| 摘要 |
1466329 Credit cards and the like MINNESOTA MINING & MFG CO 1 May 1974 [2 May 1973] 19188/74 Heading B6A [Also in Division G4] A security document such as a credit card or airline ticket has a magnetic layer 40 containing uniformly dispersed particles 30 of a magnetically anistropic magnetizable material arrangedwith the easy axis of magnetization of particles in predetermined regions 36 differently aligned relative to a reference location such as an edge of the document. The particles not within the predetermined regions may be unaligned or may be aligned in a direction different from the directions in the predetermined areas. The card may be formed by feeding sheet material from a roll 54 applying a layer of magnetic particles in a binder and solvents, applying a magnetic field to a stationary portion of the coated sheet using source 60 such as a permanent magnet to suitably align the particles and heating the sheet to immobilize the particles. A layer 70 carrying visible indicia is then attached using a suitable adhesive or heat fusing.
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