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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 07/24/2025 has been entered.
Response to Arguments
Applicant’s arguments with respect to claims have been considered but are moot 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.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-6 and 8-13 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
The term “about” in claims 1, 4-6, and 8 is a relative term which renders the claim indefinite. The term “about” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. The limitations related to weight ratios, polymer and inorganic particle contents, molecular weights, coating layer thickness have been rendered indefinite by use of the term “about.”
Claims 2-3 and 9-13 are rejected for depending on rejected claims.
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.
Claims 1-6 and 8-13 are rejected under 35 U.S.C. 103 as being unpatentable over Shibuya (JP-2016039138-A; a machine translation is attached and referenced below) in view of Sung (US 2021/0057698 A1).
Regarding claim 1, Shibuya discloses a separator for a rechargeable lithium battery ([0001]), the separator comprising: a porous substrate ([0085]); and a coating layer on at least one surface of the porous substrate ([0084]), wherein: the coating layer includes a binder resin and inorganic particles ([0084]), the binder resin includes a first polymer including a structural unit represented by Chemical Formula 1 (PVA-based resin, [0084]), the binder resin further includes an additional binder (vinyl polymer particles as dispersoid, [0028]), the additional binder including a (meth)acrylic polymer, a styrene polymer, or a combination thereof ([0047]), the additional binder is included in the binder resin in an amount of about 1 to about 40 parts by weight, based on 100 parts by weight of the binder resin included in the coating layer (resin content includes PVA-based resin and dispersoid, [0065]; content of PVA-based resin is 10 to 80 wt%, [0069], so content of dispersoid is 20 to 80 parts by weight based on 100 parts by weight of the binder resin) and in Chemical Formula 1, R1 to R3 are each independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted aryl group, and L is a single bond or a substituted or unsubstituted C1 to C10 alkylene group (see [0036] and chemical formula 1 on p. 8 of original document).
Shibuya does not disclose wherein the binder resin includes a second polymer including a structural unit represented by Chemical Formula 2, a weight ratio of the first polymer and the second polymer in the binder resin is about 60:40 to about 75:25, a weight average molecular weight of the first polymer is about 5,000 g/mol to about 25,000 g/mol, and a weight average molecular weight of the second polymer is about 50,0000 g/mol to about 70,000 g/mol.
Shibuya teaches the degree of polymerization of the first polymer, and therefore the weight average molecular weight of the first polymer, is related to the strength and stability of the coating layer ([0031]). A person having ordinary skill in the art before the effective filing date of the invention would therefore find it obvious to optimize the weight average molecular weight of the first polymer by controlling its degree of polymerization, including to a range corresponding to about 5,000 g/mol to about 25,000 g/mol, in order to achieve a balance between strength and stability as taught by Shibuya ([0031]).
Sung teaches a separator for a rechargeable lithium battery ([0053]), the separator comprising: a porous substrate ([0054]); and a coating layer on at least one surface of the porous substrate ([0055]), wherein: the coating layer includes a binder resin and inorganic particles ([0055]), the binder resin includes a second polymer including a structural unit represented by Chemical Formula 2 (polyvinyl pyrrolidone or PVP, [0055]), a weight average molecular weight of the second polymer is about 50,000 g/mol to about 70,000 g/mol (overlapping range of 10,000-1,000,000 g/mol, [0065]), and in Chemical Formula 2, R4 to R8 are each independently hydrogen and m = 2 (polyvinyl pyrrolidone), and a content of the second polymer is 2-20 parts by weight based on the total content of binder polymers ([0062]). A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to modify the coating layer of Shibuya by adding polyvinyl pyrrolidone having a weight average molecular weight of about 50,000 g/mol to about 70,000 g/mol in the amount of 2-20 parts by weight based on the total content of binder polymers because Sung teaches that the second polymer can effectively bind between particulate binder polymers and inorganic particles and anchor between the porous substrate and the coating layer ([0062]).
Sung further teaches that the content of the second polymer is related to the adhesion and resistance of the separator ([0062]-[0063]). A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have optimized the content of the second polymer in the coating layer of Shibuya, including to a range such that a weight ratio of the first polymer and the second polymer in the binder resin is about 60:40 to about 75:25, in order to achieve a balance between adhesion and resistance as taught by Sung ([0062]-[0063]).
Regarding claim 2, Shibuya in view of Sung teaches wherein R1 to R3 in Chemical Formula 1 are each independently hydrogen or a substituted or unsubstituted C1 to C5 alkyl group (Shibuya: see [0036] and chemical formula 1 on p. 8 of original document).
Regarding claim 3, Shibuya in view of Sung teaches wherein: R4 to R8 in Chemical Formula 2 are each independently hydrogen and m is 2 (Sung: polyvinyl pyrrolidone, [0055]).
Regarding claim 4, Shibuya in view of Sung teaches wherein a weight ratio of the first polymer and the second polymer in the binder resin is about 60:40 to about 70:30 (see rejection of claim 1).
Regarding claim 5, Shibuya in view of Sung teaches wherein the coating layer has a thickness of about 1 µm to about 10 µm (Shibuya: 1 µm to 5 µm, [0089]).
Regarding claim 6, Shibuya in view of Sung teaches wherein the binder resin is included in the coating layer in an amount of about 1 wt% to about 20 wt%, based on a total weight of the binder resin and the inorganic particles (Shibuya: overlapping range of 1 wt% to 35 wt% based on the solid content of the coating agent composition, [0079]).
Regarding claim 8, Shibuya in view of Sung teaches wherein the inorganic particles are included in the coating layer in an amount of about 80 wt% to about 99 wt%, based on a total weight of the binder resin and the inorganic particles (Shibuya: overlapping range of 50 to 99.9 wt% based on the solid content of the coating agent composition, [0017]).
Regarding claim 9, Shibuya in view of Sung teaches wherein the inorganic particles include Al2O3 (aluminum oxide), B2O3 (boron oxide), Ga2O3, TiO2 (titanium oxide), SnO2 (tin oxide), ZrO2 (zirconium oxide), or a combination thereof (Shibuya: [0014]).
Regarding claim 10, Shibuya in view of Sung teaches wherein the porous substrate includes polyolefin, polyester, polycarbonate, or a combination thereof (Shibuya: [0085]).
Regarding claim 11, Shibuya in view of Sung teaches wherein, after leaving the separator at about 130 °C to about 150 °C for 60 minutes, measured average shrinkage rates in a machine direction and a transverse direction are less than or equal to about 20% (since there is no distinction between the instant claims and the prior art, this feature is considered to be inherently present in the separator of Shibuya in view of Sung, see [MPEP § 2112.01]).
Regarding claim 12, Shibuya in view of Sung teaches a rechargeable lithium battery, comprising: a positive electrode; a negative electrode; and the separator for a rechargeable lithium battery as claimed in claim 1 between the positive electrode and the negative electrode (Shibuya: [0084]).
Regarding claim 13, Shibuya in view of Sung does not disclose wherein the total amount of the first polymer and the second polymer included in the coating layer is 4 wt%, based on a total weight of the binder resin and the inorganic particles.
However, Shibuya teaches that the content of the first polymer in the coating layer is 0.1 wt% to 28 wt% ([0069],[0079]) and that the content of the binder resin is related to the viscosity and the storage stability of the coating layer ([0079]). Sung teaches that the content of the second polymer is related to the adhesion and resistance of the separator ([0062]-[0063]). A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have optimized the content of the first polymer and the second polymer in the coating layer of Shibuya in view of Sung, including to a range such that the total amount of the first polymer and the second polymer included in the coating layer is 4 wt%, in order to achieve a balance between viscosity, storage stability, adhesion, and resistance as taught by Shibuya ([0079]) and Sung ([0062]-[0063]).
Conclusion
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/C.C.D./Examiner, Art Unit 1723 /TIFFANY LEGETTE/Supervisory Patent Examiner, Art Unit 1723