JPS5851670B2 - Method for manufacturing base for lead-acid battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for manufacturing a base for a lead-acid battery.

In order to reduce the weight of conventional lead-acid batteries, progress has been made to reduce the weight of the substrates that serve as the electrode plates. Among these weight reductions, lightweight substrates made of synthetic resin active material holders and lead or lead alloy current collectors have been developed. It is being widely considered.

Substrates made of synthetic resin have a smooth surface when conventionally molded, resulting in poor adhesion to the active material, which has the disadvantage that the active material tends to fall off from the substrate when using or assembling the battery. are doing.

For this reason, attempts have been made to complicate the lattice shape of the active material holder, which forms part of the base, or to make small scratches on the surface, but these have had disadvantages such as falling over and being impractical. .

In view of the above points, the present invention improves the adhesion between a synthetic resin lattice and an active material.

That is, the present invention allows the synthetic resin lattice body to maintain porosity, thereby forming uniform irregularities on the surface of the lattice body,
Furthermore, by holding powdered sulfuric acid inside the grid,
The purpose is to generate lead sulfate at the interface between the filled paste and the grid to improve the adhesion between the grid and the active material.

In the present invention, a raw material consisting of a polyolefin-based synthetic resin, powdered sulfuric acid, and a plasticizer is heated and kneaded, and then integrally formed with a current collector by injection molding or pressure molding.

The plasticizer is then eluted or extracted to form small pores in the substrate.

The thus obtained substrate has irregularities formed uniformly on its surface, so when the paste is filled, the small pores on the surface of the substrate are filled with the paste.

Furthermore, due to the moisture in the paste, the paste filled in the small pores reacts with the powdered sulfuric acid to produce lead sulfate.

Thereafter, by carrying out usual chemical formation, an electrode plate with excellent adhesion between the substrate and the active material can be obtained.

In the present invention, the strength of the lattice formed and the adhesion to the active material vary depending on the blending ratio of the synthetic resin, powdered sulfuric acid, and plasticizer.

Generally, if the amount of synthetic resin is increased in an attempt to increase the strength, the adhesion will decrease, and if the amount of powdered sulfuric acid is increased in an attempt to improve the adhesion, the lattice will become brittle.

Overall, the optimal combination of the three components is synthetic resin/powdered sulfuric acid/plasticizer=15-30/8-17158-75.

Next, one embodiment of the present invention will be described.

A raw material prepared by mixing 25% by weight of pelletized low-density polyethylene, 15% by weight of powdered sulfuric acid, and 60% by weight of petroleum oil in a mixer is heated and kneaded at 200±10°C.

Thereafter, it was integrally formed with a current collector made of a lead-antimony alloy by injection molding.

Petroleum oil was subjected to ultrasonic extraction in trichlorethylene solution.

After filling the obtained substrate with paste, usual chemical conversion was performed to obtain an electrode plate.

The substrate obtained as described above has the following characteristics compared to conventional substrates:
It is easier to manufacture a substrate that has excellent adhesion to the active material, and unlike conventional substrates, there is no need to make the shape complicated in order to maintain adhesion to the active material.

Furthermore, since the active material is less likely to fall off during use or assembly of the storage battery, the occurrence of short circuits at the bottom of the electrode plate group is also reduced, thereby extending the life of the battery.

Furthermore, since the electrolyte is retained in the small pores inside the substrate, the electrical resistance is lower than that of conventional substrates, and the voltage characteristics of batteries using the substrate of the present invention are improved compared to conventional substrates.

As mentioned above, the present invention can easily produce a substrate with excellent adhesion between the substrate and the active material, and has great industrial value, such as extending its life and improving voltage characteristics. be.

Claims (1)

[Claims] 1 Raw materials consisting of polyolefin resin, powdered sulfuric acid, and plasticizer are heated and kneaded, and then integrated by injection or pressure molding with a current collector made of lead or lead alloy, and then the plasticizer is eluted or extracted to form a base. A method for manufacturing a base for a lead-acid battery, characterized by holding powdered sulfuric acid inside.