JPS6331898B2 - - Google Patents

Description

Detailed Description of the Invention The present invention involves inserting a cylindrical separator into the hollow part of a cylindrical anode mixture, such as in an alkaline manganese battery, and inserting a gelled alkaline electrolyte and a cathode active material into the hollow part of the separator. The present invention relates to a separator used in a cylindrical alkaline battery loaded with a cathode material made of a kneaded material of particles.

The structure of this type of alkaline battery is shown in FIG.
Inside the anode can 1, a cylindrical anode mixture 2 made of a mixture of an anode active material such as manganese dioxide and a conductive agent such as phosphorous graphite is inserted. A cathode material 4 is loaded into the hollow part of the anode mixture 2 with a separator 3 interposed therebetween. The opening of the anode can 1 is sealed with a gasket 5 and a cathode terminal plate 6, and is tightened with an outer can 7.

In this alkaline battery, after inserting the anode mixture 2 and the separator 3, an alkaline electrolyte was injected into the hollow part of the separator 3. By injecting the electrolyte, the electrolyte was replenished into the anode mixture 2, and the separator 3 was moistened to improve its compatibility with the cathode material 4 containing the gelled electrolyte.

However, conventional separators have used nonwoven fabrics made of fibers with good liquid absorption properties, such as viscose rayon fibers, polyvinyl alcohol fibers, and pulp fibers. Therefore, when the separator is wetted with the electrolytic solution, the separator swells approximately twice in the thickness direction. This swelling causes disadvantages such as narrowing the hollow part of the separator into which the cathode agent is loaded, making it difficult to insert the cathode agent, and causing the cathode agent to stick to the open end of the separator. Furthermore, due to the swelling of the separator, the fiber spacing increases, and the particulate active material and conduction aid easily permeate through the separator, resulting in deterioration of discharge performance.

In order to suppress the swelling of the separator, a nonwoven fabric with good liquid absorption properties is sandwiched between synthetic resin films in the form of a sandwich, or if the separator is thermoplastic, the separator is spot-fused to partially bond the fibers together. It was proposed to unite. However, in these methods, the electrolytic solution is not held uniformly in the separator, and its compatibility with the cathode material becomes poor, making it impossible to obtain sufficient discharge performance.

An object of the present invention is to eliminate the drawbacks of the prior art described above, to provide a separator that is easy to work with, uniformly suppresses swelling due to electrolyte, and has good compatibility with cathode materials.

In order to achieve this object, the present invention inserts a cylindrical separator into the hollow part of the cylindrical anode mixture, injects a wetting liquid into the separator to moisten the separator, and then fills the hollow part of the separator with a gel-forming liquid. In a separator used in a cylindrical alkaline battery loaded with a cathode agent consisting of a kneaded mixture of an alkaline electrolyte and cathode active material particles, absorbent paper made mainly of liquid-absorbent fibers and carrier paper made mainly of thermoplastic fibers are used. The thermoplastic fibers on the side of the carrier paper that contacts the absorbent paper are heat-shrinked and entwined with the fibers of the absorbent paper to bond the absorbent paper to the carrier paper, and this composite paper is placed inside the absorbent paper. It is characterized by being bent into a cylindrical shape so that the carrier paper is placed on the outside.

Embodiments of the present invention will be described below with reference to the drawings. The separator 3 is composed of a composite paper 10 of a liquid-absorbing paper 8 and a carrier paper 9. The absorbent paper 8 is made of a nonwoven fabric mainly composed of absorbent fibers such as viscose rayon fibers, polyvinyl alcohol fibers, pulp fibers, and cotton linters. The carrier paper 9 is made of a nonwoven fabric mainly composed of thermoplastic fibers such as polyolefin fibers such as polypropylene, polyamide fibers, polyester fibers, and polyacrylonitrile fibers.

The absorbent paper 8 and the carrier paper 9 are made separately and stacked together without drying. At this time, since the fibers of both the absorbent paper 8 and the carrier paper 9 are three-dimensionally intertwined irregularly, the fibers of the absorbent paper 8 and the carrier paper 9 overlap at the overlapped portion of the absorbent paper 8 and the carrier paper 9. The fibers of No. 9 are interlocked with each other. This composite paper 1
0 is dried while being brought into pressure contact with the circumferential surface of the rotating heating roller 11, as shown in FIG. At this time, the carrier paper 9 is placed in contact with the heating roller 11, and the thermoplastic fibers on the surface of the carrier paper 9 in contact with the absorbent paper 8 are shrunk by the heat from the heating roller 11. The absorbent paper 8 and the carrier paper 9 are joined together by being entangled with the fibers of the absorbent paper 8. On the other hand, on the surface of the carrier paper 9 that comes into contact with the heating roller 11, the thermoplastic fibers are shrunk and partially fused to form a flat surface having fine holes. This flat surface approximates the tactile sensation of a microporous film, and the degree of entanglement with the fibers of the absorbent paper 8 and the aperture ratio of the flat surface are determined by the fiber length and fiber density of the carrier paper 9, the absorbent paper It is selected as appropriate depending on the pressure contact force between the carrier paper 8, the carrier paper 9, and the heating roller 11, the feeding speed of the composite paper 10, the temperature of the heating roller 11, and the like. In addition, absorbent paper 8
Since the surface on the side that does not come into contact with the carrier paper 9 is less affected by heat, a fluff-like uneven surface remains.

The composite paper 10 is processed into a cylindrical shape as shown in FIGS. 4 and 5. The composite paper 10 is wound up in advance as a paper roll 12, and this paper roll 12
The composite paper 10 fed out is spirally wound around a non-rotating shaft 13 having a circular cross section with the absorbent paper 8 inside. When the composite paper 10 is wound, the composite paper 10 is wound so that its side edge 14 overlaps the side edge 14 of the adjacent composite paper 10. Composite paper 10
A belt 15 is wound around the starting end of the shaft 13 about one turn, and by pulling this belt 15 in the direction of arrow F, the composite paper 10 is pulled onto the shaft 13.
The material is sequentially wound while rotating along the outer circumferential surface of the material.

As shown in FIG. 5, the outer side end portion 14B is superimposed on the inner side end portion 14A, and a horn 1 for ultrasonic fusion is inserted from above the overlapped portion.
6 is pressed together. The overlapping portions of both side ends 14A, 14B are subjected to ultrasonic heating while being sandwiched between the pressure contact electrode 16 and the shaft 13, and the overlapped portions of the side ends 14A, 14B are
The thermoplastic fibers in 4B are thermally melted, and the upper and lower supporting papers 9 are joined together via the absorbent paper 8.

The thus processed cylindrical body 18 is gradually extracted along the axial direction X of the shaft 13.
As shown in FIG. 2, the cylindrical body 18 has one open end 19 bent inward, and a bottom paper 20 made of a nonwoven fabric mainly composed of thermoplastic fibers and the open end 19.
9 are ultrasonically fused to form the separator 3. As shown in FIG.
It is formed in a spiral shape with approximately one turn or more over the entire length.

A liquid-absorbing paper 8 with a fluff-like uneven surface left on the inner peripheral surface of the separator 3 made in this manner, and a carrier paper 9 with an adjusted aperture ratio are arranged on the outer peripheral surface.

In the embodiment described above, an alkaline electrolyte was used as the wetting liquid for the separator 3, but it is also possible to use water as the wetting liquid instead.

The present invention is constructed as described above, in which the thermoplastic fibers of the carrier paper are entangled with the fibers of the absorbent paper, and this entanglement is made over the entire surface of the absorbent paper. Swelling is suppressed and the electrolyte absorption and retention state is uniform. In addition, since the surface of the liquid-absorbing paper that comes into contact with the cathode agent still has a fluff-like uneven surface, it is compatible with the cathode agent. Furthermore, the support paper serves as a reinforcing agent for the absorbent paper due to the thermal shrinkage of the fibers and the partial fusion of the fibers on the outer surface, and the aperture ratio of the support paper can be lowered. Permeation of the conductive aid can be effectively prevented.
For this reason, the discharge performance of the alkaline battery can be improved, and operations such as bending and cutting can be simplified by integrating the absorbent paper and the carrier paper.

[Brief explanation of drawings]

FIG. 1 is a front view of a cylindrical alkaline battery with the main part cut away, FIGS. 2 to 5 show a separator according to the present invention, and FIG. 2 is a front view of the main part of the separator cut away , Fig. 3 is a schematic diagram showing the bonding state of the absorbent paper and the carrier paper, Fig. 4 is a schematic diagram of the process of making a cylindrical body, and Fig. 5 is an enlarged sectional view taken along the line Y-Y in Fig. 4. . 2... Anode mixture, 3... Separator, 4... Cathode agent, 8... Liquid absorbing paper, 9... Support paper, 10... Composite paper.

Claims (1)

[Claims] 1. Insert a cylindrical separator into the hollow part of the cylindrical anode mixture, inject a wetting liquid into the hollow part of the separator to moisten the separator, and then fill the hollow part of the separator with gelled alkaline electrolyte and cathode active material. In a separator used in a cylindrical alkaline battery loaded with a cathode agent made of a kneaded particle, a liquid-absorbing paper made mainly of liquid-absorbing fibers and a carrier paper mainly made of thermoplastic fibers are layered to form a carrier paper. The thermoplastic fibers on the surface in contact with the absorbent paper are heat-shrinked and entwined with the fibers of the absorbent paper to bond the absorbent paper to the carrier paper, and this composite paper is arranged with the absorbent paper on the inside and the carrier paper on the outside. A method for manufacturing a cylindrical alkaline battery separator, characterized in that it is bent into a cylindrical shape.