To provide an electret filter medium excellent in the filtering efficiency, pressure loss and charge life, and an air filter using the same.
The electret filter medium comprises a molding including a resin compound containing a polyamine having a repeating structure represented by formula (1) (wherein, R1 to R8 are each independently a 1-4C alkyl group or hydrogen and n is 0 or 1. When n is 0, R9 is 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 R9 and R10 are each independently a 1-8C alkylene group and the sum of the number of carbon atoms of the alkylene groups of R9 and R10 is 2-9). The air filter is equipped with this electret filter medium.
TEZUKA HIROSHI
DOHATA TOYOFUMI
FUJII KEIICHI
SUZUKI YASUYUKI
DAINIPPON INK & CHEMICALS