In accordance with an embodiment, an image decoloring apparatus comprises a conveyance path configured to convey a sheet on which an image is formed with a coloring agent that is decolored by heat; a first heat roller configured to be arranged at the upstream side of the conveyance path; and a second heat roller configured to be arranged at the downstream side of the conveyance path. Each of the first heat roller and the second heat roller includes a cylindrical portion and a heat source. The thickness of the cylindrical portion constituting the first heat roller is larger than the thickness of the cylindrical portion constituting the second heat roller. In this way, the heat capacity of the first heat roller is also larger than the heat capacity of the second heat roller.

In accordance with one embodiment, a decoloring apparatus comprises a processor, a decoloring section, a shift roller, a paper discharge section and a paper discharge roller. The processor determines whether or not to execute either a decoloring job or a non-decoloring job. The decoloring section decolors an image on paper formed with decolorable coloring agent. The shift roller moves paper for decoloring job or paper for non-decoloring job in a direction orthogonal to a paper discharge direction of the paper on a same plane for a given distance to sort it. The paper discharge section stacks discharged papers. The paper discharge roller discharges the paper sorted by the shift roller to the paper discharge section.

Thermochromic coatings are improved by mixing thermochromic capsules with polymer resins in a manner that imparts shelf stability to flowable precursors that may be cured quickly using dodecylbenzenesulfonic acid and/or other acid catalysts to form relatively hard coatings that are capable of withstanding machine operations, such as the operations needed to make beverage can lids, bottle caps, pull tabs and the like.

A recording medium according to an embodiment of the present disclosure includes: a recording layer including a leuco dye as a coloring compound; a first barrier film that is provided on each of one surface and another surface opposed to the one surface of the recording layer, and suppresses intrusion of moisture, oxygen, or both; and a second barrier film having chemical resistance and provided on a side surface of the recording layer continuously at least from a peripheral part of the one surface to a peripheral part of the other surface of the recording layer.

A thermoreversible recording medium including a support, and a thermoreversible recording layer, which is disposed on the support, and contains a leuco dye, and a reversible color developer, wherein an average particle diameter of granules in the thermoreversible recording layer is 0.35 micrometers or smaller.

A forgery prevention medium includes a substrate and a specific invisible material layer directly or indirectly laminated on the substrate, having a specific invisible material reversibly and visually recognized through a predetermined process disposed thereon in a plane shape, and having a part of the specific invisible material inactivated in accordance with a visualized image pattern.

In accordance with one embodiment, a decoloring apparatus comprises a processor, a decoloring section, a shift roller, a paper discharge section and a paper discharge roller. The processor determines whether or not to execute either a decoloring job or a non-decoloring job. The decoloring section decolors an image on paper formed with decolorable coloring agent. The shift roller moves paper for decoloring job or paper for non-decoloring job in a direction orthogonal to a paper discharge direction of the paper on a same plane for a given distance to sort it. The paper discharge section stacks discharged papers. The paper discharge roller discharges the paper sorted by the shift roller to the paper discharge section.

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 thermochromic pigment composition including: (A) at least one electron-donor organic dye compound, (B) at least one electron-acceptor compound, and (C) at least one compound responding to the following formula (I), in which: R.sub.1 is H or a phenyl group, R.sub.2 is H or a phenyl group, and -n=1-8. The thermochromic pigment composition includes thermochromic pigment microcapsules ink compositions including such thermochromic pigment microcapsules, and writing instruments including such ink compositions.

Provided are thermochromic color-memorizing composition and thermochromic color-memorizing microcapsule pigment encapsulating the same, the thermochromic color-memorizing composition including: (a) an electron-donating color-developing organic compound; (b) an electron-accepting compound; and (c) an ester compound represented by the following formula (1) as a reaction medium which controls color reaction between the components (a) and (b): ##STR00001##