| 摘要 |
PROBLEM TO BE SOLVED: To easily provide a battery separator of a fine hydrophilized polyolefin fiber, thin, dense and excellent in liquid holding. SOLUTION: In this manufacturing method, processes are performed in order of (1), (2) and (3). Then a sheet-like object is hydrophilized. The processes comprise (1) manufacturing a molten spinning fiber composed of (A), (B), (C) and (D): (A) a polyvinyl alcohol with 200 to 500 of polymeirization degree, 90 to 99.99 mol.% of saponification degree, 70 to 99.9 mol.% of mole fraction of the central hydroxyl group of a hydroxyl group three chain to vinyl alcohol unit in terms of triad fraction, and 160 deg.C to 230 deg.C of a melting point, (B) an alkali metal ion, (C) an alkali metal-containing polyvinyl alcohol containing 0.0003 to 1 pts.wt. of (B) in terms of sodium to 100 pts.wt. of (A), and (D) a polyolefin; (2) processing a fiber obtained by the process (1) into a sheet-like object; and (3) extracting and removing the component (C) from the fiber obtained by processes (1), (2) and (3) processively with water. Then a sheet-like material is made hydrophilic. |
