| 摘要 |
PROBLEM TO BE SOLVED: To provide a separator with high mechanical strength and no pinhole, usable for a Ni-Cd battery with high capacity and high output by hydropheric treatment by irradiating corona discharge generated in a high frequency high voltage pulse electric field having specified voltage standing time, pulse duration time, and frequency to a structure made of mainly polyolefin base resin. SOLUTION: Arc discharge capable of high speed treatment in a practical level is conducted in a pulse electric field having a voltage standing time of 20 μs or less, a pulse duration time of 3-1000 μs, a frequency of 1-150 kHz, and preferably having an average field intensity of 1-250 kV/cm, to increase electrolyte retainability. A nonwoven fabric or woven fabric of polyolefin base resin fibers is sulfonated, and then corona irradiation is conducted to the fabric, and thereby, a radical is generated in an αposition of carbon having a sulfone group, and a hydrophilic group is easily bonded. When corona is generated at normal pressure, a solid dielectric having a specific dielectric constant of 10 or higher and specific thickness is preferable to be interposed between one or both flat or rolled electrodes and the structure. |
