JP2001023585A - Alkaline dry battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an external part from short-circuited caused by damage on an external material by covering a battery case for storing power generating elements and a part of a full-web-section metal bottom arranged in the opening part of the battery case and also served as a negative electrode terminal with insulating thermal contraction resin, its tube, or its film. SOLUTION: A metal sealing plate 8 also served as a negative electrode terminal is covered with a thermal contraction insulating tube 9 except for the upper face functioned as the terminal. The opening edge of a metal can 1 also served as a positive electrode terminal is bent inward so that the metal can 1 inside is sealed by an insulating gasket 6 and the metal sealing plate 8. Only if being thermal contraction materials, there is no special restriction for the materials for the insulating thermal contraction resin, however, polymer materials mainly composed of polyvinylchloride, polyethylene terephthalate, polyethylene, and polypropylene are general. The battery case for storing power generating elements is covered with an insulating thermal contraction resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alkaline battery having an outermost battery case with improved safety.

[0002]

2. Description of the Related Art In an alkaline dry battery in which a power generating element is housed in a metal battery can, the outer periphery of the battery is externally covered with a metal outer can. In many cases, the cell is covered and insulated with a heat-shrinkable exterior material such as a shrink label or a shrink tube, and the exterior structure is simpler than using a metal exterior can.

[0003]

However, the heat-shrinkable outer material as described above has a lower strength than a metal outer can, and depending on the shape of a battery housing case and terminals of a device using a battery, an excessive force may be applied. As a result, a heat-shrinkable exterior material such as a shrink label or a shrink tube may be damaged, and an external short circuit may occur in the battery. As an insulating coating material for preventing such an external short circuit, there is an example in which an ultraviolet curable resin is formed on the end face of the opening of the metal battery can and on the peripheral edge thereof (see Japanese Patent Publication No. 5-63901). Since it is harmful to the human body, it is not preferable to use this as a manufacturing environment, and generally, the ultraviolet irradiation device is large-scale and is not preferable in terms of cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and provides an alkaline dry battery which is highly safe by preventing an external short circuit due to damage to the external material in an alkaline dry battery packaged with a heat-shrinkable package. With the goal.

[0005]

In order to achieve the above object, the present invention relates to an alkaline dry battery packaged with a heat-shrinkable package material, comprising a battery case accommodating a power generating element and an opening in the battery case. A part of the hat-shaped metal bottom, which also serves as a negative electrode terminal, is covered with one of an insulating thermal resin, an insulating shrinkable tube, and a film.

According to the present invention, since an insulating resin is provided on the side of the conventional hat-shaped negative electrode terminal, even if the heat-shrinkable exterior material is damaged, an external short circuit can be prevented.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an alkaline dry battery (JIS standard LR6 type (AA size)) according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a main portion of an alkaline dry battery of FIG. .

In FIG. 1, reference numeral 1 denotes a bottomed cylindrical metal can also serving as a positive electrode terminal. The metal can 1 is filled with a positive electrode mixture 2 formed into a cylindrical pressure. The positive electrode mixture 2 is obtained by mixing a manganese dioxide powder, a graphite powder, and a potassium hydroxide electrolyte, storing the mixture in a metal can 1, and press-molding the mixture into a hollow cylinder at a predetermined pressure. The hollow portion of the positive electrode mixture 2 is filled with a gelled negative electrode 4 via a bottomed cylindrical separator 3 made of a nonwoven fabric of acetalized polyvinyl alcohol fiber. A negative electrode current collector rod 5 made of brass is inserted into the gelled negative electrode 4 so that the upper end thereof protrudes from the gelled negative electrode 4. A double annular insulating gasket 6 made of a polyamide resin is provided on the projecting outer peripheral surface of the negative electrode current collector rod 5 and the upper inner peripheral surface of the metal can 1. A ring-shaped metal plate 7 is disposed between the double annular portions of the gasket 6, and a metal sealing plate 8 of a hat-shaped metal bottom serving also as a negative electrode terminal is provided above the metal plate 7 with a head of the current collecting rod 5. It is arranged so as to abut.

As shown in FIG. 2, the metal plate 8 also serving as the negative electrode terminal is covered with a heat-shrinkable tube or film 9 except for the upper surface serving as a terminal. The inside edge of the metal can 1 is sealed by the gasket 6 and the metal sealing plate 8 by bending the opening edge of the metal can 1 inward. The material of the heat-shrinkable resin that can be used here is not particularly limited as long as it is an insulating heat-shrinkable resin, but a polymer material mainly containing vinyl chloride, polyethylene terephthalate, polyethylene, polypropylene, or the like is generally used. In this example, a 50 μm thick tube mainly composed of polyethylene terephthalate was used.

The following experiment was performed to confirm the effects of the present invention. For comparison, a conventional battery without the heat-shrinkable tube 9 and using a conventional metal sealing body also serving as a hat-shaped negative electrode terminal was prepared. In the evaluation, assuming that the shrink label was damaged, an AA sample battery partly deliberately damaged was used and set in an AA battery case (TYPE314) manufactured by Chitose Electric Co., Ltd. The existence of a battery short circuit when dropped 1000 times from a height of about 10 cm was investigated at n = 100. Table 1 shows the results.

[0011]

[Table 1]

According to the result of the drop of the battery, the number of occurrences of the short circuit of the drop sample battery was 0 in the battery of the present invention.
There were 14/100 conventional batteries, and it was easily found that the batteries of the present invention were excellent.

[0013]

As described above, in the alkaline dry battery of the present invention, since the insulating heat resin or the heat-shrinkable insulating tube or film is provided at the end face of the opening of the metal can, the heat-shrinkable outer package is provided. Even if the material is damaged, external short circuit of the battery can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view of an alkaline dry battery according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of the metal sealing plate of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal can which also serves as a positive electrode terminal, 2 ... Positive electrode mixture, 3 ... Separator, 4 ... Gelled negative electrode, 5 ... Negative electrode current collecting rod, 6 ... Insulating gasket, 7 ... Ring-shaped metal plate, 8 ... Metal sealing plate, 9 …
Heat-shrinkable insulating tube, 10 ... shrink label.

Claims (1)

[Claims] In an alkaline dry battery packaged with a heat-shrinkable package material, a battery case accommodating a power generating element and a part of a hat-shaped metal bottom serving also as a negative electrode terminal provided in an opening of the battery case are insulated. An alkaline dry battery covered with one of a thermosetting resin, an insulating shrinkable tube and a film.