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.

A recording medium according to an embodiment includes a base material; a first color developing layer that is laminated on the base material, and absorbs light having a given wavelength to develop a color; a photothermal conversion layer that is laminated closer to an incident side of the light than the first color developing layer, transmits visible light, and absorbs the light for photothermal conversion; and a second color developing layer that is laminated closer to the incident side of the light than the first color developing layer, transmits visible light and the light, and develops a color by heat converted by the photothermal conversion layer.

Heat-seal condition indicating packages include a first sealing substrate comprising a leuco dye and a second sealing substrate comprising a leuco dye developer. The packages may optionally include a leuco dye sensitizer which dissolves both the leuco dye and the leuco dye developer when melted. The packages further include a heat-seal produced between the first sealing substrate and the second seating substrate. The heat-seal comprises a reaction product of the leuco dye and the leuco dye developer. The reaction product may be colored, which may provide the heat-seal with a detectable optical characteristic. A magnitude of the optical characteristic may be proportion to the strength of the seal between the first and second seating substrates.

Heat-seal condition indicating packages include a first sealing substrate comprising a leuco dye and a second sealing substrate comprising a leuco dye developer. The packages may optionally include a leuco dye sensitizer which dissolves both the leuco dye and the leuco dye developer when melted. The packages further include a heat-seal produced between the first sealing substrate and the second seating substrate. The heat-seal comprises a reaction product of the leuco dye and the leuco dye developer. The reaction product may be colored, which may provide the heat-seal with a detectable optical characteristic. A magnitude of the optical characteristic may be proportion to the strength of the seal between the first and second seating substrates.

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.

A label assembly including one or more dissolvable thermal direct adhesive labels and methods of assembly and use. According to one embodiment, each label includes a base layer, a thermal direct layer, an adhesive layer, and a barrier layer. The base layer, which has an upper surface and a lower surface, is water-dissolvable and may be made of a water-dissolvable paper. The thermal direct layer is positioned directly over the upper surface of the base layer and functions in the conventional manner to produce markings therein in response to heat. The adhesive layer is water-dissolvable and is positioned below the lower surface of the base layer. The barrier layer, which is positioned directly below the lower surface of the base layer and directly over the adhesive layer, serves to prevent migration of the adhesive layer through the base layer and into contact with the thermal direct layer.

A drawing system according to an embodiment of the present disclosure includes a storage, an operation section, and a drawing section. The storage stores a characteristic function that derives output setting values of light sources on the basis of drawing coordinates, an absorbance correlation value, and gradation values in a leuco color space. The operation section derives the output setting values by inputting, to the characteristic function, the drawing coordinates, gradation values of leuco image data described in the leuco color space, and an absorbance correlation value obtained by measuring the recording medium. The drawing section includes the light sources, and controls output of the light sources on the basis of the output setting values derived by the operation section to thereby perform drawing on the recording medium.

A drawing system according to an embodiment of the present disclosure includes a storage, an operation section, and a drawing section. The storage stores a characteristic function that derives output setting values of light sources on the basis of drawing coordinates, an absorbance correlation value, and gradation values in a leuco color space. The operation section derives the output setting values by inputting, to the characteristic function, the drawing coordinates, gradation values of leuco image data described in the leuco color space, and an absorbance correlation value obtained by measuring the recording medium. The drawing section includes the light sources, and controls output of the light sources on the basis of the output setting values derived by the operation section to thereby perform drawing on the recording medium.

Provided is a thermosensitive recording medium including a thermosensitive coloring layer containing an electron-donating dye precursor, an electron-accepting compound, a radical polymerizable compound and a photoradical polymerization initiator, in which the radical polymerizable compound is a compound that is solid at 25° C., and the radical polymerizable compound is contained in the thermosensitive coloring layer in a state of encapsulating at least one of the electron-donating dye precursor and the electron-accepting compound.

A recording material and a recording sheet having better color-developing performance, storage stability, etc. A recording material which contains (A) at least one color former, (B) at least one compound selected from the group including compounds represented by the following formula (I), and (C) at least one compound selected from the group including compounds represented by the following formula (II) (wherein R.sup.1 to R.sup.3 each represent a halogen atom, a nitro group, a C.sub.1 to C.sub.6 alkyl group, a C.sub.1 to C.sub.6 alkoxy group, a C.sub.2 to C.sub.6 alkenyl group or a C.sub.1 to C.sub.6 haloalkyl group, n1 and n3 each independently represent any integer of 0 to 5, n2 represents any integer of 0 to 4, and X represents —SO.sub.2—O— or —O—SO.sub.2—). ##STR00001##