| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polyolefin microporous membrane having excellent compressive resistance, injecting properties of an electrolyte, mechanical characteristics, permeability and thermal shrinkage resistance. <P>SOLUTION: The polyolefin microporous membrane is obtained by forming a gelled molded product using a polyethylene having ≤5 mass% content of an ultrahigh-molecular weight polyethylene, stretching the resultant gelled molded product, washing the stretched material, restretching the washed material at 1.1-1.8 times ratio and heat-treating the stretched material. The polyolefin microporous membrane has a structure in which a pore diameter distribution curve determined by a mercury intrusion method exhibits at least two maxima. <P>COPYRIGHT: (C)2008,JPO&INPIT |
