| 摘要 |
Disclosed is a microporous membrane made from a polyolefin wherein the thickness is 1-30 mum, the porosity is 30-60%, the air permeability is 50-250 sec/100cc, the puncture strength is 3.5-20.0 N/20mum, the maximum pore diameter determined by a bubble point method is 0.08-0.20 mum, and the ratio between the maximum pore diameter and the average pore diameter (maximum pore diameter/average pore diameter) is 1.00-1.40. Since this microporous membrane made from a polyolefin is highly safe while maintaining a high permeability, it is useful especially as a separator for recent small- sized, high-capacity nonaqueous electrolyte batteries. |
