JPS6038824B2 - dry battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the sealing part of a dry battery such as an alkaline battery or a Leclanche type dry battery, and an object of the present invention is to improve leakage resistance.

In a dry battery structure in which a gasket made of polyethylene or the like that seals the entrance of the battery container has a through hole, and a current collector made of a brass rod or carbon rod is inserted into the through hole, the gasket and the force concentrator support. In order to provide liquid tightness on the surface, the current collector is designed to be larger than the through hole of the gasket, and it is press-fitted into the through hole and expanded, and the resulting repulsive force makes the sides of the current collector elastic. I was holding him.

In dry batteries with this structure, the current collector is press-fitted into the gasket, and internal stress is always generated near the through hole. However, when an alkaline or neutral electrolyte passes through the current collector and comes into contact with the gasket, the gasket Stress cracking tends to occur near the through hole, and electrolyte leaks from the cracked area.

Further, since the surface of the current collector has fine irregularities, the gasket does not come into close contact with the surface of the current collector, and therefore liquid leaks from between the gasket and the current collector. In order to improve the liquid tightness between the gasket and current collector surfaces, it has been proposed to fill the surfaces with a sealant such as asphalt pitch or polyisobutylene, but these sealants do not have sufficient electrolyte resistance. Otherwise, deterioration occurs due to heat history between high and low temperatures, and the elasticity and water repellency of the sealant decreases, making it impossible to obtain stable leakage resistance. The present invention provides a dry battery with a structure in which a gasket having elasticity is provided with a through hole, a current collector of the size of a crop is press-fitted into the through hole, and the current collector is held by the gasket. By filling the gasket and the saddle surface of the current collector with a sealant made of a phosphazene polymer containing a hydrocarbon, a dry battery having a high liquid-tight effect is provided.

Further, as a preferred embodiment of the present invention, in a dry battery having the above structure, at least a part of the side chain contains a fluorinated hydrocarbon,
Furthermore, by filling the contact surface between the gasket and the current collector with a sealant made of a phosphazene polymer that does not have a crosslinked structure, a dry battery having even higher liquid-tightness is provided. Further, as another preferred embodiment of the present invention, in the dry battery having the above structure, by filling the mirror surfaces of the gasket and the current collector with a sealant made of a phosphazene polymer having a repeating unit represented by the following general formula,
The present invention provides a dry battery having even higher liquid-tightness.

General formula However, R in the formula is -C mother (CF2)aCF3, R' is -
CF2 is a monovalent group selected from the group of bH, where 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, and phosphorus pentachloride, tetrachloroethane, and (PNCI) is a crystal obtained by dissolving it in an organic solvent such as rubenzole or nitrobenzole and reacting it with ammonium chloride, and is represented by m (however, m is an integer of 3 or 4). It has a cyclic structure as shown in {1 below. When heated, it easily undergoes ring polymerization to form a polymer compound as shown in (■) below, which has rubber elasticity, but the bond between phosphorus and chlorine in the formula is extremely unstable, and it absorbs moisture in the air. It is unsuitable as a sealant because it absorbs moisture and hydrolyzes. Therefore, in the present invention, for example, CF3 is added to the compound '2}.
0Na, CF3C wide ONa, HC2F4C ratio ONa, H
C3-1 is CH20Na, C6-day FOK, C6-day 4CF3
A phosphazene polymer having a fluorinated hydrocarbon in its side chain, obtained by reacting one or more fluorinated alkoxides such as 0K, is used as a sealing agent.
Examples of their structural formulas are as follows.

Phosphazene polymers, which have fluorinated hydrocarbons in their side chains, have excellent water repellency, so if the sealant described above is applied to the surface of the gasket and current collector, it will not be transmitted through the current collector. The vicinity of the through-hole of the gasket is not wetted by the electrolytic solution, and therefore acceleration of stress cracking of the gasket due to the electrolytic solution is suppressed.

In addition, this sealant has a high elongation rate and good elasticity, so it easily bites into the minute recesses formed on the surface of the current collector, filling the gasket and the rear surface of the current collector in a liquid-tight manner. I can do it. Furthermore, the sealant according to the present invention shows no deterioration even when immersed in a highly concentrated alkaline solution or an electrolytic solution such as a mixed solution of zinc chloride and ammonium chloride for a long period of time, and is chemically extremely stable. Since there is no deterioration in physical properties such as elasticity and water resistance even after repeated thermal history, the above-mentioned excellent leakage prevention effect can be stably obtained over a long period of time. One type of organic oxide such as diacyl peroxide, ketone peroxide, alkyl/g-oxide, dialkyl/g-oxide, peroxycarbonate, or azoisobutyronitrile is added to the phosphazene polymer having a fluorinated hydrocarbon in the side chain. Alternatively, a high molecular weight polymer having a crosslinked structure can be obtained by reacting two or more kinds.

Phosphazene polymers with this crosslinked structure have a high softening point and excellent heat resistance, but because they tend to have lower elasticity and solubility in solvents, they have fluorinated hydrocarbons in their side chains and The use of a phosphine zesopolymer without a crosslinked structure as a sealant provides better adhesion to the current collector and better solubility in solvents.
As the solvent for the phosphanzene polymer according to the present invention, organic liquids such as ketones, tetrahydrofuran, and esters are used. Among the phosphanzene polymers according to the present invention, a polymer having a repeating unit represented by the following general formula is particularly useful because it has extremely high rubber elasticity.

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

Rather than symmetrically adding the same fluorinated hydrocarbon to the side chain of the phosphanzene polymer, 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. An integer that does not exceed 9 is better than one in which the same fluorinated hydrocarbon is symmetrically added to the side chain, and a and b
It has better rubber elasticity than phosphanzene polymers with a polymorphism of more than 10. Next, an embodiment of the present invention will be described with reference to FIG.

An anode mixture 2 made of a mixture of manganese dioxide and phosphorous graphite press-molded into a cylindrical shape is inserted into the inside of an anode can 1 made of a nickel-plated iron can, and a vinylon ray is placed in the hollow part of the anode mixture 2. A cathode agent 4 made of a kneaded mixture of an amalgamated zinc powder, a gel agent made of a polyacrylate, and an alkaline electrolyte is filled through a separator 3 made of a mixed paper. The entrance of the anode can 1 is sealed with an elastic gasket 5 made of polyethylene, polypropylene, polyamide, etc., and a cathode terminal plate 7 to which a current collector 6 made of a yellow steel rod is spot-welded to the center. A resin tube 8 made of heat-shrinkable polyvinyl chloride is then tightened with a carbonized metal outer can 9 to complete the assembly of the alkaline manganese battery.

The lower part of the current collector 6, which is designed to be larger than the through hole 10 provided in the center of the gasket 5, is coated with a liquid obtained by dissolving the phosphanzene polymer according to the present invention in an organic solvent, and dried to form a continuous layer. A coating 11 of sealant is formed.

When this current collector 6 is press-fitted into the through-hole 10' of the gasket 5, the through-hole is pushed wide and a repulsive force is generated, elastically holding the sealant coating 11 and the sides of the current collector 6. do.
The sealing agent coating 11 interposed between the gasket 5 and the current collector 6 is pressed against the surface of the current collector 6 by the repulsive force of the gasket 5, and bites into the fine irregularities on the surface, so that the gasket 5 The surface of the current collector 6 is liquid-tightly filled with the sealant. Fig. 2 shows an example of a Leclanchier type dry battery, in which a mixture of manganese dioxide, acetylene black, and zinc chloride-ammonium chloride electrolyte is mixed into a zinc can 21 through a separator 22 coated with glue. An anode mixture 23 and a current collector 24 made of carbon rods are filled. A liquid prepared by dissolving the phosphanzene polymer according to the present invention in an organic solvent is applied onto the upper part of the current collector 24 and dried to form a continuous sealant coating 25.・A gasket 27 made of synthetic resin such as polyethylene or polypropylene having a through hole 26 designed in this manner is iron-bonded, and the current collector 24 and the opposite side of the gasket 27 are made liquid-tight using a sealant as in the previous embodiment. Filled with. Thereafter, a metal outer can 29 is iron-bonded to the outside of the zinc can 21 via a resin tube 28 made of heat-shrinkable polyvinyl chloride, and the ends of the outer can 29 are curled to complete battery assembly. .

The following table shows the rate of leakage when the alkaline manganese battery of the present invention shown in FIG. 1 and a conventional battery of the same type were stored at 35 oo and a relative humidity of 80%.

Table: Leakage Occurrence Rate As is clear from this table, the dry battery according to the present invention has excellent leakage resistance.

When we disassembled sample batteries that leaked from conventional products, we found cracks near the gasket holes; No occurrence was observed. It has been experimentally confirmed that other sealants belonging to the present invention not listed in the above table also provide similar excellent leakage resistance in the case of Clanssie type dry batteries.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are sectional views of essential parts of an alkaline manganese battery and a Leclanche type dry battery according to the present invention. 5, 27... Gasket, 6, 24... Current collector, 10, 26... Through hole, 11, 25...
・Coating. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. In a dry battery having a structure in which an elastic gasket is provided with a through hole, a current collector with a larger diameter is press-fitted into the through hole, and the current collector is held by the gasket, the side chain 1. A dry cell characterized in that the contact surface between a gasket and a current collector is filled with a sealant made of a phosphazene polymer having a fluorinated hydrocarbon. 2. The dry 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 dry battery according to claim 1, wherein the sealant is a phosphazene polymer having a repeating unit represented by the following general formula. General 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.