JP2002008620A - Separator for alkaline storage battery and alkaline storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separator for an alkaline storage battery which has a lower cost compared with a sulfonated polypropylene separator, or the like and which is superior in water resistance, hydrophilic property and liquid- retaining property, and which is superior in self-discharge property and cycle life property. SOLUTION: The separator for the alkaline storage battery is the separator which is composed of a positive electrode, a negative electrode, a separator and an alkaline electrolytic solution, and which is used for the alkaline storage battery. A surface of the separator substrate is coated by a coating film prepared by photocuring a composition containing diene series (co-)polymer having a sulfonate group and a photo-radical initiator. Further, this alkaline storage battery is composed of the separator for the alkaline storage battery, the positive electrode, the nagative electrode, and the alkaline electrolytic solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an alkaline storage battery separator and an alkaline storage battery. For more information,
Alkaline storage battery separator coated with a coating obtained by photocuring a composition containing a diene-based (co) polymer having a sulfonic acid group and a photoradical generator, and storage characteristics and life including the alkaline storage battery separator The present invention relates to an alkaline storage battery having excellent characteristics.

[0002]

2. Description of the Related Art Currently, lead-acid batteries are mainly used as large-sized batteries such as automobile start (SLI) batteries. Alkaline storage batteries such as nickel-cadmium storage batteries or nickel-hydrogen storage batteries that are more excellent in energy density are widely used as power supplies for small consumer appliances.

On the other hand, in recent years, in order to appropriately deal with environmental problems, efforts have been made to reduce exhaust gas from automobiles from various angles.
Although the development of electric vehicles has been promoted, development of a power supply battery having excellent storage characteristics, life characteristics, and the like is desired for practical use of electric vehicles. Currently, lead-acid batteries are mainly used as power sources for driving these electric vehicles.
The lead-acid battery has a problem that it is heavy and has low energy density because it uses lead as an active material.
For this reason, the development of alkaline storage batteries such as nickel-cadmium storage batteries or nickel-hydrogen storage batteries that can provide higher output, higher energy density, longer life, larger size, and higher capacity than lead acid storage batteries is being promoted. Was. In addition, from the viewpoint of ensuring safety and maintenance,
There has been a demand for a sealed alkaline storage battery that does not release gas generated inside the battery to the outside of the battery system.

Heretofore, as such a separator for an alkaline storage battery, a nonwoven fabric made of polyamide or polypropylene fibers has been generally used. However, polyamide separators may decompose in an alkaline electrolyte at high temperatures or due to charge / discharge cycles, resulting in a decrease in hydrophilicity. For this reason, there has been a problem that the amount of electrolyte held in the separator decreases, the internal resistance of the battery increases, and the discharge capacity decreases. Further, when the polyamide is decomposed in the alkaline electrolyte, ammonia is generated, which may cause self-discharge.

[0005] For this reason, a separator made of a polypropylene separator excellent in alkali resistance and further treated with a surfactant to impart hydrophilicity has been used. However, nonionic surfactants such as polyoxyethylene nonyl phenyl ether are used in these separators to impart hydrophilicity, but these surfactants are dissolved in the electrolyte and oxidized at the electrodes. There is a problem that it is reduced and causes self-discharge.

In order to solve such a problem, Japanese Patent Application Laid-Open Nos. 62-115657 and 64-5756 have been proposed.
In Japanese Patent Publication No. 8 (JP-A-8), an attempt has been made to apply a sulfonation treatment to a polyolefin separator which is a porous material used as a base material of the separator. However, a polyolefin-based separator obtained by subjecting a polyolefin substrate to a sulfonation treatment has, for example, the following problems.

(1) In the above sulfonation process, the separator is immersed in concentrated sulfuric acid, then neutralized, washed with a large amount of water and dried, so that the process becomes complicated and requires a long time. There are also high costs. (2) By the sulfonation treatment, the carbon-carbon bond of the polyolefin is broken, and the strength of the separator may be reduced.

(3) Since the inside of the separator fiber is not sufficiently sulfonated and the liquid retention amount of the separator is small,
The cycle life characteristics and high-rate discharge characteristics of the battery may be inferior. Furthermore, in the case of an alkaline storage battery using a polyolefin-based separator in which a polyolefin substrate is subjected to a sulfonation treatment, the following problem also occurs when an electrolyte is injected into the battery.

(4) In order to realize a high energy density, positive and negative plates are inserted at a high density into a battery case having a fixed volume. It takes a long time to disperse. (5) Even if it takes a long time to inject the electrolytic solution into the battery case, it is difficult to uniformly disperse the electrolytic solution in the electrode plate and the separator, and as a result, the charge / discharge reaction is not uniform. As a result, the cycle life characteristics may deteriorate.

(6) In the distribution of the electrolyte solution in the battery, the electrolyte solution tends to be biased toward the positive electrode, so that it is difficult to uniformly distribute the electrolyte solution on the positive electrode and the negative electrode, and the cycle life characteristics may be deteriorated.
Therefore, the present inventors have conducted intensive research to solve the above problem, and instead of sulfonating the separator substrate, for example, as a separator of an alkaline storage battery, the surface of an unsulfonated separator substrate has a sulfonated surface. When a separator coated with a coating film obtained by photocuring a composition containing a diene-based (co) polymer having an acid group and a photoradical generator is used, the hydrophilicity between the separator and the electrolytic solution can be improved.
Alternatively, a separator having excellent water retention can be obtained as well as excellent electrolyte retention properties of the separator, and a storage battery using the separator has excellent self-discharge characteristics and life characteristics of the battery, and is low-cost and simple. They have found that an alkaline storage battery can be obtained, and have completed the present invention.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems associated with the prior art as described above, and to provide a low-cost and simple separator having sufficient hydrophilicity, liquid retention and strength. It is another object of the present invention to provide an alkaline storage battery using the separator and having excellent self-discharge characteristics and life characteristics.

[0012]

SUMMARY OF THE INVENTION A separator for an alkaline storage battery according to the present invention is a separator for use in an alkaline storage battery comprising a positive electrode, a negative electrode, a separator, and an alkaline electrolyte. The composition is characterized by being coated with a photocured coating film of a composition containing a diene (co) polymer having the formula (1) and a photoradical generator.

The diene-based (co) compounds having a sulfonic acid group
The polymer preferably contains a structural unit derived from a diene compound and a structural unit derived from an aromatic compound. The coating film is preferably a coating film obtained by photocuring a composition in which a photoradical generator and a diene (co) polymer having a sulfonic acid group are emulsified and dispersed or dissolved in an aqueous medium. The separator base of the alkaline storage battery separator is preferably made of a nonwoven fabric. Further, the nonwoven fabric preferably has an average fiber diameter of 0.1 to 40 μm and a basis weight of 10 to 300 g / m ² .

[0014] The alkaline storage battery according to the present invention is characterized by comprising the alkaline storage battery separator, a positive electrode, a negative electrode, and an alkaline electrolyte.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The alkaline storage battery separator according to the present invention is a separator used for an alkaline storage battery comprising a positive electrode, a negative electrode, a separator, and an alkaline electrolyte. A composition containing a diene (co) polymer having a sulfonic acid group and a photo-radical generator (hereinafter sometimes referred to as “photo-curable hydrophilic resin composition”) is coated with a photo-cured coating film. Have been. Hereinafter, a photocurable hydrophilic resin composition, a photoradical generator, a separator for an alkaline storage battery, an alkaline storage battery, and the like comprising the same will be described.

[ Photocurable hydrophilic resin composition] The photocurable hydrophilic resin composition according to the present invention contains a diene (co) polymer having a sulfonic acid group and a photoradical generator. ing. Further, the photocurable hydrophilic resin composition may contain a compound having one or more polymerizable unsaturated bonds in the molecule, if necessary. Hereinafter, a diene (co) polymer having a sulfonic acid group, a photoradical generator, a compound having one or more polymerizable unsaturated bonds in a molecule, a photocurable hydrophilic resin composition, and the like will be described in detail. In this specification, the sulfonic acid group includes a sulfonic acid group and a salt thereof.

(Diene-based (co) polymer having sulfonic acid group) The diene-based (co) polymer (hereinafter sometimes referred to as "base polymer") according to the present invention is a diene-based compound (hereinafter referred to as "diene monomer"). ), And, if necessary, a (co) polymer containing a structural unit derived from another monomer different from the diene monomer. The diene-based (co) polymer according to the present invention may be a (co) polymer in which some or all of the unsaturated double bonds contained in these (co) polymers are hydrogenated, if necessary. It may be.

The diene (co) polymer having a sulfonic acid group according to the present invention is a sulfonated product of such a diene (co) polymer. As described later, the diene (co) polymer having a sulfonic acid group of the diene (co) polymer is obtained by sulfonating a diene (co) polymer having a diene monomer as an essential component, Alternatively, in the polymerization of the diene (co) polymer, it can be obtained by copolymerizing a monomer containing a sulfonic acid group.

Instead of the diene (co) polymer serving as the base polymer according to the present invention, a (co) polymer derived from an olefin compound such as an aromatic vinyl compound or an olefin, A (co) polymer obtained by hydrogenating the (co) polymer can also be used. Also,
Instead of the sulfonic acid group, a carboxylic acid group (carboxylic acid group), a phosphoric acid group, an amine group, an amide group, a hydroxyl group and the like can also be used.

(Diene-Based Compound (Diene Monomer)) Examples of the diene monomer capable of deriving the diene (co) polymer according to the present invention include 1,3-butadiene and
1,2-butadiene, 1,2-pentadiene, 1,3-
Pentadiene, 2,3-pentadiene, isoprene,
1,2-hexadiene, 1,3-hexadiene, 1,4
-Hexadiene, 1,5-hexadiene, 2,3-hexadiene, 2,4-hexadiene, 2,3-dimethyl-
1,3-butadiene, 2-ethyl-1,3-butadiene, 1,2-heptadiene, 1,3-heptadiene,
1,4-heptadiene, 1,5-heptadiene, 1,6
-Heptadiene, 2,3-heptadiene, 2,5-heptadiene, 3,4-heptadiene, 3,5-heptadiene, cyclopentadiene, dicyclopentadiene, ethylidene norbornene, and the like, and further having 4 to 7 carbon atoms. Branched various aliphatic or alicyclic dienes are also included. These can be used alone or in combination of two or more. In the present invention, among these, 1,3-butadiene, isoprene, 1,3-
Pentadiene can be preferably used.

(Other Monomers) The diene (co) polymer according to the present invention may contain, in addition to these diene monomers, structural units derived from other monomers. Such other monomers include, for example, styrene,
Aromatic compounds such as α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, vinylnaphthalene, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, etc. (Meth) acrylic acid alkyl ester, (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, etc., mono- or dicarboxylic acid or dicarboxylic acid anhydride, (meth) acrylonitrile, etc. vinyl chloride, chloride Vinyl, vinylidene chloride, vinyl methyl ethyl ketone, vinyl acetate, (meth) acrylamide,
And unsaturated compounds such as glycidyl (meth) acrylate. These other monomers can be used alone or in combination of two or more.

Among them, as the diene (co) polymer according to the present invention, those having a structural unit derived from the diene monomer and a structural unit derived from the aromatic compound are preferably used. When these other monomers are used in combination, the amount used is preferably 99.5% by weight.
The content is more preferably 99% by weight or less, particularly preferably 95% by weight or less. When the amount of the other monomer used in combination exceeds 99.5% by weight, the content of the diene monomer becomes less than 0.5% by weight, and the sulfonic acid (salt) group content introduced into the sulfonated product obtained by sulfonation Is lower.

(Diene (co) polymer (base polymer)
-) Production method) The diene-based (co) polymer according to the present invention is obtained by subjecting a diene monomer and, if necessary, other monomers to radical polymerization of hydrogen peroxide, benzoyl peroxide, azobisisobutyronitrile, etc. In the presence of an initiator or an anionic polymerization initiator such as n-butyllithium, sodium naphthalene, or sodium metal, a known solvent is used, if necessary, usually in the range of -100 to 150.
(Co) polymerization at 0 ° C, preferably 0 to 130 ° C.

(Co) polymers obtained by hydrogenating a part or all of the remaining double bonds of these diene (co) polymers (hereinafter referred to as "hydrogenation") can also be used. . In this case, a known hydrogenation catalyst can be used, and for example, a catalyst and a method described in JP-A-5-222115 can be employed. The order of introduction and hydrogenation of the sulfone group into the diene (system) copolymer is not particularly limited, and the diene (co) polymer may be sulfonated by the method described below after hydrogenation. , The (co)
After sulfonating the polymer, it can be hydrogenated.

The diene (co) polymer used in the present invention may be a random copolymer or a diene copolymer.
A block copolymer such as B type or ABA type may be used, and can be used without any particular limitation. Examples of the diene-based (co) polymer according to the present invention thus obtained include, for example, isoprene homopolymer, butadiene homopolymer, isoprene-styrene random copolymer, isoprene-styrene block copolymer, and styrene-copolymer. Isoprene-styrene terpolymer, butadiene-styrene random copolymer, butadiene-styrene block copolymer, styrene-butadiene-styrene block copolymer, and hydrogenated products of these (co) polymers, ethylene- A propylene-diene terpolymer and the like are preferred, and an aromatic compound-conjugated diene block copolymer is more preferred, and a styrene-isoprene block copolymer is more preferred.

Such a diene (co) polymer containing a diene monomer as an essential component has a weight average molecular weight (hereinafter also referred to as “Mw”) in terms of polystyrene of 3,000 to 3,000.
It is preferably 1,000,000, more preferably 5,000 to 500,000, particularly preferably 1 to 500,000.
It is between 0.00000 and 400,000. Mw is 3,000
If it is less than 1, the tensile strength may be low, while if it exceeds 1,000,000, the solubility in organic solvents may be poor.

(Diene (co) polymer (base polymer)
Method for introducing sulfonic acid group into ( -)) As a method for containing a sulfonic acid group in a diene (co) polymer, a method for adding a sulfonic acid group to a diene (co) polymer, and a method for containing a sulfonic acid group A method of copolymerizing a monomer may be used. Among them, in the present invention, a method of adding a hydrophilic group to the (co) polymer is preferably used.

Hereinafter, a method for introducing a sulfone group will be described.
(1) a method of copolymerizing a sulfonic acid group-containing monomer, and
(2) The method for sulfonating the (co) polymer will be described in the order. (1) Method of copolymerizing sulfonic acid group-containing monomer It is used for producing a (co) polymer containing a sulfonic acid (salt) group by copolymerizing a monomer having a sulfonic acid group. Examples of the monomer having a sulfonic acid group include those obtained by adding a sulfonic acid group to the diene monomer or the olefin compound. Specific examples of these include:
Examples thereof include sulfonic acid group-containing butadiene, sulfonic acid group-containing isoprene, sulfonic acid group-containing styrene, sulfonic acid group-containing ethylene, and sulfonic acid group-containing propylene. Of these, sulfonic acid group-containing isoprene and sulfonic acid group-containing styrene can be preferably used.

The diene (co) polymer having a sulfone group according to the present invention can be obtained by copolymerizing these sulfone group-containing monomers with the diene monomer and, if necessary, other monomers. . (2) Method for sulfonating (co) polymer As a method for sulfonating the diene (co) polymer according to the present invention, known methods, for example, edited by the Japan Society of Science, New Experimental Course (Vol. 14, III, 1773) or the method described in JP-A-2-227403.

Specifically, the diene (co) polymer has a sulfonic acid group by sulfonating a double bond portion in the (co) polymer using a sulfonating agent ( A (co) polymer can be obtained. In the sulfonation, a sulfonic acid (salt) is bonded to a double bond to form a single bond, or a hydrogen atom is replaced with a sulfonic acid (salt) while the double bond remains. When the other monomer is used, for example, a double bond derived from an aromatic compound may be sulfonated in addition to a double bond derived from a diene monomer.

As the sulfonating agent, preferably a complex of sulfuric anhydride and an electron donating compound, sulfuric acid, sulfuric anhydride, chlorosulfonic acid, fuming sulfuric acid, bisulfite (Na
Salt, K salt, Li salt, etc.).
Examples of the electron-donating compound that forms a complex with sulfuric anhydride include ethers such as N, N-dimethylformamide, dioxane, dibutyl ether, tetrahydrofuran, and diethyl ether; amines such as pyridine, piperazine, trimethylamine, triethylamine, and tributylamine. Sulfides such as dimethyl sulfide and diethyl sulfide; nitrile compounds such as acetonitrile, ethyl nitrile, and propyl nitrile;
Of these, N, N-dimethylformamide and dioxane are preferred.

The amount of the sulfonating agent is usually from 0.005 to 1.5 mol, preferably from 0.01 to 1.0 mol, in terms of sulfuric anhydride, relative to 1 mol of the diene unit in the base polymer.
Desirably it is molar. During this sulfonation,
A solvent inert to a sulfonating agent such as sulfuric anhydride may be used. Examples of the solvent include halogenated hydrocarbons such as chloroform, dichloroethane, tetrachloroethane, tetrachloroethylene and dichloromethane; nitro compounds such as nitromethane and nitrobenzene. Liquid sulfur dioxide, propane, butane, pentane,
Examples thereof include aliphatic hydrocarbons such as hexane and cyclohexane.

These solvents may be used alone or in combination of two or more. The reaction temperature for this sulfonation is usually -70 to + 200C, preferably -30 to + 50C. In this way, an intermediate in which a sulfonating agent such as sulfuric anhydride is bonded to a diene-based (co) polymer (a sulfonate of a base polymer, hereinafter referred to as an “intermediate”) can be obtained.

The diene (co) polymer having a sulfonic acid group according to the present invention is prepared by reacting the intermediate with water or a basic compound to form a sulfonic acid (salt) on a double bond.
Can be obtained by replacing a hydrogen atom with a sulfonic acid (salt) while leaving a double bond. Examples of the basic compound include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide; sodium methoxide, sodium ethoxide, potassium methoxide, sodium-t-butoxide, potassium-t-butoxide and the like. Alkali metal alkoxides; carbonates such as sodium carbonate, potassium carbonate, and lithium carbonate; methyl lithium, ethyl lithium, n-butyl lithium, sec-butyl lithium, amyl lithium, propyl sodium, methyl magnesium chloride, ethyl magnesium bromide, and propyl magnesium Iodide, diethylmagnesium,
Organometallic compounds such as diethylzinc, triethylaluminum and triisobutylaluminum; aqueous ammonia;
Examples include amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, pyridine, aniline, and piperazine; and metal compounds such as sodium, lithium, potassium, calcium, and zinc.

These basic compounds can be used alone or in combination of two or more. Among these basic compounds, alkali metal hydroxides and aqueous ammonia are preferable, and sodium hydroxide and lithium hydroxide are particularly preferable. The amount of the basic compound used is preferably 2 mol or less, and more preferably 1.3 mol or less, based on 1 mol of the sulfonating agent used.

In the reaction between the intermediate and a basic compound, the above basic compound may be used in the form of an aqueous solution, or may be used by dissolving it in an organic solvent inert to the basic compound. Can also. Such organic solvents include, in addition to the various organic solvents described above, benzene, toluene,
Aromatic hydrocarbon compounds such as xylene, alcohols such as methanol, ethanol, propanol, isopropanol, and ethylene glycol can be used. These solvents can be used alone or in combination of two or more.

When the basic compound is used as an aqueous solution or a solution in an organic solvent, the basic compound concentration is usually
It is desirably about 1 to 70% by weight, preferably about 10 to 50% by weight. The reaction temperature is usually -3.
It is carried out at 0 to + 150 ° C., preferably at 0 to + 120 ° C., more preferably at +50 to + 100 ° C., and is preferably carried out at normal pressure, reduced pressure or increased pressure.
Further, the reaction time is usually desirably 0.1 to 24 hours, preferably 0.5 to 5 hours.

The sulfonic acid (salt) group content of the sulfonic acid group-containing diene (co) polymer thus obtained is preferably from 0.1 to 5.5 mmol / g, more preferably from 0.2 to 5.5 mmol / g. 5 mmol / g, particularly preferably 0.
Desirably, it is 3 to 4.5 mmol / g. 0.1
If the amount is less than mmol / g, adhesion to the substrate, hydrophilicity,
The ion-capturing property etc. decrease, while 5.5 mmol / g
If it exceeds, the strength of the coating film itself decreases.

The structure of the diene (co) polymer having a sulfonic acid group according to the present invention can be confirmed from the absorption of the sulfone group by an infrared absorption spectrum.
It can be confirmed by elemental analysis or the like. The structure can be confirmed by a nuclear magnetic resonance spectrum. When the diene (co) polymer having a sulfonic acid group according to the present invention is a copolymer, the interaction with the substrate can be achieved by introducing a monomer other than the diene monomer. And the adhesiveness can be improved.

Such a diene (co) polymer having a sulfonic acid group can be preferably used in a state of being emulsified and dispersed or dissolved in an aqueous medium. As a method of emulsifying such a diene (co) polymer having a sulfonic acid group in water, a known method can be adopted, and there is no particular limitation. As such an emulsification step, specifically, a method of adding water to an organic solvent solution of a diene (co) polymer having a sulfonic acid group while stirring, a method of adding a diene type having a sulfonic acid group while stirring, A method in which an organic solvent solution of a (co) polymer is added to water, a method in which water and an organic solvent solution of a diene-based (co) polymer having a sulfonic acid group are added at the same time, and stirring is performed.

Examples of the organic solvent used in such an emulsification step include aromatic solvents such as toluene and xylene, aliphatic solvents such as hexane and heptane, ketone solvents such as acetone and methyl ethyl ketone, tetrahydrofuran and dioxane. Examples of such solvents include ether solvents, ester solvents such as ethyl acetate and butyl acetate, and alcohol solvents such as methanol, ethanol, and isopropyl alcohol. These solvents may be used alone or in combination of two or more.

The amount of the organic solvent used at the time of emulsification depends on the amount of the diene (co) polymer 10 having a sulfonic acid group.
The amount is preferably 20 to 5,000 parts by weight, more preferably 50 to 2,000 parts by weight, based on 0 parts by weight. The amount of water used for emulsification is determined by the amount of the diene (co) polymer 100 having a sulfonic acid group.
It is preferably 50 to 10,000 parts by weight, more preferably 100 to 5,000 parts by weight, based on parts by weight.

In the emulsification, a surfactant may be used in combination. Examples of such surfactants include nonionic surfactants such as polyoxyethylene alkyl ether, polyoxysorbitan ester, and polyoxyethylene alkylamine ether, oleate, laurate, rosinate, dodecylbenzene sulfone. Acid surfactants, anionic surfactants such as polyoxyethylene alkyl ether sulfate, cationic surfactants such as octyltrimethylammonium bromide, dioctyldimethylammonium chloride, dodecylpyridinium chloride, perfluoroalkyl sulfonates, Examples include fluorine-based surfactants such as fluoroalkyl carboxylate, fluorinated alkyl ester, perfluoroalkyl polyoxyethylene ethanol, and perfluoroalkyl alkoxylate. It is. These surfactants can be used alone or in combination of two or more.

The surfactant may be used by dissolving or dispersing it in an organic solvent solution of a diene (co) polymer having a sulfonic acid group, or may be used by dissolving or dispersing it in water. The amount of the surfactant to be used is usually 15 parts by weight or less, preferably 10 parts by weight or less, based on 100 parts by weight of the diene (co) polymer having a sulfonic acid group.

At the time of sulfonation, an alkali compound such as sodium hydroxide or lithium hydroxide, or an inorganic acid such as hydrochloric acid or sulfuric acid can be added to adjust the pH in the system. If the amount is small, an organic solvent other than water can be used in combination. The particle size of the emulsion obtained by emulsifying the diene (co) polymer having a sulfonic acid group thus obtained is usually 10 to 1,000 nm,
Preferably, it is 20 to 500 nm.

The solid concentration of the resulting diene (co) polymer emulsion having sulfonic acid groups is usually
It is desirably 5 to 50% by weight, preferably 10 to 40% by weight, and these can be appropriately selected depending on use conditions, storage conditions and the like. The diene (co) polymer having a sulfonic acid group used in the present invention may be used in combination of two or more. In this case, the combination of the preferable structures of the diene (co) polymer is not particularly limited, and various combinations such as a random type and an AB block type, an AB block type and an ABA block type, and an ABA block type and an ABA block type may be used. .

Further, the diene (co) polymer having a sulfonic acid group according to the present invention can be used as a mixture with a (co) polymer having no hydrophilic group. When the diene (co) polymer having a sulfonic acid group according to the present invention is used as a mixture of two or more kinds, or mixed with a (co) polymer having no sulfonic acid group, the sulfonation is carried out before sulfonation. During,
After sulfonation, during emulsification, after emulsification, etc., they may be mixed and used at any stage.

[Photo-radical generator] The photo-radical generator used in the present invention is not particularly limited as long as it can be decomposed by light irradiation to generate radicals and initiate polymerization, for example, acetophenone, Acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone,
4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, benzoin propyl ether, benzoin ethyl ether,
Benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-
On, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio)
Phenyl] -2-morpholino-propan-1-one, 2
-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2,4,6-trimethylbenzoyl Diphenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl ) Propanone).

As the photo-radical generator, commercially available ones can be used. For example, trade names: Irgacure 184, 369, 6 manufactured by Ciba Specialty Chemicals Co., Ltd.
51, 500, 819, 907, 784, 2959, C
GI1700, CGI1750, CGI1850, CG
24-61, Darocure 1116, 1173, BASF
Brand name: Lucirin LR8953, LR8893,
Product name: Ubecryl P36, Fratetsuri
Product name: Ember Cure KIP15, manufactured by Lamberti
0, KIP65LT, KIP100F, KT37, KT
55, KTO46, KIP75 / B and the like.

The amount of the photo-radical generator according to the present invention is determined by the amount of the diene (co) polymer 100 having a sulfonic acid group.
Preferably, the amount is 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, based on parts by weight. If the compounding ratio is less than 0.01 parts by weight, the hardness of the cured product may be insufficient, and if it exceeds 20 parts by weight, the cured product does not cure to the inside (lower layer). There is.

[ Having one or more polymerizable unsaturated groups in the molecule ]
Compound] The photocurable hydrophilic resin composition according to the present invention comprises:
If necessary, a compound containing one or more polymerizable unsaturated groups in the molecule may be contained. The compound having one or more polymerizable unsaturated groups in the molecule is not particularly limited as long as it contains one or more polymerizable unsaturated groups. For example, (meth) acrylic esters, vinyl compounds And the like.

Such (meth) acrylic esters include, for example, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth)
Acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di ( (Meth) acrylate, dipropylene glycol di (meth) acrylate, bis (2-
(Hydroxyethyl) isocyanurate di (meth) acrylate, poly (meth) acrylates of ethylene oxide or propylene oxide adducts of these starting alcohols, oligoesters having two or more (meth) acryloyl groups in the molecule A) acrylates, oligoether (meth) acrylates, oligourethane (meth) acrylates, and oligoepoxy (meth)
Acrylates and the like can be mentioned.

The vinyl compounds include, for example,
Examples include styrene, divinylbenzene, ethylene glycol divinyl ether, diethylene glycol divinyl ether, and triethylene glycol divinyl ether. Other than these, for example, methyl (meth) acrylate, ethyl (meth) acrylate, (meth)
Alkyl (meth) acrylate such as butyl acrylate, mono- or dicarboxylic acid or anhydride of dicarboxylic acid or dicarboxylic acid such as (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid; vinyl such as (meth) acrylonitrile Cyanide, vinyl chloride, vinylidene chloride, vinyl methyl ethyl ketone, vinyl acetate,
Compounds such as (meth) acrylamide, glycidyl (meth) acrylate, and N, N'-methylenebisacrylamide may be contained in the photocurable hydrophilic resin composition.

Commercially available products of such compounds include, for example, Alonix M-4 manufactured by Toagosei Co., Ltd.
00, M-408, M-450, M-305, M-30
9, M-310, M-315, M-320, M-35
0, M-360, M-208, M-210, M-21
5, M-220, M-225, M-233, M-24
0, M-245, M-260, M-270, M-110
0, M-1200, M-1210, M-1310, M-
1600, M-221, M-203, TO-924, T
O-1270, TO-1231, TO-595, TO-
756, TO-1343, TO-902, TO-90
4, TO-905, TO-1330, manufactured by Nippon Kayaku Co., Ltd. Trade name: KAYARAD D-310, D-330,
DPHA, DPCA-20, DPCA-30, DPCA
-60, DPCA-120, DN-0075, DN-2
475, SR-295, SR-355, SR-399
E, SR-494, SR-9041, SR-368, S
R-415, SR-444, SR-454, SR-49
2, SR-499, SR-502, SR-9020, S
R-9035, SR-111, SR-212, SR-2
13, SR-230, SR-259, SR-268, S
R-272, SR-344, SR-349, SR-60
1, SR-602, SR-610, SR-9003, P
ET-30, T-1420, GPO-303, TC-1
20S, HDDA, NPGDA, TPGDA, PEG4
00DA, MANDA, HX-220, HX-620,
R-551, R-712, R-167, R-526, R
-551, R-712, R-604, R-684, TM
PTA, THE-330, TPA-320, TPA-3
30, KS-HDDA, KS-TPGDA, KS-TM
PTA, manufactured by Kyoeisha Chemical Co., Ltd .: Light acrylate PE-4A, DPE-6A, DTMP-4A and the like.

When the compound having one or more polymerizable unsaturated bonds in the molecule is blended with the photocurable hydrophilic resin composition according to the present invention, the amount of the compound is as follows. The content is preferably 200% by weight or less, more preferably 100% by weight or less, and particularly preferably 50% by weight or less based on 100 parts by weight of the conductive resin composition. If the compounding amount exceeds 200% by weight, the ratio of the hydrophilic group to the obtained cured product becomes small, and the desired performance relating to hydrophilicity or the like may not be obtained.

These compounds having one or more polymerizable unsaturated bonds in the molecule can be added as they are, or the photocurable hydrophilic resin composition according to the present invention can be used in an aqueous solution,
Alternatively, when used as an emulsion, it can be added after emulsified and dispersed in water. These compounds having one or more polymerizable unsaturated bonds in the molecule can be used alone or in combination of two or more.

[Alkaline Storage Battery Separator] The separator for an alkaline storage battery according to the present invention has a composition in which the surface of the separator substrate contains the diene (co) polymer having a sulfonic acid group and a photoradical generator ( (A photo-curable hydrophilic resin composition). (Separator substrate) The separator substrate of the separator according to the present invention is not particularly limited as long as it separates the positive electrode and the negative electrode of the battery, holds the electrolytic solution, and does not allow a short-circuit current to pass. As the material, a non-woven fabric is preferable. As a material of the nonwoven fabric used in the present invention, a known (co) polymer can be used and is not particularly limited. Such (co) polymers include, for example, olefin homopolymers such as ethylene, propylene, butene-1, pentene-1, hexene-1, and 4-methylpentene-1, and random or block olefins. Copolymers, polyamides, polyesters, acrylic polymers, ethylene-vinyl alcohol copolymers and the like can be mentioned. These can be used alone or in combination of two or more. this house,
The separator according to the present invention is preferably composed of an olefin (co) polymer such as ethylene or propylene.

As a method of using two or more kinds of polymers in combination, a method of blending and melting the two into fibers, a method of mixing or twisting each fiber into fibers, a method of blending both fibers, a method of blending each fiber, And a method of forming a split fiber composed of both fibers. In addition, as the separator base material, a separator base material treated by sulfonation or the like can be used as long as the characteristics of the separator according to the present invention are not impaired.

The method for preparing the nonwoven fabric is not particularly limited, and a known method can be employed. In particular, a method produced by a spunlace method, a melt blow method, a wet papermaking method or the like can be preferably used. The nonwoven fabric may be used after being subjected to a stretching treatment by any method such as a hot roll method and a pin tenter method. The basis weight of the nonwoven fabric is preferably 10 to 300.
g / m ^2, even more preferably from 20 to 150 g / m ^2, especially 40 and 80 g / m ² is preferred. The basis weight refers to the weight of the nonwoven fabric per unit area. The average fiber diameter is preferably 0.1 to 40 μm, more preferably 1 to 40 μm.
-30 μm, particularly preferably 3-20 μm. The thickness of the nonwoven fabric is usually 10 to 5000 μm.
It is more preferable that the thickness be 20 to 2000 μm, more preferably 50 to 1000 μm.

As the nonwoven fabric used for the separator of the present invention, a nonwoven fabric containing known additives such as an antioxidant, an antioxidant, a lubricant, and an ultraviolet absorber may be used. (Coating method) The photocurable hydrophilic resin composition according to the present invention is usually used as it is or in a state of being emulsified and dispersed or dissolved in an aqueous medium, coated on a separator substrate, and further photocured. You. The coating method is not particularly limited, and brush coating, spray, roll coater, flow coater, bar coater, dipping treatment, or the like can be used.

When the composition is applied as an emulsion,
At the time of coating, aromatic solvents such as toluene and xylene, aliphatic solvents such as hexane and heptane, ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as tetrahydrofuran and dioxane, and ester solvents such as ethyl acetate and butyl acetate. It is also possible to use an alcohol-based solvent such as methanol, ethanol, isopropyl alcohol and n-butanol in combination. Coating performance and the like can be improved by using these organic solvents in combination.

The amount of the composition coated on the separator substrate when coated with the composition varies depending on the material and pore size of the separator and cannot be unconditionally defined, but is usually 0.1 to 50 g / m ² , preferably 0.1 to 50 g / m ² . 5-
30 g / m ² , more preferably 1 to 10 g / m ²
Desirably ² . If the amount is less than 0.1 g / m ^2, it is difficult to exhibit an improvement in affinity with the electrolyte for a battery and an improvement in the liquid retaining property of the electrolyte, and the improvement in battery performance such as self-discharge property may not be observed. On the other hand, if it exceeds 50 g / m ² , clogging of a base material such as a coated nonwoven fabric may occur, and battery performance may be reduced.

The coating film thickness is a dry film thickness, usually 0.01
It is desirable that the thickness be in the range of ~ 1,000 microns, preferably 0.05-500 microns. (Curing method) A separator substrate for an alkaline storage battery coated with the photocurable hydrophilic resin composition according to the present invention comprises:
Curing can be performed using a light ray such as an infrared ray, a visible ray, or an ultraviolet ray.

The radiation source is not particularly limited as long as it can be cured in a short time after coating the photocurable hydrophilic resin composition. A resistance heating plate, a laser or the like, a visible light source such as sunlight, a lamp, a fluorescent lamp, a laser or the like, and an ultraviolet ray source such as a mercury lamp, a halide lamp or a laser can be used. Among them, in the present invention, it is preferable to use ultraviolet rays. In this case, the irradiation amount of the ultraviolet rays is preferably 0.01 to 20 J / cm ² , and more preferably 0.1 to ²⁰ J / cm ² .
Desirably, it is 10 J / cm ² . These rays are 1
Irradiation of the species alone or two or more species may be carried out simultaneously or at fixed intervals.

[Alkaline Storage Battery] The alkaline storage battery according to the present invention comprises a positive electrode, a negative electrode, a separator, and an alkaline electrolyte, and uses the alkaline storage battery separator as a separator. The kind and amount of the alkaline electrolyte of the alkaline storage battery according to the present invention is not particularly limited, but contains potassium hydroxide and / or sodium hydroxide and lithium hydroxide, and the amount of the electrolyte is the battery capacity. It is preferably 1 to 5 cm ³ per 1 Ah, and more preferably 1.3 to ² cm ³ . The electrodes are also not particularly limited, but it is preferable that the positive electrode use nickel oxide and the negative electrode use a hydrogen storage alloy powder capable of electrochemically storing and releasing hydrogen.

The separator coated with the photocurable hydrophilic resin composition according to the present invention has a strong holding power for the electrolytic solution and a good resistance to the electrolytic solution. For this reason, the alkaline storage battery having the separator has excellent life characteristics because the separator is hardly withered even after repeated charge / discharge cycles, and the internal resistance of the battery does not increase. Further, since the separator can sufficiently retain the electrolytic solution in the separator, it is possible to improve the current-voltage characteristics of the alkaline storage battery, and it is difficult for the liquid storage to wither, and the cycle life characteristics are excellent. It is possible to provide an alkaline storage battery. Furthermore, since the photocurable hydrophilic resin composition is applied to the separator by dipping treatment or the like, and the composition is cured by irradiating light such as ultraviolet rays, the separator for an alkaline storage battery can be prepared. Since complicated steps such as a chemical conversion treatment can be eliminated, the cost is low.

As described above, according to the present invention, the life characteristics,
An alkaline storage battery having excellent characteristics such as storage characteristics can be provided.

[0068]

As described above, the separator for an alkaline storage battery according to the present invention is lower in cost than the separator made of sulfonated sulfonated polypropylene and has excellent water resistance, hydrophilicity, and liquid retaining property. An alkaline storage battery using a simple separator has excellent self-discharge characteristics and cycle life characteristics.

[0069]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited by these. In the examples, parts and% are by weight unless otherwise specified. Various evaluations and measurements in the examples were performed by the following methods. (1) Total content of sulfonic acid groups The synthesized sulfonated product was vacuum-dried at 80 ° C overnight. The dried product was dissolved in a toluene / isopropyl alcohol (95/5 weight ratio) solution. After dissolution, insolubles such as sulfates and hydroxides were removed with a filter, and then the solvent was removed to obtain a sulfonic acid content measurement sample. The sulfur content in the sample was determined from elemental analysis, and the amount of sulfonic acid groups in the copolymer was calculated. (2) Weight Average Molecular Weight (Mw) The weight average molecular weight (Mw) of the base polymer was measured by gel permeation chromatography (GPC) using polystyrene as a standard sample. (3) Measurement of Liquid Absorption Rate The solid content concentration of the solution (photocurable hydrophilic resin composition) containing the obtained polymer having a sulfonic acid group and a photoradical generator was adjusted to 2% by weight. A 10 cm square non-woven fabric (average fiber diameter made of polypropylene = 10 μm)
The basis weight = 50 g / m ² ) was dipped. Then, it was dried in a thermostat at 100 ° C. for 1 hour, irradiated with a light amount of 4 J / cm ² using a conveyer type mercury lamp, and then dried at 25 ° C.
After 24 hours storage, an evaluation sample was obtained. The amount of coating was 5 g / m ³ when calculated from the weight increase before and after coating due to dipping. 5cm square non-woven fabric coated and cured 3
The rate of weight increase after immersion in a 0% KOH aqueous solution for 10 minutes was measured.

Liquid absorption rate (%) = (weight of nonwoven fabric after immersion−weight of nonwoven fabric before immersion) / weight of nonwoven fabric before immersion × 100 The photocurable hydrophilic resin composition is dipped under the above conditions. Further, light curing is called coating / curing treatment. (4) Measurement of liquid retention after loading The nonwoven fabric of 5 cm square coated and cured with the photocurable hydrophilic resin composition was immersed in a 30% KOH aqueous solution for 2 hours, and the KOH aqueous solution was sufficiently absorbed by the nonwoven fabric. Later 5
After applying a load of 5 kg for 10 minutes so that the entire non-woven fabric of cm square was uniform, the liquid retention rate of the KOH aqueous solution was measured.

Liquid retention rate after loading (%) = (weight of nonwoven fabric after dipping / loading−weight of nonwoven fabric before dipping) / weight of nonwoven fabric before dipping × 1
(5) Evaluation of Water Resistance The nonwoven fabric coated and cured with the photocurable hydrophilic resin composition was immersed in water at room temperature overnight, and the polymer falling rate was measured. (6) Tensile strength of separator non-woven fabric The non-woven fabric coated and cured with the photo-curable hydrophilic resin composition is subjected to L1096 of Japanese Industrial Standards (JIS).
A tensile strength test was performed according to the above.

[0072]

Preparation Example 1 [Preparation of Solutions A to C] (1) 500 g of dioxane was placed in a glass reaction vessel, and a specified amount of sulfuric anhydride (39.0 g for solution A, 31.2 g for solution B, solution C) About 39.0 g)
Was added while maintaining the internal temperature at 25 ° C., and stirred for 2 hours.
A sulfuric anhydride-dioxane complex was obtained. (2) In a separate glass reaction vessel, the base polymer (100 g) shown in Table 1 was dissolved in 400 g of dioxane. The whole amount of the complex obtained in the above (1) was added thereto while maintaining the internal temperature at 25 ° C., and the stirring was further continued for 2 hours.

After stirring, a prescribed amount of sodium hydroxide (21.6 g for solution A, 17.3 g for solution B, 21.6 g for solution C) dissolved in 200 cc of water and 300 g of methanol were added. The mixture was stirred at 80 ° C under reflux for 1 hour. After stirring, the solvent was removed under reduced pressure, and water was added and dissolved to obtain an aqueous solution of a sulfonated polymer. The solid concentration of this aqueous solution was 20%. Table 1 shows the measurement results of the content of the sulfonic acid group.

[0074]

[Table 1]

[0075]

Example 1 Irgacure 2959 was added to 100 g of solution A.
(Product name: Ciba Specialty Chemicals Co., Ltd.)
0.8 g, N, N'-methylenebisacrylamide 2
g was blended to obtain a composition. The obtained composition is applied to a nonwoven fabric similar to the nonwoven fabric shown in (3) Method for measuring liquid absorption, and coated and cured by the same method as shown in (3) Method for measuring liquid absorption. Then, a separator was prepared, and the liquid absorption, the liquid retention after loading, the water resistance falling off rate, and the tensile strength were measured according to the methods described above. Table 2 shows the evaluation results.

[0076]

Example 2 Irgacure 2959 was added to 100 g of solution A.
Was blended with 0.8 g of divinylbenzene to obtain a composition. The obtained composition was coated and cured on the nonwoven fabric in the same manner as in Example 1 to prepare a separator, and in accordance with the method, liquid absorption, liquid retention after weighting,
The water resistance falling rate and tensile strength were measured. Table 2 shows the evaluation results.

[0077]

Example 3 Irgacure 2959 was added to 100 g of the solution A.
And 0.8 g of sodium acrylate were blended to obtain a composition. The obtained composition was coated and cured on the nonwoven fabric in the same manner as in Example 1 to prepare a separator, and in accordance with the above-described method, liquid absorption, liquid retention after loading, water resistance falling-off rate, and tensile strength. Was measured. Table 2 shows the evaluation results.

[0078]

Example 4 Irgacure 2959 was added to 100 g of the solution B.
Was blended with 0.8 g of N, N'-methylenebisacrylamide to obtain a composition. The obtained composition was coated and cured on the nonwoven fabric in the same manner as in Example 1 to prepare a separator. According to the method described above, the liquid absorbing property, the liquid retention property after loading, the water resistance falling rate and the tensile strength were measured. It was measured. Table 2 shows the evaluation results.

[0079]

EXAMPLE 5 Irgacure 2959 was added to 100 g of the solution C.
Was blended with 0.8 g of diethylene glycol dimethacrylate to obtain a composition. The obtained composition was coated and cured on the nonwoven fabric in the same manner as in Example 1 to prepare a separator. According to the method described above, the liquid absorbing property, the liquid retention property after loading, the water resistance falling rate and the tensile strength were measured. It was measured. Table 2 shows the evaluation results.

[0080]

Comparative Example 1 A non-woven fabric was coated with the solution A alone to prepare a separator in the same manner as in Example 1 except that no curing treatment was performed. The properties, liquid retention after loading, water resistance falling off rate and tensile strength were measured. Table 2 shows the evaluation results.

[0081]

Comparative Example 2 A composition was obtained by blending 2 g of N, N'-methylenebisacrylamide with 100 g of solution A. The obtained composition was coated on the non-woven fabric in the same manner as in Example 1 except that the composition was not subjected to the curing treatment in Example 1, to prepare a separator. The liquid retention, the water resistance falling off rate and the tensile strength were measured. Table 2 shows the evaluation results.

[0082]

Comparative Example 3 In the same manner as in Example 1, except that the curing treatment was not performed, a non-woven fabric was coated with the solution B alone to prepare a separator. The properties, liquid retention after loading, water resistance falling off rate and tensile strength were measured. Table 2 shows the evaluation results.

[0083]

Comparative Example 4 A non-woven fabric was coated with the solution C alone to prepare a separator in the same manner as in Example 1 except that no curing treatment was performed. The properties, liquid retention after loading, water resistance falling off rate and tensile strength were measured. Table 2 shows the evaluation results.

[0084]

Comparative Example 5 A liquid absorbing property, a liquid retention property after loading, and a water-resistant falling off were applied in the same manner as in Example 1 except that a non-woven fabric made of sulfonated polypropylene was used as a separator and coating and curing treatment were not performed in Example 1. The modulus and tensile strength were measured. Table 2 shows the evaluation results.

[0085]

Comparative Example 6 The same procedure as in Example 1 was carried out except that the nonwoven fabric made of polypropylene was used as a separator and the coating and curing treatment were not carried out. The tensile strength was measured. Table 2 shows the evaluation results.

[0086]

[Table 2]

As shown in Table 2, the separator (Examples 1 to 5) coated and cured with the photocurable hydrophilic composition according to the present invention was compared with the sulfonated polypropylene separator (Comparative Example 5). Excellent values were obtained for the liquid absorption rate and the liquid retention rate after weighting. Further, as shown in Comparative Examples 1 to 4, in a system coated with a resin composition containing no photoradical generator, a separator coated and cured with the photocurable hydrophilic composition according to the present invention (Example) Water resistance and liquid retention after load were inferior to those of 1) to 5).

Further, as shown in Comparative Examples 5 and 6, when a nonwoven fabric made of sulfonated polypropylene was used as the separator base material, the tensile strength was 9.9 (Kg / 5 cm).
Width) (Comparative Example 5), compared to the case of using a non-sulfonated polypropylene nonwoven fabric (Comparative Example 6).
The tensile strength decreased by about 30%. On the other hand, the separator (Examples 1 to 5) coated and cured with the photocurable hydrophilic composition according to the present invention exhibited excellent tensile strength almost equivalent to that of the base fabric (Comparative Example 6). The tensile strength preferably shows a high value in order to prevent the separator from being cut or short-circuited in the battery assembling process.

[0089]

Examples 6 to 10 and Comparative Example 7 Using the separator prepared in Examples 1 to 5 and the separator made of sulfonated polypropylene used in Comparative Example 5, an alkaline storage battery comprising a positive electrode, a negative electrode, an electrolytic solution and the separator Was configured.
The positive electrode was prepared by filling foamed nickel as a core material with a paste containing nickel hydroxide powder as an active material and cobalt sulfide as main components, pressing and cutting to a predetermined size.

The negative electrode is prepared by applying a paste of a hydrogen storage alloy powder having a composition of MmNi _3.6 Mn _0.4 Al _0.3 Co _0.7 capable of electrochemically storing and releasing hydrogen onto a punching metal, followed by drying and pressing. , And cut to predetermined dimensions. A sealed nickel-hydrogen storage battery having a nominal battery capacity of 100 Ah was constructed using these positive and negative electrode plates and a polypropylene separator therebetween.

As an electrolytic solution, an aqueous potassium hydroxide solution containing lithium hydroxide at a rate of 40 g / l and having a concentration of 27% by weight was used, and the amount of the solution was 170 cm ³ . When considering the cycle life, the internal pressure, and the current-voltage characteristics comprehensively, the amount of the electrolyte is 1.3 to 1.3 Ah per battery capacity.
2.0 cm ³ is appropriate. Using this sealed nickel-hydrogen storage battery, the capacity retention ratio and the cycle life characteristic of the self-discharge characteristics when stored in a 45 ° C atmosphere for 10 days were evaluated according to the following methods. Table 3 shows the evaluation results. (1) Capacity retention rate of self-discharge characteristics Capacity retention rate (%) = discharge capacity at 25 ° C. atmosphere at 0.2 ° C. after storage for 10 days in a charged state at 45 ° C. /
Standard capacity x 100 The standard capacity is 0.1 CmA up to 110% charge depth.
, And discharged to 1 V at 0.2 CmA. (2) Cycle life characteristics The life test was performed at a charging current of 0.3 CmA and a charging depth of 90%.
, And discharged to 1 V at 0.3 CmA.

[0092]

[Table 3]

As shown in Table 3, a non-woven fabric was coated with a photocurable hydrophilic composition containing a diene (co) polymer having a sulfonic acid group according to the present invention and a photoradical generator, and then coated with a light beam. Separator cured (Examples 6 to 1)
In the case of using (0), the alkaline storage battery exhibited excellent cycle life characteristics as compared with the case of using a sulfonated polypropylene separator (Comparative Example 7).

As shown in Table 2, when a photocurable hydrophilic composition containing a diene (co) polymer having a sulfonic acid group and a photoradical generator is coated and then treated with a light beam, It is considered that the liquid retaining property of the separator becomes excellent.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Makoto Hikami 2--11-24 Tsukiji, Chuo-ku, Tokyo Inside JSR Corporation (72) Inventor Katsuhiro Ishikawa 2-1-24-1 Tsukiji, Chuo-ku, Tokyo No. F-term in JSR Co., Ltd. (reference) 4F006 AA12 AB05 AB55 AB64 BA16 CA08 DA04 EA03 5H021 BB12 BB15 CC02 EE04 HH00 HH03 5H028 AA05 BB00 BB10 HH00 HH05

Claims (6)

[Claims] 1. A separator for use in an alkaline storage battery comprising a positive electrode, a negative electrode, a separator, and an alkaline electrolyte, wherein the surface of the separator substrate has a diene (co) polymer having a sulfonic acid group. A separator for an alkaline storage battery, wherein the separator is coated with a coating obtained by photocuring a composition containing a photoradical generator. 2. The diene (co) polymer having a sulfonic acid group contains a structural unit derived from a diene compound and a structural unit derived from an aromatic compound. For alkaline storage batteries. 3. The coating film is a coating film obtained by photocuring a composition in which a photoradical generator and a diene (co) polymer having a sulfonic acid group are emulsified and dispersed or dissolved in an aqueous medium. The separator for an alkaline storage battery according to claim 1 or 2, wherein: 4. The alkaline storage battery separator according to claim 1, wherein the separator substrate of the alkaline storage battery separator is made of a nonwoven fabric. 5. The nonwoven fabric has an average fiber diameter of 0.1-4.
5. The separator for an alkaline storage battery according to claim 4, wherein the separator has a weight of 0 μm and a basis weight of 10 to 300 g / m ² . 6. An alkaline storage battery comprising the alkaline storage battery separator according to claim 1, a positive electrode, a negative electrode, and an alkaline electrolyte.