METHOD FOR PROTECTING INFORMATION MEDIUM AGAINST FALSIFICATION Russian patent published in 2000 - IPC

FIELD: protection of information media against falsification. SUBSTANCE: method involves application of check mark for its visualization by means of additional external action to obtain optical effect. Mark is made of at least one layer of non-transparent heat- indicating coat of composition including polymeric matrix based on melamine formaldehyde and acrylic resins as well as heat-sensing dye having color transfer temperature at least 30 C, its ingredients being 1- hexadecanol and 4-ethylphenol in the following proportion, mas. %: 1-hexadecanol, 0.5-7.0; 4-ethylphenol, 0.5-5.0; melamine formaldehyde resin, 1.0-10.0; amide-containing acrylic resin, 1.5-15.0; butyl alcohol, 40.0-60.0; ethyl acetate, 20.0-40.0. External visualizing action is effected by heating check mark with heat flux to temperature above 30 C or by ultraviolet rays. EFFECT: facilitated manufacture, enlarged spectrum of color hue to improve reliability of protection and facilitate visualization of optical effect. 3 cl