JP2005322615A - Separator for battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a separator for a battery, having superior hydrophilic properties, alkali resistance properties, anti-oxidation properties, superior thermal resistance properties, having high capacity, superior output characteristics and life time characteristics, with which the yield of battery manufacturing becomes high. <P>SOLUTION: The separator for the battery consists of non-woven fabric, containing half-aromatic polyamide fiber with superior oxidation resistance properties, which is synthesized from dicarboxylic acid component, consisting of 60 mol% or higher aromatic carboxylic acid component and diamine component consisting of 6-12C 60 mol% or higher aliphatic alkylene diamine, and containing polyparaphenylene benzobis oxazole fiber having high mechanical strength. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a separator for an alkaline battery that can be suitably used for an alkaline secondary battery such as a nickel-cadmium battery, a nickel-zinc battery, or a nickel-hydrogen battery. More specifically, the present invention relates to an alkaline battery separator that can be rapidly charged and discharged with a large current and has excellent life characteristics.

  Alkaline secondary batteries have excellent charge / discharge characteristics and overcharge / discharge characteristics, and can be used repeatedly with a long service life. In addition to small electronic devices such as mobile phones, personal computers, and audio, recently, large-sized hybrid cars, electric bicycles, etc. Widely used in equipment. In both small electronic device applications and large device applications, it is required to increase the capacity, size and weight of alkaline secondary batteries, expand the usable temperature range, and the like. The role of the separator for the alkaline secondary battery includes separation of the positive electrode and the negative electrode, prevention of short circuit, retention of the electrolyte, and permeation of gas generated by the electrode reaction.

  Known separators for alkaline secondary batteries include polyolefin fiber nonwoven fabrics and polyamide fiber nonwoven fabrics.

  Although polyolefin fibers are excellent in alkali resistance and oxidation deterioration resistance, they are inferior in hydrophilicity, so that hydrophilicity must be imparted to the polyolefin fibers. As hydrophilicity imparting methods, treatment with hot concentrated sulfuric acid, fuming sulfuric acid or chlorosulfuric acid and sulfonation, treatment with a reactive gas containing fluorine, grafting of a group having a hydrophilic group such as acrylic acid or methacrylic acid Many methods such as a polymerization method have been proposed (for example, Patent Documents 1 to 3). However, these hydrophilicity imparting methods are expensive and have problems that the hydrophilicity cannot be maintained for a long period of time and the fibers deteriorate.

  Non-woven fabrics made of polyamide fibers, particularly aliphatic polyamide fibers such as nylon 6 and nylon 66, are superior in alkali resistance and hydrophilicity, so that they need not be subjected to sulfonation treatment, fluorine treatment, or graft polymerization treatment. The liquid retaining property of the electrolytic solution is good and the discharge capacity is large. However, since it is inferior in oxidation resistance degradation at high temperatures and has a disadvantage of being oxidized and degraded by oxygen gas generated during charging of the alkaline secondary battery, when the alkaline secondary battery is used in a high temperature environment of 60 to 130 ° C, There has been a problem that the performance of the battery is significantly reduced.

  As a battery separator using fibers having both hydrophilicity and oxidation deterioration resistance, those using a nonwoven fabric made of aromatic polyamide or wholly aromatic polyamide have been proposed (for example, Patent Documents 4 to 6). However, since the aromatic polyamide or wholly aromatic polyamide has high heat resistance, the nonwoven fabric composed only of the fibers has low adhesion itself and has a problem in the strength of the nonwoven fabric. Moreover, the adhesiveness with a general thermoplastic binder fiber was also low, and there was a problem in the strength of the nonwoven fabric. Although there is a method of performing resin bonding in order to improve adhesiveness, there is a problem that the adhesive resin is eluted into the battery electrolyte when used as a battery separator. Aromatic polyamides or wholly aromatic polyamides have poor alkali resistance at high temperatures, and the degradable products have an adverse effect on battery characteristics. May have been affected.

  A semi-aromatic polyamide fiber is a polyamide fiber that has improved the adhesion problem. Battery separators using non-woven fabric composed of MXD-6 fibers composed of aromatic diamine and aliphatic dicarboxylic acid, which is a semi-aromatic polyamide fiber, have poor resistance to oxidation degradation at high temperatures, and oxygen generated during charging In some cases, the gas was oxidized and deteriorated.

  In contrast, a semi-aromatic polyamide fiber composed of an aliphatic diamine and an aromatic dicarboxylic acid can be suitably used for a battery separator as a fiber having both hydrophilicity, alkali resistance, and oxidation degradation resistance (for example, Patent Documents 7 and 8). However, the semi-aromatic polyamide fiber has a drawback that the mechanical strength of the fiber is smaller than that of the aliphatic polyamide fiber, wholly aromatic polyamide fiber or the like.

  In recent years, alkaline secondary batteries have been reduced in size, capacity, and output, and it is necessary to increase the amount of active material of the electrode. For this reason, it is necessary to reduce the occupied volume of the battery separator in the battery, and the battery separator is becoming thinner. In addition, the battery structure has high adhesion between the electrode and the battery separator. When a thin nonwoven fabric using a semi-aromatic polyamide fiber composed of the above-mentioned aliphatic diamine and aromatic dicarboxylic acid is used as a battery separator, the electrode plate flashes through the separator and shorts, or the electrode plate There is a problem that the separator may be broken at a portion where the end and the separator are in contact with each other, resulting in a decrease in the yield of alkaline secondary battery production.

On the other hand, the thermoplastic short fiber, the polyparaphenylene benzobisoxazole fiber or its pulp-like material, and the heat-sealing fiber are entangled three-dimensionally with each other, and these fibers are heat-fused as described above. A wet nonwoven fabric for battery separators characterized by melting part or all of the attached fibers can be suitably used (for example, Patent Document 9). However, when the fibers are entangled three-dimensionally by colliding with a water flow, a relatively large through-hole is opened, and the performance of preventing the movement of the active material is lowered. Therefore, the basis weight is lowered to increase the capacity. There is a problem that it is impossible to achieve high output and a long life.
Japanese Patent Laid-Open No. 56-3973 JP 58-175256 A Japanese Patent Laid-Open No. 1-132042 Japanese Patent Application Laid-Open No. H5-283054 JP-A-53-58636 Japanese Patent Laid-Open No. 58-147756 JP-A-9-259856 JP 2002-151041 A JP 2002-151043 A

  An object of the present invention is to provide a battery separator having excellent hydrophilicity, alkali resistance, oxidation deterioration resistance, and heat resistance, high yield during battery production, high capacity, and excellent output characteristics and life characteristics. .

As a result of intensive studies to solve the above problems, the present inventors have
(1) It is synthesized from a dicarboxylic acid component in which 60 mol% or more of the dicarboxylic acid component is an aromatic carboxylic acid component and a diamine component in which 60 mol% or more of the diamine component is an aliphatic alkylenediamine having 6 to 12 carbon atoms. A battery separator comprising a non-woven fabric containing a semi-aromatic polyamide fiber and a polyparaphenylene benzobisoxazole fiber;
(2) The battery separator according to (1), wherein the content of the semi-aromatic polyamide fiber is 30 to 90% by mass of the nonwoven fabric,
(3) The battery separator according to (1) or (2), wherein the polyparaphenylene benzobisoxazole fiber is 3 to 10% by mass of the nonwoven fabric,
(4) The battery separator according to any one of (1) to (3), further containing a binder fiber,
(5) The battery separator according to (4), wherein the binder fiber is at least one of an ethylene vinyl alcohol copolymer fiber, a composite fiber containing an ethylene vinyl alcohol copolymer, and a polyolefin core-sheath type heat fusion fiber,
(6) The battery separator according to (4) or (5) above, wherein the content of the binder fiber is adjusted to 5 to 20% by mass of the nonwoven fabric.
(7) Any of the above (1) to (6), wherein the weight loss rate after 1 month of the battery separator is 10% or less in an alkali resistance test with a KOH aqueous solution at 90 ° C. and a specific gravity of 1.30 The battery separator described,
I found.

  The battery separator (1) according to the present invention is excellent in adhesion between polyparaphenylene benzobisoxazole fiber excellent in alkali resistance and mechanical strength, chemical stability such as heat resistance and oxidation resistance, and thermoplastic binder. Since it consists of the excellent semi-aromatic polyamide fiber and the nonwoven fabric containing it, the problem of a separator tearing or an electrode short circuit does not occur at the time of battery production, and a high-capacity small battery can be produced.

  In the battery separator (2) of the present invention, the content of the semi-aromatic polyamide fiber is preferably 30 to 90% by mass of the nonwoven fabric. When the content of semi-aromatic polyamide fiber is less than 30% by mass and the content of polyparaphenylene benzobisoxazole fiber is large, the electric resistance of the battery separator increases, so the internal resistance of the battery increases and the output characteristics Cannot be satisfied. In addition, the alkali resistance of the polyparaphenylene benzobisoxazole fiber is lower than that of the polyolefin fiber and causes oxidation and hydrolysis, so that the life characteristics may be lowered. On the contrary, when the content of the semi-aromatic polyamide fiber is more than 90% by mass, the mechanical strength of the semi-aromatic polyamide fiber is low, so the mechanical strength of the battery separator is reduced, and the nonwoven fabric is thin and has a low basis weight. Is used as a battery separator, the yield at the time of battery production deteriorates.

  The battery separator (3) of the present invention preferably has a content of polyparaphenylene benzobisoxazole fibers of 3 to 10% by mass. When the content of the polyparaphenylene benzobisoxazole fiber is less than 3% by mass, the puncture strength in the thickness direction of the nonwoven fabric cannot be obtained, and the nonwoven fabric penetrates or breaks due to the burr of the electrode during battery production. May enter or torn. On the other hand, when the amount is more than 10% by mass, when the separator is cut at a predetermined length during battery manufacture, it may not be cut, or the fluff of uncut fibers may cause trouble during battery manufacture. is there.

  The battery separator of the present invention may further contain a binder fiber as described in the above (4) depending on the production conditions of the nonwoven fabric. In particular, when producing a nonwoven fabric by a wet method, in order to improve the strength of the wet paper and the strength of the battery separator, as described in (5) above, it has excellent heat resistance and exhibits a fusion effect in a small amount. However, it is preferable to use one kind of ethylene vinyl alcohol copolymer fiber, composite fiber containing ethylene vinyl alcohol copolymer, and polyolefin core-sheath type heat-sealing fiber that has little influence on battery characteristics.

  In the battery separator (6) of the present invention, the binder fiber content is preferably 20% by mass or less, more preferably 10% by mass or less of the nonwoven fabric. If the binder fiber exceeds 20% by mass, the internal resistance increases due to dissolution of the binder fiber under a high temperature environment of 130 ° C., which is not preferable. However, in the case where only the binder fiber among the constituent components of the nonwoven fabric greatly contributes to the development of the strength, the mechanical strength of the separator is reduced when it is less than 5% by mass.

  In the battery separator of the present invention, it is desirable that the weight loss rate after one month of the battery separator is 10% or less in an alkali resistance test with a KOH aqueous solution at 90 ° C. and a specific gravity of 1.30. When the weight loss rate after one month of the battery separator exceeds 10%, the decomposition product not only adversely affects the battery characteristics, but also cannot retain the active material migration prevention performance.

  The battery separator of the present invention comprises a semi-aromatic polyamide fiber excellent in alkali resistance, heat resistance, oxidation degradation resistance, and adhesiveness with a binder fiber, and a polyparaphenylene benzobisoxazole fiber excellent in mechanical strength. The alkaline secondary battery using the battery separator of the present invention, because it is made of the non-woven fabric contained, has the excellent effect of having a high production yield and stable operation even at high temperatures.

  Hereinafter, the battery separator of the present invention will be described in detail.

  The battery separator (1) of the present invention comprises a nonwoven fabric containing semi-aromatic polyamide fibers and polyparaphenylene benzobisoxazole fibers.

  In the polyamide of the semi-aromatic polyamide fiber related to the battery separator of the present invention, 60 mol% or more of the dicarboxylic acid component is an aromatic dicarboxylic acid, and 60 mol% or more of the diamine component is a fatty acid having 6 to 12 carbon atoms. A semi-aromatic polyamide, which is a group alkylene diamine, is used. This polyamide is excellent in hydrophilicity, alkali resistance, and oxidation degradation resistance.

  As the aromatic dicarboxylic acid component, terephthalic acid is most preferable from the viewpoint of the heat resistance and chemical resistance of the separator. Isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid Acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, diphenic acid, dibenzoic acid, 4,4'-oxydibenzoic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone One or more aromatic dicarboxylic acids such as -4,4'-dicarboxylic acid and 4,4'-biphenyldicarboxylic acid can be used in combination.

  As dicarboxylic acid, content of aromatic dicarboxylic acid is 60 mol% or more of the dicarboxylic acid component, and preferably 75 mol% or more. In particular, the dicarboxylic acid component is preferably 100% aromatic dicarboxylic acid from the viewpoint of the strength, chemical resistance, heat resistance, etc. of the nonwoven fabric. When the content of the aromatic dicarboxylic acid is less than 60 mol%, various physical properties such as alkali resistance, oxidation resistance and strength of the resulting fiber are not preferable.

  Examples of dicarboxylic acids other than the aromatic dicarboxylic acids include malonic acid, dimethylmalonic acid, succinic acid, 3,3-diethylsuccinic acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, and trimethyl. Aliphatic dicarboxylic acids such as adipic acid, pimelic acid, azelaic acid, sebacic acid and suberic acid; and alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, These acids can be used alone or in combination of two or more. Furthermore, polyvalent carboxylic acids such as trimetric acid, trimesic acid, pyromellitic acid and the like can be contained within a range where fiberization and nonwoven fabric formation are easy.

  Further, 60 mol% or more of the diamine component is composed of an aliphatic alkylene diamine having 6 to 12 carbon atoms. Examples of the aliphatic alkylene diamine include 1,6-hexanediamine, 1,8-octanediamine, 1,9 -Nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,2, Linear chain such as 4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine Or the aliphatic diamine which has a side chain etc. can be mentioned.

  The content of the aliphatic alkylene diamine is 60 mol% or more of the diamine component, but is preferably 75 mol% or more, particularly 90 mol% or more, from the viewpoint of heat resistance. When the content of the aliphatic diamine component is less than 60 mol%, the oxidation resistance, strength, etc. of the resulting fiber are lowered. Of these, 1,9-nonanediamine, and a combination of 1,9-nonanediamine and 2-methyl-1,8-octanediamine are preferred in terms of heat resistance, hydrolysis resistance, and chemical resistance. And 60-100 mol% of a diamine component consists of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine Is preferably 40:60 to 99: 1, and more preferably 70:30 to 95: 5.

  Further, the polyamide relating to the battery separator of the present invention requires that at least 10% of the end groups of the molecular chain be sealed with an end-capping agent, and at least 40% of the ends are sealed. It is more preferable that 70% or more of the ends are sealed. By sealing the end of the polyamide, the resulting battery separator has excellent mechanical strength, alkali resistance, oxidation deterioration resistance, and the like. The end capping agent is not particularly limited as long as it is a monofunctional compound having reactivity with the amino group or carboxyl group at the end of the polyamide, but from the viewpoint of reactivity and stability of the capping end. Monocarboxylic acids and monoamines are preferred.

  The polyparaphenylene benzobisoxazole fiber related to the battery separator of the present invention has twice the strength and elastic modulus as compared with para-type wholly aromatic polyamide fiber (strength 37 cN / dtex, elastic modulus 1150 to 1720 cN / dtex). ), The decomposition temperature is 650 ° C., which is 100 ° C. higher than that of the para-type wholly aromatic polyamide fiber. Further, the alkali resistance is remarkably superior to that of para-type wholly aromatic polyamide fibers.

  The fiber diameter of the semi-aromatic polyamide fiber and polyparaphenylene benzobisoxazole fiber related to the battery separator of the present invention is preferably 1.7 dtex or less, more preferably from the viewpoint of short-circuit resistance, liquid absorption, and liquid retention. Is preferably 1 dtex or less, and preferably 0.1 dtex or more from the viewpoint of not inhibiting air permeability and the hardness of the nonwoven fabric for battery separator.

  In the battery separator of the present invention, as a method for producing a nonwoven fabric, a method of forming a fiber web and bonding, fusing, and entanglement of fibers in the fiber web can be used. The obtained nonwoven fabric may be used as it is or may be used as a laminate comprising a plurality of sheets. Examples of the method for producing the fiber web include a dry method such as a card method and an air array method, a wet method such as a papermaking method, a spun bond method, and a melt blow method. Among these, the web obtained by a wet method is homogeneous and dense, and can be suitably used as a battery separator. The wet method is a method in which fibers are dispersed in water to form a uniform papermaking slurry, and this papermaking slurry is obtained using a papermaking machine having at least one of a wire such as a circular net, a long net, and an inclined type to obtain a fiber web. is there.

  As a method for producing a nonwoven fabric from a fibrous web, a hydroentanglement method, a needle punch method, a binder adhesion method, or the like can be used.

  As binder fibers for battery separators (4) and (5) of the present invention, ethylene vinyl alcohol copolymer fibers having a fiber diameter of 0.01 to 1.0 dtex excellent in heat resistance and adhesiveness, and / or ethylene Composite fiber containing a vinyl alcohol copolymer (for example, a core-sheath type composite fiber having a PP component and a sheath component being an ethylene vinyl alcohol copolymer component, or an ethylene vinyl alcohol copolymer and a polyolefin in its cross section) One component of the polymer is interposed between the other components and divided into at least two or more, each of which is a constituent unit of the fiber cross section, and a part of each adjacent constituent fiber is Split-type composite fibers exposed on the fiber surface) and / or polyolefin core-sheath type heat-sealing fibers (the core is the PP component and the sheath component is the PE component) Or wick in PP component, the sheath component may be used in a) PP copolymer component. These binder fibers are preferably used when a nonwoven fabric is produced mainly by a wet method.

    The content of the binder fiber is preferably 20% by mass or less, more preferably 10% by mass or less, based on the nonwoven fabric. When the binder fiber exceeds 20% by mass, the internal resistance becomes high due to dissolution of the binder fiber under a high temperature environment of 130 ° C., which is not preferable. However, in the case where only the binder fiber among the constituent components of the nonwoven fabric greatly contributes to the development of the strength, that is, when the heat-fusibility of the fiber other than the binder fiber is low, the mechanical strength of the separator is less than 5% by mass. Get smaller.

  In the alkali resistance test with a KOH aqueous solution at 90 ° C. and a specific gravity of 1.30 relating to the battery separator (7) of the present invention, the weight loss rate after 1 month of the battery separator is preferably 10% or less. More preferably, the weight loss rate after one month has elapsed is 5% or less. The alkali resistance of the battery separator is related to the life characteristics of the battery. While there is a demand for higher capacity and higher output of batteries, the temperature reached inside the battery due to charge / discharge cycles tends to increase further, and deterioration due to decomposition of the battery separator in high-temperature alkaline aqueous solution that occurs at that time, The liquid retainability of the battery separator and the function of the active material or the protective film for dendrite growth of cadmium are lowered, which is a factor for accelerating the deterioration of the life characteristics. When the weight loss rate after 1 month of the battery separator exceeds 10%, the mechanical strength and liquid retention of the battery separator are reduced, and the pore diameter is increased, and the life characteristics are reduced. It will cause a decline.

  In the battery separator of the present invention, when the nonwoven fabric is produced by a wet method, the fiber length of the polyamide fiber, polyparaphenylene benzobisoxazole fiber, and binder fiber is preferably 2 to 20 mm. When the fiber length exceeds 20 mm, the wet method makes it difficult to disperse the fibers, resulting in poor formation and the like, resulting in a problem that a good fiber web cannot be formed. On the other hand, when the fiber length is less than 2 mm, the mechanical strength of the battery separator is reduced.

  The battery separator of the present invention may be subjected to a hydrophilic treatment in order to further improve the hydrophilicity. As the hydrophilization treatment, corona discharge treatment, atmospheric pressure plasma treatment, fluorination treatment, surfactant treatment or the like can be used.

  In the corona discharge treatment, an appropriate gap is provided between an electrode connected to a high voltage generator and a metal roll covered with silicon rubber, and a high voltage corona is generated by applying a voltage of thousands to tens of thousands of volts at a high frequency. The raw cloth obtained by the above method is run at an appropriate speed during this interval, and the surface of the raw cloth is reacted with ozone generated by corona or nitric oxide to generate carboxyl groups, hydroxyl groups, and peroxide groups. This is a surface modification method that improves the affinity of the electrolyte solution for the raw fabric.

  Atmospheric pressure plasma treatment consists of helium, argon, and oxygen in a plasma reactor having a dielectric coated electrode in which a solid dielectric such as polyimide, mica, ceramic, or glass is disposed on the surface of at least one of the opposing electrodes. This is a surface modification method that improves the affinity of the electrolyte by introducing a gas composition to be activated, performing plasma excitation under atmospheric pressure, oxidizing and etching the surface of the raw fabric located between the opposing electrodes .

  Fluorine treatment is performed by bringing a mixed gas of fluorine gas diluted with nitrogen gas or argon gas and one kind of gas such as oxygen gas, carbon dioxide gas, and sulfur dioxide gas into contact with the raw cloth, carboxyl groups on the surface, This is a surface modification method for improving the affinity of an electrolyte by generating a carbonyl group and a hydroxyl group.

  As the surfactant treatment, after impregnating the raw cloth in a solution of a nonionic surfactant such as polyoxyethylene alkyl ether or polyoxyethylene alkylphenol ether, or applying or spraying the solution. It is a surface modification method that improves the affinity of the electrolyte solution on the surface of the base fabric by drying.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a present Example. In the examples, all parts and% are by mass unless otherwise specified.

Example 1
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 65 parts by mass, 100 mol% of dicarboxylic acid component is terephthalic acid, diamine component Of non-stretched polyamide fiber having a fineness of 1.6 dtex and a fiber length of 10 mm (manufactured by Kuraray Co., Ltd.), in which 50 mol% of 1,9-nonanediamine and the remaining 50 mol% of diamine component are 2-methyl-1,8-octadiamine. (Melting point 265 ° C., softening temperature 145 ° C.) 25 parts by mass, fineness 1.7 dtex, fiber length 5 mm, polyparaphenylene benzobi Mixing the oxazole fibers (tensile strength 37cN / dtex) 10 parts by weight, is macerated in water pulper under stirring by agitator and forms a uniform sheet-forming slurry (1% concentration) tone. A raw fabric having a basis weight of 63.0 g / m ² and a width of 50 cm was prepared from the paper slurry using a wet method using a circular paper machine. Next, a calendar process is performed at a roll temperature of 200 ° C., and further, a corona treatment is performed on both sides of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm, and a basis weight of 63.0 g / m ² , thickness A non-woven fabric having a thickness of 140 μm was produced and used as a separator for an alkaline battery.

Example 2
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 60 parts by mass, 100 mol% of the dicarboxylic acid component is terephthalic acid, diamine component Of non-stretched polyamide fiber having a fineness of 1.6 dtex and a fiber length of 10 mm (manufactured by Kuraray Co., Ltd.), in which 50 mol% of 1,9-nonanediamine and the remaining 50 mol% of diamine component are 2-methyl-1,8-octadiamine. (Melting point 265 ° C., softening temperature 145 ° C.) 25 parts by mass, fineness 1.7 dtex, fiber length 5 mm, polyparaphenylene benzobi Mixing the oxazole fibers (tensile strength 37cN / dtex) 15 parts by weight, is macerated in water pulper under stirring by agitator and forms a uniform sheet-forming slurry (1% concentration) tone. A raw fabric having a basis weight of 63.2 g / m ² and a width of 50 cm was produced from the paper slurry using a wet method using a circular paper machine. Next, a calendar process is performed at a roll temperature of 200 ° C., and a corona treatment is performed on both surfaces of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm, and a basis weight of 63.2 g / m ^{2 is obtained} . A non-woven fabric having a thickness of 145 μm was produced and used as a separator for an alkaline battery.

Example 3
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 82 parts by mass, fineness 1.7 dtex, fiber length 5 mm polyparaphenylene benzo 3 parts by mass of bisoxazole fiber (tensile strength 37 cN / dtex), 15 parts by mass of ethylene vinyl alcohol copolymer fiber having an ethylene content of 44 mol%, a saponification degree of 99.6%, a fineness of 0.08 dtex, and a fiber length of 3 mm Are mixed together, disaggregated in the water of the pulper, and stirred uniformly with an agitator to make a uniform slurry for papermaking 1% concentration) made a tone. A raw fabric having a basis weight of 62.8 g / m ² and a width of 50 cm was produced from the paper slurry by a wet method using a circular paper machine. Next, a calendering process was performed at a roll temperature of 60 ° C., and a corona treatment was performed on both surfaces of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm to obtain a basis weight of 62.8 g / m ² , a thickness. A non-woven fabric having a thickness of 141 μm was manufactured and used as an alkaline battery separator.

Example 4
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, A stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 83 parts by mass, polyparaphenylene benzo having a fineness of 1.7 dtex and a fiber length of 5 mm 2 parts by mass of bisoxazole fiber (tensile strength 37 cN / dtex), 15 parts by mass of ethylene vinyl alcohol copolymer fiber having an ethylene content of 44 mol%, a saponification degree of 99.6%, a fineness of 0.08 dtex, and a fiber length of 3 mm Are mixed together, disaggregated in the water of the pulper, and stirred uniformly with an agitator to make a uniform slurry for papermaking 1% concentration) to ChoNaru. A raw fabric having a basis weight of 63.3 g / m ² and a width of 50 cm was prepared from the papermaking slurry by a wet papermaking method using a circular paper machine. Next, a calendar process was performed at a roll temperature of 60 ° C., and a corona treatment was performed on both surfaces of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm to obtain a basis weight of 63.3 g / m ² , a thickness. A non-woven fabric having a thickness of 145 μm was produced and used as a separator for an alkaline battery.

Example 5
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 60 parts by mass, core having a fineness of 0.8 dtex and fiber length of 10 mm is a PP component , 23 parts by mass of core-sheath type composite fiber whose sheath is a PP copolymer component, ethylene vinyl alcohol copolymer having an ethylene content of 44 mol%, a saponification degree of 99.6%, a fineness of 0.6 dtex, and a fiber length of 5 mm 10 mass parts of fiber, fineness of 1.7 dtex, fiber length of 5 mm, polyparaphenylene benzobisoxazole fiber (tensile strength: 37 cN / dtex), 7 mass Mixing the door, it is macerated in water pulper under stirring by agitator and forms a uniform sheet-forming slurry (1% concentration) tone. A raw fabric having a basis weight of 65.0 g / m ² and a width of 50 cm was prepared from the paper slurry by a wet method using a circular net paper machine. Next, a calendering process was performed at a roll temperature of 160 ° C., and a corona treatment was performed on both surfaces of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm to obtain a basis weight of 65.0 g / m ² , a thickness. A non-woven fabric having a thickness of 155 μm was produced and used as an alkaline battery separator.

Example 6
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex), 30 parts by mass, polyparaphenylene benzo having a fineness of 1.7 dtex and a fiber length of 5 mm 5 parts by mass of bisoxazole fiber (tensile strength 37 cN / dtex), a core component with a fineness of 2.2 dtex and a fiber length of 10 mm is PP, and a sheath component is an ethylene vinyl alcohol copolymer core-sheath composite fiber, 20 parts by mass; 45 parts by mass of a split type composite fiber composed of a PP component and an ethylene vinyl alcohol copolymer component are mixed together to produce a pulper It is macerated in water, under agitation by the agitator, uniform sheet-forming slurry (1% concentration) to ChoNaru. A raw fabric having a basis weight of 63.3 g / m ² and a width of 50 cm was prepared from the papermaking slurry by a wet papermaking method using a circular paper machine. Next, a calendar process was performed at a roll temperature of 60 ° C., and a corona treatment was performed on both surfaces of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm to obtain a basis weight of 63.3 g / m ² , a thickness. A non-woven fabric having a thickness of 150 μm was produced as an alkaline battery separator.

Example 7
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 87 parts by mass, fineness 1.7 dtex, fiber length 5 mm polyparaphenylene benzo 3 parts by mass of bisoxazole fiber (tensile strength 37 cN / dtex), 10 parts by mass of ethylene vinyl alcohol copolymer fiber having an ethylene content of 44 mol%, a saponification degree of 99.6%, a fineness of 0.08 dtex, and a fiber length of 3 mm Are mixed together, disaggregated in the water of the pulper, and stirred uniformly with an agitator to make a uniform slurry for papermaking 1% concentration) made a tone. A raw fabric having a basis weight of 63.5 g / m ² and a width of 50 cm was produced from the paper slurry using a wet method using a circular paper machine. Next, a calendar process is performed at a roll temperature of 60 ° C., and further, a corona treatment is performed on both sides of the base fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm, and a basis weight of 63.5 g / m ² , thickness A non-woven fabric having a thickness of 150 μm was produced as an alkaline battery separator.

Example 8
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 92 parts by mass, fineness 1.7 dtex, fiber length 5 mm polyparaphenylene benzo 3 parts by mass of bisoxazole fiber (tensile strength 37 cN / dtex), 5 parts by mass of ethylene vinyl alcohol copolymer fiber having an ethylene content of 44 mol%, a saponification degree of 99.6%, a fineness of 0.01 dtex, and a fiber length of 3 mm Are mixed together, disaggregated in pulper water, and stirred with an agitator to produce a uniform papermaking slurry ( % Concentration) made a tone. A raw fabric having a basis weight of 63.3 g / m ² and a width of 50 cm was prepared from the paper slurry by a wet method using a circular paper machine. Next, a calendar process was performed at a roll temperature of 60 ° C., and a corona treatment was performed on both surfaces of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm to obtain a basis weight of 63.3 g / m ² , a thickness. A non-woven fabric having a thickness of 153 μm was produced as an alkaline battery separator.

Example 9
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 77 parts by mass, fineness 1.7 dtex, fiber length 5 mm polyparaphenylene benzo 3 parts by mass of bisoxazole fiber (tensile strength 37 cN / dtex), 20 parts by mass of ethylene vinyl alcohol copolymer fiber having an ethylene content of 44 mol%, a saponification degree of 99.6%, a fineness of 0.08 dtex, and a fiber length of 3 mm Are mixed together, disaggregated in the water of the pulper, and stirred uniformly with an agitator to make a uniform slurry for papermaking 1% concentration) made a tone. A raw fabric having a basis weight of 64.1 g / m ² and a width of 50 cm was prepared from the paper slurry using a wet method using a circular paper machine. Next, a calendar process is performed at a roll temperature of 60 ° C., and further, a corona treatment is performed on both surfaces of the raw cloth using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm, and a basis weight of 64.1 g / m ² , a thickness is obtained. A non-woven fabric having a thickness of 148 μm was produced and used as an alkaline battery separator.

Example 10
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 77 parts by mass, fineness 1.7 dtex, fiber length 5 mm polyparaphenylene benzo 3 parts by mass of bisoxazole fiber (tensile strength 37 cN / dtex), 20 parts by mass of ethylene vinyl alcohol copolymer fiber having an ethylene content of 44 mol%, a saponification degree of 99.6%, a fineness of 0.08 dtex, and a fiber length of 3 mm Are mixed together, disaggregated in the water of the pulper, and stirred uniformly with an agitator to make a uniform slurry for papermaking 1% concentration) made a tone. A raw fabric having a basis weight of 64.4 g / m ² and a width of 50 cm was produced from the paper slurry by a wet method using a circular paper machine. Next, a calendar process is performed at a roll temperature of 60 ° C., and a corona treatment is performed on both surfaces of the raw cloth using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm to obtain a basis weight of 64.4 g / m ² , a thickness. A non-woven fabric having a thickness of 145 μm was produced and used as a separator for an alkaline battery.

Example 11
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 93 parts by mass, polyparaphenylene benzo having a fineness of 1.7 dtex and a fiber length of 5 mm 3 parts by mass of bisoxazole fiber (tensile strength 37 cN / dtex), 4 parts by mass of ethylene vinyl alcohol copolymer fiber having an ethylene content of 44 mol%, a saponification degree of 99.6%, a fineness of 0.01 dtex, and a fiber length of 3 mm Are mixed together, disaggregated in pulper water, and stirred with an agitator to produce a uniform papermaking slurry ( % Concentration) made a tone. A raw fabric having a basis weight of 63.0 g / m ² and a width of 50 cm was prepared from the paper slurry using a wet method using a circular paper machine. Next, a calendar process was performed at a roll temperature of 60 ° C., and a corona treatment was performed on both sides of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm to obtain a basis weight of 63.0 g / m ² , a thickness. A non-woven fabric having a thickness of 152 μm was produced as an alkaline battery separator.

Comparative Example 1
95 parts by mass of polyparaphenylenebenzobisoxazole fiber (tensile strength: 37 cN / dtex) with a fineness of 1.7 dtex and fiber length of 5 mm and 5 parts by mass of polyvinyl alcohol fiber (Kuraray, product name: VPW 1 × 3) are mixed together. Then, the pulper is disaggregated in water, and a uniform papermaking slurry (1% concentration) is prepared under stirring by an agitator. A raw cloth having a basis weight of 60.0 g / m ² and a width of 50 cm was produced from the slurry for paper making by a wet paper making method using a circular paper machine. Next, a corona treatment was performed on both surfaces of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm, and finally a calender treatment was performed at a roll temperature of 60 ° C. to adjust the thickness. A nonwoven fabric having a basis weight of 60.0 g / m ² and a thickness of 150 μm was produced as a separator for an alkaline battery.

Comparative Example 2
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 85 parts by mass, ethylene content 44 mol%, fineness 0.08 dtex, 15 parts by mass of ethylene vinyl alcohol copolymer fiber with a fiber length of 3 mm is mixed together, disaggregated in pulper water, and a uniform papermaking slurry (1% concentration) is prepared under stirring by an agitator or the like. . A raw cloth having a basis weight of 63.0 g / m ² and a width of 50 cm was prepared from the slurry for paper making by a wet paper making method using a circular paper machine. Next, corona treatment was performed on both surfaces of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm, and finally a calender treatment was performed at a roll temperature of 60 ° C. to adjust the thickness. A nonwoven fabric having a basis weight of 63.0 g / m ² and a thickness of 150 μm was produced as a separator for an alkaline battery.

Comparative Example 3
Aliphatic polyamide fiber having a fineness of 0.7 dtex and a fiber length of 5 mm (a nylon 66, a melting point of 260 ° C., a glass transition point of 50 ° C., 100 mol% of the dicarboxylic acid component is adipic acid, and 100 mol% of the diamine component is hexamethylene diamine. 85 parts by mass of tensile strength 6.0 cN / dtex) and 15 parts by mass of ethylene vinyl alcohol copolymer fiber having an ethylene content of 44 mol%, a fineness of 0.08 detex, and a fiber length of 3 mm were mixed together, And a uniform papermaking slurry (1% concentration) is prepared under stirring by an agitator. A raw fabric having a basis weight of 62.4 g / m ² and a width of 50 cm was prepared from the slurry for paper making by a wet paper making method using a circular paper machine. Next, corona treatment was performed on both surfaces of these two types of base fabrics using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm, and finally a calender treatment was performed at a roll temperature of 60 ° C. to adjust the thickness. A nonwoven fabric having a basis weight of 62.4 g / m ² and a thickness of 140 μm was produced as a separator for an alkaline battery.

Comparative Example 4
A fineness of 0.7 dtex in which 100 mol% of the dicarboxylic acid component is terephthalic acid, 50 mol% of the diamine component is 1,9-nonanediamine, and the remaining 50 mol% of the diamine component is 2-methyl-1,8-octadiamine, Stretched semi-aromatic polyamide fiber having a fiber length of 10 mm (manufactured by Kuraray Co., Ltd., melting point 265 ° C., softening temperature 200 ° C., tensile strength 3.7 cN / dtex) 70 parts by mass, fineness 1.7 dtex, para-type total fragrance having a fiber length of 5 mm 15 parts by mass of an aromatic polyamide fiber (tensile strength 19 cN / dtex), 15 parts by mass of an ethylene vinyl alcohol copolymer fiber having an ethylene content of 44 mol%, a saponification degree of 99.6%, a fineness of 0.08 dtex, and a fiber length of 3 mm Are mixed together, disaggregated in pulper water, and stirred with an agitator to form a uniform papermaking slurry (1% concentration). Form was. A raw fabric having a basis weight of 62.8 g / m ² and a width of 50 cm was produced from the paper slurry by a wet method using a circular paper machine. Next, a calendering process was performed at a roll temperature of 60 ° C., and a corona treatment was performed on both surfaces of the raw fabric using an electrode 20 mm wide × 600 mm and a dielectric high baron 3.2 mm to obtain a basis weight of 62.8 g / m ² , a thickness. A non-woven fabric having a thickness of 141 μm was manufactured and used as an alkaline battery separator.

  The battery separators obtained in the examples and comparative examples were evaluated as follows, and the results are shown in Table 1.

<Evaluation method>
[Evaluation of defective rate during battery manufacturing]
As the current collector of the electrode, a paste type nickel hydroxide positive electrode (41 mm width) using a foamed nickel base material and a hydrogen storage alloy negative electrode (41 mm width) using a foamed nickel base material are used one by one. Between them, the battery separator of the above-mentioned example having a width of 44 mm or the battery separator of the comparative example was interposed, and each was wound up by using a battery construction machine to produce a spiral electrode group. After the spiral electrode group is housed in a cylindrical metal case, an alkaline electrolyte mainly composed of 7N potassium hydroxide aqueous solution containing 1N lithium hydroxide is injected, a sealing lid with a safety valve is attached, and the nominal capacity is Ten thousand AA sealed nickel-hydrogen batteries of 1.8 Ah were manufactured. Thereafter, a voltage of 240 V was applied between the positive electrode and the negative electrode, and those having an electric resistance of 1 kΩ or less were determined to be defective, and the defect rate [%] during battery manufacture was determined. If the defect rate [%] during battery production exceeds 0.5%, the economic efficiency deteriorates. If it exceeds 0.9%, not only the economic efficiency is deteriorated but also the practicality is lost.

[Process cutting ability]
When the last part of the separator was cut at the time of the battery group winding process, it was cut when there was no problem, but it could be cut, but some fluff remained on the cut surface and there was a concern about trouble, and could not be cut The case is represented by x.

[Alkali resistance]
As the evaluation of alkali resistance, the weight loss rate (%) after alkali treatment was measured. The weight loss rate after the alkali treatment corresponds to the electrolytic solution after collecting three test pieces each having a size of 10 cm × 10 cm from each sample and measuring the weight W (mg) when the water equilibrium state is obtained. It is immersed in an aqueous KOH solution having a specific gravity of 1.30 and stored in an atmosphere of 90 ± 2 ° C. for 30 days. Thereafter, the sample taken out is washed with water and dried until reaching the neutralization point, and the weight W2 (mg) when the water equilibrium state is obtained again is measured. The weight loss rate (%) after the alkali treatment is calculated by the following equation 1. Asked.

(Formula 1)
Weight loss rate after alkali treatment (%) = [(W−W2) / W] × 100

[Rapid charge / discharge test]
As the current collector of the electrode, a paste type nickel hydroxide positive electrode (41 mm width) using a foamed nickel base material and a sintered cadmium negative electrode (41 mm width) using a nickel plated punching metal base material are used one by one. Between these electrodes, the battery separator of the above-mentioned Example having a width of 44 mm or the battery separator of the comparative example was interposed, and each was wound up by using a battery construction machine to prepare a spiral electrode group. After the spiral electrode group is housed in a cylindrical metal case, an alkaline electrolyte mainly composed of 7N potassium hydroxide aqueous solution containing 1N lithium hydroxide is injected, a sealing lid with a safety valve is attached, and the nominal capacity is Twenty AA sealed nickel cadmium batteries of 1.0 Ah were produced. In order to form the battery, charging and discharging were repeated four times at 25 ° C., charging at 0.1 C for 15 hours, and discharging until the terminal voltage reached 0.8 V at a current of 1 C.

  The remaining 10 formed batteries were charged at a high temperature of 90 ° C. with a current of 1 C for 1.2 hours and discharged with a current of 1 C until the terminal voltage reached 1.0 V. Lifespan was evaluated. Less than 500 cycles were represented by x, 500-749 cycles were represented by Δ, and 750 cycles or more were represented by ○.

  The battery separator of the present invention obtained in the examples is a nonwoven fabric containing a semi-aromatic polyamide fiber excellent in heat resistance and oxidation deterioration resistance and a polyparaphenylene benzobisoxazole fiber excellent in mechanical strength. As a result, good results were obtained. On the other hand, the battery separator obtained in Comparative Example 1 is composed of polyparaphenylene benzobisoxazole fibers other than the binder fibers, and the short fiber strength of the polyparaphenylene benzobisoxazole fibers is too strong. It is impossible to cut at the end of the battery separator. In addition, the battery separator obtained in Comparative Example 2 is composed of semi-aromatic polyamide fiber other than the binder fiber, and the adhesiveness with the binder fiber is good, but the mechanical strength of the fiber is low, The strength against the edges and burrs of the electrode is low, and the defect rate during battery production is high. However, in the battery separator of the present invention obtained in the examples, the semi-aromatic polyamide fiber is a binder fiber (unstretched aromatic polyamide fiber, ethylene vinyl alcohol copolymer fiber, the core is a PP component, and the sheath is a PP co-polymer. Manufactured as a battery with a combined component, such as core-sheath type composite fiber), and polyparaphenylene benzobisoxazole fiber exhibits mechanical strength. The defective rate at the time was reduced.

  In addition, the battery manufactured using the battery separator of the present invention has a higher resistance to heat at a higher temperature than the battery manufactured using the battery separator made of aliphatic polyamide fiber other than the binder fiber manufactured in Comparative Example 3. Since it was excellent in alkalinity, the battery operated stably even in the rapid charge / discharge test at 90 ° C.

  In addition, the battery manufactured using the battery separator of the present invention was compared with the battery manufactured using the battery separator made of para-type wholly aromatic polyamide fiber as the high-strength fiber manufactured in Comparative Example 4. Since the alkali resistance at high temperature was excellent, the battery operated stably even in the rapid charge / discharge test at 90 ° C.

Claims (7)

  Semi-aromatic that is polycondensed from a dicarboxylic acid component in which 60 mol% or more of the dicarboxylic acid component is an aromatic carboxylic acid component and a diamine component in which 60 mol% or more of the diamine component is an aliphatic alkylenediamine having 6 to 12 carbon atoms Battery separator comprising a non-woven fabric containing an aromatic polyamide fiber and a polyparaphenylene benzobisoxazole fiber.   The battery separator according to claim 1, wherein the content of the semi-aromatic polyamide fiber is 30 to 90% by mass of the nonwoven fabric.   The battery separator according to claim 1 or 2, wherein the content of the polyparaphenylene benzobisoxazole fiber is 3 to 10% by mass of the nonwoven fabric.   Furthermore, the separator for batteries in any one of Claims 1-3 containing a binder fiber.   The battery separator according to claim 4, wherein the binder fiber is at least one of an ethylene vinyl alcohol copolymer fiber, a composite fiber containing an ethylene vinyl alcohol copolymer, and a polyolefin-based core-sheath type heat-sealing fiber.   The battery separator according to claim 4 or 5, wherein the content of the binder fiber is adjusted to 5 to 20% by mass of the nonwoven fabric.   7. The weight loss rate after 30 days of the battery separator is 10% or less in an alkali resistance test with a KOH aqueous solution at 90 ° C. and a specific gravity of 1.30, according to claim 1. Battery separator.