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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 07/07/2026 has been entered.
Response to Amendment
This is a nonfinal Office action in response to Applicant’s remarks and amendments filed on 0707/2026. Claim 1 is amended. Claims 7 – 8 and 10 are canceled. Claims 1 – 6, 9, and 11 – 16 are pending in the current Office action.
The 35 U.S.C. 103 rejections set forth in the previous Office action are maintained, with the rejection of claim 1 rewritten to address the amended limitation.
Response to Arguments
Applicant's arguments filed 07/07/2026 have been fully considered but they are not persuasive. Applicant argues that the claimed separator produces unexpected results based on Examples 1 – 2 and comparative examples 2 – 3. Specifically, applicant argues that Examples 1 – 4 in the specification correspond to the claimed invention, including having a coverage corresponding to the claimed range of 15 – 30%, while Comparative examples 2 – 3 do not, i.e. they do not include the claimed hybrid copolymer, and that Examples 1 – 4 exhibit superior resistance change rate compared to Comparative Examples 2 and 3.
Examiner acknowledges that, Examples 1 – 4 exhibit superior resistance change range when compared to Comparative Examples 2 – 3; however, the examiner notes, in addition to the type of hybrid binder, Comparative Example 2 differs from Examples 1 – 4 with respect to solid content of the coating layer {i.e. the solid content of the coating layers in Examples 1 – 4 is 35% while the solid content of the coating layer in Comparative Example 2 is 18%} and coating layer binder type (Refer to Table 1 and Instant Specification: [0099];[0109]) and that Examples 1 – 4 only exhibit superior results over Comparative Example 3, which has a different coating layer binder that is acrylamide-based, when the coating binder type is an acrylic + PVDF-HFP binder combination, the adhesive layer binder is an acrylic binder, the adhesive layer coverage is 15% or 30%, the molar ratio of PVDF:HFP is 95 – 80 : 5 – 20, and the solid content of the adhesive layer is 1 – 4% (Refer to Table 1 and Instant Specification: [0097 – 0116]). The examiner further notes that Example 1 vs. Example 2, which differs from Example 1 with respect to adhesive layer solid content, and, in part Comparative Example 1 which differs from Example 1 with respect to adhesive layer coverage and solid content, shows that the solid content of the adhesive layer also has an affect on applicant’s unexpected results {i.e. resistance change rate} (Refer to Table 1 and Instant Specification: [0101];[0103];[0106]). Accordingly, in light of the data of the instant specification also demonstrating that the solid content of the adhesive layer affects resistance change rate and there being no limitation regarding the solid content in independent claim 1, the examiner maintains that applicant’s showing of unexpected results are not commensurate in scope with the claimed invention and applicant’s arguments regarding the unexpected results of the claimed invention are not fully persuasive.
The examiner further notes that the following parameters, based on the instant specification, also appear to contribute to applicant’s unexpected results but are unbounded by claim 1:
The thickness of the coating layer is not included within claim 1, whereas the instant specification recites the specification may be about 1 – 3 µm and that controlling the thickness within such a range resistance characteristics of the separator improves (See Instant Specification: [0059]). The examiner also notes that applicant’s working examples only utilize a coating layer thickness of 1.5 µm (See Instant Specification: [0100];[0103 – 0105]). Therefore, it is unclear if applicant’s results would occur for any coating layer thickness.
The thickness of the adhesive layer is not included within claim 1, whereas the instant specification recites that the adhesive layer may be about 0.2 – 1 µm and that within such a thickness range resistance change rate is reduced (See Instant Specification: [0080]). The examiner further notes that applicant’s working examples only utilize a thickness of 0.5 µm (See Instant Specification: [0102];[0103 – 0105]). Therefore, it is unclear if applicant’s results would occur for any adhesive layer thickness.
In response to the examiner asserting that claimed invention is not commensurate in scope due to applicant’s unexpected results being achieved by incorporating the separator into a battery, the applicant further argues that testing performance parameters of a separator in a battery cell is a common and generally accepted way to test performance of a separator and thus the unexpected results are clearly commensurate in scope with claim 1 and no additional evidence is necessary.
The examiner acknowledges that testing performance parameters of battery cell is a common and generally accepted way to test performance of a separator; however, as acknowledged in the instant specification, the results stem from incorporating the separator into a battery alongside electrolyte (See Instant Specification: [0124]) and further the results are tailored to liquid-based or liquid-containing electrolyte {i.e. in order to measure the resistance change rate the separator must be wetted with electrolyte} (See Instant Specification: [0131]); therefore, it is unclear if applicant’s results would occur when using e.g. purely solid electrolyte and the examiner maintains that, absent evidence or a declaration explaining such a discrepancy, applicant’s showing of unexpected results is not fully commensurate in scope and thus further rendered unpersuasive.
Therefore, in light of the discussion above, the examiner maintains that applicant’s showing of unexpected results is narrower than the scope of the claimed invention, and as MPEP 716.02(d) requires unexpected results to be commensurate in scope with the claimed invention, applicant’s arguments regarding the unexpected results are unpersuasive, the pending case of obviousness appears proper, and the rejections set forth in the previous Office action are maintained and included below.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1 – 2, 4 – 6 , 11 – 12, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Sung (KR20220062856A) in view of Kwon (US PG Pub. 2022/0149480 A1), Beaume (US PG Pub. 2024/0141198 A1) and Kim (KR20120126956A). {Examiner note: All prior art was cited in previous O.A. mailed 04/08/2026}.
Regarding Claim 1, Sung discloses a separator for an electrochemical device (Fig. 1, 30; [0099];[0165 – 0166]) comprising a porous polymer substrate (Fig. 1, 300; [0101 – 0102]), a coating layer provided on at least one surface of the porous polymer substrate including binder and inorganic particles (Fig. 1, 310; [0105];[0107];[0119 – 0120]).
With respect to the coating layer 310, Sung teaches the binder including styrene butadiene rubber (SBR), an acrylic copolymer, polyacrylic acid (PAA), a polyacrylate, carboxymethyl cellulose (CMC), polyvinyl alcohol, or two or more thereof ([0107]). Sung further teaches, as an example, that the first binder may be mixture of an acrylic copolymer and polyacrylic acid, and teaches that the inclusion of polyacrylic acid allows for a separator with better thermal safety ([0108]).
Therefore, while Sung does not explicitly disclose an embodiment of the coating layer including a first acrylic polymer binder, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention to include as a binder material for the coating layer of Sung, polyacrylic acid, and thus obtain the claimed first acrylic polymer binder, with a reasonable expectation of success in obtaining a separator with improved thermal safety.
Sung does not explicitly disclose the coating layer including a hybrid polymer binder.
Kwon teaches a separator for an electrochemical device including a porous coating layer ([0032 – 0033]). The porous coating layer is taught to includes a crosslinkable binder resin, a non-crosslinkable binder resin, and inorganic particles ([0018]). The cross-linkable binder resin is taught to include an acrylic copolymer and provide benefits relating to increased heat resistance ([0048];[0058]). The non-crosslinkable binder resin is taught to include a PVDF-based copolymer and further may include, in combination with the PVDF-based copolymer, an acrylic copolymer ([0049 – 0050]). The inclusion of a PVDF-copolymer is taught to allow for increased binding force ([0067]).
Since Sung already exemplifies using acrylic copolymer binder with the polyacrylic acid binder, in coating layer 310, it would have been further obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention to further include an acrylic copolymer in the coating layer of Sung, and combine the acrylic copolymer with a PVDF-based copolymer, as taught by Kwon, with a reasonable expectation of success in improving the binding force of the coating layer.
The modified binder copolymer, by including both an acrylic copolymer and PVDF-based copolymer reads on the claimed hybrid polymer binder comprising a fluorinated copolymer that is a copolymer of polyvinylidene fluoride (PVDF) {Examiner Note: In [0073] of the instant specification, the hybrid polymer binder is taught to be a polymer binder including a fluorinated copolymer and an acrylic copolymer}.
Modified Sung does not particularly disclose wherein the fluorinated copolymer is a copolymer of polyvinylidene fluoride (PVDF) and hexafluoropropylene (HFP); however, within a finite list of PVDF-based copolymers options for separator coatings, Kwon includes polyvinylidene fluoride-co-hexafluoropropylene ([0049]); therefore, selection of a copolymer of polyvinylidene fluoride (PVDF) and hexafluoropropylene (HFP) for the PVDF-based copolymer of modified Sung would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed with a reasonable expectation of success that such a selection would be a suitable material for the PVDF-based copolymer of modified Sung’s separator coating layer and further obtain the desired increased binding force effect (Kown: [0067]).
Modified Sung does not explicitly disclose wherein the content of the hexafluoropropylene (HFP) is 5 wt% to 20 wt% relative to 100 wt% of the fluorinated copolymer.
Beaume, with respect to a separator coating layer including a PVDF-HFP binder, teaches controlling the content of HFP in the copolymer to preferably be 4 – 15% by weight relative to the weight of the copolymer ([0025 – 0027];[00035]), which significantly overlaps the claimed range of 5 wt% to 20 wt%.
Kim teaches, with respect to a separator binding layer including PVDF-HFP copolymer and inorganic particles, that the content of HFP in the copolymer affects air permeability and electrolyte impregnability of the separator (Refer to highlighted text on pgs. 3 – 4). Kim further teaches that increases in the content of HFP increases the electrolyte solution impregnation of the separator as well as the air permeability (Refer to highlighted text on pg. 4).
Since Sung is concerned with achieving improved electrolyte impregnation ([0006 – 0007]), it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to control the content of HFP to be within the range taught by Beaume, and further within the overlapping portion of the taught range and claimed range, to optimize the electrolyte impregnability of modified Sung’s separator, with a reasonable expectation of success and without undue experimentation [See MPEP 2144.05(II)].
Sung further discloses an adhesive layer including a second polymer binder, on the coating layer (third polymer binder, Fig. 1, 330; [0126]), wherein the adhesive layer forms a pattern having a predetermined coverage on the coating layer (Refer to patterns of adhesive layer 330 shown in Figs. 2 – 5; [0127];[0131];[0143];[0145]; [0147];[0151]).
Sung does not explicitly disclose the second polymer binder to particularly be a second acrylic polymer binder; however, within a finite list of options for the third second polymer binder {i.e. corresponds to claimed second polymer binder}, Sung includes poly(methylmethacrylate), poly(butylacrylate), and poly(butylmethacrylate); therefore, It would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to select an acrylic polymer binder for the adhesive layer with a reasonable expectation of success that such a selection would be a suitable material for the adhesive layer.
Sung further teaches forming the adhesive layer in a pattern to obtain non-coated adhesive portions that improve the electrolyte impregnation property of the electrodes ([0128]). Sung further teaches, most specifically, that the adhesive portion can cover 5 – 50% of the total surface area of the coating layer ([0134]), which overlaps the claimed coverage range of greater than or equal to 15% and less than or equal to 30% of the surface area of the coating layer.
The taught coverage range allows for the separator and electrode to be firmly bonded and allows for sufficient penetration of electrolyte ([0134]). One with ordinary skill in the art would appreciate that, since it is the non-coated portions that are responsible for allowing the electrolyte to penetrate and the coated portions that allow for adhesion, increases in the amount of coverage would increase adhesive strength but reduce the capability of the electrolyte to penetrate. Therefore, selection of an amount of coverage within the overlapping portion of the taught coverage range and the claimed range would have been obvious to one with ordinary skill in the art, before the effective filing date to of the claimed invention, to optimize the electrolyte impregnation property of the adhesive layer while maintaining sufficient adhesive strength, with a reasonable expectation of success and without undue experimentation [See MPEP 2144.05(II)].
Regarding Claim 2, modified Sung discloses all limitations as set forth above. Sung further discloses wherein the thickness of the porous polymer substrate is 1 – 25 µm or 3 – 20 µm ([0103]), which encompasses the claimed range of 8 – 15 µm.
Kwon further teaches, with respect to electrochemical device separators, porous substrates having a thickness of 3 – 12 µm or 5 – 12 µm ([0043]). Thicknesses smaller than the taught range are taught by Kwon to not function as a conductive barrier sufficiently, furthermore Kwon suggests that larger thicknesses provide increased mechanical strength ([0043]). Increases in thickness are further taught by Kwon to increase separator resistance ([0043]).
Therefore, selection of a porous substrate thickness within the overlapping portion of the taught ranges and claimed range would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention to optimize the mechanical strength and resistance of the separator while ensuring that the separator is thick enough to serve sufficiently as a conductive barrier, with a reasonable expectation of success and without undue experimentation [See MPEP 2144.05(II)].
Regarding Claim 4, modified Sung discloses all limitations as set forth above. In modified Sung the coating layer includes inorganic particles, polyacrylic acid, and a hybrid polymer binder including an acrylic copolymer and PVDF-based copolymer (Sung: [0105];[0107 – 0108] and Kwon: [0049 – 0050]). Generally, Sung teaches a weight ratio of inorganic particles to binder polymer of 90:10 to 99:1 ([0123]); thus, based on the overall ratio of binder to inorganic particles, in modified Sung the content of the first acrylic polymer binder {i.e. polyacrylic acid} is within/overlaps the claimed range of 1 part by weight to 10 parts by weight relative to 100 parts by weight of the coating layer.
In Sung, the inorganic particles are taught to improve thermal shrinkage rate of the substrate and resistance to foreign substances from the outside ([0123]). The amount of binder is taught to maintain the adhesive force between the inorganic particles and thus improve the mechanical properties of the first porous coating layer ([0123]). Polyacrylic acid binder is particularly taught by Sung to have high resistance and poor adhesive strength but excellent heat resistance ([0108]). PVDF-based binders are taught by Sung to have excellent adhesive strength ([0115]).
Therefore, since the coating layer of modified Sung includes inorganic particles and a hybrid polymer binder including a PVDF-based copolymer, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to select an amount of first acrylic polymer binder within the overlapping potion of the taught range and claimed range, to optimize the effects of the polyacrylic acid binder {i.e. heat resistance} without negatively impacting the effects of the other components of the coating {i.e. improved mechanical strength/foreign substance resistance/adhesive strength}, with a reasonable expectation of success and without undue experimentation [See MPEP 2144.05(II)].
Regarding Claim 5, modified Sung discloses all limitations as set forth above. In modified Sung the coating layer includes inorganic particles, polyacrylic acid, and a hybrid polymer binder including an acrylic copolymer and PVDF-based copolymer (Sung: [0105];[0107 – 0108] and Kwon: [0049 – 0050]). Generally, Sung teaches a weight ratio of inorganic particles to binder polymer of 90:10 to 99:1 ([0123]); thus, in modified Sung, the content of the hybrid polymer binder {i.e. polyacrylic acid} is within/overlaps the claimed range of 1 part by weight to 10 parts by weight relative to 100 parts by weight of the coating layer.
In Sung, the inorganic particles are taught to improve thermal shrinkage rate of the substrate and resistance to foreign substances from the outside ([0123]). The amount of binder is taught to maintain the adhesive force between the inorganic particles and thus improve the mechanical properties of the first porous coating layer ([0123]). Polyacrylic acid binder is particularly taught by Sung to have high resistance and poor adhesive strength but excellent heat resistance ([0108]). PVDF-based binders are taught by Sung to have excellent adhesive strength ([0115]).
Therefore, since the hybrid polymer binder of modified Sung includes a PVDF-based copolymer, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to select an amount hybrid polymer binder within the overlapping potion of the taught range and claimed range, to optimize the effects of the hybrid polymer binder {i.e. adhesive strength} without negatively impacting the effects of the other components of the coating {i.e. improved mechanical strength/foreign substance resistance/heat resistance}, with a reasonable expectation of success and without undue experimentation [See MPEP 2144.05(II)].
Regarding Claim 6, modified Sung discloses all limitations as set forth above. The hybrid polymer of modified Sung includes an acrylic copolymer and a PVDF-based copolymer (Refer to rejection of Claim 1 and Sung: [0107 – 0108] and Kwon: [0049 – 0050]), as such, in modified Sung, the hybrid polymer further comprises an acrylic copolymer.
Regarding Claim 11, modified Sung discloses all limitations as set forth above. Sung further discloses wherein the thickness of the adhesive layer is, most specifically, 0.6 – 1.0 µm ([0155]), which is within the claimed range of 0.2 µm to 1 µm.
Regarding Claim 12, modified Sung discloses all limitations as set forth above. Sung teaches a desire to obtain an electrode assembly with improved electrolyte impregnability for the purpose of preventing increases in resistance and the deterioration of output characteristics and capacity of the electrochemical device equipped with the electrode assembly drop ([0005 – 0007]).
In the instant specification the applicant indicates that the resistance rate of change of the separator is influenced by the content of the hybrid polymer binder, the content of HFP, the % of coverage of the adhesive layer, and the thickness of the adhesive layer (Instant Specification: [0072];[0075];[0079 – 0080]).
Modified Sung, as established above, renders obvious the separator of claim 1. Generally, Sung teaches a weight ratio of inorganic particles to binder polymer of 90:10 to 99:1 ([0123]); thus, in modified Sung, the content of the hybrid polymer binder {i.e. polyacrylic acid} is within/overlaps the applicant’s claimed/taught range of 1 part by weight to 10 parts by weight relative to 100 parts by weight of the coating layer (Instant Specification: [0072]). Sung further teaches, most specifically, that the adhesive portion can cover 5 – 50% of the total surface area of the coating layer ([0134]), which overlaps the applicant’s claimed/taught coverage range of greater than 0% and less than or equal to 30% (Instant Specification: [0079]). Sung additionally teaches that a thickness of the adhesive layer is, most specifically, 0.6 – 1.0 µm ([0155]), which is within the applicant’s claimed range of 0.2 µm to 1 µm (Instant Specification: [0080]). Therefore, while modified Sung does not explicitly disclose the resistance change rate of the separator being 20 or less%, due to modified Sung teaching/rendering obvious multiple characteristics that overlap/are within the claimed scope of characteristics taught by applicant to be capable of providing the claimed resistance rate of change, one with ordinary skill in the art would reasonably expect modified Sung’s separator to provide a resistance rate of change encompassing or at least overlapping the claimed range.
Furthermore, as established above, based on the teachings of Sung, Kwon, and Beaume, and Kim II, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention to select a content of hybrid polymer (Refer to rejection of claim 5), a % of coverage (Refer to rejection of claim 1), a PVDF-HFP copolymer for modified Sung’s hybrid polymer (Refer to rejection of claim 1), and a content of HFP (Refer to rejection of claim 1) within the claimed range/scope, before the effective filing date of the claimed invention for the purpose of optimizing the effects of the hybrid polymer and the effects of the adhesive layer of modified Sung.
Therefore, since modified Sung teaches/renders obvious the characteristics suggested by the applicant to provide the claimed resistance rate of change, selection of a resistance rate of change within the claimed range would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, because such resistance rate of changes appears to be within the scope of modified Sung’s taught separator, and such a selection would have a reasonable expectation of success in arriving at a separator with suitable binder polymer materials, optimized bonding/adhesive forces/strength, and optimized electrolyte impregnability.
Regarding Claim 14, modified Sung discloses all limitations as above. Sung further discloses an electrochemical device ([0080];[0166]) comprising a positive electrode (Fig. 1, 10; [0080 – 0081]); a negative electrode (Fig.1, 20; [0080 – 0081]), and the separator being located between the positive electrode and negative electrode (Refer to separator 30 is between cathode 10 and anode 20 in Fig. 1; [0099]).
Claim(s) 3 is rejected under 35 U.S.C. 103 as being unpatentable over Sung (KR20220062856A) in view of Kwon (US PG Pub. 2022/0149480 A1), Beaume (US PG Pub. 2024/0141198 A1) and Kim (KR20120126956A), as applied to claim 1 above, and further in view of further in view of Kim (US PG Pub. 2024/0014511 A1, cited in previous O.A. mailed 04/08/2026), hereinafter Kim II.
Regarding Claim 3, modified Sung discloses all limitations as above. Sung further discloses wherein the thickness of the coating layer is 1 – 20 µm ([0109]), which encompasses the claimed range of 1 to 3 µm.
The coating layer thickness range is taught by Sung to allow the separator to have low resistance and high thermal stability ([0109]).
Kim II teaches, with respect to a lithium ion battery separator including multiple coating layers, that reducing the thickness of a separation membrane allows for the proportion of active material in the battery and for the capacity per unit volume to increase [0027 – 0032];[0067]). Kim II further teaches that increases in separator thickness causes increases in internal resistance in the battery ([0070]).
One with ordinary skill in the art would appreciate that coating layers with larger thicknesses would result in larger total separator thicknesses and thus increased internal battery resistance.
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to select a coating layer thickness within the overlapping portion of the taught range and claimed range, to optimize the internal resistance and proportion of active material within the battery without impeding the function of the coating layer, with a reasonable expectation of success and without undue experimentation [See MPEP 2144.05(II)].
Claim(s) 9 is rejected under 35 U.S.C. 103 as being unpatentable over Sung (KR20220062856A) in view of Kwon (US PG Pub. 2022/0149480 A1), Beaume (US PG Pub. 2024/0141198 A1) and Kim (KR20120126956A), as applied to claim 1 above, and further in view of Lim (WO2023136677A1, US PG Pub: US 2025/0062416 A1 equivalent used as English translation, cited in previous O.A. mailed 04/08/20526).
Regarding Claim 9, modified Sung discloses all limitations as above. In modified Sung, the adhesive layer includes a second acrylic polymer (Refer to rejection of claim 1 above). Sung further teaches the adhesive layer having a composition of only the third polymer binder or a composition including the third binder material and a solvent ([0214];[0217]).
Modified Sung does not explicitly disclose wherein the content of the second acrylic polymer binder is 80 parts by weight to 95 parts by weight relative to 100 parts by weight of the adhesive layer.
Lim teaches a separator for a secondary battery including an adhesive composition on the separator having a ceramic coating layer ([0014];[0031 – 0032]). The adhesive composition is taught to comprise the adhesive and a polymerization initiator ([0031 – 0032]). The adhesive in Lim is taught to be an acrylate-based adhesive and is included within the composition in an amount of 90 – 99 wt% ([0069 – 0070]). The polymerization initiator is included in the adhesive composition in order to cure a gel polymer electrolyte composition, specifically it prevents pre-gelation before the injection of the gel polymer electrolyte composition so that the electrode assembly can be sufficiently impregnated with the gel polymer electrolyte and the limitation of increasing resistance is prevented ([0075]). The initiator is included in an amount of 1 – 10 wt% so that sufficient polymerization of the oligomer compound is performed, and at the same time, the deterioration of adhesive strength due to a decrease in adhesive content is prevented ([0080]). Lim further teaches that use of gel electrolytes provides the advantages of preventing electrolyte leakage and improved cell stiffness when compared to liquid electrolytes ([0007 – 0008]).
Since Sung already suggests using polymer electrolyte by teaching that the electrochemical device may be a lithium-ion polymer secondary battery ([0166]), and since the adhesive layer in Lim utilizes acylate-based binder materials (Lim: [0070]), it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention to modify the adhesive layer in Sung to have a composition as taught in Lim, and thus obtain an adhesive layer including an amount of second acrylic polymer that overlaps the claimed range, with a reasonable expectation of success in achieving a separator adhesive layer capable of performing the desired function of bonding the separator to the electrodes and obtaining a separator suitable for a gel polymer electrolyte.
Selection of an amount of second acrylic polymer within the overlapping portion of the taught range and claimed range would have been obvious before the effective filing date of the claimed invention to optimize the adhesive strength of layer {i.e. related to adhesive material content} while also ensuring that a sufficient amount of initiator is included in the layer for polymerization of the oligomer compound of the gel electrolyte of modified Sung, with a reasonable expectation of success and without undue experimentation [See MPEP 2144.05(II)].
Claim(s) 13 is rejected under 35 U.S.C. 103 as being unpatentable over Sung (KR20220062856A) in view of Kwon (US PG Pub. 2022/0149480 A1), Beaume (US PG Pub. 2024/0141198 A1) and Kim (KR20120126956A), as applied to claim 1 above, and further in view of Lee (US PG Pub. 2023/0100278 A1, cited in previous O.A. mailed 04/08/2026).
Regarding Claim 13, modified Sung discloses all limitations as set forth above. Sung teaches achieving excellent adhesive strength between the electrode and the separator ([0157 – 0158]).
Modified Sung does not explicitly disclose wherein the wet adhesive strength for the separator is 8 gf/20mm to 20 gf/20mm.
Lee teaches, with a respect to separators for secondary batteries including a porous separator substrate and coating layer, that a wet adhesion strength within the range of 1.0 gf/20mm or more, or most specifically 10 gf/20mm to 20 gf/20mm, is desirable to achieve sufficient cell stiffness and to avoid inhibited electrolyte solution impregnation of the separator ([0038];[0107]). Decreases in wet adhesion strength is suggested by Lee to lower cell stiffness while increases in wet adhesion strength above 20 gf/20mm is taught by Lee to inhibit electrolyte solution impregnation of the separator due to dendrite precipitation ([0107]).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention to control the wet adhesive strength of modified Sung’s separator to be within Lee’s taught range, and further within the overlapping portion of Lee’s taught range and the claimed range, to optimize cell stiffness without inhibiting electrolyte solution impregnation of the separator, with a reasonable expectation of success and without undue experimentation [See MPEP 2144.05(II)].
Claim(s) 15 is rejected under 35 U.S.C. 103 as being unpatentable over Sung (KR20220062856A) in view of Kwon (US PG Pub. 2022/0149480 A1), Beaume (US PG Pub. 2024/0141198 A1) and Kim (KR20120126956A), as applied to claim 1 above, and further in view of Lee (WO2023146315A1, US PG Pub: US 2025/0112328 A1 equivalent used as English translation, cited in previous O.A. mailed 04/08/2026), hereinafter Lee II.
Regarding Claim 15, modified Sung discloses all limitations as set forth above. In modified Sung, the adhesive layer includes a second acrylic polymer (Refer to rejection of claim 1 above). Sung further teaches the adhesive layer having a composition of only the third polymer binder or a composition including the third binder material and a solvent ([0214];[0217]); therefore, Sung at least suggests wherein the adhesive layer is formed from a slurry, but does not disclose a particular embodiment wherein the adhesive layer is formed from a slurry having a solid content of 1% to 4%.
Lee II teaches a separator including a polymer porous support and a coating layer including binder polymer provided on the support, and further teaches forming the coating layer from a slurry of binder polymer and solvent ([0056];[0066];[0103 – 0105]). Lee II teaches, when forming the coating layer, controlling the solid content to be within the range of 1 – 7 % for the purpose of improving the stickiness of the coating layer ([0110]). More particularly, Lee II teaches that a solid content less than 1% produces little change in surface roughness (Ra), and surface roughness is desired by Lee II to obtain a separator with improved running characteristics ([0038];[0089];[0110]). At solid contents larger than 7%, Lee teaches that the cost of increasing the solid content outweighs improvements obtain from the solid content {i.e. sufficient improvement do not occur} ([0110]). In general, a solid content within the range of 7% or less, the slurry for the coating is able to induce instability of phase separation during the dipping phase separation of the coating layer, thereby forming a coating layer in which local concentration is induced and process workability of the separator is improved ([0038];[0111];[0114]).
Since Sung already suggest forming the adhesive layer form a slurry including a solvent and binder, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to form the adhesive layer of modified Sung from a slurry with a solid concentration as taught by Lee II, and thus overlapping the claimed range, with a reasonable expectation of success in coating the slurry with the adhesive layer and improving the process workability of the separator.
Furthermore, selection of a solid content within the overlapping portion of the taught range and the claimed range for modified Sung would have been before the effective filing date of the claimed invention to optimize the stickiness of the coating layer while also minimizing the cost of increasing the solid content, with a reasonable expectation of success and without undue experimentation [See MPEP 2144.05(II)].
Claim(s) 16 is rejected under 35 U.S.C. 103 as being unpatentable over Sung (KR20220062856A) in view of Kwon (US PG Pub. 2022/0149480 A1), Beaume (US PG Pub. 2024/0141198 A1) and Kim (KR20120126956A), as applied to claim 1 above, and further in view of Shin (US PG Pub. 2018/0123106 A1, cited in previous O.A. mailed 04/08/2026).
Regarding Claim 16, modified Sung discloses all limitations as set forth above. In modified Sung the coating layer includes inorganic particles, polyacrylic acid, and a hybrid polymer binder including an acrylic copolymer and PVDF-based copolymer (Refer to rejection of claim 1; Sung: [0105];[0107 – 0108] and Kwon: [0049 – 0050]). Sung further teaches that the first porous coating layer may be an aqueous coating layer using an aqueous slurry ([0106])
Modified Sung does not particularly disclose wherein the first acrylic polymer binder and the hybrid polymer are aqueous particle binders.
Shin teaches a composite separator for a battery including a porous polymeric material, a porous coating layer formed on at least one side surface of the porous polymeric material, and an electrode bonding layer formed on one of the outermost surfaces ([0006 – 0007]). Shin further teaches using particulate polymer in the electrode bonding layer, and that particulate polymer may include polyvinylidene fluoride-based polymer and methacrylate-based polymer ([0031];[0064];[0067];[0070]). The particulate binder polymer is also mixed with a water-bone solvent/aqueous medium ([0077]). The use of particulate binder is taught by Shin to allow for thin thickness, high bonding strength, and further the formation of ion conduction paths between the polymer particles and thus lower interfacial resistance ([0023]).
Since Sung is concerned the adhesion and resistance characteristics of the coating layer ([0110];[0126 – 0128]), further since modified Sung’s binder polymers for the first coating layer include an acrylic polymer and hybrid polymer including a PVDF-based copolymer taught by Shin to have particle binder forms, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to use polymer binders in particulate-form for the polymer binders of modified Sung’s coating layer, and thus obtain the claimed aqueous particle binder structure, as taught by Shin, with a reasonable expectation of success in lowering the interfacial resistance and improving the bonding strength of the coating layer.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ARYANA Y ORTIZ whose telephone number is (571)270-5986. The examiner can normally be reached M-F 7:00 AM - 5:00 PM.
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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.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/A.Y.O./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 8/6/2026
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