JPH0433644Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention relates to dry batteries, and more specifically to manganese dry batteries constructed by sealing a positive electrode mixture containing manganese dioxide as an active material in a zinc can. be.

<Conventional technology> The above-mentioned manganese dry batteries, especially zinc chloride dry batteries that use an electrolyte containing zinc chloride as a main component, suffer from significant performance deterioration due to oxygen contained in air entering from the outside, and due to air contamination. Since liquid leakage is likely to occur, a reliable sealing structure is required.

For this reason, in current dry batteries, a sealant such as pitch or wax is interposed between the sealing gasket 5 that seals the opening of the zinc can and the carbon rod 4, as shown in Fig. 2, for example. . Also,
Heat-shrinkable tube 12 shrink-bound around the periphery of the zinc can
While placing the upper end peripheral portion on the upper surface of the sealing gasket and placing the positive electrode terminal plate 6 on this upper end peripheral portion,
The negative terminal plate 11, the annular packing, and the lower edge of the heat-shrinkable tube 12 are placed on the bottom of the zinc can, and the curled ends provided on the upper and lower edges of the outer can 13 are used to connect these from above through the annular packing. It uses a complex structure in which pressure is applied from above and below.

<Problems to be solved by the invention> However, with the conventional structure described above, even if this structure is used, the sealing performance deteriorates as the discharge progresses. Outside air enters. When a dry battery becomes over-discharged, part of the side or bottom of the zinc can disappears (pinholes, etc.) due to excessive consumption of zinc.
A type of air-zinc battery is formed by the zinc near the vanishing point, the electrolyte leaked to the outside of the zinc can, and the above-mentioned external air, and the battery reaction causes the zinc can to be significantly consumed. , the negative terminal plate is corroded by the electrolyte that travels around the outer circumference of the zinc can,
There is a problem in that these reductions combine to cause external leakage. In addition, it is necessary to adopt a complex structure as described above to ensure sufficient sealing performance, and an excessive amount of zinc is required to prevent the above-mentioned disappearance in an over-discharge state and ensure a certain level of leakage resistance. There is a problem in that the zinc can must be made thicker, resulting in higher battery costs. Furthermore, in this type of case where the outer can is attached to the outer periphery of the zinc can, the size of the zinc can must be made more than one size smaller than the finished battery with standard dimensions.
Therefore, there is a problem in that the size of the zinc can and the amount of positive electrode mixture stored are limited, which limits the discharge performance.

<Means for solving the problem> The dry battery of this invention consists of a negative electrode terminal plate provided on the inner surface of an opening formed at the bottom of the zinc can in close contact with the bottom opening, and a positive electrode mixture sealed in the zinc can. A corrosion-resistant insulating layer is interposed between the zinc can and the zinc can, and the outer periphery of the zinc can is directly covered with a heat-shrinkable outer layer label.

<Function> By directly covering the outer periphery of the zinc can with the heat-shrinkable exterior label described above, intrusion of outside air and leakage of the electrolyte from the above-mentioned vanishing point can be prevented. Furthermore, the above-mentioned insulating material layer provided on the inner bottom of the zinc can prevents the bottom from disappearing even during overdischarge. These factors improve leakage resistance. In addition, since it is directly wrapped with a heat-shrinkable outer label, it is possible to use zinc cans that are slightly smaller than the standard battery size, increasing the amount of positive electrode mixture stored and improving discharge performance. . Furthermore, the sealing structure of the conventional outer can is no longer necessary, and the zinc can can be made thinner due to its improved leakage resistance, making it possible to reduce the amount of zinc used, thereby reducing battery costs accordingly.

<Example> In the example shown in FIG. 1, a cylindrical zinc can 1 whose lower end opening is bent inward to form a flange part is provided with a paper separator 2 made of kraft paper coated with a glue material and dried. A positive electrode mixture 3 formed by pressure-molding a mixture of manganese dioxide, a conductive material, an electrolyte, etc. is housed through the housing. A sealing gasket 5 made of synthetic resin is placed on the upper opening of the zinc can, and the upper part of the carbon rod 4 press-fitted into the positive electrode mixture 3 passes upward through the insertion hole formed in the sealing gasket 5. Further, a positive electrode terminal plate 6 made of metal is attached to this protruding portion. The upper peripheral edge of the heat-shrinkable exterior label 9, which is contracted and tied around the outer periphery of the zinc can, is located at the peripheral edge of the sealing gasket 5 and the positive terminal plate 6. This heat-shrinkable exterior label 9 is made of a laminated material in which a base material made of a heat-shrinkable resin film such as polyvinyl chloride resin is coated with a metal vapor deposited layer, a printed layer, etc. It is firmly fixed to the outer periphery of the zinc can by a water-repellent (alkaline electrolyte resistant) adhesive layer, and the positive terminal plate 6 and sealing gasket 5 are tightly attached to the opening of the zinc can. Note that such adhesives include, for example, thermosetting resins and ultraviolet curable resins.

On the other hand, an opening 1a is formed at the bottom of the zinc can 1, and a metal negative terminal plate 7 is located on the inner surface of the flange 1b at the bottom of the zinc can outside the opening 1a. By bringing the lower surface of the peripheral edge of the negative electrode terminal plate 7 into close contact with the upper surface of the flange portion 1b, it is possible to take out current from the negative electrode terminal plate 7. Furthermore, a corrosion-resistant insulating material layer 8 is interposed between the negative electrode terminal plate 7 and the positive electrode mixture 3 to isolate them. Specifically, the insulating material layer 8 is made of various hot melt resins, or synthetic resins such as polyethylene and polypropylene. The lower edge of the heat-shrinkable exterior label 9 wrapped around the outer periphery of the zinc can is fixed to the flange of the zinc can.

This dry battery is produced, for example, by the following steps. That is, after inserting the negative electrode terminal plate 7 from the upper opening of the zinc can 1 and bringing the periphery of the negative electrode terminal plate into contact with the flange portion 1b, the paper separator 2 is housed and heated melted hot melt resin is inserted into the same opening. Pour from the bottom to the bottom. When the hot melt resin is cooled and solidified, the positive electrode mixture 3, carbon rod 4, etc. are stored, and then a sealing gasket 5 and a positive electrode terminal plate 6 are placed in the opening of the zinc can. Next, a sheet-shaped heat-shrinkable exterior label 9 is wrapped and attached to the outer periphery of the zinc can, and the exterior label portion of the zinc can body is slightly heat-shrinked as it is or by heating at a low temperature to make the surface smooth. On the other hand, the outer label part that protrudes from the top and bottom is heated at a slightly higher temperature.
It is manufactured by a procedure such as greatly shrinking the material by heat and then adhering it closely to the positive terminal plate side or the negative terminal plate side.

<Effects of the invention> As described above, the battery of this invention not only significantly improves leakage resistance, but also reduces costs by simplifying the sealing structure and making the zinc can thinner, and reduces the cost of the outer can. Discharge capacity can be increased due to non-use. In addition, when an insulating material layer is provided on the bottom of the zinc can as in this invention, there is an advantage that the amount of metallic zinc used can be reduced by about 30 to 50% compared to the conventional structure shown in FIG.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a dry battery according to an embodiment of this invention.
FIG. 2 is a sectional view of each conventional example. 1,15...Zinc can, 3,14...Positive electrode mixture,
5... Sealing gasket, 7, 11... Negative electrode terminal plate, 8... Insulating material layer, 9... Heat-shrinkable exterior label.

Claims (1)

[Scope of utility model registration request] A corrosion-resistant insulating material layer is interposed between the negative electrode terminal plate, which is provided on the inner surface of the opening formed in the bottom of the zinc can, in close contact with the bottom opening, and the positive electrode mixture sealed in the zinc can. A dry battery characterized in that the outer periphery of a can is directly covered with a heat-shrinkable outer layer label.