Patent ID: 7214444

Claim:
A battery separator comprising: a wettable, uniform mat of melt blown fibers, said fibers being thermally bonded to one another, said fibers being made of a thermoplastic material being selected from the group consisting of: polystyrenes, polyvinyl chlorides, polyacrylics, polyacetals, polyamides, polycarbonates, polyesters, polyetherimides, polyimides, polyketones, polyphenylene ethers, polyphenylene sulfides, and polysulfones, said fibers having diameters in the range of 0.1 to 13 microns with 50% of said fibers having diameters less than 0.5 microns, said fibers having lengths greater than 12 millimeters, said mat having a basis weight ranging from 6 to 160 grams per square meter and a thickness of less than 75 microns, and an average pore size ranging from 0.3 to 50 microns.