FLUORESCENT MATERIAL FOR SELF-ERASABLE WRITING, AUTHENTIC SECURITY LABELING, CURRENCY COUNTERFEIT PREVENTION AND PROCESSES FOR THE PREPARATION THEREOF

摘要

The present invention provides a novel fluorescent molecule having formula 1 which exhibit emission color change when in contact with moisture useful for the preparation of fluorescent paper, allowing self-erasable writing, security label for document authenticity, check and prevention of currency counterfeit. Compound of formula 1 when coated on paper results in blue emitting surfaces on which writing is possible using water as ink. The images undergo self-erasal after 6 hours making the paper reusable or instantly with hot air. The images are visible only on illumination with a UV lamp having wavelength 365 nm. The material can be coated on any document to create security label which changes color on touching with a wet surface or water pen and will go back to the native color when the moisture is dried off after a time frame. This strategy is used to create a security label for currency bills for checking original and fake currency notes or any other documents for authenticity. The technique is also useful for temporary writing on recyclable papers.

主权项

1. A process for the preparation of fluorescent material or paper for self-erasable writing comprising the steps of:
i)dissolving 0.1 to 0.2 wt % compound of formula 1 wherein R is the group: in chloroform to obtain a solution; ii)spraying the solution on the material or paper; and iii) drying the material or paper under vacuum to obtain fluorescent coated material or paper.