CN107452927A

CN107452927A - Alkaline battery separator and its manufacture method

Info

Publication number: CN107452927A
Application number: CN201710377819.3A
Authority: CN
Inventors: 伊藤康博; 村田修; 村田修一; 川野明彦; 田中政尚
Original assignee: Japan Vilene Co Ltd
Current assignee: Japan Vilene Co Ltd
Priority date: 2016-05-31
Filing date: 2017-05-25
Publication date: 2017-12-08
Anticipated expiration: 2037-05-25
Also published as: JP6925784B2; JP2017216112A; CN107452927B; HK1244107A1

Abstract

The present invention provides a kind of alkaline battery separator and its manufacture method, the alkaline battery separator and used at high temperature, and also difficult short circuit caused by skeleton occurs, electrolyte difficulty exhaust, and can manufacture the battery of long lifespan.The alkaline battery separator, by being formed comprising the non-woven fabrics that cross sectional shape is accurate ultra-fine special-shaped chopped fiber non-circular, that fibre diameter is 3~5 μm, fibre length is 1~20mm, the apparent density of the non-woven fabrics is 0.33g/cm³Hereinafter, rate of mass reduction is less than 5% after friction.The alkaline battery separator, can by by flow action in the web of the composite short fiber containing Splittable, it is fabricated by the accurate ultra-fine special-shaped chopped fiber of Splittable composite short fiber generation, the Splittable composite short fiber is made up of two or more resins, split by mechanism, it is accurate ultra-fine special-shaped chopped fiber non-circular, that fibre diameter is 3~5 μm, fibre length is 1~20mm that can generate cross sectional shape.

Description

Alkaline battery separator and its manufacture method

Technical field

The present invention relates to a kind of alkaline battery separator and its manufacture method.

Background technology

Due to the lifting of environmental consciousness in recent years, as automobile, hybrid vehicle be present and electric automobile is had a preference for Tendency.As alkaline batteries such as such hybrid vehicle and the battery of the power source of electric automobile, nickel-hydrogen secondary cells Used.In alkaline battery in such a automotive field, the alkaline battery of people's livelihood purposes also gradually increases, and requires High reliability, particularly, for preventing short-circuit performance caused by skeleton, it is desirable to high reliability.In addition, vapour When alkaline battery is used in car field, use in high temperature environments is more, the battery life caused by electrolyte exhausts be present The tendency to shorten.

In addition, though without deliberately pursuing mobile applications, but conduct can be expected to prevent because skeleton is made Into short-circuit dividing plate, present applicant propose following scheme：" a kind of battery separator, it includes non-woven fabrics, the nothing Cloth is spun to include：(1) fibre diameter is less than 3 μm of micro staple fiber；(2) fibre diameter (circular scaled value) be 3~5 μm (no Include 3 μm) and cross sectional shape be the ultra-fine special-shaped chopped fiber of non-circular standard；And there is welding composition, drawing on (3) surface The composite high-strength PP type fiber that intensity is more than 4.5cN/dtex is stretched, the composite high-strength PP type fiber melts It is connected into a point welding." (patent document 1).

As the manufacture method of this battery separator, disclose and Splittable composite short fiber is split using current and given birth to Into the method for accurate ultra-fine special-shaped chopped fiber.Like this, in order to Splittable composite short fiber fully being split using current, it is necessary to high The current of hydraulic pressure, as a result cause that the high battery separator of thickness of thin, apparent density can only be manufactured.Like this, by thickness of thin, apparent When the high dividing plate of density is applied to the used alkaline battery in high temperature environments such as automotive field, due to electrolyte reserved Few, electrolyte easily exhausts, and the tendency of shortened battery life be present.

Prior art literature

Patent document

Patent document 1：Japanese Unexamined Patent Publication 2006-236991 publications

The content of the invention

The technical problem to be solved in the present invention

The present invention is made based on the above situation, and its object is to provide a kind of alkaline battery separator and its manufacture Method, due to the alkaline battery separator even if at high temperature use when also be difficult to occur caused by skeleton it is short Road, and electrolyte is difficult to exhaust, therefore the battery of long lifespan can be manufactured.

Solves the technological means of technical problem

The present invention is a kind of alkaline battery separator, by being that (circle converts non-circular, fibre diameter containing cross sectional shape Value) be 1~20mm for 3~5 μm and fibre length accurate ultra-fine special-shaped chopped fiber non-woven fabrics composition, the table of the non-woven fabrics Sight density is 0.33g/cm³Hereinafter, the rate of mass reduction and after friction is less than 5%.

The present invention is preferably further more than 5cN/dtex containing tensile strength and fibre length is the high-strength of 1~20mm Spend compoiste adhering chopped fiber.

The present invention is preferably further less than the micro staple fiber that 3 μm and fibre length are 1~20mm containing fibre diameter.

The present invention preferably comprises the accurate ultra-fine special-shaped chopped fiber being made up of methylpentene resinoid.

The thickness of preferably alkaline battery separator of the invention is more than 150 μm.

The present invention is a kind of manufacture method of alkaline battery separator, its by by flow action in compound containing Splittable The web of chopped fiber, accurate ultra-fine special-shaped chopped fiber is generated by the Splittable composite short fiber, it is ultra-fine different the standard will to be contained Shape chopped fiber, apparent density 0.33g/cm³The non-woven fabrics conduct that rate of mass reduction below and after friction is less than 5% Alkaline battery separator, the Splittable composite short fiber are made up of two or more resins, split by mechanism, can Generation cross sectional shape is that non-circular, fibre diameter (circular scaled value) is 3~5 μm and fibre length is the accurate ultra-fine of 1~20mm Special-shaped chopped fiber.

Invention effect

Because the present invention is containing accurate ultra-fine special-shaped chopped fiber, and the rate of mass reduction after rubbing is low, thus prevent because Short-circuit excellent performance caused by skeleton.That is, because containing accurate ultra-fine special-shaped chopped fiber, the path for reaching another pole is answered It is miscellaneous and long, and the low entanglement that means between fiber of rate of mass reduction after rubbing is abundant, reaches the path of another pole more It is complicated and long, therefore prevent short-circuit excellent performance caused by skeleton.In addition, if apparent density is 0.33g/ cm³Then space is more below, due to that can retain substantial amounts of electrolyte, even if therefore can manufacture at high temperature in use, electrolysis Liquid is also difficult to the alkaline battery exhausted, battery life is grown.

If the present invention bonds chopped fiber containing high-strength composite, it is difficult to damage because of pressure, therefore be able to maintain that space. Therefore, will be carried out in high temperature environments using the battery for having this alkaline battery separator in use, even if electrolyte how much can Volatilizing, electrolyte content is reduced, but because most electrolyte is retained, therefore the electrification that can be played stably for a long time Reaction.I.e. it is easy to manufacture the alkaline battery of long lifespan.

If the present invention contains micro staple fiber, the retention of electrolyte is excellent.That is, by containing micro staple fiber, shape Into trickleer space, by capillarity, the reserve capability of electrolyte is stronger, therefore even if use is had into this alkali The alkaline battery of property battery separator is used in high temperature environments, and electrolyte is also difficult to volatilize, and it is longer can to manufacture the life-span Alkaline battery.In addition, by containing micro staple fiber, it is more complicated and long to reach the path of another pole, therefore easy to manufacture It is difficult to alkaline battery short-circuit caused by skeleton occurs.

If the present invention is containing the accurate ultra-fine special-shaped chopped fiber that is made up of methylpentene resinoid, excellent heat resistance, therefore, Easy to manufacture is even if the alkaline battery that can also be used at high temperature.

If the thickness of the alkaline battery separator of the present invention is more than 150 μm, it is more to retain the space of electrolyte, because This can retain substantial amounts of electrolyte.Therefore, easy to manufacture even if at high temperature in use, electrolyte be also difficult to exhaust, battery The alkaline battery of long lifespan.

The manufacture method of the present invention can manufacture the alkaline battery separator.That is, it can manufacture and prevent because of branch Short-circuit excellent performance caused by shape crystal, and electrolyte is also difficult to exhaust, battery life is grown even if when using at high temperature Alkaline battery.

Brief description of the drawings

Fig. 1 is the section signal of the Splittable composite short fiber for the manufacture that can be used in the alkaline battery separator of the present invention Figure.

Fig. 2 is cutting for the other Splittable composite short fibers for the manufacture that can be used in the alkaline battery separator of the present invention Face schematic diagram.

Fig. 3 is another other Splittable composite short fibers for the manufacture that can be used in the alkaline battery separator of the present invention Schematic cross-section.

Fig. 4 is another other Splittable composite short fibers for the manufacture that can be used in the alkaline battery separator of the present invention Schematic cross-section.

Fig. 5 is another other Splittable composite short fibers for the manufacture that can be used in the alkaline battery separator of the present invention Schematic cross-section.

Fig. 6 is another other Splittable composite short fibers for the manufacture that can be used in the alkaline battery separator of the present invention Schematic cross-section.

Description of reference numerals

1：Splittable composite short fiber；11：Resin component；12：Resin component.

Embodiment

In order that the path for reaching another pole is complicated and long, prevent short-circuit performance caused by skeleton Excellent, alkaline battery separator (following, to be only abbreviated as sometimes " dividing plate ") of the invention contains accurate ultra-fine special-shaped chopped fiber.Separately Outside, be non-circular by the cross sectional shape for making accurate ultra-fine special-shaped chopped fiber, be also obtained also be difficult to damage even if by pressure and The effect that the reserved of electrolyte increases.

As long as the cross sectional shape of accurate ultra-fine special-shaped chopped fiber is non-circular, i.e. it is not positive round, just there is no particular limitation, But can be for example, Long Circle, ellipse, polygonal are (for example, triangle；The quadrangle such as rectangle, trapezoidal；Pentagon；Six It is angular etc.), especially since the angle on summit is smaller, reaching the path of another pole easily becomes complicated, therefore triangle, ladder The quadrangle such as shape is suitable.

In addition, in order that the surface area of fiber is wide in certain volume, electrolyte retention is excellent, of the invention is accurate ultra-fine different The fibre diameter of shape chopped fiber is less than 5 μm, preferably less than 4.5 μm, more preferably less than 4.2 μm.On the other hand, in order that Reaching the path of another pole easily becomes complicated, and can counter pressure maintain thickness, accurate ultra-fine special-shaped chopped fiber of the invention Fibre diameter be more than 3 μm, preferably more than 3.5 μm.In addition, " fibre diameter " in this specification refers to, pass through electronics The value that microphotograph calculates measurement and obtained, when the cross sectional shape as accurate ultra-fine special-shaped chopped fiber is non-circular, will have With area of section diameter of a circle of the same area as fibre diameter.

Further, in order that accurate ultra-fine special-shaped chopped fiber is uniformly dispersed, the path complexity of another pole and long, this hair are reached The fibre length of bright accurate ultra-fine special-shaped chopped fiber is 1~20mm, preferably 2~15mm, more preferably 3~10mm.The present invention In " fibre length " refer to, pass through method specified in JIS L1015-2010 8.4.1 (direct method (C methods)) determine it is flat Equal fibre length.

The resin of the accurate ultra-fine special-shaped chopped fiber of the present invention is formed, although there is no particular limitation, in order that resistance to electrolysis Fluidity is excellent, and accurate ultra-fine special-shaped chopped fiber of the invention preferably comprises polyolefin resin, preferably only by polyolefin resin structure Into.It can include [ultra-high molecular weight polyethylene, high density polyethylene (HDPE), medium density polyethylene, low close for example, polythylene resin Polyethylene, straight-chain low density polyethylene (LDPE) or ethylene copolymer are spent (for example, ethylene-vinyl alcohol copolymer, ethylene-acrylic acid are common Polymers, ethylene-methacrylic acid copolymer) etc.], polypropylene-based resin (for example, polypropylene or propylene copolymer etc.), poly- methyl Amylene resinoid (for example, polymethylpentene or methylpentene copolymer etc.).Especially because it is made up of methylpentene resinoid Accurate ultra-fine special-shaped chopped fiber excellent heat resistance, even if the alkaline battery that easy to manufacture could be used that at high temperature, therefore suitably.

In addition, accurate ultra-fine special-shaped chopped fiber can be by, for example, nylon 6, nylon66 fiber, NYLON610, nylon 612, nylon 10, The grade of nylon 12 polyamide-based resin is formed.In addition, accurate ultra-fine special-shaped chopped fiber can include two or more, cross sectional shape, fibre Tie up at least one mutually different ultra-fine special-shaped chopped fiber of standard in diameter, fibre length, resin composition.

In addition, in order that electrolyte resistance is excellent, as described above, accurate ultra-fine special-shaped chopped fiber preferably comprises TPO tree Fat, but because polyolefin resin is low with the compatibility of electrolyte, the relatively low tendency of the retention of electrolyte be present, therefore work as When accurate ultra-fine special-shaped chopped fiber contains polyolefin resin, particularly when accurate ultra-fine special-shaped chopped fiber is made up of polyolefin resin When, preferably there is hydrophilic radical (for example, sulfonic group, carboxyl, carbonyl etc.) on the fiber surface.

Such ultra-fine special-shaped chopped fiber of standard, for example, will can be made up of mechanism two or more resins Splittable composite short fiber is split and obtained.More specifically, by mechanism by as represented in figure 1 there is orange type The Splittable composite short fiber 1 of cross sectional shape is split, and can generate the accurate ultra-fine abnormity for the triangle being made up of resin component 11 Chopped fiber, and the accurate ultra-fine special-shaped chopped fiber for the triangle being made up of resin component 12.Will be such as Fig. 2 institutes table by mechanism The Splittable composite short fiber 1 of the cross sectional shape with orange type shown is split, can generate be made up of resin component 11 it is ellipse Circular accurate ultra-fine special-shaped chopped fiber and the accurate ultra-fine special-shaped chopped fiber for the triangle being made up of resin component 12.Made by machinery Split with by the Splittable composite short fiber 1 of the cross sectional shape with orange type as represented in fig. 3, can generate by resin into Divide accurate ultra-fine special-shaped chopped fiber, the accurate ultra-fine special-shaped chopped fiber for the triangle being made up of resin component 12 of 11 triangles formed And the circular accurate ultra-fine special-shaped chopped fiber being made up of resin component 12.By mechanism by having as represented by Fig. 4 The Splittable composite short fiber 1 of the cross sectional shape of orange type is split, and can generate the oval standard being made up of resin component 11 Ultra-fine special-shaped chopped fiber, the accurate ultra-fine special-shaped chopped fiber for the triangle being made up of resin component 12 and it is made up of resin component 11 Circular accurate ultra-fine special-shaped chopped fiber.By mechanism by as illustrated in fig. 5 there is multiple bimetal type cross sectional shape Splittable composite short fiber 1 split, can generate be made up of resin component 11 or resin component 12 it is trapezoidal accurate ultra-fine different Shape chopped fiber and the ultra-fine special-shaped chopped fiber of semicircular standard being made up of resin component 11 or resin component 12.Pass through mechanism The Splittable composite short fiber 1 with orange type cross sectional shape and with hollow space as represented by Fig. 6 is split, can Generate the trapezoidal accurate ultra-fine special-shaped chopped fiber being made up of resin component 11 or resin component 12.In addition, the accurate ultra-fine short fibre of abnormity Dimension can also be obtained by using that can carry out the spinning head of spinning to the fiber of shaped cross-section.

In addition, as mechanism, although can include for example, the flow of fluid such as current, calender, refiner, pulping Machine, blender, beater etc., but be discussed further below, because the rate of mass reduction after preferred friction is less than 5%, therefore preferably By the accurate ultra-fine special-shaped chopped fiber of the flow of fluid such as current generation, and at the same time tangle.

In order that the excellent strength of dividing plate, is difficult to be broken, accurate ultra-fine special-shaped chopped fiber of the invention is preferred when manufacturing battery In the state extended." state extended " in this specification refers to, fiber is in after being formed by mechanicalness extension State, for example, being not in the shape extended in extended fiber state, being formed by meltblown during fiber formation State.As long as in addition, it is in extended state, the then accurate ultra-fine special-shaped chopped fiber generated in the stage of Splittable composite short fiber It is at the state extended.

In order to easily play the effect, preferably comprised in non-woven fabrics more than 20 mass %, further preferably 25 matter Measure more than %, the ultra-fine special-shaped chopped fiber of such standard further preferably more than 30 mass %.On the other hand, due to preferred Chopped fiber and/or micro staple fiber further are bonded containing high-strength composite as described below, therefore in non-woven fabrics, it is such Accurate ultra-fine special-shaped chopped fiber is preferably below 80 mass %, more preferably below 70 mass %, more preferably 60 mass % Below.

Particularly, although the accurate ultra-fine special-shaped chopped fiber being made up of methylpentene resinoid is suitable, preferably in nonwoven This in cloth containing more than 10 mass %, further preferably more than 12.5 mass %, further preferably more than 15 mass % The accurate ultra-fine special-shaped chopped fiber being made up of methylpentene resinoid of sample.

In order that the dividing plate of the present invention is difficult to damage because of pressure, be able to maintain that space, and by using have the present invention every The battery of plate is carried out in use, even if how much electrolyte can volatilize in high temperature environments, and electrolyte content is reduced, and can also be protected Most electrolyte, and the electromotive reactions easily played stably in a long time are stayed, are containing tensile strength preferably further The high-strength composite that more than 5cN/dtex and fibre length are 1~20mm bonds chopped fiber.

Further, since by bonding chopped fiber containing high-strength composite, can obtain being difficult to the dividing plate being broken, therefore in electricity Interpolar prepares dividing plate, when assembling electrode group, it is difficult to which produce causes by the projection cut-out of electrode, because the projection of electrode wears out dividing plate The evils such as short circuit.

Further, when Splittable composite short fiber is split by mechanism to obtain accurate ultra-fine special-shaped chopped fiber, by It is high that the Young's modulus of chopped fiber is bonded in high-strength composite, and there is appropriate rigidity, therefore by Splittable composite short fiber During segmentation, the supporter that can play a part of, segmentation property is improved, the excellent non-woven fabrics of quality can be obtained.

Because tensile strength is stronger, the performance is more excellent, and therefore, the high-strength composite bonds the tensile strength of chopped fiber Preferably more than 5.5cN/dtex, more preferably more than 6.0cN/dtex, more preferably more than 6.2cN/dtex.Although draw Stretching the upper limit of intensity, there is no particular limitation, but 50cN/dtex or so is suitable." tensile strength " in the present invention refers to, According to JIS L 1015：2010 " staple fibre test method " 8.7.1 (experiment nominally), use constant speed tensioning-type Cupping machine, the tensile strength determined under conditions of clamping is 20mm/ minutes at intervals of 20mm, draw speed.

In addition, in order that high-strength composite bonds chopped fiber and is uniformly dispersed, easily equably retains electrolyte, high intensity The fibre length of compoiste adhering chopped fiber is 1~20mm, preferably 2~15mm, more preferably 3~10mm.

The high-strength composite of the present invention bonds chopped fiber and can be made up of any resin component, but in order that electrolyte resistance is excellent It is different, preferably contain polyolefin resin in the same manner as accurate ultra-fine special-shaped chopped fiber, be preferably only made up of polyolefin resin.Example Such as, preferably by selected from polythylene resin (for example, ultra-high molecular weight polyethylene, high density polyethylene (HDPE), medium density polyethylene, low Density polyethylene, straight-chain low density polyethylene (LDPE) or ethylene copolymer etc.), polypropylene-based resin is (for example, polypropylene or propylene Copolymer etc.) or polymethylpentene resinoid (for example, polymethylpentene or methylpentene copolymer etc.) two or more trees Fat is formed, and bonding component exposes on the surface.Wherein, Splittable composite short fiber is split to generate standard by mechanism During ultra-fine special-shaped chopped fiber, in order to which there is appropriate rigidity by making high-strength composite bond chopped fiber, and conduct can be obtained The effect of supporter, preferably comprises polypropylene-based resin.

The suitable polypropylene-based resin can be propylene homopolymer or propylene and alpha-olefin (for example, second Alkene, 1- butylene etc.) copolymer.More specifically, can include for example, with crystalline isotactic Noblen, ethene The poor ethylene-propylene random copolymer of unit, by the homopolymerization part that is made up of Noblen and by acetate unit content The propylene-based block copolymer that the co-polymeric share of relatively large number of ethylene-propylene random copolymer composition is formed, can further be enumerated Crystalline propylene-ethene-alpha-olefin copolymer etc., it is by each homopolymerization part or co-polymeric share in the propylene-based block copolymer The product further generated with alpha-olefin copolymers such as 1- butylene forms.Wherein, from the angle of intensity, isotactic polypropylene homopolymerization Thing is suitable, and the particularly preferred unit number of components (IPF) of isotaxy five is more than 90%, the Q values as molecular weight distribution index (weight-average molecular weight/number-average molecular weight=Mw/Mn) be less than 6, melt index (MI) MI (230 DEG C of temperature, load 2.16kg) be 3~ 50g/10 minutes.Such PP type composition can be by using Ziegler-Natta catalyst (Ziegler-Natta Catalyst) or metallocene catalyst etc., obtained by propylene homo or by propylene and other alpha-olefin copolymers.

Like this, when high-strength composite bonds chopped fiber and contains polypropylene-based resin, in order that bonding component is in bonding Shi Buhui has an impact to polypropylene-based resin, and is able to maintain that fibre morphology, preferably bonding component by polypropylene-based resin Fusing point it is lower than polypropylene-based resin more than 10 DEG C, it is more preferably low more than 20 DEG C.Specifically, as bonding component, Neng Goulie Enumerate polyvinyls (for example, polyethylene of high density, Midst density, low-density and straight-chain low density polyethylene (LDPE) etc.), third Copolymer of alkene and other alpha-olefins etc..Due in order to also be able to maintain that cementation even if when using at high temperature, and it is preferred that The fusing point of bonding component is high, therefore is preferably made up of high density polyethylene (HDPE).In addition, if bonding component is high density polyethylene (HDPE), The dividing plate with certain degree of hardness, gloss and elasticity can be obtained, the dividing plate excellent thus, it is possible to obtain operability.Further, lead to When crossing mechanism and splitting Splittable composite short fiber and generate accurate ultra-fine special-shaped chopped fiber, from by gluing high-strength composite Knot chopped fiber has appropriate rigidity, and from the point of view of obtaining the effect this point as supporter, preferably bonding component is by high density Polyethylene is formed.

The high-strength composite of the present invention is bonded in chopped fiber, in order to be bonded by bonding component, although bonding Composition occupies at least a portion of fiber surface, but the ratio that bonding component occupies in fiber surface is higher, then can participate in Cohesive bonding component is more, it is therefore preferable that bonding component occupies more than 50% (exclusion two end portions) of fiber surface, it is more excellent Choosing occupies more than 70% (exclusion two end portions), further preferably occupies more than 90% (exclusion two end portions), most preferably occupies Fiber surface is overall (exclusion two end portions).Therefore, high-strength composite bond chopped fiber section in each composition configuration status Preferably core-sheath-type, eccentric type or fabric of island-in-sea type.

As described above, in order that electrolyte resistance is excellent, high-strength composite of the invention bonding chopped fiber preferably comprises poly- Olefine kind resin, but because polyolefin resin is low with the compatibility of electrolyte, the relatively low tendency of retention of electrolyte be present, Therefore when high-strength composite, which bonds chopped fiber, contains polyolefin resin, particularly when high-strength composite bonds chopped fiber by gathering When olefine kind resin is formed, preferably there is hydrophilic radical (for example, sulfonic group, carboxyl, carbonyl etc.) on the fiber surface.

In order to obtain being difficult to damaging because of pressure, space, the excellent dividing plate of retention of electrolyte, height of the invention are maintained The Young's modulus of intensity compoiste adhering chopped fiber is preferably more than 30cN/dtex, more preferably more than 35cN/dtex, further Preferably more than 40cN/dtex.In addition, there is no particular limitation for the upper limit of Young's modulus, it is preferred that for 110cN/dtex with Under.It is by by JIS L 1015 to be somebody's turn to do " Young's modulus "：The enhanced stretch resistance at initial stage that method specified in 2010,8.11 determines is calculated The value of the apparent Young's modulus gone out.It should be noted that enhanced stretch resistance at initial stage refers to use constant speed tensioning-type cupping machine, with 20mm/ Minute draw speed and the value that determines.

The percent thermal shrinkage that the high-strength composite of the present invention bonds chopped fiber is preferably less than 10%.This is because, if this Percent thermal shrinkage, then also it is difficult to shrink when being used in the alkaline battery used under high temperature, prevents the performance of short circuit It is excellent.Percent thermal shrinkage is more preferably less than 9%.The percent thermal shrinkage is with JIS L 1015：2010 8.15 (b) xeothermic size becomes Based on rate, temperature in use is 120 DEG C of oven dryers, is heat-treated 30 minutes and the value of measure.

There is no particular limitation for the fibre diameter of the high-strength composite bonding chopped fiber of the present invention, but preferably 5~32 μm, More preferably 8~17 μm.This is because, if the fibre diameter that high-strength composite bonds chopped fiber is less than 5 μm, easily because of pressure And damage, existing becomes to be difficult to the tendency for maintaining space, wears out dividing plate additionally, there are the projection of pole plate or easily by pole plate The tendency of marginal laceration, if the fibre diameter that high-strength composite bonds chopped fiber is more than 32 μm, high-strength composite bonds short fibre Dimension is difficult to be uniformly dispersed, and existing becomes to be difficult to the tendency for equably retaining electrolyte.

Chopped fiber is bonded on such high-strength composite that can be used in the present invention, for example, Japanese Unexamined Patent Publication can be passed through 2002-180330 publications record method and manufacture.That is, can obtain in the following manner：By being used as usual method Melt spinning method, by fiber surface have bonding component it is compound do not extend yarn spinning after, with more than 100 DEG C and small In the pressurization saturated steam of the temperature of bonding component fusing point, extend 4~15 times, be cut to required fibre length.

In addition, form the present invention dividing plate non-woven fabrics in, can contain it is two or more, in fibre diameter, fiber Upper mutually different high-strength composite bonds short in terms of length, resin composition, tensile strength, Young's modulus and/or percent thermal shrinkage Fiber.

In order to obtain being difficult to damaging because of pressure, space, the excellent dividing plate of the retention of electrolyte, in non-woven fabrics are maintained It is preferred that with more than 20 mass % amount, more preferably with more than 30 mass % amount, further preferably with more than 40 mass % amount Chopped fiber is bonded comprising such high-strength composite.On the other hand, from accurate ultra-fine special-shaped chopped fiber, preferably with it is described later ultra-fine The angle of the balance of chopped fiber is set out, and it is preferably 80 matter that such high-strength composite, which bonds content of the chopped fiber in non-woven fabrics, Below % is measured, more preferably below 70 mass %, more preferably below 60 mass %.

The non-woven fabrics of the dividing plate of the present invention is formed, in addition to accurate ultra-fine special-shaped chopped fiber, preferably further contains fiber Diameter is less than 3 μm and fibre length is 1~20mm micro staple fiber.This is because, by containing micro staple fiber, can shape Into trickleer space, by capillarity, the retention of electrolyte is stronger, even if therefore can produce use having this The alkaline battery of alkaline battery separator is carried out in high temperature environments in use, electrolyte is also difficult to volatilize, life-span longer alkali Property battery.In addition, due also to, by containing micro staple fiber, it is more complicated and long to reach the path of another pole, can produce More it is difficult to the alkaline battery that the short circuit caused by skeleton occurs.

In order to easily play capillarity, in addition, also for making the path of another pole of arrival to become complicated and long, this hair The fibre diameter of micro staple fiber in bright is preferably less than 2.5 μm, more preferably less than 2 μm.On the other hand, although fiber is straight There is no particular limitation for the lower limit in footpath, but preferably more than 0.01 μm.

In order that micro staple fiber is uniformly dispersed, the electrolyte for making to be brought by capillarity retains uniformly, and makes Path up to another pole is equably complicated and long, and the fibre length of micro staple fiber of the invention is 1~20mm, preferably 1~ 15mm, more preferably 1~10mm.

It is preferred that the fibre diameter of the micro staple fiber of the present invention in the longitudinal direction is almost identical.If this is because, as this Sample fibre diameter is almost identical, then non-woven fabrics can have the hole in uniform aperture and uniform inner space, and electrolyte Be evenly distributed, the permeability of ion is excellent.The almost identical micro staple fiber of such fibre diameter can be, by by island The micro staple fiber that the island component that the sea component of type composite fibre remains after removing is formed.Particularly by composite spinning method will be passed through The micro staple fiber that island component that the sea component of the islands-in-sea bicomponent fibre of manufacture manufactures after removing, residual is formed, even if Between multiple micro staple fibers, it may have almost identical fibre diameter, therefore the performance is more excellent, therefore it is especially suitable Preferably.In addition, the superfine fibre manufactured by meltblown be not fibre diameter is almost identical in the longitudinal direction superfine fibre, And even in the superfine fibre also between multiple superfine fibres with almost identical fibre diameter.

Because the island component of the islands-in-sea bicomponent fibre is the basis of micro staple fiber, therefore, by with micro staple fiber phase With resin form, because the sea component of islands-in-sea bicomponent fibre is removed by solvent etc., therefore, by can be than island component more The resin being removed soon is formed.For example, island component is made up of polyolefin resin, sea component is made up of polyester or copolyester Islands-in-sea bicomponent fibre, sea component is only removed by alkaline solution, thus, it is possible to obtain the micro staple fiber being made up of island component.

The cross sectional shape of the micro staple fiber of the present invention can be non-circular or circular, but preferably circular.This It is due to that, if cross sectional shape is circular, the quality of non-woven fabrics is excellent, can equably retain electrolyte.

If in addition, the beam of micro staple fiber be present, in non-woven fabrics entirety, it is difficult to capillarity is played, in addition, by Become simple and short tendency in the path that reaches another pole in non-woven fabrics entirety, be present, therefore preferably micro staple fiber is not Exist with the state of beam, and each micro staple fiber is in scattered state.

In addition, in order that the excellent strength of dividing plate, is difficult to be broken when manufacturing battery, preferably micro staple fiber is in and prolonged The state stretched.As long as in addition, being in the state of extension in the stage of islands-in-sea bicomponent fibre, then it is made up of island component ultra-fine short Fiber is at the state extended.

In order that electrolyte resistance is excellent, this micro staple fiber is it is also preferred that contain polyolefin resin, more preferably by gathering Olefine kind resin is formed.For example, can by polythylene resin [for example, ultra-high molecular weight polyethylene, high density polyethylene (HDPE), in Density polyethylene, low density polyethylene (LDPE), straight-chain low density polyethylene (LDPE) or ethylene copolymer are (for example, ethylene vinyl alcohol copolymer Thing, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer) etc.], polypropylene-based resin is (for example, polypropylene or third Alkene copolymer etc.) or polymethylpentene resinoid (for example, polymethylpentene or methylpentene copolymer etc.) composition, preferably by gathering Propylene resin or polythylene resin are formed.Alternatively, it is also possible to by for example, nylon 6, nylon66 fiber, NYLON610, nylon 612, The polyamide-based resins such as nylon 10, nylon 12 are formed.

In addition, as described above, in order that electrolyte resistance is excellent, micro staple fiber preferably comprises polyolefin resin, but It is due to that polyolefin resin is low with the compatibility of electrolyte, the low tendency of the retention of electrolyte is present, therefore when ultra-fine short When fiber contains polyolefin resin, particularly when micro staple fiber is made up of polyolefin resin, preferably in fiber surface It is upper that there is hydrophilic radical (for example, sulfonic group, carboxyl, carbonyl etc.).

In addition, if micro staple fiber contains the resin component (following, be designated as sometimes " welding composition ") that can participate in welding, And micro staple fiber is fused into office in as-welded by this, then micro staple fiber is difficult to come off, fluffed, therefore suitably. When the micro staple fiber is in as-welded, micro staple fiber only can be made up of the welding composition being made up of described resin, Can also be made up of two or more compositions, i.e. by welding composition and with it is more dystectic than the fusing point of the welding composition into (following, to be designated as sometimes " non-welding composition ") is divided to form.As the latter, if micro staple fiber is by welding composition and non-is fused into Compositions more than both divided is formed, even if then welding composition welding, can also maintain fibre morphology by non-welding composition, Capillarity will not be damaged, therefore suitably.As the cross sectional shape of such micro staple fiber, in order that welding power is excellent, For example, it is preferable to it is core-sheath-type, eccentric type or fabric of island-in-sea type.In addition, in order to maintain fiber shape, preferably non-welding composition has More than 10 DEG C higher than the fusing point of welding composition of fusing point, more preferably there is more than 20 DEG C higher than the fusing point of welding composition of fusing point.

" fusing point " in this specification refers to, using differential scanning calorimetry, with 10 DEG C/min of warming temperature, from room The temperature of the imparting maximum for the dissolving and heat absorbing curve that temperature is started to warm up and obtained.When additionally, there are 2 maximums, by highest The maximum of temperature is as fusing point.

In order to easily play the effect, preferably comprised in non-woven fabrics more than 3 mass %, further preferably 5 mass % Above, such micro staple fiber further preferably more than 10 mass %.On the other hand, due to preferably from ultra-fine with standard The relation of special-shaped chopped fiber is set out, and is preferably comprised high-strength composite and is bonded chopped fiber, therefore 30 matter are preferably comprised in non-woven fabrics Measure below %, such micro staple fiber further preferably below 25 mass %, further preferably below 20 mass %.

In addition, micro staple fiber can contain it is two or more, in fibre diameter, fibre length, cross sectional shape and/or tree Upper mutually different micro staple fiber in terms of fat composition.

As the non-woven fabrics of the dividing plate of the present invention, containing the ultra-fine special-shaped chopped fiber of standard as described above, preferably comprise high-strength Spend compoiste adhering chopped fiber and/or micro staple fiber, but generate accurate ultra-fine abnormity Splittable composite short fiber is split During chopped fiber, Splittable composite short fiber is not split fully sometimes, and it is mutual to be mixed between accurate ultra-fine special-shaped chopped fiber The slurry fiber of bonding state.

As the non-woven fabrics of the dividing plate of the present invention, containing above-mentioned accurate ultra-fine special-shaped chopped fiber, but by between fiber Entanglement and/or when bonding chopped fiber containing high-strength composite, the bonding that chopped fiber is bonded by high-strength composite maintains Form.

As the non-woven fabrics of the dividing plate of the present invention, because its apparent density is 0.33g/cm³When following, space is more, can Retain substantial amounts of electrolyte, therefore can manufacture that electrolyte is also difficult to exhaust even if when using at high temperature, battery life is grown Alkaline battery.Because apparent density is lower, space is more, can more retain substantial amounts of electrolyte, therefore preferably 0.32g/cm³ Hereinafter, more preferably 0.31g/cm³Hereinafter, more preferably 0.30g/cm³Hereinafter, more preferably 0.29g/cm³With Under, more preferably 0.28g/cm³Below.On the other hand, if apparent density is too low, space is excessive, then existing forms are stable Property be deteriorated tendency, it is therefore preferable that being 0.18g/cm³More than, more preferably 0.19g/cm³More than, more preferably 0.20g/ cm³More than.The implication for being somebody's turn to do " apparent density " is the calculated value that " weight per unit area " divided by " thickness " obtains.

In addition, the thickness of the dividing plate of the present invention is preferably more than 150 μm.This is because, as described above, even if apparent density Low, the ratio in space is high, if but the dividing plate in space absolute volume it is small, the reserved of electrolyte is reduced, and is used at high temperature When, electrolyte be present and exhaust, the situation of shortened battery life.Due to dividing plate thickness thickness when, the absolute volume of dividing plate becomes big, because This is more preferably more than 160 μm, more preferably more than 170 μm, more preferably more than 180 μm, more preferably More than 190 μm.On the other hand, if because the thickness of dividing plate is blocked up, in alkaline battery, the volume that dividing plate occupies increases, and deposits In the tendency of activity substance content reduction, therefore preferably less than 250 μm, more preferably less than 230 μm, more preferably Less than 220 μm.

" thickness " of the present invention refers to, when load is 5N, uses JIS B 7502：Outside micrometer (0 as defined in 199 ~25mm), obtained from being measured to randomly selected 10 points, the arithmetic mean of instantaneous value of 10 points of the thickness.

There is no particular limitation for the weight per unit area of such dividing plate of the invention, if but weight per unit area is big, The dividing plate that fibre weight is more, quality is excellent, reliability is high, therefore preferably 30g/m can then be obtained²More than, more preferably 40g/m² More than, more preferably 50g/m²More than.On the other hand, if weight per unit area becomes big, thickness is a timing, apparent density Become big, space is reduced, it is therefore preferable that being 80g/m²Hereinafter, more preferably 70g/m²Hereinafter, more preferably 60g/m²Below. " weight per unit area " in the present invention refers to, with JIS P 8124：2011 (the measure of the weight per square meter of paper and cardboard Method) as defined in the weight per square meter that obtains based on method.

Further, since form the present invention dividing plate non-woven fabrics friction after rate of mass reduction it is low be less than 5%, fiber Between fully tangle, therefore the path for reaching another pole is complicated and long, prevents short-circuit caused by skeleton Excellent performance.Particularly, if high-strength composite bonds chopped fiber and is in bond state, high-strength composite bonds chopped fiber with fibre The state more than contact point between dimension is in bond state, therefore also can obtain the dividing plate of excellent in fracture strength.Like this, due to Entanglement degree between the lower fiber of rate of mass reduction is bigger, reaches the path complexity and length of another pole, therefore, rate of mass reduction Preferably less than 4%, more preferably less than 3%, more preferably less than 2%, more preferably less than 1%.

In addition, the rate of mass reduction in the present invention after the friction of non-woven fabrics (dividing plate) is obtained by following operation Value.

(1) at 3 on the width of non-woven fabrics, it is 25mm to take width, production mode reform is 180mm sizes length Square test piece.

(2) preparation is recorded in JIS L 0849-2013 frictional testing machine II types (vibration shape), and the test film is installed On test film platform.

(3) friction is arranged on to the top of friction with byssus (calico 3), with 2N load, in test film Between middle body 10cm, with the speed of reciprocal 30 times per minute, reciprocating friction 100 times.

(4) now, according to the quality (M0) of the test film before friction and friction after test film quality (M1), use with Lower formula calculates the rate of mass reduction (Re) after the friction of 3 test films respectively.

Re=[(M0-M1)/M0] × 100

(5) rate of mass reduction (Re) of 3 pieces of test films is subjected to arithmetic average, the friction as non-woven fabrics (dividing plate) Rate of mass reduction afterwards.

In order that fully tangled between fiber, it is difficult to the short circuit caused by skeleton occurs, in addition, in order to manufacture During dividing plate (non-woven fabrics) and when manufacturing battery, it can not occur to be broken and stably manufactured, dividing plate (nonwoven of the invention Cloth) fracture strength be preferably more than 60N/50mm, more preferably more than 80N/50mm, more preferably 100N/50mm with On.

In addition, the fracture strength of the present invention is the value to obtain by following operation.

(1) length that width is 50mm, production mode reform is 200mm sizes is taken at 3 on the width of non-woven fabrics Square test piece.

(2) by the strip method of JIS L 1096-2010 8.14.1JIS method a) methods, the stretching examination of constant speed tensioning-type is used Machine is tested, under conditions of clamping is 300mm/min at intervals of 100mm, draw speed, stretches each experiment in the longitudinal direction Piece, read tensile load during fracture.

(3) arithmetic average of the tensile load is calculated, as fracture strength.

In addition, in order to configure dividing plate between electrode, when assembling electrode group, it is difficult to occur to be broken caused by the projection of electrode Or causing short circuit because the projection of electrode wears out dividing plate, the average pin type penetration power of dividing plate of the invention (non-woven fabrics) is preferably More than 800gf, more preferably more than 900gf, more preferably more than 1000gf.In addition, average pin type penetration power is upper Limit does not provide particularly, but is that below 1800gf is more real.

In addition, the average pin type penetration power in the present invention is the value to obtain by following operation.

(1) test film that width is 1050mm, production mode reform is 50mm is taken from non-woven fabrics.

(2) test film is positioned in and is attached to manual compression testing machine (KES-G5 of KATO TECH Co., Ltd manufactures) Have area be 1cm²Circular port platform on after, the use of with area is 1cm²Circular port clip fixation test piece.Its In, it is fixed in a manner of making the hole of platform consistent with the hole of clip.

(3) from the top of the circular port, a diameter of 1mm pin (end shape is made：R=0.5mm) relative in hole Center portion point is declined with the speed of 1mm/ seconds, perpendicular to test film progress bur, required power (gf) when being penetrated for reaching, On width, the measure at 10 is carried out using 10cm as interval.

(4) calculate in each test film, reach the arithmetic average of power required when penetrating, as average needle Formula penetration power.

Further, in order to equably retain electrolyte, the quality of preferably dividing plate (non-woven fabrics) of the invention is excellent.Tool For body, average quality index is preferably less than 1.8%, more preferably less than 1.6%, more preferably less than 1.4%.

The average quality index can use quality meter (trade name：FPI MEAS, Toshiba Solutions Co., Ltd is manufactured) and determine.More specifically, using scanner that resolution ratio is 6400dpi (for example, EPSON Co., Ltd manufacture, Model GT-X970), the image (100mm × 100mm) of collection non-woven fabrics (dividing plate).By collection image by under 0.8mm angular units Luma digit (255 gray scale), quality index (Ui, unit are calculated by following formula：%).

Ui=(Lsd/Lm) × 100

In formula, Lsd, Lm represent the standard deviation of brightness and the arithmetic average of brightness respectively.

The dividing plate of the present invention, such as can manufacture in the following manner.

First, Splittable composite short fiber is prepared, the Splittable composite short fiber is made up of two or more resins, passed through It is that non-circular, fibre diameter (circular scaled value) is 3~5 μm and fibre length that mechanism, which can split generation cross sectional shape, For 1~20mm accurate ultra-fine special-shaped chopped fiber.As such Splittable composite short fiber, can include for example, as described above Such as Fig. 1~Fig. 6 Splittable composite short fiber.Further, since Splittable composite short fiber is accurate ultra-fine special-shaped chopped fiber Generation source, therefore Splittable composite short fiber is preferably to fit methylpentene resinoid, polypropylene-based resin, polythylene resin When the fiber of combination, particularly preferably, intermiscibility is relatively low, can utilize the relatively low current segmentation of pressure, web thickness not The Splittable composite short fiber that meeting is excessively thin, is made up of the combination of methylpentene resinoid and polypropylene-based resin.

In addition, as noted previously, as the present invention dividing plate preferably comprise high-strength composite bond chopped fiber, therefore it is also preferred that Prepare high-strength composite and bond chopped fiber.Chopped fiber is bonded as the high-strength composite, described fiber can be used, it is especially excellent Choosing, when Splittable composite short fiber is split, can serve supporter, be made up of polypropylene and high density polyethylene (HDPE) and The high-strength composite that high density polyethylene (HDPE) occupies the overall core sheath structure of fiber surface bonds chopped fiber.

In addition, as noted previously, as the dividing plate of the present invention preferably comprises micro staple fiber, therefore it is also preferred that preparation is ultra-fine short Fiber.As the micro staple fiber, described fiber can be used, particularly by the sea component of islands-in-sea bicomponent fibre is removed And remain island component composition micro staple fiber, due to each micro staple fiber fibre diameter in the longitudinal direction almost It is identical, there is the hole in uniform aperture and uniform inner space, the dividing plate that easy to manufacture electrolyte is evenly distributed, therefore fit Preferably.In addition, when occupying the overall high-strength composite of fiber surface containing high density polyethylene (HDPE) and bonding chopped fiber, in order to even in High-strength composite is bonded under thermal environment when chopped fiber is bonded, be also able to maintain that fibre morphology, preferably micro staple fiber It is made up of polypropylene.

Then, using Splittable composite short fiber, chopped fiber and/or ultra-fine short fibre preferably are bonded using high-strength composite Dimension, form web.There is no particular limitation for the blend ratio of these fibers, but in order to be held by accurate ultra-fine special-shaped chopped fiber The short circuit caused by skeleton is easily prevented, preferably comprises Splittable composite short fibers more than 20 mass %.In the present invention, Because preferred separator contains accurate ultra-fine special-shaped chopped fiber, high-strength composite bonds chopped fiber and micro staple fiber, thus preferably with 20~77：20~77：3~30 mass ratio, more preferably with 25~65：30~65：5~25 mass ratio, further preferably with 30~55：35~55：10~20 mass ratio contains Splittable composite short fiber, high-strength composite bonds chopped fiber, ultra-fine short Fiber.

In addition, there is no particular limitation for the forming method of web, but in order that fiber is uniformly dispersed and makes quality It is excellent and can equably retain electrolyte, preferably formed by damp process.The damp process suitable as this, can include example Such as, horizontal long net mode, inclination line style short net mode, cylinder mode or fourdrinier wire-cylinder combination.

Hereafter, by the way that flow action in web (particularly wet fiber net), is generated by Splittable composite short fiber Accurate ultra-fine special-shaped chopped fiber.By the flow action, Splittable composite short fiber can not only be split and generate accurate ultra-fine different Shape chopped fiber, it can also make to tangle between fiber.Formed as described above, being combined by methylpentene resinoid and polypropylene-based resin Splittable composite short fiber can utilize the relatively low current of pressure and be divided, the thickness of web will not be made excessively thin, therefore Suitably.If in addition, bonding chopped fiber containing high-strength composite, it plays a part of supporter, moreover it is possible to which obtaining easily will segmentation Type composite short fiber is split and generates the effect of accurate ultra-fine special-shaped chopped fiber.

If the current can split Splittable composite short fiber, while make fully to tangle between fiber, after making friction Rate of mass reduction be less than 5%, then any flow condition all can, there is no particular limitation, for example, from diameter 0.05~ 0.3mm, 0.2~3mm of spacing condition are configured with the nozzle plate of 1 row or the nozzle of the 2 row above, are to web injection pressure 1MPa~8MPa current.To the one or both sides of web, current as more than 1 time are sprayed.In addition, make water When stream is acted on, if the non-aperture segment of the supporter such as net of support web is thick, obtained dividing plate also has big hole, Become that short circuit easily occurs, therefore preferably using the supporter that line footpath is below 0.25mm.

In addition, in order to split Splittable composite short fiber using the lower current of pressure, the thickness of web is not made Spend it is thinning, preferably before flowing water is acted on, by form web fiber fix.For example, glued containing high-strength composite When tying chopped fiber, the bonding component that chopped fiber is preferably bonded by high-strength composite is bonded, the compound short fibre of fixed Splittable Dimension.Like this when Splittable composite short fiber is secured, Splittable composite short fiber is divided in the effect by current While cutting and generate accurate ultra-fine special-shaped chopped fiber, tangled.

Like this when the bonding component that chopped fiber is bonded by high-strength composite is bonded, although can be in no pressure Under conditions of carry out, lower under pressure can also carry out, can also melt bonding component under conditions of no pressure After pressurizeed, but when being bonded in the case of not pressurizeed by solids such as rollers, easy to manufacture go out apparent density compared with Non-woven fabrics (dividing plate) more than low, space, therefore suitably.As such device bonded can be implemented, for example, have hot calender, Hot-air through type annealer, cylinders contact type annealer etc..

The non-woven fabrics that accurate ultra-fine foreign fiber is generated although can will be acted on current like this is used as dividing plate, In order that the rate of mass reduction after friction becomes lower, and preferably after current are acted on, the fixed fiber for forming non-woven fabrics. For example, when bonding chopped fiber containing high-strength composite, the bonding component that chopped fiber is preferably bonded by high-strength composite is carried out Bond, fixed accurate ultra-fine special-shaped chopped fiber.Like this, enter if making high-strength composite bond chopped fiber after current are acted on Row bonds, then can manufacture the dividing plate with excellent fracture strength.In addition, being bonded to for chopped fiber is bonded by high-strength composite The bonding divided and carried out, can be implemented with the bonding identical method with the web before current are acted on, condition, When being bonded in the case of not pressurizeed by solids such as rollers, easy to manufacture goes out that apparent density is relatively low, the nothing more than space Cloth (dividing plate) is spun, therefore suitably.

In the dividing plate of the present invention, although in order that electrolyte resistance is excellent, preferably accurate ultra-fine special-shaped chopped fiber, high intensity Compoiste adhering chopped fiber, micro staple fiber are formed by polyolefin resin, but due to polyolefin resin and electrolyte Compatibility is low, therefore is preferable to carry out known hydrophilicity-imparting treatment the retention that assigns or improve electrolyte, for example, at sulfonation Reason, fluorine element gas treatment, the graft polymerization processing of vinyl monomer, discharge process, surfactant processing or hydrophilic resin are assigned Give processing.

In addition, in order that the apparent density of the dividing plate of the present invention is 0.33g/cm³Hereinafter, make space more, preferably without Thickness is adjusted, or even if carrying out thickness adjustment, also to push down the faint pressure of the extreme of the fine hair degree of fiber, (line is pressed as 20N/ Below m) carry out thickness adjustment.That is, because the current in the past using high pressure split Splittable composite short fiber, therefore dividing plate table The bumps in face are significantly, it is difficult to equably retain electrolyte, therefore can only produce needs and carry out thickness tune by higher pressure The dividing plate whole, apparent density is high and space is few, but in the present invention, due to Splittable can be answered by the current of low-pressure To close chopped fiber segmentation and generate accurate ultra-fine special-shaped chopped fiber, the bumps of baffle surface are not notable, can equably retain electrolyte, Therefore it can be adjusted without thickness, or thickness adjustment can be carried out with extremely faint pressure, so can manufacture apparent Density is low, the dividing plate more than space.That is, can manufacture can retain substantial amounts of electrolyte and even if at high temperature use when electrolyte Also it is difficult to the alkaline battery of battery life length exhausted.

In addition, for example make fully to tangle between fiber and/or bonded by using high-strength composite short by using current Fiber is bonded, and can manufacture the dividing plate of excellent in fracture strength.

Further, such as by bonding chopped fiber containing high-strength composite and/or improving nothing by blending micro staple fiber The uniformity of cloth is spun, the strong dividing plate of average pin type penetration power can be manufactured.

Further, such as by using damp process web, the hydraulic pressure by reducing current are formed and/or is surpassed by blending Thin chopped fiber, the excellent dividing plate of quality can be manufactured.

Due to the present invention dividing plate even if at high temperature by use, also be difficult to occur caused by skeleton it is short Road, and electrolyte is difficult to exhaust, as long as therefore be just difficult to exhaust using the dividing plate of the present invention, electrolyte, and be difficult to occur because of tree It is short-circuit caused by dendritic crystal, therefore the alkaline battery of long lifespan can be manufactured.Therefore, it is possible to suitably be used as at high temperature The hybrid vehicle and the battery of the power source of electric automobile used.However, even if at normal temperatures in use, passing through the present invention Dividing plate can also produce play better than traditional performance alkaline battery.

In addition, the form as battery, such as can be cylindrical, square or coin shape, as the species of battery, such as can For one-shot batteries such as alkaline manganese battery, mercury cell, silver oxide cell or air cells, or nickel-cadmium cell, silver-zinc battery, silver- The secondary cells such as cadmium cell, nickel-zinc cell, nickel-hydrogen cell or lead accumulator, particularly can be nickel-cadmium cell, nickel-hydrogen cell.

Embodiment

Hereinafter, embodiments of the invention are recorded, but the present invention is not limited by following examples.

(Splittable composite short fiber A)

Prepare the fineness with orange type cross sectional shape as represented in figure 1 be 1.7dtex and fibre length be 5mm Extended Splittable composite short fiber A, it [can generate in 8 chromosomes represented by symbol 11, section shape by polypropylene constituent The accurate ultra-fine special-shaped chopped fiber (fusing point of polypropylene that shape is class triangle and fibre diameter is 3.8 μm：160 DEG C)] and poly- methylpent Alkene composition [can generate that in 8 chromosomes represented by symbol 12, cross sectional shape is class triangle and fibre diameter is 4.0 μm poly- The accurate ultra-fine special-shaped chopped fiber (fusing point of methylpentene：235 DEG C)] form.

(Splittable composite short fiber B)

Prepare the fineness with orange type cross sectional shape as represented in figure 1 be 1.7dtex and fibre length be 5mm Extended Splittable composite short fiber B, it [can generate in 8 chromosomes represented by symbol 11, section shape by polypropylene constituent The accurate ultra-fine special-shaped chopped fiber (fusing point of polypropylene that shape is class triangle and fibre diameter is 3.8 μm：160 DEG C)] and high density gather Ethene composition [can generate that in 8 chromosomes represented by symbol 12, cross sectional shape is class triangle and fibre diameter is 3.7 μm The accurate ultra-fine special-shaped chopped fiber (fusing point of high density polyethylene (HDPE)：130 DEG C)] form.

(high-strength composite bonds chopped fiber A)

Prepare high-strength composite and bond chopped fiber A (fibre diameters：10 μm, fibre length：5mm, Young's modulus：45cN/ Dtex, percent thermal shrinkage：7%) core-sheath-type, is configured in its section, core component is by isotactic polypropylene homopolymer (fusing point：168 DEG C) form, sheath composition is by high density polyethylene (HDPE) (fusing point：135 DEG C) form, and tensile strength is 6.5cN/dtex.

(compoiste adhering chopped fiber B)

Prepare compoiste adhering chopped fiber B (fibre diameters：10 μm, fibre length：5mm, Young's modulus：24cN/dtex, heat Shrinkage factor：10%) core-sheath-type, is configured in its section, core component is by polypropylene (fusing point：165 DEG C) form, sheath composition is by low Density polyethylene (fusing point：110 DEG C) form, and tensile strength is 4.0cN/dtex.

(micro staple fiber)

By the way that composite spinning method spinning fabric of island-in-sea type is compound do not extend fiber, do not extend fiber the fabric of island-in-sea type is compound, by 61 island components being made up of polypropylene be present in the sea component that polyethylene terephthalate is formed, the sea of manufacture will be extended Island composite fibre soaks 120 minutes in alkaline aqueous solution, extracts and removes the poly terephthalic acid second two as sea component After alcohol ester, severing is carried out, making the almost identical polypropylene superfine chopped fiber of fibre diameter in the longitudinal direction, (fiber is straight Footpath：2 μm, fibre length 3mm, fusing point：168 DEG C, cross sectional shape：Circle, between multiple polypropylene superfine chopped fibers also almost It is identical).

(embodiment 1~3, comparative example 1~5)

After forming the scattered slurries of mixing according to the blending mode represented by table 1, pass through damp process (horizontal long net mode) Form web.In addition, when containing polypropylene superfine chopped fiber, each polypropylene superfine chopped fiber is in scattered shape State.

Hereafter, it is being that 140 DEG C (when bonding chopped fiber A containing high-strength composite) or 110 DEG C (contain multiple without pressurization, temperature Close when bonding chopped fiber B) under conditions of while dry the web, it is viscous to bond chopped fiber A or compound using high-strength composite Knot chopped fiber B is bonded, and is manufactured and is bonded web of staple fibers.

Hereafter, will bond web of staple fibers and be positioned in line footpath is the online of 0.15mm, by the water that pressure is 3.5MPa~11MPa Stream, it is each in a manner of two sides is alternate to spray 2 times from the nozzle plate that nozzle diameter is 0.13mm, spacing is 0.6mm, split Type composite short fiber A, B segmentation and make to tangle between fiber and manufacture current entangled fiber net.

Hereafter, it is being that 140 DEG C (when bonding chopped fiber A containing high-strength composite) or 110 DEG C (contain multiple without pressurization, temperature Close when bonding chopped fiber B) under conditions of while dry the current entangled fiber net, utilize high-strength composite to bond chopped fiber A Or compoiste adhering chopped fiber B is bonded again, manufacture and bond current entangled nonwoven cloth.

Hereafter, current entangled nonwoven cloth will be bonded in the oleum solution (15%SO that temperature is 60 DEG C₃Solution) in soak Bubble is fully washed after 2 minutes, is dried backward fiber surface and is imported sulfonic group, using the calender of normal temperature, with represented by table 1 Line pressure carry out thickness adjustment, or adjusted without thickness, manufacturer's area weight is 55~75g/m²Dividing plate.Separately Outside, when containing polypropylene superfine chopped fiber, each fiber is in scattered state.

(evaluation of physical property)

By methods described, the rate of mass reduction after the fracture strength of each dividing plate, friction, average pin type penetration are determined Liquid rate is protected in power, quality index, specific surface area and pressurization.These results are as represented by table 1.

In addition, it is believed that " specific surface area " reaches the index in the path of another pole for expression, and specific surface area is bigger, it is meant that Reach that the path of another pole is longer, and it is determined through the following steps.

(measure of specific surface area)

By each dividing plate (sample) in a vacuum, temperature be 70 DEG C under conditions of handle 4 hours after, be cooled to room temperature, take out Vacuum is to 1 × 10^-3Torr.Hereafter, precision weighing about 0.5g sample.Hereafter, device [BEL is determined using gas absorption Japan, Inc are manufactured, BELSORP 28A], it is measured by BET method.Wherein, krypton has been used as adsorbed gas.

In addition, it is the index for representing to retain the performance of electrolyte that liquid rate is protected in pressurization, it is determined through the following steps.

(measure of liquid rate is protected in pressurization)

(1) test film of 5cm square is taken from each dividing plate, respectively quality measurement (A).

(2) each test film is soaked in electrolyte (1.3g/mL potassium hydroxide aqueous solution), using electrolyte full of examination The space tested in piece.

(3) 3 filter paper (models are together utilized to the two sides of test film：ADVANTEC-TYPE2 test film) is clamped, with 1.23MPa pressure compression, electrolyte is drawn using the filter paper.

(4) measure has been drawn the quality (B) of the test film of electrolyte respectively, calculated by following equation the liquid rate of protecting (R, Unit：%).

R=[(B-A)/A] × 100

[table 1]

From the comparison of embodiment 1~3 and comparative example 1,2, because the rate of mass reduction after friction is less than 5%, no In the state fully tangled only between fiber, and specific surface area is big, reaches the path length and complexity of another pole, therefore, can It is difficult to alkaline battery short-circuit caused by skeleton occurs to infer to manufacture.

In addition, from the comparison of embodiment 2 and comparative example 3~5, because apparent density is 0.33g/m³Hereinafter, pressurize It is high to protect liquid rate, it could therefore be concluded that can manufacture even if at high temperature in use, electrolyte be also difficult to exhaust, battery life length Alkaline battery.

Further, the dividing plate of embodiment 1~3 is because the rate of mass reduction after friction is less than 5%, in filling between fiber Divide the state tangled, fracture strength, average pin type penetration power are high, it could therefore be concluded that dividing plate and alkali can be manufactured stably Property battery.

Industrial applicibility

The alkaline battery separator of the present invention, the alkaline secondary cells such as nickel-hydrogen secondary cell can be applied to.Particularly, by It is the high alkaline battery separator of reliability in it, therefore hybrid vehicle can be suitable for and alkaline battery used for electric vehicle is used Dividing plate.

Claims

1. a kind of alkaline battery separator, it is characterised in that by straight for fiber that is non-circular, being scaled circle containing cross sectional shape The non-woven fabrics of the accurate ultra-fine special-shaped chopped fiber that footpath is 3~5 μm and fibre length is 1~20mm is formed, the non-woven fabrics it is apparent Density is 0.33g/cm³Hereinafter, the rate of mass reduction and after friction is less than 5%.

2. alkaline battery separator according to claim 1, it is characterised in that be further 5cN/ containing tensile strength The high-strength composite that more than dtex and fibre length are 1~20mm bonds chopped fiber.

3. alkaline battery separator according to claim 1 or 2, it is characterised in that be further less than 3 containing fibre diameter μm and fibre length be 1~20mm micro staple fiber.

4. according to alkaline battery separator according to any one of claims 1 to 3, it is characterised in that containing by methylpentene The accurate ultra-fine special-shaped chopped fiber that resinoid is formed.

5. according to alkaline battery separator according to any one of claims 1 to 4, it is characterised in that its thickness be 150 μm with On.

A kind of 6. manufacture method of alkaline battery separator, it is characterised in that by by flow action in compound containing Splittable The web of chopped fiber, accurate ultra-fine special-shaped chopped fiber is generated by the Splittable composite short fiber, it is ultra-fine different the standard will to be contained Shape chopped fiber, apparent density 0.33g/cm³The non-woven fabrics conduct that rate of mass reduction below and after friction is less than 5% Alkaline battery separator, the Splittable composite short fiber are made up of two or more resins, split by mechanism, can The fibre diameter that generation cross sectional shape is non-circular, is scaled circle is 3~5 μm and fibre length is the accurate ultra-fine of 1~20mm Special-shaped chopped fiber.