| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a separator for batteries which is preferably applicable to alkaline secondary batteries such as nickel-cadmium batteries, nickel-zinc batteries and nickel-hydrogen batteries, the separator being obtained by applying a hydrophilic treatment with a surfactant to a nonwoven fabric that has enough self-discharge capacity even in a low sulfonation condition. <P>SOLUTION: A separator for batteries is obtained by sulfonating a polyolefin-based nonwoven fabric containing a core-sheath-type composite fiber having polypropylene as a core component and polyethylene as a sheath component. The ratio of the cross-section area of the polypropylene (β) to the cross-section area of the polyethylene (α), (β/α), is over 60/40 and is 90/10 or less (60/40<β/α≤90/10), and the ratio of a melting peak area (A) derived from the polyethylene on the lower melting point side of a DSC curve obtained by the differential scanning calorimetry of the separator to the melting peak area (B) derived from polypropylene on the higher melting point side, (A/B), is 0.15 or more and 1.20 or less (0.15≤A/B≤1.20). <P>COPYRIGHT: (C)2013,JPO&INPIT |
