Biaxially stretched film and production method thereof

摘要

The biaxially stretched film of the present invention comprises a polyamide resin composition (C) obtained by melt-kneading a smectite (B) with a polyamide (A) 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 alpha,omega-linear aliphatic dicarboxylic acid, or comprises at least one layer made of the polyamide resin composition (C). The polyamide resin composition (C) comprises the polyamide (A) in an amount of 80 to 99.9 parts by weight and the smectite (B) in an amount of 0.1 to 10 parts by weight. The layer made of the polyamide resin composition (C) 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 the strongest peak and the next stronger peak appearing in a diffraction angle 2theta ranging from 15° to 25° of a CuKalpha X-ray diffraction pattern of the layer made of the polyamide resin composition (C), 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.