Patent ID: 11958950

Abstract:
An ion exchange membrane containing a fluorinated polymer, wherein in a case where by Raman spectroscopy, polarized light orthogonal to the thickness direction of the ion exchange membrane is irradiated to obtain a spectrum chart, whereby the ratio of the peak area a2 of Raman shift 680 to 760 cm−1 to the peak area al of Raman shift 1,025 to 1,095 cm−1 is taken as A1, and by Raman spectroscopy, to a cross section in the thickness direction of the ion exchange membrane, polarized light parallel with the thickness direction is irradiated to obtain a spectrum chart, whereby the ratio of the peak area b2 of Raman shift 920 to 1,025 cm−1 to the peak area b1 of Raman shift 1,025 to 1,095 cm−1 is taken as B1, B1/A1 is at least 1.05.