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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 23 Dec, 2025 has been entered.
Claim Rejections - 35 USC § 112
The rejection of claims 22-23 under 35 USC § 112(a) is rendered moot as these claims have been withdrawn.
Response to Arguments
Applicant’s arguments, filed 23 Dec 2025, with respect to the rejection of claim 1 under 35 USC § 103 have considered but are moot because the new ground of rejection now addresses the newly-amended claims, as set forth below. With regard to the D50, D10, and D90 values that are now recited in claim 1, the examiner submits that the prior art reference Murakami et al. (US 2017/0162850) reads on these limitations, as set forth in detail in the rejection of claim 1 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.
Claim(s) 1-2 and 7-9 are rejected under 35 U.S.C. 103 as being unpatentable over Murakami et al. (US 2017/0162850) in view of Kai et al. (EP 3232494).
As to claim 1, Murakami et al. discloses a multilayer porous membrane comprising a porous membrane (see e.g. porous film [0011]) that includes a polyolefin resin as a main component (see e.g. [0011]), and a porous layer (see e.g. porous layer, [0011]) that includes inorganic particles and a binder polymer (see e.g. filler and binder resin, [0013]-[0014] and [0035]), layered on at least one side of the porous membrane (see e.g. the porous layer is laminated on one surface of the porous film, [0011]), wherein the total thickness of the porous layer is 0.1 mm to 20 mm (see e.g. [0084]), which overlaps and thereby renders obvious the claimed range of 0.5 mm or more and 3.0 mm or less. A percentage of inorganic particles occupying the porous layer of Murakami et al. is 90 weight% or more and 99 weight% or less (see e.g., [0138], showing an embodiment in which the inorganic particles are present in an amount of 100 parts by weight and the sodium carboxymethyl cellulose binder is present in an amount of 3 parts by weight, meaning the porous layer is 97% by weight inorganic particles, which anticipates the claimed range), an aspect ratio of the inorganic particles is 1.0 or more and 3.0 or less (see e.g. para [0050] describing the particles may be spherical, implying an aspect ratio 0f 1.0), a mean particle size D50 of the inorganic particles in the porous layer is 0.01 mm to 10 mm (see e.g. [0025]), which overlaps and thereby renders obvious the claimed range of 0.25 mm or more and 0.45 mm or less, the inorganic particles in the porous layer have a particle size D90 of 0.5 mm to 5.0 mm (see e.g. [0025]), which overlaps and thereby renders obvious the claimed range of 0.50 mm or more and 1.00 mm or less, and a particle size of D10 of 0.005 mm to 0.4 mm (see e.g. [0025]), which overlaps and thereby renders obvious the claimed range of 0.10 mm or more and 0.35 mm or less.
Further regarding claim 1, Murakami et al. does not disclose that the porous layer contains at least one salt or ether selected from the group consisting of a polycarboxylic acid salt, a sulfonic acid salt and a polyoxyether, in a solid-content amount of 0.2 parts by weight or more and 1.0 parts by weight or less.
Kai et al., also working in the field of porous membranes for battery separators, discloses a porous layer (see e.g. porous layer, Kai et al.: [0087]) which contains a dispersant that may include polycarboxylic acid salts or sulfonic acid salts (see e.g. polysulfonic acid salts, Kai et al.: [0091]) at a concentration of 0.1 parts by mass to 40 parts by mass, which overlaps and thereby renders obvious the claimed range of 0.2 to 1.0 parts by weight (see e.g. Kai et al.: [0091]). Additionally, Murakami et al. states that a dispersing agent may be added to the porous layer to disperse the inorganic particles (see e.g. Murakami et al.: [0067]).
It would therefore have been obvious to one of ordinary skill in the art prior to the filing date of the claimed invention modify Murakami et al.’s porous layer by adding 0.2 to 1.0 parts by weight of either polycarboxylic acid salts or sulfonic acid salts as taught by Kai et al.. Said artisan would have been motivated to make such an addition in order to improve the dispersion of particles in Murakami et al.’s porous layer.
Murakami et al. in view of Kai et al. does not disclose that the number of holes with hole areas of 0.001 mm2 or greater in the porous layer is 80 or more and 150 or less per 10 mm2 visual field, a percentage of holes with areas in the range of 0.001 mm2 to 0.05 mm2 among holes with areas of 0.001 mm2 or greater in the porous layer is 90% or greater.
With regard to the distribution of holes in Murakami et al. in view of Kai et al.’s porous layer, paragraph [0027] of the instant specification states that the pore structure is controlled by the D50, D10, D90 of the inorganic particles, the amount of dispersing agent added, the specific surface area of the inorganic particles, the viscosity of the coating solution, and the layer density of the porous layer.
As set forth above, Murakami et al. in view of Kai et al. teaches a porous layer comprising inorganic particles having D50, D10, D90 values that read on the instantly-claimed values, and an aspect ratio that reads on the claimed inorganic particles, implying a substantially similar surface area. As set forth above, Murakami et al. in view of Kai et al. teaches a dispersant of polycarboxylic acid salts or sulfonic acid salts present in an amount 0.2 to 1.0 parts by weight, which reads on the claimed dispersant. Additionally, Murakami et al. in view of Kai et al. teaches a porous layer comprising a coating solution of N-methylpyrolidone (see e.g. Murakami, [0145], the coating slurry comprises N-methyl-2-pyrolidone), which is the same coating liquid disclosed in the Instant Specification (see e.g. para [0128] of the Instant Specification), and as such has the same viscosity as the coating solution of the claimed porous layer. Additionally, Murakami et al. in view of Kai et al.’s porous layer has a layer density that reads on the layer density of the instantly-claimed porous layer, as set forth in the rejection of claim 2 below.
Because Murakami et al. in view of Kai et al.’s porous layer is substantially similar to the instantly-claimed porous layer in terms of the D50, D10, D90 of the inorganic particles, the amount of dispersing agent added, the specific surface area of the inorganic particles, the viscosity of the coating solution, and the layer density of the porous layer, and because para [0027] of the Instant Specification discloses that these parameters control the pore structure, Murakami et al. in view of Kai et al.’s porous layer must have a distribution of pores that is substantially similar to the instantly-claimed porous layer. As such, Murakami et al. in view of Kai et al. teaches a porous layer with a number of holes with hole areas of 0.001 mm2 or greater in the porous layer is 80 or more and 150 or less per 10 mm2 visual field, and a percentage of holes with areas in the range of 0.001 mm2 to 0.05 mm2 among holes with areas of 0.001 mm2 or greater in the porous layer is 90% or greater.
Further regarding claim 1, it has been held that a prima facie case for obviousness can be made when a claimed product and a prior art product are substantially identical in structure or composition, even if the prior art is silent as to the properties of the product (see MPEP § 2112.01). In the instant case, the scope of the multilayer porous membrane of Murakami et al. contains pores that have an average pore diameter of 1 mm or less, which substantially overlaps the average pore diameter range of 0.03 mm to 0.70 mm of the Instant Application (see e.g. para [0033] of Murakami et al. and para [0094] of the Instant Specification). Further, Murakami et al.’s porous layer has an air permeability of 30sec/100mL to 500 sec/100mL, which overlaps the air permeability of 10sec/100 cm3 or greater of the Instant Application (see e.g. para [0032] of Murakami et al. and para [0092] of the Instant Specification).
Because Murakami et al.’s pores have substantially similar diameters and the porous layer has a similar air permeability as the instantly-claimed porous layer, a prima facie case can be made that the hole distribution of Murakami et al. is substantially similar to that of the instantly-claimed porous layer, and therefore in Murakami et al.’s porous layer the number of holes with hole areas of 0.001 mm2 or greater in the porous layer is 80 or more and 150 or less per 10 mm2 visual field, and a percentage of holes with areas in the range of 0.001 mm2 to 0.05 mm2 among holes with areas of 0.001 mm2 or greater in the porous layer is 90% or greater.
As to claim 2, Murakami et al. in view of Kai et al. teaches the multilayer porous membrane according to claim 1, wherein the porous layer has a layer density of 1.10 g/(m2mm) or more and 3.00 g/(m2mm) or less (see e.g. Murakami et al.: [0086] and [0084], which teaches a preferred area density of 4 g/m2 to 10 g/m2 and a preferred thickness of 2 mm to 15 mm which implies a layer density that ranges from 0.26 g/(m2mm) to 5.0 g/(m2mm) because 4 g/m2 / 15 mm = 0.26 g/(m2mm) at the lowest possible area density and 10 g/m2 / 2 mm = 5.0 g/(m2mm) at the highest possible area density. This overlaps and thereby renders obvious the claimed layer of density range of 1.10 g/(m2mm) or more and 3.00 g/(m2mm) or less).
As to claim 7, Murakami et al. in view of Kai et al. teaches the multilayer porous membrane according to claim 1, wherein an air permeability of the multilayer porous membrane is 30 sec/mL to 500 sec /mL (see e.g. Murakami et al.: [0032]), which overlaps and thereby renders obvious the claimed range of 50 sec/100 cm3 or more and 250 sec/100 cm3 or less.
As to claim 8, Murakami et al. in view of Kai et al. teaches a separator for a nonaqueous electrolyte solution battery (see e.g. non-aqueous secondary battery, Murakami et al.: [0018]-[0019]) comprising a multilayer porous membrane according to claim 1, as set forth in the rejection of claim 1 above.
As to claim 9, Murakami et al. in view of Kai et al. teaches a nonaqueous electrolyte solution battery, comprising the separator for a nonaqueous electrolyte solution battery according to claim 8, as set forth in the rejection of claim 8 above. Murakami et al. in view of Kai et al further teaches a positive electrode, a negative electrode and a nonaqueous electrolyte solution (see e.g. Murakami et al.: [0017], which teaches a secondary battery comprising a positive electrode, a negative electrode, and a nonaqueous electrolyte).
Claim(s) 5 is rejected under 35 U.S.C. 103 as being unpatentable over Murakami et al. (US 2017/0162850) in view of Kai et al. (EP 3232494) as applied to claim 1 above, and further in view of Kim et al. (US 2013/0224558).
As to claim 5, Murakami et al. in view of Kai et al. teaches the multilayer porous membrane according to claim 1.
However, Murakami et al. in view of Kai et al. is silent as to the ratio of air permeability of the multilayer porous membrane with respect to air permeability of the porous membrane and does not teach a ratio of air permeability of the multilayer porous membrane with respect to air permeability of the porous membrane of 1.0 or more and 1.6 or less.
Kim et al., also working on the problem of multilayer porous membranes teaches an analogous multilayer porous membrane (see e.g. microporous composite film, Kim et al.: [0009]) comprising a polyolefin porous membrane (see e.g. microporous polyolefin film, Kim et al.: [0009], [0038]) in which the multilayer porous membrane with respect to air permeability of the porous membrane preferrably has a ratio of air permeability of 1.1 or more and 1.5 or less (see e.g. the quantity CCSp/Sp, which reads on the claimed ratio, ranges from 1.1 to 5.5. Kim et al.: [0009], [0038]), which overlaps and thereby renders obvious the claimed range of 1.0 or more and 1.6 or less. Kim et al. teaches that a ratio in this range prevents pores in the material from being blocked while also maintaining adhesion between the porous membrane and the coating layer (see e.g. Kim et al.: [0038], which states that “when a value of CCSp/Sp is less than 1.01, the high thermostable polymer resin less inserts in the pores of the microporous polyolefin film, and thus, an adhesion between the coating layer and the microporous polyolefin film can not be maintained.” Para [0038] also states that “when a value of CCSp/Sp is more than 1.5, the high thermostable polymer resin is coated on insides of the pores to prevent the occurrence of a shutdown phenomenon in which the pores of the microporous film are blocked at temperatures around 120 to 150.degree. C. Furthermore, electrolyte impregnation is decreased as the pores are blocked, and thus, performance of the battery is deteriorated. value, the coating layer is sufficiently removed by using a tape, and then measurement is performed by a pore diameter measuring device.”).
It would therefore have been obvious to one of ordinary skill in the art prior to the filing date of the instantly-claimed invention to modify Murakami et al. in view of Kai et al.’s multilayer porous membrane such that the multilayer porous membrane with respect to air permeability of the porous membrane has a ratio of air permeability of 1.0 or more and 1.6 or less, as taught by Kim et al.. Said artisan would have been motivated to make such a modification in order to prevents pores in the material from being blocked while also maintaining adhesion between the porous membrane and the coating layer, as taught by Kim et al..
Claim(s) 6 is rejected under 35 U.S.C. 103 as being unpatentable over Murakami et al. (US 2017/0162850) in view of Kai et al. (EP 3232494) as applied to claim 1 above, and further in view of Nishikawa et al. (US 2011/0143185).
As to claim 6, Murakami et al. in view of Kai et al. teaches the multilayer porous membrane according to claim 1, but is silent as to the basis weight-equivalent puncture strength of the porous membrane.
Nishikawa et al., also working in the field of porous polymer membranes for battery systems, teaches that it is preferable for a polyolefin microporous membrane to have a puncture strength of 300 g or more (see e.g. penetration strength, Nishikawa et al.: [0072]-[0073]) and a weight per unit area of 2 to 10 g/m2. (see e.g. Nishikawa et al.: [0059]). This yields a basis weight-equivalent puncture strength of greater than 30 gf./(g/m2) to 150 gf./(g/m2), which overlaps and thereby renders obvious the claimed range of 60 gf./(g/m2) or more.
It would therefore have been obvious to one of ordinary skill in the art prior to the filling date of the claimed invention to design the multilayer porous membrane of Murakami et al. in view of Kai et al. to have a basis weight-equivalent puncture strength of the porous membrane of 60 gf/(g/m2) or greater, because Nishikawa et al. teaches that this is a preferred basis weight-equivalent puncture strength of the porous membrane for a porous polymer membrane.
Conclusion
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/A.M.H./Examiner, Art Unit 1723
/TONG GUO/Supervisory Patent Examiner, Art Unit 1723