| 摘要 |
A method for producing a battery separator is disclosed. The method comprises applying a coating of an ethylenically unsaturated monomer to the fibers of a non-woven sheet and polymerizing the monomer in situ on the fiber surfaces. The non-woven sheet is from 50 to 3000 microns thick, and is composed of polyolefin fibers having an average fiber diameter from 0.5 to 5 microns and a surface area from 0.2 to 30 square meters per gram. The ethylenically unsaturated monomer is polymerizable to a thermoplastic polymer which is hydrophilic as a consequence of containing COOH, OH, sulfonyl, sulfonic acid or carbonyl groups, or a monomer which has one of the following formulas: (I), (II), (III), (IV). In the foregoing formulas, R is an aliphatic or aromatic hydrocarbon group having from 2 to 8 carbon atoms, R4 is hydrogen or methyl, n is an integer from 2 to 15, and X<+> is a cation selected from the group consisting of hydrogen, NH4, alkaly metal cations, alkaline earth cations, cations of the transition metal Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn, and ammonium cations of the formula, R5R6R7R8N<+>, where each of R5 R6, R7 and R8 is hydrogen, alkyl, alkenyl, cycloalkyl or cycloaklkenylene, and not more than one is a bivalent group bonded to N<+> and by removing two hydrogens from an alkane, an alkene, a cycloalkane or a cycloalkene; the total number of carbons in R5 R6, R7 and R8 does not exceed 21. |
