JPS5822860B2 - Alkaline battery manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an alkaline battery in which the sealing is performed using a sealing body in which a ring-shaped sealing packing made of a polymeric material is attached to the periphery of a sealing plate, and in particular, the present invention relates to a method for manufacturing an alkaline battery in which the sealing plate is sealed with a ring-shaped sealing gasket made of a polymeric material attached to the periphery of the sealing plate. This article relates to a method for manufacturing a button-type alkaline battery that also serves as a battery.

Alkaline rechargeable batteries and secondary batteries that use alkaline electrolytes have extremely excellent electrical performance in terms of voltage flatness, etc. However, due to the electrochemical capillary phenomenon unique to alkaline electrolytes, electrolyte problems during battery manufacturing The biggest problem was that liquid leakage occurred due to adhesion of the liquid to the sealing plate and the case, as well as insufficient tightening between the sealing plate and the sealing backing.

As a countermeasure against leakage, conventional methods include applying sealants such as adhesives, liquid backing agents, rust preventive oils, water repellents, electrolyte adsorbents, etc. Synthetic resin-based materials such as resin-based, polyurethane-based, resorcinol-based resins, or butadiene-based, polysulfide-based, olefin/diene-based, organosilicon compound-based, traditional Japanese, urethane-based, olefin-based, and vinyl-based materials Various synthetic rubbers, natural rubbers, etc. have been used, but especially silver oxide batteries1. mercury battery.

10 to 4 for primary and secondary batteries as a power source for birate such as nickel-zinc batteries and button-type alkaline mankan batteries.
Since a highly concentrated potassium hydroxide or sodium hydroxide aqueous solution is injected as an electrolyte so as to be accommodated as much as possible within the battery space volume, the sealant described above cannot provide sufficient sealing. The workability was extremely poor.

The present invention is a combination of polybutene, which is a copolymer of norbutene and isobutyne, with an average molecular weight of 500 to 10,000, which has extremely excellent resistance to aqueous alkaline solutions of high concentration, and has excellent workability, and asphalt. The above-mentioned problems are solved by efficiently interposing the mixture in the sealing part using the method described below.

In the present invention, the average molecular weight of the polybutene is 500 to
The reason why it is limited to 10,000 is that if the average molecular weight is less than 500, the kinematic viscosity is about 200 c, s at a temperature of 100 or less, and since it has extremely high fluidity, there is a possibility that it will leach onto the terminal surface after battery construction. If it exceeds 10,000, the liquid gasket will not be able to fully demonstrate its function, and problems will also arise in terms of compatibility with asphalt.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a bottomed, knot-shaped anode case made of nickel-plated steel plate, stainless steel, titanium alloy, or the like.

Reference numeral 2 denotes an anode mixture which is filled into the inner bottom of the anode case 1 and formed under pressure, and is made of a mixture of silver oxide as an active material and graphite as a conductive material.

3 is a separator disposed on the anode mixture 2, and 4 is an electrolyte holding material disposed on the separator 3 impregnated with an alkaline electrolyte.

Reference numeral 5 denotes a cathode located on the holding material 4, which is made of a gelatinized material obtained by mixing amalgamated zinc powder with a gelling agent such as sodium alginate or carboxymethyl cellulose.

6 is a sealing plate that closes the upper opening of the case 1, and the inner surface 6a is in contact with the cathode 5, and is made of metal that is easily amalgamated.The outer surface 6bII'i is made of nickel, which has high corrosion resistance, and serves as the cathode terminal. Made of stainless steel, gold alloy, titanium alloy, etc.

Reference numeral 7 denotes a sealing packing having a cross-sectional shape attached to the periphery of the sealing plate 6, and is made of a heat-shrinkable material such as hydrated polyamide resin, polyethylene terephthalate, methacrylic, polystyrene, polyacetal, polycarbonate, AS resin, ABS resin. The inner diameter φa is larger than the outer diameter φb of the sealing plate 6, and the outer circumference 6c of the sealing plate 6 and the inner circumference 7 of the sealing packing T are made of polyacrylate trefin, vinyl alcohol copolymer, silicone resin, etc.
A gap is provided between the
A mixture 8 of polybutene of 00 to 10,000 and blown asphalt is interposed.

Next, the construction method of the sealing plate 6 will be explained. The above-mentioned mixture 8 of polybutene and asphalt diluted with a solvent is applied to either the outer circumference 6cs of the sealing plate 6 or the inner circumference 7a of the sealing backing 7. After applying by painting or using a metered liquid injector and scattering the solvent, the sealing plate 6 and the sealing packing 7 are fitted to integrate them.

In this case, the outer diameter φb of the sealing plate 6 is the inner diameter φ of the backing 7.
Since the width of a is also small, the mixture 8 of polybutene and asphalt does not adhere to the inner and outer surfaces of the terminal of the sealing plate 6 when mating, and the mixture 8 of polybutene and asphalt is kept in a necessary and sufficient amount. It is possible to intervene.

Next, the sealing plate 6 and the banking T are fitted together at a temperature close to the heat shrinkage temperature of the material of the banking 7, that is, at a temperature of 80° C. or higher, which is the softening pour point of the mixture 8 of polybutene and asphalt. By heating for a few minutes and performing so-called baking, it is possible to fully demonstrate the strong adhesion with metal, which is a characteristic of asphalt, and it is also possible to maintain the compatibility between asphalt and polybutene over a long period of time. The adhesion between the sealing plate 6 and the sealing backing 7 through the mixture 8 of polybutene and asphalt can also be strengthened by using a heat-shrinkable material for the backing 7.

Furthermore, the mixture 8 of polybutene and asphalt is fluidized during baking, so that the outer peripheral portion 6c of the sealing plate 6
It becomes possible to evenly and uniformly interpose the mixture 8 of polybutene and asphalt.

In manufacturing a button-type alkaline battery, first, a specified amount of zinc hydrate cathode 5 is inserted into the dish-shaped sealing plate 6 of the sealing body with the insulating sealing backing 7 attached to the periphery, while the inner bottom surface of the anode case 1 is is filled with anode mixture 2, formed under pressure, and fixed.

Then, a separator 3 and a holding material 4 are placed on the upper surface of the anode mixture 2.

Next, the sealing body containing the zinc-on-gel cathode 5 and the anode case 1 provided with the anode mixture 2, the separator 3, and the holding material 4 are butted together, and the opening peripheral portion 1a of the case 1 is bent and sealed.

By the way, in a birate battery, the electrolyte is often injected onto the upper surface of the anode mixture 2 as well.

Since the battery is constructed using the method described above, even during mass production, a minimum of 5 to 15 minutes is required from injection to sealing, during which time the alkaline electrolyte creeps onto the surface of the sealing plate 6 and seals the battery. The inner peripheral part 7a of the backing 7 has already been
and the outer peripheral portion 6c of the sealing plate 6.

Naturally, under such conditions, the electrolyte tends to leak out of the battery due to the creep property of the alkaline electrolyte.

That is, when the electrode 5 containing the alkaline electrolyte is placed and filled as described above with the sealing plate 6 fitted to the backing 7, the outer circumference of the sealing plate 6 and the inner circumference of the backing 7 are almost in close contact with each other. However, some of the electrolytic solution injected into the reservoir electrode with a slight gap exists freely on the electrode surface, so it adheres to the sealing plate 6 that is in contact with it and penetrates into the above-mentioned gap by capillary action. I'll come.

If a battery is sealed in such a state, no matter how tightly the battery is sealed, leakage of the alkaline electrolyte cannot be prevented.

In the present invention, a mixture 8 of asphalt and polybutene having an appropriate viscosity is diluted with a compatible agent such as toluene to a viscosity suitable for coating on the inner periphery of the backing 7 or the outer periphery of the sealing plate 6. A heat-shrinkable material is used as the material for the banking 7 after drying, and the designed shape of the backing 1 and the sealing plate 6 is such that the aforementioned mixture 8 of polybutene and asphalt is filled in a large amount without causing any trouble in the subsequent process. After fitting the two together, baking is performed at a temperature where the softening pour point of the mixture 8 of polybutene and asphalt is higher and the material of the backing 7 can be heat-shrinkable. Accordingly, the outer circumference of the second sealing plate 6,
By uniformly interposing the mixture 8 of polybutene and asphalt on the inner circumference of the sealing packing 7, the advantages of asphalt and polybutene as partners can be fully exhibited, and the shrinkage of the backing 7 in the inner diameter direction makes the sealing packing 7 and the sealing plate 6 can be further strengthened.

Next, the effects of the present invention will be described together with comparative examples.

Example 1 (Sealant) Polybutene (average molecular weight 600) 2 parts by weight Blown asphalt (needle penetration ixo ~ 30)
・ 5 parts by weight toluene 15 parts by weight
Part (banking material) Polyamide 6.6 (equilibrium hydrated state) Dimension difference between inner and outer diameters φa-φb = 0.2-0.4 Heat treatment conditions Temperature 120°C ± 5°C Time 15 minutes ± 2 minutes Example 2 Polybutene (average Molecular weight 5ooo) ...... 5 parts by weight Blown asphalt (penetration 10-30) ...
- 5 parts by weight toluene 15 M polyamide 6.6 (equilibrium hydrated state) Difference in inner and outer diameters φa - ti b = 0.2 to 0.
4m heat treatment conditions Temperature: 120°C ± 5°C Time: 15 minutes ± 2 minutes Example 3 Polybutene (average molecular weight 5000) 4 parts by weight Blown asphalt (penetration 10-30)
・5 parts by weight toluene...15 parts by weight tm
Polyamide 6 (equilibrium hydrated state) Dimension difference between inner and outer diameters φa-φb = 0.3 to 0.6 r
Ran heat treatment conditions Temperature 150°C ± 5°C Time 20 minutes ± 5 minutes Comparative example 1 Polybutene (average molecular weight 5 ooo) 5 parts by weight Blown asphalt (penetration 10-30)
・ 5 parts by weight Toluene 15 parts by weight Polyamide 6.6 (0.8% water absorption state) Dimensional difference between inner and outer diameters φa −<1= b=0.2 to 0.4
No heat treatment.

Comparative Example 2 Polybutene (average molecular weight 12,000) 6 parts by weight Blown asphalt (needle penetration ~30)
・ 5 parts by weight toluene 18M 1 part polyamide 6.6 (equilibrium hydrated state) Dimension difference between inner and outer diameters φa-φb = 0.2 to 0.4 degrees Heat treatment Temperature 120℃±5℃ Time 15 minutes±2 Comparative example 3 Styrene-butadiene rubber...7i parts Toluene...20 parts by weight Polyamide 6.6 (0.8 water absorption state) Dimension difference between inner and outer diameters (2ia-φb=0.2~ 0.4 200 pieces of each silver oxide battery JIS product number G13 were constructed using the sealing bodies constructed based on each of the above-mentioned treatments, and the temperature was 35°C.
The table below shows the results of comparing the leakage resistance when stored in an atmosphere with a relative humidity of 80 to 90%.

Note that the numbers in the table indicate the cumulative number of batteries that leaked.

As described above, according to the present invention, leakage of alkaline electrolyte can be extremely effectively prevented.

[Brief explanation of drawings]

FIG. 1 is a sectional side view of a silver oxide battery according to an embodiment of the present invention, FIG. 2 is a sectional view of its sealing plate, and FIG. 3 is a sectional view of its sealing packing. 1... Anode case, 2... Anode mixture,
3... Separator, 4... Electrolyte holding material, 5... Cathode, 6... Sealing plate, 1.
...Sealing packing, 8...Mixture of polybutene and asphalt.

Claims (1)

[Claims] 1 At least one of the contact parts between the sealing plate and the heat-shrinkable sealing backing, which has an inner diameter larger than the outer diameter of the sealing plate and is fitted and attached to the periphery of the sealing plate, is coated with an average molecular weight of 500 to 1.
a step of applying a mixture of oooo polybutene and asphalt, a step of fitting the sealing plate and the sealing backing together through the above steps to form a sealing body, and applying the mixture of polybutene and asphalt to the sealing body. an alkaline battery characterized by comprising the steps of heating and thermally shrinking the mixture in an atmosphere at a high temperature above the softening pour point; and a step of combining the sealing body with a power generation element and a battery case to form a battery. manufacturing method.