Ricoh Company, Ltd.

Chiaki Uematsu

Masami Tomita

Satoru Inoue

Mitsuo Aoki

Kimitoshi Yamaguchi

Mitsuru Uchida

Hiroshi Gotoh

A roll-shaped thermosensitive recording material having a thermosensitive recording layer, which includes as main components an electron donating coloring agent, an electron accepting color developer and a binder resin and which is formed overlying a substrate, wherein the roll-shaped thermosensitive recording material has a variation (R) of thickness of in the lateral direction of not greater than 3 &mgr;m. Alternatively, the roll-shaped thermosensitive recording material has a difference in thickness between the left side and the right side in the lateral direction of not greater than 0.7 &mgr;m.

Thermosensitive recording material, block copy sheet using the recording material and printing plate prepared by using the block copy sheet

Carrier particles are disclosed for use in a two-component dry-type developer for developing latent electrostatic images to visible images, for use in electrophotography, electrostatic recording methods and electrostatic printing methods, which carrier particles are coated with a silicone resin coating layer having high resistance to abrasion and the so-called 'spent phenomenon' while in use, and which therefore can be used repeatedly for a long period of time, yielding developed images with high quality. The high resistance to abrasion of the silicone resin coating layer is attained by adding to the silicone coating layer, as an inorganic fortifying agent against abrasion, silicon carbide or potassium titanate.

Carrier particles for use in a two-component dry-type developer for

A two-component dry-type developer which comprises carrier particles coated with silicone resin and toner particles containing as a negative polarity control agent a monoazo metal complex dye. As the monoazo metal complex dye, the following metal complex dye is preferable for use in this two-component dry-type developer: ##STR1## wherein X, Y and Z independently represent hydrogen, halogen, a carboxyl group, a hydroxyl group, a nitro group, a sulfo group or a sulfonamide group; and A.sup.+ represents H.sup.+, K.sup.+, Na.sup.+ or an aliphatic ammonium cation.

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Fuji, Japan

Chiaki Uematsu