| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polyelectrolyte porous membrane with good durability, having uniformity in an inner structure even after being thinned, and hardly generating micro short-circuiting. <P>SOLUTION: The polyelectrolyte porous membrane has a maximum frequency of whiteness degree of 70% or more and a standard deviation value of the whiteness degree of 0.0025 or less, and is preferred to have a difference between an average value and a minimum value of the whiteness degree of within 0.015, and to contain polyvinylidene fluoride resin or/and a copolymer resin of vinylidene fluoride, with an insolubility rate to an electrolyte solvent of 90 wt.% or more. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
