JPS61116751A - Button type cell - Google Patents

Abstract

PURPOSE:To prevent creeping up of mercury by arranging a sealing agent, to which a sulphur simple substance or a sulphur compound is added, on one part or the whole, where a gasket comes in contact with a negative pole can. CONSTITUTION:A sealing agent 7, with which a sulphur simple substance or a sulphur compound is mixed, is arranged on the parts where the inside of a negative pole can 1 comes in contact with a gasket: point A - point B, point A - point C or points C - A - B. Thereby, a button pole cell having no creeping up of mercury from the cell inside to the outside of the negative pole can be obtained. Sulphur or the sulphur compound to be mixed with the sealing agent of an asphalt system is desirable to be 0.05-30wt% while being preferably to be treated at 20 deg.C-80 deg.C for 30-180min after the sealing agent is applied.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a button-type battery, and improves the sealing properties of the battery, and improves the sealability of the battery so that it can be removed from the inside of the battery to the negative electrode can, especially the outer surface of the negative electrode can that is plated with gold. This provides a button-type battery that does not contain mercury build-up.

[Conventional technology]

Conventionally, negative electrode cans in which the gasket and the connecting portion are plated with gold have been known in order to improve the leakage resistance of thin and small batteries. For example, the structure of such a battery is disclosed in Japanese Utility Model Publication No. 57-82582. However, gold plating forms an alloy with the mercury in the negative electrode active material, which may not provide sufficient leakage resistance or cause mercury to leak from inside the battery through the negative electrode can to the outside of the negative electrode can. . For this reason, in order to improve leakage resistance, gold plating is applied to the negative electrode can, and bitumen, thermosetting resin, alkene polymer, rubber, soap, etc. are mixed alone or in combination with a sealant. 90 [Problems to be solved by the invention] However, in conventional button-type batteries, although gold plating on the negative electrode can and sealant are effective in suppressing leakage,
The sealant made little contribution to preventing mercury from creeping up. The leakage of mercury from inside the battery has led to the following problems: - Mercury contamination, deterioration, and damage to electronic precision equipment that uses batteries, and human health and Occurrence of environmental pollution.

■Since the mercury content in the negative electrode active material decreases, the hydrogenation voltage of frozen zinc decreases, and frozen zinc and water form a local battery, increasing the self-discharge of the battery.

Therefore, this invention prevents mercury from climbing up in the negative electrode active material, prevents contamination, deterioration, and damage of electronic precision equipment, prevents mercury from contaminating the human body and the environment, and self-releases batteries. The purpose is to suppress the

Ru.

[Elaborate means to solve problems]

In order to solve the above-mentioned problems, this invention prevents mercury from creeping up by disposing a sealing agent containing sulfur alone or a sulfur compound on the part or the entire surface where the gasket and the negative electrode can are in contact. .

[Effect]

The present inventors used a high-temperature humidified atmosphere (60° C., relative humidity 90%, hereinafter referred to as t″HHTEI) as a method for evaluating the effect of sealants on mercury build-up.
After storing the battery inside, observe the outer surface of the negative electrode can with a microscope.
A method was adopted to confirm the presence or absence of mercury crawling.

When button-type batteries are stored in 5HT8 using conventional sealants (bitumen, thermosetting resins, alkene polymers, etc.) that do not contain sulfur or sulfur compounds,
Mercury crawling was observed in 4.0 to 7.0% of all samples in λ days.

In addition, since it has been observed that HHTB storage for 20 days has a negative effect on storage at room temperature for 1 year, it can be assumed that mercury crawling occurs after 1 year of actual use. Conventional sealants are leak-resistant, and when mercury climbs up the gap between the anode can and the gasket, the mercury pushes up the sealant and crawls up to the outside of the anode can. The effect of suppressing mercury climbing is extremely low. On the other hand, in the present invention, in which elemental sulfur or a sulfur compound is mixed in the sealant, mercury and sulfur react as shown in the following formula, and Tlg-4
-8→HJi18 It is presumed that mercury sulfide was generated, which prevented mercury from climbing up.

In particular, it was found that using an asphalt-based sealant mixed with 0.05% to 0.05% by weight of sulfur compounds or a sulfur compound had a remarkable effect on preventing mercury from creeping up. .

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Figure 2 shows an FC battery (SU512EiW) prototyped according to the present invention.
The structure has an outer diameter of 5 mg and a height of 1.2 m. In Fig. 2, the negative electrode can 1 is made of gold (2μ thick)-nickel-5vB-copper aluminum, with the copper surface facing inside the battery.The positive electrode can 5 is metal nickel, and the separator 8 is made of grafted polyethylene film and cellophane. The negative electrode active material 2 is made by adding a predetermined amount of gelling agent to frozen zinc powder (110), and the positive electrode active material 4 is made by adding a conductive material (graphite) to silver oxide powder (110). It was weighed to 85 ml, and subjected to knife-edge pressing at 2+on/cm''.The electrolyte saturated with zinc oxide was an aqueous sodium hydroxide solution weighing 85 ml/cm.

The gasket 6 is manufactured by injection molding of nylon 6,6t.

(Example 1) The sealant was 10 g of blown asphalt and 40 g of toluene.
After adding 0-30% of sulfur to the mA, the mixture was prepared by shaking for several minutes. [Table 1-a]. Similarly,
Adjusted various sealants from mouth to hole. The sealant 7f prepared in this way is shown at the part (point A to point B) where the inner surface of the negative electrode can 1 and the gasket 6 are in contact, as shown in FIG.
Arranged. The sealant 7 was dispensed using a syringe with a capacity of 8 mL, dried at room temperature for 1 hour, and then dried at 60° C. for 1 hour. The next battery manufactured as described above is H)! T
8 After four days of storage, mercury creeping onto the outer surface of the negative electrode can was observed using a microscope. Table 1 shows the number of batteries in which mercury leakage occurred out of 200 batteries.

Table 1 Number of mercury crawling occurrences C Unit: pcs A: Prone asphalt Gilo: Bronze asphalt + epoxy: Freon asphalt + rubber: Bronze asphalt + rubber + epoxy: Epoxy (Example 2) The following seals were used in Example 1 As shown in )K in FIG. 1, agents A to H were arranged from point A where the outer surface of the negative electrode can and the gasket 6 touch to point 0 along the outer surface of the negative electrode can, and as in Example 1, the HHT was 820 days. Table 2 shows the number of nine out of 200 batteries in which Q mercury leakage occurred.

Table 2 Number of mercury creeping occurrences (unit: pieces) (Example 8) As shown in Figure 1 (C) for the nine sealants A to H used in Example 1, points A to B and points A to The battery was placed at point C, and the number of mercury cavities in 200 batteries was examined on HHTB'JJ day in the same manner as in Example 1.

The results are shown in Figure 3.

Table 8 Number of mercury crawling occurrences [unit: 2] fit, fi
As is clear from Table 2 and Table 8, mercury creeping can be suppressed by mixing sulfur with 0.05 sulfur and using a sealing agent. However, if the mixing amount of elemental sulfur exceeds 30% by weight, the amount of elemental sulfur will be too large and the sulfur will not be well dispersed in the sealant, resulting in poor workability.

Next, the batteries manufactured in Example 1 were stored at 60° C. for (a) days, and the self-discharge rates of 200 batteries were determined from the capacities before and after storage. The results are shown in Table 4.

4. Self-discharge rate C units before and after storage for 820 days at HHT (2 units) From Table 4, it can be seen that when 0.05 weight or more of elemental sulfur is mixed with various sealants, the self-discharge of the battery can be considerably reduced.

By mixing elemental sulfur and placing the sealant 7 at points A to B and points A to 0 as shown in Figure 1&), (b), and (c) as shown in O above, A button-type battery without mercury creeping onto the outer surface of the negative electrode can can be obtained.
Ta. The battery we prototyped this time was a thin and small battery called 19R5128W, but this sealant can also be used for batteries of other sizes. Although the asphalt itself contains sulfur compounds, it is thought that because the carbon and sulfur in Pro/Asphalt are strongly chemically bonded, mercury sulfide cannot be produced as in the present invention.

The amount of sulfur or sulfur compound mixed in the asphalt-based sealant is preferably 0.05 to 30% by weight, and after application of the sealant, the sealant is preferably treated at 80C to 80C for an additional to 180 minutes.

〔Effect of the invention〕

As explained above, this invention is effective in preventing mercury from entering the outside of the negative electrode can of a button-type battery by using a sealant containing a sulfur compound to remove sulfur which easily reacts with mercury. There is. This contributes to preventing contamination, deterioration, and damage of electronic precision equipment due to mercury, and prevention of human body and environmental contamination due to leaked NFC mercury. Furthermore, it also has the effect of suppressing self-discharge, and the industrial value of the present invention is great.

[Brief explanation of the drawing]

FIGS. 1) to 1(c) are examples showing the locations where the sealant according to the present invention is placed, and FIG. 2 is a longitudinal cross-sectional view of a button battery. 10. Negative electrode can 60. Gasket 70. More than sealant

Claims (3)

[Claims] (1) A button-type battery, which is an alkaline battery containing mercury in the negative electrode active material, characterized in that elemental sulfur or a sulfur compound is interposed on a part or the entire surface of the contact between the gasket and the negative electrode can. (2) The sulfur compound is an inorganic compound such as sodium sulfide, potassium thiocyanate, or sodium thiosulfate, or an organic coordination compound such as methyl mercaptan, ethyl mercaptan, allyl mercaptans, maleonitrile dithiol, dithioxalic acid, or toluene-3,4-dithiol. The button-type battery according to claim 1, characterized in that: (3) In a sealant made by diluting at least one of bitumen, a thermosetting resin, and an alkene polymer with an organic solvent, elemental sulfur or a sulfur compound has a sulfur content of 0.05 to 30 The button type battery according to claim 1 or 2, characterized in that it contains % by weight.