| 摘要 |
PURPOSE: A magnetic particle and a manufacturing method thereof are provided to effectively conceal an applied area of a certificate when applying the magnetic particle to security ink for the certificate. CONSTITUTION: A magnetic particle comprises a core(100), a shell(300), and a continuous or discontinuous void(200). The core is formed by dispersing and impregnating a plurality of super-paramagnetic nano particles in a dielectric material or polymer matrix. The continuous or discontinuous void is formed between the core and the shell. The gap or diameter of the void is 10nm or greater. |
