JPS6038827B2 - alkaline battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the sealing part of an alkaline battery such as a silver battery, a mercury battery, a nickel cadmium battery, an alkaline manganese battery, etc., and an object of the present invention is to improve the leakage resistance.

A metal sealing plate is attached to the closed end of the battery container via a synthetic resin gasket, the open end of the battery container is squeezed halfway inward, and the gasket is compressed between the battery container and the sealing plate to seal the battery container. In an alkaline battery, the edge of the plate bites into the gasket, and the biting part locally prevents the electrolyte from leaking to the outside along the surface of the sealing plate. To further enhance sexuality,
Alternatively, when the sealing plate is made, the green edge may be rounded, or the sealing end of the battery container may be uneven, making it impossible to obtain high liquid tightness at the biting part.
It has been proposed to make the edge of the sealing plate bite into the gasket using a sealant such as asphalt pitch, fatty polyamide resin, fluororesin with a low degree of polymerization, or polyisobutylene.

However, with the sealants mentioned above, the coating is relatively hard and it is not possible to liquid-tightly fill the minute gap between the edge of the sealing plate and the gasket, or the alkaline electrolyte may cause damage. However, deterioration occurs due to thermal history at high and low temperatures, reducing the ballistic properties and hydrous properties of the sealant, and causing the edge of the sealing plate to dig into the gasket through the sealant film. However, there are various drawbacks such as the sealant film being torn by the edges, and the effects of the sealant are not fully exhibited.

The present invention seals the entrance end of the battery container with a gasket.
In alkaline batteries with a structure in which the plates are iron-bonded, the closed end of the battery container is squeezed inward, and the green edge of the sealing plate bites into the gasket, a sealant made of a phosphazene polymer with fluorinated hydrocarbons in the side chain is used. By making the green edge of the sealing plate bite into the gasket through the gasket, an alkaline battery having a high liquid-tight effect is provided. Further, as a preferred embodiment of the present invention, the edge of the sealing plate is bitten into the gasket through a sealant made of a phosphazene polymer having a fluorinated hydrocarbon in its side chain and not having a crosslinked structure. This provides an alkaline battery with even higher liquid-tightness. In another preferred embodiment, in the alkaline battery having the above structure, the edge of the sealing plate is bitten into the gasket through a sealing agent made of a phosphazene polymer having a repeating unit represented by the following general formula, so that even higher The present invention provides an alkaline battery having a liquid-tight effect.

General formula However, R in the formula is -C ratio (CF2)aCF3,R
' is 1 selected from the group of -C ratio (CF2)bH
It is a valence group, and a and b are integers between 0 and 9.

Phosphazene is a compound in which nitrogen and phosphorus bonds are arranged alternately as a backbone. Phosphazene is a compound made by dissolving phosphorus pentachloride in an organic solvent such as tetrachloroethane, chlorobenzole, or nitrobenzole, and reacting this with ammonium chloride. (PNC So2) m
(where m is an integer of 3 or 4), and when m is 3, it has a cyclic structure as shown in {1} below.
When heated, it easily undergoes ring-opening polymerization to form a polymer compound as shown in (■) below, which has rubber elasticity. However, the bond between phosphorus and chlorine in the formula is extremely unstable, and it absorbs moisture in the air. Because it absorbs moisture and undergoes hydrolysis, it is unsuitable as a sealant for alkaline batteries. Therefore, in the present invention, for example, CF3〇Na, CF3CH2〇Na, H
C2F4CH2〇Na, HC3F6CH20Na, C6
A phosphazene polymer having a fluorinated hydrocarbon in the side chain, which is obtained by reacting one or more fluorinated alkoxides such as FOK and C64CF30K, is used as a sealing agent. An example of the formula is as follows.

Phosphazene polymers with fluorinated hydrocarbons in their side chains have high elongation and good elasticity, so when the green edge of the sealing plate is bitten into the gasket, the film of sealant interposed between them is easily removed. It will not be torn by the green edge, and will fit well into the fine recesses formed on the surface of the sealing board, due to the local bite of the edge edge and the elasticity of the sealant at the biting part. , electrolyte leakage can be effectively prevented.

In addition, the phosphazene polymer of the present invention shows no deterioration at all even when immersed in a highly concentrated alkaline solution for a long period of time, and is chemically extremely stable.Even after repeated thermal history from low to high temperatures, the phosphazene polymer maintains its elasticity and aqueous properties. Because there is no deterioration of physical properties such as
The above-mentioned excellent leakage prevention effect can be stably obtained over a long period of time.
Organic peroxides such as diacyl peroxide, ketone/gu oxide, alkyl/gu oxide, dialkyl/geo-rside, peroxycarbonate, or azoisobutyronitrile are added to the phosphazene polymer having a fluorinated hydrocarbon in the side chain. A high molecular weight polymer having a crosslinked structure can be obtained by reacting one or more of these.

The phosphazene polymer with this crosslinked structure has good moldability, so it can be made into a thin sheet and inserted between the sealing plate and the gasket. Therefore, it is better to use a phosphazene polymer that has a fluorinated hydrocarbon in its side chain and does not have a crosslinked structure as a seal book because it has better adhesion to the sealing plate and gasket, and better resistance to solvents. Good solubility. Organic liquids such as ketones and tetrahydrofuran esters are used as solvents for the phosphazene polymer according to the present invention.Among the phosphazene polymers according to the present invention, in particular, high molecular weight polymers having a repeating unit consisting of the following general formula: can be used for prizes because it has extremely high rubber elasticity.

General formula However, R in the formula is -C Hiro(CF2)aCF3, R' is a monovalent group selected from the group of 1CQ(CF2)bH, and a and b are integers from 0 to 9. .

Rather than symmetrically adding the same fluorinated hydrocarbon to the side chain of the phosphazempo IJ mer, it is better to add different hydrocarbons to the side chain as in the general formula above, and also to add the above a and b to 9 An integer not exceeding , has better rubber elasticity than a phosphazene polymer in which the same fluorinated hydrocarbon is symmetrically added to the side chain, and a phosphazene polymer in which a and b are plasticized once. Next, an embodiment of the present invention will be described with reference to FIG. First silver oxide, second silver oxide, mercury oxide,
A disc-shaped mixture of a positive electrode active material such as manganese dioxide and a conductive agent such as phosphorous graphite or acetylene black is molded under pressure, and a metal base 1 with an inverted L-shaped cross section is integrally attached to the periphery. The anode 2 is inserted into the bottom of a battery container 3, which is made of a nickel-plated iron can and also serves as an anode terminal.

A predetermined amount of alkaline electrolyte is injected into the bottom of the battery container 3 in advance, and when the anode 2 is inserted, the electrolyte permeates into the pongee hole of the anode 2 and wets the entire anode. On the anode 2 are a porous film of polyolefin or an oxidation-resistant blocking film 4 made by graft polymerizing acrylic acid or methacrylic acid to this film, a semipermeable film 5 made of cellophane or polyvinyl alcohol film, and a vinylon fiber film. Liquid-absorbing paper 6 made of non-woven fabric, vinylon fiber and viscose rayon fiber paper, etc., is sequentially selected. A hanging part 8 with a U-shaped or V-shaped cross section is formed around the sealing plate 7, which is made of a cladding made of a steel plate on the inside and a stainless steel plate on the outside, and also serves as a cathode terminal. A continuous sealant film 9 is formed by applying a liquid prepared by dissolving the phosphazene polymer according to the present invention in an organic solvent from the inside to the outside machine edge and drying.

On the outside of the hanging part 8, a gasket 10 made of synthetic resin such as polyethylene, polypropylene, polyamide, etc. and having an L-shaped cross section is iron-bonded, and on the inside of the sealing plate 7, amalgamated zinc powder and polyacrylic A cathode agent 11 made of a mixture of alkaline electrolyte gelled with a gelling agent such as an acid salt or carboxymethyl cellulose is loaded.The sealing plate 7 and gasket 10 are inserted into the battery container 3
The seal □ is iron-fitted to the open end 12 of the battery case 3, and the closed end 12 is squeezed inward to compress the gasket 10 to exert high back pressure. The end edge 13 of the plate 7 is bitten into the gasket by one inch through the sealant coating 9. This shows another embodiment of FIG. 2, in which a crank-shaped step 14 is provided around the periphery of the sealing plate 7, and a sealing agent made of phosphazene polymer is applied from the inner surface to the outer surface of this step 14. A coating 9 is formed, and a gasket 10 having an L-shaped cross section is attached to the outside of the stepped portion 14.

The side wall 15 of the battery container 3 is tapered upward from the bottom of the can, and after the aforementioned sealing plate 7 and gasket 10 are iron-bonded to the closed end 12 of the anode can 3, the side wall 15 is opened.
is squeezed to a vertical position, and then the open □ end 12 is bent inward to complete the tightening. By narrowing the side wall 15 and bending the open end 12 inward in this way, the end edge 13 of the sealing plate 7 bites into the gasket 10 through the sealant coating 9. The following table shows the leakage rate when the alkaline battery of the present invention shown in FIG. 1 and the same type of alkaline battery using a conventional sealant were stored at 35° C. and 80% relative humidity.

Table: Rate of occurrence of liquid leakage The present invention has the above-mentioned configuration, and a stable sealing effect can be exerted for a long period of time in the part where the edge of the sealing plate is bitten into the gasket, and the sealing effect can be maintained over a long period of time. Since the electrolytic solution that is about to leak to the outside is locally blocked by the biting portion, excellent leakage resistance can be obtained as is clear from the table above.

It has been experimentally confirmed that other sealants belonging to the present invention that are not listed in the above table can also provide similarly excellent leakage resistance.

[Brief explanation of drawings]

FIG. 1 is an overall sectional view of an alkaline battery according to an embodiment of the present invention, and FIG. 2 is a sectional view of a main part of an alkaline battery according to another embodiment. 3...Battery container, 7...Sealing plate, 9...
...Coating, 10...Gasket, 12...Open □ end, 1
3...Green edge. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. An alkaline battery having a structure in which a sealing plate is fitted to the open end of a battery container via a gasket, the open end of the battery container is squeezed inward, and the edges of the sealing plate are bitten into the gasket. An alkaline battery characterized in that the edge of the sealing plate is bitten into the gasket via a sealant made of a phosphazene polymer having a fluorinated hydrocarbon in its side chain. 2. The alkaline battery according to claim 1, wherein the sealant is a phosphazene polymer having a fluorinated hydrocarbon in its side chain and not having a crosslinked structure. 3. The alkaline battery according to claim 1, wherein the sealant is a phosphazene polymer having a repeating unit represented by the following general formula. Single carrier formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ However, R in the formula is -CH_2(CF_2)aCF_3
, R' are monovalent groups selected from the group -CH_2(CF_2)bH, and a and b are integers between 0 and 9.