POLYOLEFIN MICROPOROUS MEMBRANE AND METHOD FOR PRODUCING SAME

摘要

The present invention relates to a polyolefin microporous membrane having an air permeability normalized to a thickness of 16 µm of from 100 to 220 sec/100 cc, a pin puncture strength normalized to a thickness of 16 µm of not less than 550 gf, and a crystallization half time t 1/2 of from 10 to 35 minutes when subjected to isothermal crystallization at 117°C; a separator for a battery using the same; and a production method thereof. The polyolefin microporous membrane of the present invention has excellent pin puncture strength and air permeability, suppresses curling, and has an excellent appearance without wrinkles or winding deviation when formed into a roll.