| 摘要 |
PROBLEM TO BE SOLVED: To ensure improvement in liquid absorbency, liquid storage properties, proper air ventilation, and improvement in battery capacitance by a split conjugate fiber being splitted, a extremely thin fiber being formed, an inter-fiber crossing, part of the fiber being mutually bonded, a fiber existing in a surface of a non-woven cloth having a functional group, and a rate of the functional group or bond to all carbon element being within a specific range, respectively. SOLUTION: A separator is composed of a short fiber at least comprised of 0 to 50 wt.% of a fiber degree greater than that of an extremely thin fiber formed by a split conjugate fiber of 15 to 75 wt.%, a thermally adhesive fiber of 20 to 60 wt.%, and a split conjugate fiber being splitted in which a polyolefin polymer and a polyolefin polymer including an oxygen element are adjacently disposed alternately on a fiber section. A rate of a functional group or bond to all carbon element is aldehyde group or bond of 10 to 40%, a carbonyl group or bond of 3 to 30%, a carboxinyl group or ester bond of 0 to 15%, and remaining carbon element of 15 to 87%. |
