JPS5840303B2 - alkaline battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to alkaline batteries such as silver oxide batteries and manganese dioxide batteries, and an object thereof is to improve leakage resistance.

Generally, when sealing a battery, a synthetic resin or rubber gasket is placed at the opening of the anode can, and this gasket is tightened inward at the opening end of the anode can to close the cathode current collector such as the cathode terminal plate. By pressing the contact surfaces between the anode can, the gasket, and the cathode current collector into close contact with each other, leakage of electrolyte from these contact surfaces is prevented, but an alkaline electrolyte such as caustic potash is used. Batteries that do this tend to have poor leakage resistance despite the above-mentioned sealing means.

The inventors worked on the previous research by forming a rust-preventive coating mainly composed of benzotriazole compounds or triazole compounds on cathode terminal plates, etc. whose inner surface layer is a copper or copper alloy layer. Although we succeeded in effectively suppressing liquid leakage from the contact surface with the terminal board,
In subsequent research, when we formed a coating made of such a benzotriazole compound or a combination of a triazole compound and a specific resin on the inner surface of the anode can, we found that leakage from the contact surface between the gasket and the anode can was also reduced. This invention was developed based on the knowledge that this can be sufficiently suppressed.

The present invention will be explained below based on the drawings.

FIG. 1 shows an anode can according to the present invention, and the anode can 1 is generally made of nickel-plated iron, but may also be made of a material such as Nutenrene in some cases.
A coating 2 made of a benzotriazole compound or a triazole compound and a water-repellent resin is formed on the inner surface of the can 1.

The coating 2 can be formed by adding a benzotriazole compound to an appropriate medium such as water or alcohol.

Alternatively, a treatment liquid may be prepared by adding a predetermined amount of a triazole compound and a water-repellent resin, and this may be applied to the inner surface of the can and dried.

Alternatively, the anode can 1 may be immersed in the above treatment solution and dried.

The typical benzotriazole compound used here is benzotriazole, but other derivatives of benzotriazole such as methylbenzotriazole and chlorbenzotriazole may also be used, and as triazole compounds, 1,2,3-triazole , (2) Methyltriazole, 1-aminoto 2.4-triazole, and other compounds can also be used.

Typical water-repellent resins include base resins and silicone resins, and commercially available products include Ryoe Chemical Products C, B, and Bright.

FIG. 2 shows an example of a button-type alkaline battery of the present invention using the above-mentioned anode can. A portion of the alkaline electrolyte is injected into the bottom of the anode can 1 in advance, and an anode mixture is poured on top of the alkaline electrolyte. 3
The button and separator 4 were placed, and the opening of the anode can 1 was filled with the cathode agent 5. [The terminal plate 6 was made of polyethylene,
They are fitted through an annular gasket 7 made of synthetic resin such as polypropylene or rubber and having an angular cross section, and the can opening is tightened inward to make the inside of the battery liquid-tight.

The anode mixture 3 is made of a mixture of ferrous oxide powder, manganese dioxide powder, etc. as the anode active material, and if necessary, a conductive powder such as graphite, which is then pressure-molded.
Further, the separator 4 is composed of a liquid absorbent layer such as a vinylon-rayon mixed paper, a cellophane layer, and a hydrophilically treated polypropylene film, and the cathode material 5 is made of a cathode active material such as an amalgamated zinc active material. It is made by uniformly mixing a paste with a glue such as sodium polyacrylate or carboxymethylcellulose, and then injecting most of the alkaline electrolyte into the mixture to make it gelatinized.

As is clear from the above configuration, by forming the coating 2 made of a benzotriazole compound or a triazole compound and a water-repellent resin on the inner surface of the anode can 1,
The coordination bond of the benzotriazole compound or triazole compound to the metal surface provides strong adhesion strength between the can inner surface and the coating 2, and this coating 2 allows the alkaline electrolyte inside the battery to ooze out along the can inner surface. This can be effectively prevented, and when the can opening is tightened inward, the adhesion between the gasket 7 and the anode can 1 is good, and liquid leakage from the contact surface is prevented.

The leakage prevention effect is particularly noticeable when the mouth is sealed.

In other words, if a method is adopted in which a portion of the alkaline electrolyte is injected into the bottom of the can in advance (this is to ensure that the inside of the anode mixture 3 is sufficiently impregnated with the electrolyte), the injected electrolyte will be absorbed into the anode mixture. When the agent 3 is placed on the button, it is pushed up along the inner surface of the can and leaks to the outside due to the sealing pressure.However, according to the above structure, the adhesion strength formed on the inner surface of the can is large. Such liquid leakage can be largely suppressed by the water repellent action of the coating 2 or by the good adhesion between the gasket 7 and the can 1.

The table below shows that for the above-mentioned structure, benzotriazole and silicone resin were added to water as a medium in a proportion of 10% by weight and 2% by weight, respectively, as a treatment liquid for forming coating 2. The results of a leakage test when the button-type alkaline battery A of the present invention is sealed are shown in comparison with a conventional battery B.

The numerical values in the table represent the number of batteries in which leakage was observed during sealing, when the number of batteries tested was 100.

From this table, it can be seen that the battery of the present invention has excellent leakage resistance.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of an anode can according to the present invention, and FIG. 2 is a cross-sectional view showing an example of a button-type alkaline battery according to the present invention. 1...Anode can, 2...Coating.

Claims (1)

[Claims] 1 A) L-potassium battery in which a coating 2 made of a benzotriazole compound or a triazole compound and a water-repellent resin is formed on the inner surface of an anode can 1.