| 摘要 |
PROBLEM TO BE SOLVED: To make a separator thin, reduce manufacturing cost, and keep the insulating function of an active material, strength, electrolyte retainability, or the like by using a stacked nonwoven fabric comprising the prescribed dry nonwoven fabric and an extra fine nonwoven fabric, having the prescribed Metsuke, porosity, and thickness. SOLUTION: A nonwoven fabric comprising a sheath-core composite yarn is used in a dry nonwoven fabric used as a reinforcing nonwoven fabric. As the sheath-core composite yarn, a polymer having the melting point higher 20-50 deg.C than that of a polymer for forming the sheath is used in the core. As the fiber material of an extra fine fiber nowoven fabric to be arranged on both surfaces of the reinforcing dry nonwoven fabric, a polymer having the melting point higher 20 deg.C or more than that of a polymer used in the sheath is used. The extra fine fiber nonwoven fabric is stacked on both sides of the dry nonwoven fabric formed by fusing the sheath-core yarns made of the high melting point core polymer and the low melting point sheath polymer, and they are bonded to form a stacked nonwoven fabric. By giving the Metsuke to 15-45g/m<2> , the porosity to 50-80%, and the thickness to 0.05-0.12mm, the quality is kept, and a separator is made thin. |
