JPH07130362A - Manganese battery - Google Patents

Abstract

(57) [Abstract] [Purpose] Uses a cadmium-free zinc alloy that maintains the strength and corrosion resistance of the negative electrode zinc can for manganese dry batteries, and does not impair the workability of the negative electrode zinc can manufacturing (continuous casting) process. Provide a manganese dry battery with less risk of environmental pollution. [Constitution] The negative electrode zinc can was added with 0.01 to 0.5% by weight of lead and 0.1% by weight of aluminum without adding cadmium.
Manganese composed of a negative electrode zinc can containing at least one of 0005 to 0.0025% by weight, 0.0001 to 0.0005% by weight of magnesium, or 0.0005 to 0.0025% by weight of manganese. Dry batteries.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a manganese dry battery,
More specifically, it relates to a manganese dry battery in which a negative electrode zinc can used in the dry battery does not contain cadmium.

[0002]

2. Description of the Related Art Generally, a negative electrode zinc can for a manganese dry battery is a continuous casting method in which a zinc alloy (hereinafter, a molten metal) obtained by adding a specific element to a high-purity zinc at a predetermined concentration and melting it is continuously cast. After being processed into a flat plate shape by a machine, it is punched into a circular or hexagonal pellet having a predetermined size, and these are subjected to impact extrusion molding in a cylindrical case. In FIG. 1, 1 is a melting furnace, 2 is a casting pipe serving as a molten metal supply passage from the melting furnace, 3 is a casting roller, and a groove into which the molten metal flows is formed on the surface of the roller. The molten metal is poured into the grooves, the molten metal is gradually cooled and solidified, and then processed into a predetermined thickness by the rolling roller 4.

Conventionally, a negative electrode zinc can contains 0.03% of cadmium.
1 to 0.1% by weight and 0.01 to 0.5% by weight of lead were added. It is well known that the addition of these elements contributes to the improvement of the corrosion resistance and the mechanical strength of the zinc can, but it has also contributed to the improvement of the workability in the continuous casting process of the zinc alloy. More specifically, the latter is a phenomenon relating to the flowability of the molten metal in the castig pipe 2 that supplies the molten metal to the castig roller 3. The molten metal having good flowability is that the molten metal component is solidified on the inner wall of the castig pipe 2 The blockage phenomenon in 2 is unlikely to occur, and a constant amount of molten metal is constantly and smoothly supplied to the castig roller 3. However, conversely, in the case of a molten metal having a poor flowability, the blockage phenomenon in the castig pipe 2 gradually occurs, and eventually it becomes difficult to supply the amount of the molten metal that fills the groove of the castig roller 3, resulting in a defective thickness of the semi-finished product during rolling. Therefore, it is indispensable to adjust and manage the supply volume of the molten metal,
When the blockage phenomenon in the castig pipe 2 is significant, the continuous casting process must be stopped and the castig pipe 2 must be replaced, which causes a problem that work efficiency is significantly reduced.

[0004]

Although a small amount of cadmium is contained in the negative electrode zinc can of a manganese dry battery, cadmium itself is an element that is toxic to the human body, and the use of a zinc alloy to which cadmium is not added socially Is desired.

However, when cadmium is not added, the corrosion resistance and mechanical strength of the zinc can are reduced, while the phenomenon that the flowability of the molten metal during the continuous casting process of the zinc alloy is markedly deteriorated and workability is greatly impaired. It will cause a situation that it will be.

The present invention solves the above problems.
The present invention provides a manganese dry battery without cadmium addition, which improves workability in a continuous casting process of molten metal while maintaining corrosion resistance and mechanical strength without adding cadmium to a zinc alloy.

[0007]

The present invention provides a continuous casting process of molten metal without impairing the flowability of the molten metal by constructing a zinc alloy containing the following metals in a predetermined concentration without adding cadmium. Since it was found that the workability in aluminum can be improved, aluminum: 0.0005 to 0.
0025% by weight, magnesium: 0.0001 to 0.0
005% by weight and manganese: 0.0005 to 0.00
At least one selected from 25 wt% is added, and a zinc alloy to which lead: 0.01 to 0.5 wt% is further added constitutes a negative electrode zinc can.

[0008]

The function of improving the flowability of the molten metal by the constitution of the present invention is not clear, but it is presumed as follows.

The solidification of the molten metal components on the inner wall of the casting pipe through which the molten metal is caused is due to the non-uniform molten state of the molten metal. That is, it is considered that there is a deviation in the alloy composition of the additive metal to zinc in the molten metal which should be uniform in nature. When these non-mixable and non-uniform portions pass through the casting pipe, they are pushed toward the outside of the flow, that is, the inner wall of the casting pipe and settle. The surface of the inner wall is easily affected by the outside temperature, and when part of it solidifies, these become nuclei and progress as a mass to grow, gradually covering the inner wall of the casting pipe and causing a blocking phenomenon of the casting pipe.

Cadmium added to the zinc alloy had the effect of alleviating the non-uniformity of the molten metal, but in the absence of cadmium, the non-uniformity of the molten metal is remarkable, and the casting pipe through which the molten metal passes is likely to be blocked. .

Therefore, the addition of a trace amount of aluminum, magnesium, and manganese to zinc according to the present invention acts to reduce the non-uniformity of the molten metal, suppresses the solidification of the molten metal components, and prevents the blocking phenomenon of the casting pipe. is there.

[0012]

EXAMPLE An alloy having the composition of the present invention as shown in (Table 1) was prepared by using zinc ingot having a purity of 99.99% by weight or more obtained by electrorefining and adding aluminum, magnesium, manganese and lead. Samples (Examples 1-6) were prepared. For comparison, an alloy sample having a conventional composition in which cadmium and lead are mixed (Comparative Example 1), an alloy sample in which only lead is conventionally added without adding cadmium (Comparative Example 2), and 0.01% of lead is conventionally used. Alloy sample reduced to wt% (Comparative Example 3),
A sample containing only zinc without addition of lead or cadmium (Comparative Example 4) was prepared.

[0013]

[Table 1]

As a result of casting the molten metal of each alloy composition through a casting pipe and supplying it to a rolling mill, the plugging phenomenon was not recognized in Examples 1 to 6 as in the case of the conventional Comparative Example 1, but the Comparative Example. Only with the molten metal without adding a few cadmiums and not according to the present invention, the clogging phenomenon became more and more noticeable, and it became difficult to supply a certain amount of molten metal, and it was necessary to stop the supply and clean the casting pipe.

The blockage phenomenon of the casting pipe tends to be improved with a very small amount of 0.0001% by weight or more of any of aluminum, magnesium and manganese. This effect did not change at 0.0005% by weight or more.

Further, in order to confirm the corrosion resistance and mechanical strength of the negative electrode zinc can, negative electrode zinc cans for R20 manganese dry batteries were prepared from the zinc alloys having the compositions shown in (Table 1), respectively, and converted into ordinary manganese dry batteries. Table 2 shows the results of measuring the amount of corrosion and the Vickus hardness of an aqueous solution containing 30% by weight of zinc chloride and 1% by weight of ammonium chloride. The amount of corrosion was determined by immersing the entire sample filled with the above-mentioned aqueous solution in the negative electrode zinc can in liquid paraffin and storing it at 45 ° C. for 1 week.

[0017]

[Table 2]

As shown in (Table 2), with respect to the amount of corrosion,
The negative electrode zinc cans of Examples 1 to 6 according to the present invention show better corrosion resistance than Comparative Examples 2 and 3 containing no cadmium,
This is equivalent to Comparative Example 1.

Regarding mechanical strength, Examples 1 to 3 and 6 according to the present invention are equivalent to Comparative Example 1, and Examples 4 and 5 are higher than Comparative Examples 2 and 3 although they are less than Comparative Example 1. Indicates the value.

For aluminum and manganese, the flow of the molten metal was improved by adding 0.0001% by weight or more, but it was found that 0.0005% by weight or more was necessary due to the necessity of mechanical strength. .

The amount of lead added is required to be 0.01% by weight or more because the mechanical strength of the negative electrode zinc can is required.
If it is 5% by weight or more, the segregation of lead in the molten metal is remarkable,
It is difficult to manufacture a uniform negative electrode zinc can.

[0022]

[Table 3]

Table 3 shows Examples 1 to 6 according to the present invention.
Using the negative electrode zinc can of Comparative Example 1 and the R20 type dry battery shown in the half-mounting sectional view of FIG.
The dry battery after storage at 5 ° C. for 3 months was continuously discharged under a load of 2Ω, and the time until reaching 0.9 V is shown in (Table 3).
Each value is an average value of 5 dry batteries.

From Table 3, it is shown that the dry battery using the negative electrode zinc can according to the present invention has the same performance as the conventional Comparative Example 1.

Aluminum: 0.0005 to 0.
0025% by weight, magnesium 0.0001 to 0.00
The same effect can be obtained by a combination of two or more of 0.05% by weight and 0.0005 to 0.0025% by weight of manganese. The zinc alloy composition according to the present invention contains 0.01% of cadmium as in the conventional case. Addition of up to 0.1% by weight did not cause any problems.

[0026]

As described above, the structure of the zinc alloy according to the present invention ensures the flowability of the molten metal in the continuous casting process while maintaining corrosion resistance and mechanical strength without containing cadmium in the negative electrode zinc can. Thus, a manganese dry battery containing no cadmium can be provided without impairing the working efficiency.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a zinc alloy continuous casting machine.

FIG. 2 is a half-mounting sectional view of an R20 type manganese dry battery

[Explanation of symbols]

 1 Melting Furnace 2 Casting Pipe 3 Casting Roller 4 Rolling Roller 5 Coiler 6 Positive Electrode Mixture 7 Separator 8 Negative Electrode Zinc Can 9 Bottom Insulating Paper 10 Carbon Rod 11 Positive Cap Integrated Seal Plate 12 Negative Electrode Terminal Plate 13 Exterior Can

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kouhei Nozaki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (6)

[Claims] 1. Aluminum: 0.0005 to 0.00
25% by weight, magnesium: 0.0001 to 0.000
5% by weight and manganese: 0.0005 to 0.0025
A manganese dry battery, characterized in that a negative electrode zinc can containing at least one of wt% is used. 2. Aluminum: 0.0005 to 0.00
25% by weight and magnesium: 0.0001 to 0.0
005% by weight and manganese: 0.0005 to 0.00
A manganese dry battery characterized by using a negative electrode zinc can containing at least one selected from 25% by weight and 0.01 to 0.5% by weight of lead. 3. The manganese dry battery according to claim 1 or 2, wherein the negative electrode zinc can is cadmium-free. 4. A negative electrode zinc can is used which contains no cadmium and contains aluminum: 0.0005 to 0.0025% by weight and lead: 0.01 to 0.05% by weight. And manganese dry battery. 5. The negative electrode zinc can used is a negative electrode zinc can containing no cadmium and containing magnesium: 0.0001 to 0.0005% by weight and lead: 0.01 to 0.05% by weight. And manganese dry battery. 6. A negative electrode zinc can has a cadmium-free manganese content of 0.0005 to 0.0025% by weight and a lead content of:
A manganese dry battery, characterized in that a negative electrode zinc can containing 0.01 to 0.05% by weight is used.