WO2011132533A1 - 積層多孔フィルム、非水電解液二次電池用セパレータ、および非水電解液二次電池 - Google Patents
積層多孔フィルム、非水電解液二次電池用セパレータ、および非水電解液二次電池 Download PDFInfo
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- WO2011132533A1 WO2011132533A1 PCT/JP2011/058720 JP2011058720W WO2011132533A1 WO 2011132533 A1 WO2011132533 A1 WO 2011132533A1 JP 2011058720 W JP2011058720 W JP 2011058720W WO 2011132533 A1 WO2011132533 A1 WO 2011132533A1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
- B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
- B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
- B32B5/32—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed at least two layers being foamed and next to each other
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- 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
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- 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
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- 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
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/417—Polyolefins
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- 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
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/443—Particulate material
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- 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
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- 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
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- 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
- H01M50/409—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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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2264/00—Composition or properties of particles which form a particulate layer or are present as additives
- B32B2264/10—Inorganic particles
- B32B2264/102—Oxide or hydroxide
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/30—Properties of the layers or laminate having particular thermal properties
- B32B2307/306—Resistant to heat
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/50—Properties of the layers or laminate having particular mechanical properties
- B32B2307/514—Oriented
- B32B2307/518—Oriented bi-axially
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/724—Permeability to gases, adsorption
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2457/00—Electrical equipment
- B32B2457/10—Batteries
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/249921—Web or sheet containing structurally defined element or component
- Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
- Y10T428/249982—With component specified as adhesive or bonding agent
- Y10T428/249983—As outermost component
Definitions
- the present invention relates to a laminated porous film, which can be used as a packaging, sanitary, livestock, agricultural, architectural, medical, separation membrane, light diffusion plate, battery separator, and in particular as a separator for nonaqueous electrolytic batteries. It can be used suitably.
- the polymer porous body with many fine communication holes is used for separation membranes used for the production of ultrapure water, purification of chemicals, water treatment, waterproof and moisture-permeable films used for clothing and sanitary materials, and batteries. It is used in various fields such as battery separators.
- secondary batteries are widely used as power sources for portable devices such as OA, FA, household appliances or communication devices.
- portable devices using lithium ion secondary batteries are increasing because they have a high volumetric efficiency when mounted on devices, leading to a reduction in size and weight of the devices.
- large-sized secondary batteries are being researched and developed in many fields related to energy / environmental issues, including road leveling, UPS, and electric vehicles, and are excellent in large capacity, high output, high voltage, and long-term storage. Therefore, the use of lithium ion secondary batteries, which are a kind of non-aqueous electrolyte secondary battery, is expanding.
- the working voltage of a lithium ion secondary battery is usually designed with an upper limit of 4.1V to 4.2V.
- the aqueous solution causes electrolysis and cannot be used as an electrolyte. Therefore, so-called non-aqueous electrolytes using organic solvents are used as electrolytes that can withstand high voltages.
- the solvent for the non-aqueous electrolyte a high dielectric constant organic solvent capable of allowing more lithium ions to be present is used, and organic carbonate compounds such as propylene carbonate and ethylene carbonate are mainly used as the high dielectric constant organic solvent. in use.
- a highly reactive electrolyte such as lithium hexafluorophosphate is dissolved in the solvent and used.
- a separator is interposed between the positive electrode and the negative electrode from the viewpoint of preventing an internal short circuit.
- the separator is required to have insulating properties due to its role.
- a porous film is used as a separator.
- SD characteristic As a characteristic that contributes to the safety of the battery separator, there is a shutdown characteristic (hereinafter referred to as “SD characteristic”).
- This SD characteristic is a function that can prevent a subsequent increase in the temperature inside the battery because the micropores are blocked when the temperature is about 100 to 150 ° C., and as a result, ion conduction inside the battery is cut off.
- the lowest temperature at which the micropores of the laminated porous film are blocked is referred to as a shutdown temperature (hereinafter referred to as “SD temperature”).
- SD temperature shutdown temperature
- multilayer porous films having a porous layer containing a filler and a resin binder on at least one surface of a polyolefin resin porous film are disclosed in JP-A-2004-227972 (Patent Document 1) and JP-A-2007-280911.
- Patent Document 3 Japanese Patent Laid-Open No. 2008-186721
- Patent Document 3 Japanese Patent Laid-Open No. 2008-186721
- Patent Document 4 coating is performed immediately after longitudinal stretching, which is in the middle of the process of forming a porous film, and then lateral stretching is performed. A porous layer containing a filler and a resin binder is provided simultaneously.
- Patent Documents 1 to 3 all of the methods described in Patent Documents 1 to 3 are difficult to say because they are excellent in productivity because the porous film is once formed and then subjected to a treatment such as coating. Moreover, even if the coating is performed with a wide width as a method with excellent productivity, the coating apparatus becomes wide, which is disadvantageous in terms of cost. Further, the porous film obtained in Patent Document 4 has a problem that heat resistance is low due to a low filling density of the filler.
- An object of the present invention is to solve the above problems. That is, it is an object of the present invention to provide a laminated porous film having excellent characteristics as a separator for a nonaqueous electrolyte secondary battery, which is a laminated porous film that simultaneously satisfies communication, heat resistance, and workability.
- a heat-resistant layer containing a filler (a), a resin binder (b), and a stretching aid (c) is laminated on at least one surface of a polyolefin-based resin porous film, It is a laminated porous film characterized by having an air permeability of 2000 seconds / 100 ml or less.
- the stretching aid (c) has a boiling point of 120 ° C. or higher or does not have a boiling point.
- the stretching aid (c) is more preferably at least one selected from glycol, glycol polymer, modified glycol polymer, and glycerin.
- the laminated porous film of the present invention preferably has ⁇ crystal activity.
- a laminated porous film having excellent heat resistance, stretchability, and communication properties and having excellent characteristics as a separator for a non-aqueous electrolyte secondary battery can be obtained.
- the expression “main component” includes the intention to allow other components to be contained within a range that does not interfere with the function of the main component, unless otherwise specified.
- the content ratio of the components is not specified, but the main component includes 50% by mass or more, preferably 70% by mass or more, particularly preferably 90% by mass or more (including 100%) in the composition. It is.
- “X to Y” (X and Y are arbitrary numbers) is described, it means “preferably greater than X” and “preferably smaller than Y” with the meaning of “X to Y” unless otherwise specified. Is included.
- Polyolefin resin porous film examples of the polyolefin resin used in the polyolefin resin porous film include homopolymers or copolymers obtained by polymerizing ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexane and the like. Among these, a polypropylene resin and a polyethylene resin are preferable.
- Polypropylene resins include homopropylene (propylene homopolymer), or propylene and ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, etc. Random copolymers or block copolymers with ⁇ -olefins may be mentioned. Among these, homopolypropylene is more preferably used from the viewpoint of maintaining the mechanical strength and heat resistance of the laminated porous film.
- the polypropylene resin preferably has an isotactic pentad fraction (mmmm fraction) exhibiting stereoregularity of 80 to 99%. More preferably 83 to 98%, and still more preferably 85 to 97%. If the isotactic pentad fraction is too low, the mechanical strength of the film may be reduced.
- the upper limit of the isotactic pentad fraction is defined by the upper limit that can be obtained industrially at the present time, but this is not the case when a more regular resin is developed in the industrial level in the future. is not.
- the isotactic pentad fraction (mmmm fraction) is the same direction for all five methyl groups that are side chains with respect to the main chain of carbon-carbon bonds composed of any five consecutive propylene units. Means the three-dimensional structure located at or its proportion. Signal assignment of the methyl group region is as follows. It conformed to Zambelli et al (Macromolecules 8,687, (1975)).
- Mw / Mn which is a parameter indicating a molecular weight distribution
- Mw / Mn is 2.0 to 10.0. More preferred is 2.0 to 8.0, and still more preferred is 2.0 to 6.0. This means that the smaller the Mw / Mn is, the narrower the molecular weight distribution is.
- Mw / Mn is less than 2.0, problems such as a decrease in extrusion moldability occur, and it is difficult to produce industrially.
- Mw / Mn exceeds 10.0, low molecular weight components increase, and the mechanical strength of the laminated porous film tends to decrease.
- Mw / Mn is obtained by GPC (gel permeation chromatography) method.
- the melt flow rate (MFR) of the polypropylene resin is not particularly limited, but the MFR is preferably 0.5 to 15 g / 10 minutes, and preferably 1.0 to 10 g / 10 minutes. More preferred.
- MFR is 0.5 g / 10 min or more, the resin has a high melt viscosity at the time of molding, and sufficient productivity can be ensured.
- MFR is measured according to JIS K7210 under conditions of a temperature of 230 ° C. and a load of 2.16 kg.
- the method for producing the polypropylene resin is not particularly limited, and a known polymerization method using a known polymerization catalyst, for example, a multisite catalyst represented by a Ziegler-Natta type catalyst or a metallocene catalyst. And a polymerization method using a single site catalyst.
- a known polymerization method using a known polymerization catalyst for example, a multisite catalyst represented by a Ziegler-Natta type catalyst or a metallocene catalyst.
- a polymerization method using a single site catalyst for example, a multisite catalyst represented by a Ziegler-Natta type catalyst or a metallocene catalyst.
- polypropylene resin examples include trade names “Novatech PP” “WINTEC” (manufactured by Nippon Polypro), “Versify” “Notio” “Tafmer XR” (manufactured by Mitsui Chemicals), “Zeras” “Thermolan” (Mitsubishi Chemical) ), “Sumitomo Noblen”, “Tough Selenium” (manufactured by Sumitomo Chemical), “Prime TPO” (manufactured by Prime Polymer), “Adflex”, “Adsyl”, “HMS-PP (PF814)” (manufactured by Sun Aroma) Commercially available products such as “Inspire” (Dow Chemical) can be used.
- the laminated porous film of the present invention preferably has the ⁇ crystal activity.
- the ⁇ crystal activity can be regarded as an index indicating that the polypropylene resin produced ⁇ crystals in the film-like material before stretching. If the polypropylene resin in the film-like material before stretching produces ⁇ crystals, fine pores can be easily formed by stretching even when additives such as fillers are not used. A laminated porous film having characteristics can be obtained.
- the presence or absence of “ ⁇ crystal activity” is determined when the crystal melting peak temperature derived from the ⁇ crystal is detected by a differential scanning calorimeter described later and / or the X-ray diffractometer described later.
- a diffraction peak derived from the ⁇ crystal is detected by measurement using, it is determined that the crystal has “ ⁇ crystal activity”.
- the laminated porous film is heated from 25 ° C. to 240 ° C. at a heating rate of 10 ° C./min for 1 minute with a differential scanning calorimeter, and then cooled from 240 ° C. to 25 ° C. at a cooling rate of 10 ° C./min.
- Tm ⁇ crystal melting peak temperature
- the ⁇ crystal activity of the laminated porous film is calculated by the following formula using the detected heat of crystal melting ( ⁇ Hm ⁇ ) and the heat of crystal melting ( ⁇ Hm ⁇ ) derived from the ⁇ crystal of the polypropylene tree.
- ⁇ crystal activity (%) [ ⁇ Hm ⁇ / ( ⁇ Hm ⁇ + ⁇ Hm ⁇ )] ⁇ 100
- the amount of heat of crystal melting derived from the ⁇ crystal ( ⁇ Hm ⁇ ) detected mainly in the range of 145 ° C. or higher and lower than 160 ° C., and mainly detected at 160 ° C. or higher and 170 ° C. or lower.
- the amount of heat of crystal melting ( ⁇ Hm ⁇ ) derived from the ⁇ crystal detected mainly in the range of 120 ° C. or more and less than 140 ° C. It can be calculated from the crystal melting calorie ( ⁇ Hm ⁇ ) derived from the ⁇ crystal detected in the range of from 0 ° C. to 165 ° C.
- the laminated porous film preferably has a higher ⁇ crystal activity, and the ⁇ crystal activity is preferably 20% or more. More preferably, it is 40% or more, and particularly preferably 60% or more. If the laminated porous film has a ⁇ crystal activity of 20% or more, it indicates that a large number of ⁇ crystals of polypropylene resin can be produced in the film-like material before stretching, and fine and uniform pores are formed by stretching. As a result, a separator for a lithium ion lithium battery having high mechanical strength and excellent air permeability can be obtained.
- the upper limit value of the ⁇ crystal activity is not particularly limited, but the higher the ⁇ crystal activity, the more effective the effect is obtained, so the closer it is to 100%, the better.
- the ⁇ crystal activity can be measured in the state of the entire laminated porous film even in the case where the laminated porous film of the present invention has a single-layer structure or when other porous layers are laminated. it can. Further, if a layer containing a polypropylene resin other than the layer made of polypropylene resin is laminated, it is preferable that both layers have ⁇ crystal activity.
- ⁇ crystal nucleating agent examples include those shown below, but are not particularly limited as long as they increase the formation and growth of ⁇ crystals of polypropylene resin, and two or more types are mixed. May be used.
- examples of the ⁇ crystal nucleating agent include amide compounds; tetraoxaspiro compounds; quinacridones; iron oxides having a nanoscale size; potassium 1,2-hydroxystearate, magnesium benzoate or magnesium succinate, magnesium phthalate, etc.
- Alkali or alkaline earth metal salts of carboxylic acids represented by: aromatic sulfonic acid compounds represented by sodium benzenesulfonate or sodium naphthalenesulfonate; di- or triesters of dibasic or tribasic carboxylic acids; phthalocyanine blue Phthalocyanine pigments typified by: a two-component compound comprising component A which is an organic dibasic acid and a component B which is an oxide, hydroxide or salt of a Group IIA metal of the periodic table; a cyclic phosphorus compound; Made of magnesium compound Such as the formation thereof.
- specific types of nucleating agents are described in JP-A No. 2003-306585, JP-A No. 06-289656, and JP-A No. 09-194650.
- ⁇ crystal nucleating agent Commercially available products of ⁇ crystal nucleating agent are ⁇ crystal nucleating agent “NJESTER NU-100” manufactured by Shin Nippon Rika Co., Ltd.
- Specific examples of polypropylene resins to which ⁇ crystal nucleating agent is added include polypropylene “Bepol® B” manufactured by Aristech. -022SP ”, polypropylene manufactured by Borealis“ Beta ( ⁇ ) -PP BE60-7032 ”, polypropylene manufactured by Mayzo“ BNX BETAPP-LN ”, and the like.
- the ratio of the ⁇ -crystal nucleating agent added to the polypropylene resin needs to be appropriately adjusted depending on the type of the ⁇ -crystal nucleating agent or the composition of the polypropylene-based resin.
- the agent is preferably 0.0001 to 5.0 parts by mass. 0.001 to 3.0 parts by mass is more preferable, and 0.01 to 1.0 part by mass is still more preferable. If it is 0.0001 part by mass or more, ⁇ -crystals of polypropylene resin can be sufficiently produced and grown during production, and sufficient ⁇ -crystal activity can be secured even when used as a separator, and desired air permeability performance. Is obtained.
- Addition of 5.0 parts by mass or less is preferable because it is economically advantageous and there is no bleeding of the ⁇ crystal nucleating agent on the surface of the laminated porous film.
- the amount of ⁇ crystal nucleating agent added to each layer may be the same or different.
- the porous structure of each layer can be appropriately adjusted by changing the addition amount of the ⁇ crystal nucleating agent.
- additives generally added to the resin composition can be added as appropriate within a range that does not significantly impair the effects of the present invention.
- the additive include recycling resin, silica, talc, kaolin, calcium carbonate, and the like, which are added for the purpose of improving and adjusting molding processability, productivity, and various physical properties of the laminated porous film.
- Inorganic particles such as, pigments such as titanium oxide and carbon black, flame retardants, weathering stabilizers, heat stabilizers, antistatic agents, melt viscosity improvers, crosslinking agents, lubricants, nucleating agents, plasticizers, anti-aging agents, Examples thereof include additives such as antioxidants, light stabilizers, ultraviolet absorbers, neutralizers, antifogging agents, antiblocking agents, slip agents, and coloring agents.
- additives such as antioxidants, light stabilizers, ultraviolet absorbers, neutralizers, antifogging agents, antiblocking agents, slip agents, and coloring agents.
- polyethylene resin Specific examples of the polyethylene resin include ultra low density polyethylene, low density polyethylene, high density polyethylene, linear low density polyethylene, and homopolymer polyethylene such as ultra high molecular weight polyethylene characterized by molecular weight, as well as ethylene propylene.
- a copolymer or a copolymer polyethylene of a polyethylene resin and another polyolefin resin may be mentioned.
- homopolymer polyethylene or copolymer polyethylene having an ⁇ -olefin comonomer content of 2 mol% or less is preferable, and homopolymer polyethylene is more preferable.
- the density of the polyethylene resin is preferably 0.910 to 0.970 g / cm 3 , more preferably 0.930 to 0.970 g / cm 3 , and 0.940 to 0.970 g / cm 3. 3 is more preferable.
- a density of 0.910 g / cm 3 or more is preferable because it can have appropriate SD characteristics.
- 0.970 g / cm 3 or less is preferable in that it can have an appropriate SD characteristic and can maintain stretchability.
- the density can be measured according to JIS K7112 using a density gradient tube method.
- the melt flow rate (MFR) of the polyethylene resin is not particularly limited, but usually the MFR is preferably 0.03 to 30 g / 10 minutes, and preferably 0.3 to 10 g / 10 minutes. It is more preferable. If the MFR is 0.03 g / 10 min or more, the melt viscosity of the resin during the molding process is sufficiently low, which is excellent in productivity and preferable. On the other hand, if it is 30 g / 10 minutes or less, since sufficient mechanical strength can be obtained, it is preferable. MFR is measured in accordance with JIS K7210 under conditions of a temperature of 190 ° C. and a load of 2.16 kg.
- the polymerization catalyst for the polyethylene resin is not particularly limited, and may be any one such as a Ziegler type catalyst, a Philips type catalyst, or a Kaminsky type catalyst.
- a polymerization method of the polyethylene resin there are a one-stage polymerization, a two-stage polymerization, or a multistage polymerization more than that, and any method of the polyethylene resin can be used.
- the porosity promoting compound X is not limited, but specific examples thereof include a porosity promoting compound X selected from a modified polyolefin resin, an alicyclic saturated hydrocarbon resin or a modified product thereof, an ethylene copolymer, or a wax. More preferably, at least one of them is included. Among these, an alicyclic saturated hydrocarbon resin or a modified product thereof, an ethylene copolymer, or a wax, which is more effective when made porous, is more preferable, and a wax is more preferable from the viewpoint of moldability.
- Examples of alicyclic saturated hydrocarbon resins and modified products thereof include petroleum resins, rosin resins, terpene resins, coumarone resins, indene resins, coumarone-indene resins, and modified products thereof.
- the petroleum resin in the present invention is a C4 to C10 aliphatic olefin or diolefin obtained from a by-product such as by thermal decomposition of naphtha, or a C8 or more aromatic compound having an olefinically unsaturated bond.
- a by-product such as by thermal decomposition of naphtha
- a C8 or more aromatic compound having an olefinically unsaturated bond refers to aliphatic, aromatic and copolymer petroleum resins obtained by singly or copolymerizing one or more of the compounds contained in the above.
- Examples of petroleum resins include aliphatic petroleum resins mainly containing C5 fraction, aromatic petroleum resins mainly containing C9 fraction, copolymer petroleum resins thereof, and alicyclic petroleum resins.
- Examples of the terpene resin include terpene resins and terpene-phenol resins from ⁇ -pinene
- examples of the rosin resin include rosin resins such as gum rosin and utudridine, and esterified rosin resins modified with glycerin and pentaerythritol.
- the alicyclic saturated hydrocarbon resin and the modified product thereof have relatively good compatibility when mixed with a polyethylene resin, but a petroleum resin is more preferable in terms of color tone and thermal stability, and a hydrogenated petroleum resin is used. More preferably.
- Hydrogenated petroleum resin is obtained by hydrogenating petroleum resin by a conventional method.
- Examples thereof include hydrogenated aliphatic petroleum resins, hydrogenated aromatic petroleum resins, hydrogenated copolymer petroleum resins and hydrogenated alicyclic petroleum resins, and hydrogenated terpene resins.
- hydrogenated petroleum resins hydrogenated alicyclic petroleum resins obtained by copolymerizing and hydrogenating a cyclopentadiene compound and an aromatic vinyl compound are particularly preferable.
- Examples of commercially available hydrogenated petroleum resins include “ALCON” (manufactured by Arakawa Chemical Industries).
- the ethylene copolymer in the present invention is a compound obtained by copolymerizing ethylene and one or more of vinyl acetate, unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, or carboxylic acid ester. It is.
- the ethylene copolymer preferably has an ethylene monomer unit content of 50% by mass or more, more preferably 60% by mass or more, and still more preferably 65% by mass or more.
- the content of ethylene monomer units is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less. If the content of the ethylene monomer unit is within a predetermined range, a porous structure can be formed more efficiently.
- ethylene copolymer those having an MFR (JIS K7210, temperature: 190 ° C., load: 2.16 kg) of 0.1 g / 10 min to 10 g / 10 min are preferably used.
- MFR JIS K7210, temperature: 190 ° C., load: 2.16 kg
- the MFR is 0.1 g / 10 min or more, the extrudability can be maintained satisfactorily.
- the MFR is 10 g / 10 min or less, the strength of the film is hardly lowered, which is preferable.
- the ethylene-based copolymers are “EVAFLEX” (Mitsui / DuPont Polychemical Co., Ltd.), “Novatech EVA” (Nippon Polyethylene Co., Ltd.) as an ethylene-vinyl acetate copolymer, and “NUC” as an ethylene-acrylic acid copolymer.
- the wax in the present invention is an organic compound that satisfies the following properties (a) and (b).
- the melting point is 40 ° C to 200 ° C.
- the melt viscosity at a temperature 10 ° C. higher than the melting point is 50 Pa ⁇ s or less.
- ⁇ For wax including polar or nonpolar wax, polypropylene wax, polyethylene wax and wax modifier.
- paraffin wax, polyethylene wax, and microcrystalline wax are preferable from the viewpoint of efficiently forming a porous structure, and microcrystalline wax that can further reduce the pore diameter is more preferable from the viewpoint of SD characteristics.
- examples of commercially available polyethylene wax include “FT-115” (manufactured by Nippon Seiwa), and examples of microcrystalline wax include “Hi-Mic” (manufactured by Nippon Seiwa).
- the blending amount of the porosity promoting compound X is set as a lower limit with respect to 100 parts by mass of the polyethylene resin contained in one layer when peeling the interface between the polyethylene resin and the porosity promoting compound X to form micropores. 1 part by mass or more is preferable, 5 parts by mass or more is more preferable, and 10 parts by mass or more is still more preferable.
- the upper limit is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and still more preferably 30 parts by mass or less.
- thermoplastic resin may be used as long as the thermal characteristics of the porous film, specifically, the porosity is not impaired.
- thermoplastic resins include styrene resins such as styrene, AS resin, and ABS resin: polyvinyl chloride, fluorine resin, polyethylene terephthalate, polybutylene terephthalate, and polycarbonate.
- ester resins such as polyarylate
- Ether resins such as polyacetal, polyphenylene ether, polysulfone, polyethersulfone, polyetheretherketone or polyphenylene sulfide
- polyamides such as 6 nylon, 6-6 nylon, 6-12 nylon
- thermoplastic resins such as resins.
- thermoplastic elastomer examples include styrene / butadiene, polyolefin, urethane, polyester, polyamide, 1,2-polybutadiene, polyvinyl chloride, and ionomer.
- additives or other components that are generally blended in the resin composition may be included.
- the additive include recycling resin, silica, talc, kaolin, carbonic acid, etc., which are added for the purpose of improving / adjusting the processability, productivity, and various physical properties of the laminated porous film.
- Inorganic particles such as calcium, pigments such as titanium oxide and carbon black, flame retardants, weathering stabilizers, heat stabilizers, antistatic agents, melt viscosity improvers, crosslinking agents, lubricants, nucleating agents, plasticizers, anti-aging agents And additives such as antioxidants, light stabilizers, ultraviolet absorbers, neutralizers, antifogging agents, antiblocking agents, slip agents, and coloring agents.
- the nucleating agent is preferable because it has an effect of controlling the crystal structure of the polyethylene resin and reducing the porous structure at the time of stretching and opening.
- Examples of commercially available products include “Gelall D” (manufactured by Shin Nippon Chemical Co., Ltd.), “Adeka Stub” (manufactured by Asahi Denka Kogyo Co., Ltd.), “Hyperform” (manufactured by Milliken Chemical Co., Ltd.), or “IRGACLEAR D” (Ciba Special Chemicals). Etc.).
- “Rike Master” manufactured by Riken Vitamin Co., Ltd.
- the like are commercially available.
- the polyolefin-based resin porous film may be a single layer or a laminate, but is preferably laminated in two or more layers. Especially, what laminated
- the layer structure of the polyolefin resin porous film is not particularly limited as long as at least one layer containing a polypropylene resin (hereinafter referred to as “A layer”) is present.
- other layers hereinafter referred to as “B layer” can be laminated as long as they do not interfere with the function of the polyolefin resin porous film.
- strength maintenance layer, the heat-resistant layer (high melting temperature resin layer), the shutdown layer (low melting temperature resin layer), etc. are mentioned.
- a low melting point resin layer that ensures the safety of the battery is laminated by closing the hole in a high temperature atmosphere as described in JP-A No. 04-181651.
- Specific examples include a two-layer structure in which A layers / B layers are stacked, a three-layer structure in which A layers / B layers / A layers, or B layers / A layers / B layers are stacked.
- the physical properties of the polyolefin resin porous film of the present invention can be freely adjusted by the layer constitution, lamination ratio, composition of each layer, and production method.
- the method for producing the non-porous film is not particularly limited, and a known method may be used. For example, a method of melting a thermoplastic resin composition using an extruder, extruding from a T die, and cooling and solidifying with a cast roll. Is mentioned. Moreover, the method of cutting open the film-like thing manufactured by the tubular method and making it planar is also applicable.
- There are methods for stretching the nonporous film-like material such as a roll stretching method, a rolling method, a tenter stretching method, and a simultaneous biaxial stretching method, and these methods are used alone or in combination of two or more to perform uniaxial stretching or biaxial stretching. . Among these, sequential biaxial stretching is preferable from the viewpoint of controlling the porous structure.
- the production method is roughly classified into the following four types depending on the order of porous formation and lamination.
- (I) A method in which each layer is made porous, and then the layers made porous are laminated or bonded with an adhesive or the like.
- (II) A method of laminating each layer to produce a laminated nonporous film-like material, and then making the nonporous film-like material porous.
- (III) A method in which one of the layers is made porous and then laminated with another layer of a nonporous film to make it porous.
- (IV) A method of forming a laminated porous film by preparing a porous layer and then applying a coating such as inorganic / organic particles or depositing metal particles.
- a coating such as inorganic / organic particles or depositing metal particles.
- a method of forming a porous layer after preparing is particularly preferable.
- a mixed resin composition of a polypropylene resin and, if necessary, a thermoplastic resin and additives is prepared.
- raw materials such as polypropylene resin, ⁇ crystal nucleating agent, and other additives as required, preferably using Henschel mixer, super mixer, tumbler type mixer, etc., or by hand-blending all ingredients in a bag
- the mixture is melt-kneaded with a single-screw or twin-screw extruder, a kneader or the like, preferably a twin-screw extruder, and then cut to obtain pellets.
- the pellets are put into an extruder and extruded from a T-die extrusion die to form a film.
- the type of T die is not particularly limited.
- the T die may be a multi-manifold type for two types and three layers or a feed block type for two types and three layers.
- the gap of the T die to be used is determined from the final required film thickness, stretching conditions, draft ratio, various conditions, etc., but is generally about 0.1 to 3.0 mm, preferably 0.5. -1.0 mm. If it is less than 0.1 mm, it is not preferable from the viewpoint of production speed, and if it is more than 3.0 mm, it is not preferable from the viewpoint of production stability because the draft rate increases.
- the extrusion temperature is appropriately adjusted depending on the flow characteristics and moldability of the resin composition, but is generally preferably 180 to 350 ° C, more preferably 200 to 330 ° C, and further preferably 220 to 300 ° C.
- a temperature of 180 ° C. or higher is preferable because the viscosity of the molten resin is sufficiently low and the moldability is excellent and the productivity is improved.
- the cooling and solidification temperature by the cast roll is very important in the present invention, and the ratio of the ⁇ crystal of the polypropylene resin in the film can be adjusted.
- the cooling and solidifying temperature of the cast roll is preferably 80 to 150 ° C, more preferably 90 to 140 ° C, and still more preferably 100 to 130 ° C. It is preferable to set the cooling and solidification temperature to 80 ° C. or higher because the ratio of ⁇ crystals in the film can be sufficiently increased. Further, it is preferable to set the temperature to 150 ° C. or lower because troubles such as the extruded molten resin sticking to and wrapping around the cast roll hardly occur and the film can be efficiently formed into a film.
- the ⁇ crystal ratio of the polypropylene resin of the film-like material before stretching is adjusted to 30 to 100% by setting a cast roll in the temperature range. More preferably, it is 40 to 100%, more preferably 50 to 100%, and most preferably 60 to 100%.
- a polyolefin-based resin porous film having good gas permeability can be obtained because it is easily made porous by the subsequent stretching operation.
- the ⁇ crystal ratio in the film before stretching is detected when the film is heated from 25 ° C. to 240 ° C. at a heating rate of 10 ° C./min using a differential scanning calorimeter.
- uniaxial stretching may be performed in the longitudinal direction or the transverse direction, or biaxial stretching may be performed.
- biaxial stretching simultaneous biaxial stretching may be sufficient and sequential biaxial stretching may be sufficient.
- sequential biaxial stretching is more preferable because the stretching conditions can be selected in each stretching step and the porous structure can be easily controlled.
- Biaxial stretching may be simultaneous biaxial stretching or sequential biaxial stretching, but the stretching conditions (magnification, temperature) can be easily selected in each stretching step, and the porous structure can be easily controlled. Biaxial stretching is more preferable.
- the longitudinal direction of the film-like material and the film is referred to as “longitudinal direction”, and the direction perpendicular to the longitudinal direction is referred to as “lateral direction”.
- stretching in the longitudinal direction is referred to as “longitudinal stretching”
- stretching in the direction perpendicular to the longitudinal direction is referred to as “lateral stretching”.
- the stretching temperature needs to be appropriately selected depending on the composition of the resin composition to be used and the crystallization state, but it is preferable to select within the range of the following conditions.
- the stretching temperature needs to be changed appropriately depending on the composition of the resin composition to be used, the crystal melting peak temperature, the crystallinity, etc., but the stretching temperature in the longitudinal stretching is preferably about 0 to 130 ° C., More preferably, it is controlled in the range of 10 to 120 ° C., more preferably 20 to 110 ° C.
- the longitudinal draw ratio is preferably 2 to 10 times, more preferably 3 to 8 times, still more preferably 4 to 7 times.
- the stretching temperature in transverse stretching is generally from 100 to 160 ° C., preferably from 110 to 150 ° C., more preferably from 120 to 140 ° C. Further, the preferred transverse draw ratio is 1.2 to 10 times, more preferably 1.5 to 8 times, and still more preferably 2 to 7 times.
- the stretching speed in the stretching step is preferably 500 to 12000% / min, more preferably 1500 to 10,000% / min, and further preferably 2500 to 8000% / min.
- the laminated porous film thus obtained is preferably subjected to heat treatment for the purpose of improving dimensional stability.
- the effect of dimensional stability can be expected by setting the temperature to preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and still more preferably 140 ° C. or higher.
- the heat treatment temperature is preferably 170 ° C. or lower, more preferably 165 ° C. or lower, and further preferably 160 ° C. or lower.
- the heat treatment temperature is 170 ° C. or lower, it is preferable because the heat treatment hardly melts polypropylene and maintains a porous structure.
- a relaxation treatment of 1 to 20% may be performed as necessary.
- a laminated porous film is obtained by cooling uniformly and winding up after heat processing.
- Heat resistant layer a heat-resistant layer containing a filler (a), a resin binder (b), and a stretching aid (c) is laminated on at least one surface of a polyolefin resin porous film.
- Filler (a) examples of the filler (a) that can be used in the present invention include inorganic fillers and organic fillers, but are not particularly limited.
- inorganic fillers include carbonates such as calcium carbonate, magnesium carbonate and barium carbonate; sulfates such as calcium sulfate, magnesium sulfate and barium sulfate; chlorides such as sodium chloride, calcium chloride and magnesium chloride, aluminum oxide and oxidation
- oxides such as calcium, magnesium oxide, zinc oxide, titanium oxide, and silica
- silicates such as talc, clay, and mica can be used.
- barium sulfate and aluminum oxide are preferable.
- organic fillers include ultra high molecular weight polyethylene, polystyrene, polymethyl methacrylate, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polysulfone, polyethersulfone, polyetheretherketone, polytetrafluoroethylene, polyimide, polyether.
- examples thereof include thermoplastic resins such as imide, melamine, and benzoguanamine, and thermosetting resins. Among these, cross-linked polystyrene and the like are particularly preferable.
- the average particle diameter of the filler (a) is preferably 0.1 ⁇ m or more, more preferably 0.2 ⁇ m or more, still more preferably 0.3 ⁇ m or more, and the upper limit is preferably 3.0 ⁇ m or less, more preferably 1 .5 ⁇ m or less. Sufficient heat resistance can be exhibited when the average particle diameter is within the specified range. Moreover, it is more preferable from a viewpoint of the dispersibility in the porous layer of a filler (a) that an average particle diameter shall be 1.5 micrometers or less.
- the “average particle diameter of the inorganic filler” is a value measured according to a method using SEM.
- the filler (a) and the polyolefin resin porous film can be favorably bonded are electrochemically stable, and the laminated porous film is a non-aqueous electrolyte solution.
- the non-aqueous electrolyte there is no particular limitation as long as it is stable with respect to the non-aqueous electrolyte.
- ethylene-acrylic acid copolymer such as ethylene-vinyl acetate copolymer (EVA, whose structural unit derived from vinyl acetate is 20 to 35 mol%), ethylene-ethyl acrylate copolymer, fluorine, etc.
- Resins polyvinylidene fluoride (PVDF), etc.], fluorinated rubber, styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), polybutadiene rubber (BR), polyacrylonitrile (PAN), polyacrylic acid (PAA), carboxy Examples thereof include methyl cellulose (CMC), hydroxyethyl cellulose (HEC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyvinyl pyrrolidone (PVP), poly N-vinylacetamide, cross-linked acrylic resin, polyurethane, and epoxy resin. These organic binders may be used alone or in combination of two or more.
- polyvinyl alcohol polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, and polyacrylic acid are preferable, and polyvinyl alcohol is more preferable from the viewpoint of heat resistance and stretchability.
- the stretching aid (c) is used for the purpose of improving the stretchability of the heat-resistant layer during stretching.
- the stretching aid (c) a resin or solvent compatible with the resin binder (b) is mainly used.
- the stretching aid (c) preferably has a boiling point of 120 ° C. or higher, or preferably has no boiling point, more preferably 150 ° C. or higher, and still more preferably 180 ° C. or higher.
- the stretching aid (c) has a boiling point of 120 ° C. or higher, volatilization of the stretching aid (c) generated during stretching can be sufficiently suppressed, and the heat-resistant layer can be uniformly stretched.
- Specific examples of the stretching aid (c) include xylene, styrene, chlorobenzene, ether alcohol, glycol, glycol polymer, modified glycol polymer, glycerin, and phthalate.
- glycol, glycol polymer, modified polymer of glycol polymer, and glycerin More preferably, at least one selected from the group consisting of:
- glycols include ethylene glycol (HOCH 2 CH 2 OH), propylene glycol (HOCH 2 CH (OH) CH 3 ), diethylene glycol (HOCH 2 CH 2 OCH 2 CH 2 OH), 1,3-propanediol (HOCH 2 CH 2 CH 2 OH), 1,2-butanediol (HOCH 2 CH (OH) CH 2 CH 3 ), 1,3-butanediol (HOCH 2 CH 2 CH (OH) CH 3 ), 1,4-butanediol (HOCH 2 (CH 2 ) 2 CH 2 OH), 2,3-butanediol (CH 3 CH (OH) CH (OH) CH 3 ), 1,2-pentadiol (HOCH 2 CH (OH) CH 2 CH 2 CH 3), 1,5- pentanediol (HOCH 2 (CH 2) 3 CH 2 OH), 1,2- hexane All (HOCH 2 CH (OH) CH 2 CH 2 CH 3), 1,6- hexanedio
- glycol polymer examples include polyethylene glycol (HO (CH 2 CH 2 O) n H), polypropylene glycol (HO (CH 2 CH 2 CH 2 O) n H), and the like.
- polyethylene glycol can be preferably used. Since polyethylene glycols having various degrees of polymerization exist, the average molecular weight is generally used as an index. The range of the average molecular weight is preferably 200 to 20000. If the average molecular weight is 200 or more, it is compatible with polyvinyl alcohol, so that stretchability is improved. When the average molecular weight exceeds 20000, it is not compatible with polyvinyl alcohol, and the effect of improving stretchability cannot be obtained.
- modified polymers of glycol polymers include polyethylene glycol dimethyl ether (CH 3 (CH 2 CH 2 O) n CH 3 ), polyethylene glycol distearate, polyethylene glycol divinyl ether (H 2 C ⁇ CH (OCH 2 CH 2 ).
- n OCH CH 2
- the stretching aid (c) it is preferable to use a resin compatible with the resin binder (b) in addition to glycol, glycol polymer, modified glycol polymer, and glycerin.
- a resin compatible with the resin binder (b) examples thereof include carboxymethyl cellulose, acrylic acid ester, glue, casein, sodium alginate, chitosan, gelatin, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, polyethylene oxide and the like.
- the content of the filler (a) is preferably 100% by mass or more, and more preferably 200% by mass or more with respect to 100% by mass of the resin binder (b).
- the content of the filler (a) is 100% by mass or more with respect to 100% by mass of the resin binder (b)
- a laminated porous film having connectivity can be produced and excellent air permeability can be exhibited. Is preferable.
- the content rate of the said filler (a) is 1500 mass% or less, since generation
- the content of the stretching aid (c) is preferably 5% by mass or more, and more preferably 8% by mass or more with respect to 100% by mass of the resin binder (b).
- the content of the stretching aid (c) is 5% by mass or more with respect to 100% by mass of the resin binder (b)
- sufficient stretchability is obtained.
- it is 200 mass% or less since sufficient handling property is obtained, it is preferable.
- the laminated porous film of the present invention is obtained by applying a dispersion in which the filler (a) and the resin binder (b) are dissolved or dispersed in a solvent to at least one surface of the polyolefin-based resin porous film. It can be produced by forming a heat-resistant layer on the surface of the resin porous film.
- the solvent it is preferable to use a solvent in which the filler (a) and the resin binder (b) can be dissolved or dispersed uniformly and stably.
- a solvent include N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, water, ethanol, toluene, hot xylene, and hexane.
- the dispersion includes a dispersant such as a surfactant, a thickener, a wetting agent, an antifoaming agent.
- additives such as an agent, a pH adjusting agent including an acid and an alkali may be added.
- the additive is preferably one that can be removed upon solvent removal or plasticizer extraction, but is electrochemically stable in the range of use of the nonaqueous electrolyte secondary battery, does not inhibit the battery reaction, and is about 200 ° C. If it is stable, it may remain in the battery (in the laminated porous film).
- a method for dissolving or dispersing the filler (a) and the resin binder (b) in a solvent for example, a ball mill, a bead mill, a planetary ball mill, a vibrating ball mill, a sand mill, a colloid mill, an attritor, a roll mill, a high-speed impeller dispersion, Examples thereof include a disperser, a homogenizer, a high-speed impact mill, ultrasonic dispersion, and a mechanical stirring method using stirring blades.
- the method for applying the dispersion to the surface of the polyolefin resin porous film may be after the extrusion molding, after the longitudinal stretching step, or after the transverse stretching step. Also good. In particular, after the extrusion molding or after the longitudinal stretching step, the drying step and the stretching step can be performed simultaneously.
- the application method in the application step is not particularly limited as long as it can realize a required layer thickness and application area.
- coating methods include gravure coater method, small diameter gravure coater method, reverse roll coater method, transfer roll coater method, kiss coater method, dip coater method, knife coater method, air doctor coater method, blade coater method, rod Examples include a coater method, a squeeze coater method, a cast coater method, a die coater method, a screen printing method, and a spray coating method.
- the said dispersion liquid may be apply
- the solvent is preferably a solvent that can be removed from the dispersion applied to the polyolefin resin porous film.
- a method for removing the solvent any method that does not adversely affect the polyolefin resin porous film can be adopted without any particular limitation.
- a method for removing the solvent for example, a method of drying at a temperature below its melting point while fixing a polyolefin-based resin porous film, a method of drying under reduced pressure at a low temperature, a resin immersed in a poor solvent for the resin binder (b) Examples include a method of coagulating the binder (b) and extracting the solvent at the same time.
- the laminated porous film of the present invention can be manufactured using a method different from the above-described manufacturing method.
- the raw material for polyolefin resin porous film is introduced into one extruder, the raw material for the heat-resistant layer is introduced into the other extruder, integrated with a single die, and a laminated film is formed. It is also possible to adopt a processing method.
- the film thickness of the laminated porous film of the present invention is preferably 5 to 100 ⁇ m. More preferably, it is 8 to 50 ⁇ m, and still more preferably 10 to 30 ⁇ m.
- the film thickness of the laminated porous film of the present invention is preferably 5 to 100 ⁇ m. More preferably, it is 8 to 50 ⁇ m, and still more preferably 10 to 30 ⁇ m.
- it is 5 ⁇ m or more, substantially necessary electrical insulation can be obtained. For example, even when a large force is applied to the protruding portion of the electrode, Breaks through the separator for the electrolyte secondary battery and is not easily short-circuited.
- the electrical resistance of a laminated porous film can be made small if a film thickness is 100 micrometers or less, the performance of a battery can fully be ensured.
- the thickness of the heat-resistant layer is preferably 0.5 ⁇ m or more, more preferably 2 ⁇ m or more, still more preferably 3 ⁇ m or more, and particularly preferably 4 ⁇ m or more from the viewpoint of heat resistance.
- the upper limit is preferably 90 ⁇ m or less, more preferably 50 ⁇ m or less, still more preferably 30 ⁇ m or less, and particularly preferably 10 ⁇ m or less from the viewpoint of communication.
- the porosity is preferably 30% or more, more preferably 35% or more, and further preferably 40% or more. If the porosity is 30% or more, it is possible to obtain a laminated porous film that ensures communication and has excellent air permeability.
- the upper limit is preferably 70% or less, more preferably 65% or less, and still more preferably 60% or less. If the porosity is 70% or less, the strength of the laminated porous film is hardly lowered, which is preferable from the viewpoint of handling. The porosity is measured by the method described in the examples.
- the air permeability of the laminated porous film of the present invention is preferably 2000 seconds / 100 ml or less, more preferably 10 to 10,000 seconds / 100 ml, and further preferably 50 to 800 seconds / 100 ml.
- An air permeability of 2000 seconds / 100 ml or less is preferable because it indicates that the laminated porous film has communication properties and can exhibit excellent air permeability.
- the air permeability represents the difficulty in passing through the air in the film thickness direction, and is specifically expressed by the number necessary for 100 ml of air to pass through the film. Therefore, it means that the smaller the numerical value is, the easier it is to pass through, and the higher numerical value is, the more difficult it is to pass.
- the air permeability of the laminated porous film of the present invention is low, it can be used for various applications. For example, when used as a battery separator, a low air permeability means that lithium ions can be easily transferred, which is preferable because battery performance is excellent.
- the laminated porous film of the present invention preferably has SD characteristics when used as a battery separator.
- the air permeability after heating at 135 ° C. for 5 seconds is preferably 10,000 seconds / 100 ml or more, more preferably 25000 seconds / 100 ml or more, and further preferably 50000 seconds / 100 ml or more.
- a nonaqueous electrolyte secondary battery containing the laminated porous film of the present invention as a battery separator will be described with reference to FIG.
- Both electrodes of the positive electrode plate 21 and the negative electrode plate 22 are wound in a spiral shape so as to overlap each other via the battery separator 10, and the outside is stopped with a winding tape to form a wound body.
- the winding process will be described in detail.
- One end of the battery separator is passed through the slit portion of the pin, and the pin is slightly rotated to wind one end of the battery separator around the pin. At this time, the surface of the pin is in contact with the heat-resistant layer of the battery separator.
- the positive electrode and the negative electrode are arranged so as to sandwich the battery separator, and the pins are rotated by a winding machine to wind the positive and negative electrodes and the battery separator. After winding, the pin is pulled out of the wound object.
- the wound body in which the positive electrode plate 21, the battery separator 10 and the negative electrode plate 22 are integrally wound is accommodated in a bottomed cylindrical battery case and welded to the positive and negative electrode lead bodies 24 and 25.
- the electrolyte is injected into the battery can, and after the electrolyte has sufficiently penetrated into the battery separator 10 or the like, the positive electrode lid 27 is sealed around the opening periphery of the battery can via the gasket 26, and precharging and aging are performed.
- a cylindrical non-aqueous electrolyte secondary battery is manufactured.
- an electrolytic solution in which a lithium salt is used as an electrolytic solution and is dissolved in an organic solvent is used.
- the organic solvent is not particularly limited.
- esters such as propylene carbonate, ethylene carbonate, butylene carbonate, ⁇ -butyrolactone, ⁇ -valerolactone, dimethyl carbonate, methyl propionate or butyl acetate, and nitriles such as acetonitrile.
- ethers such as tetrahydrofuran, 2-methyltetrahydrofuran or 4-methyl-1,3-dioxolane, or sulfolane.
- LiPF 6 lithium hexafluorophosphate
- an alkali metal or an alkali metal compound integrated with a current collecting material such as a stainless steel net is used as the negative electrode.
- the alkali metal include lithium, sodium, and potassium.
- the compound containing an alkali metal include an alloy of an alkali metal and aluminum, lead, indium, potassium, cadmium, tin or magnesium, a compound of an alkali metal and a carbon material, a low potential alkali metal and a metal oxide, and the like. Or a compound with a sulfide or the like.
- the carbon material may be any material that can be doped and dedoped with lithium ions, such as graphite, pyrolytic carbons, cokes, glassy carbons, a fired body of an organic polymer compound, Mesocarbon microbeads, carbon fibers, activated carbon and the like can be used.
- a carbon material having an average particle size of 10 ⁇ m is mixed with a solution in which vinylidene fluoride is dissolved in N-methylpyrrolidone to form a slurry, and this negative electrode mixture slurry is passed through a 70-mesh net. After removing the large particles, uniformly apply to both sides of the negative electrode current collector made of a strip-shaped copper foil having a thickness of 18 ⁇ m and dry, and then compression-molded with a roll press machine, cut, strip-shaped negative electrode plate and We use what we did.
- lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, manganese dioxide, metal oxide such as vanadium pentoxide or chromium oxide, metal sulfide such as molybdenum disulfide, etc. are used as active materials.
- These positive electrode active materials are combined with conductive additives and binders such as polytetrafluoroethylene as appropriate, and finished with a current collector material such as a stainless steel mesh as a core material. It is done.
- a strip-like positive electrode plate produced as follows is used as the positive electrode. That is, lithium graphite oxide (LiCoO 2 ) is added with phosphorous graphite as a conductive additive at a mass ratio of 90: 5 (lithium cobalt oxide: phosphorous graphite) and mixed, and this mixture and polyvinylidene fluoride are mixed with N Mix with a solution in methylpyrrolidone to make a slurry.
- This positive electrode mixture slurry is passed through a 70-mesh net to remove large particles, and then uniformly applied to both sides of a positive electrode current collector made of an aluminum foil having a thickness of 20 ⁇ m, dried, and then compressed by a roll press. After forming, it is cut into a strip-like positive electrode plate.
- the longitudinal direction of the laminated porous film is referred to as “longitudinal direction”, and the direction perpendicular to the longitudinal direction is referred to as “lateral direction”.
- Air permeability (Gurley value) The air permeability (second / 100 ml) was measured according to JIS P8117.
- the laminated porous film is made of two aluminum plates in the center of an oil bath (manufactured by ASONE, OB-200A) filled with glycerin (manufactured by Nacalai Tesque, grade 1) until it reaches 100 mm from the bottom.
- the sample in a state constrained to was immersed and heated for 5 seconds. Immediately after heating, it is immersed in a separately prepared cooling bath filled with 25 ° C. glycerin and cooled for 5 minutes, and then washed with 2-propanol (manufactured by Nacalai Tesque, special grade) and acetone (manufactured by Nacalai Tesque, special grade). And dried in an air atmosphere at 25 ° C. for 15 minutes. The air permeability of the sample after drying was measured according to the method (2).
- the obtained laminated porous film was cut into a 60 mm ⁇ 60 mm square, and as shown in FIG. 2 (A), an aluminum plate (material: JIS A5052, (Size: 60 mm length, 60 mm width, 1 mm thickness) was sandwiched between two sheets, and the periphery was fixed with clips as shown in FIG. 2 (B).
- a sample in which the laminated porous film is constrained by two aluminum plates is placed in a constant temperature incubator (Tabai Espec Corp., Tabai Gear Oven GPH200) at a set temperature of 180 ° C and a display temperature of 180 ° C, and held for 3 minutes.
- the shape maintenance performance was judged by checking the state of the laminated porous film.
- ⁇ shape maintained without rupture
- ⁇ shape cannot be maintained due to rupture
- the obtained laminated porous film was evaluated for ⁇ crystal activity as follows.
- DSC Differential scanning calorimetry
- the obtained laminated porous film was heated from 25 ° C. to 240 ° C. at a scanning speed of 10 ° C./min for 1 minute using a differential scanning calorimeter (DSC-7) manufactured by Perkin Elmer, and then held for 240 minutes.
- the temperature was lowered from 0 ° C. to 25 ° C. at a scanning rate of 10 ° C./min and held for 1 minute, and then heated again from 25 ° C. to 240 ° C. at a scanning rate of 10 ° C./min.
- Tm ⁇ crystal melting peak temperature
- the temperature was changed to 100 ° C., and the mixture was gradually cooled to 100 ° C. over 10 minutes or more.
- the display temperature reaches 100 ° C.
- the sample is taken out and cooled for 5 minutes in an atmosphere of 25 ° C. while being restrained by two aluminum plates.
- Wide-angle X-ray diffraction measurement was performed on a 40 mm ⁇ circular portion.
- -Wide-angle X-ray diffraction measurement device manufactured by Mac Science, model number: XMP18A X-ray source: CuK ⁇ ray, output: 40 kV, 200 mA Scanning method: 2 ⁇ / ⁇ scan, 2 ⁇ range: 5 ° to 25 °, scanning interval: 0.05 °, scanning speed: 5 ° / min
- the presence or absence of ⁇ crystal activity was evaluated as follows from the peak derived from the (300) plane of ⁇ crystal of the polypropylene resin.
- the strand was cut with a cutter to produce a polypropylene resin composition pellet.
- the ⁇ -crystal activity of the polypropylene resin composition was 80%.
- polyethylene resin composition that constitutes layer B 100 parts by mass of high-density polyethylene (Nippon Polytech Co., Ltd., Novatec HD HF560, density: 0.963 g / cm 3 , MFR: 7.0 g / 10 min) is added to glycerin. 0.04 parts by mass of monoester and 10 parts by mass of microcrystalline wax (Nippon Seiwa Co., Ltd., Hi-Mic 1080) were added and melt-kneaded at 220 ° C. using the same type twin-screw extruder. Resin composition pellets were prepared.
- the polypropylene resin composition Using the polypropylene resin composition, it was extruded from a T-die and cooled and solidified with a casting roll at 124 ° C. to prepare a nonporous film-like material.
- the non-porous film-like material was stretched 4.6 times in the longitudinal direction using a longitudinal stretching machine and subjected to corona surface treatment.
- the dispersions shown in the following examples and comparative examples were applied with a Mayer bar (NO.10), and stretched 2.3 times in the transverse direction at 150 ° C. with a transverse stretching machine, followed by heat setting / relaxation treatment. was performed to obtain a laminated porous film.
- Example 1 25.1 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, saponification degree: 98.0 to 99.0, average polymerization degree) : 2400) 1.9 parts by mass, polyethylene glycol (manufactured by Nacalai Tesque, polyethylene glycol # 200, average molecular weight 190-210) was dispersed in 72.5 parts by mass of water to obtain a dispersion.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, saponification degree: 98.0 to 99.0, average polymerization degree
- polyethylene glycol manufactured by Nacalai Tesque, polyethylene glycol # 200, average molecular weight 190
- the contents of the filler (a) and the stretching aid (c) contained in the dispersion were 1321% by mass and 26% by mass, respectively, with respect to 100% by mass of the resin binder (b). It was.
- physical properties of the laminated porous film obtained in Production Example 1 were evaluated, and the results are summarized in Table 1.
- Example 2 25.1 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, saponification degree: 98.0 to 99.0, average polymerization degree) : 2400) 1.9 parts by mass, polyethylene glycol (manufactured by Nacalai Tesque, polyethylene glycol # 200, average molecular weight 190 to 210) 1.9 parts by mass was dispersed in 71.1 parts by mass of water to obtain a dispersion.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, saponification degree: 98.0 to 99.0, average polymerization degree
- polyethylene glycol manufactured by Nacalai Tesque, polyethylene glycol # 200, average
- the contents of the filler (a) and the stretching aid (c) contained in the dispersion were 1321% by mass and 100% by mass, respectively, with respect to 100% by mass of the resin binder (b). It was.
- physical properties of the laminated porous film obtained in Production Example 1 were evaluated, and the results are summarized in Table 1.
- Example 3 23.8 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization) : 2400) 3.2 parts by mass of polyethylene glycol (manufactured by Nacalai Tesque, polyethylene glycol # 200, average molecular weight 190-210) was dispersed in 72.7 parts by mass of water to obtain a dispersion.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization
- Example 4 23.8 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization) : 2400) 3.2 parts by mass of polyethylene glycol (manufactured by Nacalai Tesque, polyethylene glycol # 200, average molecular weight 190-210) was dispersed in 72.2 parts by mass of water to obtain a dispersion.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization
- the contents of the filler (a) and the stretching aid (c) contained in the dispersion were 744 mass% and 25 mass%, respectively, with respect to 100 mass% of the resin binder (b). It was.
- physical properties of the laminated porous film obtained in Production Example 1 were evaluated, and the results are summarized in Table 1.
- Example 5 23.8 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization) : 2400) 3.2 parts by mass of polyethylene glycol (manufactured by Nacalai Tesque, polyethylene glycol # 1500, average molecular weight 1300 to 1600) 0.8 parts by mass was dispersed in 72.2 parts by mass of water to obtain a dispersion.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization
- the contents of the filler (a) and the stretching aid (c) contained in the dispersion were 744 mass% and 25 mass%, respectively, with respect to 100 mass% of the resin binder (b). It was.
- physical properties of the laminated porous film obtained in Production Example 1 were evaluated, and the results are summarized in Table 1.
- Example 6 23.8 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization) : 2400)
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization
- the contents of the filler (a) and the stretching aid (c) contained in the dispersion were 744 mass% and 25 mass%, respectively, with respect to 100 mass% of the resin binder (b). It was.
- physical properties of the laminated porous film obtained in Production Example 1 were evaluated, and the results are summarized in Table 1.
- Example 7 25.1 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, saponification degree: 98.0 to 99.0, average polymerization degree) : 2400) A dispersion in which 1.9 parts by mass and 0.5 part by mass of glycerin (manufactured by Nacalai Tesque) were dispersed in 72.5 parts by mass of water was obtained.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, saponification degree: 98.0 to 99.0, average polymerization degree
- the contents of the filler (a) and the stretching aid (c) contained in the dispersion were 1321% by mass and 26% by mass, respectively, with respect to 100% by mass of the resin binder (b). It was.
- physical properties of the laminated porous film obtained in Production Example 1 were evaluated, and the results are summarized in Table 1.
- Example 8 23.8 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization) : 2400)
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization
- Example 9 18.1 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization) : 2400) 8.9 parts by mass, polyethylene glycol (manufactured by Nacalai Tesque, polyethylene glycol # 200, average molecular weight 190 to 210) 2.2 parts by mass was dispersed in 70.8 parts by mass of water to obtain a dispersion.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization
- Example 10 23.8 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization) : 2400) 3.2 parts by mass of polyethylene glycol dimethyl ether (Sigma Aldrich, average molecular weight ⁇ 250) 0.8 parts by mass was dispersed in 72.2 parts by mass of water to obtain a dispersion.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization
- 2400 3.2 parts by mass of polyethylene glycol dimethyl ether (Sigma Aldrich, average molecular weight
- the contents of the filler (a) and the stretching aid (c) contained in the dispersion were 744 mass% and 25 mass%, respectively, with respect to 100 mass% of the resin binder (b). It was.
- physical properties of the laminated porous film obtained in Production Example 1 were evaluated, and the results are summarized in Table 1.
- Example 11 18.1 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization) : 2400) 8.9 parts by mass, polyethylene glycol dimethyl ether (manufactured by Sigma-Aldrich, average molecular weight ⁇ 250) 2.2 parts by mass was dispersed in 70.8 parts by mass of water to obtain a dispersion.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization
- polyethylene glycol dimethyl ether manufactured by Sigma-Aldrich, average molecular
- Example 12 24.3 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization) : 2400) 2.7 parts by mass, polyethylene glycol (manufactured by Nacalai Tesque, polyethylene glycol # 200, average molecular weight 190 to 210) 0.7 parts by mass was dispersed in 72.3 parts by mass of water to obtain a dispersion.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization
- the contents of the filler (a) and the stretching aid (c) contained in the dispersion were 900% by mass and 26% by mass, respectively, with respect to 100% by mass of the resin binder (b). It was.
- physical properties of the laminated porous film obtained in Production Example 2 were evaluated, and the results are summarized in Table 1.
- Example 13 23.8 parts by mass of alumina (manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m), polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization) : 2400) 3.2 parts by mass of polyethylene glycol (manufactured by Nacalai Tesque, polyethylene glycol # 200, average molecular weight 190-210) was dispersed in 72.7 parts by mass of water to obtain a dispersion.
- alumina manufactured by Sumitomo Chemical Co., Sumiko Random AA-06, average particle size: 0.6 ⁇ m
- polyvinyl alcohol manufactured by Kuraray Co., Ltd., PVA124, degree of saponification: 98.0 to 99.0, average degree of polymerization
- the contents of the filler (a) and the stretching aid (c) contained in the dispersion were 87% by mass and 10% by mass, respectively, with respect to 100% by mass of the resin binder (b). It was.
- physical properties of the laminated porous film obtained in Production Example 1 were evaluated, and the results are summarized in Table 1.
- the laminated porous films obtained in the examples could all have excellent stretchability, heat resistance, and communication properties.
- the dispersing agent (c) was not included in the dispersant as in Comparative Examples 1 and 3, the stretchability was insufficient. Further, when the proportion of the resin binder (b) in the dispersant was increased as in Comparative Example 2, the stretchability was good, but the connectivity was insufficient. In addition, as in Comparative Example 4, when the filler (a) and the stretching aid (c) were not included in the dispersant, the connectivity and stretchability were insufficient. Moreover, when the filler (a) was not included in the dispersant as in Comparative Example 5, although the stretchability was good, the communication property was insufficient. Moreover, since the comparative examples 6 and 7 did not laminate
- the laminated porous film of the present invention can be applied to various uses that require air permeability.
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Abstract
Description
また、前記特許文献4で得た多孔フィルムは、フィラーの充填密度が低いために、耐熱性が低いという問題があった。
透気度が2000秒/100ml以下であることを特徴とする積層多孔フィルムである。
なお、本発明において、「主成分」と表現した場合には、特に記載しない限り、当該主成分の機能を妨げない範囲で他の成分を含有することを許容する意を包含し、特に当該主成分の含有割合を特定するものではないが、主成分は組成物中の50質量%以上、好ましくは70質量%以上、特に好ましくは90質量%以上(100%含む)を占める意を包含するものである。
また、「X~Y」(X,Yは任意の数字)と記載した場合、特にことわらない限り「X以上Y以下」の意と共に、「好ましくはXより大きい」及び「好ましくはYより小さい」の意を包含するものである。
ポリオレフィン系樹脂多孔フィルムで用いるポリオレフィン系樹脂として、エチレン、プロピレン、1-ブテン、4-メチル-1-ペンテン、1-ヘキサンなどを重合した単独重合体または共重合体が挙げられる。この中でも、ポリプロピレン系樹脂、ポリエチレン系樹脂が好ましい。
ポリプロピレン系樹脂としては、ホモプロピレン(プロピレン単独重合体)、またはプロピレンとエチレン、1-ブテン、1-ペンテン、1-へキセン、1-へプテン、1-オクテン、1-ノネンもしくは1-デセンなどα-オレフィンとのランダム共重合体またはブロック共重合体などが挙げられる。この中でも、積層多孔フィルムの機械的強度、耐熱性などを維持する観点から、ホモポリプロピレンがより好適に使用される。
アイソタクチックペンタッド分率(mmmm分率)とは、任意の連続する5つのプロピレン単位で構成される炭素-炭素結合による主鎖に対して側鎖である5つのメチル基がいずれも同方向に位置する立体構造あるいはその割合を意味する。メチル基領域のシグナルの帰属は、A.Zambelli et al(Macromolecules8,687,(1975))に準拠した。
β晶活性は、延伸前の膜状物においてポリプロピレン系樹脂がβ晶を生成していたことを示す一指標と捉えることができる。延伸前の膜状物中のポリプロピレン系樹脂がβ晶を生成していれば、フィラー等の添加剤を使用しない場合においても、延伸を施すことで微細孔が容易に形成されるため、透気特性を有する積層多孔フィルムを得ることができる。
具体的には、示差走査型熱量計で積層多孔フィルムを25℃から240℃まで加熱速度10℃/分で昇温後1分間保持し、次に240℃から25℃まで冷却速度10℃/分で降温後1分間保持し、更に25℃から240℃まで加熱速度10℃/分で再昇温させた際に、ポリプロピレン系樹脂のβ晶に由来する結晶融解ピーク温度(Tmβ)が検出された場合、β晶活性を有すると判断している。
β晶活性度(%)=〔ΔHmβ/(ΔHmβ+ΔHmα)〕×100
例えば、ポリプロピレン系樹脂がホモポリプロピレンの場合は、主に145℃以上160℃未満の範囲で検出されるβ晶由来の結晶融解熱量(ΔHmβ)と、主に160℃以上170℃以下に検出されるα晶由来の結晶融解熱量(ΔHmα)から計算することができる。また、例えばエチレンが1~4モル%共重合されているランダムポリプロピレンの場合は、主に120℃以上140℃未満の範囲で検出されるβ晶由来の結晶融解熱量(ΔHmβ)と、主に140℃以上165℃以下の範囲に検出されるα晶由来の結晶融解熱量(ΔHmα)から計算することができる。
β晶活性度の上限値は特に限定されないが、β晶活性度が高いほど前記効果がより有効に得られるので100%に近いほど好ましい。
詳細には、ポリプロピレン系樹脂の融点を超える温度である170℃~190℃の熱処理を施し、徐冷してβ晶を生成・成長させた積層多孔フィルムについて広角X線測定を行い、ポリプロピレン系樹脂のβ晶の(300)面に由来する回折ピークが2θ=16.0°~16.5°の範囲に検出された場合、β晶活性が有ると判断している。
ポリプロピレン系樹脂のβ晶構造と広角X線回折に関する詳細は、Macromol.Chem.187,643-652(1986)、Prog.Polym.Sci.Vol.16,361-404(1991)、Macromol.Symp.89,499-511(1995)、Macromol.Chem.75,134(1964)、及びこれらの文献中に挙げられた参考文献を参照することができる。広角X線回折を用いたβ晶活性の詳細な評価方法については、後述の実施例にて示す。
また、仮に、ポリプロピレン系樹脂からなる層以外に、ポリプロピレン系樹脂を含有する層などを積層させる場合には、両層ともにβ晶活性を有することが好ましい。
本発明で用いるβ晶核剤としては以下に示すものが挙げられるが、ポリプロピレン系樹脂のβ晶の生成・成長を増加させるものであれば特に限定される訳ではなく、また2種類以上を混合して用いても良い。
β晶核剤としては、例えば、アミド化合物;テトラオキサスピロ化合物;キナクリドン類;ナノスケールのサイズを有する酸化鉄;1,2-ヒドロキシステアリン酸カリウム、安息香酸マグネシウムもしくはコハク酸マグネシウム、フタル酸マグネシウムなどに代表されるカルボン酸のアルカリもしくはアルカリ土類金属塩;ベンゼンスルホン酸ナトリウムもしくはナフタレンスルホン酸ナトリウムなどに代表される芳香族スルホン酸化合物;二もしくは三塩基カルボン酸のジもしくはトリエステル類;フタロシアニンブルーなどに代表されるフタロシアニン系顔料;有機二塩基酸である成分Aと周期律表第IIA族金属の酸化物、水酸化物もしくは塩である成分Bとからなる二成分系化合物;環状リン化合物とマグネシウム化合物からなる組成物などが挙げられる。そのほか核剤の具体的な種類については、特開2003-306585号公報、特開平06-289566号公報、特開平09-194650号公報に記載されている。
また、仮にポリプロピレン系樹脂からなる層以外に、ポリプロピレン系樹脂を含有する層などを積層させる場合には、各層のβ晶核剤の添加量は同じであっても、異なっていても良い。β晶核剤の添加量を変更することで各層の多孔構造を適宜調整することができる。
本発明においては、前述した成分のほか、本発明の効果を著しく阻害しない範囲内で、一般に樹脂組成物に配合される添加剤を適宜添加できる。前記添加剤としては、成形加工性、生産性および積層多孔フィルムの諸物性を改良・調整する目的で添加される、耳などのトリミングロス等から発生するリサイクル樹脂やシリカ、タルク、カオリン、炭酸カルシウム等の無機粒子、酸化チタン、カーボンブラック等の顔料、難燃剤、耐候性安定剤、耐熱安定剤、帯電防止剤、溶融粘度改良剤、架橋剤、滑剤、核剤、可塑剤、老化防止剤、酸化防止剤、光安定剤、紫外線吸収剤、中和剤、防曇剤、アンチブロッキング剤、スリップ剤または着色剤などの添加剤が挙げられる。具体的には、「プラスチックス配合剤」のP154~P158に記載されている酸化防止剤、P178~P182に記載されている紫外線吸収剤、P271~P275に記載されている帯電防止剤としての界面活性剤、P283~P294に記載されている滑剤などが挙げられる。
ポリエチレン系樹脂としては、具体的に超低密度ポリエチレン、低密度ポリエチレン、高密度ポリエチレン、線状低密度ポリエチレン、また分子量に特徴のある超高分子量ポリエチレンのようなホモポリマーポリエチレンだけでなく、エチレンプロピレン共重合体、またはポリエチレン系樹脂と他のポリオレフィン系樹脂とのコポリマーポリエチレンが挙げられる。中でも、ホモポリマーポリエチレン、或いはα-オレフィンコモノマー含量が2モル%以下のコポリマーポリエチレンが好ましく、ホモポリマーポリエチレンであることが更に好ましい。α-オレフィンコモノマーの種類については特に制限はない。
MFRはJIS K7210に従い、温度190℃、荷重2.16kgの条件で測定している。
ポリエチレン系樹脂に、多孔化を促進させる多孔化促進化合物Xを添加することが好ましい。前記多孔化促進化合物Xを添加することにより、より効率的に多孔構造を得ることができ、孔の形状や孔径を制御しやすくなる。
前記多孔化促進化合物Xは限定はしないが、具体的に例示すると、変性ポリオレフィン樹脂、脂環族飽和炭化水素樹脂若しくはその変性体、エチレン系共重合体、またはワックスから選ばれる多孔化促進化合物Xのうち少なくとも1種が含まれていることがより好ましい。中でも、多孔化でより効果の大きい脂環族飽和炭化水素樹脂若しくはその変性体、エチレン系共重合体、またはワックスがより好ましく、成形性の観点からワックスが更に好ましい。
(ア)融点が40℃~200℃である。
(イ)融点より10℃高い温度での溶融粘度が50Pa・s以下である。
中でも、核剤はポリエチレン系樹脂の結晶構造を制御し、延伸開孔時の多孔構造を細かくするという効果があるため好ましい。市販されているものとして、「ゲルオールD」(新日本理化社製)、「アデカ スタブ」(旭電化工業社製)、「Hyperform」(ミリケンケミカル社製)、または「IRGACLEAR D」(チバ スペシャルケミカルズ社製)等が挙げられる。また、核剤の添加されたポリエチレン系樹脂の具体例としては、「リケマスター」(理研ビタミン社製)等が商業的に入手できる。
本発明において、ポリオレフィン系樹脂多孔フィルムは、単層でも積層でも構わないが、2層以上に積層させることが好ましい。中でも、ポリプロピレン系樹脂を含有する層とポリエチレン系樹脂を含有する層とを積層したものがより好ましい。
ポリオレフィン系樹脂多孔フィルムの層構成は、ポリプロピレン系樹脂を含有する層(以降「A層」と称す)を少なくとも1層存在すれば特に限定されるものではない。また、ポリオレフィン系樹脂多孔フィルムの機能を妨げない範囲で他の層(以降「B層」と称す)を積層することもできる。強度保持層、耐熱層(高融解温度樹脂層)、シャットダウン層(低融解温度樹脂層)などを積層させた構成が挙げられる。例えば、リチウムイオン電池用セパレータとして用いる際には、特開平04-181651号公報に記載されているような高温雰囲気化で孔閉塞し、電池の安全性を確保する低融点樹脂層を積層させることが好ましい。
具体的にはA層/B層を積層した2層構造、A層/B層/A層、若しくは、B層/A層/B層として積層した3層構造などが例示できる。また、他の機能を持つ層と組み合わせて3種3層の様な形態も可能である。この場合、他の機能を持つ層との積層順序は特に問わない。更に層数としては4層、5層、6層、7層と必要に応じて増やしても良い。
次に本発明のポリオレフィン系樹脂多孔フィルムの製造方法について説明するが、本発明はかかる製造方法により製造される積層多孔フィルムのみに限定されるものではない。
無孔膜状物の延伸方法については、ロール延伸法、圧延法、テンター延伸法、同時二軸延伸法などの手法があり、これらを単独あるいは2つ以上組み合わせて一軸延伸あるいは二軸延伸を行う。中でも、多孔構造制御の観点から逐次二軸延伸が好ましい。
(I)各層を多孔化したのち、多孔化された各層をラミネートしたり接着剤等で接着したりして積層する方法。
(II)各層を積層して積層無孔膜状物を作製し、ついで当該無孔膜状物を多孔化する方法。
(III)各層のうちいずれか1層を多孔化したのち、もう1層の無孔膜状物と積層し、多孔化する方法。
(IV)多孔層を作製した後、無機・有機粒子などのコーティング塗布や、金属粒子の蒸着などを行うことにより積層多孔フィルムとする方法。
本発明においては、その工程の簡略さ、生産性の観点から(II)の方法を用いることが好ましく、なかでも2層の層間接着性を確保するために、共押出で積層無孔膜状物を作製した後、多孔化する方法が特に好ましい。
まずポリプロピレン系樹脂と、必要であれば熱可塑性樹脂、添加剤の混合樹脂組成物を作製する。例えば、ポリプロピレン系樹脂、β晶核剤、および所望によりその他添加物等の原材料を、好ましくはヘンシェルミキサー、スーパーミキサー、タンブラー型ミキサー等を用いて、または袋の中に全成分を入れてハンドブレンドにて混合した後、一軸あるいは二軸押出機、ニーダー等、好ましくは二軸押出機で溶融混練後、カッティングしてペレットを得る。
Tダイの種類としては特に限定されない。例えば本発明の積層多孔フィルムが2種3層の積層構造をとる場合、Tダイは2種3層用マルチマニホールドタイプでも構わないし、2種3層用フィードブロックタイプでも構わない。
使用するTダイのギャップは、最終的に必要なフィルムの厚み、延伸条件、ドラフト率、各種条件等から決定されるが、一般的には0.1~3.0mm程度、好ましくは0.5~1.0mmである。0.1mm未満では生産速度という観点から好ましくなく、また3.0mmより大きければ、ドラフト率が大きくなるので生産安定性の観点から好ましくない。
キャストロールによる冷却固化温度は本発明において非常に重要であり、膜状物中のポリプロピレン系樹脂のβ晶の比率を調整することができる。キャストロールの冷却固化温度は好ましくは80~150℃、より好ましくは90~140℃、更に好ましくは100~130℃である。冷却固化温度を80℃以上とすることで、膜状物中のβ晶の比率を十分に増加させることができるために好ましい。また、150℃以下とすることで押出された溶融樹脂がキャストロールへ粘着し巻き付いてしまうなどのトラブルが起こりにくく、効率よく膜状物化することが可能であるので好ましい。
延伸前の膜状物中のβ晶比率は、示差走査型熱量計を用いて、該膜状物を25℃から240℃まで加熱速度10℃/分で昇温させた際に、検出されるポリプロピレン系樹脂(A)のα晶由来の結晶融解熱量(ΔHmα)とβ晶由来の結晶融解熱量(ΔHmβ)を用いて下記式で計算される。
β晶比率(%)=〔ΔHmβ/(ΔHmβ+ΔHmα)〕×100
ついで、得られた無孔膜状物を少なくとも二軸延伸することがより好ましい。二軸延伸は同時二軸延伸であってもよいし、逐次二軸延伸であってもよいが、各延伸工程で延伸条件(倍率、温度)を簡便に選択でき、多孔構造を制御し易い逐次二軸延伸がより好ましい。なお、膜状物及びフィルムの長手方向を「縦方向」、長手方向に対して垂直方向を「横方向」と称する。また、長手方向への延伸を「縦延伸」、長手方向に対して垂直方向への延伸を「横延伸」と称する。
一方、横延伸での延伸温度は概ね100~160℃、好ましくは110~150℃、更に好ましくは120~140℃である。また、好ましい横延伸倍率は1.2~10倍、より好ましくは1.5~8倍、更に好ましくは2~7倍である。前記範囲内で横延伸することで、縦延伸により形成された空孔起点を適度に拡大させ、微細な多孔構造を発現させることができる。
前記延伸工程の延伸速度としては、500~12000%/分が好ましく、1500~10000%/分がさらに好ましく、2500~8000%/分であることが更に好ましい。
本発明は、ポリオレフィン系樹脂多孔フィルムの少なくとも片面に、フィラー(a)、樹脂バインダー(b)、および延伸助剤(c)を含む耐熱層を積層している。
本発明に用いることができるフィラー(a)として、無機フィラー、有機フィラーなどが挙げられるが、特に制約されるものではない。
なお、本実施の形態において「無機フィラーの平均粒径」とは、SEMを用いる方法に準じて測定される値である。
本発明に用いることができる樹脂バインダー(b)として、前記フィラー(a)、および前記ポリオレフィン系樹脂多孔フィルムを良好に接着でき、電気化学的に安定で、かつ積層多孔フィルムを非水電解液二次電池として使用する場合には、非水電解液に対して安定であれば特に制限はない。
具体的には、エチレン-酢酸ビニル共重合体(EVA、酢酸ビニル由来の構造単位が20~35モル%のもの)、エチレン-エチルアクリレート共重合体などのエチレン-アクリル酸、共重合体、フッ素樹脂[ポリフッ化ビニリデン(PVDF)など]、フッ素系ゴム、スチレン-ブタジエンゴム(SBR)、ニトリルブタジエンゴム(NBR)、ポリブタジエンゴム(BR)、ポリアクリロニトリル(PAN)、ポリアクリル酸(PAA)、カルボキシメチルセルロース(CMC)、ヒドロキシエチルセルロース(HEC)、ポリビニルアルコール(PVA)、ポリビニルブチラール(PVB)、ポリビニルピロリドン(PVP)、ポリN-ビニルアセトアミド、架橋アクリル樹脂、ポリウレタン、エポキシ樹脂などが挙げられる。これらの有機バインダーは1種単独で使用してもよく、2種以上を併用しても構わない。これらの中でもポリビニルアルコール、ポリフッ化ビニリデン、スチレン-ブタジエンゴム、カルボキシメチルセルロース、ポリアクリル酸が好ましく、耐熱性と延伸性の観点からポリビニルアルコールがより好ましい。
本発明は、延伸時における耐熱層の延伸性を向上させる目的で延伸助剤(c)を用いる。延伸助剤(c)としては、前記樹脂バインダー(b)と相溶性のある樹脂もしくは溶媒が主に用いられる。前記延伸助剤(c)を前記フィラー(a)、前記樹脂バインダー(b)に添加することで、延伸時に生じる耐熱層の割れや剥離等の延伸不良が抑えられ、耐熱層を均一に延伸することができる。詳細は不明であるが、前記延伸助剤(c)を加えることで、前記樹脂バインダー(b)が可塑化し、延伸性が向上するものと考えられる。
前記延伸助剤(c)は、具体的には、キシレン、スチレン、クロロベンゼン、エーテルアルコール、グリコール、グリコール重合体、グリコール重合体の変性体、グリセリン、フタル酸エステルなどが挙げられる。中でも、後述する耐熱層の製造方法において、分散液に含まれている前記樹脂バインダー(b)および溶媒との相溶性の観点から、グリコール、グリコール重合体、グリコール重合体の変性体、および、グリセリンから選択される少なくとも1種以上であることがより好ましい。
ポリエチレングリコールは、様々な重合度を有するものが存在するため、平均分子量を指標とするのが一般的である。平均分子量の範囲としては、200~20000が好ましい。平均分子量が200以上であれば、ポリビニルアルコールと相溶するため、延伸性が向上する。平均分子量が20000を超えると、ポリビニルアルコールと相溶せず、延伸性が向上する効果を得られない。
本発明の積層多孔フィルムは、前記フィラー(a)と前記樹脂バインダー(b)とを溶媒に溶解または分散させた分散液を、前記ポリオレフィン系樹脂多孔フィルムの少なくとも片面に塗布することによって、ポリオレフィン系樹脂多孔フィルム表面に耐熱層を形成して製造することができる。
本発明の積層多孔フィルムの膜厚は5~100μmが好ましい。より好ましくは8~50μm、更に好ましくは10~30μmである。非水電解液二次電池用セパレータとして使用する場合、5μm以上であれば、実質的に必要な電気絶縁性を得ることができ、例えば電極の突起部分に大きな力がかかった場合でも、非水電解液二次電池用セパレータを突き破って短絡しにくく安全性に優れる。また、膜厚が100μm以下であれば、積層多孔フィルムの電気抵抗を小さくすることができるので、電池の性能が十分に確保することができる。
一方、上限については70%以下が好ましく、65%以下がより好ましく、60%以下が更に好ましい。空孔率が70%以下であれば、積層多孔フィルムの強度が低下しにくく、ハンドリングの観点からも好ましい。なお、空孔率は実施例に記載の方法で測定している。
透気度はフィルム厚み方向の空気の通り抜け難さを表し、具体的には100mlの空気が当該フィルムを通過するのに必要な数で表現されている。そのため、数値が小さい方が通り抜け易く、数値が大きい方が通り抜け難いことを意味する。すなわち、その数値が小さい方がフィルムの厚み方向の連通性が良いことを意味し、その数値が大きい方がフィルムの厚み方向の連通性が悪いことを意味する。連通性とはフィルム厚み方向の孔のつながり度合いである。本発明の積層多孔フィルムの透気度が低ければ様々な用途に使用することができる。例えば電池用セパレータとして使用した場合、透気度が低いということはリチウムイオンの移動が容易であることを意味し、電池性能に優れるため好ましい。
続いて、本発明の前記積層多孔フィルムを電池用セパレータとして収容している非水電解液二次電池について、図1に参照して説明する。
正極板21、負極板22の両極は電池用セパレータ10を介して互いに重なるようにして渦巻き状に捲回し、巻き止めテープで外側を止めて捲回体としている。
前記捲回工程について詳しく説明する。電池用セパレータの片端をピンのスリット部に通し、ピンを少しだけ回転させて電池用セパレータの一端をピンに巻きつけておく。この時、ピンの表面と電池用セパレータの耐熱層とが接触している。その後、電池用セパレータを間に挟むようにして正極と負極を配置し、捲回機によってピンを回転させて、正負極と電池用セパレータを捲回する。捲回後、ピンは捲回物から引き抜かれる。
なかでも、エチレンカーボネート1質量部に対してメチルエチルカーボネートを2質量部混合した溶媒中に六フッ化リン酸リチウム(LiPF6)を1.0mol/Lの割合で溶解した電解質が好ましい。
負極に炭素材料を用いる場合、炭素材料としてはリチウムイオンをドープ、脱ドープできるものであればよく、例えば黒鉛、熱分解炭素類、コークス類、ガラス状炭素類、有機高分子化合物の焼成体、メソカーボンマイクロビーズ、炭素繊維、活性炭などを用いることができる。
1/1000mmのダイアルゲージにて、面内を不特定に30箇所測定し、その平均値を膜厚とした。
フィラー(a)の含有率は、分散液中の樹脂バインダー(b)100質量%に対する比率とした。
延伸助剤(c)の含有率は、分散液中の樹脂バインダー(b)100質量%に対する比率とした。
JIS P8117に準拠して透気度(秒/100ml)を測定した。
得られた積層多孔フィルムを縦60mm×横60mm角に切り出し、図2(A)に示すように中央部にφ40mmの円状の穴を空けたアルミ板(材質:JIS A5052、サイズ:縦60mm、横60mm、厚さ1mm)2枚の間にはさみ、図2(B)に示すように周囲をクリップで固定した。
次に、グリセリン(ナカライテスク社製、1級)を底面から100mmとなるまで満たした、135℃のオイルバス(アズワン社製、OB-200A)の中央部に、積層多孔フィルムをアルミ板2枚に拘束した状態のサンプルを浸漬し、5秒間加熱した。加熱後直ちに、別途用意した25℃のグリセリンを満たした冷却槽に浸漬して5分間冷却した後、2-プロパノール(ナカライテスク社製、特級)、アセトン(ナカライテスク社製、特級)で洗浄し、25℃の空気雰囲気下にて15分間乾燥した。乾燥後のサンプルについて、透気度を前記(2)の方法に従い測定した。
得られた積層多孔フィルムを目視で観察し、以下の評価基準によって延伸性を評価した。
○:耐熱層に割れやヒビ、剥離が認められず、良好な状態。
×:耐熱層に割れやヒビ、剥離が認められる状態。
得られた積層多孔フィルムを縦60mm×横60mm角に切り出し、図2(A)に示すように中央部が40mmφの円状に穴の空いたアルミ板(材質:JIS A5052、サイズ:縦60mm、横60mm、厚さ1mm)2枚の間にはさみ、図2(B)に示すように周囲をクリップで固定した。
積層多孔フィルムをアルミ板2枚に拘束した状態のサンプルを設定温度180℃、表示温度180℃である送風定温恒温器(タバイエスペック社製、タバイギヤオ-ブンGPH200)に入れ3分間保持した後、サンプルを取り出し、積層多孔フィルムの状態を確認して形状維持性能を判断した。
○:破膜せずに形状維持
×:破膜して形状維持できず
(8)示差走査型熱量測定(DSC)
得られた積層多孔フィルムをパーキンエルマー社製の示差走査型熱量計(DSC-7)をもちいて、25℃から240℃まで走査速度10℃/分で昇温後1分間保持し、次に240℃~25℃まで走査速度10℃/分で降温後1分間保持し、次に25℃から240℃まで走査速度10℃/分で再昇温させた。この再昇温時にポリプロピレン系樹脂のβ晶に由来する結晶融解ピーク温度(Tmβ)である145~160℃にピークが検出されるか否かによりβ晶活性の有無をいかの基準にて評価した。
○:Tmβが145℃~160℃の範囲内に検出された場合(β晶活性あり)
×:Tmβが145℃~160℃の範囲内に検出されなかった場合(β晶活性なし)
なお、β晶活性の測定は、試料量10mgで、窒素雰囲気下にて行った。
得られた積層多孔フィルムを縦60mm×横60mm角に切り出し、図2(A)に示すように中央部が40mmφの円状に穴の空いたアルミ板(材質:JIS A5052、サイズ:縦60mm、横60mm、厚さ1mm)2枚の間にはさみ、図2(B)に示すように周囲をクリップで固定した。
積層多孔フィルムをアルミ板2枚に拘束した状態のサンプルを設定温度180℃、表示温度180℃である送風定温恒温器(ヤマト科学株式会社製、型式:DKN602)に入れ3分間保持した後、設定温度を100℃に変更し、10分以上の時間をかけて100℃まで徐冷を行った。表示温度が100℃になった時点でサンプルを取り出し、アルミ板2枚に拘束した状態のまま25℃の雰囲気下で5分間冷却して得られたサンプルについて、以下の測定条件で、中央部の40mmφの円状の部分について広角X線回折測定を行った。
・広角X線回折測定装置:マックサイエンス社製、型番:XMP18A
・X線源:CuKα線、出力:40kV、200mA
・走査方法:2θ/θスキャン、2θ範囲:5°~25°、走査間隔:0.05°、走査速度:5°/min
得られた回折プロファイルについて、ポリプロピレン系樹脂のβ晶の(300)面に由来するピークより、β晶活性の有無を以下のように評価した。
○:ピークが2θ=16.0~16.5°の範囲に検出された場合(β晶活性あり)
×:ピークが2θ=16.0~16.5°の範囲に検出されなかった場合(β晶活性なし)
なお、積層多孔フィルム片が60mm×60mm角に切り出せない場合は、中央部に40mmφの円状の穴に積層多孔フィルムが設置されるように調整し、サンプルを作成しても構わない。
A層を構成するポリプロピレン樹脂組成物として、ポリプロピレン系樹脂(プライムポリマー社製、プライムポリプロ F300SV、密度:0.90g/cm3、MFR:3.0g/10分)100質量部に対して、β晶核剤として、3,9-ビス[4-(N-シクロヘキシルカルバモイル)フェニル]-2,4,8,10-テトラオキサスピロ[5.5]ウンデカンを0.2質量部添加した後、同方向二軸押出機(東芝機械株式会社製、口径:40mmφ、L/D:32)に投入し、設定温度300℃で溶融混練してストランドダイより押出した後、ストランドを水中で冷却固化し、カッターによりストランドをカットし、ポリプロピレン系樹脂組成物のペレットを作製した。ポリプロピレン系樹脂組成物のβ晶活性は80%であった。
前記積層膜状物を、縦延伸機を用いて縦方向に4.6倍延伸し、コロナ表面処理を施した。その後、メイヤーバー(NO.10)にて以下の実施例、比較例で示す分散液を塗工し、横延伸機にて100℃で横方向に2倍延伸後、熱固定/弛緩処理を行うことで積層多孔フィルムを得た。
ポリプロピレン系樹脂(プライムポリマー社製、プライムポリプロ F300SV、密度:0.90g/cm3、MFR:3.0g/10分)100質量部に対して、β晶核剤として、3,9-ビス[4-(N-シクロヘキシルカルバモイル)フェニル]-2,4,8,10-テトラオキサスピロ[5.5]ウンデカンを0.2質量部添加した後、同方向二軸押出機(東芝機械株式会社製、口径:40mmφ、L/D:32)に投入し、設定温度300℃で溶融混練してストランドダイより押出した後、ストランドを水中で冷却固化し、カッターによりストランドをカットし、ポリプロピレン系樹脂組成物のペレットを作製した。ポリプロピレン系樹脂組成物のβ晶活性は80%であった。
前記無孔膜状物を、縦延伸機を用いて縦方向で4.6倍延伸し、コロナ表面処理を施した。その後、メイヤーバー(NO.10)にて以下の実施例、比較例で示す分散液を塗工し、横延伸機にて150℃で横方向に2.3倍延伸後、熱固定/弛緩処理を行うことで積層多孔フィルムを得た。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)25.1質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)1.9質量部、ポリエチレングリコール(ナカライテスク社製、ポリエチレングリコール#200、平均分子量190~210)0.5質量部を水72.5質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ1321質量%、26質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)25.1質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)1.9質量部、ポリエチレングリコール(ナカライテスク社製、ポリエチレングリコール#200、平均分子量190~210)1.9質量部を水71.1質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ1321質量%、100質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)23.8質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)3.2質量部、ポリエチレングリコール(ナカライテスク社製、ポリエチレングリコール#200、平均分子量190~210)0.3質量部を水72.7質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ744質量%、9質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)23.8質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)3.2質量部、ポリエチレングリコール(ナカライテスク社製、ポリエチレングリコール#200、平均分子量190~210)0.8質量部を水72.2質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ744質量%、25質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)23.8質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)3.2質量部、ポリエチレングリコール(ナカライテスク社製、ポリエチレングリコール#1500、平均分子量1300~1600)0.8質量部を水72.2質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ744質量%、25質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)23.8質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)3.2質量部、ポリエチレングリコール(HAMPTON RESEARCH社製、ポリエチレングリコール10000)0.8質量部を水72.2質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ744質量%、25質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)25.1質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)1.9質量部、グリセリン(ナカライテスク社製)0.5質量部を水72.5質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ1321質量%、26質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)23.8質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)3.2質量部、グリセリン(ナカライテスク社製)0.3質量部を水72.7質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ744質量%、9質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)18.1質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)8.9質量部、ポリエチレングリコール(ナカライテスク社製、ポリエチレングリコール#200、平均分子量190~210)2.2質量部を水70.8質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ203質量%、25質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)23.8質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)3.2質量部、ポリエチレングリコールジメチルエーテル(シグマアルドリッチ社製、平均分子量~250)0.8質量部を水72.2質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ744質量%、25質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)18.1質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)8.9質量部、ポリエチレングリコールジメチルエーテル(シグマアルドリッチ社製、平均分子量~250)2.2質量部を水70.8質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ203質量%、25質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)24.3質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)2.7質量部、ポリエチレングリコール(ナカライテスク社製、ポリエチレングリコール#200、平均分子量190~210)0.7質量部を水72.3質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ900質量%、26質量%であった。
得られた分散液を用いて、前記製造例2により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)23.8質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)3.2質量部、ポリエチレングリコール(ナカライテスク社製、ポリエチレングリコール#200、平均分子量190~210)0.3量部を水72.7質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ744質量%、9質量%であった。
得られた分散液を用いて、前記製造例2により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)26.5質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)0.5質量部を水73.0質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ5300質量%、0質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)12.3質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)14.7質量部、ポリエチレングリコール(ナカライテスク社製ポリエチレングリコール#200、平均分子量190~210)1.5質量部を水71.5質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ87質量%、10質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
アルミナ(住友化学社製、スミコランダムAA-06、平均粒径:0.6μm)23.8質量部、ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)3.2質量部を水73.0質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ744質量%、0質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)27.0質量部を水73.0質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、いずれも0質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
ポリビニルアルコール(クラレ社製、PVA124、鹸化度:98.0~99.0、平均重合度:2400)27.0質量部、ポリエチレングリコール(ナカライテスク社製ポリエチレングリコール#200、平均分子量190~210)6.8質量部を水66.3質量部に分散させた分散液を得た。この時、分散液に含まれている前記フィラー(a)、前記延伸助剤(c)の含有率は、樹脂バインダー(b)100質量%に対して、それぞれ0質量%、25質量%であった。
得られた分散液を用いて、前記製造例1により得た積層多孔フィルムの物性評価を行い、その結果を表1にまとめた。
分散液の塗工工程を行わず、前記製造例1により得たポリオレフィン系樹脂多孔フィルムの物性評価を行い、その結果を表1にまとめた。
分散液の塗工工程を行わず、前記製造例2により得たポリオレフィン系樹脂多孔フィルムの物性評価を行い、その結果を表1にまとめた。
一方、比較例1,3のように分散剤に延伸助剤(c)が含まれていないと、延伸性が不十分であった。また、比較例2のように分散剤に樹脂バインダー(b)の割合が多くなると、延伸性は良好であったものの、連通性は不十分であった。また、比較例4のように分散剤にフィラー(a)、延伸助剤(c)が含まれていないと、連通性、延伸性が不十分であった。また、比較例5のように分散剤にフィラー(a)が含まれていないと、延伸性は良好であったものの、連通性が不十分であった。
また、比較例6,7は、耐熱層を積層していないため、耐熱性が不十分であった。
21 正極板
22 負極板
24 正極リード体
25 負極リード体
26 ガスケット
27 正極蓋
31 アルミ板
32 セパレータ
33 クリップ
34 フィルム縦方向
35 フィルム横方向
Claims (6)
- ポリオレフィン系樹脂多孔フィルムの少なくとも片面に、フィラー(a)、樹脂バインダー(b)、および延伸助剤(c)を含む耐熱層を積層しており、
透気度が2000秒/100ml以下であることを特徴とする積層多孔フィルム。 - 前記延伸助剤(c)は、沸点が120℃以上、もしくは沸点を有さないことを特徴とする請求項1に記載の積層多孔フィルム。
- 前記延伸助剤(c)は、グリコール、グリコール重合体、グリコール重合体の変性体、および、グリセリンから選択される少なくとも1種以上であることを特徴とする請求項1または2に記載の積層多孔フィルム。
- β晶活性を有することを特徴とする請求項1~3のいずれか1項に記載の積層多孔フィルム。
- 請求項1~4のいずれか1項に記載の積層多孔フィルムを用いた非水電解液二次電池用セパレータ。
- 請求項5に記載の非水電解液二次電池用セパレータを用いた非水電解液二次電池。
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CN201180011693.9A CN102781667B (zh) | 2010-04-19 | 2011-04-06 | 叠层多孔膜、非水电解质二次电池用隔板、以及非水电解质二次电池 |
KR1020127023199A KR20120124478A (ko) | 2010-04-19 | 2011-04-06 | 적층 다공 필름, 비수 전해액 2 차 전지용 세퍼레이터, 및 비수 전해액 2 차 전지 |
KR1020147023446A KR20140113743A (ko) | 2010-04-19 | 2011-04-06 | 적층 다공 필름, 비수 전해액 2 차 전지용 세퍼레이터, 및 비수 전해액 2 차 전지 |
EP11771869.2A EP2561984A4 (en) | 2010-04-19 | 2011-04-06 | POROUS LAMINATED FILM, SEPARATOR FOR NONAQUEOUS ELECTROLYTE RECHARGEABLE BATTERY, AND NONAQUEOUS ELECTROLYTE RECHARGEABLE BATTERY |
JP2012511605A JP5676577B2 (ja) | 2010-04-19 | 2011-04-06 | 積層多孔フィルム、非水電解液二次電池用セパレータ、および非水電解液二次電池 |
US13/641,883 US20130034769A1 (en) | 2010-04-19 | 2011-04-06 | Laminated porous film, separator for non-aqueous electrolyte battery, and non-aqueous electrolyte secondary battery |
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JP (1) | JP5676577B2 (ja) |
KR (2) | KR20140113743A (ja) |
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KR101329220B1 (ko) * | 2012-04-25 | 2013-11-14 | 에스케이씨 주식회사 | 적층 다공성 필름, 이의 제조방법 및 이를 포함하는 이차전지용 분리막 |
JP2013237203A (ja) * | 2012-05-16 | 2013-11-28 | Mitsubishi Plastics Inc | 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 |
KR101584627B1 (ko) * | 2014-10-10 | 2016-01-12 | 주식회사 케이엠지 | 전지용 접착제를 이용한 전지 및 이의 제조 방법 |
CN114024090A (zh) * | 2021-10-27 | 2022-02-08 | 长园泽晖新能源材料研究院(珠海)有限公司 | 一种复合锂离子电池隔膜及其制备方法 |
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EP2561984A1 (en) | 2013-02-27 |
JPWO2011132533A1 (ja) | 2013-07-18 |
JP5676577B2 (ja) | 2015-02-25 |
US20130034769A1 (en) | 2013-02-07 |
CN102781667A (zh) | 2012-11-14 |
KR20120124478A (ko) | 2012-11-13 |
CN102781667B (zh) | 2016-08-17 |
EP2561984A4 (en) | 2014-08-27 |
KR20140113743A (ko) | 2014-09-24 |
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