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 permeable molded material, nonwoven fabric or felt comprising polyimide fiber having a repeating unit represented by formula (I) is described. The permeable molded material, nonwoven fabric or felt is covered with a condensed polycyclic polynucleus aromatic resin, a melting fluorine resin, a solvent-soluble cold setting fluorine resin or a fluorine elastomer: X, R and n are defined in the specification. A water vapor resistant antistatic filter is also described, which comprises a permeable molded material, nonwoven fabric or felt comprising polyimide fiber having a repeating unit represented by the above-described formula (I). The permeable molded material, nonwoven fabric or felt is covered with an electroconductive material and a condensed polycyclic polynucleus aromatic resin, a solvent-soluble cold setting fluorine resin or a fluorine elastomer. Processes for producing these filters are also described.