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 Application
Claims 1, 5-6, 8-11 are currently pending. Claim 1 is currently amended. Claims 2-4, 7, 13-14 are canceled. Claim 12 is withdrawn.
Response to Arguments
Applicant's arguments filed 12/16/2025 have been fully considered but they are not persuasive because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Specifically, amended claim 1 now recites “performing a pore forming process comprising a step of allowing the coating support member to stand under a humidified condition followed by a step of dipping the coating support member in a non-solvent”. Previously, claim 1 required the pore forming process to include at least one of the humidifying step and the dipping step.
A new reference (Huang) teaches a pore forming process comprising a step of allowing the coated support member to stand under a humidified condition (See rejection below).
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1,5-6 and 9-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kajita (US20170200933A1, previously cited), in view of Huang (CN107195838A, copy/translation attached), Sakurai (previously cited, US20180254464A1).
Regarding claims 1 and 10, Kajita discloses a method for manufacturing a separator for an electrochemical device ([0190]; Sample 1),
the separator comprising a heat resistant layer (“a resin layer of polyvinylidene fluoride” [0190]),
wherein the heat resistant layer is formed by the steps of:
applying a slurry comprising a binder resin (“a solution obtained by dissolving polyvinylidene fluoride in N-methyl-2-pyrrolidone” [0190]; Sample 1]) to at least one surface of a support member (a polyethylene fine porous membrane [0190]) to form a coated support member
Kajita in Sample 1 does not disclose wherein the slurry comprises a ceramic precursor as claimed. However, Kajita discloses that the second resin layer 204b (i.e., the slurry) may further comprise glass, wherein polysilazane is preferably used as a raw material of glass [0161] to improve heat stability and electrochemical stability of the separator [0161].
Thus, it would have been obvious for a person having ordinary skill in the art to have added polysilazane compound as a ceramic precursor in the slurry for the heat resistant layer, with a reasonable expectation to provide a separator with improved heat and electrochemical stabilities [Kajita 0161].
Kajita further discloses the step of drying the coated support member [0097 Kajita],
Kajita further discloses wherein the coated porous membrane is placed in a water bath to separate the phase and form a three-dimensional mesh [0154, 0190 Kajita] (i.e., pore forming process; i.e., the claimed “dipping the coated support member in a non-solvent” before drying).
However, Kajita does not disclose wherein the pore forming process comprises a step of allowing the coated support member to stand under a humidified condition prior to dipping the coated support member in a non-solvent.
In this regard, Huang teaches a method for preparing a separator comprising a porous heat-resistant coating, wherein the method comprises:
Coating a heat-resistant coating slurry onto a surface of a substrate (i.e., coating step [0019]),
Placing the coated substrate in a humidity chamber having a relative humidity of 60-100% to make pores (i.e., “hole making” step [0020]), and
Cleaning [0020] (i.e., “washed with deionized water” [0041]), and drying in hot air to obtain microporous coating membrane [0021, 0041].
Huang teaches that in a high humidity environment, water vapor condenses on the surface of the polymer solution to form water droplets and forms an ordered porous structure on the surface of the polymer film as the organic solvent and water evaporate [Huang 0028].
It would have been obvious for a person having ordinary skill in the art to have added the step of “allowing the coated support member to stand under a humidified condition” prior to placing the coated substrate in a water bath and drying, with a reasonable expectation to form an ordered porous structure on the surface of the coating [Huang 0028].
Regarding the claimed limitation of “controlling a rate of converting the ceramic precursor into a ceramic material by performing the pore forming process”, Kajita discloses that the polysilazane converts to glass by reaction of water content [0161] (i.e., when placed in a water bath). Since the rate of converting the ceramic precursor into a ceramic material changes from 0% (prior to reacting with water) to at least some conversion rate when polysilazane is introduced to water during the pore forming step, the limitation of “controlling a rate” is considered met.
Kajita further discloses wherein the ceramic precursor comprises polysilazane, and the polysilazane comprises at least one compound represented by Chemical Formula 1:
PNG
media_image1.png
209
825
media_image1.png
Greyscale
wherein each of R independently represents hydrogen and alkyl group [0067 Kajita].
Kajita further discloses wherein the binder resin comprises a polyvinylidene fluoride-based polymer resin (i.e., polyvinylidene fluoride [0190]) comprising vinylidene fluoride as a polymerization unit.
However, Kajita does not disclose wherein the polyvinylidene fluoride-based polymer resin comprises:
a copolymer of vinylidene fluoride with a copolymerizable monomer, and
the copolymer has a substitution degree with the monomer of 1 wt% to 30 wt%.
In this regard, Sakurai also teaches a separator for a non-aqueous secondary battery including a porous substrate and an adhesive porous layer comprising a polyvinlidene fluoride type resin and carboxylic anhydride (e.g., polysiloxanes [0075]), wherein the polyvinlidene fluoride-based resin may include homopolymers of vinylidene fluoride (i.e. polyvinylidene fluoride) and copolymers of vinylidene fluoride and other copolymerizable monomer (polyvinlidene fluoride copolymers), such as a VDF-HFP copolymer [0059 Sakurai], which is “a copolymer of vinylidene fluoride with a copolymerizable monomer” as claimed.
It would have been obvious for a person having ordinary skill in the art to have copolymerized VDF of Kajita with a copolymerizable monomer (e.g., HFP), as Sakurai teaches that by copolymerizing hexafluoropropylene with vinylidene fluoride, crystallinity, heat resistance, resistance to dissolution in an electrolytic solution and the like of the polyvinylidene fluoride type resin can be each controlled [0059 Sakurai].
Sakurai further discloses that the VDF-HFP copolymer preferably has a HFP monomer content of from 3% by mass to 25% by mass with respect to the total amount of all monomer components, which falls within the claimed range of “1 wt% to 30 wt%”. A person having ordinary skill in the art would select the encompassed amount of the monomer as Sakurai teaches that the copolymer having such amount of HFP monomer content is hardly dissolved and is not excessively swollen in the electrolytic solution, which is beneficial for maintaining adhesion between the electrode and the separator [Sakurai 0062].
Regarding claim 5, modified Kajita teaches the method for manufacturing the separator for the electrochemical device according to claim 1, wherein the slurry is prepared by preparing a polymer solution comprising the binder resin (Sample 1; [0190]).
However, Kajita in Sample 1 does not explicitly disclose the step of:
preparing precursor solution comprising the ceramic precursor separately, and mixing the polymer solution and the precursor solution with each other.
In this regard, Kajita discloses that the polysilazane compound can be preferably used in the second resin layer, wherein the compound can be converted to glass by reaction of water content [0160-0161], wherein the polysilazane may be in a viscous liquid form [0116 Kajita]. Thus, a person having ordinary skill in the art would add the polysilazane solution to the polymer solution comprising the binder resin, as Kajita discloses it improves heat stability and electrochemical stability [0161 Kajita].
Regarding claim 6, modified Kajita teaches the method for manufacturing the separator for the electrochemical device according to claim 1. Kajita does not disclose wherein the polyvinylidene fluoride-based polymer resin has a weight average molecular weight of from 300,000 to 1,500,000.
In this regard, Sakurai teaches wherein the polyvinylidene fluoride-based polymer resin has a weight average molecular weight of from 100,000 to 1,500,000 [0060 Sakurai], which encompasses the claimed “weight average molecular weight of from 300,000 to 1,500,000”. A person having ordinary skill in the art would modify the polyvinlidene fluoride-based polymer of Kajita, such that it is in the encompassed weight average molecular weight, as Sakurai teaches that such copolymer is hardly dissolved in the electrolytic solution and the adhesiveness of the electrode and the heat resistant layer is easily maintained in a battery [0063-0064 Sakurai].
Regarding claim 9, modified Kajita teaches the method for manufacturing the separator for the electrochemical device according to claim 1. Kajita does not disclose the step of allowing the coated support member to stand under a humidified condition is carried out under a relative humidity of 30% to 60%.
In this regard, Huang teaches wherein the step of allowing the coated support member to stand under a humidified condition is carried out under a relative humidity of 60-100%, which overlaps with the claimed relative humidity of “30% to 60%”.
Huang further teaches that in a high humidity environment, water vapor condenses on the surface of the polymer solution to form water droplets and forms an ordered porous structure on the surface of the polymer film as the organic solvent and water evaporate [Huang 0028].
It would have been obvious for a person having ordinary skill in the art to have selected the overlapping relative humidity, with a reasonable expectation to form an ordered porous structure on the surface of the coating by forming water droplets on the surface of the polymer film [Huang 0028].
Regarding claim 11, modified Kajita teaches the method for manufacturing the separator for the electrochemical device according to claim 1. Kajita does not disclose the method further comprising at least one step selected from the group consisting of a UV irradiation step and a plasma treatment step, after drying.
In this regard, Sakurai teaches that surface treatments such as a corona treatment, a plasma treatment, a flame treatment and an ultraviolet ray irradiation treatment improves wettability [0048 Lee]. Thus, a person having ordinary skill in the art would have been motivated to add the step of a plasma treatment and a UV irradiation step to improve wettability of the coating layer [0048 Lee].
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kajita (US20170200933A1), in view of Sakurai (previously cited, US20180254464A1) and Joo (US20180337379A1, IDS cited 02/02/2022).
Regarding claim 8, modified Kajita teaches the method for manufacturing the separator for the electrochemical device according to claim 1. Kajita is silent to an amount of the ceramic precursor in the slurry. Thus, Kajita does not disclose “wherein an amount of the ceramic precursor in the slurry is 10 wt% to 85 wt% based on 100 wt% of a combined weight of the ceramic precursor and the binder resin”.
In this regard, Joo is also directed to a separator comprising a substrate and and/or a continuous coating or shell material [0067 Joo], wherein fluid stocks for forming the continuous coating or shell material may comprise PVDF and a ceramic precursor such as a polysilazane [0059 Joo]. Joo further teaches that the film may comprise 30 wt. % to about 99 wt. % polymer and about 1 wt. % to about 70 wt. % ceramic [0026 Joo], which overlaps with the claimed range of the ceramic precursor in “10wt% to 85 wt% based on 100 wt% of a combined weight of the ceramic precursor and the binder resin”.
A person having ordinary skill in the art would select the overlapping amount of the ceramic precursor, as Joo teaches that providing a good surface coverage of the polymeric material with ceramic improved ionic mobility of the material (e.g., and in turn rate capability and/or capacity of a battery comprising the same), wettability (e.g., reducing the need for excess electrolyte, e.g., reducing the cost and volume of the overall cell), improving mechanical properties (e.g., tensile strength in the medial (md) and/or transverse (td) directions) (e.g., improving processability, reducing probability of damage caused during use, and/or improving safety parameters), improving thermal stability (e.g., reducing shrinkage at elevated temperatures, e.g., improving safety parameters) [0022 Joo].
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 TAEYOUNG SON whose telephone number is (703)756-1427. The examiner can normally be reached M-F 8-5pm.
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/T.S./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 3/23/2026