| 摘要 |
PURPOSE:To improve the hydrophilic property and electrolyte holding ability by forming a separator of a non-woven fabric containing a core-sheath type composite fiber consisting of a core part made of polypropylene and a sheath part made of a specified ethylene-vinyl alcohol copolymer and containing no binder. CONSTITUTION:A core-sheath type composite fiber (pp-EVOH composite fiber) consisting of a core part made of polypropylene and a sheath part made of an excellently alkali resistant and phydrophilic ethylene.vinyl alcohol copolymer having the ethylene molar ratio of 25-55% is used, and the pp-EVOH composite fiber is contained in an amount of at least 10wt.% or more. A fiber web preferably containing polypropylene fiber as the main constituting fiber which is uniformly unbound and laminated is wetted with water and pressurized by a heat roller to provide a highly strong unwoven fabric separator. Hence, the penetrating property, holding property and durability of electrolyte can be improved. |
