| 摘要 |
<p>PURPOSE: To obtain a random magnetic ink capable of giving random magnetic data having high security and with difficult forgery or falsification to securities such as cards in high accuracy at an extremely low cost by ununiformly dispersing magnetic particles in a polymeric binding material. CONSTITUTION: In this random magnetic ink, magnetic particles (preferably iron-based alloy such as Fe, Ni alloy, etc.) having 2-100μm particle size are ununiformly dispersed in a polymeric binding material (e.g.; an ink vehicle such as a polyester resin, etc.). When a printing film thickness is set thin and a magnetic output having needed accuracy is required, it is preferable to use flake magnetic particles having 2-100μm particle size and <=2μm thickness. As a solvent used in the ink, an organic solvent having a low boiling point such as toluene, etc., in case of a gravure printing ink, a drying oil-based solvent such as linseed oil, etc., in case of an offset printing and a solvent having >=10 deg.C boiling point such as xylene, etc., in case of a screen printing can be preferably used.</p> |
