Patent ID: 7390351

Claim:
An electret filter media comprising a fibrous web that comprises fibers comprising: thermoplastic resin, and a compound of the formula Y 2 -A(R 1 ) n —Y 1 (I) where A is benzene, naphthalene or anthracene, Y 1 and Y 2 are each independently R 2 -R 3 , R 2 is an ester linking group or an amide linking group, R 3 is a straight chain alkyl group having from 10 to 22 carbon atoms, R 1 is R 2 -R 3 , where R 2 and R 3 are each independently as defined above, and when A is benzene, n is from 0 to 4, when A is naphthalene, n is from 0 to 6, and when A is anthracene, n is from 0 to 8.