A colour 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 colour laser markable layers further include a Diffusion Hindered Molecular Assembly (DHMA) which contains a leuco dye.

A laser markable composition includes (a) an aqueous medium; (b) a leuco dye; (c) an optothermal converting agent; and (d) a colour developing agent, characterized in that the colour developing agent is a polymer particle capable of forming an acid upon exposure to heat.

A main object of the present invention is to provide a thermosensitive recording material having excellent recording color developability and recording image quality, having no inhibition of a color-developing reaction due to the adhesive component after being processed into a thermosensitive recording label (glue desensitization), and being able to withstand long-term storage while retaining excellent recording performance. The present invention is a thermosensitive recording material (1) having at least an anchor layer (1) containing a sizing agent on a support, an undercoat layer containing at least one member selected from the group consisting of plastic hollow particles and sizing agents on the anchor layer (1), and a thermosensitive recording layer containing a leuco dye and a coloring agent on the undercoat layer; and is a thermosensitive recording material (2a) having an anchor layer (2) containing specific amounts of a pigment and a specific sizing agent on a support, and a thermosensitive recording layer containing a leuco dye and a coloring agent on the anchor layer (2); a thermosensitive recording material (2b) having an anchor layer (2) containing a pigment and a specific sizing agent on a support, and a thermosensitive recording layer containing a leuco dye and a specific coloring agent on the anchor layer (2); or a thermosensitive recording material (2c) having an anchor layer (2) containing a sizing agent and a water resistance-imparting agent on a support, and a thermosensitive recording layer containing a leuco dye and a coloring agent on the anchor layer.

A colour laser markable laminate includes a colour laser markable layer including a leuco dye and an infrared absorbing compound, an optional adhesive layer, a polymeric support, an optional outerlayer, wherein the colour laser markable layer further includes an acid scavenger. The support, the optional adhesive layer, or the optional outer layer includes a UV absorbing compound.

The invention relates to a heat-sensitive recording material, comprising a supporting substrate and a heat-sensitive color-forming layer, which contains at least one color former and at least one phenol-free color developer, characterized in that the at least one color developer is a compound of formula (I), wherein Ar is an aryl residue, a heteroaryl residue, or a benyzl residue and Y is an aryl residue, a heteroaryl residue, a benzyl residue, an aryloxy residue, a heteroaryloxy residue, a benzyloxy residue, an arylamino residue, a heteroarylamino residue, or a benzylamino residue. The invention further relates to a method for producing said heat-sensitive recording material.

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An object of the invention is to provide a recording material and recording sheet having excellent color-developing performance, storage stability, etc. A recording material having good color-developing performance and storage stability may be obtained by using a specific compound having a benzhydrol skeleton as an additive in a recording material employing color development through a reaction between a color former and a color-developing agent.

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.

The present invention provides a heat-sensitive recording material which has improved thermal responsiveness and improved stability of the print part and the background in comparison to conventional heat-sensitive recording materials that contain a non-phenolic compound as a color developer. The present invention provides a heat-sensitive recording composition which contains a color former, a color developer and a stabilizer, wherein: N-[2-(3-phenylureido)phenyl]benzenesulfonamide or N-(p-toluenesulfonyl)-N-(3-p-toluenesulfonyloxyphenyl) urea is contained as the color developer, and 1,3-diphenyl urea is contained as the stabilizer.

Disclosed is a heat-sensitive recording material containing at least an undercoat layer and a heat-sensitive recording layer in this order on a support, the undercoat layer containing hollow particles, a binder, and an inorganic pigment I, the heat-sensitive recording layer containing a leuco dye and a developer, wherein (A) the heat-sensitive recording layer contains 5-(N-3-methylphenyl-sulfonamide)-N,N-bis-(3-methylphenyl)-isophthalic acid diamide as a stability improver, or (B) the heat-sensitive recording layer contains 5-(N-3-methylphenyl-sulfonamide)-N,N-bis-(3-methylphenyl)-isophthalic acid diamide as the developer and contains a pigment with an oil absorption of 130 ml/100 g or less as an inorganic pigment II.

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.