JPH08138635A - Cylindrical manganese dry battery - Google Patents

Abstract

PURPOSE: To provide a cylindrical manganese dry battery excellent in shelf life by preventing the intrusion of oxygen in the atmosphere into a battery even in the case of an occurrence of a pinhole. CONSTITUTION: A sealing body 7 in the center through hole 7a of which a carbon rod 6 is interposed is arranged in the opening of a zinc can 1 in which a positive electrode mixture 3 and a separator 2 are filled, while a negative electrode terminal plate 9 and the insulation ring 10 of a negative electrode side are arranged in the bottom of the can 1. A heat contractive resin tube 11 is arranged on the periphery of the zinc can 1, the heat contractive resin tube 11 is heat-contracted, a positive electrode terminal plate 12 is fitted on the upper end portion of the carbon rod 6, and the insulation ring 13 of a positive electrode side is arranged on the periphery of the positive electrode terminal plate 12 and is clamped in an axial direction by a metal armor can 14 so as to seal the opening portion of the zinc can 1. In this cylindrical manganese dry battery, volatile resistant or nonvolatile fluid organic substance such as machine oil, liquid paraffin or the like is interposed on the whole faces or a part between the zinc can 1 and the heat contractive resin tube 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical manganese dry battery, and more particularly, to a zinc can which is locally corroded during storage in an unused or off state. The present invention relates to a cylindrical manganese dry battery that has improved storage performance by preventing oxygen in the atmosphere from penetrating into the battery even if a pinhole is generated on the side surface of the can.

[0002]

2. Description of the Related Art Conventionally, in a cylindrical manganese dry battery, mercury is dissolved in an electrolytic solution and zinc is amalgamated with mercury to prevent corrosion of the zinc can, or zinc is alloyed with cadmium to corrode the zinc can. And the storage performance has been improved.

However, recently, from the viewpoint of preventing environmental pollution, harmful substances such as mercury and cadmium cannot be used, and as a result, local corrosion of the zinc can occurs during storage, which promotes zinc. A pinhole will be created in the zinc can through the can. The occurrence of such pinholes does not immediately lead to abnormal discharge characteristics, but oxygen in the atmosphere from the pinholes inside the battery (in this case, especially in the power generation element inside the zinc can means Do)
And the pinhole portion becomes a local battery of oxygen and zinc, further promoting the corrosion of the zinc can, and the pinhole expands to become a large hole.

That is, in the cylindrical manganese dry battery, as shown in FIG.
As shown in FIG. 1, the outer periphery of the zinc can 1 is covered with a heat-shrinkable resin tube 11, and the opening of the zinc can 1 has a sealing body 7 and a carbon rod 6.
However, the cylindrical shape is used to prevent the battery from swelling or bursting due to gas generated during discharge or gas generated by charging by reverse loading due to misuse. The manganese dry battery does not adopt a completely sealed structure, and the gas generated in the battery passes between the zinc can 1 and the sealing body 7 or between the sealing body 7 and the carbon rod 6 to cause further heat shrinkage. Since it is designed to escape to the outside of the battery between the lower end of the heat-shrinkable resin tube 11 and the insulating ring 10 or between the positive electrode terminal plate 12 and the insulating ring 13, the lower end of the heat-shrinkable resin tube 11 is particularly preferable. Oxygen in the atmosphere enters between the zinc can 1 and the heat-shrinkable resin tube 11 through the gap between the insulating ring 10 and the insulating ring 10, and if there is a pinhole in the zinc can 1, as described above, the pinhole From inside the zinc can 1 Conductive element portion penetrates, the pin hole portion becomes local cell of oxygen and zinc, corrosion of the zinc can is further advanced, it is of a major hole pinhole spreads.

As a result, the paste material applied to the separator 2 is dried, and basic zinc oxide produced by the reaction of oxygen and zinc is deposited and deposited between the zinc can 1 and the separator 2 to cause internal resistance. Therefore, the discharge characteristics are significantly reduced.

Therefore, most of the cylindrical manganese dry batteries to date have added an inhibitor for suppressing the generation of pinholes, but none of them has a performance comparable to that of mercury or cadmium.

Further, it has been proposed to prevent oxygen in the atmosphere from entering the battery by sealing the entire battery with the outer casing except for the terminal portion, even if a pinhole occurs. In this case, gas generated during discharge,
Alternatively, the gas generated by incorrect charging cannot escape, which may cause the battery to swell or burst.

[0008]

SUMMARY OF THE INVENTION The present invention solves the problem that the conventional cylindrical manganese dry battery has a problem that the storage performance is deteriorated due to the pinhole generated in the zinc can, and the pinhole is generated in the zinc can. Even in such a case, it is an object of the present invention to provide a cylindrical manganese dry battery having excellent storage performance by preventing oxygen in the atmosphere from entering the battery without impairing the degassing property.

[0009]

The structure of the present invention for solving the above problems will be described with reference to FIGS. 1 and 2 corresponding to the embodiments. The present invention is based on a zinc can 1 and a heat-shrinkable resin. A refractory or non-volatile liquid organic substance 15 such as machine oil or liquid paraffin is interposed on the entire surface or a part of the tube 11.

Between the zinc can 1 and the heat-shrinkable resin tube 11, the heat-shrinkable resin tube 11 is heat-shrinked and brought into close contact with the zinc can 1. Therefore, under normal conditions, the two are in close contact with each other. . Therefore, when the fluid organic substance 15 is interposed between the zinc can 1 and the heat-shrinkable resin tube 11,
Even a very small amount of the fluid organic substance 15 spreads over the entire surface, and the spread state is maintained by the surface tension.

Therefore, the fluid organic substance 15 to be used
May be a small amount that wets the surface of the zinc can 1 thinly.
When the fluid organic substance 15 is interposed between the zinc can 1 and the heat-shrinkable resin tube 11, it is preferable that the fluid organic substance 15 is interposed between the zinc can 1 and the heat-shrinkable resin tube 11, but a part thereof may be used. As a part in that case, the lower end portion or both end portions between the zinc can 1 and the heat-shrinkable resin tube 11 is preferable, and in the case where the lower end portion has a closed structure, even the upper end portion Good. In practice, when the flowable organic substance 15 is interposed between these portions, the heat-shrinkable resin tube 11 is heat-shrinked, so that the above-mentioned flowable organic substance 15 is almost between the zinc can 1 and the heat-shrinkable resin tube 11. Spread all over.

If the fluid organic substance 15 is interposed between the zinc can 1 and the heat-shrinkable resin tube 11 as described above, even if a pinhole is generated in the zinc can 1, the fluid organic substance 15 is used. As a result, oxygen in the atmosphere does not enter between the portion where the pinhole of the zinc can 1 was and the heat-shrinkable resin tube 11, so that a local battery is formed between zinc and oxygen. Therefore, the expansion of the pinhole is prevented, the large deterioration of the discharge characteristic does not occur, and the cylindrical manganese dry battery having excellent storage performance can be obtained.

Further, the zinc can 1 and the heat-shrinkable resin tube 1
The zinc can 1 can be
Separator 2 that was in contact with the part where the pinhole of
Since the drying of the sizing material is prevented, the deterioration of the discharge characteristics can be prevented also from this aspect.

Since a very small amount of the fluid organic substance 15 interposed between the zinc can 1 and the heat-shrinkable resin tube 11 is sufficient, gas is generated during discharge, or gas is generated by charging by reverse loading due to misuse. When the gas is generated, the heat-shrinkable resin tube 11 is swollen by the gas, and a sufficient gap is formed for the gas to escape, so that the battery is not swollen or ruptured.

The above-mentioned liquid organic substance 15 is required to be a substance which is hardly volatile or non-volatile, which is its role if the liquid organic substance 15 is easily volatilized and disappears. It is because it cannot fulfill. Then, specific examples of the fluid organic substance 15 having the requirement of being hardly volatile or non-volatile include machine oil (particularly machine oil No. 2 is preferable), liquid paraffin, and polybutene. Low-viscosity synthetic polymers such as silicone oil, oils and fats such as olive oil and castor oil, and surfactants such as score rolls can be used, but in particular, the weight ratio of machine oil to liquid paraffin is 1: 1 to 1: 1.
A 9: 1 mixture is preferred because it has suitable flowability and does not easily wash off.

[0016]

Embodiments of the present invention will now be described with reference to the drawings. However, the present invention is not limited to the examples illustrated in the embodiments. Needless to say, the material of each component is not limited to the examples.

FIG. 1 is a partial sectional view showing an embodiment of the cylindrical manganese dry battery of the present invention. FIG. 2 is an enlarged view of part A of FIG.

In the figure, 1 is a zinc can, 2 is a separator, 3 is a positive electrode mixture, 4 is bottom paper, 5 is top lid paper, 6 is a carbon rod, 7 is a sealing body, 8 is a sealing material, and 9 is a negative electrode terminal. Plate, 10 is a negative side insulating ring, 11 is a heat-shrinkable resin tube, 12 is a positive terminal plate, 13 is a positive side insulating ring, 14 is a metal outer can,
15 is a fluid organic substance.

The zinc can 1 is made of a metal zinc plate formed into a cup shape and acts as a negative electrode active material. The separator 2 is made of kraft paper, and a paste material is applied to the surface of the separator 2 that contacts the zinc can 1.
The separator 2 is arranged between the positive electrode mixture 3 and the zinc can 1 such that the paste material contacts the zinc can 1.

The positive electrode mixture 3 comprises a mixture of manganese dioxide as a positive electrode active material and acetylene black to which an electrolytic solution is added and mixed. As the electrolytic solution, a zinc chloride aqueous solution having a concentration of 34% is used.

The bottom paper 4 is made of paperboard and is arranged on the inner surface of the bottom of the zinc can 1, the top paper 5 is made of paperboard, and the carbon rod 6 is used.
Has a center hole through which the positive electrode mixture 3 is inserted. The carbon rod 6 is made by solidifying carbon powder, penetrates the through hole 7a of the sealing body 7 and the central hole of the upper lid paper 5, the lower end thereof reaches near the lowermost portion of the positive electrode mixture 3, and the upper end portion thereof It is in contact with the positive electrode terminal plate 12 and acts as a current collector on the positive electrode side.

The sealing body 7 is formed by molding a polyolefin resin such as polyethylene or polypropylene, or a polyamide resin such as nylon, and has a through hole 7a for inserting the carbon rod 6 in the center thereof. The open end of the zinc can 1 is in contact with the outer peripheral portion. The sealing material 8 is made of a mixture of polybutene and asphalt pitch, and is formed around the carbon rod 6 below the sealing body 7.

The negative electrode terminal plate 9 is made of a tin plate, and the outer peripheral portion thereof has a flat plate shape. The insulating ring 10 on the negative electrode side is
It is made of punched paperboard impregnated with paraffin in a ring shape, and is arranged in contact with the outer surface side (lower side in the figure) of the flat plate-shaped outer peripheral portion of the negative electrode terminal plate 9.

The heat-shrinkable resin tube 11 is made of a heat-shrinkable vinyl chloride resin film or the like, and the zinc can 1
The liquid organic substance 15 is interposed between the insulating ring 1 and the upper part of the insulating ring 1.
It covers a part of the lower surface of 0.

The positive electrode terminal plate 12 is made of a tin plate, and its central portion has a cap shape fitted to the upper end portion of the carbon rod 6, and its outer peripheral portion has a flat plate shape. The insulating ring 13 on the positive electrode side is formed by punching a vinyl chloride resin plate into a ring shape, and is arranged on the flat outer peripheral portion of the positive electrode terminal plate 12.

The metal outer can 14 is formed by rolling a tin plate into a cylindrical shape, is arranged on the outer peripheral side of the heat-shrinkable resin tube 11, has its lower end bent inward, and its upper end inward. Curled in one direction, the tip of which is an insulating ring 1
3, the insulating ring 13, the flat plate-shaped outer periphery of the positive electrode terminal plate 12, the upper end of the heat-shrinkable resin tube 11, the outer periphery of the sealing body 7, the open end of the zinc can 1, and the heat-shrinkable resin. Lower end of tube 11, insulating ring 10, negative electrode terminal plate 9
Are pressed in the axial direction to fix them in predetermined positions.

As described above, the fluid organic substance 15 comprises low viscosity synthetic polymer such as machine oil, liquid paraffin, polybutene and silicone oil, fats and oils such as olive oil and castor oil, and a surfactant such as score roll. It is interposed between the zinc can 1 and the heat-shrinkable resin tube 11. 1 and 2 show the fluid organic substance 15 thicker than it actually is so that it can be easily seen from the drawings, but the fluid organic substance 15 may be thin such as about 0.001 to 10 μm. It has a sufficient function.

Next, the batteries of the above examples and the conventional battery (conventional product) shown in FIG. 3 were stored at room temperature for 1 year and 2 years, and the discharge characteristics after the storage were examined.

Each battery has an outer diameter of 14 mm and a total height of 50.
It is a 5 mm R6 type cylindrical manganese dry battery, and the number of batteries used in the test is 100 for each battery.

In the battery of the embodiment, a mixture of machine oil (No. 2) and liquid paraffin having a weight ratio of 3: 1 is fluidized between the upper end of the zinc can 1 and the heat-shrinkable resin tube 11. The liquid organic substance 15 is dripped as the organic substance 15 and the heat shrinkage of the heat shrinkable resin tube 11 and the capillarity of the liquid organic substance 15 are used to spread the liquid organic substance 15 on almost the entire surface between the zinc can 1 and the heat shrinkable resin tube. Distribute, liquid organic matter 15
Is interposed between the zinc can 1 and the heat-shrinkable resin tube 11, but in the conventional battery, such a fluid organic substance 15 is used.
Is not interposed between the zinc can 1 and the heat-shrinkable resin tube 11, but the heat-shrinkable resin tube 11 is directly coated around the zinc can 1.

As a result of investigating the generation of pinholes due to self-corrosion between zinc 1 after storage for 1 year and 50 years after storage for 2 years, 4% in one year and 16% in 2 years Had occurred.

A discharge test was carried out on the battery of the example and the conventional battery in which pinholes were generated, and the conventional battery in which no pinholes were generated. The discharge performance of the battery after storage for 1 year and 2 years was 20 ° C, 5Ω, and the final voltage was 0.
The battery was continuously discharged to 9 V, the discharge duration was measured, and an index was determined with the discharge duration of the battery having no pinhole immediately after assembly taken as 100. Table 1 shows the results.
The discharge time of the battery immediately after assembly was 150 minutes for both the example and the conventional battery, and in Table 1, the conventional battery is indicated as the conventional product.

[0033]

[Table 1]

As is clear from the results shown in Table 1, the batteries of the examples of the present invention are significantly different from the conventional batteries in which no zinc pinholes are generated, even when the zinc cans are pinholes. However, in the comparison of the ones in which pinholes were generated, the performance of the battery of the example was significantly improved as compared with the conventional battery, and the battery of the example of the present invention showed self-corrosion during storage. Even when a pinhole was generated in the zinc can, it had the same discharge performance as that in which no pinhole was generated, and the storage performance was excellent.

[0035]

As described above, according to the present invention, even when a pinhole is generated in a zinc can due to self-corrosion of the zinc can during storage, oxygen in the atmosphere from the pinhole is transferred to the battery. It has been possible to provide a cylindrical manganese dry battery with excellent storage performance by preventing intrusion.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of a cylindrical manganese dry battery of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a partial cross-sectional view showing a conventional cylindrical manganese dry battery.

[Explanation of symbols]

 1 Zinc Can 2 Separator 3 Positive Electrode Mixture 4 Bottom Paper 5 Top Cover Paper 6 Carbon Rod 7 Sealing Body 7a Through Hole 9 Negative Electrode Terminal Plate 10 Insulation Ring 11 Heat Shrinkable Resin Tube 12 Positive Electrode Terminal Plate 13 Insulation Ring 14 Metal Outer Can 15 Flow Organic matter

Claims (2)

[Claims] 1. A zinc can 1 having a positive electrode mixture 3 and a separator 2 filled therein is provided with a sealing body 7 in which a carbon rod 6 is inserted into a central through hole 7a, and the bottom of the zinc can 1 is provided. The negative electrode terminal plate 9 and the insulating ring 10 on the negative electrode side are arranged, and the heat-shrinkable resin tube 11 is arranged on the outer peripheral portion of the zinc can 1, and the heat-shrinkable resin tube 11 is heat-shrinked to form the carbon rod. The positive electrode terminal plate 12 is fitted to the upper end portion of 6, and the insulating ring 13 on the positive electrode side is disposed on the outer peripheral portion of the positive electrode terminal plate 12, and the metal outer can 14 is axially tightened to fix the zinc can 1. In a cylindrical manganese dry battery with an opening sealed, a non-volatile or non-volatile liquid organic substance 15 is interposed between the zinc can 1 and the heat-shrinkable resin tube 11 in whole or in part. A cylindrical manganese dry battery. 2. The cylindrical manganese dry battery according to claim 1, wherein the fluid organic substance is a mixture of machine oil and liquid paraffin.