Stable polyether-imide fibers, for use in air filters, are obtained by spinning solution of polymer in mixture of high-boiling polar aprotic solvent, cyclic ether and precipitant

摘要

Production of polyether-imide (PEI) fibers (I) involves (a) forming a solution of PEI in a mixture of (i) high-boiling polar aprotic solvent(s), (ii) cyclic ether(s) and (iii) precipitant(s) and (b) spinning the mixture to form the fibers (I). The polar aprotic solvent (i) has b.pt. more than 130[deg] C. An independent claim is included for PEI fibers (I') (preferably prepared as described for (I)), containing PEI particles are located on and/or between the fibers in an amount of 10-85% based on the overall weight of particles and fibers.