YELLOW TONER AND FULL-COLOR DEVELOPING TONER USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a yellow toner which gives stable image density and hue of the print without causing toner fog on a photoreceptor even when the toner is used for a nonmagnetic single-component developing method and which is suitable for a full-color development, and to provide a full-color developing toner by using that yellow toner. SOLUTION: The yellow toner consists of a mixture of the following components (YA) and (YB). The component (YA) consists of toner particles containing a polyester resin, a yellow pigment such as C.I.pigment yellow 74, yellow 155 or the like, and a negative charge controlling agent. The polyester resin has <=30 KOHmg/g acid value, 2,000 to 20,000 number average mol.wt. (Mn), 5,000 to 300,000 weight average mol.wt. (Mw), 2 to 150 of Mw/Mn, 70 to 100 wt.% tetrahydrofuran-soluble content, 80 to 160 deg.C softening point, and 50 to 75 deg.C glass transition temperature. The component (YB) consists of inorganic fine powder such as silica, titania and alumina subjected to the surface treatment with silicone oil and having 5 to 500 m2/g specific surface area.