HEAT-RESISTANT FILM OR SHEET

摘要

PURPOSE:To manufacture a magnetic recording film which is superior in workability and electrical properties, by orienting an article to be obtained by mixing inorganic particles with polyester ketone having the specific secondary transition and fusion points. CONSTITUTION:Polyether-ketone powder is melted and pelletized by adding 0.05wt% kaolin whose average particle diameter is 0.8mum. An unoriented film is made by melting and extruding the pellet. The unoriented film possesses crystallizability whose secondary transition point is more than 120 deg.C and fusion point is more than 280 deg.C. Biaxial orientation of the unoriented film is performed longitudinally and laterally, to which thermal fixing is applied at the temperature of 320 deg.C. As for an obtained biaxially oriented film, thermal shrinkage factor is low, heat resistance is favorable and there is no generation of a flaw and creases.