摘要 |
PURPOSE:To obtain a film excellent in transparency, mechanical strength and heat resistance by a method wherein polycyanoaryl ether with specified configuration is employed. CONSTITUTION:Polycyanoaryl ether, which contains 50 mole-percent or more of a repeated base unit represented by the formula I and at the same time the reduced viscosity of which is 0.3-2.0 dl/g in the solution with the concentration of 0.2g/dl by p-chlorophenold as solvent at 60 deg.C, is formed by extrusion within the temperature range of 370-460 deg.C and, after that cooled in order to obtain polycyanoaryl ether film. |