Meta-xylylene diamine/aliphatic dicarboxylic acid polyamide film

摘要

A drawn film of polyamide having an oxygen permeability coefficient of not more than 5 x 10-13 ml.cm/cm2.sec.cmHg, a breaking strength of not less than 14 kg/mm2, a breaking elongation of 30 to 150%, a yield strength of not less than 7 kg/mm2 and a yield elongation of 2 to 6%, which can be manufactured by drawing an undrawn polyamide film biaxially at a temperature within a certain range and optionally heat treating the resulting drawn film, the said undrawn polyamide film being made of a polyamide having a relative viscosity of about 2.0 to 4.0 when measured with a solution thereof in 96% sulfuric acid at a concentration of 1 g/100 ml at 25 DEG C and containing in the molecule not less than 70% (mol) of the repeating unit constituted with metaxylylenediamine or its mixture with paraxylylenediamine and an alpha , omega -aliphatic dicarboxylic acid having 6 to 10 carbon atoms, which is useful as a packaging material due to its excellent properties in tensile strength, yield strength, Young's modulus, heat stability, size stability, transparency, gas barrier property, etc.