JP2964802B2 - Glue-type manganese dry battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mercury-free glue type manganese dry battery.

[0002]

2. Description of the Related Art In the prior art, 0.01 to 0.1% by weight of a mercury compound such as mercuric chloride is added to a paste layer in order to suppress self-discharge of a paste type manganese dry battery. The purpose of adding these mercury compounds was to amalgamate the zinc surface and to maintain the hydrogen overpotential at a high level so that the zinc had an anticorrosive effect.

At present, almost no glue type dry battery is produced in Japan, but it accounts for more than half of the dry battery production from a global perspective. The awareness of the problem of global environmental pollution of dry cells in each country has been increasing day by day, and it has been desired that mercury type dry cells be mercury-free. However, at present, no effective means has been found yet.

On the other hand, a number of technical announcements have been made on paper-lined zinc chloride type dry batteries, which are the mainstream of manganese dry batteries in Japan, and the paper-lined manganese dry batteries currently produced in Japan are already mercury-free. Has been established and is being manufactured and sold.

For example, one of these technologies is to add indium, which is a metal having a high hydrogen overvoltage like mercury, in the form of an indium salt in a positive electrode mixture or paste of wrapping paper, and add indium to zinc. A method has been reported in which a hydrogen overvoltage is maintained at a high level on the surface (see, for example,
224265, JP-A-61-78051). It is a well-known fact that a metal with a high hydrogen overvoltage is present on the zinc surface to suppress the corrosion of zinc, but these actions dissolve the indium salt in the electrolytic solution and perform an electron exchange reaction between indium ions and zinc. The purpose is to deposit indium on the zinc surface. However, in the electrolytic solution used in zinc chloride type dry batteries, these indium salts are hardly soluble, and only a small amount is present as ions, and the effective indium deposition on the zinc surface is insufficient. In fact, it has not been possible to improve the storage characteristics of batteries that do not use mercury.

[0006]

When mercury, which is a corrosion inhibitor for zinc, is not added to a paste layer in a paste-type dry battery, the corrosion of zinc is severe. This leads to a problem that the corrosion of the positive electrode mixture starts drying and the discharge performance is significantly deteriorated.

An object of the present invention is to solve the above problems and to provide a mercury-free dry battery excellent in storage characteristics and discharge performance.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is to add indium chloride to a paste layer of a paste-type manganese dry battery.

Further, it has been found that various indium salts are hardly soluble in a zinc chloride type electrolyte, but it is possible to easily dissolve indium chloride in an ammonium chloride type electrolyte.

From this fact, in particular, an indium chloride such as indium chloride, which is soluble in an ammonium chloride type electrolytic solution composed of those having an ammonium chloride concentration of 10% or more in the composition ratio of the electrolytic solution, is added to the paste-like paste layer. In addition, indium is deposited on the zinc surface by an electron exchange reaction between indium ions and zinc, thereby increasing the hydrogen overvoltage on the zinc surface and imparting an anticorrosive effect.

[0011]

The function of indium chloride in the above technical means will be described. The indium chloride added to the paste layer dissolves in the electrolytic solution having an ammonium chloride concentration of 10% or more in the liquid composition and exists as indium ions in the paste layer. Then, the indium ions are quickly precipitated as metal indium by an electron exchange reaction with the metal zinc on the zinc surface, and the hydrogen overvoltage on the zinc surface can be increased. Therefore, it has the effect of suppressing self-discharge and inhibiting corrosion in the same manner as mercury.

[0012]

EXAMPLES First, the fact that indium is dissolved in the electrolyte is shown in Table 1.

[0013]

[Table 1]

The composition of each electrolytic solution composed of zinc chloride, ammonium chloride and water is as shown in Table 1,
0.01% by weight of indium composed of indium chloride was added to each of the electrolyte solutions, stirred and allowed to stand, and the indium ion concentration in the electrolyte solutions was measured. The results are as shown in the table. According to these, it was found that indium was completely dissolved in the electrolyte having an ammonium chloride concentration of 10% or more in the composition of the electrolyte. On the other hand, in an electrolyte having an ammonium chloride concentration of 5% or less, indium contains 0.002%.
% Or less, it is clear that indium is hardly soluble in the zinc chloride type electrolyte. In electrolytes 4 and 5, indium was 0.5
All were soluble even when added by weight%.

Thus, the ammonium chloride concentration is 10%
All indium added when using the above electrolytic solution is present in the glue layer as indium ions, the indium ion concentration can be increased near zinc, and the fact that indium can be deposited more effectively and effectively has been found. Was.

The structure of a typical glue-type dry battery will be described with reference to FIG. FIG. 1 is a half-mounted side view of a typical glue-type dry battery using a metal outer can. Carbon rod 1 and mixture 2 inside
The opening of the zinc can is covered with a resin sealing body 9 in the state of a positive electrode made of, a negative electrode made of a zinc can 3, a glue layer 4 for separating the two electrodes and a bottom paper 5, and the bottom plate 10 and the seal ring 13 are separated. Use, wrap the whole battery in the resin tube 11,
The upper part is closed using a cap 6, a sealing plate 7, and an insulating ring 8, and is entirely covered with a metal outer can 12.

Therefore, in the examples described below, an electrolyte solution having an ammonium chloride concentration of 10% or more which can sufficiently dissolve indium was used to form the paste layer.

Zinc chloride: 10%, ammonium chloride: 2
75% electrolytic solution composed of 0% and 70% water
%, Starch powder 24%, and water-soluble sizing agent 1% were mixed and a predetermined amount of mercuric chloride and indium chloride as shown in Table 2 was added to a paste obtained by stirring to form a sizing layer 4. .

[0019]

[Table 2]

In Table 2, a comparative example in which 0.05% by weight of conventional mercury chloride containing mercuric chloride was added was used as a comparative example.
Those added with 0% by weight are shown in Examples 1 to 7. The battery was disassembled after 20 years of each state and stored at room temperature for one year, and the corrosion state of the zinc can was confirmed. The results shown in Table 3 were obtained.

[0021]

[Table 3]

Table 3 shows that the number of batteries that reached the through-holes due to partial corrosion and the number of batteries per one battery were determined for each of the zinc cans taken out by disassembling 20 batteries constructed according to each embodiment. It represents the average number of holes.

From the results shown in Table 3, those of Examples 3 to 7 in which indium consisting of indium chloride was added in an amount of 0.01% by weight to 1.0% by weight were equal to or more than the comparative examples in which mercuric chloride was added. Storage performance was obtained.

Next, in order to compare the discharge performances in the states shown in Table 2, 20 batteries were constructed, and the results of the battery discharge performance immediately after the construction and one year after storage at room temperature are shown in Table 4.

[0025]

[Table 4]

Table 4 shows that immediately after the configuration and after storage at room temperature for one year, the battery voltage dropped to 0.9 V when 10 batteries were used at a resistance of 40Ω for 4 hours a day. The average discharge time is shown.

As is clear from Table 4, in the state of Examples 3 to 7 in which indium consisting of indium chloride was added in an amount of 0.01% by weight to 1.0% by weight, the conventional mercuric chloride was used. It had the same discharge performance as the comparative example to which it was added.

As described above, according to the present embodiment, indium composed of indium chloride is added in an amount of 0.01 to the weight of the adhesive layer.
If it is added in an amount of at least% by weight, the same storage performance and discharge performance as those of a conventional dry cell to which mercury is added can be obtained.

However, even when the amount of indium composed of indium chloride exceeds 0.5% by weight, the effect is recognized, but if the amount is more than this, the production cost increases.

Although the present embodiment has been described using indium chloride (InCl ₃ ) as the indium chloride, other indium chlorides InCl, In ₂ Cl ₃ , In
Similar effects were obtained when ₄ Cl ₇ and In ₅ Cl ₉ were used.

[0031]

As described above, the paste-type dry battery of the present invention to which indium chloride is added has the same storage performance and discharge performance as the conventional paste-type dry cell to which a mercury compound is added, and can produce a pollution-free battery. It was made.

[Brief description of the drawings]

FIG. 1 is a half-mounted side view of a typical glue-type dry battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carbon rod 2 Mixture 3 Zinc can 4 Adhesive layer 5 Bottom paper 6 Cap 7 Sealing slope 8 Insulating ring 9 Resin sealing body 10 Bottom plate 11 Resin tube 12 Outer can 13 Seal ring

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Ryohei Ashihara 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-61-78051 (JP, A) JP-A-61- 224265 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) H01M 2/14

Claims (1)

(57) [Claims] 1. A paste made of starch, a water-soluble glue, and an electrolytic solution for separating an outer cylindrical zinc can from an inner positive electrode mixture comprising manganese dioxide, carbon powder, and an electrolytic solution. A glue-type manganese dry battery in which indium chloride is added in an isolation layer (hereinafter, referred to as a glue layer),
The ammonium chloride concentration in the electrolyte composition of the layer is 10
% Of the electrolyte solution that is composed of
Indium chloride in indium chloride relative to the weight of the electrolyte
A glue-type manganese dry battery , wherein the glue layer is added to the glue layer in a range of 0.01 to 0.5% by weight .