JPH0458509A - Electrolytic capacitor - Google Patents

Abstract

PURPOSE:To lengthen life by using, as a separator, the unwoven fabric of aromatic polymer fibers, which contain heterocycles being stable to the ingredients of electrolyte and expressed by a specified general formula. CONSTITUTION:The unwoven fabric of aromatic polymer fibers 1 which have heterocycles being expressed by a specified general formula, is used as a separator for electrolytic capacitor. And the density of the unwoven fabric is made 5-50g/cm<3> and the thickness 10-200mum. Hereby, the progress of chemical reaction in use can be avoided, and the life lengthened, and the resistance to chemicals improved.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an electrolytic capacitor using a separator with a unique configuration. By using it, the life of the capacitor can be extended, and
This article relates to electrolytic capacitors that have excellent chemical resistance.

[Prior Art] Electrolytic capacitors are small, large in capacity, inexpensive, and exhibit excellent characteristics such as smoothing of rectified output, and are one of the important components of various electrical and electronic devices.

In general, electrolytic solution-type aluminum electrolytic capacitors use an anode foil with a surface oxide film formed by electrolytic oxidation, this oxide film is used as a dielectric, and a predetermined electrolyte is interposed between the current collector cathode foil and the electrolytic capacitor. or manufactured.

At this time, a porous separator is often sandwiched between the anode foil and the current collecting cathode foil to ensure that the electrolyte is supported and to ensure that the anode foil and cathode foil are separated in the product. used.

In general, the product characteristics of electrolytic capacitors are mainly determined by the properties of the electrolytic solution interposed between the anode and the cathode in the case of electrolytic capacitors. Unlike the anode, cathode, dielectric oxide film, electrolyte, etc., the separator is not a basic component of an electrolytic capacitor, but if it is used to improve product stability and life characteristics, As a result, the basic performance of the capacitor is affected by the properties of the separator used.

When evaluating the product characteristics of an electrolytic capacitor, the capacitance (Cap) and dielectric loss tangent (tanδ) of the electrolytic capacitor are
), impedance (Imp), and other indicators are used.

These indicators are primarily based on the basic characteristics of electrolytic capacitors.
Although it represents the performance, if the basic components of the electrolytic capacitor such as the anode, cathode, dielectric oxide film, electrolyte, etc. are the same, it will vary to reflect the properties of the separator.

Therefore, in such cases, indicators such as electrostatic capacitance (Cap), dielectric loss tangent (tanδ), and impedance (Imp) can be considered to represent the overall performance of the electrolytic capacitor, including the properties of the separator. can.

Cellulose fibers such as manila paper and kraft paper are widely used as separators for electrolytic capacitors.
Conventionally, when a capacitor is used for a long period of time, chemical reactions occur between the electrolyte and the separator, making it difficult to maintain sufficiently stable characteristics.

Considering the chemical properties of commonly used electrolytic solution components and conventional separator materials, chemical reactions that may occur between the electrolytic solution and the separator include, for example, the hydroxyl groups of cellulose fibers and the carboxylic acid that is a component of the electrolytic solution. Examples include an esterification reaction with. Since this type of esterification reaction consumes ions in the electrolyte, it is thought that this reaction was one of the major causes of deterioration of the characteristics of the electrolytic capacitor.

[Problems to be Solved by the Invention] The present invention is an electrolytic capacitor using a separator with a unique configuration, and by using a chemically stable material with excellent heat resistance as the separator for an electrolytic capacitor, The purpose is to provide an electrolytic capacitor that has a long service life and has excellent chemical resistance.

[Means for Solving the Problems] According to the present invention, as a separator for an electrolytic capacitor,
The following general formula: (wherein X is -8-1-〇- or -NH, and Ar
There is provided an electrolytic capacitor characterized in that it uses a nonwoven fabric of a heterocycle-containing aromatic polymer fiber represented by:

A nonwoven fabric of aromatic polymer fibers containing heterocycles has a density of 0,
05 to 50 g/cm3 and a thickness of 10 to 200 μm are suitable.

[Function] As mentioned above, cellulose fibers have been widely used as separators for electrolytic capacitors, but in this type of separator, esters of hydroxyl groups of cellulose fibers and carbonic acid, which is a component of the electrolytic solution, are used. Due to the progress of chemical reactions such as oxidation reactions, ions in the electrolytic solution are consumed and, for example, when used at high temperatures for a long period of time, the characteristics of electrolytic capacitors deteriorate.

The present invention provides an electrolytic capacitor with stable characteristics by using a separator made of a material that is chemically stable with respect to the components of the electrolytic solution, thereby avoiding the progression of chemical reactions during use of the electrolytic capacitor. It is intended.

Such an effect is more pronounced when a nonwoven fabric of a heterocycle-containing aromatic polymer fiber having a specific density and thickness is used8. In other words, the heterocycle-containing aromatic polymer used in the present invention is heat-resistant It has excellent durability and chemical resistance, and by applying this to separators, it is possible to extend the life of electrolytic capacitors. Further, since the heterocycle-containing aromatic polymer compound having the above-described structure has high fiber tensile strength, it is possible to reduce the density of the separator.

[Effects of the Invention] The present invention provides an electrolytic capacitor using a separator with a unique structure, and uses a nonwoven fabric of aromatic polymer fiber containing a hetero-O ring as a chemically stable material with excellent heat resistance for the electrolytic capacitor. By using it as a separator, it is possible to provide an electrolytic capacitor that can extend the life of the capacitor and has excellent chemical resistance.

[Examples] The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited only to the following Examples.

Manufacture of electrolytic capacitors Using the electrolytic solution and separator shown below, combine them as shown in Table 1, set the density and thickness of the separator as shown in Table 1, and adjust the rated voltage to 10
An aluminum electrolytic capacitor with a rated capacitance of 1000 μF was manufactured.

Electrolyte A: γ-butyrolactone/tetraethylammonium maleate electrolyte B: γ-butyrolactone/tetramethylammonium phthalate electrolyte C: ethylene glycol/ammonium adipate electrolyte Separator HER: Manila/Esparto ( Weight ratio 60:40) mixed paper PBT: polybenzothiazole (in the above general formula,
X=-S-, PBI: polybenzimitazole (in the general formula described above, X=-NH-, PBO: polybenzoxazole (in the general formula described above,
X=-O-, Table 1 1 Presentation ■ Butt Top Example 1-I A PBT O, 4758 Example 1-2 A PBT 0.43 44 Comparative Example I A HERO, 4540 Example 2-
I B PBOO, 4860 Example 2-2
B PBO0,4545 Comparative Example 2 B
HERO, 4540 Example 3-1 CPBI
0.46 55 Example 3-2. CPBI O,
4342 Comparative Example 3 CHERO, 4540 In Table 1, the unit of density is g/cn', and the unit of thickness is μm.
It is.

Test results Regarding the manufactured electrolytic capacitor, capacitance (μF) (Cap) at 120 Hz, capacitance change rate (%)
Performance tests were performed by measuring the tangent of the loss angle (tanδ) at 120 Hz, and the impedance (Ω) (IMP, ) at 100 Hz.

These values determine the initial properties and 5000 at 105°C.
Test results are shown in Table 2 as characteristics after time use.

Cap, tan δ Inp, ΔCap ta
n δ l+np.

iltMil 9780.0730.079-7.1
1 0.221 0.302! Ill! ! +-2105
40,0550,050-6,540,1700,20
9 comparison old 11300.0680.049 -13
0.5440.392&1H2-19670,094
0,109-4,40,1150,146g11 example 2-
2 10270.071 0.072 -4.460.
081 0.090 ratio 1ft2 1136 0.0
70 0.062 -4 0.081 0.07
4 implementation 1113-1 980 0.152 0.18
6 -8.16 0.226 0.313g1kli!
3-2 1065 0.118 0.127-7.83
0.1690°209 ratio It! 13 1125 0
．． 138 0.132 -10 0.248 0.
229 From the results in Table 2, the electrolytic capacitor according to the present invention has stable characteristics by using nonwoven fabric of aromatic polymer fiber containing heterocycles as a separator for electrolytic capacitors, which is a chemically stable material with excellent heat resistance. It can be seen that the capacitor has a long life span and can realize a long life span.

\, -, /

Claims (2)

[Claims] (1) As a separator for electrolytic capacitors, the following general formula: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, X is -S-, -O- or -NH-,
An electrolytic capacitor characterized by using a non-woven fabric of aromatic polymer fibers containing a heterocycle, where the r group is represented by ▲a mathematical formula, a chemical formula, a table, etc.). (2) The nonwoven fabric of aromatic polymer fiber containing heterocycle has a density of 0.05 to 50 g/cm^3 and a thickness of 10 to 200 μm.
The electrolytic capacitor according to claim 1, characterized in that: