The present invention relates to method of manufacturing a tamper-proof medium for thermal printing, wherein a liquid treatment composition comprising at least one acid is deposited on a substrate which comprises a thermochromic coating layer comprising at least one halochromic leuco dye.

A security element (1) as well as a method for producing a security element (1). The security element (1), in particular a security strip or a security thread or a patch or a transfer film (2) or a laminating film or a print, for protecting security documents (3), includes at least one thermochromic element (11), wherein i) the at least one thermochromic element (11) has haptic properties; and/or ii) the security element (1) has at least one haptic layer (12).

The present invention provides a process for manufacturing a security feature for securing a value document, wherein said security feature exhibits a blue color upon viewing in transmitted light and a metallic yellow color upon viewing in Incident light. The manufacturing process comprises the following steps: a) printing a specific UV-Vis radiation curable ink on a transparent or partially transparent region of a substrate of a value document; b) heating the ink layer obtained at step a) at a temperature of about 55° C. to about 100° C. for at least one second so that the ink layer exhibits a metallic yellow color upon viewing in incident light; and c) UV-Vis curing the ink layer obtained at step b) to form the security feature. The manufacturing process according to the present invention enables the expedient production of security features exhibiting a blue color upon viewing in transmitted light and a metallic yellow color upon viewing in incident light and is particularly useful for industrial printing of value documents.

Disclosed is a method for manufacturing a multilayer data medium (1), in which method: a multilayer data medium, including at least one transparent security layer (16), and at least one marking layer (17), sensitive to electromagnetic-marking radiation (5), are selected; the transparent security layer (16) includes at least one semi-transparent printed image including at least one thermochromic dye; at least one marking (30) is made using the electromagnetic-marking radiation, through the printed image; the semi-transparent printed image reveals, in a first state referred to as the inactivated state, at least one semi-transparent visible pattern that makes it possible, after the marking step, to view the marking (30) through the image, the pattern not being visible in a second state, referred to as the activated state. The invention also relates to a multilayer data medium (1).

A color laser markable article includes a color laser markable layer provided on a support, the laser markable layer including an infrared absorbing compound; a leuco-dye; and an acid generating compound, wherein the acid generating compound has a structure according to Formulae (I) or (II): ##STR00001##
wherein R1 and R3 independently represent an optionally substituted alkyl group, an optionally substituted (hetero)cyclic alkyl group, an optionally substituted (hetero)aryl group, an optionally substituted aralkyl group, an optionally substituted alkoxy group, an optionally substituted (hetero)cyclic alkoxy group, or an optionally substituted (hetero)aryl group; R2, R4 and R5 independently represent an optionally substituted alkyl, an optionally substituted (hetero)cyclic alkyl group or an optionally substituted aralkyl group; and R1 and R2, R4 and R5, R3 and R4, and R3 and R5 may represent the necessary atoms to form a ring.

A secure lens sheet or layer suitable for use in a micro-optic system, which is made up of a plurality of joined fine lens arrays (e.g., joined fine lenticular and/or joined fine non-cylindrical lens arrays), is provided. Each array has a lens pitch different from adjacent or contiguous arrays and/or is orientated in a direction different from adjacent or contiguous arrays. A micro-optic security device, which utilizes the inventive secure lens sheet and one or more overlying or underlying arrangements of micro-sized image icons (e.g., line data), is also provided. The image icon arrangement(s) and the secure lens layer are configured such that one or more synthetic images are projected by the security device. These projected images may show a number of different optical effects. With such a combination lens layer, some regions could be optically active when the device is tilted in one direction, some could be active when tilted in the opposite direction, and some areas could be active when the device is tilted in either (or any) direction. The inventive micro-optic security device may be partially embedded in and/or mounted on a surface of a security article (e.g., paper or polymer security document, label, card), or integrated therein.

A thermochromic ink composition includes, in a liquid medium, known as solvent, a dispersion of thermochromic microcapsules incorporating at least one leuco-dye and a thermoplastic binder selected from the group containing polyacrylic polyesters, polyurethanes and copolymers thereof. The composition is characterized in that the solvent is aprotic. A a method for producing a card and such a card incorporating at least one thermochromic pattern produced with a thermochromic ink composition are also described.

Apparatus to produce a spatially and temporally uniform heat source is described and this is used to visualize latent fingerprints deposited onto thermal paper by raising the temperature of the paper. Results show an improvement over previous techniques, particularly when fingerprint deposits are aged or the developed fingerprints faint; visualization being enhanced by the use of an LED light source. An investigation of the components in fingerprint sweat likely to affect the solubility and hence colour change of the dye present in the thermal paper has shown that polar protic solvents able to donate a proton are favoured and a polar amino acid found commonly in eccrine fingerprint sweat (lysine) has been shown able to produce the desired colour change. Aged fingerprint deposits on thermal paper from a variety of sources up to four years old have been visualized with this technique.

A direct thermal printable construct, such as a ticket, game piece, coupon, collection piece, label, security card, or voucher includes a thermally printable medium and a metallized layer bonded directly or indirectly to the thermally printable medium. A thermosensitive imaging layer of the thermally printable medium is printable by exposing the metallized layer to localized heat of a thermal printer for inducing local changes in the color of the thermosensitive imaging layer that are obscured from view through both the metallized layer and a base substrate of the thermally printable medium. One or more areas of the metallized layer are arranged to be removable by a scratching action using a fingernail or coin for revealing the underlying local changes in the color of the thermosensitive imaging layer.

The present invention addresses the problem of providing a temperature detection label capable of preventing falsification using a simple structure. To solve this problem, the present invention provides a temperature detection label that is characterized by comprising a supporting member and a temperature detection part provided on the supporting member and in that: the temperature detection part has a temperature detection material that, in a heating process, starts color development at temperature T.sub.1 and starts losing color as a result of melting at temperature T.sub.2 and, in a cooling process, solidifies while remaining colorless by being cooled to temperature T.sub.1 or lower; the temperature detection material includes a leuco dye, decolorizer, and developer; and the temperature detection label also comprises a member having an appearance that changes between T.sub.1 and T.sub.2, inclusive, or a high-melting-point material having a melting point or glass transition temperature higher than T.sub.2.