JPS6146943B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves heating and melting a heat-melting sealant between the anode carbon rod of a dry battery, the upper surface of the mixture, and the separator paper disposed on the inner surface of the zinc can, and applying the sealant to the separator paper. The purpose is to prevent the electrolyte of the dry battery from leaking to the outside by penetrating the zinc can into close contact with the inner surface of the zinc can.

Conventionally, in order to prevent the electrolyte inside the battery from leaking to the outside, melted wax was placed on a flange paper placed on top of the mixture, and a sealant such as a mixture of wax and fatty acid polyamide resin or pitch was injected to seal the anode carbon rod and the wax. A method is being used to seal the gap between the two. However, in this conventional method, when the melted sealant is injected onto the top of the mixture, the sealant is sequentially exposed to heat by the zinc can, the separator paper, and the carbon rod, and the sealant is sequentially cooled starting from the contact area between these and the sealant. Due to solidification, the sealant could not pass through the separator paper, and the zinc can and the separator paper could not be tightly bonded, resulting in poor battery sealing performance.

The present invention is intended to prevent the above-mentioned drawbacks of the conventional method, and embodiments of the present invention will be described below with reference to the drawings.

In the figure, 1 is an anode mixture mainly consisting of manganese dioxide and carbon powder and holding a carbon rod 2 in the center, 3 is a zinc can, and 4 is a JISK type with a glue layer on the surface facing the inner wall of the zinc can 3. 90, JISK-70 kraft paper is interposed between the anode mixture and the zinc can 3, and the anode mixture 1 is prevented from coming into contact with the mouth end of the zinc can 3 when the anode mixture 1 is filled inside. The upper end 7 of the separator paper 4 is located between the upper surface 5 of the anode mixture 1 and the mouth end 6 of the zinc can 3. 8 is a flange paper made of cardboard, kraft paper, etc. with a wall thickness of about 0.5 to 1 mm, with a through hole 9 in the center into which the carbon rod 2 is inserted, and a thermofusible microcrystalline wax on the top surface of the flange paper. A heat-melting sealant layer 10 such as wax, a mixture of fatty acid polyamide resin and microcrystalline wax, or pitch is applied to a thickness of about 3 to 5 mm.

The flange paper 8 provided with the heat-melting sealant layer 10 is pressed down and fixed by the pressing jig 11 until the flange paper 9 comes into contact with the upper surface 5 of the anode mixture 1, and then the temperature
A heating jig 13 is heated to 150 to 230°C with a heat source such as an electric heater or gas, and is provided with a recess 12 that contacts the isolation paper and the outer periphery of the carbon rod.
The lower end surface of the heating jig 13 is brought into contact with the heat-melting sealant layer 10 and melted into a liquid while heating the separator paper and the anode carbon rod. The aged sealant penetrated between the fibers of the separator paper and reached the inner surface of the zinc can on the upper surface of the mixture, and the separator paper and the inner surface of the zinc can were brought into close contact with the sealant, and the sealant penetrated into the carbon rod as well. Afterwards, the heating jig 13 is taken out from inside the zinc can. Reference numeral 14 denotes a plastic sealing plate for closing the end of the zinc can mouth, and the outer periphery of this sealing plate is covered with a heat-shrinkable tube 15, a metal sealing plate 16, and a metal outer can 17, and a dry battery is sealed by a conventional sealing method. It's sealed.

As shown in FIG. 2, the manufacturing method of the present invention with the above-mentioned configuration is such that the heating jig 13 preheats the separator paper and the outer periphery of the anode carbon rod, and the heat-melting sealant layer 10 is made of heat-melting microcrystalline. Since it is composed of wax, fatty acid polyamide resin, and pitch, it melts and becomes liquid in the temperature range of 100 to 180℃, but the temperature of the heating jig is 150℃ because it absorbs heat from the zinc can or carbon rod of the dry battery. If it is less than that, melting will be insufficient. In addition, the flash point of the sealant layer is 250 to 320.
℃ range, preferably 230℃ or less to prevent the separator paper from burning or scorching. Then, the air between the fibers of the preheated isolation paper and inside the pores of the carbon rod 2 is heated and expelled, and the liquid sealant penetrates, so that the sealant spreads between the inner surface of the zinc can, the isolation paper, and the carbon rod. Therefore, it can be sealed and prevent electrolyte from leaking inside the battery.

By the way, 100 dry batteries [A] made by the method of the present invention and 100 dry batteries [B] made by the conventional method were manufactured, and the results of investigating leakage accidents to the outside of the batteries after 30 days of short-circuit discharge are shown in the table below. .

Test batteries Number of leaking cells [A] 2 pieces [B] 11 pieces As is clear from the above table, the dry cell produced by the method of the present invention has excellent leakage resistance, and its industrial value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a dry battery according to the present invention, with the main parts missing, and FIG. 2 is a cross-sectional view of the main parts illustrating the manufacturing process of the dry battery. 1...Anode mixture, 2...Carbon rod, 4...Isolation paper, 8...
Flange paper, 10... Heat-melting sealant layer, 13... Heating jig.

Claims (1)

[Claims] 1. Into a zinc can filled with an anode mixture that holds a carbon rod in the center via a separator paper, a flange paper with a heat-melting sealant layer formed on the top surface is inserted using a pressing jig to remove the anode. After placing the mixture on top of the mixture, a heating jig is inserted in contact with the upper part of the carbon rod and the separator paper on the inner wall of the zinc can to preheat the carbon rod, separator paper, and zinc can while thermally melting the flange paper. A heating jig is brought into contact with the sealant layer to melt the sealant layer, and the liquid sealant is allowed to penetrate between the fibers of the separator paper and reach the inner surface of the zinc can on the top of the mixture. A method for manufacturing a dry cell battery, which comprises closely contacting a zinc can and a carbon rod, and also infiltrating and adhering a sealant to a carbon rod.