [0063-64]. This reads upon “the dispersant comprises . . . . carboxy methyl cellulose.”
Claim 4 is obvious over Seong, in view of Zhang, Wiley and Nakajima.
Regarding Claim 7, Claim 7 relies upon Claim 1. Claim 1 is taught by the modification of Seong. Seong teaches a separator wherein the first binder is 0.1 – 10 parts by weight, and Seong teaches a second binder is 0.1 to 20 parts by weight. Seong at [0007, 22-29, 30, 41]. As such, the modification of Seong teaches the separator for a lithium secondary battery according to claim 1, wherein the weight (A) of the polyvinylpyrrolidone binder polymer and the weight (B) of the polyvinylidene fluoride-based binder polymer satisfy the ratio of 0.15 < A/B < 0.35.
Claim 7 is obvious over Seong, in view of Zhang, Wiley and Nakajima.
Regarding Claim 9, Claim 9 relies upon Claim 1. Claim 1 is taught by the modification of Seong. Seong teaches a polyvinylidene fluoride-based binder polymer comprises polyvinylidene fluoride. Seong at [0007, 22-29, 30, 41]. As such the modification of Seong teaches the separator for a lithium secondary battery according to claim 1, wherein the polyvinylidene fluoride-based binder polymer comprises at least one of polyvinylidene fluoride, polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trifluoroethylene, polyvinylidene fluoride-co-chlorotrifluoroethylene, or polyvinylidene fluoride-co-tetrafluoroethylene, or a combination thereof. As such, Claim 9 is obvious over Seong, in view of Zhang, Wiley, and Nakajima.
Regarding Claim 12, Claim 12 relies upon Claim 1. Claim 1 is taught by the modification of Seong. Seong teaches a lithium secondary battery, comprising: a positive electrode a negative electrode, and a separator interposed between the positive electrode and the negative electrode. Seong at [0007, 22-29, 30, 41]. The modification of Seong teaches a separator, wherein the separator is defined in claim 1.
Claim 12 is obvious over Seong, in view of Zhang, Wiley and Nakajima.
Regarding Claim 14, Claim 14 relies upon Claim 1. Claim 1 is obvious over modified Seong.
While modified Seong does not utilize the term “non-particulate,” because the binder polymer mixture of Seong acts as a dispersant which coats inorganic particles in solution prior to being coated upon a separator, Seong teaches the polyvinylidene fluoride-based binder polymer is a nonparticulate polyvinylidene fluoride-based binder polymer, and the polyvinylpyrrolidone binder polymer is a nonparticulate polyvinylpyrrolidone binder polymer under the broadest reasonable interpretation.
Claim 14 is obvious over Seong, in view of Zhang, Wiley and Nakajima.
Regarding Claim 15, Claim 15 relies upon Claim 1. Claim 1 is obvious over modified Seong.
Modified Seong teaches the polyvinylidene fluoride-based binder polymer and the polyvinylpyrrolidone binder polymer are in a blend, and are applied during a pre-wetting process to coat inorganic particles as taught by Zhang. Wiley teaches K-90-120 PVP acts as a “binder,” “stabilizer,” and “viscosity modifier,” making it suitable for stabilizing dispersions. Wiley at p. 25. Because “solubilized” under the broadest reasonable interpretation includes “acts as a solubility increasing agent, or is modified to increase solubility, modified Seong teaches the polyvinylidene fluoride-based binder polymer is a solubilized polyvinylidene fluoride-based binder polymer, and the polyvinylpyrrolidone binder polymer is a solubilized polyvinylpyrrolidone binder polymer.
Claim 15 is obvious over Seong, in view of Zhang, Wiley and Nakajima.
Regarding Claim 16, Claim 16 relies upon Claim 1. Claim 1 is obvious over modified Seong.
Modified Seong teaches the polyvinylidene fluoride-based binder polymer and the polyvinylpyrrolidone binder polymer are in a blend, and are applied during a pre-wetting process to coat inorganic particles as taught by Zhang. Wiley teaches K-90-120 PVP acts as a “binder,” “stabilizer,” and “viscosity modifier,” making it suitable for stabilizing dispersions. Wiley at p. 25. Because “solubilized” under the broadest reasonable interpretation includes “acts as a solubility increasing agent, or is modified to increase solubility, modified Seong reads upon “the polyvinylidene fluoride-based binder polymer and the polyvinylpyrrolidone binder polymer are dissolved in a solvent coat and applied to the surface of the inorganic particles so that solubilized polyvinylidene fluoride-based binder polymer and solubilized polyvinylpyrrolidone binder polymer form the polymer coating layer on the surface of the inorganic particles.”
As such, Claim 16 is obvious over Seong, in view of Zhang, Wiley and Nakajima.
Regarding Claim 17, Claim 17 relies upon Claim 1. Claim 1 is obvious over modified Seong.
Wiley teaches the k-value of the polyvinylpyrrolidone binder polymer is in a range of more than 90 to 120 or less.
Claim 17 is obvious over Seong, in view of Zhang, Wiley and Nakajima.
Regarding Claim 20, Claim 20 relies upon Claim 1. Claim 1 is obvious over modified Seong.
Nakajima teaches the weight average molecular weight of the polyvinylpyrrolidone binder polymer is 10,000 to 10,000,000, which presents an encompassing range with 2,500,000 to 3,500,000.
Claim 17 is obvious over Seong, in view of Zhang, Wiley and Nakajima.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Seong, in view of Zhang, Wiley, and Nakajima as applied to claim 1, and further in view of Jung, et. al. (US 20160293920 A1).
Regarding Claim 8, Claim 8 relies upon Claim 1. Claim 1 is obvious over modified Seong.
Jung teaches a separator for a rechargeable lithium battery having a heat-resistant porous layer comprising a binder, comprising a cross-linked binder and a non-crosslinked binder. Jung at [0080- 83]. This porous layer further comprises a filler which may include an inorganic particle. Jung at [0006, 17].
The non-crosslinked binder may be polyvinylpyrrolidone, and may be different from the cross-linked binder. Id. Jung teaches “[0083] when the non-crosslinked binder is used with the crosslinked binder, adherence to the substrate may be improved and a uniform heat-resistant porous layer may be formed. Thus, a safer separator may be ensured. In addition, electrolyte solution impregnation properties may be improved, and thus cycle-life characteristics, high rate charge, and discharge characteristics of a battery may be improved.” Id. The Office notes that polyvinylidene fluoride (PVDF) may be cross-linked or uncross-linked. An amount of the filler may be 50 wt% - 95 wt% based upon the total amount of a total amount of a binder “including the crosslinked binder and the non-crosslinked binder and the filler.” Id. at [0089]. This completely encompasses the claimed range of a weight ratio of the inorganic particles (i.e., an inorganic particle filler) and a total amount of the binder polymer (the cross-linked binder and a non-crosslinked binder, or an applicable two polymer blend) is 80:20 to 50:50. An encompassing range presents a prima facie case of obviousness. MPEP 2144.05 (I).
One of ordinary skill in the art before the effective filing date of the claimed invention would find it obvious to further modify the polymer coating layer of Seong, such that it comprises a non-crosslinked polyvinylpyrrolidone binder polymer and a cross-linked PVDF binder polymer, and further comprise a weight ratio of the inorganic particles (i.e., an inorganic particle filler) and a total amount of the binder polymer (the cross-linked binder and a non-crosslinked binder, or an applicable two polymer blend) is 80:20 to 50:50, because Jung teaches a benefit to cycle-life characteristics and safety when using a cross-linked and non-crosslinked polymer binder together, and because . an encompassing range presents a prima facie case of obviousness. MPEP 2144.05 (I).
Claim 8 is obvious over Seong, in view of Zhang, Wiley and Nakajima, and further in view of Jung.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Seong, in view of Zhang, Wiley, and Nakajima as applied to claim 1, and further in view of Usami, et. al. (WO2010074151A1).
Regarding Claim 10, Claim 10 relies upon Claim 1. Claim 1 is taught by the modification of Seong. Seong teaches a battery separator, but is silent as to internal resistance of the separator. Seong at [0007, 22-29, 30, 41].
Usami teaches a battery separator, wherein “electrical resistance at 25 ° C. is preferably 10 Ω or less, more preferably 5.0 Ω or less, further preferably 3.0 Ω or less. By setting it to 10 Ω or less, it can have sufficiently superior battery performance when used at room temperature . . . .if the electric resistance at 25 ° C. is 0.1 Ω or more, troubles such as internal short circuit can be sufficiently avoided as a battery separator.” Usami at p. 10. As such, this suggests a resistance range of preferably 0.1 - 3 Ω. As such, this is an overlapping range with the claimed 1 Ω or less.
One of skill would find it obvious to modify the modified separator of modified Seong with the resistance range of Usami, because Usami teaches a benefit to performance and safety, and 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).
Claim 10 is obvious over Seong, in view of Zhang, Wiley, and Nakajima, and further in view of Usami.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Seong, and in view of Zhang, Wiley, and Nakajima, as applied to claim 1 above, and further in view of Nishimura, et. al. (KR 20150035548 A).
Regarding Claim 11, Claim 11 relies upon Claim 1. Claim 1 is taught by the modification of Seong. Seong teaches a separator, having a porous separator with
a polyvinylpyrrolidone binder and a polyvinylidene fluoride-based binder polymer, but is silent as to whether these are dissolved in an organic solvent.
Nishimura teaches a porous separator with a polyvinylpyrrolidone binder and a polyvinylidene fluoride-based binder polymer, which may be “dissolved,” in an “organic solvent,” such as gamma-butyrolactone. Nishimura at Abstract, p.1-2. The porous film as produced by these steps may “suppress an increase in separator resistance.” Nishimura at p.2.
One of ordinary skill in the art before the effective filing date of the claimed invention would find it obvious to further modify the separator of modified Seong to be feature its binders as dissolved in organic solvents as in Nishimura, because this may contribute to improvements to internal resistance.
Claim 11 is obvious unpatentable over Seong, and in view of Zhang, Wiley, and Nakajima, and further in view of Nishimura.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Seong, in view of Zhang, Wiley, and Nakajima as applied to Claim 1 above, and further in view of Sunano, et. al. (EP1139480B1).
Regarding Claim 13, Claim 13 relies upon Claim 12. Claim 12 is taught by the modification of Seong. Regarding the interpretation of Claim 13, Lami Strength is taken to include “peel strength,” under the broadest reasonable interpretation, and as converted, the peel strength is 0.6 gf / mm or more. Seong is silent as to specific peel strength.
Sunano teaches a peel strength between a positive electrode and a separator of a secondary battery cell being 1.5 – 2.8 gf / mm due to an adhesive layer within the separator. Further, Sunano teaches a benefit in a peel strength of 0.2 gf / mm or higher, assisting in preventing in detachment during decomposition of the liquid electrolyte. (“if the adhesive strength between the positive electrode and the separator is 0.02 N/10 mm (2 gf/10 mm) or higher as in the above construction, even when the cell is overcharged, oxidation and decomposition of the liquid electrolyte and the gel begins at the positive electrode, and gas is generated, because the stack strength is large, detachment of the bonded portion of the positive electrode and the separator is suppressed.” As such, Sunano encompasses the claimed range.
The modification of Seong may be further modified such that the adhesive layer of Seong has the peel strength specified in Sunano, because Sunano teaches a benefit in preventing detachment during oxidation or decomposition, and because an encompassing range presents a prima facie case of obviousness. MPEP 2144.05 (I)..
As such, Claim 13 is obvious over Seong, in view of Zhang, Wiley, and Nakajima, and further in view of Sunano.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Seong, in view of Zhang, Wiley, and Nakajima, as applied to claim 1, and further in view of Jung, Nishimura and Usami.
Regarding Claim 18, Claim 18 relies upon Claim 1. Claim 1 is obvious over modified Seong.
Jung teaches that within its porous layer, the cross-linked and non-cross-linked binder may be included in a porous layer, comprising a filler which may include an inorganic particle. Jung at [0006, 17]. An amount of the filler may be 50 wt% - 95 wt% based upon the total amount of a total amount of a binder “including the crosslinked binder and the non-crosslinked binder and the filler.” Id. at [0089]. This completely encompasses the claimed range of a weight ratio of the inorganic particles and a total amount of the binder polymer is 80:20 to 50:50.
Jung teaches a separator for a rechargeable lithium battery having a heat-resistant porous layer comprising a binder, comprising a cross-linked binder and a non-crosslinked binder. Jung at [0080- 83]. This porous layer further comprises a filler which may include an inorganic particle. Jung at [0006, 17].
The non-crosslinked binder may be polyvinylpyrrolidone, and may be different from the cross-linked binder. Id. Jung teaches “[0083] when the non-crosslinked binder is used with the crosslinked binder, adherence to the substrate may be improved and a uniform heat-resistant porous layer may be formed. Thus, a safer separator may be ensured. In addition, electrolyte solution impregnation properties may be improved, and thus cycle-life characteristics, high rate charge, and discharge characteristics of a battery may be improved.” Id. The Office notes that polyvinylidene fluoride (PVDF) may be cross-linked or uncross-linked. An amount of the filler may be 50 wt% - 95 wt% based upon the total amount of a total amount of a binder “including the crosslinked binder and the non-crosslinked binder and the filler.” Id. at [0089]. This completely encompasses the claimed range of a weight ratio of the inorganic particles (i.e., an inorganic particle filler) and a total amount of the binder polymer (the cross-linked binder and a non-crosslinked binder, or an applicable two polymer blend) is 80:20 to 50:50. An encompassing range presents a prima facie case of obviousness. MPEP 2144.05 (I).
One of ordinary skill in the art before the effective filing date of the claimed invention would find it obvious to further modify the polymer coating layer of Seong, such that it comprises a non-crosslinked polyvinylpyrrolidone binder polymer and a cross-linked PVDF binder polymer, and further comprise a weight ratio of the inorganic particles (i.e., an inorganic particle filler) and a total amount of the binder polymer (the cross-linked binder and a non-crosslinked binder, or an applicable two polymer blend) is 80:20 to 50:50, because Jung teaches a benefit to cycle-life characteristics and safety when using a cross-linked and non-crosslinked polymer binder together.
Seong teaches a battery separator, but is silent as to internal resistance of the separator. Seong at [0007, 22-29, 30, 41].
Usami teaches a battery separator, wherein “electrical resistance at 25 ° C. is preferably 10 Ω or less, more preferably 5.0 Ω or less, further preferably 3.0 Ω or less. By setting it to 10 Ω or less, it can have sufficiently superior battery performance when used at room temperature . . . .if the electric resistance at 25 ° C. is 0.1 Ω or more, troubles such as internal short circuit can be sufficiently avoided as a battery separator.” Usami at p. 10. As such, this suggests a resistance range of preferably 0.1 - 3 Ω. As such, this is an overlapping range with the claimed 1 Ω or less.
One of skill would find it obvious to modify the modified separator of modified Seong with the resistance range of Usami, because Usami teaches a benefit to performance and safety, and 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).
However, modified Seong is silent as to the dissolution as claimed.
Nishimura teaches a porous separator with a polyvinylpyrrolidone binder and a polyvinylidene fluoride-based binder polymer, which may be “dissolved,” in an “organic solvent,” such as gamma-butyrolactone. Nishimura at Abstract, p.1-2. The porous film as produced by these steps may “suppress an increase in separator resistance.” Nishimura at p.2.
One of ordinary skill in the art before the effective filing date of the claimed invention would find it obvious to further modify the separator of modified Seong to be feature its binders as dissolved in organic solvents as in Nishimura, because this may contribute to improvements to internal resistance.
Claim 18 is obvious over Seong, in view of Zhang, Jung, Wiley, and Nakajima, and further in view of Nishimura and Usami.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Seong, in view of Zhang, Wiley, and Nakajima as applied to claim 1, and further in view of Yang, et. al. (US2016285063A1).
Regarding Claim 20, Claim 20 relies upon Claim 1. Claim 1 is obvious over modified Seong.
Modified Seong is silent as to whether the polyvinylpyrrolidone is non-crosslinked.
Yang teaches a separator for a rechargeable lithium battery, wherein this separator comprises a heat-resistant porous layer, having a main binder (“a cross-linked binder”) and a secondary non-crosslinked binder, wherein the non-crosslinked binder may comprise polyvinylpyrrolidone. Yang at [0008, 53]. Yang teaches “[0168] The rechargeable lithium battery according to an embodiment may realize cell performance such as cycle-life characteristics and safety as well as thermal stability due to the separator for a rechargeable lithium battery having improved mechanical strength and wettability for an electrolyte solution.” One of ordinary skill before the effective filing date of the claimed invention would find it obvious to modify the separator of modified Seong, such that the polyvinylpyrrolidone is not crosslinked, because Yang teaches such a secondary binder contributes to cell performance such as cycle-life, safety, and mechanical strength.
Claim 19 is obvious over Seong, in view of Zhang, Wiley, and Nakajima, and further in view of Yang.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-2, 4, 7-18 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claims 19 and 20 are newly rejected in this action.
Conclusion
THIS ACTION IS MADE FINAL. 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.
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/K.R.H./Examiner, Art Unit 1728
/NICOLE M. BUIE-HATCHER/Supervisory Patent Examiner, Art Unit 1725