| 摘要 |
The present invention is in the field of security documents, more particularly in the field of security elements aimed to protect security documents against copying (illegal reproduction) and counterfeiting. It discloses a security element having a coating layer(s) which changes its visual appearance after irradiation with light, especially with UV light and reverts back to the original state within a few seconds. Security documents comprising said security element, as well as a method for producing said security element, are also disclosed. |
