A thermosensitive recording body has at least a thermosensitive recording layer and a topcoat layer formed on a substrate. The substrate consists of a transparent film. At least the thermosensitive recording layer and the topcoat layer includes a diffuse reflection suppressor component that suppresses diffuse reflection of light from particles constituting the thermosensitive recording layer and the topcoat layer.

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 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.

Aqueous composition comprising a color former, a developer, and a binder, wherein (a) the weight ratio between the developer and the color former is in the range of from 1 to 5; (b) the binder comprises an acrylate binder, comprising acrylic acid and styrene, and at least one additional monomer selected from the group consisting of -methyl styrene, ethyl acrylate and 2-ethylhexyl acrylate; and (c) the color former and/or the developer are present in an un-encapsulated form; a process for the preparation of these compositions, substrates coated with this composition and a process for its preparation, and a process for preparing a marked substrate using this composition.

A colour laser markable composition includes at least a first and a second Diffusion Hindered Molecular Assembly (DHMA), each including a leuco dye and, respectively, a first and second sensitizer. With the laser markable composition, at least two different colours may be formed in a single layer.

A colour laser markable composition includes at least a first and a second Diffusion Hindered Molecular Assembly (DHMA), each including a leuco dye and, respectively, a first and second sensitizer. With the laser markable composition, at least two different colours may be formed in a single layer.

A laser markable composition includes (a) an aqueous medium; (b) polymeric particles dispersed in the aqueous medium; (c) a colour developing agent or colour developing agent precursor; and (d) an optothermal converting agent; characterized in that a leuco dye is covalently bonded to the polymeric particles.

A laser markable composition includes (a) an aqueous medium; (b) polymeric particles dispersed in the aqueous medium; (c) a colour developing agent or colour developing agent precursor; and (d) an optothermal converting agent; characterized in that a leuco dye is covalently bonded to the polymeric particles.

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.

Hollow resin particles for thermosensitive recording media containing a thermoplastic resin shell and a hollow part surrounded by the shell. The hollow resin particles contain a thermally-vaporizable hydrocarbon in an encapsulation ratio of at least 0.2 wt %. The hollow resin particles preferably have a mean volume particle size ranging from 0.1 to 10 m.