JPH0888009A - Manganese battery - Google Patents

Abstract

(57) [Summary] [Purpose] Using a zinc can with a lead content of 30 ppm or less,
Improves the corrosion resistance of zinc cans in manganese dry batteries containing no added mercury and cadmium. [Constitution] Polyethylene glycol is added into the battery. As the polyethylene glycol, those represented by the following general formula (I) HO (CH ₂ CH ₂ O) _n H (I) (wherein, n = 4 to 150) are preferable, and the addition amount thereof is It is preferably 0.01 to 0.5% by weight with respect to the electrolytic solution in the battery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manganese dry battery using a zinc can having a low lead content and containing neither mercury nor cadmium. It is about.

[0002]

2. Description of the Related Art In conventional manganese dry batteries, mercury, cadmium, lead, etc. have been added to improve the corrosion resistance of zinc cans.

However, recently, from the viewpoint of preventing environmental pollution, mercury and cadmium cannot be used, and it is necessary to reduce lead. However,
With the reduction of lead, the corrosion resistance of the zinc can decreases, hydrogen gas is generated from the zinc can, and the discharge characteristics of the battery decrease.Therefore, instead of lead, there is a measure to improve the corrosion resistance of the zinc can. I need it.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a manganese dry battery in which the deterioration of corrosion resistance of a zinc can due to the reduction of lead is eliminated and the corrosion resistance of the zinc can is improved.

[0005]

The present invention has achieved the above object by adding polyethylene glycol into a battery.

As the polyethylene glycol, those represented by the following general formula (I) HO (CH ₂ CH ₂ O) _n H (I) (wherein n = 4 to 150) are preferable. When n is less than 4, the effect of improving the corrosion resistance of the zinc can is not sufficiently exhibited, while when n is more than 150, the discharge duration tends to be shortened and the discharge characteristics tend to deteriorate.

The polyethylene glycol may be added to the battery by dissolving or dispersing polyethylene glycol in the electrolyte and adding it into the battery, or by adding polyethylene glycol to the paste material to be applied to the separator. At the same time, a method of applying it to a separator and adding it to the battery, a method of mixing polyethylene glycol into the positive electrode mixture when adding the positive electrode mixture, and adding it to the battery can be adopted.

The mechanism by which polyethylene glycol inhibits corrosion of zinc cans, that is, the mechanism of improving the corrosion resistance of zinc cans, is not always clear at present, but polyethylene glycol adheres to the surface of zinc cans to form a film in the battery. It is believed that this is due to the formation of zinc and suppressing corrosion of the zinc can. When polyethylene glycol is added to the paste material or the positive electrode mixture as described above, the polyethylene glycol is eluted into the electrolytic solution and then contacts the zinc can to form a film on the surface of the zinc can. It is thought to suppress the corrosion of.

Polyethylene glycol is added in an amount of 0.01
It is preferably about 0.5% by weight. In addition, when polyethylene glycol is added to the paste material or the positive electrode mixture,
The added amount is converted to the amount with respect to the electrolytic solution. The amount of polyethylene glycol added is 0.01 with respect to the electrolyte.
If it is less than 0.5% by weight, the effect of improving the corrosion resistance of the zinc can is not sufficiently expressed, and if the amount of polyethylene glycol added is more than 0.5% by weight with respect to the electrolytic solution, the discharge characteristics tend to deteriorate. The amount of polyethylene glycol added is particularly preferably 0.05 to 0.2% by weight of polyethylene glycol with respect to the electrolytic solution.

In the present invention, the lead content of the zinc can is 30%.
Although it is set to be not more than ppm, this is based on the fact that the JIS standard for zinc plates (JIS-H2107 pure zinc metal) is such. That is, on an industrial scale, it is difficult to obtain a zinc plate that does not contain lead at all (a material for zinc cans). Therefore, even if the lead content rate is 30 ppm or less in JIS, lead is permitted on a small scale. This is because even if it is possible to obtain a zinc can that does not contain lead, it is difficult to obtain a zinc can that does not contain lead at all when a large number of zinc cans are obtained on an industrial scale. Previously used zinc cans contain 0.4% lead by weight
(4000ppm) contained, 30p as above
Even if the lead content is pm or less, it is much lower than that of conventional zinc cans, and if the lead content is 30ppm or less, it is considered that lead will not cause much environmental pollution and human impact. To be However, it is preferable that the content of lead is as small as possible, and if possible, it is preferable not to contain lead at all from the viewpoint of preventing environmental pollution and safety.

No mercury or cadmium is added to the manganese dry battery of the present invention. However, the zinc can may contain a metal such as aluminum or magnesium that does not adversely affect the human body or the environment in order to improve the can making property. The manganese dry battery of the present invention can be constructed in the same manner as the conventional one, except that polyethylene glycol is added to the battery and that the zinc can has a small lead content.

[0012]

EXAMPLES Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only those examples. In addition, prior to the Examples, the result of examining the corrosion inhibiting effect of polyethylene glycol on a zinc can without using a practical battery is shown as Experimental Example 1. Such Experimental Example 1 is for accurately grasping the corrosion inhibiting effect of polyethylene glycol on a zinc can while avoiding the influence of other constituent materials in the case of a practical battery. In the following experimental examples, examples, etc., the% indicating the concentration is% by weight.

Experimental Example 1 In a 32% zinc chloride aqueous solution serving as an electrolytic solution, n = 2, 4, 8, 13, 90, 15 in the general formula (I) was used.
0, 300 polyethylene glycol 0.1 each
% Added.

A 10-ml 32% zinc chloride aqueous solution containing 0.1% of polyethylene glycol was dipped into an AA zinc can containing about 200 ppm of aluminum and 10 ppm of magnesium containing no lead as a zinc composition. It was stored at 45 ° C for 15 days, and the amount of gas generated during storage was measured. The results are shown in Table 1. The zinc can was covered with a resin adhesive at its opening end prior to the dipping so that the opening end did not come into contact with the liquid.

For comparison, carbazole was added to 0.1
% Of the 32% zinc chloride aqueous solution to which 32% zinc chloride was added and the 32% zinc chloride aqueous solution to which no additive was added were immersed in the zinc can under the same conditions to measure the gas generation amount. The results are shown in Table 1.

Further, no additives are added 3
Conventionally used lead 0.4% (400% in 2% zinc chloride solution)
A zinc can containing 0 ppm) (containing 5 ppm of magnesium) was immersed under the same conditions as above to measure the amount of gas generated. Table 1 also shows the results.

[0017]

[Table 1]

As shown in Table 1, when n of polyethylene glycol is 4 or more, the amount of gas generated is small, and from the viewpoint of improving the corrosion resistance of the zinc can, polyethylene glycol preferably has n = 4 or more. Conceivable.

Example 1 As in the case of Experimental Example 1, lead was not contained, aluminum was contained at about 200 ppm, and magnesium was contained at 10 ppm.
Using the included AA zinc can and a 32% aqueous zinc chloride solution containing 0.1% polyethylene glycol as an electrolyte, a zinc chloride type manganese dry battery having the structure shown in FIG. 5Ω continuous discharge duration (final voltage is 0.
9 V) was measured. The results are shown in Table 2.

The manganese dry battery shown in FIG. 1 will now be described. In the figure, 1 is a zinc can as a negative electrode, 2 is a separator, 3 is a bottom paper, 4 is a positive electrode mixture, 5 is a top cover paper, and 6 is carbon. Rod, 7 sealing body, 8 sealing material, 9 negative electrode terminal plate, 1
Reference numeral 0 is an insulating ring, 11 is a heat-shrinkable resin tube, 12 is a positive electrode terminal plate, 13 is an insulating ring, and 14 is a metal outer can.

The zinc can 1 is cup-shaped, and the zinc can 1 of this embodiment does not contain lead as described above, but contains about 200 ppm of aluminum and 10 ppm of magnesium. The separator 2 is made of kraft paper,
A paste material is applied to the surface of the separator 2 on the side that contacts the zinc can 1, and the separator 2 is placed between the positive electrode mixture 4 and the zinc can 1 so that the paste material contacts the zinc can 1. It is arranged.

The positive electrode mixture 4 is composed of a mixture of manganese dioxide as a positive electrode active material and acetylene black with an electrolytic solution added and mixed, and the electrolytic solution of this battery is a 32% zinc chloride aqueous solution, in which polyethylene is contained. Glycol is added at 0.1%. The total amount of the electrolytic solution of this battery, that is, the total amount of the electrolytic solution added to the positive electrode mixture and the electrolytic solution injected at the time of assembly is about 2 ml.

The above battery was assembled as follows. First, inside a cup-shaped zinc can 1, a separator 2 and a bottom paper 3 are provided.
After inserting the positive electrode mixture 4 and injecting the electrolytic solution, the upper lid paper 5 is placed on the positive electrode mixture 4, and after prepressing, the carbon rod 6 is passed through the through hole provided in the center of the upper lid paper 5 to form the positive electrode mixture. Agent 4
Inserted inside.

Then, the opening edge of the zinc can 1 is curled inward, the sealing material 8 is applied near the upper end of the carbon rod 6, and the sealing body 7 having a through hole in the center is fitted to the carbon rod 6. Then, the negative electrode terminal plate 9 is disposed on the outer surface of the bottom of the zinc can 1, the insulating ring 10 is disposed on the peripheral portion of the negative electrode terminal plate 9, and then the heat-shrinkable resin tube 11 is disposed on the side surface of the zinc can 1. Then, the heat-shrinkable resin tube 11 is heat-shrinked by heating, and the peripheral portion of the sealing body 7 disposed on the side surface of the zinc can 1 and on the insulating ring 10 disposed on the bottom of the zinc can 1 and on the top of the zinc can 1. Was coated.

Next, the positive electrode terminal plate 12 is attached to the head of the carbon rod 6.
The insulating ring 1 on the outer peripheral edge of the positive electrode terminal plate 12.
After arranging 3, the respective components were axially fastened and packaged with a metal outer can 14 to form a manganese dry battery whose schematic structure is shown in FIG.

For comparison, carbazole was added to 0.1
% 32% zinc chloride aqueous solution added and 32% zinc chloride aqueous solution containing no additive at all are used as electrolytes, the zinc can does not contain lead like the above, aluminum is contained about 200 ppm, magnesium To 10 pp
Using a zinc can containing m, an AA-type manganese dry battery was produced in the same manner as described above.

Furthermore, a 32% zinc chloride aqueous solution containing no additives was used as an electrolytic solution, and a zinc can containing 0.4% of lead used in the past (however, magnesium can also contain 5 ppm). AA-type manganese dry battery was produced in the same manner as above.

For these batteries as well, 5
Ω continuous discharge duration (final voltage 0.9 V) was measured, and the results are shown in Table 2.

[0029]

[Table 2]

As shown in Table 2, when n of polyethylene glycol is 300, the continuous discharge duration becomes short and the deterioration of discharge characteristics becomes large, but in the range up to n = 150, the conventional zinc can is used. It showed a continuous discharge duration equal to or close to that when used, and no significant deterioration in discharge characteristics was observed.

From the results shown in Tables 1 and 2 above, it is considered that polyethylene glycol having n = 4 to 150 is particularly preferable.

Example 2 From the above results, polyethylene glycol [HO (CH ₂ CH ₂ O) ₁₃ H] of n = 13, which has both excellent corrosion inhibiting effect on zinc cans and good discharge characteristics, was used, and the addition amount was varied. In order to examine the appropriate amount, the same experiment as in Experimental Example 1 and Example 1 was conducted, and the results are shown in Table 3.

That is, in a 32% zinc chloride aqueous solution, n =
The amount of polyethylene glycol 13 is 0.00
5%, 0.01%, 0.05%, 0.1%, 0.2%,
Various amounts of 0.5% and 1% were added, the amount of gas generated was examined in the same manner as in Experimental Example 1, and an AA-type manganese dry battery was prepared in the same manner as in Example 1 above. The time (final voltage 0.9 V) was measured. Table 3 shows the results. In addition, Table 3 also shows the results of the case of no addition and the case of using the conventionally used zinc can (conventional product), which were examined in Experimental Example 1 and Example 1.

[0034]

[Table 3]

As shown in Table 3, the amount of gas generated decreases when the amount of polyethylene glycol added is 0.01% or more, and particularly decreases when the amount added is 0.05% or more. In addition, the continuous discharge duration shows a continuous discharge duration equal to or close to the conventional value when the amount of polyethylene glycol added is up to 0.2%. Although the continuous discharge duration was not so much decreased as compared with the above, the continuous discharge duration was shortened when the amount of polyethylene glycol added was 1%. From this result, as the addition amount of polyethylene glycol, 0.01 to 0.5%
It is considered that the range is particularly preferable, and the range of 0.05 to 0.2% is particularly preferable.

[0036]

As described above, according to the present invention, a zinc can whose lead content is reduced to 30 ppm or less is used, and in a manganese dry battery containing neither mercury nor cadmium, polyethylene glycol is added to the inside of the battery. As a result, the corrosion resistance of the zinc can was improved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view schematically showing an example of a manganese dry battery according to the present invention.

[Explanation of symbols]

 1 Zinc can 2 Separator 4 Positive electrode mixture

Claims (4)

[Claims] 1. A manganese dry battery, wherein a zinc can having a lead content of 30 ppm or less is used, and in a manganese dry battery to which mercury and cadmium are not added, polyethylene glycol is added into the battery. 2. The manganese according to claim 1, wherein the polyethylene glycol is represented by the following general formula (I) HO (CH ₂ CH ₂ O) _n H (wherein n is from 4 to 150). Dry batteries. 3. The manganese dry battery according to claim 1, wherein the amount of polyethylene glycol added is 0.01 to 0.5% by weight based on the electrolytic solution in the battery. 4. The manganese dry battery according to claim 1, wherein polyethylene glycol is added to an electrolytic solution, a paste material applied to a separator, or a positive electrode mixture.