JP3463360B2 - Button type alkaline battery and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a button type alkaline battery, and more particularly to a button type alkaline battery having a sealing packing formed with a dry coating film of a sealant having a high film forming property.

[0002]

2. Description of the Related Art In recent years, button type alkaline batteries have been developed with the development of small electronic devices such as electronic wrist watches and electronic desk calculators.
Demand is increasing more and more. Under these circumstances, the button type alkaline battery is required to have a long life as the electric current consumption of these electronic devices is reduced, and a large current is also required to be highly functionalized. Conventionally, as a method of manufacturing a button type alkaline battery, generally, a positive electrode can that also serves as a positive electrode terminal is filled with a positive electrode mixture, and a negative electrode cup that also serves as a negative electrode terminal is filled with a negative electrode mixture and an alkaline electrolyte, and then a separator is interposed. Then, a method of fitting the positive electrode can and the negative electrode cup through the sealing packing is adopted. Sealing packing for button type alkaline batteries has a dry coating film of polyamide resin, chlorosulphonated polyethylene, asphalt, etc. on the entire surface of the sealing packing for the purpose of suppressing liquid leakage due to creeping up of alkaline electrolyte. Formed and used. As the film forming method, the sealing agent is immersed in a solution prepared by dissolving the sealing agent in an organic solvent such as trichloromethane, trichloroethylene, butanol, xylene, and toluene, and then the sealing packing is dipped to evaporate the solvent to seal it. A method of forming a dry coating film of the agent is used.

Conventionally, there has been a tendency that the sealant is difficult to dissolve in the step of dissolving the sealant in a solvent. In particular, the polyamide resin has a problem that it is difficult to dissolve in a single solvent because it has a hydrogen bond between molecules.
If the sealant is difficult to dissolve in the solvent, it is difficult to form a dry coating film having a thickness that can sufficiently bring out the effect as the sealant. This is because the solvent of the dissolution ability can not increase the concentration of the low and the sealing agent, one immersion - The drying step can not play sufficiently the function of the sealing film very thin dry coating film . Therefore, in order to form a dry coating film having a thickness that can sufficiently bring out the effect as a sealing agent,
Immersed - it must be repeated several times a drying step. On the other hand, when the concentration of the sealant is increased, the film thickness becomes non-uniform, and this also fails to sufficiently fulfill the function as the sealing film.

[0004]

Up to now, as a solvent for the polyamide resin used as the encapsulant, there have been used chlorine-based organic solvents such as trichloromethane, trichloroethylene, and tetrachloroethylene, which have a relatively high ability to dissolve the polyamide resin. It was being done. However, most of these chlorine-based organic solvents are substances subject to environmental regulations. Specifically, since trichloromethane is an ozone depleting substance, its future use is prohibited. In addition, trichlorethylene, tetrachloroethylene, etc. are substances that require strict management under the Water Pollution Control Act and the like because they cause soil pollution and groundwater pollution. From such a background, an alternative substance replacing the chlorine-based organic solvent is desired, but a solvent having sufficient performance could not be found.

An object of the present invention is as a sealant for an insulating sealing packing interposed between a battery positive electrode can and a negative electrode cup.
It is intended to provide a button type alkaline battery on which a dry coating film having a thickness that can sufficiently bring out the effect is formed. Further, an object of the present invention is to use a solvent having a sufficient dissolving ability of the sealing agent of the sealing packing of the button type battery to form a dry coating film of a thickness sufficient to bring out its effect as the sealing agent. It is to provide a battery. A further object of the present invention is to use a solvent having a sufficient ability to dissolve a polyamide resin encapsulant, which is a substance that is not subject to legal regulations related to the environment.
Polyamide resin, which is superior to chlorine-based organic solvents, using a solvent that has the ability to dissolve, a button type that forms a dry coating film with a thickness that can sufficiently bring out its effect as a sealing agent for the sealing packing of button type batteries It is to provide an alkaline battery.

[0006]

The above objects of the present invention can be achieved by the following constitutions. That is, the button-type alkaline battery according to the present invention is a battery positive electrode can also serving as a positive electrode terminal containing a positive electrode mixture, a negative electrode cup also serving as a negative electrode terminal containing a negative electrode mixture, a battery positive electrode can and a negative electrode cup. A button-type alkaline battery provided with an insulative sealing packing arranged at a joint part of the sealing material, wherein a mixed solvent solution of xylene and ethanol of a polyamide-based resin having a concentration of 1 to 20 wt% is formed on the entire surface of the sealing packing. The resulting dry coating film is formed and ethanol is added to xylene at 0.05 to 30 vo
It is characterized by using a mixed solvent solution added in the range of 1%. Further, a method for manufacturing a button type alkaline battery according to the present invention, a battery positive electrode can also serving as a positive electrode terminal containing a positive electrode mixture, a negative electrode cup also serving as a negative electrode terminal containing a negative electrode mixture, and a battery positive electrode can. A method of manufacturing a button-type alkaline battery provided with an insulative sealing packing arranged at a joint with a negative electrode cup, wherein a concentration is provided on the entire surface of the sealing packing interposed between the battery positive electrode can and the negative electrode cup. When a mixed solvent solution of 1 to 20 wt% of polyamide resin xylene and ethanol is applied and dried to form a sealant coating film on the entire surface of the sealing packing, the ratio of ethanol to xylene is 0. 05-30vol%
It is characterized by using a mixed solvent of According to the invention, the ratio of ethanol to xylene is 0.
If a mixed solvent of 05 to 30 vol% is used, the dissolution time of the encapsulant such as polyamide resin is short and good results can be obtained. When xylene is used as the petroleum aromatic hydrocarbon in the mixed solvent, the concentration at which the polyamide resin can be dissolved is high and the dissolution rate is excellent.

[0007]

FUNCTION The mechanism by which ethanol is added to xylene so that the sealant is easily dissolved will be described below. Figure 3 (a)
As shown in, for example, a polyamide resin has a hydrogen bond in the molecule, and thus has a property of being hardly dissolved in various solvents. As the solvent, 0.05 to 30% by volume of ethanol was mixed with xylene to obtain the mixture shown in FIG.
As shown in (b), the hydroxyl group of ethanol forms a hydrogen bond with the amide group, and breaks the intramolecular hydrogen bond of the polyamide resin. Between the molecules that have broken this intramolecular hydrogen bond,
Xylene, which is a sterically bulky lipophilic petroleum-based aromatic hydrocarbon, is incorporated to facilitate dissolution.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. The present invention will be described below with reference to a dissolution test of a polyamide resin and an example in which a solution of a polyamide resin is applied as a sealing agent for a sealing packing of a battery. First, the ratio of ethanol to xylene, which is an example of the present invention, is 10 v.
Table 1 shows the dissolution test results of the polyamide resin when using a solvent having an ol%, when using trichlorethylene, and when using xylene alone. As the dissolution conditions,
It was dissolved in various solvents so that the concentration of the polyamide resin was 4 wt% with respect to the solvent at room temperature.

[Table 1] As can be seen from Table 1, by using a solvent obtained by adding an alcohol to a petroleum-based aromatic hydrocarbon, the dissolving ability is superior to that of trichlorethylene, which is a chlorine-based organic solvent.

Next, the present invention will be described with reference to an example in which a solvent containing a petroleum aromatic hydrocarbon plus an alcohol is used in a battery. A polyamide resin having a concentration of 4 wt% is dissolved in a mixed solvent having a ratio of ethanol to xylene of 10 vol% on the entire surface of an insulating sealing packing interposed between the battery positive electrode can and the negative electrode cup. Then, the sealing packing is dipped in the solution and then dried to evaporate the solvent and form a dry coating film of the sealant. Figure 1
This sealing packing is used for silver oxide battery SR626SW
An example applied to (outer diameter 6.8 mm, height 2.6 mm) is shown. In FIG. 1, a positive electrode mixture 1 containing silver oxide as a main component and a negative electrode mixture 2 containing zinc as a main component are separated by a separator 5 composed of an ethylene film, a cellophane film and a non-woven fabric. The positive electrode can 3 is disposed on the side, the negative electrode cup 4 is disposed on the side of the negative electrode mixture 2, and the sealing packing 6 formed with the dry coating film obtained from the mixed solution in which the resin component of the present invention is dissolved is the positive electrode can 3. It is used as a sealant between the negative electrode cups 4.

In order to confirm the effect of the solvent according to the present invention on the leakage resistance property, the leakage resistance of the battery using the solvent according to the present invention and the chlorine-based organic solvent trichlorethylene was examined. A comparison was made. Table 2 shows the number of leaks of 100 liquids after the battery was stored for 180 days under the storage condition of 45 ° C. and 93% RH.

[Table 2] From Table 2, it was confirmed that the use of the solvent according to the present invention had better leakage resistance than the case of using trichlorethylene, which is a chlorine-based organic solvent.

Next, Table 3 shows the results of examinations of the solvent ratio according to the present invention of the alcohol to the petroleum-based aromatic hydrocarbon, the dissolving ability of the polyamide resin depending on the kind of the petroleum-based aromatic hydrocarbon, and the leakage resistance in the actual battery. Shown in.

[Table 3] As can be seen from Table 3, the ratio of the alcohol to the petroleum-based aromatic hydrocarbon was 0.05 to 30 vol% and the dissolution time of the polyamide resin was short and good.

FIG. 2 shows the results of investigation on the solubility of the polyamide resin in the petroleum aromatic hydrocarbon + alcohol solvent and the chlorine organic solvent. As can be seen from FIG. 2, the petroleum-based aromatic hydrocarbon + alcohol solvent (curve a) has a higher concentration capable of dissolving the polyamide resin and has a higher dissolution rate than the chlorine-based organic solvent (curve b). Admitted. Further, as petroleum-based aromatic hydrocarbons, benzene,
It was confirmed that a similar tendency was obtained with toluene, xylene and a mixed solvent thereof. Further, as the alcohol added to the petroleum-based aromatic hydrocarbon, the number of carbon atoms in the alkyl group is 1
It was confirmed that almost the same tendency could be obtained at ~ 5.

[0013]

EFFECT OF THE INVENTION By using a solvent obtained by adding 0.05 to 30% by volume of ethanol to xylene, which is a petroleum-based aromatic hydrocarbon, as a solvent when using a polyamide resin and a polyamide-imide resin as a sealant, There are three advantages below. 1. Since the solvent according to the present invention is a mixed solvent of xylene and ethanol, it is a substance that is not subject to environmental laws and regulations, and can be used without the use equipment and management to comply with environmental regulations. 2. Since the solvent according to the present invention has a high ability to dissolve the polyamide resin encapsulant, it is easy to form a dry coating film having a thickness sufficient to bring out its effect as an encapsulant. 3. By using the solvent according to the present invention, the dispersion state of the polyamide resin becomes better than that of the chlorine-based organic solvent, and the uniformity of the dry coating film is improved. By increasing the uniformity of the sealant dry coating film, it is possible to provide a battery having excellent liquid leakage resistance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example in which the sealing packing of the present invention is applied to a silver oxide battery.

FIG. 2 is a diagram showing the results of investigations on the solubility of a polyamide resin in a petroleum-based aromatic hydrocarbon + alcohol solvent and a chlorine-based organic solvent.

FIG. 3 is a speculative view of a mechanism by which a mixed solvent of petroleum-based aromatic hydrocarbon and alcohol of the present invention makes a polyamide-based resin sealant easily dissolved.

[Explanation of symbols]

1 ... Positive electrode mixture, 2 ... Negative electrode mixture, 3 ... Positive electrode can, 4 ... Negative cup, 5 ... Separator, 6 ... Seal packing

Claims (2)

(57) [Claims] 1. A battery positive electrode can that also serves as a positive electrode terminal that contains a positive electrode mixture, a negative electrode cup that also serves as a negative electrode terminal that contains a negative electrode mixture, and is arranged at the junction between the battery positive electrode can and the negative electrode cup. A button-type alkaline battery having an insulative sealing packing , wherein a mixed solvent of xylene and ethanol of a polyamide-based resin having a concentration of 1 to 20 wt% is provided on the entire surface of the sealing packing.
A dry coating film is formed from the solution, and the mixed solvent solution is prepared by converting the ethanol into the xylene.
The button-type alkaline battery is characterized by being added in an amount of 0.05 to 30% by volume . 2. A battery positive electrode can that also serves as a positive electrode terminal that contains a positive electrode mixture, a negative electrode cup that also serves as a negative electrode terminal that contains a negative electrode mixture, and is arranged at the joint between the battery positive electrode can and the negative electrode cup. A method of manufacturing a button-type alkaline battery having an insulative sealing packing, wherein a polyamide-based resin having a concentration of 1 to 20 wt% is formed on the entire surface of the sealing packing interposed between the battery positive electrode can and the negative electrode cup. When a mixed solvent solution of resin xylene and ethanol is applied and dried to form a sealant coating film on the entire surface of the sealing packing, the above
A mixture in which the ratio of ethanol is 0.05 to 30 vol%
A method for manufacturing a button type alkaline battery, which comprises using a mixed solvent .