| 简介 |
FIELD : protection coatings.
SUBSTANCE : invention aims at protecting bank notes and security papers against counterfeiting. Optically changing pigment contains interferential multilayer structure including light-transmitting dielectric layer having at least one luminescent material. Dielectric layer is selected from of rare-earth metal, bismuth, and principal group III element trifluorides; of principal group II element difluorides; mixtures thereof; organic or organometallic compounds. Luminescent material should be selected from organic or organometallic compounds containing transition or rare-earth metal ions. Above-defined structure may contain one or more semitransparent, partly reflecting layers, one or more nontransparent, fully reflecting layers, and one or more conducting layers. Pigment is prepared by a method including physical or chemical precipitation of the dielectric layer.
EFFECT : preserved proper properties of color shift, increased reliability of protection, and ensured identification simplicity at relatively low cost.
30 cl, 1 tbl, 9 ex |
客服热线：
手机版
二维码
