JPS5851671B2 - 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 base material that serves as the electrode plate. Among these weight reductions, the lightweight base material consisting of a synthetic resin active material holder and a lead or lead alloy current collector has been developed. It is being widely considered.

Substrates made of synthetic resins that have been molded normally have a smooth surface, which results in poor adhesion to the active material, which has the disadvantage that the active material easily falls off the substrate when assembling or using the storage battery. ing.

- For this reason, attempts have been made to complicate the lattice shape of the active material holder that forms part of the substrate, or to make small scratches on the surface, but these methods have drawbacks such as being impractical. Ta.

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 aims to maintain porosity in a synthetic resin lattice body, thereby forming irregularities uniformly on the surface of the lattice body, thereby improving the adhesion with the active material.

In the present invention, a raw material consisting of a polyolefin synthetic resin, a filler, and a plasticizer is heated and kneaded, and then injection molded or pressure molded with a current collector to integrate it with the current collector.

Thereafter, the plasticizer or plasticizer and filler are eluted or extracted to form small pores in the substrate.

The substrate obtained by this process has uniform irregularities on its surface, so when it is filled with paste, the paste is packed into the small holes on the surface of the substrate, so in the subsequent process the electrode plate is dried and
Even after chemical conversion, the adhesion between the substrate and the active material is good.

In the present invention, the size of the small pores formed and the strength of the lattice body can be changed by changing the particle size of the filler and the proportion of the plasticizer.

In reality, the pore diameter can be within a range of about 10 microns or less, but most of the lead powder particles currently used are around 0.5 to 1 micron, so ideally the pore diameter is about 1 micron. The more it is, the better the adhesion is.

Furthermore, if the amount of filler is increased in an attempt to improve adhesion, the lattice will become brittle, and if the amount of synthetic resin is increased in an attempt to increase strength, the adhesion will decrease. Resin/filler/plasticizer=15~30/8~
17158-75.

An embodiment of the present invention will be described.

Example 1 A raw material prepared by mixing 25% by weight of pelletized low-density polyethylene, 15% by weight of silica powder with an average particle size of 1.5μ, and 60% by weight of plasticizer dioctyl phthalate in a mixer is heated and kneaded at 200±10°C. .

Thereafter, it was integrated with a current collector by injection molding with a current collector made of a lead-antimony alloy, and then the plasticizer was removed by ultrasonic extraction in a trichlorethylene solution to obtain a substrate.

Example 2 A raw material prepared by mixing 25% by weight of pelletized low density polyethylene, 5% by weight of carbon black, 10% by weight of silica powder, and 60% by weight of petroleum oil in a mixer is heated and kneaded at 200±10°C.

This was injection molded with a current collector made of a lead-calcium alloy to integrate it with the current collector, and the plasticizer was extracted with trichlorethylene to obtain a base.

The substrates obtained as in each of the above examples have superior adhesion to the active material compared to conventional substrates, and unlike conventional substrates, there is no need to complicate the shape. has become easier to manufacture.

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, because the electrolyte penetrates into the small pores of the substrate, the electrical resistance is lower than that of conventional substrates, and the batteries using the substrate of the present invention and the low-temperature high-rate discharge performance are better than those using conventional substrates. It has superior voltage characteristics compared to other products.

As mentioned above, the present invention enables the easy production of a substrate with excellent adhesion between the substrate and the active material, and has great industrial value such as extending the life and improving voltage characteristics. It is.

Claims (1)

[Claims] 1 After heating and kneading the raw materials consisting of polyolefin resin, filler and plasticizer, they are integrated by injection or pressure molding with a current collector made of lead or lead alloy, and then the plasticizer or plasticizer and filler are combined. A method for producing a base for a lead-acid battery, characterized in that pores are formed by eluting or extracting.