JPH0368529B2 - - Google Patents

Abstract

PURPOSE:To make it possible to manufacture an electrolytic capacitor characterized by a low equivalent series resistance value and excellent sound quality, by including floss silk in at least a part. CONSTITUTION:The raw material of floss silk is cocoons. The thickness of the fiber is as thin as 1/5-1/100 that of Manila hemp. The bends of the fiber is complex. The thickness are not uniform. Only the floss silk can hold sufficient amount of electrolyte by cutting, beating, paper manufacturing and so forth. Since the quality is close, an electric resistance can be made small when the electrolyte is impregnated. When the floss silk is mixed with vegetable fiber such as Manila hemp and craft in order to increase mechanical strength and to make mixed paper, the floss silk fiber is finely entangled in the gaps between the thick fibers of the Manila hemp and the craft. Thus the very thin gaps are formed. The withstand voltage of a separator, which is electrolytic paper, is improved. When the separator including the floss silk fiber is used, repelling force is less since the separator is soft against minute bending force caused by vibration. Therefore, deterioration in audio signals and distortion in sound quality can be prevented.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a separator in an electrolytic capacitor in which an anode foil and a cathode foil made of aluminum foil or the like are laminated or wound with a separator in between. [Prior Art] Generally, an aluminum electrolytic capacitor is manufactured by laminating an anode foil and a cathode foil made of aluminum foil with a separator in between, or by impregnating a wound capacitor element with an electrolytic solution and assembling it together with a sealing body in an exterior case. It has an intricate structure. In such laminated or wound type electrolytic capacitors, a separator is used to retain a sufficient amount of electrolyte and to prevent short circuits between the electrodes. The material for manufacturing the separator is vegetable fiber or synthetic resin fiber. Most separators made of vegetable fibers are kraft paper or Manila hemp paper. In addition, small amounts of items made from Indian solar hemp and cotton are also used. Although kraft paper is cheap and strong, it has the disadvantage that the fibers are flat, so the current path after being impregnated with electrolyte becomes long and the electrical resistance increases. Manila hemp paper has a slightly more circular shape than kraft paper in the form of fibers, so the current path is shorter, so it has the advantage of reducing resistance, but it is expensive. Papers made from a mixture of kraft and manila hemp are also used. Materials for separators made of synthetic fibers include polypropylene, vinylon, rayon, polyethylene, and polyester. Such synthetic fibers can be obtained in a shape close to a perfect circle, so they can have a low resistance value after being impregnated with an electrolyte, but they have the disadvantage that it is difficult to obtain a material with good properties as paper. It is often used as a mixed paper with kraft or manila hemp. [Problems to be solved by the invention] Electrolytic capacitors using separators as described above still have a high resistance value and a small amount of electrolyte retention, and when viewed as electrolytic capacitors, electrical performance at room temperature and low temperature is low. Due to its high resistance value, it has caused problems when used in switching power supplies, etc. In addition, when electrolytic capacitors are used as power supply smoothing capacitors or coupling capacitors for audio equipment, their resistance against frequency is high and they cannot absorb internal or external vibrations, preventing deterioration of audio signals and distortion of sound quality. It was becoming difficult to do so. [Means for Solving the Problems] However, in order to solve the above-mentioned problems, the present invention provides a separator containing cotton cotton. The raw material for cotton cotton is cocoon, and the thickness of each fiber is 1/5 to 1/100 that of Manila hemp, and the fibers have complicated bends and are uneven in thickness, making it difficult to cut, beat, and make paper. As a result, the retention of the electrolyte is improved even in the case of cotton alone, and since it is dense, the electrical resistance value when soaked with the electrolyte can be reduced. In addition, when making mixed paper by incorporating vegetable fibers such as manila hemp and kraft in order to strengthen the mechanical strength, the cotton fibers are tightly entangled in the gaps between the thick fibers of manila hemp and kraft, and the very thin gaps are , the withstand voltage of the separator, which is electrolytic paper, is improved. It was also found that the electrical resistance value when impregnated with electrolyte was significantly smaller than that of Manila hemp or kraft alone. Furthermore, according to separators containing cotton fibers, the separators are soft and have little repulsive force against minute bending forces caused by vibrations, thus preventing deterioration of audio signals and distortion of sound quality. It is something. The separator according to the present invention is made of cotton fiber alone, or mixed with other vegetable fibers, synthetic resin fibers, glass fibers, or mixed fibers thereof. [Examples] Example 1 A single fiber separator made of cotton cotton with an average fiber diameter of 1 μm and having a thickness of 60 μm and a density of 0.6 g/cm ³ was prepared. The tensile strength is 2.1Kg/15mm width,
The equivalent series resistance (ESR) when this separator is impregnated with γ-butyrolactone electrolyte is
It was 0.10Ω. Note that this equivalent series resistance value is 20
℃ and 120Hz. Example 2 70% cotton fiber with an average fiber diameter of 1 μm and an average fiber diameter
A separator made of 30% Manila hemp with a thickness of 60 μm and a density of 0.6 g/cm ³ was prepared. The tensile strength is 2.7Kg/15mm width at 20℃ when impregnated with γ-butyrolactone electrolyte.
The ESR at 120Hz was 1.20Ω. Reference Example A separator made of Manila hemp alone with an average fiber diameter of 10 μm and a thickness of 60 μm and a density of 0.6 g/cm ³ was prepared. When impregnated with a γ-butyrolactone electrolyte, the ESR at 20°C and 120Hz was 1.80Ω. Next, use the separator described above to create an aluminum electrolytic capacitor with a rating of 50V and a capacitance of
A 100μF one was made and the frequency characteristics of the equivalent series resistance (ESR) at 20°C were measured. The results are shown in Table 1.

[Table] When we investigated the 3rd harmonic distortion rate when a 10kHz signal was input when 1kHz vibration was applied to these electrolytic capacitors, the one in Example 2 was 4 to 5 dB lower than the one in the reference example. It was found that the amount decreased. In addition, when these electrolytic capacitors were replaced in the coupling circuit of a CD player and listened to, it was found that the distortion in high-frequency sound quality was significantly reduced in the case of Example 2 compared to that of the reference example, and the sound quality was The amount of information has increased significantly, resulting in a well-balanced, high-quality sound. [Effects] As described above, according to the separator of the present invention containing cotton at least in part, it is possible to provide an electrolytic capacitor with a low equivalent series resistance value and an electrolytic capacitor with good sound quality. In addition to aluminum electrolytic capacitors, the separator according to the present invention can also be used for energy storage devices such as electric double layer capacitors, solid electrolytic capacitors, other special capacitors, primary batteries, secondary batteries, and other special batteries. Can be applied as a separator.

Claims (1)

[Claims] 1. A separator for electrolytic capacitors containing at least a portion of cotton.