| 摘要 |
The invention relates to the compositions used with the view of reducing the risk of documents unauthorized reproduction, in particular of banknotes. The composition is composed of an organic matrix, wherein there are contained at least two photoluminescent components, forming a luminous cascade, with that, at least one of the components is luminescent in upward conversion. Said luminous cascade contains the first component, excited in the ultraviolet and emitting in the infra-red, and the second component excited in the infra-red and emitting in the visible spectrum.Claims: 6 |
