SHEATH-CORE TYPE FIBER, FIBER SHEET USING THE FIBER AND SEPARATOR FOR BATTERY USING THE FIBER

摘要

PROBLEM TO BE SOLVED: To obtain a sheath-core type fiber improvable so as to have an excellent inhibitory action on self discharge of buttery, a sheath-core type fiber containing an introduced sulfonic group, a fiber sheet using the sheath-core type fiber and to provide a separator for battery composed of the fiber sheet using the sheath-core fiber. SOLUTION: This sheath-core type fiber comprises a core component in which a methacrylic acid-ethylene copolymer and a polymer having 100-1,000 poise viscosity exist together and a core component composed of a polymer having 100-2,000 poise viscosity. This fiber sheet uses the sheath-core fiber in which the sheath component of the sheath-core fiber is contained in a fused and/or fibrillated state. This separator for battery comprises the fiber sheet in which the sheath component of the sheath-core type fiber to which a sulfonic group is introduced is contained in a fused and/or fibrillated state.