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 .
Status of Claims and Other Notes
Claims 1–12 are pending.
Claims 1–7 are being treated on their merits.
Claims 8–12 are withdrawn from consideration.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The paragraph numbers cited in this Office Action in reference to the instant application are referring to the paragraph numbering of the PG-Pub of the instant application. See US 2023/0268615 A1.
Election/Restrictions
Withdrawn process claims 8–12 do not include all the limitations of the product claim. Withdrawn process claims that are not commensurate in scope with an allowable product/apparatus claim will not be rejoined. See MPEP § 821.04. Applicant is advised that the process claims should be amended during prosecution to require the limitations of the product/apparatus claims. Failure to do so may result in no rejoinder. Further, note that the prohibition against double patenting rejections of 35 U.S.C. 121 does not apply where the restriction requirement is withdrawn by the examiner before the patent issues. See MPEP § 804.01.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 29 December 2025 was filed after the mailing date of the non-final Office Action on 24 October 2025. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Drawings
The drawings were received on 23 January 2026. These drawings are acceptable.
Applicants' amendments have overcome the objections to the drawings.
Specification
Applicants' amendments have overcome the objections to the specification.
Claim Rejections - 35 USC § 112
Applicants' amendments have overcome the rejections of claims 1–7 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph.
Claim Rejections - 35 USC § 102
Claims 1–6 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Brant et al. (US 2011/0206973 A1, hereinafter Brant).
Regarding claim 1, Brant discloses a separator (200, [0032]; 400, [0042]; 500, [0043]) for an electrochemical device, comprising:
a porous polymer substrate (207, [0032]; 405, [0042]; 509, [0043]); and
a porous coating layer (201–206, [0032]; 401–404; [0042]; 501–508, [0043]) on at least one surface of the porous polymer substrate (207, FIG. 2; 405, FIG. 4; 509, FIG. 5),
wherein the porous coating layer (201–206, [0032]; 401–404; [0042]; 501–508, [0043]) comprises inorganic particles (see inorganic species, [0088]) and a binder polymer (see first polymer, [0032]),
wherein the porous coating layer (201–206, 401–404; 501–508) comprises a first region (206, 404, 508) that is in contact with the porous polymer substrate (207, 405, 509) and a second region (201–205, 401–403; 501–507) on an opposite side of the first region (206, 404, 508) that is not in contact with the porous polymer substrate (207, [0032]; 405, [0042]; 509, [0043]),
wherein the binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer (FIG. 2, [0034]; FIG. 4, [0042]; FIG. 5, [0046]), and
wherein the concentration gradient of the binder polymer present in the second region has a larger slope than a slope of the concentration gradient of the binder polymer present in the first region (FIG. 2, [0034]; FIG. 4, [0042]; FIG. 5, [0046]).
Regarding claim 2, Brant discloses all the claim limitations as set forth above and further discloses a separator for the electrochemical device:
wherein an amount of the binder polymer present in the first region is the same as an amount of the binder polymer present in the second region (see equal amounts, [0054]).
Regarding claim 3, Brant discloses all the claim limitations as set forth above and further discloses a separator for the electrochemical device:
wherein a ratio of a thickness of the first region to a thickness of the second region is 4:6 to 1:9 (see thicknesses, [0033]).
Regarding claim 4, Brant discloses all the claim limitations as set forth above and further discloses a separator for the electrochemical device:
wherein the binder polymer comprises at least one of polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethyl methacrylate, polybutyl acrylate, polyacrylonitrile, polyvinyl pyrrolidone, polyvinyl acetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinylalcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxymethyl cellulose, acrylonitrile-styrene-butadiene copolymer, or polyimide (see polyolefins, [0051]).
Regarding claim 5, Brant discloses an electrochemical device, comprising an electrode assembly in a battery casing comprising a positive electrode and a negative electrode; and a separator interposed between the positive electrode and the negative electrode (see battery, [0206]), wherein the separator comprises:
a porous polymer substrate (207, [0032]; 405, [0042]; 509, [0043]); and
a porous coating layer (201–206, [0032]; 401–404; [0042]; 501–508, [0043]) on at least one surface of the porous polymer substrate (207, FIG. 2; 405, FIG. 4; 509, FIG. 5),
wherein the porous coating layer (201–206, [0032]; 401–404; [0042]; 501–508, [0043]) comprises inorganic particles (see inorganic species, [0088]) and a binder polymer (see first polymer, [0032]),
wherein the porous coating layer (201–206, 401–404; 501–508) comprises a first region (206, 404, 508) that is in contact with the porous polymer substrate (207, 405, 509) and a second region (201–205, 401–403; 501–507) on an opposite side of the first region (206, 404, 508) that is not in contact with the porous polymer substrate (207, [0032]; 405, [0042]; 509, [0043]),
wherein the binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer (FIG. 2, [0034]; FIG. 4, [0042]; FIG. 5, [0046]), and
wherein the concentration gradient of the binder polymer present in the second region has a larger slope than a slope of the concentration gradient of the binder polymer present in the first region (FIG. 2, [0034]; FIG. 4, [0042]; FIG. 5, [0046]).
Regarding claim 6, Brant discloses all the claim limitations as set forth above and further discloses an electrochemical device:
wherein the porous coating layer faces the positive electrode (see cathode, [0206]).
Claim Rejections - 35 USC § 103
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Brant (US 2011/0206973 A1) as applied to claim 6 above, and further in view of Mizuno (US 2017/0229698 A1).
Regarding claim 7, Brant discloses all the claim limitations as set forth above, but does not explicitly disclose an electrochemical device having:
an adhesion strength of 30 gf/25 mm or more at an interface between the separator and the positive electrode,
wherein the adhesion strength is measured by heating and pressurizing the separator and the positive electrode at 80° C. under a pressure of 1000 kgf for 1 second, and then applying force at 180° and a rate of 100 mm/min.
Mizuno discloses a separator having an adhesion strength of 30 gf/25 mm or more (i.e., 120 mN/10 mm) at an interface between the separator and a positive electrode (TABLE 1, [0074]), wherein the adhesion strength is measured by heating and pressurizing the separator and the positive electrode at 80° C. under a pressure of 1000 kgf for 1 second, and then applying force at 180° and a rate of 100 mm/min (TABLE 1, [0074]) to improve the cycle characteristics of the electrochemical device (see battery, [0003]). Brant and Mizuno are analogous because they are directed to separators for electrochemical devices. Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention to make the electrochemical device of Brant with the adhesion strength of Mizuno in order to improve the cycle characteristics of the electrochemical device.
Response to Arguments
Applicant's arguments filed 23 January 2026 have been fully considered but they are not persuasive.
Applicants argue Brant does not teach or suggest (1) the porous coating layer comprises a first region that is in contact with the porous polymer substrate and a second region on an opposite side of the first region that is not in contact with the porous polymer substrate, (2) the binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer, and (3) the concentration gradient of the binder polymer present in the second region has a larger slope than a slope of the concentration gradient of the binder polymer present in the first region (P8/¶5). Brant discloses a separator (200, [0032]; 400, [0042]; 500, [0043]) for an electrochemical device, comprising a porous polymer substrate (207, [0032]; 405, [0042]; 509, [0043]); and a porous coating layer (201–206, [0032]; 401–404; [0042]; 501–508, [0043]) on at least one surface of the porous polymer substrate (207, FIG. 2; 405, FIG. 4; 509, FIG. 5), wherein the porous coating layer (201–206, [0032]; 401–404; [0042]; 501–508, [0043]) comprises inorganic particles (see inorganic species, [0088]) and a binder polymer (see first polymer, [0032]), wherein the porous coating layer (201–206, 401–404; 501–508) comprises a first region (206, 404, 508) that is in contact with the porous polymer substrate (207, 405, 509) and a second region (201–205, 401–403; 501–507) on an opposite side of the first region (206, 404, 508) that is not in contact with the porous polymer substrate (207, [0032]; 405, [0042]; 509, [0043]), wherein the binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer (FIG. 2, [0034]; FIG. 4, [0042]; FIG. 5, [0046]), and wherein the concentration gradient of the binder polymer present in the second region has a larger slope than a slope of the concentration gradient of the binder polymer present in the first region (FIG. 2, [0034]; FIG. 4, [0042]; FIG. 5, [0046]).
Applicants argue Brant does not disclose the binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer (P9/¶2). Brant discloses the concentration of the binder polymer present in FIGS. 2, 4, and 5 (see annotated figures below). The concentration is 0% at the interface between layer 206 and layer 207 and increases to 100% at an outermost surface of layer 201 in FIG. 2; the concentration is 0% at the interface between layer 404 and layer 405 and increases to 100% at an outermost surface of layer 401 in FIG. 4; and the concentration is 0% at the interface between layer 508 and layer 509 and increases to 100% at an outermost surface of layer 501 in FIG. 1. FIGS. 2, 4, and 5 illustrate binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer. Therefore, Brant discloses the binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer.
Applicants argue the concentration of the first binder composition is constant in layer 205 and never increases higher than in layer 206 throughout layers (P9/¶2). It is noted that the features upon which applicant relies (i.e., the concentration is not constant, the concentration continuously increases, or the concentration increases to its maximum only at the outermost surface) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Claim 1 recites inter alia "the binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer." The limitation does not require the concentration gradient increases to its maximum at an outermost surface, the concentration never decreases, nor the concentration gradient is continuously increasing. Therefore, the concentration of the first binder composition being constant in layer 205 and never increases higher than in layer 206 throughout layers does not prevent Brant from discloses "the binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer."
Applicants argue Brant discloses the curve in FIG. 4 is sinusoidal and includes decreasing concentrations along the path (P10/¶1). It is noted that the features upon which applicant relies (i.e., the concentration is not sinusoidal or the concentration does not decrease) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Claim 1 recites inter alia "the binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer." The limitation does not require the concentration gradient increases to its maximum at an outermost surface, the concentration never decreases, the concentration gradient is continuously increasing, nor the concentration cannot be sinusoidal. Therefore, Brant disclosing the curve in FIG. 4 is sinusoidal and includes decreasing concentrations along the path does not prevent Brant from discloses "the binder polymer present in the first region and the second region has a concentration gradient increasing from the porous polymer substrate toward an outermost surface of the porous coating layer."
Applicants argue Brant does not disclose the concentration gradient of the binder polymer present in the second region has a larger slope than a slope of the concentration gradient of the binder polymer present in the first region (P10/¶2). Slope is defined as the degree of steepness of a graph at any point (see slope and gradient, New Oxford American Dictionary). Slope can also be defined as m = Δx/Δy. FIGS. 2, 4, and 5 illustrate concentration of the binder polymer. FIGS. 2, 4, and 5 illustrate portions with m2 > 0 (e.g., dashed-line rectangles) and portions with m1 = 0 (e.g., solid-line rectangles). FIGS. 2, 4, and 5 illustrate the concentration gradient of the binder polymer present in the second region has a larger slope than a slope of the concentration gradient of the binder polymer present in the first region (i.e., m2 > m1). Therefore, Brant discloses the concentration gradient of the binder polymer present in the second region has a larger slope than a slope of the concentration gradient of the binder polymer present in the first region
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Applicants argue the claimed configuration would not have been an obvious modification of Brant (P10/¶3). Brant is not required to modified to meet the claimed configuration as detailed above.
Applicants argue the claimed configuration produces unexpected results (P10/¶3). Evidence of secondary considerations, such as unexpected results or commercial success, is irrelevant to 35 U.S.C. 102 rejections and thus cannot overcome a rejection so based. In re Wiggins, 488 F.2d 538, 543, 179 USPQ 421, 425 (CCPA 1973). See MPEP § 2131.04. Further, an affidavit or declaration under 37 CFR 1.132 must compare the claimed subject matter with the closest prior art to be effective to rebut a prima facie case of obviousness. In re Burckel, 592 F.2d 1175, 201 USPQ 67 (CCPA 1979). Applicants may compare the claimed invention with prior art that is more closely related to the invention than the prior art relied upon by the examiner. In re Holladay, 584 F.2d 384, 199 USPQ 516 (CCPA 1978); Ex parte Humber, 217 USPQ 265 (Bd. App. 1961). In other words, the evidence of unexpected results must be compared with prior art. Emphasis added. See MPEP § 716.02(e). The closest prior art of record is Brant. Example 1 is compared with comparative examples 1 and 2, which are not examples of Brant. The evidence relied upon should establish "that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance." Ex parte Gelles, 22 USPQ2d 1318, 1319 (Bd. Pat. App. & Inter. 1992). See MPEP § 716.02(b). No analysis has provided indicating that the results are statistically and practically significant. To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960). Applicants have provided a single example, which is not sufficient to establish the results would occur throughout the claimed range. As set forth in § MPEP 716.02(d), whether unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occurred over the entire claimed range, In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980). Applicants have not provided data to show that the unexpected results do in fact occur over the entire claimed range of porous polymer substrate, inorganic particles, and binder polymer. Therefore, unexpected results have not been demonstrated.
Applicants argue Mizuno does not cure the deficiencies of Brant (P10/¶5). Brant is not deficient as detailed above.
Applicants argue the dependent claims are allowable because they depend from an allowable base claim and for the addition features recited (P10/¶5). Claim 1 is not allowable as detailed above; and Brant and Mizuno disclose the additional features as detailed above.
Applicants request the rejoinder of claims 8–12 (P10/¶6). Withdrawn process claims 8–12 do not include all the limitations of the product claim. Withdrawn process claims that are not commensurate in scope with an allowable product/apparatus claim will not be rejoined. See MPEP § 821.04.
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 Sean P Cullen, Ph.D. whose telephone number is (571)270-1251. The examiner can normally be reached Monday to Thursday 6:00 am to 4:00 pm CT, Friday 6:00 am to 12:00 pm CT.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Basia A Ridley can be reached at (571)272-1453. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Sean P Cullen, Ph.D./Primary Examiner, Art Unit 1725