ELECTRET FILTER MEDIUM AND AIR FILTER USING THE SAME

PROBLEM TO BE SOLVED: To provide an electret filter medium excellent in the filtering efficiency, pressure loss and charge life, and an air filter using the same. SOLUTION: The electret filter medium comprises a molding including a resin compound containing a polyamine having a repeating structure represented by formula (1) (wherein, R1to R8are each independently a 1-4C alkyl group or hydrogen and n is 0 or 1. When n is 0, R9is a 4-15C alkylene group, which may have a substituent selected from the group consisting of a 1-4C alkyl group and a phenyl group. When n is 1, A is a 1-4C alkyl group or a phenylene group wherein a hydrogen atom on a ring may be substituted and R9and R10are each independently a 1-8C alkylene group and the sum of the number of carbon atoms of the alkylene groups of R9and R10is 2-9). The air filter is equipped with this electret filter medium. COPYRIGHT: (C)2003,JPO