| 摘要 |
PURPOSE:To obtain the method of forming the polycyano allyl ether film, excellent in transparency, resistance to heat and mechanical strength, by a method wherein specified polycyano allyl ether is heated and formed by extrusion under a predetermined temperature, thereafter, is cooled suddenly. CONSTITUTION:The polycyano ally ether, including 50mol% or more of repeating unit, shown by the formula, and having the some average molecular weight of 20,000-90,000, is formed by extrusion under the temperature of 350-450 deg.C and, thereafter, is cooled suddenly to a temperature of 170 deg.C or less. In case the including amount of repeating unit is less than 50mol%, the resistance to heat and the mechanical strength thereof is deteriorated. The some average molecular weight means the some average molecular weight of a solution, obtained by solving the polycyano allyl ether into N-methyl pyrrolidone so that the concentration thereof becomes 70mg/dl, and which is converted into polystylene by high-temperature gel permeation chromatography method. In case the average molecular weight is smaller than 20,000, the strength of the film is reduced but the polymer melting viscosity is increased and the extrusion forming thereof becomes difficult in case the average molecular weight exceeds 90,000. |
