Biaxially Stretched Film and Production Method Thereof
November 8, 2005
Patented is a biaxially stretched film comprising a polyamide resin composition obtained by melt-kneading a smectite with a polyamide. The polyamide is produced by the polycondensation of a diamine component containing 70 mol % or higher of m-xylylenediamine and a dicarboxylic acid component containing 70 mol % or higher of a C4-C20 a,w-linear aliphatic dicarboxylic acid, or comprising at least one layer made of the polyamide resin composition. The polyamide resin composition comprises the polyamide in an amount of 80 to 99.9 parts by weight and the smectite in an amount of 0.1 to 10 parts by weight. The biaxially stretched film comprises the polyamide resin composition or at least one layer made of the polyamide resin composition, which has a relative peak intensity ratio of 60 or less. The relative peak intensity ratio is represented by the formula: B/Ax100 wherein A and B are intensities of a strongest peak and a next stronger peak appears in a diffraction angle 2q ranging from 15° to 25° of a CuKa X-ray diffraction pattern of the layer made of the polyamide resin composition. This is provided that A is the peak intensity of the peak at a lower angle and B is the peak intensity of the peak at a higher angle.