JPS6122414B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to alkaline batteries such as silver oxide batteries, alkaline manganese batteries, and air batteries, and particularly relates to improvements in their sealing parts. In this type of battery, a metal layer made of copper or copper alloy is formed on the surface of the cathode current collector to suppress gas generation at the contact between the cathode current collector and the cathode active material. . However, the alkaline electrolyte tends to cause a creeping phenomenon on the surface of the charged metal layer of the cathode, and even if the sealing part is firmly tightened with a gasket, the alkaline electrolyte will leak out through the surface of the cathode current collector. There are drawbacks to doing so. In order to improve this problem, various proposals have been made to change the shape of the cathode current collector or to insert a water repellent or liquid packing between the cathode current collector and the gasket, but these are effective measures to prevent liquid leakage. has not been obtained. An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide an alkaline battery with excellent leakage resistance. To achieve this object, the present invention provides a coating containing benzotriazole or a derivative thereof and a polyoxyethylene fatty amine on at least the surface of the metal layer made of copper or copper alloy in the cathode current collector, which corresponds to the sealing member. is formed, and a liquid packing is interposed between the coating and the sealing member. The benzotriazole used in the present invention has the following structural formula. Further, derivatives of benzotriazole are compounds represented by the following general formula, such as methylbenzotriazole and chlorobenzotriazole. In the formula, R is an alkyl group or a halogen. On the other hand, polyoxyethylene fatty amine is a compound represented by the following general formula, where n is 5 to 40.
It is preferably around 10. 〓〓〓〓
One way to use benzotriazole or its derivative and polyoxyethylene fatty amine is to dissolve both in water or a non-aqueous solvent such as alcohol, and apply the mixed solution to a predetermined location on the cathode current collector. There is a method of forming a film. The concentration of benzotriazole or its derivative in this case is about 0.01-0.5% by weight, preferably about 0.05-0.2
In weight percent, the concentration of polyoxyethylene fatty amine is about 0.01 to 0.2 weight percent, preferably about 0.02 to 0.05 weight percent. In another usage mode, a first coating containing benzotriazole or its derivative is first formed on the surface of the cathode current collector, and then a second coating made of polyoxyethylene fatty amine is formed on the first coating. It is also possible to form a composite film formed with a film. Benzotriazole or its derivatives chemically combine with copper to form a very dense complex film on the surface, and this film remains extremely stable without peeling or deterioration even at high temperatures of around 200°C. It is. In addition, polyoxyethylene fatty amines
It imparts alkali resistance to benzotriazole or its derivatives, helps reinforce the film, and improves its adhesion. Furthermore, the liquid packing fills minute gaps between the coating and the sealing member, and further improves liquid tightness by working together with the coating. If the cathode current collector is treated to generate chemically active copper on the surface before forming the coating containing benzotriazole or its derivative and polyoxyethylene fatty amine, the adhesion of the coating will be extremely high. One such treatment method is to treat the cathode current collector with dilute sulfuric acid or the like to dissolve and remove copper oxide on the surface and expose the active copper surface. Another method is to treat the cathode current collector in an atmosphere containing a reducing gas such as hydrogen or carbon monoxide to reduce the surface of the metal layer of the cathode current collector to copper. 1 and 2 show a first embodiment of the invention. The anode can 1 is sequentially loaded with an anode mixture 2, a separator 3, and an absorbent liquid 4 that absorbs and retains an alkaline electrolyte. A plate-shaped cathode current collector 7 filled with a cathode mixture 6 made of a mixture of alkaline electrolyte and zinc powder is fitted into the opening of the anode can 1 via a gasket 5 made of polyamide resin. , are tightened by the open end of the anode can 1. As shown in FIG. 2, the cathode current collector 7 has a metal layer 9 made of copper on the side of the substrate 8 made of stainless steel in contact with the cathode mixture 6, and a surface made of nickel on the outer surface of the substrate 8. A covering layer 10 is formed respectively. The cathode current collector 7 is subjected to the following treatment before forming a coating 11, which will be described later. That is, first, Henken degreasing and pickling with dilute sulfuric acid were performed.
Oil adhering to the surface and copper oxide (CuO) generated on the surface of the metal layer 9 are removed. Next, chemical polishing is performed in a solution containing sulfuric acid and hydrogen peroxide as main components, and the surface state of the metal layer 9 is smoothed, particularly at the bent portions 12 provided around the cathode current collector 7. Then pickling with dilute sulfuric acid is carried out.
An active copper surface is exposed on the surface of metal layer 9. After these pretreatments are performed, the cathode current collector 7
A coating 11 containing benzotriazole or a derivative thereof and a polyoxyethylene fatty amine is formed on the outer surface of the peripheral bent portion 12 , that is, on the metal layer 9 . On the other hand, asphalt pitch, silicone resin,
A liquid packing 13 made of fluororesin, fatty polyamide, etc. is applied and formed. and anode can 1
Due to the tightening force exerted by the open end of the liquid packing 13, the liquid packing 13 adheres well to the coating 11 having a smooth surface. 3 and 4 show a second embodiment of the invention. The hollow part of the anode can 1 is filled with a cylindrical anode mixture 2, a drop-shaped separator 3 which also serves as a liquid absorber, and a paste cathode mixture 6. The opening of the anode can 1 has a cathode terminal plate 14 with a rod-shaped cathode current collector 7 spot-welded in the center.
and is sealed by a synthetic resin gasket 5,
It is tightened with an exterior can 16 via a resin tube 15. The cathode current collector 7 is made of an alloy of copper and zinc (brass), and at least the surface corresponding to the gasket 5 is first pretreated in the same manner as in the first embodiment, and then a coating 11 is formed. . A liquid patch is applied from the top of this coating 11 to the top surface of the cathode terminal plate 14.
After the coating 13 is applied, the cathode current collector 7 is press-fitted into the central hole of the gasket 5, and the lower surface of the gasket 5 is brought into contact with the upper surface of the cathode terminal plate 14.
Due to the tightening force of the outer can 16 and the internal stress of the gasket 5 itself, the gasket 5 is compressed to the cathode current collector 7 and the cathode terminal plate 14 through the liquid packing 13, respectively. Table 1 below shows the results of alkaline solution creep tests using various samples. This test is 2.6mm in diameter
After chemically polishing and pickling a copper rod, it is immersed in various treatment solutions for 5 minutes, dried, and the surface of the copper rod is coated with about 50 to 100 particles.
Forms a film with a thickness of Å. Then, hold these various samples vertically and cut the parts corresponding to about 1/5 of the total length by 35cm.
Immersed in an aqueous solution of potassium hydroxide at 20% by weight.
After 10 days at ℃ and 60% relative humidity, the height of the alkaline solution climbing from the liquid surface through the copper rod was measured.

[Table] Note 1: Anstex N-100 is manufactured by Toho Chemical Industry.
Trade name of polyoxyethylene fatty amine manufactured by Co., Ltd. Note 2: Pegnol HA-120 is manufactured by Toho Chemical Industry Co., Ltd.
Trade name of polyoxyethylene fatty amine manufactured by Manufacturer. Table 2 below shows the leakage rate between the button type battery according to the present invention assembled according to the first embodiment and a conventional battery of the same type. In the battery according to the present invention, a film containing benzotriazole and Pegnol HA-120 was formed on the cathode current collector, and asphalt pitch was used as the liquid packing. Conventional batteries have a structure in which the cathode current collector is chemically polished and a liquid packing made of asphalt pitch is directly bonded to the cathode current collector. In addition, the leakage rate in the table indicates the number of leakages after 100 sample batteries were stored at 45° C. and 90% relative humidity.

[Table] The following Table 3 shows the leakage rate of the cylindrical alkaline battery according to the present invention assembled according to the second embodiment and a conventional battery of the same type. In the battery according to the present invention, a film containing benzotriazole and Pegnol HA-120 was formed on the cathode current collector, and asphalt pitch was used as the liquid packing. On the other hand, conventional batteries have a structure in which the cathode current collector is chemically polished and liquid packing made of asphalt pitch is directly bonded to the cathode current collector. The leakage rate in the table is the same as in the above test, with 100 sample batteries each heated at 45°C.
Shows the number of leaked pieces after storage under conditions of 90% relative humidity.

[Table] As is clear from Tables 1 to 3 above, by forming a film containing benzotriazole and polyoxyethylene fatty amine, the creeping phenomenon of the alkaline electrolyte can be effectively prevented and leakage resistance can be improved. We can provide excellent alkaline batteries.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view of a button-type alkaline battery according to a first embodiment of the present invention, FIG. 2 is an enlarged sectional view of the main part of FIG. 1, and FIG.
FIG. 4 is a partially sectional front view of the cylindrical alkaline battery according to the embodiment, and FIG. 4 is an enlarged sectional view of the main part of FIG. 3. 5... Gasket, 7... Cathode current collector, 9...
Metal layer, 11... film. 〓〓〓〓

Claims (1)

[Claims] 1. In an alkaline battery using a cathode current collector having a metal layer made of copper or a copper alloy on the surface, benzotriazole or a derivative thereof and a polyoxyethylene fatty amine are added to at least the surface of the metal layer corresponding to the sealing member. What is claimed is: 1. An alkaline battery characterized by forming a coating containing the above-mentioned and having a liquid packing interposed between the coating and the sealing member.