To provide a biaxially stretched polyamide film lowered in moisture absorbing elongation under a high humidity condition and reduced in hot water shrinkage factor without damaging excellent properties.
A biaxially stretched polyamide film is characterized in that the hot water shrinkage factor (BS) in the lateral direction (TD) of the film when the film is treated in hot water at 100°C for 5 min is 4.0% or less at all of positions in the TD direction and moisture absorbing irreversible elongation(IE) defined by formula: IE(%)=[(l2-l0)/l0]×100 (wherein l0 is the length of the film at first 40% RH when environment where the film is allowed to stand is changed in the order of 20°C/40% RH → 20°C/65% RH → 20°C/40% RH and l2 is the length of the film when the environment is again set to 40% RH) is 0.5% or less.
FUKUSHIMA YASUMASA
SAKAKI TAKUYA
