JPH11339738A - Cylindrical manganese dry battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical manganese dry battery having an excellent storing function by preventing air from flowing into the battery while being stored and preventing deterioration of voltage and current caused by air inflow. SOLUTION: This cylindrical manganese dry battery has such a constitution that, a closure body 7 provided with a carbon rod 6 in a center transmission hole 7a and in which the positive electrode terminal 11 is mounted on an upper end of the carbon rod 6, is disposed in an opening of a zinc can 1 filled with a positive electrode mix and a separator, and a negative electrode plate is disposed on a bottom of the zinc can 1, and a thermally contractible resin tube 10 is arranged on an outer periphery of the zinc can 1, and this thermo- shrinking resin tube 10 is thermally contracted so as to curl the opening end of the zinc can 1, and the closure body 7 is fastened and sealed by grooving. A silicone oil 12 is interposed in all surfaces or a part of surface defined between the zinc can 1 and the closure body 7. A viscosity of the silicone oil 12 is preferably set to 200-2000 cSt (25 deg.C).

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 preventing deterioration of voltage and current due to inflow of air during storage when the battery is not in use or in an OFF state during use. The present invention relates to a cylindrical manganese dry battery having improved storage performance.

[0002]

2. Description of the Related Art In a cylindrical manganese dry battery, the opening of a zinc can containing a positive electrode mixture and a separator is sealed with a sealing body. However, in a conventional cylindrical manganese dry battery, the zinc can is sealed during storage. Machine oil is interposed between the zinc can and the sealing body in order to prevent air from flowing into the battery from between the body and the voltage and the current, which are deteriorated. However,
The AAA-size cylindrical manganese dry battery having the above-described configuration may have a defective voltage or current within two years of the recommended expiration date if it is kept at a high temperature of 45 to 60 ° C. even in an unused state.

[0003] Then, a detailed examination of the battery in which the above-mentioned voltage and current defects occurred revealed that the machine oil interposed between the zinc can and the sealing member had completely disappeared. Therefore, air flows into the battery from between the zinc can and the sealing body,
Zinc corrosion is promoted, causing voltage failure, and
A zinc / electrolyte / air layer is formed, producing a white or off-white product between the zinc can and the separator that does not diffuse into the cathode mix but accumulates between the separator and the zinc can As a result, the impedance inside the battery rises, causing a current failure.

The reason why the machine oil has completely disappeared is that the viscosity of the machine oil was extremely reduced when the battery was placed at a high temperature of 45 to 60 ° C., and the machine oil flowed out between the zinc can and the sealing body. It is considered to be. That is,
Machine oil has a viscosity of 145 cSt at 20 ° C., but at 60 ° C., the viscosity is reduced to about 1/7 of 20 cSt, so that the fluidity increases and the oil flows out between the zinc can and the sealing body. It is considered that it flowed into the battery. In addition, machine oil is easily oxidized in the air, and it is difficult to maintain its quality for a long period of time. Even if it is not exposed to high temperatures, it decomposes and flows out between the zinc can and the sealing body, and its sealing effect Is thought to lose.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the conventional cylindrical manganese dry battery,
It is an object of the present invention to provide a cylindrical manganese dry battery having excellent storage performance by preventing occurrence of voltage and current defects due to inflow of air into the battery during storage.

[0006]

The structure of the present invention for solving the above problem will be described with reference to FIGS. 1 to 3 (particularly, FIG. 2) corresponding to the embodiment. The silicone oil 12 is interposed on the entire surface or a part of the space between the sealing body 7 and the sealing body 7.

That is, in the cylindrical manganese dry battery, the gap between the zinc can 1 and the sealing body 7 is tightened by curling at the open end of the zinc can 1 and grooving near the open end. Since a minute gap is formed between the two and air flows into the battery through the gap, in the present invention, a silicone oil 12 is interposed between the zinc can 1 and the sealing body 7 to form a gap. Silicone oil 1
2, the inflow of air into the battery was prevented.

[0008] Silicone oil has better heat resistance, less change in viscosity due to temperature change, and is more chemically stable than petroleum oils such as machine oil, so that it does not attack the zinc can 1 or the sealing body 7. In addition, there is almost no deterioration due to oxidation itself, so that quality can be maintained for a long period of time.

Therefore, the silicone oil 12 is supplied to the zinc can 1
When the battery is exposed to a high temperature (up to 60 ° C.), the silicone oil maintains its quality even if the battery is exposed to high temperatures (up to 60 ° C.). Of the air into the battery is prevented by the silicone oil 12, whereby the deterioration of the voltage and current due to the flow of the air into the battery can be prevented, and a cylindrical manganese dry battery having excellent storage performance can be obtained. .

When the battery is charged by reverse loading due to misuse and hydrogen gas is generated in the battery and the pressure inside the battery rises, the silicone oil 12 is supplied to the zinc can 1 and the sealing member 7.
Between the battery and the outside of the battery (here, outside of the battery means outside the sealing body 7), and the sealing body 7 rises, and the inside of the battery and the outside of the battery escape gas. Since the gas is connected through the groove 13 and the gas is discharged out of the battery, there is no fear that the battery is ruptured. Similarly, due to the generation of hydrogen gas by self-discharge during storage, the sealing body 7
When the curl portion (curved portion) at the open end of the battery is to be pushed up, the gas in the battery is discharged out of the battery through the gas release groove 13 in the same manner as described above.
4 is a JIS standard for manganese dry batteries of AAA size.
There is no danger of exceeding 50 mm. Further, the silicone oil 12 that has once escaped from the battery returns to its original position by capillary action, and thus acts as a sealing material again after gas release.

Even if the silicone oil 12 flows into the battery, the silicone oil is an electrically insulating substance.
It does not cause an internal short circuit. In addition, since silicone oil is a chemically inert substance, it does not react with battery constituent chemicals such as a positive electrode active material and an electrolytic solution, and does not affect electric characteristics.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Silicone oils are roughly classified into straight silicone oils and modified silicone oils, and are further classified according to various applications. It is only necessary to use a straight silicone oil which is easily available and inexpensive, because it is low in chemical content and is chemically stable.

The silicone oil used in the present invention has a viscosity of 200 to 2000 cSt (at 25 ° C.).
Is suitable. That is, only when the silicone oil is uniformly blended between the zinc can 1 and the sealing body 7, the silicone oil sufficiently exerts its sealing ability.
When the viscosity is lower than 200 cSt, the fluidity becomes too large, and the silicone oil may flow out between the zinc can 1 and the sealing body 7 and may not function as a sealing material. 2000cSt
If it is higher, the silicone oil may not be uniformly applied to the contact surface between the zinc can 1 and the sealing body 7, and the function as a sealing material may be reduced.

[0014]

Next, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to only those illustrated in the embodiments. Of course, the material of each component is not limited to the example. In the following,% indicating the concentration and the like is% by weight.

FIG. 1 is a partial sectional view schematically showing an embodiment of a cylindrical manganese dry battery of the present invention, and FIG. 2 is an enlarged sectional view of a sealing portion of the cylindrical manganese dry battery shown in FIG. 3 is an enlarged sectional view of the bottom of the cylindrical manganese dry battery shown in FIG.

First, the relationship between reference numerals and constituent members in the drawing will be described. 1 is a zinc can, 2 is a separator, 3 is a positive electrode mixture, 4 is bottom paper, 5 is top cover paper, 6 is a carbon rod, 7 Is a sealing body, 8 is a sealing material, 9 is a negative electrode terminal plate, 10 is a heat-shrinkable resin tube, 11 is a positive electrode terminal, 12 is silicone oil,
13 is a gas vent groove.

The zinc can 1 is formed by forming a metal zinc plate into a cup shape and functions as a negative electrode active material. The separator 2 is made of kraft paper, and a paste material is applied to a surface of the separator 2 that contacts the zinc can 1,
The separator 2 is disposed 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 is composed of a mixture of manganese dioxide and acetylene black, which are positive electrode active materials, and an electrolytic solution added thereto. The electrolytic solution is a 34% aqueous zinc chloride solution. .

The bottom paper 4 is shown in FIG. 3 and is made of paperboard, has a cup shape and is installed on the inner side of the bottom of the zinc can 1, and the top cover paper 5 is made of paperboard and has carbon It has a central hole through which the rod 6 is inserted, and is installed above the positive electrode mixture 3. The carbon rod 6 is formed by hardening carbon powder, penetrates through the through-hole 7a of the sealing body 7 (see FIG. 2) and the center hole of the top cover paper 5, and the lower end thereof has the positive electrode mixture 3 as shown in FIG. And a cap-shaped positive electrode terminal 11 is attached to the upper end thereof, and functions as a current collector on the positive electrode side.

As shown in FIG. 2, the sealing body 7 is made of polyethylene resin, and has a through hole 7a in which a carbon rod 6 is inserted. Is in contact with the inner peripheral surface of the open end of the zinc can 1. The sealing material 8 is composed of a mixture of 95% of polybutene and 5% of a modifying agent.
Covering the top.

The negative electrode terminal plate 9 is made of a tin plate.
The heat-shrinkable resin tube 10 which is shaped like a cap and is attached to the outside of the bottom of the zinc can 1 is made of a heat-shrinkable vinyl chloride resin film tube or the like. The outer periphery of the plate 9 is covered.

The silicone oil 12 has a viscosity of 200 c
An ordinary straight silicone oil (KF96-200cS (trade name), manufactured by Shin-Etsu Chemical Co., Ltd.) of St (25 ° C.) is used and is interposed on the entire surface between the zinc can 1 and the sealing body 7. I have.

The battery of the above embodiment, the zinc can 1 and the sealing member 7
The conventional battery (conventional product) in which machine oil (Machine Oil 68P (trade name), manufactured by Nippon Oil Co., Ltd.) was interposed on the entire surface between the batteries was stored at 45 ° C. for 1 month, 2 months, and 3 months. Open-circuit voltage and short-circuit current during storage (17
The change in the current flowing through the battery when short-circuited at mΩ) was examined. The results are shown in FIG. 4 and FIG.

Each of the batteries was a AAA cylindrical manganese dry battery, and the number of batteries used in the test was 100 for each battery. The storage test at 45 ° C. is an accelerated test, and storage at 45 ° C. for one month is considered to be equivalent to storage at room temperature for one year.

In the battery of the above embodiment, when the silicone oil 12 is interposed between the zinc can 1 and the sealing member 7, the zinc can 1 before the sealing member 7 and the grooving are applied.
The silicone oil 12 is injected into the contact between the zinc can 1 and the sealing body 7 by using the capillary phenomenon at normal temperature, so that the silicone oil is interposed between the zinc can 1 and the sealing body 7. I made it.

FIG. 4 shows the change in the open circuit voltage caused by the storage of the battery of the embodiment and the conventional product (conventional battery). As is apparent from FIG. 4, the battery of the embodiment is the conventional product. The decrease in the open circuit voltage was smaller, and the variation (variation) was smaller. That is, in FIG. 4, the open circuit voltage after storage is slightly shifted between the embodiment and the conventional product, and the respective average values are indicated by ●, the conventional product is indicated by ●, the maximum value and the minimum value are indicated by Δ, respectively. Are shown above and below, but the batteries of Examples have a smaller decrease in open-circuit voltage due to storage than conventional products, and have less variation.

FIG. 5 shows a change in short-circuit current due to storage of the battery of the embodiment and the conventional product (conventional battery). As is apparent from FIG. 5, the battery of the embodiment is better. The short-circuit current was less reduced than the conventional product, and the variation was small. That is, in FIG. 5, the position is slightly shifted between the embodiment and the conventional product, the average value of the respective short-circuit currents is indicated by ●, the conventional product is indicated by ◆, and the maximum value and the minimum value are respectively indicated above and below. As shown in the figures, the batteries of the examples exhibited less reduction in short-circuit current due to storage than conventional products, and had less variation.

[0028]

As described above, in the present invention, by interposing silicone oil between the zinc can and the sealing body, air can be stored during storage in the OFF state when not in use or in use. To prevent the battery from flowing into the battery, preventing the deterioration of the voltage and current based on the air flowing into the battery,
A cylindrical manganese dry battery with excellent storage performance could be provided.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view of a sealing portion of the cylindrical manganese dry battery shown in FIG.

FIG. 3 is an enlarged sectional view of the bottom of the cylindrical manganese dry battery shown in FIG.

FIG. 4 is a diagram showing a change in open circuit voltage accompanying storage of a battery according to an embodiment of the present invention and a conventional product (conventional battery).

FIG. 5 is a diagram showing a change in short circuit due to storage of the battery of the embodiment of the present invention and a conventional product (conventional battery).

[Explanation of symbols]

 DESCRIPTION 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 8 Sealing material 9 Negative terminal plate 10 Heat-shrinkable resin tube 11 Positive electrode terminal 12 Silicone oil 13 Gas release groove 14 Total battery High

Claims (3)

[Claims] 1. A carbon rod (6) is disposed in a central through hole (7a) at an opening of a zinc can (1) containing a positive electrode mixture (3) and a separator (2). A sealing body (7) equipped with a positive electrode terminal (11) is provided at the upper end of a rod (6), and a negative electrode terminal plate (9) is provided at the bottom of a zinc can (1).
And a heat-shrinkable resin tube (1)
0), the heat-shrinkable resin tube (10) is thermally shrunk, the open end of the zinc can (1) is curled, and the sealing body (7) is fastened by grooving to seal the cylindrical manganese dry battery. , Zinc can (1) and sealing body (7)
Characterized in that a silicone oil (12) is interposed on the entire surface or part of the manganese dry battery. 2. The cylindrical manganese dry battery according to claim 1, wherein the silicone oil is a general straight silicone oil. 3. The silicone oil has a viscosity of 200 to 20.
The cylindrical manganese dry battery according to claim 1, wherein the dry temperature is 00 cSt (25 ° C.).