The process for producing separator for batteries, the separator for batteries, and alkaline storage batteries using the same

摘要

Production of separator comprising polyolefin resin fibre nonwoven cloth including a sulphonation process giving an even and higher degree of sulphonation on the surface of the nonwoven cloth. The sulphonation process comprises passing the nonwoven cloth through water vapour airflow with nearly saturated moisture, then immediately exposing to airflow containing gaseous sulphur trioxide (SO3). An independent claim is included for the production of the separator as above where the SO3 gas flow contains no more than 1% hydrogen fluoride (HF) and/or no more than 1% carbon dioxide (CO2). A further INDEPENDENT CLAIM is included for the production of the separator where the nonwoven cloth is rinsed after the treatment described above, dried, then roll pressed at 60-90 degreesC to adjust the thickness. An independent claim is also included for an alkaline storage battery comprising a nickel oxide anode, hydrogen absorbing alloy or cadmium cathode, separator as described above and an alkaline electrolyte in a sealed container. In the separator, the ratio of atomic mass of sulphur to atomic mass of carbon is 5-30x10power-3> and the tensile strength is not less than 3 kg/cm3>. The separator is also INDEPENDENTLY CLAIMED.