JPH06140006A - Manganese dry battery and manufacturing method thereof - Google Patents

Abstract

PURPOSE:To make the adhesion between a zinc can and a resin cover firm and improve the leakage resistance and weak current discharge performance by forming the cover with a heated resin on the zinc can, and drying it by surface heating. CONSTITUTION:The acrylic resin 2 of a cover paint dried at the ordinary temperature is heated and sprayed to the outer periphery of a zinc can constituting a unit cell 10 with a hot-spray device 1. Since the paint is kept at a high temperature, a solvent constituent is immediately volatilized, and only a resin layer 12 is solidified and formed on the outer periphery of the unit cell 10 as a uniform film. It is immediately dried by a near infrared heater 14 at the preset surface temperature for a preset period, then it is cooled at the ordinary temperature while the solvent constituent is completely volatilized, and a product is obtained via the winding process of a shrink tack label 16. A stiff resin layer film is uniformly formed, the flow of air is completely shut, the leakage resistance and weak current discharge performance can be improved, and the adhesive force of the shrink tack label 16 can be improved by the smoothness of the resin layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a film-clad manganese dry battery, in which the adhesion between a zinc can and a film jacket constituting a unit cell is improved to improve the performance and the liquid leakage resistance in the application where the current consumption is reduced. The present invention relates to a manganese dry battery having improved temperature and a manufacturing method thereof.

[0002]

2. Description of the Related Art Manganese dry batteries of film exterior type are
It has the advantages that the filling amount of the contents can be increased, the number of parts can be reduced, and the manufacturing cost can be relatively reduced as compared with the conventionally used metal jacket exterior type battery.

In this film-clad manganese dry battery, a heat-shrinkable shrink tack label is wrapped around the outer surface of a zinc can that constitutes a unit cell, and is adhered to the zinc can via an adhesive layer provided on the back surface thereof. After that, if the upper and lower sides of the shrink tack label are thermally contracted by the supply of hot air, the shrink tack label is bent around both extreme surfaces and the exterior is completed, so that the manufacturing method is simpler than that of the metal jacket method.

[0004]

However, in this film packaging method, the adhesion of the adhesive layer to the outer circumference of the zinc can has been a problem. That is, while the shrink tack label is wound, the overlapping margin is formed,
The non-adhesive portion between the shrink tack label and the zinc can was formed due to the stepped portion at this portion, and the complete adhesive state was not obtained. Further, the surface of the zinc can was not a simple smooth surface, and pinholes and the like in the adhesive layer were not negligible. In the case where they are not completely in close contact with each other as described above, they are likely to be peeled off by an external force, and air passages are formed, which causes a problem in leakage resistance.

That is, for example, in applications such as memory backup for which the current consumption is reduced, the inner surface of the zinc can does not react uniformly due to the weak current consumption, resulting in local disappearance.

When the locally disappeared portion of the zinc can is formed in the vicinity of the non-adhesive portion between the shrink tack label and the zinc can, it naturally becomes a leakage path for liquid from the inside of the battery, and also from the outside to the inside of the battery. It serves as an oxygen invasion path and accelerates the deterioration of discharge performance and liquid leakage.

On the other hand, a baking type resin powder is adhered to the outer periphery of a unit cell completed by filling a zinc can or a positive electrode mixture, for example, and this is heated and melted to form a coating film, which is used as an exterior. Methods have also been proposed. However, in practice, it is difficult to control the resin thickness to a constant level with a resin-baked exterior, and the heating temperature for baking is too high to keep the contents sealed in the unit cell state. Implementation was impossible.

The present invention provides a manganese dry battery of film exterior type, in which the adhesion between the shrink tack label and the zinc can is further improved and the liquid leakage resistance is improved, and a method for producing the same.

[0009]

In order to achieve the above object, the manganese dry battery of the present invention is characterized in that a zinc can constituting a unit cell is covered with a shrink tack label on the outer peripheral surface through a resin layer. To do. The resin layer is preferably a room temperature dry type acrylic resin or an acrylic modified resin as a main component.

Further, in the manufacturing method of the present invention, the liquid resin is sprayed onto the outer periphery of the zinc can by the hot airless spray method while rotating the zinc can, and then the liquid resin is dried and solidified by the near infrared ray drying means. .

[0011]

In the liquid resin adhered to the outer circumference of the zinc can while being heated by the hot airless spray method, the solvent component immediately evaporates. The near-infrared ray drying means heats only the surface to a high temperature so as not to affect the contents of the battery, and uniformly forms a tough resin layer coating on the surface of the zinc can within a short time.

The formed resin layer has smoothness and has good affinity with the adhesive layer of the label jacket.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the following examples. FIG. 1 is a schematic view showing the method of the present invention. In the figure, a hot airless spray device 1
Supplies the coating paint (liquid resin) contained in the paint tank 2 to the spray gun 6 via the pump 3, the heater 4 and the filter 5, and partially sprays the paint through the circulation valve 7. The pump 3 is circulated from 6 to maintain the temperature of the paint heated by the heater 4. Further, by heating the paint, the influence of seasonal fluctuations in the ambient temperature can be eliminated, the viscosity of the paint can be easily controlled, and stable spraying of the paint can be realized.

The coating material for coating comprises a resin, a plasticizer, a solvent, a pigment, and other additives. As the resin component, a material which is a room temperature dry type and is dried and solidified in a short time is used. Specifically, an acrylic resin, a nitrocellulose-modified acrylic resin or a CAB-modified acrylic resin is preferable, but a nitrocellulose-modified acrylic resin is advantageous in consideration of the drying time, and in addition to this, a small amount of a fluororesin is added. In some cases, after blending and drying and solidification, the tack-freeness and smoothness of the surface are enhanced. In addition,
The pigment component dispersed in the paint is for confirming the spray finish state.

The manganese battery 10 held between the upper and lower end surfaces of the spray gun 6, that is, the positive and negative electrodes being masked, is opposed to the rotating jig 9, and the paint from the spray gun 6 is rotated by the rotating jig 9. Spray painting is done.

In the case of the acrylic resin, the pump pressure is 4 kg
/ Cm ² , spray time is 30 to 200 msec, and jig rotation speed is 300 to 2000 rpm. The coating composition sprayed on the outer periphery of the unit cell 10 in a heated state has a solvent component immediately volatilized due to the high temperature, and only the resin layer (and the pigment component dispersed therein) 12 is evenly distributed on the outer periphery of the unit cell 10. It forms a film and is dried and solidified.

The unit cell 10 which has completed this coating step immediately passes while rotating in a drying furnace by the near infrared heater 14 and is cooled to room temperature in a state where solvent components are almost completely vaporized, whereby the resin layer is formed. After 12 is completely solidified, the shrink tack label 16 is wound to be a product.

The surface temperature of the zinc can during heating is 1
When the hot air stove and the near-infrared heater were compared and examined for the presence or absence of liquid leakage when the heating time was set to 60 ° C. and the heating time was changed from 30 seconds to 300 seconds, it was found that 6
In the case of the near-infrared heater, the battery started to leak in about 0 seconds, whereas in the case of the near-infrared heater, there was no change in the battery up to 240 seconds and it started to leak in 270 seconds and completely leaked in 300 seconds. Therefore, the upper limit of heating using this near-infrared heater is 240 seconds, but considering the economy and the time until the resin layer is completely solidified,
It may be set to 30 to 120 seconds, preferably about 60 seconds. The surface heating temperature is preferably in the range of 60 to 170 ° C. Further, in order to ensure the dry solidification, the temperature is from room temperature to 80.
It is also effective to carry out the preliminary drying at about 0 ° C. for about 20 to 60 seconds.

FIG. 2 shows a part of the completed manganese dry battery. A shrink tack label 16 is firmly adhered to the outer periphery of the zinc can 10a constituting the outer periphery of the unit cell 10 via the resin layer 12. There is. Shrink tack label 1
In No. 6, a strong adhesion layer 16c is laminated on the back surface of a PVC or PET film 16a via an aluminum vapor deposition layer 16b, and the surface of the film 16a is printed.
In the figure, 10b is a separator arranged in the zinc can 10a, 10c is a positive electrode mixture, and 10d is a carbon rod.

Resin layer 12 obtained through the heating and drying process
Has a high affinity for the zinc can 10a, firmly adheres to form a tough film, and does not form pinholes. On the other hand, since the surface of the resin layer 12 is smooth and has a good affinity for the adhesive layer 16c on the shrink tack label 16 side, the shrink tack label 16 firmly adheres to the resin layer 12 in the label winding step. To do.

As shown in FIG. 3, a predetermined overlapping margin 20 is provided on the winding end of the shrink tack label 16.
Is provided, and a gap d is generated at this step. When the resin layer 12 is not provided, an air passage is formed in the gap d, whereas when the resin layer 12 is provided, the air passage is blocked by the resin layer 12 even if the gap d is formed. Will be done.

By the way, a AAA manganese dry battery provided with a resin layer 12 obtained through a heating and drying process made of the acrylic resin, and a manganese dry battery provided with a resin layer simply coated and naturally dried, A conventional manganese dry battery without a resin layer is compared with the one in the atmosphere, and
When it was over-discharged in oxygen having twice the accelerating property at 1 kΩ, which belongs to the weak current discharge, and the leakage occurrence rate after 90 days was examined, it was 0% for the one dried by heating and 10% for the one only coated. %, 80% for the conventional one, and it was confirmed that there is a marked difference in the leakage resistance performance.

In addition, in the discharge performance of 1 kΩ in oxygen, the rate of occurrence of the discharge abnormality product, which is inferior in performance by 10% or more, is 0% when heated and dried, 15% when coated only, and 75% when conventional. Therefore, a marked difference also occurred in the weak current discharge performance.

If the thickness of the resin layer 12 is about 10 μm, the strength may be weak and liquid leakage may occur due to over-discharge, and if it exceeds 150 μm, the outer appearance may affect the appearance of the product. Or, conversely, the internal volume is forced to decrease, resulting in reduced battery performance. Therefore, it is desirable to set the film thickness within the range of 15 to 100 μm, which is the minimum value of 15 in view of economical efficiency.
Most preferably, it is controlled to be not less than 30 μm.

As a material forming the resin layer 12,
There are epoxy-based and vinyl chloride-based resins in addition to the acrylic resin, but all have poor liquid leakage resistance, and it has been confirmed that abnormalities occur in liquid leakage resistance and weak current discharge performance due to peeling, cracking, or swelling. There is.

Further, even if the present invention is applied to a battery of film exterior type using a printed heat-shrinkable resin tube, the same effect can be obtained, and even if it is applied to a battery of metal jacket exterior type, the same effect can be obtained. Is considered to be obtained.

[0027]

INDUSTRIAL APPLICABILITY As described in detail in the above examples, in the manganese dry battery and the method for manufacturing the same of the present invention, the manganese dry battery is sprayed in a heated state by the hot airless spray method and adhered to the outer periphery of the zinc can. The resin component immediately volatilizes the solvent component. The near-infrared drying means heats only the surface to a high temperature to the extent that it does not affect the contents of the battery, and it is possible to uniformly form a tough resin layer coating on the zinc can surface in a short time,
Since it completely blocks the passage of air, liquid leakage resistance and weak current discharge performance can be improved. Further, the formed resin layer has smoothness and has good affinity with the adhesive layer of the shrink tack label, so that various excellent effects such as the adhesion of the shrink tack label can be enhanced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a manganese dry battery manufacturing process of the present invention.

FIG. 2 is a partially enlarged sectional view of a manganese dry battery obtained by the manufacturing process of the present invention.

FIG. 3 is a partial cross-sectional view of an overlapping portion of a shrink tack label.

[Explanation of symbols]

 1 Hot airless spray device 10 Unit cell 10a Zinc can 12 Resin layer 14 Near infrared heater 16 Shrink tack label

(72) Inventor Koichiro Yokoyama, 218 Genma-cho, Kita-ku, Nagoya-shi, Aichi Tokyo Paint Co., Ltd.

Claims (3)

[Claims] 1. The outer peripheral surface of a zinc can, which constitutes a unit cell,
A manganese dry battery characterized in that it is covered with a shrink tack label through a resin layer. 2. The manganese dry battery according to claim 1, wherein the resin layer is mainly composed of a room temperature dry type acrylic resin or an acrylic modified resin. 3. A manganese dry battery characterized in that a liquid resin is sprayed onto the outer periphery of a zinc can by a hot airless spray method while rotating the zinc can, and then the liquid resin is dried and solidified by a near infrared ray drying means. Method.