Ricoh Company, Ltd.

Takayuki Hoshina

Yoshikazu Kaneko

Hiroshi Yamashita

Masanaka Nagamoto

Masanori Rimoto

Kazumi Ohtaki

Yoshihiro Suguro

Kenkichi Muto

Michihisa Takahashi

Masaki Takatsugi

A method of producing a toner for developing latent electrostatic images is disclosed, which comprises the steps of dispersing resin particles comprising a resin in an organic solvent in which the resin is not dissolved; dissolving a dye in the organic solvent before or after dispersing the resin particles in the organic solvent to prepare a dispersion in which the resin particles and the dye are contained, thereby dying the resin particles with the dye; and removing the organic solvent from the dispersion, wherein the ratio of the solubility [D.sub.1 ] of the dye in the organic solvent to the solubility [D.sub.2 ] of the dye in the resin of the resin particles, [D.sub.1 ]/[D.sub.2 ], is not more than 0.5.

Method of producing toner for developing latent electrostatic images

A toner for developing latent electrostatic images to visible toner images, composed of toner particles containing a thermoplastic resin and a compound with formula (I) or a compound with formula (II) serving as a coloring agent: ##STR1## The toner particles may be composed of thermoplastic resin particles which are dyed with one of the compounds (I) or (II) serving as a coloring agent.

Toner for developing latent electrostatic images

A diazo-type thermosensitive recording material is disclosed, which comprises a support material and a thermosensitive coloring layer formed on the support material, which thermosensitive coloring layer comprises a diazonium compound, a coupler and a thermo-fusible or thermo-softening material, the coupler being a combination of a hydrazone-type coupler of the formula of R.sup.1 --NH--N.dbd.CH--R.sup.2 (wherein R.sup.1 and R.sup.2 are defined in detail in the specification) and a two-valence metal compound capable of chelating with the coupled product produced by the coupling of the diazonium compound and the hydrazone-type coupler.

Diazo-type thermosensitive recording material with hydrazone coupler and

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Fuji, Japan

Takayuki Hoshina