| abstract |
A polyethylene microporous membrane has a Gurley air permeability of 1 to 1,000 sec/100 mL/25 μm, wherein the total length of waviness widths in the width direction of the polyethylene microporous membrane is not more than one-third of the overall width of the microporous membrane. The polyethylene microporous membrane has excellent planarity without compromising any other important physical property such as permeability. |