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
The Amendment filed November 12th, 2025 has been entered. Claims 1-2 & 4-7 remain pending in the application. Claim 3 was cancelled by the Applicant. Claims 8-15 remain withdrawn. Applicant's amendment to Claim 2 has overcome the 112(b) rejection previously set forth.
Applicant' s arguments with respect to the 103 rejections of Claims 1 & 2 have been fully considered and are persuasive. Therefore, the rejections have been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Takaoka et al. US 6,589,383 B1. New rejections follow.
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.
Claims 1, 5, & 6 are rejected under 35 U.S.C. 103 as unpatentable over Zhang et al. US 2023/0111013 A1 in view of Takaoka et al. US 6,589,383 B1.
Regarding Claim 1, Zhang discloses a crosslinked polyolefin separator ("separator for an electricity storage device comprising a silane-modified polyolefin, wherein silane crosslinking reaction…takes place”) [0077] having a storage/loss modulus ratio of at least 2 (see Figure 4 Example 1 showing logarithmic scale graph of storage/loss modulus versus frequency, the chart showing a storage/loss ratio of at least 2 for all temperatures tested). Zhang does not specifically disclose that the storage/loss modulus ratio was measured at the claimed frequency, however Zhang discloses the same material to that of the instant specification. Zhang discloses a crosslinked polyolefin separator made up of a polyolefin modified by silane (polyethylene with a MW of 30,000-920,000 as the main chain polyolefin starting material and trimethoxyalkoxide-substituted vinylsilane as the silane group grafted onto the main chain [0690]) and describes that the obtained silane-grafted polyolefin was then heated for 2 days to crosslink [0690], and the instant specification uses a similar material of polyolefin modified with silane (polyethylene with a MW of 600,000 as the main component polyolefin modified by vinyltrimethoxysilane as the silane group) then heated for 2 days to make a crosslinked silane-modified polyolefin separator in the examples [Page 35 Line 20-Page 36 Line 9]. (Examiner notes that trimethoxyalkoxide-substituted vinylsilane and vinyltrimethoxysilane are considered in the art to be the same.) Additionally, Zhang discloses that the separator was formed into a sheet through a T-die and cold molding [0694] then fed through a tenter (stretching machine) under stretching conditions such as an MD factor of 7 and a TD factor of 6 [0695], then placed in a bath (tank) to remove the liquid paraffin diluting agent and form a porous body [0696], followed by an additional stretching step and relaxation step [0697]. Similarly, the instant specification forms the composition into a molded sheet through the use of a T-die and cold cast roller, then stretched under stretching conditions such as an MD factor of 6 times and a TD factor of 7 times by using a tenter, followed by dipping the sheet in a bath to remove the liquid paraffin diluting agent and provide a porous body, then subjecting the sheet to another stretching step and relaxation step [Page 36 Lines 10-21]. Thus, Zhang discloses the same material, formed into a sheet in the same method, to that which is claimed in Claim 1, and inherently would possess the same properties as the claimed material. More specifically, Zhang’s material would inherently have a storage/loss ratio of 2 or more when measured at a frequency of 1 rad/s. In regards to the shared properties of the claimed material and the disclosed material of Zhang, in which “the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established.” In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). “When the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not.” In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP 2112.01(I).
Zhang discloses that the mean storage modulus is 1.0 MPa to 12 MPa [0135], which is 1.0x106 to 1.2 x107 Pa, however fails to disclose a storage modulus within the claimed range.
Takaoka discloses a ionically conductive composition for use as a gel electrolyte in a battery [Column 2 Lines 65-67, Column 5 Lines 56-62]. Takaoka discloses that the ionically conductive composition is a gel composition comprising a crosslinked polymer [Column 5 Lines 60-62] further infused with an electrolyte [Column 20 Lines 15-17] such as a lithium salt for lithium ion conductivity [Column 21 Lines 18-33]. Takaoka discloses that the ionically conductive gel composition is layered between a cathode and an anode to form a battery [Column 24 Lines 62-65], similar to the separator of Zhang. Takaoka discloses that the ionically conductive gel composition has a storage modulus of 5x103 Pa or more [Column 22 Lines 30-32], and more specifically in the examples discloses that the composition has a storage modulus of 6.5x103 Pa (Example 2) [Column 24 Lines 57-58] to 3.5x105 Pa (Example 20) [Column 33 Lines 39-40].
Takaoka discloses that the storage modulus is indicative of gel strength and form retention, wherein a higher storage modulus indicates high form retention [Column 21 Lines 43-48]]. Takaoka further discloses that a composition with a storage modulus in the listed range (5x103 Pa or more) has good mechanical properties and good ionic conductivity, and discloses that the composition would show good form stability [Column 22 Lines 28-35].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to modify the separator of Zhang to have storage modulus in the range as suggested Takaoka to achieve a composition with good mechanical properties like form retention stability as well as good ionic conductivity.
Regarding Claim 5, Zhang discloses that the crosslinked polyolefin separator is crosslinked in solution of electrolyte, thus formed by aqueous crosslinking.
In regards to the limitation “formed by aqueous crosslinking or UV crosslinking”, the Examiner is treating it as a product by process claim, specifically regarding the phrase “formed by”. It has been shown that even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process (MPEP 2113).
Regarding Claim 6, as mentioned with regards to Claim 5, Zhang discloses that the crosslinked polyolefin separator is crosslinked in solution of electrolyte, thus formed by aqueous crosslinking. Further, Zhang discloses that the crosslinked polyolefin separator comprises silane-modified polyolefin in addition to other polyolefins in the separator [0239]. In Chemical Formula 20, reaction I, Zhang shows that the silane modified polyolefin crosslinking compound comprises Si-O-Si bonds [0354]. Further, Zhang discloses that the silicon content (i.e. content of silane modified polyolefin) is contained in an amount of 5-40wt% compared to the total weight of the separator [0242].
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Annotated Chemical Formula 20 – Reaction I
In regards to the limitation “formed by aqueous crosslinking or UV crosslinking”, the Examiner is treating it as a product by process claim, specifically regarding the phrase “formed by”. It has been shown that even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process (MPEP 2113).
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Nakagawa et al. JP 2010/285528 A in view of Takaoka et al. US 6,589,383 B1.
Regarding Claim 2, as best understood by the examiner, Nakagawa discloses a crosslinked polyolefin separator wherein the gradient of the curve of storage modulus versus frequency is 0.2-0.6 when the frequency ranges from 0.1-10 rad/s [Page 5 Lines 41-42], which overlaps with the claimed range. In regards to the gradient of the curve, the Examiner directs Applicant to MPEP 2144.05 I. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. Accordingly, it would have been obvious to one of ordinary skill in the art to have selected the overlapping ranged disclosed by Nakagawa because selection of the overlapping portion or ranges has been held to be a prima facie case of obviousness. See MPEP 2144.05 I.
Nakagawa discloses that the storage modulus is 1.0x105 or less [Page 5 Lines 53-54], however fails to disclose a storage modulus within the claimed range.
Takaoka discloses a ionically conductive composition for use as a gel electrolyte in a battery [Column 2 Lines 65-67, Column 5 Lines 56-62]. Takaoka discloses that the ionically conductive composition is a gel composition comprising a crosslinked polymer [Column 5 Lines 60-62] further infused with an electrolyte [Column 20 Lines 15-17] such as a lithium salt for lithium ion conductivity [Column 21 Lines 18-33]. Takaoka discloses that the ionically conductive gel composition is layered between a cathode and an anode to form a battery [Column 24 Lines 62-65], similar to the separator of Zhang. Takaoka discloses that the ionically conductive gel composition has a storage modulus of 5x103 Pa or more [Column 22 Lines 30-32], and more specifically in the examples discloses that the composition has a storage modulus of 6.5x103 Pa (Example 2) [Column 24 Lines 57-58] to 3.5x105 Pa (Example 20) [Column 33 Lines 39-40].
Takaoka discloses that the storage modulus is indicative of gel strength and form retention, wherein a higher storage modulus indicates high form retention [Column 21 Lines 43-48]]. Takaoka further discloses that a composition with a storage modulus in the listed range (5x103 Pa or more) has good mechanical properties and good ionic conductivity, and discloses that the composition would show good form stability [Column 22 Lines 28-35].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to modify the separator of Zhang to have storage modulus in the range as suggested Takaoka to achieve a composition with good mechanical properties like form retention stability as well as good ionic conductivity.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Zhang et al. US 2023/0111013 A1 and Takaoka et al. US 6,589,383 B1 as applied to Claim 1 above, and further evidenced by Li et al. “Rheological and mechanical properties of ultrahigh molecular weight polyethylene/high density polyethylene/polyethylene glycol blends”.
Zhang discloses an electricity storage device (battery) comprising a crosslinked polyolefin separator, as mentioned with regards to Claim 1. Further, Zhang discloses that the separator comprises ultrahigh molecular weight polyethylene (UHMWPE) [0319].
Li discloses mechanical properties of ultrahigh molecular weight polyethylene (UHMWPE) [Li Abstract], which makes up Zhang’s separator [Zhang 0319] as mentioned above. Li discloses that the UHMWPE has a loss modulus (G’’) of less than 2.0x105 Pa (Figures 11 & 12 Page 7).
Thus, as evidenced by Li’s mechanical properties (loss modulus) of UHMWPE, the separator of Zhang has a loss modulus of less than 2.0x105 Pa, which falls within the claimed range.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Zhang et al. US 2023/0111013 A1 and Takaoka et al. US 6,589,383 B1 as applied to Claim 1 above, in further view of Yamamoto et al. US 6,559,195 B1.
Regarding Claim 7, Zhang discloses that the separator comprises pores (microporous membrane) [0114]. Further, Zhang discloses that the chains of polyolefin form small lamella (or fibrils) which aggregate during crosslinking to form the membrane [0255].
However, Zhang is silent as to the crosslinked polyolefin separator being formed by UV crosslinking.
Yamamoto discloses a microporous film made of polyolefin [Column 3 Lines 40-63] that is crosslinked [Column 5 Lines 57-60]. Yamamoto specifically discloses that UV radiation is desirable as the crosslinking method [Column 5 Lines 63-67].
Yamamoto discloses that crosslinking polyolefins by UV radiation increases the heat resistance of the film, as well as improves the structural stability [Column 5 Line 63-Column 6 Line 4].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to incorporate the method of crosslinking as suggested by Yamamoto to crosslink the polyolefin in the separator of Zhang to increase the heat resistance and improve structural stability.
Response to Arguments
Applicant’s arguments with regards to amended Claims 1 & 2, specifically that Zhang and Nakagawa fail to disclose the added limitation of the storage modulus, has been fully considered but is moot as neither Zhang nor Nakagawa are relied upon for teaching that limitation. Examiner respectfully points out that as stated in the rejections above, Takaoka is used to teach a range of storage modulus values that encompasses the entire claimed range and further teaches why one of ordinary skill in the art would seek to optimize the storage modulus for a crosslinked polyolefin. Accordingly, for the reasons stated above, these arguments are unpersuasive.
Applicant argues that Zhang would not inherently have the claimed ratio. Applicant further argues that Zhang simply sharing the same materials as the experimental examples would not inherently provide a separator that exhibits the same properties. Applicant points out that the Comparative Examples (such as Comparative Example 5) share the same materials as the experimental examples (such as Example 1) however differ in properties such as storage modulus [see Remarks page 8 paragraph 2], which results in differing storage/loss modulus ratio results. See Table 1 in Instant Specification, primarily comparing Example 1, having a storage modulus of 3.51x105 Pa which is within the claimed range and resulting in a ratio of 2 or more (4.60), to Comparative Example 5, having a storage modulus of 9.7x104 Pa which is outside of the claimed range and resulting in a ratio of below 2 (1.12). Examiner respectfully points out that modified Zhang discloses a storage modulus within the claimed range, as stated in the rejection above, and therefore would be similar to the experimental examples and not similar to the comparative examples, and would therefore be expected to share inherently the same properties as the experimental examples and not the comparative examples. Examiner further points out that Zhang does disclose a storage/loss ratio of 2 or more as shown in Figure 4 and as stated in the rejection above, which is similar to Example 1 and not the comparative examples. Examiner additionally points out that as stated in the rejection above, Zhang further shares a similar molecular weight of the main polymer component (polyethylene) with that of Example 1, as well as the sheet formation and stretching method steps. Accordingly, for the reasons stated above, this argument is unpersuasive.
Applicant argues that the data of Nakagawa is not analogous to the claimed invention since the data was obtained from a “composition” and not from specifically a separator. Examiner respectfully points out that Nakagawa discloses a crosslinked thermoplastic resin composition that is a solid [Page 5 Lines 53-57], which is used to make a molded sheet [Page 7 Lines 22-30], to be used in a variety of applications such as appliances and automobile parts [Page 10 Lines 6-7]. Thus the data reported by Zhang related to the crosslinked thermoplastic resin composition in the form of a solid sheet would be analogous to that of the instant invention “separator”. Accordingly, for the reasons stated above, this argument is unpersuasive.
Applicant argues that neither Zhang nor Jayanarayanan disclose the loss modulus of Claim 4. This argument has been considered but is moot because the new ground of rejection for Claim 4 does not rely on Zhang or Jayanarayanan applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Accordingly, for the reasons stated above, this argument is unpersuasive.
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.
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/A.E.G./Examiner, Art Unit 1726 /DANIEL P MALLEY JR./Primary Examiner, Art Unit 1726