| abstract |
Providing a microporous membrane with an excellent balance of temperature characteristics, shrinkage characteristics, permeability and strength, thereby providing a high-performance and safe non-aqueous electrolyte secondary battery separator and non-aqueous electrolyte system 2 Realize the next battery. The difference between the shutdown shrinkage temperature in the TD direction and the maximum shrinkage temperature measured by TMA is 7.2 ° C. or more, the difference between the shutdown shrinkage rate in the TD direction and the maximum shrinkage rate is less than 25%, and the film thickness is 16 μm. The puncture strength at the time is 400 gf or more, and the ratio between the puncture strength and the air resistance when the film thickness is 16 μm is 2.0 to 4.0 (gf / (sec / 100 cc)). Polyolefin microporous membrane. |