JPH0888010A - Manganese dry battery - Google Patents

Abstract

PURPOSE: To increase corrosion resistance of a zinc can of a manganese dry battery whose zinc can contains 30ppm or less of lead and no mercury and no cadmium. CONSTITUTION: A fluorine-base compound represented by a formula of F(CF2 )n CH2 CH2 SO3 H (wherein n=1-25, preferably n=2-16) is added to a battery. The added amount of the fluorine-base compound is preferably 0.01-0.5wt.% based on the weight of an electrolyte.

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]

According to the present invention, the following general formula (I) F (CF ₂ ) _n CH ₂ CH ₂ SO ₃ H (I) (wherein n is 1 to 25) is provided in a battery. The above object is achieved by adding a fluorine-based compound represented by (4).

Fluorine compounds represented by the above general formula (I) are those in which n in the formula is 2 to 16 [that is, F (CF ₂ ) ₂ CH ₂ CH ₂ SO ₃ H of n = 2]. To F (CF ₂ ) ₁₆ CH ₂ CH ₂ SO ₃ H of n = 16] are preferred. When n is smaller than the above range,
The effect of improving the corrosion resistance of the zinc can is not sufficiently exhibited, while when n is larger than the above range, the discharge characteristics tend to be deteriorated such that the discharge duration becomes short.

As a method for adding the fluorine-based compound represented by the general formula (I) to the battery, the fluorine-based compound represented by the general formula (I) is dissolved or dispersed in an electrolytic solution and added to the battery. The method, the method of mixing the fluorinated compound represented by the general formula (I) with the paste material to be applied to the separator, applying the paste compound together with the paste material to the separator and adding it to the battery, the general formula (I It is possible to employ a method in which the fluorine-based compound represented by (4) is mixed in the positive electrode mixture and added into the battery.

The mechanism for suppressing corrosion of zinc cans by the fluorine-based compound represented by the general formula (I), that is, the mechanism for improving the corrosion resistance of the zinc cans is not clear at present, but the general formula (I The fluorine-based compound represented by the formula ( ₄ ) is adsorbed on the surface of the zinc can by its sulfonic acid group (SO ₃ H group) and has water repellency.
It is considered that the H ₂ ) _n CH ₂ CH ₂ portion inhibits the affinity between the zinc can and the electrolytic solution and reduces the contact area between the two, thereby suppressing the corrosion of the zinc can. When the fluorine-based compound represented by the general formula (I) is added to the paste material or the positive electrode mixture as described above, the fluorine-based compound represented by the general formula (I) is eluted into the electrolytic solution and then zinc is added. It is considered that the corrosion of the zinc can is suppressed by coming into contact with the can and by the mechanism as described above.

The addition amount of the fluorine-based compound represented by the general formula (I) is 0.01 to 0.5% by weight of the fluorine-based compound represented by the general formula (I) with respect to the electrolytic solution. preferable. When the fluorine compound represented by the general formula (I) is added to the paste material or the positive electrode mixture, the addition amount is converted as the amount with respect to the electrolytic solution. The addition amount of the fluorine compound represented by the general formula (I) is 0.0 with respect to the electrolytic solution.
If the amount is less than 1% by weight, the effect of improving the corrosion resistance of the zinc can is not sufficiently exhibited, and if the addition amount of the fluorine-based compound represented by the general formula (I) is more than 0.5% by weight with respect to the electrolytic solution. The discharge characteristics tend to deteriorate, and the amount of the fluorine-based compound represented by the general formula (I) added is 0.05 to 0.
It is particularly preferably 2% by weight.

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). This is because even if it is possible to obtain a zinc can containing no lead, it is difficult to obtain a zinc can containing no lead when a large amount of zinc can is obtained on an industrial scale. Conventionally used zinc cans contain 0.4 wt% (4000 ppm) of lead, and
Even a lead content of 0 ppm or less is much lower than that of conventional zinc cans, and if the lead content is 30 ppm or less, it is considered that lead will not cause much environmental pollution and human effects. 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 has the same structure as the conventional one except that the fluorine-based compound represented by the general formula (I) is added to the battery and that the zinc can has a small lead content. can do.

[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, Experimental Example 1 shows the results of investigating the corrosion inhibiting effect of the fluorine-based compound represented by the general formula (I) on the zinc can without making it into a practical battery. In Experimental Example 1 as described above, the influence of other constituent materials in the case of being used as a practical battery is avoided, and the general formula (I) is used.
This is for accurately understanding the corrosion inhibiting effect of the fluorine-based compound on the zinc can. In the following experimental examples, examples, etc., the% indicating the concentration is% by weight.

Example 1 In a 32% zinc chloride aqueous solution as an electrolytic solution, n = 2, 4, 6, 8, 12, 16, 2 in the general formula (I) was used.
0.1% of each of the fluorine-based compounds represented by the general formula (I) of 5 was added.

10 ml of 32% zinc chloride aqueous solution containing 0.1% of the fluorine compound represented by the general formula (I)
In addition, as a zinc composition, it does not contain lead but contains 1 magnesium.
Dip AA zinc can containing 0ppm, 15 at 45 ℃
It was stored for a day 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 the fluorine-based compound represented by the general formula (I) is 2 or more, the gas generation amount decreases, and from the viewpoint of improving the corrosion resistance of the zinc can, the general formula ( It is considered that the fluorine-based compound represented by I) preferably has n = 2 or more.

Example 1 As in the case of Experimental Example 1, an AA zinc can containing no lead and containing 10 ppm of magnesium was used, and the fluorine-based compound represented by the general formula (I) was used as the electrolytic solution. Using a 32% zinc chloride aqueous solution added with 0.1%, a zinc chloride-type manganese dry battery having a structure shown in FIG. 1 was prepared, and a 5Ω continuous discharge duration (final voltage 0.9 V) was measured at 20 ° C. 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 the present embodiment does not contain lead as described above but contains 10 ppm of magnesium. The separator 2 is made of kraft paper, and the surface of the separator 2 that contacts the zinc can 1 is coated with a paste material. The separator 2 contacts the zinc can 1 so that the positive electrode mixture 4 And the zinc can 1.

The positive electrode mixture 4 is composed of a mixture of manganese dioxide as a positive electrode active material and acetylene black and mixed with an electrolytic solution. The electrolytic solution of this battery is composed of a 32% zinc chloride aqueous solution. The fluorine compound represented by the formula (I) is added in an amount of 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 containing 32% zinc chloride and 32% zinc chloride aqueous solution containing no additive are used as electrolytes, and the zinc can contains a zinc can containing 10 ppm of magnesium and not containing lead as described above. Using the same, an AA-type manganese dry battery was prepared 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 the fluorine-based compound represented by the general formula (I) becomes 25, continuous discharge duration becomes short and discharge characteristics deteriorate largely, but n = 1.
In the range up to 6, the continuous discharge duration was equal to or close to that in the case of using the conventionally used zinc can, and no significant deterioration in discharge characteristics was observed.

From the results shown in Tables 1 and 2 above, n = 2 for the fluorine-based compound represented by the general formula (I).
Those of ˜16 are considered to be particularly preferable.

Example 2 From the above results, the fluorine-based compound [F (CH ₂ ) ₈ CH ₂ CH ₂ represented by the general formula (I) with n = 8, which has both excellent corrosion inhibiting effect on zinc cans and good discharge characteristics, is obtained. SO
_[3 H] was used, the addition amount was variously changed, and in order to examine the appropriate amount, the same experiment as in Experimental Example 1 and Example 1 was performed, and the results are shown in Table 3.

That is, in a 32% zinc chloride aqueous solution, F (CF ₂ ) ₈ CH ₂ CH _{2 with} n = 8 in the general formula (I) was used.
The amount of SO ₃ H added is 0.005%, 0.01%,
0.05%, 0.1%, 0.2%, 0.5%, 1% were added variously, the amount of gas generated was examined in the same manner as in Experimental Example 1, and the same as in Example 1 above. AA manganese dry battery was prepared for 5 Ω continuous discharge duration (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 gas generation amount is F (CF
₂ ) When the amount of ₈ CH ₂ CH ₂ SO ₃ H added is 0.01% or more, the amount decreases, and particularly when the amount added is 0.05% or more, the amount decreases remarkably. The continuous discharge duration is F
Addition amount of (CF ₂ ) ₈ CH ₂ CH ₂ SO ₃ H is 0.2%
The continuous discharge duration is equal to or close to that of the conventional product in the range up to, and even when the amount of F (CF ₂ ) ₈ CH ₂ CH ₂ SO ₃ H added is 0.5%, the decrease is much larger than that of the conventional product. No continuous discharge duration was shown, but F (C
When the amount of F ₂ ) ₈ CH ₂ CH ₂ SO ₃ H added was 1%, the continuous discharge duration became short. From this result, as the addition amount of the fluorine-based compound represented by the general formula (I),
It is considered that the range of 0.01 to 0.5%, particularly the range of 0.05 to 0.2% is preferable.

[0036]

As described above, according to the present invention, in a manganese dry battery which does not contain mercury and cadmium, a zinc can whose lead content is reduced to 30 ppm or less is used. It was possible to improve the corrosion resistance of the zinc can by adding the indicated fluorine compound.

[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. In a manganese dry battery using a zinc can having a lead content of 30 ppm or less and containing neither mercury nor cadmium, the following general formula (I) F (CF ₂ ) _n CH ₂ CH ₂ SO ₃ H ( I) A manganese dry battery in which a fluorine-based compound represented by the formula (wherein n is 1 to 25) is added to the battery. 2. The manganese dry battery according to claim 1, wherein n in the general formula (I) is 2 to 16. 3. The amount of the fluorine-based compound represented by the general formula (I) added is 0.01 to 0.5 with respect to the electrolytic solution in the battery.
The manganese dry battery according to claim 1, which has a weight percentage. 4. The manganese dry battery according to claim 1, wherein the fluorine-based compound represented by the general formula (I) is added to an electrolytic solution, a paste material applied to a separator, or a positive electrode mixture.