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.

An aqueous dispersion resin composition contains a first polymer produced by polymerizing a first monomer component containing (meth)acrylamide and a second polymer produced by polymerizing a second monomer component containing a carboxy group-containing vinyl monomer, wherein at least a portion of the carboxy group in the second polymer is neutralized.

A heat-sensitive recording material suitable for offset printing, having a web-shaped substrate, having a front side and a reverse side opposite the front side, a heat-sensitive recording layer disposed at least on one of the two sides of the web-shaped substrate having at least one dye precursor and at least one (color) developer reactive with the dye precursor. The heat-sensitive recording layer has particles including an organic surface whose extent in the direction of the thickness of web-shaped substrate and heat-sensitive recording layer is greater than the thickness of the heat-sensitive recording layer.

Provided is a thermosensitive recording medium having a sufficient water resistance to moisture and humidity, such as for outdoor use in rainy weather and the like, and also having a superior color developing sensitivity, print image quality when printing at high speed, ink fixability and solvent resistance and the like. As the protective layer comprises a specific silane-modified acrylic resin which is an aqueous emulsion of core-shell type p articles, in a thermosensitive recording medium having a thermosensitive recording layer on a substrate and a protective layer on the thermosensitive recording layer, the thermosensitive re cording medium has a sufficient water resistance and also has a superior color developing sensitivity, print image quality when printing at high speed, ink fixability and solvent resistance and the like.

A color laser markable article includes at least a first and a second laser markable layer including, respectively, a first infrared dye IR-1 having an absorption maximum in the infrared region .sub.max(IR-1) and a second infrared dye IR-2 having an absorption maximum in the infrared region .sub.max(IR-2), characterized in that the color laser markable layers further include a Diffusion Hindered Molecular Assembly (DHMA) which contains a leuco dye.

A heat-sensitive recording material including a web-shaped substrate having a front side and an opposite reverse side, and at least one heat-sensitive recording layer on either or both of the sides of the web-shaped substrate. The heat-sensitive recording layer contains at least one dye precursor at least one salicylic acid derivative as a (color) developer reactive with this at least one dye precursor, and polyvinylpyrrolidone as auxiliary component augmenting the (color) developer the at least one salicylic acid derivative is 3,5-di(-methylbenzyl)salicylic acid.

The present invention relates to a thermally printable paper article with an elastomeric underlayer, which imparts improved printing performance.

To provide a thermosensitive recording material, containing: a support; an under layer; a thermosensitive recording layer; and a protective layer, where the under layer, the thermosensitive recording layer, and the protective layer are provided in this order on at least one surface of the support, wherein the support is synthetic paper, or a synthetic resin film, wherein the under layer contains a binder resin, and hollow particles, wherein an adhesive force of the thermosensitive recording material at 20 C., as measured by the described measuring method of the adhesive force, is 10.0 N/25 mm or greater.

A reversible recording medium according to an embodiment of the present disclosure includes: a recording layer including a coloring compound having an electron-donating property, a color developing/quenching agent having an electron-accepting property, a photothermal conversion agent, and a macromolecular material; and an ultraviolet absorbing layer provided on the recording layer, the macromolecular material including an organic material that has solubility of 20 wt % or more and 80 wt % or less at 25? C. or less and contains 0.5 wt % or less of chlorine atoms, fluorine atoms, and sulfur atoms in a molecule.

A thermosensitive recording material including a support and a thermosensitive coloring layer provided on the support, in which the thermosensitive coloring layer contains (A) a coloring substance, (B) a kraft lignin in which a content of dimethyl disulfide is 2.5 ppm or less and (C) a specific developer.