SULFONATED CONJUGATE FIBER, NONWOVEN FABRIC, CELL SEPARATOR AND PRODUCTION OF CELL SEPARATOR

摘要

PURPOSE:To improve hydrophilic nature of polyolefin fibers by making conjugate fibers comprising an ethylene copolymer of a specific structure containing an introduced sulfone group as a sheath component. CONSTITUTION:Ethylene copolymer containing a unit of the formula -[CH2-CH (COOH)]- is used as a surface layer of conjugate fibers and polyolefin fibers such as polypropylene are used as a core component so that sulfone group can be readily introduced by treatment with concentrated sulfuric acid and the conjugate fibers are provided with hydrophilic nature. The conjugate fibers are made into thermally bonded nonwoven fabric and used as an alkali cell separator, discharge capacity retention ratio can be highly maintained.