| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem with a magnetic film having a display layer allowing nontransparent writing and printing thereon and a magnetic card using the magnetic film that curls occur due to residual molding distortion, temperature variation, and humidity variation, and to give the magnetic card a function of preventing magnetic attraction of magnetic cards to each other by solving the problem.SOLUTION: Both faces of a flexible magnetic film 11 made of a bond magnet with its one face multipole-magnetized is covered with display layers 12 and 13 to form a magnetic film P1. According to the magnetic film P1, the thickness of the flexible magnetic film 11 is determined to be 50 to 400 μm, a curl caused by an expansive and contractive force difference between one display layer and the other display layer is calculated at 3.0 mm or less in a specific acceleration test, and the thickness of the display layer 13 serving as a magnetic attraction surface is determined to be 15 to 100 μm. The thicknesses of the display layers 12 and 13 may be determined to be identical. If the magnetic directions or the distances between magnetic poles on the multipole magnetized surface are randomly configured, magnetic attraction can be prevented. This technique is applicable to a magnetic film that is not subjected to a magnetization process. |
