FILTER HAVING CHEMICAL RESISTANCE, ANTISTATIC PROPERTY AND WATER VAPOR RESISTANCE, AND PROCESS FOR PRODUCING THE SAME

摘要

A water vapor resistant filter comprising a permeablemolded material, nonwoven fabric or felt comprising polyimidefiber having a repeating unit represented by formula (I) isdescribed. The permeable molded material, nonwoven fabric orfelt is covered with a condensed polycyclic polynucleusaromatic resin, a melting fluorine resin, a solvent-solublecold setting fluorine resin or a fluorine elastomer:(see formula I)X, R and n are defined in the specification. A water vaporresistant antistatic filter is also described, which comprisesa permeable molded material, nonwoven fabric or felt comprisingpolyimide fiber having a repeating unit represented by theabove-described formula (I). The permeable molded material,nonwoven fabric or felt is covered with an electroconductivematerial and a condensed polycyclic polynucleus aromatic resin,a solvent-soluble cold setting fluorine resin or a fluorineelastomer. Processes for producing these filters are alsodescribed.