FIELD: physics.
SUBSTANCE: invention relates to a method of verifying the authenticity of a security document, in particular a fiduciary document containing a zone with an invertible luminescent mechanical compound located inside or on its surface, of the formula:
where R is an alkyl chain having 1 to 12 carbon atoms. The method includes the step of subjecting said zone to ultraviolet irradiation so that the entire zone becomes visible to the naked eye in the first colour (C1) of the fluorescence. The method also includes the step of heating at least mentioned zone to a temperature of at least 50°C without any friction or mechanical stress. In this case, the authenticity of the protected document is confirmed by changing the first colour (C1) of fluorescence to a second colour (C2) of fluorescence, different from the first.
EFFECT: additional enhancement to authenticate a protected document.
16 cl, 4 dwg
