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
This Office Action is responsive to the amendment filed on 8/10/2026. Claims 8-38 have been canceled. Claims 1, 2, 6 are pending. Claims 3-5, 7 are withdrawn from further consideration as being drawn to a non-elected invention, in accordance with 37 CFR 1.142(b). Claim 1 has been amended. Claims 3-5 and 7 are objected to. Applicant’s arguments have been considered. Claims 1, 2, 6 are finally rejected for reasons necessitated by applicant’s amendment.
Claim Objection
The status identifiers for claims 3-5 and 7 should be “Withdrawn” or “Withdrawn-Currently Amended”.
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.
Claims 1, 2, 6 are rejected under 35 U.S.C. 103 as being unpatentable over Zhu (A Highly Thermostable Ceramic-Grafter Microporous Polyethylene Separator for Safer Lithium-Ion Batteries, ACS Applied Materials and Interfaces, 2015, 7, 24119-24126) in view of Hasegawa (US 6054498) and Tsujimoto (WO 2019/187727, using US 2021/0017363 as translation).
Regarding claim 1, a separator for a nonaqueous secondary battery, comprising silicon (Si)-containing molecules, wherein
the separator for a nonaqueous secondary battery is a polyethylene microporous membrane, the polyethylene microporous membrane contains a silane-modified polyolefin,
in a Si-containing image detected by a time-of-flight secondary ion mass spectrometry (TOF-SIMS) measurement of the separator for a nonaqueous secondary battery, a Voronoi area (mu) at maximum frequency of Voronoi polygons obtained by carrying out Voronoi tessellation is within a range of 1.0 µm² to 17.5 µm², and
a spread (σ) of a Voronoi area frequency distribution of the Si-containing image detected by the TOF-SIMS measurement is within a range of 0.5 µm² to 8.5 µm², the instant Specification states:
[0029] When the Voronoi area (mu) at maximum frequency of Voronoi polygons obtained by carrying out Voronoi tessellation is within a range of 1.0 μm.sup.2 to 17.5 μm.sup.2, the Si-containing molecules tend to be dispersed in a state of not being a sea-island structure in the separator. For example, when the nonaqueous secondary battery is a lithium ion secondary battery, if the separator containing Si elements dispersed uniformly therein coexist with a lithium (Li) complex solvated with an electrolytic solution having unshared electron pair such as oxygen atoms, it is considered that the product life in a battery cycle characteristic test is prolonged by the following phenomena (i) and (ii).
(i) The Li complex exhibits high affinity with Si atoms and therefore exists in the vicinity of Si atoms with high probability. For such a phenomenon, a reaction in which non-fed electron pairs in the molecular structure of the electrolytic solution are coordinated to Si atoms is important. As mentioned in NPL1, since the Si atom has a large atomic radius, it is possible to have tetra or higher-coordination, and to have special properties in which a structure using 4-electron-3-center bonds and d-orbitals can exist. That is, it is possible to form a path in which Li ions can easily flow uniformly over the entire surface of the separator. Therefore, for example, a secondary battery including a positive electrode such as an NMC positive electrode containing lithium (Li)-nickel (Ni)-manganese (Mn)-cobalt (Co) composite oxide is uniformly charged and discharged, thereby suppressing crystal breakage.
(ii) For example, when the negative electrode is a Si-containing negative electrode, charging/discharging of the Si elements in the negative electrode can be uniformly carried out, and uniform expansion convergence of the Si-containing negative electrode enables suppression of deformation inside the secondary battery.
[0030] While not wishing to be bound by any theory, it is considered that the above phenomena (i) and (ii) occur when a complex is homogeneously formed and thus Li+ ions of the separator uniformly flow in a nonaqueous secondary battery,… (emphasis added)
Further, the instant Specification states:
[0034] From the viewpoint of achieving both longer life of the cycle characteristics and the safety of the nonaqueous secondary battery and/or balancing them, the Voronoi area (mu) at maximum frequency of Voronoi polygons obtained by carrying out Voronoi tessellation is preferably within a range of 1.5 μm2 to 17.0 μm2, more preferably 4.0 μm2 to 16.0 μm2, and still more preferably 6.0 μm2 to 13.0 μm2. From the same point of view, the spread (σ) of the Voronoi area frequency distribution of the Si-containing image detected by the TOF-SIMS measurement is preferably within a range of 0.5 μm2 to 8.5 μm2, more preferably 1.7 μm2 to 6.3 μm2, and still more preferably 1.8 μm2 to 4.2 μm2. (emphasis added)
Zhu discloses a polyethylene separator grafted with SiO2. The separator contains a three-dimensional network structure with uniform distribution of SiO2 nanoparticles on the surface of the polyethylene. See Abstract and page 24123. It appears that the uniform distribution of SiO2 grafted onto the polyethylene separator of Zhu meets the limitations of claim 1.
MPEP 2112 V states that "once a reference teaching product appearing to be substantially identical is made the basis of a rejection, and the Examiner presents evidence or reasoning tending to show inherency, the burden shifts to the Applicant to show an unobvious difference."
Regarding claim 2, a ratio (σ/mu) of the spread (σ) of the Voronoi area frequency distribution to the Voronoi area (mu) at maximum frequency is 0.06 to 0.70, the instant Specification states:
[0037] Regarding a Si-containing image detected by the TOF-SIMS measurement, the ratio (σ/mu) of the spread (σ) of the Voronoi area frequency distribution to the Voronoi area (mu) at maximum frequency preferably satisfies the following relationship.
0.06≤σ/mu≤0.7
In the first embodiment, the ratio (σ/mu) in Voronoi tessellation can be regarded as an indicator that indicates whether or not the Si-containing molecules are uniformly dispersed on the separator surface. When the ratio (σ/mu) is within a range of 0.06 to 0.70, the Si-containing molecules are uniformly dispersed on the separator surface and sufficiently contribute to the coexistence of the Li complex derived from the electrolytic solution and the separator and the silane crosslinking reaction of the separator in the nonaqueous secondary battery, and thus the cycle product life of the battery can be prolonged. While not wishing to be bound by any theory, it was experimentally discovered in PTL 1 that the concentration at which an intermediate in which the Li complex is coordinated in the plane of the separator is present, or the life of the intermediate in an equilibrium state is important, and the ratio (σ/mu) in Voronoi tessellation can uniformly contribute to the intercalation reaction to electrodes. From the viewpoint of further prolonging the cycle product life of the battery, the ratio (σ/mu) is preferably within a range of 0.07 to 0.57, and more preferably 0.19 to 0.38.
It appears that the uniform distribution of SiO2 grafted onto the polyethylene separator of Zhu meets the limitations of claim 2.
MPEP 2112 V states that "once a reference teaching product appearing to be substantially identical is made the basis of a rejection, and the Examiner presents evidence or reasoning tending to show inherency, the burden shifts to the Applicant to show an unobvious difference."
Regarding claim 6, Zhu ‘s separator meets the limitation “the Si-containing molecules are dispersed in a state of not being a sea-island structure in the separator for a nonaqueous secondary battery”, see instant Specification [0029].
Regarding claim 1, Zhu does not disclose a propylene (C₃) unit modification rate of the silane-modified polyolefin is 0.01 to 2.0 mol% or a butene (C₄) unit modification rate of the silane-modified polyolefin is 0.01 to 1.0 mol%. Hasegawa teaches a polyethylene separator containing propylene or butene in an amount of 4 mol% or less for lowering the fuse temperature (2:40-45). It would have been to an ordinary skilled in the art at the time the invention was made to add small amount of propylene or butene, as taught by Hawgawa, for the benefit of lowering the fuse temperature and prevent a battery from reaching a high temperature causing thermal runaway.
Regarding claim 1, Zhu modified by Hasegawa does not teach an ultra-high molecular weight polyethylene (UHMWPE) having a viscosity-average molecular weight (Mv) of 1,800,000 or more, Tsujimoto teaches the ultrahigh-molecular-weight polyethylene has a much higher molecular weight than that of general-purpose polyethylene and is therefore expected to produce a molded product having high strength and high elasticity if the ultrahigh-molecular-weight polyethylene can be highly oriented. However, the high orientation of the ultrahigh-molecular-weight polyethylene requires sufficiently disentangling the molecular chain. For this reason, the ultrahigh-molecular-weight polyethylene has heretofore been sufficiently impregnated with a solvent before kneading. Since improvement in the production efficiency of ultrahigh-molecular-weight polyethylene has been demanded in recent years, the ultrahigh-molecular-weight polyethylene is kneaded in a state that is not sufficiently impregnated with a solvent in order to shorten a processing time. This breaks the molecular chain of the resulting ultrahigh-molecular-weight polyethylene due to shear during kneading because the molecular chain is not disentangled. As a result, strength is disadvantageously reduced, though high orientation is achieved [0006]. Tsujimoto teaches a separator made from an ultrahigh-molecular-weight polyethylene powder that is excellent in appearance, ease of processing, and reduction in the amount of lamp black during processing and achieves both of high strength and high drawing [0007, 0029]. Tsujimoto teaches an ultrahigh-molecular-weight polyethylene powder having a viscosity-average molecular weight Mv of 10×104 or higher and 1000×104 or lower [0010]. It would have been obvious to one of ordinary skilled in the art at the time the invention was made to add the ultrahigh-molecular-weight polyethylene powder of Tsukimoto to the separator of Zhu for the benefit of adding extra strength to Zhu’s separator.
Regarding claim 1, a content of the silane-modified polyolefin in a polyolefin starting material is 3 to 70% by weight, a content of the UHMWPE in the polyolefin starting material is 3 to 70% by weight, it would have been obvious to one of ordinary skilled in the art at the time the invention was made to adjust the amount of Tsujimoto’s ultrahigh-molecular-weight polyethylene powder depending on the desired strength of the separator, without compromising on the thermal stability of Zhu’s silane-modified polyethylene separator.
Regarding claim 1, a silanol unit modification rate of the silane-modified polyolefin is 0.03 to 1.0 mol%, Zhu discloses a silanol modification rate of 16.1% (page 24121). Zhu discloses the silane modification of polyethylene causes a slightly reduced modification of tensile strength compared to a baser polyethylene separator (figure 7 and its corresponding text). Tsujimoto teaches UHMWPE has a high orientation of the polyethylene molecular chain, and hence high strength [0053]. It would have been obvious to one of ordinary skilled in the art at the time the invention was made to reduce the amount of Si since the Tsujimoto’s UHMWPE assists in Zhu’s separator having increased mechanical strength.
Response to Arguments
Arguments dated 8/10/2026 are addressed below:
Applicant asserts that calculation was made for Zhu’s separator in terms of a Voronoi area at maximum frequency (mu) and a spread of the Voronoi area frequency distribution. In response, the argument has been considered, but was not found to be persuasive because it was not supported by evidence in the form of a declaration. Hence, the rejection is maintained.
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 CYNTHIA KYUNG SOO WALLS whose telephone number is (571)272-8699. The examiner can normally be reached on M-F until 5pm.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jonathan Leong can be reached at 571-270-1292. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/CYNTHIA K WALLS/ Primary Examiner, Art Unit 1751
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