JPS5837945B2 - 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.

In this type of battery, a sealing agent made of liquid packing such as asphalt pitch or unvulcanized rubber is generally inserted between the battery container, metal sealing plate, current collector rod, etc. and the gasket to maintain the liquid tightness inside the battery. However, the above-mentioned sealants did not have sufficient liquid-tightness and were rather inferior in leakage resistance.

As a result of intensive studies in light of the above circumstances, the inventors have found that a sealant made by adding a specific rust preventive agent to a liquid packing such as conventional asphalt pitch has an excellent liquid-tight effect. I realized this and came up with this invention.

This invention will be explained below based on the drawings.

Figures 1 and 2 show an example of an alkaline battery according to the present invention. 2 is a mixture of amalgamated zinc active material and a glue such as sodium polyacrylate or carboxymethylcellulose, which is then mixed with an alkaline electrolyte. Most of the cathode material was injected and gelatinized, and 3 is a separator consisting of a liquid absorbent layer such as vinylon-rayon mixed paper, a cellophane layer, and a hydrophilically treated microporous polypropylene film.

Reference numeral 4 denotes an anode can constituting a battery container in which the above-mentioned anode mixture 1 and separator 3 are placed, and a part of alkaline electrolyte is injected into the bottom of this can in advance, and the above-mentioned cathode material 2 is filled inside. The cathode terminal plate 5 constituting the metal sealing plate is fitted with an annular gasket 6 having an L-shaped cross section made of synthetic resin such as polyethylene, and the can opening is tightened inward to seal the inside of the battery. do.

7 is a sealant interposed in a small gap 8 at the interface between the gasket 6, anode can 4, and cathode terminal plate 5, and this sealant is a conventional liquid packing containing a specific rust preventive agent. .

The above-mentioned specific rust inhibitor is at least one selected from penzotriazole, pensothiazole, and derivatives thereof, and the derivative of penzotriazole has the following general formula (■): (R is an alkyl group, (representing a substituent such as halogen), such as methylbenzotriazole,
What about chlorbenzotriazole? Examples include methylbenzothiazole and chlorobenzothiazole.

As a conventional liquid packing containing such a rust preventive agent, asphalt pitch is preferably used, but other materials such as unvulcanized rubber, fatty acid polyad, microcrystalline wax, polybdenum, and grease can also be used. If necessary, a certain amount of oil such as process oil may be added to the packing to impart appropriate tackiness and flexibility during coating and drying.

To prepare a sealant containing both components, first add a rust inhibitor to an organic solvent such as benzene, toluene, or xylene.
．． The sealing agent is added and dissolved at a ratio of 0.05 to 0.5 weight cake, preferably 0.2 weight cake, and the liquid packing component is added to this. After applying it to the required portions of the plate 5 or gasket 6, it is air-dried to be inserted into the gap 8.

As is clear from the above configuration, a specific rust preventive agent is contained in the sealant 7 made of liquid packing that is interposed in the slight gap 8 at the interface between the gasket 6, anode can 4, and cathode terminal plate 5. This rust preventive agent chemically bonds to the metal surfaces of the anode can 4 and cathode terminal plate 5 to enhance the adhesion function of the sealant and also has good water repellent properties. This function also has the effect of suppressing the deterioration of the surface condition caused by the oxide film that forms on the surfaces of the anode can 4 and the anode terminal board when this rust preventive is not included, and as a result, the sealing function is significantly improved. As a result, leakage resistance is greatly improved.

The table below shows the above configuration with asphalt pitch containing penzotriazole as a sealant (Battery A).
The results of the leakage resistance test of the button-type alkaline battery of this invention using asphalt pitch containing penzothiazole (Battery B) were compared with those of the conventional button-type alkaline battery using asphalt pitch with no rust preventive added as a sealant. Battery C
It can be seen from this table that the alkaline batteries A and B of the present invention have very excellent leakage resistance.

In addition, for the leakage resistance test, the number of tested batteries A, B, and C is 100.
The number of batteries in which leakage was observed when these batteries were left in an atmosphere of 45'C and 901RH for three months was investigated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of an alkaline battery of the present invention;
FIG. 2 is an enlarged view of the section ■ in FIG. 1. 7...Sealant, 8...Gap.

Claims (1)

[Claims] 1. A sealant 7 containing at least one rust preventive agent selected from penzotriazole, penzothiazole, and derivatives thereof is interposed in the gap 8 between the battery container, metal sealing plate, current collector rod, etc. and the gasket. An alkaline battery characterized by: