JPS6151383B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grid for lead-acid batteries and a method for manufacturing the same.

Lattice bodies for lead-acid batteries can be made using the casting method, or recently, expanded lattice bodies or lath lattice bodies, in which diamond-shaped meshes are formed by expanding lead or lead alloy plates, which have superior continuity and workability compared to casting methods, have been used. is proposed.

This expanded lattice or lath lattice is lighter than a cast lattice and has a better material yield, but considering that it is made only of lead or lead alloy as before, it is heavier than other secondary batteries. Although it was possible to only slightly reduce the weight of the physically heavy lead-acid battery, it was not possible to significantly improve the energy density per unit weight, nor was it possible to reduce the cost.

The present invention significantly improves the drawbacks of these expanded lattice bodies and lath lattice bodies. Originally, the main functions required of the lattice of a lead-acid battery are to hold the filled active material and to take it out as a conductor for the electromotive force generated electrochemically. For example, a part of the body
The object of the present invention is to provide a lattice body that can be manufactured with good workability without any hindrance to its function as a lattice body by replacing it with a synthetic resin material, and a method for manufacturing the same.

Compared to lead or lead alloys, the use of synthetic resin, which is cheaper in cost, has a smaller density, and is lighter, is easier to work with, especially since the lattice can be manufactured continuously, which not only reduces the cost of the lattice itself. For lead-acid batteries, where the lattice body accounts for most of the weight of the entire battery, we were able to reduce the total weight, increase the energy density per unit weight, and substantially improve the performance.

Examples of the present invention will be described below.

FIG. 1 shows a lattice body for a unit electrode plate in the present invention, in which 1 is a lug piece formed integrally with a surrounding frame 2;
3 is a lattice portion in which a diamond-shaped mesh is formed by expanding processing. FIG. 2 is an enlarged perspective view of the part shown in FIG. 1, and the lattice section 3 has a lead or lead alloy thin plate 4 as the central core material, and synthetic resin layers 5 are integrally arranged on both upper and lower sides of the core material. The lead or lead alloy part is thinner than previous grid bodies.
It is also light in weight, and the synthetic resin layer 5 compensates for the lack of mechanical strength such as rigidity.

This lattice body is formed by, for example, expanding a laminated substrate 6, which is formed by integrating a lead or lead alloy thin plate 4 and a synthetic resin film 5' in a layered manner, as shown in FIGS. 3 and 4, using an expander. Ru.

In this case, it is important that the synthetic resin membrane 5' has adhesive or welding properties that allow it to be integrated with the central thin lead or lead alloy thin plate in a laminated form, and that the synthetic resin membrane 5' has adhesive or welding properties that allow it to be integrated into a laminated form with the lead or lead alloy thin plate in the center, and that the lead or The aim is to follow the lead alloy and elongate it by an equivalent amount.

As a result of studying synthetic resins having both of these characteristics, the present inventors found that a vinyl monomer having ethylene and a polar functional group represented by -COOR (where R is hydrogen, an alkyl group, or an alkali metal) It has been found that a copolymer with

The blending amount of the vinyl monomer having a polar functional group in this ethylene-vinyl monomer copolymer is 3 to 3.
It is preferably 18 mol%, and has appropriate flexibility, high elongation, and excellent acid and alkali resistance. Specific synthetic resins include ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer,
There are ethylene-methyl acrylate copolymers and ethylene-ethyl methacrylate copolymers.

Either of these resin films is integrated into the upper and lower surfaces of a lead or lead alloy thin plate to form a laminate, and then applied to an expander to make cuts and extend the cuts into a diamond shape to expand the area. A strip-shaped expanded body is obtained, and by cutting this to a predetermined size, a lattice body shown in FIG. 1 is obtained. In the figure, the peripheral frame 2 and the lug 1 are not expanded at all during the expanding process, and the lug can be easily formed when cutting.

The lattice formed in this way has less lead or lead alloy parts than before, but by filling it with the paste-like active material, this gets stuck in the mesh, and the thickness of the paste-like active material is spread from the center to the entire thickness. Current can be collected over the entire range.

Therefore, the synthetic resin can reduce the weight of the lattice body and increase the mechanical strength of the lattice body, making it possible to manufacture continuous plates without any problems in terms of plate performance.

The layered integration of the synthetic resin film and the lead or lead alloy thin plate is achieved by using a relatively thick resin sheet 5'' as the core, as shown in Fig. 4, as well as in Fig. It may be one in which lead or a lead alloy is integrated, and even with this structure, similar expanding processing can be performed, and an expanded lattice body can be obtained continuously.

Furthermore, the synthetic resin layer can be formed in the form of a membrane or sheet by laminating it with lead or lead alloy.
It can also be formed by introducing a strip of lead or lead alloy heated above the melting point of the resin of ~300° C. into the resin powder bath and melting and adhering the resin powder to the portion forming the lattice portion. In this case, the same lattice bodies as described above can be continuously produced by cooling and solidifying the resin powder after it has been deposited, and then applying the expander to a processing machine.

In this way, in the present invention, a lead or lead alloy thin plate and a synthetic resin layer having the same extensibility as the thin plate are bonded or thermally welded to a layered integrated substrate.
The synthetic resin layer follows the lead or lead alloy thin plate during the expanding process and is elongated by the same amount as the lead or lead alloy thin plate, so the expanded lattice body can be continuously formed without cutting the resin part. can be manufactured. As described above, the present invention is much superior in terms of workability during the production of lattice bodies compared to conventional casting methods that integrate lead or lead alloys and synthetic resin members. It is possible to provide a lattice body in which a synthetic resin and lead or a lead alloy are integrated with a thickness of 1 mm or less by using a lead-calcium alloy that cannot be produced.

[Brief explanation of the drawing]

Fig. 1 is a front view of a lead-acid battery grid according to the present invention, Fig. 2 is an enlarged perspective view of the part shown in Fig. 1, and Fig. 3 is a perspective view of a substrate in which lead or lead alloy and synthetic resin are integrated in a layered manner. , FIG. 4 is a sectional view thereof, and FIG. 5 is a sectional view showing another example of the substrate. 4...Lead or lead alloy thin plate, 5, 5', 5''...Synthetic resin film.

Claims (1)

[Scope of Claims] 1. A lead-acid battery characterized in that a mesh is formed by expanding processing on a layered integrated substrate in which a lead or lead alloy thin plate and a synthetic resin layer having the same extensibility as the thin plate are adhered. lattice body. 2. A sheet-like substrate made by integrating a lead or lead alloy thin plate and a synthetic resin layer with equivalent stretchability in a layered manner is expanded and stretched while making intermittent cuts to form a rhombus shape. A method for manufacturing a lead-acid battery grid characterized by forming a mesh. 3. The synthetic resin film is made of a copolymer of ethylene and a vinyl monomer having a polar functional group represented by -COOR (where R is hydrogen, an alkyl group, or an alkali metal); The method for producing a lead-acid battery lattice body according to claim 2, wherein the lattice body is arranged between two lead or lead alloy thin plates or on both the front and back sides of the thin plates. 4. A sheet-like substrate is formed by thermally welding thermoplastic synthetic resin powder to both the front and back sides of a lead or lead alloy thin plate to form a resin layer with the same extensibility as the thin plate, and is then expanded and intermittently cut. A method for producing a grid for lead-acid batteries characterized by forming a diamond-shaped mesh by stretching the grid while inserting the grid.