Abstract: Ultraviolet light-curable deposits are printed onto a substrate in a predetermined pattern to make tactile marks (e.g. Braille-like resin dots) for use by people with impaired vision to, for example, recognize the denominations of banknotes. The deposit demonstrates high adhesion due to: (1) presence of 20-80% (wt.) of a low viscosity acrylate component to provide a substrate-penetrating property; and, (2) 2-30% (wt.) of an adhesion-promoting acid acrylate. The deposit material further includes 1-30% (wt.) of urethane acrylate, 1-30% by weight of reactive diluent, photoinitiator and 1-10% (wt.) of rheological adsorbing additive. Optimally, the adhesion promoter is added after the other components have been mixed with the rheological additive. The printing step may be followed by heating before the curing step to increase penetration of the ink into the substrate. The deposit may comprise a taggant for use as a security feature.

Abstract: Improved ultraviolet light-curable compositions are provided for printing onto a security document substrate in a predetermined pattern to make tactile features for use by people with impaired vision to, for example, recognize the denominations of banknotes. The improved compositions substantially comprise an acidic trifunctional acrylate ester, preferably in an amount of 60-80 wt %, and include urethane acrylate and effective amounts of flexibilizer (e.g. low viscosity aromatic monoacrylate having an elongation parameter of about 200), photoinitiator and a rheological additive (e.g. silica). The composition unexpectedly provides flexibility and is particular useful for printing tactile features in the form of relatively large continuous graphical patterns.

Abstract: Durable, easily recognizable and easy-to-feel tactile marks are provided which may be incorporated into security documents, such as banknotes, to assist visually impaired people in validating such security documents. Deposits are printed onto the substrate, using an ink, resin or ink-like printing material, in a predetermined pattern to form tactile marks adhering to the substrate. A sufficiently high pressure is applied to the substrate with the printed tactile marks to calender the tactile marks, thereby forming corresponding protrusions in the substrate on the opposite sides of the printed tactile marks. An energy curable printing material may be used to print the deposits and the calendering of the tactile marks may be performed by intaglio printing.

Abstract: Ultraviolet light-curable deposits are printed onto a substrate in a predetermined pattern to make tactile marks (e.g. Braille-like resin dots) for use by people with impaired vision to, for example, recognize the denominations of banknotes. The deposit demonstrates high adhesion due to: (1) presence of 20-80% (wt.) of a low viscosity acrylate component to provide a substrate-penetrating property; and, (2) 2-30% (wt.) of an adhesion-promoting acid acrylate. The deposit material further includes 1-30% (wt.) of urethane acrylate, 1-30% by weight of reactive diluent, photoinitiator and 1-10% (wt.) of rheological adsorbing additive. Optimally, the adhesion promoter is added after the other components have been mixed with the rheological additive. The printing step may be followed by heating before the curing step to increase penetration of the ink into the substrate. The deposit may comprise a taggant for use as a security feature.