JPH0817408A - Alkaline zinc battery - Google Patents

Abstract

(57) [Abstract] [Purpose] An object is to provide an alkaline zinc battery in which permeation of hydrogen gas to the outside of the battery is suppressed. A resin sealing member (6) is provided on its surface with a coating layer (A) made of a substance impermeable to hydrogen gas, or a sealing material (B) made of a substance impermeable to hydrogen gas is provided at a sealing portion. hand,
The structure of the alkaline zinc battery suppresses leakage of hydrogen gas to the outside of the battery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alkaline zinc battery, and more particularly to a hermetically sealing member used in the alkaline zinc battery.

[0002]

2. Description of the Related Art An alkaline zinc battery, for example, an alkaline dry battery, has a structure provided with a gel electrode mainly containing zinc alloy powder as a negative electrode active material. And because it has excellent continuous discharge and high-load discharge characteristics compared to manganese dry batteries using zinc chloride electrolyte, it is used as a power source for portable recording devices and flashlights of cameras that are subject to a heavy load. It is used as a power source for film-integrated cameras (disposable cameras).

[0003]

However, in an alkaline zinc battery, hydrogen gas is generated due to corrosion of zinc, which is a negative electrode active material, even if the battery is not discharged, and the hydrogen gas generated inside the battery is made of resin. Through the sealing body or through the gap between the sealing case and the sealing body to leak to the outside of the battery.

For example, when an alkaline dry battery as a power source for the film-integrated camera is used together with the film in a hermetically sealed container, hydrogen gas leaking from the alkaline dry battery through the resin sealing body is accumulated in the sealed bag. This hydrogen gas contaminates the film and significantly deteriorates photographic performance.

In view of the above, in order to suppress corrosion of zinc, which is the negative electrode active material, in alkaline zinc batteries, the development of a zinc alloy having excellent corrosion resistance, the development of a corrosion inhibitor, the improvement of the zinc powder refining method, etc. Various efforts have been made, and even in mercury-free alkaline zinc batteries, they have excellent corrosion resistance. However, the corrosion of zinc is not completely suppressed, and zinc is corroded and hydrogen gas is generated during battery storage.

On the other hand, regarding the sealing of the battery, the battery is sealed mainly by using a polyamide-based or polypropylene-based resin sealing body. However, the hydrogen gas generated inside is sealed inside the resin sealing body. Permeate or pass through the gap of the sealing part and escape to the outside of the battery.

As described above, the hydrogen gas leaked to the outside of the battery has a problem of exposing and contaminating the film of the film-integrated camera used with the alkaline dry battery. The present invention has been made in consideration of the above conventional problems, and an object thereof is to provide an alkaline zinc battery that suppresses permeation of hydrogen gas to the outside.

[0008]

In order to solve the above-mentioned problems, the present invention comprises a material having a low hydrogen gas permeability as a coating layer on the front surface of a resin sealing body or the surface which is not in contact with an alkaline electrolyte. Alternatively, an alkaline zinc battery is configured such that a sealing material made of a substance impermeable to hydrogen gas is interposed between the case of the sealing portion and the sealing body.

[0009]

In the alkaline zinc battery having the above-mentioned structure, the hydrogen gas impermeable substance coating layer or the sealing material suppresses the permeation of hydrogen gas, and eliminates the troubles to the equipment and materials due to the presence of hydrogen gas. It will be possible.

[0010]

Embodiments of the present invention will be specifically described below. FIG. 1 shows a cross section of an alkaline dry battery according to an embodiment of the present invention.

In FIG. 1, as constituent elements, 1 is a positive electrode mixture formed by adding graphite as a conductive material to manganese dioxide, and 2 is a zinc alloy in which an alkaline electrolyte solution in which zinc oxide is dissolved and a gelling agent together with no mercury is added. It is a gelled zinc negative electrode in which powder is dispersed. Reference numeral 3 is a separator, 4 is a negative electrode current collector, 5 is a metal positive electrode case, 6 is a resin sealing member, and 7 is a negative electrode bottom plate which forms a negative electrode terminal.

The feature of this embodiment lies in the following configuration. That is, as Example 1, a coating layer made of polyvinyl acetate as a substance impermeable to hydrogen gas is formed on the surface of the polyamide-based nylon resin sealing body 6 that is not in contact with the alkaline electrolyte (A in FIG. 2). Is formed.

Further, as a second embodiment, a polyvinyl acetate sealing material (B in FIG. 2) is provided between the case 5 of the sealing portion and the resin sealing body 6. Further, as Example 3, the resin sealing body 6 having the coating layer A of polyvinyl acetate is used, and the sealing material B of polyvinyl acetate is provided at the sealing portion after sealing.

Here, a resin sealing body 6 having the coating layer A of polyvinyl acetate and a sealing material B applied after sealing and a resin sealing body having no coating layer A were used. The conventional product which was used and which was not provided with the sealing material B at the sealing portion after the sealing was immersed in liquid paraffin at 45 ° C. for 7 days, and the hydrogen gas generation amount to the outside of the battery during that period was 100% compared with the conventional product.
As compared.

The results are shown in Table 1.

[0016]

[Table 1]

As shown in Table 1, in all three examples, the amount of gas generated outside the battery was lower than that of the conventional product.

[0018]

As is apparent from the above description of the embodiments, the alkaline zinc battery according to the present invention can suppress the amount of hydrogen gas generated outside the battery, and the equipment and materials used with the battery are contaminated by the hydrogen gas. Can be prevented.

[Brief description of drawings]

FIG. 1 is a side sectional view of an alkaline dry battery according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the main part of the alkaline dry battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode mixture 2 Gel-like zinc negative electrode 3 Separator 4 Negative electrode collector 5 Positive electrode case 6 Resin sealing body 7 Negative electrode bottom plate A Polyvinyl acetate coating layer B Polyvinyl acetate sealing material

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

Claims (4)

[Claims] 1. An alkaline zinc battery provided with a gelled negative electrode mainly composed of zinc alloy powder as a negative electrode active material and sealed with a resin sealing body, wherein the sealed resin sealing body has at least an outer surface. An alkaline zinc battery provided with a coating layer impermeable to hydrogen gas. 2. The alkaline zinc battery according to claim 1, wherein a polyvinyl acetate resin is used as the coating layer. 3. An alkaline zinc battery provided with a gelled negative electrode containing zinc alloy powder as a negative electrode active material and sealed with a resin sealing body, which is impermeable to hydrogen gas after sealing the case. An alkaline zinc battery in which a sealing material made of a conductive substance is interposed between the case and the sealing body. 4. The alkaline zinc battery according to claim 3, wherein a polyvinyl acetate resin is used as a sealing material of a substance impermeable to hydrogen gas.