Photochromic printing inks are disclosed which are in particular used for the printing of security documents. Prints are normally nearly colorless and become colored when energy irradiated, such as by ultraviolet light. This photocoloration is reversible. The printing inks contain photochromic compounds which are protected against oxygen and other ink components. Methods are described to prepare the inks, to print security documents, and to detect counterfeiting.
已公开的光致变色印刷油墨特别适用于安全文件的印刷。印刷品通常几乎是无色的,当受到能量(如紫外线)照射时就会变色。这种光致变色是可逆的。印刷油墨中含有光致变色化合物,可防止
氧气和其他油墨成分的影响。本文介绍了制备油墨、印刷防伪文件和检测伪造文件的方法。