DETAILED ACTION
Response to Amendment
Claims 3-7, 9-17, and 21-25 are currently pending. Claims 1, 2, 8, and 18-20 are cancelled. Claims 9-17 are withdrawn from further consideration as being drawn to a non-elected invention. New claims 21-25 have been added. The amended claim 5 does not overcome the previously stated 103 rejections. Therefore, upon further consideration, claims 3-7 and 21-25 are rejected under the following 103 rejections.
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.
Claims 5-7, 21-23, and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Kidokoro (JP 2017069108 A, machine translation) in view of Kay (US 2011/0117432).
Regarding claims 5-7, Kidokoro discloses a slurry composition (binder composition) for a lithium ion secondary battery electrode comprising: a negative electrode active material / positive electrode active material; a conductive material (conductive additive); a water-soluble chitosan compound; a particulate polymer (phosphate salt), wherein the particulate polymer contains an acidic group-containing monomer unit, wherein examples of the acidic group-containing monomer unit include monomers having a phosphate group; and a dispersion medium such as water; wherein the solid concentration of the slurry composition is 53 wt% ([0021],[0027],[0029]-[0031], [0065]).
However, Kidokoro does not expressly teach a binder composition comprising at least one phosphate salt or a conjugate acid thereof, wherein the at least one phosphate salt is selected from the group consisting of orthophosphate metal salts, pyrophosphate metal salts, and polyphosphate metal salts (claim 5).
Kay discloses an inorganic binder that is sodium polyphosphate (polyphosphate metal salt) such as (NaPO3)n; wherein the inorganic binder is combined with an organic polymer binder (chitosan) in order to take advantage of synergistic effects ([0016], [0019]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the Kidokoro particulate polymer to include sodium polyphosphate in order to improve cohesion of the active electrode material and the adhesion strength between the active electrode material and the current collector ([0009]).
However, Kidokoro as modified by Kay does not expressly teach the at least one phosphate salt and chitosan that are present in a 1:5 to 1:50 mass ratio (claim 5).
However, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the Kidokoro/Kay binder to include phosphate salt and chitosan that are present in a 1:5 to 1:50 mass ratio because it has been held that the discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art. In re Boesch, 205 USPQ 215 (CCPA 1980). The mass ratio of phosphate salt and chitosan is a result effective variable of improving the coatability of the slurry composition, thereby obtaining an electrode having excellent peel strength ([0022]). Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. In re Aller, 220 F.2d 454. 456, 105 USPQ 233, 235 (CCPA 1955)). As disclosed in para. [089] of the specification of the present application, “the binder may comprise the at least one phosphate salt … and chitosan in a 1:1 to 1:10,000 … or 1:8 to 1:9”. In addition, the examples disclosed are based upon a single binder composition comprising sodium tripolyphosphate and chitosan in a 1:8.3 mass ratio. Since there is no data comparing to other mass ratios, there is no evidence of criticality of the claimed mass ratio of 1:5 to 1:50.
Regarding claims 21-23, Kidokoro also discloses examples of the negative electrode active material including silicon and SiOx; examples of the positive electrode active material include lithium transition metal oxides; and examples of conductive material (conducting additive) including carbon black, carbon fiber, carbon nanotubes, and graphite ([0067],[0068],[0071]).
Regarding claim 25, Kidokoro as modified by Kay does not expressly teach a binder composition having a viscosity of 7138.4 cP, an initial peeling force of 14.84 N, or a combination thereof (claim 25).
However, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the Kidokoro/Kay binder composition to include a binder composition having a viscosity of 7138.4 cP, an initial peeling force of 14.84 N, or a combination thereof because it has been held that the discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art. In re Boesch, 205 USPQ 215 (CCPA 1980). The viscosity and initial peeling force are result effective variables of optimizing the coatability and peel strength of the electrode in a well-balanced manner ([0022]). Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. In re Aller, 220 F.2d 454. 456, 105 USPQ 233, 235 (CCPA 1955)). Although para. [146] and Table 1 disclose a viscosity of ChitosanTPP of 7138.4 cP and an initial peeling force of ChitosanTPP and Si composite that is as high as 14.84 N, there is no evidence of criticality of the claimed viscosity and initial peeling force.
Claims 3 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Kidokoro (JP 2017069108 A, machine translation) in view of Kay (US 2011/0117432) as applied to claim 5 above, and further in view of Yammine et al (US 2017/0362123).
Regarding claims 3 and 4, Kidokoro as modified by Kay does not expressly teach at least one phosphate salt that is sodium tripolyphosphate (claim 3); wherein the sodium tripolyphosphate and chitosan are present in a 1:5 to 1:10 mass ratio (claim 4).
Yammine et al discloses a binder activator that is a salt chosen from polyphosphates of sodium, potassium, or lithium, wherein the activator is preferably sodium triphosphate (sodium tripolyphosphate) ([0007]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the Kidokoro/Kay binder composition to include sodium tripolyphosphate in order to improve the mechanical strength of the binder ([0007]). In addition, the substitution of one known type of polyphosphate for another would have yielded predictable results to one of ordinary skill in the art at the time of the invention. Further, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the Kidokoro/Kay/Yammine slurry composition to include sodium tripolyphosphate and chitosan that are present in a 1:5 to 1:10 mass ratio because it has been held that the discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art. In re Boesch, 205 USPQ 215 (CCPA 1980). Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. In re Aller, 220 F.2d 454. 456, 105 USPQ 233, 235 (CCPA 1955)). There is no evidence of criticality of the claimed type of polyphosphate or mass ratio of tripolyphosphate and chitosan.
Claim 24 is rejected under 35 U.S.C. 103 as being unpatentable over Kidokoro (JP 2017069108 A, machine translation) in view of Kay (US 2011/0117432) as applied to claim 5 above, and further in view of Li et al (CN 107863499 A).
Regarding claim 24, Kidokoro as modified by Kay does not expressly teach a chitosan that is selected from polycationic or neutral chitosan, wherein when the polycationic chitosan is used, the at least one phosphate salt is mixed with the polycationic chitosan to form a network of ionically phosphate crosslinked chitosan chains, whereas when the neutral chitosan is used, the conjugate acid of the at least one phosphate salt is mixed with the neutral chitosan to form the network of ionically phosphate crosslinked chitosan chains (claim 24).
Li et al teaches the concept of utilizing polycationic chitosan having strong interfacial bonding in a battery electrode ([0012]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the Kidokoro/Kay water-soluble chitosan compound to include polycationic chitosan that inherently form a network of ionically phosphate crosslinked chitosan chains in order to utilize a chitosan compound with strong interfacial bonding ([0012]). In addition, the selection of a known material based on its suitability for its intended use has generally been held to be prima facie obvious (MPEP §2144.07). As such, it would be obvious to use polycationic chitosan.
Response to Arguments
Applicant's arguments filed 11/13/25 have been fully considered but they are not persuasive.
The Applicant argues that “Chitosan and phosphate salts (e.g. TPP) crosslinks and forms a dense crosslinking network of the binder gel ([83] of the instant application). The viscosity of the binder gel increases with increasing concentration of phosphate salts (e.g. sodium tripolyphosphate (TPP)) because of higher degree of crosslinking. Too low or too high viscosity of the binder gel would reflect the crosslinking extent of the binder gel and affect the quality of the binder gel. Specifically, when TPP /chitosan is 1: 8.3, the viscosity of the resulting binder slurry is 7,138.4 cP (Table 1, paragraph [181] and [223]). Accordingly, when the mass ratio of phosphate salt/chitosan increases to 1:1, or even to 1:0.02, the viscosity of the slurry would be much higher than 7,138.4 cP. However, Kidokoro discloses a preferred viscosity range of 3,600-5,000 cP for good coating properties (paragraph [0076]), which is substantially lower than the instant application. The viscosity of Kidokoro's binder slurry would unavoidably increase when
phosphate salts is additionally included. The viscosity of the binder slurry including
phosphate salts/chitosan at the mass ratio of 1:8.3 already exceeds 5,000 cP, and would be even higher at 1:1 or at 1:0.02. Such high viscosity provided by phosphate salts would destroy intended coating properties of Kidokoro's binder slurry and lead to an uneven and nonuniform electrode mixture layer. Thus, a person having ordinary skill in the art would not include phosphate salts into Kidokoro's slurry”.
In addition, the Office first points out there is only a single example of a binder composition comprising sodium tripolyphosphate (TPP) and chitosan at a mass ratio of 1:8.3. Also, there is no data showing a comparison to the closest prior, Kidokoro, which discloses a binder composition comprising a water-soluble chitosan and a particular polymer. Absent evidence of unexpected results (such as peel strength / initial peel force) of the combination of polyphosphate and chitosan, the Office maintains the contention that it would have been obvious to one of ordinary skill in the art to substitute one known phosphate compound for another with a reasonable expectation of success. In response to the argument that Kidokoro discloses a preferred viscosity range of 3,600-5,000 cP, while the present invention discloses a viscosity of 7,138.4 cP, the Office first points that the Kidokoro viscosity is based on the slurry composition (electrode composition) which is not the same as the viscosity of the binder composition of the present invention. Also, the argument that “the mass ratio of phosphate salt/chitosan increases to 1:1, or even to 1:0.02, the viscosity of the slurry would be much higher than 7,138.4 cP” appears to be based on opinion and not based on any factual evidence since there is no data showing a mass ratio of 1:1 disclosed in the present application. Lastly, the Office disagrees that “Such high viscosity provided by phosphate salts would destroy intended coating properties of Kidokoro's binder slurry and lead to an uneven and nonuniform electrode mixture layer” because the purpose of Kidokoro is to provide excellent coatability and excellent peel strength which is the same as the present invention.
Conclusion
THIS ACTION IS MADE FINAL. 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 TONY S CHUO whose telephone number is (571)272-0717. The examiner can normally be reached Monday - Friday, 9:00am - 5:30pm.
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, Jonathan Leong can be reached on 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.
/T.S.C/Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 1/12/2026