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 .
Response to Arguments
Applicant's arguments filed 17 Jul 2026 have been fully considered but they are not persuasive.
Applicant argues that the newly-added limitations of “the inorganic particles are boehmite, the binder polymer is an acrylic-based polymer latex” in claim 1 are not taught by the prior art and thereby render the claim patentable.
The Examiner respectfully disagrees, and maintains that the limitation “the binder polymer is an acrylic-based polymer latex” is taught by the primary reference Murakami et al. (US 2017/0162850), and the limitation “the inorganic particles are boehmite” is taught by the reference Tsujimoto et al. (WO 2018124176A1, as read via machine translation), as set forth in the rejection of claim 1 below.
Applicant further argues that Murakami et al. discloses that a water-soluble polymer is preferable as a binder resin, and uses the water-soluble polymer carboxymethyl cellulose as an example of a binder resin (see pg. 8, para 1 of Applicant’s remarks). In Applicant’s view, Murakami et al. does not substantially disclose water-insoluble polymers as a binder resin, and does not disclose an acrylic-based polymer latex (which is water insoluble) as the binder resin.
The Examiner respectfully disagrees, and maintains that while Murakami et al. suggests that water-soluble polymers are preferred as a binder resin, Murakami et al. also lists multiple water-insoluble polymers as possible binder materials, including styrene-acrylic acid ester copolymer resin, which reads on an acrylic-based polymer latex (see e.g. Murakami et al.: [0048]). While Murakami et al. may prefer a water-soluble polymer as a binder resin, the water-insoluble binder resins are also within the scope of Murakami et al.’s disclosure.
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, 7-9, and 24 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) and Tsujimoto et al. (WO 2018124176A1, as read via machine translation).
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 91.5 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 0.42 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 0.68 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 0.22 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.
Further regarding claim 1, Murakami et al. in view of Kai et al.’s multilayer porous membrane comprises inorganic particles that may be selected from a variety of materials, including calcium carbonate, kaolin, talc, alumina, barium sulfate, zeolite, magnesium oxide, or mica (see e.g. Murakami et al.: [0054]-[0055]). However, Murakami et al. in view of Kai et al. does not teach boehmite as a material for the inorganic particles.
Tsujimoto et al., also working in the field of battery separator coatings, teaches an analogous coating layer for a polyolefin separator that also comprises inorganic particles and a binder (see e.g. Tsujimoto et al.: [0020]). Tsujimoto et al. teaches that these inorganic particles may comprise calcium carbonate, kaolin, talc, alumina, barium sulfate, zeolite, mica, magnesium oxide, or boehmite (see e.g. Tsujimoto et al.: [0069]).
It would therefore have been obvious to one or ordinary skill in the art prior to the filing date of the claimed invention to modify the multilayer porous membrane of Murakami et al. in view of Kai et al. by replacing the inorganic particles with the boehmite particles taught by Tsujimoto et al.. This is because Tsujimoto et al. teaches that boehmite is a functional equivalent to calcium carbonate, kaolin, talc, alumina, barium sulfate, zeolite, magnesium oxide, or mica that performs the same function of serving as an inorganic component of a porous layer in a separator. Further, the use of the boehmite particles taught by Murakami et al. in view of Kai et al. would fail to provide any new benefit or effect that would not have been obvious to one of ordinary skill in the art.
Further regarding claim 1, Murakami et al. in view of Kai et al. and Tsujimoto et al. teaches a binder polymer that may be an acrylic-based polymer latex (see e.g. styrene-acrylic acid ester copolymer resin, Murakami et al., [0047]-[0051]).
As to claim 2, Murakami et al. in view of Kai et al. and Tsujimoto 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. and Tsujimoto 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. and Tsujimoto 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. and Tsujimoto 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).
As to claim 24, Murakami et al. in view of Kai et al. and Tsujimoto et al. teaches the multilayer porous membrane according to claim 1, wherein the binder polymer is distributed at the points of contact between the inorganic particles, in the porous layer (see e.g. Murakami et al.: [0052], the porous layer comprises a binder polymer resin that acts as a binder resin. This resin is mixed with a filler material that reads on inorganic particles via dispersing device such as a homogenizer as per Murakami et al.: [0067]. Because the binder polymer is randomly mixed with the inorganic particles in a homogenizer, the binder polymer is necessarily distributed at points of contact between inorganic particles).
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) and Tsujimoto et al. (WO 2018124176A1, as read via machine translation) 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. and Tsujimoto et al. teaches the multilayer porous membrane according to claim 1.
However, Murakami et al. in view of Kai et al. and Tsujimoto 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 preferably 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. and Tsujimoto 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) and Tsujimoto et al. (WO 2018124176A1, as read via machine translation) 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.
Claim(s) 25 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), Tsujimoto et al. (WO 2018124176A1, as read via machine translation), and Yokoyama et al. (WO 2013146811A1, as read via machine translation).
As to claim 25, 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 m to 20 m (see e.g. [0084]), which overlaps and thereby renders obvious the claimed range of 2.0 m or more and 3.0 m or less,
a percentage of inorganic particles occupying the porous layer of Murakami et al. is 91.5 weight% or more and 98 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),
a mean particle size D50 of the inorganic particles in the porous layer is 0.01 m to 10 m (see e.g. [0025]), which overlaps and thereby renders obvious the claimed range of 0.25 m or more and 0.42 m or less,
the inorganic particles in the porous layer have a particle size D90 of 0.5 m to 5.0 m (see e.g. [0025]), which overlaps and thereby renders obvious the claimed range of 0.50 m or more and 0.68 m or less, and a particle size of D10 of 0.005 m to 0.4 m (see e.g. [0025]), which overlaps and thereby renders obvious the claimed range of 0.13 m or more and 0.22 m or less.
Further regarding claim 25, 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 m2 or greater in the porous layer is 80 or more and 150 or less per 10 m2 visual field, a percentage of holes with areas in the range of 0.001 m2 to 0.05 m2 among holes with areas of 0.001 m2 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. 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 m2 or greater in the porous layer is 80 or more and 150 or less per 10 m2 visual field, and a percentage of holes with areas in the range of 0.001 m2 to 0.05 m2 among holes with areas of 0.001 m2 or greater in the porous layer is 90% or greater.
Further regarding claim 25, 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 m or less, which substantially overlaps the average pore diameter range of 0.03 m to 0.70m 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 m2 or greater in the porous layer is 80 or more and 150 or less per 10 m2 visual field, and a percentage of holes with areas in the range of 0.001 m2 to 0.05 m2 among holes with areas of 0.001 m2 or greater in the porous layer is 90% or greater.
Further regarding claim 25, Murakami et al. in view of Kai et al.’s multilayer porous membrane comprises inorganic particles that may be selected from a variety of materials, including calcium carbonate, kaolin, talc, alumina, barium sulfate, zeolite, magnesium oxide, or mica (see e.g. Murakami et al.: [0054]-[0055]). However, Murakami et al. in view of Kai et al. does not teach boehmite as a material for the inorganic particles.
Tsujimoto et al., also working in the field of battery separator coatings, teaches an analogous coating layer for a polyolefin separator that also comprises inorganic particles and a binder (see e.g. Tsujimoto et al.: [0020]). Tsujimoto et al. teaches that these inorganic particles may comprise calcium carbonate, kaolin, talc, alumina, barium sulfate, zeolite, mica, magnesium oxide, or boehmite (see e.g. Tsujimoto et al.: [0069]).
It would therefore have been obvious to one or ordinary skill in the art prior to the filing date of the claimed invention to modify the multilayer porous membrane of Murakami et al. in view of Kai et al. by replacing the inorganic particles with the boehmite particles taught by Tsujimoto et al.. This is because Tsujimoto et al. teaches that boehmite is a functional equivalent to calcium carbonate, kaolin, talc, alumina, barium sulfate, zeolite, magnesium oxide, or mica that performs the same function of serving as an inorganic component of a porous layer in a separator. Further, the use of the boehmite particles taught by Murakami et al. in view of Kai et al. would fail to provide any new benefit or effect that would not have been obvious to one of ordinary skill in the art.
Murakami et al. in view of Kai et al. and Tsujimoto et al. teaches a binder polymer that may be an acrylic-based polymer latex (see e.g. styrene-acrylic acid ester copolymer resin, Murakami et al., [0047]-[0051]).
Further regarding claim 25, Murakami et al. in view of Kai et al. and Tsujimoto et al. teaches a porous layer comprising inorganic particles having an aspect ratio of 1, (see e.g. Murakami et al.: para [0050], describing the particles may be spherical, implying an aspect ratio 0f 1.0), and does not teach inorganic particles having an aspect ratio of 1.7 or more or 1.8 or less.
Yokoyama et al., also working on the problem of porous coating layers for battery separators, teaches an analogous porous layer comprising inorganic particles that have an aspect ratio in the range of 1.5 to 10, which overlaps and thereby renders obvious the claimed range of 1.7 or more to 1.7 or less (see e.g. Yokoyama et al.: Pg. 15, para 1). Yokoyama et al. teaches that this aspect ratio advantageously suppresses the decrease in air permeability resistance when the porous layer is laminated onto a separator (see e.g. Yokoyama et al.: pg. 15, para 1).
It would therefore have been obvious to one of ordinary skill in the art prior to the filing date of the claimed invention to modify the porous layer of Murakami et al. in view of Kai et al. and Tsujimoto et al. by selecting inorganic particles having an aspect ratio in the range of 1.7 or more to 1.8 or less as suggested by Yokoyama et al.. This is because Yokoyama et al. teaches that an aspect ratio in this range suppresses the decrease in air permeability resistance when the porous layer is laminated onto a separator.
Claim(s) 26 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), Tsujimoto et al. (WO 2018124176A1, as read via machine translation), and Yokoyama et al. (WO 2013146811A1, as read via machine translation) as applied to claim 25 above, and further in view of Sakamoto et al. (US 20150221917).
As to claim 26, Murakami et al. in view of Kai et al., Tsujimoto et al., and Yokoyama et al. et al. teaches the multilayer porous membrane according to claim 25, wherein the percentage of inorganic particles occupying the porous layer is 97 weight% (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 lies outside the claimed range of 91.5 weight% or more and 95.6 weight% or less.
Sakamoto et al., also working in the field of separators for batteries, teaches an analogous porous coating layer for a separator that comprises inorganic particles and a binder (see e.g. heat-resistant layer, Sakamoto et al.: [0020]). In Sakamoto et al.’s porous layer, the percentage of inorganic particles occupying the porous layer is 40 weight% to 98 weight%, which overlaps and thereby renders obvious the claimed range of 91.5 weight% or more and 95.6 weight% or less (see e.g. Sakamoto et al.: [0040]). Sakamoto et al. further teaches that this weight% yields a good balance between the adhesion with the filler and/or the microporous membrane and the air permeability of the composite porous film, while providing excellent heat resistance (see e.g. Sakamoto et al.: [0040]).
It would therefore have been obvious to one of ordinary skill in the art prior to the filing date of the claimed invention to modify the multilayer porous membrane of Murakami et al. in view of Kai et al., Tsujimoto et al., and Yokoyama et al. et al. by setting the weight percentage of the inorganic particles occupying the porous layer to be 91.5 weight% or more and 95.6 weight% or less in the manner suggested by Sakamoto et al.. Said artisan would have been motivated to make such a modification in order to provide the multilayer porous membrane with a good balance between the adhesion with the filler and/or the porous membrane and the air permeability of the composite porous film, while providing the porous membrane with excellent heat resistance, as taught by Sakamoto et al..
As to claim 27, Murakami et al. discloses a nonaqueous electrolyte solution battery (see e.g. non-aqueous electrolyte secondary battery, Murakami et al.: [0149]) comprising a separator (see e.g. porous film, Murakami et al.: [0011]), a positive electrode (see e.g. positive electrode, Murakami et al.: [0149]), a negative electrode (see e.g. negative electrode, Murakami et al.: [0149]), and a nonaqueous electrolyte solution (see e.g. non-aqueous electrolyte, Murakami et al.: [0150]).
As set forth in the rejection of claim 26 above, the teachings of Murakami et al. in view of Kai et al., Tsujimoto et al., Yokoyama et al. et al., and Sakamoto et al. render obvious a separator comprising the multilayer porous membrane according to claim 26.
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.
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/A.M.H./Examiner, Art Unit 1723
/CHRISTIAN ROLDAN/Primary Examiner, Art Unit 1723
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