Abstract: High refractive index coatings having metal oxide particles are disclosed. Dispersions of metal oxide particles in solvent are also disclosed. These find use in the protection of surface relief structures. In some disclosed embodiments, the coatings or dispersions contain UV-curable resins. The coatings and dispersions find application in the field of security devices and documents and tokens incorporating security devices.

Abstract: A method of manufacturing a security document comprising the steps of providing a transparent plastics substrate, applying a radiation curable ink directly to at least side of the substrate and simultaneously embossing and curing with radiation different regions in the same area of the ink on one side of the substrate with at least two different embossed relief structures, each forming a different type of diffractive security element integrated within the same area to form a composite security device.

Abstract: An optical security device, including a substrate (102) having a first surface and a second surface; and a metallic nanoparticle ink (104) provided intermittently in at least one area on the first surface (102) to produce a reflective or partially reflective patch or patches; wherein a high refractive index coating (106) is applied over the area or areas (108) in which the metallic nanoparticle ink is provided, the high refractive index coating (106) adhering to the first surface (102) where the metallic nanoparticle ink is not present, thereby retaining the metallic nanoparticle ink (104) between the first surface (102) and the high refractive index coating (106).

Abstract: A security document and a method of manufacturing a security document are provided in which a radiation curable ink is applied to at least one side of a substrate including at least one region of transparent plastics material forming a window or half-window area. The ink is embossed while soft and cured with radiation to form an embossed security device within the window or half-window area including one or more of a diffractive structure, a lens structure or other security element having a relief structure.

Abstract: High refractive index coatings having metal oxide particles are disclosed. Dispersions of metal oxide particles in solvent are also disclosed. These find use in the protection of surface relief structures. In some disclosed embodiments, the coatings or dispersions contain UV-curable resins. The coatings and dispersions find application in the field of security devices and documents and tokens incorporating security devices.

Abstract: A security document (1) is provided having a substrate (4) and an integral security device (10) which includes an image layer (12) and a focussing layer (11). each formed from a radiation curable ink layer embossed with relief formations (13; 15). The first radiation curable layer embossed with relief formations (13) to form the image layer (12) is provided on a first surface of the document, and the second radiation curable layer (11) embossed with focussing element relief formations (15) is provided on a second surface of the document. The first and second surfaces are separated by a predetermined distance D to produce a visible optical effect when viewing the image layer (12) through the focussing layer (11). In preferred embodiments, at least one of the first and second radiation curable layers is embossed with diffractive relief structures and high refractive index or reflective coatings may be applied to the embossed relief formations in the image layer (12) and/or the focussing layer (11).

Abstract: A security document or device is provided which incorporates one or more optical components. Each component includes at least one orientating layer, preferably a photo-orientated polymer network (PPN), and at least one liquid crystal polymer (LCP) layer, and either or both of the orientating layers and LCP layers include a cross-linker to improve the robustness of the document or device without detracting from the desired optical properties. Such a document or device can be authenticated using an external polariser, or using a polariser integral to the document or device itself.

Abstract: A security document and a method of manufacturing a security document are provided in which a radiation curable ink is applied to at least one side of a substrate including at least one region of transparent plastics material forming a window or half-window area. The ink is embossed while soft and cured with radiation to form an embossed security device within the window or half-window area including one or more of a diffractive structure, a lens structure or other security element having a relief structure.