JP2014123443A - Alkali battery separator, and alkali battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an alkali battery separator which allows the improvement in the shieldability to prevent the internal short circuit attributed to a metal oxide dendrite, etc., and the discharge performance, and which meets the requirement of liquid-holding property; and an alkali battery arranged by use of the separator.SOLUTION: The alkali battery separator is composed of a wet type nonwoven fabric having a multilayer structure which comprises an alkali-resistive cellulose fiber, an alkali resistance synthetic fiber, and a binder component. The alkali battery separator has an average pore diameter of 10 μm or smaller, which is an index showing the shieldability of the wet type nonwoven fabric, and has a liquid-holding rate of 400% or larger. The alkali battery is arranged by use of the separator.

Description

  The present invention relates to an alkaline battery separator used in various alkaline batteries such as an alkaline manganese battery, a silver oxide battery, a mercury battery, and an air zinc battery, and an alkaline battery using the separator.

  Conventionally, characteristics required for a separator for separating a positive electrode active material and a negative electrode active material in an alkaline battery include an internal short circuit due to contact between the positive electrode active material and the negative electrode active material, a conductive metal oxide, etc. (dendrites) Prevents internal short-circuit due to, and has durability that does not cause shrinkage and alteration to electrolyte solutions such as potassium hydroxide and positive electrode active materials such as manganese dioxide, nickel oxyhydroxide, silver oxide, etc. Therefore, it is mentioned that a sufficient amount of electrolytic solution is maintained for a long time so as not to prevent ionic conduction.

  Conventionally, as an alkaline battery separator having such characteristics, cellulose pulp and regenerated cellulose fiber excellent in alkali resistance are blended with alkali-resistant synthetic fibers such as vinylon fiber, and further, water is added at 60 ° C to 90 ° C. Nonwoven fabrics made by mixing alkali-resistant synthetic fibers and cellulose fibers, to which easily soluble polyvinyl alcohol fibers that dissolve are added as binder components, are used.

  This is because the electrolyte solution retention of the separator is poor with only alkali-resistant synthetic fibers, and by adding cellulose fibers with excellent lyophilic properties, the amount of electrolyte solution retained in the separator is increased, and the discharge characteristics of alkaline batteries are increased. The purpose is to increase Further, by blending the alkali-resistant synthetic fiber and the cellulose fiber, the shrinkage of the cellulose fiber in the electrolytic solution is reduced, and a separator having a small dimensional change can be obtained.

  In the production of a separator, cellulose fibers that can be fibrillated are used after being subjected to beating treatment as necessary to fibrillate the fibers. The blending of the fibrillated cellulose fibers can impart a denseness to the separator and prevent the occurrence of an internal short circuit due to dendrites.

  Among the regenerated cellulose fibers, polynosic fibers, cupra fibers, and solvent-spun cellulose fibers can be divided into very thin fibrils having a diameter of 1 μm or less by a beating process. In particular, solvent-spun cellulose fibers have a high degree of crystallinity, and the internal structure of the fibers consists of cellulose crystal parts and non-crystal parts. The crystal parts adhere to each other through the non-crystal parts. It is composed. When a beating action is applied to this fiber, the non-crystal part is destroyed, the crystal part peels off from the fiber, and fibrils having a diameter of 1 μm or less are generated. The separator constituted by the fibrillated product has a dense structure.

  Further, since the fibril is cellulose having a high degree of crystallinity, the rigidity is high, and the fibril itself is not flattened by the press in the paper making process, and the cross-sectional shape close to a circle is maintained, so that the density is hardly increased. Therefore, the separator containing the fibrillated product has a fine paper quality, but has a small ion channel redundancy and an excellent ion permeability.

For this reason, cellulose fibers that can be fibrillated are subjected to beating treatment as necessary, and paper is made by blending alkali-resistant synthetic fibers such as vinylon fibers and easily soluble polyvinyl alcohol fibers that are binder components. Has been widely used as.
As solvent-spun cellulose fibers used in such separators, currently regenerated cellulose fibers known as lyocell (registered trademark) or tencel (registered trademark) are known. A separator excellent in the shielding properties of the bipolar active material can be obtained.

  In conventional alkaline battery separators, separators made by mixing alkali-resistant synthetic fibers and cellulose fibers have durability against electrolytes and bipolar active materials and electrolyte retention, but the separator material has a large pore size. However, there is a problem that the shielding property is insufficient in terms of preventing an internal short circuit due to contact between the bipolar active materials. In order to cope with this, means for beating the alkali-resistant cellulose fiber and lyocell fiber and blending them with synthetic fibers with low fineness has been taken when manufacturing the separator.

  For example, Patent Document 1 provides a separator containing 95% of lyocell fibers subjected to beating treatment, and Patent Document 2 provides a separator containing 90% of lyocell fibers beaten, but as described above, When 60% or more of the treated lyocell fiber is blended, the amount of lyocell fiber or fibrillated product of lyocell fiber that dissolves in the alkaline electrolyte increases too much, and there is a high risk of internal short circuit due to a decrease in the shielding property of the separator and dimensional shrinkage. For example, an alkaline battery separator having practical performance could not be provided.

  Moreover, in patent document 3, each ratio is mix | blended in the ratio of 30% -60%: 5% -20%: 35% -50% of vinylon fiber, beaten-treated lyocell fiber, and beaten-treated mercerized pulp. A separator is provided, and in Patent Document 4, a separator having a laminated structure composed of at least two layers of a coarse layer and a dense layer, and the coarse layer and the dense layer are combined to make vinylon fibers 32.5% to 37.37%. A separator is provided in which 5%, 6% to 32.5% lyocell fiber, and 15% to 50% of mercerized pulp are blended.

  By blending mercerized pulp in addition to vinylon fibers, deterioration of the isolation performance of the bipolar active material due to dissolution of lyocell fibers constituting the separator and occurrence of internal short circuit due to dimensional shrinkage of the separator are suppressed.

Japanese Patent Laid-Open No. 06-163024 JP-A-6-231746 JP 2006-236808 A International Publication No. WO2012 / 036025

  However, the lyocell fiber that has been used for the separator for alkaline batteries has an α-cellulose content of 80% or less and a mercerized pulp, a dissolved pulp or the like that is an alkali-resistant cellulose fiber with an α-cellulose content of 97% or more. The α-cellulose content is low, and the lyocell fiber and the fibrillated product of the lyocell fiber are dissolved in the alkaline electrolyte, resulting in a problem that the shielding performance as a separator is lowered. In addition, lyocell fiber has large dimensional shrinkage in an alkaline electrolyte, and in a separator containing 60% or more of lyocell fiber, the amount of lyocell fiber and fibrillated product of lyocell fiber is too large, and the positive electrode active material and the negative electrode active material There was a problem that the isolation performance deteriorated and an internal short circuit occurred.

  In order to solve this problem, in order to suppress dissolution and dimensional shrinkage of the separator in the alkaline electrolyte, a large amount of polyvinyl alcohol fiber, which is an alkali-resistant synthetic fiber, has been incorporated. However, when the alkali-resistant synthetic fiber is increased, the ratio of the cellulose fiber that secures the shielding property is lowered, and there is a problem that the shielding property of the separator is lowered.

  In addition, when mercerized pulp is blended, the hemicellulose remaining in the mercerized pulp is gradually eluted into the alkaline electrolyte, and the eluted hemicellulose causes corrosion of the zinc alloy powder that is the negative electrode active material of the alkaline battery, There was a problem of increasing the amount of hydrogen gas generated and deteriorating the characteristics of the battery after storage.

The present invention has been made for the purpose of solving the above-described problems, and includes, for example, the following configuration as a means for achieving the objects and solving the problems.
That is, 5% solvent-spun cellulose fiber having an α-cellulose content of 85% or more is used in an alkaline battery separator that is interposed between a positive electrode active material and a negative electrode active material of an alkaline battery and used to isolate the bipolar active material. A separator containing at least 5% by weight, more preferably a separator containing 5% by weight or more of solvent-spun cellulose fibers having an α-cellulose content of 90% or more.

And, for example, it contains alkali-resistant synthetic fiber together with the solvent-spun cellulose fiber.
For example, the alkali-resistant synthetic fiber contains 5% by weight to 20% by weight of an easily soluble polyvinyl alcohol component having a dissolution temperature in water of 60 ° C. to 90 ° C.

In addition, for example, at least one kind of cellulose fiber selected from cotton linter pulp, dissolving pulp, mercerized pulp or regenerated cellulose fiber is contained together with the solvent-spun cellulose fiber.
And, for example, together with the solvent-spun cellulose fiber, it contains at least one cellulose fiber selected from cotton linter pulp, dissolving pulp, mercerized pulp or regenerated cellulose fiber, and further contains alkali-resistant synthetic fiber Features.

For example, the thickness of the separator is 50 μm to 120 μm, and the average pore diameter of the separator is 10 μm or less.
Or it is set as the alkaline battery characterized by using any separator for alkaline batteries mentioned above.

  ADVANTAGE OF THE INVENTION According to this invention, the melt | dissolution of the fiber which comprises the separator in alkaline electrolyte is little, and the separator for batteries with small dimensional shrinkage can be provided. Further, the fibrillated product of the solvent-spun cellulose fiber can obtain the same effect as described above.

  According to another separator of the present invention, since dissolution and dimensional shrinkage in an alkaline electrolyte can be suppressed, the shielding property of the separator is maintained, an internal short circuit due to dendrite does not occur, and the shape of the separator is maintained. It is possible to provide an alkaline battery without an internal short circuit due to contact between the active material and the positive electrode active material.

  Moreover, since the solvent-spun cellulose fiber of the present invention has few dissolved components in the alkaline electrolyte, the amount of hydrogen gas generated in the separator is reduced, and an increase in internal pressure inside the battery can be suppressed. That is, an alkaline battery without leakage can be provided.

Hereinafter, an embodiment of an invention according to the present invention will be described in detail.
In this embodiment, the α-cellulose content of lyocell fibers conventionally used as a raw material for alkaline battery separators is 80% or less, such as mercerized pulp conventionally used for alkaline battery separators. The α-cellulose content is low compared to pulp. For this reason, separators using only lyocell fibers are easy to dissolve in alkaline electrolyte, and the separator shape cannot be maintained by long-term storage after being assembled in a battery, resulting in reduced shielding. Cause internal short circuit.

  In comparison, the solvent-spun cellulose fiber having an α-cellulose content of 85% or more used in this embodiment is less soluble in an alkaline electrolyte and has a small dimensional shrinkage when used as a separator. The shielding property can be maintained, and the internal short circuit of the alkaline battery can be prevented.

  The lyocell fiber is a cellulose fiber obtained by a so-called amine oxide or lyocell process. In this process, the cellulose dissolves directly in the aqueous tertiary amine oxide solution without forming a derivative. The cellulose solution is formed by spinning from a spinning nozzle and precipitated in a settling tank through an air gap, thereby obtaining a formed body. Thereafter, after further processing steps, it is washed and dried if necessary. A method for producing lyocell fibers is described, for example, in US-A 4,246,221.

  These fibers are called solvent-spun cellulose fibers, and lyocell is a collective term assigned by BISFA (The International Bureau of the Standardization of Man-made Fibers).

  Usually, eucalyptus pulp having an α-cellulose content of about 85% is used as the cellulose raw material for producing lyocell fiber, but the inventors of the present application have an α-cellulose content of 50% or more of the cellulose raw material. Using a pulp of 90% or more, solvent-spun cellulose fibers having an α-cellulose content of 85% or more were produced.

As the separator configuration according to this embodiment, 5% by weight or more of solvent-spun cellulose fibers having an α-cellulose content of 85% or more, or 5 solvent-spun cellulose fibers having an α-cellulose content of 90% or more. By containing at least% by weight, dissolution of the solvent-spun cellulose fibers and the dimensional shrinkage of the separator in the alkaline electrolyte can be suppressed, and the shielding property of the separator can be ensured.
It has also been found that when the solvent-spun cellulose fiber is 5% by weight or less, the separator cannot be sufficiently shielded and an internal short circuit due to generation of dendrites cannot be prevented.

  Moreover, it is also possible to add a polyamine epichlorohydrin resin as a wet paper strength enhancer together with solvent-spun cellulose fibers as necessary. This ensures the wet strength of the separator in the alkaline electrolyte, and is sufficient to withstand the breakage of the separator when filling the negative electrode active material and the vibration during battery transportation in the alkaline battery manufacturing process. High strength can be obtained.

Moreover, it is also possible to suppress dimensional shrinkage of the separator in the alkaline electrolyte by containing an alkali-resistant synthetic fiber together with the solvent-spun cellulose fiber.
Moreover, 5 to 20 weight% of easily soluble polyvinyl alcohol fibers having a dissolution temperature in water of 60 ° C. to 90 ° C. are blended, and the dissolved easily soluble polyvinyl alcohol fibers bind cellulose fibers and alkali-resistant synthetic fibers. Dimensional shrinkage of the separator in the alkaline electrolyte can be suppressed, and the wet strength can be ensured.

  When the blending ratio of the easily soluble polyvinyl alcohol fiber is 5% by weight or less, it does not contribute to the improvement of the mechanical strength of the separator, so that there is not much merit in blending. Moreover, when 20 weight% or more is mix | blended, the melt | dissolved easily soluble polyvinyl alcohol fiber will form a film between fibers, ion permeability will be inhibited, and the discharge capacity of a battery will fall.

  In addition, especially for AA (LR6 or AA) and AAA (LR03 or AAA) batteries as alkaline battery separators, the separator is made thinner so that more battery pole materials are blended to improve battery performance. It was. Therefore, it is desirable that the thickness of the AA / AAA battery separator is 50 μm to 120 μm and the average pore size of the pore size is 10 μm or less. If the thickness is less than 50 μm, the distance between the electrodes is shortened, and the risk of internal short circuit is increased.

  Furthermore, since the absolute amount for holding the alkaline electrolyte is reduced, the discharge capacity may be reduced. When the thickness is 120 μm or more, the distance between the electrodes becomes long, so that the ionic resistance inside the battery becomes high. Furthermore, the proportion of the separator in the battery is increased, and the positive electrode active material and the negative electrode active material are reduced, so that the discharge capacity is reduced.

  Further, if the average pore diameter of the separator is larger than 10 μm, sufficient shielding performance against dendrite growth cannot be obtained, and sufficient shielding performance to withstand intermittent discharge cannot be obtained. Therefore, the average pore diameter of the separator is 10 μm. The following is preferable.

  On the other hand, in the single 1 (LR20 or D) and single 2 (LR14 or C) battery, the performance required for the separator is different from the single 3 or single battery, and liquid retention is regarded as important. For this reason, a thick separator having a thickness of 200 μm or more is used. Even if dendrites are generated because the separator is thick, the battery life is reached before the dendrites reach the positive electrode, and there is no problem even if the pore size is larger than 10 μm.

  The cellulose fiber contained together with the solvent-spun cellulose fiber can be selected from mercerized pulp, cotton linter pulp, dissolved pulp, and regenerated cellulose fiber. Moreover, you may beat-treat these cellulose fibers as needed.

In order to satisfy the separator shielding property and the electrolyte retention property at a high level, the cellulose content in the separator is preferably 100%.
In the case of blending other cellulose pulp with the solvent-spun cellulose fiber in the present invention, it is necessary to use a dissolved pulp having a low hemicellulose content from the viewpoint of reduction of hydrogen gas generation amount and dimensional stability when incorporated in a battery. Further preferred.

  In the following description, hemicellulose is a generic term for polysaccharides other than cellulose contained in wood pulp and non-wood pulp. Hemicellulose is an amorphous polysaccharide with a lower molecular weight than cellulose. As typical hemicelluloses, for example, polysaccharides such as xylan, arabinoxylan, mannan, glucomannan, and gluconoxylan are known.

  In addition, as the alkali-resistant synthetic fiber, an acetalized polyvinyl alcohol fiber (hereinafter referred to as “vinylon fiber”) and an acetalized polyvinyl alcohol fiber (hereinafter referred to as “PVA fiber”) excellent in dimensional stability in an alkaline electrolyte. ), Polyamide fiber, polypropylene fiber, polyethylene fiber, polypropylene / polyethylene composite fiber, polypropylene / modified polypropylene composite fiber, polyamide / modified polyamide composite fiber, polypropylene synthetic pulp, and polyethylene synthetic pulp.

  Next, the manufacturing method of the separator for alkaline batteries of the present embodiment will be described. The separator according to the present embodiment is manufactured by dispersing the above-mentioned lyocell fiber in water and beating it to a predetermined CSF value with a paper making beating machine such as a beater or a refiner, or by using a beating-processed solvent spinning. The cellulose fiber is mixed with one or more of the above-mentioned other cellulose fibers, and further mixed with one or more of the alkali-resistant synthetic fibers excellent in dimensional stability in the alkaline electrolyte. A mixture of easily soluble polyvinyl alcohol is used as a papermaking raw material.

  Using these raw materials, paper is made with a circular paper machine, a slanted short paper machine, or a long paper machine, and a separator is obtained by laminating and integrating as necessary. In addition, the other cellulose fiber used in combination with the lyocell fiber can be beaten as necessary.

  The paper making method using the slanted short net paper machine and the long net paper machine here can freely control the fiber orientation by increasing or decreasing the amount of water to be fed onto the net. This is a papermaking method suitable for improving the workability of the separator during battery manufacture, such as the ease of bending of the separator in the direction and the width direction.

  Hereinafter, the solvent-spun cellulose fiber of this embodiment will be described in comparison with conventionally used lyocell fibers. Table 1 shows the measurement results of α-cellulose content, alkali decomposition resistance, alkali area shrinkage resistance, and hydrogen gas generation rate for solvent-spun cellulose fibers and lyocell fibers used in one example and comparative example according to the present invention. .

(1) α-cellulose content The α-cellulose content (%) was measured by the measurement method of “α, β and γ-cellulose in pulp” defined in TAPPI standard method T203.
(2) Hemicellulose content rate The hemicellulose content rate was measured based on the measurement method of "analysis of carbohydrate composition by gas-liquid chromatography of organic solvent-extracted wood and wood pulp" of TAPPI standard method T249hm-85.

(3) Alkali degradation resistance 5 g of lyocell fiber is prepared with an absolutely dry weight, immersed in a 40% KOH aqueous solution for 8 hours, thoroughly washed with running water, dried with 40% KOH, and weight before and after immersion Was measured, and the alkali decomposition resistance (%) was calculated according to Formula 1.
Decomposition rate (%) = (W2−W1) / W1 × 100 Equation 1
W1 = mass before immersion W2 = mass after immersion

(4) Alkali area shrinkage resistance Lyocell fiber 90%, easy-dissolvable vinylon binder fiber 10% blended handsheets, cut into dimensions 100mm x 100mm, immersed in 70% 40% KOH, 8 Leave for hours. After 8 hours, the sheet was taken out, the area was measured in a wet state, and the area shrinkage rate (%) was calculated by Equation 2.
Area shrinkage rate (%) = (A1-A2) / A1 × 100 Equation 2
A1 = Area before immersion A2 = Area after immersion

(5) Hydrogen gas generation amount Hydrogen gas generation amount generated by adding lyocell fiber and KOH electrolyte (dissolving zinc oxide) to commercially available zinc alloy powder for alkaline manganese battery negative electrode and leaving it at 70 ° C for 10 days (Volume of hydrogen gas generated per 1 g of zinc (μl)) was measured. In measurement, the zinc alloy powder: lyocell fiber: KOH electrolyte takes a certain amount of 1: 0.05: 1 by mass ratio, and an apparatus similar to FIG. 2 disclosed in Japanese Patent Application Laid-Open No. 2008-171767 is used. Used to measure the amount of hydrogen gas generated.

In Table 1, solvent-spun cellulose fibers A, B, C, and D are manufactured by the above manufacturing method. The α-cellulose content of the solvent-spun cellulose fibers A, B, C, and D is 85.3%, 91.1%, 94.6%, respectively, compared with the α-cellulose content of 77.0% of the lyocell fiber. The solvent-spun cellulose fiber of the present invention has a lower alkali-decomposition rate and alkali-resistant area shrinkage rate of 83.9%.
However, compared with solvent-spun cellulose fibers A, B, and C, solvent-spun cellulose fiber D has a low α-cellulose content of 83.9%, so the decomposition rate and area shrinkage rate in alkaline electrolyte are high. ing. For this reason, it is thought that the isolation performance of a positive electrode active material and a negative electrode active material is inadequate.

  That is, as the α-cellulose content increases, the deterioration of the separator in the alkaline electrolyte can be suppressed. Further, the solvent-spun cellulose fibers A, B, and C have a low hemicellulose content, can suppress the amount of hydrogen gas generated inside the battery, and can prevent liquid leakage during storage.

Hereinafter, an alkaline battery separator according to an embodiment of the present invention and an alkaline battery using the separator will be described in detail. In addition, this invention is not limited to the content of description of these Examples.
(Test method)
The measured values of the separators according to Examples, Comparative Examples, and Conventional Examples were measured by the following methods.

(1) CSF (Canadian Standard Freeness) Measured by the Canadian standard method defined in JIS P 8121.
(2) Thickness Two separators are stacked and the thickness is measured at equal intervals using a dial thickness gauge. One half of the thickness is obtained as the thickness per sheet, and the average value of the measurement points is further determined. Thickness (μm).

(3) Basis weight The area and weight of the separator were measured to determine the weight (g) per separator area (m ² ).
(4) Wet strength A test piece having a width of 15 mm was taken from the separator in the vertical direction, and the test piece was dipped in a 40% KOH aqueous solution, and then excess 40% KOH aqueous solution adhering to the test piece was blotted with a filter paper. The tensile strength of the test piece wetted with this 40% KOH aqueous solution was measured according to the method specified in JIS P8113, and the wet strength (N / 15 mm) of the separator was obtained.

(5) Liquid retention ratio The separator was cut into a square of 50 mm x 50 mm, measured for the mass after drying, and then immersed in an aqueous 40% KOH solution for 10 minutes. This test piece was directly attached to a glass plate inclined at an angle of 45 degrees and fixed for 3 minutes, and excess 40% KOH aqueous solution was removed by flowing down, and the mass of the test piece retained as it was was measured. The liquid retention rate (%) was calculated by
Liquid retention rate (%) = (W2−W1) / W1 × 100 Formula 3
W1 = mass before immersion W2 = mass after immersion

(6) Ion resistance A separator is inserted between platinum electrodes immersed in a 40% KOH aqueous solution and parallel to each other at an interval of about 2 mm (platinum-plated disk-shaped electrode with a diameter of 20 mm). The increase in electrical resistance during this period was taken as the electrical resistance of the separator. In addition, the electrical resistance between electrodes measured the ion resistance (m (ohm)) using the LCR meter with the frequency of 1000 Hz.
(7) Average pore diameter Using a Palm-Porometer manufactured by PMI, the average pore diameter (μm) was determined from the pore diameter distribution of the separator measured by the bubble point method (ASTMF 316-86, JIS K3832).

(8) Hydrogen gas generation amount Hydrogen gas generation amount generated by adding separator and KOH electrolyte (dissolving zinc oxide) to commercially available zinc alloy powder for alkaline manganese battery negative electrode and leaving it at 70 ° C for 10 days ( The volume of hydrogen gas generated per gram of zinc (μl)) was measured.
In the measurement of each pulp, the zinc alloy powder: separator: KOH electrolyte took a certain amount of 1: 0.05: 1 by mass ratio, and was similar to FIG. 2 disclosed in Japanese Patent Application Laid-Open No. 2008-171767. The amount of hydrogen gas generation was measured using an apparatus.

(9) Alkali degradation resistance 5g separator was weighed in absolute dry weight, immersed in 40% KOH aqueous solution for 8 hours, washed thoroughly with 40% KOH with running water, dried, and weight before and after immersion Measured, and the alkali decomposition resistance rate (%) was calculated by Equation 4.
Alkali decomposition resistance (%) = (W2−W1) / W1 × 100 Formula 4
W1 = mass before immersion W2 = mass after immersion (10) A separator having an alkali-resistant area shrinkage ratio of 100 mm × 100 mm is cut out, immersed in 40% KOH at 70 ° C., and left for 8 hours. The separator was taken out after 8 hours, the area was measured in a wet state, and the alkali shrinkage resistance (%) was calculated by Equation 5.
Alkali area shrinkage resistance (%) = (A1-A2) / A1 × 100 Formula 5
A1 = Area before immersion A2 = Area after immersion

(11) Discharge test a. Battery production Inside-out structure alkali composed of exterior material, positive electrode can, positive electrode mixture, separator, gelled negative electrode, negative electrode current collector, insulating gasket, ring washer, negative electrode sealing plate using separator of the present invention Ten manganese batteries (LR6) were produced.

  First, in a bottomed cylindrical positive electrode can also serving as a positive electrode terminal, a positive electrode mixture pressure-molded into a hollow cylinder made of manganese dioxide and graphite is press-fitted, and the separators are overlapped three times on average. What was wound up in a cylindrical shape was thermally processed into a bottomed cylindrical shape and inserted into the hollow portion of the positive electrode mixture.

  Next, a mercury-free zinc alloy powder dispersed and mixed in a gel electrolyte solution is filled with a gelled negative electrode inside the separator, and together with an insulating gasket and ring washer that closes the opening of the positive electrode can, a negative electrode current collector And a negative electrode sealing plate serving also as a negative electrode terminal were welded and arranged.

Further, an alkaline manganese battery was manufactured by caulking the opening of the positive electrode can inward to fix the negative electrode sealing plate, and mounting an exterior material.
In addition, the inhibitor which suppresses the growth of zinc oxide dendrite was not added at the time of manufacture of a battery.

b. Discharge test method The high-rate discharge test is a load discharge test that measures the time (minutes) to 0.9V end voltage with a 2Ω load, and the time (hours) to 0.9V end voltage with a 100Ω load. The average value (n = 10) was calculated by performing a light load discharge test.
In the intermittent discharge test, discharge was performed for 5 minutes / day under a load of 3.9Ω, and batteries that fell to 0.9 V or less within 50 days were counted as defective.

[Example 1]
Solvent-spun cellulose fibers C (α-cellulose content: 94.6%, fineness 3.3 dtex. Fiber length 6 mm) 50% by weight beaten to 760 ml with a CSF value, and unbeaten dissolved pulp (α- Cellulose content: 98.0%) 20% by weight, vinylon fiber (fineness 1.1 dtex. Fiber length 3 mm) 10% by weight, PVA fiber (1.1 dtex. Fiber length 3 mm) 10% by weight, easy as alkali-resistant synthetic fiber 10% by weight of soluble polyvinyl alcohol fiber (fineness 1.1 dtex, fiber length 3 mm) was mixed. This mixed raw material was subjected to paper making using an inclined short net paper machine to obtain a separator having a thickness of 119.4 μm and a basis weight of 34.4 g / m ² .

[Example 2]
30% by weight of solvent-spun cellulose fiber B (α-cellulose content: 91.1%, fineness 1.7 dtex. Fiber length 4 mm) beaten to 760 ml with a CSF value, and unbeaten cotton linter pulp (α -Cellulose content: 99.6%) 25% by weight, vinylon fiber (fineness 1.1 dtex. Fiber length 3 mm) 25% by weight as an alkali-resistant synthetic fiber, easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) ) 20% by weight was mixed. This mixed raw material was subjected to paper making with an inclined short net paper machine to obtain a separator having a thickness of 105.8 μm and a basis weight of 30.1 g / m ² .

Example 3
30% by weight of solvent-spun cellulose fiber B (α-cellulose content: 91.1%, fineness 1.7 dtex. Fiber length 4 mm) beaten to a CSF value of 500 ml, and unbeaten mercerized pulp (α -Cellulose content: 97.1%) 25% by weight, vinylon fiber (fineness 1.1 dtex. Fiber length 3 mm) 25% by weight as an alkali-resistant synthetic fiber, polypropylene / polyethylene core-sheath type composite fiber (fineness 0.8 dtex. Fiber) 10% by weight (long: 5 mm) and 10% by weight of easily soluble polyvinyl alcohol fiber (fineness: 1.1 dtex, fiber length: 3 mm). This mixed raw material was subjected to paper making with an inclined short net paper machine to obtain a separator having a thickness of 99.7 μm and a basis weight of 31.3 g / m ² .

Example 4
Solvent-spun cellulose fiber C beaten to 300 ml with a CSF value (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) was 40% by weight, and was beaten to 300 ml as a cellulose fiber with a CSF value. Dissolving pulp (α-cellulose content: 98.0%) 30% by weight, vinylon fiber (fineness 1.1 dtex, fiber length 3 mm) 10% by weight as alkali-resistant synthetic fiber, semi-aromatic polyamide fiber (fineness 0.8 dtex. Fiber length: 5 mm) 10% and easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) 10% by weight were mixed. This mixed raw material was subjected to paper making with an inclined short net paper machine to obtain a separator having a thickness of 87.9 μm and a basis weight of 30.5 g / m ² .

Example 5
Solvent-spun cellulose fiber A (α-cellulose content: 85.3%, fineness 1.7 dtex. Fiber length 4 mm) 20% by weight with beating treatment to 150 ml with a CSF value and beating treatment to 150 ml with a CSF value as cellulose fiber Cotton linter pulp (α-cellulose content: 99.6%) 15% by weight, vinylon fiber (fineness 1.1 dtex. Fiber length 3 mm) 50% by weight as alkali-resistant synthetic fiber, polyethylene fiber (fineness 0.8 dtex. Fiber length) : 5 mm) 10% and easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex, fiber length 3 mm) 5% by weight were mixed. This mixed raw material was subjected to paper making with an inclined short net paper machine to obtain a separator having a thickness of 85.1 μm and a basis weight of 28.4 g / m ² .

Example 6
Solvent-spun cellulose fiber A (α-cellulose content: 85.3%, fineness 1.7 dtex. Fiber length 4 mm) 20% by weight with beating treatment to 150 ml with a CSF value and beating treatment to 150 ml with a CSF value as cellulose fiber Dissolving pulp (α-cellulose content: 98.0%) 15% by weight, 15% by weight of mercerized pulp (α-cellulose content: 97.1%) beating to 150 ml with a CSF value, as alkali-resistant synthetic fiber 20% by weight of vinylon fiber (fineness 1.1 dtex. Fiber length 3 mm), 20% by weight of PVA fiber (fineness 1.1 dtex. Fiber length 3 mm), easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) 10 The weight percent was mixed. This mixed raw material was subjected to paper making with an inclined short net paper machine to obtain a separator having a thickness of 86.3 μm and a basis weight of 28.1 g / m ² .

Example 7
Solvent-spun cellulose fibers A (α-cellulose content: 85.3%, fineness 3.3 dtex. Fiber length 6 mm) 15% by weight beaten up to 0 ml with a CSF value, and unbeaten dissolved pulp (α- Cellulose content: 98.0%) 35% by weight, vinylon fiber (fineness 1.1 dtex. Fiber length 3 mm) 20% by weight, polypropylene fiber (fineness 0.8 dtex. Fiber length 5 mm) 10% by weight as alkali-resistant synthetic fiber 10% by weight of easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex, fiber length 3 mm) was mixed. This mixed raw material was laminated and made with an inclined short net / circular net combination paper machine to obtain a separator having a thickness of 86.4 μm and a basis weight of 24.6 g / m ² .

Example 8
Solvent-spun cellulose fiber C (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) 10% by weight beaten up to 0 ml with a CSF value, and vinylon fiber (fineness 1. 1 dtex, fiber length 3 mm) 65% by weight, polypropylene / modified polypropylene core-sheath composite fiber (fineness 0.8 dtex. Fiber length: 5 mm) 10%, readily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) 15 The weight percent was mixed. This mixed raw material was paper-made with a long paper machine to obtain a separator having a thickness of 71.1 μm and a basis weight of 24.3 g / m ² .

Example 9
Solvent-spun cellulose fibers B (α-cellulose content: 91.1%, fineness 1.7 dtex. Fiber length 4 mm) 15% by weight with CSF value beaten to 150 ml, and lyocell fibers beaten to 150 ml with CSF value ( α-cellulose content: 77% fineness, 1.7 dtex, fiber length 4 mm: manufactured by Lenzing Co., Ltd.) 15 wt%, undissolved dissolving pulp as cellulose fibers (α-cellulose content: 98.0%) 30 wt% As the alkali-resistant synthetic fiber, 30% by weight of vinylon fiber (fineness 1.1 dtex. Fiber length 3 mm) and 10% by weight of easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) were mixed. This mixed raw material was laminated into a three-layer paper with a circular mesh paper machine to obtain a separator having a thickness of 92.4 μm and a basis weight of 27.4 g / m ² .

Example 10
Solvent-spun cellulose fiber C beaten to a CSF value of 15 ml (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm), 25% by weight, and lyocell fiber beaten to a CSF value of 15 ml ( α-cellulose content: 77% fineness, 1.7 dtex, fiber length 4 mm: manufactured by Lenzing Co., Ltd., 25% by weight, viscose rayon (fineness 1.1 dtex, fiber length 3 mm), 10% by weight, vinylon as alkali-resistant synthetic fiber 30% by weight of fiber (fineness 1.1 dtex. Fiber length 3 mm) and 10% by weight of easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) were mixed. This mixed raw material was paper-made with a circular paper machine to obtain a separator having a thickness of 75.0 μm and a basis weight of 24.0 g / m ² .

Example 11
Solvent-spun cellulose fiber C beaten to a CSF value of 15 ml (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) 90% by weight, easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex) (Fiber length 3 mm) 10% by weight was mixed. This mixed raw material was paper-made with a long paper machine to obtain a separator having a thickness of 55.2 μm and a basis weight of 26.6 g / m ² .

Example 12
Solvent-spun cellulose fiber C beaten to a CSF value of 50 ml (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) 65% by weight, polypropylene / modified polypropylene core-sheath composite fiber (fineness) 0.8 dtex. Fiber length: 5 mm) 35% by weight was mixed. This mixed raw material was paper-made with a circular paper machine to obtain a separator having a thickness of 74.4 μm and a basis weight of 30.1 g / m ² .

Example 13
The solvent-spun cellulose fiber C (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) 55% by weight, which was beaten to a CSF value of 150 ml, was beaten to a cellulose fiber CSF value of 150 ml. Dissolving pulp (α-cellulose content: 98.0%) 45% by weight was mixed. The mixed raw material was paper-made with a short net paper machine to obtain a separator having a thickness of 69.4 μm and a basis weight of 31.6 g / m ² .

Example 14
Solvent-spun cellulose fiber C beaten to 0 ml with a CSF value (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) 100% by weight, polyamide epichlorohydrin resin (Seiko PMC Co., Ltd.) The raw material was adjusted by adding 0.25% of a wet paper strength enhancer WS4010) manufactured as a resin solid content. This mixed raw material was paper-made with a long paper machine to obtain a separator having a thickness of 50.5 μm and a basis weight of 22.4 g / m ² .

Example 15
Solvent-spun cellulose fiber C (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) 100% by weight, which was beaten to a CSF value of 0 ml, was paper-made with a long net paper machine. A separator having a thickness of 99.8 μm and a basis weight of 40.0 g / m ² was obtained.

[Comparative Example 1]
Solvent-spun cellulose fiber D (α-cellulose content: 83.9%, fineness 1.7 dtex. Fiber length 4 mm) 50% by weight beaten up to 300 ml with CSF value and dissolved by beating up to 150 ml as cellulose fiber with CSF value Pulp (α-cellulose content: 98.0%) 20% by weight, vinylon fiber (fineness 1.1 dtex. Fiber length 3 mm) 20% by weight as an alkali-resistant synthetic fiber, easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) 10% by weight was mixed. This mixed raw material was paper-made with a circular paper machine to obtain a separator having a thickness of 98.7 μm and a basis weight of 33.9 g / m ² .

[Comparative Example 2]
Solvent-spun cellulose fiber C beaten to 0 ml with a CSF value (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) 100% by weight, polyamide epichlorohydrin resin (Seiko PMC Co., Ltd.) The raw material was adjusted by adding 0.25% of a wet paper strength enhancer WS4010) manufactured as a resin solid content. This mixed raw material was paper-made with a long paper machine to obtain a separator having a thickness of 46.9 μm and a basis weight of 20.4 g / m ² .

[Comparative Example 3]
Solvent-spun cellulose fibers C (α-cellulose content: 94.6%, fineness 3.3 dtex. Fiber length 6 mm) 50% by weight beaten to 760 ml with a CSF value, and unbeaten dissolved pulp (α- Cellulose content: 98.0%) 20% by weight, vinylon fiber (fineness 1.1 dtex. Fiber length 3 mm) 10% by weight, PVA fiber (1.1 dtex. Fiber length 3 mm) 10% by weight, easy as alkali-resistant synthetic fiber 10% by weight of soluble polyvinyl alcohol fiber (fineness 1.1 dtex, fiber length 3 mm) was mixed. This mixed raw material was subjected to paper making with an inclined short net paper machine to obtain a separator having a thickness of 124.7 μm and a basis weight of 37.3 g / m ² .

[Comparative Example 4]
Solvent-spun cellulose fiber C beaten to a CSF value of 150 ml (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) 3% by weight, and lyocell fiber beaten to a CSF value of 150 ml ( α-cellulose content: 77.0%, fineness 1.7 dtex, fiber length 4 mm: manufactured by Lenzing Co.) 50% by weight, vinylon fiber (fineness 1.1 dtex. fiber length 3 mm) 37% by weight as an alkali-resistant synthetic fiber, 10% by weight of easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex, fiber length 3 mm) was mixed. The mixed raw material was paper-made with a short net paper machine to obtain a separator having a thickness of 77.0 μm and a basis weight of 25.1 g / m ² .

[Comparative Example 5]
Solvent-spun cellulose fiber C beaten to 0 ml with a CSF value (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) 10% by weight and unbeaten dissolved pulp (α- Cellulose content: 98.0%) 30% by weight, vinylon fiber (fineness 1.1 dtex. Fiber length 3 mm) 30% by weight as an alkali-resistant synthetic fiber, readily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) 30% by weight was mixed. The mixed raw material was paper-made with a short net paper machine to obtain a separator having a thickness of 80.2 μm and a basis weight of 27.8 g / m ² .

[Comparative Example 6]
Solvent-spun cellulose fiber C (α-cellulose content: 94.6%, fineness 1.7 dtex. Fiber length 4 mm) 4% by weight beaten to 0 ml with a CSF value, and vinylon fiber (fineness 1. 1 dtex. Fiber length 3 mm) 86% by weight and easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) 10% by weight were mixed. The mixed raw material was paper-made with a short net paper machine to obtain a separator having a thickness of 89.6 μm and a basis weight of 25.7 g / m ² .

[Conventional example 1]
The lyocell fiber (α-cellulose content: 77.0%, fineness 1.7 dtex. Fiber length 4 mm: manufactured by Lenzing) 65% by weight beaten up to 500 ml with a CSF value, and PVA fiber (fineness 1) as an alkali-resistant synthetic fiber 0.1 dtex. Fiber length 3 mm) 20 wt% and readily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) 15 wt% were mixed. This mixed raw material was subjected to paper making with a short net paper machine to obtain a separator having a thickness of 91.5 μm and a basis weight of 25.8 g / m ² .

[Conventional example 2]
A lyocell fiber (α-cellulose content: 77.0%, fineness 1.7 dtex. Fiber length 4 mm: manufactured by Lenzing) 80% by weight beaten to 550 ml with a CSF value, and vinylon fiber (fineness 1) as an alkali-resistant synthetic fiber 0.1 dtex. Fiber length 3 mm) 10% by weight and easily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. Fiber length 3 mm) 10% by weight were mixed. This mixed raw material was made with a short paper machine to obtain a separator having a thickness of 121.7 μm and a basis weight of 38.6 g / m ² .

[Conventional example 3]
15% by weight of lyocell fiber (α-cellulose content: 77.0%, fineness 1.7 dtex, fiber length 4 mm: manufactured by Lenzing Co., Ltd.) beaten to 450 ml with a CSF value, and unbeaten mercerized pulp (as cellulose fiber) α-cellulose content: 97.1%) 35% by weight, vinylon fiber (fineness 1.1 dtex. fiber length 3 mm) 35% by weight as an alkali-resistant synthetic fiber, readily soluble polyvinyl alcohol fiber (fineness 1.1 dtex. fiber length) 3 mm) 15% by weight was mixed. The mixed raw material was paper-made with a short net paper machine to obtain a separator having a thickness of 87.4 μm and a basis weight of 25.3 g / m ² .

[Conventional Example 4]
According to Example 10 of Patent Document 3, 15% by weight of solvent-spun cellulose fiber (α-cellulose content: 77.0%, fineness 1.7 dtex. Fiber length 2 mm: manufactured by Lenzing) was beaten to 150 ml with a CSF value. . 30% by weight of mercerized pulp (α-cellulose content is 97.3%) beaten to 705 ml as a cellulose fiber and 40% vinylon fiber (fineness 0.3 dtex. Fiber length 2 mm) 40 as an alkali-resistant synthetic fiber. A coarse layer was prepared by mixing 15% by weight of P readily soluble polyvinyl alcohol fiber (fineness: 1.1 dtex, fiber length: 3 mm) as a binder component.

On the other hand, 50% by weight of solvent-spun cellulose fiber (fineness: 1.7 dtex. Fiber length: 2 mm: lyocell fiber from Lenzing) was beaten to 125 ml in terms of CSF value. To this, 35% by weight of vinylon fiber (fineness: 0.3 dtex. Fiber length: 2 mm) as an alkali-resistant synthetic fiber, and an easily soluble polyvinyl alcohol fiber fineness of 1.1 dtex. As a binder component. A fiber layer of 3 mm) was mixed to form a dense layer. These two types of raw materials were laminated and paper-made with a circular multi-layer paper machine to obtain a separator having a thickness of 86.0 μm and a basis weight of 27.2 g / m ² .
Table 2 shows various measurement data of the separators according to Examples 1 to 15, Comparative Examples 1 to 6, and Conventional Examples 1 to 4.

  The separators obtained in Examples 1 to 15 are excellent in 2Ω discharge, which is a high rate discharge characteristic, and light load discharge of 100Ω, which is an index of discharge capacity. Further, the number of defects in the intermittent discharge test is 0, and it is understood that the separator has the ability to shield the zinc oxide dendrite, which has been considered to be contradictory so far.

  Among the separators obtained in Examples 1 to 15, the separators of Examples 14 and 15 are separators composed of 100% alkali-resistant solvent-spun cellulose fibers. These separators had a high electrolyte retention rate, and good results were obtained in each discharge test. Moreover, since the separator of Example 14 is as thin as 50.5 μm but has a high liquid retention rate, it can be filled with a large amount of an electrode active material, and a high discharge capacity can be expected. Further, since the resistance is low in spite of the high separator density, an increase in battery current can be expected.

  Since the separator obtained in Example 15 was a separator using only solvent-spun cellulose fibers, it did not have wet paper strength, and the separator was broken due to vibration during transportation and an internal short circuit occurred. However, in the case of a button-type battery, a separator punched out in a circle is stacked on the pole material and used, so that it can be used without any problem in practice.

  The separator obtained in Comparative Example 1 has a large number of defects in the intermittent discharge test. This is because the solvent-spun cellulose fiber D used as a raw material had a low α-cellulose content of 83.9%, so that the solvent-spun cellulose fiber was dissolved in the alkaline electrolyte and the dimensional shrinkage of the separator was increased. It is considered that the shielding property was impaired and an internal short circuit occurred.

The separator obtained in Comparative Example 2 has a large number of defects in the intermittent discharge test. This is probably because an internal short circuit occurred because the separator thickness was as thin as 46.9 μm and the shielding performance against dendrite growth was insufficient.

The separator obtained in Comparative Example 3 was not defective in the intermittent discharge test, but the light load discharge characteristic of 100Ω, which is an index of discharge capacity, was deteriorated. This is because the thickness of the separator is 124.7 μm, the permeation of ions is inhibited and the proportion of the separator in the battery is increased, so that the filling amount of the positive electrode active material and the negative electrode active material is decreased, and the electromotive reaction is reduced. It is considered damaged.

The separator obtained in Comparative Example 4 has a large number of defects in the intermittent discharge test. This is because the blending ratio of the lyocell fiber having an α-cellulose content of 77.0% is high and the dissolution of the lyocell fiber in the alkaline electrolyte and the dimensional shrinkage of the separator are increased. It is thought that occurred.

  The separator obtained in Comparative Example 5 was not defective in the intermittent discharge test, but the light load discharge characteristic of 100Ω, which is an index of discharge capacity, was deteriorated. This is probably because the blending ratio of the easily soluble polyvinyl alcohol fiber is high, so that the melted polyvinyl alcohol is formed into a film between the fibers and the ion permeation is significantly inhibited. In addition, the melted polyvinyl alcohol coats the surface of the cellulose fiber and inhibits the retention of the electrolytic solution, so that the liquid retention rate of the alkaline electrolytic solution is lowered and the 2Ω discharge characteristic, which is a high rate discharge characteristic, is deteriorated. .

  The separator obtained in Comparative Example 6 has many failures in the intermittent discharge test, and has a short 2Ω discharge time which is a high rate discharge characteristic and a light load discharge time of 100Ω which is an index of discharge capacity. This is thought to be because the amount of the alkaline electrolyte solution decreased and the electromotive reaction was remarkably impaired due to the high blending ratio of vinylon fiber, which is an alkali-resistant synthetic fiber. Moreover, since the average pore diameter of the separator was as large as 11.5 μm, a defect occurred in intermittent discharge.

  The separators obtained in Conventional Examples 1 and 2 have a large number of defects in the intermittent discharge test. Since the average pore diameter of the separator was as large as 10 μm or more, defects were generated by intermittent discharge. In addition, since lyocell fiber having an α-cellulose content of 77.0% was used, the dimensional shrinkage of the separator, which is thought to be due to dissolution of lyocell fiber in the alkaline electrolyte, was increased, and the shielding performance of the separator was impaired, resulting in an internal short circuit. Is considered to have occurred.

  The separators obtained in the conventional examples 3 to 4 have a large amount of hydrogen gas generation and a high alkali-resistant area shrinkage ratio, a high-rate discharge characteristic of 2Ω discharge and a 100Ω light-load discharge performance and intermittent discharge as an indicator of discharge capacity. The test result is bad. This is presumably because the dimensional shrinkage of the separator occurred in the alkaline electrolyte due to the large amount of fibers dissolved in the alkaline electrolyte, and the positive electrode active material and the negative electrode active material contacted each other, thereby causing an internal short circuit. Moreover, since the average pore diameter of the separator was as large as 10 μm or more, defects were generated by intermittent discharge. Furthermore, the separators of the conventional examples 3 to 4 have a risk of leading to battery leakage due to hydrogen gas generated from the dissolved components of lyocell fibers.

  As described above, according to the embodiments and examples of the present invention, solvent-spun cellulose fibers having an α-cellulose content of 85% or more, more preferably solvent-spun cellulose having an α-cellulose content of 90% or more. By using fibers, it is possible to provide a separator that suppresses dissolution and dimensional shrinkage in an alkaline electrolyte.

  Furthermore, a separator having excellent dimensional stability can be provided by using any one or several kinds of alkali-spun synthetic fiber, easily soluble polyvinyl alcohol fiber, or cellulose fiber in addition to the solvent-spun cellulose fiber. It can be widely used for alkaline batteries using zinc as a negative electrode active material, such as alkaline manganese batteries, nickel zinc batteries, silver oxide batteries, and air zinc batteries.

Claims (7)

In a separator that is interposed between the positive electrode and negative electrode of an alkaline battery and used to isolate the active material of both electrodes,
An alkaline battery separator comprising 5% by weight or more of solvent-spun cellulose fibers having an α-cellulose content of 85% or more. In a separator that is interposed between the positive electrode and negative electrode of an alkaline battery and used to isolate the active material of both electrodes,
An alkaline battery separator comprising 5% by weight or more of solvent-spun cellulose fiber having an α-cellulose content of 90% or more.   3. The alkaline battery separator according to claim 1, wherein a thickness of the alkaline battery separator is 50 to 120 μm, and an average pore diameter of the separator is 10 μm or less. 4.   The alkaline battery separator further contains at least one cellulose fiber selected from cotton linter pulp, dissolved pulp, mercerized pulp, or regenerated cellulose fiber. The separator for alkaline batteries as described.   The alkaline battery separator according to any one of claims 1 to 4, wherein the alkaline battery separator further contains an alkali-resistant synthetic fiber.   The alkaline battery according to any one of claims 1 to 5, wherein the alkaline battery separator further contains 5 to 20 wt% of an easily soluble polyvinyl alcohol component having a dissolution temperature in water of 60 to 90 ° C. Separator for use.   An alkaline battery comprising the alkaline battery separator according to claim 1.