| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery separator suitable for an alkaline secondary battery such as a nickel-cadmium battery, a nickel-zinc battery and a nickel-hydrogen battery, excellent in tearing strength, and obtained by subjecting nonwoven fabric to hydrophilic treatment using a surfactant, the nonwoven fabric contributing to reduction in a short circuit incidence rate.SOLUTION: A battery separator comprises nonwoven fabric containing a core-sheath type complex fiber with polypropylene as a composition of a core and polyethylene as a composition of a sheath. A ratio (&bgr;/α) of a sectional area (&bgr;) of polypropylene and a sectional area (α) of polyethylene is 50/50 or more and 90/10 or less. In a DSC curve obtained by differential scanning thermal analysis of the battery separator, a ratio (A/B) of a fusing peak area (A) derived from the polyethylene on a low-melting-point side and a fusing peak area (B) derived from the polypropylene on a high-melting-point side is 0.15 or more and 1.20 or less. |
