WO2014017662A1 - アルミナスラリーおよびその製造方法並びに塗工液 - Google Patents
アルミナスラリーおよびその製造方法並びに塗工液 Download PDFInfo
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- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
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- H01M50/409—Separators, membranes or diaphragms characterised by the material
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- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/417—Polyolefins
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- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
- H01M50/451—Separators, membranes or diaphragms characterised by the material having a layered structure comprising layers of only organic material and layers containing inorganic material
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- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
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- C08K3/22—Oxides; Hydroxides of metals
- C08K2003/2227—Oxides; Hydroxides of metals of aluminium
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Definitions
- the present invention relates to an alumina slurry, a production method thereof, and a coating liquid. More specifically, the present invention relates to an alumina slurry as a raw material for a coating liquid suitable for forming a heat resistant layer in a laminated porous film obtained by laminating a heat resistant layer and a polyolefin porous film, and a method for producing the same.
- Non-aqueous electrolyte secondary batteries particularly lithium ion secondary batteries, are widely used as batteries for personal computers, mobile phones, portable information terminals and the like because of their high energy density.
- Non-aqueous electrolyte secondary batteries typified by lithium ion secondary batteries have high energy density, and when an internal short circuit or external short circuit occurs due to an accident such as damage to the battery or equipment that uses the battery. , A large current flows and generates intense heat. Therefore, non-aqueous electrolyte secondary batteries are required to prevent heat generation beyond a certain level and ensure high safety.
- a porous film made of a material that melts during abnormal heat generation is used as a separator.
- a separator for example, a porous film mainly composed of polyolefin is used.
- a separator made of a polyolefin porous film suppresses further heat generation by blocking (shutdown) the passage of ions by melting and non-porous at about 80 to 180 ° C. during abnormal heat generation of the battery.
- the positive electrode and the negative electrode may be in direct contact with each other due to shrinkage or breakage of the separator made of the polyolefin porous film, which may cause a short circuit.
- the separator made of a polyolefin porous film has insufficient shape stability and sometimes cannot suppress abnormal heat generation due to a short circuit.
- a heat-resistant layer containing a fine powder alumina filler is laminated on a porous film mainly composed of polyolefin as a substrate (hereinafter sometimes referred to as “substrate porous film”).
- substrate porous film a porous film mainly composed of polyolefin as a substrate
- a separator made of a laminated porous film has been proposed (see, for example, Patent Document 1).
- the heat resistant layer containing the alumina filler constituting the laminated porous film is difficult to shrink even in abnormal heat generation, the shape change of the entire separator can be suppressed.
- the filler may fall off from the heat-resistant layer on the surface, so-called “powder-off” may occur. Suppressing “powder-off” because powder separation from the separator does not exhibit the expected physical properties of the separator and causes process failures such as contamination of the device due to the powder dropped when assembled into a battery. Development of an alumina slurry capable of obtaining a heat-resistant layer capable of achieving this is desired.
- an object of the present invention is to easily and stably produce a heat-resistant layer that suppresses powder falling and has chemical stability and shape stability at high temperatures in a separator for a non-aqueous electrolyte secondary battery.
- An object of the present invention is to provide an alumina slurry that is a raw material for a coating solution that is particularly suitable.
- Another object of the present invention is to provide a method for producing the alumina slurry.
- the present invention relates to the following inventions.
- An alumina slurry substantially composed of ⁇ -alumina particles and water, The ⁇ -alumina particles satisfy all the following particle size distribution conditions (a) to (d), The alumina purity of the ⁇ alumina particles is 90% by weight or more, The alumina content in the slurry is 20 wt% or more and 50 wt% or less, and An alumina slurry having a slurry viscosity of 0.5 Pa ⁇ s to 15 Pa ⁇ s.
- the ⁇ -alumina particles further include the following particle diameter distribution condition ( e) The alumina slurry according to ⁇ 1>, which satisfies all of (g) to (g).
- Condition (g) In the condition (d), among the frequency maxima appearing in the region of the particle diameter of 0.1 ⁇ m or more and less than 0.5 ⁇ m, the maximum particle diameter of the frequency maximum showing the smallest maximum particle diameter is D1, the maximum value is M1, and the condition ( In f), when the maximum particle diameter of the frequency maximum showing the largest maximum particle diameter among the frequency maximums appearing in the region having a particle diameter of 1 ⁇ m or more is D2, and the maximum value is M2, the following formulas (1) and (2) Satisfy the relationship 2 ⁇ D1 ⁇ D2 ⁇ 5 ⁇ D1 (1) (M1 / M2) ⁇ 0.8 (2) ⁇ 3>
- ⁇ 4> The alumina slurry according to any one of ⁇ 1> to ⁇ 3>, wherein the Zr content in the alumina solid content is 300 ppm or more in terms of weight.
- ⁇ 5> The method for producing an alumina slurry according to any one of ⁇ 1> to ⁇ 4>, Raw material ⁇ -alumina particles having an alumina purity of 90 wt% or more, a BET specific surface area of 15 m 2 / g or less, and an average particle diameter of 1 ⁇ m or more and 30 ⁇ m or less have an alumina content of 20 wt% with respect to water as a solvent.
- a method for producing an alumina slurry wherein the raw material ⁇ -alumina particles are wet pulverized by adding so as to be 50% by weight or less.
- an alumina slurry serving as a raw material for a coating solution capable of stably producing a separator for a non-aqueous electrolyte secondary battery having a heat-resistant layer with suppressed powder fall and excellent shape stability, and A coating solution containing the alumina slurry is provided.
- Example 3 is a particle size distribution of alumina particles in alumina slurries 1 to 4 (Examples 1 and 2 and Comparative Examples 1 and 2).
- the alumina slurry of the present invention is a heat-resistant layer (hereinafter referred to as “B layer”) comprising a polyolefin-based porous film (hereinafter sometimes referred to as “A layer”) and a filler comprising a binder and alumina particles.
- B layer heat-resistant layer
- a layer polyolefin-based porous film
- a layer filler comprising a binder and alumina particles.
- a coating liquid prepared by dissolving and dispersing the alumina slurry of the present invention in a suitable solvent together with a binder is applied to one side or both sides of the A layer, and the solvent is removed to remove one side of the A layer or
- the layer B is laminated on both sides to form the laminated porous film.
- the A layer imparts a shutdown function to the laminated porous film by melting and becoming non-porous at the time of abnormal heat generation when a battery accident occurs.
- the B layer has heat resistance at a high temperature at which shutdown occurs, and imparts a shape stability function to the laminated porous film.
- the alumina slurry of the present invention is an alumina slurry consisting essentially of ⁇ -alumina particles and water, and may contain components other than ⁇ -alumina particles and water as long as the object of the present invention can be achieved.
- components other than water include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and t-butanol, and known dispersants.
- the alumina slurry of the present invention can be obtained without using a solvent or dispersant other than water.
- the ⁇ -alumina particles contained in the alumina slurry of the present invention satisfy all the following particle size distribution conditions (a) to (d).
- the particle size distribution can be obtained by a laser diffraction method. The details will be described later in Examples.
- the average particle diameter means the cumulative percentage of 50% equivalent particle diameter (D 50) by weight.
- the ⁇ alumina particles satisfy the following particle size distribution conditions (e) to (g).
- Condition (e) Particles having a particle diameter of 0.5 ⁇ m or more and less than 1 ⁇ m are 40% by weight or less
- Condition (f) One or more frequency maximums are present in a region having a particle diameter of 1 ⁇ m or more.
- the alumina particles contained in the alumina slurry of the present invention are ⁇ -alumina having excellent thermal and chemical stability. Therefore, the heat-resistant layer formed from the alumina slurry of the present invention is excellent in thermal and chemical stability.
- ⁇ -alumina there are ⁇ -alumina, ⁇ -alumina, ⁇ -alumina, etc., and it is easier to obtain fine particles than ⁇ -alumina. It is inferior in stability chemically and chemically and is unsuitable for forming a heat-resistant layer.
- the alumina purity of the ⁇ -alumina particles according to the present invention is 90% by weight or more, preferably 99% by weight or more, more preferably 99.9% by weight or more, and most preferably 99.99% by weight or more. It is.
- impurities such as Si, Na and Fe contained in the ⁇ -alumina powder increase, resulting in not being able to obtain good electrical insulation, This is not preferable because the amount of the metallic foreign matter is increased.
- the alumina purity can be determined by solid state emission analysis. The details will be described later in Examples.
- the alumina content in the alumina slurry of the present invention is 20% by weight or more and 50% by weight or less, and preferably 20% by weight or more and 40% by weight or less.
- the alumina content is less than 20% by weight, the alumina concentration of the coating solution becomes thin, and energy is required for drying after coating.
- it exceeds 50% by weight the viscosity of the slurry is excessively increased, and the grinding efficiency is decreased, for example, the liquid feeding speed of the slurry is decreased.
- the alumina slurry of the present invention has a viscosity of 0.5 Pa ⁇ s to 15 Pa ⁇ s, preferably 1.0 Pa ⁇ s to 4.0 Pa ⁇ s.
- the viscosity of the slurry is a value determined with a B-type viscometer. The details will be described later in Examples.
- the ⁇ -alumina particles in the alumina slurry of the present invention preferably have an amount of coarse particles having a particle diameter of 10 ⁇ m or more of 10 ppm or less, more preferably 3 ppm or less.
- the amount of coarse particles of 10 ⁇ m or more exceeds 10 ppm, coarse voids due to defects such as streaks or aggregated particles may be partially generated in the coating film.
- the amount of coarse particles can be determined by the wet sieving method described in Examples described later.
- the Zr content in the alumina solid content is preferably 300 ppm or more, more preferably 500 ppm or more in terms of weight. Moreover, it is preferable that the upper limit of Zr content is 1500 ppm or less in weight conversion.
- the Zr content in the alumina solid content can be measured by the ICP emission analysis method described in Examples described later.
- the above-described alumina slurry of the present invention is not particularly limited as long as it has the above physical properties.
- the alumina slurry satisfying the alumina purity and particle size distribution is dispersed in a predetermined amount of water, and the slurry is obtained. What is necessary is just to adjust so that a viscosity may be satisfy
- the alumina particles contained in the alumina slurry of the present invention may agglomerate during storage or the like to produce an aggregate.
- the coating properties will decrease, resulting in an increase in film defects in layer B, resulting in insufficient film properties such as shutdown performance and ion permeability (breathability) of the separator. is there. Therefore, fine alumina particles are difficult to disperse in water, and usually a dispersant other than water is substantially required.
- the alumina slurry of the present invention satisfying the particle size distribution can be obtained using a solvent containing only water without using a dispersant. That is, the alumina slurry production method of the present invention (hereinafter referred to as “the production method of the present invention”) has an alumina purity of 90% by weight or more, a BET specific surface area of 15 m 2 / g or less, and an average particle diameter of 1 ⁇ m.
- the raw material ⁇ -alumina particles having a thickness of 30 ⁇ m or less are added to water as a solvent so that the alumina content is 20% by weight or more and 50% by weight or less, and the raw material ⁇ -alumina particles are wet-ground.
- the relatively coarse raw material ⁇ -alumina particles can be directly pulverized in an aqueous solvent by wet pulverization in an aqueous solvent, so that in the absence of a dispersant, Even when wet pulverization is performed, there is an advantage that the alumina slurry of the present invention exhibiting the above physical properties can be obtained.
- the production method of the present invention will be described in more detail.
- ⁇ -alumina particles (hereinafter referred to as “raw-material ⁇ -alumina particles”) as raw materials will be described.
- the raw material ⁇ -alumina particles have an alumina purity of 90% by weight or more, preferably 99% by weight or more, more preferably 99.9% by weight or more, and most preferably 99.99% by weight or more.
- the alumina purity can be determined by solid state emission analysis.
- the BET specific surface area of the raw material ⁇ -alumina particles is 15 m 2 / g or less, preferably 10 m 2 / g or less.
- the average particle diameter of the raw material ⁇ -alumina particles is 1 ⁇ m or more and 30 ⁇ m or less, preferably 1 ⁇ m or more and 20 ⁇ m or less.
- the average particle diameter of the raw material ⁇ -alumina particles can be determined by a laser diffraction method.
- the raw ⁇ -alumina particles are added to water as a solvent and wet pulverized.
- the addition amount of the raw material ⁇ -alumina particles is determined in a range in which the viscosity of the slurry after wet pulverization is 0.5 Pa ⁇ s or more and 15 Pa ⁇ s or less, and the total amount of the raw material ⁇ -alumina particles and the water solvent is 100% by weight.
- the alumina content is 20 wt% or more and 50 wt% or less.
- a conventionally known disperser such as a homogenizer, a media-type disperser, or a pressure disperser can be used.
- a media-type disperser is preferable, and specific examples include a tower mill, a pearl mill, a sand mill, a dyno mill, an ultra visco mill, an attritor, and an annular mill.
- alumina beads or zirconia (ZrO 2 ) beads are used, but ZrO 2 beads having a diameter of 0.65 mm to 1.5 mm are preferable in terms of high specific gravity, excellent wear resistance and pulverization. .
- the wet pulverization conditions are not unambiguous depending on the equipment used, the dispersion media, etc., and appropriate pulverization conditions may be determined by conducting a preliminary test.
- the amount of dispersed media in the pulverizer capacity is about 30% to 90% by volume, and the residence time is usually 2 minutes or more under the condition that the alumina content is 20% by weight to 50% by weight. About 10 minutes.
- the alumina slurry of the present invention comprises a filler made of ⁇ -alumina particles (hereinafter sometimes simply referred to as “filler”), a heat-resistant layer containing a binder, and a polyolefin-based porous film by mixing with a binder and a solvent. It is used as a coating liquid containing a binder, ⁇ -alumina particles and a solvent, which is used for forming a heat-resistant layer in a laminated separator for a nonaqueous electrolyte secondary battery. As described above, the coating liquid can be obtained by mixing and dispersing the alumina slurry of the present invention until the binder and the solvent are uniform, for forming a heat resistant layer (B layer) of the laminated porous film. Used.
- the method of mixing the alumina slurry, the binder and the solvent is not particularly limited.
- a conventionally known disperser such as a stirring emulsifier, a three-one motor, a homogenizer, a media type disperser, or a pressure disperser may be used. it can.
- Solvents used in the preparation of the coating liquid are water, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, acetone, ethyl methyl ketone, N-methylpyrrolidone, dimethyl sulfoxide, N, An organic solvent such as N-dimethylformamide or a mixed solvent of water and an organic solvent is used.
- a binder having a property of binding a filler made of alumina particles and adhering to the A layer and being dissolved or dispersed in the solvent is selected.
- a water-soluble polymer is preferable because an aqueous coating solution can be prepared.
- the water-soluble polymer preferably has a hydrophilic functional group.
- hydrophilic functional group carboxymethyl cellulose, alkyl cellulose, hydroxyalkyl cellulose, starch, polyvinyl alcohol, and sodium alginate have high adhesiveness with the A layer and are preferably used. Further, these salts may be used.
- the alumina slurry (in terms of solid content) is 100 to 10,000 parts by weight, preferably 1000 to 5000 parts by weight, with respect to 100 parts by weight of the binder.
- the binder When there are too few fillers, ion permeability will become inadequate, and when there are too many fillers, the amount of powder falling will become large.
- the filler concentration is preferably 6 to 50% by weight, more preferably 10 to 40% by weight.
- the concentration of the binder is preferably 0.30% by weight or more and 2.0% by weight or less, more preferably 0.40% by weight or more and 1.5% by weight with respect to the weight of the binder and the solvent. % Or less.
- the binder may be used by appropriately selecting the molecular weight or the like so that the viscosity is suitable for coating.
- a surfactant a pH adjuster, a dispersant, a plasticizer, and the like can be added to the coating solution as long as the object of the present invention is not impaired.
- the solvent can be removed to form a heat-resistant layer containing a filler and a binder.
- the A layer is a polyolefin porous film and does not dissolve in the electrolyte solution in the non-aqueous secondary battery. It is preferable that a high molecular weight component having a weight average molecular weight of 5 ⁇ 10 5 to 15 ⁇ 10 6 is contained.
- the polyolefin include a high molecular weight homopolymer or copolymer obtained by polymerizing ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene and the like. Among these, high molecular weight polyethylene mainly composed of ethylene is preferable.
- the porosity of the A layer is preferably 20 to 80% by volume, more preferably 30 to 70% by volume. If the porosity is less than 20% by volume, the amount of electrolyte retained may be small, and if it exceeds 80% by volume, non-porous formation at a high temperature causing shutdown will be insufficient, that is, when the battery generates heat due to an accident. The current may not be cut off.
- the thickness of the A layer is usually 4 to 50 ⁇ m, preferably 5 to 30 ⁇ m. If the thickness is less than 4 ⁇ m, the shutdown may be insufficient, and if it exceeds 50 ⁇ m, the thickness of the laminated porous film increases, and the electric capacity of the battery may decrease.
- the pore size of the A layer is preferably 3 ⁇ m or less, and more preferably 1 ⁇ m or less.
- the A layer has a structure having pores connected to the inside thereof, and gas or liquid can pass from one surface to the other surface.
- the transmittance (air permeability) is usually represented by a Gurley value.
- the Gurley value of the laminated porous film of the present invention is preferably in the range of 30 to 400 seconds / 100 cc, and preferably in the range of 50 to 300 seconds / 100 cc.
- the method for producing the A layer is not particularly limited.
- a plasticizer is added to a thermoplastic resin to form a film, and then the plasticizer is used in an appropriate solvent.
- a film made of a thermoplastic resin produced by a known method is used, and a structurally weak amorphous portion of the film is selectively stretched.
- a method of forming micropores For example, when the A layer is formed from a polyolefin resin containing ultrahigh molecular weight polyethylene and a low molecular weight polyolefin having a weight average molecular weight of 10,000 or less, it should be produced by the following method from the viewpoint of production cost. Is preferred.
- step (3) A method comprising a step of obtaining the layer A by stretching the obtained sheet, or (1) 100 parts by weight of ultrahigh molecular weight polyethylene, 5 to 200 parts by weight of a low molecular weight polyolefin having a weight average molecular weight of 10,000 or less, and an inorganic filler Step of kneading 100 to 400 parts by weight to obtain a polyolefin resin composition (2) Step of molding a sheet using the polyolefin resin composition (3) Step ( This is a method including a step of removing the inorganic filler from the sheet obtained in 2) (4) and a step of obtaining the A layer by stretching the sheet obtained in the step (3).
- the commercial item which has the characteristic of the said description can be used.
- the method for applying the coating liquid of the present invention to the A layer is not particularly limited as long as it can uniformly wet coat, and a conventionally known method can be adopted.
- a capillary coating method, a spin coating method, a slit die coating method, a spray coating method, a dip coating method, a roll coating method, a screen printing method, a flexographic printing method, a bar coater method, a gravure coater method, a die coater method, etc. Can do.
- the thickness of the B layer can be controlled by adjusting the thickness of the coating film, the concentration of the binder in the coating liquid, and the ratio of the filler to the binder.
- As the support a resin film, a metal belt, a drum, or the like can be used.
- the solvent removal method is generally a drying method.
- the temperature which does not reduce the air permeability of A layer is preferable for the drying temperature of a solvent.
- the heat-resistant layer (B layer) is formed on the A layer.
- the thickness of the B layer is usually 0.1 ⁇ m or more and 20 ⁇ m or less, preferably 1 ⁇ m or more and 15 ⁇ m or less. If the B layer is too thick, the thickness of the laminated porous film including the A layer is increased, which may reduce the electric capacity of the battery. If the B layer is too thin, the laminated porous film may shrink due to the heat shrinkage of the polyolefin porous film (A layer) when the battery generates heat due to an accident or the like. When the B layer is formed on both sides of the A layer, the thickness of the B layer is the total thickness of both sides.
- the B layer is a porous film in which fillers are connected by a binder, and pores formed in the gaps between the fillers are connected, so that gas or liquid can pass from one surface to the other surface.
- the pore diameter is preferably 3 ⁇ m or less, more preferably 1 ⁇ m or less, as an average value of the diameters of the spheres when the pores are approximated to a sphere.
- the porosity of the B layer is preferably 30 to 65% by volume, more preferably 40 to 60% by volume.
- the powder falling rate of the B layer is preferably 30% or less, more preferably 25% or less.
- the B layer is formed on the A layer by the method described above. That is, after coating the coating liquid of the present invention on one or both sides of the substrate porous film (A layer), by removing the solvent, on one or both sides of the substrate porous film (A layer), The laminated porous film of the present invention in which a heat-resistant layer (B layer) containing ⁇ -alumina particles and a binder is formed is obtained.
- the laminated porous film of the present invention can be used as a separator for a nonaqueous electrolyte secondary battery.
- the total thickness of the laminated porous film of the present invention is usually 5 to 80 ⁇ m, preferably 5 to 50 ⁇ m, and particularly preferably 6 to 35 ⁇ m. If the thickness of the entire laminated porous film is less than 5 ⁇ m, the film tends to be broken, and if it exceeds 80 ⁇ m, the thickness of the laminated porous film is increased, which may reduce the electric capacity of the battery. Further, the porosity of the entire laminated porous film of the present invention is usually 30 to 85%, preferably 40 to 80%.
- the air permeability of the laminated porous film is preferably 50 to 2000 seconds / 100 cc, 1000 seconds / 100 cc is more preferable, and 50 to 300 seconds / 100 cc is more preferable.
- the air permeability is 2000 seconds / 100 cc or more, the ion permeability of the laminated porous film and the load characteristics of the battery may be lowered.
- the smaller value in the MD direction or TD direction of the A layer is 85% or more, preferably 90% or more, more preferably 95% or more. is there.
- the MD direction refers to the long direction during film molding
- the TD direction refers to the width direction during film molding.
- the high temperature at which shutdown occurs is a temperature of 80 to 180 ° C., usually about 130 to 160 ° C.
- a porous film such as an adhesive film and a protective film is included in the laminated porous film of the present invention as long as the object of the present invention is not impaired. Also good.
- the separator When a non-aqueous electrolyte secondary battery is manufactured using the laminated porous film of the present invention as a separator, the separator has a high load characteristic, and even if the battery generates intense heat due to an accident, the separator exhibits a shutdown function. Contact between the positive electrode and the negative electrode due to shrinkage is avoided, and a highly safe non-aqueous electrolyte secondary battery is obtained.
- Alumina purity 100-total weight of impurities (wt%)
- BET specific surface area The BET specific surface area of the alumina particles was determined by a nitrogen adsorption method according to the method defined in JIS-Z-8830. In addition, “Furosorb II 2300” manufactured by Shimadzu Corporation was used as a specific surface area measuring apparatus.
- the particle size distribution of alumina particles on a mass basis was determined by a laser diffraction method using a laser particle size distribution measuring apparatus ["MICROTRACK: MT-3300EX II” manufactured by Nikkiso Co., Ltd.]. Further, the particle diameter corresponding to a cumulative percentage of 50% on the mass basis was defined as the average particle diameter. The measurement was performed by ultrasonically dispersing the sample with a 0.2 wt% aqueous solution of sodium hexametaphosphate.
- Zr content The Zr content in the alumina solid content was measured by ICP emission analysis after evaporating and drying the alumina slurry at 200 ° C.
- the physical properties of the separator were measured by the following methods.
- Thickness measurement (unit: ⁇ m): The thickness of the separator was measured with a high precision micrometer manufactured by Mitutoyo Corporation.
- the basis weight of the B layer was calculated after subtracting the basis weight of the porous base material (A layer) from the basis weight of the laminated porous film.
- Porosity The film was cut into a square with a side length of 8 cm, and weight: W (g) and thickness: D (cm) were measured. The weight of the material in the sample was calculated, the weight of each material: Wi (g) was divided by the true specific gravity, the volume of each material was calculated, and the porosity (volume%) was obtained from the following equation. The date of each material was calculated from the amount and ratio used for film formation.
- Porosity (volume%) 100 ⁇ [ ⁇ (W1 / true specific gravity 1) + (W2 / true specific gravity 2) + ⁇ + (Wn / true specific gravity n) ⁇ / (100 ⁇ D)] ⁇ 100 (4) Air permeability: Measured with a digital timer type Gurley type densometer manufactured by Toyo Seiki Seisakusho Co., Ltd. according to JIS P8117. (5) Heated shape maintenance rate: The film was cut into 8 cm ⁇ 8 cm, and a film in which a 6 cm ⁇ 6 cm square was written was sandwiched between papers and placed in an oven heated to 150 ° C.
- Powder fall rate (%) powder fall amount (g / m 2 ) / weight per unit area (g / m 2 ) ⁇ 100 (7)
- Surface smoothness The SEM image of the film surface was observed and surface smoothness was evaluated. The evaluation criteria are as follows. ⁇ : High smoothness and almost no unevenness ⁇ : Some unevenness is found ⁇ : Unevenness is recognized throughout the film
- Example 1 (Preparation of alumina slurry 1) Alumina-water suspension by adding alumina particles having a BET specific surface area of 4.1 m 2 / g and an average particle size of 6.2 ⁇ m to water with stirring so that the alumina concentration is 30% by weight. A liquid was obtained. Subsequently, wet grinding conditions (peripheral speed: 10 m / sec, bead material: ZrO 2 , bead diameter: 1.0 mm, bead filling rate: 85 in a pass method using a dyno mill (KDL-PILOT A type) manufactured by AG MASCHINENFABRIK BASEL Volume%, flow rate: 0.5 L / min, residence time: 4.4 min) to obtain alumina slurry 1.
- alumina slurry 1 Alumina-water suspension by adding alumina particles having a BET specific surface area of 4.1 m 2 / g and an average particle size of 6.2 ⁇ m to water with stirring so that the alumina concentration is 30%
- the particles having a particle diameter of less than 0.2 ⁇ m are 4.6% by weight, Particles having a particle diameter exceeding 1.5 ⁇ m are 8.3 wt%,
- One frequency maximum is shown in the region of particle diameter of 0.1 ⁇ m or more and less than 0.5 ⁇ m, 29.2% by weight of particles having a particle size of 0.5 ⁇ m or more and less than 1 ⁇ m,
- One frequency maximum appears in the region with a particle diameter of 1 ⁇ m or more
- D1 is 0.34 ⁇ m
- D2 is 1.06 ⁇ m
- M1 is 4.30
- M2 is 4.19.
- the ratio of M1 to M2 (M1 / M2) was 1.03.
- Table 1 summarizes the physical properties of the alumina slurry 1 and the alumina particles in the alumina slurry 1.
- an evaluation separator made of a laminated porous film in which a base material porous film (A layer) and a heat-resistant layer (B layer) were laminated by the following method was prepared.
- the A layer was produced by the following method.
- ⁇ Method for producing layer A> Ultra high molecular weight polyethylene powder (340M, manufactured by Mitsui Chemicals Co., Ltd.) is mixed with 70% by weight, and polyethylene wax (FNP-0115, manufactured by Nippon Seiki Co., Ltd.) with a weight average molecular weight of 1000 is mixed with 30% by weight.
- antioxidant Irg1010, manufactured by Ciba Specialty Chemicals Co., Ltd.
- antioxidant P168, manufactured by Ciba Specialty Chemicals Co., Ltd.
- calcium carbonate manufactured by Maruo Calcium Co., Ltd.
- the polyolefin resin composition was rolled with a pair of rolls having a surface temperature of 150 ° C.
- a substrate porous film A1 (film thickness: 16.1 ⁇ m, basis weight: 7.0 g / m 2 , air permeability: 129 seconds / 100 cc) was obtained.
- B-layer preparation coating liquid 2.9 parts by weight of carboxymethyl cellulose (CMC, Daiichi Kogyo Seiyaku Co., Ltd., Cellogen 3H) with respect to 100 parts by weight of alumina using the alumina slurry 1 of Example 1. Then, 312 parts by weight of pure water and 156 parts by weight of ethanol were mixed (alumina solid content concentration: 17.5% by weight), and after ultrasonic dispersion for 10 minutes, Creamix (“CLM-0.” Manufactured by M Technique Co., Ltd.). 8S ”) was dispersed in a circulation system so that the residence time was 10 minutes, and then filtered through a poly net mesh having an opening of 10 ⁇ m to prepare a coating liquid 1.
- CMC carboxymethyl cellulose
- the separator 1 of Example 1 was manufactured by laminating the B layer on both surfaces of the A layer by applying and drying the coating liquid 1 on the other surface of the A layer in the same manner.
- the thickness of B layer is the total thickness of B layer provided in both surfaces.
- the formed B layer has a porosity of 49% by volume, an air permeability of 189 seconds / 100 cc, an MD heating shape retention rate of 98%, and an MD heating shape retention rate of 98%. It had sufficient porosity and air permeability, had a low powder falling rate, and had high heat resistance.
- Table 2 shows the physical properties of the separator 1 obtained by the above method.
- Example 2 Except for the wet grinding conditions: peripheral speed: 10 m / sec, bead material: ZrO 2 , bead diameter: 1.0 mm, bead filling rate: 85 vol%, flow rate 0.5 L / min, residence time: 5.8 min,
- the alumina slurry 2 of Example 2 was produced by the same operation as Example 1.
- a coating liquid 2 and a separator 2 of Example 2 were obtained in the same manner as in Example 1 except that the alumina slurry 2 was used instead of the alumina slurry 1.
- the A layer used base-material porous film A1 similarly to Example 1.
- FIG. In the separator 2, the formed B layer has a porosity of 40% by volume, an air permeability of 202 sec / 100 cc, an MD heating shape retention rate of 98%, and an MD heating shape retention rate of 98%. It had sufficient porosity and air permeability, had a low powder falling rate, and had high heat resistance. Table 2 summarizes the physical properties of the obtained separator 2.
- Comparative Example 1 Implemented except that the wet pulverization conditions were as follows: peripheral speed: 10 m / sec, bead material: ZrO 2 , bead diameter: 1.0 mm, bead filling rate: 85%, flow rate 0.5 L / min, residence time: 1.5 min
- An alumina slurry 3 of Comparative Example 1 was produced in the same manner as in Example 1.
- the alumina slurry 3 was evaporated to dryness, and the Zr content in the solid alumina measured was 340 ppm. Further, from the particle size distribution of the alumina particles in the alumina slurry 3 shown in FIG.
- the particles having a particle diameter of less than 0.2 ⁇ m are 4.1% by weight, 43.7% by weight of particles having a particle diameter of more than 1.5 ⁇ m,
- One frequency maximum is shown in the region of particle diameter of 0.1 ⁇ m or more and less than 0.5 ⁇ m, 13.6% by weight of particles having a particle size of 0.5 ⁇ m or more and less than 1 ⁇ m,
- One frequency maximum appears in the region with a particle diameter of 1 ⁇ m or more, D1 is 0.29 ⁇ m, D2 is 1.64 ⁇ m, M1 is 2.54, and M2 is 3.97.
- the ratio of M1 to M2 was 0.64.
- Table 1 shows the physical properties of the alumina slurry 3 obtained by the above method and the alumina particles
- the coating liquid 3 and the separator 3 of the comparative example 1 were obtained by the same operation as Example 2 except having used the alumina slurry 3.
- the A layer used base-material porous film A1 similarly to Example 1.
- the physical properties of the obtained separator 3 are shown together in Table 2. Since the ratio of coarse particles in the alumina slurry was large, the porosity was excessive, and as a result of SEM image observation, the surface unevenness was large, and the powder fall rate was 31%, and the coating film strength was low.
- Comparative Example 2 Except for the wet grinding conditions: peripheral speed: 10 m / sec, bead material: ZrO 2 , bead diameter: 0.3 mm, bead filling rate: 85% by volume, flow rate 0.5 L / min, residence time: 4.4 min.
- Alumina slurry 4 of Comparative Example 2 was produced in the same manner as in Example 1.
- the alumina slurry 4 was evaporated to dryness, and the Zr content in the solid alumina measured was 2000 ppm.
- Particles having a particle diameter of less than 0.2 ⁇ m are 8.0% by weight, 0% by weight of particles having a particle diameter of more than 1.5 ⁇ m,
- One frequency maximum is shown in the region of particle diameter of 0.1 ⁇ m or more and less than 0.5 ⁇ m
- Particles having a particle size of 0.5 ⁇ m or more and less than 1 ⁇ m were 24.3% by weight, No frequency maximum was observed in the region having a particle diameter of 1 ⁇ m or more.
- Table 1 shows the alumina slurry 4 obtained by the above method and the physical properties of the alumina particles in the alumina slurry 4.
- the coating liquid 4 and the separator 4 of the comparative example 2 were obtained by the same operation as Example 2 except having used the alumina slurry 4.
- the A layer used base-material porous film A1 similarly to Example 1.
- the physical properties of the obtained separator 4 are shown together in Table 2.
- the alumina slurry of the present invention By using the alumina slurry of the present invention, it is possible to provide a separator for a non-aqueous secondary battery excellent in shutdown performance and ion permeability.
- the non-aqueous electrolyte secondary battery using the separator prevents the separator from directly contacting the positive electrode and the negative electrode even when the battery generates intense heat, and maintains the insulating property by rapidly making the polyolefin porous film nonporous. Therefore, the present invention is extremely useful industrially because the non-aqueous electrolyte secondary battery is highly safe.
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Abstract
Description
そのような方法として、異常発熱時に溶融する材質からなる多孔質フィルムをセパレータとして用いる方法が挙げられる。
<1> 実質的にαアルミナ粒子と水とからなるアルミナスラリーであって、
前記αアルミナ粒子が、下記粒子径分布条件(a)~(d)をすべて満たし、
前記αアルミナ粒子のアルミナ純度が90重量%以上であり、
スラリーにおけるアルミナ含有量が20重量%以上50重量%以下であり、且つ、
スラリーの粘度が0.5Pa・s以上15Pa・s以下であるアルミナスラリー。
条件(a):平均粒子径が1μm以下であること
条件(b):粒子径0.2μm未満の粒子が7重量%以下であること
条件(c):粒子径1.5μmを超える粒子が15重量%以下であること
条件(d):粒子径0.1μm以上0.5μm未満の領域に1つ以上の頻度極大を有すこと
<2> 前記αアルミナ粒子が、さらに下記粒子径分布条件(e)~(g)をすべて満たす前記<1>に記載のアルミナスラリー。
条件(e):粒子径0.5μm以上で1μm未満の粒子が40重量%以下であること
条件(f):粒子径1μm以上の領域に1つ以上の頻度極大を有すこと
条件(g):条件(d)における、粒子径0.1μm以上0.5μm未満の領域に現れる頻度極大のうち、最も小さな極大粒子径を示す頻度極大の極大粒子径をD1、極大値をM1とし、条件(f)における、粒子径1μm以上の領域に現れる頻度極大のうち最も大きな極大粒子径を示す頻度極大の極大粒子径をD2、極大値をM2としたとき、下記式(1)及び(2)の関係を満たすこと
2×D1≦D2≦5×D1 (1)
(M1/M2)≧0.8 (2)
<3> 前記αアルミナ粒子において、粒子径10μm以上の粗粒子量が10ppm以下である前記<1>又は<2>に記載のアルミナスラリー。
<4> アルミナ固形分中のZr含有量が重量換算で300ppm以上である前記<1>から<3>のいずれかに記載のアルミナスラリー。
<5> 前記<1>から<4>のいずれかに記載のアルミナスラリーの製造方法であって、
アルミナ純度が90重量%以上、BET比表面積が15m2/g以下、且つ、平均粒子径が1μm以上30μm以下の原料αアルミナ粒子を、溶媒である水に対して、アルミナ含有量が20重量%以上50重量%以下になるように添加して、前記原料αアルミナ粒子を湿式粉砕するアルミナスラリーの製造方法。
<6> 前記湿式粉砕を、分散剤非存在下で行う前記<5>に記載のアルミナスラリーの製造方法。
<7> 前記湿式粉砕が、分散メディアによる湿式粉砕であって、該分散メディアの直径が0.65mm~1.5mmのZrO2ビーズである前記<5>または<6>に記載のアルミナスラリーの製造方法。
<8> αアルミナ粒子及びバインダーを含む耐熱層とポリオレフィン基材多孔質フィルムとが積層されてなる非水電解液二次電池用セパレータにおける耐熱層の形成に用いられる、バインダー、αアルミナ粒子及び溶媒を含む塗工液であって、
前記<1>から<4>のいずれかに記載のアルミナスラリーとバインダーとを混合して調整され、バインダー100重量部に対してαアルミナ粒子100~10000重量部含む塗工液。
具体的には、本発明のアルミナスラリーを、バインダーと共に適当な溶媒に溶解・分散させた塗工液を、A層の片面又は両面に塗布し、溶媒を除去することにより、A層の片面又は両面にB層を積層して、上記積層多孔質フィルムを形成する。
なお、A層は、電池の事故発生時の異常発熱時に、溶融して無孔化することにより、積層多孔質フィルムにシャットダウンの機能を付与する。また、B層は、シャットダウンが生じる高温における耐熱性を有しており、積層多孔質フィルムに形状安定性の機能を付与する。
以下、本発明のアルミナスラリーにつき、詳細に説明する。
本発明のアルミナスラリーは、実質的にαアルミナ粒子と水とからなるアルミナスラリーであり、本発明の目的を達成できる範囲で、αアルミナ粒子と水以外の成分を含んでいてもよい。
水以外の成分としては、例えば、メタノール、エタノール、n−プロパノール、イソプロパノール、n−ブタノール、イソブタノール、t−ブタノール等のアルコール類や、公知の分散剤等が挙げられる。
なお、後述するように、本発明の製造方法によれば、水以外の溶媒や分散剤を使用せずとも、本発明のアルミナスラリーを得ることができる。
条件(a):平均粒子径が1μm以下、好ましくは0.4μm以上0.7μm以下であること
条件(b):粒子径0.2μm未満の粒子が7重量%以下、好ましくは、5重量%以下であること
条件(c):粒子径1.5μmを超える粒子が15重量%以下、好ましくは、10重量%以下であること
条件(d):粒子径0.1μm以上0.5μm未満の領域に1つ以上、好ましくは1つの頻度極大を有す
条件(e):粒子径0.5μm以上で1μm未満の粒子が40重量%以下であること
条件(f):粒子径1μm以上の領域に1つ以上の頻度極大を有すこと
条件(g):条件(d)における、粒子径0.1μm以上0.5μm未満の領域に現れる頻度極大のうち、最も小さな極大粒子径を示す頻度極大の極大粒子径をD1、極大値をM1とし、条件(f)における、粒子径1μm以上の領域に現れる頻度極大のうち最も大きな極大粒子径を示す頻度極大の極大粒子径をD2、極大値をM2としたとき、下記式(1)及び(2)の関係を満たすこと
2×D1≦D2≦5×D1 (1)
(M1/M2)≧0.8 (2)
ここで、アルミナ純度は、固体発光分析法で求めることができる。具体的には実施例にて後述する。
10μm以上の粗粒子量が10ppmを超えて含まれる場合、塗膜にスジ等の欠陥あるいは凝集粒子に起因した粗大な空隙が部分的に生成する場合がある。なお、粗粒子量は、後述の実施例に記載の湿式篩法により求めることができる。
アルミナ固形分中のZr含有量は、後述の実施例に記載のICP発光分析法で測定することができる。
上述した本発明のアルミナスラリーは、上記物性を有すれば、製造方法は特に限定されず、例えば、上記アルミナ純度、粒度分布を満たす、αアルミナ粉末を所定量の水に分散させて、上記スラリー粘度を満たすように調整すればよい。
一方で、本発明のアルミナスラリーにおいて、含有されるアルミナ粒子は、保管時などに凝集して、凝集体を生成する場合がある。スラリーに大きな凝集体を含有すると、塗工性低下のため、B層に膜欠陥が多くなり、結果としてセパレータのシャットダウン性やイオン透過性(通気性)等の膜特性が不十分となる場合がある。そのため、微粒のアルミナ粒子は、水に分散しづらく、通常、水以外に分散剤が実質的に必要となる。
すなわち、本発明のアルミナスラリーの製造方法(以下、「本発明の製造方法」と称す)は、アルミナ純度が90重量%以上、BET比表面積が15m2/g以下、且つ、平均粒子径が1μm以上30μm以下の原料αアルミナ粒子を、溶媒である水に対して、アルミナ含有量が20重量%以上50重量%以下になるように添加して、前記原料αアルミナ粒子を湿式粉砕することを特徴とする。
本発明の製造方法では、比較的粗大な上記原料αアルミナ粒子を、水溶媒中で湿式粉砕することにより、直接的に水溶媒にαアルミナを分散させることができるため、分散剤非存在下で湿式粉砕を行っても、上記物性を示す本発明のアルミナスラリーを得ることができるという利点がある。
以下、本発明の製造方法をより詳細に説明する。
本発明の製造方法において、原料となるαアルミナ粒子(以下、「原料αアルミナ粒子」と称す。)について説明する。
本発明の製造方法では、上記原料αアルミナ粒子を、溶媒である水に添加して湿式粉砕を行う。
原料αアルミナ粒子の添加量は、湿式粉砕後のスラリーの粘度が0.5Pa・s以上15Pa・s以下になるような範囲で決定され、原料αアルミナ粒子と水溶媒の合計を100重量%としたときに、アルミナ含有量が20重量%以上50重量%以下である。
この中でも、メディア型分散機が好ましく、具体的には、タワーミル、パールミル、サンドミル、ダイノミル、ウルトラビスコミル、アトライター、アニュラーミル等が挙げられる。
本発明のアルミナスラリーは、バインダー及び溶媒と混合することにより、αアルミナ粒子からなるフィラー(以下、単に「フィラー」と称す場合がある)とバインダーを含む耐熱層とポリオレフィン基材多孔質フィルムとが積層されてなる非水電解液二次電池用セパレータにおける耐熱層の形成に用いられる、バインダー、αアルミナ粒子及び溶媒を含む塗工液として用いられる。
該塗工液は、上述のように本発明のアルミナスラリーを、バインダーと溶媒とを均一になるまで混合・分散することによって得ることができ、積層多孔質フィルムの耐熱層(B層)形成に用いられる。
上記方法で得た本発明の塗工液を、基材多孔質フィルム(A層)の片面又は両面に塗布した後に、溶媒を除去してフィラー及びバインダーを含む耐熱層を形成することができる。
A層の孔径は3μm以下が好ましく、1μm以下がさらに好ましい。
すなわち、(1)超高分子量ポリエチレン100重量部と、重量平均分子量1万以下の低分子量ポリオレフィン5~200重量部と、炭酸カルシウム等の無機充填剤100~400重量部とを混練してポリオレフィン樹脂組成物を得る工程
(2)前記ポリオレフィン樹脂組成物を用いてシートを成形する工程
(3)工程(2)で得られたシート中から無機充填剤を除去する工程
(4)工程(3)で得られたシートを延伸してA層を得る工程
を含む方法、または
(1)超高分子量ポリエチレン100重量部と、重量平均分子量1万以下の低分子量ポリオレフィン5~200重量部と、無機充填剤100~400重量部とを混練してポリオレフィン樹脂組成物を得る工程
(2)前記ポリオレフィン樹脂組成物を用いてシートを成形する工程
(3)工程(2)で得られたシートから、無機充填剤を除去する工程
(4)工程(3)で得られたシートを延伸して、A層を得る工程
を含む方法である。
なお、A層については上記記載の特性を有する市販品を用いることができる。
なお、支持体としては、樹脂製のフィルム、金属製のベルト、ドラム等を用いることができる。
B層の厚みは、通常、0.1μm以上20μm以下であり、好ましくは1μm以上15μm以下の範囲である。B層が厚すぎると、A層も含めた積層多孔質フィルムの厚みが厚くなり、電池の電気容量が小さくなるおそれがある。B層が薄すぎると、事故等により該電池の発熱が生じたときにポリオレフィンの多孔質フィルム(A層)の熱収縮に抗しきれず積層多孔質フィルムが収縮するおそれがある。
なお、B層がA層の両面に形成される場合、B層の厚みは両面の合計厚みとする。
該細孔の孔径は、細孔を球形に近似したときの球の直径の平均値として3μm以下が好ましく、1μm以下がさらに好ましい。孔径の平均の大きさが3μmを超える場合には、正極や負極の主成分である炭素粉やその小片が脱落したときに、短絡しやすいなどの問題が生じるおそれがある。
また、B層の空隙率は30~65体積%が好ましく、より好ましくは40~60体積%である。
また、B層の剥離強度が弱いとフィルムの巻取りの際に粉落ちが発生するなどの問題が生じる恐れがある。B層の粉落ち率は、30%以下が好ましく、より好ましくは25%以下である。
本発明の積層多孔質フィルムは、A層に上述の方法にてB層が形成されてなる。すなわち、本発明の塗工液を、基材多孔質フィルム(A層)の片面又は両面に塗布した後に、溶媒を除去することによって、基材多孔質フィルム(A層)の片面又は両面に、αアルミナ粒子およびバインダーを含む耐熱層(B層)が形成された、本発明の積層多孔質フィルムが得られる。本発明の積層多孔質フィルムを非水電解液二次電池用セパレータとして用いることができる。
また、本発明の積層多孔質フィルム全体の空隙率は、通常、30~85%であり、好ましくは40~80%である。
また、本発明の積層多孔質フィルムを用いて非水二次電池を製造した場合、高い負荷特性が得られるが、積層多孔質フィルムの透気度は50~2000秒/100ccが好ましく、50~1000秒/100ccがより好ましく、50~300秒/100ccがさらに好ましい。透気度が2000秒/100cc以上となると、積層多孔質フィルムのイオン透過性、および電池の負荷特性が低くなるおそれがある。
(アルミナ純度)
アルミナ純度は、基準となる酸化物(αアルミナ)中に含まれるSiO2、Na2O、MgO、CuO、Fe2O3の重量の総和(%)を100から差し引いたものを用いた。算出式は以下のとおりである。Si、Na、Mg、Cu、Feの含有量は、固体発光分光法にて測定した。
アルミナ純度(重量%)=100−不純物の重量の総和(重量%)
アルミナ粒子のBET比表面積は、JIS−Z−8830に規定された方法に従って、窒素吸着法により求めた。なお、比表面積測定装置として島津製作所社製の「フロソーブII 2300」を使用した。
レーザー粒度分布測定装置〔日機装(株)製「マイクロトラック:MT−3300EX II」〕を用いてレーザー回折法により、質量基準でのアルミナ粒子の粒子径分布を求めた。また、質量基準で累積百分率50%相当粒子径を平均粒子径とした。測定は、試料を0.2重量%のヘキサメタ燐酸ソーダ水溶液で超音波分散して行った。
アルミナ固形分中のZr含有量は、アルミナスラリーを200℃蒸発乾固させ、ICP発光分析により測定した。
アルミナスラリー100gを、分散剤としてヘキサメタリン酸ソーダを0.2%含有する純水4Lに、超音波を照射して分散させた後、該スラリーを10μmの篩を通過させて、篩上に残存するアルミナ粉末を回収して、その含有量を測定した。
粗粒子含有量(ppm)=残存アルミナ粉末重量/アルミナスラリー固形分重量
B型粘度計(東機産業(株)製「TVB10M」)を用い、No.3ロータを6rpmで回転させてアルミナスラリーの粘度を測定した。
(1)厚み測定(単位:μm):
セパレータの厚みは、株式会社ミツトヨ製の高精度マイクロメーターで測定した。
(2)目付(単位:g/m2):
セパレータを一辺の長さ8cmの正方形に切り、重量W(g)を測定した。目付(g/m2)=W/(0.08×0.08)で算出した。B層の目付は、積層多孔質フィルムの目付から多孔質基材(A層)の目付を差し引いた上で算出した。
(3)空隙率:
フィルムを一辺の長さ8cmの正方形に切り取り、重量:W(g)と厚み:D(cm)を測定した。サンプル中の材質の重量を計算で割り出し、それぞれの材質の重量:Wi(g)を真比重で割り、それぞれの材質の体積を算出して、次式より空隙率(体積%)を求めた。各材料の日付は製膜に使用した量、比率より算出した。
空隙率(体積%)=100−[{(W1/真比重1)+(W2/真比重2)+・・+(Wn/真比重n)}/(100×D)]×100
(4)透気度:JIS P8117 に準拠して、株式会社東洋精機製作所製のデジタルタイマー式ガーレ式デンソメータで測定した。
(5)加熱形状維持率:
フィルムを8cm×8cmに切り出し、その中に6cm×6cmの四角を書き入れたフィルムを紙に挟んで、150℃に加熱したオーブンに入れた。1時間後、オーブンからフィルムを取り出し、書き入れた四角の辺の寸法を測定し、加熱形状維持率を計算した。計算方法は以下の通りである。
MD方向の加熱前の書き入れ線長さ:L1
TD方向の加熱前の書き入れ線長さ:L2
MD方向の加熱後の書き入れ線長さ:L3
MD方向の加熱後の書き入れ線長さ:L4
MD加熱形状維持率(%)=(L3/L1)×100
TD加熱形状維持率(%)=(L4/L2)×100
(6)粉落ち率
往復磨耗試験機(新東科学株式会社製、TRIBOGEAR TYPE:30)を用いて測定した。重量W0(g)のフィルムに対し、白布(カナキン3号)を荷重100g/m2(接触面積16mmφ)で押し付け、5cm幅で100回往復させた後、フィルムの重量W(g)を測定し、粉落ち量(g/m2)を求めた。粉落ち率は以下式より算出した。
粉落ち率(%)=粉落ち量(g/m2)/目付(g/m2)×100
(7)表面平滑性
フィルム表面のSEM像を観察し、表面平滑性を評価した。なお、評価基準は以下のとおりである。
○:平滑性が高く、凹凸はほぼ認められない
△:一部凹凸のある箇所が認められる
×:フィルム全体に凹凸が認められる
(アルミナスラリー1の作製)
BET比表面積=4.1m2/g、平均粒子径=6.2μmのアルミナ粒子を、アルミナ濃度が30重量%となるように水にアルミナ粒子を攪拌しながら添加することでアルミナ−水懸濁液を得た。引き続き、AG MASCHINENFABRIK BASEL社製ダイノーミル(KDL−PILOT A型)を用いたパス方式における湿式粉砕条件(周速:10m/sec,ビーズ材質:ZrO2、ビーズ径:1.0mm、ビーズ充填率:85体積%、流量:0.5L/min、滞留時間:4.4min)で分散させて、アルミナスラリー1を得た。
アルミナスラリー1は、粘度=2.75Pa・s、含有するアルミナ粒子は、平均粒子径=0.57μmであり、10μm以上の粗粒子量が3ppm以下であった。また、アルミナスラリー1を蒸発乾固し、測定した固形アルミナ中のZr含有量は重量換算で、1010ppmであった。
また、図1に示すアルミナスラリー1におけるアルミナ粒子の粒子径分布から、アルミナスラリー1におけるアルミナ粒子は、
粒子径0.2μm未満の粒子が4.6重量%であり、
粒子径1.5μmを超える粒子が8.3重量%であり、
粒子径0.1μm以上、0.5μm未満の領域に1つの頻度極大を示し、
粒子径0.5μm以上で1μm未満の粒子が29.2重量%であり、
粒子径1μm以上の領域に1つの頻度極大が現れ、
D1が0.34μm、D2が1.06μm、M1が4.30、M2が4.19
M1とM2との比(M1/M2)が1.03であった。表1にアルミナスラリー1およびアルミナスラリー1におけるアルミナ粒子の物性をまとめて示す。
評価用セパレータとして、以下の方法で基材多孔質フィルム(A層)と、耐熱層(B層)とが積層した積層多孔質フィルムからなる評価用セパレータを作製した。なお、A層は、以下の方法で作製した。
<A層の作製方法>
超高分子量ポリエチレン粉末(340M、三井化学株式会社製)を70重量%、重量平均分子量1000のポリエチレンワックス(FNP−0115、日本精鑞株式会社製)30重量%を混合し、この超高分子量ポリエチレンとポリエチレンワックスの合計量100重量部に対して、酸化防止剤(Irg1010、チバ・スペシャリティ・ケミカルズ株式会社製)0.4重量部、酸化防止剤(P168、チバ・スペシャリティ・ケミカルズ株式会社製)0.1重量部、ステアリン酸ナトリウム1.3重量部を加え、さらに全体積に対して38体積%となるように平均粒径0.1μmの炭酸カルシウム(丸尾カルシウム株式会社製)を加え、これらを粉末のままヘンシェルミキサーで混合した後、二軸混練機で溶融混練してポリオレフィン樹脂組成物とした。該ポリオレフィン樹脂組成物を表面温度が150℃の一対のロールにて圧延しシートを作製した。このシートを塩酸水溶液(塩酸4mol/L、非イオン系界面活性剤0.5重量%)に浸漬させることで炭酸カルシウムを溶解して、除去し、続いて105℃で6倍に延伸して、基材多孔質フィルムA1(膜厚:16.1μm、目付:7.0g/m2、透気度:129秒/100cc)を得た。
実施例1のアルミナスラリー1を用いて、アルミナ100重量部に対して、カルボキシメチルセルロース(CMC、第一工業製薬株式会社 セロゲン3H)2.9重量部、純水312重量部、エタノール156重量部になるように混合し(アルミナ固形分濃度17.5重量%)、10分超音波分散後、さらにクレアミクス(エム・テクニック株式会社製「CLM−0.8S」)で滞留時間10分となるように循環方式分散させ、その後、目開きが10μmのポリ網メッシュでろ過することで、塗工液1を作製した。
A層上にバーコーター(バーNo.16)を用いて塗工液1を塗布、乾燥した。次いで、A層のもう一方の面に、同様の方法で塗工液1を塗布、乾燥することでA層の両面にB層を積層することで実施例1のセパレータ1を製造した。なお、B層の厚みは、両面に設けられたB層の合計厚みである。
セパレータ1において、形成されたB層の空隙率は49体積%、透気度は189秒/100cc、MD加熱形状維持率は98%、MD加熱形状維持率は98%であり、リチウムイオン透過に対する十分な空隙率、透気度を有し、粉落ち率が低く、且つ、高い耐熱性を有していた。
表2に上記方法により得られたセパレータ1の物性を示す。
湿式粉砕条件を周速:10m/sec,ビーズ材質:ZrO2、ビーズ径:1.0mm、ビーズ充填率:85体積%、流量0.5L/min、滞留時間:5.8minとした以外は、実施例1と同様の操作で実施例2のアルミナスラリー2を作製した。得られたアルミナスラリー2は、粘度=3.04Pa・s、含有するアルミナ粒子の平均粒子径=0.52μmであり、10μm以上の粗粒子量が3ppm以下であった。また、アルミナスラリーを蒸発乾固し、測定したアルミナ固形分中のZr含有量は1270ppmであった。
また、図1に示すアルミナスラリー2におけるアルミナ粒子の粒子径分布から、アルミナスラリー2におけるアルミナ粒子は、
粒子径0.2μm未満の粒子が4.6重量%であり、
粒子径1.5μmを超える粒子が4.7重量%であり、
粒子径0.1μm以上、0.5μm未満の領域に1つの頻度極大を示し、
粒子径0.5μm以上で1μm未満の粒子が31.8重量%であり、
粒子径1μm以上の領域に1つの頻度極大が現れ、
D1が0.34、D2が0.97、M1が4.75、M2が4.07
M1とM2との比(M1/M2)が1.17であった。
表1に上記方法により得られたアルミナスラリー2及びアルミナスラリー2におけるアルミナ粒子の物性を示す。
セパレータ2において、形成されたB層の空隙率は40体積%、透気度は202秒/100cc、MD加熱形状維持率は98%、MD加熱形状維持率は98%であり、リチウムイオン透過に対する十分な空隙率、透気度を有し、粉落ち率が低く、且つ、高い耐熱性を有していた。
得られたセパレータ2の物性を表2にまとめて示す。
湿式粉砕条件を周速:10m/sec,ビーズ材質:ZrO2、ビーズ径:1.0mm、ビーズ充填率:85%、流量0.5L/min、滞留時間:1.5minとした以外は、実施例1と同様な操作で比較例1のアルミナスラリー3を作製した。得られたアルミナスラリー3は、粘度=1.74Pa・s、含有するアルミナ粒子の平均粒子径=1.30μmであり、10μm以上の粗粒子量が3531ppmであり、スラリー中の粗粒子含有量が多かった。また、アルミナスラリー3を蒸発乾固し、測定した固形アルミナ中のZr含有量は340ppmであった。
また、図1に示すアルミナスラリー3におけるアルミナ粒子の粒子径分布から、アルミナスラリー3におけるアルミナ粒子は、
粒子径0.2μm未満の粒子が4.1重量%であり、
粒子径1.5μmを超える粒子が43.7重量%であり、
粒子径0.1μm以上、0.5μm未満の領域に1つの頻度極大を示し、
粒子径0.5μm以上で1μm未満の粒子が13.6重量%であり、
粒子径1μm以上の領域に1つの頻度極大が現れ、
D1が0.29μm、D2が1.64μm、M1が2.54、M2が3.97
M1とM2との比(M1/M2)が0.64であった。
表1に上記方法により得られたアルミナスラリー3及びアルミナスラリー3におけるアルミナ粒子の物性を示す。
セパレータ3において、形成されたB層の空隙率は68体積%、透気度は189秒/100cc、MD加熱形状維持率は97%、MD加熱形状維持率は96%であった。得られたセパレータ3の物性を表2にまとめて示す。アルミナスラリー中の粗粒子の割合が多いため、空隙率が過大となり、また、SEM像観察の結果、表面凹凸が大きく、さらに粉落ち率も31%であり塗膜強度が低かった。
湿式粉砕条件を周速:10m/sec,ビーズ材質:ZrO2、ビーズ径:0.3mm、ビーズ充填率:85体積%、流量0.5L/min、滞留時間:4.4minとした以外は、実施例1と同様な操作で比較例2のアルミナスラリー4を作製した。得られたアルミナスラリー4は、粘度=4.60Pa・s、含有するアルミナ粒子の平均粒子径=0.37μmであり、10μm以上の粗粒子量が3ppm以下であった。また、アルミナスラリー4を蒸発乾固し、測定した固形アルミナ中のZr含有量は2000ppmであった。
また、図1に示すアルミナスラリー4におけるアルミナ粒子の粒子径分布から、アルミナスラリー4におけるアルミナ粒子は、
粒子径0.2μm未満の粒子が8.0重量%であり、
粒子径1.5μmを超える粒子が0重量%であり、
粒子径0.1μm以上、0.5μm未満の領域に1つの頻度極大を示し、
粒子径0.5μm以上で1μm未満の粒子が24.3重量%であったが、
粒子径1μm以上の領域に頻度極大は認められなかった。
表1に上記方法により得られたアルミナスラリー4およびアルミナスラリー4におけるアルミナ粒子の物性を示す。
セパレータ4において、形成されたB層の空隙率は29体積%、透気度は190秒/100cc、MD加熱形状維持率は99%、MD加熱形状維持率は99%であった。高い耐熱性を有するものの、リチウムイオン透過に対する十分な空隙率が得られなかった。
得られたセパレータ4の物性を表2にまとめて示す。
Claims (8)
- 実質的にαアルミナ粒子と水とからなるアルミナスラリーであって、
前記αアルミナ粒子が、下記粒子径分布条件(a)~(d)をすべて満たし、
前記αアルミナ粒子のアルミナ純度が90重量%以上であり、
スラリーにおけるアルミナ含有量が20重量%以上50重量%以下であり、且つ、
スラリーの粘度が0.5Pa・s以上15Pa・s以下であることを特徴とするアルミナスラリー。
条件(a):平均粒子径が1μm以下であること
条件(b):粒子径0.2μm未満の粒子が7重量%以下であること
条件(c):粒子径1.5μmを超える粒子が15重量%以下であること
条件(d):粒子径0.1μm以上0.5μm未満の領域に1つ以上の頻度極大を有すこと - 前記αアルミナ粒子が、さらに下記粒子径分布条件(e)~(g)をすべて満たす請求項1に記載のアルミナスラリー。
条件(e):粒子径0.5μm以上で1μm未満の粒子が40重量%以下であること
条件(f):粒子径1μm以上の領域に1つ以上の頻度極大を有すこと
条件(g):条件(d)における、粒子径0.1μm以上0.5μm未満の領域に現れる頻度極大のうち、最も小さな極大粒子径を示す頻度極大の極大粒子径をD1、極大値をM1とし、条件(f)における、粒子径1μm以上の領域に現れる頻度極大のうち最も大きな極大粒子径を示す頻度極大の極大粒子径をD2、極大値をM2としたとき、下記式(1)及び(2)の関係を満たすこと
2×D1≦D2≦5×D1 (1)
(M1/M2)≧0.8 (2) - 前記αアルミナ粒子において、粒子径10μm以上の粗粒子量が10ppm以下である請求項1に記載のアルミナスラリー。
- アルミナ固形分中のZr含有量が重量換算で、300ppm以上である請求項1に記載のアルミナスラリー。
- 請求項1に記載のアルミナスラリーの製造方法であって、
アルミナ純度が90重量%以上、BET比表面積が15m2/g以下、且つ、平均粒子径が1μm以上30μm以下の原料αアルミナ粒子を、溶媒である水に対して、アルミナ含有量が20重量%以上50重量%以下になるように添加して、前記原料αアルミナ粒子を湿式粉砕することを特徴とするアルミナスラリーの製造方法。 - 前記湿式粉砕を、分散剤非存在下で行うことを特徴とする請求項5に記載のアルミナスラリーの製造方法。
- 前記湿式粉砕が、分散メディアによる湿式粉砕であって、該分散メディアの直径が0.65mm~1.5mmのZrO2ビーズである請求項5に記載のアルミナスラリーの製造方法。
- αアルミナ粒子及びバインダーを含む耐熱層とポリオレフィン基材多孔質フィルムとが積層されてなる非水電解液二次電池用セパレータにおける耐熱層の形成に用いられる、バインダー、αアルミナ粒子及び溶媒を含む塗工液であって、
請求項1に記載のアルミナスラリーとバインダーとを混合して調整され、バインダー100重量部に対してαアルミナ粒子100~10000重量部含む塗工液。
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Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2016093941A (ja) * | 2014-11-13 | 2016-05-26 | 三菱樹脂株式会社 | 積層多孔フィルム、非水電解液二次電池用セパレータ、及び非水電解液二次電池 |
JP2016108210A (ja) * | 2014-12-10 | 2016-06-20 | 三菱樹脂株式会社 | アルミナスラリー及びその製造方法 |
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0729563A (ja) | 1993-05-11 | 1995-01-31 | Mitsubishi Chem Corp | バッテリーセパレーター及びそれを用いたリチウム電池 |
JPH07304110A (ja) | 1994-05-12 | 1995-11-21 | Ube Ind Ltd | 積層多孔質フイルム及びその製法 |
WO2008149986A1 (ja) * | 2007-06-06 | 2008-12-11 | Asahi Kasei E-Materials Corporation | 多層多孔膜 |
JP2011216257A (ja) * | 2010-03-31 | 2011-10-27 | Teijin Ltd | 非水系二次電池用セパレータ |
JP2012004103A (ja) * | 2010-02-25 | 2012-01-05 | Sumitomo Chemical Co Ltd | 無機酸化物粉末および無機酸化物含有スラリーならびに該スラリーを使用したリチウムイオン二次電池およびその製造方法 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE69326950T2 (de) * | 1992-06-02 | 2000-04-20 | Sumitomo Chemical Co | Verfahren zur herstellung von alpha-aluminiumoxid |
US6521203B1 (en) | 1992-06-02 | 2003-02-18 | Sumitomo Chemical Co., Ltd. | Process for producing α-alumina |
JP4792688B2 (ja) | 2003-01-24 | 2011-10-12 | 住友化学株式会社 | 非水電解液二次電池用セパレータの製造方法 |
KR100803470B1 (ko) | 2004-04-19 | 2008-02-14 | 마쯔시다덴기산교 가부시키가이샤 | 리튬이온 2차전지 및 그 제조법 |
JP4763253B2 (ja) | 2004-05-17 | 2011-08-31 | パナソニック株式会社 | リチウムイオン二次電池 |
TWI330136B (en) * | 2005-11-28 | 2010-09-11 | Lg Chemical Ltd | Organic/inorganic composite porous membrane and electrochemical device using the same |
JP2008156146A (ja) * | 2006-12-22 | 2008-07-10 | Sumitomo Chemical Co Ltd | αアルミナスラリー |
KR100983161B1 (ko) * | 2008-01-11 | 2010-09-20 | 삼성에스디아이 주식회사 | 전극조립체 및 이를 구비한 이차전지 |
JP5636312B2 (ja) * | 2010-03-09 | 2014-12-03 | 住友化学株式会社 | サファイア単結晶製造用αアルミナおよびその製造方法 |
JP5362132B2 (ja) | 2012-01-20 | 2013-12-11 | 住友化学株式会社 | 無機酸化物粉末および無機酸化物含有スラリーならびに該スラリーを使用したリチウムイオン二次電池およびその製造方法 |
-
2013
- 2013-07-24 US US14/416,901 patent/US20150203686A1/en not_active Abandoned
- 2013-07-24 WO PCT/JP2013/070674 patent/WO2014017662A1/ja active Application Filing
- 2013-07-24 CN CN201380039585.1A patent/CN104488109B/zh active Active
- 2013-07-24 KR KR1020157001874A patent/KR101739211B1/ko active IP Right Grant
- 2013-07-24 JP JP2014527044A patent/JP6067016B2/ja active Active
- 2013-07-24 EP EP13822125.4A patent/EP2879205B1/en active Active
- 2013-07-25 TW TW102126667A patent/TW201410799A/zh unknown
-
2017
- 2017-11-30 US US15/826,811 patent/US10836913B2/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0729563A (ja) | 1993-05-11 | 1995-01-31 | Mitsubishi Chem Corp | バッテリーセパレーター及びそれを用いたリチウム電池 |
JPH07304110A (ja) | 1994-05-12 | 1995-11-21 | Ube Ind Ltd | 積層多孔質フイルム及びその製法 |
WO2008149986A1 (ja) * | 2007-06-06 | 2008-12-11 | Asahi Kasei E-Materials Corporation | 多層多孔膜 |
JP2012004103A (ja) * | 2010-02-25 | 2012-01-05 | Sumitomo Chemical Co Ltd | 無機酸化物粉末および無機酸化物含有スラリーならびに該スラリーを使用したリチウムイオン二次電池およびその製造方法 |
JP2011216257A (ja) * | 2010-03-31 | 2011-10-27 | Teijin Ltd | 非水系二次電池用セパレータ |
Non-Patent Citations (1)
Title |
---|
See also references of EP2879205A4 |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2016093941A (ja) * | 2014-11-13 | 2016-05-26 | 三菱樹脂株式会社 | 積層多孔フィルム、非水電解液二次電池用セパレータ、及び非水電解液二次電池 |
JP2016108210A (ja) * | 2014-12-10 | 2016-06-20 | 三菱樹脂株式会社 | アルミナスラリー及びその製造方法 |
JP2016126853A (ja) * | 2014-12-26 | 2016-07-11 | 積水化学工業株式会社 | セパレータ及び電気化学デバイス |
US20170155114A1 (en) * | 2015-11-30 | 2017-06-01 | Sumitomo Chemical Company, Limited | Nonaqueous electrolyte secondary battery separator |
JP2019003951A (ja) * | 2018-09-26 | 2019-01-10 | 積水化学工業株式会社 | セパレータ及び電気化学デバイス |
JP2020105031A (ja) * | 2018-12-26 | 2020-07-09 | 住友化学株式会社 | αアルミナ、スラリー、多孔膜、積層セパレータ、並びに非水電解液二次電池及びその製造方法 |
WO2020138014A1 (ja) * | 2018-12-26 | 2020-07-02 | 住友化学株式会社 | αアルミナ、スラリー、多孔膜、積層セパレータ、並びに非水電解液二次電池及びその製造方法 |
KR20210108430A (ko) * | 2018-12-26 | 2021-09-02 | 스미또모 가가꾸 가부시끼가이샤 | α-알루미나, 슬러리, 다공막, 적층 세퍼레이터, 그리고 비수전해액 이차전지 및 이의 제조 방법 |
KR102356572B1 (ko) | 2018-12-26 | 2022-02-08 | 스미또모 가가꾸 가부시끼가이샤 | α-알루미나, 슬러리, 다공막, 적층 세퍼레이터, 그리고 비수전해액 이차전지 및 이의 제조 방법 |
US11990640B2 (en) | 2018-12-26 | 2024-05-21 | Sumitomo Chemical Company, Limited | α-alumina, slurry, porous membrane, laminated separator, and nonaqueous electrolyte secondary battery and method for producing same |
WO2022210259A1 (ja) * | 2021-03-30 | 2022-10-06 | デンカ株式会社 | 無機質粉末、無機質組成物、及び樹脂組成物 |
WO2023095871A1 (ja) * | 2021-11-26 | 2023-06-01 | 住友化学株式会社 | アルミナ粉末およびそれを含むアルミナスラリー |
WO2024085058A1 (ja) * | 2022-10-17 | 2024-04-25 | 東レ株式会社 | 積層多孔質膜および積層多孔質膜を含む電池用セパレータ |
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