JPH04155752A - Manufacturing method for button-type alkaline batteries - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improved method for manufacturing button-type alkaline batteries.

Conventional technology Conventionally, button-type alkaline batteries have used separators with high liquid-retaining properties or undergone hydrophilic treatment in order to retain a sufficient amount of electrolyte in the separator in order to improve closed-circuit voltage characteristics. I used to use the ones I made.

Problems to be Solved by the Invention However, in these conventional methods, in a button-type alkaline battery in which the end of the positive electrode case is caulked and sealed after the positive electrode part and the negative electrode part are fitted, the peripheral edge of the separator in contact with the bottom of the gasket is There is a drawback that the electrolyte contained in the separator is pushed by the pressure applied when sealing the battery and leaks out to the outside, and there is a limit to the improvement of the liquid-retaining property of the separator.

The present invention aims to solve these problems and improve the closed circuit voltage characteristics of a button-type alkaline battery.

Means for Solving the Problems In order to solve the above problems, the present invention uses a separator whose peripheral edge in contact with the bottom of the gasket is coated with a synthetic resin and then treated with a surfactant to make it hydrophilic.

Function: According to the method of manufacturing a button-type alkaline battery of the present invention, when the positive electrode case end is caulked to seal the battery, the peripheral edge of the separator in contact with the bottom of the gasket is covered with synthetic resin;
Since it is sealed and no electrolyte exists here, leakage of electrolyte from this part will not occur. Moreover, by using a surfactant, a hydrophilic-deficient embodiment of the present invention can be applied to the silver oxide battery SR626SW (Fig. 1).
(diameter: 6.8 ms, height: 2.6 m).

First, a separator 3 punched into a separator shape is inserted into a positive electrode case 2 filled with a positive electrode active material 1 . Thereafter, polyethylene dissolved in toluene is applied to the peripheral edge 4 of the separator in contact with the bottom of the gasket, and after drying, a 7-ion surfactant is dripped into the middle of the separator 3. Finally, the negative electrode part is fitted into the positive electrode case 2, and the end of the positive electrode case is caulked to seal the battery.

FIG. 1 is a sectional view of the silver oxide battery 5R626SW manufactured in this manner. In the figure, 1 is a positive electrode active material whose main component is silver oxide, 2 is a positive electrode case, 3 is a separator made of a polyethylene graft film, cellophane, and a liquid-containing material, 4 is a polyethylene coating layer, 5 is a gasket, and 6 is a negative electrode. A sealing plate 7 which also serves as a terminal is a negative electrode active material containing zinc as a main component.

Table 1 shows the results of measuring the closed circuit voltage characteristics of 50 batteries each of battery A of the present invention and conventional battery B using a separator not subjected to the treatment used in battery A.

Table 1: Closed circuit voltage characteristics (V) As is clear from Table 1, battery A of the present invention has better closed circuit voltage characteristics than conventional battery B. This is because, compared to the conventional battery B, the battery A of the present invention has a separator with superior liquid-retaining properties.

Next, 1000 each of the battery A of the present invention, the battery C made using a separator that had been previously treated to make it hydrophilic, and the battery made using a separator whose periphery was coated with polyethylene after being treated to make it hydrophilic in advance were prepared. Making,
Table 2 shows the results of investigating the number of occurrences of electrolyte leakage from inside the battery immediately after production.

Table 2: Judgments were made based on cresol red color reaction.

The result for battery C is due to the fact that a large amount of electrolyte was present at the periphery of the separator in contact with the bottom of the gasket when the end of the positive electrode case was caulked to seal the battery.

As for the battery test results, since the separator was previously subjected to hydrophilic treatment, the capillary action of the electrolyte progressed to the periphery of the separator in contact with the bottom of the gasket faster than in Battery A of the present invention, and the battery sealing was This appears to be due to electrolyte leaking from a pinhole in the polyethylene coating layer.

In the examples of the present invention, polyethylene was used as the resin, but any resin may be used as long as it has alkali resistance and does not generate gas due to decomposition.

Furthermore, although a nonionic surfactant was used as the hydrophilic treatment agent, a nonionic surfactant having alkali resistance is preferred.

Effects of the Invention As described above, according to the method of manufacturing a button-type alkaline battery of the present invention, when the end of the positive electrode case is caulked and the battery is sealed, the electrolyte is not present at the periphery of the separator that contacts the bottom of the gasket. Therefore, leakage of the electrolyte does not occur, and the separator portion that has been hydrophilized with a surfactant sufficiently absorbs the electrolyte, so that a battery with excellent closed circuit voltage characteristics can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a battery in an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Positive electrode active material, 2... Positive electrode case, 3... Separator layer, 4... Polyethylene coating layer, 5... Gasket, 6... Sealing plate, 7... Negative electrode active material . Name of agent: Patent attorney Akira Koeji and 2 others Figure 1 3-tHa'L-Yu1 →---Seaside Rie+L Soi-broiled11 5-g"Sγ...noto

Claims (1)

[Claims] A method for manufacturing a button-shaped alkaline battery, characterized by using a separator whose peripheral edge in contact with the bottom of the gasket is coated with a synthetic resin and then treated with a surfactant to make it hydrophilic.