Filter with chemical resistance, antistatic property and water vapor resistance, as well as a method for its production

摘要

PURPOSE: To provide a filter medium excelling in antistatic property by coating nonwoven fabric or felt made of polyimide fiber with a conducting material and condensation polycyclic polynuclear aromatic resin or the like. ;CONSTITUTION: Nonwoven fabric or felt made of polyimide fiber having a repeated unit represented by the general formula I (where n is an integer larger than 1, X is a tetravalent aromatic group, such as the formula II, and R is a kind of divalent aromatic groups, such as the formula III). The nonwoven fabric or the like is coated with a conducting material, condensation polycyclic polynuclear aromatic resin and/or solvent soluble cold hardening fluororesin and fluoroelastomer dispersed in an organic solvent. After that, the obtained product is left at room temp. or heated. In this way, a filter medium excelling in heat resistance and chemical resistance and less apt to clog and having good antistatic property is obtained.;COPYRIGHT: (C)1995,JPO