| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive separator for low self-discharge type charge storage device exhibiting excellent heat resistance and extrusion performance without sacrifice of mechanical strength. SOLUTION: A material composite principally comprising a polyolefin based resin, inorganic powder and a plasticizer is thermally fused and extrusion molded into a sheet which is then drawn at least in one axial direction and the plasticizer is removed therefrom thus producing a separator for low self- discharge type charge storage device. The separator principally comprises 20-40% by mass of polyolefin based resin having a mean molecular weight of 800,000 or above, and 80-60% by mass of inorganic powder having an oil absorption of 150 cc/100 g or less and has a porosity of 55% or less. COPYRIGHT: (C)2004,JPO
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