JP2001006980A - Acoustic electrolytic capacitor and separator therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acoustic electrolytic capacitor which can produce high- quality reproduced sounds the tone qualities of which do not change much even when the pressures of the sounds change or the sounds vibrate and a separator used for the capacitor. SOLUTION: A separator contains fluoro-mica particles having particle diameters between 1 nm and 1 μm at a rate of 0.05-50 wt.%. An acoustic electrolytic capacitor is obtained by housing a capacitor element formed by winding anode foil and cathode foil, with the separator being sandwiched between the two foil, and dipping the wound body in an electrolyte and sealing the case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a separator for an acoustic electrolytic capacitor and an acoustic electrolytic capacitor.

[0002]

2. Description of the Related Art An electrolytic capacitor is obtained by impregnating a capacitor element, which is formed by winding an anode foil and a cathode foil with a separator interposed therebetween, with an electrolytic solution, and then housing the capacitor element in a bottomed metal case. Is sealed with a sealing body made of rubber or the like, and lead wires connected to the anode foil and the cathode foil, respectively, are drawn out to the outside through through holes of the sealing body. As the separator, usually, a separator made from fibers such as kraft pulp fiber and Manila hemp fiber is used.

[0003]

However, when an electrolytic capacitor having such a structure is used as a power supply smoothing capacitor or a coupling capacitor for audio equipment, a change in sound pressure or the present electrolytic capacitor is mounted. Vibration transmitted from the printed circuit board changes the fastening force of the capacitor element foil to the separator. In particular, since the separator impregnated with the electrolyte is in a swelling state in which the mechanical bond between the fibers is weak, the separator is easily affected by the thickness and the bending state of the anode foil and the cathode foil.

As a result, in the electrical equivalent circuit of the electrolytic capacitor shown in FIG. 1, the resistance Re of the separator, which is the resistance of the separator itself and the resistance of the electrolyte impregnated in the separator, fluctuates, and the electrical constant of the electrolytic capacitor changes. Will fluctuate. In this circuit, Rf is a film resistance,
L is the inductance of the winding structure of the capacitor or the lead, D is the polarity of the film, C + is the capacitance of the anodic oxide film, and C− is the capacitance of the natural air oxide film of the cathode.

Therefore, when an electrolytic capacitor having such a separator is used as a sound electrolytic capacitor for a power supply smoothing capacitor or a coupling capacitor of audio equipment, a change in sound pressure, internal vibration, external vibration, etc. Deterioration of audio signals and distortion of sound quality were likely to occur.

In order to reduce the change in sound quality due to the change in sound pressure and vibration in an acoustic electrolytic capacitor, a ceramic powder is contained in the separator (Japanese Patent Laid-Open No. 59-1984).
Japanese Patent Application Laid-Open No. 149017/1989), and a method of mixing and reinforcing ceramic fibers (Japanese Patent Publication No. 6-30326) has been proposed.

Another object of the present invention is to provide an acoustic electrolytic capacitor having a high quality reproduced sound with little change in sound quality due to a change in sound pressure or vibration and a separator used for the same. The reinforcement is intended to minimize the change in the resistance of the separator.

[0008]

The separator for an acoustic electrolytic capacitor according to the present invention is characterized by containing fluorine mica particles.

Further, the acoustic electrolytic capacitor of the present invention comprises a capacitor element formed by impregnating an electrolytic solution by winding a fiber-made separator between an anode foil and a cathode foil to impregnate it with a metal. It is housed and sealed in a case, and the separator contains fluorine mica particles.

As the anode foil, a foil formed by etching an aluminum foil can be used, and as the cathode foil, a foil obtained by etching an aluminum foil can be used.

In the electrolytic solution, for example, an inorganic acid,
Organic acids such as aromatic carboxylic acids and aliphatic carboxylic acids can be used, and the solvent can be an aprotic solvent such as γ-butyrolactone or a protic solvent such as ethylene glycol, but is not limited thereto.

The electrolyte has an initial loss tangent (tan).
Other additives may be added, such as adding a ketone to improve δ) or adding a pH adjuster to adjust the pH.

[0013] The separator is made of paper made of paper, such as paper. As the fiber, plant fiber such as kraft pulp fiber or manila hemp fiber, or synthetic fiber such as polypropylene, vinylon, rayon, polyethylene or polyester is used alone. Or a mixture of these, or a mixture of these with glass fibers.

The fluoromica particles may be swellable or non-swellable. The fluoromica particles may be natural or synthetic, but are preferably synthesized from the viewpoint of a small amount of impurities, and examples of the synthetic fluoromica particles include fluorine moth and fluorine moth. The particle diameter of the fluoromica particles is preferably in the range of 1 nm to 10 μm. Particle size is 1
If it is less than 10 nm, there is no reinforcing effect, and if it exceeds 10 μm, the impregnation of the electrolytic solution is affected and the capacitor characteristics deteriorate.

For example, the fluoromica particles are sprayed on the formed separator in a state of being dispersed in water, or applied to the formed separator in a state of being dispersed in water,
Alternatively, fluorine mica particles may be added to the fiber liquid before papermaking, for example. By the above-described method, the fluoromica particles are held in a state of having entered between the fibers of the separator.

The amount of fluorine mica particles used is preferably 0.05 to 50% by weight relative to the separator, and is preferably 0.05% to 50%.
If it is less than 50%, there is no reinforcing effect, and if it exceeds 50%, the impregnation of the electrolytic solution is affected and the capacitor characteristics are deteriorated.

The separator thus formed may be composed of a plurality of layers. In this case, some or all of the plurality of layers contain fluorine mica particles.

The type of acoustic electrolytic capacitor is JIS
The shape is not limited to the 04 shape, and may be another shape.

[0019]

Example: Aluminum foil of 80 μm thickness (purity 4N)
Etching and forming the anode foil, 40μ thick
m of aluminum foil (purity: 2N) was used as a cathode foil, and the specifications of a separator (thickness: 50 μm, consisting of one layer) were changed between them as shown in Table 1. made. After impregnating this with an ethylene glycol-based electrolytic solution, put it in a bottomed aluminum case, and pull out the lead-out to the outside through the through hole of the rubber sealing body, and seal the opening with the sealing body, Diameter 8mm, height 20mm, rating 50V
100 μF acoustic electrolytic capacitors (Examples 1 to 8 and Comparative Examples 1 to 14) were prepared.

Kraft pulp fiber or Manila hemp fiber was used as the material of the separator. As fluorine mica particles, synthetic fluorine mica particles (“Somasif” manufactured by Corp Chemical Co., Ltd., particle size: 1 nm to 10 μm) were dispersed in water and applied to a separator. The content of fluoromica is a weight ratio to the separator.

[0021]

[Table 1]

Using the aluminum electrolytic capacitors of Examples 1 to 8 and Comparative Examples 1 to 14 as capacitors for smoothing the power supply of audio equipment, music playback sounds were listened to by six people, and the sound quality was evaluated in terms of band and texture. , Resolution, sound image and sound field. Table 2 shows the results.
In addition, in the aluminum electrolytic capacitors of Comparative Examples 9 to 14, the retention rate of the electrolytic solution was poor, and the capacitor characteristics were too poor to be commercialized.

Note that the band is a frequency characteristic, and the higher the score, the wider the frequency band of the sound that can be reproduced. The texture is the S / N ratio of the sound and means the reproducibility of the sound elongation. Further, the resolution is the resolution of the sound, and means, for example, the degree to which the overlapping melody can be grasped. The sound image is the beauty of the sound, meaning the sense of transparency and contour of the sound, and the sound field means the thickness of the sound, that is, the sense of convergence of the sound.

[0024]

[Table 2]

From the results shown in Table 2, it can be seen that the acoustic electrolytic capacitors of the present invention (Examples 1 to 8) have much better sound quality than the acoustic electrolytic capacitors of Comparative Examples 1 to 8.

[0026]

By using the separator containing the fluoromica particles of the present invention, there is obtained an electrolytic capacitor capable of reproducing high quality sound with little change in resistance of the separator against change in sound pressure or vibration. Can be

[Brief description of the drawings]

FIG. 1 is an equivalent circuit of an electrolytic capacitor.

[Explanation of symbols]

 Re Resistance of separator Rf Film resistance D Polarity of film L Inductance C + Capacitance of anodic oxide film C− Capacitance of natural oxide film of cathode

Claims (6)

[Claims] 1. A separator for an acoustic electrolytic capacitor, characterized by containing fluorine mica particles. 2. The particle size of fluorine mica particles is 1 nm to 10 μm.
The separator for an acoustic electrolytic capacitor according to claim 1, wherein m is m. 3. The separator for an acoustic electrolytic capacitor according to claim 1, wherein the content of fluorine mica particles is 0.05 to 50% by weight relative to the separator. 4. A capacitor element obtained by impregnating an electrolyte by winding a separator made of fibers between an anode foil and a cathode foil and sealing the capacitor element in a metal case. An acoustic electrolytic capacitor comprising: a separator containing fluorine mica particles; 5. The fluoromica particles having a particle diameter of 1 nm to 10 μm.
The acoustic electrolytic capacitor according to claim 4, wherein m is m. 6. The acoustic electrolytic capacitor according to claim 4, wherein the content of the fluorine mica particles is 0.05 to 50% by weight relative to the separator.