A method for the secure protection of a portion of the surface of an official document bearing markings, in which: a transparent security layer (17) is selected, the layer including at least one semi-transparent printed image including at least one transparent binder and at least one thermochromic pigment (14, 13, 12, 11); the semi-transparent printed image reveals at least one semi-transparent visible pattern in a first non-activated state at least a first temperature, such that the markings can be seen through the image, the pattern not being visible in a second activated state at least a second temperature different from the first temperature. A device for the secure protection of a portion of the surface of an official document and such an official document are also described.

A method for the secure protection of a portion of the surface of an official document bearing markings, in which: a transparent security layer (17) is selected, the layer including at least one semi-transparent printed image including at least one transparent binder and at least one thermochromic pigment (14, 13, 12, 11); the semi-transparent printed image reveals at least one semi-transparent visible pattern in a first non-activated state at least a first temperature, such that the markings can be seen through the image, the pattern not being visible in a second activated state at least a second temperature different from the first temperature. A device for the secure protection of a portion of the surface of an official document and such an official document are also described.

A roll of direct-thermal material may have a length of direct-thermal material including a facestock. An adhesive layer is on a first side of the facestock. A direct thermal coating is on a second side of the facestock, the direct thermal coating configured to selectively darken by heat activation when direct thermal printed. a cured ultraviolet LED coating is on the direct thermal coating, the cured ultraviolet LED coating having photoinitiators with substantial activation at an exposure limited to LED radiation at a 365 nm-450 nm wavelength range, and configured to allow direct thermal printing of the direct thermal coating therethrough, the cured ultraviolet LED coating curable without heat activating the direct thermal coating. The length of direct-thermal material being rolled on itself.

A roll of direct-thermal material may have a length of direct-thermal material including a facestock. An adhesive layer is on a first side of the facestock. A direct thermal coating is on a second side of the facestock, the direct thermal coating configured to selectively darken by heat activation when direct thermal printed. a cured ultraviolet LED coating is on the direct thermal coating, the cured ultraviolet LED coating having photoinitiators with substantial activation at an exposure limited to LED radiation at a 365 nm-450 nm wavelength range, and configured to allow direct thermal printing of the direct thermal coating therethrough, the cured ultraviolet LED coating curable without heat activating the direct thermal coating. The length of direct-thermal material being rolled on itself.

Provided are a packaging sheet and a packaging container where it is unnecessary to paste a printed label and disappearance or color development due to friction or the like after thermal printing do not occur. The packaging sheet includes a heat seal layer 10 for thermally welding by heating, a heat-sensitive layer 40 including a color developing material that develops a color by heating, and a base material layer 70 that secures the strength and protects the heat-sensitive layer 40. The heat seal layer 10, the heat-sensitive layer 40, and the base material layer 70 are provided in this order from a back surface side in a thickness direction. The packaging sheet is transparent before the heat-sensitive layer 40 develops the color.

A mess-free coloring system comprising a coloring medium and optionally one or more coloring utensils is disclosed. The coloring medium can include a substrate with or without decorative effects and one or more coating layers on a surface of the substrate. In various examples, the one or more coating layers include a color-triggering developer, e.g., in the form of a substantially clear resin, and an opaque pigment. Decorative effects integrated with or disposed on the substrate, while initially obscured by the one or more coating layers, can be revealed when the coating layers are mixed with at least one color precursor stored and dispensed from a coloring utensil. The opaque pigment is selected and configured such that, upon receipt of at least one color precursor by the one or more coating layers, a change in the pigment's reflective index occurs as the pigment dissolves into the clear resin developer.

A mess-free coloring system comprising a coloring medium and optionally one or more coloring utensils is disclosed. The coloring medium can include a substrate with or without decorative effects and one or more coating layers on a surface of the substrate. In various examples, the one or more coating layers include a color-triggering developer, e.g., in the form of a substantially clear resin, and an opaque pigment. Decorative effects integrated with or disposed on the substrate, while initially obscured by the one or more coating layers, can be revealed when the coating layers are mixed with at least one color precursor stored and dispensed from a coloring utensil. The opaque pigment is selected and configured such that, upon receipt of at least one color precursor by the one or more coating layers, a change in the pigment's reflective index occurs as the pigment dissolves into the clear resin developer.

The present invention relates to thermal recording materials comprising (in order): a support (base) layer; one or more undercoat layers; a thermal layer (thermosensitive coloring layer); and one or more protective layers, wherein the thermal recording material contains an aminocarboxylic and/or phosphorus-based chelating agent.

The thermal (thermosensitive) recording materials of the invention show enhanced plasticizer resistance and/or preprint uniformity.

Color change compositions that transition from a first to second color state upon application of an applied stimulus are provided. Also provided are substrates having the compositions on a surface thereof, as well as methods of making and using the compositions.

The invention relates to a heat-sensitive recording material. A heat-sensitive recording material, comprising a carrier substrate and a heat-sensitive, color-forming layer that contains at least one color former and at least one phenol-free color developer, is characterized in that said at least one color developer is a compound of formula (I) where Ar.sub.1 and Ar.sub.2 are a phenyl group and/or a C.sub.1-C.sub.4-alkyl substituted phenyl group. The invention also relates to a method for producing this heat-sensitive recording material and to the use, in a heat-sensitive recording material, of the color developer of formula (I) that is present in said heat-sensitive, color-forming layer. ##STR00001##