JP2002151358A - Capacitor separator and method of manufacturing the same - Google Patents

Abstract

(57) [Problem] To provide a separator for a capacitor which is excellent in an electrolytic solution and heat resistance and has a uniform formation. SOLUTION: A fiber (A) comprising a polyamide (a) synthesized from a dicarboxylic acid component containing at least 60 mol% of an aromatic dicarboxylic acid and a diamine component containing at least 60 mol% of an aliphatic alkylenediamine having 6 to 12 carbon atoms. A) A capacitor separator comprising:

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a separator for a capacitor, and more particularly to a separator suitable for an electric double layer capacitor using an organic solvent as an electrolyte and a method for producing the same.

[0002]

2. Description of the Related Art An electric double layer capacitor has a large capacity, which is the same as that of a nickel-cadmium battery, a nickel-metal hydride battery, or a lithium ion battery. In addition to applications such as absorption, it has come to be used as a memory backup power source for personal computers, as an auxiliary or substitute for secondary batteries, and the like. The conventional secondary battery has a high capacity, but has a relatively short life and is difficult to rapidly charge and discharge. On the other hand, an electric double-layer capacitor has a relatively large capacity but has the advantages inherent in the capacitor. Some long life,
It has the good property that rapid charge and discharge are possible. The main components of the electric double layer capacitor are an electrode, an electrolyte, a separator, a current collector, and the like. The purpose of the separator is to prevent contact between the positive and negative electrodes, but not to obstruct the flow of ions. As the thickness of the separator increases, the passage of the electrolytic solution increases and the internal resistance increases. Therefore, it is desired to reduce the thickness of the separator. Aqueous (such as aqueous sulfuric acid solution) and organic (such as tetraethylammonium / tetrafluoroborate dissolved in propylene carbonate) electrolytes have been used as electrolytes. Attention has been paid to higher energy density than voltage. In organic systems, water becomes an impurity and lowers the performance of the capacitor.
Water must be thoroughly removed. Therefore, it is desired that the separator be dried at the highest possible temperature under vacuum, and heat resistance in the drying step is an important required property. Conventionally used for capacitors,
Cellulose paper separators are relatively excellent in heat resistance in the presence of oxygen, but discolor to brown at 150 ° C., and improvement in heat resistance is desired. The separator is naturally required to be chemically stable with respect to the electrolytic solution.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a capacitor separator formed of a nonwoven fabric containing polyamide fiber (A) as a main component, which retains chemical stability to an electrolytic solution and has excellent heat resistance. It is to provide a manufacturing method thereof.

[0004]

That is, the present invention provides a dicarboxylic acid component containing at least 60 mol% of an aromatic dicarboxylic acid and a diamine component containing at least 60 mol% of an aliphatic alkylenediamine having 6 to 12 carbon atoms. A capacitor separator comprising a fiber (A) made of a synthesized polyamide (a).

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyamide (a) constituting the capacitor separator of the present invention comprises a dicarboxylic acid component and a diamine component, and comprises 60 mol% of the dicarboxylic acid component.
It is characterized in that the above is an aromatic dicarboxylic acid and that 60 mol% or more of the diamine component is an aliphatic alkylenediamine having 6 to 12 carbon atoms.

As the aromatic dicarboxylic acid, terephthalic acid is preferred in terms of heat resistance and electrolytic solution resistance of the capacitor separator, and isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4 -Naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, diphenic acid,
Aromatic dicarboxylic acids such as dibenzoic acid, 4,4'-oxydibenzoic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, 4,4'-biphenyldicarboxylic acid; More than one kind can be used in combination. The content of the aromatic dicarboxylic acid is 60 mol% or more of the dicarboxylic acid component, and
It is preferably at least 5 mol%. Examples of the dicarboxylic acids other than the aromatic dicarboxylic acids include malonic acid, dimethylmalonic acid, succinic acid, 3,3-diethylsuccinic acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid,
Aliphatic dicarboxylic acids such as methyl adipic acid, trimethyl adipic acid, pimelic acid, azelaic acid, sebacic acid and suberic acid; alicyclic dicarboxylic acids such as 1,3-cyclopentane dicarboxylic acid and 1,4-cyclohexane dicarboxylic acid These acids can be used not only one kind but also two or more kinds. Among them, it is preferable that the dicarboxylic acid component is 100% aromatic dicarboxylic acid in view of the strength, electrolyte resistance, heat resistance and the like of the nonwoven fabric. Further, polyvalent carboxylic acids such as trimellitic acid, trimesic acid, pyromellitic acid and the like can be contained within a range that can be easily formed into a fiber and a nonwoven fabric.

Further, 60 mol% or more of the diamine component is composed of an alkylenediamine having 6 to 12 carbon atoms. Such aliphatic alkylenediamines include 1,6-hexanediamine, 1,8-octanediamine, 9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 2-
Methyl-1,5-pentanediamine, 3-methyl-1,
5-pentanediamine, 2,2,4-trimethyl-1,
6-hexanediamine, 2,4,4-trimethyl-1,
Examples thereof include aliphatic diamines having a linear or side chain such as 6-hexanediamine, 2-methyl-1,8-octanediamine, and 5-methyl-1,9-nonanediamine. Among them, 1,9-nonanediamine, 1,9-nonanediamine and 2-methyl-1,
Combination with 8-octanediamine is preferred. The content of the aliphatic alkylenediamine is at least 60 mol% of the diamine component, but is preferably at least 75 mol%, particularly preferably at least 90 mol%, from the viewpoint of heat resistance.

Diamines other than the above-mentioned aliphatic alkylenediamines include aliphatic diamines such as ethylenediamine and 1,4-butanediamine; and fats such as cyclohexanediamine, methylcyclohexanediamine, isophoronediamine, norbornanedimethyldiamine and tricyclodecanedimethyldiamine. Cyclic diamine; p-phenylenediamine, m-phenylenediamine, xylylenediamine, xylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4 '
And aromatic diamines such as diaminodiphenyl ether, and mixtures thereof.
Two or more types can be used as well as types.

[0009] 1,9-
When nonanediamine and 2-methyl-1,8-octanediamine are used in combination, 60 to 100 mol% of the diamine component is composed of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and the molar ratio thereof is as follows. The former: the latter = 3
0: 70-99: 1, especially the former: the latter = 40: 60-
The ratio is preferably 95: 5.

The polyamide used in the present invention is
[CONH / CH in the molecular chain of _Two] Is 1/2 to 2
It is preferably 1/8, particularly preferably 1/3 to 1/5.
The use of polyamides in this range allows for electrolyte resistance
And a capacitor separator with excellent heat resistance.
Because

The limiting viscosity of the above polyamide (concentrated sulfuric acid 30
C) is preferably 0.6 to 2.0 dl / g, particularly 0.6 to 1.8 dl / g, and 0.7 to 2.0 dl / g.
1.6 dl / g is preferred. Polyamides within the intrinsic viscosity range have good melt viscosity characteristics when fiberized and nonwoven, and furthermore, the resulting separator has excellent strength, electrolyte resistance, and heat resistance.

Further, in the above-mentioned polyamide, it is preferable that at least 10% of the terminal groups of the molecular chain are blocked with a terminal blocking agent, and at least 40% of the terminal groups, more preferably 70% of the terminal groups.
% Or more is preferably sealed. By sealing the terminal of the molecular chain, the obtained separator has excellent strength, electrolytic solution resistance, heat resistance and the like. The terminal capping agent is not particularly limited as long as it is a monofunctional compound having reactivity with an amino group or a carboxyl group at the polyamide terminus, but monocarboxylic acid is preferred from the viewpoints of reactivity and stability of the capping terminus. And monoamines are preferred. Monocarboxylic acids are preferred in terms of ease of handling, reactivity, stability of the sealed end, and price. As monocarboxylic acids, acetic acid,
Examples thereof include propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, and benzoic acid. In addition, the terminal capping rate can be determined by 1H-NMR from the integral value of the characteristic signal corresponding to each terminal group.

The method for producing the polyamide used in the present invention is not particularly limited, and any known method for producing a crystalline polyamide can be used. For example, it can be produced by a solution polymerization method or an interfacial polymerization method using an acid chloride and a diamine as raw materials, a melt polymerization method using a dicarboxylic acid or an alkyl ester of a dicarboxylic acid and a diamine as raw materials, a solid phase polymerization method, or the like.

For example, an end capping agent, a catalyst, a diamine component and a dicarboxylic acid component are reacted at once,
After the nylon salt is produced, the intrinsic viscosity is temporarily changed to a prepolymer having a limiting viscosity of 0.15 to 0.30 dl / g at a temperature of 280 ° C. or lower, and further subjected to solid phase polymerization or polymerization using a melt extruder. It can be easily manufactured. When the final stage of the polymerization is carried out by solid-phase polymerization, it is preferable to carry out the reaction under reduced pressure or under an inert gas flow. If the polymerization temperature is in the range of 200 to 250 ° C., the polymerization rate is high, the productivity is excellent, and the coloring is performed. It is preferable because gelation can be effectively suppressed. When the final stage of the polymerization is carried out by a melt extruder, it is preferable that the polymerization temperature is 370 ° C. or lower, since the polyamide is hardly decomposed and a polyamide with little deterioration is obtained.

Examples of the polymerization catalyst include phosphoric acid, phosphorous acid, hypophosphorous acid, ammonium salts thereof, metal salts thereof, and esters thereof. Of these, sodium hypophosphite is available. It is preferable in terms of ease and handling. Polycondensation of stabilizers such as copper compounds, coloring agents, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, flame retardants, plasticizers, lubricants, and crystallization retarders, if necessary It can be added during or after the reaction.
In particular, when organic stabilizers such as hindered phenol, copper halides such as copper iodide, and alkali metal halides such as potassium iodide are added as heat stabilizers, the melt retention stability during fiberization is improved. In addition, heat resistance when used as a separator is improved, which is preferable.

The production of the fiber (A) using the polyamide (a) of the present invention can use a known melt spinning apparatus. Fibers may be formed by any of single spinning and composite spinning. For example, in the case of composite spinning, polyamide (a) and another thermoplastic polymer are melt-kneaded in separate extruders, and then the same. May be discharged from the spinning nozzle. In this case, a mixture of the polyamide (a) and a plurality of polymers in advance may be used as one of the composite components.

As a method for obtaining an ultrafine polyamide fiber (A) having a single fiber fineness of 0.5 dtex or less, there are a direct spinning method, a sea-island method, and a splitting method. preferable. The splittable composite fiber may be composed of three or more components,
From the viewpoints of spinnability, splitting properties and the like, bicomponent fibers are preferred. When the polyamide (a) is used as one component, a fiber in which the polyamide (a) is divided into two or more, particularly 8 to 200 regions by another thermoplastic polymer in a fiber cross section is preferable. Further, a fiber in which the polyamide (a) is substantially continuous in the fiber length direction is preferable. More specifically, a multi-layer split type as shown in (1) to (6) of FIG.
Composite fibers such as a radial split type can be suitably used.

The fineness of the fiber (A) constituting the separator (or the fineness of the fiber after division if divided) is from 0.005 to 0.5 from the viewpoints of thinning, formation and separation.
It is preferably dtex. The fiber cross section is
It is preferable that the cross-sectional flatness represented by the ratio of the major axis to the minor axis (Dl / Ds) is 2.0 to 50.0. More preferably, it is 2.0 to 25.0, and still more preferably 2.2.
~ 15.0 are preferably used. Fineness is 0.00
If it is less than 5 dtex, it may be difficult to form a sheet, and the durability of the separator may be significantly reduced. Also,
If it exceeds 0.5 dtex, formation will be significantly deteriorated if the separator is made thinner. By making the fibers of the fabric have such a fineness and a flat cross section, 100 μm
Even in the case of the following sheets, the pore size is reduced, the separation properties can be further improved, and the formation can be made uniform. Further, the fiber length is not particularly limited, and can be appropriately set depending on a method for forming the separator.
In order to obtain a thin and uniform nonwoven fabric, it is preferable to form the nonwoven fabric by a wet papermaking method.
It is preferably 0 mm. Regarding the fiber cross-section, when the cross-sectional flatness expressed by the ratio of the major axis to the minor axis (Dl / Ds) is less than 2.0, the deterioration of the sheet formation due to the thinning of the separator increases, and the feature is exhibited. Hateful. When the cross-sectional flatness exceeds 50, it may be difficult to obtain a fiber having a stable cross-sectional shape. In the present invention, the major axis D1 and the minor axis Ds of the flat fiber cross section are determined as shown in FIG. 2 in the case of, for example, a multilayer splittable conjugate fiber as shown in FIG.

The other thermoplastic polymer is not particularly limited, but may be, for example, a polyester resin, an olefin resin, or a polyphenylene resin for splitting and dividing the splittable conjugate fiber by mechanical stress such as shearing force. Sulfide and the like can be suitably used. When these resins are used, a fiber having excellent splitting properties can be obtained due to poor compatibility with the polyamide (a). In this case, fibers which are substantially completely split by the pulverizing force of a pulper or a mixer during wet papermaking can be obtained. For this reason, it is not necessary to perform high-pressure water entanglement for division thinning, and pinholes due to water entanglement traces do not occur, and since it is possible to make a substantially completely split fiber, it is possible to form a paper after pressurizing etc. There is an advantage that a sheet having a uniform formation can be obtained as compared with a wet sheet in which fibers are divided and thinned by the treatment. In particular, by using a resin of polyethylene terephthalate, aromatic polyester, polymethylpentene, or polyphenylene sulfide, a separator having excellent electrolytic solution resistance and heat resistance can be obtained.

In the present invention, a separator may be obtained by blending other fibers in addition to the polyamide fiber (A). For example, polyesters such as polyethylene terephthalate, polybutylene terephthalate and wholly aromatic polyester, aliphatic polyamides such as polyphenylene sulfide, nylon 6, nylon 66;
Vinyl alcohol copolymer, polypropylene, polyethylene, polybutene, polymethylpentene, ethylene-
Polyolefin-based resin such as propylene copolymer, ethylene-butene copolymer, and the like, or fibers of composite form composed of two or more types; cellulose-based fiber obtained by mercerizing natural cellulose fiber; mercerized pulp; polyamide having different fineness And the like. In addition, it is possible to improve the morphological stability of the nonwoven fabric by using a known heat-fusible binder, particularly, a binder fiber, a sizing agent, or the like. The monofilament fineness of these fibers is preferably from 0.01 to 3 dtex from the viewpoints of thinning, formation, separation, strength, etc., and from the viewpoint of electrolytic solution resistance and heat resistance, polyester-based and polyolefin-based It is preferable to blend a single fiber of fiber, polyphenylene sulfide or polyamide (a). The fiber cross section is not particularly limited, such as a round shape, a cocoon shape, a hollow shape, and a T shape. Further, a binder, particularly a binder fiber, may be further blended in order to enhance the separator strength, form stability and the like. When a fibrous binder is blended, the above effects can be obtained without increasing the internal resistance more than necessary. It is preferable that the fineness of the binder fiber is about 0.5 to 6 dtex from the viewpoint of the separator strength, homogeneity, processability and the like. Note that the fibrous binder does not need to clearly maintain the fiber shape after being formed into a nonwoven fabric, and the above effects can be obtained by manufacturing the nonwoven fabric using the fibrous binder.

The binder fiber may be composed of a single component, but is preferably composed of two or more components, since it has an adhesive effect and can maintain a sufficient strength. Composite fibers such as a core-sheath type, a side-by-side type, a laminar split type, and a radial split type, and sea-island fibers can be suitably used. The cross section of the fiber is not particularly limited, such as a round type, a flat type, a cocoon type, a hollow type, and a T type.

The polyamide (a) thus obtained
Is converted into a fiber and used as a separator member, whereby remarkable effects can be obtained in terms of resistance to electrolytes and heat. In producing the capacitor separator, a sheet may be formed using such fibers, and a sheet such as a woven or knitted fabric, a dry nonwoven fabric, or a wet nonwoven fabric can be obtained. It is also possible to form a sheet immediately after fiberization by a melt blown method or a spun bond method. A nonwoven fabric is preferred from the viewpoints of separation properties, mechanical performance, and the like, and sheet formation by wet papermaking is particularly preferred from the viewpoint of obtaining a thin and uniform sheet. After forming the sheet, it is preferable to perform a heat calendering treatment for improving the surface smoothness, adjusting the thickness of the sheet, and developing the strength and density.

The separator of the present invention has a flat cross section.
Use of amide fiber (A) as a separator member
With low thickness, low internal resistance, uniform separator
It is also possible to obtain a lator. Specifically, a thickness of 1
It is possible to make it less than 00 μm. Poria of the present invention
To use a thin separator using mid fiber (A)
Thus, the internal resistance can be reduced. As non-woven fabric
Considering the mechanical strength, the thickness is preferably 50 μm or more.
Thinner to improve the energy density of the capacitor.
For this purpose, the thickness is preferably 100 μm or less. The grammage is 2
0-60g / m ^TwoDegree, density 0.1-0.6g / cm^ThreeAbout
It is preferably a degree.

The capacitor separator sheet can be used as it is or by processing it into a desired shape such as a bag-like body or a spiral body. Of course, a capacitor separator may be manufactured in combination with a material other than the sheet. For example, it can be laminated or spliced with another sheet (nonwoven fabric, film, etc.). However, from the viewpoint of efficiently obtaining the effects of the present invention, it is preferable to manufacture the capacitor separator substantially only from the above-described sheet, particularly from the nonwoven fabric. By incorporating the capacitor separator of the present invention, a capacitor excellent in various performances can be obtained.

Such a capacitor separator can be used not only for a capacitor separator but also for a battery separator, a filter, a wiper, a packaging material and the like.

[0026]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Each measurement value in the examples is a value measured by the following method. [Thickness (mm)] The thickness was measured in accordance with JIS P 8118 “Test method for thickness and density of paper and paperboard”. [Basic weight (g / m ² )] Measured according to JIS P 8124 “Measurement of metric basis weight of paper”. [Strength (kg / 15 mm)] Measured according to JIS P 8113 “Test method for tensile strength of paper and paperboard”. [Air permeability (cm ³ / cm ² / sec)] JIS L10
It was measured with a Frazier-type air permeability tester manufactured by Toyo Seiki Seisaku-Sho, Ltd. in accordance with the air permeability measurement method of "General Textile Test Method" (1996-1996). [Electrolyte resistance (%)] According to JIS P 8113,
The strength (N / 15 mm) of the test piece before and after the electrolytic solution resistance treatment was measured, and expressed by the strength retention. In the treatment, the nonwoven fabric test piece was immersed in polycarbonate (manufactured by Wako Pure Chemical Industries, Ltd.) at 50 ° C. for 1 hour in a nitrogen atmosphere. [Heat resistance (%)] 150 ° C and 200 ° C in a nitrogen stream
The weight loss rate (%) of the separator held for 1 hour is checked with a thermogravimeter (Rigaku: TAS-200).
Visual observation of morphological changes.

[Reference Example 1] [Production of polyamide (a) using 1,9-nonanediamine and 2-methyl-1,8-octanediamine as a diamine component and terephthalic acid as a dicarboxylic acid component] 19.5 terephthalic acid Mol, 10.0 mol of 1,9-nonanediamine, 10.0 mol of 2-methyl-1,8-octanediamine, 1.0 mol of benzoic acid, 0.06 mol of sodium hypophosphite-hydrate and distilled water 2.2 liters were added to an autoclave having an internal volume of 20 liters, followed by purging with nitrogen. Then, the mixture was stirred at 100 ° C for 30 minutes, and the internal temperature was raised to 210 ° C over 2 hours. At this time, the pressure in the autoclave was increased to 2.2 MPa. After continuing the reaction for 1 hour, the temperature was raised to 230 ° C., and then kept at 230 ° C. for 2 hours. The reaction was continued while gradually removing water vapor and maintaining the pressure at 2.2 MPa. Next, the pressure was increased to 1.0 over 30 minutes.
The reaction was continued for 1 hour to obtain a prepolymer. The prepolymer was heated at 100 ° C. under reduced pressure for 12 hours.
Dry for hours and pulverize to a size of 2 mm or less. This pulverized product was subjected to solid-phase polymerization at 230 ° C. under 10 Pa for 10 hours to obtain a polymer. The intrinsic viscosity of the obtained polymer was 0.9 dl / g.

Example 1 The polyamide (a) produced in Reference Example 1 was melt-extruded using an extruder and had a hole diameter of 0.15.
mm and discharged at a winding speed of 1,000 m / min to obtain an undrawn yarn. Then, the undrawn yarn was drawn using a water bath at a water bath temperature of 90 ° C. to obtain a tow having a fineness of 1.5 dtex. The obtained tow is cut into a cut length of 5 mm,
This was a shortcut of the polyamide (a) single fiber. Handmade paper machine (square 25cm x 25)
cm) to make a wet nonwoven fabric having a basis weight of about 40 g / m ² , and then hot-pressed with an emboss calender (emboss roll temperature 240 ° C., linear pressure 40 kg / cm) to obtain a capacitor separator. The obtained separator was uniform and high in electrolyte resistance, heat resistance, and mechanical properties, and had excellent performance as a capacitor separator. The performance is shown in Table 1.

Example 2 67% by mass (X layer) of the polyamide (a) obtained in Reference Example 1 and an intrinsic viscosity of 0.68
Polyethylene terephthalate (measured at 30 ° C. with a phenol / tetrachloroethane equal mass mixed solvent)
The compound was compounded at a compounding ratio of mass%, and was melt-extruded with an extruder.
An elliptical multilayer splittable conjugate fiber composed of alternately laminated X and Y layers as shown in (1) of FIG. 1 was produced by discharging from a 25 mmφ round hole nozzle. The number of layers of the splittable conjugate fiber is 6 in the X layer and 5 in the Y layer, for a total of 11 layers.
Subsequently, the film was stretched using a water bath at a water bath temperature of 90 ° C. to obtain a tow having a fineness of 3.0 dtex. The obtained tow was cut into a cut length of 5 mm to provide a short cut of a splittable conjugate fiber composed of polyamide (a) and polyester. The cross-sectional flatness (Dl / Ds) of the splittable conjugate fiber after splitting is 2.4.
７7.5. In addition, polyethylene terephthalate having an intrinsic viscosity of 0.55 was fiberized in the same manner as in Example 1 to obtain an undrawn yarn, which was cut into 5 mm cuts. Short cut 70% by mass of the splittable conjugate fiber composed of the polyamide (a) and polyester and short cut 30% by mass of an undrawn polyester yarn are made into a papermaking machine (square 25 cm × 25 cm) and weighed. About 40g /
A wet nonwoven fabric of m ² was prepared and then hot-pressed with a calender (roll temperature: 230 ° C., linear pressure: 40 kg / cm) to obtain a capacitor separator. The obtained separator was uniform and high in electrolyte resistance, heat resistance, and mechanical properties, and had excellent performance as a capacitor separator. The performance is shown in Table 1.

Example 3 A shortcut for a splittable conjugate fiber was obtained in the same manner as in Example 2, except that polymethylpentene (Mitsui Chemicals, DX820) was used instead of polyethylene terephthalate having an intrinsic viscosity of 0.68. . A shortcut for undrawn yarn of polyamide (a) was obtained in the same manner as in Example 2, except that polyamide (a) having an intrinsic viscosity of 0.65 was used instead of polyethylene terephthalate having an intrinsic viscosity of 0.55. These were paper-made and calendered in the same manner as in Example 2 to obtain a separator. The obtained separator was uniform and high in electrolyte resistance, heat resistance, and mechanical properties, and had excellent performance as a capacitor separator. The performance is shown in Table 1.

Example 4 A separator was obtained in the same manner as in Example 3 except that polyphenylene sulfide (Toray Co., Ltd .: Fortron E2481) was used instead of polymethylpentene. The obtained separator is uniform and has high electrolyte resistance, heat resistance, and high mechanical properties,
It had excellent performance as a capacitor separator. The performance is shown in Table 1.

Example 5 A short cut of a splittable conjugate fiber was obtained in the same manner as in Example 3 except that polypropylene (Nippon Polychem, SD2) was used instead of polymethylpentene. The short cut 80% by mass of the splittable conjugate fiber and the short cut 20% by mass of the drawn polyamide (a) yarn of Example 1 were made in the same manner as in Example 3,
It was calendered at 170 ° C. to obtain a separator. The resulting separator has a uniform and electrolyte-resistant, heat-resistant (but the polypropylene melts at 200 ° C., the morphology has changed greatly), and mechanical properties, the polypropylene component of the splittable conjugate fiber serves as a binder. It was high and had excellent performance as a capacitor separator. The performance is shown in Table 1.

Comparative Example 1 In Example 1, instead of polyamide (a), polyethylene (Nippon Polychem, HE
Except that 483) was used, fiberization, papermaking and embossing were performed at 100 ° C. in the same manner as in Example 1 to obtain a polyethylene separator. The obtained separator was uniform and excellent in electrolyte resistance, but had low heat resistance (polyethylene melted at 150 ° C., and the morphology changed greatly) and low mechanical properties. The performance is shown in Table 1.

[0034]

[Table 1]

[0035]

According to the present invention, it is possible to provide a capacitor separator which is excellent in electrolyte resistance and heat resistance and has a uniform formation.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of an example of a splittable conjugate fiber applicable to the present invention.

FIG. 2 is a diagram for explaining a major axis and a minor axis of a polyamide fiber (A).

[Explanation of symbols]

 X: polyamide (a) Y: other thermoplastic polymer Dl: major axis Ds: minor axis

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01G 9/24 Z F-term (Reference) 4L041 AA07 BA04 BA05 BA09 BA11 BA26 BA27 BA32 BA34 BA42 BD11 CA06 CA30 CA39 CA55 DD01 DD06 EE07 4L055 AF15 AF33 AF35 EA15 EA16 FA19 GA01

Claims (5)

[Claims] 1. A fiber comprising a polyamide (a) synthesized from a dicarboxylic acid component containing at least 60 mol% of an aromatic dicarboxylic acid and a diamine component containing at least 60 mol% of an aliphatic alkylenediamine having 6 to 12 carbon atoms. A capacitor separator comprising (A). 2. The fiber (A) has a single fiber fineness of 0.005 to 0.005.
2. The capacitor separator according to claim 1, wherein the separator has a cross section flatness of 0.5 to 50.0 dtex. 3. A polyamide (a) synthesized from a dicarboxylic acid component containing at least 60 mol% of an aromatic dicarboxylic acid and a diamine component containing at least 60 mol% of an aliphatic alkylenediamine having 6 to 12 carbon atoms; 2. The method for producing a separator for a capacitor according to claim 1, wherein a paper stock containing 20 to 80% of the splittable conjugate fiber made of the thermoplastic resin is produced. 4. The thermoplastic resin is a polyester resin,
4. The method for producing a capacitor separator according to claim 3, wherein the method is a polyolefin-based resin or polyphenyl sulfide. 5. A capacitor incorporating the separator according to claim 1 or 2.