A recording medium according to one embodiment of the present disclosure includes a recording layer and an optical thin film. The recording layer includes a heat-sensitive color-developing composition and a photothermal conversion material. The photothermal conversion material absorbs a wavelength in an infrared region and generates heat. The optical thin film is provided on one surface of the recording layer. The optical thin film reflects the wavelength in the infrared region and transmits a wavelength in a visible region.

A reversible recording medium according to an embodiment of the present disclosure includes a first recording layer to be colored in a first color, a second recording layer to be colored in a second color, the second color being different from the first color, and a first intermediate layer provided between the first recording layer and the second recording layer, the first intermediate layer including a plurality of layers respectively containing materials different from each other.

The invention relates to a heat-sensitive recording material, comprising a carrier substrate and a heat-sensitive colour-forming layer, which contains at least one colour former and at least one phenol-free colour developer, characterised in that the at least one colour developer is the compound of formula (A), Ar(NHCONHCONHAr.sup.1).sub.n (A), wherein Ar is an unsubstituted or substituted phenyl or naphthyl group, Ar.sup.1 is an unsubstituted or substituted phenyl, naphthyl, pyridyl, thiazolyl or benzothiazolyl group, and n is 1 or 2.

An example of an imaging medium includes a substrate, a color-forming layer on the substrate, and a registration mark. The color-forming layer includes a repeated pattern. A repeat of the pattern includes four adjacent color-forming stripes including a black-forming stripe, a cyan-forming stripe, a magenta-forming stripe, and a yellow-forming stripe, or a grid of four color-forming sections including i) a color-forming section selected from the group consisting of black-forming, cyan-forming, light cyan-forming, yellow-forming, magenta-forming, and light magenta-forming, ii) a cyan-forming section, iii) a magenta-forming section, and iv) a yellow-forming section.

A thermosensitive recording material comprising a support; an insulating layer that includes a porous polymeric pigment; and an image-forming layer.

In the present invention, there is provided a use of 1,1,1-tris(4-hydroxyphenyl)ethane in a composition in the formation of an image on a substrate having said composition applied thereon, wherein the image is formed upon exposure of the composition to NIR or IR radiation, and wherein the image is capable of being retained on the substrate for at least 1 day under conditions of at least 50% relative humidity. The present invention is further directed towards compositions comprising 1,1,1-tris(4-hydroxyphenly)ethane, in addition to substrates, methods of forming an image and printing processes comprising said compositions.

To provide a heat-sensitive recording material which produces images with excellent resistance to water, while producing background with resistance to heat. A heat-sensitive recording material which is characterized by containing at least one compound represented by general formula (1) as a color-developing compound: ##STR00001##
wherein, R1-R5 each independently represents a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an alkylcarbonylamino group, an arylcarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, a monoalkylamino group, a dialkylamino group or an arylamino group.

A composition includes a capsules having an improved solvent and heat resistance. The capsules are prepared via interfacial polymerization between a polyisocyanate including at least one substituted or unsubstituted arylene or heterearyl group and a compound including an active hydrogen. The capsules include a leuco dye and may be used in laser markable compositions.

A composition includes a capsules having an improved solvent and heat resistance. The capsules are prepared via interfacial polymerization between a polyisocyanate and a polyhydrazide. The capsules include a leuco dye and may be used in laser markable compositions.

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.