THERMOSENSITIVE COMPOSITION FOR PROTECTION OF PAPER DOCUMENTS AGAINST FALSIFICATION Russian patent published in 1998 - IPC

FIELD: protection of documents. SUBSTANCE: composition contains two kinds of color-formation agents placed in microcapsules. Microcapsules 3-6 mcm in diameter are made on the basis of melamine-formaldehyde resin and those with diameter 1-2 mcm on the basis of maleate derivative of gelatin. Composition also contains bis- phenol A, zinc carbonate, carboxymethylcellulose sodium salt (binding agent), and water. Melamine-formaldehyde resin-based microcapsules are filled with solution containing 1,3-dimethyl-6-dimethylaminofluorane, 10-benzoyl-3,7-bis(dimethylamino)phenothiazine, 2-octylamino-6- diethylaminofluorane, crystal-violet acetone (crystalline violet lactone), and di-iso-propylnaphthalene. Maleate gelatin derivative- based microcapsules are filled with solution containing 6'-nitro- 1,3,3-trimethyl-spiro-[(2H'-1'-benzopyrane)-2,2'-indoline] , industrial-grade castor oil, scintillation xylene, and N,N- dimethylformamide. EFFECT: increased protection degree.