Security threads
AssigneePortals (Bathford) Limited
InventorsRichard B. Jotcham, Gerald S. Payne
Life of this patent
Estimating the term…
Abstract
A security thread (11) for use in security articles (10), includes a substrate having a coating on one or both sides thereof, the coating containing a thermochromic material selected from pigments and dyestuffs which changes from coloured to colourless when the temperature of the pigment or dyestuff is changed to the activation temperature. The thermochromic material may be coloured when the temperature is below the activation temperature and become colourless when the material is at the activation temperature or above. The thread (11) is for security paper (10) for use in producing banknotes and the like.
Claims63
A security thread for use in security articles, said thread comprising a substrate bearing indicia, the thread having a thermochromic coating on one side of the thread, said thermochromic coating comprising a coating containing a thermochromic material selected from pigments and dyestuffs, which material is coloured when the temperature of said thermochromic coating is below an activation temperature and is colourless when the temperature is at or above said activation temperature, the indicia being obscured when the material is coloured and visible when the material is colourless.
A security thread for use in security articles, said thread comprising a substrate bearing indicia, the thread having a thermochromic coating on one side of the thread, said thermochromic coating comprising a coating containing a thermochromic material selected from pigments and dyestuffs, which material is colourless when the temperature of the thermochromic coating is below an activation temperature and which is coloured when the temperature of the thermochromic coating is at or above the activation temperature, the indicia being visible when the material is colourless and obscured when the material is coloured.
A security thread for use in security articles, said thread comprising a substrate bearing indicia, the substrate incorporating a thermochromic material selected from pigments and dyestuffs, which material is coloured when the temperature of the substrate is below an activation temperature and is colourless when the temperature is at or above said activation temperature, the indicia being obscured when the material is coloured and visible when the material is colourless.
A security thread for use in security articles, said thread comprising a substrate bearing indicia, the substrate incorporating a thermochromic material selected from pigments and dyestuffs, which material is colourless when the temperature of the substrate is below an activation temperature and is coloured when the temperature is at or above said activation temperature, the indicia being obscured when the material is coloured and visible when the material is colourless.
Dependencies are inferred from the claim text.