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 .
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.
Claims 1-2 are rejected under 35 U.S.C. 103 as being unpatentable over Nagai (JP2013218913A) and further in view of Fukumoto (JP2014137985A).
Regarding claim 1, Nagai teaches:
A non-aqueous electrolyte secondary battery (claim 1), comprising:
a wound electrode assembly (claim 2) in which a positive electrode (positive electrode 30) and a negative electrode (negative electrode 50) are wound with a first separator (double-sided HRL separator 70B) disposed on an inner side of winding of the positive electrode (double-sided HRL separator 70B is on the inner side of positive electrode 30; Figs. 4-5) and
a second separator (single-sided HRL separator 70A) disposed on an outer side of winding of the positive electrode interposed therebetween (single-sided HRL separator 70A is on the outer side of positive electrode 30; Figs. 4-5);
an electrolytic solution (electrolyte; pg. 14 lines 16-28);
and an exterior that houses the electrode assembly and the electrolytic solution (battery case 80; pg. 14 lines 12-17),
wherein the first separator (double-sided HRL separator 70B) has a first substrate layer (substrate/base material 72, pg. 5 lines 43-46) and a first coating layer (heat-resistant layer 74, pg. 5 lines 45-48) formed on a surface of the first substrate layer (the double-sided HRL separator 70B is provided with a heat-resistant layer 74 containing an inorganic filler on both sides of the substrate/base material 72, pg. 5 lines 43-46) facing the positive electrode (heat-resistant layer 74 is facing the positive electrode 30; Fig. 4),
and the second separator (single-sided HRL separator 70A) has a second substrate layer (substrate/base material 72, pg. 5 lines 43-45) and a second coating layer (heat-resistant layer 74, pg. 5 lines 43-45) formed on a surface of the second substrate layer (the single-sided HRL separator 70A is provided with a heat-resistant layer 74 containing an inorganic filler on any one side of the surface of the substrate/base material 72, pg. 5 lines 43-45) facing the positive electrode (heat-resistant layer 74 faces the positive electrode 30; Fig. 4).
Nagai further teaches the first coating layer and the second coating layer (both layers correspond to heat-resistant layer 74) each include a filler and an organic material. In particular, Nagai discloses the heat-resistant layer can be composed of an inorganic filler and a binder (pg. 12 lines 1-2), wherein the binder is selected from organic materials such as polyvinylidene fluoride (PVdF), polyvinylidene chloride (PVdC), or polyacrylonitrile (PAN) (pg. 9 lines 56-58). Nagai further discloses the heat-resistant layer may also include a mixture of two or more organic polymer materials such as aromatic polyamide, polyimide, polyamideimide, polysulfone and polyethersulfone (pg. 4 lines 31-36).
Regarding the filler content of the first and second coating layers (both layers correspond to heat-resistant layer 74), Nagai does not expressly disclose a content rate of the filler in the first coating layer is higher than a content rate of the filler in the second coating layer, as claimed.
Fukumoto discloses a secondary battery with a wound electrode body including two long sheet-like separators (separator sheets 50A and 50B; Fig. 3; pg.003, para.3) disposed between the positive and negative electrode sheets. Fukumoto further discloses a heat-resistant layer (heat-resistant layer 51) is formed on a surface of a separator sheet (claim 1). Regarding the composition of the heat-resistant layer, Fukumoto discloses it may contain a filler such as an inorganic filler, organic filler, or a combination thereof; however, in consideration of heat resistance, dispersibility, and stability, an inorganic filler may be preferably used (pg. 009, lines 6-13). Fukumoto also teaches other configurations featuring two or more heat-resistant layers located between positive and negative electrodes, with potential configurations including both opposing sides of a separator or a combination of separator and electrode surfaces; further, when a plurality of heat-resistant layers are provided, the structures (for example, composition and thickness) of the heat-resistant layers may be the same or different (pg. 005, para. 3).
Fukumoto teaches that when using an inorganic filler and an organic filler together in the heat-resistant layer(s), the ratio of inorganic filler:organic filler is within a range of 20:80 to 70:30 on a mass basis (pg. 009, para. 5). Fukumoto further teaches a ratio of inorganic filler in the entire heat-resistant layer is preferably about 50% by mass or more (for example, 70 to 99.5% by mass or 90 to 99% by mass), and that when the ratio of inorganic filler is within this range, a desired heat resistance effect can be exhibited, and the anchoring property of the heat-resistant layer and the strength (shape retention) of the heat-resistant layer itself are improved (pg. 009, para. 7).
It should be noted that the amount of filler in the respective coating layers is a result effective variable. Fukumoto expressly teaches that the compositions of a plurality of heat-resistant layers may be different and further teaches that the amount of inorganic filler affects the heat resistance, anchoring property, and strength/shape retention of the heat-resistant layer. Thus, Fukumoto recognizes that varying the filler content affects properties of the coating layer(s).
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the respective filler content rates of the first and second coating layers of Nagai (hereby referred to as “modified Nagai”) by adjusting the content rate of filler in the first coating layer to be higher than in the second coating layer through routine optimization, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). In the present invention, one would have been motivated to optimize the filler content rate of the respective coating layers in order to obtain the desired balance of heat resistance, anchoring property, and strength/shape retention of each coating layer, as taught by Fukumoto.
Accordingly, providing different filler content rates in the respective coating layers such that the content rate of the filler in the first coating layer is higher than the second coating layer would have been an obvious optimization of a known result effective variable, yielding predictable electrochemical results. Therefore, modified Nagai teaches all features of the claim.
Regarding claim 2, modified Nagai teaches all features of claim 1, including that the content rate of the filler in the first coating layer is higher than a content rate of the filler in the second coating layer, as described above. However, modified Nagai does not expressly teach the non-aqueous electrolyte secondary battery wherein the content rate of the filler in the first coating layer is greater than or equal to 75 mass%, and the content rate of the filler in the second coating layer is less than or equal to 60 mass%, as claimed.
Fukumoto discloses that the inorganic filler may be present in a heat-resistant layer in an amount of 50% by mass or greater, and further discloses exemplary ranges of 70 to 99.5% by mass or 90 to 99% by mass (pg. 009, para. 7). Thus, Fukumoto teaches filler content rates encompassing values greater than or equal to 75 mass% as claimed for the first coating layer, and Fukumoto also teaches filler content rates within the range of 50-60% by mass. Fukumoto further teaches that when a plurality of heat-resistant layers are provided, the structures (for example, composition and thickness) of the respective heat-resistant layers may be the same or different (pg. 005, para. 3).
As discussed in the rejection of claim 1 above, it should be noted that the filler content of the respective coating layers is a result effective variable. Fukumoto teaches that the amount of inorganic filler affects the heat resistance, anchoring property, and strength/shape retention of the heat-resistant layer (pg. 009, para. 7). Thus, Fukumoto recognizes that varying the filler content affects properties of the coating layer(s).
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to further modify the respective filler content rates of the first and second coating layers of Nagai by adjusting the content rate of filler in the first coating layer to be greater than or equal to 75 mass%, and the content rate of filler in the second coating layer to be less than or equal to 60 mass%, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). In the present invention, one would have been motivated to optimize the filler content rate of the respective coating layers in order to obtain the desired balance of heat resistance, anchoring property, and strength/shape retention of each coating layer, as taught by Fukumoto.
Accordingly, providing different filler content rates such that the content rate of filler in the first coating layer is greater than or equal to 75 mass%, and the content rate of filler in the second coating layer is less than or equal to 60 mass%, would have been an obvious optimization of a known result effective variable, yielding predictable electrochemical results.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Katayama (US20120174386A1): appears to disclose an electrochemical device including a non-aqueous electrolyte and a separator, wherein the separator includes a first porous layer composed mainly of a thermoplastic resin and a second porous layer composed mainly of insulating particles with a heat-resistant temperature of 150°C or higher.
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/A.R.O./Examiner, Art Unit 1789
/MARLA D MCCONNELL/Supervisory Patent Examiner, Art Unit 1789
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