SEPARATOR FOR POWER STORAGE DEVICE, AND POWER STORAGE DEVICE
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 .
Response to Amendment
In response to communication filed on 1/8/2026:
Claims 1, 8, 10, 21, and 23 have been amended; claims 2, 9, 11, 15, and 16 have been canceled. No new matter has been entered.
Previous rejections under 35 USC 112(b) and 102(a)(1) have been withdrawn due to amendment.
Previous rejections under 35 USC 103 have been modified due to amendment.
Previous drawing objections have been withdrawn.
Response to Arguments
Applicant's arguments filed 1/8/2026 have been fully considered but they are not persuasive.
The Applicant discloses: “Neither of Hamasaki or any of the secondary references disclose nor suggest the pentad fraction, and neither of them focuses on the importance of controlling the crystallinity of polypropylene. The rationale to support a conclusion that a claim would be obvious is that all the claimed elements were known in the prior art. See MPEP § 2143. Here, the primary reference Hamasaki does not disclose nor suggest all of the features of the amended claims as discussed above. The secondary references do not cure this deficiency. Accordingly, Applicant submits that the amended claims are non-obvious in view of the cited references.
In addition, the benefit of the claimed invention according to amended claim 1 or 21 is further supported by the Example section of the specification. The claimed pentad fraction is advantageous in achieving good air permeability without significantly degrading strength. For amended claim 1 (first aspect), the experimental results indicated in Tables 1 and 2 can be summarized as follows.
Example 1 satisfying high crystallinity results in an appropriately large pore diameter (265 nm) and high puncture strength (323 gf). It is remarkable that in this Example, the air permeability resistance is low (152 s/100 cm3) but the puncture strength is still high. This Example also exhibits a sufficiently high cycle capacity retention rate (80%).
Examples 2 and 4 having slightly lower crystallinity than Example 1 (99.3% vs. 97.9% or 97.1%) results in a slightly smaller maximum pore diameter (265 nm vs. 253 nm or 257 nm). Examples 2 and 4 exhibit decreased air permeability due to lower crystallinity (and thereby poorly- oriented pores) (152 s/100 cm3 vs. 186 s/100 cm3 or 160 s/100 cm3). Example 3 having further lower crystallinity exhibits lower puncture strength (307 gf) due to low crystallinity (and thereby poorly- oriented pores). Example 5 having high crystallinity but extremely large pore size (649 nm) results in low puncture strength (309 gf). Applicant notes that the porous layer of this Example was produced with a very long annealing time in order to intentionally make the pore size large. For claim 21 (second aspect), the experimental results indicated in Table 11 can be summarized as follows.
Examples 1 and 5 satisfy high crystallinity and result in good air permeability (185 s/100 cm3 for Example 1, 172 s/100 cm3 for Example 5). Even though exhibiting such good air permeability, these Examples exhibit satisfactory puncture strength (345 gf and 330 gf). On the other hand, Examples 2 to 4 have lower crystallinity (97.9%, 98.3%, 94.8%) and thereby poorer air permeability (225 s/100 cm3, 241 s/100 cm3, 249 s/100 cm3).
The presence of an unexpected property not possessed by the prior art is evidence of non- obviousness. See MPEP § 716.02(A). Here, the separator as set forth in the amended claims exhibits good air permeability with unexpected puncture strength. Such features are not disclosed nor suggested in any of the cited references. Accordingly, Applicant submits that the claimed invention is non-obvious in view of the cited references, either alone or in combination. Withdrawal of the rejections is requested.”
The Examiner respectfully traverses. The data in Tables 1, 2, and 11 appear to be inconclusive in regards to demonstrating criticality for the claimed pentad fraction values. Examples 1-5 all show puncture strength values within the 5% error range. Further, Example 3 shows a puncture strength of 307 gf (within the 5% (4.95%) error range of 323 gf of Example 1) and an air permeability resistance of 148 s/100 cm3 (a difference of 2.6% when compared to 152 s/100 cm3 for example 1). Further, as indicated by Applicant, Example 5 has an extremely large pore size due to a long annealing time but also the highest cycle capacity retention rate. Therefore, Table 1 only shows consistent appreciable results for Example 1 to support the claimed pentad fraction range. Meanwhile, Example 3 shows results very close and within the 5% error range of Example 1 but having a pentad fraction outside the claimed range at 95.8%. Further, to note, Example 3 shows a capacity retention rate of 81% vs Example 1’s 80%.
The experimental parameters for Examples 1-5 vary between each other. The molecular weight of polypropylene in Examples 1 and 5 is at 900000 while Examples 2-4 vary greatly. Mw/Mn of polypropylene also varies in addition to separator thickness and porosity. In order to demonstrate criticality of one variable, all others need to be constant with each other.
Therefore, results in Tables 1 and 2 show inconsistency in results when demonstrating criticality of pentad fraction.
In addition, Table 4 shows results for comparative examples for the same single layer separator as shown in Tables 1 and 2 having pentad fractions inside and outside the claimed range showing higher air permeability regardless of the value. This does not support criticality of the pentad fraction limitation.
Finally, the Applicant discusses Table 11 showing criticality. However, the results are for an entirely different embodiment from the separator claimed. Claims 1 and 21 disclose a single layer separator while Table 11 shows results for a three-layer separator. These data are not commensurate within the scope of the claim.
New grounds of rejection are submitted due to amendment.
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, 5, 7-8, 10, 14, and 17-20 are rejected under 35 U.S.C. 103 as being unpatentable over Hamasaki et al. (WO 2019/103947 A1 using US 2021/0367309 A as an English language translation.) and further in view Nemoto et al. (US 2013/0196208 A1).
Regarding claims 1, 19, and 20, Hamasaki et al. teach an electricity storage device separator comprising a microporous layer (X) mainly composed of a polyolefin (A) (Abstract; paragraph 0062 discloses a separator for an electric storage device comprising a microporous membrane comprising polyolefin. Further, claim 1 discloses the polyolefin is comprised of polypropylene.),
wherein a melt flow rate (MFR) of the microporous layer (X) at a load of 2.16 kg and a temperature of 230 °C is 0.9 g/10 min or less (Paragraph 0141 discloses determining melt flow rate at a load of 2.16 kg and a temperature of 230 °C. Claim 1 discloses a melt flow rate of 1.0 g/10 min or less.), and
in an MD-TD surface observation or an ND-MD cross-section observation of the microporous layer (X) by a scanning electron microscope (SEM) (Paragraph 0137), an average long pore diameter of pores present in the microporous layer (X) is 100 nm or more and 400 nm or less (Claim 28 discloses the average longest pore diameter is 100-2000 nm.).
However, Hamasaki et al. do not teach a pentad fraction of the polypropylene is 98.5% or greater.
Nemoto et al. teach a separator for a battery (Abstract). The separator can comprise a polypropylene resin having a pentad fraction of 80-99% (Paragraph 0045).
Therefore, it would have been obvious to one of ordinary skill in the art to modify the polypropylene material of the separator of Hamasaki with that of Nemoto in order to improve air permeability and mechanical strength.
Regarding claim 5, Hamasaki and Nemoto et al. teach the electricity storage device separator according to claim 1. Further, Hamasaki et al. teach wherein a ratio (SMD/STD) of tensile strength in machine direction (SMD) to tensile strength in width direction (STD) of the electricity storage device separator is SMD/STD > 5 (Table 7 discloses tensile strength results in MD and TD direction. The ratio of SMD/STD for example 1 is 13.).
Regarding claim 7, Hamasaki and Nemoto et al. teach the electricity storage device separator according to claim 1. Further, Hamasaki et al. teach wherein an air permeability of the electricity storage device separator when converted into a thickness of 14 µm (Paragraph 0129 discloses a separator thickness of 14 microns.) is 250 s/100 cm3 or less (Paragraph 0052 discloses an air permeability resistance of 100-500 seconds/100 mL.).
Regarding claim 8, Hamasaki and Nemoto et al. teach the electricity storage device separator according to claim 1. Further, Hamasaki et al. teach having a thickness of 8 µm or more and 18 µm or less and a puncture strength of 230 gf or more when the separator is converted into a thickness of 14 µm (Paragraph 0053 discloses the separator has a puncture strength of 400 gf or more, provided that the puncture strength is a value obtained by multiplying an actual measured puncture strength of the separator by 14 µm after dividing the actual measured puncture strength by a thickness of the separator.).
Regarding claims 10, Hamasaki and Nemoto et al. teach the electricity storage device separator according to claim 1. Further, Hamasaki et al. teach wherein a ratio of the polypropylene to the polyolefin (A) is 50 to 100% by mass. (Claim 1 discloses the microporous membrane comprises a polypropylene resin and a thermoplastic monomer. Claim 7 discloses the weight ratio of the polypropylene resin (A) to the thermoplastic elastomer (B) is 99.9:0.1 to 80:20.).
Regarding claims 14 and 17, Hamasaki and Nemoto et al. teach the electricity storage device separator according to claim 1. Further, Hamasaki et al. teach further comprising a microporous layer (Y) mainly composed of a polyolefin (B); wherein a main component of the polyolefin (A) is polypropylene, and a main component of the polyolefin (B) is polyethylene (Paragraph 0056 discloses a the separator comprises a microporous multi-layered membrane in which the microporous membrane comprising the polypropylene resin (A) and the thermoplastic elastomer (B) and a microporous membrane comprising a polyethylene as a major component.).
Regarding claim 18, Hamasaki and Nemoto et al. teach the electricity storage device separator according to claim 1. Further, Hamasaki et al. teach wherein a porosity of the electricity storage device separator is 20% or greater and 70% or less (Paragraph 0095 discloses a porosity of the microporous membrane is 30 to 80%.).
Claims 3 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Hamasaki et al. (WO 2019/103947 A1 using US 2021/0367309 A as an English language translation.) and Nemoto et al. (US 2013/0196208 A1) as applied to claim 1 above, and further in view of Obara et al. (JP 2012-092286 A).
Regarding claim 3 and 4, Hamasaki and Nemoto et al. teach the electricity storage device separator according to claim 1. Further, Hamasaki et al. disclose a melt tension of the microporous layer (X) is measured at a temperature of 230 °C (Paragraphs 0139-0141). However, they do not teach wherein the melt tension is 16 mN or more and 40 mN or less
Obara et al. teach a propylene-based resin micropore film for use in a lithium-ion battery (Abstract). Further, the melt tension is at 1.1-3.2 grams which would yield 11-31 mN (Abstract).
Therefore, it would have been obvious to one of ordinary skill in the art to modify Hamasaki with Obara in order to improve mechanical strength.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Hamasaki et al. (WO 2019/103947 A1 using US 2021/0367309 A as an English language translation.) and Nemoto et al. (US 2013/0196208 A1) as applied to claim 1 above, and further in view of Ishihara et al. (US 2013/0302696 A1), and further in view of Ohya et al. (US 2018/0233730 A1).
Regarding claim 6, Hamasaki and Nemoto et al. teach the electricity storage device separator according to claim 1. However, they do not teach wherein a heat shrinkage rate of the electricity storage device separator after 1 h of heat treatment at 105 °C is 1% or less in TD and 4% or less in MD, and a heat shrinkage rate of the electricity storage device separator after 1 h of heat treatment at 120 °C is 1% or less in TD and 10% or less in MD.
Ishihara et al. teach a microporous membrane comprising polyolefin materials (Abstract; claim 1) to be used in a separator for a battery device (Paragraph 0001). Further, the microporous membrane of the present invention preferably has a TD heat shrinkage rate at 105°C of 5% or less, more preferably 2.0%, and still more preferably 0.01 to 0.5%. The microporous membrane of the present invention preferably has a MD heat shrinkage at 105°C of 5% or less, and more preferably 0.5 to 5% (Paragraph 0103).
Therefore, it would have been obvious to one of ordinary skill in the art to modify Hamasaki with Ishihara in order to provide a microporous membrane having a high meltdown temperature, a low shutdown temperature, and resistance to heat shrinkage at high temperatures.
However, neither Hamasaki nor Ishihara et al. teach a heat shrinkage rate of the electricity storage device separator after 1 h of heat treatment at 120 °C is 1% or less in TD and 10% or less in MD.
Ohya et al. teach a porous film comprising a polyolefin such as polypropylene for use in a battery separator (Abstract; claim 1; paragraph 001). Further, the film has a heat shrinkage percentage in the machine direction is 1% or less at 110° C. and a heat shrinkage percentage in the direction substantially orthogonal to machine direction is −1.7% to −1.0% at 110° C (Claim 4). Further, while Ohya does not teach 120° C, this is merely an example of optimization within prior art conditions or through routine experimentation MPEP 2144.05 IIA: Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Therefore, it would have been obvious to one of ordinary skill in the art to modify Hamasaki and Ishihara with Ohya in order to minimize warpage.
Claims 12 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Hamasaki et al. (WO 2019/103947 A1 using US 2021/0367309 A as an English language translation.) and Nemoto et al. (US 2013/0196208 A1) as applied to claim 1 above, and further in view of Mizuno et al. (US 2016/0013461 A1).
Regarding claims 12 and 13, Hamasaki and Nemoto et al. teach the electricity storage device separator according to claim 1. However, they do not teach wherein a weight average molecular weight (Mw) of the microporous layer (X) is 500,000 or greater and 1,500,000 or less; wherein a value (Mw/Mn) obtained by dividing a weight average molecular weight (Mw) by a number average molecular weight (Mn) of the microporous layer (X) is 6 or less.
Mizuno et al. teach a polyolefin porous membrane for use in a battery separator (Abstract). Further, the molecular weight of the microporous layer (X) is 500,000 or greater and 1,500,000 or less (Paragraph 0051) and wherein a value (Mw/Mn) obtained by dividing a weight average molecular weight (Mw) by a number average molecular weight (Mn) of the microporous layer (X) is 6 or less (Paragraph 0055 discloses a molecular weight distribution (Mw/Mn) of the polyethylene resin, namely, the ratio of weight average molecular weight (Mw) to number-average molecular weight (Mn), is preferably in the range from 5 to 200.).
Therefore, it would have obvious to one of ordinary skill in the art to modify Hamasaki with Mizuno in order to provide sufficient mechanical strength upon decreasing polyethylene porous membrane thickness.
Claims 21-28 are rejected under 35 U.S.C. 103 as being unpatentable over Hamasaki et al. (WO 2019/103947 A1 using US 2021/0367309 A as an English language translation.) as applied to claim 1 above, and further in view of Takeda et al. (US 2010/0099838 A1) and further in view of Mizuno et al. (US 2016/0013461 A1) and further in view of Nemoto et al. (US 2013/0196208 A1).
Regarding claims 21, 22, 24, and 28, Hamasaki et al. teach an electricity storage device separator comprising a microporous layer (X) mainly composed of a polyolefin (A) (Abstract; paragraph 0062 discloses a separator for an electric storage device comprising a microporous membrane comprising polyolefin. Further, claim 1 discloses the polyolefin is comprised of polypropylene.),
wherein the polyolefin comprises a polypropylene having a melt flow rate (MFR) of the microporous layer (X) at a load of 2.16 kg and a temperature of 230 °C is 0.9 g/10 min or less (Paragraph 0141 discloses determining melt flow rate at a load of 2.16 kg and a temperature of 230 °C. Claim 1 discloses a melt flow rate of 1.0 g/10 min or less.).
However, Hamasaki et al. do not teach a short-circuit temperature in a fuse short-circuit test of the electricity storage device separator is 200 °C or higher, and a heat shrinkage rate in width direction (TD) and a heat shrinkage rate in machine direction (MD) when the electricity storage device separator is heat-treated at 105 °C for 1 h are TD ≤1% and MD ≤ 4%, respectively.
Takeda et al. teach a polyolefin microporous film comprising polyethylene and polypropylene having a viscosity average molecular weight of 100,000 or higher (Abstract). Further, the temperature and electrical resistance are continuously measured with a fuse short-circuit test (Paragraph 0129). Table 1 shows a short-circuit temperature of > 200 °C (See Table 1, Examples 1-5); Table 1 further shows a fuse temperature in the fuse short-circuit test is 150°C or lower (Table 1, Examples 1-5 disclose 135-137°C.)
Therefore, it would have been obvious to one of ordinary skill in the art to modify Hamasaki with Takeda in order to provide a good film breaking resistance and a low thermal shrinkage.
However, neither Hamasaki nor Takeda disclose a heat shrinkage rate in width direction (TD) and a heat shrinkage rate in machine direction (MD) when the electricity storage device separator is heat-treated at 105 °C for 1 h are TD ≤1% and MD ≤ 4%, respectively.
Mizuno et al. teach a polyolefin porous membrane for use in a battery separator (Abstract). By shrinking the porous molded material in at least one of MD and TD, while the porous molded material is fixed in the both directions, MD and TD, the thermal shrinkage of the porous molded material is good. The ratio of shrinking the porous molded material in at least one of MD and TD, is from 0.01 to 50%, and preferably 3 to 20% at 105°C (Paragraph 0089).
Therefore, it would have been obvious to one of ordinary skill in the art to modify Hamasaki and Takeda with Mizuno in order to improve heat shrinkage and maintain air permeation resistance.
However, Hamasaki, Takeda, and Mizuno et al. do not teach a pentad fraction of the polypropylene is 98.5% or greater.
Nemoto et al. teach a separator for a battery (Abstract). The separator can comprise a polypropylene resin having a pentad fraction of 80-99% (Paragraph 0045).
Therefore, it would have been obvious to one of ordinary skill in the art to modify the polypropylene material of the separator of Hamasaki with that of Nemoto in order to improve air permeability and mechanical strength.
Regarding claim 23, the combination of Hamasaki, Takeda, Mizuno, and Nemoto et al. teach the electricity storage device separator according to claim 21. Further, Takeda teaches wherein a value (Mw/Mn) obtained by dividing a weight average molecular weight (Mw) by a number average molecular weight (Mn) of the microporous layer (X) is 6 or less (Paragraph 0055 discloses a molecular weight distribution (Mw/Mn) of the polyethylene resin, namely, the ratio of weight average molecular weight (Mw) to number-average molecular weight (Mn), is preferably in the range from 5 to 200.).
Therefore, it would have obvious to one of ordinary skill in the art to modify Hamasaki with Mizuno in order to provide sufficient mechanical strength upon decreasing polyethylene porous membrane thickness.
Regarding claim 25, the combination of Hamasaki, Takeda, Mizuno, and Nemoto et al. teach the electricity storage device separator according to claim 21. Further, Hamasaki et al. teach comprising a multilayer structure of a microporous layer mainly composed of polypropylene and a microporous layer mainly composed of polyethylene (Paragraph 0172).
Regarding claim 26, the combination of Hamasaki, Takeda, Mizuno, and Nemoto et al. teach the electricity storage device separator according to claim 21. Further, Hamasaki et al. teach wherein in a wide-angle X-ray scattering measurement of the microporous layer (Paragraph 0332), a ratio MD/TD of an orientation ratio in machine direction (MD) to an orientation ratio in width direction (TD) is 1.3 or greater (Claim 1 discloses 1.5 or more and 10.0 or less.).
Regarding claim 27, the combination of Hamasaki, Takeda, Mizuno, and Nemoto et al. teach the electricity storage device separator according to claim 21. Further, Hamasaki et al. teach having a thickness of 18 µm or less, a porosity of 42% or greater (Paragraph 0051 discloses a porosity of 30-80%.), and an air permeability resistance of 250s/100cm3 or less when converted into a thickness of 14 µm (Paragraph 0052 discloses wherein the separator has an air permeability resistance of 100 to 500 seconds/100 ml, provided that the air permeability resistance is a value obtained by multiplying an actual measured air permeability resistance of the separator by 14 µm after dividing the actual measured air permeability resistance by a thickness of the separator.).
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 DANIEL S GATEWOOD whose telephone number is (571)270-7958. The examiner can normally be reached M-F 8:00-5:30.
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Daniel S. Gatewood, Ph.D.
Primary Examiner
Art Unit 1729
/DANIEL S GATEWOOD, Ph. D/Primary Examiner, Art Unit 1729 February 2nd, 2026